From: Richard Guenther <rguenther@suse.de>
Date: Tue, 3 Jan 2012 13:54:44 +0000 (+0000)
Subject: backport: re PR tree-optimization/49279 (Optimization incorrectly presuming constant... 
X-Git-Tag: releases/gcc-4.5.4~292
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ce1831c16abffc465f4ee9add742222bc782dc4f;p=thirdparty%2Fgcc.git

backport: re PR tree-optimization/49279 (Optimization incorrectly presuming constant variable inside loop in g++ 4.5 and 4.6 with -O2 and -O3 for x86_64 targets)

2012-01-03  Richard Guenther  <rguenther@suse.de>

	Backport from mainline
	2011-10-06  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/49279
	* tree-ssa-structalias.c (find_func_aliases): Don't handle
	CAST_RESTRICT.

	2011-10-06  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/49279
	* gcc.c-torture/execute/pr49279.c: New test.

From-SVN: r182846
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f7f00b5d8494..d8f3174d587a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2012-01-03  Richard Guenther  <rguenther@suse.de>
+
+	Backport from mainline
+	2011-10-06  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/49279
+	* tree-ssa-structalias.c (find_func_aliases): Don't handle
+	CAST_RESTRICT.
+
 2012-01-03  Richard Guenther  <rguenther@suse.de>
  
 	Backport from mainline
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 25e5c8299ce0..1fedf3408125 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2012-01-03  Richard Guenther  <rguenther@suse.de>
+
+	Backport from mainline
+	2011-10-06  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/49279
+	* gcc.c-torture/execute/pr49279.c: New test.
+
 2012-01-03  Richard Guenther  <rguenther@suse.de>
 
 	Backport from mainline
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr49279.c b/gcc/testsuite/gcc.c-torture/execute/pr49279.c
new file mode 100644
index 000000000000..7f2c0d22129b
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr49279.c
@@ -0,0 +1,35 @@
+/* PR tree-optimization/49279 */
+extern void abort (void);
+
+struct S { int a; int *__restrict p; };
+
+__attribute__((noinline, noclone))
+struct S *bar (struct S *p)
+{
+  struct S *r;
+  asm volatile ("" : "=r" (r) : "0" (p) : "memory");
+  return r;
+}
+
+__attribute__((noinline, noclone))
+int
+foo (int *p, int *q)
+{
+  struct S s, *t;
+  s.a = 1;
+  s.p = p;
+  t = bar (&s);
+  t->p = q;
+  s.p[0] = 0;
+  t->p[0] = 1;
+  return s.p[0];
+}
+
+int
+main ()
+{
+  int a, b;
+  if (foo (&a, &b) != 1)
+    abort ();
+  return 0;
+}
diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index 88b23c028e69..b2ba385be0a7 100644
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -3968,15 +3968,6 @@ find_func_aliases (gimple origt)
 	  && DECL_P (lhsop)
 	  && is_global_var (lhsop))
 	make_escape_constraint (rhsop);
-      /* If this is a conversion of a non-restrict pointer to a
-	 restrict pointer track it with a new heapvar.  */
-      else if (gimple_assign_cast_p (t)
-	       && POINTER_TYPE_P (TREE_TYPE (rhsop))
-	       && POINTER_TYPE_P (TREE_TYPE (lhsop))
-	       && !TYPE_RESTRICT (TREE_TYPE (rhsop))
-	       && TYPE_RESTRICT (TREE_TYPE (lhsop)))
-	make_constraint_from_restrict (get_vi_for_tree (lhsop),
-				       "CAST_RESTRICT");
     }
   /* Handle escapes through return.  */
   else if (gimple_code (t) == GIMPLE_RETURN