blob: 53d1d08d52a926f9d634db67e46b6391deb91768 (
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
|
Merge from Sourcery G++ 4.4:
2009-05-21 Sandra Loosemore <sandra@codesourcery.com>
Merge from Sourcery G++ 4.3:
2009-04-04 Sandra Loosemore <sandra@codesourcery.com>
Issue #5104
PR tree-optimization/39604
gcc/testsuite
* g++.dg/tree-ssa/sink-1.C: New.
gcc/
* tree_ssa-sink.c (sink_code_in_bb): Do not sink statements out
of a lexical block containing variable definitions.
2010-07-09 Sandra Loosemore <sandra@codesourcery.com>
Backport from mainline (originally on Sourcery G++ 4.4):
2010-07-02 Julian Brown <julian@codesourcery.com>
=== added file 'gcc/testsuite/g++.dg/tree-ssa/sink-1.C'
--- old/gcc/testsuite/g++.dg/tree-ssa/sink-1.C 1970-01-01 00:00:00 +0000
+++ new/gcc/testsuite/g++.dg/tree-ssa/sink-1.C 2010-07-30 12:14:18 +0000
@@ -0,0 +1,50 @@
+/* { dg-do run } */
+/* { dg-options "-O1" } */
+
+class A {
+ public:
+ A() {}
+ virtual ~A() {}
+ void * dostuff();
+
+ virtual int dovirtual() = 0;
+};
+
+
+class B : public A {
+ public:
+ B() {}
+ int dovirtual() { return 0;}
+ virtual ~B() {};
+};
+
+class C : public B {
+ public:
+ C() {}
+ virtual ~C() {};
+};
+
+void* A::dostuff()
+{
+ return (void*)dovirtual();
+}
+
+/* tree-ssa-sink was sinking the inlined destructor for STUFF out of
+ the first inner block and into the second one, where it was ending up
+ after the inlined constructor for STUFF2. This is bad because
+ cfgexpand aliases STUFF and STUFF2 to the same storage at -O1
+ (i.e., without -fstrict-aliasing), with the result that STUFF2's
+ vtable was getting trashed. */
+
+int main() {
+ {
+ B stuff;
+ stuff.dostuff();
+ }
+ {
+ C stuff2;
+ stuff2.dostuff();
+ }
+ return 0;
+}
+
=== modified file 'gcc/tree-ssa-sink.c'
--- old/gcc/tree-ssa-sink.c 2009-11-28 16:21:00 +0000
+++ new/gcc/tree-ssa-sink.c 2010-07-30 12:14:18 +0000
@@ -470,6 +470,47 @@
last = false;
continue;
}
+
+ /* We cannot move statements that contain references to block-scope
+ variables out of that block, as this may lead to incorrect aliasing
+ when we lay out the stack frame in cfgexpand.c.
+ In lieu of more sophisticated analysis, be very conservative here
+ and prohibit moving any statement that references memory out of a
+ block with variables. */
+ if (gimple_references_memory_p (stmt))
+ {
+ tree fromblock = gimple_block (stmt);
+ while (fromblock
+ && fromblock != current_function_decl
+ && !BLOCK_VARS (fromblock))
+ fromblock = BLOCK_SUPERCONTEXT (fromblock);
+ if (fromblock && fromblock != current_function_decl)
+ {
+ gimple tostmt;
+ tree toblock;
+
+ if (gsi_end_p (togsi))
+ tostmt = gimple_seq_last_stmt (gsi_seq (togsi));
+ else
+ tostmt = gsi_stmt (togsi);
+ if (tostmt)
+ toblock = gimple_block (tostmt);
+ else
+ toblock = NULL;
+ while (toblock
+ && toblock != current_function_decl
+ && toblock != fromblock)
+ toblock = BLOCK_SUPERCONTEXT (toblock);
+ if (!toblock || toblock != fromblock)
+ {
+ if (!gsi_end_p (gsi))
+ gsi_prev (&gsi);
+ last = false;
+ continue;
+ }
+ }
+ }
+
if (dump_file)
{
fprintf (dump_file, "Sinking ");
|
