constant folding for && and ||

[r18614]

diff --git a/ast2firm.c b/ast2firm.c
index 23bb4ca..f3b7be6 100644 (file)
--- a/ast2firm.c
+++ b/ast2firm.c
@@ -1267,6 +1267,19 @@ static ir_node *create_lazy_op(const binary_expression_t *expression)
        type_t   *type = expression->expression.datatype;
        ir_mode  *mode = get_ir_mode(type);
 
+       if(is_constant_expression(expression->left)) {
+               long val = fold_constant(expression->left);
+               expression_type_t etype = expression->expression.type;
+               if((etype == EXPR_BINARY_LOGICAL_AND && val != 0)
+                               || (etype == EXPR_BINARY_LOGICAL_OR && val == 0)) {
+                       return expression_to_firm(expression->right);
+               } else {
+                       assert((etype == EXPR_BINARY_LOGICAL_AND && val == 0)
+                                       || (etype == EXPR_BINARY_LOGICAL_OR && val != 0));
+                       return new_Const(mode, get_mode_one(mode));
+               }
+       }
+
        ir_node *cur_block = get_cur_block();
 
        ir_node *one_block = new_immBlock();