genmatch.c (add_operator): Allow SSA_NAME as predicate.

2015-07-24  Richard Biener  <rguenther@suse.de>

	* genmatch.c (add_operator): Allow SSA_NAME as predicate.
	* fold-const.c (fold_comparison): Move parameter does not
	alias &local simplification ...
	* match.pd: ... as a pattern here.

From-SVN: r226140

gcc/ChangeLog

 2015-07-24  Richard Biener  <rguenther@suse.de>
 
+	* genmatch.c (add_operator): Allow SSA_NAME as predicate.
+	* fold-const.c (fold_comparison): Move parameter does not
+	alias &local simplification ...
+	* match.pd: ... as a pattern here.
+
+2015-07-24  Richard Biener  <rguenther@suse.de>
+
 	* gimple-fold.c (replace_stmt_with_simplification): Special-case
 	valueizing call operands.
 	* gimple-match-head.c (maybe_push_res_to_seq): Take

gcc/fold-const.c

@@ -8467,33 +8467,9 @@ fold_comparison (location_t loc, enum tree_code code, tree type,
 	    }
 	}
 
-      /* A local variable can never be pointed to by
-         the default SSA name of an incoming parameter.  */
-      if ((TREE_CODE (arg0) == ADDR_EXPR
-           && indirect_base0
-           && TREE_CODE (base0) == VAR_DECL
-           && auto_var_in_fn_p (base0, current_function_decl)
-           && !indirect_base1
-           && TREE_CODE (base1) == SSA_NAME
-           && SSA_NAME_IS_DEFAULT_DEF (base1)
-	   && TREE_CODE (SSA_NAME_VAR (base1)) == PARM_DECL)
-          || (TREE_CODE (arg1) == ADDR_EXPR
-              && indirect_base1
-              && TREE_CODE (base1) == VAR_DECL
-              && auto_var_in_fn_p (base1, current_function_decl)
-              && !indirect_base0
-              && TREE_CODE (base0) == SSA_NAME
-              && SSA_NAME_IS_DEFAULT_DEF (base0)
-	      && TREE_CODE (SSA_NAME_VAR (base0)) == PARM_DECL))
-        {
-          if (code == NE_EXPR)
-            return constant_boolean_node (1, type);
-          else if (code == EQ_EXPR)
-            return constant_boolean_node (0, type);
-        }
       /* If we have equivalent bases we might be able to simplify.  */
-      else if (indirect_base0 == indirect_base1
-               && operand_equal_p (base0, base1, 0))
+      if (indirect_base0 == indirect_base1
+	  && operand_equal_p (base0, base1, 0))
 	{
 	  /* We can fold this expression to a constant if the non-constant
 	     offset parts are equal.  */

gcc/genmatch.c

@@ -395,7 +395,9 @@ add_operator (enum tree_code code, const char *id,
       /* To have INTEGER_CST and friends as "predicate operators".  */
       && strcmp (tcc, "tcc_constant") != 0
       /* And allow CONSTRUCTOR for vector initializers.  */
-      && !(code == CONSTRUCTOR))
+      && !(code == CONSTRUCTOR)
+      /* Allow SSA_NAME as predicate operator.  */
+      && !(code == SSA_NAME))
     return;
   /* Treat ADDR_EXPR as atom, thus don't allow matching its operand.  */
   if (code == ADDR_EXPR)

gcc/match.pd

@@ -1743,6 +1743,21 @@ along with GCC; see the file COPYING3.  If not see
 	   (if (cmp == GT_EXPR || cmp == GE_EXPR)
 	    { constant_boolean_node (above ? false : true, type); }))))))))))))
 
+(for cmp (eq ne)
+ /* A local variable can never be pointed to by
+    the default SSA name of an incoming parameter.
+    SSA names are canonicalized to 2nd place.  */
+ (simplify
+  (cmp addr@0 SSA_NAME@1)
+  (if (SSA_NAME_IS_DEFAULT_DEF (@1)
+       && TREE_CODE (SSA_NAME_VAR (@1)) == PARM_DECL)
+   (with { tree base = get_base_address (TREE_OPERAND (@0, 0)); }
+    (if (TREE_CODE (base) == VAR_DECL
+         && auto_var_in_fn_p (base, current_function_decl))
+     (if (cmp == NE_EXPR)
+      { constant_boolean_node (true, type); }
+      { constant_boolean_node (false, type); }))))))
+
 /* Equality compare simplifications from fold_binary  */
 (for cmp (eq ne)