X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Ffold-const.c;h=cdae661733c5b4e59e93745e3529e08b5325e255;hb=0395dc5ef775b63c96fcb017b334b4fae14447d2;hp=c1af8248a395f55c1d51a914681dbfada7ec3a21;hpb=fa1dbb88a8819f4730461c128c83b7732720a77c;p=pf3gnuchains%2Fgcc-fork.git

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index c1af8248a39..cdae661733c 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -8643,9 +8643,33 @@ fold_comparison (location_t loc, enum tree_code code, tree type,
 	  offset1 = TREE_OPERAND (arg1, 1);
 	}
 
+      /* 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
+           && TREE_CODE (SSA_NAME_VAR (base1)) == PARM_DECL
+           && SSA_NAME_IS_DEFAULT_DEF (base1))
+          || (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
+              && TREE_CODE (SSA_NAME_VAR (base0)) == PARM_DECL
+              && SSA_NAME_IS_DEFAULT_DEF (base0)))
+        {
+          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.  */
-      if (indirect_base0 == indirect_base1
-	  && operand_equal_p (base0, base1, 0))
+      else 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.  */
@@ -8695,24 +8719,19 @@ fold_comparison (location_t loc, enum tree_code code, tree type,
 		   && ((code == EQ_EXPR || code == NE_EXPR)
 		       || POINTER_TYPE_OVERFLOW_UNDEFINED))
 	    {
-	      tree signed_size_type_node;
-	      signed_size_type_node = signed_type_for (size_type_node);
-
 	      /* By converting to signed size type we cover middle-end pointer
 	         arithmetic which operates on unsigned pointer types of size
 	         type size and ARRAY_REF offsets which are properly sign or
 	         zero extended from their type in case it is narrower than
 	         size type.  */
 	      if (offset0 == NULL_TREE)
-		offset0 = build_int_cst (signed_size_type_node, 0);
+		offset0 = build_int_cst (ssizetype, 0);
 	      else
-		offset0 = fold_convert_loc (loc, signed_size_type_node,
-					    offset0);
+		offset0 = fold_convert_loc (loc, ssizetype, offset0);
 	      if (offset1 == NULL_TREE)
-		offset1 = build_int_cst (signed_size_type_node, 0);
+		offset1 = build_int_cst (ssizetype, 0);
 	      else
-		offset1 = fold_convert_loc (loc, signed_size_type_node,
-					    offset1);
+		offset1 = fold_convert_loc (loc, ssizetype, offset1);
 
 	      if (code != EQ_EXPR
 		  && code != NE_EXPR