fold-const.c (fold): Guard (-A)+B -> B-A transformation with reorder_operands_p.

	* fold-const.c (fold) <PLUS_EXPR>: Guard (-A)+B -> B-A transformation
	with reorder_operands_p.

From-SVN: r80381

gcc/ChangeLog

+2004-04-03  Roger Sayle  <roger@eyesopen.com>
+
+	* fold-const.c (fold) <PLUS_EXPR>: Guard (-A)+B -> B-A transformation
+	with reorder_operands_p.
+
 2004-04-03  Jan Hubicka  <jh@suse.cz>
 
 	* md.texi (vec_set, vec_extract, vec_init): Document.

gcc/fold-const.c

@@ -5861,9 +5861,10 @@ fold (tree expr)
       if (TREE_CODE (arg1) == NEGATE_EXPR)
 	return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
       /* (-A) + B -> B - A */
-      if (TREE_CODE (arg0) == NEGATE_EXPR)
+      if (TREE_CODE (arg0) == NEGATE_EXPR
+	  && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
 	return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
-      else if (! FLOAT_TYPE_P (type))
+      if (! FLOAT_TYPE_P (type))
 	{
 	  if (integer_zerop (arg1))
 	    return non_lvalue (fold_convert (type, arg0));