fold-const.c (fold_comparison): Remove equality folding of decl addresses ...

2015-07-28  Richard Biener  <rguenther@suse.de>

	* fold-const.c (fold_comparison): Remove equality folding
	of decl addresses ...
	* match.pd: ... here and merge with existing pattern.

From-SVN: r226299

gcc/ChangeLog

+2015-07-28  Richard Biener  <rguenther@suse.de>
+
+	* fold-const.c (fold_comparison): Remove equality folding
+	of decl addresses ...
+	* match.pd: ... here and merge with existing pattern.
+
 2015-07-28  Thomas Preud'homme  <thomas.preudhomme@arm.com>
 
 	PR tree-optimization/66828

gcc/fold-const.c

@@ -8511,30 +8511,6 @@ fold_comparison (location_t loc, enum tree_code code, tree type,
 	      return fold_build2_loc (loc, code, type, offset0, offset1);
 	    }
 	}
-      /* For non-equal bases we can simplify if they are addresses
-	 declarations with different addresses.  */
-      else if (indirect_base0 && indirect_base1
-	       /* We know that !operand_equal_p (base0, base1, 0)
-		  because the if condition was false.  But make
-		  sure two decls are not the same.  */
-	       && base0 != base1
-	       && TREE_CODE (arg0) == ADDR_EXPR
-	       && TREE_CODE (arg1) == ADDR_EXPR
-	       && DECL_P (base0)
-	       && DECL_P (base1)
-	       /* Watch for aliases.  */
-	       && (!decl_in_symtab_p (base0)
-		   || !decl_in_symtab_p (base1)
-		   || !symtab_node::get_create (base0)->equal_address_to
-			 (symtab_node::get_create (base1))))
-	{
-	  if (code == EQ_EXPR)
-	    return omit_two_operands_loc (loc, type, boolean_false_node,
-				      arg0, arg1);
-	  else if (code == NE_EXPR)
-	    return omit_two_operands_loc (loc, type, boolean_true_node,
-				      arg0, arg1);
-	}
       /* For equal offsets we can simplify to a comparison of the
 	 base addresses.  */
       else if (bitpos0 == bitpos1

gcc/match.pd

@@ -1808,15 +1808,20 @@ along with GCC; see the file COPYING3.  If not see
     have access to attributes for externs), then we know the result.  */
  (simplify
   (cmp (convert? addr@0) (convert? addr@1))
-  (if (decl_in_symtab_p (TREE_OPERAND (@0, 0))
-       && decl_in_symtab_p (TREE_OPERAND (@1, 0)))
-   (with
-    {
-      int equal = symtab_node::get_create (TREE_OPERAND (@0, 0))
+  (if (DECL_P (TREE_OPERAND (@0, 0))
+       && DECL_P (TREE_OPERAND (@1, 0)))
+   (if (decl_in_symtab_p (TREE_OPERAND (@0, 0))
+	&& decl_in_symtab_p (TREE_OPERAND (@1, 0)))
+    (with
+     {
+       int equal = symtab_node::get_create (TREE_OPERAND (@0, 0))
            ->equal_address_to (symtab_node::get_create (TREE_OPERAND (@1, 0)));
-    }
-    (if (equal != 2)
-     { constant_boolean_node (equal ? cmp == EQ_EXPR : cmp != EQ_EXPR, type); }))))
+     }
+     (if (equal != 2)
+      { constant_boolean_node (equal
+			       ? cmp == EQ_EXPR : cmp != EQ_EXPR, type); }))
+    (if (TREE_OPERAND (@0, 0) != TREE_OPERAND (@1, 0))
+     { constant_boolean_node (cmp == EQ_EXPR ? false : true, type); }))))
 
  (simplify
   (cmp (convert? addr@0) integer_zerop)