re PR middle-end/67120 (wrong code for volatile pointers at -O1 and above on x86_64-linux-gnu)

2015-08-05  Richard Biener  <rguenther@suse.de>

	PR middle-end/67120
	* match.pd: Compare address bases with == if they are decls
	or SSA names, not operand_equal_p.  Otherwise fail.

	* gcc.dg/torture/pr67120.c: New testcase.

From-SVN: r226623

gcc/ChangeLog

 2015-08-05  Richard Biener  <rguenther@suse.de>
 
+	PR middle-end/67120
+	* match.pd: Compare address bases with == if they are decls
+	or SSA names, not operand_equal_p.  Otherwise fail.
+
+2015-08-05  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/67055
 	* tree-ssa-ccp.c (fold_builtin_alloca_with_align): Handle
 	NULL gimple_block.

gcc/match.pd

@@ -1848,13 +1848,14 @@ along with GCC; see the file COPYING3.  If not see
    (if (base0 && base1)
     (with
      {
-       int equal;
+       int equal = 2;
        if (decl_in_symtab_p (base0)
 	   && decl_in_symtab_p (base1))
          equal = symtab_node::get_create (base0)
 	           ->equal_address_to (symtab_node::get_create (base1));
-       else
-         equal = operand_equal_p (base0, base1, 0);
+       else if ((DECL_P (base0) || TREE_CODE (base0) == SSA_NAME)
+		&& (DECL_P (base1) || TREE_CODE (base1) == SSA_NAME))
+         equal = (base0 == base1);
      }
      (if (equal == 1
 	  && (cmp == EQ_EXPR || cmp == NE_EXPR

gcc/testsuite/ChangeLog

+2015-08-05  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/67120
+	* gcc.dg/torture/pr67120.c: New testcase.
+
 2015-08-05  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/52846

gcc/testsuite/gcc.dg/torture/pr67120.c

+/* { dg-do run } */
+
+volatile int *volatile *a;
+static volatile int *volatile **b = &a;
+
+int
+main ()
+{
+  volatile int *volatile c;
+  *b = &c;
+
+  if (a != &c) 
+    __builtin_abort (); 
+
+  return 0;
+}