7045693: java/util/EnumSet/EnumSetBash.java still failing intermittently
Summary: New limit for unrolled loop should be set only for zero trip guard and loop iteration test.
Reviewed-by: never
--- a/hotspot/src/share/vm/opto/loopTransform.cpp Fri May 20 22:27:48 2011 -0700
+++ b/hotspot/src/share/vm/opto/loopTransform.cpp Sat May 21 11:44:31 2011 -0700
@@ -1292,9 +1292,23 @@
}
assert(new_limit != NULL, "");
// Replace in loop test.
- _igvn.hash_delete(cmp);
- cmp->set_req(2, new_limit);
-
+ assert(loop_end->in(1)->in(1) == cmp, "sanity");
+ if (cmp->outcnt() == 1 && loop_end->in(1)->outcnt() == 1) {
+ // Don't need to create new test since only one user.
+ _igvn.hash_delete(cmp);
+ cmp->set_req(2, new_limit);
+ } else {
+ // Create new test since it is shared.
+ Node* ctrl2 = loop_end->in(0);
+ Node* cmp2 = cmp->clone();
+ cmp2->set_req(2, new_limit);
+ register_new_node(cmp2, ctrl2);
+ Node* bol2 = loop_end->in(1)->clone();
+ bol2->set_req(1, cmp2);
+ register_new_node(bol2, ctrl2);
+ _igvn.hash_delete(loop_end);
+ loop_end->set_req(1, bol2);
+ }
// Step 3: Find the min-trip test guaranteed before a 'main' loop.
// Make it a 1-trip test (means at least 2 trips).