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Upstream-Status: Inappropriate [Backport]
From d0c1a282504a0fa941a9ae22536c73f64d8c5762 Mon Sep 17 00:00:00 2001
From: rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 21 Apr 2011 14:40:53 +0000
Subject: [PATCH 162/200] 2011-04-21 Richard Guenther <rguenther@suse.de>
PR middle-end/48695
* tree-ssa-alias.c (aliasing_component_refs_p): Compute base
objects and types here. Adjust for their offset before
comparing.
* g++.dg/torture/pr48695.C: New testcase.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@172831 138bc75d-0d04-0410-961f-82ee72b054a4
index e26c75d..3b0e585 100644
new file mode 100644
index 0000000..44e6c77
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr48695.C
@@ -0,0 +1,38 @@
+// { dg-do run }
+
+typedef __SIZE_TYPE__ size_t;
+
+inline void *operator new (size_t, void *__p) throw() { return __p; }
+
+struct _Vector_impl
+{
+ int *_M_start;
+ int *_M_finish;
+ _Vector_impl () :_M_start (0), _M_finish (0) {}
+};
+
+struct vector
+{
+ _Vector_impl _M_impl;
+ int *_M_allocate (size_t __n)
+ {
+ return __n != 0 ? new int[__n] : 0;
+ }
+ void push_back ()
+ {
+ new (this->_M_impl._M_finish) int ();
+ this->_M_impl._M_finish =
+ this->_M_allocate (this->_M_impl._M_finish - this->_M_impl._M_start) + 1;
+ }
+};
+
+int
+main ()
+{
+ for (int i = 0; i <= 1; i++)
+ for (int j = 0; j <= 1; j++)
+ {
+ vector a[2];
+ a[i].push_back ();
+ }
+}
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index bd8953b..8434179 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -594,11 +594,11 @@ same_type_for_tbaa (tree type1, tree type2)
are the respective alias sets. */
static bool
-aliasing_component_refs_p (tree ref1, tree type1,
+aliasing_component_refs_p (tree ref1,
alias_set_type ref1_alias_set,
alias_set_type base1_alias_set,
HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1,
- tree ref2, tree type2,
+ tree ref2,
alias_set_type ref2_alias_set,
alias_set_type base2_alias_set,
HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2,
@@ -610,9 +610,21 @@ aliasing_component_refs_p (tree ref1, tree type1,
struct A { int i; int j; } *q;
struct B { struct A a; int k; } *p;
disambiguating q->i and p->a.j. */
+ tree base1, base2;
+ tree type1, type2;
tree *refp;
int same_p;
+ /* Choose bases and base types to search for. */
+ base1 = ref1;
+ while (handled_component_p (base1))
+ base1 = TREE_OPERAND (base1, 0);
+ type1 = TREE_TYPE (base1);
+ base2 = ref2;
+ while (handled_component_p (base2))
+ base2 = TREE_OPERAND (base2, 0);
+ type2 = TREE_TYPE (base2);
+
/* Now search for the type1 in the access path of ref2. This
would be a common base for doing offset based disambiguation on. */
refp = &ref2;
@@ -628,6 +640,8 @@ aliasing_component_refs_p (tree ref1, tree type1,
HOST_WIDE_INT offadj, sztmp, msztmp;
get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp);
offset2 -= offadj;
+ get_ref_base_and_extent (base1, &offadj, &sztmp, &msztmp);
+ offset1 -= offadj;
return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
}
/* If we didn't find a common base, try the other way around. */
@@ -644,6 +658,8 @@ aliasing_component_refs_p (tree ref1, tree type1,
HOST_WIDE_INT offadj, sztmp, msztmp;
get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp);
offset1 -= offadj;
+ get_ref_base_and_extent (base2, &offadj, &sztmp, &msztmp);
+ offset2 -= offadj;
return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
}
@@ -805,11 +821,10 @@ indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED, tree base1,
&& TREE_CODE (base1) != TARGET_MEM_REF
&& (TREE_CODE (base1) != MEM_REF
|| same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1))
- return aliasing_component_refs_p (ref1, TREE_TYPE (ptrtype1),
+ return aliasing_component_refs_p (ref1,
ref1_alias_set, base1_alias_set,
offset1, max_size1,
- ref2, TREE_TYPE
- (reference_alias_ptr_type (ref2)),
+ ref2,
ref2_alias_set, base2_alias_set,
offset2, max_size2, true);
@@ -952,10 +967,10 @@ indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED, tree base1,
|| same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1)
&& (TREE_CODE (base2) != MEM_REF
|| same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) == 1))
- return aliasing_component_refs_p (ref1, TREE_TYPE (ptrtype1),
+ return aliasing_component_refs_p (ref1,
ref1_alias_set, base1_alias_set,
offset1, max_size1,
- ref2, TREE_TYPE (ptrtype2),
+ ref2,
ref2_alias_set, base2_alias_set,
offset2, max_size2, false);
--
1.7.0.4
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