Check for constant conditions in create_condition_evaluation().

If the condition was folded to a constant, then make an unconditional jump to the appropriate target instead of constructing a Cond.
This avoids further unnecessary basic blocks and Bad nodes.

diff --git a/ast2firm.c b/ast2firm.c
index 1030bf7..b425a1e 100644 (file)
--- a/ast2firm.c
+++ b/ast2firm.c
@@ -3424,26 +3424,33 @@ static ir_node *create_condition_evaluation(expression_t const *const expression
                break;
        }
 
-       dbg_info *dbgi       = get_dbg_info(&expression->base.source_position);
-       ir_node  *cond_expr  = _expression_to_firm(expression);
-       ir_node  *condition  = create_conv(dbgi, cond_expr, mode_b);
-       ir_node  *cond       = new_d_Cond(dbgi, condition);
-       ir_node  *true_proj  = new_d_Proj(dbgi, cond, mode_X, pn_Cond_true);
-       ir_node  *false_proj = new_d_Proj(dbgi, cond, mode_X, pn_Cond_false);
-
-       /* set branch prediction info based on __builtin_expect */
-       if (is_builtin_expect(expression) && is_Cond(cond)) {
-               call_argument_t *argument = expression->call.arguments->next;
-               if (is_constant_expression(argument->expression) == EXPR_CLASS_CONSTANT) {
-                       bool               const cnst = fold_constant_to_bool(argument->expression);
-                       cond_jmp_predicate const pred = cnst ? COND_JMP_PRED_TRUE : COND_JMP_PRED_FALSE;
-                       set_Cond_jmp_pred(cond, pred);
+       ir_node *cond_expr = _expression_to_firm(expression);
+       if (is_Const(cond_expr)) {
+               if (tarval_is_null(get_Const_tarval(cond_expr))) {
+                       jump_to_target(false_target);
+               } else {
+                       jump_to_target(true_target);
+               }
+       } else {
+               dbg_info *dbgi       = get_dbg_info(&expression->base.source_position);
+               ir_node  *condition  = create_conv(dbgi, cond_expr, mode_b);
+               ir_node  *cond       = new_d_Cond(dbgi, condition);
+               ir_node  *true_proj  = new_d_Proj(dbgi, cond, mode_X, pn_Cond_true);
+               ir_node  *false_proj = new_d_Proj(dbgi, cond, mode_X, pn_Cond_false);
+
+               /* set branch prediction info based on __builtin_expect */
+               if (is_builtin_expect(expression) && is_Cond(cond)) {
+                       call_argument_t *argument = expression->call.arguments->next;
+                       if (is_constant_expression(argument->expression) == EXPR_CLASS_CONSTANT) {
+                               bool               const cnst = fold_constant_to_bool(argument->expression);
+                               cond_jmp_predicate const pred = cnst ? COND_JMP_PRED_TRUE : COND_JMP_PRED_FALSE;
+                               set_Cond_jmp_pred(cond, pred);
+                       }
                }
-       }
-
-       add_pred_to_jump_target(true_target,  true_proj);
-       add_pred_to_jump_target(false_target, false_proj);
 
+               add_pred_to_jump_target(true_target,  true_proj);
+               add_pred_to_jump_target(false_target, false_proj);
+       }
        set_unreachable_now();
        return cond_expr;
 }