summaryrefslogtreecommitdiffstats
path: root/contrib/gdtoa/dmisc.c
blob: 14b5d7e6834b5ad83992573e77b79b611b4402fc (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
/****************************************************************

The author of this software is David M. Gay.

Copyright (C) 1998 by Lucent Technologies
All Rights Reserved

Permission to use, copy, modify, and distribute this software and
its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appear in all
copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the name of Lucent or any of its entities
not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.

LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
THIS SOFTWARE.

****************************************************************/

/* Please send bug reports to
	David M. Gay
	Bell Laboratories, Room 2C-463
	600 Mountain Avenue
	Murray Hill, NJ 07974-0636
	U.S.A.
	dmg@bell-labs.com
 */

#include "gdtoaimp.h"

#ifndef MULTIPLE_THREADS
 char *dtoa_result;
#endif

 char *
#ifdef KR_headers
rv_alloc(i) int i;
#else
rv_alloc(int i)
#endif
{
	int j, k, *r;

	j = sizeof(ULong);
	for(k = 0;
		sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <= i;
		j <<= 1)
			k++;
	r = (int*)Balloc(k);
	*r = k;
	return
#ifndef MULTIPLE_THREADS
	dtoa_result =
#endif
		(char *)(r+1);
	}

 char *
#ifdef KR_headers
nrv_alloc(s, rve, n) char *s, **rve; int n;
#else
nrv_alloc(char *s, char **rve, int n)
#endif
{
	char *rv, *t;

	t = rv = rv_alloc(n);
	while((*t = *s++) !=0)
		t++;
	if (rve)
		*rve = t;
	return rv;
	}

/* freedtoa(s) must be used to free values s returned by dtoa
 * when MULTIPLE_THREADS is #defined.  It should be used in all cases,
 * but for consistency with earlier versions of dtoa, it is optional
 * when MULTIPLE_THREADS is not defined.
 */

 void
#ifdef KR_headers
freedtoa(s) char *s;
#else
freedtoa(char *s)
#endif
{
	Bigint *b = (Bigint *)((int *)s - 1);
	b->maxwds = 1 << (b->k = *(int*)b);
	Bfree(b);
#ifndef MULTIPLE_THREADS
	if (s == dtoa_result)
		dtoa_result = 0;
#endif
	}

 int
quorem
#ifdef KR_headers
	(b, S) Bigint *b, *S;
#else
	(Bigint *b, Bigint *S)
#endif
{
	int n;
	ULong *bx, *bxe, q, *sx, *sxe;
#ifdef ULLong
	ULLong borrow, carry, y, ys;
#else
	ULong borrow, carry, y, ys;
#ifdef Pack_32
	ULong si, z, zs;
#endif
#endif

	n = S->wds;
#ifdef DEBUG
	/*debug*/ if (b->wds > n)
	/*debug*/	Bug("oversize b in quorem");
#endif
	if (b->wds < n)
		return 0;
	sx = S->x;
	sxe = sx + --n;
	bx = b->x;
	bxe = bx + n;
	q = *bxe / (*sxe + 1);	/* ensure q <= true quotient */
#ifdef DEBUG
	/*debug*/ if (q > 9)
	/*debug*/	Bug("oversized quotient in quorem");
#endif
	if (q) {
		borrow = 0;
		carry = 0;
		do {
#ifdef ULLong
			ys = *sx++ * (ULLong)q + carry;
			carry = ys >> 32;
			y = *bx - (ys & 0xffffffffUL) - borrow;
			borrow = y >> 32 & 1UL;
			*bx++ = y & 0xffffffffUL;
#else
#ifdef Pack_32
			si = *sx++;
			ys = (si & 0xffff) * q + carry;
			zs = (si >> 16) * q + (ys >> 16);
			carry = zs >> 16;
			y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
			borrow = (y & 0x10000) >> 16;
			z = (*bx >> 16) - (zs & 0xffff) - borrow;
			borrow = (z & 0x10000) >> 16;
			Storeinc(bx, z, y);
#else
			ys = *sx++ * q + carry;
			carry = ys >> 16;
			y = *bx - (ys & 0xffff) - borrow;
			borrow = (y & 0x10000) >> 16;
			*bx++ = y & 0xffff;
#endif
#endif
			}
			while(sx <= sxe);
		if (!*bxe) {
			bx = b->x;
			while(--bxe > bx && !*bxe)
				--n;
			b->wds = n;
			}
		}
	if (cmp(b, S) >= 0) {
		q++;
		borrow = 0;
		carry = 0;
		bx = b->x;
		sx = S->x;
		do {
#ifdef ULLong
			ys = *sx++ + carry;
			carry = ys >> 32;
			y = *bx - (ys & 0xffffffffUL) - borrow;
			borrow = y >> 32 & 1UL;
			*bx++ = y & 0xffffffffUL;
#else
#ifdef Pack_32
			si = *sx++;
			ys = (si & 0xffff) + carry;
			zs = (si >> 16) + (ys >> 16);
			carry = zs >> 16;
			y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
			borrow = (y & 0x10000) >> 16;
			z = (*bx >> 16) - (zs & 0xffff) - borrow;
			borrow = (z & 0x10000) >> 16;
			Storeinc(bx, z, y);
#else
			ys = *sx++ + carry;
			carry = ys >> 16;
			y = *bx - (ys & 0xffff) - borrow;
			borrow = (y & 0x10000) >> 16;
			*bx++ = y & 0xffff;
#endif
#endif
			}
			while(sx <= sxe);
		bx = b->x;
		bxe = bx + n;
		if (!*bxe) {
			while(--bxe > bx && !*bxe)
				--n;
			b->wds = n;
			}
		}
	return q;
	}
OpenPOWER on IntegriCloud