1.1 --- a/src/share/vm/opto/macro.cpp Wed Dec 07 11:35:03 2011 +0100
1.2 +++ b/src/share/vm/opto/macro.cpp Tue Dec 20 16:56:50 2011 +0100
1.3 @@ -1088,6 +1088,12 @@
1.4 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1.5 Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1.6
1.7 + Node* storestore = alloc->storestore();
1.8 + if (storestore != NULL) {
1.9 + // Break this link that is no longer useful and confuses register allocation
1.10 + storestore->set_req(MemBarNode::Precedent, top());
1.11 + }
1.12 +
1.13 assert(ctrl != NULL, "must have control");
1.14 // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1.15 // they will not be used if "always_slow" is set
1.16 @@ -1289,10 +1295,66 @@
1.17 0, new_alloc_bytes, T_LONG);
1.18 }
1.19
1.20 + InitializeNode* init = alloc->initialization();
1.21 fast_oop_rawmem = initialize_object(alloc,
1.22 fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1.23 klass_node, length, size_in_bytes);
1.24
1.25 + // If initialization is performed by an array copy, any required
1.26 + // MemBarStoreStore was already added. If the object does not
1.27 + // escape no need for a MemBarStoreStore. Otherwise we need a
1.28 + // MemBarStoreStore so that stores that initialize this object
1.29 + // can't be reordered with a subsequent store that makes this
1.30 + // object accessible by other threads.
1.31 + if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) {
1.32 + if (init == NULL || init->req() < InitializeNode::RawStores) {
1.33 + // No InitializeNode or no stores captured by zeroing
1.34 + // elimination. Simply add the MemBarStoreStore after object
1.35 + // initialization.
1.36 + MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot, fast_oop_rawmem);
1.37 + transform_later(mb);
1.38 +
1.39 + mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1.40 + mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1.41 + fast_oop_ctrl = new (C, 1) ProjNode(mb,TypeFunc::Control);
1.42 + transform_later(fast_oop_ctrl);
1.43 + fast_oop_rawmem = new (C, 1) ProjNode(mb,TypeFunc::Memory);
1.44 + transform_later(fast_oop_rawmem);
1.45 + } else {
1.46 + // Add the MemBarStoreStore after the InitializeNode so that
1.47 + // all stores performing the initialization that were moved
1.48 + // before the InitializeNode happen before the storestore
1.49 + // barrier.
1.50 +
1.51 + Node* init_ctrl = init->proj_out(TypeFunc::Control);
1.52 + Node* init_mem = init->proj_out(TypeFunc::Memory);
1.53 +
1.54 + MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1.55 + transform_later(mb);
1.56 +
1.57 + Node* ctrl = new (C, 1) ProjNode(init,TypeFunc::Control);
1.58 + transform_later(ctrl);
1.59 + Node* mem = new (C, 1) ProjNode(init,TypeFunc::Memory);
1.60 + transform_later(mem);
1.61 +
1.62 + // The MemBarStoreStore depends on control and memory coming
1.63 + // from the InitializeNode
1.64 + mb->init_req(TypeFunc::Memory, mem);
1.65 + mb->init_req(TypeFunc::Control, ctrl);
1.66 +
1.67 + ctrl = new (C, 1) ProjNode(mb,TypeFunc::Control);
1.68 + transform_later(ctrl);
1.69 + mem = new (C, 1) ProjNode(mb,TypeFunc::Memory);
1.70 + transform_later(mem);
1.71 +
1.72 + // All nodes that depended on the InitializeNode for control
1.73 + // and memory must now depend on the MemBarNode that itself
1.74 + // depends on the InitializeNode
1.75 + _igvn.replace_node(init_ctrl, ctrl);
1.76 + _igvn.replace_node(init_mem, mem);
1.77 + }
1.78 + }
1.79 +
1.80 if (C->env()->dtrace_extended_probes()) {
1.81 // Slow-path call
1.82 int size = TypeFunc::Parms + 2;
