2009-10-16 Joel Sherrill <joel.sherrill@oarcorp.com>

[pf3gnuchains/gcc-fork.git] / gcc / fold-const.c

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index d754bee..1539ad2 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -2830,8 +2830,6 @@ maybe_lvalue_p (const_tree x)
   case TARGET_EXPR:
   case COND_EXPR:
   case BIND_EXPR:
-  case MIN_EXPR:
-  case MAX_EXPR:
     break;
 
   default:
@@ -6512,7 +6510,19 @@ extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
       /* If this was a subtraction, negate OP1 and set it to be an addition.
         This simplifies the logic below.  */
       if (tcode == MINUS_EXPR)
-       tcode = PLUS_EXPR, op1 = negate_expr (op1);
+       {
+         tcode = PLUS_EXPR, op1 = negate_expr (op1);
+         /* If OP1 was not easily negatable, the constant may be OP0.  */
+         if (TREE_CODE (op0) == INTEGER_CST)
+           {
+             tree tem = op0;
+             op0 = op1;
+             op1 = tem;
+             tem = t1;
+             t1 = t2;
+             t2 = tem;
+           }
+       }
 
       if (TREE_CODE (op1) != INTEGER_CST)
        break;
@@ -12604,6 +12614,11 @@ fold_binary_loc (location_t loc,
         return fold_build1_loc (loc, TRUTH_NOT_EXPR, type,
                            fold_convert_loc (loc, type, arg0));
 
+      /* !exp != 0 becomes !exp */
+      if (TREE_CODE (arg0) == TRUTH_NOT_EXPR && integer_zerop (arg1)
+         && code == NE_EXPR)
+        return non_lvalue_loc (loc, fold_convert_loc (loc, type, arg0));
+
       /* If this is an equality comparison of the address of two non-weak,
         unaliased symbols neither of which are extern (since we do not
         have access to attributes for externs), then we know the result.  */