re PR tree-optimization/2480 (aliasing problem with global structures)

2009-04-03  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/2480
	PR tree-optimization/23086
	* gcc.dg/tree-ssa/pr2480.c: New testcase.
	* gcc.dg/tree-ssa/pr23086.c: Likewise.

From-SVN: r145499

gcc/testsuite/ChangeLog

 2009-04-03  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/2480
+	PR tree-optimization/23086
+	* gcc.dg/tree-ssa/pr2480.c: New testcase.
+	* gcc.dg/tree-ssa/pr23086.c: Likewise.
+
+2009-04-03  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/34743
 	* gcc.dg/pr38984.c: Remove XFAIL, adjust.
 	* gcc.dg/tree-ssa/20070302-1.c: Remove XFAIL.

gcc/testsuite/gcc.dg/tree-ssa/pr23086.c

+/* { dg-do run } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+extern void link_error (void);
+extern void abort (void);
+
+int *t;
+int __attribute__((noinline)) g(int *a)
+{
+  t = a;
+  *a = 2;
+}
+
+void __attribute__((noinline)) f(int *a)
+{
+  int b;
+  b = 1;
+  g(&b);
+  b = 2;
+  *a = 1;
+  if (b != 2)
+    link_error();
+}
+
+int main(void)
+{
+  int t;
+  f(&t);
+  if (t != 1)
+    abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-not "link_error" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/testsuite/gcc.dg/tree-ssa/pr2480.c

+/* { dg-do link } */
+/* { dg-options "-O2" } */
+
+/* We have enough cascading at -O2 to cover the missed control-dependence
+   in SCCVN (which considers the link_error calls to clobber the structs).  */
+
+struct example
+{
+  char a;
+  int b;
+  char c;
+} *ex1;
+
+extern void link_error(void);
+
+void
+bar (void)
+{
+  ex1->a = 1;
+  ex1->b = 2;
+  ex1->c = 3;
+
+  if (ex1->a != 1)
+    link_error ();
+  if (ex1->b != 2)
+    link_error ();
+  if (ex1->c != 3)
+    link_error ();
+
+}
+
+void
+foo (struct example *ex2)
+{
+  ex2->a = 1;
+  ex2->b = 2;
+  ex2->c = 3;
+
+  if (ex2->a != 1)
+    link_error ();
+  if (ex2->b != 2)
+    link_error ();
+  if (ex2->c != 3)
+    link_error ();
+
+}
+
+int main (void)
+{
+  bar ();
+  foo (ex1);
+  return 0;
+}