--- old/src/share/vm/opto/cfgnode.cpp Wed Jul 20 14:06:31 2011 +++ new/src/share/vm/opto/cfgnode.cpp Wed Jul 20 14:06:31 2011 @@ -1349,17 +1349,9 @@ static void split_once(PhaseIterGVN *igvn, Node *phi, Node *val, Node *n, Node *newn) { igvn->hash_delete(n); // Remove from hash before hacking edges - Node* predicate_proj = NULL; uint j = 1; for (uint i = phi->req()-1; i > 0; i--) { if (phi->in(i) == val) { // Found a path with val? - if (n->is_Region()) { - Node* proj = PhaseIdealLoop::find_predicate(n->in(i)); - if (proj != NULL) { - assert(predicate_proj == NULL, "only one predicate entry expected"); - predicate_proj = proj; - } - } // Add to NEW Region/Phi, no DU info newn->set_req( j++, n->in(i) ); // Remove from OLD Region/Phi @@ -1371,11 +1363,6 @@ // entire Region/Phi conglomerate has been hacked as a single huge transform. igvn->register_new_node_with_optimizer( newn ); - // Clone loop predicates - if (predicate_proj != NULL) { - newn = igvn->clone_loop_predicates(predicate_proj, newn, !n->is_CountedLoop()); - } - // Now I can point to the new node. n->add_req(newn); igvn->_worklist.push(n); @@ -1404,13 +1391,18 @@ Node *val = phi->in(i); // Constant to split for uint hit = 0; // Number of times it occurs + Node *r = phi->region(); for( ; i < phi->req(); i++ ){ // Count occurrences of constant Node *n = phi->in(i); if( !n ) return NULL; if( phase->type(n) == Type::TOP ) return NULL; - if( phi->in(i) == val ) + if( phi->in(i) == val ) { hit++; + if (PhaseIdealLoop::find_predicate(r->in(i)) != NULL) { + return NULL; // don't split loop entry path + } + } } if( hit <= 1 || // Make sure we find 2 or more @@ -1420,7 +1412,6 @@ // Now start splitting out the flow paths that merge the same value. // Split first the RegionNode. PhaseIterGVN *igvn = phase->is_IterGVN(); - Node *r = phi->region(); RegionNode *newr = new (phase->C, hit+1) RegionNode(hit+1); split_once(igvn, phi, val, r, newr);