re PR tree-optimization/61437 (wrong code on x86_64-linux-gnu when compile separately)

2014-06-11  Richard Biener  <rguenther@suse.de>

	PR middle-end/61437
	Revert
	2014-06-04  Richard Biener  <rguenther@suse.de>

	* tree.h (may_be_aliased): Trust TREE_ADDRESSABLE from
	TREE_PUBLIC and DECL_EXTERNAL decls.

	* gcc.dg/torture/20140610-1.c: New testcase.
	* gcc.dg/torture/20140610-2.c: Likewise.

From-SVN: r211436

gcc/ChangeLog

+2014-06-11  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/61437
+	Revert
+	2014-06-04  Richard Biener  <rguenther@suse.de>
+
+	* tree.h (may_be_aliased): Trust TREE_ADDRESSABLE from
+	TREE_PUBLIC and DECL_EXTERNAL decls.
+
 2014-06-10  Jan Hubicka  <hubicka@ucw.cz>
 
 	* varasm.c (set_implicit_section): New function.
@@ -7,7 +16,8 @@
 	(default_function_section): Likewise.
 	(decl_binds_to_current_def_p): Constify argument.
 	* varasm.h (decl_binds_to_current_def_p): Update prototype.
-	* asan.c (asan_protect_global): Use symtab_get_node (decl)->implicit_section.
+	* asan.c (asan_protect_global): Use
+	symtab_get_node (decl)->implicit_section.
 	* symtab.c (dump_symtab_base): Dump implicit sections.
 	(verify_symtab_base): Verify sanity of sectoins and comdats.
 	(symtab_resolve_alias): Alias share the section of its target.

gcc/testsuite/ChangeLog

+2014-06-11  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/61437
+	* gcc.dg/torture/20140610-1.c: New testcase.
+	* gcc.dg/torture/20140610-2.c: Likewise.
+
 2014-06-10  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/61438

gcc/testsuite/gcc.dg/torture/20140610-1.c

+/* { dg-do run } */
+/* { dg-additional-sources "20140610-2.c" } */
+
+extern int a;
+extern int *p;
+
+void test (void);
+
+int main ()
+{
+  *p = 0;
+  a = 1;
+  test ();
+  return 0;
+}

gcc/testsuite/gcc.dg/torture/20140610-2.c

+/* { dg-do compile } */
+
+extern void abort (void);
+
+int a;
+int *p = &a;
+
+void test (void)
+{
+  if (a != 1)
+    abort ();
+}

gcc/tree.h

@@ -4524,7 +4524,9 @@ static inline bool
 may_be_aliased (const_tree var)
 {
   return (TREE_CODE (var) != CONST_DECL
-	  && TREE_ADDRESSABLE (var)
+	  && (TREE_PUBLIC (var)
+	      || DECL_EXTERNAL (var)
+	      || TREE_ADDRESSABLE (var))
 	  && !((TREE_STATIC (var) || TREE_PUBLIC (var) || DECL_EXTERNAL (var))
 	       && ((TREE_READONLY (var)
 		    && !TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (var)))