/* * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "ci/bcEscapeAnalyzer.hpp" #include "compiler/compileLog.hpp" #include "libadt/vectset.hpp" #include "memory/allocation.hpp" #include "opto/c2compiler.hpp" #include "opto/callnode.hpp" #include "opto/cfgnode.hpp" #include "opto/compile.hpp" #include "opto/escape.hpp" #include "opto/phaseX.hpp" #include "opto/rootnode.hpp" ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) : _nodes(C->comp_arena(), C->unique(), C->unique(), NULL), _collecting(true), _verify(false), _compile(C), _igvn(igvn), _node_map(C->comp_arena()) { // Add unknown java object. add_java_object(C->top(), PointsToNode::GlobalEscape); phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject(); // Add ConP(#NULL) and ConN(#NULL) nodes. Node* oop_null = igvn->zerocon(T_OBJECT); assert(oop_null->_idx < nodes_size(), "should be created already"); add_java_object(oop_null, PointsToNode::NoEscape); null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject(); if (UseCompressedOops) { Node* noop_null = igvn->zerocon(T_NARROWOOP); assert(noop_null->_idx < nodes_size(), "should be created already"); map_ideal_node(noop_null, null_obj); } _pcmp_neq = NULL; // Should be initialized _pcmp_eq = NULL; } bool ConnectionGraph::has_candidates(Compile *C) { // EA brings benefits only when the code has allocations and/or locks which // are represented by ideal Macro nodes. int cnt = C->macro_count(); for( int i=0; i < cnt; i++ ) { Node *n = C->macro_node(i); if ( n->is_Allocate() ) return true; if( n->is_Lock() ) { Node* obj = n->as_Lock()->obj_node()->uncast(); if( !(obj->is_Parm() || obj->is_Con()) ) return true; } } return false; } void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) { Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true); ResourceMark rm; // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction // to create space for them in ConnectionGraph::_nodes[]. Node* oop_null = igvn->zerocon(T_OBJECT); Node* noop_null = igvn->zerocon(T_NARROWOOP); ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn); // Perform escape analysis if (congraph->compute_escape()) { // There are non escaping objects. C->set_congraph(congraph); } // Cleanup. if (oop_null->outcnt() == 0) igvn->hash_delete(oop_null); if (noop_null->outcnt() == 0) igvn->hash_delete(noop_null); } bool ConnectionGraph::compute_escape() { Compile* C = _compile; PhaseGVN* igvn = _igvn; // Worklists used by EA. Unique_Node_List delayed_worklist; GrowableArray alloc_worklist; GrowableArray ptr_cmp_worklist; GrowableArray storestore_worklist; GrowableArray ptnodes_worklist; GrowableArray java_objects_worklist; GrowableArray non_escaped_worklist; GrowableArray oop_fields_worklist; DEBUG_ONLY( GrowableArray addp_worklist; ) { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true); // 1. Populate Connection Graph (CG) with PointsTo nodes. ideal_nodes.map(C->unique(), NULL); // preallocate space // Initialize worklist if (C->root() != NULL) { ideal_nodes.push(C->root()); } for( uint next = 0; next < ideal_nodes.size(); ++next ) { Node* n = ideal_nodes.at(next); // Create PointsTo nodes and add them to Connection Graph. Called // only once per ideal node since ideal_nodes is Unique_Node list. add_node_to_connection_graph(n, &delayed_worklist); PointsToNode* ptn = ptnode_adr(n->_idx); if (ptn != NULL) { ptnodes_worklist.append(ptn); if (ptn->is_JavaObject()) { java_objects_worklist.append(ptn->as_JavaObject()); if ((n->is_Allocate() || n->is_CallStaticJava()) && (ptn->escape_state() < PointsToNode::GlobalEscape)) { // Only allocations and java static calls results are interesting. non_escaped_worklist.append(ptn->as_JavaObject()); } } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) { oop_fields_worklist.append(ptn->as_Field()); } } if (n->is_MergeMem()) { // Collect all MergeMem nodes to add memory slices for // scalar replaceable objects in split_unique_types(). _mergemem_worklist.append(n->as_MergeMem()); } else if (OptimizePtrCompare && n->is_Cmp() && (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) { // Collect compare pointers nodes. ptr_cmp_worklist.append(n); } else if (n->is_MemBarStoreStore()) { // Collect all MemBarStoreStore nodes so that depending on the // escape status of the associated Allocate node some of them // may be eliminated. storestore_worklist.append(n); #ifdef ASSERT } else if(n->is_AddP()) { // Collect address nodes for graph verification. addp_worklist.append(n); #endif } for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { Node* m = n->fast_out(i); // Get user ideal_nodes.push(m); } } if (non_escaped_worklist.length() == 0) { _collecting = false; return false; // Nothing to do. } // Add final simple edges to graph. while(delayed_worklist.size() > 0) { Node* n = delayed_worklist.pop(); add_final_edges(n); } int ptnodes_length = ptnodes_worklist.length(); #ifdef ASSERT if (VerifyConnectionGraph) { // Verify that no new simple edges could be created and all // local vars has edges. _verify = true; for (int next = 0; next < ptnodes_length; ++next) { PointsToNode* ptn = ptnodes_worklist.at(next); add_final_edges(ptn->ideal_node()); if (ptn->is_LocalVar() && ptn->edge_count() == 0) { ptn->dump(); assert(ptn->as_LocalVar()->edge_count() > 0, "sanity"); } } _verify = false; } #endif // 2. Finish Graph construction by propagating references to all // java objects through graph. if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist, java_objects_worklist, oop_fields_worklist)) { // All objects escaped or hit time or iterations limits. _collecting = false; return false; } // 3. Adjust scalar_replaceable state of nonescaping objects and push // scalar replaceable allocations on alloc_worklist for processing // in split_unique_types(). int non_escaped_length = non_escaped_worklist.length(); for (int next = 0; next < non_escaped_length; next++) { JavaObjectNode* ptn = non_escaped_worklist.at(next); if (ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable()) { adjust_scalar_replaceable_state(ptn); if (ptn->scalar_replaceable()) { alloc_worklist.append(ptn->ideal_node()); } } } #ifdef ASSERT if (VerifyConnectionGraph) { // Verify that graph is complete - no new edges could be added or needed. verify_connection_graph(ptnodes_worklist, non_escaped_worklist, java_objects_worklist, addp_worklist); } assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build"); assert(null_obj->escape_state() == PointsToNode::NoEscape && null_obj->edge_count() == 0 && !null_obj->arraycopy_src() && !null_obj->arraycopy_dst(), "sanity"); #endif _collecting = false; } // TracePhase t3("connectionGraph") // 4. Optimize ideal graph based on EA information. bool has_non_escaping_obj = (non_escaped_worklist.length() > 0); if (has_non_escaping_obj) { optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist); } #ifndef PRODUCT if (PrintEscapeAnalysis) { dump(ptnodes_worklist); // Dump ConnectionGraph } #endif bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0); #ifdef ASSERT if (VerifyConnectionGraph) { int alloc_length = alloc_worklist.length(); for (int next = 0; next < alloc_length; ++next) { Node* n = alloc_worklist.at(next); PointsToNode* ptn = ptnode_adr(n->_idx); assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity"); } } #endif // 5. Separate memory graph for scalar replaceable allcations. if (has_scalar_replaceable_candidates && C->AliasLevel() >= 3 && EliminateAllocations) { // Now use the escape information to create unique types for // scalar replaceable objects. split_unique_types(alloc_worklist); if (C->failing()) return false; C->print_method("After Escape Analysis", 2); #ifdef ASSERT } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) { tty->print("=== No allocations eliminated for "); C->method()->print_short_name(); if(!EliminateAllocations) { tty->print(" since EliminateAllocations is off ==="); } else if(!has_scalar_replaceable_candidates) { tty->print(" since there are no scalar replaceable candidates ==="); } else if(C->AliasLevel() < 3) { tty->print(" since AliasLevel < 3 ==="); } tty->cr(); #endif } return has_non_escaping_obj; } // Populate Connection Graph with PointsTo nodes and create simple // connection graph edges. void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) { assert(!_verify, "this method sould not be called for verification"); PhaseGVN* igvn = _igvn; uint n_idx = n->_idx; PointsToNode* n_ptn = ptnode_adr(n_idx); if (n_ptn != NULL) return; // No need to redefine PointsTo node during first iteration. if (n->is_Call()) { // Arguments to allocation and locking don't escape. if (n->is_AbstractLock()) { // Put Lock and Unlock nodes on IGVN worklist to process them during // first IGVN optimization when escape information is still available. record_for_optimizer(n); } else if (n->is_Allocate()) { add_call_node(n->as_Call()); record_for_optimizer(n); } else { if (n->is_CallStaticJava()) { const char* name = n->as_CallStaticJava()->_name; if (name != NULL && strcmp(name, "uncommon_trap") == 0) return; // Skip uncommon traps } // Don't mark as processed since call's arguments have to be processed. delayed_worklist->push(n); // Check if a call returns an object. if (n->as_Call()->returns_pointer() && n->as_Call()->proj_out(TypeFunc::Parms) != NULL) { add_call_node(n->as_Call()); } } return; } // Put this check here to process call arguments since some call nodes // point to phantom_obj. if (n_ptn == phantom_obj || n_ptn == null_obj) return; // Skip predefined nodes. int opcode = n->Opcode(); switch (opcode) { case Op_AddP: { Node* base = get_addp_base(n); PointsToNode* ptn_base = ptnode_adr(base->_idx); // Field nodes are created for all field types. They are used in // adjust_scalar_replaceable_state() and split_unique_types(). // Note, non-oop fields will have only base edges in Connection // Graph because such fields are not used for oop loads and stores. int offset = address_offset(n, igvn); add_field(n, PointsToNode::NoEscape, offset); if (ptn_base == NULL) { delayed_worklist->push(n); // Process it later. } else { n_ptn = ptnode_adr(n_idx); add_base(n_ptn->as_Field(), ptn_base); } break; } case Op_CastX2P: { map_ideal_node(n, phantom_obj); break; } case Op_CastPP: case Op_CheckCastPP: case Op_EncodeP: case Op_DecodeN: { add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist); break; } case Op_CMoveP: { add_local_var(n, PointsToNode::NoEscape); // Do not add edges during first iteration because some could be // not defined yet. delayed_worklist->push(n); break; } case Op_ConP: case Op_ConN: { // assume all oop constants globally escape except for null PointsToNode::EscapeState es; if (igvn->type(n) == TypePtr::NULL_PTR || igvn->type(n) == TypeNarrowOop::NULL_PTR) { es = PointsToNode::NoEscape; } else { es = PointsToNode::GlobalEscape; } add_java_object(n, es); break; } case Op_CreateEx: { // assume that all exception objects globally escape add_java_object(n, PointsToNode::GlobalEscape); break; } case Op_LoadKlass: case Op_LoadNKlass: { // Unknown class is loaded map_ideal_node(n, phantom_obj); break; } case Op_LoadP: case Op_LoadN: case Op_LoadPLocked: { // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because // ThreadLocal has RawPrt type. const Type* t = igvn->type(n); if (t->make_ptr() != NULL) { Node* adr = n->in(MemNode::Address); #ifdef ASSERT if (!adr->is_AddP()) { assert(igvn->type(adr)->isa_rawptr(), "sanity"); } else { assert((ptnode_adr(adr->_idx) == NULL || ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity"); } #endif add_local_var_and_edge(n, PointsToNode::NoEscape, adr, delayed_worklist); } break; } case Op_Parm: { map_ideal_node(n, phantom_obj); break; } case Op_PartialSubtypeCheck: { // Produces Null or notNull and is used in only in CmpP so // phantom_obj could be used. map_ideal_node(n, phantom_obj); // Result is unknown break; } case Op_Phi: { // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because // ThreadLocal has RawPrt type. const Type* t = n->as_Phi()->type(); if (t->make_ptr() != NULL) { add_local_var(n, PointsToNode::NoEscape); // Do not add edges during first iteration because some could be // not defined yet. delayed_worklist->push(n); } break; } case Op_Proj: { // we are only interested in the oop result projection from a call if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() && n->in(0)->as_Call()->returns_pointer()) { add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), delayed_worklist); } break; } case Op_Rethrow: // Exception object escapes case Op_Return: { if (n->req() > TypeFunc::Parms && igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) { // Treat Return value as LocalVar with GlobalEscape escape state. add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), delayed_worklist); } break; } case Op_StoreP: case Op_StoreN: case Op_StorePConditional: case Op_CompareAndSwapP: case Op_CompareAndSwapN: { Node* adr = n->in(MemNode::Address); const Type *adr_type = igvn->type(adr); adr_type = adr_type->make_ptr(); if (adr_type->isa_oopptr() || (opcode == Op_StoreP || opcode == Op_StoreN) && (adr_type == TypeRawPtr::NOTNULL && adr->in(AddPNode::Address)->is_Proj() && adr->in(AddPNode::Address)->in(0)->is_Allocate())) { delayed_worklist->push(n); // Process it later. #ifdef ASSERT assert(adr->is_AddP(), "expecting an AddP"); if (adr_type == TypeRawPtr::NOTNULL) { // Verify a raw address for a store captured by Initialize node. int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot); assert(offs != Type::OffsetBot, "offset must be a constant"); } #endif } else { // Ignore copy the displaced header to the BoxNode (OSR compilation). if (adr->is_BoxLock()) break; // Stored value escapes in unsafe access. if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) { // Pointer stores in G1 barriers looks like unsafe access. // Ignore such stores to be able scalar replace non-escaping // allocations. if (UseG1GC && adr->is_AddP()) { Node* base = get_addp_base(adr); if (base->Opcode() == Op_LoadP && base->in(MemNode::Address)->is_AddP()) { adr = base->in(MemNode::Address); Node* tls = get_addp_base(adr); if (tls->Opcode() == Op_ThreadLocal) { int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot); if (offs == in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_buf())) { break; // G1 pre barier previous oop value store. } if (offs == in_bytes(JavaThread::dirty_card_queue_offset() + PtrQueue::byte_offset_of_buf())) { break; // G1 post barier card address store. } } } } delayed_worklist->push(n); // Process unsafe access later. break; } #ifdef ASSERT n->dump(1); assert(false, "not unsafe or G1 barrier raw StoreP"); #endif } break; } case Op_AryEq: case Op_StrComp: case Op_StrEquals: case Op_StrIndexOf: { add_local_var(n, PointsToNode::ArgEscape); delayed_worklist->push(n); // Process it later. break; } case Op_ThreadLocal: { add_java_object(n, PointsToNode::ArgEscape); break; } default: ; // Do nothing for nodes not related to EA. } return; } #ifdef ASSERT #define ELSE_FAIL(name) \ /* Should not be called for not pointer type. */ \ n->dump(1); \ assert(false, name); \ break; #else #define ELSE_FAIL(name) \ break; #endif // Add final simple edges to graph. void ConnectionGraph::add_final_edges(Node *n) { PointsToNode* n_ptn = ptnode_adr(n->_idx); #ifdef ASSERT if (_verify && n_ptn->is_JavaObject()) return; // This method does not change graph for JavaObject. #endif if (n->is_Call()) { process_call_arguments(n->as_Call()); return; } assert(n->is_Store() || n->is_LoadStore() || (n_ptn != NULL) && (n_ptn->ideal_node() != NULL), "node should be registered already"); int opcode = n->Opcode(); switch (opcode) { case Op_AddP: { Node* base = get_addp_base(n); PointsToNode* ptn_base = ptnode_adr(base->_idx); assert(ptn_base != NULL, "field's base should be registered"); add_base(n_ptn->as_Field(), ptn_base); break; } case Op_CastPP: case Op_CheckCastPP: case Op_EncodeP: case Op_DecodeN: { add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), NULL); break; } case Op_CMoveP: { for (uint i = CMoveNode::IfFalse; i < n->req(); i++) { Node* in = n->in(i); if (in == NULL) continue; // ignore NULL Node* uncast_in = in->uncast(); if (uncast_in->is_top() || uncast_in == n) continue; // ignore top or inputs which go back this node PointsToNode* ptn = ptnode_adr(in->_idx); assert(ptn != NULL, "node should be registered"); add_edge(n_ptn, ptn); } break; } case Op_LoadP: case Op_LoadN: case Op_LoadPLocked: { // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because // ThreadLocal has RawPrt type. const Type* t = _igvn->type(n); if (t->make_ptr() != NULL) { Node* adr = n->in(MemNode::Address); add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL); break; } ELSE_FAIL("Op_LoadP"); } case Op_Phi: { // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because // ThreadLocal has RawPrt type. const Type* t = n->as_Phi()->type(); if (t->make_ptr() != NULL) { for (uint i = 1; i < n->req(); i++) { Node* in = n->in(i); if (in == NULL) continue; // ignore NULL Node* uncast_in = in->uncast(); if (uncast_in->is_top() || uncast_in == n) continue; // ignore top or inputs which go back this node PointsToNode* ptn = ptnode_adr(in->_idx); assert(ptn != NULL, "node should be registered"); add_edge(n_ptn, ptn); } break; } ELSE_FAIL("Op_Phi"); } case Op_Proj: { // we are only interested in the oop result projection from a call if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() && n->in(0)->as_Call()->returns_pointer()) { add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL); break; } ELSE_FAIL("Op_Proj"); } case Op_Rethrow: // Exception object escapes case Op_Return: { if (n->req() > TypeFunc::Parms && _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) { // Treat Return value as LocalVar with GlobalEscape escape state. add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), NULL); break; } ELSE_FAIL("Op_Return"); } case Op_StoreP: case Op_StoreN: case Op_StorePConditional: case Op_CompareAndSwapP: case Op_CompareAndSwapN: { Node* adr = n->in(MemNode::Address); const Type *adr_type = _igvn->type(adr); adr_type = adr_type->make_ptr(); if (adr_type->isa_oopptr() || (opcode == Op_StoreP || opcode == Op_StoreN) && (adr_type == TypeRawPtr::NOTNULL && adr->in(AddPNode::Address)->is_Proj() && adr->in(AddPNode::Address)->in(0)->is_Allocate())) { // Point Address to Value PointsToNode* adr_ptn = ptnode_adr(adr->_idx); assert(adr_ptn != NULL && adr_ptn->as_Field()->is_oop(), "node should be registered"); Node *val = n->in(MemNode::ValueIn); PointsToNode* ptn = ptnode_adr(val->_idx); assert(ptn != NULL, "node should be registered"); add_edge(adr_ptn, ptn); break; } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) { // Stored value escapes in unsafe access. Node *val = n->in(MemNode::ValueIn); PointsToNode* ptn = ptnode_adr(val->_idx); assert(ptn != NULL, "node should be registered"); ptn->set_escape_state(PointsToNode::GlobalEscape); // Add edge to object for unsafe access with offset. PointsToNode* adr_ptn = ptnode_adr(adr->_idx); assert(adr_ptn != NULL, "node should be registered"); if (adr_ptn->is_Field()) { assert(adr_ptn->as_Field()->is_oop(), "should be oop field"); add_edge(adr_ptn, ptn); } break; } ELSE_FAIL("Op_StoreP"); } case Op_AryEq: case Op_StrComp: case Op_StrEquals: case Op_StrIndexOf: { // char[] arrays passed to string intrinsic do not escape but // they are not scalar replaceable. Adjust escape state for them. // Start from in(2) edge since in(1) is memory edge. for (uint i = 2; i < n->req(); i++) { Node* adr = n->in(i); const Type* at = _igvn->type(adr); if (!adr->is_top() && at->isa_ptr()) { assert(at == Type::TOP || at == TypePtr::NULL_PTR || at->isa_ptr() != NULL, "expecting a pointer"); if (adr->is_AddP()) { adr = get_addp_base(adr); } PointsToNode* ptn = ptnode_adr(adr->_idx); assert(ptn != NULL, "node should be registered"); add_edge(n_ptn, ptn); } } break; } default: { // This method should be called only for EA specific nodes which may // miss some edges when they were created. #ifdef ASSERT n->dump(1); #endif guarantee(false, "unknown node"); } } return; } void ConnectionGraph::add_call_node(CallNode* call) { assert(call->returns_pointer(), "only for call which returns pointer"); uint call_idx = call->_idx; if (call->is_Allocate()) { Node* k = call->in(AllocateNode::KlassNode); const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr(); assert(kt != NULL, "TypeKlassPtr required."); ciKlass* cik = kt->klass(); PointsToNode::EscapeState es = PointsToNode::NoEscape; bool scalar_replaceable = true; if (call->is_AllocateArray()) { if (!cik->is_array_klass()) { // StressReflectiveCode es = PointsToNode::GlobalEscape; } else { int length = call->in(AllocateNode::ALength)->find_int_con(-1); if (length < 0 || length > EliminateAllocationArraySizeLimit) { // Not scalar replaceable if the length is not constant or too big. scalar_replaceable = false; } } } else { // Allocate instance if (cik->is_subclass_of(_compile->env()->Thread_klass()) || !cik->is_instance_klass() || // StressReflectiveCode cik->as_instance_klass()->has_finalizer()) { es = PointsToNode::GlobalEscape; } } add_java_object(call, es); PointsToNode* ptn = ptnode_adr(call_idx); if (!scalar_replaceable && ptn->scalar_replaceable()) { ptn->set_scalar_replaceable(false); } } else if (call->is_CallStaticJava()) { // Call nodes could be different types: // // 1. CallDynamicJavaNode (what happened during call is unknown): // // - mapped to GlobalEscape JavaObject node if oop is returned; // // - all oop arguments are escaping globally; // // 2. CallStaticJavaNode (execute bytecode analysis if possible): // // - the same as CallDynamicJavaNode if can't do bytecode analysis; // // - mapped to GlobalEscape JavaObject node if unknown oop is returned; // - mapped to NoEscape JavaObject node if non-escaping object allocated // during call is returned; // - mapped to ArgEscape LocalVar node pointed to object arguments // which are returned and does not escape during call; // // - oop arguments escaping status is defined by bytecode analysis; // // For a static call, we know exactly what method is being called. // Use bytecode estimator to record whether the call's return value escapes. ciMethod* meth = call->as_CallJava()->method(); if (meth == NULL) { const char* name = call->as_CallStaticJava()->_name; assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check"); // Returns a newly allocated unescaped object. add_java_object(call, PointsToNode::NoEscape); ptnode_adr(call_idx)->set_scalar_replaceable(false); } else { BCEscapeAnalyzer* call_analyzer = meth->get_bcea(); call_analyzer->copy_dependencies(_compile->dependencies()); if (call_analyzer->is_return_allocated()) { // Returns a newly allocated unescaped object, simply // update dependency information. // Mark it as NoEscape so that objects referenced by // it's fields will be marked as NoEscape at least. add_java_object(call, PointsToNode::NoEscape); ptnode_adr(call_idx)->set_scalar_replaceable(false); } else { // Determine whether any arguments are returned. const TypeTuple* d = call->tf()->domain(); bool ret_arg = false; for (uint i = TypeFunc::Parms; i < d->cnt(); i++) { if (d->field_at(i)->isa_ptr() != NULL && call_analyzer->is_arg_returned(i - TypeFunc::Parms)) { ret_arg = true; break; } } if (ret_arg) { add_local_var(call, PointsToNode::ArgEscape); } else { // Returns unknown object. map_ideal_node(call, phantom_obj); } } } } else { // An other type of call, assume the worst case: // returned value is unknown and globally escapes. assert(call->Opcode() == Op_CallDynamicJava, "add failed case check"); map_ideal_node(call, phantom_obj); } } void ConnectionGraph::process_call_arguments(CallNode *call) { bool is_arraycopy = false; switch (call->Opcode()) { #ifdef ASSERT case Op_Allocate: case Op_AllocateArray: case Op_Lock: case Op_Unlock: assert(false, "should be done already"); break; #endif case Op_CallLeafNoFP: is_arraycopy = (call->as_CallLeaf()->_name != NULL && strstr(call->as_CallLeaf()->_name, "arraycopy") != 0); // fall through case Op_CallLeaf: { // Stub calls, objects do not escape but they are not scale replaceable. // Adjust escape state for outgoing arguments. const TypeTuple * d = call->tf()->domain(); bool src_has_oops = false; for (uint i = TypeFunc::Parms; i < d->cnt(); i++) { const Type* at = d->field_at(i); Node *arg = call->in(i); const Type *aat = _igvn->type(arg); if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr()) continue; if (arg->is_AddP()) { // // The inline_native_clone() case when the arraycopy stub is called // after the allocation before Initialize and CheckCastPP nodes. // Or normal arraycopy for object arrays case. // // Set AddP's base (Allocate) as not scalar replaceable since // pointer to the base (with offset) is passed as argument. // arg = get_addp_base(arg); } PointsToNode* arg_ptn = ptnode_adr(arg->_idx); assert(arg_ptn != NULL, "should be registered"); PointsToNode::EscapeState arg_esc = arg_ptn->escape_state(); if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) { assert(aat == Type::TOP || aat == TypePtr::NULL_PTR || aat->isa_ptr() != NULL, "expecting an Ptr"); bool arg_has_oops = aat->isa_oopptr() && (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() || (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass())); if (i == TypeFunc::Parms) { src_has_oops = arg_has_oops; } // // src or dst could be j.l.Object when other is basic type array: // // arraycopy(char[],0,Object*,0,size); // arraycopy(Object*,0,char[],0,size); // // Don't add edges in such cases. // bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy && arg_has_oops && (i > TypeFunc::Parms); #ifdef ASSERT if (!(is_arraycopy || call->as_CallLeaf()->_name != NULL && (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 || strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 )) ) { call->dump(); assert(false, "EA: unexpected CallLeaf"); } #endif // Always process arraycopy's destination object since // we need to add all possible edges to references in // source object. if (arg_esc >= PointsToNode::ArgEscape && !arg_is_arraycopy_dest) { continue; } set_escape_state(arg_ptn, PointsToNode::ArgEscape); if (arg_is_arraycopy_dest) { Node* src = call->in(TypeFunc::Parms); if (src->is_AddP()) { src = get_addp_base(src); } PointsToNode* src_ptn = ptnode_adr(src->_idx); assert(src_ptn != NULL, "should be registered"); if (arg_ptn != src_ptn) { // Special arraycopy edge: // A destination object's field can't have the source object // as base since objects escape states are not related. // Only escape state of destination object's fields affects // escape state of fields in source object. add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn); } } } } break; } case Op_CallStaticJava: { // For a static call, we know exactly what method is being called. // Use bytecode estimator to record the call's escape affects #ifdef ASSERT const char* name = call->as_CallStaticJava()->_name; assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only"); #endif ciMethod* meth = call->as_CallJava()->method(); BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL; // fall-through if not a Java method or no analyzer information if (call_analyzer != NULL) { PointsToNode* call_ptn = ptnode_adr(call->_idx); const TypeTuple* d = call->tf()->domain(); for (uint i = TypeFunc::Parms; i < d->cnt(); i++) { const Type* at = d->field_at(i); int k = i - TypeFunc::Parms; Node* arg = call->in(i); PointsToNode* arg_ptn = ptnode_adr(arg->_idx); if (at->isa_ptr() != NULL && call_analyzer->is_arg_returned(k)) { // The call returns arguments. if (call_ptn != NULL) { // Is call's result used? assert(call_ptn->is_LocalVar(), "node should be registered"); assert(arg_ptn != NULL, "node should be registered"); add_edge(call_ptn, arg_ptn); } } if (at->isa_oopptr() != NULL && arg_ptn->escape_state() < PointsToNode::GlobalEscape) { if (!call_analyzer->is_arg_stack(k)) { // The argument global escapes set_escape_state(arg_ptn, PointsToNode::GlobalEscape); } else { set_escape_state(arg_ptn, PointsToNode::ArgEscape); if (!call_analyzer->is_arg_local(k)) { // The argument itself doesn't escape, but any fields might set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape); } } } } if (call_ptn != NULL && call_ptn->is_LocalVar()) { // The call returns arguments. assert(call_ptn->edge_count() > 0, "sanity"); if (!call_analyzer->is_return_local()) { // Returns also unknown object. add_edge(call_ptn, phantom_obj); } } break; } } default: { // Fall-through here if not a Java method or no analyzer information // or some other type of call, assume the worst case: all arguments // globally escape. const TypeTuple* d = call->tf()->domain(); for (uint i = TypeFunc::Parms; i < d->cnt(); i++) { const Type* at = d->field_at(i); if (at->isa_oopptr() != NULL) { Node* arg = call->in(i); if (arg->is_AddP()) { arg = get_addp_base(arg); } assert(ptnode_adr(arg->_idx) != NULL, "should be defined already"); set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape); } } } } } // Finish Graph construction. bool ConnectionGraph::complete_connection_graph( GrowableArray& ptnodes_worklist, GrowableArray& non_escaped_worklist, GrowableArray& java_objects_worklist, GrowableArray& oop_fields_worklist) { // Normally only 1-3 passes needed to build Connection Graph depending // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler. // Set limit to 20 to catch situation when something did go wrong and // bailout Escape Analysis. // Also limit build time to 30 sec (60 in debug VM). #define CG_BUILD_ITER_LIMIT 20 #ifdef ASSERT #define CG_BUILD_TIME_LIMIT 60.0 #else #define CG_BUILD_TIME_LIMIT 30.0 #endif // Propagate GlobalEscape and ArgEscape escape states and check that // we still have non-escaping objects. The method pushs on _worklist // Field nodes which reference phantom_object. if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) { return false; // Nothing to do. } // Now propagate references to all JavaObject nodes. int java_objects_length = java_objects_worklist.length(); elapsedTimer time; int new_edges = 1; int iterations = 0; do { while ((new_edges > 0) && (iterations++ < CG_BUILD_ITER_LIMIT) && (time.seconds() < CG_BUILD_TIME_LIMIT)) { time.start(); new_edges = 0; // Propagate references to phantom_object for nodes pushed on _worklist // by find_non_escaped_objects() and find_field_value(). new_edges += add_java_object_edges(phantom_obj, false); for (int next = 0; next < java_objects_length; ++next) { JavaObjectNode* ptn = java_objects_worklist.at(next); new_edges += add_java_object_edges(ptn, true); } if (new_edges > 0) { // Update escape states on each iteration if graph was updated. if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) { return false; // Nothing to do. } } time.stop(); } if ((iterations < CG_BUILD_ITER_LIMIT) && (time.seconds() < CG_BUILD_TIME_LIMIT)) { time.start(); // Find fields which have unknown value. int fields_length = oop_fields_worklist.length(); for (int next = 0; next < fields_length; next++) { FieldNode* field = oop_fields_worklist.at(next); if (field->edge_count() == 0) { new_edges += find_field_value(field); // This code may added new edges to phantom_object. // Need an other cycle to propagate references to phantom_object. } } time.stop(); } else { new_edges = 0; // Bailout } } while (new_edges > 0); // Bailout if passed limits. if ((iterations >= CG_BUILD_ITER_LIMIT) || (time.seconds() >= CG_BUILD_TIME_LIMIT)) { Compile* C = _compile; if (C->log() != NULL) { C->log()->begin_elem("connectionGraph_bailout reason='reached "); C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time"); C->log()->end_elem(" limit'"); } assert(false, err_msg("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d", time.seconds(), iterations, nodes_size(), ptnodes_worklist.length())); // Possible infinite build_connection_graph loop, // bailout (no changes to ideal graph were made). return false; } #ifdef ASSERT if (Verbose && PrintEscapeAnalysis) { tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d", iterations, nodes_size(), ptnodes_worklist.length()); } #endif #undef CG_BUILD_ITER_LIMIT #undef CG_BUILD_TIME_LIMIT // Find fields initialized by NULL for non-escaping Allocations. int non_escaped_length = non_escaped_worklist.length(); for (int next = 0; next < non_escaped_length; next++) { JavaObjectNode* ptn = non_escaped_worklist.at(next); PointsToNode::EscapeState es = ptn->escape_state(); assert(es <= PointsToNode::ArgEscape, "sanity"); if (es == PointsToNode::NoEscape) { if (find_init_values(ptn, null_obj, _igvn) > 0) { // Adding references to NULL object does not change escape states // since it does not escape. Also no fields are added to NULL object. add_java_object_edges(null_obj, false); } } Node* n = ptn->ideal_node(); if (n->is_Allocate()) { // The object allocated by this Allocate node will never be // seen by an other thread. Mark it so that when it is // expanded no MemBarStoreStore is added. InitializeNode* ini = n->as_Allocate()->initialization(); if (ini != NULL) ini->set_does_not_escape(); } } return true; // Finished graph construction. } // Propagate GlobalEscape and ArgEscape escape states to all nodes // and check that we still have non-escaping java objects. bool ConnectionGraph::find_non_escaped_objects(GrowableArray& ptnodes_worklist, GrowableArray& non_escaped_worklist) { GrowableArray escape_worklist; // First, put all nodes with GlobalEscape and ArgEscape states on worklist. int ptnodes_length = ptnodes_worklist.length(); for (int next = 0; next < ptnodes_length; ++next) { PointsToNode* ptn = ptnodes_worklist.at(next); if (ptn->escape_state() >= PointsToNode::ArgEscape || ptn->fields_escape_state() >= PointsToNode::ArgEscape) { escape_worklist.push(ptn); } } // Set escape states to referenced nodes (edges list). while (escape_worklist.length() > 0) { PointsToNode* ptn = escape_worklist.pop(); PointsToNode::EscapeState es = ptn->escape_state(); PointsToNode::EscapeState field_es = ptn->fields_escape_state(); if (ptn->is_Field() && ptn->as_Field()->is_oop() && es >= PointsToNode::ArgEscape) { // GlobalEscape or ArgEscape state of field means it has unknown value. if (add_edge(ptn, phantom_obj)) { // New edge was added add_field_uses_to_worklist(ptn->as_Field()); } } for (EdgeIterator i(ptn); i.has_next(); i.next()) { PointsToNode* e = i.get(); if (e->is_Arraycopy()) { assert(ptn->arraycopy_dst(), "sanity"); // Propagate only fields escape state through arraycopy edge. if (e->fields_escape_state() < field_es) { set_fields_escape_state(e, field_es); escape_worklist.push(e); } } else if (es >= field_es) { // fields_escape_state is also set to 'es' if it is less than 'es'. if (e->escape_state() < es) { set_escape_state(e, es); escape_worklist.push(e); } } else { // Propagate field escape state. bool es_changed = false; if (e->fields_escape_state() < field_es) { set_fields_escape_state(e, field_es); es_changed = true; } if ((e->escape_state() < field_es) && e->is_Field() && ptn->is_JavaObject() && e->as_Field()->is_oop()) { // Change escape state of referenced fileds. set_escape_state(e, field_es); es_changed = true;; } else if (e->escape_state() < es) { set_escape_state(e, es); es_changed = true;; } if (es_changed) { escape_worklist.push(e); } } } } // Remove escaped objects from non_escaped list. for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) { JavaObjectNode* ptn = non_escaped_worklist.at(next); if (ptn->escape_state() >= PointsToNode::GlobalEscape) { non_escaped_worklist.delete_at(next); } if (ptn->escape_state() == PointsToNode::NoEscape) { // Find fields in non-escaped allocations which have unknown value. find_init_values(ptn, phantom_obj, NULL); } } return (non_escaped_worklist.length() > 0); } // Add all references to JavaObject node by walking over all uses. int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) { int new_edges = 0; if (populate_worklist) { // Populate _worklist by uses of jobj's uses. for (UseIterator i(jobj); i.has_next(); i.next()) { PointsToNode* use = i.get(); if (use->is_Arraycopy()) continue; add_uses_to_worklist(use); if (use->is_Field() && use->as_Field()->is_oop()) { // Put on worklist all field's uses (loads) and // related field nodes (same base and offset). add_field_uses_to_worklist(use->as_Field()); } } } while(_worklist.length() > 0) { PointsToNode* use = _worklist.pop(); if (PointsToNode::is_base_use(use)) { // Add reference from jobj to field and from field to jobj (field's base). use = PointsToNode::get_use_node(use)->as_Field(); if (add_base(use->as_Field(), jobj)) { new_edges++; } continue; } assert(!use->is_JavaObject(), "sanity"); if (use->is_Arraycopy()) { if (jobj == null_obj) // NULL object does not have field edges continue; // Added edge from Arraycopy node to arraycopy's source java object if (add_edge(use, jobj)) { jobj->set_arraycopy_src(); new_edges++; } // and stop here. continue; } if (!add_edge(use, jobj)) continue; // No new edge added, there was such edge already. new_edges++; if (use->is_LocalVar()) { add_uses_to_worklist(use); if (use->arraycopy_dst()) { for (EdgeIterator i(use); i.has_next(); i.next()) { PointsToNode* e = i.get(); if (e->is_Arraycopy()) { if (jobj == null_obj) // NULL object does not have field edges continue; // Add edge from arraycopy's destination java object to Arraycopy node. if (add_edge(jobj, e)) { new_edges++; jobj->set_arraycopy_dst(); } } } } } else { // Added new edge to stored in field values. // Put on worklist all field's uses (loads) and // related field nodes (same base and offset). add_field_uses_to_worklist(use->as_Field()); } } return new_edges; } // Put on worklist all related field nodes. void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) { assert(field->is_oop(), "sanity"); int offset = field->offset(); add_uses_to_worklist(field); // Loop over all bases of this field and push on worklist Field nodes // with the same offset and base (since they may reference the same field). for (BaseIterator i(field); i.has_next(); i.next()) { PointsToNode* base = i.get(); add_fields_to_worklist(field, base); // Check if the base was source object of arraycopy and go over arraycopy's // destination objects since values stored to a field of source object are // accessable by uses (loads) of fields of destination objects. if (base->arraycopy_src()) { for (UseIterator j(base); j.has_next(); j.next()) { PointsToNode* arycp = j.get(); if (arycp->is_Arraycopy()) { for (UseIterator k(arycp); k.has_next(); k.next()) { PointsToNode* abase = k.get(); if (abase->arraycopy_dst() && abase != base) { // Look for the same arracopy reference. add_fields_to_worklist(field, abase); } } } } } } } // Put on worklist all related field nodes. void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) { int offset = field->offset(); if (base->is_LocalVar()) { for (UseIterator j(base); j.has_next(); j.next()) { PointsToNode* f = j.get(); if (PointsToNode::is_base_use(f)) { // Field f = PointsToNode::get_use_node(f); if (f == field || !f->as_Field()->is_oop()) continue; int offs = f->as_Field()->offset(); if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) { add_to_worklist(f); } } } } else { assert(base->is_JavaObject(), "sanity"); if (// Skip phantom_object since it is only used to indicate that // this field's content globally escapes. (base != phantom_obj) && // NULL object node does not have fields. (base != null_obj)) { for (EdgeIterator i(base); i.has_next(); i.next()) { PointsToNode* f = i.get(); // Skip arraycopy edge since store to destination object field // does not update value in source object field. if (f->is_Arraycopy()) { assert(base->arraycopy_dst(), "sanity"); continue; } if (f == field || !f->as_Field()->is_oop()) continue; int offs = f->as_Field()->offset(); if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) { add_to_worklist(f); } } } } } // Find fields which have unknown value. int ConnectionGraph::find_field_value(FieldNode* field) { // Escaped fields should have init value already. assert(field->escape_state() == PointsToNode::NoEscape, "sanity"); int new_edges = 0; for (BaseIterator i(field); i.has_next(); i.next()) { PointsToNode* base = i.get(); if (base->is_JavaObject()) { // Skip Allocate's fields which will be processed later. if (base->ideal_node()->is_Allocate()) return 0; assert(base == null_obj, "only NULL ptr base expected here"); } } if (add_edge(field, phantom_obj)) { // New edge was added new_edges++; add_field_uses_to_worklist(field); } return new_edges; } // Find fields initializing values for allocations. int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) { assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only"); int new_edges = 0; Node* alloc = pta->ideal_node(); if (init_val == phantom_obj) { // Do nothing for Allocate nodes since its fields values are "known". if (alloc->is_Allocate()) return 0; assert(alloc->as_CallStaticJava(), "sanity"); #ifdef ASSERT if (alloc->as_CallStaticJava()->method() == NULL) { const char* name = alloc->as_CallStaticJava()->_name; assert(strncmp(name, "_multianewarray", 15) == 0, "sanity"); } #endif // Non-escaped allocation returned from Java or runtime call have // unknown values in fields. for (EdgeIterator i(pta); i.has_next(); i.next()) { PointsToNode* ptn = i.get(); if (ptn->is_Field() && ptn->as_Field()->is_oop()) { if (add_edge(ptn, phantom_obj)) { // New edge was added new_edges++; add_field_uses_to_worklist(ptn->as_Field()); } } } return new_edges; } assert(init_val == null_obj, "sanity"); // Do nothing for Call nodes since its fields values are unknown. if (!alloc->is_Allocate()) return 0; InitializeNode* ini = alloc->as_Allocate()->initialization(); Compile* C = _compile; bool visited_bottom_offset = false; GrowableArray offsets_worklist; // Check if an oop field's initializing value is recorded and add // a corresponding NULL if field's value if it is not recorded. // Connection Graph does not record a default initialization by NULL // captured by Initialize node. // for (EdgeIterator i(pta); i.has_next(); i.next()) { PointsToNode* ptn = i.get(); // Field (AddP) if (!ptn->is_Field() || !ptn->as_Field()->is_oop()) continue; // Not oop field int offset = ptn->as_Field()->offset(); if (offset == Type::OffsetBot) { if (!visited_bottom_offset) { // OffsetBot is used to reference array's element, // always add reference to NULL to all Field nodes since we don't // known which element is referenced. if (add_edge(ptn, null_obj)) { // New edge was added new_edges++; add_field_uses_to_worklist(ptn->as_Field()); visited_bottom_offset = true; } } } else { // Check only oop fields. const Type* adr_type = ptn->ideal_node()->as_AddP()->bottom_type(); if (adr_type->isa_rawptr()) { #ifdef ASSERT // Raw pointers are used for initializing stores so skip it // since it should be recorded already Node* base = get_addp_base(ptn->ideal_node()); assert(adr_type->isa_rawptr() && base->is_Proj() && (base->in(0) == alloc),"unexpected pointer type"); #endif continue; } if (!offsets_worklist.contains(offset)) { offsets_worklist.append(offset); Node* value = NULL; if (ini != NULL) { BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT; Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase); if (store != NULL && store->is_Store()) { value = store->in(MemNode::ValueIn); } else { // There could be initializing stores which follow allocation. // For example, a volatile field store is not collected // by Initialize node. // // Need to check for dependent loads to separate such stores from // stores which follow loads. For now, add initial value NULL so // that compare pointers optimization works correctly. } } if (value == NULL) { // A field's initializing value was not recorded. Add NULL. if (add_edge(ptn, null_obj)) { // New edge was added new_edges++; add_field_uses_to_worklist(ptn->as_Field()); } } } } } return new_edges; } // Adjust scalar_replaceable state after Connection Graph is built. void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) { // Search for non-escaping objects which are not scalar replaceable // and mark them to propagate the state to referenced objects. // 1. An object is not scalar replaceable if the field into which it is // stored has unknown offset (stored into unknown element of an array). // for (UseIterator i(jobj); i.has_next(); i.next()) { PointsToNode* use = i.get(); assert(!use->is_Arraycopy(), "sanity"); if (use->is_Field()) { FieldNode* field = use->as_Field(); assert(field->is_oop() && field->scalar_replaceable() && field->fields_escape_state() == PointsToNode::NoEscape, "sanity"); if (field->offset() == Type::OffsetBot) { jobj->set_scalar_replaceable(false); return; } } assert(use->is_Field() || use->is_LocalVar(), "sanity"); // 2. An object is not scalar replaceable if it is merged with other objects. for (EdgeIterator j(use); j.has_next(); j.next()) { PointsToNode* ptn = j.get(); if (ptn->is_JavaObject() && ptn != jobj) { // Mark all objects. jobj->set_scalar_replaceable(false); ptn->set_scalar_replaceable(false); } } if (!jobj->scalar_replaceable()) { return; } } for (EdgeIterator j(jobj); j.has_next(); j.next()) { // Non-escaping object node should point only to field nodes. FieldNode* field = j.get()->as_Field(); int offset = field->as_Field()->offset(); // 3. An object is not scalar replaceable if it has a field with unknown // offset (array's element is accessed in loop). if (offset == Type::OffsetBot) { jobj->set_scalar_replaceable(false); return; } // 4. Currently an object is not scalar replaceable if a LoadStore node // access its field since the field value is unknown after it. // Node* n = field->ideal_node(); for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { if (n->fast_out(i)->is_LoadStore()) { jobj->set_scalar_replaceable(false); return; } } // 5. Or the address may point to more then one object. This may produce // the false positive result (set not scalar replaceable) // since the flow-insensitive escape analysis can't separate // the case when stores overwrite the field's value from the case // when stores happened on different control branches. // // Note: it will disable scalar replacement in some cases: // // Point p[] = new Point[1]; // p[0] = new Point(); // Will be not scalar replaced // // but it will save us from incorrect optimizations in next cases: // // Point p[] = new Point[1]; // if ( x ) p[0] = new Point(); // Will be not scalar replaced // if (field->base_count() > 1) { for (BaseIterator i(field); i.has_next(); i.next()) { PointsToNode* base = i.get(); // Don't take into account LocalVar nodes which // may point to only one object which should be also // this field's base by now. if (base->is_JavaObject() && base != jobj) { // Mark all bases. jobj->set_scalar_replaceable(false); base->set_scalar_replaceable(false); } } } } } #ifdef ASSERT void ConnectionGraph::verify_connection_graph( GrowableArray& ptnodes_worklist, GrowableArray& non_escaped_worklist, GrowableArray& java_objects_worklist, GrowableArray& addp_worklist) { // Verify that graph is complete - no new edges could be added. int java_objects_length = java_objects_worklist.length(); int non_escaped_length = non_escaped_worklist.length(); int new_edges = 0; for (int next = 0; next < java_objects_length; ++next) { JavaObjectNode* ptn = java_objects_worklist.at(next); new_edges += add_java_object_edges(ptn, true); } assert(new_edges == 0, "graph was not complete"); // Verify that escape state is final. int length = non_escaped_worklist.length(); find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist); assert((non_escaped_length == non_escaped_worklist.length()) && (non_escaped_length == length) && (_worklist.length() == 0), "escape state was not final"); // Verify fields information. int addp_length = addp_worklist.length(); for (int next = 0; next < addp_length; ++next ) { Node* n = addp_worklist.at(next); FieldNode* field = ptnode_adr(n->_idx)->as_Field(); if (field->is_oop()) { // Verify that field has all bases Node* base = get_addp_base(n); PointsToNode* ptn = ptnode_adr(base->_idx); if (ptn->is_JavaObject()) { assert(field->has_base(ptn->as_JavaObject()), "sanity"); } else { assert(ptn->is_LocalVar(), "sanity"); for (EdgeIterator i(ptn); i.has_next(); i.next()) { PointsToNode* e = i.get(); if (e->is_JavaObject()) { assert(field->has_base(e->as_JavaObject()), "sanity"); } } } // Verify that all fields have initializing values. if (field->edge_count() == 0) { field->dump(); assert(field->edge_count() > 0, "sanity"); } } } } #endif // Optimize ideal graph. void ConnectionGraph::optimize_ideal_graph(GrowableArray& ptr_cmp_worklist, GrowableArray& storestore_worklist) { Compile* C = _compile; PhaseIterGVN* igvn = _igvn; if (EliminateLocks) { // Mark locks before changing ideal graph. int cnt = C->macro_count(); for( int i=0; i < cnt; i++ ) { Node *n = C->macro_node(i); if (n->is_AbstractLock()) { // Lock and Unlock nodes AbstractLockNode* alock = n->as_AbstractLock(); if (!alock->is_non_esc_obj()) { if (not_global_escape(alock->obj_node())) { assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity"); // The lock could be marked eliminated by lock coarsening // code during first IGVN before EA. Replace coarsened flag // to eliminate all associated locks/unlocks. alock->set_non_esc_obj(); } } } } } if (OptimizePtrCompare) { // Add ConI(#CC_GT) and ConI(#CC_EQ). _pcmp_neq = igvn->makecon(TypeInt::CC_GT); _pcmp_eq = igvn->makecon(TypeInt::CC_EQ); // Optimize objects compare. while (ptr_cmp_worklist.length() != 0) { Node *n = ptr_cmp_worklist.pop(); Node *res = optimize_ptr_compare(n); if (res != NULL) { #ifndef PRODUCT if (PrintOptimizePtrCompare) { tty->print_cr("++++ Replaced: %d %s(%d,%d) --> %s", n->_idx, (n->Opcode() == Op_CmpP ? "CmpP" : "CmpN"), n->in(1)->_idx, n->in(2)->_idx, (res == _pcmp_eq ? "EQ" : "NotEQ")); if (Verbose) { n->dump(1); } } #endif igvn->replace_node(n, res); } } // cleanup if (_pcmp_neq->outcnt() == 0) igvn->hash_delete(_pcmp_neq); if (_pcmp_eq->outcnt() == 0) igvn->hash_delete(_pcmp_eq); } // For MemBarStoreStore nodes added in library_call.cpp, check // escape status of associated AllocateNode and optimize out // MemBarStoreStore node if the allocated object never escapes. while (storestore_worklist.length() != 0) { Node *n = storestore_worklist.pop(); MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore(); Node *alloc = storestore->in(MemBarNode::Precedent)->in(0); assert (alloc->is_Allocate(), "storestore should point to AllocateNode"); if (not_global_escape(alloc)) { MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot); mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory)); mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control)); igvn->register_new_node_with_optimizer(mb); igvn->replace_node(storestore, mb); } } } // Optimize objects compare. Node* ConnectionGraph::optimize_ptr_compare(Node* n) { assert(OptimizePtrCompare, "sanity"); PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx); PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx); JavaObjectNode* jobj1 = unique_java_object(n->in(1)); JavaObjectNode* jobj2 = unique_java_object(n->in(2)); assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity"); assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity"); // Check simple cases first. if (jobj1 != NULL) { if (jobj1->escape_state() == PointsToNode::NoEscape) { if (jobj1 == jobj2) { // Comparing the same not escaping object. return _pcmp_eq; } Node* obj = jobj1->ideal_node(); // Comparing not escaping allocation. if ((obj->is_Allocate() || obj->is_CallStaticJava()) && !ptn2->points_to(jobj1)) { return _pcmp_neq; // This includes nullness check. } } } if (jobj2 != NULL) { if (jobj2->escape_state() == PointsToNode::NoEscape) { Node* obj = jobj2->ideal_node(); // Comparing not escaping allocation. if ((obj->is_Allocate() || obj->is_CallStaticJava()) && !ptn1->points_to(jobj2)) { return _pcmp_neq; // This includes nullness check. } } } if (jobj1 != NULL && jobj1 != phantom_obj && jobj2 != NULL && jobj2 != phantom_obj && jobj1->ideal_node()->is_Con() && jobj2->ideal_node()->is_Con()) { // Klass or String constants compare. Need to be careful with // compressed pointers - compare types of ConN and ConP instead of nodes. const Type* t1 = jobj1->ideal_node()->bottom_type()->make_ptr(); const Type* t2 = jobj2->ideal_node()->bottom_type()->make_ptr(); assert(t1 != NULL && t2 != NULL, "sanity"); if (t1->make_ptr() == t2->make_ptr()) { return _pcmp_eq; } else { return _pcmp_neq; } } if (ptn1->meet(ptn2)) { return NULL; // Sets are not disjoint } // Sets are disjoint. bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj); bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj); bool set1_has_null_ptr = ptn1->points_to(null_obj); bool set2_has_null_ptr = ptn2->points_to(null_obj); if (set1_has_unknown_ptr && set2_has_null_ptr || set2_has_unknown_ptr && set1_has_null_ptr) { // Check nullness of unknown object. return NULL; } // Disjointness by itself is not sufficient since // alias analysis is not complete for escaped objects. // Disjoint sets are definitely unrelated only when // at least one set has only not escaping allocations. if (!set1_has_unknown_ptr && !set1_has_null_ptr) { if (ptn1->non_escaping_allocation()) { return _pcmp_neq; } } if (!set2_has_unknown_ptr && !set2_has_null_ptr) { if (ptn2->non_escaping_allocation()) { return _pcmp_neq; } } return NULL; } // Connection Graph constuction functions. void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) { PointsToNode* ptadr = _nodes.at(n->_idx); if (ptadr != NULL) { assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity"); return; } Compile* C = _compile; ptadr = new (C->comp_arena()) LocalVarNode(C, n, es); _nodes.at_put(n->_idx, ptadr); } void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) { PointsToNode* ptadr = _nodes.at(n->_idx); if (ptadr != NULL) { assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity"); return; } Compile* C = _compile; ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es); _nodes.at_put(n->_idx, ptadr); } void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) { PointsToNode* ptadr = _nodes.at(n->_idx); if (ptadr != NULL) { assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity"); return; } Compile* C = _compile; bool is_oop = is_oop_field(n, offset); FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop); _nodes.at_put(n->_idx, field); } void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es, PointsToNode* src, PointsToNode* dst) { assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar"); assert((src != null_obj) && (dst != null_obj), "not for ConP NULL"); PointsToNode* ptadr = _nodes.at(n->_idx); if (ptadr != NULL) { assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity"); return; } Compile* C = _compile; ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es); _nodes.at_put(n->_idx, ptadr); // Add edge from arraycopy node to source object. (void)add_edge(ptadr, src); src->set_arraycopy_src(); // Add edge from destination object to arraycopy node. (void)add_edge(dst, ptadr); dst->set_arraycopy_dst(); } bool ConnectionGraph::is_oop_field(Node* n, int offset) { const Type* adr_type = n->as_AddP()->bottom_type(); BasicType bt = T_INT; if (offset == Type::OffsetBot) { // Check only oop fields. if (!adr_type->isa_aryptr() || (adr_type->isa_aryptr()->klass() == NULL) || adr_type->isa_aryptr()->klass()->is_obj_array_klass()) { // OffsetBot is used to reference array's element. Ignore first AddP. if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) { bt = T_OBJECT; } } } else if (offset != oopDesc::klass_offset_in_bytes()) { if (adr_type->isa_instptr()) { ciField* field = _compile->alias_type(adr_type->isa_instptr())->field(); if (field != NULL) { bt = field->layout_type(); } else { // Ignore non field load (for example, klass load) } } else if (adr_type->isa_aryptr()) { if (offset == arrayOopDesc::length_offset_in_bytes()) { // Ignore array length load. } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) { // Ignore first AddP. } else { const Type* elemtype = adr_type->isa_aryptr()->elem(); bt = elemtype->array_element_basic_type(); } } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) { // Allocation initialization, ThreadLocal field access, unsafe access for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { int opcode = n->fast_out(i)->Opcode(); if (opcode == Op_StoreP || opcode == Op_LoadP || opcode == Op_StoreN || opcode == Op_LoadN) { bt = T_OBJECT; } } } } return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY); } // Returns unique pointed java object or NULL. JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) { assert(!_collecting, "should not call when contructed graph"); // If the node was created after the escape computation we can't answer. uint idx = n->_idx; if (idx >= nodes_size()) { return NULL; } PointsToNode* ptn = ptnode_adr(idx); if (ptn->is_JavaObject()) { return ptn->as_JavaObject(); } assert(ptn->is_LocalVar(), "sanity"); // Check all java objects it points to. JavaObjectNode* jobj = NULL; for (EdgeIterator i(ptn); i.has_next(); i.next()) { PointsToNode* e = i.get(); if (e->is_JavaObject()) { if (jobj == NULL) { jobj = e->as_JavaObject(); } else if (jobj != e) { return NULL; } } } return jobj; } // Return true if this node points only to non-escaping allocations. bool PointsToNode::non_escaping_allocation() { if (is_JavaObject()) { Node* n = ideal_node(); if (n->is_Allocate() || n->is_CallStaticJava()) { return (escape_state() == PointsToNode::NoEscape); } else { return false; } } assert(is_LocalVar(), "sanity"); // Check all java objects it points to. for (EdgeIterator i(this); i.has_next(); i.next()) { PointsToNode* e = i.get(); if (e->is_JavaObject()) { Node* n = e->ideal_node(); if ((e->escape_state() != PointsToNode::NoEscape) || !(n->is_Allocate() || n->is_CallStaticJava())) { return false; } } } return true; } // Return true if we know the node does not escape globally. bool ConnectionGraph::not_global_escape(Node *n) { assert(!_collecting, "should not call during graph construction"); // If the node was created after the escape computation we can't answer. uint idx = n->_idx; if (idx >= nodes_size()) { return false; } PointsToNode* ptn = ptnode_adr(idx); PointsToNode::EscapeState es = ptn->escape_state(); // If we have already computed a value, return it. if (es >= PointsToNode::GlobalEscape) return false; if (ptn->is_JavaObject()) { return true; // (es < PointsToNode::GlobalEscape); } assert(ptn->is_LocalVar(), "sanity"); // Check all java objects it points to. for (EdgeIterator i(ptn); i.has_next(); i.next()) { if (i.get()->escape_state() >= PointsToNode::GlobalEscape) return false; } return true; } // Helper functions // Return true if this node points to specified node or nodes it points to. bool PointsToNode::points_to(JavaObjectNode* ptn) const { if (is_JavaObject()) { return (this == ptn); } assert(is_LocalVar(), "sanity"); for (EdgeIterator i(this); i.has_next(); i.next()) { if (i.get() == ptn) return true; } return false; } // Return true if one node points to an other. bool PointsToNode::meet(PointsToNode* ptn) { if (this == ptn) { return true; } else if (ptn->is_JavaObject()) { return this->points_to(ptn->as_JavaObject()); } else if (this->is_JavaObject()) { return ptn->points_to(this->as_JavaObject()); } assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity"); int ptn_count = ptn->edge_count(); for (EdgeIterator i(this); i.has_next(); i.next()) { PointsToNode* this_e = i.get(); for (int j = 0; j < ptn_count; j++) { if (this_e == ptn->edge(j)) return true; } } return false; } #ifdef ASSERT // Return true if bases point to this java object. bool FieldNode::has_base(JavaObjectNode* jobj) const { for (BaseIterator i(this); i.has_next(); i.next()) { if (i.get() == jobj) return true; } return false; } #endif int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) { const Type *adr_type = phase->type(adr); if (adr->is_AddP() && adr_type->isa_oopptr() == NULL && adr->in(AddPNode::Address)->is_Proj() && adr->in(AddPNode::Address)->in(0)->is_Allocate()) { // We are computing a raw address for a store captured by an Initialize // compute an appropriate address type. AddP cases #3 and #5 (see below). int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot); assert(offs != Type::OffsetBot || adr->in(AddPNode::Address)->in(0)->is_AllocateArray(), "offset must be a constant or it is initialization of array"); return offs; } const TypePtr *t_ptr = adr_type->isa_ptr(); assert(t_ptr != NULL, "must be a pointer type"); return t_ptr->offset(); } Node* ConnectionGraph::get_addp_base(Node *addp) { assert(addp->is_AddP(), "must be AddP"); // // AddP cases for Base and Address inputs: // case #1. Direct object's field reference: // Allocate // | // Proj #5 ( oop result ) // | // CheckCastPP (cast to instance type) // | | // AddP ( base == address ) // // case #2. Indirect object's field reference: // Phi // | // CastPP (cast to instance type) // | | // AddP ( base == address ) // // case #3. Raw object's field reference for Initialize node: // Allocate // | // Proj #5 ( oop result ) // top | // \ | // AddP ( base == top ) // // case #4. Array's element reference: // {CheckCastPP | CastPP} // | | | // | AddP ( array's element offset ) // | | // AddP ( array's offset ) // // case #5. Raw object's field reference for arraycopy stub call: // The inline_native_clone() case when the arraycopy stub is called // after the allocation before Initialize and CheckCastPP nodes. // Allocate // | // Proj #5 ( oop result ) // | | // AddP ( base == address ) // // case #6. Constant Pool, ThreadLocal, CastX2P or // Raw object's field reference: // {ConP, ThreadLocal, CastX2P, raw Load} // top | // \ | // AddP ( base == top ) // // case #7. Klass's field reference. // LoadKlass // | | // AddP ( base == address ) // // case #8. narrow Klass's field reference. // LoadNKlass // | // DecodeN // | | // AddP ( base == address ) // Node *base = addp->in(AddPNode::Base); if (base->uncast()->is_top()) { // The AddP case #3 and #6. base = addp->in(AddPNode::Address); while (base->is_AddP()) { // Case #6 (unsafe access) may have several chained AddP nodes. assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only"); base = base->in(AddPNode::Address); } Node* uncast_base = base->uncast(); int opcode = uncast_base->Opcode(); assert(opcode == Op_ConP || opcode == Op_ThreadLocal || opcode == Op_CastX2P || uncast_base->is_DecodeN() || (uncast_base->is_Mem() && uncast_base->bottom_type() == TypeRawPtr::NOTNULL) || (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity"); } return base; } Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) { assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes"); Node* addp2 = addp->raw_out(0); if (addp->outcnt() == 1 && addp2->is_AddP() && addp2->in(AddPNode::Base) == n && addp2->in(AddPNode::Address) == addp) { assert(addp->in(AddPNode::Base) == n, "expecting the same base"); // // Find array's offset to push it on worklist first and // as result process an array's element offset first (pushed second) // to avoid CastPP for the array's offset. // Otherwise the inserted CastPP (LocalVar) will point to what // the AddP (Field) points to. Which would be wrong since // the algorithm expects the CastPP has the same point as // as AddP's base CheckCastPP (LocalVar). // // ArrayAllocation // | // CheckCastPP // | // memProj (from ArrayAllocation CheckCastPP) // | || // | || Int (element index) // | || | ConI (log(element size)) // | || | / // | || LShift // | || / // | AddP (array's element offset) // | | // | | ConI (array's offset: #12(32-bits) or #24(64-bits)) // | / / // AddP (array's offset) // | // Load/Store (memory operation on array's element) // return addp2; } return NULL; } // // Adjust the type and inputs of an AddP which computes the // address of a field of an instance // bool ConnectionGraph::split_AddP(Node *addp, Node *base) { PhaseGVN* igvn = _igvn; const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr(); assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr"); const TypeOopPtr *t = igvn->type(addp)->isa_oopptr(); if (t == NULL) { // We are computing a raw address for a store captured by an Initialize // compute an appropriate address type (cases #3 and #5). assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer"); assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation"); intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot); assert(offs != Type::OffsetBot, "offset must be a constant"); t = base_t->add_offset(offs)->is_oopptr(); } int inst_id = base_t->instance_id(); assert(!t->is_known_instance() || t->instance_id() == inst_id, "old type must be non-instance or match new type"); // The type 't' could be subclass of 'base_t'. // As result t->offset() could be large then base_t's size and it will // cause the failure in add_offset() with narrow oops since TypeOopPtr() // constructor verifies correctness of the offset. // // It could happened on subclass's branch (from the type profiling // inlining) which was not eliminated during parsing since the exactness // of the allocation type was not propagated to the subclass type check. // // Or the type 't' could be not related to 'base_t' at all. // It could happened when CHA type is different from MDO type on a dead path // (for example, from instanceof check) which is not collapsed during parsing. // // Do nothing for such AddP node and don't process its users since // this code branch will go away. // if (!t->is_known_instance() && !base_t->klass()->is_subtype_of(t->klass())) { return false; // bail out } const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr(); // Do NOT remove the next line: ensure a new alias index is allocated // for the instance type. Note: C++ will not remove it since the call // has side effect. int alias_idx = _compile->get_alias_index(tinst); igvn->set_type(addp, tinst); // record the allocation in the node map set_map(addp, get_map(base->_idx)); // Set addp's Base and Address to 'base'. Node *abase = addp->in(AddPNode::Base); Node *adr = addp->in(AddPNode::Address); if (adr->is_Proj() && adr->in(0)->is_Allocate() && adr->in(0)->_idx == (uint)inst_id) { // Skip AddP cases #3 and #5. } else { assert(!abase->is_top(), "sanity"); // AddP case #3 if (abase != base) { igvn->hash_delete(addp); addp->set_req(AddPNode::Base, base); if (abase == adr) { addp->set_req(AddPNode::Address, base); } else { // AddP case #4 (adr is array's element offset AddP node) #ifdef ASSERT const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr(); assert(adr->is_AddP() && atype != NULL && atype->instance_id() == inst_id, "array's element offset should be processed first"); #endif } igvn->hash_insert(addp); } } // Put on IGVN worklist since at least addp's type was changed above. record_for_optimizer(addp); return true; } // // Create a new version of orig_phi if necessary. Returns either the newly // created phi or an existing phi. Sets create_new to indicate whether a new // phi was created. Cache the last newly created phi in the node map. // PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray &orig_phi_worklist, bool &new_created) { Compile *C = _compile; PhaseGVN* igvn = _igvn; new_created = false; int phi_alias_idx = C->get_alias_index(orig_phi->adr_type()); // nothing to do if orig_phi is bottom memory or matches alias_idx if (phi_alias_idx == alias_idx) { return orig_phi; } // Have we recently created a Phi for this alias index? PhiNode *result = get_map_phi(orig_phi->_idx); if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) { return result; } // Previous check may fail when the same wide memory Phi was split into Phis // for different memory slices. Search all Phis for this region. if (result != NULL) { Node* region = orig_phi->in(0); for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { Node* phi = region->fast_out(i); if (phi->is_Phi() && C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) { assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice"); return phi->as_Phi(); } } } if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) { if (C->do_escape_analysis() == true && !C->failing()) { // Retry compilation without escape analysis. // If this is the first failure, the sentinel string will "stick" // to the Compile object, and the C2Compiler will see it and retry. C->record_failure(C2Compiler::retry_no_escape_analysis()); } return NULL; } orig_phi_worklist.append_if_missing(orig_phi); const TypePtr *atype = C->get_adr_type(alias_idx); result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype); C->copy_node_notes_to(result, orig_phi); igvn->set_type(result, result->bottom_type()); record_for_optimizer(result); set_map(orig_phi, result); new_created = true; return result; } // // Return a new version of Memory Phi "orig_phi" with the inputs having the // specified alias index. // PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray &orig_phi_worklist) { assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory"); Compile *C = _compile; PhaseGVN* igvn = _igvn; bool new_phi_created; PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created); if (!new_phi_created) { return result; } GrowableArray phi_list; GrowableArray cur_input; PhiNode *phi = orig_phi; uint idx = 1; bool finished = false; while(!finished) { while (idx < phi->req()) { Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist); if (mem != NULL && mem->is_Phi()) { PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created); if (new_phi_created) { // found an phi for which we created a new split, push current one on worklist and begin // processing new one phi_list.push(phi); cur_input.push(idx); phi = mem->as_Phi(); result = newphi; idx = 1; continue; } else { mem = newphi; } } if (C->failing()) { return NULL; } result->set_req(idx++, mem); } #ifdef ASSERT // verify that the new Phi has an input for each input of the original assert( phi->req() == result->req(), "must have same number of inputs."); assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match"); #endif // Check if all new phi's inputs have specified alias index. // Otherwise use old phi. for (uint i = 1; i < phi->req(); i++) { Node* in = result->in(i); assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond."); } // we have finished processing a Phi, see if there are any more to do finished = (phi_list.length() == 0 ); if (!finished) { phi = phi_list.pop(); idx = cur_input.pop(); PhiNode *prev_result = get_map_phi(phi->_idx); prev_result->set_req(idx++, result); result = prev_result; } } return result; } // // The next methods are derived from methods in MemNode. // Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) { Node *mem = mmem; // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally // means an array I have not precisely typed yet. Do not do any // alias stuff with it any time soon. if (toop->base() != Type::AnyPtr && !(toop->klass() != NULL && toop->klass()->is_java_lang_Object() && toop->offset() == Type::OffsetBot)) { mem = mmem->memory_at(alias_idx); // Update input if it is progress over what we have now } return mem; } // // Move memory users to their memory slices. // void ConnectionGraph::move_inst_mem(Node* n, GrowableArray &orig_phis) { Compile* C = _compile; PhaseGVN* igvn = _igvn; const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr(); assert(tp != NULL, "ptr type"); int alias_idx = C->get_alias_index(tp); int general_idx = C->get_general_index(alias_idx); // Move users first for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { Node* use = n->fast_out(i); if (use->is_MergeMem()) { MergeMemNode* mmem = use->as_MergeMem(); assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice"); if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) { continue; // Nothing to do } // Replace previous general reference to mem node. uint orig_uniq = C->unique(); Node* m = find_inst_mem(n, general_idx, orig_phis); assert(orig_uniq == C->unique(), "no new nodes"); mmem->set_memory_at(general_idx, m); --imax; --i; } else if (use->is_MemBar()) { assert(!use->is_Initialize(), "initializing stores should not be moved"); if (use->req() > MemBarNode::Precedent && use->in(MemBarNode::Precedent) == n) { // Don't move related membars. record_for_optimizer(use); continue; } tp = use->as_MemBar()->adr_type()->isa_ptr(); if (tp != NULL && C->get_alias_index(tp) == alias_idx || alias_idx == general_idx) { continue; // Nothing to do } // Move to general memory slice. uint orig_uniq = C->unique(); Node* m = find_inst_mem(n, general_idx, orig_phis); assert(orig_uniq == C->unique(), "no new nodes"); igvn->hash_delete(use); imax -= use->replace_edge(n, m); igvn->hash_insert(use); record_for_optimizer(use); --i; #ifdef ASSERT } else if (use->is_Mem()) { if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) { // Don't move related cardmark. continue; } // Memory nodes should have new memory input. tp = igvn->type(use->in(MemNode::Address))->isa_ptr(); assert(tp != NULL, "ptr type"); int idx = C->get_alias_index(tp); assert(get_map(use->_idx) != NULL || idx == alias_idx, "Following memory nodes should have new memory input or be on the same memory slice"); } else if (use->is_Phi()) { // Phi nodes should be split and moved already. tp = use->as_Phi()->adr_type()->isa_ptr(); assert(tp != NULL, "ptr type"); int idx = C->get_alias_index(tp); assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice"); } else { use->dump(); assert(false, "should not be here"); #endif } } } // // Search memory chain of "mem" to find a MemNode whose address // is the specified alias index. // Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray &orig_phis) { if (orig_mem == NULL) return orig_mem; Compile* C = _compile; PhaseGVN* igvn = _igvn; const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr(); bool is_instance = (toop != NULL) && toop->is_known_instance(); Node *start_mem = C->start()->proj_out(TypeFunc::Memory); Node *prev = NULL; Node *result = orig_mem; while (prev != result) { prev = result; if (result == start_mem) break; // hit one of our sentinels if (result->is_Mem()) { const Type *at = igvn->type(result->in(MemNode::Address)); if (at == Type::TOP) break; // Dead assert (at->isa_ptr() != NULL, "pointer type required."); int idx = C->get_alias_index(at->is_ptr()); if (idx == alias_idx) break; // Found if (!is_instance && (at->isa_oopptr() == NULL || !at->is_oopptr()->is_known_instance())) { break; // Do not skip store to general memory slice. } result = result->in(MemNode::Memory); } if (!is_instance) continue; // don't search further for non-instance types // skip over a call which does not affect this memory slice if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) { Node *proj_in = result->in(0); if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) { break; // hit one of our sentinels } else if (proj_in->is_Call()) { CallNode *call = proj_in->as_Call(); if (!call->may_modify(toop, igvn)) { result = call->in(TypeFunc::Memory); } } else if (proj_in->is_Initialize()) { AllocateNode* alloc = proj_in->as_Initialize()->allocation(); // Stop if this is the initialization for the object instance which // which contains this memory slice, otherwise skip over it. if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) { result = proj_in->in(TypeFunc::Memory); } } else if (proj_in->is_MemBar()) { result = proj_in->in(TypeFunc::Memory); } } else if (result->is_MergeMem()) { MergeMemNode *mmem = result->as_MergeMem(); result = step_through_mergemem(mmem, alias_idx, toop); if (result == mmem->base_memory()) { // Didn't find instance memory, search through general slice recursively. result = mmem->memory_at(C->get_general_index(alias_idx)); result = find_inst_mem(result, alias_idx, orig_phis); if (C->failing()) { return NULL; } mmem->set_memory_at(alias_idx, result); } } else if (result->is_Phi() && C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) { Node *un = result->as_Phi()->unique_input(igvn); if (un != NULL) { orig_phis.append_if_missing(result->as_Phi()); result = un; } else { break; } } else if (result->is_ClearArray()) { if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) { // Can not bypass initialization of the instance // we are looking for. break; } // Otherwise skip it (the call updated 'result' value). } else if (result->Opcode() == Op_SCMemProj) { assert(result->in(0)->is_LoadStore(), "sanity"); const Type *at = igvn->type(result->in(0)->in(MemNode::Address)); if (at != Type::TOP) { assert (at->isa_ptr() != NULL, "pointer type required."); int idx = C->get_alias_index(at->is_ptr()); assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field"); break; } result = result->in(0)->in(MemNode::Memory); } } if (result->is_Phi()) { PhiNode *mphi = result->as_Phi(); assert(mphi->bottom_type() == Type::MEMORY, "memory phi required"); const TypePtr *t = mphi->adr_type(); if (!is_instance) { // Push all non-instance Phis on the orig_phis worklist to update inputs // during Phase 4 if needed. orig_phis.append_if_missing(mphi); } else if (C->get_alias_index(t) != alias_idx) { // Create a new Phi with the specified alias index type. result = split_memory_phi(mphi, alias_idx, orig_phis); } } // the result is either MemNode, PhiNode, InitializeNode. return result; } // // Convert the types of unescaped object to instance types where possible, // propagate the new type information through the graph, and update memory // edges and MergeMem inputs to reflect the new type. // // We start with allocations (and calls which may be allocations) on alloc_worklist. // The processing is done in 4 phases: // // Phase 1: Process possible allocations from alloc_worklist. Create instance // types for the CheckCastPP for allocations where possible. // Propagate the the new types through users as follows: // casts and Phi: push users on alloc_worklist // AddP: cast Base and Address inputs to the instance type // push any AddP users on alloc_worklist and push any memnode // users onto memnode_worklist. // Phase 2: Process MemNode's from memnode_worklist. compute new address type and // search the Memory chain for a store with the appropriate type // address type. If a Phi is found, create a new version with // the appropriate memory slices from each of the Phi inputs. // For stores, process the users as follows: // MemNode: push on memnode_worklist // MergeMem: push on mergemem_worklist // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice // moving the first node encountered of each instance type to the // the input corresponding to its alias index. // appropriate memory slice. // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes. // // In the following example, the CheckCastPP nodes are the cast of allocation // results and the allocation of node 29 is unescaped and eligible to be an // instance type. // // We start with: // // 7 Parm #memory // 10 ConI "12" // 19 CheckCastPP "Foo" // 20 AddP _ 19 19 10 Foo+12 alias_index=4 // 29 CheckCastPP "Foo" // 30 AddP _ 29 29 10 Foo+12 alias_index=4 // // 40 StoreP 25 7 20 ... alias_index=4 // 50 StoreP 35 40 30 ... alias_index=4 // 60 StoreP 45 50 20 ... alias_index=4 // 70 LoadP _ 60 30 ... alias_index=4 // 80 Phi 75 50 60 Memory alias_index=4 // 90 LoadP _ 80 30 ... alias_index=4 // 100 LoadP _ 80 20 ... alias_index=4 // // // Phase 1 creates an instance type for node 29 assigning it an instance id of 24 // and creating a new alias index for node 30. This gives: // // 7 Parm #memory // 10 ConI "12" // 19 CheckCastPP "Foo" // 20 AddP _ 19 19 10 Foo+12 alias_index=4 // 29 CheckCastPP "Foo" iid=24 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24 // // 40 StoreP 25 7 20 ... alias_index=4 // 50 StoreP 35 40 30 ... alias_index=6 // 60 StoreP 45 50 20 ... alias_index=4 // 70 LoadP _ 60 30 ... alias_index=6 // 80 Phi 75 50 60 Memory alias_index=4 // 90 LoadP _ 80 30 ... alias_index=6 // 100 LoadP _ 80 20 ... alias_index=4 // // In phase 2, new memory inputs are computed for the loads and stores, // And a new version of the phi is created. In phase 4, the inputs to // node 80 are updated and then the memory nodes are updated with the // values computed in phase 2. This results in: // // 7 Parm #memory // 10 ConI "12" // 19 CheckCastPP "Foo" // 20 AddP _ 19 19 10 Foo+12 alias_index=4 // 29 CheckCastPP "Foo" iid=24 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24 // // 40 StoreP 25 7 20 ... alias_index=4 // 50 StoreP 35 7 30 ... alias_index=6 // 60 StoreP 45 40 20 ... alias_index=4 // 70 LoadP _ 50 30 ... alias_index=6 // 80 Phi 75 40 60 Memory alias_index=4 // 120 Phi 75 50 50 Memory alias_index=6 // 90 LoadP _ 120 30 ... alias_index=6 // 100 LoadP _ 80 20 ... alias_index=4 // void ConnectionGraph::split_unique_types(GrowableArray &alloc_worklist) { GrowableArray memnode_worklist; GrowableArray orig_phis; PhaseIterGVN *igvn = _igvn; uint new_index_start = (uint) _compile->num_alias_types(); Arena* arena = Thread::current()->resource_area(); VectorSet visited(arena); ideal_nodes.clear(); // Reset for use with set_map/get_map. uint unique_old = _compile->unique(); // Phase 1: Process possible allocations from alloc_worklist. // Create instance types for the CheckCastPP for allocations where possible. // // (Note: don't forget to change the order of the second AddP node on // the alloc_worklist if the order of the worklist processing is changed, // see the comment in find_second_addp().) // while (alloc_worklist.length() != 0) { Node *n = alloc_worklist.pop(); uint ni = n->_idx; if (n->is_Call()) { CallNode *alloc = n->as_Call(); // copy escape information to call node PointsToNode* ptn = ptnode_adr(alloc->_idx); PointsToNode::EscapeState es = ptn->escape_state(); // We have an allocation or call which returns a Java object, // see if it is unescaped. if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable()) continue; // Find CheckCastPP for the allocate or for the return value of a call n = alloc->result_cast(); if (n == NULL) { // No uses except Initialize node if (alloc->is_Allocate()) { // Set the scalar_replaceable flag for allocation // so it could be eliminated if it has no uses. alloc->as_Allocate()->_is_scalar_replaceable = true; } continue; } if (!n->is_CheckCastPP()) { // not unique CheckCastPP. assert(!alloc->is_Allocate(), "allocation should have unique type"); continue; } // The inline code for Object.clone() casts the allocation result to // java.lang.Object and then to the actual type of the allocated // object. Detect this case and use the second cast. // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when // the allocation result is cast to java.lang.Object and then // to the actual Array type. if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL && (alloc->is_AllocateArray() || igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) { Node *cast2 = NULL; for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { Node *use = n->fast_out(i); if (use->is_CheckCastPP()) { cast2 = use; break; } } if (cast2 != NULL) { n = cast2; } else { // Non-scalar replaceable if the allocation type is unknown statically // (reflection allocation), the object can't be restored during // deoptimization without precise type. continue; } } if (alloc->is_Allocate()) { // Set the scalar_replaceable flag for allocation // so it could be eliminated. alloc->as_Allocate()->_is_scalar_replaceable = true; } set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state // in order for an object to be scalar-replaceable, it must be: // - a direct allocation (not a call returning an object) // - non-escaping // - eligible to be a unique type // - not determined to be ineligible by escape analysis set_map(alloc, n); set_map(n, alloc); const TypeOopPtr *t = igvn->type(n)->isa_oopptr(); if (t == NULL) continue; // not a TypeOopPtr const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni); igvn->hash_delete(n); igvn->set_type(n, tinst); n->raise_bottom_type(tinst); igvn->hash_insert(n); record_for_optimizer(n); if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) { // First, put on the worklist all Field edges from Connection Graph // which is more accurate then putting immediate users from Ideal Graph. for (EdgeIterator e(ptn); e.has_next(); e.next()) { PointsToNode* tgt = e.get(); Node* use = tgt->ideal_node(); assert(tgt->is_Field() && use->is_AddP(), "only AddP nodes are Field edges in CG"); if (use->outcnt() > 0) { // Don't process dead nodes Node* addp2 = find_second_addp(use, use->in(AddPNode::Base)); if (addp2 != NULL) { assert(alloc->is_AllocateArray(),"array allocation was expected"); alloc_worklist.append_if_missing(addp2); } alloc_worklist.append_if_missing(use); } } // An allocation may have an Initialize which has raw stores. Scan // the users of the raw allocation result and push AddP users // on alloc_worklist. Node *raw_result = alloc->proj_out(TypeFunc::Parms); assert (raw_result != NULL, "must have an allocation result"); for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) { Node *use = raw_result->fast_out(i); if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes Node* addp2 = find_second_addp(use, raw_result); if (addp2 != NULL) { assert(alloc->is_AllocateArray(),"array allocation was expected"); alloc_worklist.append_if_missing(addp2); } alloc_worklist.append_if_missing(use); } else if (use->is_MemBar()) { memnode_worklist.append_if_missing(use); } } } } else if (n->is_AddP()) { JavaObjectNode* jobj = unique_java_object(get_addp_base(n)); if (jobj == NULL || jobj == phantom_obj) { #ifdef ASSERT ptnode_adr(get_addp_base(n)->_idx)->dump(); ptnode_adr(n->_idx)->dump(); assert(jobj != NULL && jobj != phantom_obj, "escaped allocation"); #endif _compile->record_failure(C2Compiler::retry_no_escape_analysis()); return; } Node *base = get_map(jobj->idx()); // CheckCastPP node if (!split_AddP(n, base)) continue; // wrong type from dead path } else if (n->is_Phi() || n->is_CheckCastPP() || n->is_EncodeP() || n->is_DecodeN() || (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) { if (visited.test_set(n->_idx)) { assert(n->is_Phi(), "loops only through Phi's"); continue; // already processed } JavaObjectNode* jobj = unique_java_object(n); if (jobj == NULL || jobj == phantom_obj) { #ifdef ASSERT ptnode_adr(n->_idx)->dump(); assert(jobj != NULL && jobj != phantom_obj, "escaped allocation"); #endif _compile->record_failure(C2Compiler::retry_no_escape_analysis()); return; } else { Node *val = get_map(jobj->idx()); // CheckCastPP node TypeNode *tn = n->as_Type(); const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr(); assert(tinst != NULL && tinst->is_known_instance() && tinst->instance_id() == jobj->idx() , "instance type expected."); const Type *tn_type = igvn->type(tn); const TypeOopPtr *tn_t; if (tn_type->isa_narrowoop()) { tn_t = tn_type->make_ptr()->isa_oopptr(); } else { tn_t = tn_type->isa_oopptr(); } if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) { if (tn_type->isa_narrowoop()) { tn_type = tinst->make_narrowoop(); } else { tn_type = tinst; } igvn->hash_delete(tn); igvn->set_type(tn, tn_type); tn->set_type(tn_type); igvn->hash_insert(tn); record_for_optimizer(n); } else { assert(tn_type == TypePtr::NULL_PTR || tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()), "unexpected type"); continue; // Skip dead path with different type } } } else { debug_only(n->dump();) assert(false, "EA: unexpected node"); continue; } // push allocation's users on appropriate worklist for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { Node *use = n->fast_out(i); if(use->is_Mem() && use->in(MemNode::Address) == n) { // Load/store to instance's field memnode_worklist.append_if_missing(use); } else if (use->is_MemBar()) { memnode_worklist.append_if_missing(use); } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes Node* addp2 = find_second_addp(use, n); if (addp2 != NULL) { alloc_worklist.append_if_missing(addp2); } alloc_worklist.append_if_missing(use); } else if (use->is_Phi() || use->is_CheckCastPP() || use->is_EncodeP() || use->is_DecodeN() || (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) { alloc_worklist.append_if_missing(use); #ifdef ASSERT } else if (use->is_Mem()) { assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path"); } else if (use->is_MergeMem()) { assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist"); } else if (use->is_SafePoint()) { // Look for MergeMem nodes for calls which reference unique allocation // (through CheckCastPP nodes) even for debug info. Node* m = use->in(TypeFunc::Memory); if (m->is_MergeMem()) { assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist"); } } else { uint op = use->Opcode(); if (!(op == Op_CmpP || op == Op_Conv2B || op == Op_CastP2X || op == Op_StoreCM || op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_StrEquals || op == Op_StrIndexOf)) { n->dump(); use->dump(); assert(false, "EA: missing allocation reference path"); } #endif } } } // New alias types were created in split_AddP(). uint new_index_end = (uint) _compile->num_alias_types(); assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1"); // Phase 2: Process MemNode's from memnode_worklist. compute new address type and // compute new values for Memory inputs (the Memory inputs are not // actually updated until phase 4.) if (memnode_worklist.length() == 0) return; // nothing to do while (memnode_worklist.length() != 0) { Node *n = memnode_worklist.pop(); if (visited.test_set(n->_idx)) continue; if (n->is_Phi() || n->is_ClearArray()) { // we don't need to do anything, but the users must be pushed } else if (n->is_MemBar()) { // Initialize, MemBar nodes // we don't need to do anything, but the users must be pushed n = n->as_MemBar()->proj_out(TypeFunc::Memory); if (n == NULL) continue; } else { assert(n->is_Mem(), "memory node required."); Node *addr = n->in(MemNode::Address); const Type *addr_t = igvn->type(addr); if (addr_t == Type::TOP) continue; assert (addr_t->isa_ptr() != NULL, "pointer type required."); int alias_idx = _compile->get_alias_index(addr_t->is_ptr()); assert ((uint)alias_idx < new_index_end, "wrong alias index"); Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis); if (_compile->failing()) { return; } if (mem != n->in(MemNode::Memory)) { // We delay the memory edge update since we need old one in // MergeMem code below when instances memory slices are separated. set_map(n, mem); } if (n->is_Load()) { continue; // don't push users } else if (n->is_LoadStore()) { // get the memory projection for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { Node *use = n->fast_out(i); if (use->Opcode() == Op_SCMemProj) { n = use; break; } } assert(n->Opcode() == Op_SCMemProj, "memory projection required"); } } // push user on appropriate worklist for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { Node *use = n->fast_out(i); if (use->is_Phi() || use->is_ClearArray()) { memnode_worklist.append_if_missing(use); } else if(use->is_Mem() && use->in(MemNode::Memory) == n) { if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores continue; memnode_worklist.append_if_missing(use); } else if (use->is_MemBar()) { memnode_worklist.append_if_missing(use); #ifdef ASSERT } else if(use->is_Mem()) { assert(use->in(MemNode::Memory) != n, "EA: missing memory path"); } else if (use->is_MergeMem()) { assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist"); } else { uint op = use->Opcode(); if (!(op == Op_StoreCM || (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL && strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) || op == Op_AryEq || op == Op_StrComp || op == Op_StrEquals || op == Op_StrIndexOf)) { n->dump(); use->dump(); assert(false, "EA: missing memory path"); } #endif } } } // Phase 3: Process MergeMem nodes from mergemem_worklist. // Walk each memory slice moving the first node encountered of each // instance type to the the input corresponding to its alias index. uint length = _mergemem_worklist.length(); for( uint next = 0; next < length; ++next ) { MergeMemNode* nmm = _mergemem_worklist.at(next); assert(!visited.test_set(nmm->_idx), "should not be visited before"); // Note: we don't want to use MergeMemStream here because we only want to // scan inputs which exist at the start, not ones we add during processing. // Note 2: MergeMem may already contains instance memory slices added // during find_inst_mem() call when memory nodes were processed above. igvn->hash_delete(nmm); uint nslices = nmm->req(); for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) { Node* mem = nmm->in(i); Node* cur = NULL; if (mem == NULL || mem->is_top()) continue; // First, update mergemem by moving memory nodes to corresponding slices // if their type became more precise since this mergemem was created. while (mem->is_Mem()) { const Type *at = igvn->type(mem->in(MemNode::Address)); if (at != Type::TOP) { assert (at->isa_ptr() != NULL, "pointer type required."); uint idx = (uint)_compile->get_alias_index(at->is_ptr()); if (idx == i) { if (cur == NULL) cur = mem; } else { if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) { nmm->set_memory_at(idx, mem); } } } mem = mem->in(MemNode::Memory); } nmm->set_memory_at(i, (cur != NULL) ? cur : mem); // Find any instance of the current type if we haven't encountered // already a memory slice of the instance along the memory chain. for (uint ni = new_index_start; ni < new_index_end; ni++) { if((uint)_compile->get_general_index(ni) == i) { Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni); if (nmm->is_empty_memory(m)) { Node* result = find_inst_mem(mem, ni, orig_phis); if (_compile->failing()) { return; } nmm->set_memory_at(ni, result); } } } } // Find the rest of instances values for (uint ni = new_index_start; ni < new_index_end; ni++) { const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr(); Node* result = step_through_mergemem(nmm, ni, tinst); if (result == nmm->base_memory()) { // Didn't find instance memory, search through general slice recursively. result = nmm->memory_at(_compile->get_general_index(ni)); result = find_inst_mem(result, ni, orig_phis); if (_compile->failing()) { return; } nmm->set_memory_at(ni, result); } } igvn->hash_insert(nmm); record_for_optimizer(nmm); } // Phase 4: Update the inputs of non-instance memory Phis and // the Memory input of memnodes // First update the inputs of any non-instance Phi's from // which we split out an instance Phi. Note we don't have // to recursively process Phi's encounted on the input memory // chains as is done in split_memory_phi() since they will // also be processed here. for (int j = 0; j < orig_phis.length(); j++) { PhiNode *phi = orig_phis.at(j); int alias_idx = _compile->get_alias_index(phi->adr_type()); igvn->hash_delete(phi); for (uint i = 1; i < phi->req(); i++) { Node *mem = phi->in(i); Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis); if (_compile->failing()) { return; } if (mem != new_mem) { phi->set_req(i, new_mem); } } igvn->hash_insert(phi); record_for_optimizer(phi); } // Update the memory inputs of MemNodes with the value we computed // in Phase 2 and move stores memory users to corresponding memory slices. // Disable memory split verification code until the fix for 6984348. // Currently it produces false negative results since it does not cover all cases. #if 0 // ifdef ASSERT visited.Reset(); Node_Stack old_mems(arena, _compile->unique() >> 2); #endif for (uint i = 0; i < ideal_nodes.size(); i++) { Node* n = ideal_nodes.at(i); Node* nmem = get_map(n->_idx); assert(nmem != NULL, "sanity"); if (n->is_Mem()) { #if 0 // ifdef ASSERT Node* old_mem = n->in(MemNode::Memory); if (!visited.test_set(old_mem->_idx)) { old_mems.push(old_mem, old_mem->outcnt()); } #endif assert(n->in(MemNode::Memory) != nmem, "sanity"); if (!n->is_Load()) { // Move memory users of a store first. move_inst_mem(n, orig_phis); } // Now update memory input igvn->hash_delete(n); n->set_req(MemNode::Memory, nmem); igvn->hash_insert(n); record_for_optimizer(n); } else { assert(n->is_Allocate() || n->is_CheckCastPP() || n->is_AddP() || n->is_Phi(), "unknown node used for set_map()"); } } #if 0 // ifdef ASSERT // Verify that memory was split correctly while (old_mems.is_nonempty()) { Node* old_mem = old_mems.node(); uint old_cnt = old_mems.index(); old_mems.pop(); assert(old_cnt == old_mem->outcnt(), "old mem could be lost"); } #endif } #ifndef PRODUCT static const char *node_type_names[] = { "UnknownType", "JavaObject", "LocalVar", "Field", "Arraycopy" }; static const char *esc_names[] = { "UnknownEscape", "NoEscape", "ArgEscape", "GlobalEscape" }; void PointsToNode::dump(bool print_state) const { NodeType nt = node_type(); tty->print("%s ", node_type_names[(int) nt]); if (print_state) { EscapeState es = escape_state(); EscapeState fields_es = fields_escape_state(); tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]); if (nt == PointsToNode::JavaObject && !this->scalar_replaceable()) tty->print("NSR"); } if (is_Field()) { FieldNode* f = (FieldNode*)this; tty->print("("); for (BaseIterator i(f); i.has_next(); i.next()) { PointsToNode* b = i.get(); tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : "")); } tty->print(" )"); } tty->print("["); for (EdgeIterator i(this); i.has_next(); i.next()) { PointsToNode* e = i.get(); tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : ""); } tty->print(" ["); for (UseIterator i(this); i.has_next(); i.next()) { PointsToNode* u = i.get(); bool is_base = false; if (PointsToNode::is_base_use(u)) { is_base = true; u = PointsToNode::get_use_node(u)->as_Field(); } tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : ""); } tty->print(" ]] "); if (_node == NULL) tty->print_cr(""); else _node->dump(); } void ConnectionGraph::dump(GrowableArray& ptnodes_worklist) { bool first = true; int ptnodes_length = ptnodes_worklist.length(); for (int i = 0; i < ptnodes_length; i++) { PointsToNode *ptn = ptnodes_worklist.at(i); if (ptn == NULL || !ptn->is_JavaObject()) continue; PointsToNode::EscapeState es = ptn->escape_state(); if (ptn->ideal_node()->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) { if (first) { tty->cr(); tty->print("======== Connection graph for "); _compile->method()->print_short_name(); tty->cr(); first = false; } ptn->dump(); // Print all locals and fields which reference this allocation for (UseIterator j(ptn); j.has_next(); j.next()) { PointsToNode* use = j.get(); if (use->is_LocalVar()) { use->dump(Verbose); } else if (Verbose) { use->dump(); } } tty->cr(); } } } #endif