1 files changed, 38 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/20041122-1.c b/gcc/testsuite/gcc.dg/tree-ssa/20041122-1.c
new file mode 100644
index 000000000..600794954
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/20041122-1.c
@@ -0,0 +1,38 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fstrict-aliasing -fdump-tree-fre" } */
+
+__extension__ typedef __SIZE_TYPE__ size_t;
+extern void *xmalloc (size_t) __attribute__ ((__malloc__));
+struct edge_def
+{
+  struct basic_block_def *dest;
+  int flags;
+};
+typedef struct edge_def *edge;
+struct basic_block_def
+{
+  int flags;
+};
+typedef struct basic_block_def *basic_block;
+extern int n_basic_blocks;
+extern edge frob ();
+basic_block *
+find_unreachable_blocks (void)
+{
+  basic_block *tos, *worklist;
+  tos = worklist = xmalloc (sizeof (basic_block) * n_basic_blocks);
+  edge e = frob();
+  if (!(e->dest->flags & 4))
+    {
+      e->dest->flags |= 4;
+      *tos++ = e->dest;
+    }
+  return worklist;
+}
+
+/* If the aliasing code does its job properly, then we should be
+   able to determine that modifying e->dest->flags does not
+   modify e or e->dest if we can assert strict-aliasing rules.
+   The net result is that we only need one load of e->dest.  */
+/* { dg-final { scan-tree-dump-times "->dest" 1 "fre" } } */
+/* { dg-final { cleanup-tree-dump "fre" } } */