1.1 --- a/src/share/vm/opto/escape.cpp Wed Dec 07 11:35:03 2011 +0100
1.2 +++ b/src/share/vm/opto/escape.cpp Tue Dec 20 16:56:50 2011 +0100
1.3 @@ -1595,6 +1595,7 @@
1.4 GrowableArray<Node*> alloc_worklist;
1.5 GrowableArray<Node*> addp_worklist;
1.6 GrowableArray<Node*> ptr_cmp_worklist;
1.7 + GrowableArray<Node*> storestore_worklist;
1.8 PhaseGVN* igvn = _igvn;
1.9
1.10 // Push all useful nodes onto CG list and set their type.
1.11 @@ -1618,6 +1619,11 @@
1.12 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
1.13 // Compare pointers nodes
1.14 ptr_cmp_worklist.append(n);
1.15 + } else if (n->is_MemBarStoreStore()) {
1.16 + // Collect all MemBarStoreStore nodes so that depending on the
1.17 + // escape status of the associated Allocate node some of them
1.18 + // may be eliminated.
1.19 + storestore_worklist.append(n);
1.20 }
1.21 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1.22 Node* m = n->fast_out(i); // Get user
1.23 @@ -1724,11 +1730,20 @@
1.24 uint alloc_length = alloc_worklist.length();
1.25 for (uint next = 0; next < alloc_length; ++next) {
1.26 Node* n = alloc_worklist.at(next);
1.27 - if (ptnode_adr(n->_idx)->escape_state() == PointsToNode::NoEscape) {
1.28 + PointsToNode::EscapeState es = ptnode_adr(n->_idx)->escape_state();
1.29 + if (es == PointsToNode::NoEscape) {
1.30 has_non_escaping_obj = true;
1.31 if (n->is_Allocate()) {
1.32 find_init_values(n, &visited, igvn);
1.33 + // The object allocated by this Allocate node will never be
1.34 + // seen by an other thread. Mark it so that when it is
1.35 + // expanded no MemBarStoreStore is added.
1.36 + n->as_Allocate()->initialization()->set_does_not_escape();
1.37 }
1.38 + } else if ((es == PointsToNode::ArgEscape) && n->is_Allocate()) {
1.39 + // Same as above. Mark this Allocate node so that when it is
1.40 + // expanded no MemBarStoreStore is added.
1.41 + n->as_Allocate()->initialization()->set_does_not_escape();
1.42 }
1.43 }
1.44
1.45 @@ -1874,6 +1889,25 @@
1.46 igvn->hash_delete(_pcmp_eq);
1.47 }
1.48
1.49 + // For MemBarStoreStore nodes added in library_call.cpp, check
1.50 + // escape status of associated AllocateNode and optimize out
1.51 + // MemBarStoreStore node if the allocated object never escapes.
1.52 + while (storestore_worklist.length() != 0) {
1.53 + Node *n = storestore_worklist.pop();
1.54 + MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1.55 + Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1.56 + assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1.57 + PointsToNode::EscapeState es = ptnode_adr(alloc->_idx)->escape_state();
1.58 + if (es == PointsToNode::NoEscape || es == PointsToNode::ArgEscape) {
1.59 + MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1.60 + mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1.61 + mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1.62 +
1.63 + _igvn->register_new_node_with_optimizer(mb);
1.64 + _igvn->replace_node(storestore, mb);
1.65 + }
1.66 + }
1.67 +
1.68 #ifndef PRODUCT
1.69 if (PrintEscapeAnalysis) {
1.70 dump(); // Dump ConnectionGraph
