small improvements:

- value_not_zero(): safely skip Minus and Abs nodes
- classify_value_sign(): handle Minus nodes

[r18197]

diff --git a/ir/opt/opt_confirms.c b/ir/opt/opt_confirms.c
index ef18b69..0e6ca9a 100644 (file)
--- a/ir/opt/opt_confirms.c
+++ b/ir/opt/opt_confirms.c
@@ -107,7 +107,15 @@ int value_not_zero(ir_node *n, ir_node **confirm) {
        *confirm = NULL;
 
        /* there might be several Confirms one after other that form an interval */
-       for (; is_Confirm(n); n = get_Confirm_value(n)) {
+       for (;;) {
+               if (is_Minus(n) || is_Abs(n)) {
+                       /* we can safely skip Minus and Abs when checking for != 0 */
+                       n = get_unop_op(n);
+                       continue;
+               }
+               if (! is_Confirm(n))
+                       break;
+
                /*
                 * Note: A Confirm is never after a Const. So,
                 * we simply can check the bound for being a Const
@@ -143,6 +151,7 @@ int value_not_zero(ir_node *n, ir_node **confirm) {
                default:
                        break;
                }
+               n = get_Confirm_value(n);
        }
        tv = value_of(n);
 
@@ -209,7 +218,23 @@ value_classify_sign classify_value_sign(ir_node *n) {
        tarval *tv, *c;
        ir_mode *mode;
        pn_Cmp cmp, ncmp;
+       int negate = 1;
 
+       for (;;) {
+               ir_opcode code = get_irn_opcode(n);
+
+               switch (code) {
+               case iro_Minus:
+                       negate *= -1;
+                       n = get_Minus_op(n);
+                       continue;
+               case iro_Confirm:
+                       break;
+               default:
+                       return value_classified_unknown;
+               }
+               break;
+       }
        if (get_irn_op(n) != op_Confirm)
                return value_classified_unknown;
 
@@ -252,7 +277,7 @@ value_classify_sign classify_value_sign(ir_node *n) {
                        return value_classified_unknown;
 
                /* yep, negative */
-               return value_classified_negative;
+               return value_classified_negative * negate;
 
        case pn_Cmp_Ge:
                /*
@@ -283,7 +308,7 @@ value_classify_sign classify_value_sign(ir_node *n) {
                }
 
                /* yep, positive */
-               return value_classified_positive;
+               return value_classified_positive * negate;
 
        default:
                return value_classified_unknown;