* alias.c (component_uses_parent_alias_set): Rename from

        can_address_p.  Return bool.  Reverse the sense of the result.
        Reinstate the check for alias set zero.
        (get_alias_set): Update to match.
        * alias.h (component_uses_parent_alias_set): Likewise.
        * emit-rtl.c (set_mem_attributes_minus_bitpos): Likewise.
        * expr.c (expand_assignment): Likewise.
        * expr.h: Remove commented out prototypes that were moved to alias.h.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@91712 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 15 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/attr-may-alias-1.c b/gcc/testsuite/gcc.dg/attr-may-alias-1.c
new file mode 100644
index 00000000000..30e2bca6f48
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/attr-may-alias-1.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler "dont_delete" } } */
+
+typedef struct { int x; } __attribute__((may_alias)) S;
+
+extern void dont_delete (void);
+
+void f(S *s, float *f)
+{
+  s->x = 1;
+  *f = 0;
+  if (s->x != 1)
+    dont_delete ();
+}