BugFix: equivalent_node_Bound() was too greedy, reduced to a safe minimum (now mostly...

[libfirm] / ir / ir / iropt.c

diff --git a/ir/ir/iropt.c b/ir/ir/iropt.c
index ccc0daf..ce862ea 100644 (file)
--- a/ir/ir/iropt.c
+++ b/ir/ir/iropt.c
@@ -1577,34 +1577,27 @@ static ir_node *equivalent_node_CopyB(ir_node *n) {
  * Optimize Bounds(idx, idx, upper) into idx.
  */
 static ir_node *equivalent_node_Bound(ir_node *n) {
-       ir_node *idx   = get_Bound_index(n);
-       ir_node *lower = get_Bound_lower(n);
+       ir_node *idx  = get_Bound_index(n);
+       ir_node *pred = skip_Proj(idx);
        int ret_tuple = 0;
 
-       /* By definition lower < upper, so if idx == lower -->
-       lower <= idx && idx < upper */
-       if (idx == lower) {
-               /* Turn Bound into a tuple (mem, jmp, bad, idx) */
-               ret_tuple = 1;
-       } else {
-               ir_node *pred = skip_Proj(idx);
-
-               if (get_irn_op(pred) == op_Bound) {
+       if (is_Bound(pred)) {
+               /*
+                * idx was Bounds checked in the same MacroBlock previously,
+                * it is still valid if lower <= pred_lower && pred_upper <= upper.
+                */
+               ir_node *lower = get_Bound_lower(n);
+               ir_node *upper = get_Bound_upper(n);
+               if (get_Bound_lower(pred) == lower &&
+                       get_Bound_upper(pred) == upper &&
+                       get_irn_MacroBlock(n) == get_irn_MacroBlock(pred)) {
                        /*
-                        * idx was Bounds_check previously, it is still valid if
-                        * lower <= pred_lower && pred_upper <= upper.
+                        * One could expect that we simply return the previous
+                        * Bound here. However, this would be wrong, as we could
+                        * add an exception Proj to a new location then.
+                        * So, we must turn in into a tuple.
                         */
-                       ir_node *upper = get_Bound_upper(n);
-                       if (get_Bound_lower(pred) == lower &&
-                               get_Bound_upper(pred) == upper) {
-                               /*
-                                * One could expect that we simply return the previous
-                                * Bound here. However, this would be wrong, as we could
-                                * add an exception Proj to a new location then.
-                                * So, we must turn in into a tuple.
-                                */
-                               ret_tuple = 1;
-                       }
+                       ret_tuple = 1;
                }
        }
        if (ret_tuple) {