gcc/gcc41-pr29272.patch
Jakub Jelinek 4f7e86848f 4.1.1-28
2006-09-30 19:13:59 +00:00

111 lines
3.3 KiB
Diff

2006-09-28 Jakub Jelinek <jakub@redhat.com>
PR middle-end/29272
* builtins.c (fold_builtin_memset, fold_builtin_memory_op): Restrict
single entry optimization to variables and components thereof.
* gcc.c-torture/execute/20060930-1.c: New test.
--- gcc/builtins.c.jj 2006-09-22 10:29:55.000000000 +0200
+++ gcc/builtins.c 2006-09-28 20:31:30.000000000 +0200
@@ -7905,7 +7905,7 @@ fold_builtin_exponent (tree fndecl, tree
static tree
fold_builtin_memset (tree arglist, tree type, bool ignore)
{
- tree dest, c, len, var, ret;
+ tree dest, c, len, var, ret, inner;
unsigned HOST_WIDE_INT length, cval;
if (!validate_arglist (arglist,
@@ -7939,6 +7939,15 @@ fold_builtin_memset (tree arglist, tree
&& !POINTER_TYPE_P (TREE_TYPE (var)))
return 0;
+ /* If var is a VAR_DECL or a component thereof,
+ we can use its alias set, otherwise we'd need to make
+ sure we go through alias set 0. */
+ inner = var;
+ while (handled_component_p (inner))
+ inner = TREE_OPERAND (inner, 0);
+ if (! SSA_VAR_P (inner))
+ return 0;
+
length = tree_low_cst (len, 1);
if (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (var))) != length
|| get_pointer_alignment (dest, BIGGEST_ALIGNMENT) / BITS_PER_UNIT
@@ -8009,7 +8018,7 @@ fold_builtin_bzero (tree arglist, bool i
static tree
fold_builtin_memory_op (tree arglist, tree type, bool ignore, int endp)
{
- tree dest, src, len, destvar, srcvar, expr;
+ tree dest, src, len, destvar, srcvar, expr, inner;
unsigned HOST_WIDE_INT length;
if (! validate_arglist (arglist,
@@ -8050,6 +8059,15 @@ fold_builtin_memory_op (tree arglist, tr
&& !SCALAR_FLOAT_TYPE_P (TREE_TYPE (destvar)))
return 0;
+ /* If destvar is a VAR_DECL or a component thereof,
+ we can use its alias set, otherwise we'd need to make
+ sure we go through alias set 0. */
+ inner = destvar;
+ while (handled_component_p (inner))
+ inner = TREE_OPERAND (inner, 0);
+ if (! SSA_VAR_P (inner))
+ return 0;
+
srcvar = src;
STRIP_NOPS (srcvar);
if (TREE_CODE (srcvar) != ADDR_EXPR)
@@ -8064,6 +8082,15 @@ fold_builtin_memory_op (tree arglist, tr
&& !SCALAR_FLOAT_TYPE_P (TREE_TYPE (srcvar)))
return 0;
+ /* If srcvar is a VAR_DECL or a component thereof,
+ we can use its alias set, otherwise we'd need to make
+ sure we go through alias set 0. */
+ inner = srcvar;
+ while (handled_component_p (inner))
+ inner = TREE_OPERAND (inner, 0);
+ if (! SSA_VAR_P (inner))
+ return 0;
+
length = tree_low_cst (len, 1);
if (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (destvar))) != length
|| get_pointer_alignment (dest, BIGGEST_ALIGNMENT) / BITS_PER_UNIT
--- gcc/testsuite/gcc.c-torture/execute/20060930-1.c.jj 2006-09-30 21:10:17.000000000 +0200
+++ gcc/testsuite/gcc.c-torture/execute/20060930-1.c 2006-09-30 21:09:33.000000000 +0200
@@ -0,0 +1,31 @@
+/* PR middle-end/29272 */
+
+extern void abort (void);
+
+struct S { struct S *s; } s;
+struct T { struct T *t; } t;
+
+static inline void
+foo (void *s)
+{
+ struct T *p = s;
+ __builtin_memcpy (&p->t, &t.t, sizeof (t.t));
+}
+
+void *
+__attribute__((noinline))
+bar (void *p, struct S *q)
+{
+ q->s = &s;
+ foo (p);
+ return q->s;
+}
+
+int
+main (void)
+{
+ t.t = &t;
+ if (bar (&s, &s) != (void *) &t)
+ abort ();
+ return 0;
+}