jdk8-mips64-public/hotspot: src/share/vm/opto/escape.cpp@ee138854b3a6 (annotated)

src/share/vm/opto/escape.cpp@ee138854b3a6 (annotated)

src/share/vm/opto/escape.cpp

Mon, 12 Mar 2012 10:46:47 -0700

author: kvn
date: Mon, 12 Mar 2012 10:46:47 -0700
changeset 3651: ee138854b3a6
parent 3604: 9a72c7ece7fb
child 3657: ed4c92f54c2d
permissions: -rw-r--r--

7147744: CTW: assert(false) failed: infinite EA connection graph build
Summary: rewrote Connection graph construction code in EA to reduce time spent there.
Reviewed-by: never

 /*
  * 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<Node*> alloc_worklist;
   GrowableArray<Node*> ptr_cmp_worklist;
   GrowableArray<Node*> storestore_worklist;
   GrowableArray<PointsToNode*>   ptnodes_worklist;
   GrowableArray<JavaObjectNode*> java_objects_worklist;
   GrowableArray<JavaObjectNode*> non_escaped_worklist;
   GrowableArray<FieldNode*>      oop_fields_worklist;
   DEBUG_ONLY( GrowableArray<Node*> 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");
         }
       } else {
         // Ignore copy the displaced header to the BoxNode (OSR compilation).
         if (adr->is_BoxLock())
           break;
         if (!adr->is_AddP()) {
           n->dump(1);
           assert(adr->is_AddP(), "expecting an AddP");
         }
         // Ignore G1 barrier's stores.
         if (!UseG1GC || (opcode != Op_StoreP) ||
             (adr_type != TypeRawPtr::BOTTOM)) {
           n->dump(1);
           assert(false, "not 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_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<PointsToNode*>&   ptnodes_worklist,
                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
                          GrowableArray<FieldNode*>&      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<PointsToNode*>& ptnodes_worklist,
                                                GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
   GrowableArray<PointsToNode*> 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<int> 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<PointsToNode*>&   ptnodes_worklist,
                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
                          GrowableArray<Node*>& 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<Node*>& ptr_cmp_worklist,
                                            GrowableArray<Node*>& 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<PhiNode *>  &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<PhiNode *>  &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<PhiNode *>  phi_list;
   GrowableArray<uint>  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<PhiNode *>  &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<PhiNode *>  &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<Node *>  &alloc_worklist) {
   GrowableArray<Node *>  memnode_worklist;
   GrowableArray<PhiNode *>  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("<null>");
   else
     _node->dump();
 }
 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& 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

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/escape.cpp@ee138854b3a6 (annotated)

src/share/vm/opto/escape.cpp