--- old/src/share/vm/opto/loopTransform.cpp Wed May 18 15:31:42 2011 +++ new/src/share/vm/opto/loopTransform.cpp Wed May 18 15:31:41 2011 @@ -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).