summaryrefslogtreecommitdiffstats
path: root/contrib/gcc/fold-const.c
blob: 37d99f89d0ef3e7c64e85c319693b92a6c2ddf45 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
6909
6910
6911
6912
6913
6914
6915
6916
6917
6918
6919
6920
6921
6922
6923
6924
6925
6926
6927
6928
6929
6930
6931
6932
6933
6934
6935
6936
6937
6938
6939
6940
6941
6942
6943
6944
6945
6946
6947
6948
6949
6950
6951
6952
6953
6954
6955
6956
6957
6958
6959
6960
6961
6962
6963
6964
6965
6966
6967
6968
6969
6970
6971
6972
6973
6974
6975
6976
6977
6978
6979
6980
6981
6982
6983
6984
6985
6986
6987
6988
6989
6990
6991
6992
6993
6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
7024
7025
7026
7027
7028
7029
7030
7031
7032
7033
7034
7035
7036
7037
7038
7039
7040
7041
7042
7043
7044
7045
7046
7047
7048
7049
7050
7051
7052
7053
7054
7055
7056
7057
7058
7059
7060
7061
7062
7063
7064
7065
7066
7067
7068
7069
7070
7071
7072
7073
7074
7075
7076
7077
7078
7079
7080
7081
7082
7083
7084
7085
7086
7087
7088
7089
7090
7091
7092
7093
7094
7095
7096
7097
7098
7099
7100
7101
7102
7103
7104
7105
7106
7107
7108
7109
7110
7111
7112
7113
7114
7115
7116
7117
7118
7119
7120
7121
7122
7123
7124
7125
7126
7127
7128
7129
7130
7131
7132
7133
7134
7135
7136
7137
7138
7139
7140
7141
7142
7143
7144
7145
7146
7147
7148
7149
7150
7151
7152
7153
7154
7155
7156
7157
7158
7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
7194
7195
7196
7197
7198
7199
7200
7201
7202
7203
7204
7205
7206
7207
7208
7209
7210
7211
7212
7213
7214
7215
7216
7217
7218
7219
7220
7221
7222
7223
7224
7225
7226
7227
7228
7229
7230
7231
7232
7233
7234
7235
7236
7237
7238
7239
7240
7241
7242
7243
7244
7245
7246
7247
7248
7249
7250
7251
7252
7253
7254
7255
7256
7257
7258
7259
7260
7261
7262
7263
7264
7265
7266
7267
7268
7269
7270
7271
7272
7273
7274
7275
7276
7277
7278
7279
7280
7281
7282
7283
7284
7285
7286
7287
7288
7289
7290
7291
7292
7293
7294
7295
7296
7297
7298
7299
7300
7301
7302
7303
7304
7305
7306
7307
7308
7309
7310
7311
7312
7313
7314
7315
7316
7317
7318
7319
7320
7321
7322
7323
7324
7325
7326
7327
7328
7329
7330
7331
7332
7333
7334
7335
7336
7337
7338
7339
7340
7341
7342
7343
7344
7345
7346
7347
7348
7349
7350
7351
7352
7353
7354
7355
7356
7357
7358
7359
7360
7361
7362
7363
7364
7365
7366
7367
7368
7369
7370
7371
7372
7373
7374
7375
7376
7377
7378
7379
7380
7381
7382
7383
7384
7385
7386
7387
7388
7389
7390
7391
7392
7393
7394
7395
7396
7397
7398
7399
7400
7401
7402
7403
7404
7405
7406
7407
7408
7409
7410
7411
7412
7413
7414
7415
7416
7417
7418
7419
7420
7421
7422
7423
7424
7425
7426
7427
7428
7429
7430
7431
7432
7433
7434
7435
7436
7437
7438
7439
7440
7441
7442
7443
7444
7445
7446
7447
7448
7449
7450
7451
7452
7453
7454
7455
7456
7457
7458
7459
7460
7461
7462
7463
7464
7465
7466
7467
7468
7469
7470
7471
7472
7473
7474
7475
7476
7477
7478
7479
7480
7481
7482
7483
7484
7485
7486
7487
7488
7489
7490
7491
7492
7493
7494
7495
7496
7497
7498
7499
7500
7501
7502
7503
7504
7505
7506
7507
7508
7509
7510
7511
7512
7513
7514
7515
7516
7517
7518
7519
7520
7521
7522
7523
7524
7525
7526
7527
7528
7529
7530
7531
7532
7533
7534
7535
7536
7537
7538
7539
7540
7541
7542
7543
7544
7545
7546
7547
7548
7549
7550
7551
7552
7553
7554
7555
7556
7557
7558
7559
7560
7561
7562
7563
7564
7565
7566
7567
7568
7569
7570
7571
7572
7573
7574
7575
7576
7577
7578
7579
7580
7581
7582
7583
7584
7585
7586
7587
7588
7589
7590
7591
7592
7593
7594
7595
7596
7597
7598
7599
7600
7601
7602
7603
7604
7605
7606
7607
7608
7609
7610
7611
7612
7613
7614
7615
7616
7617
7618
7619
7620
7621
7622
7623
7624
7625
7626
7627
7628
7629
7630
7631
7632
7633
7634
7635
7636
7637
7638
7639
7640
7641
7642
7643
7644
7645
7646
7647
7648
7649
7650
7651
7652
7653
7654
7655
7656
7657
7658
7659
7660
7661
7662
7663
7664
7665
7666
7667
7668
7669
7670
7671
7672
7673
7674
7675
7676
7677
7678
7679
7680
7681
7682
7683
7684
7685
7686
7687
7688
7689
7690
7691
7692
7693
7694
7695
7696
7697
7698
7699
7700
7701
7702
7703
7704
7705
7706
7707
7708
7709
7710
7711
7712
7713
7714
7715
7716
7717
7718
7719
7720
7721
7722
7723
7724
7725
7726
7727
7728
7729
7730
7731
7732
7733
7734
7735
7736
7737
7738
7739
7740
7741
7742
7743
7744
7745
7746
7747
7748
7749
7750
7751
7752
7753
7754
7755
7756
7757
7758
7759
7760
7761
7762
7763
7764
7765
7766
7767
7768
7769
7770
7771
7772
7773
7774
7775
7776
7777
7778
7779
7780
7781
7782
7783
7784
7785
7786
7787
7788
7789
7790
7791
7792
7793
7794
7795
7796
7797
7798
7799
7800
7801
7802
7803
7804
7805
7806
7807
7808
7809
7810
7811
7812
7813
7814
7815
7816
7817
7818
7819
7820
7821
7822
7823
7824
7825
7826
7827
7828
7829
7830
7831
7832
7833
7834
7835
7836
7837
7838
7839
7840
7841
7842
7843
7844
7845
7846
7847
7848
7849
7850
7851
7852
7853
7854
7855
7856
7857
7858
7859
7860
7861
7862
7863
7864
7865
7866
7867
7868
7869
7870
7871
7872
7873
7874
7875
7876
7877
7878
7879
7880
7881
7882
7883
7884
7885
7886
7887
7888
7889
7890
7891
7892
7893
7894
7895
7896
7897
7898
7899
7900
7901
7902
7903
7904
7905
7906
7907
7908
7909
7910
7911
7912
7913
7914
7915
7916
7917
7918
7919
7920
7921
7922
7923
7924
7925
7926
7927
7928
7929
7930
7931
7932
7933
7934
7935
7936
7937
7938
7939
7940
7941
7942
7943
7944
7945
7946
7947
7948
7949
7950
7951
7952
7953
7954
7955
7956
7957
7958
7959
7960
7961
7962
7963
7964
7965
7966
7967
7968
7969
7970
7971
7972
7973
7974
7975
7976
7977
7978
7979
7980
7981
7982
7983
7984
7985
7986
7987
7988
7989
7990
7991
7992
7993
7994
7995
7996
7997
7998
7999
8000
8001
8002
8003
8004
8005
8006
8007
8008
8009
8010
8011
8012
8013
8014
8015
8016
8017
8018
8019
8020
8021
8022
8023
8024
8025
8026
8027
8028
8029
8030
8031
8032
8033
8034
8035
8036
8037
8038
8039
8040
8041
8042
8043
8044
8045
8046
8047
8048
8049
8050
8051
8052
8053
8054
8055
8056
8057
8058
8059
8060
8061
8062
8063
8064
8065
8066
8067
8068
8069
8070
8071
8072
8073
8074
8075
8076
8077
8078
8079
8080
8081
8082
8083
8084
8085
8086
8087
8088
8089
8090
8091
8092
8093
8094
8095
8096
8097
8098
8099
8100
8101
8102
8103
8104
8105
8106
8107
8108
8109
8110
8111
8112
8113
8114
8115
8116
8117
8118
8119
8120
8121
8122
8123
8124
8125
8126
8127
8128
8129
8130
8131
8132
8133
8134
8135
8136
8137
8138
8139
8140
8141
8142
8143
8144
8145
8146
8147
8148
8149
8150
8151
8152
8153
8154
8155
8156
8157
8158
8159
8160
8161
8162
8163
8164
8165
8166
8167
8168
8169
8170
8171
8172
8173
8174
8175
8176
8177
8178
8179
8180
8181
8182
8183
8184
8185
8186
8187
8188
8189
8190
8191
8192
8193
8194
8195
8196
8197
8198
8199
8200
8201
8202
8203
8204
8205
8206
8207
8208
8209
8210
8211
8212
8213
8214
8215
8216
8217
8218
8219
8220
8221
8222
8223
8224
8225
8226
8227
8228
8229
8230
8231
8232
8233
8234
8235
8236
8237
8238
8239
8240
8241
8242
8243
8244
8245
8246
8247
8248
8249
8250
8251
8252
8253
8254
8255
8256
8257
8258
8259
8260
8261
8262
8263
8264
8265
8266
8267
8268
8269
8270
8271
8272
8273
8274
8275
8276
8277
8278
8279
8280
8281
8282
8283
8284
8285
8286
8287
8288
8289
8290
8291
8292
8293
8294
8295
8296
8297
8298
8299
8300
8301
8302
8303
8304
8305
8306
8307
8308
8309
8310
8311
8312
8313
8314
8315
8316
8317
8318
8319
8320
8321
8322
8323
8324
8325
8326
8327
8328
8329
8330
8331
8332
8333
8334
8335
8336
8337
8338
8339
8340
8341
8342
8343
8344
8345
8346
8347
8348
8349
8350
8351
8352
8353
8354
8355
8356
8357
8358
8359
8360
8361
8362
8363
8364
8365
8366
8367
8368
8369
8370
8371
8372
8373
8374
8375
8376
8377
8378
8379
8380
8381
8382
8383
8384
8385
8386
8387
8388
8389
8390
8391
8392
8393
8394
8395
8396
8397
8398
8399
8400
8401
8402
8403
8404
8405
8406
8407
8408
8409
8410
8411
8412
8413
8414
8415
8416
8417
8418
8419
8420
8421
8422
8423
8424
8425
8426
8427
8428
8429
8430
8431
8432
8433
8434
8435
8436
8437
8438
8439
8440
8441
8442
8443
8444
8445
8446
8447
8448
8449
8450
8451
8452
8453
8454
8455
8456
8457
8458
8459
8460
8461
8462
8463
8464
8465
8466
8467
8468
8469
8470
8471
8472
8473
8474
8475
8476
8477
8478
8479
8480
8481
8482
8483
8484
8485
8486
8487
8488
8489
8490
8491
8492
8493
8494
8495
8496
8497
8498
8499
8500
8501
8502
8503
8504
8505
8506
8507
8508
8509
8510
8511
8512
8513
8514
8515
8516
8517
8518
8519
8520
8521
8522
8523
8524
8525
8526
8527
8528
8529
8530
8531
8532
8533
8534
8535
8536
8537
8538
8539
8540
8541
8542
8543
8544
8545
8546
8547
8548
8549
8550
8551
8552
8553
8554
8555
8556
8557
8558
8559
8560
8561
8562
8563
8564
8565
8566
8567
8568
8569
8570
8571
8572
8573
8574
8575
8576
8577
8578
8579
8580
8581
8582
8583
8584
8585
8586
8587
8588
8589
8590
8591
8592
8593
8594
8595
8596
8597
8598
8599
8600
8601
8602
8603
8604
8605
8606
8607
8608
8609
8610
8611
8612
8613
8614
8615
8616
8617
8618
8619
8620
8621
8622
8623
8624
8625
8626
8627
8628
8629
8630
8631
8632
8633
8634
8635
8636
8637
8638
8639
8640
8641
8642
8643
8644
8645
8646
8647
8648
8649
8650
8651
8652
8653
8654
8655
8656
8657
8658
8659
8660
8661
8662
8663
8664
8665
8666
8667
8668
8669
8670
8671
8672
8673
8674
8675
8676
8677
8678
8679
8680
8681
8682
8683
8684
8685
8686
8687
8688
8689
8690
8691
8692
8693
8694
8695
8696
8697
8698
8699
8700
8701
8702
8703
8704
8705
8706
8707
8708
8709
8710
8711
8712
8713
8714
8715
8716
8717
8718
8719
8720
8721
8722
8723
8724
8725
8726
8727
8728
8729
8730
8731
8732
8733
8734
8735
8736
8737
8738
8739
8740
8741
8742
8743
8744
8745
8746
8747
8748
8749
8750
8751
8752
8753
8754
8755
8756
8757
8758
8759
8760
8761
8762
8763
8764
8765
8766
8767
8768
8769
8770
8771
8772
8773
8774
8775
8776
8777
8778
8779
8780
8781
8782
8783
8784
8785
8786
8787
8788
8789
8790
8791
8792
8793
8794
8795
8796
8797
8798
8799
8800
8801
8802
8803
8804
8805
8806
8807
8808
8809
8810
8811
8812
8813
8814
8815
8816
8817
8818
8819
8820
8821
8822
8823
8824
8825
8826
8827
8828
8829
8830
8831
8832
8833
8834
8835
8836
8837
8838
8839
8840
8841
8842
8843
8844
8845
8846
8847
8848
8849
8850
8851
8852
8853
8854
8855
8856
8857
8858
8859
8860
8861
8862
8863
8864
8865
8866
8867
8868
8869
8870
8871
8872
8873
8874
8875
8876
8877
8878
8879
8880
8881
8882
8883
8884
8885
8886
8887
8888
8889
8890
8891
8892
8893
8894
8895
8896
8897
8898
8899
8900
8901
8902
8903
8904
8905
8906
8907
8908
8909
8910
8911
8912
8913
8914
8915
8916
8917
8918
8919
8920
8921
8922
8923
8924
8925
8926
8927
8928
8929
8930
8931
8932
8933
8934
8935
8936
8937
8938
8939
8940
8941
8942
8943
8944
8945
8946
8947
8948
8949
8950
8951
8952
8953
8954
8955
8956
8957
8958
8959
8960
8961
8962
8963
8964
8965
8966
8967
8968
8969
8970
8971
8972
8973
8974
8975
8976
8977
8978
8979
8980
8981
8982
8983
8984
8985
8986
8987
8988
8989
8990
8991
8992
8993
8994
8995
8996
8997
8998
8999
9000
9001
9002
9003
9004
9005
9006
9007
9008
9009
9010
9011
9012
9013
9014
9015
9016
9017
9018
9019
9020
9021
9022
9023
9024
9025
9026
9027
9028
9029
9030
9031
9032
9033
9034
9035
9036
9037
9038
9039
9040
9041
9042
9043
9044
9045
9046
9047
9048
9049
9050
9051
9052
9053
9054
9055
9056
9057
9058
9059
9060
9061
9062
9063
9064
9065
9066
9067
9068
9069
9070
9071
9072
9073
9074
9075
9076
9077
9078
9079
9080
9081
9082
9083
9084
9085
9086
9087
9088
9089
9090
9091
9092
9093
9094
9095
9096
9097
9098
9099
9100
9101
9102
9103
9104
9105
9106
9107
9108
9109
9110
9111
9112
9113
9114
9115
9116
9117
9118
9119
9120
9121
9122
9123
9124
9125
9126
9127
9128
9129
9130
9131
9132
9133
9134
9135
9136
9137
9138
9139
9140
9141
9142
9143
9144
9145
9146
9147
9148
9149
9150
9151
9152
9153
9154
9155
9156
9157
9158
9159
9160
9161
9162
9163
9164
9165
9166
9167
9168
9169
9170
9171
9172
9173
9174
9175
9176
9177
9178
9179
9180
9181
9182
9183
9184
9185
9186
9187
9188
9189
9190
9191
9192
9193
9194
9195
9196
9197
9198
9199
9200
9201
9202
9203
9204
9205
9206
9207
9208
9209
9210
9211
9212
9213
9214
9215
9216
9217
9218
9219
9220
9221
9222
9223
9224
9225
9226
9227
9228
9229
9230
9231
9232
9233
9234
9235
9236
9237
9238
9239
9240
9241
9242
9243
9244
9245
9246
9247
9248
9249
9250
9251
9252
9253
9254
9255
9256
9257
9258
9259
9260
9261
9262
9263
9264
9265
9266
9267
9268
9269
9270
9271
9272
9273
9274
9275
9276
9277
9278
9279
9280
9281
9282
9283
9284
9285
9286
9287
9288
9289
9290
9291
9292
9293
9294
9295
9296
9297
9298
9299
9300
9301
9302
9303
9304
9305
9306
9307
9308
9309
9310
9311
9312
9313
9314
9315
9316
9317
9318
9319
9320
9321
9322
9323
9324
9325
9326
9327
9328
9329
9330
9331
9332
9333
9334
9335
9336
9337
9338
9339
9340
9341
9342
9343
9344
9345
9346
9347
9348
9349
9350
9351
9352
9353
9354
9355
9356
9357
9358
9359
9360
9361
9362
9363
9364
9365
9366
9367
9368
9369
9370
9371
9372
9373
9374
9375
9376
9377
9378
9379
9380
9381
9382
9383
9384
9385
9386
9387
9388
9389
9390
9391
9392
9393
9394
9395
9396
9397
9398
9399
9400
9401
9402
9403
9404
9405
9406
9407
9408
9409
9410
9411
9412
9413
9414
9415
9416
9417
9418
9419
9420
9421
9422
9423
9424
9425
9426
9427
9428
9429
9430
9431
9432
9433
9434
9435
9436
9437
9438
9439
9440
9441
9442
9443
9444
9445
9446
9447
9448
9449
9450
9451
9452
9453
9454
9455
9456
9457
9458
9459
9460
9461
9462
9463
9464
9465
9466
9467
9468
9469
9470
9471
9472
9473
9474
9475
9476
9477
9478
9479
9480
9481
9482
9483
9484
9485
9486
9487
9488
9489
9490
9491
9492
9493
9494
9495
9496
9497
9498
9499
9500
9501
9502
9503
9504
9505
9506
9507
9508
9509
9510
9511
9512
9513
9514
9515
9516
9517
9518
9519
9520
9521
9522
9523
9524
9525
9526
9527
9528
9529
9530
9531
9532
9533
9534
9535
9536
9537
9538
9539
9540
9541
9542
9543
9544
9545
9546
9547
9548
9549
9550
9551
9552
9553
9554
9555
9556
9557
9558
9559
9560
9561
9562
9563
9564
9565
9566
9567
9568
9569
9570
9571
9572
9573
9574
9575
9576
9577
9578
9579
9580
9581
9582
9583
9584
9585
9586
9587
9588
9589
9590
9591
9592
9593
9594
9595
9596
9597
9598
9599
9600
9601
9602
9603
9604
9605
9606
9607
9608
9609
9610
9611
9612
9613
9614
9615
9616
9617
9618
9619
9620
9621
9622
9623
9624
9625
9626
9627
9628
9629
9630
9631
9632
9633
9634
9635
9636
9637
9638
9639
9640
9641
9642
9643
9644
9645
9646
9647
9648
9649
9650
9651
9652
9653
9654
9655
9656
9657
9658
9659
9660
9661
9662
9663
9664
9665
9666
9667
9668
9669
9670
9671
9672
9673
9674
9675
9676
9677
9678
9679
9680
9681
9682
9683
9684
9685
9686
9687
9688
9689
9690
9691
9692
9693
9694
9695
9696
9697
9698
9699
9700
9701
9702
9703
9704
9705
9706
9707
9708
9709
9710
9711
9712
9713
9714
9715
9716
9717
9718
9719
9720
9721
9722
9723
9724
9725
9726
9727
9728
9729
9730
9731
9732
9733
9734
9735
9736
9737
9738
9739
9740
9741
9742
9743
9744
9745
9746
9747
9748
9749
9750
9751
9752
9753
9754
9755
9756
9757
9758
9759
9760
9761
9762
9763
9764
9765
9766
9767
9768
9769
9770
9771
9772
9773
9774
9775
9776
9777
9778
9779
9780
9781
9782
9783
9784
9785
9786
9787
9788
9789
9790
9791
9792
9793
9794
9795
9796
9797
9798
9799
9800
9801
9802
9803
9804
9805
9806
9807
9808
9809
9810
9811
9812
9813
9814
9815
9816
9817
9818
9819
9820
9821
9822
9823
9824
9825
9826
9827
9828
9829
9830
9831
9832
9833
9834
9835
9836
9837
9838
9839
9840
9841
9842
9843
9844
9845
9846
9847
9848
9849
9850
9851
9852
9853
9854
9855
9856
9857
9858
9859
9860
9861
9862
9863
9864
9865
9866
9867
9868
9869
9870
9871
9872
9873
9874
9875
9876
9877
9878
9879
9880
9881
9882
9883
9884
9885
9886
9887
9888
9889
9890
9891
9892
9893
9894
9895
9896
9897
9898
9899
9900
9901
9902
9903
9904
9905
9906
9907
9908
9909
9910
9911
9912
9913
9914
9915
9916
9917
9918
9919
9920
9921
9922
9923
9924
9925
9926
9927
9928
9929
9930
9931
9932
9933
9934
9935
9936
9937
9938
9939
9940
9941
9942
9943
9944
9945
9946
9947
9948
9949
9950
9951
9952
9953
9954
9955
9956
9957
9958
9959
9960
9961
9962
9963
9964
9965
9966
9967
9968
9969
9970
9971
9972
9973
9974
9975
9976
9977
9978
9979
9980
9981
9982
9983
9984
9985
9986
9987
9988
9989
9990
9991
9992
9993
9994
9995
9996
9997
9998
9999
10000
10001
10002
10003
10004
10005
10006
10007
10008
10009
10010
10011
10012
10013
10014
10015
10016
10017
10018
10019
10020
10021
10022
10023
10024
10025
10026
10027
10028
10029
10030
10031
10032
10033
10034
10035
10036
10037
10038
10039
10040
10041
10042
10043
10044
10045
10046
10047
10048
10049
10050
10051
10052
10053
10054
10055
10056
10057
10058
10059
10060
10061
10062
10063
10064
10065
10066
10067
10068
10069
10070
10071
10072
10073
10074
10075
10076
10077
10078
10079
10080
10081
10082
10083
10084
10085
10086
10087
10088
10089
10090
10091
10092
10093
10094
10095
10096
10097
10098
10099
10100
10101
10102
10103
10104
10105
10106
10107
10108
10109
10110
10111
10112
10113
10114
10115
10116
10117
10118
10119
10120
10121
10122
10123
10124
10125
10126
10127
10128
10129
10130
10131
10132
10133
10134
10135
10136
10137
10138
10139
10140
10141
10142
10143
10144
10145
10146
10147
10148
10149
10150
10151
10152
10153
10154
10155
10156
10157
10158
10159
10160
10161
10162
10163
10164
10165
10166
10167
10168
10169
10170
10171
10172
10173
10174
10175
10176
10177
10178
10179
10180
10181
10182
10183
10184
10185
10186
10187
10188
10189
10190
10191
10192
10193
10194
10195
10196
10197
10198
10199
10200
10201
10202
10203
10204
10205
10206
10207
10208
10209
10210
10211
10212
10213
10214
10215
10216
10217
10218
10219
10220
10221
10222
10223
10224
10225
10226
10227
10228
10229
10230
10231
10232
10233
10234
10235
10236
10237
10238
10239
10240
10241
10242
10243
10244
10245
10246
10247
10248
10249
10250
10251
10252
10253
10254
10255
10256
10257
10258
10259
10260
10261
10262
10263
10264
10265
10266
10267
10268
10269
10270
10271
10272
10273
10274
10275
10276
10277
10278
10279
10280
10281
10282
10283
10284
10285
10286
10287
10288
10289
10290
10291
10292
10293
10294
10295
10296
10297
10298
10299
10300
10301
10302
10303
10304
10305
10306
10307
10308
10309
10310
10311
10312
10313
10314
10315
10316
10317
10318
10319
10320
10321
10322
10323
10324
10325
10326
10327
10328
10329
10330
10331
10332
10333
10334
10335
10336
10337
10338
10339
10340
10341
10342
10343
10344
10345
10346
10347
10348
10349
10350
10351
10352
10353
10354
10355
10356
10357
10358
10359
10360
10361
10362
10363
10364
10365
10366
10367
10368
10369
10370
10371
10372
10373
10374
10375
10376
10377
10378
10379
10380
10381
10382
10383
10384
10385
10386
10387
10388
10389
10390
10391
10392
10393
10394
10395
10396
10397
10398
10399
10400
10401
10402
10403
10404
10405
10406
10407
10408
10409
10410
10411
10412
10413
10414
10415
10416
10417
10418
10419
10420
10421
10422
10423
10424
10425
10426
10427
10428
10429
10430
10431
10432
10433
10434
10435
10436
10437
10438
10439
10440
10441
10442
10443
10444
10445
10446
10447
10448
10449
10450
10451
10452
10453
10454
10455
10456
10457
10458
10459
10460
10461
10462
10463
10464
10465
10466
10467
10468
10469
10470
10471
10472
10473
10474
10475
10476
10477
10478
10479
10480
10481
10482
10483
10484
10485
10486
10487
10488
10489
10490
10491
10492
10493
10494
10495
10496
10497
10498
10499
10500
10501
10502
10503
10504
10505
10506
10507
10508
10509
10510
10511
10512
10513
10514
10515
10516
10517
10518
10519
10520
10521
10522
10523
10524
10525
10526
10527
10528
10529
10530
10531
10532
10533
10534
10535
10536
10537
10538
10539
10540
10541
10542
10543
10544
10545
10546
10547
10548
10549
10550
10551
10552
10553
10554
10555
10556
10557
10558
10559
10560
10561
10562
10563
10564
10565
10566
10567
10568
10569
10570
10571
10572
10573
10574
10575
10576
10577
10578
10579
10580
10581
10582
10583
10584
10585
10586
10587
10588
10589
10590
10591
10592
10593
10594
10595
10596
10597
10598
10599
10600
10601
10602
10603
10604
10605
10606
10607
10608
10609
10610
10611
10612
10613
10614
10615
10616
10617
10618
10619
10620
10621
10622
10623
10624
10625
10626
10627
10628
10629
10630
10631
10632
10633
10634
10635
10636
10637
10638
10639
10640
10641
10642
10643
10644
10645
10646
10647
10648
10649
10650
10651
10652
10653
10654
10655
10656
10657
10658
10659
10660
10661
10662
10663
10664
10665
10666
10667
10668
10669
10670
10671
10672
10673
10674
10675
10676
10677
10678
10679
10680
10681
10682
10683
10684
10685
10686
10687
10688
10689
10690
10691
10692
10693
10694
10695
10696
10697
10698
10699
10700
10701
10702
10703
10704
10705
10706
10707
10708
10709
10710
10711
10712
10713
10714
10715
10716
10717
10718
10719
10720
10721
10722
10723
10724
10725
10726
10727
10728
10729
10730
10731
10732
10733
10734
10735
10736
10737
10738
10739
10740
10741
10742
10743
10744
10745
10746
10747
10748
10749
10750
10751
10752
10753
10754
10755
10756
10757
10758
10759
10760
10761
10762
10763
10764
10765
10766
10767
10768
10769
10770
10771
10772
10773
10774
10775
10776
10777
10778
10779
10780
10781
10782
10783
10784
10785
10786
10787
10788
10789
10790
10791
10792
10793
10794
10795
10796
10797
10798
10799
10800
10801
10802
10803
10804
10805
10806
10807
10808
10809
10810
10811
10812
10813
10814
10815
10816
10817
10818
10819
10820
10821
10822
10823
10824
10825
10826
10827
10828
10829
10830
10831
10832
10833
10834
10835
10836
10837
10838
10839
10840
10841
10842
10843
10844
10845
10846
10847
10848
10849
10850
10851
10852
10853
10854
10855
10856
10857
10858
10859
10860
10861
10862
10863
10864
10865
10866
10867
10868
10869
10870
10871
10872
10873
10874
10875
10876
10877
10878
10879
10880
10881
10882
10883
10884
10885
10886
10887
10888
10889
10890
10891
10892
10893
10894
10895
10896
10897
10898
10899
10900
10901
10902
10903
10904
10905
10906
10907
10908
10909
10910
10911
10912
10913
10914
10915
10916
10917
10918
10919
10920
10921
10922
10923
10924
10925
10926
10927
10928
10929
10930
10931
10932
10933
10934
10935
10936
10937
10938
10939
10940
10941
10942
10943
10944
10945
10946
10947
10948
10949
10950
10951
10952
10953
10954
10955
10956
10957
10958
10959
10960
10961
10962
10963
10964
10965
10966
10967
10968
10969
10970
10971
10972
10973
10974
10975
10976
10977
10978
10979
10980
10981
10982
10983
10984
10985
10986
10987
10988
10989
10990
10991
10992
10993
10994
10995
10996
10997
10998
10999
11000
11001
11002
11003
11004
11005
11006
11007
11008
11009
11010
11011
11012
11013
11014
11015
11016
11017
11018
11019
11020
11021
11022
11023
11024
11025
11026
11027
11028
11029
11030
11031
11032
11033
11034
11035
11036
11037
11038
11039
11040
11041
11042
11043
11044
11045
11046
11047
11048
11049
11050
11051
11052
11053
11054
11055
11056
11057
11058
11059
11060
11061
11062
11063
11064
11065
11066
11067
11068
11069
11070
11071
11072
11073
11074
11075
11076
11077
11078
11079
11080
11081
11082
11083
11084
11085
11086
11087
11088
11089
11090
11091
11092
11093
11094
11095
11096
11097
11098
11099
11100
11101
11102
11103
11104
11105
11106
11107
11108
11109
11110
11111
11112
11113
11114
11115
11116
11117
11118
11119
11120
11121
11122
11123
11124
11125
11126
11127
11128
11129
11130
11131
11132
11133
11134
11135
11136
11137
11138
11139
11140
11141
11142
11143
11144
11145
11146
11147
11148
11149
11150
11151
11152
11153
11154
11155
11156
11157
11158
11159
11160
11161
11162
11163
11164
11165
11166
11167
11168
11169
11170
11171
11172
11173
11174
11175
11176
11177
11178
11179
11180
11181
11182
11183
11184
11185
11186
11187
11188
11189
11190
11191
11192
11193
11194
11195
11196
11197
11198
11199
11200
11201
11202
11203
11204
11205
11206
11207
11208
11209
11210
11211
11212
11213
11214
11215
11216
11217
11218
11219
11220
11221
11222
11223
11224
11225
11226
11227
11228
11229
11230
11231
11232
11233
11234
11235
11236
11237
11238
11239
11240
11241
11242
11243
11244
11245
11246
11247
11248
11249
11250
11251
11252
11253
11254
11255
11256
11257
11258
11259
11260
11261
11262
11263
11264
11265
11266
11267
11268
11269
11270
11271
11272
11273
11274
11275
11276
11277
11278
11279
11280
11281
11282
11283
11284
11285
11286
11287
11288
11289
11290
11291
11292
11293
11294
11295
11296
11297
11298
11299
11300
11301
11302
11303
11304
11305
11306
11307
11308
11309
11310
11311
11312
11313
11314
11315
11316
11317
11318
11319
11320
11321
11322
11323
11324
11325
11326
11327
11328
11329
11330
11331
11332
11333
11334
11335
11336
11337
11338
11339
11340
11341
11342
11343
11344
11345
11346
11347
11348
11349
11350
11351
11352
11353
11354
11355
11356
11357
11358
11359
11360
11361
11362
11363
11364
11365
11366
11367
11368
11369
11370
11371
11372
11373
11374
11375
11376
11377
11378
11379
11380
11381
11382
11383
11384
11385
11386
11387
11388
11389
11390
11391
11392
11393
11394
11395
11396
11397
11398
11399
11400
11401
11402
11403
11404
11405
11406
11407
11408
11409
11410
11411
11412
11413
11414
11415
11416
11417
11418
11419
11420
11421
11422
11423
11424
11425
11426
11427
11428
11429
11430
11431
11432
11433
11434
11435
11436
11437
11438
11439
11440
11441
11442
11443
11444
11445
11446
11447
11448
11449
11450
11451
11452
11453
11454
11455
11456
11457
11458
11459
11460
11461
11462
11463
11464
11465
11466
11467
11468
11469
11470
11471
11472
11473
11474
11475
11476
11477
11478
11479
11480
11481
11482
11483
11484
11485
11486
11487
11488
11489
11490
11491
11492
11493
11494
11495
11496
11497
11498
11499
11500
11501
11502
11503
11504
11505
11506
11507
11508
11509
11510
11511
11512
11513
11514
11515
11516
11517
11518
11519
11520
11521
11522
11523
11524
11525
11526
11527
11528
11529
11530
11531
11532
11533
11534
11535
11536
11537
11538
11539
11540
11541
11542
11543
11544
11545
11546
11547
11548
11549
11550
11551
11552
11553
11554
11555
11556
11557
11558
11559
11560
11561
11562
11563
11564
11565
11566
11567
11568
11569
11570
11571
11572
11573
11574
11575
11576
11577
11578
11579
11580
11581
11582
11583
11584
11585
11586
11587
11588
11589
11590
11591
11592
11593
11594
11595
11596
11597
11598
11599
11600
11601
11602
11603
11604
11605
11606
11607
11608
11609
11610
11611
11612
11613
11614
11615
11616
11617
11618
11619
11620
11621
11622
11623
11624
11625
11626
11627
11628
11629
11630
11631
11632
11633
11634
11635
11636
11637
11638
11639
11640
11641
11642
11643
11644
11645
11646
11647
11648
11649
11650
11651
11652
11653
11654
11655
11656
11657
11658
11659
11660
11661
11662
11663
11664
11665
11666
11667
11668
11669
11670
11671
11672
11673
11674
11675
11676
11677
11678
11679
11680
11681
11682
11683
11684
11685
11686
11687
11688
11689
11690
11691
11692
11693
11694
11695
11696
11697
11698
11699
11700
11701
11702
11703
11704
11705
11706
11707
11708
11709
11710
11711
11712
11713
11714
11715
11716
11717
11718
11719
11720
11721
11722
11723
11724
11725
11726
11727
11728
11729
11730
11731
11732
11733
11734
11735
11736
11737
11738
11739
11740
11741
11742
11743
11744
11745
11746
11747
11748
11749
11750
11751
11752
11753
11754
11755
11756
11757
11758
11759
11760
11761
11762
11763
11764
11765
11766
11767
11768
11769
11770
11771
11772
11773
11774
11775
11776
11777
11778
11779
11780
11781
11782
11783
11784
11785
11786
11787
11788
11789
11790
11791
11792
11793
11794
11795
11796
11797
11798
11799
11800
11801
11802
11803
11804
11805
11806
11807
11808
11809
11810
11811
11812
11813
11814
11815
11816
11817
11818
11819
11820
11821
11822
11823
11824
11825
11826
11827
11828
11829
11830
11831
11832
11833
11834
11835
11836
11837
11838
11839
11840
11841
11842
11843
11844
11845
11846
11847
11848
11849
11850
11851
11852
11853
11854
11855
11856
11857
11858
11859
11860
11861
11862
11863
11864
11865
11866
11867
11868
11869
11870
11871
11872
11873
11874
11875
11876
11877
11878
11879
11880
11881
11882
11883
11884
11885
11886
11887
11888
11889
11890
11891
11892
11893
11894
11895
11896
11897
11898
11899
11900
11901
11902
11903
11904
11905
11906
11907
11908
11909
11910
11911
11912
11913
11914
11915
11916
11917
11918
11919
11920
11921
11922
11923
11924
11925
11926
11927
11928
11929
11930
11931
11932
11933
11934
11935
11936
11937
11938
11939
11940
11941
11942
11943
11944
11945
11946
11947
11948
11949
11950
11951
11952
11953
11954
11955
11956
11957
11958
11959
11960
11961
11962
11963
11964
11965
11966
11967
11968
11969
11970
11971
11972
11973
11974
11975
11976
11977
11978
11979
11980
11981
11982
11983
11984
11985
11986
11987
11988
11989
11990
11991
11992
11993
11994
11995
11996
11997
11998
11999
12000
12001
12002
12003
12004
12005
12006
12007
12008
12009
12010
12011
12012
12013
12014
12015
12016
12017
12018
12019
12020
12021
12022
12023
12024
12025
12026
12027
12028
12029
12030
12031
12032
12033
12034
12035
12036
12037
12038
12039
12040
12041
12042
12043
12044
12045
12046
12047
12048
12049
12050
12051
12052
12053
12054
12055
12056
12057
12058
12059
12060
12061
12062
12063
12064
12065
12066
12067
12068
12069
12070
12071
12072
12073
12074
12075
12076
12077
12078
12079
12080
12081
12082
12083
12084
12085
12086
12087
12088
12089
12090
12091
12092
12093
12094
12095
12096
12097
12098
12099
12100
12101
12102
12103
12104
12105
12106
12107
12108
12109
12110
12111
12112
12113
12114
12115
12116
12117
12118
12119
12120
12121
12122
12123
12124
12125
12126
12127
12128
12129
12130
12131
12132
12133
12134
12135
12136
12137
12138
12139
12140
12141
12142
12143
12144
12145
12146
12147
12148
12149
12150
12151
12152
12153
12154
12155
12156
12157
12158
12159
12160
12161
12162
12163
12164
12165
12166
12167
12168
12169
12170
12171
12172
12173
12174
12175
12176
12177
12178
12179
12180
12181
12182
12183
12184
12185
12186
12187
12188
12189
12190
12191
12192
12193
12194
12195
12196
12197
12198
12199
12200
12201
12202
12203
12204
12205
12206
12207
12208
12209
12210
12211
12212
12213
12214
12215
12216
12217
12218
12219
12220
12221
12222
12223
12224
12225
12226
12227
12228
12229
12230
12231
12232
12233
12234
12235
12236
12237
12238
12239
12240
12241
12242
12243
12244
12245
12246
12247
12248
12249
12250
12251
12252
12253
12254
12255
12256
12257
12258
12259
12260
12261
12262
12263
12264
12265
12266
12267
12268
12269
12270
12271
12272
12273
12274
12275
12276
12277
12278
12279
12280
12281
12282
12283
12284
12285
12286
12287
12288
12289
12290
12291
12292
12293
12294
12295
12296
12297
12298
12299
12300
12301
12302
12303
12304
12305
12306
12307
12308
12309
12310
12311
12312
12313
12314
12315
12316
12317
12318
12319
12320
12321
12322
12323
12324
12325
12326
12327
12328
12329
12330
12331
12332
12333
12334
12335
12336
12337
12338
12339
12340
12341
12342
12343
12344
12345
12346
12347
12348
12349
12350
12351
12352
12353
12354
12355
12356
12357
12358
12359
12360
12361
12362
12363
12364
12365
12366
12367
12368
12369
12370
12371
12372
12373
12374
12375
12376
12377
12378
12379
12380
12381
12382
12383
12384
12385
12386
12387
12388
12389
12390
12391
12392
12393
12394
12395
12396
12397
12398
12399
12400
12401
12402
12403
12404
12405
12406
12407
12408
12409
12410
12411
12412
12413
12414
12415
12416
12417
12418
12419
12420
12421
12422
12423
12424
12425
12426
12427
12428
12429
12430
12431
12432
12433
12434
12435
12436
12437
12438
12439
12440
12441
12442
12443
12444
12445
12446
12447
12448
12449
12450
12451
12452
12453
12454
12455
12456
12457
12458
12459
12460
12461
12462
12463
12464
12465
12466
12467
12468
12469
12470
12471
12472
12473
12474
12475
12476
12477
12478
12479
12480
12481
12482
12483
12484
12485
12486
12487
12488
12489
12490
12491
12492
12493
12494
12495
12496
12497
12498
12499
12500
12501
12502
12503
12504
12505
12506
12507
12508
12509
12510
12511
12512
12513
12514
12515
12516
12517
12518
12519
12520
12521
12522
12523
12524
12525
12526
12527
12528
12529
12530
12531
12532
12533
12534
12535
12536
12537
12538
12539
12540
12541
12542
12543
12544
12545
12546
12547
12548
12549
12550
12551
12552
12553
12554
12555
12556
12557
12558
12559
12560
12561
12562
12563
12564
12565
12566
12567
12568
12569
12570
12571
12572
12573
12574
12575
12576
12577
12578
12579
12580
12581
12582
12583
12584
12585
12586
12587
12588
12589
12590
12591
12592
12593
12594
12595
12596
12597
12598
12599
12600
12601
12602
12603
12604
12605
12606
12607
12608
12609
12610
12611
12612
12613
12614
12615
12616
12617
12618
12619
12620
12621
12622
12623
12624
12625
12626
12627
12628
12629
12630
12631
12632
12633
12634
12635
12636
12637
12638
12639
12640
12641
12642
12643
12644
12645
12646
12647
12648
12649
12650
12651
12652
12653
12654
12655
12656
12657
12658
12659
12660
12661
12662
12663
12664
12665
12666
12667
12668
12669
12670
12671
12672
12673
12674
12675
12676
12677
12678
12679
12680
12681
12682
12683
12684
12685
12686
12687
12688
12689
12690
12691
12692
12693
12694
12695
12696
12697
12698
12699
12700
12701
12702
12703
12704
12705
12706
12707
12708
12709
12710
12711
12712
12713
12714
12715
12716
12717
12718
12719
12720
12721
12722
12723
12724
12725
12726
12727
12728
12729
12730
12731
12732
12733
12734
12735
12736
12737
12738
12739
12740
12741
12742
12743
12744
12745
12746
12747
12748
12749
12750
12751
12752
12753
12754
12755
12756
12757
12758
12759
12760
12761
12762
12763
12764
12765
12766
12767
12768
12769
12770
12771
12772
12773
12774
12775
12776
12777
12778
12779
12780
12781
12782
12783
12784
12785
12786
12787
12788
12789
12790
12791
12792
12793
12794
12795
12796
12797
12798
12799
12800
12801
12802
12803
12804
12805
12806
12807
12808
12809
12810
12811
12812
12813
12814
12815
12816
12817
12818
12819
12820
12821
12822
12823
12824
12825
12826
12827
12828
12829
12830
12831
12832
12833
12834
12835
12836
12837
12838
12839
12840
12841
12842
12843
12844
12845
12846
12847
12848
12849
12850
12851
12852
12853
12854
12855
12856
12857
12858
12859
12860
12861
12862
12863
12864
12865
12866
12867
12868
12869
12870
12871
12872
12873
12874
12875
12876
12877
12878
12879
12880
12881
12882
12883
12884
12885
12886
12887
12888
12889
12890
12891
12892
12893
12894
12895
12896
12897
12898
12899
12900
12901
12902
12903
12904
12905
12906
12907
12908
12909
12910
12911
12912
12913
12914
12915
12916
12917
12918
12919
12920
12921
12922
12923
12924
12925
12926
12927
12928
12929
12930
12931
12932
12933
12934
12935
12936
12937
12938
12939
12940
12941
12942
12943
12944
12945
12946
12947
12948
12949
12950
12951
12952
12953
12954
12955
12956
12957
12958
12959
12960
12961
12962
12963
12964
12965
12966
12967
12968
12969
12970
12971
12972
12973
12974
12975
12976
12977
12978
12979
12980
12981
12982
12983
12984
12985
12986
12987
12988
12989
12990
12991
12992
12993
12994
12995
12996
12997
12998
12999
13000
13001
13002
13003
13004
13005
13006
13007
13008
13009
13010
13011
13012
13013
13014
13015
13016
13017
13018
13019
13020
13021
13022
13023
13024
13025
13026
13027
13028
13029
13030
13031
13032
13033
13034
13035
13036
13037
13038
13039
13040
13041
13042
13043
13044
13045
13046
13047
13048
13049
13050
13051
13052
13053
13054
13055
13056
13057
13058
13059
13060
13061
13062
13063
13064
13065
13066
13067
13068
13069
13070
13071
13072
13073
13074
13075
13076
13077
13078
13079
13080
13081
13082
13083
13084
13085
13086
13087
13088
13089
13090
13091
13092
13093
13094
13095
13096
13097
13098
13099
13100
13101
13102
13103
13104
13105
13106
13107
13108
13109
13110
13111
13112
13113
13114
13115
13116
13117
13118
13119
13120
13121
13122
13123
13124
13125
13126
13127
13128
13129
13130
13131
13132
13133
13134
13135
13136
13137
13138
13139
13140
13141
13142
13143
13144
13145
13146
13147
13148
13149
13150
13151
13152
13153
13154
13155
13156
13157
13158
13159
13160
13161
13162
13163
13164
13165
13166
13167
13168
13169
13170
13171
13172
13173
13174
13175
13176
13177
13178
13179
13180
13181
13182
13183
13184
13185
13186
13187
13188
13189
13190
13191
13192
13193
13194
13195
13196
13197
13198
13199
13200
13201
13202
13203
13204
13205
13206
13207
13208
13209
13210
13211
13212
13213
13214
13215
13216
13217
13218
13219
13220
13221
13222
13223
13224
13225
13226
13227
13228
13229
13230
13231
13232
13233
13234
13235
13236
13237
13238
13239
13240
13241
13242
13243
13244
13245
13246
13247
13248
13249
13250
13251
13252
13253
13254
13255
13256
13257
13258
13259
13260
13261
13262
13263
13264
13265
13266
13267
13268
13269
13270
13271
13272
13273
13274
13275
13276
13277
13278
13279
13280
13281
13282
13283
13284
13285
13286
13287
13288
13289
13290
13291
13292
13293
13294
13295
13296
13297
13298
13299
13300
13301
13302
13303
13304
13305
13306
13307
13308
13309
13310
13311
13312
13313
13314
13315
13316
13317
13318
13319
13320
13321
13322
13323
13324
13325
13326
13327
13328
13329
13330
13331
13332
13333
13334
13335
13336
13337
13338
13339
13340
13341
13342
13343
13344
13345
13346
13347
13348
13349
13350
13351
13352
13353
13354
13355
13356
13357
13358
13359
13360
13361
13362
13363
13364
13365
13366
13367
13368
13369
13370
13371
13372
13373
13374
13375
13376
13377
13378
13379
13380
13381
13382
13383
13384
13385
13386
13387
13388
13389
13390
13391
13392
13393
13394
13395
13396
13397
13398
13399
13400
13401
13402
13403
13404
13405
13406
13407
13408
13409
13410
13411
13412
13413
13414
13415
13416
13417
13418
13419
13420
13421
13422
13423
13424
13425
13426
13427
13428
13429
13430
13431
13432
13433
13434
13435
13436
13437
13438
13439
13440
13441
13442
13443
13444
13445
13446
13447
13448
13449
13450
13451
13452
13453
13454
13455
13456
13457
13458
13459
13460
13461
13462
13463
13464
13465
13466
13467
13468
13469
13470
13471
13472
13473
13474
13475
13476
13477
13478
13479
13480
13481
13482
13483
13484
13485
13486
13487
13488
13489
13490
13491
13492
13493
13494
13495
13496
13497
13498
13499
13500
13501
13502
13503
13504
13505
13506
13507
13508
13509
13510
13511
13512
13513
13514
13515
13516
13517
13518
13519
13520
13521
13522
13523
13524
13525
13526
13527
13528
13529
13530
13531
13532
13533
13534
13535
13536
13537
13538
13539
13540
13541
13542
13543
13544
13545
13546
13547
13548
13549
13550
13551
13552
13553
13554
13555
13556
13557
13558
13559
13560
13561
13562
13563
13564
13565
13566
13567
13568
13569
13570
13571
13572
13573
13574
13575
13576
13577
13578
13579
13580
13581
13582
13583
13584
13585
13586
13587
13588
13589
13590
13591
13592
13593
13594
13595
13596
13597
13598
13599
13600
13601
13602
13603
13604
13605
13606
13607
13608
13609
13610
13611
13612
13613
13614
13615
13616
13617
13618
13619
13620
13621
13622
13623
13624
13625
13626
13627
/* Fold a constant sub-tree into a single node for C-compiler
   Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
   Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA.  */

/*@@ This file should be rewritten to use an arbitrary precision
  @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
  @@ Perhaps the routines could also be used for bc/dc, and made a lib.
  @@ The routines that translate from the ap rep should
  @@ warn if precision et. al. is lost.
  @@ This would also make life easier when this technology is used
  @@ for cross-compilers.  */

/* The entry points in this file are fold, size_int_wide, size_binop
   and force_fit_type.

   fold takes a tree as argument and returns a simplified tree.

   size_binop takes a tree code for an arithmetic operation
   and two operands that are trees, and produces a tree for the
   result, assuming the type comes from `sizetype'.

   size_int takes an integer value, and creates a tree constant
   with type from `sizetype'.

   force_fit_type takes a constant, an overflowable flag and prior
   overflow indicators.  It forces the value to fit the type and sets
   TREE_OVERFLOW and TREE_CONSTANT_OVERFLOW as appropriate.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "flags.h"
#include "tree.h"
#include "real.h"
#include "rtl.h"
#include "expr.h"
#include "tm_p.h"
#include "toplev.h"
#include "intl.h"
#include "ggc.h"
#include "hashtab.h"
#include "langhooks.h"
#include "md5.h"

/* Non-zero if we are folding constants inside an initializer; zero
   otherwise.  */
int folding_initializer = 0;

/* The following constants represent a bit based encoding of GCC's
   comparison operators.  This encoding simplifies transformations
   on relational comparison operators, such as AND and OR.  */
enum comparison_code {
  COMPCODE_FALSE = 0,
  COMPCODE_LT = 1,
  COMPCODE_EQ = 2,
  COMPCODE_LE = 3,
  COMPCODE_GT = 4,
  COMPCODE_LTGT = 5,
  COMPCODE_GE = 6,
  COMPCODE_ORD = 7,
  COMPCODE_UNORD = 8,
  COMPCODE_UNLT = 9,
  COMPCODE_UNEQ = 10,
  COMPCODE_UNLE = 11,
  COMPCODE_UNGT = 12,
  COMPCODE_NE = 13,
  COMPCODE_UNGE = 14,
  COMPCODE_TRUE = 15
};

static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
static bool negate_mathfn_p (enum built_in_function);
static bool negate_expr_p (tree);
static tree negate_expr (tree);
static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
static tree associate_trees (tree, tree, enum tree_code, tree);
static tree const_binop (enum tree_code, tree, tree, int);
static enum comparison_code comparison_to_compcode (enum tree_code);
static enum tree_code compcode_to_comparison (enum comparison_code);
static tree combine_comparisons (enum tree_code, enum tree_code,
				 enum tree_code, tree, tree, tree);
static int truth_value_p (enum tree_code);
static int operand_equal_for_comparison_p (tree, tree, tree);
static int twoval_comparison_p (tree, tree *, tree *, int *);
static tree eval_subst (tree, tree, tree, tree, tree);
static tree pedantic_omit_one_operand (tree, tree, tree);
static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
static tree make_bit_field_ref (tree, tree, int, int, int);
static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
				    enum machine_mode *, int *, int *,
				    tree *, tree *);
static int all_ones_mask_p (tree, int);
static tree sign_bit_p (tree, tree);
static int simple_operand_p (tree);
static tree range_binop (enum tree_code, tree, tree, int, tree, int);
static tree range_predecessor (tree);
static tree range_successor (tree);
static tree make_range (tree, int *, tree *, tree *, bool *);
static tree build_range_check (tree, tree, int, tree, tree);
static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
			 tree);
static tree fold_range_test (enum tree_code, tree, tree, tree);
static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
static tree unextend (tree, int, int, tree);
static tree fold_truthop (enum tree_code, tree, tree, tree);
static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
static int multiple_of_p (tree, tree, tree);
static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
						 tree, tree,
						 tree, tree, int);
static bool fold_real_zero_addition_p (tree, tree, int);
static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
				 tree, tree, tree);
static tree fold_inf_compare (enum tree_code, tree, tree, tree);
static tree fold_div_compare (enum tree_code, tree, tree, tree);
static bool reorder_operands_p (tree, tree);
static tree fold_negate_const (tree, tree);
static tree fold_not_const (tree, tree);
static tree fold_relational_const (enum tree_code, tree, tree, tree);
static int native_encode_expr (tree, unsigned char *, int);
static tree native_interpret_expr (tree, unsigned char *, int);


/* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
   overflow.  Suppose A, B and SUM have the same respective signs as A1, B1,
   and SUM1.  Then this yields nonzero if overflow occurred during the
   addition.

   Overflow occurs if A and B have the same sign, but A and SUM differ in
   sign.  Use `^' to test whether signs differ, and `< 0' to isolate the
   sign.  */
#define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)

/* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
   We do that by representing the two-word integer in 4 words, with only
   HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
   number.  The value of the word is LOWPART + HIGHPART * BASE.  */

#define LOWPART(x) \
  ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
#define HIGHPART(x) \
  ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
#define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)

/* Unpack a two-word integer into 4 words.
   LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
   WORDS points to the array of HOST_WIDE_INTs.  */

static void
encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
{
  words[0] = LOWPART (low);
  words[1] = HIGHPART (low);
  words[2] = LOWPART (hi);
  words[3] = HIGHPART (hi);
}

/* Pack an array of 4 words into a two-word integer.
   WORDS points to the array of words.
   The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces.  */

static void
decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
	HOST_WIDE_INT *hi)
{
  *low = words[0] + words[1] * BASE;
  *hi = words[2] + words[3] * BASE;
}

/* T is an INT_CST node.  OVERFLOWABLE indicates if we are interested
   in overflow of the value, when >0 we are only interested in signed
   overflow, for <0 we are interested in any overflow.  OVERFLOWED
   indicates whether overflow has already occurred.  CONST_OVERFLOWED
   indicates whether constant overflow has already occurred.  We force
   T's value to be within range of T's type (by setting to 0 or 1 all
   the bits outside the type's range).  We set TREE_OVERFLOWED if,
  	OVERFLOWED is nonzero,
	or OVERFLOWABLE is >0 and signed overflow occurs
	or OVERFLOWABLE is <0 and any overflow occurs
   We set TREE_CONSTANT_OVERFLOWED if,
        CONST_OVERFLOWED is nonzero
	or we set TREE_OVERFLOWED.
  We return either the original T, or a copy.  */

tree
force_fit_type (tree t, int overflowable,
		bool overflowed, bool overflowed_const)
{
  unsigned HOST_WIDE_INT low;
  HOST_WIDE_INT high;
  unsigned int prec;
  int sign_extended_type;

  gcc_assert (TREE_CODE (t) == INTEGER_CST);

  low = TREE_INT_CST_LOW (t);
  high = TREE_INT_CST_HIGH (t);

  if (POINTER_TYPE_P (TREE_TYPE (t))
      || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
    prec = POINTER_SIZE;
  else
    prec = TYPE_PRECISION (TREE_TYPE (t));
  /* Size types *are* sign extended.  */
  sign_extended_type = (!TYPE_UNSIGNED (TREE_TYPE (t))
			|| (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
			    && TYPE_IS_SIZETYPE (TREE_TYPE (t))));

  /* First clear all bits that are beyond the type's precision.  */

  if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
    ;
  else if (prec > HOST_BITS_PER_WIDE_INT)
    high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
  else
    {
      high = 0;
      if (prec < HOST_BITS_PER_WIDE_INT)
	low &= ~((HOST_WIDE_INT) (-1) << prec);
    }

  if (!sign_extended_type)
    /* No sign extension */;
  else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
    /* Correct width already.  */;
  else if (prec > HOST_BITS_PER_WIDE_INT)
    {
      /* Sign extend top half? */
      if (high & ((unsigned HOST_WIDE_INT)1
		  << (prec - HOST_BITS_PER_WIDE_INT - 1)))
	high |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
    }
  else if (prec == HOST_BITS_PER_WIDE_INT)
    {
      if ((HOST_WIDE_INT)low < 0)
	high = -1;
    }
  else
    {
      /* Sign extend bottom half? */
      if (low & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
	{
	  high = -1;
	  low |= (HOST_WIDE_INT)(-1) << prec;
	}
    }

  /* If the value changed, return a new node.  */
  if (overflowed || overflowed_const
      || low != TREE_INT_CST_LOW (t) || high != TREE_INT_CST_HIGH (t))
    {
      t = build_int_cst_wide (TREE_TYPE (t), low, high);

      if (overflowed
	  || overflowable < 0
	  || (overflowable > 0 && sign_extended_type))
	{
	  t = copy_node (t);
	  TREE_OVERFLOW (t) = 1;
	  TREE_CONSTANT_OVERFLOW (t) = 1;
	}
      else if (overflowed_const)
	{
	  t = copy_node (t);
	  TREE_CONSTANT_OVERFLOW (t) = 1;
	}
    }

  return t;
}

/* Add two doubleword integers with doubleword result.
   Return nonzero if the operation overflows according to UNSIGNED_P.
   Each argument is given as two `HOST_WIDE_INT' pieces.
   One argument is L1 and H1; the other, L2 and H2.
   The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV.  */

int
add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
		      unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
		      unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
		      bool unsigned_p)
{
  unsigned HOST_WIDE_INT l;
  HOST_WIDE_INT h;

  l = l1 + l2;
  h = h1 + h2 + (l < l1);

  *lv = l;
  *hv = h;

  if (unsigned_p)
    return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
  else
    return OVERFLOW_SUM_SIGN (h1, h2, h);
}

/* Negate a doubleword integer with doubleword result.
   Return nonzero if the operation overflows, assuming it's signed.
   The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
   The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV.  */

int
neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
	    unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
{
  if (l1 == 0)
    {
      *lv = 0;
      *hv = - h1;
      return (*hv & h1) < 0;
    }
  else
    {
      *lv = -l1;
      *hv = ~h1;
      return 0;
    }
}

/* Multiply two doubleword integers with doubleword result.
   Return nonzero if the operation overflows according to UNSIGNED_P.
   Each argument is given as two `HOST_WIDE_INT' pieces.
   One argument is L1 and H1; the other, L2 and H2.
   The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV.  */

int
mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
		      unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
		      unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
		      bool unsigned_p)
{
  HOST_WIDE_INT arg1[4];
  HOST_WIDE_INT arg2[4];
  HOST_WIDE_INT prod[4 * 2];
  unsigned HOST_WIDE_INT carry;
  int i, j, k;
  unsigned HOST_WIDE_INT toplow, neglow;
  HOST_WIDE_INT tophigh, neghigh;

  encode (arg1, l1, h1);
  encode (arg2, l2, h2);

  memset (prod, 0, sizeof prod);

  for (i = 0; i < 4; i++)
    {
      carry = 0;
      for (j = 0; j < 4; j++)
	{
	  k = i + j;
	  /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000.  */
	  carry += arg1[i] * arg2[j];
	  /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF.  */
	  carry += prod[k];
	  prod[k] = LOWPART (carry);
	  carry = HIGHPART (carry);
	}
      prod[i + 4] = carry;
    }

  decode (prod, lv, hv);
  decode (prod + 4, &toplow, &tophigh);

  /* Unsigned overflow is immediate.  */
  if (unsigned_p)
    return (toplow | tophigh) != 0;

  /* Check for signed overflow by calculating the signed representation of the
     top half of the result; it should agree with the low half's sign bit.  */
  if (h1 < 0)
    {
      neg_double (l2, h2, &neglow, &neghigh);
      add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
    }
  if (h2 < 0)
    {
      neg_double (l1, h1, &neglow, &neghigh);
      add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
    }
  return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
}

/* Shift the doubleword integer in L1, H1 left by COUNT places
   keeping only PREC bits of result.
   Shift right if COUNT is negative.
   ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
   Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV.  */

void
lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
	       HOST_WIDE_INT count, unsigned int prec,
	       unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
{
  unsigned HOST_WIDE_INT signmask;

  if (count < 0)
    {
      rshift_double (l1, h1, -count, prec, lv, hv, arith);
      return;
    }

  if (SHIFT_COUNT_TRUNCATED)
    count %= prec;

  if (count >= 2 * HOST_BITS_PER_WIDE_INT)
    {
      /* Shifting by the host word size is undefined according to the
	 ANSI standard, so we must handle this as a special case.  */
      *hv = 0;
      *lv = 0;
    }
  else if (count >= HOST_BITS_PER_WIDE_INT)
    {
      *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
      *lv = 0;
    }
  else
    {
      *hv = (((unsigned HOST_WIDE_INT) h1 << count)
	     | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
      *lv = l1 << count;
    }

  /* Sign extend all bits that are beyond the precision.  */

  signmask = -((prec > HOST_BITS_PER_WIDE_INT
		? ((unsigned HOST_WIDE_INT) *hv
		   >> (prec - HOST_BITS_PER_WIDE_INT - 1))
		: (*lv >> (prec - 1))) & 1);

  if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
    ;
  else if (prec >= HOST_BITS_PER_WIDE_INT)
    {
      *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
      *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
    }
  else
    {
      *hv = signmask;
      *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
      *lv |= signmask << prec;
    }
}

/* Shift the doubleword integer in L1, H1 right by COUNT places
   keeping only PREC bits of result.  COUNT must be positive.
   ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
   Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV.  */

void
rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
	       HOST_WIDE_INT count, unsigned int prec,
	       unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
	       int arith)
{
  unsigned HOST_WIDE_INT signmask;

  signmask = (arith
	      ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
	      : 0);

  if (SHIFT_COUNT_TRUNCATED)
    count %= prec;

  if (count >= 2 * HOST_BITS_PER_WIDE_INT)
    {
      /* Shifting by the host word size is undefined according to the
	 ANSI standard, so we must handle this as a special case.  */
      *hv = 0;
      *lv = 0;
    }
  else if (count >= HOST_BITS_PER_WIDE_INT)
    {
      *hv = 0;
      *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
    }
  else
    {
      *hv = (unsigned HOST_WIDE_INT) h1 >> count;
      *lv = ((l1 >> count)
	     | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
    }

  /* Zero / sign extend all bits that are beyond the precision.  */

  if (count >= (HOST_WIDE_INT)prec)
    {
      *hv = signmask;
      *lv = signmask;
    }
  else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
    ;
  else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
    {
      *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
      *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
    }
  else
    {
      *hv = signmask;
      *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
      *lv |= signmask << (prec - count);
    }
}

/* Rotate the doubleword integer in L1, H1 left by COUNT places
   keeping only PREC bits of result.
   Rotate right if COUNT is negative.
   Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV.  */

void
lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
		HOST_WIDE_INT count, unsigned int prec,
		unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
{
  unsigned HOST_WIDE_INT s1l, s2l;
  HOST_WIDE_INT s1h, s2h;

  count %= prec;
  if (count < 0)
    count += prec;

  lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
  rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
  *lv = s1l | s2l;
  *hv = s1h | s2h;
}

/* Rotate the doubleword integer in L1, H1 left by COUNT places
   keeping only PREC bits of result.  COUNT must be positive.
   Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV.  */

void
rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
		HOST_WIDE_INT count, unsigned int prec,
		unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
{
  unsigned HOST_WIDE_INT s1l, s2l;
  HOST_WIDE_INT s1h, s2h;

  count %= prec;
  if (count < 0)
    count += prec;

  rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
  lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
  *lv = s1l | s2l;
  *hv = s1h | s2h;
}

/* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
   for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
   CODE is a tree code for a kind of division, one of
   TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
   or EXACT_DIV_EXPR
   It controls how the quotient is rounded to an integer.
   Return nonzero if the operation overflows.
   UNS nonzero says do unsigned division.  */

int
div_and_round_double (enum tree_code code, int uns,
		      unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
		      HOST_WIDE_INT hnum_orig,
		      unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
		      HOST_WIDE_INT hden_orig,
		      unsigned HOST_WIDE_INT *lquo,
		      HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
		      HOST_WIDE_INT *hrem)
{
  int quo_neg = 0;
  HOST_WIDE_INT num[4 + 1];	/* extra element for scaling.  */
  HOST_WIDE_INT den[4], quo[4];
  int i, j;
  unsigned HOST_WIDE_INT work;
  unsigned HOST_WIDE_INT carry = 0;
  unsigned HOST_WIDE_INT lnum = lnum_orig;
  HOST_WIDE_INT hnum = hnum_orig;
  unsigned HOST_WIDE_INT lden = lden_orig;
  HOST_WIDE_INT hden = hden_orig;
  int overflow = 0;

  if (hden == 0 && lden == 0)
    overflow = 1, lden = 1;

  /* Calculate quotient sign and convert operands to unsigned.  */
  if (!uns)
    {
      if (hnum < 0)
	{
	  quo_neg = ~ quo_neg;
	  /* (minimum integer) / (-1) is the only overflow case.  */
	  if (neg_double (lnum, hnum, &lnum, &hnum)
	      && ((HOST_WIDE_INT) lden & hden) == -1)
	    overflow = 1;
	}
      if (hden < 0)
	{
	  quo_neg = ~ quo_neg;
	  neg_double (lden, hden, &lden, &hden);
	}
    }

  if (hnum == 0 && hden == 0)
    {				/* single precision */
      *hquo = *hrem = 0;
      /* This unsigned division rounds toward zero.  */
      *lquo = lnum / lden;
      goto finish_up;
    }

  if (hnum == 0)
    {				/* trivial case: dividend < divisor */
      /* hden != 0 already checked.  */
      *hquo = *lquo = 0;
      *hrem = hnum;
      *lrem = lnum;
      goto finish_up;
    }

  memset (quo, 0, sizeof quo);

  memset (num, 0, sizeof num);	/* to zero 9th element */
  memset (den, 0, sizeof den);

  encode (num, lnum, hnum);
  encode (den, lden, hden);

  /* Special code for when the divisor < BASE.  */
  if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
    {
      /* hnum != 0 already checked.  */
      for (i = 4 - 1; i >= 0; i--)
	{
	  work = num[i] + carry * BASE;
	  quo[i] = work / lden;
	  carry = work % lden;
	}
    }
  else
    {
      /* Full double precision division,
	 with thanks to Don Knuth's "Seminumerical Algorithms".  */
      int num_hi_sig, den_hi_sig;
      unsigned HOST_WIDE_INT quo_est, scale;

      /* Find the highest nonzero divisor digit.  */
      for (i = 4 - 1;; i--)
	if (den[i] != 0)
	  {
	    den_hi_sig = i;
	    break;
	  }

      /* Insure that the first digit of the divisor is at least BASE/2.
	 This is required by the quotient digit estimation algorithm.  */

      scale = BASE / (den[den_hi_sig] + 1);
      if (scale > 1)
	{		/* scale divisor and dividend */
	  carry = 0;
	  for (i = 0; i <= 4 - 1; i++)
	    {
	      work = (num[i] * scale) + carry;
	      num[i] = LOWPART (work);
	      carry = HIGHPART (work);
	    }

	  num[4] = carry;
	  carry = 0;
	  for (i = 0; i <= 4 - 1; i++)
	    {
	      work = (den[i] * scale) + carry;
	      den[i] = LOWPART (work);
	      carry = HIGHPART (work);
	      if (den[i] != 0) den_hi_sig = i;
	    }
	}

      num_hi_sig = 4;

      /* Main loop */
      for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
	{
	  /* Guess the next quotient digit, quo_est, by dividing the first
	     two remaining dividend digits by the high order quotient digit.
	     quo_est is never low and is at most 2 high.  */
	  unsigned HOST_WIDE_INT tmp;

	  num_hi_sig = i + den_hi_sig + 1;
	  work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
	  if (num[num_hi_sig] != den[den_hi_sig])
	    quo_est = work / den[den_hi_sig];
	  else
	    quo_est = BASE - 1;

	  /* Refine quo_est so it's usually correct, and at most one high.  */
	  tmp = work - quo_est * den[den_hi_sig];
	  if (tmp < BASE
	      && (den[den_hi_sig - 1] * quo_est
		  > (tmp * BASE + num[num_hi_sig - 2])))
	    quo_est--;

	  /* Try QUO_EST as the quotient digit, by multiplying the
	     divisor by QUO_EST and subtracting from the remaining dividend.
	     Keep in mind that QUO_EST is the I - 1st digit.  */

	  carry = 0;
	  for (j = 0; j <= den_hi_sig; j++)
	    {
	      work = quo_est * den[j] + carry;
	      carry = HIGHPART (work);
	      work = num[i + j] - LOWPART (work);
	      num[i + j] = LOWPART (work);
	      carry += HIGHPART (work) != 0;
	    }

	  /* If quo_est was high by one, then num[i] went negative and
	     we need to correct things.  */
	  if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
	    {
	      quo_est--;
	      carry = 0;		/* add divisor back in */
	      for (j = 0; j <= den_hi_sig; j++)
		{
		  work = num[i + j] + den[j] + carry;
		  carry = HIGHPART (work);
		  num[i + j] = LOWPART (work);
		}

	      num [num_hi_sig] += carry;
	    }

	  /* Store the quotient digit.  */
	  quo[i] = quo_est;
	}
    }

  decode (quo, lquo, hquo);

 finish_up:
  /* If result is negative, make it so.  */
  if (quo_neg)
    neg_double (*lquo, *hquo, lquo, hquo);

  /* Compute trial remainder:  rem = num - (quo * den)  */
  mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
  neg_double (*lrem, *hrem, lrem, hrem);
  add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);

  switch (code)
    {
    case TRUNC_DIV_EXPR:
    case TRUNC_MOD_EXPR:	/* round toward zero */
    case EXACT_DIV_EXPR:	/* for this one, it shouldn't matter */
      return overflow;

    case FLOOR_DIV_EXPR:
    case FLOOR_MOD_EXPR:	/* round toward negative infinity */
      if (quo_neg && (*lrem != 0 || *hrem != 0))   /* ratio < 0 && rem != 0 */
	{
	  /* quo = quo - 1;  */
	  add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT)  -1,
		      lquo, hquo);
	}
      else
	return overflow;
      break;

    case CEIL_DIV_EXPR:
    case CEIL_MOD_EXPR:		/* round toward positive infinity */
      if (!quo_neg && (*lrem != 0 || *hrem != 0))  /* ratio > 0 && rem != 0 */
	{
	  add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
		      lquo, hquo);
	}
      else
	return overflow;
      break;

    case ROUND_DIV_EXPR:
    case ROUND_MOD_EXPR:	/* round to closest integer */
      {
	unsigned HOST_WIDE_INT labs_rem = *lrem;
	HOST_WIDE_INT habs_rem = *hrem;
	unsigned HOST_WIDE_INT labs_den = lden, ltwice;
	HOST_WIDE_INT habs_den = hden, htwice;

	/* Get absolute values.  */
	if (*hrem < 0)
	  neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
	if (hden < 0)
	  neg_double (lden, hden, &labs_den, &habs_den);

	/* If (2 * abs (lrem) >= abs (lden)) */
	mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
		    labs_rem, habs_rem, &ltwice, &htwice);

	if (((unsigned HOST_WIDE_INT) habs_den
	     < (unsigned HOST_WIDE_INT) htwice)
	    || (((unsigned HOST_WIDE_INT) habs_den
		 == (unsigned HOST_WIDE_INT) htwice)
		&& (labs_den < ltwice)))
	  {
	    if (*hquo < 0)
	      /* quo = quo - 1;  */
	      add_double (*lquo, *hquo,
			  (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
	    else
	      /* quo = quo + 1; */
	      add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
			  lquo, hquo);
	  }
	else
	  return overflow;
      }
      break;

    default:
      gcc_unreachable ();
    }

  /* Compute true remainder:  rem = num - (quo * den)  */
  mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
  neg_double (*lrem, *hrem, lrem, hrem);
  add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
  return overflow;
}

/* If ARG2 divides ARG1 with zero remainder, carries out the division
   of type CODE and returns the quotient.
   Otherwise returns NULL_TREE.  */

static tree
div_if_zero_remainder (enum tree_code code, tree arg1, tree arg2)
{
  unsigned HOST_WIDE_INT int1l, int2l;
  HOST_WIDE_INT int1h, int2h;
  unsigned HOST_WIDE_INT quol, reml;
  HOST_WIDE_INT quoh, remh;
  tree type = TREE_TYPE (arg1);
  int uns = TYPE_UNSIGNED (type);

  int1l = TREE_INT_CST_LOW (arg1);
  int1h = TREE_INT_CST_HIGH (arg1);
  int2l = TREE_INT_CST_LOW (arg2);
  int2h = TREE_INT_CST_HIGH (arg2);

  div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
		  	&quol, &quoh, &reml, &remh);
  if (remh != 0 || reml != 0)
    return NULL_TREE;

  return build_int_cst_wide (type, quol, quoh);
}

/* This is non-zero if we should defer warnings about undefined
   overflow.  This facility exists because these warnings are a
   special case.  The code to estimate loop iterations does not want
   to issue any warnings, since it works with expressions which do not
   occur in user code.  Various bits of cleanup code call fold(), but
   only use the result if it has certain characteristics (e.g., is a
   constant); that code only wants to issue a warning if the result is
   used.  */

static int fold_deferring_overflow_warnings;

/* If a warning about undefined overflow is deferred, this is the
   warning.  Note that this may cause us to turn two warnings into
   one, but that is fine since it is sufficient to only give one
   warning per expression.  */

static const char* fold_deferred_overflow_warning;

/* If a warning about undefined overflow is deferred, this is the
   level at which the warning should be emitted.  */

static enum warn_strict_overflow_code fold_deferred_overflow_code;

/* Start deferring overflow warnings.  We could use a stack here to
   permit nested calls, but at present it is not necessary.  */

void
fold_defer_overflow_warnings (void)
{
  ++fold_deferring_overflow_warnings;
}

/* Stop deferring overflow warnings.  If there is a pending warning,
   and ISSUE is true, then issue the warning if appropriate.  STMT is
   the statement with which the warning should be associated (used for
   location information); STMT may be NULL.  CODE is the level of the
   warning--a warn_strict_overflow_code value.  This function will use
   the smaller of CODE and the deferred code when deciding whether to
   issue the warning.  CODE may be zero to mean to always use the
   deferred code.  */

void
fold_undefer_overflow_warnings (bool issue, tree stmt, int code)
{
  const char *warnmsg;
  location_t locus;

  gcc_assert (fold_deferring_overflow_warnings > 0);
  --fold_deferring_overflow_warnings;
  if (fold_deferring_overflow_warnings > 0)
    {
      if (fold_deferred_overflow_warning != NULL
	  && code != 0
	  && code < (int) fold_deferred_overflow_code)
	fold_deferred_overflow_code = code;
      return;
    }

  warnmsg = fold_deferred_overflow_warning;
  fold_deferred_overflow_warning = NULL;

  if (!issue || warnmsg == NULL)
    return;

  /* Use the smallest code level when deciding to issue the
     warning.  */
  if (code == 0 || code > (int) fold_deferred_overflow_code)
    code = fold_deferred_overflow_code;

  if (!issue_strict_overflow_warning (code))
    return;

  if (stmt == NULL_TREE || !EXPR_HAS_LOCATION (stmt))
    locus = input_location;
  else
    locus = EXPR_LOCATION (stmt);
  warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
}

/* Stop deferring overflow warnings, ignoring any deferred
   warnings.  */

void
fold_undefer_and_ignore_overflow_warnings (void)
{
  fold_undefer_overflow_warnings (false, NULL_TREE, 0);
}

/* Whether we are deferring overflow warnings.  */

bool
fold_deferring_overflow_warnings_p (void)
{
  return fold_deferring_overflow_warnings > 0;
}

/* This is called when we fold something based on the fact that signed
   overflow is undefined.  */

static void
fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
{
  gcc_assert (!flag_wrapv && !flag_trapv);
  if (fold_deferring_overflow_warnings > 0)
    {
      if (fold_deferred_overflow_warning == NULL
	  || wc < fold_deferred_overflow_code)
	{
	  fold_deferred_overflow_warning = gmsgid;
	  fold_deferred_overflow_code = wc;
	}
    }
  else if (issue_strict_overflow_warning (wc))
    warning (OPT_Wstrict_overflow, gmsgid);
}

/* Return true if the built-in mathematical function specified by CODE
   is odd, i.e. -f(x) == f(-x).  */

static bool
negate_mathfn_p (enum built_in_function code)
{
  switch (code)
    {
    CASE_FLT_FN (BUILT_IN_ASIN):
    CASE_FLT_FN (BUILT_IN_ASINH):
    CASE_FLT_FN (BUILT_IN_ATAN):
    CASE_FLT_FN (BUILT_IN_ATANH):
    CASE_FLT_FN (BUILT_IN_CBRT):
    CASE_FLT_FN (BUILT_IN_SIN):
    CASE_FLT_FN (BUILT_IN_SINH):
    CASE_FLT_FN (BUILT_IN_TAN):
    CASE_FLT_FN (BUILT_IN_TANH):
      return true;

    default:
      break;
    }
  return false;
}

/* Check whether we may negate an integer constant T without causing
   overflow.  */

bool
may_negate_without_overflow_p (tree t)
{
  unsigned HOST_WIDE_INT val;
  unsigned int prec;
  tree type;

  gcc_assert (TREE_CODE (t) == INTEGER_CST);

  type = TREE_TYPE (t);
  if (TYPE_UNSIGNED (type))
    return false;

  prec = TYPE_PRECISION (type);
  if (prec > HOST_BITS_PER_WIDE_INT)
    {
      if (TREE_INT_CST_LOW (t) != 0)
	return true;
      prec -= HOST_BITS_PER_WIDE_INT;
      val = TREE_INT_CST_HIGH (t);
    }
  else
    val = TREE_INT_CST_LOW (t);
  if (prec < HOST_BITS_PER_WIDE_INT)
    val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
  return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
}

/* Determine whether an expression T can be cheaply negated using
   the function negate_expr without introducing undefined overflow.  */

static bool
negate_expr_p (tree t)
{
  tree type;

  if (t == 0)
    return false;

  type = TREE_TYPE (t);

  STRIP_SIGN_NOPS (t);
  switch (TREE_CODE (t))
    {
    case INTEGER_CST:
      if (TYPE_OVERFLOW_WRAPS (type))
	return true;

      /* Check that -CST will not overflow type.  */
      return may_negate_without_overflow_p (t);
    case BIT_NOT_EXPR:
      return (INTEGRAL_TYPE_P (type)
	      && TYPE_OVERFLOW_WRAPS (type));

    case REAL_CST:
    case NEGATE_EXPR:
      return true;

    case COMPLEX_CST:
      return negate_expr_p (TREE_REALPART (t))
	     && negate_expr_p (TREE_IMAGPART (t));

    case PLUS_EXPR:
      if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
	return false;
      /* -(A + B) -> (-B) - A.  */
      if (negate_expr_p (TREE_OPERAND (t, 1))
	  && reorder_operands_p (TREE_OPERAND (t, 0),
				 TREE_OPERAND (t, 1)))
	return true;
      /* -(A + B) -> (-A) - B.  */
      return negate_expr_p (TREE_OPERAND (t, 0));

    case MINUS_EXPR:
      /* We can't turn -(A-B) into B-A when we honor signed zeros.  */
      return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
	     && reorder_operands_p (TREE_OPERAND (t, 0),
				    TREE_OPERAND (t, 1));

    case MULT_EXPR:
      if (TYPE_UNSIGNED (TREE_TYPE (t)))
        break;

      /* Fall through.  */

    case RDIV_EXPR:
      if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
	return negate_expr_p (TREE_OPERAND (t, 1))
	       || negate_expr_p (TREE_OPERAND (t, 0));
      break;

    case TRUNC_DIV_EXPR:
    case ROUND_DIV_EXPR:
    case FLOOR_DIV_EXPR:
    case CEIL_DIV_EXPR:
    case EXACT_DIV_EXPR:
      /* In general we can't negate A / B, because if A is INT_MIN and
	 B is 1, we may turn this into INT_MIN / -1 which is undefined
	 and actually traps on some architectures.  But if overflow is
	 undefined, we can negate, because - (INT_MIN / 1) is an
	 overflow.  */
      if (INTEGRAL_TYPE_P (TREE_TYPE (t))
	  && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
        break;
      return negate_expr_p (TREE_OPERAND (t, 1))
             || negate_expr_p (TREE_OPERAND (t, 0));

    case NOP_EXPR:
      /* Negate -((double)float) as (double)(-float).  */
      if (TREE_CODE (type) == REAL_TYPE)
	{
	  tree tem = strip_float_extensions (t);
	  if (tem != t)
	    return negate_expr_p (tem);
	}
      break;

    case CALL_EXPR:
      /* Negate -f(x) as f(-x).  */
      if (negate_mathfn_p (builtin_mathfn_code (t)))
	return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
      break;

    case RSHIFT_EXPR:
      /* Optimize -((int)x >> 31) into (unsigned)x >> 31.  */
      if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
	{
	  tree op1 = TREE_OPERAND (t, 1);
	  if (TREE_INT_CST_HIGH (op1) == 0
	      && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
		 == TREE_INT_CST_LOW (op1))
	    return true;
	}
      break;

    default:
      break;
    }
  return false;
}

/* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
   simplification is possible.
   If negate_expr_p would return true for T, NULL_TREE will never be
   returned.  */

static tree
fold_negate_expr (tree t)
{
  tree type = TREE_TYPE (t);
  tree tem;

  switch (TREE_CODE (t))
    {
    /* Convert - (~A) to A + 1.  */
    case BIT_NOT_EXPR:
      if (INTEGRAL_TYPE_P (type))
        return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
                            build_int_cst (type, 1));
      break;
      
    case INTEGER_CST:
      tem = fold_negate_const (t, type);
      if (!TREE_OVERFLOW (tem)
	  || !TYPE_OVERFLOW_TRAPS (type))
	return tem;
      break;

    case REAL_CST:
      tem = fold_negate_const (t, type);
      /* Two's complement FP formats, such as c4x, may overflow.  */
      if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
	return tem;
      break;

    case COMPLEX_CST:
      {
	tree rpart = negate_expr (TREE_REALPART (t));
	tree ipart = negate_expr (TREE_IMAGPART (t));

	if ((TREE_CODE (rpart) == REAL_CST
	     && TREE_CODE (ipart) == REAL_CST)
	    || (TREE_CODE (rpart) == INTEGER_CST
		&& TREE_CODE (ipart) == INTEGER_CST))
	  return build_complex (type, rpart, ipart);
      }
      break;

    case NEGATE_EXPR:
      return TREE_OPERAND (t, 0);

    case PLUS_EXPR:
      if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
	{
	  /* -(A + B) -> (-B) - A.  */
	  if (negate_expr_p (TREE_OPERAND (t, 1))
	      && reorder_operands_p (TREE_OPERAND (t, 0),
				     TREE_OPERAND (t, 1)))
	    {
	      tem = negate_expr (TREE_OPERAND (t, 1));
	      return fold_build2 (MINUS_EXPR, type,
				  tem, TREE_OPERAND (t, 0));
	    }

	  /* -(A + B) -> (-A) - B.  */
	  if (negate_expr_p (TREE_OPERAND (t, 0)))
	    {
	      tem = negate_expr (TREE_OPERAND (t, 0));
	      return fold_build2 (MINUS_EXPR, type,
				  tem, TREE_OPERAND (t, 1));
	    }
	}
      break;

    case MINUS_EXPR:
      /* - (A - B) -> B - A  */
      if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
	  && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
	return fold_build2 (MINUS_EXPR, type,
			    TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
      break;

    case MULT_EXPR:
      if (TYPE_UNSIGNED (type))
        break;

      /* Fall through.  */

    case RDIV_EXPR:
      if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
	{
	  tem = TREE_OPERAND (t, 1);
	  if (negate_expr_p (tem))
	    return fold_build2 (TREE_CODE (t), type,
				TREE_OPERAND (t, 0), negate_expr (tem));
	  tem = TREE_OPERAND (t, 0);
	  if (negate_expr_p (tem))
	    return fold_build2 (TREE_CODE (t), type,
				negate_expr (tem), TREE_OPERAND (t, 1));
	}
      break;

    case TRUNC_DIV_EXPR:
    case ROUND_DIV_EXPR:
    case FLOOR_DIV_EXPR:
    case CEIL_DIV_EXPR:
    case EXACT_DIV_EXPR:
      /* In general we can't negate A / B, because if A is INT_MIN and
	 B is 1, we may turn this into INT_MIN / -1 which is undefined
	 and actually traps on some architectures.  But if overflow is
	 undefined, we can negate, because - (INT_MIN / 1) is an
	 overflow.  */
      if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
        {
	  const char * const warnmsg = G_("assuming signed overflow does not "
					  "occur when negating a division");
          tem = TREE_OPERAND (t, 1);
          if (negate_expr_p (tem))
	    {
	      if (INTEGRAL_TYPE_P (type)
		  && (TREE_CODE (tem) != INTEGER_CST
		      || integer_onep (tem)))
		fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
	      return fold_build2 (TREE_CODE (t), type,
				  TREE_OPERAND (t, 0), negate_expr (tem));
	    }
          tem = TREE_OPERAND (t, 0);
          if (negate_expr_p (tem))
	    {
	      if (INTEGRAL_TYPE_P (type)
		  && (TREE_CODE (tem) != INTEGER_CST
		      || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
		fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
	      return fold_build2 (TREE_CODE (t), type,
				  negate_expr (tem), TREE_OPERAND (t, 1));
	    }
        }
      break;

    case NOP_EXPR:
      /* Convert -((double)float) into (double)(-float).  */
      if (TREE_CODE (type) == REAL_TYPE)
	{
	  tem = strip_float_extensions (t);
	  if (tem != t && negate_expr_p (tem))
	    return negate_expr (tem);
	}
      break;

    case CALL_EXPR:
      /* Negate -f(x) as f(-x).  */
      if (negate_mathfn_p (builtin_mathfn_code (t))
	  && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
	{
	  tree fndecl, arg, arglist;

	  fndecl = get_callee_fndecl (t);
	  arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
	  arglist = build_tree_list (NULL_TREE, arg);
	  return build_function_call_expr (fndecl, arglist);
	}
      break;

    case RSHIFT_EXPR:
      /* Optimize -((int)x >> 31) into (unsigned)x >> 31.  */
      if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
	{
	  tree op1 = TREE_OPERAND (t, 1);
	  if (TREE_INT_CST_HIGH (op1) == 0
	      && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
		 == TREE_INT_CST_LOW (op1))
	    {
	      tree ntype = TYPE_UNSIGNED (type)
			   ? lang_hooks.types.signed_type (type)
			   : lang_hooks.types.unsigned_type (type);
	      tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
	      temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
	      return fold_convert (type, temp);
	    }
	}
      break;

    default:
      break;
    }

  return NULL_TREE;
}

/* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
   negated in a simpler way.  Also allow for T to be NULL_TREE, in which case
   return NULL_TREE. */

static tree
negate_expr (tree t)
{
  tree type, tem;

  if (t == NULL_TREE)
    return NULL_TREE;

  type = TREE_TYPE (t);
  STRIP_SIGN_NOPS (t);

  tem = fold_negate_expr (t);
  if (!tem)
    tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
  return fold_convert (type, tem);
}

/* Split a tree IN into a constant, literal and variable parts that could be
   combined with CODE to make IN.  "constant" means an expression with
   TREE_CONSTANT but that isn't an actual constant.  CODE must be a
   commutative arithmetic operation.  Store the constant part into *CONP,
   the literal in *LITP and return the variable part.  If a part isn't
   present, set it to null.  If the tree does not decompose in this way,
   return the entire tree as the variable part and the other parts as null.

   If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR.  In that
   case, we negate an operand that was subtracted.  Except if it is a
   literal for which we use *MINUS_LITP instead.

   If NEGATE_P is true, we are negating all of IN, again except a literal
   for which we use *MINUS_LITP instead.

   If IN is itself a literal or constant, return it as appropriate.

   Note that we do not guarantee that any of the three values will be the
   same type as IN, but they will have the same signedness and mode.  */

static tree
split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
	    tree *minus_litp, int negate_p)
{
  tree var = 0;

  *conp = 0;
  *litp = 0;
  *minus_litp = 0;

  /* Strip any conversions that don't change the machine mode or signedness.  */
  STRIP_SIGN_NOPS (in);

  if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
    *litp = in;
  else if (TREE_CODE (in) == code
	   || (! FLOAT_TYPE_P (TREE_TYPE (in))
	       /* We can associate addition and subtraction together (even
		  though the C standard doesn't say so) for integers because
		  the value is not affected.  For reals, the value might be
		  affected, so we can't.  */
	       && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
		   || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
    {
      tree op0 = TREE_OPERAND (in, 0);
      tree op1 = TREE_OPERAND (in, 1);
      int neg1_p = TREE_CODE (in) == MINUS_EXPR;
      int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;

      /* First see if either of the operands is a literal, then a constant.  */
      if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
	*litp = op0, op0 = 0;
      else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
	*litp = op1, neg_litp_p = neg1_p, op1 = 0;

      if (op0 != 0 && TREE_CONSTANT (op0))
	*conp = op0, op0 = 0;
      else if (op1 != 0 && TREE_CONSTANT (op1))
	*conp = op1, neg_conp_p = neg1_p, op1 = 0;

      /* If we haven't dealt with either operand, this is not a case we can
	 decompose.  Otherwise, VAR is either of the ones remaining, if any.  */
      if (op0 != 0 && op1 != 0)
	var = in;
      else if (op0 != 0)
	var = op0;
      else
	var = op1, neg_var_p = neg1_p;

      /* Now do any needed negations.  */
      if (neg_litp_p)
	*minus_litp = *litp, *litp = 0;
      if (neg_conp_p)
	*conp = negate_expr (*conp);
      if (neg_var_p)
	var = negate_expr (var);
    }
  else if (TREE_CONSTANT (in))
    *conp = in;
  else
    var = in;

  if (negate_p)
    {
      if (*litp)
	*minus_litp = *litp, *litp = 0;
      else if (*minus_litp)
	*litp = *minus_litp, *minus_litp = 0;
      *conp = negate_expr (*conp);
      var = negate_expr (var);
    }

  return var;
}

/* Re-associate trees split by the above function.  T1 and T2 are either
   expressions to associate or null.  Return the new expression, if any.  If
   we build an operation, do it in TYPE and with CODE.  */

static tree
associate_trees (tree t1, tree t2, enum tree_code code, tree type)
{
  if (t1 == 0)
    return t2;
  else if (t2 == 0)
    return t1;

  /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
     try to fold this since we will have infinite recursion.  But do
     deal with any NEGATE_EXPRs.  */
  if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
      || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
    {
      if (code == PLUS_EXPR)
	{
	  if (TREE_CODE (t1) == NEGATE_EXPR)
	    return build2 (MINUS_EXPR, type, fold_convert (type, t2),
			   fold_convert (type, TREE_OPERAND (t1, 0)));
	  else if (TREE_CODE (t2) == NEGATE_EXPR)
	    return build2 (MINUS_EXPR, type, fold_convert (type, t1),
			   fold_convert (type, TREE_OPERAND (t2, 0)));
	  else if (integer_zerop (t2))
	    return fold_convert (type, t1);
	}
      else if (code == MINUS_EXPR)
	{
	  if (integer_zerop (t2))
	    return fold_convert (type, t1);
	}

      return build2 (code, type, fold_convert (type, t1),
		     fold_convert (type, t2));
    }

  return fold_build2 (code, type, fold_convert (type, t1),
		      fold_convert (type, t2));
}

/* Combine two integer constants ARG1 and ARG2 under operation CODE
   to produce a new constant.  Return NULL_TREE if we don't know how
   to evaluate CODE at compile-time.

   If NOTRUNC is nonzero, do not truncate the result to fit the data type.  */

tree
int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
{
  unsigned HOST_WIDE_INT int1l, int2l;
  HOST_WIDE_INT int1h, int2h;
  unsigned HOST_WIDE_INT low;
  HOST_WIDE_INT hi;
  unsigned HOST_WIDE_INT garbagel;
  HOST_WIDE_INT garbageh;
  tree t;
  tree type = TREE_TYPE (arg1);
  int uns = TYPE_UNSIGNED (type);
  int is_sizetype
    = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
  int overflow = 0;

  int1l = TREE_INT_CST_LOW (arg1);
  int1h = TREE_INT_CST_HIGH (arg1);
  int2l = TREE_INT_CST_LOW (arg2);
  int2h = TREE_INT_CST_HIGH (arg2);

  switch (code)
    {
    case BIT_IOR_EXPR:
      low = int1l | int2l, hi = int1h | int2h;
      break;

    case BIT_XOR_EXPR:
      low = int1l ^ int2l, hi = int1h ^ int2h;
      break;

    case BIT_AND_EXPR:
      low = int1l & int2l, hi = int1h & int2h;
      break;

    case RSHIFT_EXPR:
      int2l = -int2l;
    case LSHIFT_EXPR:
      /* It's unclear from the C standard whether shifts can overflow.
	 The following code ignores overflow; perhaps a C standard
	 interpretation ruling is needed.  */
      lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
		     &low, &hi, !uns);
      break;

    case RROTATE_EXPR:
      int2l = - int2l;
    case LROTATE_EXPR:
      lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
		      &low, &hi);
      break;

    case PLUS_EXPR:
      overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
      break;

    case MINUS_EXPR:
      neg_double (int2l, int2h, &low, &hi);
      add_double (int1l, int1h, low, hi, &low, &hi);
      overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
      break;

    case MULT_EXPR:
      overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
      break;

    case TRUNC_DIV_EXPR:
    case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
    case EXACT_DIV_EXPR:
      /* This is a shortcut for a common special case.  */
      if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
	  && ! TREE_CONSTANT_OVERFLOW (arg1)
	  && ! TREE_CONSTANT_OVERFLOW (arg2)
	  && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
	{
	  if (code == CEIL_DIV_EXPR)
	    int1l += int2l - 1;

	  low = int1l / int2l, hi = 0;
	  break;
	}

      /* ... fall through ...  */

    case ROUND_DIV_EXPR:
      if (int2h == 0 && int2l == 0)
	return NULL_TREE;
      if (int2h == 0 && int2l == 1)
	{
	  low = int1l, hi = int1h;
	  break;
	}
      if (int1l == int2l && int1h == int2h
	  && ! (int1l == 0 && int1h == 0))
	{
	  low = 1, hi = 0;
	  break;
	}
      overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
				       &low, &hi, &garbagel, &garbageh);
      break;

    case TRUNC_MOD_EXPR:
    case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
      /* This is a shortcut for a common special case.  */
      if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
	  && ! TREE_CONSTANT_OVERFLOW (arg1)
	  && ! TREE_CONSTANT_OVERFLOW (arg2)
	  && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
	{
	  if (code == CEIL_MOD_EXPR)
	    int1l += int2l - 1;
	  low = int1l % int2l, hi = 0;
	  break;
	}

      /* ... fall through ...  */

    case ROUND_MOD_EXPR:
      if (int2h == 0 && int2l == 0)
	return NULL_TREE;
      overflow = div_and_round_double (code, uns,
				       int1l, int1h, int2l, int2h,
				       &garbagel, &garbageh, &low, &hi);
      break;

    case MIN_EXPR:
    case MAX_EXPR:
      if (uns)
	low = (((unsigned HOST_WIDE_INT) int1h
		< (unsigned HOST_WIDE_INT) int2h)
	       || (((unsigned HOST_WIDE_INT) int1h
		    == (unsigned HOST_WIDE_INT) int2h)
		   && int1l < int2l));
      else
	low = (int1h < int2h
	       || (int1h == int2h && int1l < int2l));

      if (low == (code == MIN_EXPR))
	low = int1l, hi = int1h;
      else
	low = int2l, hi = int2h;
      break;

    default:
      return NULL_TREE;
    }

  t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);

  if (notrunc)
    {
      /* Propagate overflow flags ourselves.  */
      if (((!uns || is_sizetype) && overflow)
	  | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
	{
	  t = copy_node (t);
	  TREE_OVERFLOW (t) = 1;
	  TREE_CONSTANT_OVERFLOW (t) = 1;
	}
      else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
	{
	  t = copy_node (t);
	  TREE_CONSTANT_OVERFLOW (t) = 1;
	}
    }
  else
    t = force_fit_type (t, 1,
			((!uns || is_sizetype) && overflow)
			| TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2),
			TREE_CONSTANT_OVERFLOW (arg1)
			| TREE_CONSTANT_OVERFLOW (arg2));

  return t;
}

/* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
   constant.  We assume ARG1 and ARG2 have the same data type, or at least
   are the same kind of constant and the same machine mode.  Return zero if
   combining the constants is not allowed in the current operating mode.

   If NOTRUNC is nonzero, do not truncate the result to fit the data type.  */

static tree
const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
{
  /* Sanity check for the recursive cases.  */
  if (!arg1 || !arg2)
    return NULL_TREE;

  STRIP_NOPS (arg1);
  STRIP_NOPS (arg2);

  if (TREE_CODE (arg1) == INTEGER_CST)
    return int_const_binop (code, arg1, arg2, notrunc);

  if (TREE_CODE (arg1) == REAL_CST)
    {
      enum machine_mode mode;
      REAL_VALUE_TYPE d1;
      REAL_VALUE_TYPE d2;
      REAL_VALUE_TYPE value;
      REAL_VALUE_TYPE result;
      bool inexact;
      tree t, type;

      /* The following codes are handled by real_arithmetic.  */
      switch (code)
	{
	case PLUS_EXPR:
	case MINUS_EXPR:
	case MULT_EXPR:
	case RDIV_EXPR:
	case MIN_EXPR:
	case MAX_EXPR:
	  break;

	default:
	  return NULL_TREE;
	}

      d1 = TREE_REAL_CST (arg1);
      d2 = TREE_REAL_CST (arg2);

      type = TREE_TYPE (arg1);
      mode = TYPE_MODE (type);

      /* Don't perform operation if we honor signaling NaNs and
	 either operand is a NaN.  */
      if (HONOR_SNANS (mode)
	  && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
	return NULL_TREE;

      /* Don't perform operation if it would raise a division
	 by zero exception.  */
      if (code == RDIV_EXPR
	  && REAL_VALUES_EQUAL (d2, dconst0)
	  && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
	return NULL_TREE;

      /* If either operand is a NaN, just return it.  Otherwise, set up
	 for floating-point trap; we return an overflow.  */
      if (REAL_VALUE_ISNAN (d1))
	return arg1;
      else if (REAL_VALUE_ISNAN (d2))
	return arg2;

      inexact = real_arithmetic (&value, code, &d1, &d2);
      real_convert (&result, mode, &value);

      /* Don't constant fold this floating point operation if
	 the result has overflowed and flag_trapping_math.  */
      if (flag_trapping_math
	  && MODE_HAS_INFINITIES (mode)
	  && REAL_VALUE_ISINF (result)
	  && !REAL_VALUE_ISINF (d1)
	  && !REAL_VALUE_ISINF (d2))
	return NULL_TREE;

      /* Don't constant fold this floating point operation if the
	 result may dependent upon the run-time rounding mode and
	 flag_rounding_math is set, or if GCC's software emulation
	 is unable to accurately represent the result.  */
      if ((flag_rounding_math
	   || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
	       && !flag_unsafe_math_optimizations))
	  && (inexact || !real_identical (&result, &value)))
	return NULL_TREE;

      t = build_real (type, result);

      TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
      TREE_CONSTANT_OVERFLOW (t)
	= TREE_OVERFLOW (t)
	  | TREE_CONSTANT_OVERFLOW (arg1)
	  | TREE_CONSTANT_OVERFLOW (arg2);
      return t;
    }

  if (TREE_CODE (arg1) == COMPLEX_CST)
    {
      tree type = TREE_TYPE (arg1);
      tree r1 = TREE_REALPART (arg1);
      tree i1 = TREE_IMAGPART (arg1);
      tree r2 = TREE_REALPART (arg2);
      tree i2 = TREE_IMAGPART (arg2);
      tree real, imag;

      switch (code)
	{
	case PLUS_EXPR:
	case MINUS_EXPR:
	  real = const_binop (code, r1, r2, notrunc);
	  imag = const_binop (code, i1, i2, notrunc);
	  break;

	case MULT_EXPR:
	  real = const_binop (MINUS_EXPR,
			      const_binop (MULT_EXPR, r1, r2, notrunc),
			      const_binop (MULT_EXPR, i1, i2, notrunc),
			      notrunc);
	  imag = const_binop (PLUS_EXPR,
			      const_binop (MULT_EXPR, r1, i2, notrunc),
			      const_binop (MULT_EXPR, i1, r2, notrunc),
			      notrunc);
	  break;

	case RDIV_EXPR:
	  {
	    tree magsquared
	      = const_binop (PLUS_EXPR,
			     const_binop (MULT_EXPR, r2, r2, notrunc),
			     const_binop (MULT_EXPR, i2, i2, notrunc),
			     notrunc);
	    tree t1
	      = const_binop (PLUS_EXPR,
			     const_binop (MULT_EXPR, r1, r2, notrunc),
			     const_binop (MULT_EXPR, i1, i2, notrunc),
			     notrunc);
	    tree t2
	      = const_binop (MINUS_EXPR,
			     const_binop (MULT_EXPR, i1, r2, notrunc),
			     const_binop (MULT_EXPR, r1, i2, notrunc),
			     notrunc);

	    if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
	      code = TRUNC_DIV_EXPR;

	    real = const_binop (code, t1, magsquared, notrunc);
	    imag = const_binop (code, t2, magsquared, notrunc);
	  }
	  break;

	default:
	  return NULL_TREE;
	}

      if (real && imag)
	return build_complex (type, real, imag);
    }

  return NULL_TREE;
}

/* Create a size type INT_CST node with NUMBER sign extended.  KIND
   indicates which particular sizetype to create.  */

tree
size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
{
  return build_int_cst (sizetype_tab[(int) kind], number);
}

/* Combine operands OP1 and OP2 with arithmetic operation CODE.  CODE
   is a tree code.  The type of the result is taken from the operands.
   Both must be the same type integer type and it must be a size type.
   If the operands are constant, so is the result.  */

tree
size_binop (enum tree_code code, tree arg0, tree arg1)
{
  tree type = TREE_TYPE (arg0);

  if (arg0 == error_mark_node || arg1 == error_mark_node)
    return error_mark_node;

  gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
	      && type == TREE_TYPE (arg1));

  /* Handle the special case of two integer constants faster.  */
  if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
    {
      /* And some specific cases even faster than that.  */
      if (code == PLUS_EXPR && integer_zerop (arg0))
	return arg1;
      else if ((code == MINUS_EXPR || code == PLUS_EXPR)
	       && integer_zerop (arg1))
	return arg0;
      else if (code == MULT_EXPR && integer_onep (arg0))
	return arg1;

      /* Handle general case of two integer constants.  */
      return int_const_binop (code, arg0, arg1, 0);
    }

  return fold_build2 (code, type, arg0, arg1);
}

/* Given two values, either both of sizetype or both of bitsizetype,
   compute the difference between the two values.  Return the value
   in signed type corresponding to the type of the operands.  */

tree
size_diffop (tree arg0, tree arg1)
{
  tree type = TREE_TYPE (arg0);
  tree ctype;

  gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
	      && type == TREE_TYPE (arg1));

  /* If the type is already signed, just do the simple thing.  */
  if (!TYPE_UNSIGNED (type))
    return size_binop (MINUS_EXPR, arg0, arg1);

  ctype = type == bitsizetype ? sbitsizetype : ssizetype;

  /* If either operand is not a constant, do the conversions to the signed
     type and subtract.  The hardware will do the right thing with any
     overflow in the subtraction.  */
  if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
    return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
		       fold_convert (ctype, arg1));

  /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
     Otherwise, subtract the other way, convert to CTYPE (we know that can't
     overflow) and negate (which can't either).  Special-case a result
     of zero while we're here.  */
  if (tree_int_cst_equal (arg0, arg1))
    return build_int_cst (ctype, 0);
  else if (tree_int_cst_lt (arg1, arg0))
    return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
  else
    return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
		       fold_convert (ctype, size_binop (MINUS_EXPR,
							arg1, arg0)));
}

/* A subroutine of fold_convert_const handling conversions of an
   INTEGER_CST to another integer type.  */

static tree
fold_convert_const_int_from_int (tree type, tree arg1)
{
  tree t;

  /* Given an integer constant, make new constant with new type,
     appropriately sign-extended or truncated.  */
  t = build_int_cst_wide (type, TREE_INT_CST_LOW (arg1),
			  TREE_INT_CST_HIGH (arg1));

  t = force_fit_type (t,
		      /* Don't set the overflow when
		      	 converting a pointer  */
		      !POINTER_TYPE_P (TREE_TYPE (arg1)),
		      (TREE_INT_CST_HIGH (arg1) < 0
		       && (TYPE_UNSIGNED (type)
			   < TYPE_UNSIGNED (TREE_TYPE (arg1))))
		      | TREE_OVERFLOW (arg1),
		      TREE_CONSTANT_OVERFLOW (arg1));

  return t;
}

/* A subroutine of fold_convert_const handling conversions a REAL_CST
   to an integer type.  */

static tree
fold_convert_const_int_from_real (enum tree_code code, tree type, tree arg1)
{
  int overflow = 0;
  tree t;

  /* The following code implements the floating point to integer
     conversion rules required by the Java Language Specification,
     that IEEE NaNs are mapped to zero and values that overflow
     the target precision saturate, i.e. values greater than
     INT_MAX are mapped to INT_MAX, and values less than INT_MIN
     are mapped to INT_MIN.  These semantics are allowed by the
     C and C++ standards that simply state that the behavior of
     FP-to-integer conversion is unspecified upon overflow.  */

  HOST_WIDE_INT high, low;
  REAL_VALUE_TYPE r;
  REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);

  switch (code)
    {
    case FIX_TRUNC_EXPR:
      real_trunc (&r, VOIDmode, &x);
      break;

    case FIX_CEIL_EXPR:
      real_ceil (&r, VOIDmode, &x);
      break;

    case FIX_FLOOR_EXPR:
      real_floor (&r, VOIDmode, &x);
      break;

    case FIX_ROUND_EXPR:
      real_round (&r, VOIDmode, &x);
      break;

    default:
      gcc_unreachable ();
    }

  /* If R is NaN, return zero and show we have an overflow.  */
  if (REAL_VALUE_ISNAN (r))
    {
      overflow = 1;
      high = 0;
      low = 0;
    }

  /* See if R is less than the lower bound or greater than the
     upper bound.  */

  if (! overflow)
    {
      tree lt = TYPE_MIN_VALUE (type);
      REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
      if (REAL_VALUES_LESS (r, l))
	{
	  overflow = 1;
	  high = TREE_INT_CST_HIGH (lt);
	  low = TREE_INT_CST_LOW (lt);
	}
    }

  if (! overflow)
    {
      tree ut = TYPE_MAX_VALUE (type);
      if (ut)
	{
	  REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
	  if (REAL_VALUES_LESS (u, r))
	    {
	      overflow = 1;
	      high = TREE_INT_CST_HIGH (ut);
	      low = TREE_INT_CST_LOW (ut);
	    }
	}
    }

  if (! overflow)
    REAL_VALUE_TO_INT (&low, &high, r);

  t = build_int_cst_wide (type, low, high);

  t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg1),
		      TREE_CONSTANT_OVERFLOW (arg1));
  return t;
}

/* A subroutine of fold_convert_const handling conversions a REAL_CST
   to another floating point type.  */

static tree
fold_convert_const_real_from_real (tree type, tree arg1)
{
  REAL_VALUE_TYPE value;
  tree t;

  real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
  t = build_real (type, value);

  TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
  TREE_CONSTANT_OVERFLOW (t)
    = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
  return t;
}

/* Attempt to fold type conversion operation CODE of expression ARG1 to
   type TYPE.  If no simplification can be done return NULL_TREE.  */

static tree
fold_convert_const (enum tree_code code, tree type, tree arg1)
{
  if (TREE_TYPE (arg1) == type)
    return arg1;

  if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
    {
      if (TREE_CODE (arg1) == INTEGER_CST)
	return fold_convert_const_int_from_int (type, arg1);
      else if (TREE_CODE (arg1) == REAL_CST)
	return fold_convert_const_int_from_real (code, type, arg1);
    }
  else if (TREE_CODE (type) == REAL_TYPE)
    {
      if (TREE_CODE (arg1) == INTEGER_CST)
	return build_real_from_int_cst (type, arg1);
      if (TREE_CODE (arg1) == REAL_CST)
	return fold_convert_const_real_from_real (type, arg1);
    }
  return NULL_TREE;
}

/* Construct a vector of zero elements of vector type TYPE.  */

static tree
build_zero_vector (tree type)
{
  tree elem, list;
  int i, units;

  elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
  units = TYPE_VECTOR_SUBPARTS (type);
  
  list = NULL_TREE;
  for (i = 0; i < units; i++)
    list = tree_cons (NULL_TREE, elem, list);
  return build_vector (type, list);
}

/* Convert expression ARG to type TYPE.  Used by the middle-end for
   simple conversions in preference to calling the front-end's convert.  */

tree
fold_convert (tree type, tree arg)
{
  tree orig = TREE_TYPE (arg);
  tree tem;

  if (type == orig)
    return arg;

  if (TREE_CODE (arg) == ERROR_MARK
      || TREE_CODE (type) == ERROR_MARK
      || TREE_CODE (orig) == ERROR_MARK)
    return error_mark_node;

  if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
      || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
					TYPE_MAIN_VARIANT (orig)))
    return fold_build1 (NOP_EXPR, type, arg);

  switch (TREE_CODE (type))
    {
    case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
    case POINTER_TYPE: case REFERENCE_TYPE:
    case OFFSET_TYPE:
      if (TREE_CODE (arg) == INTEGER_CST)
	{
	  tem = fold_convert_const (NOP_EXPR, type, arg);
	  if (tem != NULL_TREE)
	    return tem;
	}
      if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
	  || TREE_CODE (orig) == OFFSET_TYPE)
        return fold_build1 (NOP_EXPR, type, arg);
      if (TREE_CODE (orig) == COMPLEX_TYPE)
	{
	  tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
	  return fold_convert (type, tem);
	}
      gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
		  && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
      return fold_build1 (NOP_EXPR, type, arg);

    case REAL_TYPE:
      if (TREE_CODE (arg) == INTEGER_CST)
	{
	  tem = fold_convert_const (FLOAT_EXPR, type, arg);
	  if (tem != NULL_TREE)
	    return tem;
	}
      else if (TREE_CODE (arg) == REAL_CST)
	{
	  tem = fold_convert_const (NOP_EXPR, type, arg);
	  if (tem != NULL_TREE)
	    return tem;
	}

      switch (TREE_CODE (orig))
	{
	case INTEGER_TYPE:
	case BOOLEAN_TYPE: case ENUMERAL_TYPE:
	case POINTER_TYPE: case REFERENCE_TYPE:
	  return fold_build1 (FLOAT_EXPR, type, arg);

	case REAL_TYPE:
	  return fold_build1 (NOP_EXPR, type, arg);

	case COMPLEX_TYPE:
	  tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
	  return fold_convert (type, tem);

	default:
	  gcc_unreachable ();
	}

    case COMPLEX_TYPE:
      switch (TREE_CODE (orig))
	{
	case INTEGER_TYPE:
	case BOOLEAN_TYPE: case ENUMERAL_TYPE:
	case POINTER_TYPE: case REFERENCE_TYPE:
	case REAL_TYPE:
	  return build2 (COMPLEX_EXPR, type,
			 fold_convert (TREE_TYPE (type), arg),
			 fold_convert (TREE_TYPE (type), integer_zero_node));
	case COMPLEX_TYPE:
	  {
	    tree rpart, ipart;

	    if (TREE_CODE (arg) == COMPLEX_EXPR)
	      {
		rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
		ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
		return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
	      }

	    arg = save_expr (arg);
	    rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
	    ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
	    rpart = fold_convert (TREE_TYPE (type), rpart);
	    ipart = fold_convert (TREE_TYPE (type), ipart);
	    return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
	  }

	default:
	  gcc_unreachable ();
	}

    case VECTOR_TYPE:
      if (integer_zerop (arg))
	return build_zero_vector (type);
      gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
      gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
		  || TREE_CODE (orig) == VECTOR_TYPE);
      return fold_build1 (VIEW_CONVERT_EXPR, type, arg);

    case VOID_TYPE:
      return fold_build1 (NOP_EXPR, type, fold_ignored_result (arg));

    default:
      gcc_unreachable ();
    }
}

/* Return false if expr can be assumed not to be an lvalue, true
   otherwise.  */

static bool
maybe_lvalue_p (tree x)
{
  /* We only need to wrap lvalue tree codes.  */
  switch (TREE_CODE (x))
  {
  case VAR_DECL:
  case PARM_DECL:
  case RESULT_DECL:
  case LABEL_DECL:
  case FUNCTION_DECL:
  case SSA_NAME:

  case COMPONENT_REF:
  case INDIRECT_REF:
  case ALIGN_INDIRECT_REF:
  case MISALIGNED_INDIRECT_REF:
  case ARRAY_REF:
  case ARRAY_RANGE_REF:
  case BIT_FIELD_REF:
  case OBJ_TYPE_REF:

  case REALPART_EXPR:
  case IMAGPART_EXPR:
  case PREINCREMENT_EXPR:
  case PREDECREMENT_EXPR:
  case SAVE_EXPR:
  case TRY_CATCH_EXPR:
  case WITH_CLEANUP_EXPR:
  case COMPOUND_EXPR:
  case MODIFY_EXPR:
  case TARGET_EXPR:
  case COND_EXPR:
  case BIND_EXPR:
  case MIN_EXPR:
  case MAX_EXPR:
    break;

  default:
    /* Assume the worst for front-end tree codes.  */
    if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
      break;
    return false;
  }

  return true;
}

/* Return an expr equal to X but certainly not valid as an lvalue.  */

tree
non_lvalue (tree x)
{
  /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
     us.  */
  if (in_gimple_form)
    return x;

  if (! maybe_lvalue_p (x))
    return x;
  return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
}

/* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
   Zero means allow extended lvalues.  */

int pedantic_lvalues;

/* When pedantic, return an expr equal to X but certainly not valid as a
   pedantic lvalue.  Otherwise, return X.  */

static tree
pedantic_non_lvalue (tree x)
{
  if (pedantic_lvalues)
    return non_lvalue (x);
  else
    return x;
}

/* Given a tree comparison code, return the code that is the logical inverse
   of the given code.  It is not safe to do this for floating-point
   comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
   as well: if reversing the comparison is unsafe, return ERROR_MARK.  */

enum tree_code
invert_tree_comparison (enum tree_code code, bool honor_nans)
{
  if (honor_nans && flag_trapping_math)
    return ERROR_MARK;

  switch (code)
    {
    case EQ_EXPR:
      return NE_EXPR;
    case NE_EXPR:
      return EQ_EXPR;
    case GT_EXPR:
      return honor_nans ? UNLE_EXPR : LE_EXPR;
    case GE_EXPR:
      return honor_nans ? UNLT_EXPR : LT_EXPR;
    case LT_EXPR:
      return honor_nans ? UNGE_EXPR : GE_EXPR;
    case LE_EXPR:
      return honor_nans ? UNGT_EXPR : GT_EXPR;
    case LTGT_EXPR:
      return UNEQ_EXPR;
    case UNEQ_EXPR:
      return LTGT_EXPR;
    case UNGT_EXPR:
      return LE_EXPR;
    case UNGE_EXPR:
      return LT_EXPR;
    case UNLT_EXPR:
      return GE_EXPR;
    case UNLE_EXPR:
      return GT_EXPR;
    case ORDERED_EXPR:
      return UNORDERED_EXPR;
    case UNORDERED_EXPR:
      return ORDERED_EXPR;
    default:
      gcc_unreachable ();
    }
}

/* Similar, but return the comparison that results if the operands are
   swapped.  This is safe for floating-point.  */

enum tree_code
swap_tree_comparison (enum tree_code code)
{
  switch (code)
    {
    case EQ_EXPR:
    case NE_EXPR:
    case ORDERED_EXPR:
    case UNORDERED_EXPR:
    case LTGT_EXPR:
    case UNEQ_EXPR:
      return code;
    case GT_EXPR:
      return LT_EXPR;
    case GE_EXPR:
      return LE_EXPR;
    case LT_EXPR:
      return GT_EXPR;
    case LE_EXPR:
      return GE_EXPR;
    case UNGT_EXPR:
      return UNLT_EXPR;
    case UNGE_EXPR:
      return UNLE_EXPR;
    case UNLT_EXPR:
      return UNGT_EXPR;
    case UNLE_EXPR:
      return UNGE_EXPR;
    default:
      gcc_unreachable ();
    }
}


/* Convert a comparison tree code from an enum tree_code representation
   into a compcode bit-based encoding.  This function is the inverse of
   compcode_to_comparison.  */

static enum comparison_code
comparison_to_compcode (enum tree_code code)
{
  switch (code)
    {
    case LT_EXPR:
      return COMPCODE_LT;
    case EQ_EXPR:
      return COMPCODE_EQ;
    case LE_EXPR:
      return COMPCODE_LE;
    case GT_EXPR:
      return COMPCODE_GT;
    case NE_EXPR:
      return COMPCODE_NE;
    case GE_EXPR:
      return COMPCODE_GE;
    case ORDERED_EXPR:
      return COMPCODE_ORD;
    case UNORDERED_EXPR:
      return COMPCODE_UNORD;
    case UNLT_EXPR:
      return COMPCODE_UNLT;
    case UNEQ_EXPR:
      return COMPCODE_UNEQ;
    case UNLE_EXPR:
      return COMPCODE_UNLE;
    case UNGT_EXPR:
      return COMPCODE_UNGT;
    case LTGT_EXPR:
      return COMPCODE_LTGT;
    case UNGE_EXPR:
      return COMPCODE_UNGE;
    default:
      gcc_unreachable ();
    }
}

/* Convert a compcode bit-based encoding of a comparison operator back
   to GCC's enum tree_code representation.  This function is the
   inverse of comparison_to_compcode.  */

static enum tree_code
compcode_to_comparison (enum comparison_code code)
{
  switch (code)
    {
    case COMPCODE_LT:
      return LT_EXPR;
    case COMPCODE_EQ:
      return EQ_EXPR;
    case COMPCODE_LE:
      return LE_EXPR;
    case COMPCODE_GT:
      return GT_EXPR;
    case COMPCODE_NE:
      return NE_EXPR;
    case COMPCODE_GE:
      return GE_EXPR;
    case COMPCODE_ORD:
      return ORDERED_EXPR;
    case COMPCODE_UNORD:
      return UNORDERED_EXPR;
    case COMPCODE_UNLT:
      return UNLT_EXPR;
    case COMPCODE_UNEQ:
      return UNEQ_EXPR;
    case COMPCODE_UNLE:
      return UNLE_EXPR;
    case COMPCODE_UNGT:
      return UNGT_EXPR;
    case COMPCODE_LTGT:
      return LTGT_EXPR;
    case COMPCODE_UNGE:
      return UNGE_EXPR;
    default:
      gcc_unreachable ();
    }
}

/* Return a tree for the comparison which is the combination of
   doing the AND or OR (depending on CODE) of the two operations LCODE
   and RCODE on the identical operands LL_ARG and LR_ARG.  Take into account
   the possibility of trapping if the mode has NaNs, and return NULL_TREE
   if this makes the transformation invalid.  */

tree
combine_comparisons (enum tree_code code, enum tree_code lcode,
		     enum tree_code rcode, tree truth_type,
		     tree ll_arg, tree lr_arg)
{
  bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
  enum comparison_code lcompcode = comparison_to_compcode (lcode);
  enum comparison_code rcompcode = comparison_to_compcode (rcode);
  enum comparison_code compcode;

  switch (code)
    {
    case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
      compcode = lcompcode & rcompcode;
      break;

    case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
      compcode = lcompcode | rcompcode;
      break;

    default:
      return NULL_TREE;
    }

  if (!honor_nans)
    {
      /* Eliminate unordered comparisons, as well as LTGT and ORD
	 which are not used unless the mode has NaNs.  */
      compcode &= ~COMPCODE_UNORD;
      if (compcode == COMPCODE_LTGT)
	compcode = COMPCODE_NE;
      else if (compcode == COMPCODE_ORD)
	compcode = COMPCODE_TRUE;
    }
   else if (flag_trapping_math)
     {
	/* Check that the original operation and the optimized ones will trap
	   under the same condition.  */
	bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
		     && (lcompcode != COMPCODE_EQ)
		     && (lcompcode != COMPCODE_ORD);
	bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
		     && (rcompcode != COMPCODE_EQ)
		     && (rcompcode != COMPCODE_ORD);
	bool trap = (compcode & COMPCODE_UNORD) == 0
		    && (compcode != COMPCODE_EQ)
		    && (compcode != COMPCODE_ORD);

        /* In a short-circuited boolean expression the LHS might be
	   such that the RHS, if evaluated, will never trap.  For
	   example, in ORD (x, y) && (x < y), we evaluate the RHS only
	   if neither x nor y is NaN.  (This is a mixed blessing: for
	   example, the expression above will never trap, hence
	   optimizing it to x < y would be invalid).  */
        if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
            || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
          rtrap = false;

        /* If the comparison was short-circuited, and only the RHS
	   trapped, we may now generate a spurious trap.  */
	if (rtrap && !ltrap
	    && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
	  return NULL_TREE;

	/* If we changed the conditions that cause a trap, we lose.  */
	if ((ltrap || rtrap) != trap)
	  return NULL_TREE;
      }

  if (compcode == COMPCODE_TRUE)
    return constant_boolean_node (true, truth_type);
  else if (compcode == COMPCODE_FALSE)
    return constant_boolean_node (false, truth_type);
  else
    return fold_build2 (compcode_to_comparison (compcode),
			truth_type, ll_arg, lr_arg);
}

/* Return nonzero if CODE is a tree code that represents a truth value.  */

static int
truth_value_p (enum tree_code code)
{
  return (TREE_CODE_CLASS (code) == tcc_comparison
	  || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
	  || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
	  || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
}

/* Return nonzero if two operands (typically of the same tree node)
   are necessarily equal.  If either argument has side-effects this
   function returns zero.  FLAGS modifies behavior as follows:

   If OEP_ONLY_CONST is set, only return nonzero for constants.
   This function tests whether the operands are indistinguishable;
   it does not test whether they are equal using C's == operation.
   The distinction is important for IEEE floating point, because
   (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
   (2) two NaNs may be indistinguishable, but NaN!=NaN.

   If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
   even though it may hold multiple values during a function.
   This is because a GCC tree node guarantees that nothing else is
   executed between the evaluation of its "operands" (which may often
   be evaluated in arbitrary order).  Hence if the operands themselves
   don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
   same value in each operand/subexpression.  Hence leaving OEP_ONLY_CONST
   unset means assuming isochronic (or instantaneous) tree equivalence.
   Unless comparing arbitrary expression trees, such as from different
   statements, this flag can usually be left unset.

   If OEP_PURE_SAME is set, then pure functions with identical arguments
   are considered the same.  It is used when the caller has other ways
   to ensure that global memory is unchanged in between.  */

int
operand_equal_p (tree arg0, tree arg1, unsigned int flags)
{
  /* If either is ERROR_MARK, they aren't equal.  */
  if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
    return 0;

  /* If both types don't have the same signedness, then we can't consider
     them equal.  We must check this before the STRIP_NOPS calls
     because they may change the signedness of the arguments.  */
  if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
    return 0;

  /* If both types don't have the same precision, then it is not safe
     to strip NOPs.  */
  if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
    return 0;

  STRIP_NOPS (arg0);
  STRIP_NOPS (arg1);

  /* In case both args are comparisons but with different comparison
     code, try to swap the comparison operands of one arg to produce
     a match and compare that variant.  */
  if (TREE_CODE (arg0) != TREE_CODE (arg1)
      && COMPARISON_CLASS_P (arg0)
      && COMPARISON_CLASS_P (arg1))
    {
      enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));

      if (TREE_CODE (arg0) == swap_code)
	return operand_equal_p (TREE_OPERAND (arg0, 0),
			        TREE_OPERAND (arg1, 1), flags)
	       && operand_equal_p (TREE_OPERAND (arg0, 1),
				   TREE_OPERAND (arg1, 0), flags);
    }

  if (TREE_CODE (arg0) != TREE_CODE (arg1)
      /* This is needed for conversions and for COMPONENT_REF.
	 Might as well play it safe and always test this.  */
      || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
      || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
      || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
    return 0;

  /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
     We don't care about side effects in that case because the SAVE_EXPR
     takes care of that for us. In all other cases, two expressions are
     equal if they have no side effects.  If we have two identical
     expressions with side effects that should be treated the same due
     to the only side effects being identical SAVE_EXPR's, that will
     be detected in the recursive calls below.  */
  if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
      && (TREE_CODE (arg0) == SAVE_EXPR
	  || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
    return 1;

  /* Next handle constant cases, those for which we can return 1 even
     if ONLY_CONST is set.  */
  if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
    switch (TREE_CODE (arg0))
      {
      case INTEGER_CST:
	return (! TREE_CONSTANT_OVERFLOW (arg0)
		&& ! TREE_CONSTANT_OVERFLOW (arg1)
		&& tree_int_cst_equal (arg0, arg1));

      case REAL_CST:
	return (! TREE_CONSTANT_OVERFLOW (arg0)
		&& ! TREE_CONSTANT_OVERFLOW (arg1)
		&& REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
					  TREE_REAL_CST (arg1)));

      case VECTOR_CST:
	{
	  tree v1, v2;

	  if (TREE_CONSTANT_OVERFLOW (arg0)
	      || TREE_CONSTANT_OVERFLOW (arg1))
	    return 0;

	  v1 = TREE_VECTOR_CST_ELTS (arg0);
	  v2 = TREE_VECTOR_CST_ELTS (arg1);
	  while (v1 && v2)
	    {
	      if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
				    flags))
		return 0;
	      v1 = TREE_CHAIN (v1);
	      v2 = TREE_CHAIN (v2);
	    }

	  return v1 == v2;
	}

      case COMPLEX_CST:
	return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
				 flags)
		&& operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
				    flags));

      case STRING_CST:
	return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
		&& ! memcmp (TREE_STRING_POINTER (arg0),
			      TREE_STRING_POINTER (arg1),
			      TREE_STRING_LENGTH (arg0)));

      case ADDR_EXPR:
	return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
				0);
      default:
	break;
      }

  if (flags & OEP_ONLY_CONST)
    return 0;

/* Define macros to test an operand from arg0 and arg1 for equality and a
   variant that allows null and views null as being different from any
   non-null value.  In the latter case, if either is null, the both
   must be; otherwise, do the normal comparison.  */
#define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N),	\
				    TREE_OPERAND (arg1, N), flags)

#define OP_SAME_WITH_NULL(N)				\
  ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N))	\
   ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))

  switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
    {
    case tcc_unary:
      /* Two conversions are equal only if signedness and modes match.  */
      switch (TREE_CODE (arg0))
        {
        case NOP_EXPR:
        case CONVERT_EXPR:
        case FIX_CEIL_EXPR:
        case FIX_TRUNC_EXPR:
        case FIX_FLOOR_EXPR:
        case FIX_ROUND_EXPR:
	  if (TYPE_UNSIGNED (TREE_TYPE (arg0))
	      != TYPE_UNSIGNED (TREE_TYPE (arg1)))
	    return 0;
	  break;
	default:
	  break;
	}

      return OP_SAME (0);


    case tcc_comparison:
    case tcc_binary:
      if (OP_SAME (0) && OP_SAME (1))
	return 1;

      /* For commutative ops, allow the other order.  */
      return (commutative_tree_code (TREE_CODE (arg0))
	      && operand_equal_p (TREE_OPERAND (arg0, 0),
				  TREE_OPERAND (arg1, 1), flags)
	      && operand_equal_p (TREE_OPERAND (arg0, 1),
				  TREE_OPERAND (arg1, 0), flags));

    case tcc_reference:
      /* If either of the pointer (or reference) expressions we are
	 dereferencing contain a side effect, these cannot be equal.  */
      if (TREE_SIDE_EFFECTS (arg0)
	  || TREE_SIDE_EFFECTS (arg1))
	return 0;

      switch (TREE_CODE (arg0))
	{
	case INDIRECT_REF:
	case ALIGN_INDIRECT_REF:
	case MISALIGNED_INDIRECT_REF:
	case REALPART_EXPR:
	case IMAGPART_EXPR:
	  return OP_SAME (0);

	case ARRAY_REF:
	case ARRAY_RANGE_REF:
	  /* Operands 2 and 3 may be null.  */
	  return (OP_SAME (0)
		  && OP_SAME (1)
		  && OP_SAME_WITH_NULL (2)
		  && OP_SAME_WITH_NULL (3));

	case COMPONENT_REF:
	  /* Handle operand 2 the same as for ARRAY_REF.  Operand 0
	     may be NULL when we're called to compare MEM_EXPRs.  */
	  return OP_SAME_WITH_NULL (0)
		 && OP_SAME (1)
		 && OP_SAME_WITH_NULL (2);

	case BIT_FIELD_REF:
	  return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);

	default:
	  return 0;
	}

    case tcc_expression:
      switch (TREE_CODE (arg0))
	{
	case ADDR_EXPR:
	case TRUTH_NOT_EXPR:
	  return OP_SAME (0);

	case TRUTH_ANDIF_EXPR:
	case TRUTH_ORIF_EXPR:
	  return OP_SAME (0) && OP_SAME (1);

	case TRUTH_AND_EXPR:
	case TRUTH_OR_EXPR:
	case TRUTH_XOR_EXPR:
	  if (OP_SAME (0) && OP_SAME (1))
	    return 1;

	  /* Otherwise take into account this is a commutative operation.  */
	  return (operand_equal_p (TREE_OPERAND (arg0, 0),
				   TREE_OPERAND (arg1, 1), flags)
		  && operand_equal_p (TREE_OPERAND (arg0, 1),
				      TREE_OPERAND (arg1, 0), flags));

	case CALL_EXPR:
	  /* If the CALL_EXPRs call different functions, then they
	     clearly can not be equal.  */
	  if (!OP_SAME (0))
	    return 0;

	  {
	    unsigned int cef = call_expr_flags (arg0);
	    if (flags & OEP_PURE_SAME)
	      cef &= ECF_CONST | ECF_PURE;
	    else
	      cef &= ECF_CONST;
	    if (!cef)
	      return 0;
	  }

	  /* Now see if all the arguments are the same.  operand_equal_p
	     does not handle TREE_LIST, so we walk the operands here
	     feeding them to operand_equal_p.  */
	  arg0 = TREE_OPERAND (arg0, 1);
	  arg1 = TREE_OPERAND (arg1, 1);
	  while (arg0 && arg1)
	    {
	      if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
				     flags))
		return 0;

	      arg0 = TREE_CHAIN (arg0);
	      arg1 = TREE_CHAIN (arg1);
	    }

	  /* If we get here and both argument lists are exhausted
	     then the CALL_EXPRs are equal.  */
	  return ! (arg0 || arg1);

	default:
	  return 0;
	}

    case tcc_declaration:
      /* Consider __builtin_sqrt equal to sqrt.  */
      return (TREE_CODE (arg0) == FUNCTION_DECL
	      && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
	      && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
	      && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));

    default:
      return 0;
    }

#undef OP_SAME
#undef OP_SAME_WITH_NULL
}

/* Similar to operand_equal_p, but see if ARG0 might have been made by
   shorten_compare from ARG1 when ARG1 was being compared with OTHER.

   When in doubt, return 0.  */

static int
operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
{
  int unsignedp1, unsignedpo;
  tree primarg0, primarg1, primother;
  unsigned int correct_width;

  if (operand_equal_p (arg0, arg1, 0))
    return 1;

  if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
      || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
    return 0;

  /* Discard any conversions that don't change the modes of ARG0 and ARG1
     and see if the inner values are the same.  This removes any
     signedness comparison, which doesn't matter here.  */
  primarg0 = arg0, primarg1 = arg1;
  STRIP_NOPS (primarg0);
  STRIP_NOPS (primarg1);
  if (operand_equal_p (primarg0, primarg1, 0))
    return 1;

  /* Duplicate what shorten_compare does to ARG1 and see if that gives the
     actual comparison operand, ARG0.

     First throw away any conversions to wider types
     already present in the operands.  */

  primarg1 = get_narrower (arg1, &unsignedp1);
  primother = get_narrower (other, &unsignedpo);

  correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
  if (unsignedp1 == unsignedpo
      && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
      && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
    {
      tree type = TREE_TYPE (arg0);

      /* Make sure shorter operand is extended the right way
	 to match the longer operand.  */
      primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
			       (unsignedp1, TREE_TYPE (primarg1)), primarg1);

      if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
	return 1;
    }

  return 0;
}

/* See if ARG is an expression that is either a comparison or is performing
   arithmetic on comparisons.  The comparisons must only be comparing
   two different values, which will be stored in *CVAL1 and *CVAL2; if
   they are nonzero it means that some operands have already been found.
   No variables may be used anywhere else in the expression except in the
   comparisons.  If SAVE_P is true it means we removed a SAVE_EXPR around
   the expression and save_expr needs to be called with CVAL1 and CVAL2.

   If this is true, return 1.  Otherwise, return zero.  */

static int
twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
{
  enum tree_code code = TREE_CODE (arg);
  enum tree_code_class class = TREE_CODE_CLASS (code);

  /* We can handle some of the tcc_expression cases here.  */
  if (class == tcc_expression && code == TRUTH_NOT_EXPR)
    class = tcc_unary;
  else if (class == tcc_expression
	   && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
	       || code == COMPOUND_EXPR))
    class = tcc_binary;

  else if (class == tcc_expression && code == SAVE_EXPR
	   && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
    {
      /* If we've already found a CVAL1 or CVAL2, this expression is
	 two complex to handle.  */
      if (*cval1 || *cval2)
	return 0;

      class = tcc_unary;
      *save_p = 1;
    }

  switch (class)
    {
    case tcc_unary:
      return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);

    case tcc_binary:
      return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
	      && twoval_comparison_p (TREE_OPERAND (arg, 1),
				      cval1, cval2, save_p));

    case tcc_constant:
      return 1;

    case tcc_expression:
      if (code == COND_EXPR)
	return (twoval_comparison_p (TREE_OPERAND (arg, 0),
				     cval1, cval2, save_p)
		&& twoval_comparison_p (TREE_OPERAND (arg, 1),
					cval1, cval2, save_p)
		&& twoval_comparison_p (TREE_OPERAND (arg, 2),
					cval1, cval2, save_p));
      return 0;

    case tcc_comparison:
      /* First see if we can handle the first operand, then the second.  For
	 the second operand, we know *CVAL1 can't be zero.  It must be that
	 one side of the comparison is each of the values; test for the
	 case where this isn't true by failing if the two operands
	 are the same.  */

      if (operand_equal_p (TREE_OPERAND (arg, 0),
			   TREE_OPERAND (arg, 1), 0))
	return 0;

      if (*cval1 == 0)
	*cval1 = TREE_OPERAND (arg, 0);
      else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
	;
      else if (*cval2 == 0)
	*cval2 = TREE_OPERAND (arg, 0);
      else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
	;
      else
	return 0;

      if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
	;
      else if (*cval2 == 0)
	*cval2 = TREE_OPERAND (arg, 1);
      else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
	;
      else
	return 0;

      return 1;

    default:
      return 0;
    }
}

/* ARG is a tree that is known to contain just arithmetic operations and
   comparisons.  Evaluate the operations in the tree substituting NEW0 for
   any occurrence of OLD0 as an operand of a comparison and likewise for
   NEW1 and OLD1.  */

static tree
eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
{
  tree type = TREE_TYPE (arg);
  enum tree_code code = TREE_CODE (arg);
  enum tree_code_class class = TREE_CODE_CLASS (code);

  /* We can handle some of the tcc_expression cases here.  */
  if (class == tcc_expression && code == TRUTH_NOT_EXPR)
    class = tcc_unary;
  else if (class == tcc_expression
	   && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
    class = tcc_binary;

  switch (class)
    {
    case tcc_unary:
      return fold_build1 (code, type,
			  eval_subst (TREE_OPERAND (arg, 0),
				      old0, new0, old1, new1));

    case tcc_binary:
      return fold_build2 (code, type,
			  eval_subst (TREE_OPERAND (arg, 0),
				      old0, new0, old1, new1),
			  eval_subst (TREE_OPERAND (arg, 1),
				      old0, new0, old1, new1));

    case tcc_expression:
      switch (code)
	{
	case SAVE_EXPR:
	  return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);

	case COMPOUND_EXPR:
	  return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);

	case COND_EXPR:
	  return fold_build3 (code, type,
			      eval_subst (TREE_OPERAND (arg, 0),
					  old0, new0, old1, new1),
			      eval_subst (TREE_OPERAND (arg, 1),
					  old0, new0, old1, new1),
			      eval_subst (TREE_OPERAND (arg, 2),
					  old0, new0, old1, new1));
	default:
	  break;
	}
      /* Fall through - ???  */

    case tcc_comparison:
      {
	tree arg0 = TREE_OPERAND (arg, 0);
	tree arg1 = TREE_OPERAND (arg, 1);

	/* We need to check both for exact equality and tree equality.  The
	   former will be true if the operand has a side-effect.  In that
	   case, we know the operand occurred exactly once.  */

	if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
	  arg0 = new0;
	else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
	  arg0 = new1;

	if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
	  arg1 = new0;
	else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
	  arg1 = new1;

	return fold_build2 (code, type, arg0, arg1);
      }

    default:
      return arg;
    }
}

/* Return a tree for the case when the result of an expression is RESULT
   converted to TYPE and OMITTED was previously an operand of the expression
   but is now not needed (e.g., we folded OMITTED * 0).

   If OMITTED has side effects, we must evaluate it.  Otherwise, just do
   the conversion of RESULT to TYPE.  */

tree
omit_one_operand (tree type, tree result, tree omitted)
{
  tree t = fold_convert (type, result);

  if (TREE_SIDE_EFFECTS (omitted))
    return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);

  return non_lvalue (t);
}

/* Similar, but call pedantic_non_lvalue instead of non_lvalue.  */

static tree
pedantic_omit_one_operand (tree type, tree result, tree omitted)
{
  tree t = fold_convert (type, result);

  if (TREE_SIDE_EFFECTS (omitted))
    return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);

  return pedantic_non_lvalue (t);
}

/* Return a tree for the case when the result of an expression is RESULT
   converted to TYPE and OMITTED1 and OMITTED2 were previously operands
   of the expression but are now not needed.

   If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
   If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
   evaluated before OMITTED2.  Otherwise, if neither has side effects,
   just do the conversion of RESULT to TYPE.  */

tree
omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
{
  tree t = fold_convert (type, result);

  if (TREE_SIDE_EFFECTS (omitted2))
    t = build2 (COMPOUND_EXPR, type, omitted2, t);
  if (TREE_SIDE_EFFECTS (omitted1))
    t = build2 (COMPOUND_EXPR, type, omitted1, t);

  return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
}


/* Return a simplified tree node for the truth-negation of ARG.  This
   never alters ARG itself.  We assume that ARG is an operation that
   returns a truth value (0 or 1).

   FIXME: one would think we would fold the result, but it causes
   problems with the dominator optimizer.  */

tree
fold_truth_not_expr (tree arg)
{
  tree type = TREE_TYPE (arg);
  enum tree_code code = TREE_CODE (arg);

  /* If this is a comparison, we can simply invert it, except for
     floating-point non-equality comparisons, in which case we just
     enclose a TRUTH_NOT_EXPR around what we have.  */

  if (TREE_CODE_CLASS (code) == tcc_comparison)
    {
      tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
      if (FLOAT_TYPE_P (op_type)
	  && flag_trapping_math
	  && code != ORDERED_EXPR && code != UNORDERED_EXPR
	  && code != NE_EXPR && code != EQ_EXPR)
	return NULL_TREE;
      else
	{
	  code = invert_tree_comparison (code,
					 HONOR_NANS (TYPE_MODE (op_type)));
	  if (code == ERROR_MARK)
	    return NULL_TREE;
	  else
	    return build2 (code, type,
			   TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
	}
    }

  switch (code)
    {
    case INTEGER_CST:
      return constant_boolean_node (integer_zerop (arg), type);

    case TRUTH_AND_EXPR:
      return build2 (TRUTH_OR_EXPR, type,
		     invert_truthvalue (TREE_OPERAND (arg, 0)),
		     invert_truthvalue (TREE_OPERAND (arg, 1)));

    case TRUTH_OR_EXPR:
      return build2 (TRUTH_AND_EXPR, type,
		     invert_truthvalue (TREE_OPERAND (arg, 0)),
		     invert_truthvalue (TREE_OPERAND (arg, 1)));

    case TRUTH_XOR_EXPR:
      /* Here we can invert either operand.  We invert the first operand
	 unless the second operand is a TRUTH_NOT_EXPR in which case our
	 result is the XOR of the first operand with the inside of the
	 negation of the second operand.  */

      if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
	return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
		       TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
      else
	return build2 (TRUTH_XOR_EXPR, type,
		       invert_truthvalue (TREE_OPERAND (arg, 0)),
		       TREE_OPERAND (arg, 1));

    case TRUTH_ANDIF_EXPR:
      return build2 (TRUTH_ORIF_EXPR, type,
		     invert_truthvalue (TREE_OPERAND (arg, 0)),
		     invert_truthvalue (TREE_OPERAND (arg, 1)));

    case TRUTH_ORIF_EXPR:
      return build2 (TRUTH_ANDIF_EXPR, type,
		     invert_truthvalue (TREE_OPERAND (arg, 0)),
		     invert_truthvalue (TREE_OPERAND (arg, 1)));

    case TRUTH_NOT_EXPR:
      return TREE_OPERAND (arg, 0);

    case COND_EXPR:
      {
	tree arg1 = TREE_OPERAND (arg, 1);
	tree arg2 = TREE_OPERAND (arg, 2);
	/* A COND_EXPR may have a throw as one operand, which
	   then has void type.  Just leave void operands
	   as they are.  */
	return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
		       VOID_TYPE_P (TREE_TYPE (arg1))
		       ? arg1 : invert_truthvalue (arg1),
		       VOID_TYPE_P (TREE_TYPE (arg2))
		       ? arg2 : invert_truthvalue (arg2));
      }

    case COMPOUND_EXPR:
      return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
		     invert_truthvalue (TREE_OPERAND (arg, 1)));

    case NON_LVALUE_EXPR:
      return invert_truthvalue (TREE_OPERAND (arg, 0));

    case NOP_EXPR:
      if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
	return build1 (TRUTH_NOT_EXPR, type, arg);

    case CONVERT_EXPR:
    case FLOAT_EXPR:
      return build1 (TREE_CODE (arg), type,
		     invert_truthvalue (TREE_OPERAND (arg, 0)));

    case BIT_AND_EXPR:
      if (!integer_onep (TREE_OPERAND (arg, 1)))
	break;
      return build2 (EQ_EXPR, type, arg,
		     build_int_cst (type, 0));

    case SAVE_EXPR:
      return build1 (TRUTH_NOT_EXPR, type, arg);

    case CLEANUP_POINT_EXPR:
      return build1 (CLEANUP_POINT_EXPR, type,
		     invert_truthvalue (TREE_OPERAND (arg, 0)));

    default:
      break;
    }

  return NULL_TREE;
}

/* Return a simplified tree node for the truth-negation of ARG.  This
   never alters ARG itself.  We assume that ARG is an operation that
   returns a truth value (0 or 1).

   FIXME: one would think we would fold the result, but it causes
   problems with the dominator optimizer.  */

tree
invert_truthvalue (tree arg)
{
  tree tem;

  if (TREE_CODE (arg) == ERROR_MARK)
    return arg;

  tem = fold_truth_not_expr (arg);
  if (!tem)
    tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);

  return tem;
}

/* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
   operands are another bit-wise operation with a common input.  If so,
   distribute the bit operations to save an operation and possibly two if
   constants are involved.  For example, convert
	(A | B) & (A | C) into A | (B & C)
   Further simplification will occur if B and C are constants.

   If this optimization cannot be done, 0 will be returned.  */

static tree
distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
{
  tree common;
  tree left, right;

  if (TREE_CODE (arg0) != TREE_CODE (arg1)
      || TREE_CODE (arg0) == code
      || (TREE_CODE (arg0) != BIT_AND_EXPR
	  && TREE_CODE (arg0) != BIT_IOR_EXPR))
    return 0;

  if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
    {
      common = TREE_OPERAND (arg0, 0);
      left = TREE_OPERAND (arg0, 1);
      right = TREE_OPERAND (arg1, 1);
    }
  else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
    {
      common = TREE_OPERAND (arg0, 0);
      left = TREE_OPERAND (arg0, 1);
      right = TREE_OPERAND (arg1, 0);
    }
  else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
    {
      common = TREE_OPERAND (arg0, 1);
      left = TREE_OPERAND (arg0, 0);
      right = TREE_OPERAND (arg1, 1);
    }
  else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
    {
      common = TREE_OPERAND (arg0, 1);
      left = TREE_OPERAND (arg0, 0);
      right = TREE_OPERAND (arg1, 0);
    }
  else
    return 0;

  return fold_build2 (TREE_CODE (arg0), type, common,
		      fold_build2 (code, type, left, right));
}

/* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
   with code CODE.  This optimization is unsafe.  */
static tree
distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
{
  bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
  bool mul1 = TREE_CODE (arg1) == MULT_EXPR;

  /* (A / C) +- (B / C) -> (A +- B) / C.  */
  if (mul0 == mul1
      && operand_equal_p (TREE_OPERAND (arg0, 1),
		       TREE_OPERAND (arg1, 1), 0))
    return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
			fold_build2 (code, type,
				     TREE_OPERAND (arg0, 0),
				     TREE_OPERAND (arg1, 0)),
			TREE_OPERAND (arg0, 1));

  /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2).  */
  if (operand_equal_p (TREE_OPERAND (arg0, 0),
		       TREE_OPERAND (arg1, 0), 0)
      && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
      && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
    {
      REAL_VALUE_TYPE r0, r1;
      r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
      r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
      if (!mul0)
	real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
      if (!mul1)
        real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
      real_arithmetic (&r0, code, &r0, &r1);
      return fold_build2 (MULT_EXPR, type,
			  TREE_OPERAND (arg0, 0),
			  build_real (type, r0));
    }

  return NULL_TREE;
}

/* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
   starting at BITPOS.  The field is unsigned if UNSIGNEDP is nonzero.  */

static tree
make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
		    int unsignedp)
{
  tree result;

  if (bitpos == 0)
    {
      tree size = TYPE_SIZE (TREE_TYPE (inner));
      if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
	   || POINTER_TYPE_P (TREE_TYPE (inner)))
	  && host_integerp (size, 0) 
	  && tree_low_cst (size, 0) == bitsize)
	return fold_convert (type, inner);
    }

  result = build3 (BIT_FIELD_REF, type, inner,
		   size_int (bitsize), bitsize_int (bitpos));

  BIT_FIELD_REF_UNSIGNED (result) = unsignedp;

  return result;
}

/* Optimize a bit-field compare.

   There are two cases:  First is a compare against a constant and the
   second is a comparison of two items where the fields are at the same
   bit position relative to the start of a chunk (byte, halfword, word)
   large enough to contain it.  In these cases we can avoid the shift
   implicit in bitfield extractions.

   For constants, we emit a compare of the shifted constant with the
   BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
   compared.  For two fields at the same position, we do the ANDs with the
   similar mask and compare the result of the ANDs.

   CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
   COMPARE_TYPE is the type of the comparison, and LHS and RHS
   are the left and right operands of the comparison, respectively.

   If the optimization described above can be done, we return the resulting
   tree.  Otherwise we return zero.  */

static tree
optimize_bit_field_compare (enum tree_code code, tree compare_type,
			    tree lhs, tree rhs)
{
  HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
  tree type = TREE_TYPE (lhs);
  tree signed_type, unsigned_type;
  int const_p = TREE_CODE (rhs) == INTEGER_CST;
  enum machine_mode lmode, rmode, nmode;
  int lunsignedp, runsignedp;
  int lvolatilep = 0, rvolatilep = 0;
  tree linner, rinner = NULL_TREE;
  tree mask;
  tree offset;

  /* Get all the information about the extractions being done.  If the bit size
     if the same as the size of the underlying object, we aren't doing an
     extraction at all and so can do nothing.  We also don't want to
     do anything if the inner expression is a PLACEHOLDER_EXPR since we
     then will no longer be able to replace it.  */
  linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
				&lunsignedp, &lvolatilep, false);
  if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
      || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
    return 0;

 if (!const_p)
   {
     /* If this is not a constant, we can only do something if bit positions,
	sizes, and signedness are the same.  */
     rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
				   &runsignedp, &rvolatilep, false);

     if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
	 || lunsignedp != runsignedp || offset != 0
	 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
       return 0;
   }

  /* See if we can find a mode to refer to this field.  We should be able to,
     but fail if we can't.  */
  nmode = get_best_mode (lbitsize, lbitpos,
			 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
			 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
				TYPE_ALIGN (TREE_TYPE (rinner))),
			 word_mode, lvolatilep || rvolatilep);
  if (nmode == VOIDmode)
    return 0;

  /* Set signed and unsigned types of the precision of this mode for the
     shifts below.  */
  signed_type = lang_hooks.types.type_for_mode (nmode, 0);
  unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);

  /* Compute the bit position and size for the new reference and our offset
     within it. If the new reference is the same size as the original, we
     won't optimize anything, so return zero.  */
  nbitsize = GET_MODE_BITSIZE (nmode);
  nbitpos = lbitpos & ~ (nbitsize - 1);
  lbitpos -= nbitpos;
  if (nbitsize == lbitsize)
    return 0;

  if (BYTES_BIG_ENDIAN)
    lbitpos = nbitsize - lbitsize - lbitpos;

  /* Make the mask to be used against the extracted field.  */
  mask = build_int_cst (unsigned_type, -1);
  mask = force_fit_type (mask, 0, false, false);
  mask = fold_convert (unsigned_type, mask);
  mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
  mask = const_binop (RSHIFT_EXPR, mask,
		      size_int (nbitsize - lbitsize - lbitpos), 0);

  if (! const_p)
    /* If not comparing with constant, just rework the comparison
       and return.  */
    return build2 (code, compare_type,
		   build2 (BIT_AND_EXPR, unsigned_type,
			   make_bit_field_ref (linner, unsigned_type,
					       nbitsize, nbitpos, 1),
			   mask),
		   build2 (BIT_AND_EXPR, unsigned_type,
			   make_bit_field_ref (rinner, unsigned_type,
					       nbitsize, nbitpos, 1),
			   mask));

  /* Otherwise, we are handling the constant case. See if the constant is too
     big for the field.  Warn and return a tree of for 0 (false) if so.  We do
     this not only for its own sake, but to avoid having to test for this
     error case below.  If we didn't, we might generate wrong code.

     For unsigned fields, the constant shifted right by the field length should
     be all zero.  For signed fields, the high-order bits should agree with
     the sign bit.  */

  if (lunsignedp)
    {
      if (! integer_zerop (const_binop (RSHIFT_EXPR,
					fold_convert (unsigned_type, rhs),
					size_int (lbitsize), 0)))
	{
	  warning (0, "comparison is always %d due to width of bit-field",
		   code == NE_EXPR);
	  return constant_boolean_node (code == NE_EXPR, compare_type);
	}
    }
  else
    {
      tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
			      size_int (lbitsize - 1), 0);
      if (! integer_zerop (tem) && ! integer_all_onesp (tem))
	{
	  warning (0, "comparison is always %d due to width of bit-field",
		   code == NE_EXPR);
	  return constant_boolean_node (code == NE_EXPR, compare_type);
	}
    }

  /* Single-bit compares should always be against zero.  */
  if (lbitsize == 1 && ! integer_zerop (rhs))
    {
      code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
      rhs = build_int_cst (type, 0);
    }

  /* Make a new bitfield reference, shift the constant over the
     appropriate number of bits and mask it with the computed mask
     (in case this was a signed field).  If we changed it, make a new one.  */
  lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
  if (lvolatilep)
    {
      TREE_SIDE_EFFECTS (lhs) = 1;
      TREE_THIS_VOLATILE (lhs) = 1;
    }

  rhs = const_binop (BIT_AND_EXPR,
		     const_binop (LSHIFT_EXPR,
				  fold_convert (unsigned_type, rhs),
				  size_int (lbitpos), 0),
		     mask, 0);

  return build2 (code, compare_type,
		 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
		 rhs);
}

/* Subroutine for fold_truthop: decode a field reference.

   If EXP is a comparison reference, we return the innermost reference.

   *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
   set to the starting bit number.

   If the innermost field can be completely contained in a mode-sized
   unit, *PMODE is set to that mode.  Otherwise, it is set to VOIDmode.

   *PVOLATILEP is set to 1 if the any expression encountered is volatile;
   otherwise it is not changed.

   *PUNSIGNEDP is set to the signedness of the field.

   *PMASK is set to the mask used.  This is either contained in a
   BIT_AND_EXPR or derived from the width of the field.

   *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.

   Return 0 if this is not a component reference or is one that we can't
   do anything with.  */

static tree
decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
			HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
			int *punsignedp, int *pvolatilep,
			tree *pmask, tree *pand_mask)
{
  tree outer_type = 0;
  tree and_mask = 0;
  tree mask, inner, offset;
  tree unsigned_type;
  unsigned int precision;

  /* All the optimizations using this function assume integer fields.
     There are problems with FP fields since the type_for_size call
     below can fail for, e.g., XFmode.  */
  if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
    return 0;

  /* We are interested in the bare arrangement of bits, so strip everything
     that doesn't affect the machine mode.  However, record the type of the
     outermost expression if it may matter below.  */
  if (TREE_CODE (exp) == NOP_EXPR
      || TREE_CODE (exp) == CONVERT_EXPR
      || TREE_CODE (exp) == NON_LVALUE_EXPR)
    outer_type = TREE_TYPE (exp);
  STRIP_NOPS (exp);

  if (TREE_CODE (exp) == BIT_AND_EXPR)
    {
      and_mask = TREE_OPERAND (exp, 1);
      exp = TREE_OPERAND (exp, 0);
      STRIP_NOPS (exp); STRIP_NOPS (and_mask);
      if (TREE_CODE (and_mask) != INTEGER_CST)
	return 0;
    }

  inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
			       punsignedp, pvolatilep, false);
  if ((inner == exp && and_mask == 0)
      || *pbitsize < 0 || offset != 0
      || TREE_CODE (inner) == PLACEHOLDER_EXPR)
    return 0;

  /* If the number of bits in the reference is the same as the bitsize of
     the outer type, then the outer type gives the signedness. Otherwise
     (in case of a small bitfield) the signedness is unchanged.  */
  if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
    *punsignedp = TYPE_UNSIGNED (outer_type);

  /* Compute the mask to access the bitfield.  */
  unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
  precision = TYPE_PRECISION (unsigned_type);

  mask = build_int_cst (unsigned_type, -1);
  mask = force_fit_type (mask, 0, false, false);

  mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
  mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);

  /* Merge it with the mask we found in the BIT_AND_EXPR, if any.  */
  if (and_mask != 0)
    mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
			fold_convert (unsigned_type, and_mask), mask);

  *pmask = mask;
  *pand_mask = and_mask;
  return inner;
}

/* Return nonzero if MASK represents a mask of SIZE ones in the low-order
   bit positions.  */

static int
all_ones_mask_p (tree mask, int size)
{
  tree type = TREE_TYPE (mask);
  unsigned int precision = TYPE_PRECISION (type);
  tree tmask;

  tmask = build_int_cst (lang_hooks.types.signed_type (type), -1);
  tmask = force_fit_type (tmask, 0, false, false);

  return
    tree_int_cst_equal (mask,
			const_binop (RSHIFT_EXPR,
				     const_binop (LSHIFT_EXPR, tmask,
						  size_int (precision - size),
						  0),
				     size_int (precision - size), 0));
}

/* Subroutine for fold: determine if VAL is the INTEGER_CONST that
   represents the sign bit of EXP's type.  If EXP represents a sign
   or zero extension, also test VAL against the unextended type.
   The return value is the (sub)expression whose sign bit is VAL,
   or NULL_TREE otherwise.  */

static tree
sign_bit_p (tree exp, tree val)
{
  unsigned HOST_WIDE_INT mask_lo, lo;
  HOST_WIDE_INT mask_hi, hi;
  int width;
  tree t;

  /* Tree EXP must have an integral type.  */
  t = TREE_TYPE (exp);
  if (! INTEGRAL_TYPE_P (t))
    return NULL_TREE;

  /* Tree VAL must be an integer constant.  */
  if (TREE_CODE (val) != INTEGER_CST
      || TREE_CONSTANT_OVERFLOW (val))
    return NULL_TREE;

  width = TYPE_PRECISION (t);
  if (width > HOST_BITS_PER_WIDE_INT)
    {
      hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
      lo = 0;

      mask_hi = ((unsigned HOST_WIDE_INT) -1
		 >> (2 * HOST_BITS_PER_WIDE_INT - width));
      mask_lo = -1;
    }
  else
    {
      hi = 0;
      lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);

      mask_hi = 0;
      mask_lo = ((unsigned HOST_WIDE_INT) -1
		 >> (HOST_BITS_PER_WIDE_INT - width));
    }

  /* We mask off those bits beyond TREE_TYPE (exp) so that we can
     treat VAL as if it were unsigned.  */
  if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
      && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
    return exp;

  /* Handle extension from a narrower type.  */
  if (TREE_CODE (exp) == NOP_EXPR
      && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
    return sign_bit_p (TREE_OPERAND (exp, 0), val);

  return NULL_TREE;
}

/* Subroutine for fold_truthop: determine if an operand is simple enough
   to be evaluated unconditionally.  */

static int
simple_operand_p (tree exp)
{
  /* Strip any conversions that don't change the machine mode.  */
  STRIP_NOPS (exp);

  return (CONSTANT_CLASS_P (exp)
	  || TREE_CODE (exp) == SSA_NAME
	  || (DECL_P (exp)
	      && ! TREE_ADDRESSABLE (exp)
	      && ! TREE_THIS_VOLATILE (exp)
	      && ! DECL_NONLOCAL (exp)
	      /* Don't regard global variables as simple.  They may be
		 allocated in ways unknown to the compiler (shared memory,
		 #pragma weak, etc).  */
	      && ! TREE_PUBLIC (exp)
	      && ! DECL_EXTERNAL (exp)
	      /* Loading a static variable is unduly expensive, but global
		 registers aren't expensive.  */
	      && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
}

/* The following functions are subroutines to fold_range_test and allow it to
   try to change a logical combination of comparisons into a range test.

   For example, both
	X == 2 || X == 3 || X == 4 || X == 5
   and
	X >= 2 && X <= 5
   are converted to
	(unsigned) (X - 2) <= 3

   We describe each set of comparisons as being either inside or outside
   a range, using a variable named like IN_P, and then describe the
   range with a lower and upper bound.  If one of the bounds is omitted,
   it represents either the highest or lowest value of the type.

   In the comments below, we represent a range by two numbers in brackets
   preceded by a "+" to designate being inside that range, or a "-" to
   designate being outside that range, so the condition can be inverted by
   flipping the prefix.  An omitted bound is represented by a "-".  For
   example, "- [-, 10]" means being outside the range starting at the lowest
   possible value and ending at 10, in other words, being greater than 10.
   The range "+ [-, -]" is always true and hence the range "- [-, -]" is
   always false.

   We set up things so that the missing bounds are handled in a consistent
   manner so neither a missing bound nor "true" and "false" need to be
   handled using a special case.  */

/* Return the result of applying CODE to ARG0 and ARG1, but handle the case
   of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
   and UPPER1_P are nonzero if the respective argument is an upper bound
   and zero for a lower.  TYPE, if nonzero, is the type of the result; it
   must be specified for a comparison.  ARG1 will be converted to ARG0's
   type if both are specified.  */

static tree
range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
	     tree arg1, int upper1_p)
{
  tree tem;
  int result;
  int sgn0, sgn1;

  /* If neither arg represents infinity, do the normal operation.
     Else, if not a comparison, return infinity.  Else handle the special
     comparison rules. Note that most of the cases below won't occur, but
     are handled for consistency.  */

  if (arg0 != 0 && arg1 != 0)
    {
      tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
			 arg0, fold_convert (TREE_TYPE (arg0), arg1));
      STRIP_NOPS (tem);
      return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
    }

  if (TREE_CODE_CLASS (code) != tcc_comparison)
    return 0;

  /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
     for neither.  In real maths, we cannot assume open ended ranges are
     the same. But, this is computer arithmetic, where numbers are finite.
     We can therefore make the transformation of any unbounded range with
     the value Z, Z being greater than any representable number. This permits
     us to treat unbounded ranges as equal.  */
  sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
  sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
  switch (code)
    {
    case EQ_EXPR:
      result = sgn0 == sgn1;
      break;
    case NE_EXPR:
      result = sgn0 != sgn1;
      break;
    case LT_EXPR:
      result = sgn0 < sgn1;
      break;
    case LE_EXPR:
      result = sgn0 <= sgn1;
      break;
    case GT_EXPR:
      result = sgn0 > sgn1;
      break;
    case GE_EXPR:
      result = sgn0 >= sgn1;
      break;
    default:
      gcc_unreachable ();
    }

  return constant_boolean_node (result, type);
}

/* Given EXP, a logical expression, set the range it is testing into
   variables denoted by PIN_P, PLOW, and PHIGH.  Return the expression
   actually being tested.  *PLOW and *PHIGH will be made of the same
   type as the returned expression.  If EXP is not a comparison, we
   will most likely not be returning a useful value and range.  Set
   *STRICT_OVERFLOW_P to true if the return value is only valid
   because signed overflow is undefined; otherwise, do not change
   *STRICT_OVERFLOW_P.  */

static tree
make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
	    bool *strict_overflow_p)
{
  enum tree_code code;
  tree arg0 = NULL_TREE, arg1 = NULL_TREE;
  tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
  int in_p, n_in_p;
  tree low, high, n_low, n_high;

  /* Start with simply saying "EXP != 0" and then look at the code of EXP
     and see if we can refine the range.  Some of the cases below may not
     happen, but it doesn't seem worth worrying about this.  We "continue"
     the outer loop when we've changed something; otherwise we "break"
     the switch, which will "break" the while.  */

  in_p = 0;
  low = high = build_int_cst (TREE_TYPE (exp), 0);

  while (1)
    {
      code = TREE_CODE (exp);
      exp_type = TREE_TYPE (exp);

      if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
	{
	  if (TREE_CODE_LENGTH (code) > 0)
	    arg0 = TREE_OPERAND (exp, 0);
	  if (TREE_CODE_CLASS (code) == tcc_comparison
	      || TREE_CODE_CLASS (code) == tcc_unary
	      || TREE_CODE_CLASS (code) == tcc_binary)
	    arg0_type = TREE_TYPE (arg0);
	  if (TREE_CODE_CLASS (code) == tcc_binary
	      || TREE_CODE_CLASS (code) == tcc_comparison
	      || (TREE_CODE_CLASS (code) == tcc_expression
		  && TREE_CODE_LENGTH (code) > 1))
	    arg1 = TREE_OPERAND (exp, 1);
	}

      switch (code)
	{
	case TRUTH_NOT_EXPR:
	  in_p = ! in_p, exp = arg0;
	  continue;

	case EQ_EXPR: case NE_EXPR:
	case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
	  /* We can only do something if the range is testing for zero
	     and if the second operand is an integer constant.  Note that
	     saying something is "in" the range we make is done by
	     complementing IN_P since it will set in the initial case of
	     being not equal to zero; "out" is leaving it alone.  */
	  if (low == 0 || high == 0
	      || ! integer_zerop (low) || ! integer_zerop (high)
	      || TREE_CODE (arg1) != INTEGER_CST)
	    break;

	  switch (code)
	    {
	    case NE_EXPR:  /* - [c, c]  */
	      low = high = arg1;
	      break;
	    case EQ_EXPR:  /* + [c, c]  */
	      in_p = ! in_p, low = high = arg1;
	      break;
	    case GT_EXPR:  /* - [-, c] */
	      low = 0, high = arg1;
	      break;
	    case GE_EXPR:  /* + [c, -] */
	      in_p = ! in_p, low = arg1, high = 0;
	      break;
	    case LT_EXPR:  /* - [c, -] */
	      low = arg1, high = 0;
	      break;
	    case LE_EXPR:  /* + [-, c] */
	      in_p = ! in_p, low = 0, high = arg1;
	      break;
	    default:
	      gcc_unreachable ();
	    }

	  /* If this is an unsigned comparison, we also know that EXP is
	     greater than or equal to zero.  We base the range tests we make
	     on that fact, so we record it here so we can parse existing
	     range tests.  We test arg0_type since often the return type
	     of, e.g. EQ_EXPR, is boolean.  */
	  if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
	    {
	      if (! merge_ranges (&n_in_p, &n_low, &n_high,
				  in_p, low, high, 1,
				  build_int_cst (arg0_type, 0),
				  NULL_TREE))
		break;

	      in_p = n_in_p, low = n_low, high = n_high;

	      /* If the high bound is missing, but we have a nonzero low
		 bound, reverse the range so it goes from zero to the low bound
		 minus 1.  */
	      if (high == 0 && low && ! integer_zerop (low))
		{
		  in_p = ! in_p;
		  high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
				      integer_one_node, 0);
		  low = build_int_cst (arg0_type, 0);
		}
	    }

	  exp = arg0;
	  continue;

	case NEGATE_EXPR:
	  /* (-x) IN [a,b] -> x in [-b, -a]  */
	  n_low = range_binop (MINUS_EXPR, exp_type,
			       build_int_cst (exp_type, 0),
			       0, high, 1);
	  n_high = range_binop (MINUS_EXPR, exp_type,
				build_int_cst (exp_type, 0),
				0, low, 0);
	  low = n_low, high = n_high;
	  exp = arg0;
	  continue;

	case BIT_NOT_EXPR:
	  /* ~ X -> -X - 1  */
	  exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
			build_int_cst (exp_type, 1));
	  continue;

	case PLUS_EXPR:  case MINUS_EXPR:
	  if (TREE_CODE (arg1) != INTEGER_CST)
	    break;

	  /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
	     move a constant to the other side.  */
	  if (!TYPE_UNSIGNED (arg0_type)
	      && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
	    break;

	  /* If EXP is signed, any overflow in the computation is undefined,
	     so we don't worry about it so long as our computations on
	     the bounds don't overflow.  For unsigned, overflow is defined
	     and this is exactly the right thing.  */
	  n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
			       arg0_type, low, 0, arg1, 0);
	  n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
				arg0_type, high, 1, arg1, 0);
	  if ((n_low != 0 && TREE_OVERFLOW (n_low))
	      || (n_high != 0 && TREE_OVERFLOW (n_high)))
	    break;

	  if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
	    *strict_overflow_p = true;

	  /* Check for an unsigned range which has wrapped around the maximum
	     value thus making n_high < n_low, and normalize it.  */
	  if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
	    {
	      low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
				 integer_one_node, 0);
	      high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
				  integer_one_node, 0);

	      /* If the range is of the form +/- [ x+1, x ], we won't
		 be able to normalize it.  But then, it represents the
		 whole range or the empty set, so make it
		 +/- [ -, - ].  */
	      if (tree_int_cst_equal (n_low, low)
		  && tree_int_cst_equal (n_high, high))
		low = high = 0;
	      else
		in_p = ! in_p;
	    }
	  else
	    low = n_low, high = n_high;

	  exp = arg0;
	  continue;

	case NOP_EXPR:  case NON_LVALUE_EXPR:  case CONVERT_EXPR:
	  if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
	    break;

	  if (! INTEGRAL_TYPE_P (arg0_type)
	      || (low != 0 && ! int_fits_type_p (low, arg0_type))
	      || (high != 0 && ! int_fits_type_p (high, arg0_type)))
	    break;

	  n_low = low, n_high = high;

	  if (n_low != 0)
	    n_low = fold_convert (arg0_type, n_low);

	  if (n_high != 0)
	    n_high = fold_convert (arg0_type, n_high);


	  /* If we're converting arg0 from an unsigned type, to exp,
	     a signed type,  we will be doing the comparison as unsigned.
	     The tests above have already verified that LOW and HIGH
	     are both positive.

	     So we have to ensure that we will handle large unsigned
	     values the same way that the current signed bounds treat
	     negative values.  */

	  if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
	    {
	      tree high_positive;
	      tree equiv_type = lang_hooks.types.type_for_mode
		(TYPE_MODE (arg0_type), 1);

	      /* A range without an upper bound is, naturally, unbounded.
		 Since convert would have cropped a very large value, use
		 the max value for the destination type.  */
	      high_positive
		= TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
		: TYPE_MAX_VALUE (arg0_type);

	      if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
		high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
					     fold_convert (arg0_type,
							   high_positive),
					     fold_convert (arg0_type,
							   integer_one_node));

	      /* If the low bound is specified, "and" the range with the
		 range for which the original unsigned value will be
		 positive.  */
	      if (low != 0)
		{
		  if (! merge_ranges (&n_in_p, &n_low, &n_high,
				      1, n_low, n_high, 1,
				      fold_convert (arg0_type,
						    integer_zero_node),
				      high_positive))
		    break;

		  in_p = (n_in_p == in_p);
		}
	      else
		{
		  /* Otherwise, "or" the range with the range of the input
		     that will be interpreted as negative.  */
		  if (! merge_ranges (&n_in_p, &n_low, &n_high,
				      0, n_low, n_high, 1,
				      fold_convert (arg0_type,
						    integer_zero_node),
				      high_positive))
		    break;

		  in_p = (in_p != n_in_p);
		}
	    }

	  exp = arg0;
	  low = n_low, high = n_high;
	  continue;

	default:
	  break;
	}

      break;
    }

  /* If EXP is a constant, we can evaluate whether this is true or false.  */
  if (TREE_CODE (exp) == INTEGER_CST)
    {
      in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
						 exp, 0, low, 0))
		      && integer_onep (range_binop (LE_EXPR, integer_type_node,
						    exp, 1, high, 1)));
      low = high = 0;
      exp = 0;
    }

  *pin_p = in_p, *plow = low, *phigh = high;
  return exp;
}

/* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
   type, TYPE, return an expression to test if EXP is in (or out of, depending
   on IN_P) the range.  Return 0 if the test couldn't be created.  */

static tree
build_range_check (tree type, tree exp, int in_p, tree low, tree high)
{
  tree etype = TREE_TYPE (exp);
  tree value;

#ifdef HAVE_canonicalize_funcptr_for_compare
  /* Disable this optimization for function pointer expressions
     on targets that require function pointer canonicalization.  */
  if (HAVE_canonicalize_funcptr_for_compare
      && TREE_CODE (etype) == POINTER_TYPE
      && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
    return NULL_TREE;
#endif

  if (! in_p)
    {
      value = build_range_check (type, exp, 1, low, high);
      if (value != 0)
        return invert_truthvalue (value);

      return 0;
    }

  if (low == 0 && high == 0)
    return build_int_cst (type, 1);

  if (low == 0)
    return fold_build2 (LE_EXPR, type, exp,
			fold_convert (etype, high));

  if (high == 0)
    return fold_build2 (GE_EXPR, type, exp,
			fold_convert (etype, low));

  if (operand_equal_p (low, high, 0))
    return fold_build2 (EQ_EXPR, type, exp,
			fold_convert (etype, low));

  if (integer_zerop (low))
    {
      if (! TYPE_UNSIGNED (etype))
	{
	  etype = lang_hooks.types.unsigned_type (etype);
	  high = fold_convert (etype, high);
	  exp = fold_convert (etype, exp);
	}
      return build_range_check (type, exp, 1, 0, high);
    }

  /* Optimize (c>=1) && (c<=127) into (signed char)c > 0.  */
  if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
    {
      unsigned HOST_WIDE_INT lo;
      HOST_WIDE_INT hi;
      int prec;

      prec = TYPE_PRECISION (etype);
      if (prec <= HOST_BITS_PER_WIDE_INT)
	{
	  hi = 0;
	  lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
	}
      else
	{
	  hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
	  lo = (unsigned HOST_WIDE_INT) -1;
	}

      if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
	{
	  if (TYPE_UNSIGNED (etype))
	    {
	      etype = lang_hooks.types.signed_type (etype);
	      exp = fold_convert (etype, exp);
	    }
	  return fold_build2 (GT_EXPR, type, exp,
			      build_int_cst (etype, 0));
	}
    }

  /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
     This requires wrap-around arithmetics for the type of the expression.  */
  switch (TREE_CODE (etype))
    {
    case INTEGER_TYPE:
      /* There is no requirement that LOW be within the range of ETYPE
	 if the latter is a subtype.  It must, however, be within the base
	 type of ETYPE.  So be sure we do the subtraction in that type.  */
      if (TREE_TYPE (etype))
	etype = TREE_TYPE (etype);
      break;

    case ENUMERAL_TYPE:
    case BOOLEAN_TYPE:
      etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
					      TYPE_UNSIGNED (etype));
      break;

    default:
      break;
    }

  /* If we don't have wrap-around arithmetics upfront, try to force it.  */
  if (TREE_CODE (etype) == INTEGER_TYPE
      && !TYPE_OVERFLOW_WRAPS (etype))
    {
      tree utype, minv, maxv;

      /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
	 for the type in question, as we rely on this here.  */
      utype = lang_hooks.types.unsigned_type (etype);
      maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
      maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
			  integer_one_node, 1);
      minv = fold_convert (utype, TYPE_MIN_VALUE (etype));

      if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
				      minv, 1, maxv, 1)))
	etype = utype;
      else
	return 0;
    }

  high = fold_convert (etype, high);
  low = fold_convert (etype, low);
  exp = fold_convert (etype, exp);

  value = const_binop (MINUS_EXPR, high, low, 0);

  if (value != 0 && !TREE_OVERFLOW (value))
    return build_range_check (type,
			      fold_build2 (MINUS_EXPR, etype, exp, low),
			      1, build_int_cst (etype, 0), value);

  return 0;
}

/* Return the predecessor of VAL in its type, handling the infinite case.  */

static tree
range_predecessor (tree val)
{
  tree type = TREE_TYPE (val);

  if (INTEGRAL_TYPE_P (type)
      && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
    return 0;
  else
    return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
}

/* Return the successor of VAL in its type, handling the infinite case.  */

static tree
range_successor (tree val)
{
  tree type = TREE_TYPE (val);

  if (INTEGRAL_TYPE_P (type)
      && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
    return 0;
  else
    return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
}

/* Given two ranges, see if we can merge them into one.  Return 1 if we
   can, 0 if we can't.  Set the output range into the specified parameters.  */

static int
merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
	      tree high0, int in1_p, tree low1, tree high1)
{
  int no_overlap;
  int subset;
  int temp;
  tree tem;
  int in_p;
  tree low, high;
  int lowequal = ((low0 == 0 && low1 == 0)
		  || integer_onep (range_binop (EQ_EXPR, integer_type_node,
						low0, 0, low1, 0)));
  int highequal = ((high0 == 0 && high1 == 0)
		   || integer_onep (range_binop (EQ_EXPR, integer_type_node,
						 high0, 1, high1, 1)));

  /* Make range 0 be the range that starts first, or ends last if they
     start at the same value.  Swap them if it isn't.  */
  if (integer_onep (range_binop (GT_EXPR, integer_type_node,
				 low0, 0, low1, 0))
      || (lowequal
	  && integer_onep (range_binop (GT_EXPR, integer_type_node,
					high1, 1, high0, 1))))
    {
      temp = in0_p, in0_p = in1_p, in1_p = temp;
      tem = low0, low0 = low1, low1 = tem;
      tem = high0, high0 = high1, high1 = tem;
    }

  /* Now flag two cases, whether the ranges are disjoint or whether the
     second range is totally subsumed in the first.  Note that the tests
     below are simplified by the ones above.  */
  no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
					  high0, 1, low1, 0));
  subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
				      high1, 1, high0, 1));

  /* We now have four cases, depending on whether we are including or
     excluding the two ranges.  */
  if (in0_p && in1_p)
    {
      /* If they don't overlap, the result is false.  If the second range
	 is a subset it is the result.  Otherwise, the range is from the start
	 of the second to the end of the first.  */
      if (no_overlap)
	in_p = 0, low = high = 0;
      else if (subset)
	in_p = 1, low = low1, high = high1;
      else
	in_p = 1, low = low1, high = high0;
    }

  else if (in0_p && ! in1_p)
    {
      /* If they don't overlap, the result is the first range.  If they are
	 equal, the result is false.  If the second range is a subset of the
	 first, and the ranges begin at the same place, we go from just after
	 the end of the second range to the end of the first.  If the second
	 range is not a subset of the first, or if it is a subset and both
	 ranges end at the same place, the range starts at the start of the
	 first range and ends just before the second range.
	 Otherwise, we can't describe this as a single range.  */
      if (no_overlap)
	in_p = 1, low = low0, high = high0;
      else if (lowequal && highequal)
	in_p = 0, low = high = 0;
      else if (subset && lowequal)
	{
	  low = range_successor (high1);
	  high = high0;
	  in_p = 1;
	  if (low == 0)
	    {
	      /* We are in the weird situation where high0 > high1 but
		 high1 has no successor.  Punt.  */
	      return 0;
	    }
	}
      else if (! subset || highequal)
	{
	  low = low0;
	  high = range_predecessor (low1);
	  in_p = 1;
	  if (high == 0)
	    {
	      /* low0 < low1 but low1 has no predecessor.  Punt.  */
	      return 0;
	    }
	}
      else
	return 0;
    }

  else if (! in0_p && in1_p)
    {
      /* If they don't overlap, the result is the second range.  If the second
	 is a subset of the first, the result is false.  Otherwise,
	 the range starts just after the first range and ends at the
	 end of the second.  */
      if (no_overlap)
	in_p = 1, low = low1, high = high1;
      else if (subset || highequal)
	in_p = 0, low = high = 0;
      else
	{
	  low = range_successor (high0);
	  high = high1;
	  in_p = 1;
	  if (low == 0)
	    {
	      /* high1 > high0 but high0 has no successor.  Punt.  */
	      return 0;
	    }
	}
    }

  else
    {
      /* The case where we are excluding both ranges.  Here the complex case
	 is if they don't overlap.  In that case, the only time we have a
	 range is if they are adjacent.  If the second is a subset of the
	 first, the result is the first.  Otherwise, the range to exclude
	 starts at the beginning of the first range and ends at the end of the
	 second.  */
      if (no_overlap)
	{
	  if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
					 range_successor (high0),
					 1, low1, 0)))
	    in_p = 0, low = low0, high = high1;
	  else
	    {
	      /* Canonicalize - [min, x] into - [-, x].  */
	      if (low0 && TREE_CODE (low0) == INTEGER_CST)
		switch (TREE_CODE (TREE_TYPE (low0)))
		  {
		  case ENUMERAL_TYPE:
		    if (TYPE_PRECISION (TREE_TYPE (low0))
			!= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
		      break;
		    /* FALLTHROUGH */
		  case INTEGER_TYPE:
		    if (tree_int_cst_equal (low0,
					    TYPE_MIN_VALUE (TREE_TYPE (low0))))
		      low0 = 0;
		    break;
		  case POINTER_TYPE:
		    if (TYPE_UNSIGNED (TREE_TYPE (low0))
			&& integer_zerop (low0))
		      low0 = 0;
		    break;
		  default:
		    break;
		  }

	      /* Canonicalize - [x, max] into - [x, -].  */
	      if (high1 && TREE_CODE (high1) == INTEGER_CST)
		switch (TREE_CODE (TREE_TYPE (high1)))
		  {
		  case ENUMERAL_TYPE:
		    if (TYPE_PRECISION (TREE_TYPE (high1))
			!= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
		      break;
		    /* FALLTHROUGH */
		  case INTEGER_TYPE:
		    if (tree_int_cst_equal (high1,
					    TYPE_MAX_VALUE (TREE_TYPE (high1))))
		      high1 = 0;
		    break;
		  case POINTER_TYPE:
		    if (TYPE_UNSIGNED (TREE_TYPE (high1))
			&& integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
						       high1, 1,
						       integer_one_node, 1)))
		      high1 = 0;
		    break;
		  default:
		    break;
		  }

	      /* The ranges might be also adjacent between the maximum and
	         minimum values of the given type.  For
	         - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
	         return + [x + 1, y - 1].  */
	      if (low0 == 0 && high1 == 0)
	        {
		  low = range_successor (high0);
		  high = range_predecessor (low1);
		  if (low == 0 || high == 0)
		    return 0;

		  in_p = 1;
		}
	      else
		return 0;
	    }
	}
      else if (subset)
	in_p = 0, low = low0, high = high0;
      else
	in_p = 0, low = low0, high = high1;
    }

  *pin_p = in_p, *plow = low, *phigh = high;
  return 1;
}


/* Subroutine of fold, looking inside expressions of the form
   A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
   of the COND_EXPR.  This function is being used also to optimize
   A op B ? C : A, by reversing the comparison first.

   Return a folded expression whose code is not a COND_EXPR
   anymore, or NULL_TREE if no folding opportunity is found.  */

static tree
fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
{
  enum tree_code comp_code = TREE_CODE (arg0);
  tree arg00 = TREE_OPERAND (arg0, 0);
  tree arg01 = TREE_OPERAND (arg0, 1);
  tree arg1_type = TREE_TYPE (arg1);
  tree tem;

  STRIP_NOPS (arg1);
  STRIP_NOPS (arg2);

  /* If we have A op 0 ? A : -A, consider applying the following
     transformations:

     A == 0? A : -A    same as -A
     A != 0? A : -A    same as A
     A >= 0? A : -A    same as abs (A)
     A > 0?  A : -A    same as abs (A)
     A <= 0? A : -A    same as -abs (A)
     A < 0?  A : -A    same as -abs (A)

     None of these transformations work for modes with signed
     zeros.  If A is +/-0, the first two transformations will
     change the sign of the result (from +0 to -0, or vice
     versa).  The last four will fix the sign of the result,
     even though the original expressions could be positive or
     negative, depending on the sign of A.

     Note that all these transformations are correct if A is
     NaN, since the two alternatives (A and -A) are also NaNs.  */
  if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
       ? real_zerop (arg01)
       : integer_zerop (arg01))
      && ((TREE_CODE (arg2) == NEGATE_EXPR
	   && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
	     /* In the case that A is of the form X-Y, '-A' (arg2) may
	        have already been folded to Y-X, check for that. */
	  || (TREE_CODE (arg1) == MINUS_EXPR
	      && TREE_CODE (arg2) == MINUS_EXPR
	      && operand_equal_p (TREE_OPERAND (arg1, 0),
				  TREE_OPERAND (arg2, 1), 0)
	      && operand_equal_p (TREE_OPERAND (arg1, 1),
				  TREE_OPERAND (arg2, 0), 0))))
    switch (comp_code)
      {
      case EQ_EXPR:
      case UNEQ_EXPR:
	tem = fold_convert (arg1_type, arg1);
	return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
      case NE_EXPR:
      case LTGT_EXPR:
	return pedantic_non_lvalue (fold_convert (type, arg1));
      case UNGE_EXPR:
      case UNGT_EXPR:
	if (flag_trapping_math)
	  break;
	/* Fall through.  */
      case GE_EXPR:
      case GT_EXPR:
	if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
	  arg1 = fold_convert (lang_hooks.types.signed_type
			       (TREE_TYPE (arg1)), arg1);
	tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
	return pedantic_non_lvalue (fold_convert (type, tem));
      case UNLE_EXPR:
      case UNLT_EXPR:
	if (flag_trapping_math)
	  break;
      case LE_EXPR:
      case LT_EXPR:
	if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
	  arg1 = fold_convert (lang_hooks.types.signed_type
			       (TREE_TYPE (arg1)), arg1);
	tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
	return negate_expr (fold_convert (type, tem));
      default:
	gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
	break;
      }

  /* A != 0 ? A : 0 is simply A, unless A is -0.  Likewise
     A == 0 ? A : 0 is always 0 unless A is -0.  Note that
     both transformations are correct when A is NaN: A != 0
     is then true, and A == 0 is false.  */

  if (integer_zerop (arg01) && integer_zerop (arg2))
    {
      if (comp_code == NE_EXPR)
	return pedantic_non_lvalue (fold_convert (type, arg1));
      else if (comp_code == EQ_EXPR)
	return build_int_cst (type, 0);
    }

  /* Try some transformations of A op B ? A : B.

     A == B? A : B    same as B
     A != B? A : B    same as A
     A >= B? A : B    same as max (A, B)
     A > B?  A : B    same as max (B, A)
     A <= B? A : B    same as min (A, B)
     A < B?  A : B    same as min (B, A)

     As above, these transformations don't work in the presence
     of signed zeros.  For example, if A and B are zeros of
     opposite sign, the first two transformations will change
     the sign of the result.  In the last four, the original
     expressions give different results for (A=+0, B=-0) and
     (A=-0, B=+0), but the transformed expressions do not.

     The first two transformations are correct if either A or B
     is a NaN.  In the first transformation, the condition will
     be false, and B will indeed be chosen.  In the case of the
     second transformation, the condition A != B will be true,
     and A will be chosen.

     The conversions to max() and min() are not correct if B is
     a number and A is not.  The conditions in the original
     expressions will be false, so all four give B.  The min()
     and max() versions would give a NaN instead.  */
  if (operand_equal_for_comparison_p (arg01, arg2, arg00)
      /* Avoid these transformations if the COND_EXPR may be used
	 as an lvalue in the C++ front-end.  PR c++/19199.  */
      && (in_gimple_form
	  || (strcmp (lang_hooks.name, "GNU C++") != 0
	      && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
	  || ! maybe_lvalue_p (arg1)
	  || ! maybe_lvalue_p (arg2)))
    {
      tree comp_op0 = arg00;
      tree comp_op1 = arg01;
      tree comp_type = TREE_TYPE (comp_op0);

      /* Avoid adding NOP_EXPRs in case this is an lvalue.  */
      if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
	{
	  comp_type = type;
	  comp_op0 = arg1;
	  comp_op1 = arg2;
	}

      switch (comp_code)
	{
	case EQ_EXPR:
	  return pedantic_non_lvalue (fold_convert (type, arg2));
	case NE_EXPR:
	  return pedantic_non_lvalue (fold_convert (type, arg1));
	case LE_EXPR:
	case LT_EXPR:
	case UNLE_EXPR:
	case UNLT_EXPR:
	  /* In C++ a ?: expression can be an lvalue, so put the
	     operand which will be used if they are equal first
	     so that we can convert this back to the
	     corresponding COND_EXPR.  */
	  if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
	    {
	      comp_op0 = fold_convert (comp_type, comp_op0);
	      comp_op1 = fold_convert (comp_type, comp_op1);
	      tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
		    ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
		    : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
	      return pedantic_non_lvalue (fold_convert (type, tem));
	    }
	  break;
	case GE_EXPR:
	case GT_EXPR:
	case UNGE_EXPR:
	case UNGT_EXPR:
	  if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
	    {
	      comp_op0 = fold_convert (comp_type, comp_op0);
	      comp_op1 = fold_convert (comp_type, comp_op1);
	      tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
		    ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
		    : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
	      return pedantic_non_lvalue (fold_convert (type, tem));
	    }
	  break;
	case UNEQ_EXPR:
	  if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
	    return pedantic_non_lvalue (fold_convert (type, arg2));
	  break;
	case LTGT_EXPR:
	  if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
	    return pedantic_non_lvalue (fold_convert (type, arg1));
	  break;
	default:
	  gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
	  break;
	}
    }

  /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
     we might still be able to simplify this.  For example,
     if C1 is one less or one more than C2, this might have started
     out as a MIN or MAX and been transformed by this function.
     Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE.  */

  if (INTEGRAL_TYPE_P (type)
      && TREE_CODE (arg01) == INTEGER_CST
      && TREE_CODE (arg2) == INTEGER_CST)
    switch (comp_code)
      {
      case EQ_EXPR:
	/* We can replace A with C1 in this case.  */
	arg1 = fold_convert (type, arg01);
	return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);

      case LT_EXPR:
	/* If C1 is C2 + 1, this is min(A, C2).  */
	if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
			       OEP_ONLY_CONST)
	    && operand_equal_p (arg01,
				const_binop (PLUS_EXPR, arg2,
					     integer_one_node, 0),
				OEP_ONLY_CONST))
	  return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
						   type, arg1, arg2));
	break;

      case LE_EXPR:
	/* If C1 is C2 - 1, this is min(A, C2).  */
	if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
			       OEP_ONLY_CONST)
	    && operand_equal_p (arg01,
				const_binop (MINUS_EXPR, arg2,
					     integer_one_node, 0),
				OEP_ONLY_CONST))
	  return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
						   type, arg1, arg2));
	break;

      case GT_EXPR:
	/* If C1 is C2 - 1, this is max(A, C2).  */
	if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
			       OEP_ONLY_CONST)
	    && operand_equal_p (arg01,
				const_binop (MINUS_EXPR, arg2,
					     integer_one_node, 0),
				OEP_ONLY_CONST))
	  return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
						   type, arg1, arg2));
	break;

      case GE_EXPR:
	/* If C1 is C2 + 1, this is max(A, C2).  */
	if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
			       OEP_ONLY_CONST)
	    && operand_equal_p (arg01,
				const_binop (PLUS_EXPR, arg2,
					     integer_one_node, 0),
				OEP_ONLY_CONST))
	  return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
						   type, arg1, arg2));
	break;
      case NE_EXPR:
	break;
      default:
	gcc_unreachable ();
      }

  return NULL_TREE;
}



#ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
#define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
#endif

/* EXP is some logical combination of boolean tests.  See if we can
   merge it into some range test.  Return the new tree if so.  */

static tree
fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
{
  int or_op = (code == TRUTH_ORIF_EXPR
	       || code == TRUTH_OR_EXPR);
  int in0_p, in1_p, in_p;
  tree low0, low1, low, high0, high1, high;
  bool strict_overflow_p = false;
  tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
  tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
  tree tem;
  const char * const warnmsg = G_("assuming signed overflow does not occur "
				  "when simplifying range test");

  /* If this is an OR operation, invert both sides; we will invert
     again at the end.  */
  if (or_op)
    in0_p = ! in0_p, in1_p = ! in1_p;

  /* If both expressions are the same, if we can merge the ranges, and we
     can build the range test, return it or it inverted.  If one of the
     ranges is always true or always false, consider it to be the same
     expression as the other.  */
  if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
      && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
		       in1_p, low1, high1)
      && 0 != (tem = (build_range_check (type,
					 lhs != 0 ? lhs
					 : rhs != 0 ? rhs : integer_zero_node,
					 in_p, low, high))))
    {
      if (strict_overflow_p)
	fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
      return or_op ? invert_truthvalue (tem) : tem;
    }

  /* On machines where the branch cost is expensive, if this is a
     short-circuited branch and the underlying object on both sides
     is the same, make a non-short-circuit operation.  */
  else if (LOGICAL_OP_NON_SHORT_CIRCUIT
	   && lhs != 0 && rhs != 0
	   && (code == TRUTH_ANDIF_EXPR
	       || code == TRUTH_ORIF_EXPR)
	   && operand_equal_p (lhs, rhs, 0))
    {
      /* If simple enough, just rewrite.  Otherwise, make a SAVE_EXPR
	 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
	 which cases we can't do this.  */
      if (simple_operand_p (lhs))
	return build2 (code == TRUTH_ANDIF_EXPR
		       ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
		       type, op0, op1);

      else if (lang_hooks.decls.global_bindings_p () == 0
	       && ! CONTAINS_PLACEHOLDER_P (lhs))
	{
	  tree common = save_expr (lhs);

	  if (0 != (lhs = build_range_check (type, common,
					     or_op ? ! in0_p : in0_p,
					     low0, high0))
	      && (0 != (rhs = build_range_check (type, common,
						 or_op ? ! in1_p : in1_p,
						 low1, high1))))
	    {
	      if (strict_overflow_p)
		fold_overflow_warning (warnmsg,
				       WARN_STRICT_OVERFLOW_COMPARISON);
	      return build2 (code == TRUTH_ANDIF_EXPR
			     ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
			     type, lhs, rhs);
	    }
	}
    }

  return 0;
}

/* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
   bit value.  Arrange things so the extra bits will be set to zero if and
   only if C is signed-extended to its full width.  If MASK is nonzero,
   it is an INTEGER_CST that should be AND'ed with the extra bits.  */

static tree
unextend (tree c, int p, int unsignedp, tree mask)
{
  tree type = TREE_TYPE (c);
  int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
  tree temp;

  if (p == modesize || unsignedp)
    return c;

  /* We work by getting just the sign bit into the low-order bit, then
     into the high-order bit, then sign-extend.  We then XOR that value
     with C.  */
  temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
  temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);

  /* We must use a signed type in order to get an arithmetic right shift.
     However, we must also avoid introducing accidental overflows, so that
     a subsequent call to integer_zerop will work.  Hence we must
     do the type conversion here.  At this point, the constant is either
     zero or one, and the conversion to a signed type can never overflow.
     We could get an overflow if this conversion is done anywhere else.  */
  if (TYPE_UNSIGNED (type))
    temp = fold_convert (lang_hooks.types.signed_type (type), temp);

  temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
  temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
  if (mask != 0)
    temp = const_binop (BIT_AND_EXPR, temp,
			fold_convert (TREE_TYPE (c), mask), 0);
  /* If necessary, convert the type back to match the type of C.  */
  if (TYPE_UNSIGNED (type))
    temp = fold_convert (type, temp);

  return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
}

/* Find ways of folding logical expressions of LHS and RHS:
   Try to merge two comparisons to the same innermost item.
   Look for range tests like "ch >= '0' && ch <= '9'".
   Look for combinations of simple terms on machines with expensive branches
   and evaluate the RHS unconditionally.

   For example, if we have p->a == 2 && p->b == 4 and we can make an
   object large enough to span both A and B, we can do this with a comparison
   against the object ANDed with the a mask.

   If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
   operations to do this with one comparison.

   We check for both normal comparisons and the BIT_AND_EXPRs made this by
   function and the one above.

   CODE is the logical operation being done.  It can be TRUTH_ANDIF_EXPR,
   TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.

   TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
   two operands.

   We return the simplified tree or 0 if no optimization is possible.  */

static tree
fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
{
  /* If this is the "or" of two comparisons, we can do something if
     the comparisons are NE_EXPR.  If this is the "and", we can do something
     if the comparisons are EQ_EXPR.  I.e.,
	(a->b == 2 && a->c == 4) can become (a->new == NEW).

     WANTED_CODE is this operation code.  For single bit fields, we can
     convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
     comparison for one-bit fields.  */

  enum tree_code wanted_code;
  enum tree_code lcode, rcode;
  tree ll_arg, lr_arg, rl_arg, rr_arg;
  tree ll_inner, lr_inner, rl_inner, rr_inner;
  HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
  HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
  HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
  HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
  int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
  enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
  enum machine_mode lnmode, rnmode;
  tree ll_mask, lr_mask, rl_mask, rr_mask;
  tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
  tree l_const, r_const;
  tree lntype, rntype, result;
  int first_bit, end_bit;
  int volatilep;
  tree orig_lhs = lhs, orig_rhs = rhs;
  enum tree_code orig_code = code;

  /* Start by getting the comparison codes.  Fail if anything is volatile.
     If one operand is a BIT_AND_EXPR with the constant one, treat it as if
     it were surrounded with a NE_EXPR.  */

  if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
    return 0;

  lcode = TREE_CODE (lhs);
  rcode = TREE_CODE (rhs);

  if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
    {
      lhs = build2 (NE_EXPR, truth_type, lhs,
		    build_int_cst (TREE_TYPE (lhs), 0));
      lcode = NE_EXPR;
    }

  if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
    {
      rhs = build2 (NE_EXPR, truth_type, rhs,
		    build_int_cst (TREE_TYPE (rhs), 0));
      rcode = NE_EXPR;
    }

  if (TREE_CODE_CLASS (lcode) != tcc_comparison
      || TREE_CODE_CLASS (rcode) != tcc_comparison)
    return 0;

  ll_arg = TREE_OPERAND (lhs, 0);
  lr_arg = TREE_OPERAND (lhs, 1);
  rl_arg = TREE_OPERAND (rhs, 0);
  rr_arg = TREE_OPERAND (rhs, 1);

  /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations.  */
  if (simple_operand_p (ll_arg)
      && simple_operand_p (lr_arg))
    {
      tree result;
      if (operand_equal_p (ll_arg, rl_arg, 0)
          && operand_equal_p (lr_arg, rr_arg, 0))
	{
          result = combine_comparisons (code, lcode, rcode,
					truth_type, ll_arg, lr_arg);
	  if (result)
	    return result;
	}
      else if (operand_equal_p (ll_arg, rr_arg, 0)
               && operand_equal_p (lr_arg, rl_arg, 0))
	{
          result = combine_comparisons (code, lcode,
					swap_tree_comparison (rcode),
					truth_type, ll_arg, lr_arg);
	  if (result)
	    return result;
	}
    }

  code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
	  ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);

  /* If the RHS can be evaluated unconditionally and its operands are
     simple, it wins to evaluate the RHS unconditionally on machines
     with expensive branches.  In this case, this isn't a comparison
     that can be merged.  Avoid doing this if the RHS is a floating-point
     comparison since those can trap.  */

  if (BRANCH_COST >= 2
      && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
      && simple_operand_p (rl_arg)
      && simple_operand_p (rr_arg))
    {
      /* Convert (a != 0) || (b != 0) into (a | b) != 0.  */
      if (code == TRUTH_OR_EXPR
	  && lcode == NE_EXPR && integer_zerop (lr_arg)
	  && rcode == NE_EXPR && integer_zerop (rr_arg)
	  && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
	return build2 (NE_EXPR, truth_type,
		       build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
			       ll_arg, rl_arg),
		       build_int_cst (TREE_TYPE (ll_arg), 0));

      /* Convert (a == 0) && (b == 0) into (a | b) == 0.  */
      if (code == TRUTH_AND_EXPR
	  && lcode == EQ_EXPR && integer_zerop (lr_arg)
	  && rcode == EQ_EXPR && integer_zerop (rr_arg)
	  && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
	return build2 (EQ_EXPR, truth_type,
		       build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
			       ll_arg, rl_arg),
		       build_int_cst (TREE_TYPE (ll_arg), 0));

      if (LOGICAL_OP_NON_SHORT_CIRCUIT)
	{
	  if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
	    return build2 (code, truth_type, lhs, rhs);
	  return NULL_TREE;
	}
    }

  /* See if the comparisons can be merged.  Then get all the parameters for
     each side.  */

  if ((lcode != EQ_EXPR && lcode != NE_EXPR)
      || (rcode != EQ_EXPR && rcode != NE_EXPR))
    return 0;

  volatilep = 0;
  ll_inner = decode_field_reference (ll_arg,
				     &ll_bitsize, &ll_bitpos, &ll_mode,
				     &ll_unsignedp, &volatilep, &ll_mask,
				     &ll_and_mask);
  lr_inner = decode_field_reference (lr_arg,
				     &lr_bitsize, &lr_bitpos, &lr_mode,
				     &lr_unsignedp, &volatilep, &lr_mask,
				     &lr_and_mask);
  rl_inner = decode_field_reference (rl_arg,
				     &rl_bitsize, &rl_bitpos, &rl_mode,
				     &rl_unsignedp, &volatilep, &rl_mask,
				     &rl_and_mask);
  rr_inner = decode_field_reference (rr_arg,
				     &rr_bitsize, &rr_bitpos, &rr_mode,
				     &rr_unsignedp, &volatilep, &rr_mask,
				     &rr_and_mask);

  /* It must be true that the inner operation on the lhs of each
     comparison must be the same if we are to be able to do anything.
     Then see if we have constants.  If not, the same must be true for
     the rhs's.  */
  if (volatilep || ll_inner == 0 || rl_inner == 0
      || ! operand_equal_p (ll_inner, rl_inner, 0))
    return 0;

  if (TREE_CODE (lr_arg) == INTEGER_CST
      && TREE_CODE (rr_arg) == INTEGER_CST)
    l_const = lr_arg, r_const = rr_arg;
  else if (lr_inner == 0 || rr_inner == 0
	   || ! operand_equal_p (lr_inner, rr_inner, 0))
    return 0;
  else
    l_const = r_const = 0;

  /* If either comparison code is not correct for our logical operation,
     fail.  However, we can convert a one-bit comparison against zero into
     the opposite comparison against that bit being set in the field.  */

  wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
  if (lcode != wanted_code)
    {
      if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
	{
	  /* Make the left operand unsigned, since we are only interested
	     in the value of one bit.  Otherwise we are doing the wrong
	     thing below.  */
	  ll_unsignedp = 1;
	  l_const = ll_mask;
	}
      else
	return 0;
    }

  /* This is analogous to the code for l_const above.  */
  if (rcode != wanted_code)
    {
      if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
	{
	  rl_unsignedp = 1;
	  r_const = rl_mask;
	}
      else
	return 0;
    }

  /* After this point all optimizations will generate bit-field
     references, which we might not want.  */
  if (! lang_hooks.can_use_bit_fields_p ())
    return 0;

  /* See if we can find a mode that contains both fields being compared on
     the left.  If we can't, fail.  Otherwise, update all constants and masks
     to be relative to a field of that size.  */
  first_bit = MIN (ll_bitpos, rl_bitpos);
  end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
  lnmode = get_best_mode (end_bit - first_bit, first_bit,
			  TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
			  volatilep);
  if (lnmode == VOIDmode)
    return 0;

  lnbitsize = GET_MODE_BITSIZE (lnmode);
  lnbitpos = first_bit & ~ (lnbitsize - 1);
  lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
  xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;

  if (BYTES_BIG_ENDIAN)
    {
      xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
      xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
    }

  ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
			 size_int (xll_bitpos), 0);
  rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
			 size_int (xrl_bitpos), 0);

  if (l_const)
    {
      l_const = fold_convert (lntype, l_const);
      l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
      l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
      if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
					fold_build1 (BIT_NOT_EXPR,
						     lntype, ll_mask),
					0)))
	{
	  warning (0, "comparison is always %d", wanted_code == NE_EXPR);

	  return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
	}
    }
  if (r_const)
    {
      r_const = fold_convert (lntype, r_const);
      r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
      r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
      if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
					fold_build1 (BIT_NOT_EXPR,
						     lntype, rl_mask),
					0)))
	{
	  warning (0, "comparison is always %d", wanted_code == NE_EXPR);

	  return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
	}
    }

  /* If the right sides are not constant, do the same for it.  Also,
     disallow this optimization if a size or signedness mismatch occurs
     between the left and right sides.  */
  if (l_const == 0)
    {
      if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
	  || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
	  /* Make sure the two fields on the right
	     correspond to the left without being swapped.  */
	  || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
	return 0;

      first_bit = MIN (lr_bitpos, rr_bitpos);
      end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
      rnmode = get_best_mode (end_bit - first_bit, first_bit,
			      TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
			      volatilep);
      if (rnmode == VOIDmode)
	return 0;

      rnbitsize = GET_MODE_BITSIZE (rnmode);
      rnbitpos = first_bit & ~ (rnbitsize - 1);
      rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
      xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;

      if (BYTES_BIG_ENDIAN)
	{
	  xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
	  xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
	}

      lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
			     size_int (xlr_bitpos), 0);
      rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
			     size_int (xrr_bitpos), 0);

      /* Make a mask that corresponds to both fields being compared.
	 Do this for both items being compared.  If the operands are the
	 same size and the bits being compared are in the same position
	 then we can do this by masking both and comparing the masked
	 results.  */
      ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
      lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
      if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
	{
	  lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
				    ll_unsignedp || rl_unsignedp);
	  if (! all_ones_mask_p (ll_mask, lnbitsize))
	    lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);

	  rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
				    lr_unsignedp || rr_unsignedp);
	  if (! all_ones_mask_p (lr_mask, rnbitsize))
	    rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);

	  return build2 (wanted_code, truth_type, lhs, rhs);
	}

      /* There is still another way we can do something:  If both pairs of
	 fields being compared are adjacent, we may be able to make a wider
	 field containing them both.

	 Note that we still must mask the lhs/rhs expressions.  Furthermore,
	 the mask must be shifted to account for the shift done by
	 make_bit_field_ref.  */
      if ((ll_bitsize + ll_bitpos == rl_bitpos
	   && lr_bitsize + lr_bitpos == rr_bitpos)
	  || (ll_bitpos == rl_bitpos + rl_bitsize
	      && lr_bitpos == rr_bitpos + rr_bitsize))
	{
	  tree type;

	  lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
				    MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
	  rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
				    MIN (lr_bitpos, rr_bitpos), lr_unsignedp);

	  ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
				 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
	  lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
				 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);

	  /* Convert to the smaller type before masking out unwanted bits.  */
	  type = lntype;
	  if (lntype != rntype)
	    {
	      if (lnbitsize > rnbitsize)
		{
		  lhs = fold_convert (rntype, lhs);
		  ll_mask = fold_convert (rntype, ll_mask);
		  type = rntype;
		}
	      else if (lnbitsize < rnbitsize)
		{
		  rhs = fold_convert (lntype, rhs);
		  lr_mask = fold_convert (lntype, lr_mask);
		  type = lntype;
		}
	    }

	  if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
	    lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);

	  if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
	    rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);

	  return build2 (wanted_code, truth_type, lhs, rhs);
	}

      return 0;
    }

  /* Handle the case of comparisons with constants.  If there is something in
     common between the masks, those bits of the constants must be the same.
     If not, the condition is always false.  Test for this to avoid generating
     incorrect code below.  */
  result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
  if (! integer_zerop (result)
      && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
			   const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
    {
      if (wanted_code == NE_EXPR)
	{
	  warning (0, "%<or%> of unmatched not-equal tests is always 1");
	  return constant_boolean_node (true, truth_type);
	}
      else
	{
	  warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
	  return constant_boolean_node (false, truth_type);
	}
    }

  /* Construct the expression we will return.  First get the component
     reference we will make.  Unless the mask is all ones the width of
     that field, perform the mask operation.  Then compare with the
     merged constant.  */
  result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
			       ll_unsignedp || rl_unsignedp);

  ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
  if (! all_ones_mask_p (ll_mask, lnbitsize))
    result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);

  return build2 (wanted_code, truth_type, result,
		 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
}

/* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
   constant.  */

static tree
optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
{
  tree arg0 = op0;
  enum tree_code op_code;
  tree comp_const = op1;
  tree minmax_const;
  int consts_equal, consts_lt;
  tree inner;

  STRIP_SIGN_NOPS (arg0);

  op_code = TREE_CODE (arg0);
  minmax_const = TREE_OPERAND (arg0, 1);
  consts_equal = tree_int_cst_equal (minmax_const, comp_const);
  consts_lt = tree_int_cst_lt (minmax_const, comp_const);
  inner = TREE_OPERAND (arg0, 0);

  /* If something does not permit us to optimize, return the original tree.  */
  if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
      || TREE_CODE (comp_const) != INTEGER_CST
      || TREE_CONSTANT_OVERFLOW (comp_const)
      || TREE_CODE (minmax_const) != INTEGER_CST
      || TREE_CONSTANT_OVERFLOW (minmax_const))
    return NULL_TREE;

  /* Now handle all the various comparison codes.  We only handle EQ_EXPR
     and GT_EXPR, doing the rest with recursive calls using logical
     simplifications.  */
  switch (code)
    {
    case NE_EXPR:  case LT_EXPR:  case LE_EXPR:
      {
	tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
					  type, op0, op1);
	if (tem)
	  return invert_truthvalue (tem);
	return NULL_TREE;
      }

    case GE_EXPR:
      return
	fold_build2 (TRUTH_ORIF_EXPR, type,
		     optimize_minmax_comparison
		     (EQ_EXPR, type, arg0, comp_const),
		     optimize_minmax_comparison
		     (GT_EXPR, type, arg0, comp_const));

    case EQ_EXPR:
      if (op_code == MAX_EXPR && consts_equal)
	/* MAX (X, 0) == 0  ->  X <= 0  */
	return fold_build2 (LE_EXPR, type, inner, comp_const);

      else if (op_code == MAX_EXPR && consts_lt)
	/* MAX (X, 0) == 5  ->  X == 5   */
	return fold_build2 (EQ_EXPR, type, inner, comp_const);

      else if (op_code == MAX_EXPR)
	/* MAX (X, 0) == -1  ->  false  */
	return omit_one_operand (type, integer_zero_node, inner);

      else if (consts_equal)
	/* MIN (X, 0) == 0  ->  X >= 0  */
	return fold_build2 (GE_EXPR, type, inner, comp_const);

      else if (consts_lt)
	/* MIN (X, 0) == 5  ->  false  */
	return omit_one_operand (type, integer_zero_node, inner);

      else
	/* MIN (X, 0) == -1  ->  X == -1  */
	return fold_build2 (EQ_EXPR, type, inner, comp_const);

    case GT_EXPR:
      if (op_code == MAX_EXPR && (consts_equal || consts_lt))
	/* MAX (X, 0) > 0  ->  X > 0
	   MAX (X, 0) > 5  ->  X > 5  */
	return fold_build2 (GT_EXPR, type, inner, comp_const);

      else if (op_code == MAX_EXPR)
	/* MAX (X, 0) > -1  ->  true  */
	return omit_one_operand (type, integer_one_node, inner);

      else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
	/* MIN (X, 0) > 0  ->  false
	   MIN (X, 0) > 5  ->  false  */
	return omit_one_operand (type, integer_zero_node, inner);

      else
	/* MIN (X, 0) > -1  ->  X > -1  */
	return fold_build2 (GT_EXPR, type, inner, comp_const);

    default:
      return NULL_TREE;
    }
}

/* T is an integer expression that is being multiplied, divided, or taken a
   modulus (CODE says which and what kind of divide or modulus) by a
   constant C.  See if we can eliminate that operation by folding it with
   other operations already in T.  WIDE_TYPE, if non-null, is a type that
   should be used for the computation if wider than our type.

   For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
   (X * 2) + (Y * 4).  We must, however, be assured that either the original
   expression would not overflow or that overflow is undefined for the type
   in the language in question.

   We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
   the machine has a multiply-accumulate insn or that this is part of an
   addressing calculation.

   If we return a non-null expression, it is an equivalent form of the
   original computation, but need not be in the original type.

   We set *STRICT_OVERFLOW_P to true if the return values depends on
   signed overflow being undefined.  Otherwise we do not change
   *STRICT_OVERFLOW_P.  */

static tree
extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
		bool *strict_overflow_p)
{
  /* To avoid exponential search depth, refuse to allow recursion past
     three levels.  Beyond that (1) it's highly unlikely that we'll find
     something interesting and (2) we've probably processed it before
     when we built the inner expression.  */

  static int depth;
  tree ret;

  if (depth > 3)
    return NULL;

  depth++;
  ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
  depth--;

  return ret;
}

static tree
extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
		  bool *strict_overflow_p)
{
  tree type = TREE_TYPE (t);
  enum tree_code tcode = TREE_CODE (t);
  tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
				   > GET_MODE_SIZE (TYPE_MODE (type)))
		? wide_type : type);
  tree t1, t2;
  int same_p = tcode == code;
  tree op0 = NULL_TREE, op1 = NULL_TREE;
  bool sub_strict_overflow_p;

  /* Don't deal with constants of zero here; they confuse the code below.  */
  if (integer_zerop (c))
    return NULL_TREE;

  if (TREE_CODE_CLASS (tcode) == tcc_unary)
    op0 = TREE_OPERAND (t, 0);

  if (TREE_CODE_CLASS (tcode) == tcc_binary)
    op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);

  /* Note that we need not handle conditional operations here since fold
     already handles those cases.  So just do arithmetic here.  */
  switch (tcode)
    {
    case INTEGER_CST:
      /* For a constant, we can always simplify if we are a multiply
	 or (for divide and modulus) if it is a multiple of our constant.  */
      if (code == MULT_EXPR
	  || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
	return const_binop (code, fold_convert (ctype, t),
			    fold_convert (ctype, c), 0);
      break;

    case CONVERT_EXPR:  case NON_LVALUE_EXPR:  case NOP_EXPR:
      /* If op0 is an expression ...  */
      if ((COMPARISON_CLASS_P (op0)
	   || UNARY_CLASS_P (op0)
	   || BINARY_CLASS_P (op0)
	   || EXPRESSION_CLASS_P (op0))
	  /* ... and is unsigned, and its type is smaller than ctype,
	     then we cannot pass through as widening.  */
	  && ((TYPE_UNSIGNED (TREE_TYPE (op0))
	       && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
		     && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
	       && (GET_MODE_SIZE (TYPE_MODE (ctype))
	           > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
	      /* ... or this is a truncation (t is narrower than op0),
		 then we cannot pass through this narrowing.  */
	      || (GET_MODE_SIZE (TYPE_MODE (type))
		  < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
	      /* ... or signedness changes for division or modulus,
		 then we cannot pass through this conversion.  */
	      || (code != MULT_EXPR
		  && (TYPE_UNSIGNED (ctype)
		      != TYPE_UNSIGNED (TREE_TYPE (op0))))))
	break;

      /* Pass the constant down and see if we can make a simplification.  If
	 we can, replace this expression with the inner simplification for
	 possible later conversion to our or some other type.  */
      if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
	  && TREE_CODE (t2) == INTEGER_CST
	  && ! TREE_CONSTANT_OVERFLOW (t2)
	  && (0 != (t1 = extract_muldiv (op0, t2, code,
					 code == MULT_EXPR
					 ? ctype : NULL_TREE,
					 strict_overflow_p))))
	return t1;
      break;

    case ABS_EXPR:
      /* If widening the type changes it from signed to unsigned, then we
         must avoid building ABS_EXPR itself as unsigned.  */
      if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
        {
          tree cstype = (*lang_hooks.types.signed_type) (ctype);
          if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
	      != 0)
            {
              t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
              return fold_convert (ctype, t1);
            }
          break;
        }
      /* If the constant is negative, we cannot simplify this.  */
      if (tree_int_cst_sgn (c) == -1)
	break;
      /* FALLTHROUGH */
    case NEGATE_EXPR:
      if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
	  != 0)
	return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
      break;

    case MIN_EXPR:  case MAX_EXPR:
      /* If widening the type changes the signedness, then we can't perform
	 this optimization as that changes the result.  */
      if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
	break;

      /* MIN (a, b) / 5 -> MIN (a / 5, b / 5)  */
      sub_strict_overflow_p = false;
      if ((t1 = extract_muldiv (op0, c, code, wide_type,
				&sub_strict_overflow_p)) != 0
	  && (t2 = extract_muldiv (op1, c, code, wide_type,
				   &sub_strict_overflow_p)) != 0)
	{
	  if (tree_int_cst_sgn (c) < 0)
	    tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
	  if (sub_strict_overflow_p)
	    *strict_overflow_p = true;
	  return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
			      fold_convert (ctype, t2));
	}
      break;

    case LSHIFT_EXPR:  case RSHIFT_EXPR:
      /* If the second operand is constant, this is a multiplication
	 or floor division, by a power of two, so we can treat it that
	 way unless the multiplier or divisor overflows.  Signed
	 left-shift overflow is implementation-defined rather than
	 undefined in C90, so do not convert signed left shift into
	 multiplication.  */
      if (TREE_CODE (op1) == INTEGER_CST
	  && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
	  /* const_binop may not detect overflow correctly,
	     so check for it explicitly here.  */
	  && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
	  && TREE_INT_CST_HIGH (op1) == 0
	  && 0 != (t1 = fold_convert (ctype,
				      const_binop (LSHIFT_EXPR,
						   size_one_node,
						   op1, 0)))
	  && ! TREE_OVERFLOW (t1))
	return extract_muldiv (build2 (tcode == LSHIFT_EXPR
				       ? MULT_EXPR : FLOOR_DIV_EXPR,
				       ctype, fold_convert (ctype, op0), t1),
			       c, code, wide_type, strict_overflow_p);
      break;

    case PLUS_EXPR:  case MINUS_EXPR:
      /* See if we can eliminate the operation on both sides.  If we can, we
	 can return a new PLUS or MINUS.  If we can't, the only remaining
	 cases where we can do anything are if the second operand is a
	 constant.  */
      sub_strict_overflow_p = false;
      t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
      t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
      if (t1 != 0 && t2 != 0
	  && (code == MULT_EXPR
	      /* If not multiplication, we can only do this if both operands
		 are divisible by c.  */
	      || (multiple_of_p (ctype, op0, c)
	          && multiple_of_p (ctype, op1, c))))
	{
	  if (sub_strict_overflow_p)
	    *strict_overflow_p = true;
	  return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
			      fold_convert (ctype, t2));
	}

      /* If this was a subtraction, negate OP1 and set it to be an addition.
	 This simplifies the logic below.  */
      if (tcode == MINUS_EXPR)
	tcode = PLUS_EXPR, op1 = negate_expr (op1);

      if (TREE_CODE (op1) != INTEGER_CST)
	break;

      /* If either OP1 or C are negative, this optimization is not safe for
	 some of the division and remainder types while for others we need
	 to change the code.  */
      if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
	{
	  if (code == CEIL_DIV_EXPR)
	    code = FLOOR_DIV_EXPR;
	  else if (code == FLOOR_DIV_EXPR)
	    code = CEIL_DIV_EXPR;
	  else if (code != MULT_EXPR
		   && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
	    break;
	}

      /* If it's a multiply or a division/modulus operation of a multiple
         of our constant, do the operation and verify it doesn't overflow.  */
      if (code == MULT_EXPR
	  || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
	{
	  op1 = const_binop (code, fold_convert (ctype, op1),
			     fold_convert (ctype, c), 0);
	  /* We allow the constant to overflow with wrapping semantics.  */
	  if (op1 == 0
	      || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
	    break;
	}
      else
	break;

      /* If we have an unsigned type is not a sizetype, we cannot widen
	 the operation since it will change the result if the original
	 computation overflowed.  */
      if (TYPE_UNSIGNED (ctype)
	  && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
	  && ctype != type)
	break;

      /* If we were able to eliminate our operation from the first side,
	 apply our operation to the second side and reform the PLUS.  */
      if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
	return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);

      /* The last case is if we are a multiply.  In that case, we can
	 apply the distributive law to commute the multiply and addition
	 if the multiplication of the constants doesn't overflow.  */
      if (code == MULT_EXPR)
	return fold_build2 (tcode, ctype,
			    fold_build2 (code, ctype,
					 fold_convert (ctype, op0),
					 fold_convert (ctype, c)),
			    op1);

      break;

    case MULT_EXPR:
      /* We have a special case here if we are doing something like
	 (C * 8) % 4 since we know that's zero.  */
      if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
	   || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
	  && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
	  && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
	return omit_one_operand (type, integer_zero_node, op0);

      /* ... fall through ...  */

    case TRUNC_DIV_EXPR:  case CEIL_DIV_EXPR:  case FLOOR_DIV_EXPR:
    case ROUND_DIV_EXPR:  case EXACT_DIV_EXPR:
      /* If we can extract our operation from the LHS, do so and return a
	 new operation.  Likewise for the RHS from a MULT_EXPR.  Otherwise,
	 do something only if the second operand is a constant.  */
      if (same_p
	  && (t1 = extract_muldiv (op0, c, code, wide_type,
				   strict_overflow_p)) != 0)
	return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
			    fold_convert (ctype, op1));
      else if (tcode == MULT_EXPR && code == MULT_EXPR
	       && (t1 = extract_muldiv (op1, c, code, wide_type,
					strict_overflow_p)) != 0)
	return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
			    fold_convert (ctype, t1));
      else if (TREE_CODE (op1) != INTEGER_CST)
	return 0;

      /* If these are the same operation types, we can associate them
	 assuming no overflow.  */
      if (tcode == code
	  && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
				     fold_convert (ctype, c), 0))
	  && ! TREE_OVERFLOW (t1))
	return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);

      /* If these operations "cancel" each other, we have the main
	 optimizations of this pass, which occur when either constant is a
	 multiple of the other, in which case we replace this with either an
	 operation or CODE or TCODE.

	 If we have an unsigned type that is not a sizetype, we cannot do
	 this since it will change the result if the original computation
	 overflowed.  */
      if ((TYPE_OVERFLOW_UNDEFINED (ctype)
	   || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
	  && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
	      || (tcode == MULT_EXPR
		  && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
		  && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
	{
	  if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
	    {
	      if (TYPE_OVERFLOW_UNDEFINED (ctype))
		*strict_overflow_p = true;
	      return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
				  fold_convert (ctype,
						const_binop (TRUNC_DIV_EXPR,
							     op1, c, 0)));
	    }
	  else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
	    {
	      if (TYPE_OVERFLOW_UNDEFINED (ctype))
		*strict_overflow_p = true;
	      return fold_build2 (code, ctype, fold_convert (ctype, op0),
				  fold_convert (ctype,
						const_binop (TRUNC_DIV_EXPR,
							     c, op1, 0)));
	    }
	}
      break;

    default:
      break;
    }

  return 0;
}

/* Return a node which has the indicated constant VALUE (either 0 or
   1), and is of the indicated TYPE.  */

tree
constant_boolean_node (int value, tree type)
{
  if (type == integer_type_node)
    return value ? integer_one_node : integer_zero_node;
  else if (type == boolean_type_node)
    return value ? boolean_true_node : boolean_false_node;
  else
    return build_int_cst (type, value);
}


/* Return true if expr looks like an ARRAY_REF and set base and
   offset to the appropriate trees.  If there is no offset,
   offset is set to NULL_TREE.  Base will be canonicalized to
   something you can get the element type from using
   TREE_TYPE (TREE_TYPE (base)).  Offset will be the offset
   in bytes to the base.  */

static bool
extract_array_ref (tree expr, tree *base, tree *offset)
{
  /* One canonical form is a PLUS_EXPR with the first
     argument being an ADDR_EXPR with a possible NOP_EXPR
     attached.  */
  if (TREE_CODE (expr) == PLUS_EXPR)
    {
      tree op0 = TREE_OPERAND (expr, 0);
      tree inner_base, dummy1;
      /* Strip NOP_EXPRs here because the C frontends and/or
	 folders present us (int *)&x.a + 4B possibly.  */
      STRIP_NOPS (op0);
      if (extract_array_ref (op0, &inner_base, &dummy1))
	{
	  *base = inner_base;
	  if (dummy1 == NULL_TREE)
	    *offset = TREE_OPERAND (expr, 1);
	  else
	    *offset = fold_build2 (PLUS_EXPR, TREE_TYPE (expr),
				   dummy1, TREE_OPERAND (expr, 1));
	  return true;
	}
    }
  /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
     which we transform into an ADDR_EXPR with appropriate
     offset.  For other arguments to the ADDR_EXPR we assume
     zero offset and as such do not care about the ADDR_EXPR
     type and strip possible nops from it.  */
  else if (TREE_CODE (expr) == ADDR_EXPR)
    {
      tree op0 = TREE_OPERAND (expr, 0);
      if (TREE_CODE (op0) == ARRAY_REF)
	{
	  tree idx = TREE_OPERAND (op0, 1);
	  *base = TREE_OPERAND (op0, 0);
	  *offset = fold_build2 (MULT_EXPR, TREE_TYPE (idx), idx,
				 array_ref_element_size (op0)); 
	}
      else
	{
	  /* Handle array-to-pointer decay as &a.  */
	  if (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE)
	    *base = TREE_OPERAND (expr, 0);
	  else
	    *base = expr;
	  *offset = NULL_TREE;
	}
      return true;
    }
  /* The next canonical form is a VAR_DECL with POINTER_TYPE.  */
  else if (SSA_VAR_P (expr)
	   && TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
    {
      *base = expr;
      *offset = NULL_TREE;
      return true;
    }

  return false;
}


/* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
   Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'.  Here
   CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
   expression, and ARG to `a'.  If COND_FIRST_P is nonzero, then the
   COND is the first argument to CODE; otherwise (as in the example
   given here), it is the second argument.  TYPE is the type of the
   original expression.  Return NULL_TREE if no simplification is
   possible.  */

static tree
fold_binary_op_with_conditional_arg (enum tree_code code,
				     tree type, tree op0, tree op1,
				     tree cond, tree arg, int cond_first_p)
{
  tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
  tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
  tree test, true_value, false_value;
  tree lhs = NULL_TREE;
  tree rhs = NULL_TREE;

  /* This transformation is only worthwhile if we don't have to wrap
     arg in a SAVE_EXPR, and the operation can be simplified on at least
     one of the branches once its pushed inside the COND_EXPR.  */
  if (!TREE_CONSTANT (arg))
    return NULL_TREE;

  if (TREE_CODE (cond) == COND_EXPR)
    {
      test = TREE_OPERAND (cond, 0);
      true_value = TREE_OPERAND (cond, 1);
      false_value = TREE_OPERAND (cond, 2);
      /* If this operand throws an expression, then it does not make
	 sense to try to perform a logical or arithmetic operation
	 involving it.  */
      if (VOID_TYPE_P (TREE_TYPE (true_value)))
	lhs = true_value;
      if (VOID_TYPE_P (TREE_TYPE (false_value)))
	rhs = false_value;
    }
  else
    {
      tree testtype = TREE_TYPE (cond);
      test = cond;
      true_value = constant_boolean_node (true, testtype);
      false_value = constant_boolean_node (false, testtype);
    }

  arg = fold_convert (arg_type, arg);
  if (lhs == 0)
    {
      true_value = fold_convert (cond_type, true_value);
      if (cond_first_p)
	lhs = fold_build2 (code, type, true_value, arg);
      else
	lhs = fold_build2 (code, type, arg, true_value);
    }
  if (rhs == 0)
    {
      false_value = fold_convert (cond_type, false_value);
      if (cond_first_p)
	rhs = fold_build2 (code, type, false_value, arg);
      else
	rhs = fold_build2 (code, type, arg, false_value);
    }

  test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
  return fold_convert (type, test);
}


/* Subroutine of fold() that checks for the addition of +/- 0.0.

   If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
   TYPE, X + ADDEND is the same as X.  If NEGATE, return true if X -
   ADDEND is the same as X.

   X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
   and finite.  The problematic cases are when X is zero, and its mode
   has signed zeros.  In the case of rounding towards -infinity,
   X - 0 is not the same as X because 0 - 0 is -0.  In other rounding
   modes, X + 0 is not the same as X because -0 + 0 is 0.  */

static bool
fold_real_zero_addition_p (tree type, tree addend, int negate)
{
  if (!real_zerop (addend))
    return false;

  /* Don't allow the fold with -fsignaling-nans.  */
  if (HONOR_SNANS (TYPE_MODE (type)))
    return false;

  /* Allow the fold if zeros aren't signed, or their sign isn't important.  */
  if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
    return true;

  /* Treat x + -0 as x - 0 and x - -0 as x + 0.  */
  if (TREE_CODE (addend) == REAL_CST
      && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
    negate = !negate;

  /* The mode has signed zeros, and we have to honor their sign.
     In this situation, there is only one case we can return true for.
     X - 0 is the same as X unless rounding towards -infinity is
     supported.  */
  return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
}

/* Subroutine of fold() that checks comparisons of built-in math
   functions against real constants.

   FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
   operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR.  TYPE
   is the type of the result and ARG0 and ARG1 are the operands of the
   comparison.  ARG1 must be a TREE_REAL_CST.

   The function returns the constant folded tree if a simplification
   can be made, and NULL_TREE otherwise.  */

static tree
fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
		     tree type, tree arg0, tree arg1)
{
  REAL_VALUE_TYPE c;

  if (BUILTIN_SQRT_P (fcode))
    {
      tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
      enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));

      c = TREE_REAL_CST (arg1);
      if (REAL_VALUE_NEGATIVE (c))
	{
	  /* sqrt(x) < y is always false, if y is negative.  */
	  if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
	    return omit_one_operand (type, integer_zero_node, arg);

	  /* sqrt(x) > y is always true, if y is negative and we
	     don't care about NaNs, i.e. negative values of x.  */
	  if (code == NE_EXPR || !HONOR_NANS (mode))
	    return omit_one_operand (type, integer_one_node, arg);

	  /* sqrt(x) > y is the same as x >= 0, if y is negative.  */
	  return fold_build2 (GE_EXPR, type, arg,
			      build_real (TREE_TYPE (arg), dconst0));
	}
      else if (code == GT_EXPR || code == GE_EXPR)
	{
	  REAL_VALUE_TYPE c2;

	  REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
	  real_convert (&c2, mode, &c2);

	  if (REAL_VALUE_ISINF (c2))
	    {
	      /* sqrt(x) > y is x == +Inf, when y is very large.  */
	      if (HONOR_INFINITIES (mode))
		return fold_build2 (EQ_EXPR, type, arg,
				    build_real (TREE_TYPE (arg), c2));

	      /* sqrt(x) > y is always false, when y is very large
		 and we don't care about infinities.  */
	      return omit_one_operand (type, integer_zero_node, arg);
	    }

	  /* sqrt(x) > c is the same as x > c*c.  */
	  return fold_build2 (code, type, arg,
			      build_real (TREE_TYPE (arg), c2));
	}
      else if (code == LT_EXPR || code == LE_EXPR)
	{
	  REAL_VALUE_TYPE c2;

	  REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
	  real_convert (&c2, mode, &c2);

	  if (REAL_VALUE_ISINF (c2))
	    {
	      /* sqrt(x) < y is always true, when y is a very large
		 value and we don't care about NaNs or Infinities.  */
	      if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
		return omit_one_operand (type, integer_one_node, arg);

	      /* sqrt(x) < y is x != +Inf when y is very large and we
		 don't care about NaNs.  */
	      if (! HONOR_NANS (mode))
		return fold_build2 (NE_EXPR, type, arg,
				    build_real (TREE_TYPE (arg), c2));

	      /* sqrt(x) < y is x >= 0 when y is very large and we
		 don't care about Infinities.  */
	      if (! HONOR_INFINITIES (mode))
		return fold_build2 (GE_EXPR, type, arg,
				    build_real (TREE_TYPE (arg), dconst0));

	      /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large.  */
	      if (lang_hooks.decls.global_bindings_p () != 0
		  || CONTAINS_PLACEHOLDER_P (arg))
		return NULL_TREE;

	      arg = save_expr (arg);
	      return fold_build2 (TRUTH_ANDIF_EXPR, type,
				  fold_build2 (GE_EXPR, type, arg,
					       build_real (TREE_TYPE (arg),
							   dconst0)),
				  fold_build2 (NE_EXPR, type, arg,
					       build_real (TREE_TYPE (arg),
							   c2)));
	    }

	  /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs.  */
	  if (! HONOR_NANS (mode))
	    return fold_build2 (code, type, arg,
				build_real (TREE_TYPE (arg), c2));

	  /* sqrt(x) < c is the same as x >= 0 && x < c*c.  */
	  if (lang_hooks.decls.global_bindings_p () == 0
	      && ! CONTAINS_PLACEHOLDER_P (arg))
	    {
	      arg = save_expr (arg);
	      return fold_build2 (TRUTH_ANDIF_EXPR, type,
				  fold_build2 (GE_EXPR, type, arg,
					       build_real (TREE_TYPE (arg),
							   dconst0)),
				  fold_build2 (code, type, arg,
					       build_real (TREE_TYPE (arg),
							   c2)));
	    }
	}
    }

  return NULL_TREE;
}

/* Subroutine of fold() that optimizes comparisons against Infinities,
   either +Inf or -Inf.

   CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
   GE_EXPR or LE_EXPR.  TYPE is the type of the result and ARG0 and ARG1
   are the operands of the comparison.  ARG1 must be a TREE_REAL_CST.

   The function returns the constant folded tree if a simplification
   can be made, and NULL_TREE otherwise.  */

static tree
fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
{
  enum machine_mode mode;
  REAL_VALUE_TYPE max;
  tree temp;
  bool neg;

  mode = TYPE_MODE (TREE_TYPE (arg0));

  /* For negative infinity swap the sense of the comparison.  */
  neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
  if (neg)
    code = swap_tree_comparison (code);

  switch (code)
    {
    case GT_EXPR:
      /* x > +Inf is always false, if with ignore sNANs.  */
      if (HONOR_SNANS (mode))
        return NULL_TREE;
      return omit_one_operand (type, integer_zero_node, arg0);

    case LE_EXPR:
      /* x <= +Inf is always true, if we don't case about NaNs.  */
      if (! HONOR_NANS (mode))
	return omit_one_operand (type, integer_one_node, arg0);

      /* x <= +Inf is the same as x == x, i.e. isfinite(x).  */
      if (lang_hooks.decls.global_bindings_p () == 0
	  && ! CONTAINS_PLACEHOLDER_P (arg0))
	{
	  arg0 = save_expr (arg0);
	  return fold_build2 (EQ_EXPR, type, arg0, arg0);
	}
      break;

    case EQ_EXPR:
    case GE_EXPR:
      /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX.  */
      real_maxval (&max, neg, mode);
      return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
			  arg0, build_real (TREE_TYPE (arg0), max));

    case LT_EXPR:
      /* x < +Inf is always equal to x <= DBL_MAX.  */
      real_maxval (&max, neg, mode);
      return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
			  arg0, build_real (TREE_TYPE (arg0), max));

    case NE_EXPR:
      /* x != +Inf is always equal to !(x > DBL_MAX).  */
      real_maxval (&max, neg, mode);
      if (! HONOR_NANS (mode))
	return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
			    arg0, build_real (TREE_TYPE (arg0), max));

      /* The transformation below creates non-gimple code and thus is
	 not appropriate if we are in gimple form.  */
      if (in_gimple_form)
	return NULL_TREE;

      temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
			  arg0, build_real (TREE_TYPE (arg0), max));
      return fold_build1 (TRUTH_NOT_EXPR, type, temp);

    default:
      break;
    }

  return NULL_TREE;
}

/* Subroutine of fold() that optimizes comparisons of a division by
   a nonzero integer constant against an integer constant, i.e.
   X/C1 op C2.

   CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
   GE_EXPR or LE_EXPR.  TYPE is the type of the result and ARG0 and ARG1
   are the operands of the comparison.  ARG1 must be a TREE_REAL_CST.

   The function returns the constant folded tree if a simplification
   can be made, and NULL_TREE otherwise.  */

static tree
fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
{
  tree prod, tmp, hi, lo;
  tree arg00 = TREE_OPERAND (arg0, 0);
  tree arg01 = TREE_OPERAND (arg0, 1);
  unsigned HOST_WIDE_INT lpart;
  HOST_WIDE_INT hpart;
  bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
  bool neg_overflow;
  int overflow;

  /* We have to do this the hard way to detect unsigned overflow.
     prod = int_const_binop (MULT_EXPR, arg01, arg1, 0);  */
  overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
				   TREE_INT_CST_HIGH (arg01),
				   TREE_INT_CST_LOW (arg1),
				   TREE_INT_CST_HIGH (arg1),
				   &lpart, &hpart, unsigned_p);
  prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
  prod = force_fit_type (prod, -1, overflow, false);
  neg_overflow = false;

  if (unsigned_p)
    {
      tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
      lo = prod;

      /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0).  */
      overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
				       TREE_INT_CST_HIGH (prod),
				       TREE_INT_CST_LOW (tmp),
				       TREE_INT_CST_HIGH (tmp),
				       &lpart, &hpart, unsigned_p);
      hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
      hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
			   TREE_CONSTANT_OVERFLOW (prod));
    }
  else if (tree_int_cst_sgn (arg01) >= 0)
    {
      tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
      switch (tree_int_cst_sgn (arg1))
	{
	case -1:
	  neg_overflow = true;
	  lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
	  hi = prod;
	  break;

	case  0:
	  lo = fold_negate_const (tmp, TREE_TYPE (arg0));
	  hi = tmp;
	  break;

	case  1:
          hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
	  lo = prod;
	  break;

	default:
	  gcc_unreachable ();
	}
    }
  else
    {
      /* A negative divisor reverses the relational operators.  */
      code = swap_tree_comparison (code);

      tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
      switch (tree_int_cst_sgn (arg1))
	{
	case -1:
	  hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
	  lo = prod;
	  break;

	case  0:
	  hi = fold_negate_const (tmp, TREE_TYPE (arg0));
	  lo = tmp;
	  break;

	case  1:
	  neg_overflow = true;
	  lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
	  hi = prod;
	  break;

	default:
	  gcc_unreachable ();
	}
    }

  switch (code)
    {
    case EQ_EXPR:
      if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
	return omit_one_operand (type, integer_zero_node, arg00);
      if (TREE_OVERFLOW (hi))
	return fold_build2 (GE_EXPR, type, arg00, lo);
      if (TREE_OVERFLOW (lo))
	return fold_build2 (LE_EXPR, type, arg00, hi);
      return build_range_check (type, arg00, 1, lo, hi);

    case NE_EXPR:
      if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
	return omit_one_operand (type, integer_one_node, arg00);
      if (TREE_OVERFLOW (hi))
	return fold_build2 (LT_EXPR, type, arg00, lo);
      if (TREE_OVERFLOW (lo))
	return fold_build2 (GT_EXPR, type, arg00, hi);
      return build_range_check (type, arg00, 0, lo, hi);

    case LT_EXPR:
      if (TREE_OVERFLOW (lo))
	{
	  tmp = neg_overflow ? integer_zero_node : integer_one_node;
	  return omit_one_operand (type, tmp, arg00);
	}
      return fold_build2 (LT_EXPR, type, arg00, lo);

    case LE_EXPR:
      if (TREE_OVERFLOW (hi))
	{
	  tmp = neg_overflow ? integer_zero_node : integer_one_node;
	  return omit_one_operand (type, tmp, arg00);
	}
      return fold_build2 (LE_EXPR, type, arg00, hi);

    case GT_EXPR:
      if (TREE_OVERFLOW (hi))
	{
	  tmp = neg_overflow ? integer_one_node : integer_zero_node;
	  return omit_one_operand (type, tmp, arg00);
	}
      return fold_build2 (GT_EXPR, type, arg00, hi);

    case GE_EXPR:
      if (TREE_OVERFLOW (lo))
	{
	  tmp = neg_overflow ? integer_one_node : integer_zero_node;
	  return omit_one_operand (type, tmp, arg00);
	}
      return fold_build2 (GE_EXPR, type, arg00, lo);

    default:
      break;
    }

  return NULL_TREE;
}


/* If CODE with arguments ARG0 and ARG1 represents a single bit
   equality/inequality test, then return a simplified form of the test
   using a sign testing.  Otherwise return NULL.  TYPE is the desired
   result type.  */

static tree
fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
				     tree result_type)
{
  /* If this is testing a single bit, we can optimize the test.  */
  if ((code == NE_EXPR || code == EQ_EXPR)
      && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
      && integer_pow2p (TREE_OPERAND (arg0, 1)))
    {
      /* If we have (A & C) != 0 where C is the sign bit of A, convert
	 this into A < 0.  Similarly for (A & C) == 0 into A >= 0.  */
      tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));

      if (arg00 != NULL_TREE
	  /* This is only a win if casting to a signed type is cheap,
	     i.e. when arg00's type is not a partial mode.  */
	  && TYPE_PRECISION (TREE_TYPE (arg00))
	     == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
	{
	  tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
	  return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
			      result_type, fold_convert (stype, arg00),
			      build_int_cst (stype, 0));
	}
    }

  return NULL_TREE;
}

/* If CODE with arguments ARG0 and ARG1 represents a single bit
   equality/inequality test, then return a simplified form of
   the test using shifts and logical operations.  Otherwise return
   NULL.  TYPE is the desired result type.  */

tree
fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
		      tree result_type)
{
  /* If this is testing a single bit, we can optimize the test.  */
  if ((code == NE_EXPR || code == EQ_EXPR)
      && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
      && integer_pow2p (TREE_OPERAND (arg0, 1)))
    {
      tree inner = TREE_OPERAND (arg0, 0);
      tree type = TREE_TYPE (arg0);
      int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
      enum machine_mode operand_mode = TYPE_MODE (type);
      int ops_unsigned;
      tree signed_type, unsigned_type, intermediate_type;
      tree tem;

      /* First, see if we can fold the single bit test into a sign-bit
	 test.  */
      tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
						 result_type);
      if (tem)
	return tem;

      /* Otherwise we have (A & C) != 0 where C is a single bit,
	 convert that into ((A >> C2) & 1).  Where C2 = log2(C).
	 Similarly for (A & C) == 0.  */

      /* If INNER is a right shift of a constant and it plus BITNUM does
	 not overflow, adjust BITNUM and INNER.  */
      if (TREE_CODE (inner) == RSHIFT_EXPR
	  && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
	  && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
	  && bitnum < TYPE_PRECISION (type)
	  && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
				   bitnum - TYPE_PRECISION (type)))
	{
	  bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
	  inner = TREE_OPERAND (inner, 0);
	}

      /* If we are going to be able to omit the AND below, we must do our
	 operations as unsigned.  If we must use the AND, we have a choice.
	 Normally unsigned is faster, but for some machines signed is.  */
#ifdef LOAD_EXTEND_OP
      ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND 
		      && !flag_syntax_only) ? 0 : 1;
#else
      ops_unsigned = 1;
#endif

      signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
      unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
      intermediate_type = ops_unsigned ? unsigned_type : signed_type;
      inner = fold_convert (intermediate_type, inner);

      if (bitnum != 0)
	inner = build2 (RSHIFT_EXPR, intermediate_type,
			inner, size_int (bitnum));

      if (code == EQ_EXPR)
	inner = fold_build2 (BIT_XOR_EXPR, intermediate_type,
			     inner, integer_one_node);

      /* Put the AND last so it can combine with more things.  */
      inner = build2 (BIT_AND_EXPR, intermediate_type,
		      inner, integer_one_node);

      /* Make sure to return the proper type.  */
      inner = fold_convert (result_type, inner);

      return inner;
    }
  return NULL_TREE;
}

/* Check whether we are allowed to reorder operands arg0 and arg1,
   such that the evaluation of arg1 occurs before arg0.  */

static bool
reorder_operands_p (tree arg0, tree arg1)
{
  if (! flag_evaluation_order)
      return true;
  if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
    return true;
  return ! TREE_SIDE_EFFECTS (arg0)
	 && ! TREE_SIDE_EFFECTS (arg1);
}

/* Test whether it is preferable two swap two operands, ARG0 and
   ARG1, for example because ARG0 is an integer constant and ARG1
   isn't.  If REORDER is true, only recommend swapping if we can
   evaluate the operands in reverse order.  */

bool
tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
{
  STRIP_SIGN_NOPS (arg0);
  STRIP_SIGN_NOPS (arg1);

  if (TREE_CODE (arg1) == INTEGER_CST)
    return 0;
  if (TREE_CODE (arg0) == INTEGER_CST)
    return 1;

  if (TREE_CODE (arg1) == REAL_CST)
    return 0;
  if (TREE_CODE (arg0) == REAL_CST)
    return 1;

  if (TREE_CODE (arg1) == COMPLEX_CST)
    return 0;
  if (TREE_CODE (arg0) == COMPLEX_CST)
    return 1;

  if (TREE_CONSTANT (arg1))
    return 0;
  if (TREE_CONSTANT (arg0))
    return 1;

  if (optimize_size)
    return 0;

  if (reorder && flag_evaluation_order
      && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
    return 0;

  if (DECL_P (arg1))
    return 0;
  if (DECL_P (arg0))
    return 1;

  /* It is preferable to swap two SSA_NAME to ensure a canonical form
     for commutative and comparison operators.  Ensuring a canonical
     form allows the optimizers to find additional redundancies without
     having to explicitly check for both orderings.  */
  if (TREE_CODE (arg0) == SSA_NAME
      && TREE_CODE (arg1) == SSA_NAME
      && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
    return 1;

  return 0;
}

/* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
   ARG0 is extended to a wider type.  */

static tree
fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
{
  tree arg0_unw = get_unwidened (arg0, NULL_TREE);
  tree arg1_unw;
  tree shorter_type, outer_type;
  tree min, max;
  bool above, below;

  if (arg0_unw == arg0)
    return NULL_TREE;
  shorter_type = TREE_TYPE (arg0_unw);

#ifdef HAVE_canonicalize_funcptr_for_compare
  /* Disable this optimization if we're casting a function pointer
     type on targets that require function pointer canonicalization.  */
  if (HAVE_canonicalize_funcptr_for_compare
      && TREE_CODE (shorter_type) == POINTER_TYPE
      && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
    return NULL_TREE;
#endif

  if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
    return NULL_TREE;

  arg1_unw = get_unwidened (arg1, NULL_TREE);

  /* If possible, express the comparison in the shorter mode.  */
  if ((code == EQ_EXPR || code == NE_EXPR
       || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
      && (TREE_TYPE (arg1_unw) == shorter_type
	  || (TYPE_PRECISION (shorter_type)
	      >= TYPE_PRECISION (TREE_TYPE (arg1_unw)))
	  || (TREE_CODE (arg1_unw) == INTEGER_CST
	      && (TREE_CODE (shorter_type) == INTEGER_TYPE
		  || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
	      && int_fits_type_p (arg1_unw, shorter_type))))
    return fold_build2 (code, type, arg0_unw,
		       fold_convert (shorter_type, arg1_unw));

  if (TREE_CODE (arg1_unw) != INTEGER_CST
      || TREE_CODE (shorter_type) != INTEGER_TYPE
      || !int_fits_type_p (arg1_unw, shorter_type))
    return NULL_TREE;

  /* If we are comparing with the integer that does not fit into the range
     of the shorter type, the result is known.  */
  outer_type = TREE_TYPE (arg1_unw);
  min = lower_bound_in_type (outer_type, shorter_type);
  max = upper_bound_in_type (outer_type, shorter_type);

  above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
						   max, arg1_unw));
  below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
						   arg1_unw, min));

  switch (code)
    {
    case EQ_EXPR:
      if (above || below)
	return omit_one_operand (type, integer_zero_node, arg0);
      break;

    case NE_EXPR:
      if (above || below)
	return omit_one_operand (type, integer_one_node, arg0);
      break;

    case LT_EXPR:
    case LE_EXPR:
      if (above)
	return omit_one_operand (type, integer_one_node, arg0);
      else if (below)
	return omit_one_operand (type, integer_zero_node, arg0);

    case GT_EXPR:
    case GE_EXPR:
      if (above)
	return omit_one_operand (type, integer_zero_node, arg0);
      else if (below)
	return omit_one_operand (type, integer_one_node, arg0);

    default:
      break;
    }

  return NULL_TREE;
}

/* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
   ARG0 just the signedness is changed.  */

static tree
fold_sign_changed_comparison (enum tree_code code, tree type,
			      tree arg0, tree arg1)
{
  tree arg0_inner, tmp;
  tree inner_type, outer_type;

  if (TREE_CODE (arg0) != NOP_EXPR
      && TREE_CODE (arg0) != CONVERT_EXPR)
    return NULL_TREE;

  outer_type = TREE_TYPE (arg0);
  arg0_inner = TREE_OPERAND (arg0, 0);
  inner_type = TREE_TYPE (arg0_inner);

#ifdef HAVE_canonicalize_funcptr_for_compare
  /* Disable this optimization if we're casting a function pointer
     type on targets that require function pointer canonicalization.  */
  if (HAVE_canonicalize_funcptr_for_compare
      && TREE_CODE (inner_type) == POINTER_TYPE
      && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
    return NULL_TREE;
#endif

  if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
    return NULL_TREE;

  if (TREE_CODE (arg1) != INTEGER_CST
      && !((TREE_CODE (arg1) == NOP_EXPR
	    || TREE_CODE (arg1) == CONVERT_EXPR)
	   && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
    return NULL_TREE;

  if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
      && code != NE_EXPR
      && code != EQ_EXPR)
    return NULL_TREE;

  if (TREE_CODE (arg1) == INTEGER_CST)
    {
      tmp = build_int_cst_wide (inner_type,
				TREE_INT_CST_LOW (arg1),
				TREE_INT_CST_HIGH (arg1));
      arg1 = force_fit_type (tmp, 0,
			     TREE_OVERFLOW (arg1),
			     TREE_CONSTANT_OVERFLOW (arg1));
    }
  else
    arg1 = fold_convert (inner_type, arg1);

  return fold_build2 (code, type, arg0_inner, arg1);
}

/* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
   step of the array.  Reconstructs s and delta in the case of s * delta
   being an integer constant (and thus already folded).
   ADDR is the address. MULT is the multiplicative expression.
   If the function succeeds, the new address expression is returned.  Otherwise
   NULL_TREE is returned.  */

static tree
try_move_mult_to_index (enum tree_code code, tree addr, tree op1)
{
  tree s, delta, step;
  tree ref = TREE_OPERAND (addr, 0), pref;
  tree ret, pos;
  tree itype;

  /* Canonicalize op1 into a possibly non-constant delta
     and an INTEGER_CST s.  */
  if (TREE_CODE (op1) == MULT_EXPR)
    {
      tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);

      STRIP_NOPS (arg0);
      STRIP_NOPS (arg1);
  
      if (TREE_CODE (arg0) == INTEGER_CST)
        {
          s = arg0;
          delta = arg1;
        }
      else if (TREE_CODE (arg1) == INTEGER_CST)
        {
          s = arg1;
          delta = arg0;
        }
      else
        return NULL_TREE;
    }
  else if (TREE_CODE (op1) == INTEGER_CST)
    {
      delta = op1;
      s = NULL_TREE;
    }
  else
    {
      /* Simulate we are delta * 1.  */
      delta = op1;
      s = integer_one_node;
    }

  for (;; ref = TREE_OPERAND (ref, 0))
    {
      if (TREE_CODE (ref) == ARRAY_REF)
	{
	  itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
	  if (! itype)
	    continue;

	  step = array_ref_element_size (ref);
	  if (TREE_CODE (step) != INTEGER_CST)
	    continue;

	  if (s)
	    {
	      if (! tree_int_cst_equal (step, s))
                continue;
	    }
	  else
	    {
	      /* Try if delta is a multiple of step.  */
	      tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
	      if (! tmp)
		continue;
	      delta = tmp;
	    }

	  break;
	}

      if (!handled_component_p (ref))
	return NULL_TREE;
    }

  /* We found the suitable array reference.  So copy everything up to it,
     and replace the index.  */

  pref = TREE_OPERAND (addr, 0);
  ret = copy_node (pref);
  pos = ret;

  while (pref != ref)
    {
      pref = TREE_OPERAND (pref, 0);
      TREE_OPERAND (pos, 0) = copy_node (pref);
      pos = TREE_OPERAND (pos, 0);
    }

  TREE_OPERAND (pos, 1) = fold_build2 (code, itype,
				       fold_convert (itype,
						     TREE_OPERAND (pos, 1)),
				       fold_convert (itype, delta));

  return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
}


/* Fold A < X && A + 1 > Y to A < X && A >= Y.  Normally A + 1 > Y
   means A >= Y && A != MAX, but in this case we know that
   A < X <= MAX.  INEQ is A + 1 > Y, BOUND is A < X.  */

static tree
fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
{
  tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;

  if (TREE_CODE (bound) == LT_EXPR)
    a = TREE_OPERAND (bound, 0);
  else if (TREE_CODE (bound) == GT_EXPR)
    a = TREE_OPERAND (bound, 1);
  else
    return NULL_TREE;

  typea = TREE_TYPE (a);
  if (!INTEGRAL_TYPE_P (typea)
      && !POINTER_TYPE_P (typea))
    return NULL_TREE;

  if (TREE_CODE (ineq) == LT_EXPR)
    {
      a1 = TREE_OPERAND (ineq, 1);
      y = TREE_OPERAND (ineq, 0);
    }
  else if (TREE_CODE (ineq) == GT_EXPR)
    {
      a1 = TREE_OPERAND (ineq, 0);
      y = TREE_OPERAND (ineq, 1);
    }
  else
    return NULL_TREE;

  if (TREE_TYPE (a1) != typea)
    return NULL_TREE;

  diff = fold_build2 (MINUS_EXPR, typea, a1, a);
  if (!integer_onep (diff))
    return NULL_TREE;

  return fold_build2 (GE_EXPR, type, a, y);
}

/* Fold a sum or difference of at least one multiplication.
   Returns the folded tree or NULL if no simplification could be made.  */

static tree
fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
{
  tree arg00, arg01, arg10, arg11;
  tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;

  /* (A * C) +- (B * C) -> (A+-B) * C.
     (A * C) +- A -> A * (C+-1).
     We are most concerned about the case where C is a constant,
     but other combinations show up during loop reduction.  Since
     it is not difficult, try all four possibilities.  */

  if (TREE_CODE (arg0) == MULT_EXPR)
    {
      arg00 = TREE_OPERAND (arg0, 0);
      arg01 = TREE_OPERAND (arg0, 1);
    }
  else
    {
      arg00 = arg0;
      arg01 = build_one_cst (type);
    }
  if (TREE_CODE (arg1) == MULT_EXPR)
    {
      arg10 = TREE_OPERAND (arg1, 0);
      arg11 = TREE_OPERAND (arg1, 1);
    }
  else
    {
      arg10 = arg1;
      arg11 = build_one_cst (type);
    }
  same = NULL_TREE;

  if (operand_equal_p (arg01, arg11, 0))
    same = arg01, alt0 = arg00, alt1 = arg10;
  else if (operand_equal_p (arg00, arg10, 0))
    same = arg00, alt0 = arg01, alt1 = arg11;
  else if (operand_equal_p (arg00, arg11, 0))
    same = arg00, alt0 = arg01, alt1 = arg10;
  else if (operand_equal_p (arg01, arg10, 0))
    same = arg01, alt0 = arg00, alt1 = arg11;

  /* No identical multiplicands; see if we can find a common
     power-of-two factor in non-power-of-two multiplies.  This
     can help in multi-dimensional array access.  */
  else if (host_integerp (arg01, 0)
	   && host_integerp (arg11, 0))
    {
      HOST_WIDE_INT int01, int11, tmp;
      bool swap = false;
      tree maybe_same;
      int01 = TREE_INT_CST_LOW (arg01);
      int11 = TREE_INT_CST_LOW (arg11);

      /* Move min of absolute values to int11.  */
      if ((int01 >= 0 ? int01 : -int01)
	  < (int11 >= 0 ? int11 : -int11))
        {
	  tmp = int01, int01 = int11, int11 = tmp;
	  alt0 = arg00, arg00 = arg10, arg10 = alt0;
	  maybe_same = arg01;
	  swap = true;
	}
      else
	maybe_same = arg11;

      if (exact_log2 (int11) > 0 && int01 % int11 == 0)
        {
	  alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
			      build_int_cst (TREE_TYPE (arg00),
					     int01 / int11));
	  alt1 = arg10;
	  same = maybe_same;
	  if (swap)
	    maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
	}
    }

  if (same)
    return fold_build2 (MULT_EXPR, type,
			fold_build2 (code, type,
				     fold_convert (type, alt0),
				     fold_convert (type, alt1)),
			fold_convert (type, same));

  return NULL_TREE;
}

/* Subroutine of native_encode_expr.  Encode the INTEGER_CST
   specified by EXPR into the buffer PTR of length LEN bytes.
   Return the number of bytes placed in the buffer, or zero
   upon failure.  */

static int
native_encode_int (tree expr, unsigned char *ptr, int len)
{
  tree type = TREE_TYPE (expr);
  int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
  int byte, offset, word, words;
  unsigned char value;

  if (total_bytes > len)
    return 0;
  words = total_bytes / UNITS_PER_WORD;

  for (byte = 0; byte < total_bytes; byte++)
    {
      int bitpos = byte * BITS_PER_UNIT;
      if (bitpos < HOST_BITS_PER_WIDE_INT)
	value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
      else
	value = (unsigned char) (TREE_INT_CST_HIGH (expr)
				 >> (bitpos - HOST_BITS_PER_WIDE_INT));

      if (total_bytes > UNITS_PER_WORD)
	{
	  word = byte / UNITS_PER_WORD;
	  if (WORDS_BIG_ENDIAN)
	    word = (words - 1) - word;
	  offset = word * UNITS_PER_WORD;
	  if (BYTES_BIG_ENDIAN)
	    offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
	  else
	    offset += byte % UNITS_PER_WORD;
	}
      else
	offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
      ptr[offset] = value;
    }
  return total_bytes;
}


/* Subroutine of native_encode_expr.  Encode the REAL_CST
   specified by EXPR into the buffer PTR of length LEN bytes.
   Return the number of bytes placed in the buffer, or zero
   upon failure.  */

static int
native_encode_real (tree expr, unsigned char *ptr, int len)
{
  tree type = TREE_TYPE (expr);
  int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
  int byte, offset, word, words, bitpos;
  unsigned char value;

  /* There are always 32 bits in each long, no matter the size of
     the hosts long.  We handle floating point representations with
     up to 192 bits.  */
  long tmp[6];

  if (total_bytes > len)
    return 0;
  words = 32 / UNITS_PER_WORD;

  real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));

  for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
       bitpos += BITS_PER_UNIT)
    {
      byte = (bitpos / BITS_PER_UNIT) & 3;
      value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));

      if (UNITS_PER_WORD < 4)
	{
	  word = byte / UNITS_PER_WORD;
	  if (WORDS_BIG_ENDIAN)
	    word = (words - 1) - word;
	  offset = word * UNITS_PER_WORD;
	  if (BYTES_BIG_ENDIAN)
	    offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
	  else
	    offset += byte % UNITS_PER_WORD;
	}
      else
	offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
      ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
    }
  return total_bytes;
}

/* Subroutine of native_encode_expr.  Encode the COMPLEX_CST
   specified by EXPR into the buffer PTR of length LEN bytes.
   Return the number of bytes placed in the buffer, or zero
   upon failure.  */

static int
native_encode_complex (tree expr, unsigned char *ptr, int len)
{
  int rsize, isize;
  tree part;

  part = TREE_REALPART (expr);
  rsize = native_encode_expr (part, ptr, len);
  if (rsize == 0)
    return 0;
  part = TREE_IMAGPART (expr);
  isize = native_encode_expr (part, ptr+rsize, len-rsize);
  if (isize != rsize)
    return 0;
  return rsize + isize;
}


/* Subroutine of native_encode_expr.  Encode the VECTOR_CST
   specified by EXPR into the buffer PTR of length LEN bytes.
   Return the number of bytes placed in the buffer, or zero
   upon failure.  */

static int
native_encode_vector (tree expr, unsigned char *ptr, int len)
{
  int i, size, offset, count;
  tree itype, elem, elements;

  offset = 0;
  elements = TREE_VECTOR_CST_ELTS (expr);
  count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
  itype = TREE_TYPE (TREE_TYPE (expr));
  size = GET_MODE_SIZE (TYPE_MODE (itype));
  for (i = 0; i < count; i++)
    {
      if (elements)
	{
	  elem = TREE_VALUE (elements);
	  elements = TREE_CHAIN (elements);
	}
      else
	elem = NULL_TREE;

      if (elem)
	{
	  if (native_encode_expr (elem, ptr+offset, len-offset) != size)
	    return 0;
	}
      else
	{
	  if (offset + size > len)
	    return 0;
	  memset (ptr+offset, 0, size);
	}
      offset += size;
    }
  return offset;
}


/* Subroutine of fold_view_convert_expr.  Encode the INTEGER_CST,
   REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
   buffer PTR of length LEN bytes.  Return the number of bytes
   placed in the buffer, or zero upon failure.  */

static int
native_encode_expr (tree expr, unsigned char *ptr, int len)
{
  switch (TREE_CODE (expr))
    {
    case INTEGER_CST:
      return native_encode_int (expr, ptr, len);

    case REAL_CST:
      return native_encode_real (expr, ptr, len);

    case COMPLEX_CST:
      return native_encode_complex (expr, ptr, len);

    case VECTOR_CST:
      return native_encode_vector (expr, ptr, len);

    default:
      return 0;
    }
}


/* Subroutine of native_interpret_expr.  Interpret the contents of
   the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
   If the buffer cannot be interpreted, return NULL_TREE.  */

static tree
native_interpret_int (tree type, unsigned char *ptr, int len)
{
  int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
  int byte, offset, word, words;
  unsigned char value;
  unsigned int HOST_WIDE_INT lo = 0;
  HOST_WIDE_INT hi = 0;

  if (total_bytes > len)
    return NULL_TREE;
  if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
    return NULL_TREE;
  words = total_bytes / UNITS_PER_WORD;

  for (byte = 0; byte < total_bytes; byte++)
    {
      int bitpos = byte * BITS_PER_UNIT;
      if (total_bytes > UNITS_PER_WORD)
	{
	  word = byte / UNITS_PER_WORD;
	  if (WORDS_BIG_ENDIAN)
	    word = (words - 1) - word;
	  offset = word * UNITS_PER_WORD;
	  if (BYTES_BIG_ENDIAN)
	    offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
	  else
	    offset += byte % UNITS_PER_WORD;
	}
      else
	offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
      value = ptr[offset];

      if (bitpos < HOST_BITS_PER_WIDE_INT)
	lo |= (unsigned HOST_WIDE_INT) value << bitpos;
      else
	hi |= (unsigned HOST_WIDE_INT) value
	      << (bitpos - HOST_BITS_PER_WIDE_INT);
    }

  return force_fit_type (build_int_cst_wide (type, lo, hi),
			 0, false, false);
}


/* Subroutine of native_interpret_expr.  Interpret the contents of
   the buffer PTR of length LEN as a REAL_CST of type TYPE.
   If the buffer cannot be interpreted, return NULL_TREE.  */

static tree
native_interpret_real (tree type, unsigned char *ptr, int len)
{
  enum machine_mode mode = TYPE_MODE (type);
  int total_bytes = GET_MODE_SIZE (mode);
  int byte, offset, word, words, bitpos;
  unsigned char value;
  /* There are always 32 bits in each long, no matter the size of
     the hosts long.  We handle floating point representations with
     up to 192 bits.  */
  REAL_VALUE_TYPE r;
  long tmp[6];

  total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
  if (total_bytes > len || total_bytes > 24)
    return NULL_TREE;
  words = 32 / UNITS_PER_WORD;

  memset (tmp, 0, sizeof (tmp));
  for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
       bitpos += BITS_PER_UNIT)
    {
      byte = (bitpos / BITS_PER_UNIT) & 3;
      if (UNITS_PER_WORD < 4)
	{
	  word = byte / UNITS_PER_WORD;
	  if (WORDS_BIG_ENDIAN)
	    word = (words - 1) - word;
	  offset = word * UNITS_PER_WORD;
	  if (BYTES_BIG_ENDIAN)
	    offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
	  else
	    offset += byte % UNITS_PER_WORD;
	}
      else
	offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
      value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];

      tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
    }

  real_from_target (&r, tmp, mode);
  return build_real (type, r);
}


/* Subroutine of native_interpret_expr.  Interpret the contents of
   the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
   If the buffer cannot be interpreted, return NULL_TREE.  */

static tree
native_interpret_complex (tree type, unsigned char *ptr, int len)
{
  tree etype, rpart, ipart;
  int size;

  etype = TREE_TYPE (type);
  size = GET_MODE_SIZE (TYPE_MODE (etype));
  if (size * 2 > len)
    return NULL_TREE;
  rpart = native_interpret_expr (etype, ptr, size);
  if (!rpart)
    return NULL_TREE;
  ipart = native_interpret_expr (etype, ptr+size, size);
  if (!ipart)
    return NULL_TREE;
  return build_complex (type, rpart, ipart);
}


/* Subroutine of native_interpret_expr.  Interpret the contents of
   the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
   If the buffer cannot be interpreted, return NULL_TREE.  */

static tree
native_interpret_vector (tree type, unsigned char *ptr, int len)
{
  tree etype, elem, elements;
  int i, size, count;

  etype = TREE_TYPE (type);
  size = GET_MODE_SIZE (TYPE_MODE (etype));
  count = TYPE_VECTOR_SUBPARTS (type);
  if (size * count > len)
    return NULL_TREE;

  elements = NULL_TREE;
  for (i = count - 1; i >= 0; i--)
    {
      elem = native_interpret_expr (etype, ptr+(i*size), size);
      if (!elem)
	return NULL_TREE;
      elements = tree_cons (NULL_TREE, elem, elements);
    }
  return build_vector (type, elements);
}


/* Subroutine of fold_view_convert_expr.  Interpret the contents of
   the buffer PTR of length LEN as a constant of type TYPE.  For
   INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
   we return a REAL_CST, etc...  If the buffer cannot be interpreted,
   return NULL_TREE.  */

static tree
native_interpret_expr (tree type, unsigned char *ptr, int len)
{
  switch (TREE_CODE (type))
    {
    case INTEGER_TYPE:
    case ENUMERAL_TYPE:
    case BOOLEAN_TYPE:
      return native_interpret_int (type, ptr, len);

    case REAL_TYPE:
      return native_interpret_real (type, ptr, len);

    case COMPLEX_TYPE:
      return native_interpret_complex (type, ptr, len);

    case VECTOR_TYPE:
      return native_interpret_vector (type, ptr, len);

    default:
      return NULL_TREE;
    }
}


/* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
   TYPE at compile-time.  If we're unable to perform the conversion
   return NULL_TREE.  */

static tree
fold_view_convert_expr (tree type, tree expr)
{
  /* We support up to 512-bit values (for V8DFmode).  */
  unsigned char buffer[64];
  int len;

  /* Check that the host and target are sane.  */
  if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
    return NULL_TREE;

  len = native_encode_expr (expr, buffer, sizeof (buffer));
  if (len == 0)
    return NULL_TREE;

  return native_interpret_expr (type, buffer, len);
}


/* Fold a unary expression of code CODE and type TYPE with operand
   OP0.  Return the folded expression if folding is successful.
   Otherwise, return NULL_TREE.  */

tree
fold_unary (enum tree_code code, tree type, tree op0)
{
  tree tem;
  tree arg0;
  enum tree_code_class kind = TREE_CODE_CLASS (code);

  gcc_assert (IS_EXPR_CODE_CLASS (kind)
	      && TREE_CODE_LENGTH (code) == 1);

  arg0 = op0;
  if (arg0)
    {
      if (code == NOP_EXPR || code == CONVERT_EXPR
	  || code == FLOAT_EXPR || code == ABS_EXPR)
	{
	  /* Don't use STRIP_NOPS, because signedness of argument type
	     matters.  */
	  STRIP_SIGN_NOPS (arg0);
	}
      else
	{
	  /* Strip any conversions that don't change the mode.  This
	     is safe for every expression, except for a comparison
	     expression because its signedness is derived from its
	     operands.

	     Note that this is done as an internal manipulation within
	     the constant folder, in order to find the simplest
	     representation of the arguments so that their form can be
	     studied.  In any cases, the appropriate type conversions
	     should be put back in the tree that will get out of the
	     constant folder.  */
	  STRIP_NOPS (arg0);
	}
    }

  if (TREE_CODE_CLASS (code) == tcc_unary)
    {
      if (TREE_CODE (arg0) == COMPOUND_EXPR)
	return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
		       fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
      else if (TREE_CODE (arg0) == COND_EXPR)
	{
	  tree arg01 = TREE_OPERAND (arg0, 1);
	  tree arg02 = TREE_OPERAND (arg0, 2);
	  if (! VOID_TYPE_P (TREE_TYPE (arg01)))
	    arg01 = fold_build1 (code, type, arg01);
	  if (! VOID_TYPE_P (TREE_TYPE (arg02)))
	    arg02 = fold_build1 (code, type, arg02);
	  tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
			     arg01, arg02);

	  /* If this was a conversion, and all we did was to move into
	     inside the COND_EXPR, bring it back out.  But leave it if
	     it is a conversion from integer to integer and the
	     result precision is no wider than a word since such a
	     conversion is cheap and may be optimized away by combine,
	     while it couldn't if it were outside the COND_EXPR.  Then return
	     so we don't get into an infinite recursion loop taking the
	     conversion out and then back in.  */

	  if ((code == NOP_EXPR || code == CONVERT_EXPR
	       || code == NON_LVALUE_EXPR)
	      && TREE_CODE (tem) == COND_EXPR
	      && TREE_CODE (TREE_OPERAND (tem, 1)) == code
	      && TREE_CODE (TREE_OPERAND (tem, 2)) == code
	      && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
	      && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
	      && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
		  == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
	      && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
		     && (INTEGRAL_TYPE_P
			 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
		     && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
		  || flag_syntax_only))
	    tem = build1 (code, type,
			  build3 (COND_EXPR,
				  TREE_TYPE (TREE_OPERAND
					     (TREE_OPERAND (tem, 1), 0)),
				  TREE_OPERAND (tem, 0),
				  TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
				  TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
	  return tem;
	}
      else if (COMPARISON_CLASS_P (arg0))
	{
	  if (TREE_CODE (type) == BOOLEAN_TYPE)
	    {
	      arg0 = copy_node (arg0);
	      TREE_TYPE (arg0) = type;
	      return arg0;
	    }
	  else if (TREE_CODE (type) != INTEGER_TYPE)
	    return fold_build3 (COND_EXPR, type, arg0,
				fold_build1 (code, type,
					     integer_one_node),
				fold_build1 (code, type,
					     integer_zero_node));
	}
   }

  switch (code)
    {
    case NOP_EXPR:
    case FLOAT_EXPR:
    case CONVERT_EXPR:
    case FIX_TRUNC_EXPR:
    case FIX_CEIL_EXPR:
    case FIX_FLOOR_EXPR:
    case FIX_ROUND_EXPR:
      if (TREE_TYPE (op0) == type)
	return op0;
      
      /* If we have (type) (a CMP b) and type is an integral type, return
         new expression involving the new type.  */
      if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
	return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
			    TREE_OPERAND (op0, 1));

      /* Handle cases of two conversions in a row.  */
      if (TREE_CODE (op0) == NOP_EXPR
	  || TREE_CODE (op0) == CONVERT_EXPR)
	{
	  tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
	  tree inter_type = TREE_TYPE (op0);
	  int inside_int = INTEGRAL_TYPE_P (inside_type);
	  int inside_ptr = POINTER_TYPE_P (inside_type);
	  int inside_float = FLOAT_TYPE_P (inside_type);
	  int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
	  unsigned int inside_prec = TYPE_PRECISION (inside_type);
	  int inside_unsignedp = TYPE_UNSIGNED (inside_type);
	  int inter_int = INTEGRAL_TYPE_P (inter_type);
	  int inter_ptr = POINTER_TYPE_P (inter_type);
	  int inter_float = FLOAT_TYPE_P (inter_type);
	  int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
	  unsigned int inter_prec = TYPE_PRECISION (inter_type);
	  int inter_unsignedp = TYPE_UNSIGNED (inter_type);
	  int final_int = INTEGRAL_TYPE_P (type);
	  int final_ptr = POINTER_TYPE_P (type);
	  int final_float = FLOAT_TYPE_P (type);
	  int final_vec = TREE_CODE (type) == VECTOR_TYPE;
	  unsigned int final_prec = TYPE_PRECISION (type);
	  int final_unsignedp = TYPE_UNSIGNED (type);

	  /* In addition to the cases of two conversions in a row
	     handled below, if we are converting something to its own
	     type via an object of identical or wider precision, neither
	     conversion is needed.  */
	  if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
	      && (((inter_int || inter_ptr) && final_int)
		  || (inter_float && final_float))
	      && inter_prec >= final_prec)
	    return fold_build1 (code, type, TREE_OPERAND (op0, 0));

	  /* Likewise, if the intermediate and final types are either both
	     float or both integer, we don't need the middle conversion if
	     it is wider than the final type and doesn't change the signedness
	     (for integers).  Avoid this if the final type is a pointer
	     since then we sometimes need the inner conversion.  Likewise if
	     the outer has a precision not equal to the size of its mode.  */
	  if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
	       || (inter_float && inside_float)
	       || (inter_vec && inside_vec))
	      && inter_prec >= inside_prec
	      && (inter_float || inter_vec
		  || inter_unsignedp == inside_unsignedp)
	      && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
		    && TYPE_MODE (type) == TYPE_MODE (inter_type))
	      && ! final_ptr
	      && (! final_vec || inter_prec == inside_prec))
	    return fold_build1 (code, type, TREE_OPERAND (op0, 0));

	  /* If we have a sign-extension of a zero-extended value, we can
	     replace that by a single zero-extension.  */
	  if (inside_int && inter_int && final_int
	      && inside_prec < inter_prec && inter_prec < final_prec
	      && inside_unsignedp && !inter_unsignedp)
	    return fold_build1 (code, type, TREE_OPERAND (op0, 0));

	  /* Two conversions in a row are not needed unless:
	     - some conversion is floating-point (overstrict for now), or
	     - some conversion is a vector (overstrict for now), or
	     - the intermediate type is narrower than both initial and
	       final, or
	     - the intermediate type and innermost type differ in signedness,
	       and the outermost type is wider than the intermediate, or
	     - the initial type is a pointer type and the precisions of the
	       intermediate and final types differ, or
	     - the final type is a pointer type and the precisions of the
	       initial and intermediate types differ.
	     - the final type is a pointer type and the initial type not
	     - the initial type is a pointer to an array and the final type
	       not.  */
	  /* Java pointer type conversions generate checks in some
	     cases, so we explicitly disallow this optimization.  */
	  if (! inside_float && ! inter_float && ! final_float
	      && ! inside_vec && ! inter_vec && ! final_vec
	      && (inter_prec >= inside_prec || inter_prec >= final_prec)
	      && ! (inside_int && inter_int
		    && inter_unsignedp != inside_unsignedp
		    && inter_prec < final_prec)
	      && ((inter_unsignedp && inter_prec > inside_prec)
		  == (final_unsignedp && final_prec > inter_prec))
	      && ! (inside_ptr && inter_prec != final_prec)
	      && ! (final_ptr && inside_prec != inter_prec)
	      && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
		    && TYPE_MODE (type) == TYPE_MODE (inter_type))
	      && final_ptr == inside_ptr
	      && ! (inside_ptr
		    && TREE_CODE (TREE_TYPE (inside_type)) == ARRAY_TYPE
		    && TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE)
	      && ! ((strcmp (lang_hooks.name, "GNU Java") == 0)
		    && final_ptr))
	    return fold_build1 (code, type, TREE_OPERAND (op0, 0));
	}

      /* Handle (T *)&A.B.C for A being of type T and B and C
	 living at offset zero.  This occurs frequently in
	 C++ upcasting and then accessing the base.  */
      if (TREE_CODE (op0) == ADDR_EXPR
	  && POINTER_TYPE_P (type)
	  && handled_component_p (TREE_OPERAND (op0, 0)))
        {
	  HOST_WIDE_INT bitsize, bitpos;
	  tree offset;
	  enum machine_mode mode;
	  int unsignedp, volatilep;
          tree base = TREE_OPERAND (op0, 0);
	  base = get_inner_reference (base, &bitsize, &bitpos, &offset,
				      &mode, &unsignedp, &volatilep, false);
	  /* If the reference was to a (constant) zero offset, we can use
	     the address of the base if it has the same base type
	     as the result type.  */
	  if (! offset && bitpos == 0
	      && TYPE_MAIN_VARIANT (TREE_TYPE (type))
		  == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
	    return fold_convert (type, build_fold_addr_expr (base));
        }

      if (TREE_CODE (op0) == MODIFY_EXPR
	  && TREE_CONSTANT (TREE_OPERAND (op0, 1))
	  /* Detect assigning a bitfield.  */
	  && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
	       && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
	{
	  /* Don't leave an assignment inside a conversion
	     unless assigning a bitfield.  */
	  tem = fold_build1 (code, type, TREE_OPERAND (op0, 1));
	  /* First do the assignment, then return converted constant.  */
	  tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
	  TREE_NO_WARNING (tem) = 1;
	  TREE_USED (tem) = 1;
	  return tem;
	}

      /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
	 constants (if x has signed type, the sign bit cannot be set
	 in c).  This folds extension into the BIT_AND_EXPR.  */
      if (INTEGRAL_TYPE_P (type)
	  && TREE_CODE (type) != BOOLEAN_TYPE
	  && TREE_CODE (op0) == BIT_AND_EXPR
	  && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
	{
	  tree and = op0;
	  tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
	  int change = 0;

	  if (TYPE_UNSIGNED (TREE_TYPE (and))
	      || (TYPE_PRECISION (type)
		  <= TYPE_PRECISION (TREE_TYPE (and))))
	    change = 1;
	  else if (TYPE_PRECISION (TREE_TYPE (and1))
		   <= HOST_BITS_PER_WIDE_INT
		   && host_integerp (and1, 1))
	    {
	      unsigned HOST_WIDE_INT cst;

	      cst = tree_low_cst (and1, 1);
	      cst &= (HOST_WIDE_INT) -1
		     << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
	      change = (cst == 0);
#ifdef LOAD_EXTEND_OP
	      if (change
		  && !flag_syntax_only
		  && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
		      == ZERO_EXTEND))
		{
		  tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
		  and0 = fold_convert (uns, and0);
		  and1 = fold_convert (uns, and1);
		}
#endif
	    }
	  if (change)
	    {
	      tem = build_int_cst_wide (type, TREE_INT_CST_LOW (and1),
					TREE_INT_CST_HIGH (and1));
	      tem = force_fit_type (tem, 0, TREE_OVERFLOW (and1),
				    TREE_CONSTANT_OVERFLOW (and1));
	      return fold_build2 (BIT_AND_EXPR, type,
				  fold_convert (type, and0), tem);
	    }
	}

      /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
	 T2 being pointers to types of the same size.  */
      if (POINTER_TYPE_P (type)
	  && BINARY_CLASS_P (arg0)
	  && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
	  && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
	{
	  tree arg00 = TREE_OPERAND (arg0, 0);
	  tree t0 = type;
	  tree t1 = TREE_TYPE (arg00);
	  tree tt0 = TREE_TYPE (t0);
	  tree tt1 = TREE_TYPE (t1);
	  tree s0 = TYPE_SIZE (tt0);
	  tree s1 = TYPE_SIZE (tt1);

	  if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
	    return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
			   TREE_OPERAND (arg0, 1));
	}

      /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
	 of the same precision, and X is a integer type not narrower than
	 types T1 or T2, i.e. the cast (T2)X isn't an extension.  */
      if (INTEGRAL_TYPE_P (type)
	  && TREE_CODE (op0) == BIT_NOT_EXPR
	  && INTEGRAL_TYPE_P (TREE_TYPE (op0))
	  && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
	      || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
	  && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
	{
	  tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
	  if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
	      && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
	    return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
	}

      tem = fold_convert_const (code, type, op0);
      return tem ? tem : NULL_TREE;

    case VIEW_CONVERT_EXPR:
      if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
	return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
      return fold_view_convert_expr (type, op0);

    case NEGATE_EXPR:
      tem = fold_negate_expr (arg0);
      if (tem)
	return fold_convert (type, tem);
      return NULL_TREE;

    case ABS_EXPR:
      if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
	return fold_abs_const (arg0, type);
      else if (TREE_CODE (arg0) == NEGATE_EXPR)
	return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
      /* Convert fabs((double)float) into (double)fabsf(float).  */
      else if (TREE_CODE (arg0) == NOP_EXPR
	       && TREE_CODE (type) == REAL_TYPE)
	{
	  tree targ0 = strip_float_extensions (arg0);
	  if (targ0 != arg0)
	    return fold_convert (type, fold_build1 (ABS_EXPR,
						    TREE_TYPE (targ0),
						    targ0));
	}
      /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on.  */
      else if (TREE_CODE (arg0) == ABS_EXPR)
	return arg0;
      else if (tree_expr_nonnegative_p (arg0))
	return arg0;

      /* Strip sign ops from argument.  */
      if (TREE_CODE (type) == REAL_TYPE)
	{
	  tem = fold_strip_sign_ops (arg0);
	  if (tem)
	    return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
	}
      return NULL_TREE;

    case CONJ_EXPR:
      if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
	return fold_convert (type, arg0);
      if (TREE_CODE (arg0) == COMPLEX_EXPR)
	{
	  tree itype = TREE_TYPE (type);
	  tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
	  tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
	  return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
	}
      if (TREE_CODE (arg0) == COMPLEX_CST)
	{
	  tree itype = TREE_TYPE (type);
	  tree rpart = fold_convert (itype, TREE_REALPART (arg0));
	  tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
	  return build_complex (type, rpart, negate_expr (ipart));
	}
      if (TREE_CODE (arg0) == CONJ_EXPR)
	return fold_convert (type, TREE_OPERAND (arg0, 0));
      return NULL_TREE;

    case BIT_NOT_EXPR:
      if (TREE_CODE (arg0) == INTEGER_CST)
        return fold_not_const (arg0, type);
      else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
	return TREE_OPERAND (arg0, 0);
      /* Convert ~ (-A) to A - 1.  */
      else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
	return fold_build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
			    build_int_cst (type, 1));
      /* Convert ~ (A - 1) or ~ (A + -1) to -A.  */
      else if (INTEGRAL_TYPE_P (type)
	       && ((TREE_CODE (arg0) == MINUS_EXPR
		    && integer_onep (TREE_OPERAND (arg0, 1)))
		   || (TREE_CODE (arg0) == PLUS_EXPR
		       && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
	return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
      /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify.  */
      else if (TREE_CODE (arg0) == BIT_XOR_EXPR
	       && (tem = fold_unary (BIT_NOT_EXPR, type,
			       	     fold_convert (type,
					     	   TREE_OPERAND (arg0, 0)))))
	return fold_build2 (BIT_XOR_EXPR, type, tem,
			    fold_convert (type, TREE_OPERAND (arg0, 1)));
      else if (TREE_CODE (arg0) == BIT_XOR_EXPR
	       && (tem = fold_unary (BIT_NOT_EXPR, type,
			       	     fold_convert (type,
					     	   TREE_OPERAND (arg0, 1)))))
	return fold_build2 (BIT_XOR_EXPR, type,
			    fold_convert (type, TREE_OPERAND (arg0, 0)), tem);

      return NULL_TREE;

    case TRUTH_NOT_EXPR:
      /* The argument to invert_truthvalue must have Boolean type.  */
      if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
          arg0 = fold_convert (boolean_type_node, arg0);

      /* Note that the operand of this must be an int
	 and its values must be 0 or 1.
	 ("true" is a fixed value perhaps depending on the language,
	 but we don't handle values other than 1 correctly yet.)  */
      tem = fold_truth_not_expr (arg0);
      if (!tem)
	return NULL_TREE;
      return fold_convert (type, tem);

    case REALPART_EXPR:
      if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
	return fold_convert (type, arg0);
      if (TREE_CODE (arg0) == COMPLEX_EXPR)
	return omit_one_operand (type, TREE_OPERAND (arg0, 0),
				 TREE_OPERAND (arg0, 1));
      if (TREE_CODE (arg0) == COMPLEX_CST)
	return fold_convert (type, TREE_REALPART (arg0));
      if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
	{
	  tree itype = TREE_TYPE (TREE_TYPE (arg0));
	  tem = fold_build2 (TREE_CODE (arg0), itype,
			     fold_build1 (REALPART_EXPR, itype,
					  TREE_OPERAND (arg0, 0)),
			     fold_build1 (REALPART_EXPR, itype,
					  TREE_OPERAND (arg0, 1)));
	  return fold_convert (type, tem);
	}
      if (TREE_CODE (arg0) == CONJ_EXPR)
	{
	  tree itype = TREE_TYPE (TREE_TYPE (arg0));
	  tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
	  return fold_convert (type, tem);
	}
      return NULL_TREE;

    case IMAGPART_EXPR:
      if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
	return fold_convert (type, integer_zero_node);
      if (TREE_CODE (arg0) == COMPLEX_EXPR)
	return omit_one_operand (type, TREE_OPERAND (arg0, 1),
				 TREE_OPERAND (arg0, 0));
      if (TREE_CODE (arg0) == COMPLEX_CST)
	return fold_convert (type, TREE_IMAGPART (arg0));
      if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
	{
	  tree itype = TREE_TYPE (TREE_TYPE (arg0));
	  tem = fold_build2 (TREE_CODE (arg0), itype,
			     fold_build1 (IMAGPART_EXPR, itype,
					  TREE_OPERAND (arg0, 0)),
			     fold_build1 (IMAGPART_EXPR, itype,
					  TREE_OPERAND (arg0, 1)));
	  return fold_convert (type, tem);
	}
      if (TREE_CODE (arg0) == CONJ_EXPR)
	{
	  tree itype = TREE_TYPE (TREE_TYPE (arg0));
	  tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
	  return fold_convert (type, negate_expr (tem));
	}
      return NULL_TREE;

    default:
      return NULL_TREE;
    } /* switch (code) */
}

/* Fold a binary expression of code CODE and type TYPE with operands
   OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
   Return the folded expression if folding is successful.  Otherwise,
   return NULL_TREE.  */

static tree
fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
{
  enum tree_code compl_code;

  if (code == MIN_EXPR)
    compl_code = MAX_EXPR;
  else if (code == MAX_EXPR)
    compl_code = MIN_EXPR;
  else
    gcc_unreachable ();

  /* MIN (MAX (a, b), b) == b.  */
  if (TREE_CODE (op0) == compl_code
      && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
    return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));

  /* MIN (MAX (b, a), b) == b.  */
  if (TREE_CODE (op0) == compl_code
      && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
      && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
    return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));

  /* MIN (a, MAX (a, b)) == a.  */
  if (TREE_CODE (op1) == compl_code
      && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
      && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
    return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));

  /* MIN (a, MAX (b, a)) == a.  */
  if (TREE_CODE (op1) == compl_code
      && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
      && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
    return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));

  return NULL_TREE;
}

/* Subroutine of fold_binary.  This routine performs all of the
   transformations that are common to the equality/inequality
   operators (EQ_EXPR and NE_EXPR) and the ordering operators
   (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR).  Callers other than
   fold_binary should call fold_binary.  Fold a comparison with
   tree code CODE and type TYPE with operands OP0 and OP1.  Return
   the folded comparison or NULL_TREE.  */

static tree
fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
{
  tree arg0, arg1, tem;

  arg0 = op0;
  arg1 = op1;

  STRIP_SIGN_NOPS (arg0);
  STRIP_SIGN_NOPS (arg1);

  tem = fold_relational_const (code, type, arg0, arg1);
  if (tem != NULL_TREE)
    return tem;

  /* If one arg is a real or integer constant, put it last.  */
  if (tree_swap_operands_p (arg0, arg1, true))
    return fold_build2 (swap_tree_comparison (code), type, op1, op0);

  /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1.  */
  if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
      && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
	  && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
	  && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
      && (TREE_CODE (arg1) == INTEGER_CST
	  && !TREE_OVERFLOW (arg1)))
    {
      tree const1 = TREE_OPERAND (arg0, 1);
      tree const2 = arg1;
      tree variable = TREE_OPERAND (arg0, 0);
      tree lhs;
      int lhs_add;
      lhs_add = TREE_CODE (arg0) != PLUS_EXPR;

      lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
			 TREE_TYPE (arg1), const2, const1);
      if (TREE_CODE (lhs) == TREE_CODE (arg1)
	  && (TREE_CODE (lhs) != INTEGER_CST
	      || !TREE_OVERFLOW (lhs)))
	{
	  fold_overflow_warning (("assuming signed overflow does not occur "
				  "when changing X +- C1 cmp C2 to "
				  "X cmp C1 +- C2"),
				 WARN_STRICT_OVERFLOW_COMPARISON);
	  return fold_build2 (code, type, variable, lhs);
	}
    }

  /* If this is a comparison of two exprs that look like an ARRAY_REF of the
     same object, then we can fold this to a comparison of the two offsets in
     signed size type.  This is possible because pointer arithmetic is
     restricted to retain within an object and overflow on pointer differences
     is undefined as of 6.5.6/8 and /9 with respect to the signed ptrdiff_t.

     We check flag_wrapv directly because pointers types are unsigned,
     and therefore TYPE_OVERFLOW_WRAPS returns true for them.  That is
     normally what we want to avoid certain odd overflow cases, but
     not here.  */
  if (POINTER_TYPE_P (TREE_TYPE (arg0))
      && !flag_wrapv
      && !TYPE_OVERFLOW_TRAPS (TREE_TYPE (arg0)))
    {
      tree base0, offset0, base1, offset1;

      if (extract_array_ref (arg0, &base0, &offset0)
	  && extract_array_ref (arg1, &base1, &offset1)
	  && operand_equal_p (base0, base1, 0))
        {
	  tree signed_size_type_node;
	  signed_size_type_node = signed_type_for (size_type_node);

	  /* By converting to signed size type we cover middle-end pointer
	     arithmetic which operates on unsigned pointer types of size
	     type size and ARRAY_REF offsets which are properly sign or
	     zero extended from their type in case it is narrower than
	     size type.  */
	  if (offset0 == NULL_TREE)
	    offset0 = build_int_cst (signed_size_type_node, 0);
	  else
	    offset0 = fold_convert (signed_size_type_node, offset0);
	  if (offset1 == NULL_TREE)
	    offset1 = build_int_cst (signed_size_type_node, 0);
	  else
	    offset1 = fold_convert (signed_size_type_node, offset1);

	  return fold_build2 (code, type, offset0, offset1);
	}
    }

  if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
    {
      tree targ0 = strip_float_extensions (arg0);
      tree targ1 = strip_float_extensions (arg1);
      tree newtype = TREE_TYPE (targ0);

      if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
	newtype = TREE_TYPE (targ1);

      /* Fold (double)float1 CMP (double)float2 into float1 CMP float2.  */
      if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
	return fold_build2 (code, type, fold_convert (newtype, targ0),
			    fold_convert (newtype, targ1));

      /* (-a) CMP (-b) -> b CMP a  */
      if (TREE_CODE (arg0) == NEGATE_EXPR
	  && TREE_CODE (arg1) == NEGATE_EXPR)
	return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
			    TREE_OPERAND (arg0, 0));

      if (TREE_CODE (arg1) == REAL_CST)
	{
	  REAL_VALUE_TYPE cst;
	  cst = TREE_REAL_CST (arg1);

	  /* (-a) CMP CST -> a swap(CMP) (-CST)  */
	  if (TREE_CODE (arg0) == NEGATE_EXPR)
	    return fold_build2 (swap_tree_comparison (code), type,
				TREE_OPERAND (arg0, 0),
				build_real (TREE_TYPE (arg1),
					    REAL_VALUE_NEGATE (cst)));

	  /* IEEE doesn't distinguish +0 and -0 in comparisons.  */
	  /* a CMP (-0) -> a CMP 0  */
	  if (REAL_VALUE_MINUS_ZERO (cst))
	    return fold_build2 (code, type, arg0,
				build_real (TREE_TYPE (arg1), dconst0));

	  /* x != NaN is always true, other ops are always false.  */
	  if (REAL_VALUE_ISNAN (cst)
	      && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
	    {
	      tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
	      return omit_one_operand (type, tem, arg0);
	    }

	  /* Fold comparisons against infinity.  */
	  if (REAL_VALUE_ISINF (cst))
	    {
	      tem = fold_inf_compare (code, type, arg0, arg1);
	      if (tem != NULL_TREE)
		return tem;
	    }
	}

      /* If this is a comparison of a real constant with a PLUS_EXPR
	 or a MINUS_EXPR of a real constant, we can convert it into a
	 comparison with a revised real constant as long as no overflow
	 occurs when unsafe_math_optimizations are enabled.  */
      if (flag_unsafe_math_optimizations
	  && TREE_CODE (arg1) == REAL_CST
	  && (TREE_CODE (arg0) == PLUS_EXPR
	      || TREE_CODE (arg0) == MINUS_EXPR)
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
	  && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
				      ? MINUS_EXPR : PLUS_EXPR,
				      arg1, TREE_OPERAND (arg0, 1), 0))
	  && ! TREE_CONSTANT_OVERFLOW (tem))
	return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);

      /* Likewise, we can simplify a comparison of a real constant with
         a MINUS_EXPR whose first operand is also a real constant, i.e.
         (c1 - x) < c2 becomes x > c1-c2.  */
      if (flag_unsafe_math_optimizations
	  && TREE_CODE (arg1) == REAL_CST
	  && TREE_CODE (arg0) == MINUS_EXPR
	  && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
	  && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
				      arg1, 0))
	  && ! TREE_CONSTANT_OVERFLOW (tem))
	return fold_build2 (swap_tree_comparison (code), type,
			    TREE_OPERAND (arg0, 1), tem);

      /* Fold comparisons against built-in math functions.  */
      if (TREE_CODE (arg1) == REAL_CST
	  && flag_unsafe_math_optimizations
	  && ! flag_errno_math)
	{
	  enum built_in_function fcode = builtin_mathfn_code (arg0);

	  if (fcode != END_BUILTINS)
	    {
	      tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
	      if (tem != NULL_TREE)
		return tem;
	    }
	}
    }

  /* Convert foo++ == CONST into ++foo == CONST + INCR.  */
  if (TREE_CONSTANT (arg1)
      && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
	  || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
      /* This optimization is invalid for ordered comparisons
         if CONST+INCR overflows or if foo+incr might overflow.
	 This optimization is invalid for floating point due to rounding.
	 For pointer types we assume overflow doesn't happen.  */
      && (POINTER_TYPE_P (TREE_TYPE (arg0))
	  || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
	      && (code == EQ_EXPR || code == NE_EXPR))))
    {
      tree varop, newconst;

      if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
	{
	  newconst = fold_build2 (PLUS_EXPR, TREE_TYPE (arg0),
				  arg1, TREE_OPERAND (arg0, 1));
	  varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
			  TREE_OPERAND (arg0, 0),
			  TREE_OPERAND (arg0, 1));
	}
      else
	{
	  newconst = fold_build2 (MINUS_EXPR, TREE_TYPE (arg0),
				  arg1, TREE_OPERAND (arg0, 1));
	  varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
			  TREE_OPERAND (arg0, 0),
			  TREE_OPERAND (arg0, 1));
	}


      /* If VAROP is a reference to a bitfield, we must mask
	 the constant by the width of the field.  */
      if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
	  && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
	  && host_integerp (DECL_SIZE (TREE_OPERAND
					 (TREE_OPERAND (varop, 0), 1)), 1))
	{
	  tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
	  HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
	  tree folded_compare, shift;

	  /* First check whether the comparison would come out
	     always the same.  If we don't do that we would
	     change the meaning with the masking.  */
	  folded_compare = fold_build2 (code, type,
					TREE_OPERAND (varop, 0), arg1);
	  if (TREE_CODE (folded_compare) == INTEGER_CST)
	    return omit_one_operand (type, folded_compare, varop);

	  shift = build_int_cst (NULL_TREE,
				 TYPE_PRECISION (TREE_TYPE (varop)) - size);
	  shift = fold_convert (TREE_TYPE (varop), shift);
	  newconst = fold_build2 (LSHIFT_EXPR, TREE_TYPE (varop),
				  newconst, shift);
	  newconst = fold_build2 (RSHIFT_EXPR, TREE_TYPE (varop),
				  newconst, shift);
	}

      return fold_build2 (code, type, varop, newconst);
    }

  if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
      && (TREE_CODE (arg0) == NOP_EXPR
	  || TREE_CODE (arg0) == CONVERT_EXPR))
    {
      /* If we are widening one operand of an integer comparison,
	 see if the other operand is similarly being widened.  Perhaps we
	 can do the comparison in the narrower type.  */
      tem = fold_widened_comparison (code, type, arg0, arg1);
      if (tem)
	return tem;

      /* Or if we are changing signedness.  */
      tem = fold_sign_changed_comparison (code, type, arg0, arg1);
      if (tem)
	return tem;
    }

  /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
     constant, we can simplify it.  */
  if (TREE_CODE (arg1) == INTEGER_CST
      && (TREE_CODE (arg0) == MIN_EXPR
	  || TREE_CODE (arg0) == MAX_EXPR)
      && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
    {
      tem = optimize_minmax_comparison (code, type, op0, op1);
      if (tem)
	return tem;
    }

  /* Simplify comparison of something with itself.  (For IEEE
     floating-point, we can only do some of these simplifications.)  */
  if (operand_equal_p (arg0, arg1, 0))
    {
      switch (code)
	{
	case EQ_EXPR:
	  if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
	      || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
	    return constant_boolean_node (1, type);
	  break;

	case GE_EXPR:
	case LE_EXPR:
	  if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
	      || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
	    return constant_boolean_node (1, type);
	  return fold_build2 (EQ_EXPR, type, arg0, arg1);

	case NE_EXPR:
	  /* For NE, we can only do this simplification if integer
	     or we don't honor IEEE floating point NaNs.  */
	  if (FLOAT_TYPE_P (TREE_TYPE (arg0))
	      && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
	    break;
	  /* ... fall through ...  */
	case GT_EXPR:
	case LT_EXPR:
	  return constant_boolean_node (0, type);
	default:
	  gcc_unreachable ();
	}
    }

  /* If we are comparing an expression that just has comparisons
     of two integer values, arithmetic expressions of those comparisons,
     and constants, we can simplify it.  There are only three cases
     to check: the two values can either be equal, the first can be
     greater, or the second can be greater.  Fold the expression for
     those three values.  Since each value must be 0 or 1, we have
     eight possibilities, each of which corresponds to the constant 0
     or 1 or one of the six possible comparisons.

     This handles common cases like (a > b) == 0 but also handles
     expressions like  ((x > y) - (y > x)) > 0, which supposedly
     occur in macroized code.  */

  if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
    {
      tree cval1 = 0, cval2 = 0;
      int save_p = 0;

      if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
	  /* Don't handle degenerate cases here; they should already
	     have been handled anyway.  */
	  && cval1 != 0 && cval2 != 0
	  && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
	  && TREE_TYPE (cval1) == TREE_TYPE (cval2)
	  && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
	  && TYPE_MAX_VALUE (TREE_TYPE (cval1))
	  && TYPE_MAX_VALUE (TREE_TYPE (cval2))
	  && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
				TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
	{
	  tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
	  tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));

	  /* We can't just pass T to eval_subst in case cval1 or cval2
	     was the same as ARG1.  */

	  tree high_result
		= fold_build2 (code, type,
			       eval_subst (arg0, cval1, maxval,
					   cval2, minval),
			       arg1);
	  tree equal_result
		= fold_build2 (code, type,
			       eval_subst (arg0, cval1, maxval,
					   cval2, maxval),
			       arg1);
	  tree low_result
		= fold_build2 (code, type,
			       eval_subst (arg0, cval1, minval,
					   cval2, maxval),
			       arg1);

	  /* All three of these results should be 0 or 1.  Confirm they are.
	     Then use those values to select the proper code to use.  */

	  if (TREE_CODE (high_result) == INTEGER_CST
	      && TREE_CODE (equal_result) == INTEGER_CST
	      && TREE_CODE (low_result) == INTEGER_CST)
	    {
	      /* Make a 3-bit mask with the high-order bit being the
		 value for `>', the next for '=', and the low for '<'.  */
	      switch ((integer_onep (high_result) * 4)
		      + (integer_onep (equal_result) * 2)
		      + integer_onep (low_result))
		{
		case 0:
		  /* Always false.  */
		  return omit_one_operand (type, integer_zero_node, arg0);
		case 1:
		  code = LT_EXPR;
		  break;
		case 2:
		  code = EQ_EXPR;
		  break;
		case 3:
		  code = LE_EXPR;
		  break;
		case 4:
		  code = GT_EXPR;
		  break;
		case 5:
		  code = NE_EXPR;
		  break;
		case 6:
		  code = GE_EXPR;
		  break;
		case 7:
		  /* Always true.  */
		  return omit_one_operand (type, integer_one_node, arg0);
		}

	      if (save_p)
		return save_expr (build2 (code, type, cval1, cval2));
	      return fold_build2 (code, type, cval1, cval2);
	    }
	}
    }

  /* Fold a comparison of the address of COMPONENT_REFs with the same
     type and component to a comparison of the address of the base
     object.  In short, &x->a OP &y->a to x OP y and
     &x->a OP &y.a to x OP &y  */
  if (TREE_CODE (arg0) == ADDR_EXPR
      && TREE_CODE (TREE_OPERAND (arg0, 0)) == COMPONENT_REF
      && TREE_CODE (arg1) == ADDR_EXPR
      && TREE_CODE (TREE_OPERAND (arg1, 0)) == COMPONENT_REF)
    {
      tree cref0 = TREE_OPERAND (arg0, 0);
      tree cref1 = TREE_OPERAND (arg1, 0);
      if (TREE_OPERAND (cref0, 1) == TREE_OPERAND (cref1, 1))
	{
	  tree op0 = TREE_OPERAND (cref0, 0);
	  tree op1 = TREE_OPERAND (cref1, 0);
	  return fold_build2 (code, type,
			      build_fold_addr_expr (op0),
			      build_fold_addr_expr (op1));
	}
    }

  /* We can fold X/C1 op C2 where C1 and C2 are integer constants
     into a single range test.  */
  if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
       || TREE_CODE (arg0) == EXACT_DIV_EXPR)
      && TREE_CODE (arg1) == INTEGER_CST
      && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
      && !integer_zerop (TREE_OPERAND (arg0, 1))
      && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
      && !TREE_OVERFLOW (arg1))
    {
      tem = fold_div_compare (code, type, arg0, arg1);
      if (tem != NULL_TREE)
	return tem;
    }

  return NULL_TREE;
}


/* Subroutine of fold_binary.  Optimize complex multiplications of the
   form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2).  The
   argument EXPR represents the expression "z" of type TYPE.  */

static tree
fold_mult_zconjz (tree type, tree expr)
{
  tree itype = TREE_TYPE (type);
  tree rpart, ipart, tem;

  if (TREE_CODE (expr) == COMPLEX_EXPR)
    {
      rpart = TREE_OPERAND (expr, 0);
      ipart = TREE_OPERAND (expr, 1);
    }
  else if (TREE_CODE (expr) == COMPLEX_CST)
    {
      rpart = TREE_REALPART (expr);
      ipart = TREE_IMAGPART (expr);
    }
  else
    {
      expr = save_expr (expr);
      rpart = fold_build1 (REALPART_EXPR, itype, expr);
      ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
    }

  rpart = save_expr (rpart);
  ipart = save_expr (ipart);
  tem = fold_build2 (PLUS_EXPR, itype,
		     fold_build2 (MULT_EXPR, itype, rpart, rpart),
		     fold_build2 (MULT_EXPR, itype, ipart, ipart));
  return fold_build2 (COMPLEX_EXPR, type, tem,
		      fold_convert (itype, integer_zero_node));
}


/* Fold a binary expression of code CODE and type TYPE with operands
   OP0 and OP1.  Return the folded expression if folding is
   successful.  Otherwise, return NULL_TREE.  */

tree
fold_binary (enum tree_code code, tree type, tree op0, tree op1)
{
  enum tree_code_class kind = TREE_CODE_CLASS (code);
  tree arg0, arg1, tem;
  tree t1 = NULL_TREE;
  bool strict_overflow_p;

  gcc_assert (IS_EXPR_CODE_CLASS (kind)
	      && TREE_CODE_LENGTH (code) == 2
	      && op0 != NULL_TREE
	      && op1 != NULL_TREE);

  arg0 = op0;
  arg1 = op1;

  /* Strip any conversions that don't change the mode.  This is
     safe for every expression, except for a comparison expression
     because its signedness is derived from its operands.  So, in
     the latter case, only strip conversions that don't change the
     signedness.

     Note that this is done as an internal manipulation within the
     constant folder, in order to find the simplest representation
     of the arguments so that their form can be studied.  In any
     cases, the appropriate type conversions should be put back in
     the tree that will get out of the constant folder.  */

  if (kind == tcc_comparison)
    {
      STRIP_SIGN_NOPS (arg0);
      STRIP_SIGN_NOPS (arg1);
    }
  else
    {
      STRIP_NOPS (arg0);
      STRIP_NOPS (arg1);
    }

  /* Note that TREE_CONSTANT isn't enough: static var addresses are
     constant but we can't do arithmetic on them.  */
  if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
      || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
      || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
      || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
    {
      if (kind == tcc_binary)
	tem = const_binop (code, arg0, arg1, 0);
      else if (kind == tcc_comparison)
	tem = fold_relational_const (code, type, arg0, arg1);
      else
	tem = NULL_TREE;

      if (tem != NULL_TREE)
	{
	  if (TREE_TYPE (tem) != type)
	    tem = fold_convert (type, tem);
	  return tem;
	}
    }

  /* If this is a commutative operation, and ARG0 is a constant, move it
     to ARG1 to reduce the number of tests below.  */
  if (commutative_tree_code (code)
      && tree_swap_operands_p (arg0, arg1, true))
    return fold_build2 (code, type, op1, op0);

  /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.

     First check for cases where an arithmetic operation is applied to a
     compound, conditional, or comparison operation.  Push the arithmetic
     operation inside the compound or conditional to see if any folding
     can then be done.  Convert comparison to conditional for this purpose.
     The also optimizes non-constant cases that used to be done in
     expand_expr.

     Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
     one of the operands is a comparison and the other is a comparison, a
     BIT_AND_EXPR with the constant 1, or a truth value.  In that case, the
     code below would make the expression more complex.  Change it to a
     TRUTH_{AND,OR}_EXPR.  Likewise, convert a similar NE_EXPR to
     TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR.  */

  if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
       || code == EQ_EXPR || code == NE_EXPR)
      && ((truth_value_p (TREE_CODE (arg0))
	   && (truth_value_p (TREE_CODE (arg1))
	       || (TREE_CODE (arg1) == BIT_AND_EXPR
		   && integer_onep (TREE_OPERAND (arg1, 1)))))
	  || (truth_value_p (TREE_CODE (arg1))
	      && (truth_value_p (TREE_CODE (arg0))
		  || (TREE_CODE (arg0) == BIT_AND_EXPR
		      && integer_onep (TREE_OPERAND (arg0, 1)))))))
    {
      tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
			 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
			 : TRUTH_XOR_EXPR,
			 boolean_type_node,
			 fold_convert (boolean_type_node, arg0),
			 fold_convert (boolean_type_node, arg1));

      if (code == EQ_EXPR)
	tem = invert_truthvalue (tem);

      return fold_convert (type, tem);
    }

  if (TREE_CODE_CLASS (code) == tcc_binary
      || TREE_CODE_CLASS (code) == tcc_comparison)
    {
      if (TREE_CODE (arg0) == COMPOUND_EXPR)
	return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
		       fold_build2 (code, type,
				    TREE_OPERAND (arg0, 1), op1));
      if (TREE_CODE (arg1) == COMPOUND_EXPR
	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
	return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
		       fold_build2 (code, type,
				    op0, TREE_OPERAND (arg1, 1)));

      if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
	{
	  tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
						     arg0, arg1, 
						     /*cond_first_p=*/1);
	  if (tem != NULL_TREE)
	    return tem;
	}

      if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
	{
	  tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
						     arg1, arg0, 
					             /*cond_first_p=*/0);
	  if (tem != NULL_TREE)
	    return tem;
	}
    }

  switch (code)
    {
    case PLUS_EXPR:
      /* A + (-B) -> A - B */
      if (TREE_CODE (arg1) == NEGATE_EXPR)
	return fold_build2 (MINUS_EXPR, type,
			    fold_convert (type, arg0),
			    fold_convert (type, TREE_OPERAND (arg1, 0)));
      /* (-A) + B -> B - A */
      if (TREE_CODE (arg0) == NEGATE_EXPR
	  && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
	return fold_build2 (MINUS_EXPR, type,
			    fold_convert (type, arg1),
			    fold_convert (type, TREE_OPERAND (arg0, 0)));
      /* Convert ~A + 1 to -A.  */
      if (INTEGRAL_TYPE_P (type)
	  && TREE_CODE (arg0) == BIT_NOT_EXPR
	  && integer_onep (arg1))
	return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));

      /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
	 same or one.  */
      if ((TREE_CODE (arg0) == MULT_EXPR
	   || TREE_CODE (arg1) == MULT_EXPR)
	  && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
        {
	  tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
	  if (tem)
	    return tem;
	}

      if (! FLOAT_TYPE_P (type))
	{
	  if (integer_zerop (arg1))
	    return non_lvalue (fold_convert (type, arg0));

	  /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
	     with a constant, and the two constants have no bits in common,
	     we should treat this as a BIT_IOR_EXPR since this may produce more
	     simplifications.  */
	  if (TREE_CODE (arg0) == BIT_AND_EXPR
	      && TREE_CODE (arg1) == BIT_AND_EXPR
	      && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
	      && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
	      && integer_zerop (const_binop (BIT_AND_EXPR,
					     TREE_OPERAND (arg0, 1),
					     TREE_OPERAND (arg1, 1), 0)))
	    {
	      code = BIT_IOR_EXPR;
	      goto bit_ior;
	    }

	  /* Reassociate (plus (plus (mult) (foo)) (mult)) as
	     (plus (plus (mult) (mult)) (foo)) so that we can
	     take advantage of the factoring cases below.  */
	  if (((TREE_CODE (arg0) == PLUS_EXPR
		|| TREE_CODE (arg0) == MINUS_EXPR)
	       && TREE_CODE (arg1) == MULT_EXPR)
	      || ((TREE_CODE (arg1) == PLUS_EXPR
		   || TREE_CODE (arg1) == MINUS_EXPR)
		  && TREE_CODE (arg0) == MULT_EXPR))
	    {
	      tree parg0, parg1, parg, marg;
	      enum tree_code pcode;

	      if (TREE_CODE (arg1) == MULT_EXPR)
		parg = arg0, marg = arg1;
	      else
		parg = arg1, marg = arg0;
	      pcode = TREE_CODE (parg);
	      parg0 = TREE_OPERAND (parg, 0);
	      parg1 = TREE_OPERAND (parg, 1);
	      STRIP_NOPS (parg0);
	      STRIP_NOPS (parg1);

	      if (TREE_CODE (parg0) == MULT_EXPR
		  && TREE_CODE (parg1) != MULT_EXPR)
		return fold_build2 (pcode, type,
				    fold_build2 (PLUS_EXPR, type,
						 fold_convert (type, parg0),
						 fold_convert (type, marg)),
				    fold_convert (type, parg1));
	      if (TREE_CODE (parg0) != MULT_EXPR
		  && TREE_CODE (parg1) == MULT_EXPR)
		return fold_build2 (PLUS_EXPR, type,
				    fold_convert (type, parg0),
				    fold_build2 (pcode, type,
						 fold_convert (type, marg),
						 fold_convert (type,
							       parg1)));
	    }

	  /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
	     of the array.  Loop optimizer sometimes produce this type of
	     expressions.  */
	  if (TREE_CODE (arg0) == ADDR_EXPR)
	    {
	      tem = try_move_mult_to_index (PLUS_EXPR, arg0, arg1);
	      if (tem)
		return fold_convert (type, tem);
	    }
	  else if (TREE_CODE (arg1) == ADDR_EXPR)
	    {
	      tem = try_move_mult_to_index (PLUS_EXPR, arg1, arg0);
	      if (tem)
		return fold_convert (type, tem);
	    }
	}
      else
	{
	  /* See if ARG1 is zero and X + ARG1 reduces to X.  */
	  if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
	    return non_lvalue (fold_convert (type, arg0));

	  /* Likewise if the operands are reversed.  */
	  if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
	    return non_lvalue (fold_convert (type, arg1));

	  /* Convert X + -C into X - C.  */
	  if (TREE_CODE (arg1) == REAL_CST
	      && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
	    {
	      tem = fold_negate_const (arg1, type);
	      if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
		return fold_build2 (MINUS_EXPR, type,
				    fold_convert (type, arg0),
				    fold_convert (type, tem));
	    }

          if (flag_unsafe_math_optimizations
	      && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
	      && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
	      && (tem = distribute_real_division (code, type, arg0, arg1)))
	    return tem;

	  /* Convert x+x into x*2.0.  */
	  if (operand_equal_p (arg0, arg1, 0)
	      && SCALAR_FLOAT_TYPE_P (type))
	    return fold_build2 (MULT_EXPR, type, arg0,
				build_real (type, dconst2));

          /* Convert a + (b*c + d*e) into (a + b*c) + d*e.  */
          if (flag_unsafe_math_optimizations
              && TREE_CODE (arg1) == PLUS_EXPR
              && TREE_CODE (arg0) != MULT_EXPR)
            {
              tree tree10 = TREE_OPERAND (arg1, 0);
              tree tree11 = TREE_OPERAND (arg1, 1);
              if (TREE_CODE (tree11) == MULT_EXPR
		  && TREE_CODE (tree10) == MULT_EXPR)
                {
                  tree tree0;
                  tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
                  return fold_build2 (PLUS_EXPR, type, tree0, tree11);
                }
            }
          /* Convert (b*c + d*e) + a into b*c + (d*e +a).  */
          if (flag_unsafe_math_optimizations
              && TREE_CODE (arg0) == PLUS_EXPR
              && TREE_CODE (arg1) != MULT_EXPR)
            {
              tree tree00 = TREE_OPERAND (arg0, 0);
              tree tree01 = TREE_OPERAND (arg0, 1);
              if (TREE_CODE (tree01) == MULT_EXPR
		  && TREE_CODE (tree00) == MULT_EXPR)
                {
                  tree tree0;
                  tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
                  return fold_build2 (PLUS_EXPR, type, tree00, tree0);
                }
            }
	}

     bit_rotate:
      /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
	 is a rotate of A by C1 bits.  */
      /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
	 is a rotate of A by B bits.  */
      {
	enum tree_code code0, code1;
	code0 = TREE_CODE (arg0);
	code1 = TREE_CODE (arg1);
	if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
	     || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
	    && operand_equal_p (TREE_OPERAND (arg0, 0),
			        TREE_OPERAND (arg1, 0), 0)
	    && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
	  {
	    tree tree01, tree11;
	    enum tree_code code01, code11;

	    tree01 = TREE_OPERAND (arg0, 1);
	    tree11 = TREE_OPERAND (arg1, 1);
	    STRIP_NOPS (tree01);
	    STRIP_NOPS (tree11);
	    code01 = TREE_CODE (tree01);
	    code11 = TREE_CODE (tree11);
	    if (code01 == INTEGER_CST
		&& code11 == INTEGER_CST
		&& TREE_INT_CST_HIGH (tree01) == 0
		&& TREE_INT_CST_HIGH (tree11) == 0
		&& ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
		    == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
	      return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
			     code0 == LSHIFT_EXPR ? tree01 : tree11);
	    else if (code11 == MINUS_EXPR)
	      {
		tree tree110, tree111;
		tree110 = TREE_OPERAND (tree11, 0);
		tree111 = TREE_OPERAND (tree11, 1);
		STRIP_NOPS (tree110);
		STRIP_NOPS (tree111);
		if (TREE_CODE (tree110) == INTEGER_CST
		    && 0 == compare_tree_int (tree110,
					      TYPE_PRECISION
					      (TREE_TYPE (TREE_OPERAND
							  (arg0, 0))))
		    && operand_equal_p (tree01, tree111, 0))
		  return build2 ((code0 == LSHIFT_EXPR
				  ? LROTATE_EXPR
				  : RROTATE_EXPR),
				 type, TREE_OPERAND (arg0, 0), tree01);
	      }
	    else if (code01 == MINUS_EXPR)
	      {
		tree tree010, tree011;
		tree010 = TREE_OPERAND (tree01, 0);
		tree011 = TREE_OPERAND (tree01, 1);
		STRIP_NOPS (tree010);
		STRIP_NOPS (tree011);
		if (TREE_CODE (tree010) == INTEGER_CST
		    && 0 == compare_tree_int (tree010,
					      TYPE_PRECISION
					      (TREE_TYPE (TREE_OPERAND
							  (arg0, 0))))
		    && operand_equal_p (tree11, tree011, 0))
		  return build2 ((code0 != LSHIFT_EXPR
				  ? LROTATE_EXPR
				  : RROTATE_EXPR),
				 type, TREE_OPERAND (arg0, 0), tree11);
	      }
	  }
      }

    associate:
      /* In most languages, can't associate operations on floats through
	 parentheses.  Rather than remember where the parentheses were, we
	 don't associate floats at all, unless the user has specified
	 -funsafe-math-optimizations.  */

      if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
	{
	  tree var0, con0, lit0, minus_lit0;
	  tree var1, con1, lit1, minus_lit1;
	  bool ok = true;

	  /* Split both trees into variables, constants, and literals.  Then
	     associate each group together, the constants with literals,
	     then the result with variables.  This increases the chances of
	     literals being recombined later and of generating relocatable
	     expressions for the sum of a constant and literal.  */
	  var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
	  var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
			     code == MINUS_EXPR);

	  /* With undefined overflow we can only associate constants
	     with one variable.  */
	  if ((POINTER_TYPE_P (type)
	       || (INTEGRAL_TYPE_P (type)
		   && !(TYPE_UNSIGNED (type) || flag_wrapv)))
	      && var0 && var1)
	    {
	      tree tmp0 = var0;
	      tree tmp1 = var1;

	      if (TREE_CODE (tmp0) == NEGATE_EXPR)
	        tmp0 = TREE_OPERAND (tmp0, 0);
	      if (TREE_CODE (tmp1) == NEGATE_EXPR)
	        tmp1 = TREE_OPERAND (tmp1, 0);
	      /* The only case we can still associate with two variables
		 is if they are the same, modulo negation.  */
	      if (!operand_equal_p (tmp0, tmp1, 0))
	        ok = false;
	    }

	  /* Only do something if we found more than two objects.  Otherwise,
	     nothing has changed and we risk infinite recursion.  */
	  if (ok
	      && (2 < ((var0 != 0) + (var1 != 0)
		       + (con0 != 0) + (con1 != 0)
		       + (lit0 != 0) + (lit1 != 0)
		       + (minus_lit0 != 0) + (minus_lit1 != 0))))
	    {
	      /* Recombine MINUS_EXPR operands by using PLUS_EXPR.  */
	      if (code == MINUS_EXPR)
		code = PLUS_EXPR;

	      var0 = associate_trees (var0, var1, code, type);
	      con0 = associate_trees (con0, con1, code, type);
	      lit0 = associate_trees (lit0, lit1, code, type);
	      minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);

	      /* Preserve the MINUS_EXPR if the negative part of the literal is
		 greater than the positive part.  Otherwise, the multiplicative
		 folding code (i.e extract_muldiv) may be fooled in case
		 unsigned constants are subtracted, like in the following
		 example: ((X*2 + 4) - 8U)/2.  */
	      if (minus_lit0 && lit0)
		{
		  if (TREE_CODE (lit0) == INTEGER_CST
		      && TREE_CODE (minus_lit0) == INTEGER_CST
		      && tree_int_cst_lt (lit0, minus_lit0))
		    {
		      minus_lit0 = associate_trees (minus_lit0, lit0,
						    MINUS_EXPR, type);
		      lit0 = 0;
		    }
		  else
		    {
		      lit0 = associate_trees (lit0, minus_lit0,
					      MINUS_EXPR, type);
		      minus_lit0 = 0;
		    }
		}
	      if (minus_lit0)
		{
		  if (con0 == 0)
		    return fold_convert (type,
					 associate_trees (var0, minus_lit0,
							  MINUS_EXPR, type));
		  else
		    {
		      con0 = associate_trees (con0, minus_lit0,
					      MINUS_EXPR, type);
		      return fold_convert (type,
					   associate_trees (var0, con0,
							    PLUS_EXPR, type));
		    }
		}

	      con0 = associate_trees (con0, lit0, code, type);
	      return fold_convert (type, associate_trees (var0, con0,
							  code, type));
	    }
	}

      return NULL_TREE;

    case MINUS_EXPR:
      /* A - (-B) -> A + B */
      if (TREE_CODE (arg1) == NEGATE_EXPR)
	return fold_build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0));
      /* (-A) - B -> (-B) - A  where B is easily negated and we can swap.  */
      if (TREE_CODE (arg0) == NEGATE_EXPR
	  && (FLOAT_TYPE_P (type)
	      || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
	  && negate_expr_p (arg1)
	  && reorder_operands_p (arg0, arg1))
	return fold_build2 (MINUS_EXPR, type, negate_expr (arg1),
			    TREE_OPERAND (arg0, 0));
      /* Convert -A - 1 to ~A.  */
      if (INTEGRAL_TYPE_P (type)
	  && TREE_CODE (arg0) == NEGATE_EXPR
	  && integer_onep (arg1))
	return fold_build1 (BIT_NOT_EXPR, type,
			    fold_convert (type, TREE_OPERAND (arg0, 0)));

      /* Convert -1 - A to ~A.  */
      if (INTEGRAL_TYPE_P (type)
	  && integer_all_onesp (arg0))
	return fold_build1 (BIT_NOT_EXPR, type, arg1);

      if (! FLOAT_TYPE_P (type))
	{
	  if (integer_zerop (arg0))
	    return negate_expr (fold_convert (type, arg1));
	  if (integer_zerop (arg1))
	    return non_lvalue (fold_convert (type, arg0));

	  /* Fold A - (A & B) into ~B & A.  */
	  if (!TREE_SIDE_EFFECTS (arg0)
	      && TREE_CODE (arg1) == BIT_AND_EXPR)
	    {
	      if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
		return fold_build2 (BIT_AND_EXPR, type,
				    fold_build1 (BIT_NOT_EXPR, type,
						 TREE_OPERAND (arg1, 0)),
				    arg0);
	      if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
		return fold_build2 (BIT_AND_EXPR, type,
				    fold_build1 (BIT_NOT_EXPR, type,
						 TREE_OPERAND (arg1, 1)),
				    arg0);
	    }

	  /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
	     any power of 2 minus 1.  */
	  if (TREE_CODE (arg0) == BIT_AND_EXPR
	      && TREE_CODE (arg1) == BIT_AND_EXPR
	      && operand_equal_p (TREE_OPERAND (arg0, 0),
				  TREE_OPERAND (arg1, 0), 0))
	    {
	      tree mask0 = TREE_OPERAND (arg0, 1);
	      tree mask1 = TREE_OPERAND (arg1, 1);
	      tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);

	      if (operand_equal_p (tem, mask1, 0))
		{
		  tem = fold_build2 (BIT_XOR_EXPR, type,
				     TREE_OPERAND (arg0, 0), mask1);
		  return fold_build2 (MINUS_EXPR, type, tem, mask1);
		}
	    }
	}

      /* See if ARG1 is zero and X - ARG1 reduces to X.  */
      else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
	return non_lvalue (fold_convert (type, arg0));

      /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0).  So check whether
	 ARG0 is zero and X + ARG0 reduces to X, since that would mean
	 (-ARG1 + ARG0) reduces to -ARG1.  */
      else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
	return negate_expr (fold_convert (type, arg1));

      /* Fold &x - &x.  This can happen from &x.foo - &x.
	 This is unsafe for certain floats even in non-IEEE formats.
	 In IEEE, it is unsafe because it does wrong for NaNs.
	 Also note that operand_equal_p is always false if an operand
	 is volatile.  */

      if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
	  && operand_equal_p (arg0, arg1, 0))
	return fold_convert (type, integer_zero_node);

      /* A - B -> A + (-B) if B is easily negatable.  */
      if (negate_expr_p (arg1)
	  && ((FLOAT_TYPE_P (type)
               /* Avoid this transformation if B is a positive REAL_CST.  */
	       && (TREE_CODE (arg1) != REAL_CST
		   ||  REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
	      || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
	return fold_build2 (PLUS_EXPR, type,
			    fold_convert (type, arg0),
			    fold_convert (type, negate_expr (arg1)));

      /* Try folding difference of addresses.  */
      {
	HOST_WIDE_INT diff;

	if ((TREE_CODE (arg0) == ADDR_EXPR
	     || TREE_CODE (arg1) == ADDR_EXPR)
	    && ptr_difference_const (arg0, arg1, &diff))
	  return build_int_cst_type (type, diff);
      }

      /* Fold &a[i] - &a[j] to i-j.  */
      if (TREE_CODE (arg0) == ADDR_EXPR
	  && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
	  && TREE_CODE (arg1) == ADDR_EXPR
	  && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
        {
	  tree aref0 = TREE_OPERAND (arg0, 0);
	  tree aref1 = TREE_OPERAND (arg1, 0);
	  if (operand_equal_p (TREE_OPERAND (aref0, 0),
			       TREE_OPERAND (aref1, 0), 0))
	    {
	      tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
	      tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
	      tree esz = array_ref_element_size (aref0);
	      tree diff = build2 (MINUS_EXPR, type, op0, op1);
	      return fold_build2 (MULT_EXPR, type, diff,
			          fold_convert (type, esz));
			          
	    }
	}

      /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
	 of the array.  Loop optimizer sometimes produce this type of
	 expressions.  */
      if (TREE_CODE (arg0) == ADDR_EXPR)
	{
	  tem = try_move_mult_to_index (MINUS_EXPR, arg0, arg1);
	  if (tem)
	    return fold_convert (type, tem);
	}

      if (flag_unsafe_math_optimizations
	  && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
	  && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
	  && (tem = distribute_real_division (code, type, arg0, arg1)))
	return tem;

      /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
	 same or one.  */
      if ((TREE_CODE (arg0) == MULT_EXPR
	   || TREE_CODE (arg1) == MULT_EXPR)
	  && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
        {
	  tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
	  if (tem)
	    return tem;
	}

      goto associate;

    case MULT_EXPR:
      /* (-A) * (-B) -> A * B  */
      if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
	return fold_build2 (MULT_EXPR, type,
			    fold_convert (type, TREE_OPERAND (arg0, 0)),
			    fold_convert (type, negate_expr (arg1)));
      if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
	return fold_build2 (MULT_EXPR, type,
			    fold_convert (type, negate_expr (arg0)),
			    fold_convert (type, TREE_OPERAND (arg1, 0)));

      if (! FLOAT_TYPE_P (type))
	{
	  if (integer_zerop (arg1))
	    return omit_one_operand (type, arg1, arg0);
	  if (integer_onep (arg1))
	    return non_lvalue (fold_convert (type, arg0));
	  /* Transform x * -1 into -x.  */
	  if (integer_all_onesp (arg1))
	    return fold_convert (type, negate_expr (arg0));

	  /* (a * (1 << b)) is (a << b)  */
	  if (TREE_CODE (arg1) == LSHIFT_EXPR
	      && integer_onep (TREE_OPERAND (arg1, 0)))
	    return fold_build2 (LSHIFT_EXPR, type, arg0,
				TREE_OPERAND (arg1, 1));
	  if (TREE_CODE (arg0) == LSHIFT_EXPR
	      && integer_onep (TREE_OPERAND (arg0, 0)))
	    return fold_build2 (LSHIFT_EXPR, type, arg1,
				TREE_OPERAND (arg0, 1));

	  strict_overflow_p = false;
	  if (TREE_CODE (arg1) == INTEGER_CST
	      && 0 != (tem = extract_muldiv (op0,
					     fold_convert (type, arg1),
					     code, NULL_TREE,
					     &strict_overflow_p)))
	    {
	      if (strict_overflow_p)
		fold_overflow_warning (("assuming signed overflow does not "
					"occur when simplifying "
					"multiplication"),
				       WARN_STRICT_OVERFLOW_MISC);
	      return fold_convert (type, tem);
	    }

	  /* Optimize z * conj(z) for integer complex numbers.  */
	  if (TREE_CODE (arg0) == CONJ_EXPR
	      && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
	    return fold_mult_zconjz (type, arg1);
	  if (TREE_CODE (arg1) == CONJ_EXPR
	      && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
	    return fold_mult_zconjz (type, arg0);
	}
      else
	{
	  /* Maybe fold x * 0 to 0.  The expressions aren't the same
	     when x is NaN, since x * 0 is also NaN.  Nor are they the
	     same in modes with signed zeros, since multiplying a
	     negative value by 0 gives -0, not +0.  */
	  if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
	      && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
	      && real_zerop (arg1))
	    return omit_one_operand (type, arg1, arg0);
	  /* In IEEE floating point, x*1 is not equivalent to x for snans.  */
	  if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
	      && real_onep (arg1))
	    return non_lvalue (fold_convert (type, arg0));

	  /* Transform x * -1.0 into -x.  */
	  if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
	      && real_minus_onep (arg1))
	    return fold_convert (type, negate_expr (arg0));

	  /* Convert (C1/X)*C2 into (C1*C2)/X.  */
	  if (flag_unsafe_math_optimizations
	      && TREE_CODE (arg0) == RDIV_EXPR
	      && TREE_CODE (arg1) == REAL_CST
	      && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
	    {
	      tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
				      arg1, 0);
	      if (tem)
		return fold_build2 (RDIV_EXPR, type, tem,
				    TREE_OPERAND (arg0, 1));
	    }

          /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y.  */
	  if (operand_equal_p (arg0, arg1, 0))
	    {
	      tree tem = fold_strip_sign_ops (arg0);
	      if (tem != NULL_TREE)
		{
		  tem = fold_convert (type, tem);
		  return fold_build2 (MULT_EXPR, type, tem, tem);
		}
	    }

	  /* Optimize z * conj(z) for floating point complex numbers.
	     Guarded by flag_unsafe_math_optimizations as non-finite
	     imaginary components don't produce scalar results.  */
	  if (flag_unsafe_math_optimizations
	      && TREE_CODE (arg0) == CONJ_EXPR
	      && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
	    return fold_mult_zconjz (type, arg1);
	  if (flag_unsafe_math_optimizations
	      && TREE_CODE (arg1) == CONJ_EXPR
	      && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
	    return fold_mult_zconjz (type, arg0);

	  if (flag_unsafe_math_optimizations)
	    {
	      enum built_in_function fcode0 = builtin_mathfn_code (arg0);
	      enum built_in_function fcode1 = builtin_mathfn_code (arg1);

	      /* Optimizations of root(...)*root(...).  */
	      if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
		{
		  tree rootfn, arg, arglist;
		  tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
		  tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));

		  /* Optimize sqrt(x)*sqrt(x) as x.  */
		  if (BUILTIN_SQRT_P (fcode0)
		      && operand_equal_p (arg00, arg10, 0)
		      && ! HONOR_SNANS (TYPE_MODE (type)))
		    return arg00;

	          /* Optimize root(x)*root(y) as root(x*y).  */
		  rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
		  arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
		  arglist = build_tree_list (NULL_TREE, arg);
		  return build_function_call_expr (rootfn, arglist);
		}

	      /* Optimize expN(x)*expN(y) as expN(x+y).  */
	      if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
		{
		  tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
		  tree arg = fold_build2 (PLUS_EXPR, type,
					  TREE_VALUE (TREE_OPERAND (arg0, 1)),
					  TREE_VALUE (TREE_OPERAND (arg1, 1)));
		  tree arglist = build_tree_list (NULL_TREE, arg);
		  return build_function_call_expr (expfn, arglist);
		}

	      /* Optimizations of pow(...)*pow(...).  */
	      if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
		  || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
		  || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
		{
		  tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
		  tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
								     1)));
		  tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
		  tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
								     1)));

		  /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y).  */
		  if (operand_equal_p (arg01, arg11, 0))
		    {
		      tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
		      tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
		      tree arglist = tree_cons (NULL_TREE, arg,
						build_tree_list (NULL_TREE,
								 arg01));
		      return build_function_call_expr (powfn, arglist);
		    }

		  /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z).  */
		  if (operand_equal_p (arg00, arg10, 0))
		    {
		      tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
		      tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
		      tree arglist = tree_cons (NULL_TREE, arg00,
						build_tree_list (NULL_TREE,
								 arg));
		      return build_function_call_expr (powfn, arglist);
		    }
		}

	      /* Optimize tan(x)*cos(x) as sin(x).  */
	      if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
		   || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
		   || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
		   || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
		   || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
		   || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
		  && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
				      TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
		{
		  tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);

		  if (sinfn != NULL_TREE)
		    return build_function_call_expr (sinfn,
						     TREE_OPERAND (arg0, 1));
		}

	      /* Optimize x*pow(x,c) as pow(x,c+1).  */
	      if (fcode1 == BUILT_IN_POW
		  || fcode1 == BUILT_IN_POWF
		  || fcode1 == BUILT_IN_POWL)
		{
		  tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
		  tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
								     1)));
		  if (TREE_CODE (arg11) == REAL_CST
		      && ! TREE_CONSTANT_OVERFLOW (arg11)
		      && operand_equal_p (arg0, arg10, 0))
		    {
		      tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
		      REAL_VALUE_TYPE c;
		      tree arg, arglist;

		      c = TREE_REAL_CST (arg11);
		      real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
		      arg = build_real (type, c);
		      arglist = build_tree_list (NULL_TREE, arg);
		      arglist = tree_cons (NULL_TREE, arg0, arglist);
		      return build_function_call_expr (powfn, arglist);
		    }
		}

	      /* Optimize pow(x,c)*x as pow(x,c+1).  */
	      if (fcode0 == BUILT_IN_POW
		  || fcode0 == BUILT_IN_POWF
		  || fcode0 == BUILT_IN_POWL)
		{
		  tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
		  tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
								     1)));
		  if (TREE_CODE (arg01) == REAL_CST
		      && ! TREE_CONSTANT_OVERFLOW (arg01)
		      && operand_equal_p (arg1, arg00, 0))
		    {
		      tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
		      REAL_VALUE_TYPE c;
		      tree arg, arglist;

		      c = TREE_REAL_CST (arg01);
		      real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
		      arg = build_real (type, c);
		      arglist = build_tree_list (NULL_TREE, arg);
		      arglist = tree_cons (NULL_TREE, arg1, arglist);
		      return build_function_call_expr (powfn, arglist);
		    }
		}

	      /* Optimize x*x as pow(x,2.0), which is expanded as x*x.  */
	      if (! optimize_size
		  && operand_equal_p (arg0, arg1, 0))
		{
		  tree powfn = mathfn_built_in (type, BUILT_IN_POW);

		  if (powfn)
		    {
		      tree arg = build_real (type, dconst2);
		      tree arglist = build_tree_list (NULL_TREE, arg);
		      arglist = tree_cons (NULL_TREE, arg0, arglist);
		      return build_function_call_expr (powfn, arglist);
		    }
		}
	    }
	}
      goto associate;

    case BIT_IOR_EXPR:
    bit_ior:
      if (integer_all_onesp (arg1))
	return omit_one_operand (type, arg1, arg0);
      if (integer_zerop (arg1))
	return non_lvalue (fold_convert (type, arg0));
      if (operand_equal_p (arg0, arg1, 0))
	return non_lvalue (fold_convert (type, arg0));

      /* ~X | X is -1.  */
      if (TREE_CODE (arg0) == BIT_NOT_EXPR
	  && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
	{
	  t1 = build_int_cst (type, -1);
	  t1 = force_fit_type (t1, 0, false, false);
	  return omit_one_operand (type, t1, arg1);
	}

      /* X | ~X is -1.  */
      if (TREE_CODE (arg1) == BIT_NOT_EXPR
	  && INTEGRAL_TYPE_P (TREE_TYPE (arg0))
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
	{
	  t1 = build_int_cst (type, -1);
	  t1 = force_fit_type (t1, 0, false, false);
	  return omit_one_operand (type, t1, arg0);
	}

      /* Canonicalize (X & C1) | C2.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && TREE_CODE (arg1) == INTEGER_CST
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
	{
	  unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, mlo, mhi;
	  int width = TYPE_PRECISION (type);
	  hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
	  lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
	  hi2 = TREE_INT_CST_HIGH (arg1);
	  lo2 = TREE_INT_CST_LOW (arg1);

	  /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2).  */
	  if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
	    return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));

	  if (width > HOST_BITS_PER_WIDE_INT)
	    {
	      mhi = (unsigned HOST_WIDE_INT) -1 
		    >> (2 * HOST_BITS_PER_WIDE_INT - width);
	      mlo = -1;
	    }
	  else
	    {
	      mhi = 0;
	      mlo = (unsigned HOST_WIDE_INT) -1
		    >> (HOST_BITS_PER_WIDE_INT - width);
	    }

	  /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2.  */
	  if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
	    return fold_build2 (BIT_IOR_EXPR, type,
				TREE_OPERAND (arg0, 0), arg1);

	  /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2.  */
	  hi1 &= mhi;
	  lo1 &= mlo;
	  if ((hi1 & ~hi2) != hi1 || (lo1 & ~lo2) != lo1)
	    return fold_build2 (BIT_IOR_EXPR, type,
				fold_build2 (BIT_AND_EXPR, type,
					     TREE_OPERAND (arg0, 0),
					     build_int_cst_wide (type,
								 lo1 & ~lo2,
								 hi1 & ~hi2)),
				arg1);
	}

      /* (X & Y) | Y is (X, Y).  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
	return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
      /* (X & Y) | X is (Y, X).  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
	  && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
	return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
      /* X | (X & Y) is (Y, X).  */
      if (TREE_CODE (arg1) == BIT_AND_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
	return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
      /* X | (Y & X) is (Y, X).  */
      if (TREE_CODE (arg1) == BIT_AND_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
	return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));

      t1 = distribute_bit_expr (code, type, arg0, arg1);
      if (t1 != NULL_TREE)
	return t1;

      /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).

	 This results in more efficient code for machines without a NAND
	 instruction.  Combine will canonicalize to the first form
	 which will allow use of NAND instructions provided by the
	 backend if they exist.  */
      if (TREE_CODE (arg0) == BIT_NOT_EXPR
	  && TREE_CODE (arg1) == BIT_NOT_EXPR)
	{
	  return fold_build1 (BIT_NOT_EXPR, type,
			      build2 (BIT_AND_EXPR, type,
				      TREE_OPERAND (arg0, 0),
				      TREE_OPERAND (arg1, 0)));
	}

      /* See if this can be simplified into a rotate first.  If that
	 is unsuccessful continue in the association code.  */
      goto bit_rotate;

    case BIT_XOR_EXPR:
      if (integer_zerop (arg1))
	return non_lvalue (fold_convert (type, arg0));
      if (integer_all_onesp (arg1))
	return fold_build1 (BIT_NOT_EXPR, type, arg0);
      if (operand_equal_p (arg0, arg1, 0))
	return omit_one_operand (type, integer_zero_node, arg0);

      /* ~X ^ X is -1.  */
      if (TREE_CODE (arg0) == BIT_NOT_EXPR
	  && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
	{
	  t1 = build_int_cst (type, -1);
	  t1 = force_fit_type (t1, 0, false, false);
	  return omit_one_operand (type, t1, arg1);
	}

      /* X ^ ~X is -1.  */
      if (TREE_CODE (arg1) == BIT_NOT_EXPR
	  && INTEGRAL_TYPE_P (TREE_TYPE (arg0))
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
	{
	  t1 = build_int_cst (type, -1);
	  t1 = force_fit_type (t1, 0, false, false);
	  return omit_one_operand (type, t1, arg0);
	}

      /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
         with a constant, and the two constants have no bits in common,
	 we should treat this as a BIT_IOR_EXPR since this may produce more
	 simplifications.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && TREE_CODE (arg1) == BIT_AND_EXPR
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
	  && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
	  && integer_zerop (const_binop (BIT_AND_EXPR,
					 TREE_OPERAND (arg0, 1),
					 TREE_OPERAND (arg1, 1), 0)))
	{
	  code = BIT_IOR_EXPR;
	  goto bit_ior;
	}

      /* (X | Y) ^ X -> Y & ~ X*/
      if (TREE_CODE (arg0) == BIT_IOR_EXPR
          && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
        {
	  tree t2 = TREE_OPERAND (arg0, 1);
	  t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
			    arg1);
	  t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
			    fold_convert (type, t1));
	  return t1;
	}

      /* (Y | X) ^ X -> Y & ~ X*/
      if (TREE_CODE (arg0) == BIT_IOR_EXPR
          && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
        {
	  tree t2 = TREE_OPERAND (arg0, 0);
	  t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
			    arg1);
	  t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
			    fold_convert (type, t1));
	  return t1;
	}

      /* X ^ (X | Y) -> Y & ~ X*/
      if (TREE_CODE (arg1) == BIT_IOR_EXPR
          && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
        {
	  tree t2 = TREE_OPERAND (arg1, 1);
	  t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
			    arg0);
	  t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
			    fold_convert (type, t1));
	  return t1;
	}

      /* X ^ (Y | X) -> Y & ~ X*/
      if (TREE_CODE (arg1) == BIT_IOR_EXPR
          && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
        {
	  tree t2 = TREE_OPERAND (arg1, 0);
	  t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
			    arg0);
	  t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
			    fold_convert (type, t1));
	  return t1;
	}
	
      /* Convert ~X ^ ~Y to X ^ Y.  */
      if (TREE_CODE (arg0) == BIT_NOT_EXPR
	  && TREE_CODE (arg1) == BIT_NOT_EXPR)
	return fold_build2 (code, type,
			    fold_convert (type, TREE_OPERAND (arg0, 0)),
			    fold_convert (type, TREE_OPERAND (arg1, 0)));

      /* Fold (X & 1) ^ 1 as (X & 1) == 0.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && integer_onep (TREE_OPERAND (arg0, 1))
	  && integer_onep (arg1))
	return fold_build2 (EQ_EXPR, type, arg0,
			    build_int_cst (TREE_TYPE (arg0), 0));

      /* Fold (X & Y) ^ Y as ~X & Y.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
	{
	  tem = fold_convert (type, TREE_OPERAND (arg0, 0));
	  return fold_build2 (BIT_AND_EXPR, type, 
			      fold_build1 (BIT_NOT_EXPR, type, tem),
			      fold_convert (type, arg1));
	}
      /* Fold (X & Y) ^ X as ~Y & X.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
	  && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
	{
	  tem = fold_convert (type, TREE_OPERAND (arg0, 1));
	  return fold_build2 (BIT_AND_EXPR, type,
			      fold_build1 (BIT_NOT_EXPR, type, tem),
			      fold_convert (type, arg1));
	}
      /* Fold X ^ (X & Y) as X & ~Y.  */
      if (TREE_CODE (arg1) == BIT_AND_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
	{
	  tem = fold_convert (type, TREE_OPERAND (arg1, 1));
	  return fold_build2 (BIT_AND_EXPR, type,
			      fold_convert (type, arg0),
			      fold_build1 (BIT_NOT_EXPR, type, tem));
	}
      /* Fold X ^ (Y & X) as ~Y & X.  */
      if (TREE_CODE (arg1) == BIT_AND_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
	{
	  tem = fold_convert (type, TREE_OPERAND (arg1, 0));
	  return fold_build2 (BIT_AND_EXPR, type,
			      fold_build1 (BIT_NOT_EXPR, type, tem),
			      fold_convert (type, arg0));
	}

      /* See if this can be simplified into a rotate first.  If that
	 is unsuccessful continue in the association code.  */
      goto bit_rotate;

    case BIT_AND_EXPR:
      if (integer_all_onesp (arg1))
	return non_lvalue (fold_convert (type, arg0));
      if (integer_zerop (arg1))
	return omit_one_operand (type, arg1, arg0);
      if (operand_equal_p (arg0, arg1, 0))
	return non_lvalue (fold_convert (type, arg0));

      /* ~X & X is always zero.  */
      if (TREE_CODE (arg0) == BIT_NOT_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
	return omit_one_operand (type, integer_zero_node, arg1);

      /* X & ~X is always zero.  */
      if (TREE_CODE (arg1) == BIT_NOT_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
	return omit_one_operand (type, integer_zero_node, arg0);

      /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2).  */
      if (TREE_CODE (arg0) == BIT_IOR_EXPR
	  && TREE_CODE (arg1) == INTEGER_CST
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
	return fold_build2 (BIT_IOR_EXPR, type,
			    fold_build2 (BIT_AND_EXPR, type,
					 TREE_OPERAND (arg0, 0), arg1),
			    fold_build2 (BIT_AND_EXPR, type,
					 TREE_OPERAND (arg0, 1), arg1));

      /* (X | Y) & Y is (X, Y).  */
      if (TREE_CODE (arg0) == BIT_IOR_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
	return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
      /* (X | Y) & X is (Y, X).  */
      if (TREE_CODE (arg0) == BIT_IOR_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
	  && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
	return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
      /* X & (X | Y) is (Y, X).  */
      if (TREE_CODE (arg1) == BIT_IOR_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
	return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
      /* X & (Y | X) is (Y, X).  */
      if (TREE_CODE (arg1) == BIT_IOR_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
	return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));

      /* Fold (X ^ 1) & 1 as (X & 1) == 0.  */
      if (TREE_CODE (arg0) == BIT_XOR_EXPR
	  && integer_onep (TREE_OPERAND (arg0, 1))
	  && integer_onep (arg1))
	{
	  tem = TREE_OPERAND (arg0, 0);
	  return fold_build2 (EQ_EXPR, type,
			      fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
					   build_int_cst (TREE_TYPE (tem), 1)),
			      build_int_cst (TREE_TYPE (tem), 0));
	}
      /* Fold ~X & 1 as (X & 1) == 0.  */
      if (TREE_CODE (arg0) == BIT_NOT_EXPR
	  && integer_onep (arg1))
	{
	  tem = TREE_OPERAND (arg0, 0);
	  return fold_build2 (EQ_EXPR, type,
			      fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
					   build_int_cst (TREE_TYPE (tem), 1)),
			      build_int_cst (TREE_TYPE (tem), 0));
	}

      /* Fold (X ^ Y) & Y as ~X & Y.  */
      if (TREE_CODE (arg0) == BIT_XOR_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
	{
	  tem = fold_convert (type, TREE_OPERAND (arg0, 0));
	  return fold_build2 (BIT_AND_EXPR, type, 
			      fold_build1 (BIT_NOT_EXPR, type, tem),
			      fold_convert (type, arg1));
	}
      /* Fold (X ^ Y) & X as ~Y & X.  */
      if (TREE_CODE (arg0) == BIT_XOR_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
	  && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
	{
	  tem = fold_convert (type, TREE_OPERAND (arg0, 1));
	  return fold_build2 (BIT_AND_EXPR, type,
			      fold_build1 (BIT_NOT_EXPR, type, tem),
			      fold_convert (type, arg1));
	}
      /* Fold X & (X ^ Y) as X & ~Y.  */
      if (TREE_CODE (arg1) == BIT_XOR_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
	{
	  tem = fold_convert (type, TREE_OPERAND (arg1, 1));
	  return fold_build2 (BIT_AND_EXPR, type,
			      fold_convert (type, arg0),
			      fold_build1 (BIT_NOT_EXPR, type, tem));
	}
      /* Fold X & (Y ^ X) as ~Y & X.  */
      if (TREE_CODE (arg1) == BIT_XOR_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
	{
	  tem = fold_convert (type, TREE_OPERAND (arg1, 0));
	  return fold_build2 (BIT_AND_EXPR, type,
			      fold_build1 (BIT_NOT_EXPR, type, tem),
			      fold_convert (type, arg0));
	}

      t1 = distribute_bit_expr (code, type, arg0, arg1);
      if (t1 != NULL_TREE)
	return t1;
      /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char.  */
      if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
	  && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
	{
	  unsigned int prec
	    = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));

	  if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
	      && (~TREE_INT_CST_LOW (arg1)
		  & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
	    return fold_convert (type, TREE_OPERAND (arg0, 0));
	}

      /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).

	 This results in more efficient code for machines without a NOR
	 instruction.  Combine will canonicalize to the first form
	 which will allow use of NOR instructions provided by the
	 backend if they exist.  */
      if (TREE_CODE (arg0) == BIT_NOT_EXPR
	  && TREE_CODE (arg1) == BIT_NOT_EXPR)
	{
	  return fold_build1 (BIT_NOT_EXPR, type,
			      build2 (BIT_IOR_EXPR, type,
				      TREE_OPERAND (arg0, 0),
				      TREE_OPERAND (arg1, 0)));
	}

      goto associate;

    case RDIV_EXPR:
      /* Don't touch a floating-point divide by zero unless the mode
	 of the constant can represent infinity.  */
      if (TREE_CODE (arg1) == REAL_CST
	  && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
	  && real_zerop (arg1))
	return NULL_TREE;

      /* Optimize A / A to 1.0 if we don't care about
	 NaNs or Infinities.  Skip the transformation
	 for non-real operands.  */
      if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
	  && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
	  && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
	  && operand_equal_p (arg0, arg1, 0))
	{
	  tree r = build_real (TREE_TYPE (arg0), dconst1);

	  return omit_two_operands (type, r, arg0, arg1);
	}

      /* The complex version of the above A / A optimization.  */
      if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
	  && operand_equal_p (arg0, arg1, 0))
	{
	  tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
	  if (! HONOR_NANS (TYPE_MODE (elem_type))
	      && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
	    {
	      tree r = build_real (elem_type, dconst1);
	      /* omit_two_operands will call fold_convert for us.  */
	      return omit_two_operands (type, r, arg0, arg1);
	    }
	}

      /* (-A) / (-B) -> A / B  */
      if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
	return fold_build2 (RDIV_EXPR, type,
			    TREE_OPERAND (arg0, 0),
			    negate_expr (arg1));
      if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
	return fold_build2 (RDIV_EXPR, type,
			    negate_expr (arg0),
			    TREE_OPERAND (arg1, 0));

      /* In IEEE floating point, x/1 is not equivalent to x for snans.  */
      if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
	  && real_onep (arg1))
	return non_lvalue (fold_convert (type, arg0));

      /* In IEEE floating point, x/-1 is not equivalent to -x for snans.  */
      if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
	  && real_minus_onep (arg1))
	return non_lvalue (fold_convert (type, negate_expr (arg0)));

      /* If ARG1 is a constant, we can convert this to a multiply by the
	 reciprocal.  This does not have the same rounding properties,
	 so only do this if -funsafe-math-optimizations.  We can actually
	 always safely do it if ARG1 is a power of two, but it's hard to
	 tell if it is or not in a portable manner.  */
      if (TREE_CODE (arg1) == REAL_CST)
	{
	  if (flag_unsafe_math_optimizations
	      && 0 != (tem = const_binop (code, build_real (type, dconst1),
					  arg1, 0)))
	    return fold_build2 (MULT_EXPR, type, arg0, tem);
	  /* Find the reciprocal if optimizing and the result is exact.  */
	  if (optimize)
	    {
	      REAL_VALUE_TYPE r;
	      r = TREE_REAL_CST (arg1);
	      if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
		{
		  tem = build_real (type, r);
		  return fold_build2 (MULT_EXPR, type,
				      fold_convert (type, arg0), tem);
		}
	    }
	}
      /* Convert A/B/C to A/(B*C).  */
      if (flag_unsafe_math_optimizations
	  && TREE_CODE (arg0) == RDIV_EXPR)
	return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
			    fold_build2 (MULT_EXPR, type,
					 TREE_OPERAND (arg0, 1), arg1));

      /* Convert A/(B/C) to (A/B)*C.  */
      if (flag_unsafe_math_optimizations
	  && TREE_CODE (arg1) == RDIV_EXPR)
	return fold_build2 (MULT_EXPR, type,
			    fold_build2 (RDIV_EXPR, type, arg0,
					 TREE_OPERAND (arg1, 0)),
			    TREE_OPERAND (arg1, 1));

      /* Convert C1/(X*C2) into (C1/C2)/X.  */
      if (flag_unsafe_math_optimizations
	  && TREE_CODE (arg1) == MULT_EXPR
	  && TREE_CODE (arg0) == REAL_CST
	  && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
	{
	  tree tem = const_binop (RDIV_EXPR, arg0,
				  TREE_OPERAND (arg1, 1), 0);
	  if (tem)
	    return fold_build2 (RDIV_EXPR, type, tem,
				TREE_OPERAND (arg1, 0));
	}

      if (flag_unsafe_math_optimizations)
	{
	  enum built_in_function fcode0 = builtin_mathfn_code (arg0);
	  enum built_in_function fcode1 = builtin_mathfn_code (arg1);

	  /* Optimize sin(x)/cos(x) as tan(x).  */
	  if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
	       || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
	       || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
	      && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
				  TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
	    {
	      tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);

	      if (tanfn != NULL_TREE)
		return build_function_call_expr (tanfn,
						 TREE_OPERAND (arg0, 1));
	    }

	  /* Optimize cos(x)/sin(x) as 1.0/tan(x).  */
	  if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
	       || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
	       || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
	      && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
				  TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
	    {
	      tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);

	      if (tanfn != NULL_TREE)
		{
		  tree tmp = TREE_OPERAND (arg0, 1);
		  tmp = build_function_call_expr (tanfn, tmp);
		  return fold_build2 (RDIV_EXPR, type,
				      build_real (type, dconst1), tmp);
		}
	    }

 	  /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
	     NaNs or Infinities.  */
 	  if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
 	       || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
 	       || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
	    {
	      tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
	      tree arg01 = TREE_VALUE (TREE_OPERAND (arg1, 1));

	      if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
		  && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
		  && operand_equal_p (arg00, arg01, 0))
		{
		  tree cosfn = mathfn_built_in (type, BUILT_IN_COS);

		  if (cosfn != NULL_TREE)
		    return build_function_call_expr (cosfn,
						     TREE_OPERAND (arg0, 1));
		}
	    }

 	  /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
	     NaNs or Infinities.  */
 	  if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
 	       || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
 	       || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
	    {
	      tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
	      tree arg01 = TREE_VALUE (TREE_OPERAND (arg1, 1));

	      if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
		  && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
		  && operand_equal_p (arg00, arg01, 0))
		{
		  tree cosfn = mathfn_built_in (type, BUILT_IN_COS);

		  if (cosfn != NULL_TREE)
		    {
		      tree tmp = TREE_OPERAND (arg0, 1);
		      tmp = build_function_call_expr (cosfn, tmp);
		      return fold_build2 (RDIV_EXPR, type,
					  build_real (type, dconst1),
					  tmp);
		    }
		}
	    }

	  /* Optimize pow(x,c)/x as pow(x,c-1).  */
	  if (fcode0 == BUILT_IN_POW
	      || fcode0 == BUILT_IN_POWF
	      || fcode0 == BUILT_IN_POWL)
	    {
	      tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
	      tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
	      if (TREE_CODE (arg01) == REAL_CST
		  && ! TREE_CONSTANT_OVERFLOW (arg01)
		  && operand_equal_p (arg1, arg00, 0))
		{
		  tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
		  REAL_VALUE_TYPE c;
		  tree arg, arglist;

		  c = TREE_REAL_CST (arg01);
		  real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
		  arg = build_real (type, c);
		  arglist = build_tree_list (NULL_TREE, arg);
		  arglist = tree_cons (NULL_TREE, arg1, arglist);
		  return build_function_call_expr (powfn, arglist);
		}
	    }

	  /* Optimize x/expN(y) into x*expN(-y).  */
	  if (BUILTIN_EXPONENT_P (fcode1))
	    {
	      tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
	      tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
	      tree arglist = build_tree_list (NULL_TREE,
					      fold_convert (type, arg));
	      arg1 = build_function_call_expr (expfn, arglist);
	      return fold_build2 (MULT_EXPR, type, arg0, arg1);
	    }

	  /* Optimize x/pow(y,z) into x*pow(y,-z).  */
	  if (fcode1 == BUILT_IN_POW
	      || fcode1 == BUILT_IN_POWF
	      || fcode1 == BUILT_IN_POWL)
	    {
	      tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
	      tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
	      tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
	      tree neg11 = fold_convert (type, negate_expr (arg11));
	      tree arglist = tree_cons(NULL_TREE, arg10,
				       build_tree_list (NULL_TREE, neg11));
	      arg1 = build_function_call_expr (powfn, arglist);
	      return fold_build2 (MULT_EXPR, type, arg0, arg1);
	    }
	}
      return NULL_TREE;

    case TRUNC_DIV_EXPR:
    case FLOOR_DIV_EXPR:
      /* Simplify A / (B << N) where A and B are positive and B is
	 a power of 2, to A >> (N + log2(B)).  */
      strict_overflow_p = false;
      if (TREE_CODE (arg1) == LSHIFT_EXPR
	  && (TYPE_UNSIGNED (type)
	      || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
	{
	  tree sval = TREE_OPERAND (arg1, 0);
	  if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
	    {
	      tree sh_cnt = TREE_OPERAND (arg1, 1);
	      unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));

	      if (strict_overflow_p)
		fold_overflow_warning (("assuming signed overflow does not "
					"occur when simplifying A / (B << N)"),
				       WARN_STRICT_OVERFLOW_MISC);

	      sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
				    sh_cnt, build_int_cst (NULL_TREE, pow2));
	      return fold_build2 (RSHIFT_EXPR, type,
				  fold_convert (type, arg0), sh_cnt);
	    }
	}
      /* Fall thru */

    case ROUND_DIV_EXPR:
    case CEIL_DIV_EXPR:
    case EXACT_DIV_EXPR:
      if (integer_onep (arg1))
	return non_lvalue (fold_convert (type, arg0));
      if (integer_zerop (arg1))
	return NULL_TREE;
      /* X / -1 is -X.  */
      if (!TYPE_UNSIGNED (type)
	  && TREE_CODE (arg1) == INTEGER_CST
	  && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
	  && TREE_INT_CST_HIGH (arg1) == -1)
	return fold_convert (type, negate_expr (arg0));

      /* Convert -A / -B to A / B when the type is signed and overflow is
	 undefined.  */
      if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
	  && TREE_CODE (arg0) == NEGATE_EXPR
	  && negate_expr_p (arg1))
	{
	  if (INTEGRAL_TYPE_P (type))
	    fold_overflow_warning (("assuming signed overflow does not occur "
				    "when distributing negation across "
				    "division"),
				   WARN_STRICT_OVERFLOW_MISC);
	  return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
			      negate_expr (arg1));
	}
      if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
	  && TREE_CODE (arg1) == NEGATE_EXPR
	  && negate_expr_p (arg0))
	{
	  if (INTEGRAL_TYPE_P (type))
	    fold_overflow_warning (("assuming signed overflow does not occur "
				    "when distributing negation across "
				    "division"),
				   WARN_STRICT_OVERFLOW_MISC);
	  return fold_build2 (code, type, negate_expr (arg0),
			      TREE_OPERAND (arg1, 0));
	}

      /* If arg0 is a multiple of arg1, then rewrite to the fastest div
	 operation, EXACT_DIV_EXPR.

	 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
	 At one time others generated faster code, it's not clear if they do
	 after the last round to changes to the DIV code in expmed.c.  */
      if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
	  && multiple_of_p (type, arg0, arg1))
	return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);

      strict_overflow_p = false;
      if (TREE_CODE (arg1) == INTEGER_CST
	  && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
					 &strict_overflow_p)))
	{
	  if (strict_overflow_p)
	    fold_overflow_warning (("assuming signed overflow does not occur "
				    "when simplifying division"),
				   WARN_STRICT_OVERFLOW_MISC);
	  return fold_convert (type, tem);
	}

      return NULL_TREE;

    case CEIL_MOD_EXPR:
    case FLOOR_MOD_EXPR:
    case ROUND_MOD_EXPR:
    case TRUNC_MOD_EXPR:
      /* X % 1 is always zero, but be sure to preserve any side
	 effects in X.  */
      if (integer_onep (arg1))
	return omit_one_operand (type, integer_zero_node, arg0);

      /* X % 0, return X % 0 unchanged so that we can get the
	 proper warnings and errors.  */
      if (integer_zerop (arg1))
	return NULL_TREE;

      /* 0 % X is always zero, but be sure to preserve any side
	 effects in X.  Place this after checking for X == 0.  */
      if (integer_zerop (arg0))
	return omit_one_operand (type, integer_zero_node, arg1);

      /* X % -1 is zero.  */
      if (!TYPE_UNSIGNED (type)
	  && TREE_CODE (arg1) == INTEGER_CST
	  && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
	  && TREE_INT_CST_HIGH (arg1) == -1)
	return omit_one_operand (type, integer_zero_node, arg0);

      /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
         i.e. "X % C" into "X & (C - 1)", if X and C are positive.  */
      strict_overflow_p = false;
      if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
	  && (TYPE_UNSIGNED (type)
	      || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
	{
	  tree c = arg1;
	  /* Also optimize A % (C << N)  where C is a power of 2,
	     to A & ((C << N) - 1).  */
	  if (TREE_CODE (arg1) == LSHIFT_EXPR)
	    c = TREE_OPERAND (arg1, 0);

	  if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
	    {
	      tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1),
				       arg1, integer_one_node);
	      if (strict_overflow_p)
		fold_overflow_warning (("assuming signed overflow does not "
					"occur when simplifying "
					"X % (power of two)"),
				       WARN_STRICT_OVERFLOW_MISC);
	      return fold_build2 (BIT_AND_EXPR, type,
				  fold_convert (type, arg0),
				  fold_convert (type, mask));
	    }
	}

      /* X % -C is the same as X % C.  */
      if (code == TRUNC_MOD_EXPR
	  && !TYPE_UNSIGNED (type)
	  && TREE_CODE (arg1) == INTEGER_CST
	  && !TREE_CONSTANT_OVERFLOW (arg1)
	  && TREE_INT_CST_HIGH (arg1) < 0
	  && !TYPE_OVERFLOW_TRAPS (type)
	  /* Avoid this transformation if C is INT_MIN, i.e. C == -C.  */
	  && !sign_bit_p (arg1, arg1))
	return fold_build2 (code, type, fold_convert (type, arg0),
			    fold_convert (type, negate_expr (arg1)));

      /* X % -Y is the same as X % Y.  */
      if (code == TRUNC_MOD_EXPR
	  && !TYPE_UNSIGNED (type)
	  && TREE_CODE (arg1) == NEGATE_EXPR
	  && !TYPE_OVERFLOW_TRAPS (type))
	return fold_build2 (code, type, fold_convert (type, arg0),
			    fold_convert (type, TREE_OPERAND (arg1, 0)));

      if (TREE_CODE (arg1) == INTEGER_CST
	  && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
					 &strict_overflow_p)))
	{
	  if (strict_overflow_p)
	    fold_overflow_warning (("assuming signed overflow does not occur "
				    "when simplifying modulos"),
				   WARN_STRICT_OVERFLOW_MISC);
	  return fold_convert (type, tem);
	}

      return NULL_TREE;

    case LROTATE_EXPR:
    case RROTATE_EXPR:
      if (integer_all_onesp (arg0))
	return omit_one_operand (type, arg0, arg1);
      goto shift;

    case RSHIFT_EXPR:
      /* Optimize -1 >> x for arithmetic right shifts.  */
      if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
	return omit_one_operand (type, arg0, arg1);
      /* ... fall through ...  */

    case LSHIFT_EXPR:
    shift:
      if (integer_zerop (arg1))
	return non_lvalue (fold_convert (type, arg0));
      if (integer_zerop (arg0))
	return omit_one_operand (type, arg0, arg1);

      /* Since negative shift count is not well-defined,
	 don't try to compute it in the compiler.  */
      if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
	return NULL_TREE;

      /* Turn (a OP c1) OP c2 into a OP (c1+c2).  */
      if (TREE_CODE (op0) == code && host_integerp (arg1, false)
	  && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
	  && host_integerp (TREE_OPERAND (arg0, 1), false)
	  && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
	{
	  HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
			       + TREE_INT_CST_LOW (arg1));

	  /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
	     being well defined.  */
	  if (low >= TYPE_PRECISION (type))
	    {
	      if (code == LROTATE_EXPR || code == RROTATE_EXPR)
	        low = low % TYPE_PRECISION (type);
	      else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
	        return build_int_cst (type, 0);
	      else
		low = TYPE_PRECISION (type) - 1;
	    }

	  return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
			      build_int_cst (type, low));
	}

      /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
         into x & ((unsigned)-1 >> c) for unsigned types.  */
      if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
           || (TYPE_UNSIGNED (type)
	       && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
	  && host_integerp (arg1, false)
	  && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
	  && host_integerp (TREE_OPERAND (arg0, 1), false)
	  && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
	{
	  HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
	  HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
	  tree lshift;
	  tree arg00;

	  if (low0 == low1)
	    {
	      arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));

	      lshift = build_int_cst (type, -1);
	      lshift = int_const_binop (code, lshift, arg1, 0);

	      return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
	    }
	}

      /* Rewrite an LROTATE_EXPR by a constant into an
	 RROTATE_EXPR by a new constant.  */
      if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
	{
	  tree tem = build_int_cst (NULL_TREE,
				    GET_MODE_BITSIZE (TYPE_MODE (type)));
	  tem = fold_convert (TREE_TYPE (arg1), tem);
	  tem = const_binop (MINUS_EXPR, tem, arg1, 0);
	  return fold_build2 (RROTATE_EXPR, type, arg0, tem);
	}

      /* If we have a rotate of a bit operation with the rotate count and
	 the second operand of the bit operation both constant,
	 permute the two operations.  */
      if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
	  && (TREE_CODE (arg0) == BIT_AND_EXPR
	      || TREE_CODE (arg0) == BIT_IOR_EXPR
	      || TREE_CODE (arg0) == BIT_XOR_EXPR)
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
	return fold_build2 (TREE_CODE (arg0), type,
			    fold_build2 (code, type,
					 TREE_OPERAND (arg0, 0), arg1),
			    fold_build2 (code, type,
					 TREE_OPERAND (arg0, 1), arg1));

      /* Two consecutive rotates adding up to the width of the mode can
	 be ignored.  */
      if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
	  && TREE_CODE (arg0) == RROTATE_EXPR
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
	  && TREE_INT_CST_HIGH (arg1) == 0
	  && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
	  && ((TREE_INT_CST_LOW (arg1)
	       + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
	      == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
	return TREE_OPERAND (arg0, 0);

      return NULL_TREE;

    case MIN_EXPR:
      if (operand_equal_p (arg0, arg1, 0))
	return omit_one_operand (type, arg0, arg1);
      if (INTEGRAL_TYPE_P (type)
	  && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
	return omit_one_operand (type, arg1, arg0);
      tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
      if (tem)
	return tem;
      goto associate;

    case MAX_EXPR:
      if (operand_equal_p (arg0, arg1, 0))
	return omit_one_operand (type, arg0, arg1);
      if (INTEGRAL_TYPE_P (type)
	  && TYPE_MAX_VALUE (type)
	  && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
	return omit_one_operand (type, arg1, arg0);
      tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
      if (tem)
	return tem;
      goto associate;

    case TRUTH_ANDIF_EXPR:
      /* Note that the operands of this must be ints
	 and their values must be 0 or 1.
	 ("true" is a fixed value perhaps depending on the language.)  */
      /* If first arg is constant zero, return it.  */
      if (integer_zerop (arg0))
	return fold_convert (type, arg0);
    case TRUTH_AND_EXPR:
      /* If either arg is constant true, drop it.  */
      if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
	return non_lvalue (fold_convert (type, arg1));
      if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
	  /* Preserve sequence points.  */
	  && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
	return non_lvalue (fold_convert (type, arg0));
      /* If second arg is constant zero, result is zero, but first arg
	 must be evaluated.  */
      if (integer_zerop (arg1))
	return omit_one_operand (type, arg1, arg0);
      /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
	 case will be handled here.  */
      if (integer_zerop (arg0))
	return omit_one_operand (type, arg0, arg1);

      /* !X && X is always false.  */
      if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
	return omit_one_operand (type, integer_zero_node, arg1);
      /* X && !X is always false.  */
      if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
	return omit_one_operand (type, integer_zero_node, arg0);

      /* A < X && A + 1 > Y ==> A < X && A >= Y.  Normally A + 1 > Y
	 means A >= Y && A != MAX, but in this case we know that
	 A < X <= MAX.  */

      if (!TREE_SIDE_EFFECTS (arg0)
	  && !TREE_SIDE_EFFECTS (arg1))
	{
	  tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
	  if (tem && !operand_equal_p (tem, arg0, 0))
	    return fold_build2 (code, type, tem, arg1);

	  tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
	  if (tem && !operand_equal_p (tem, arg1, 0))
	    return fold_build2 (code, type, arg0, tem);
	}

    truth_andor:
      /* We only do these simplifications if we are optimizing.  */
      if (!optimize)
	return NULL_TREE;

      /* Check for things like (A || B) && (A || C).  We can convert this
	 to A || (B && C).  Note that either operator can be any of the four
	 truth and/or operations and the transformation will still be
	 valid.   Also note that we only care about order for the
	 ANDIF and ORIF operators.  If B contains side effects, this
	 might change the truth-value of A.  */
      if (TREE_CODE (arg0) == TREE_CODE (arg1)
	  && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
	      || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
	      || TREE_CODE (arg0) == TRUTH_AND_EXPR
	      || TREE_CODE (arg0) == TRUTH_OR_EXPR)
	  && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
	{
	  tree a00 = TREE_OPERAND (arg0, 0);
	  tree a01 = TREE_OPERAND (arg0, 1);
	  tree a10 = TREE_OPERAND (arg1, 0);
	  tree a11 = TREE_OPERAND (arg1, 1);
	  int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
			      || TREE_CODE (arg0) == TRUTH_AND_EXPR)
			     && (code == TRUTH_AND_EXPR
				 || code == TRUTH_OR_EXPR));

	  if (operand_equal_p (a00, a10, 0))
	    return fold_build2 (TREE_CODE (arg0), type, a00,
				fold_build2 (code, type, a01, a11));
	  else if (commutative && operand_equal_p (a00, a11, 0))
	    return fold_build2 (TREE_CODE (arg0), type, a00,
				fold_build2 (code, type, a01, a10));
	  else if (commutative && operand_equal_p (a01, a10, 0))
	    return fold_build2 (TREE_CODE (arg0), type, a01,
				fold_build2 (code, type, a00, a11));

	  /* This case if tricky because we must either have commutative
	     operators or else A10 must not have side-effects.  */

	  else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
		   && operand_equal_p (a01, a11, 0))
	    return fold_build2 (TREE_CODE (arg0), type,
				fold_build2 (code, type, a00, a10),
				a01);
	}

      /* See if we can build a range comparison.  */
      if (0 != (tem = fold_range_test (code, type, op0, op1)))
	return tem;

      /* Check for the possibility of merging component references.  If our
	 lhs is another similar operation, try to merge its rhs with our
	 rhs.  Then try to merge our lhs and rhs.  */
      if (TREE_CODE (arg0) == code
	  && 0 != (tem = fold_truthop (code, type,
				       TREE_OPERAND (arg0, 1), arg1)))
	return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);

      if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
	return tem;

      return NULL_TREE;

    case TRUTH_ORIF_EXPR:
      /* Note that the operands of this must be ints
	 and their values must be 0 or true.
	 ("true" is a fixed value perhaps depending on the language.)  */
      /* If first arg is constant true, return it.  */
      if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
	return fold_convert (type, arg0);
    case TRUTH_OR_EXPR:
      /* If either arg is constant zero, drop it.  */
      if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
	return non_lvalue (fold_convert (type, arg1));
      if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
	  /* Preserve sequence points.  */
	  && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
	return non_lvalue (fold_convert (type, arg0));
      /* If second arg is constant true, result is true, but we must
	 evaluate first arg.  */
      if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
	return omit_one_operand (type, arg1, arg0);
      /* Likewise for first arg, but note this only occurs here for
	 TRUTH_OR_EXPR.  */
      if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
	return omit_one_operand (type, arg0, arg1);

      /* !X || X is always true.  */
      if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
	return omit_one_operand (type, integer_one_node, arg1);
      /* X || !X is always true.  */
      if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
	return omit_one_operand (type, integer_one_node, arg0);

      goto truth_andor;

    case TRUTH_XOR_EXPR:
      /* If the second arg is constant zero, drop it.  */
      if (integer_zerop (arg1))
	return non_lvalue (fold_convert (type, arg0));
      /* If the second arg is constant true, this is a logical inversion.  */
      if (integer_onep (arg1))
	{
	  /* Only call invert_truthvalue if operand is a truth value.  */
	  if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
	    tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
	  else
	    tem = invert_truthvalue (arg0);
	  return non_lvalue (fold_convert (type, tem));
	}
      /* Identical arguments cancel to zero.  */
      if (operand_equal_p (arg0, arg1, 0))
	return omit_one_operand (type, integer_zero_node, arg0);

      /* !X ^ X is always true.  */
      if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
	return omit_one_operand (type, integer_one_node, arg1);

      /* X ^ !X is always true.  */
      if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
	return omit_one_operand (type, integer_one_node, arg0);

      return NULL_TREE;

    case EQ_EXPR:
    case NE_EXPR:
      tem = fold_comparison (code, type, op0, op1);
      if (tem != NULL_TREE)
	return tem;

      /* bool_var != 0 becomes bool_var. */
      if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
          && code == NE_EXPR)
        return non_lvalue (fold_convert (type, arg0));

      /* bool_var == 1 becomes bool_var. */
      if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
          && code == EQ_EXPR)
        return non_lvalue (fold_convert (type, arg0));

      /* bool_var != 1 becomes !bool_var. */
      if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
          && code == NE_EXPR)
        return fold_build1 (TRUTH_NOT_EXPR, type, arg0);

      /* bool_var == 0 becomes !bool_var. */
      if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
          && code == EQ_EXPR)
        return fold_build1 (TRUTH_NOT_EXPR, type, arg0);

      /*  ~a != C becomes a != ~C where C is a constant.  Likewise for ==.  */
      if (TREE_CODE (arg0) == BIT_NOT_EXPR
	  && TREE_CODE (arg1) == INTEGER_CST)
	{
	  tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
	  return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
			      fold_build1 (BIT_NOT_EXPR, cmp_type, 
					   fold_convert (cmp_type, arg1)));
	}

      /* If this is an equality comparison of the address of a non-weak
	 object against zero, then we know the result.  */
      if (TREE_CODE (arg0) == ADDR_EXPR
	  && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
	  && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
	  && integer_zerop (arg1))
	return constant_boolean_node (code != EQ_EXPR, type);

      /* If this is an equality comparison of the address of two non-weak,
	 unaliased symbols neither of which are extern (since we do not
	 have access to attributes for externs), then we know the result.  */
      if (TREE_CODE (arg0) == ADDR_EXPR
	  && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
	  && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
	  && ! lookup_attribute ("alias",
				 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
	  && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
	  && TREE_CODE (arg1) == ADDR_EXPR
	  && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
	  && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
	  && ! lookup_attribute ("alias",
				 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
	  && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
	{
	  /* We know that we're looking at the address of two
	     non-weak, unaliased, static _DECL nodes.

	     It is both wasteful and incorrect to call operand_equal_p
	     to compare the two ADDR_EXPR nodes.  It is wasteful in that
	     all we need to do is test pointer equality for the arguments
	     to the two ADDR_EXPR nodes.  It is incorrect to use
	     operand_equal_p as that function is NOT equivalent to a
	     C equality test.  It can in fact return false for two
	     objects which would test as equal using the C equality
	     operator.  */
	  bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
	  return constant_boolean_node (equal
				        ? code == EQ_EXPR : code != EQ_EXPR,
				        type);
	}

      /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
	 a MINUS_EXPR of a constant, we can convert it into a comparison with
	 a revised constant as long as no overflow occurs.  */
      if (TREE_CODE (arg1) == INTEGER_CST
	  && (TREE_CODE (arg0) == PLUS_EXPR
	      || TREE_CODE (arg0) == MINUS_EXPR)
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
	  && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
				      ? MINUS_EXPR : PLUS_EXPR,
				      fold_convert (TREE_TYPE (arg0), arg1),
				      TREE_OPERAND (arg0, 1), 0))
	  && ! TREE_CONSTANT_OVERFLOW (tem))
	return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);

      /* Similarly for a NEGATE_EXPR.  */
      if (TREE_CODE (arg0) == NEGATE_EXPR
	  && TREE_CODE (arg1) == INTEGER_CST
	  && 0 != (tem = negate_expr (arg1))
	  && TREE_CODE (tem) == INTEGER_CST
	  && ! TREE_CONSTANT_OVERFLOW (tem))
	return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);

      /* If we have X - Y == 0, we can convert that to X == Y and similarly
	 for !=.  Don't do this for ordered comparisons due to overflow.  */
      if (TREE_CODE (arg0) == MINUS_EXPR
	  && integer_zerop (arg1))
	return fold_build2 (code, type,
			    TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));

      /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0.  */
      if (TREE_CODE (arg0) == ABS_EXPR
	  && (integer_zerop (arg1) || real_zerop (arg1)))
	return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);

      /* If this is an EQ or NE comparison with zero and ARG0 is
	 (1 << foo) & bar, convert it to (bar >> foo) & 1.  Both require
	 two operations, but the latter can be done in one less insn
	 on machines that have only two-operand insns or on which a
	 constant cannot be the first operand.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && integer_zerop (arg1))
	{
	  tree arg00 = TREE_OPERAND (arg0, 0);
	  tree arg01 = TREE_OPERAND (arg0, 1);
	  if (TREE_CODE (arg00) == LSHIFT_EXPR
	      && integer_onep (TREE_OPERAND (arg00, 0)))
	    {
	      tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
				      arg01, TREE_OPERAND (arg00, 1));
	      tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
				 build_int_cst (TREE_TYPE (arg0), 1));
	      return fold_build2 (code, type,
				  fold_convert (TREE_TYPE (arg1), tem), arg1);
	    }
	  else if (TREE_CODE (arg01) == LSHIFT_EXPR
		   && integer_onep (TREE_OPERAND (arg01, 0)))
	    {
	      tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
				      arg00, TREE_OPERAND (arg01, 1));
	      tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
				 build_int_cst (TREE_TYPE (arg0), 1));
	      return fold_build2 (code, type,
				  fold_convert (TREE_TYPE (arg1), tem), arg1);
	    }
	}

      /* If this is an NE or EQ comparison of zero against the result of a
	 signed MOD operation whose second operand is a power of 2, make
	 the MOD operation unsigned since it is simpler and equivalent.  */
      if (integer_zerop (arg1)
	  && !TYPE_UNSIGNED (TREE_TYPE (arg0))
	  && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
	      || TREE_CODE (arg0) == CEIL_MOD_EXPR
	      || TREE_CODE (arg0) == FLOOR_MOD_EXPR
	      || TREE_CODE (arg0) == ROUND_MOD_EXPR)
	  && integer_pow2p (TREE_OPERAND (arg0, 1)))
	{
	  tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
	  tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
				     fold_convert (newtype,
						   TREE_OPERAND (arg0, 0)),
				     fold_convert (newtype,
						   TREE_OPERAND (arg0, 1)));

	  return fold_build2 (code, type, newmod,
			      fold_convert (newtype, arg1));
	}

      /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
	 C1 is a valid shift constant, and C2 is a power of two, i.e.
	 a single bit.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
	  && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
	     == INTEGER_CST
	  && integer_pow2p (TREE_OPERAND (arg0, 1))
	  && integer_zerop (arg1))
	{
	  tree itype = TREE_TYPE (arg0);
	  unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
	  tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);

	  /* Check for a valid shift count.  */
	  if (TREE_INT_CST_HIGH (arg001) == 0
	      && TREE_INT_CST_LOW (arg001) < prec)
	    {
	      tree arg01 = TREE_OPERAND (arg0, 1);
	      tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
	      unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
	      /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
		 can be rewritten as (X & (C2 << C1)) != 0.  */
	      if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
		{
		  tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
		  tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
		  return fold_build2 (code, type, tem, arg1);
		}
	      /* Otherwise, for signed (arithmetic) shifts,
		 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
		 ((X >> C1) & C2) == 0 is rewritten as X >= 0.  */
	      else if (!TYPE_UNSIGNED (itype))
		return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
				    arg000, build_int_cst (itype, 0));
	      /* Otherwise, of unsigned (logical) shifts,
		 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
		 ((X >> C1) & C2) == 0 is rewritten as (X,true).  */
	      else
		return omit_one_operand (type,
					 code == EQ_EXPR ? integer_one_node
							 : integer_zero_node,
					 arg000);
	    }
	}

      /* If this is an NE comparison of zero with an AND of one, remove the
	 comparison since the AND will give the correct value.  */
      if (code == NE_EXPR
	  && integer_zerop (arg1)
	  && TREE_CODE (arg0) == BIT_AND_EXPR
	  && integer_onep (TREE_OPERAND (arg0, 1)))
	return fold_convert (type, arg0);

      /* If we have (A & C) == C where C is a power of 2, convert this into
	 (A & C) != 0.  Similarly for NE_EXPR.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && integer_pow2p (TREE_OPERAND (arg0, 1))
	  && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
	return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
			    arg0, fold_convert (TREE_TYPE (arg0),
						integer_zero_node));

      /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
	 bit, then fold the expression into A < 0 or A >= 0.  */
      tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
      if (tem)
	return tem;

      /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
	 Similarly for NE_EXPR.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && TREE_CODE (arg1) == INTEGER_CST
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
	{
	  tree notc = fold_build1 (BIT_NOT_EXPR,
				   TREE_TYPE (TREE_OPERAND (arg0, 1)),
				   TREE_OPERAND (arg0, 1));
	  tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
				       arg1, notc);
	  tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
	  if (integer_nonzerop (dandnotc))
	    return omit_one_operand (type, rslt, arg0);
	}

      /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
	 Similarly for NE_EXPR.  */
      if (TREE_CODE (arg0) == BIT_IOR_EXPR
	  && TREE_CODE (arg1) == INTEGER_CST
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
	{
	  tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
	  tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
				       TREE_OPERAND (arg0, 1), notd);
	  tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
	  if (integer_nonzerop (candnotd))
	    return omit_one_operand (type, rslt, arg0);
	}

      /* If this is a comparison of a field, we may be able to simplify it.  */
      if (((TREE_CODE (arg0) == COMPONENT_REF
	    && lang_hooks.can_use_bit_fields_p ())
	   || TREE_CODE (arg0) == BIT_FIELD_REF)
	  /* Handle the constant case even without -O
	     to make sure the warnings are given.  */
	  && (optimize || TREE_CODE (arg1) == INTEGER_CST))
	{
	  t1 = optimize_bit_field_compare (code, type, arg0, arg1);
	  if (t1)
	    return t1;
	}

      /* Optimize comparisons of strlen vs zero to a compare of the
	 first character of the string vs zero.  To wit,
		strlen(ptr) == 0   =>  *ptr == 0
		strlen(ptr) != 0   =>  *ptr != 0
	 Other cases should reduce to one of these two (or a constant)
	 due to the return value of strlen being unsigned.  */
      if (TREE_CODE (arg0) == CALL_EXPR
	  && integer_zerop (arg1))
	{
	  tree fndecl = get_callee_fndecl (arg0);
	  tree arglist;

	  if (fndecl
	      && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
	      && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
	      && (arglist = TREE_OPERAND (arg0, 1))
	      && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
	      && ! TREE_CHAIN (arglist))
	    {
	      tree iref = build_fold_indirect_ref (TREE_VALUE (arglist));
	      return fold_build2 (code, type, iref,
				  build_int_cst (TREE_TYPE (iref), 0));
	    }
	}

      /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
	 of X.  Similarly fold (X >> C) == 0 into X >= 0.  */
      if (TREE_CODE (arg0) == RSHIFT_EXPR
	  && integer_zerop (arg1)
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
	{
	  tree arg00 = TREE_OPERAND (arg0, 0);
	  tree arg01 = TREE_OPERAND (arg0, 1);
	  tree itype = TREE_TYPE (arg00);
	  if (TREE_INT_CST_HIGH (arg01) == 0
	      && TREE_INT_CST_LOW (arg01)
		 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
	    {
	      if (TYPE_UNSIGNED (itype))
		{
		  itype = lang_hooks.types.signed_type (itype);
		  arg00 = fold_convert (itype, arg00);
		}
	      return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
				  type, arg00, build_int_cst (itype, 0));
	    }
	}

      /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y.  */
      if (integer_zerop (arg1)
	  && TREE_CODE (arg0) == BIT_XOR_EXPR)
	return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
			    TREE_OPERAND (arg0, 1));

      /* (X ^ Y) == Y becomes X == 0.  We know that Y has no side-effects.  */
      if (TREE_CODE (arg0) == BIT_XOR_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
	return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
			    build_int_cst (TREE_TYPE (arg1), 0));
      /* Likewise (X ^ Y) == X becomes Y == 0.  X has no side-effects.  */
      if (TREE_CODE (arg0) == BIT_XOR_EXPR
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
	  && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
	return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
			    build_int_cst (TREE_TYPE (arg1), 0));

      /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2).  */
      if (TREE_CODE (arg0) == BIT_XOR_EXPR
	  && TREE_CODE (arg1) == INTEGER_CST
	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
	return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
			    fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
					 TREE_OPERAND (arg0, 1), arg1));

      /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
	 (X & C) == 0 when C is a single bit.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
	  && integer_zerop (arg1)
	  && integer_pow2p (TREE_OPERAND (arg0, 1)))
	{
	  tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
			     TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
			     TREE_OPERAND (arg0, 1));
	  return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
			      type, tem, arg1);
	}

      /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
	 constant C is a power of two, i.e. a single bit.  */
      if (TREE_CODE (arg0) == BIT_XOR_EXPR
	  && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
	  && integer_zerop (arg1)
	  && integer_pow2p (TREE_OPERAND (arg0, 1))
	  && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
			      TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
	{
	  tree arg00 = TREE_OPERAND (arg0, 0);
	  return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
			      arg00, build_int_cst (TREE_TYPE (arg00), 0));
	}

      /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
	 when is C is a power of two, i.e. a single bit.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
	  && integer_zerop (arg1)
	  && integer_pow2p (TREE_OPERAND (arg0, 1))
	  && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
			      TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
	{
	  tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
	  tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
			     arg000, TREE_OPERAND (arg0, 1));
	  return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
			      tem, build_int_cst (TREE_TYPE (tem), 0));
	}

      if (integer_zerop (arg1)
	  && tree_expr_nonzero_p (arg0))
        {
	  tree res = constant_boolean_node (code==NE_EXPR, type);
	  return omit_one_operand (type, res, arg0);
	}
      return NULL_TREE;

    case LT_EXPR:
    case GT_EXPR:
    case LE_EXPR:
    case GE_EXPR:
      tem = fold_comparison (code, type, op0, op1);
      if (tem != NULL_TREE)
	return tem;

      /* Transform comparisons of the form X +- C CMP X.  */
      if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
	  && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
	       && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
	      || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
		  && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
	{
	  tree arg01 = TREE_OPERAND (arg0, 1);
	  enum tree_code code0 = TREE_CODE (arg0);
	  int is_positive;

	  if (TREE_CODE (arg01) == REAL_CST)
	    is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
	  else
	    is_positive = tree_int_cst_sgn (arg01);

	  /* (X - c) > X becomes false.  */
	  if (code == GT_EXPR
	      && ((code0 == MINUS_EXPR && is_positive >= 0)
		  || (code0 == PLUS_EXPR && is_positive <= 0)))
	    {
	      if (TREE_CODE (arg01) == INTEGER_CST
		  && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
		fold_overflow_warning (("assuming signed overflow does not "
					"occur when assuming that (X - c) > X "
					"is always false"),
				       WARN_STRICT_OVERFLOW_ALL);
	      return constant_boolean_node (0, type);
	    }

	  /* Likewise (X + c) < X becomes false.  */
	  if (code == LT_EXPR
	      && ((code0 == PLUS_EXPR && is_positive >= 0)
		  || (code0 == MINUS_EXPR && is_positive <= 0)))
	    {
	      if (TREE_CODE (arg01) == INTEGER_CST
		  && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
		fold_overflow_warning (("assuming signed overflow does not "
					"occur when assuming that "
					"(X + c) < X is always false"),
				       WARN_STRICT_OVERFLOW_ALL);
	      return constant_boolean_node (0, type);
	    }

	  /* Convert (X - c) <= X to true.  */
	  if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
	      && code == LE_EXPR
	      && ((code0 == MINUS_EXPR && is_positive >= 0)
		  || (code0 == PLUS_EXPR && is_positive <= 0)))
	    {
	      if (TREE_CODE (arg01) == INTEGER_CST
		  && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
		fold_overflow_warning (("assuming signed overflow does not "
					"occur when assuming that "
					"(X - c) <= X is always true"),
				       WARN_STRICT_OVERFLOW_ALL);
	      return constant_boolean_node (1, type);
	    }

	  /* Convert (X + c) >= X to true.  */
	  if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
	      && code == GE_EXPR
	      && ((code0 == PLUS_EXPR && is_positive >= 0)
		  || (code0 == MINUS_EXPR && is_positive <= 0)))
	    {
	      if (TREE_CODE (arg01) == INTEGER_CST
		  && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
		fold_overflow_warning (("assuming signed overflow does not "
					"occur when assuming that "
					"(X + c) >= X is always true"),
				       WARN_STRICT_OVERFLOW_ALL);
	      return constant_boolean_node (1, type);
	    }

	  if (TREE_CODE (arg01) == INTEGER_CST)
	    {
	      /* Convert X + c > X and X - c < X to true for integers.  */
	      if (code == GT_EXPR
	          && ((code0 == PLUS_EXPR && is_positive > 0)
		      || (code0 == MINUS_EXPR && is_positive < 0)))
		{
		  if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
		    fold_overflow_warning (("assuming signed overflow does "
					    "not occur when assuming that "
					    "(X + c) > X is always true"),
					   WARN_STRICT_OVERFLOW_ALL);
		  return constant_boolean_node (1, type);
		}

	      if (code == LT_EXPR
	          && ((code0 == MINUS_EXPR && is_positive > 0)
		      || (code0 == PLUS_EXPR && is_positive < 0)))
		{
		  if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
		    fold_overflow_warning (("assuming signed overflow does "
					    "not occur when assuming that "
					    "(X - c) < X is always true"),
					   WARN_STRICT_OVERFLOW_ALL);
		  return constant_boolean_node (1, type);
		}

	      /* Convert X + c <= X and X - c >= X to false for integers.  */
	      if (code == LE_EXPR
	          && ((code0 == PLUS_EXPR && is_positive > 0)
		      || (code0 == MINUS_EXPR && is_positive < 0)))
		{
		  if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
		    fold_overflow_warning (("assuming signed overflow does "
					    "not occur when assuming that "
					    "(X + c) <= X is always false"),
					   WARN_STRICT_OVERFLOW_ALL);
		  return constant_boolean_node (0, type);
		}

	      if (code == GE_EXPR
	          && ((code0 == MINUS_EXPR && is_positive > 0)
		      || (code0 == PLUS_EXPR && is_positive < 0)))
		{
		  if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
		    fold_overflow_warning (("assuming signed overflow does "
					    "not occur when assuming that "
					    "(X - c) >= X is always true"),
					   WARN_STRICT_OVERFLOW_ALL);
		  return constant_boolean_node (0, type);
		}
	    }
	}

      /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
	 This transformation affects the cases which are handled in later
	 optimizations involving comparisons with non-negative constants.  */
      if (TREE_CODE (arg1) == INTEGER_CST
	  && TREE_CODE (arg0) != INTEGER_CST
	  && tree_int_cst_sgn (arg1) > 0)
	{
	  if (code == GE_EXPR)
	    {
	      arg1 = const_binop (MINUS_EXPR, arg1,
			          build_int_cst (TREE_TYPE (arg1), 1), 0);
	      return fold_build2 (GT_EXPR, type, arg0,
				  fold_convert (TREE_TYPE (arg0), arg1));
	    }
	  if (code == LT_EXPR)
	    {
	      arg1 = const_binop (MINUS_EXPR, arg1,
			          build_int_cst (TREE_TYPE (arg1), 1), 0);
	      return fold_build2 (LE_EXPR, type, arg0,
				  fold_convert (TREE_TYPE (arg0), arg1));
	    }
	}

      /* Comparisons with the highest or lowest possible integer of
	 the specified size will have known values.  */
      {
	int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));

	if (TREE_CODE (arg1) == INTEGER_CST
	    && ! TREE_CONSTANT_OVERFLOW (arg1)
	    && width <= 2 * HOST_BITS_PER_WIDE_INT
	    && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
		|| POINTER_TYPE_P (TREE_TYPE (arg1))))
	  {
	    HOST_WIDE_INT signed_max_hi;
	    unsigned HOST_WIDE_INT signed_max_lo;
	    unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;

	    if (width <= HOST_BITS_PER_WIDE_INT)
	      {
		signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
				- 1;
		signed_max_hi = 0;
		max_hi = 0;

		if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
		  {
		    max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
		    min_lo = 0;
		    min_hi = 0;
		  }
		else
		  {
		    max_lo = signed_max_lo;
		    min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
		    min_hi = -1;
		  }
	      }
	    else
	      {
		width -= HOST_BITS_PER_WIDE_INT;
		signed_max_lo = -1;
		signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
				- 1;
		max_lo = -1;
		min_lo = 0;

		if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
		  {
		    max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
		    min_hi = 0;
		  }
		else
		  {
		    max_hi = signed_max_hi;
		    min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
		  }
	      }

	    if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
		&& TREE_INT_CST_LOW (arg1) == max_lo)
	      switch (code)
		{
		case GT_EXPR:
		  return omit_one_operand (type, integer_zero_node, arg0);

		case GE_EXPR:
		  return fold_build2 (EQ_EXPR, type, op0, op1);

		case LE_EXPR:
		  return omit_one_operand (type, integer_one_node, arg0);

		case LT_EXPR:
		  return fold_build2 (NE_EXPR, type, op0, op1);

		/* The GE_EXPR and LT_EXPR cases above are not normally
		   reached because of previous transformations.  */

		default:
		  break;
		}
	    else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
		     == max_hi
		     && TREE_INT_CST_LOW (arg1) == max_lo - 1)
	      switch (code)
		{
		case GT_EXPR:
		  arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
		  return fold_build2 (EQ_EXPR, type,
				      fold_convert (TREE_TYPE (arg1), arg0),
				      arg1);
		case LE_EXPR:
		  arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
		  return fold_build2 (NE_EXPR, type,
				      fold_convert (TREE_TYPE (arg1), arg0),
				      arg1);
		default:
		  break;
		}
	    else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
		     == min_hi
		     && TREE_INT_CST_LOW (arg1) == min_lo)
	      switch (code)
		{
		case LT_EXPR:
		  return omit_one_operand (type, integer_zero_node, arg0);

		case LE_EXPR:
		  return fold_build2 (EQ_EXPR, type, op0, op1);

		case GE_EXPR:
		  return omit_one_operand (type, integer_one_node, arg0);

		case GT_EXPR:
		  return fold_build2 (NE_EXPR, type, op0, op1);

		default:
		  break;
		}
	    else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
		     == min_hi
		     && TREE_INT_CST_LOW (arg1) == min_lo + 1)
	      switch (code)
		{
		case GE_EXPR:
		  arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
		  return fold_build2 (NE_EXPR, type,
				      fold_convert (TREE_TYPE (arg1), arg0),
				      arg1);
		case LT_EXPR:
		  arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
		  return fold_build2 (EQ_EXPR, type,
				      fold_convert (TREE_TYPE (arg1), arg0),
				      arg1);
		default:
		  break;
		}

	    else if (!in_gimple_form
		     && TREE_INT_CST_HIGH (arg1) == signed_max_hi
		     && TREE_INT_CST_LOW (arg1) == signed_max_lo
		     && TYPE_UNSIGNED (TREE_TYPE (arg1))
		     /* signed_type does not work on pointer types.  */
		     && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
	      {
		/* The following case also applies to X < signed_max+1
		   and X >= signed_max+1 because previous transformations.  */
		if (code == LE_EXPR || code == GT_EXPR)
		  {
		    tree st;
		    st = lang_hooks.types.signed_type (TREE_TYPE (arg1));
		    return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
					type, fold_convert (st, arg0),
					build_int_cst (st, 0));
		  }
	      }
	  }
      }

      /* If we are comparing an ABS_EXPR with a constant, we can
	 convert all the cases into explicit comparisons, but they may
	 well not be faster than doing the ABS and one comparison.
	 But ABS (X) <= C is a range comparison, which becomes a subtraction
	 and a comparison, and is probably faster.  */
      if (code == LE_EXPR
	  && TREE_CODE (arg1) == INTEGER_CST
	  && TREE_CODE (arg0) == ABS_EXPR
	  && ! TREE_SIDE_EFFECTS (arg0)
	  && (0 != (tem = negate_expr (arg1)))
	  && TREE_CODE (tem) == INTEGER_CST
	  && ! TREE_CONSTANT_OVERFLOW (tem))
	return fold_build2 (TRUTH_ANDIF_EXPR, type,
			    build2 (GE_EXPR, type,
				    TREE_OPERAND (arg0, 0), tem),
			    build2 (LE_EXPR, type,
				    TREE_OPERAND (arg0, 0), arg1));

      /* Convert ABS_EXPR<x> >= 0 to true.  */
      strict_overflow_p = false;
      if (code == GE_EXPR
	  && (integer_zerop (arg1)
	      || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
		  && real_zerop (arg1)))
	  && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
	{
	  if (strict_overflow_p)
	    fold_overflow_warning (("assuming signed overflow does not occur "
				    "when simplifying comparison of "
				    "absolute value and zero"),
				   WARN_STRICT_OVERFLOW_CONDITIONAL);
	  return omit_one_operand (type, integer_one_node, arg0);
	}

      /* Convert ABS_EXPR<x> < 0 to false.  */
      strict_overflow_p = false;
      if (code == LT_EXPR
	  && (integer_zerop (arg1) || real_zerop (arg1))
	  && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
	{
	  if (strict_overflow_p)
	    fold_overflow_warning (("assuming signed overflow does not occur "
				    "when simplifying comparison of "
				    "absolute value and zero"),
				   WARN_STRICT_OVERFLOW_CONDITIONAL);
	  return omit_one_operand (type, integer_zero_node, arg0);
	}

      /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
	 and similarly for >= into !=.  */
      if ((code == LT_EXPR || code == GE_EXPR)
	  && TYPE_UNSIGNED (TREE_TYPE (arg0))
	  && TREE_CODE (arg1) == LSHIFT_EXPR
	  && integer_onep (TREE_OPERAND (arg1, 0)))
	return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
		       build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
			       TREE_OPERAND (arg1, 1)),
		       build_int_cst (TREE_TYPE (arg0), 0));

      if ((code == LT_EXPR || code == GE_EXPR)
	  && TYPE_UNSIGNED (TREE_TYPE (arg0))
	  && (TREE_CODE (arg1) == NOP_EXPR
	      || TREE_CODE (arg1) == CONVERT_EXPR)
	  && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
	  && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
	return
	  build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
		  fold_convert (TREE_TYPE (arg0),
				build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
					TREE_OPERAND (TREE_OPERAND (arg1, 0),
						      1))),
		  build_int_cst (TREE_TYPE (arg0), 0));

      return NULL_TREE;

    case UNORDERED_EXPR:
    case ORDERED_EXPR:
    case UNLT_EXPR:
    case UNLE_EXPR:
    case UNGT_EXPR:
    case UNGE_EXPR:
    case UNEQ_EXPR:
    case LTGT_EXPR:
      if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
	{
	  t1 = fold_relational_const (code, type, arg0, arg1);
	  if (t1 != NULL_TREE)
	    return t1;
	}

      /* If the first operand is NaN, the result is constant.  */
      if (TREE_CODE (arg0) == REAL_CST
	  && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
	  && (code != LTGT_EXPR || ! flag_trapping_math))
	{
	  t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
	       ? integer_zero_node
	       : integer_one_node;
	  return omit_one_operand (type, t1, arg1);
	}

      /* If the second operand is NaN, the result is constant.  */
      if (TREE_CODE (arg1) == REAL_CST
	  && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
	  && (code != LTGT_EXPR || ! flag_trapping_math))
	{
	  t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
	       ? integer_zero_node
	       : integer_one_node;
	  return omit_one_operand (type, t1, arg0);
	}

      /* Simplify unordered comparison of something with itself.  */
      if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
	  && operand_equal_p (arg0, arg1, 0))
	return constant_boolean_node (1, type);

      if (code == LTGT_EXPR
	  && !flag_trapping_math
	  && operand_equal_p (arg0, arg1, 0))
	return constant_boolean_node (0, type);

      /* Fold (double)float1 CMP (double)float2 into float1 CMP float2.  */
      {
	tree targ0 = strip_float_extensions (arg0);
	tree targ1 = strip_float_extensions (arg1);
	tree newtype = TREE_TYPE (targ0);

	if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
	  newtype = TREE_TYPE (targ1);

	if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
	  return fold_build2 (code, type, fold_convert (newtype, targ0),
			      fold_convert (newtype, targ1));
      }

      return NULL_TREE;

    case COMPOUND_EXPR:
      /* When pedantic, a compound expression can be neither an lvalue
	 nor an integer constant expression.  */
      if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
	return NULL_TREE;
      /* Don't let (0, 0) be null pointer constant.  */
      tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
				 : fold_convert (type, arg1);
      return pedantic_non_lvalue (tem);

    case COMPLEX_EXPR:
      if ((TREE_CODE (arg0) == REAL_CST
	   && TREE_CODE (arg1) == REAL_CST)
	  || (TREE_CODE (arg0) == INTEGER_CST
	      && TREE_CODE (arg1) == INTEGER_CST))
	return build_complex (type, arg0, arg1);
      return NULL_TREE;

    case ASSERT_EXPR:
      /* An ASSERT_EXPR should never be passed to fold_binary.  */
      gcc_unreachable ();

    default:
      return NULL_TREE;
    } /* switch (code) */
}

/* Callback for walk_tree, looking for LABEL_EXPR.
   Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
   Do not check the sub-tree of GOTO_EXPR.  */

static tree
contains_label_1 (tree *tp,
                  int *walk_subtrees,
                  void *data ATTRIBUTE_UNUSED)
{
  switch (TREE_CODE (*tp))
    {
    case LABEL_EXPR:
      return *tp;
    case GOTO_EXPR:
      *walk_subtrees = 0;
    /* no break */
    default:
      return NULL_TREE;
    }
}

/* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
   accessible from outside the sub-tree. Returns NULL_TREE if no
   addressable label is found.  */

static bool
contains_label_p (tree st)
{
  return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
}

/* Fold a ternary expression of code CODE and type TYPE with operands
   OP0, OP1, and OP2.  Return the folded expression if folding is
   successful.  Otherwise, return NULL_TREE.  */

tree
fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
{
  tree tem;
  tree arg0 = NULL_TREE, arg1 = NULL_TREE;
  enum tree_code_class kind = TREE_CODE_CLASS (code);

  gcc_assert (IS_EXPR_CODE_CLASS (kind)
	      && TREE_CODE_LENGTH (code) == 3);

  /* Strip any conversions that don't change the mode.  This is safe
     for every expression, except for a comparison expression because
     its signedness is derived from its operands.  So, in the latter
     case, only strip conversions that don't change the signedness.

     Note that this is done as an internal manipulation within the
     constant folder, in order to find the simplest representation of
     the arguments so that their form can be studied.  In any cases,
     the appropriate type conversions should be put back in the tree
     that will get out of the constant folder.  */
  if (op0)
    {
      arg0 = op0;
      STRIP_NOPS (arg0);
    }

  if (op1)
    {
      arg1 = op1;
      STRIP_NOPS (arg1);
    }

  switch (code)
    {
    case COMPONENT_REF:
      if (TREE_CODE (arg0) == CONSTRUCTOR
	  && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
	{
	  unsigned HOST_WIDE_INT idx;
	  tree field, value;
	  FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
	    if (field == arg1)
	      return value;
	}
      return NULL_TREE;

    case COND_EXPR:
      /* Pedantic ANSI C says that a conditional expression is never an lvalue,
	 so all simple results must be passed through pedantic_non_lvalue.  */
      if (TREE_CODE (arg0) == INTEGER_CST)
	{
	  tree unused_op = integer_zerop (arg0) ? op1 : op2;
	  tem = integer_zerop (arg0) ? op2 : op1;
	  /* Only optimize constant conditions when the selected branch
	     has the same type as the COND_EXPR.  This avoids optimizing
             away "c ? x : throw", where the throw has a void type.
             Avoid throwing away that operand which contains label.  */
          if ((!TREE_SIDE_EFFECTS (unused_op)
               || !contains_label_p (unused_op))
              && (! VOID_TYPE_P (TREE_TYPE (tem))
                  || VOID_TYPE_P (type)))
	    return pedantic_non_lvalue (tem);
	  return NULL_TREE;
	}
      if (operand_equal_p (arg1, op2, 0))
	return pedantic_omit_one_operand (type, arg1, arg0);

      /* If we have A op B ? A : C, we may be able to convert this to a
	 simpler expression, depending on the operation and the values
	 of B and C.  Signed zeros prevent all of these transformations,
	 for reasons given above each one.

         Also try swapping the arguments and inverting the conditional.  */
      if (COMPARISON_CLASS_P (arg0)
	  && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
					     arg1, TREE_OPERAND (arg0, 1))
	  && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
	{
	  tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
	  if (tem)
	    return tem;
	}

      if (COMPARISON_CLASS_P (arg0)
	  && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
					     op2,
					     TREE_OPERAND (arg0, 1))
	  && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
	{
	  tem = fold_truth_not_expr (arg0);
	  if (tem && COMPARISON_CLASS_P (tem))
	    {
	      tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
	      if (tem)
		return tem;
	    }
	}

      /* If the second operand is simpler than the third, swap them
	 since that produces better jump optimization results.  */
      if (truth_value_p (TREE_CODE (arg0))
	  && tree_swap_operands_p (op1, op2, false))
	{
	  /* See if this can be inverted.  If it can't, possibly because
	     it was a floating-point inequality comparison, don't do
	     anything.  */
	  tem = fold_truth_not_expr (arg0);
	  if (tem)
	    return fold_build3 (code, type, tem, op2, op1);
	}

      /* Convert A ? 1 : 0 to simply A.  */
      if (integer_onep (op1)
	  && integer_zerop (op2)
	  /* If we try to convert OP0 to our type, the
	     call to fold will try to move the conversion inside
	     a COND, which will recurse.  In that case, the COND_EXPR
	     is probably the best choice, so leave it alone.  */
	  && type == TREE_TYPE (arg0))
	return pedantic_non_lvalue (arg0);

      /* Convert A ? 0 : 1 to !A.  This prefers the use of NOT_EXPR
	 over COND_EXPR in cases such as floating point comparisons.  */
      if (integer_zerop (op1)
	  && integer_onep (op2)
	  && truth_value_p (TREE_CODE (arg0)))
	return pedantic_non_lvalue (fold_convert (type,
						  invert_truthvalue (arg0)));

      /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>).  */
      if (TREE_CODE (arg0) == LT_EXPR
	  && integer_zerop (TREE_OPERAND (arg0, 1))
	  && integer_zerop (op2)
	  && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
	{
	  /* sign_bit_p only checks ARG1 bits within A's precision.
	     If <sign bit of A> has wider type than A, bits outside
	     of A's precision in <sign bit of A> need to be checked.
	     If they are all 0, this optimization needs to be done
	     in unsigned A's type, if they are all 1 in signed A's type,
	     otherwise this can't be done.  */
	  if (TYPE_PRECISION (TREE_TYPE (tem))
	      < TYPE_PRECISION (TREE_TYPE (arg1))
	      && TYPE_PRECISION (TREE_TYPE (tem))
		 < TYPE_PRECISION (type))
	    {
	      unsigned HOST_WIDE_INT mask_lo;
	      HOST_WIDE_INT mask_hi;
	      int inner_width, outer_width;
	      tree tem_type;

	      inner_width = TYPE_PRECISION (TREE_TYPE (tem));
	      outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
	      if (outer_width > TYPE_PRECISION (type))
		outer_width = TYPE_PRECISION (type);

	      if (outer_width > HOST_BITS_PER_WIDE_INT)
		{
		  mask_hi = ((unsigned HOST_WIDE_INT) -1
			     >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
		  mask_lo = -1;
		}
	      else
		{
		  mask_hi = 0;
		  mask_lo = ((unsigned HOST_WIDE_INT) -1
			     >> (HOST_BITS_PER_WIDE_INT - outer_width));
		}
	      if (inner_width > HOST_BITS_PER_WIDE_INT)
		{
		  mask_hi &= ~((unsigned HOST_WIDE_INT) -1
			       >> (HOST_BITS_PER_WIDE_INT - inner_width));
		  mask_lo = 0;
		}
	      else
		mask_lo &= ~((unsigned HOST_WIDE_INT) -1
			     >> (HOST_BITS_PER_WIDE_INT - inner_width));

	      if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
		  && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
		{
		  tem_type = lang_hooks.types.signed_type (TREE_TYPE (tem));
		  tem = fold_convert (tem_type, tem);
		}
	      else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
		       && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
		{
		  tem_type = lang_hooks.types.unsigned_type (TREE_TYPE (tem));
		  tem = fold_convert (tem_type, tem);
		}
	      else
		tem = NULL;
	    }

	  if (tem)
	    return fold_convert (type,
				 fold_build2 (BIT_AND_EXPR,
					      TREE_TYPE (tem), tem,
					      fold_convert (TREE_TYPE (tem),
							    arg1)));
	}

      /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N).  A & 1 was
	 already handled above.  */
      if (TREE_CODE (arg0) == BIT_AND_EXPR
	  && integer_onep (TREE_OPERAND (arg0, 1))
	  && integer_zerop (op2)
	  && integer_pow2p (arg1))
	{
	  tree tem = TREE_OPERAND (arg0, 0);
	  STRIP_NOPS (tem);
	  if (TREE_CODE (tem) == RSHIFT_EXPR
              && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
              && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
	         TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
	    return fold_build2 (BIT_AND_EXPR, type,
				TREE_OPERAND (tem, 0), arg1);
	}

      /* A & N ? N : 0 is simply A & N if N is a power of two.  This
	 is probably obsolete because the first operand should be a
	 truth value (that's why we have the two cases above), but let's
	 leave it in until we can confirm this for all front-ends.  */
      if (integer_zerop (op2)
	  && TREE_CODE (arg0) == NE_EXPR
	  && integer_zerop (TREE_OPERAND (arg0, 1))
	  && integer_pow2p (arg1)
	  && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
	  && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
			      arg1, OEP_ONLY_CONST))
	return pedantic_non_lvalue (fold_convert (type,
						  TREE_OPERAND (arg0, 0)));

      /* Convert A ? B : 0 into A && B if A and B are truth values.  */
      if (integer_zerop (op2)
	  && truth_value_p (TREE_CODE (arg0))
	  && truth_value_p (TREE_CODE (arg1)))
	return fold_build2 (TRUTH_ANDIF_EXPR, type,
			    fold_convert (type, arg0),
			    arg1);

      /* Convert A ? B : 1 into !A || B if A and B are truth values.  */
      if (integer_onep (op2)
	  && truth_value_p (TREE_CODE (arg0))
	  && truth_value_p (TREE_CODE (arg1)))
	{
	  /* Only perform transformation if ARG0 is easily inverted.  */
	  tem = fold_truth_not_expr (arg0);
	  if (tem)
	    return fold_build2 (TRUTH_ORIF_EXPR, type,
				fold_convert (type, tem),
				arg1);
	}

      /* Convert A ? 0 : B into !A && B if A and B are truth values.  */
      if (integer_zerop (arg1)
	  && truth_value_p (TREE_CODE (arg0))
	  && truth_value_p (TREE_CODE (op2)))
	{
	  /* Only perform transformation if ARG0 is easily inverted.  */
	  tem = fold_truth_not_expr (arg0);
	  if (tem)
	    return fold_build2 (TRUTH_ANDIF_EXPR, type,
				fold_convert (type, tem),
				op2);
	}

      /* Convert A ? 1 : B into A || B if A and B are truth values.  */
      if (integer_onep (arg1)
	  && truth_value_p (TREE_CODE (arg0))
	  && truth_value_p (TREE_CODE (op2)))
	return fold_build2 (TRUTH_ORIF_EXPR, type,
			    fold_convert (type, arg0),
			    op2);

      return NULL_TREE;

    case CALL_EXPR:
      /* Check for a built-in function.  */
      if (TREE_CODE (op0) == ADDR_EXPR
	  && TREE_CODE (TREE_OPERAND (op0, 0)) == FUNCTION_DECL
	  && DECL_BUILT_IN (TREE_OPERAND (op0, 0)))
	return fold_builtin (TREE_OPERAND (op0, 0), op1, false);
      return NULL_TREE;

    case BIT_FIELD_REF:
      if (TREE_CODE (arg0) == VECTOR_CST
	  && type == TREE_TYPE (TREE_TYPE (arg0))
	  && host_integerp (arg1, 1)
	  && host_integerp (op2, 1))
	{
	  unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
	  unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);

	  if (width != 0
	      && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
	      && (idx % width) == 0
	      && (idx = idx / width)
		 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
	    {
	      tree elements = TREE_VECTOR_CST_ELTS (arg0);
	      while (idx-- > 0 && elements)
		elements = TREE_CHAIN (elements);
	      if (elements)
		return TREE_VALUE (elements);
	      else
		return fold_convert (type, integer_zero_node);
	    }
	}
      return NULL_TREE;

    default:
      return NULL_TREE;
    } /* switch (code) */
}

/* Perform constant folding and related simplification of EXPR.
   The related simplifications include x*1 => x, x*0 => 0, etc.,
   and application of the associative law.
   NOP_EXPR conversions may be removed freely (as long as we
   are careful not to change the type of the overall expression).
   We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
   but we can constant-fold them if they have constant operands.  */

#ifdef ENABLE_FOLD_CHECKING
# define fold(x) fold_1 (x)
static tree fold_1 (tree);
static
#endif
tree
fold (tree expr)
{
  const tree t = expr;
  enum tree_code code = TREE_CODE (t);
  enum tree_code_class kind = TREE_CODE_CLASS (code);
  tree tem;

  /* Return right away if a constant.  */
  if (kind == tcc_constant)
    return t;

  if (IS_EXPR_CODE_CLASS (kind))
    {
      tree type = TREE_TYPE (t);
      tree op0, op1, op2;

      switch (TREE_CODE_LENGTH (code))
	{
	case 1:
	  op0 = TREE_OPERAND (t, 0);
	  tem = fold_unary (code, type, op0);
	  return tem ? tem : expr;
	case 2:
	  op0 = TREE_OPERAND (t, 0);
	  op1 = TREE_OPERAND (t, 1);
	  tem = fold_binary (code, type, op0, op1);
	  return tem ? tem : expr;
	case 3:
	  op0 = TREE_OPERAND (t, 0);
	  op1 = TREE_OPERAND (t, 1);
	  op2 = TREE_OPERAND (t, 2);
	  tem = fold_ternary (code, type, op0, op1, op2);
	  return tem ? tem : expr;
	default:
	  break;
	}
    }

  switch (code)
    {
    case CONST_DECL:
      return fold (DECL_INITIAL (t));

    default:
      return t;
    } /* switch (code) */
}

#ifdef ENABLE_FOLD_CHECKING
#undef fold

static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
static void fold_check_failed (tree, tree);
void print_fold_checksum (tree);

/* When --enable-checking=fold, compute a digest of expr before
   and after actual fold call to see if fold did not accidentally
   change original expr.  */

tree
fold (tree expr)
{
  tree ret;
  struct md5_ctx ctx;
  unsigned char checksum_before[16], checksum_after[16];
  htab_t ht;

  ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
  md5_init_ctx (&ctx);
  fold_checksum_tree (expr, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_before);
  htab_empty (ht);

  ret = fold_1 (expr);

  md5_init_ctx (&ctx);
  fold_checksum_tree (expr, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_after);
  htab_delete (ht);

  if (memcmp (checksum_before, checksum_after, 16))
    fold_check_failed (expr, ret);

  return ret;
}

void
print_fold_checksum (tree expr)
{
  struct md5_ctx ctx;
  unsigned char checksum[16], cnt;
  htab_t ht;

  ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
  md5_init_ctx (&ctx);
  fold_checksum_tree (expr, &ctx, ht);
  md5_finish_ctx (&ctx, checksum);
  htab_delete (ht);
  for (cnt = 0; cnt < 16; ++cnt)
    fprintf (stderr, "%02x", checksum[cnt]);
  putc ('\n', stderr);
}

static void
fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
{
  internal_error ("fold check: original tree changed by fold");
}

static void
fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
{
  void **slot;
  enum tree_code code;
  struct tree_function_decl buf;
  int i, len;
  
recursive_label:

  gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
	       <= sizeof (struct tree_function_decl))
	      && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
  if (expr == NULL)
    return;
  slot = htab_find_slot (ht, expr, INSERT);
  if (*slot != NULL)
    return;
  *slot = expr;
  code = TREE_CODE (expr);
  if (TREE_CODE_CLASS (code) == tcc_declaration
      && DECL_ASSEMBLER_NAME_SET_P (expr))
    {
      /* Allow DECL_ASSEMBLER_NAME to be modified.  */
      memcpy ((char *) &buf, expr, tree_size (expr));
      expr = (tree) &buf;
      SET_DECL_ASSEMBLER_NAME (expr, NULL);
    }
  else if (TREE_CODE_CLASS (code) == tcc_type
	   && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
	       || TYPE_CACHED_VALUES_P (expr)
	       || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
    {
      /* Allow these fields to be modified.  */
      memcpy ((char *) &buf, expr, tree_size (expr));
      expr = (tree) &buf;
      TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr) = 0;
      TYPE_POINTER_TO (expr) = NULL;
      TYPE_REFERENCE_TO (expr) = NULL;
      if (TYPE_CACHED_VALUES_P (expr))
	{
	  TYPE_CACHED_VALUES_P (expr) = 0;
	  TYPE_CACHED_VALUES (expr) = NULL;
	}
    }
  md5_process_bytes (expr, tree_size (expr), ctx);
  fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
  if (TREE_CODE_CLASS (code) != tcc_type
      && TREE_CODE_CLASS (code) != tcc_declaration
      && code != TREE_LIST)
    fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
  switch (TREE_CODE_CLASS (code))
    {
    case tcc_constant:
      switch (code)
	{
	case STRING_CST:
	  md5_process_bytes (TREE_STRING_POINTER (expr),
			     TREE_STRING_LENGTH (expr), ctx);
	  break;
	case COMPLEX_CST:
	  fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
	  fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
	  break;
	case VECTOR_CST:
	  fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
	  break;
	default:
	  break;
	}
      break;
    case tcc_exceptional:
      switch (code)
	{
	case TREE_LIST:
	  fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
	  fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
	  expr = TREE_CHAIN (expr);
	  goto recursive_label;
	  break;
	case TREE_VEC:
	  for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
	    fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
	  break;
	default:
	  break;
	}
      break;
    case tcc_expression:
    case tcc_reference:
    case tcc_comparison:
    case tcc_unary:
    case tcc_binary:
    case tcc_statement:
      len = TREE_CODE_LENGTH (code);
      for (i = 0; i < len; ++i)
	fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
      break;
    case tcc_declaration:
      fold_checksum_tree (DECL_NAME (expr), ctx, ht);
      fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
      if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
	{
	  fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
	  fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
	  fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
	  fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
	  fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
	}
      if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
	fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
	  
      if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
	{
	  fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
	  fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
	  fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
	}
      break;
    case tcc_type:
      if (TREE_CODE (expr) == ENUMERAL_TYPE)
        fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
      fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
      fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
      fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
      fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
      if (INTEGRAL_TYPE_P (expr)
          || SCALAR_FLOAT_TYPE_P (expr))
	{
	  fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
	  fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
	}
      fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
      if (TREE_CODE (expr) == RECORD_TYPE
	  || TREE_CODE (expr) == UNION_TYPE
	  || TREE_CODE (expr) == QUAL_UNION_TYPE)
	fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
      fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
      break;
    default:
      break;
    }
}

#endif

/* Fold a unary tree expression with code CODE of type TYPE with an
   operand OP0.  Return a folded expression if successful.  Otherwise,
   return a tree expression with code CODE of type TYPE with an
   operand OP0.  */

tree
fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
{
  tree tem;
#ifdef ENABLE_FOLD_CHECKING
  unsigned char checksum_before[16], checksum_after[16];
  struct md5_ctx ctx;
  htab_t ht;

  ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
  md5_init_ctx (&ctx);
  fold_checksum_tree (op0, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_before);
  htab_empty (ht);
#endif
  
  tem = fold_unary (code, type, op0);
  if (!tem)
    tem = build1_stat (code, type, op0 PASS_MEM_STAT);
  
#ifdef ENABLE_FOLD_CHECKING
  md5_init_ctx (&ctx);
  fold_checksum_tree (op0, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_after);
  htab_delete (ht);

  if (memcmp (checksum_before, checksum_after, 16))
    fold_check_failed (op0, tem);
#endif
  return tem;
}

/* Fold a binary tree expression with code CODE of type TYPE with
   operands OP0 and OP1.  Return a folded expression if successful.
   Otherwise, return a tree expression with code CODE of type TYPE
   with operands OP0 and OP1.  */

tree
fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
		  MEM_STAT_DECL)
{
  tree tem;
#ifdef ENABLE_FOLD_CHECKING
  unsigned char checksum_before_op0[16],
                checksum_before_op1[16],
		checksum_after_op0[16],
		checksum_after_op1[16];
  struct md5_ctx ctx;
  htab_t ht;

  ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
  md5_init_ctx (&ctx);
  fold_checksum_tree (op0, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_before_op0);
  htab_empty (ht);

  md5_init_ctx (&ctx);
  fold_checksum_tree (op1, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_before_op1);
  htab_empty (ht);
#endif

  tem = fold_binary (code, type, op0, op1);
  if (!tem)
    tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
  
#ifdef ENABLE_FOLD_CHECKING
  md5_init_ctx (&ctx);
  fold_checksum_tree (op0, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_after_op0);
  htab_empty (ht);

  if (memcmp (checksum_before_op0, checksum_after_op0, 16))
    fold_check_failed (op0, tem);
  
  md5_init_ctx (&ctx);
  fold_checksum_tree (op1, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_after_op1);
  htab_delete (ht);

  if (memcmp (checksum_before_op1, checksum_after_op1, 16))
    fold_check_failed (op1, tem);
#endif
  return tem;
}

/* Fold a ternary tree expression with code CODE of type TYPE with
   operands OP0, OP1, and OP2.  Return a folded expression if
   successful.  Otherwise, return a tree expression with code CODE of
   type TYPE with operands OP0, OP1, and OP2.  */

tree
fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
	     MEM_STAT_DECL)
{
  tree tem;
#ifdef ENABLE_FOLD_CHECKING
  unsigned char checksum_before_op0[16],
                checksum_before_op1[16],
                checksum_before_op2[16],
		checksum_after_op0[16],
		checksum_after_op1[16],
		checksum_after_op2[16];
  struct md5_ctx ctx;
  htab_t ht;

  ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
  md5_init_ctx (&ctx);
  fold_checksum_tree (op0, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_before_op0);
  htab_empty (ht);

  md5_init_ctx (&ctx);
  fold_checksum_tree (op1, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_before_op1);
  htab_empty (ht);

  md5_init_ctx (&ctx);
  fold_checksum_tree (op2, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_before_op2);
  htab_empty (ht);
#endif
  
  tem = fold_ternary (code, type, op0, op1, op2);
  if (!tem)
    tem =  build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
      
#ifdef ENABLE_FOLD_CHECKING
  md5_init_ctx (&ctx);
  fold_checksum_tree (op0, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_after_op0);
  htab_empty (ht);

  if (memcmp (checksum_before_op0, checksum_after_op0, 16))
    fold_check_failed (op0, tem);
  
  md5_init_ctx (&ctx);
  fold_checksum_tree (op1, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_after_op1);
  htab_empty (ht);

  if (memcmp (checksum_before_op1, checksum_after_op1, 16))
    fold_check_failed (op1, tem);
  
  md5_init_ctx (&ctx);
  fold_checksum_tree (op2, &ctx, ht);
  md5_finish_ctx (&ctx, checksum_after_op2);
  htab_delete (ht);

  if (memcmp (checksum_before_op2, checksum_after_op2, 16))
    fold_check_failed (op2, tem);
#endif
  return tem;
}

/* Perform constant folding and related simplification of initializer
   expression EXPR.  These behave identically to "fold_buildN" but ignore
   potential run-time traps and exceptions that fold must preserve.  */

#define START_FOLD_INIT \
  int saved_signaling_nans = flag_signaling_nans;\
  int saved_trapping_math = flag_trapping_math;\
  int saved_rounding_math = flag_rounding_math;\
  int saved_trapv = flag_trapv;\
  int saved_folding_initializer = folding_initializer;\
  flag_signaling_nans = 0;\
  flag_trapping_math = 0;\
  flag_rounding_math = 0;\
  flag_trapv = 0;\
  folding_initializer = 1;

#define END_FOLD_INIT \
  flag_signaling_nans = saved_signaling_nans;\
  flag_trapping_math = saved_trapping_math;\
  flag_rounding_math = saved_rounding_math;\
  flag_trapv = saved_trapv;\
  folding_initializer = saved_folding_initializer;

tree
fold_build1_initializer (enum tree_code code, tree type, tree op)
{
  tree result;
  START_FOLD_INIT;

  result = fold_build1 (code, type, op);

  END_FOLD_INIT;
  return result;
}

tree
fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
{
  tree result;
  START_FOLD_INIT;

  result = fold_build2 (code, type, op0, op1);

  END_FOLD_INIT;
  return result;
}

tree
fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
			 tree op2)
{
  tree result;
  START_FOLD_INIT;

  result = fold_build3 (code, type, op0, op1, op2);

  END_FOLD_INIT;
  return result;
}

#undef START_FOLD_INIT
#undef END_FOLD_INIT

/* Determine if first argument is a multiple of second argument.  Return 0 if
   it is not, or we cannot easily determined it to be.

   An example of the sort of thing we care about (at this point; this routine
   could surely be made more general, and expanded to do what the *_DIV_EXPR's
   fold cases do now) is discovering that

     SAVE_EXPR (I) * SAVE_EXPR (J * 8)

   is a multiple of

     SAVE_EXPR (J * 8)

   when we know that the two SAVE_EXPR (J * 8) nodes are the same node.

   This code also handles discovering that

     SAVE_EXPR (I) * SAVE_EXPR (J * 8)

   is a multiple of 8 so we don't have to worry about dealing with a
   possible remainder.

   Note that we *look* inside a SAVE_EXPR only to determine how it was
   calculated; it is not safe for fold to do much of anything else with the
   internals of a SAVE_EXPR, since it cannot know when it will be evaluated
   at run time.  For example, the latter example above *cannot* be implemented
   as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
   evaluation time of the original SAVE_EXPR is not necessarily the same at
   the time the new expression is evaluated.  The only optimization of this
   sort that would be valid is changing

     SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)

   divided by 8 to

     SAVE_EXPR (I) * SAVE_EXPR (J)

   (where the same SAVE_EXPR (J) is used in the original and the
   transformed version).  */

static int
multiple_of_p (tree type, tree top, tree bottom)
{
  if (operand_equal_p (top, bottom, 0))
    return 1;

  if (TREE_CODE (type) != INTEGER_TYPE)
    return 0;

  switch (TREE_CODE (top))
    {
    case BIT_AND_EXPR:
      /* Bitwise and provides a power of two multiple.  If the mask is
	 a multiple of BOTTOM then TOP is a multiple of BOTTOM.  */
      if (!integer_pow2p (bottom))
	return 0;
      /* FALLTHRU */

    case MULT_EXPR:
      return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
	      || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));

    case PLUS_EXPR:
    case MINUS_EXPR:
      return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
	      && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));

    case LSHIFT_EXPR:
      if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
	{
	  tree op1, t1;

	  op1 = TREE_OPERAND (top, 1);
	  /* const_binop may not detect overflow correctly,
	     so check for it explicitly here.  */
	  if (TYPE_PRECISION (TREE_TYPE (size_one_node))
	      > TREE_INT_CST_LOW (op1)
	      && TREE_INT_CST_HIGH (op1) == 0
	      && 0 != (t1 = fold_convert (type,
					  const_binop (LSHIFT_EXPR,
						       size_one_node,
						       op1, 0)))
	      && ! TREE_OVERFLOW (t1))
	    return multiple_of_p (type, t1, bottom);
	}
      return 0;

    case NOP_EXPR:
      /* Can't handle conversions from non-integral or wider integral type.  */
      if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
	  || (TYPE_PRECISION (type)
	      < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
	return 0;

      /* .. fall through ...  */

    case SAVE_EXPR:
      return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);

    case INTEGER_CST:
      if (TREE_CODE (bottom) != INTEGER_CST
	  || (TYPE_UNSIGNED (type)
	      && (tree_int_cst_sgn (top) < 0
		  || tree_int_cst_sgn (bottom) < 0)))
	return 0;
      return integer_zerop (const_binop (TRUNC_MOD_EXPR,
					 top, bottom, 0));

    default:
      return 0;
    }
}

/* Return true if `t' is known to be non-negative.  If the return
   value is based on the assumption that signed overflow is undefined,
   set *STRICT_OVERFLOW_P to true; otherwise, don't change
   *STRICT_OVERFLOW_P.  */

int
tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
{
  if (t == error_mark_node)
    return 0;

  if (TYPE_UNSIGNED (TREE_TYPE (t)))
    return 1;

  switch (TREE_CODE (t))
    {
    case SSA_NAME:
      /* Query VRP to see if it has recorded any information about
	 the range of this object.  */
      return ssa_name_nonnegative_p (t);

    case ABS_EXPR:
      /* We can't return 1 if flag_wrapv is set because
	 ABS_EXPR<INT_MIN> = INT_MIN.  */
      if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
	return 1;
      if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
	{
	  *strict_overflow_p = true;
	  return 1;
	}
      break;

    case INTEGER_CST:
      return tree_int_cst_sgn (t) >= 0;

    case REAL_CST:
      return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));

    case PLUS_EXPR:
      if (FLOAT_TYPE_P (TREE_TYPE (t)))
	return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
					       strict_overflow_p)
		&& tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
						  strict_overflow_p));

      /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
	 both unsigned and at least 2 bits shorter than the result.  */
      if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
	  && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
	  && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
	{
	  tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
	  tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
	  if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
	      && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
	    {
	      unsigned int prec = MAX (TYPE_PRECISION (inner1),
				       TYPE_PRECISION (inner2)) + 1;
	      return prec < TYPE_PRECISION (TREE_TYPE (t));
	    }
	}
      break;

    case MULT_EXPR:
      if (FLOAT_TYPE_P (TREE_TYPE (t)))
	{
	  /* x * x for floating point x is always non-negative.  */
	  if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
	    return 1;
	  return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
						 strict_overflow_p)
		  && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
						    strict_overflow_p));
	}

      /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
	 both unsigned and their total bits is shorter than the result.  */
      if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
	  && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
	  && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
	{
	  tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
	  tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
	  if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
	      && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
	    return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
		   < TYPE_PRECISION (TREE_TYPE (t));
	}
      return 0;

    case BIT_AND_EXPR:
    case MAX_EXPR:
      return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
					     strict_overflow_p)
	      || tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
						strict_overflow_p));

    case BIT_IOR_EXPR:
    case BIT_XOR_EXPR:
    case MIN_EXPR:
    case RDIV_EXPR:
    case TRUNC_DIV_EXPR:
    case CEIL_DIV_EXPR:
    case FLOOR_DIV_EXPR:
    case ROUND_DIV_EXPR:
      return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
					     strict_overflow_p)
	      && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
						strict_overflow_p));

    case TRUNC_MOD_EXPR:
    case CEIL_MOD_EXPR:
    case FLOOR_MOD_EXPR:
    case ROUND_MOD_EXPR:
    case SAVE_EXPR:
    case NON_LVALUE_EXPR:
    case FLOAT_EXPR:
    case FIX_TRUNC_EXPR:
      return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
					    strict_overflow_p);

    case COMPOUND_EXPR:
    case MODIFY_EXPR:
      return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
					    strict_overflow_p);

    case BIND_EXPR:
      return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
					    strict_overflow_p);

    case COND_EXPR:
      return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
					     strict_overflow_p)
	      && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
						strict_overflow_p));

    case NOP_EXPR:
      {
	tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
	tree outer_type = TREE_TYPE (t);

	if (TREE_CODE (outer_type) == REAL_TYPE)
	  {
	    if (TREE_CODE (inner_type) == REAL_TYPE)
	      return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
						    strict_overflow_p);
	    if (TREE_CODE (inner_type) == INTEGER_TYPE)
	      {
		if (TYPE_UNSIGNED (inner_type))
		  return 1;
		return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
						      strict_overflow_p);
	      }
	  }
	else if (TREE_CODE (outer_type) == INTEGER_TYPE)
	  {
	    if (TREE_CODE (inner_type) == REAL_TYPE)
	      return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t,0),
						    strict_overflow_p);
	    if (TREE_CODE (inner_type) == INTEGER_TYPE)
	      return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
		      && TYPE_UNSIGNED (inner_type);
	  }
      }
      break;

    case TARGET_EXPR:
      {
	tree temp = TARGET_EXPR_SLOT (t);
	t = TARGET_EXPR_INITIAL (t);

	/* If the initializer is non-void, then it's a normal expression
	   that will be assigned to the slot.  */
	if (!VOID_TYPE_P (t))
	  return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);

	/* Otherwise, the initializer sets the slot in some way.  One common
	   way is an assignment statement at the end of the initializer.  */
	while (1)
	  {
	    if (TREE_CODE (t) == BIND_EXPR)
	      t = expr_last (BIND_EXPR_BODY (t));
	    else if (TREE_CODE (t) == TRY_FINALLY_EXPR
		     || TREE_CODE (t) == TRY_CATCH_EXPR)
	      t = expr_last (TREE_OPERAND (t, 0));
	    else if (TREE_CODE (t) == STATEMENT_LIST)
	      t = expr_last (t);
	    else
	      break;
	  }
	if (TREE_CODE (t) == MODIFY_EXPR
	    && TREE_OPERAND (t, 0) == temp)
	  return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
						strict_overflow_p);

	return 0;
      }

    case CALL_EXPR:
      {
	tree fndecl = get_callee_fndecl (t);
	tree arglist = TREE_OPERAND (t, 1);
	if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
	  switch (DECL_FUNCTION_CODE (fndecl))
	    {
	    CASE_FLT_FN (BUILT_IN_ACOS):
	    CASE_FLT_FN (BUILT_IN_ACOSH):
	    CASE_FLT_FN (BUILT_IN_CABS):
	    CASE_FLT_FN (BUILT_IN_COSH):
	    CASE_FLT_FN (BUILT_IN_ERFC):
	    CASE_FLT_FN (BUILT_IN_EXP):
	    CASE_FLT_FN (BUILT_IN_EXP10):
	    CASE_FLT_FN (BUILT_IN_EXP2):
	    CASE_FLT_FN (BUILT_IN_FABS):
	    CASE_FLT_FN (BUILT_IN_FDIM):
	    CASE_FLT_FN (BUILT_IN_HYPOT):
	    CASE_FLT_FN (BUILT_IN_POW10):
	    CASE_INT_FN (BUILT_IN_FFS):
	    CASE_INT_FN (BUILT_IN_PARITY):
	    CASE_INT_FN (BUILT_IN_POPCOUNT):
	      /* Always true.  */
	      return 1;

	    CASE_FLT_FN (BUILT_IN_SQRT):
	      /* sqrt(-0.0) is -0.0.  */
	      if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
		return 1;
	      return tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
						    strict_overflow_p);

	    CASE_FLT_FN (BUILT_IN_ASINH):
	    CASE_FLT_FN (BUILT_IN_ATAN):
	    CASE_FLT_FN (BUILT_IN_ATANH):
	    CASE_FLT_FN (BUILT_IN_CBRT):
	    CASE_FLT_FN (BUILT_IN_CEIL):
	    CASE_FLT_FN (BUILT_IN_ERF):
	    CASE_FLT_FN (BUILT_IN_EXPM1):
	    CASE_FLT_FN (BUILT_IN_FLOOR):
	    CASE_FLT_FN (BUILT_IN_FMOD):
	    CASE_FLT_FN (BUILT_IN_FREXP):
	    CASE_FLT_FN (BUILT_IN_LCEIL):
	    CASE_FLT_FN (BUILT_IN_LDEXP):
	    CASE_FLT_FN (BUILT_IN_LFLOOR):
	    CASE_FLT_FN (BUILT_IN_LLCEIL):
	    CASE_FLT_FN (BUILT_IN_LLFLOOR):
	    CASE_FLT_FN (BUILT_IN_LLRINT):
	    CASE_FLT_FN (BUILT_IN_LLROUND):
	    CASE_FLT_FN (BUILT_IN_LRINT):
	    CASE_FLT_FN (BUILT_IN_LROUND):
	    CASE_FLT_FN (BUILT_IN_MODF):
	    CASE_FLT_FN (BUILT_IN_NEARBYINT):
	    CASE_FLT_FN (BUILT_IN_POW):
	    CASE_FLT_FN (BUILT_IN_RINT):
	    CASE_FLT_FN (BUILT_IN_ROUND):
	    CASE_FLT_FN (BUILT_IN_SIGNBIT):
	    CASE_FLT_FN (BUILT_IN_SINH):
	    CASE_FLT_FN (BUILT_IN_TANH):
	    CASE_FLT_FN (BUILT_IN_TRUNC):
	      /* True if the 1st argument is nonnegative.  */
	      return tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
						    strict_overflow_p);

	    CASE_FLT_FN (BUILT_IN_FMAX):
	      /* True if the 1st OR 2nd arguments are nonnegative.  */
	      return (tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
						     strict_overflow_p)
		      || (tree_expr_nonnegative_warnv_p
			  (TREE_VALUE (TREE_CHAIN (arglist)),
			   strict_overflow_p)));

	    CASE_FLT_FN (BUILT_IN_FMIN):
	      /* True if the 1st AND 2nd arguments are nonnegative.  */
	      return (tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
						     strict_overflow_p)
		      && (tree_expr_nonnegative_warnv_p
			  (TREE_VALUE (TREE_CHAIN (arglist)),
			   strict_overflow_p)));

	    CASE_FLT_FN (BUILT_IN_COPYSIGN):
	      /* True if the 2nd argument is nonnegative.  */
	      return (tree_expr_nonnegative_warnv_p
		      (TREE_VALUE (TREE_CHAIN (arglist)),
		       strict_overflow_p));

	    default:
	      break;
	    }
      }

      /* ... fall through ...  */

    default:
      {
	tree type = TREE_TYPE (t);
	if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
	    && truth_value_p (TREE_CODE (t)))
	  /* Truth values evaluate to 0 or 1, which is nonnegative unless we
             have a signed:1 type (where the value is -1 and 0).  */
	  return true;
      }
    }

  /* We don't know sign of `t', so be conservative and return false.  */
  return 0;
}

/* Return true if `t' is known to be non-negative.  Handle warnings
   about undefined signed overflow.  */

int
tree_expr_nonnegative_p (tree t)
{
  int ret;
  bool strict_overflow_p;

  strict_overflow_p = false;
  ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
  if (strict_overflow_p)
    fold_overflow_warning (("assuming signed overflow does not occur when "
			    "determining that expression is always "
			    "non-negative"),
			   WARN_STRICT_OVERFLOW_MISC);
  return ret;
}

/* Return true when T is an address and is known to be nonzero.
   For floating point we further ensure that T is not denormal.
   Similar logic is present in nonzero_address in rtlanal.h.

   If the return value is based on the assumption that signed overflow
   is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
   change *STRICT_OVERFLOW_P.  */

bool
tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
{
  tree type = TREE_TYPE (t);
  bool sub_strict_overflow_p;

  /* Doing something useful for floating point would need more work.  */
  if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
    return false;

  switch (TREE_CODE (t))
    {
    case SSA_NAME:
      /* Query VRP to see if it has recorded any information about
	 the range of this object.  */
      return ssa_name_nonzero_p (t);

    case ABS_EXPR:
      return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
					strict_overflow_p);

    case INTEGER_CST:
      /* We used to test for !integer_zerop here.  This does not work correctly
	 if TREE_CONSTANT_OVERFLOW (t).  */
      return (TREE_INT_CST_LOW (t) != 0
	      || TREE_INT_CST_HIGH (t) != 0);

    case PLUS_EXPR:
      if (TYPE_OVERFLOW_UNDEFINED (type))
	{
	  /* With the presence of negative values it is hard
	     to say something.  */
	  sub_strict_overflow_p = false;
	  if (!tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
					      &sub_strict_overflow_p)
	      || !tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
						 &sub_strict_overflow_p))
	    return false;
	  /* One of operands must be positive and the other non-negative.  */
	  /* We don't set *STRICT_OVERFLOW_P here: even if this value
	     overflows, on a twos-complement machine the sum of two
	     nonnegative numbers can never be zero.  */
	  return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
					     strict_overflow_p)
	          || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
						strict_overflow_p));
	}
      break;

    case MULT_EXPR:
      if (TYPE_OVERFLOW_UNDEFINED (type))
	{
	  if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
					 strict_overflow_p)
	      && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
					    strict_overflow_p))
	    {
	      *strict_overflow_p = true;
	      return true;
	    }
	}
      break;

    case NOP_EXPR:
      {
	tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
	tree outer_type = TREE_TYPE (t);

	return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
		&& tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
					      strict_overflow_p));
      }
      break;

   case ADDR_EXPR:
      {
	tree base = get_base_address (TREE_OPERAND (t, 0));

	if (!base)
	  return false;

	/* Weak declarations may link to NULL.  */
	if (VAR_OR_FUNCTION_DECL_P (base))
	  return !DECL_WEAK (base);

	/* Constants are never weak.  */
	if (CONSTANT_CLASS_P (base))
	  return true;

	return false;
      }

    case COND_EXPR:
      sub_strict_overflow_p = false;
      if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
				     &sub_strict_overflow_p)
	  && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
					&sub_strict_overflow_p))
	{
	  if (sub_strict_overflow_p)
	    *strict_overflow_p = true;
	  return true;
	}
      break;

    case MIN_EXPR:
      sub_strict_overflow_p = false;
      if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
				     &sub_strict_overflow_p)
	  && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
					&sub_strict_overflow_p))
	{
	  if (sub_strict_overflow_p)
	    *strict_overflow_p = true;
	}
      break;

    case MAX_EXPR:
      sub_strict_overflow_p = false;
      if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
				     &sub_strict_overflow_p))
	{
	  if (sub_strict_overflow_p)
	    *strict_overflow_p = true;

	  /* When both operands are nonzero, then MAX must be too.  */
	  if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
					 strict_overflow_p))
	    return true;

	  /* MAX where operand 0 is positive is positive.  */
	  return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
					       strict_overflow_p);
	}
      /* MAX where operand 1 is positive is positive.  */
      else if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
					  &sub_strict_overflow_p)
	       && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
						 &sub_strict_overflow_p))
	{
	  if (sub_strict_overflow_p)
	    *strict_overflow_p = true;
	  return true;
	}
      break;

    case COMPOUND_EXPR:
    case MODIFY_EXPR:
    case BIND_EXPR:
      return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
					strict_overflow_p);

    case SAVE_EXPR:
    case NON_LVALUE_EXPR:
      return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
					strict_overflow_p);

    case BIT_IOR_EXPR:
      return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
					strict_overflow_p)
	      || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
					    strict_overflow_p));

    case CALL_EXPR:
      return alloca_call_p (t);

    default:
      break;
    }
  return false;
}

/* Return true when T is an address and is known to be nonzero.
   Handle warnings about undefined signed overflow.  */

bool
tree_expr_nonzero_p (tree t)
{
  bool ret, strict_overflow_p;

  strict_overflow_p = false;
  ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
  if (strict_overflow_p)
    fold_overflow_warning (("assuming signed overflow does not occur when "
			    "determining that expression is always "
			    "non-zero"),
			   WARN_STRICT_OVERFLOW_MISC);
  return ret;
}

/* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
   attempt to fold the expression to a constant without modifying TYPE,
   OP0 or OP1.

   If the expression could be simplified to a constant, then return
   the constant.  If the expression would not be simplified to a
   constant, then return NULL_TREE.  */

tree
fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
{
  tree tem = fold_binary (code, type, op0, op1);
  return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
}

/* Given the components of a unary expression CODE, TYPE and OP0,
   attempt to fold the expression to a constant without modifying
   TYPE or OP0.

   If the expression could be simplified to a constant, then return
   the constant.  If the expression would not be simplified to a
   constant, then return NULL_TREE.  */

tree
fold_unary_to_constant (enum tree_code code, tree type, tree op0)
{
  tree tem = fold_unary (code, type, op0);
  return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
}

/* If EXP represents referencing an element in a constant string
   (either via pointer arithmetic or array indexing), return the
   tree representing the value accessed, otherwise return NULL.  */

tree
fold_read_from_constant_string (tree exp)
{
  if ((TREE_CODE (exp) == INDIRECT_REF
       || TREE_CODE (exp) == ARRAY_REF)
      && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
    {
      tree exp1 = TREE_OPERAND (exp, 0);
      tree index;
      tree string;

      if (TREE_CODE (exp) == INDIRECT_REF)
	string = string_constant (exp1, &index);
      else
	{
	  tree low_bound = array_ref_low_bound (exp);
	  index = fold_convert (sizetype, TREE_OPERAND (exp, 1));

	  /* Optimize the special-case of a zero lower bound.

	     We convert the low_bound to sizetype to avoid some problems
	     with constant folding.  (E.g. suppose the lower bound is 1,
	     and its mode is QI.  Without the conversion,l (ARRAY
	     +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
	     +INDEX), which becomes (ARRAY+255+INDEX).  Opps!)  */
	  if (! integer_zerop (low_bound))
	    index = size_diffop (index, fold_convert (sizetype, low_bound));

	  string = exp1;
	}

      if (string
	  && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
	  && TREE_CODE (string) == STRING_CST
	  && TREE_CODE (index) == INTEGER_CST
	  && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
	  && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
	      == MODE_INT)
	  && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
	return fold_convert (TREE_TYPE (exp),
			     build_int_cst (NULL_TREE,
					    (TREE_STRING_POINTER (string)
					     [TREE_INT_CST_LOW (index)])));
    }
  return NULL;
}

/* Return the tree for neg (ARG0) when ARG0 is known to be either
   an integer constant or real constant.

   TYPE is the type of the result.  */

static tree
fold_negate_const (tree arg0, tree type)
{
  tree t = NULL_TREE;

  switch (TREE_CODE (arg0))
    {
    case INTEGER_CST:
      {
	unsigned HOST_WIDE_INT low;
	HOST_WIDE_INT high;
	int overflow = neg_double (TREE_INT_CST_LOW (arg0),
				   TREE_INT_CST_HIGH (arg0),
				   &low, &high);
	t = build_int_cst_wide (type, low, high);
	t = force_fit_type (t, 1,
			    (overflow | TREE_OVERFLOW (arg0))
			    && !TYPE_UNSIGNED (type),
			    TREE_CONSTANT_OVERFLOW (arg0));
	break;
      }

    case REAL_CST:
      t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
      break;

    default:
      gcc_unreachable ();
    }

  return t;
}

/* Return the tree for abs (ARG0) when ARG0 is known to be either
   an integer constant or real constant.

   TYPE is the type of the result.  */

tree
fold_abs_const (tree arg0, tree type)
{
  tree t = NULL_TREE;

  switch (TREE_CODE (arg0))
    {
    case INTEGER_CST:
      /* If the value is unsigned, then the absolute value is
	 the same as the ordinary value.  */
      if (TYPE_UNSIGNED (type))
	t = arg0;
      /* Similarly, if the value is non-negative.  */
      else if (INT_CST_LT (integer_minus_one_node, arg0))
	t = arg0;
      /* If the value is negative, then the absolute value is
	 its negation.  */
      else
	{
	  unsigned HOST_WIDE_INT low;
	  HOST_WIDE_INT high;
	  int overflow = neg_double (TREE_INT_CST_LOW (arg0),
				     TREE_INT_CST_HIGH (arg0),
				     &low, &high);
	  t = build_int_cst_wide (type, low, high);
	  t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
			      TREE_CONSTANT_OVERFLOW (arg0));
	}
      break;

    case REAL_CST:
      if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
	t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
      else
	t =  arg0;
      break;

    default:
      gcc_unreachable ();
    }

  return t;
}

/* Return the tree for not (ARG0) when ARG0 is known to be an integer
   constant.  TYPE is the type of the result.  */

static tree
fold_not_const (tree arg0, tree type)
{
  tree t = NULL_TREE;

  gcc_assert (TREE_CODE (arg0) == INTEGER_CST);

  t = build_int_cst_wide (type,
			  ~ TREE_INT_CST_LOW (arg0),
			  ~ TREE_INT_CST_HIGH (arg0));
  t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
		      TREE_CONSTANT_OVERFLOW (arg0));

  return t;
}

/* Given CODE, a relational operator, the target type, TYPE and two
   constant operands OP0 and OP1, return the result of the
   relational operation.  If the result is not a compile time
   constant, then return NULL_TREE.  */

static tree
fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
{
  int result, invert;

  /* From here on, the only cases we handle are when the result is
     known to be a constant.  */

  if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
    {
      const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
      const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);

      /* Handle the cases where either operand is a NaN.  */
      if (real_isnan (c0) || real_isnan (c1))
	{
	  switch (code)
	    {
	    case EQ_EXPR:
	    case ORDERED_EXPR:
	      result = 0;
	      break;

	    case NE_EXPR:
	    case UNORDERED_EXPR:
	    case UNLT_EXPR:
	    case UNLE_EXPR:
	    case UNGT_EXPR:
	    case UNGE_EXPR:
	    case UNEQ_EXPR:
              result = 1;
	      break;

	    case LT_EXPR:
	    case LE_EXPR:
	    case GT_EXPR:
	    case GE_EXPR:
	    case LTGT_EXPR:
	      if (flag_trapping_math)
		return NULL_TREE;
	      result = 0;
	      break;

	    default:
	      gcc_unreachable ();
	    }

	  return constant_boolean_node (result, type);
	}

      return constant_boolean_node (real_compare (code, c0, c1), type);
    }

  /* Handle equality/inequality of complex constants.  */
  if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
    {
      tree rcond = fold_relational_const (code, type,
					  TREE_REALPART (op0),
					  TREE_REALPART (op1));
      tree icond = fold_relational_const (code, type,
					  TREE_IMAGPART (op0),
					  TREE_IMAGPART (op1));
      if (code == EQ_EXPR)
	return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
      else if (code == NE_EXPR)
	return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
      else
	return NULL_TREE;
    }

  /* From here on we only handle LT, LE, GT, GE, EQ and NE.

     To compute GT, swap the arguments and do LT.
     To compute GE, do LT and invert the result.
     To compute LE, swap the arguments, do LT and invert the result.
     To compute NE, do EQ and invert the result.

     Therefore, the code below must handle only EQ and LT.  */

  if (code == LE_EXPR || code == GT_EXPR)
    {
      tree tem = op0;
      op0 = op1;
      op1 = tem;
      code = swap_tree_comparison (code);
    }

  /* Note that it is safe to invert for real values here because we
     have already handled the one case that it matters.  */

  invert = 0;
  if (code == NE_EXPR || code == GE_EXPR)
    {
      invert = 1;
      code = invert_tree_comparison (code, false);
    }

  /* Compute a result for LT or EQ if args permit;
     Otherwise return T.  */
  if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
    {
      if (code == EQ_EXPR)
	result = tree_int_cst_equal (op0, op1);
      else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
	result = INT_CST_LT_UNSIGNED (op0, op1);
      else
	result = INT_CST_LT (op0, op1);
    }
  else
    return NULL_TREE;

  if (invert)
    result ^= 1;
  return constant_boolean_node (result, type);
}

/* Build an expression for the a clean point containing EXPR with type TYPE.
   Don't build a cleanup point expression for EXPR which don't have side
   effects.  */

tree
fold_build_cleanup_point_expr (tree type, tree expr)
{
  /* If the expression does not have side effects then we don't have to wrap
     it with a cleanup point expression.  */
  if (!TREE_SIDE_EFFECTS (expr))
    return expr;

  /* If the expression is a return, check to see if the expression inside the
     return has no side effects or the right hand side of the modify expression
     inside the return. If either don't have side effects set we don't need to
     wrap the expression in a cleanup point expression.  Note we don't check the
     left hand side of the modify because it should always be a return decl.  */
  if (TREE_CODE (expr) == RETURN_EXPR)
    {
      tree op = TREE_OPERAND (expr, 0);
      if (!op || !TREE_SIDE_EFFECTS (op))
        return expr;
      op = TREE_OPERAND (op, 1);
      if (!TREE_SIDE_EFFECTS (op))
        return expr;
    }
  
  return build1 (CLEANUP_POINT_EXPR, type, expr);
}

/* Build an expression for the address of T.  Folds away INDIRECT_REF to
   avoid confusing the gimplify process.  */

tree
build_fold_addr_expr_with_type (tree t, tree ptrtype)
{
  /* The size of the object is not relevant when talking about its address.  */
  if (TREE_CODE (t) == WITH_SIZE_EXPR)
    t = TREE_OPERAND (t, 0);

  /* Note: doesn't apply to ALIGN_INDIRECT_REF */
  if (TREE_CODE (t) == INDIRECT_REF
      || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
    {
      t = TREE_OPERAND (t, 0);
      if (TREE_TYPE (t) != ptrtype)
	t = build1 (NOP_EXPR, ptrtype, t);
    }
  else
    {
      tree base = t;

      while (handled_component_p (base))
	base = TREE_OPERAND (base, 0);
      if (DECL_P (base))
	TREE_ADDRESSABLE (base) = 1;

      t = build1 (ADDR_EXPR, ptrtype, t);
    }

  return t;
}

tree
build_fold_addr_expr (tree t)
{
  return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
}

/* Given a pointer value OP0 and a type TYPE, return a simplified version
   of an indirection through OP0, or NULL_TREE if no simplification is
   possible.  */

tree
fold_indirect_ref_1 (tree type, tree op0)
{
  tree sub = op0;
  tree subtype;

  STRIP_NOPS (sub);
  subtype = TREE_TYPE (sub);
  if (!POINTER_TYPE_P (subtype))
    return NULL_TREE;

  if (TREE_CODE (sub) == ADDR_EXPR)
    {
      tree op = TREE_OPERAND (sub, 0);
      tree optype = TREE_TYPE (op);
      /* *&CONST_DECL -> to the value of the const decl.  */
      if (TREE_CODE (op) == CONST_DECL)
	return DECL_INITIAL (op);
      /* *&p => p;  make sure to handle *&"str"[cst] here.  */
      if (type == optype)
	{
	  tree fop = fold_read_from_constant_string (op);
	  if (fop)
	    return fop;
	  else
	    return op;
	}
      /* *(foo *)&fooarray => fooarray[0] */
      else if (TREE_CODE (optype) == ARRAY_TYPE
	       && type == TREE_TYPE (optype))
	{
	  tree type_domain = TYPE_DOMAIN (optype);
	  tree min_val = size_zero_node;
	  if (type_domain && TYPE_MIN_VALUE (type_domain))
	    min_val = TYPE_MIN_VALUE (type_domain);
	  return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
	}
      /* *(foo *)&complexfoo => __real__ complexfoo */
      else if (TREE_CODE (optype) == COMPLEX_TYPE
	       && type == TREE_TYPE (optype))
	return fold_build1 (REALPART_EXPR, type, op);
    }

  /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
  if (TREE_CODE (sub) == PLUS_EXPR
      && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
    {
      tree op00 = TREE_OPERAND (sub, 0);
      tree op01 = TREE_OPERAND (sub, 1);
      tree op00type;

      STRIP_NOPS (op00);
      op00type = TREE_TYPE (op00);
      if (TREE_CODE (op00) == ADDR_EXPR
 	  && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
	  && type == TREE_TYPE (TREE_TYPE (op00type)))
	{
	  tree size = TYPE_SIZE_UNIT (type);
	  if (tree_int_cst_equal (size, op01))
	    return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
	}
    }
  
  /* *(foo *)fooarrptr => (*fooarrptr)[0] */
  if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
      && type == TREE_TYPE (TREE_TYPE (subtype)))
    {
      tree type_domain;
      tree min_val = size_zero_node;
      sub = build_fold_indirect_ref (sub);
      type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
      if (type_domain && TYPE_MIN_VALUE (type_domain))
	min_val = TYPE_MIN_VALUE (type_domain);
      return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
    }

  return NULL_TREE;
}

/* Builds an expression for an indirection through T, simplifying some
   cases.  */

tree
build_fold_indirect_ref (tree t)
{
  tree type = TREE_TYPE (TREE_TYPE (t));
  tree sub = fold_indirect_ref_1 (type, t);

  if (sub)
    return sub;
  else
    return build1 (INDIRECT_REF, type, t);
}

/* Given an INDIRECT_REF T, return either T or a simplified version.  */

tree
fold_indirect_ref (tree t)
{
  tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));

  if (sub)
    return sub;
  else
    return t;
}

/* Strip non-trapping, non-side-effecting tree nodes from an expression
   whose result is ignored.  The type of the returned tree need not be
   the same as the original expression.  */

tree
fold_ignored_result (tree t)
{
  if (!TREE_SIDE_EFFECTS (t))
    return integer_zero_node;

  for (;;)
    switch (TREE_CODE_CLASS (TREE_CODE (t)))
      {
      case tcc_unary:
	t = TREE_OPERAND (t, 0);
	break;

      case tcc_binary:
      case tcc_comparison:
	if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
	  t = TREE_OPERAND (t, 0);
	else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
	  t = TREE_OPERAND (t, 1);
	else
	  return t;
	break;

      case tcc_expression:
	switch (TREE_CODE (t))
	  {
	  case COMPOUND_EXPR:
	    if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
	      return t;
	    t = TREE_OPERAND (t, 0);
	    break;

	  case COND_EXPR:
	    if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
		|| TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
	      return t;
	    t = TREE_OPERAND (t, 0);
	    break;

	  default:
	    return t;
	  }
	break;

      default:
	return t;
      }
}

/* Return the value of VALUE, rounded up to a multiple of DIVISOR.
   This can only be applied to objects of a sizetype.  */

tree
round_up (tree value, int divisor)
{
  tree div = NULL_TREE;

  gcc_assert (divisor > 0);
  if (divisor == 1)
    return value;

  /* See if VALUE is already a multiple of DIVISOR.  If so, we don't
     have to do anything.  Only do this when we are not given a const,
     because in that case, this check is more expensive than just
     doing it.  */
  if (TREE_CODE (value) != INTEGER_CST)
    {
      div = build_int_cst (TREE_TYPE (value), divisor);

      if (multiple_of_p (TREE_TYPE (value), value, div))
	return value;
    }

  /* If divisor is a power of two, simplify this to bit manipulation.  */
  if (divisor == (divisor & -divisor))
    {
      tree t;

      t = build_int_cst (TREE_TYPE (value), divisor - 1);
      value = size_binop (PLUS_EXPR, value, t);
      t = build_int_cst (TREE_TYPE (value), -divisor);
      value = size_binop (BIT_AND_EXPR, value, t);
    }
  else
    {
      if (!div)
	div = build_int_cst (TREE_TYPE (value), divisor);
      value = size_binop (CEIL_DIV_EXPR, value, div);
      value = size_binop (MULT_EXPR, value, div);
    }

  return value;
}

/* Likewise, but round down.  */

tree
round_down (tree value, int divisor)
{
  tree div = NULL_TREE;

  gcc_assert (divisor > 0);
  if (divisor == 1)
    return value;

  /* See if VALUE is already a multiple of DIVISOR.  If so, we don't
     have to do anything.  Only do this when we are not given a const,
     because in that case, this check is more expensive than just
     doing it.  */
  if (TREE_CODE (value) != INTEGER_CST)
    {
      div = build_int_cst (TREE_TYPE (value), divisor);

      if (multiple_of_p (TREE_TYPE (value), value, div))
	return value;
    }

  /* If divisor is a power of two, simplify this to bit manipulation.  */
  if (divisor == (divisor & -divisor))
    {
      tree t;

      t = build_int_cst (TREE_TYPE (value), -divisor);
      value = size_binop (BIT_AND_EXPR, value, t);
    }
  else
    {
      if (!div)
	div = build_int_cst (TREE_TYPE (value), divisor);
      value = size_binop (FLOOR_DIV_EXPR, value, div);
      value = size_binop (MULT_EXPR, value, div);
    }

  return value;
}

/* Returns the pointer to the base of the object addressed by EXP and
   extracts the information about the offset of the access, storing it
   to PBITPOS and POFFSET.  */

static tree
split_address_to_core_and_offset (tree exp,
				  HOST_WIDE_INT *pbitpos, tree *poffset)
{
  tree core;
  enum machine_mode mode;
  int unsignedp, volatilep;
  HOST_WIDE_INT bitsize;

  if (TREE_CODE (exp) == ADDR_EXPR)
    {
      core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
				  poffset, &mode, &unsignedp, &volatilep,
				  false);
      core = build_fold_addr_expr (core);
    }
  else
    {
      core = exp;
      *pbitpos = 0;
      *poffset = NULL_TREE;
    }

  return core;
}

/* Returns true if addresses of E1 and E2 differ by a constant, false
   otherwise.  If they do, E1 - E2 is stored in *DIFF.  */

bool
ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
{
  tree core1, core2;
  HOST_WIDE_INT bitpos1, bitpos2;
  tree toffset1, toffset2, tdiff, type;

  core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
  core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);

  if (bitpos1 % BITS_PER_UNIT != 0
      || bitpos2 % BITS_PER_UNIT != 0
      || !operand_equal_p (core1, core2, 0))
    return false;

  if (toffset1 && toffset2)
    {
      type = TREE_TYPE (toffset1);
      if (type != TREE_TYPE (toffset2))
	toffset2 = fold_convert (type, toffset2);

      tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
      if (!cst_and_fits_in_hwi (tdiff))
	return false;

      *diff = int_cst_value (tdiff);
    }
  else if (toffset1 || toffset2)
    {
      /* If only one of the offsets is non-constant, the difference cannot
	 be a constant.  */
      return false;
    }
  else
    *diff = 0;

  *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
  return true;
}

/* Simplify the floating point expression EXP when the sign of the
   result is not significant.  Return NULL_TREE if no simplification
   is possible.  */

tree
fold_strip_sign_ops (tree exp)
{
  tree arg0, arg1;

  switch (TREE_CODE (exp))
    {
    case ABS_EXPR:
    case NEGATE_EXPR:
      arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
      return arg0 ? arg0 : TREE_OPERAND (exp, 0);

    case MULT_EXPR:
    case RDIV_EXPR:
      if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
	return NULL_TREE;
      arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
      arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
      if (arg0 != NULL_TREE || arg1 != NULL_TREE)
	return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
			    arg0 ? arg0 : TREE_OPERAND (exp, 0),
			    arg1 ? arg1 : TREE_OPERAND (exp, 1));
      break;

    default:
      break;
    }
  return NULL_TREE;
}

OpenPOWER on IntegriCloud