1 /*
   2  * Copyright (c) 2005, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/bcEscapeAnalyzer.hpp"
  27 #include "compiler/compileLog.hpp"
  28 #include "libadt/vectset.hpp"
  29 #include "memory/allocation.hpp"
  30 #include "memory/resourceArea.hpp"
  31 #include "opto/c2compiler.hpp"
  32 #include "opto/arraycopynode.hpp"
  33 #include "opto/callnode.hpp"
  34 #include "opto/cfgnode.hpp"
  35 #include "opto/compile.hpp"
  36 #include "opto/escape.hpp"
  37 #include "opto/phaseX.hpp"
  38 #include "opto/movenode.hpp"
  39 #include "opto/rootnode.hpp"
  40 
  41 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
  42   _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
  43   _in_worklist(C->comp_arena()),
  44   _next_pidx(0),
  45   _collecting(true),
  46   _verify(false),
  47   _compile(C),
  48   _igvn(igvn),
  49   _node_map(C->comp_arena()) {
  50   // Add unknown java object.
  51   add_java_object(C->top(), PointsToNode::GlobalEscape);
  52   phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
  53   // Add ConP(#NULL) and ConN(#NULL) nodes.
  54   Node* oop_null = igvn->zerocon(T_OBJECT);
  55   assert(oop_null->_idx < nodes_size(), "should be created already");
  56   add_java_object(oop_null, PointsToNode::NoEscape);
  57   null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
  58   if (UseCompressedOops) {
  59     Node* noop_null = igvn->zerocon(T_NARROWOOP);
  60     assert(noop_null->_idx < nodes_size(), "should be created already");
  61     map_ideal_node(noop_null, null_obj);
  62   }
  63   _pcmp_neq = NULL; // Should be initialized
  64   _pcmp_eq  = NULL;
  65 }
  66 
  67 bool ConnectionGraph::has_candidates(Compile *C) {
  68   // EA brings benefits only when the code has allocations and/or locks which
  69   // are represented by ideal Macro nodes.
  70   int cnt = C->macro_count();
  71   for (int i = 0; i < cnt; i++) {
  72     Node *n = C->macro_node(i);
  73     if (n->is_Allocate())
  74       return true;
  75     if (n->is_Lock()) {
  76       Node* obj = n->as_Lock()->obj_node()->uncast();
  77       if (!(obj->is_Parm() || obj->is_Con()))
  78         return true;
  79     }
  80     if (n->is_CallStaticJava() &&
  81         n->as_CallStaticJava()->is_boxing_method()) {
  82       return true;
  83     }
  84   }
  85   return false;
  86 }
  87 
  88 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
  89   Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
  90   ResourceMark rm;
  91 
  92   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
  93   // to create space for them in ConnectionGraph::_nodes[].
  94   Node* oop_null = igvn->zerocon(T_OBJECT);
  95   Node* noop_null = igvn->zerocon(T_NARROWOOP);
  96   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
  97   // Perform escape analysis
  98   if (congraph->compute_escape()) {
  99     // There are non escaping objects.
 100     C->set_congraph(congraph);
 101   }
 102   // Cleanup.
 103   if (oop_null->outcnt() == 0)
 104     igvn->hash_delete(oop_null);
 105   if (noop_null->outcnt() == 0)
 106     igvn->hash_delete(noop_null);
 107 }
 108 
 109 bool ConnectionGraph::compute_escape() {
 110   Compile* C = _compile;
 111   PhaseGVN* igvn = _igvn;
 112 
 113   // Worklists used by EA.
 114   Unique_Node_List delayed_worklist;
 115   GrowableArray<Node*> alloc_worklist;
 116   GrowableArray<Node*> ptr_cmp_worklist;
 117   GrowableArray<Node*> storestore_worklist;
 118   GrowableArray<ArrayCopyNode*> arraycopy_worklist;
 119   GrowableArray<PointsToNode*>   ptnodes_worklist;
 120   GrowableArray<JavaObjectNode*> java_objects_worklist;
 121   GrowableArray<JavaObjectNode*> non_escaped_worklist;
 122   GrowableArray<FieldNode*>      oop_fields_worklist;
 123   DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
 124 
 125   { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
 126 
 127   // 1. Populate Connection Graph (CG) with PointsTo nodes.
 128   ideal_nodes.map(C->live_nodes(), NULL);  // preallocate space
 129   // Initialize worklist
 130   if (C->root() != NULL) {
 131     ideal_nodes.push(C->root());
 132   }
 133   // Processed ideal nodes are unique on ideal_nodes list
 134   // but several ideal nodes are mapped to the phantom_obj.
 135   // To avoid duplicated entries on the following worklists
 136   // add the phantom_obj only once to them.
 137   ptnodes_worklist.append(phantom_obj);
 138   java_objects_worklist.append(phantom_obj);
 139   for( uint next = 0; next < ideal_nodes.size(); ++next ) {
 140     Node* n = ideal_nodes.at(next);
 141     // Create PointsTo nodes and add them to Connection Graph. Called
 142     // only once per ideal node since ideal_nodes is Unique_Node list.
 143     add_node_to_connection_graph(n, &delayed_worklist);
 144     PointsToNode* ptn = ptnode_adr(n->_idx);
 145     if (ptn != NULL && ptn != phantom_obj) {
 146       ptnodes_worklist.append(ptn);
 147       if (ptn->is_JavaObject()) {
 148         java_objects_worklist.append(ptn->as_JavaObject());
 149         if ((n->is_Allocate() || n->is_CallStaticJava()) &&
 150             (ptn->escape_state() < PointsToNode::GlobalEscape)) {
 151           // Only allocations and java static calls results are interesting.
 152           non_escaped_worklist.append(ptn->as_JavaObject());
 153         }
 154       } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
 155         oop_fields_worklist.append(ptn->as_Field());
 156       }
 157     }
 158     if (n->is_MergeMem()) {
 159       // Collect all MergeMem nodes to add memory slices for
 160       // scalar replaceable objects in split_unique_types().
 161       _mergemem_worklist.append(n->as_MergeMem());
 162     } else if (OptimizePtrCompare && n->is_Cmp() &&
 163                (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
 164       // Collect compare pointers nodes.
 165       ptr_cmp_worklist.append(n);
 166     } else if (n->is_MemBarStoreStore()) {
 167       // Collect all MemBarStoreStore nodes so that depending on the
 168       // escape status of the associated Allocate node some of them
 169       // may be eliminated.
 170       storestore_worklist.append(n);
 171     } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
 172                (n->req() > MemBarNode::Precedent)) {
 173       record_for_optimizer(n);
 174 #ifdef ASSERT
 175     } else if (n->is_AddP()) {
 176       // Collect address nodes for graph verification.
 177       addp_worklist.append(n);
 178 #endif
 179     } else if (n->is_ArrayCopy()) {
 180       // Keep a list of ArrayCopy nodes so if one of its input is non
 181       // escaping, we can record a unique type
 182       arraycopy_worklist.append(n->as_ArrayCopy());
 183     }
 184     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 185       Node* m = n->fast_out(i);   // Get user
 186       ideal_nodes.push(m);
 187     }
 188   }
 189   if (non_escaped_worklist.length() == 0) {
 190     _collecting = false;
 191     return false; // Nothing to do.
 192   }
 193   // Add final simple edges to graph.
 194   while(delayed_worklist.size() > 0) {
 195     Node* n = delayed_worklist.pop();
 196     add_final_edges(n);
 197   }
 198   int ptnodes_length = ptnodes_worklist.length();
 199 
 200 #ifdef ASSERT
 201   if (VerifyConnectionGraph) {
 202     // Verify that no new simple edges could be created and all
 203     // local vars has edges.
 204     _verify = true;
 205     for (int next = 0; next < ptnodes_length; ++next) {
 206       PointsToNode* ptn = ptnodes_worklist.at(next);
 207       add_final_edges(ptn->ideal_node());
 208       if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
 209         ptn->dump();
 210         assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
 211       }
 212     }
 213     _verify = false;
 214   }
 215 #endif
 216   // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
 217   // processing, calls to CI to resolve symbols (types, fields, methods)
 218   // referenced in bytecode. During symbol resolution VM may throw
 219   // an exception which CI cleans and converts to compilation failure.
 220   if (C->failing())  return false;
 221 
 222   // 2. Finish Graph construction by propagating references to all
 223   //    java objects through graph.
 224   if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
 225                                  java_objects_worklist, oop_fields_worklist)) {
 226     // All objects escaped or hit time or iterations limits.
 227     _collecting = false;
 228     return false;
 229   }
 230 
 231   // 3. Adjust scalar_replaceable state of nonescaping objects and push
 232   //    scalar replaceable allocations on alloc_worklist for processing
 233   //    in split_unique_types().
 234   int non_escaped_length = non_escaped_worklist.length();
 235   for (int next = 0; next < non_escaped_length; next++) {
 236     JavaObjectNode* ptn = non_escaped_worklist.at(next);
 237     bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
 238     Node* n = ptn->ideal_node();
 239     if (n->is_Allocate()) {
 240       n->as_Allocate()->_is_non_escaping = noescape;
 241     }
 242     if (n->is_CallStaticJava()) {
 243       n->as_CallStaticJava()->_is_non_escaping = noescape;
 244     }
 245     if (noescape && ptn->scalar_replaceable()) {
 246       adjust_scalar_replaceable_state(ptn);
 247       if (ptn->scalar_replaceable()) {
 248         alloc_worklist.append(ptn->ideal_node());
 249       }
 250     }
 251   }
 252 
 253 #ifdef ASSERT
 254   if (VerifyConnectionGraph) {
 255     // Verify that graph is complete - no new edges could be added or needed.
 256     verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
 257                             java_objects_worklist, addp_worklist);
 258   }
 259   assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
 260   assert(null_obj->escape_state() == PointsToNode::NoEscape &&
 261          null_obj->edge_count() == 0 &&
 262          !null_obj->arraycopy_src() &&
 263          !null_obj->arraycopy_dst(), "sanity");
 264 #endif
 265 
 266   _collecting = false;
 267 
 268   } // TracePhase t3("connectionGraph")
 269 
 270   // 4. Optimize ideal graph based on EA information.
 271   bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
 272   if (has_non_escaping_obj) {
 273     optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
 274   }
 275 
 276 #ifndef PRODUCT
 277   if (PrintEscapeAnalysis) {
 278     dump(ptnodes_worklist); // Dump ConnectionGraph
 279   }
 280 #endif
 281 
 282   bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
 283 #ifdef ASSERT
 284   if (VerifyConnectionGraph) {
 285     int alloc_length = alloc_worklist.length();
 286     for (int next = 0; next < alloc_length; ++next) {
 287       Node* n = alloc_worklist.at(next);
 288       PointsToNode* ptn = ptnode_adr(n->_idx);
 289       assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
 290     }
 291   }
 292 #endif
 293 
 294   // 5. Separate memory graph for scalar replaceable allcations.
 295   if (has_scalar_replaceable_candidates &&
 296       C->AliasLevel() >= 3 && EliminateAllocations) {
 297     // Now use the escape information to create unique types for
 298     // scalar replaceable objects.
 299     split_unique_types(alloc_worklist, arraycopy_worklist);
 300     if (C->failing())  return false;
 301     C->print_method(PHASE_AFTER_EA, 2);
 302 
 303 #ifdef ASSERT
 304   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
 305     tty->print("=== No allocations eliminated for ");
 306     C->method()->print_short_name();
 307     if(!EliminateAllocations) {
 308       tty->print(" since EliminateAllocations is off ===");
 309     } else if(!has_scalar_replaceable_candidates) {
 310       tty->print(" since there are no scalar replaceable candidates ===");
 311     } else if(C->AliasLevel() < 3) {
 312       tty->print(" since AliasLevel < 3 ===");
 313     }
 314     tty->cr();
 315 #endif
 316   }
 317   return has_non_escaping_obj;
 318 }
 319 
 320 // Utility function for nodes that load an object
 321 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 322   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 323   // ThreadLocal has RawPtr type.
 324   const Type* t = _igvn->type(n);
 325   if (t->make_ptr() != NULL) {
 326     Node* adr = n->in(MemNode::Address);
 327 #ifdef ASSERT
 328     if (!adr->is_AddP()) {
 329       assert(_igvn->type(adr)->isa_rawptr(), "sanity");
 330     } else {
 331       assert((ptnode_adr(adr->_idx) == NULL ||
 332               ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
 333     }
 334 #endif
 335     add_local_var_and_edge(n, PointsToNode::NoEscape,
 336                            adr, delayed_worklist);
 337   }
 338 }
 339 
 340 // Populate Connection Graph with PointsTo nodes and create simple
 341 // connection graph edges.
 342 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 343   assert(!_verify, "this method should not be called for verification");
 344   PhaseGVN* igvn = _igvn;
 345   uint n_idx = n->_idx;
 346   PointsToNode* n_ptn = ptnode_adr(n_idx);
 347   if (n_ptn != NULL)
 348     return; // No need to redefine PointsTo node during first iteration.
 349 
 350   if (n->is_Call()) {
 351     // Arguments to allocation and locking don't escape.
 352     if (n->is_AbstractLock()) {
 353       // Put Lock and Unlock nodes on IGVN worklist to process them during
 354       // first IGVN optimization when escape information is still available.
 355       record_for_optimizer(n);
 356     } else if (n->is_Allocate()) {
 357       add_call_node(n->as_Call());
 358       record_for_optimizer(n);
 359     } else {
 360       if (n->is_CallStaticJava()) {
 361         const char* name = n->as_CallStaticJava()->_name;
 362         if (name != NULL && strcmp(name, "uncommon_trap") == 0)
 363           return; // Skip uncommon traps
 364       }
 365       // Don't mark as processed since call's arguments have to be processed.
 366       delayed_worklist->push(n);
 367       // Check if a call returns an object.
 368       if ((n->as_Call()->returns_pointer() &&
 369            n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
 370           (n->is_CallStaticJava() &&
 371            n->as_CallStaticJava()->is_boxing_method())) {
 372         add_call_node(n->as_Call());
 373       }
 374     }
 375     return;
 376   }
 377   // Put this check here to process call arguments since some call nodes
 378   // point to phantom_obj.
 379   if (n_ptn == phantom_obj || n_ptn == null_obj)
 380     return; // Skip predefined nodes.
 381 
 382   int opcode = n->Opcode();
 383   switch (opcode) {
 384     case Op_AddP: {
 385       Node* base = get_addp_base(n);
 386       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 387       // Field nodes are created for all field types. They are used in
 388       // adjust_scalar_replaceable_state() and split_unique_types().
 389       // Note, non-oop fields will have only base edges in Connection
 390       // Graph because such fields are not used for oop loads and stores.
 391       int offset = address_offset(n, igvn);
 392       add_field(n, PointsToNode::NoEscape, offset);
 393       if (ptn_base == NULL) {
 394         delayed_worklist->push(n); // Process it later.
 395       } else {
 396         n_ptn = ptnode_adr(n_idx);
 397         add_base(n_ptn->as_Field(), ptn_base);
 398       }
 399       break;
 400     }
 401     case Op_CastX2P: {
 402       map_ideal_node(n, phantom_obj);
 403       break;
 404     }
 405     case Op_CastPP:
 406     case Op_CheckCastPP:
 407     case Op_EncodeP:
 408     case Op_DecodeN:
 409     case Op_EncodePKlass:
 410     case Op_DecodeNKlass: {
 411       add_local_var_and_edge(n, PointsToNode::NoEscape,
 412                              n->in(1), delayed_worklist);
 413       break;
 414     }
 415     case Op_CMoveP: {
 416       add_local_var(n, PointsToNode::NoEscape);
 417       // Do not add edges during first iteration because some could be
 418       // not defined yet.
 419       delayed_worklist->push(n);
 420       break;
 421     }
 422     case Op_ConP:
 423     case Op_ConN:
 424     case Op_ConNKlass: {
 425       // assume all oop constants globally escape except for null
 426       PointsToNode::EscapeState es;
 427       const Type* t = igvn->type(n);
 428       if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
 429         es = PointsToNode::NoEscape;
 430       } else {
 431         es = PointsToNode::GlobalEscape;
 432       }
 433       add_java_object(n, es);
 434       break;
 435     }
 436     case Op_CreateEx: {
 437       // assume that all exception objects globally escape
 438       map_ideal_node(n, phantom_obj);
 439       break;
 440     }
 441     case Op_LoadKlass:
 442     case Op_LoadNKlass: {
 443       // Unknown class is loaded
 444       map_ideal_node(n, phantom_obj);
 445       break;
 446     }
 447     case Op_LoadP:
 448     case Op_LoadN:
 449     case Op_LoadPLocked: {
 450       add_objload_to_connection_graph(n, delayed_worklist);
 451       break;
 452     }
 453     case Op_Parm: {
 454       map_ideal_node(n, phantom_obj);
 455       break;
 456     }
 457     case Op_PartialSubtypeCheck: {
 458       // Produces Null or notNull and is used in only in CmpP so
 459       // phantom_obj could be used.
 460       map_ideal_node(n, phantom_obj); // Result is unknown
 461       break;
 462     }
 463     case Op_Phi: {
 464       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 465       // ThreadLocal has RawPtr type.
 466       const Type* t = n->as_Phi()->type();
 467       if (t->make_ptr() != NULL) {
 468         add_local_var(n, PointsToNode::NoEscape);
 469         // Do not add edges during first iteration because some could be
 470         // not defined yet.
 471         delayed_worklist->push(n);
 472       }
 473       break;
 474     }
 475     case Op_Proj: {
 476       // we are only interested in the oop result projection from a call
 477       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
 478           n->in(0)->as_Call()->returns_pointer()) {
 479         add_local_var_and_edge(n, PointsToNode::NoEscape,
 480                                n->in(0), delayed_worklist);
 481       }
 482       break;
 483     }
 484     case Op_Rethrow: // Exception object escapes
 485     case Op_Return: {
 486       if (n->req() > TypeFunc::Parms &&
 487           igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 488         // Treat Return value as LocalVar with GlobalEscape escape state.
 489         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 490                                n->in(TypeFunc::Parms), delayed_worklist);
 491       }
 492       break;
 493     }
 494     case Op_CompareAndExchangeP:
 495     case Op_CompareAndExchangeN:
 496     case Op_GetAndSetP:
 497     case Op_GetAndSetN: {
 498       add_objload_to_connection_graph(n, delayed_worklist);
 499       // fallthrough
 500     }
 501     case Op_StoreP:
 502     case Op_StoreN:
 503     case Op_StoreNKlass:
 504     case Op_StorePConditional:
 505     case Op_WeakCompareAndSwapP:
 506     case Op_WeakCompareAndSwapN:
 507     case Op_CompareAndSwapP:
 508     case Op_CompareAndSwapN: {
 509       Node* adr = n->in(MemNode::Address);
 510       const Type *adr_type = igvn->type(adr);
 511       adr_type = adr_type->make_ptr();
 512       if (adr_type == NULL) {
 513         break; // skip dead nodes
 514       }
 515       if (adr_type->isa_oopptr() ||
 516           (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
 517                         (adr_type == TypeRawPtr::NOTNULL &&
 518                          adr->in(AddPNode::Address)->is_Proj() &&
 519                          adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 520         delayed_worklist->push(n); // Process it later.
 521 #ifdef ASSERT
 522         assert(adr->is_AddP(), "expecting an AddP");
 523         if (adr_type == TypeRawPtr::NOTNULL) {
 524           // Verify a raw address for a store captured by Initialize node.
 525           int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 526           assert(offs != Type::OffsetBot, "offset must be a constant");
 527         }
 528 #endif
 529       } else {
 530         // Ignore copy the displaced header to the BoxNode (OSR compilation).
 531         if (adr->is_BoxLock())
 532           break;
 533         // Stored value escapes in unsafe access.
 534         if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
 535           // Pointer stores in G1 barriers looks like unsafe access.
 536           // Ignore such stores to be able scalar replace non-escaping
 537           // allocations.
 538           if (UseG1GC && adr->is_AddP()) {
 539             Node* base = get_addp_base(adr);
 540             if (base->Opcode() == Op_LoadP &&
 541                 base->in(MemNode::Address)->is_AddP()) {
 542               adr = base->in(MemNode::Address);
 543               Node* tls = get_addp_base(adr);
 544               if (tls->Opcode() == Op_ThreadLocal) {
 545                 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 546                 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
 547                                      SATBMarkQueue::byte_offset_of_buf())) {
 548                   break; // G1 pre barrier previous oop value store.
 549                 }
 550                 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
 551                                      DirtyCardQueue::byte_offset_of_buf())) {
 552                   break; // G1 post barrier card address store.
 553                 }
 554               }
 555             }
 556           }
 557           delayed_worklist->push(n); // Process unsafe access later.
 558           break;
 559         }
 560 #ifdef ASSERT
 561         n->dump(1);
 562         assert(false, "not unsafe or G1 barrier raw StoreP");
 563 #endif
 564       }
 565       break;
 566     }
 567     case Op_AryEq:
 568     case Op_HasNegatives:
 569     case Op_StrComp:
 570     case Op_StrEquals:
 571     case Op_StrIndexOf:
 572     case Op_StrIndexOfChar:
 573     case Op_StrInflatedCopy:
 574     case Op_StrCompressedCopy:
 575     case Op_EncodeISOArray: {
 576       add_local_var(n, PointsToNode::ArgEscape);
 577       delayed_worklist->push(n); // Process it later.
 578       break;
 579     }
 580     case Op_ThreadLocal: {
 581       add_java_object(n, PointsToNode::ArgEscape);
 582       break;
 583     }
 584     default:
 585       ; // Do nothing for nodes not related to EA.
 586   }
 587   return;
 588 }
 589 
 590 #ifdef ASSERT
 591 #define ELSE_FAIL(name)                               \
 592       /* Should not be called for not pointer type. */  \
 593       n->dump(1);                                       \
 594       assert(false, name);                              \
 595       break;
 596 #else
 597 #define ELSE_FAIL(name) \
 598       break;
 599 #endif
 600 
 601 // Add final simple edges to graph.
 602 void ConnectionGraph::add_final_edges(Node *n) {
 603   PointsToNode* n_ptn = ptnode_adr(n->_idx);
 604 #ifdef ASSERT
 605   if (_verify && n_ptn->is_JavaObject())
 606     return; // This method does not change graph for JavaObject.
 607 #endif
 608 
 609   if (n->is_Call()) {
 610     process_call_arguments(n->as_Call());
 611     return;
 612   }
 613   assert(n->is_Store() || n->is_LoadStore() ||
 614          (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
 615          "node should be registered already");
 616   int opcode = n->Opcode();
 617   switch (opcode) {
 618     case Op_AddP: {
 619       Node* base = get_addp_base(n);
 620       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 621       assert(ptn_base != NULL, "field's base should be registered");
 622       add_base(n_ptn->as_Field(), ptn_base);
 623       break;
 624     }
 625     case Op_CastPP:
 626     case Op_CheckCastPP:
 627     case Op_EncodeP:
 628     case Op_DecodeN:
 629     case Op_EncodePKlass:
 630     case Op_DecodeNKlass: {
 631       add_local_var_and_edge(n, PointsToNode::NoEscape,
 632                              n->in(1), NULL);
 633       break;
 634     }
 635     case Op_CMoveP: {
 636       for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
 637         Node* in = n->in(i);
 638         if (in == NULL)
 639           continue;  // ignore NULL
 640         Node* uncast_in = in->uncast();
 641         if (uncast_in->is_top() || uncast_in == n)
 642           continue;  // ignore top or inputs which go back this node
 643         PointsToNode* ptn = ptnode_adr(in->_idx);
 644         assert(ptn != NULL, "node should be registered");
 645         add_edge(n_ptn, ptn);
 646       }
 647       break;
 648     }
 649     case Op_LoadP:
 650     case Op_LoadN:
 651     case Op_LoadPLocked: {
 652       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 653       // ThreadLocal has RawPtr type.
 654       const Type* t = _igvn->type(n);
 655       if (t->make_ptr() != NULL) {
 656         Node* adr = n->in(MemNode::Address);
 657         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 658         break;
 659       }
 660       ELSE_FAIL("Op_LoadP");
 661     }
 662     case Op_Phi: {
 663       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 664       // ThreadLocal has RawPtr type.
 665       const Type* t = n->as_Phi()->type();
 666       if (t->make_ptr() != NULL) {
 667         for (uint i = 1; i < n->req(); i++) {
 668           Node* in = n->in(i);
 669           if (in == NULL)
 670             continue;  // ignore NULL
 671           Node* uncast_in = in->uncast();
 672           if (uncast_in->is_top() || uncast_in == n)
 673             continue;  // ignore top or inputs which go back this node
 674           PointsToNode* ptn = ptnode_adr(in->_idx);
 675           assert(ptn != NULL, "node should be registered");
 676           add_edge(n_ptn, ptn);
 677         }
 678         break;
 679       }
 680       ELSE_FAIL("Op_Phi");
 681     }
 682     case Op_Proj: {
 683       // we are only interested in the oop result projection from a call
 684       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
 685           n->in(0)->as_Call()->returns_pointer()) {
 686         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
 687         break;
 688       }
 689       ELSE_FAIL("Op_Proj");
 690     }
 691     case Op_Rethrow: // Exception object escapes
 692     case Op_Return: {
 693       if (n->req() > TypeFunc::Parms &&
 694           _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 695         // Treat Return value as LocalVar with GlobalEscape escape state.
 696         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 697                                n->in(TypeFunc::Parms), NULL);
 698         break;
 699       }
 700       ELSE_FAIL("Op_Return");
 701     }
 702     case Op_StoreP:
 703     case Op_StoreN:
 704     case Op_StoreNKlass:
 705     case Op_StorePConditional:
 706     case Op_CompareAndExchangeP:
 707     case Op_CompareAndExchangeN:
 708     case Op_CompareAndSwapP:
 709     case Op_CompareAndSwapN:
 710     case Op_WeakCompareAndSwapP:
 711     case Op_WeakCompareAndSwapN:
 712     case Op_GetAndSetP:
 713     case Op_GetAndSetN: {
 714       Node* adr = n->in(MemNode::Address);
 715       const Type *adr_type = _igvn->type(adr);
 716       adr_type = adr_type->make_ptr();
 717 #ifdef ASSERT
 718       if (adr_type == NULL) {
 719         n->dump(1);
 720         assert(adr_type != NULL, "dead node should not be on list");
 721         break;
 722       }
 723 #endif
 724       if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
 725           opcode == Op_CompareAndExchangeN || opcode == Op_CompareAndExchangeP) {
 726         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 727       }
 728       if (adr_type->isa_oopptr() ||
 729           (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
 730                         (adr_type == TypeRawPtr::NOTNULL &&
 731                          adr->in(AddPNode::Address)->is_Proj() &&
 732                          adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 733         // Point Address to Value
 734         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 735         assert(adr_ptn != NULL &&
 736                adr_ptn->as_Field()->is_oop(), "node should be registered");
 737         Node *val = n->in(MemNode::ValueIn);
 738         PointsToNode* ptn = ptnode_adr(val->_idx);
 739         assert(ptn != NULL, "node should be registered");
 740         add_edge(adr_ptn, ptn);
 741         break;
 742       } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
 743         // Stored value escapes in unsafe access.
 744         Node *val = n->in(MemNode::ValueIn);
 745         PointsToNode* ptn = ptnode_adr(val->_idx);
 746         assert(ptn != NULL, "node should be registered");
 747         set_escape_state(ptn, PointsToNode::GlobalEscape);
 748         // Add edge to object for unsafe access with offset.
 749         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 750         assert(adr_ptn != NULL, "node should be registered");
 751         if (adr_ptn->is_Field()) {
 752           assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
 753           add_edge(adr_ptn, ptn);
 754         }
 755         break;
 756       }
 757       ELSE_FAIL("Op_StoreP");
 758     }
 759     case Op_AryEq:
 760     case Op_HasNegatives:
 761     case Op_StrComp:
 762     case Op_StrEquals:
 763     case Op_StrIndexOf:
 764     case Op_StrIndexOfChar:
 765     case Op_StrInflatedCopy:
 766     case Op_StrCompressedCopy:
 767     case Op_EncodeISOArray: {
 768       // char[]/byte[] arrays passed to string intrinsic do not escape but
 769       // they are not scalar replaceable. Adjust escape state for them.
 770       // Start from in(2) edge since in(1) is memory edge.
 771       for (uint i = 2; i < n->req(); i++) {
 772         Node* adr = n->in(i);
 773         const Type* at = _igvn->type(adr);
 774         if (!adr->is_top() && at->isa_ptr()) {
 775           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
 776                  at->isa_ptr() != NULL, "expecting a pointer");
 777           if (adr->is_AddP()) {
 778             adr = get_addp_base(adr);
 779           }
 780           PointsToNode* ptn = ptnode_adr(adr->_idx);
 781           assert(ptn != NULL, "node should be registered");
 782           add_edge(n_ptn, ptn);
 783         }
 784       }
 785       break;
 786     }
 787     default: {
 788       // This method should be called only for EA specific nodes which may
 789       // miss some edges when they were created.
 790 #ifdef ASSERT
 791       n->dump(1);
 792 #endif
 793       guarantee(false, "unknown node");
 794     }
 795   }
 796   return;
 797 }
 798 
 799 void ConnectionGraph::add_call_node(CallNode* call) {
 800   assert(call->returns_pointer(), "only for call which returns pointer");
 801   uint call_idx = call->_idx;
 802   if (call->is_Allocate()) {
 803     Node* k = call->in(AllocateNode::KlassNode);
 804     const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
 805     assert(kt != NULL, "TypeKlassPtr  required.");
 806     ciKlass* cik = kt->klass();
 807     PointsToNode::EscapeState es = PointsToNode::NoEscape;
 808     bool scalar_replaceable = true;
 809     if (call->is_AllocateArray()) {
 810       if (!cik->is_array_klass()) { // StressReflectiveCode
 811         es = PointsToNode::GlobalEscape;
 812       } else {
 813         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
 814         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
 815           // Not scalar replaceable if the length is not constant or too big.
 816           scalar_replaceable = false;
 817         }
 818       }
 819     } else {  // Allocate instance
 820       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
 821           cik->is_subclass_of(_compile->env()->Reference_klass()) ||
 822          !cik->is_instance_klass() || // StressReflectiveCode
 823          !cik->as_instance_klass()->can_be_instantiated() ||
 824           cik->as_instance_klass()->has_finalizer()) {
 825         es = PointsToNode::GlobalEscape;
 826       }
 827     }
 828     add_java_object(call, es);
 829     PointsToNode* ptn = ptnode_adr(call_idx);
 830     if (!scalar_replaceable && ptn->scalar_replaceable()) {
 831       ptn->set_scalar_replaceable(false);
 832     }
 833   } else if (call->is_CallStaticJava()) {
 834     // Call nodes could be different types:
 835     //
 836     // 1. CallDynamicJavaNode (what happened during call is unknown):
 837     //
 838     //    - mapped to GlobalEscape JavaObject node if oop is returned;
 839     //
 840     //    - all oop arguments are escaping globally;
 841     //
 842     // 2. CallStaticJavaNode (execute bytecode analysis if possible):
 843     //
 844     //    - the same as CallDynamicJavaNode if can't do bytecode analysis;
 845     //
 846     //    - mapped to GlobalEscape JavaObject node if unknown oop is returned;
 847     //    - mapped to NoEscape JavaObject node if non-escaping object allocated
 848     //      during call is returned;
 849     //    - mapped to ArgEscape LocalVar node pointed to object arguments
 850     //      which are returned and does not escape during call;
 851     //
 852     //    - oop arguments escaping status is defined by bytecode analysis;
 853     //
 854     // For a static call, we know exactly what method is being called.
 855     // Use bytecode estimator to record whether the call's return value escapes.
 856     ciMethod* meth = call->as_CallJava()->method();
 857     if (meth == NULL) {
 858       const char* name = call->as_CallStaticJava()->_name;
 859       assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
 860       // Returns a newly allocated unescaped object.
 861       add_java_object(call, PointsToNode::NoEscape);
 862       ptnode_adr(call_idx)->set_scalar_replaceable(false);
 863     } else if (meth->is_boxing_method()) {
 864       // Returns boxing object
 865       PointsToNode::EscapeState es;
 866       vmIntrinsics::ID intr = meth->intrinsic_id();
 867       if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
 868         // It does not escape if object is always allocated.
 869         es = PointsToNode::NoEscape;
 870       } else {
 871         // It escapes globally if object could be loaded from cache.
 872         es = PointsToNode::GlobalEscape;
 873       }
 874       add_java_object(call, es);
 875     } else {
 876       BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
 877       call_analyzer->copy_dependencies(_compile->dependencies());
 878       if (call_analyzer->is_return_allocated()) {
 879         // Returns a newly allocated unescaped object, simply
 880         // update dependency information.
 881         // Mark it as NoEscape so that objects referenced by
 882         // it's fields will be marked as NoEscape at least.
 883         add_java_object(call, PointsToNode::NoEscape);
 884         ptnode_adr(call_idx)->set_scalar_replaceable(false);
 885       } else {
 886         // Determine whether any arguments are returned.
 887         const TypeTuple* d = call->tf()->domain_sig();
 888         bool ret_arg = false;
 889         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 890           if (d->field_at(i)->isa_ptr() != NULL &&
 891               call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
 892             ret_arg = true;
 893             break;
 894           }
 895         }
 896         if (ret_arg) {
 897           add_local_var(call, PointsToNode::ArgEscape);
 898         } else {
 899           // Returns unknown object.
 900           map_ideal_node(call, phantom_obj);
 901         }
 902       }
 903     }
 904   } else {
 905     // An other type of call, assume the worst case:
 906     // returned value is unknown and globally escapes.
 907     assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
 908     map_ideal_node(call, phantom_obj);
 909   }
 910 }
 911 
 912 void ConnectionGraph::process_call_arguments(CallNode *call) {
 913     bool is_arraycopy = false;
 914     switch (call->Opcode()) {
 915 #ifdef ASSERT
 916     case Op_Allocate:
 917     case Op_AllocateArray:
 918     case Op_Lock:
 919     case Op_Unlock:
 920       assert(false, "should be done already");
 921       break;
 922 #endif
 923     case Op_ArrayCopy:
 924     case Op_CallLeafNoFP:
 925       // Most array copies are ArrayCopy nodes at this point but there
 926       // are still a few direct calls to the copy subroutines (See
 927       // PhaseStringOpts::copy_string())
 928       is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
 929         call->as_CallLeaf()->is_call_to_arraycopystub();
 930       // fall through
 931     case Op_CallLeaf: {
 932       // Stub calls, objects do not escape but they are not scale replaceable.
 933       // Adjust escape state for outgoing arguments.
 934       const TypeTuple * d = call->tf()->domain_sig();
 935       bool src_has_oops = false;
 936       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 937         const Type* at = d->field_at(i);
 938         Node *arg = call->in(i);
 939         if (arg == NULL) {
 940           continue;
 941         }
 942         const Type *aat = _igvn->type(arg);
 943         if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
 944           continue;
 945         if (arg->is_AddP()) {
 946           //
 947           // The inline_native_clone() case when the arraycopy stub is called
 948           // after the allocation before Initialize and CheckCastPP nodes.
 949           // Or normal arraycopy for object arrays case.
 950           //
 951           // Set AddP's base (Allocate) as not scalar replaceable since
 952           // pointer to the base (with offset) is passed as argument.
 953           //
 954           arg = get_addp_base(arg);
 955         }
 956         PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
 957         assert(arg_ptn != NULL, "should be registered");
 958         PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
 959         if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
 960           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
 961                  aat->isa_ptr() != NULL, "expecting an Ptr");
 962           bool arg_has_oops = aat->isa_oopptr() &&
 963                               (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
 964                                (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
 965           if (i == TypeFunc::Parms) {
 966             src_has_oops = arg_has_oops;
 967           }
 968           //
 969           // src or dst could be j.l.Object when other is basic type array:
 970           //
 971           //   arraycopy(char[],0,Object*,0,size);
 972           //   arraycopy(Object*,0,char[],0,size);
 973           //
 974           // Don't add edges in such cases.
 975           //
 976           bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
 977                                        arg_has_oops && (i > TypeFunc::Parms);
 978 #ifdef ASSERT
 979           if (!(is_arraycopy ||
 980                 (call->as_CallLeaf()->_name != NULL &&
 981                  (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
 982                   strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
 983                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
 984                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
 985                   strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
 986                   strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
 987                   strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
 988                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
 989                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
 990                   strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
 991                   strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
 992                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
 993                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
 994                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
 995                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
 996                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
 997                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
 998                   strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
 999                   strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1000                   strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1001                   strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1002                   strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1003                   strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1004                  ))) {
1005             call->dump();
1006             fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1007           }
1008 #endif
1009           // Always process arraycopy's destination object since
1010           // we need to add all possible edges to references in
1011           // source object.
1012           if (arg_esc >= PointsToNode::ArgEscape &&
1013               !arg_is_arraycopy_dest) {
1014             continue;
1015           }
1016           PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1017           if (call->is_ArrayCopy()) {
1018             ArrayCopyNode* ac = call->as_ArrayCopy();
1019             if (ac->is_clonebasic() ||
1020                 ac->is_arraycopy_validated() ||
1021                 ac->is_copyof_validated() ||
1022                 ac->is_copyofrange_validated()) {
1023               es = PointsToNode::NoEscape;
1024             }
1025           }
1026           set_escape_state(arg_ptn, es);
1027           if (arg_is_arraycopy_dest) {
1028             Node* src = call->in(TypeFunc::Parms);
1029             if (src->is_AddP()) {
1030               src = get_addp_base(src);
1031             }
1032             PointsToNode* src_ptn = ptnode_adr(src->_idx);
1033             assert(src_ptn != NULL, "should be registered");
1034             if (arg_ptn != src_ptn) {
1035               // Special arraycopy edge:
1036               // A destination object's field can't have the source object
1037               // as base since objects escape states are not related.
1038               // Only escape state of destination object's fields affects
1039               // escape state of fields in source object.
1040               add_arraycopy(call, es, src_ptn, arg_ptn);
1041             }
1042           }
1043         }
1044       }
1045       break;
1046     }
1047     case Op_CallStaticJava: {
1048       // For a static call, we know exactly what method is being called.
1049       // Use bytecode estimator to record the call's escape affects
1050 #ifdef ASSERT
1051       const char* name = call->as_CallStaticJava()->_name;
1052       assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1053 #endif
1054       ciMethod* meth = call->as_CallJava()->method();
1055       if ((meth != NULL) && meth->is_boxing_method()) {
1056         break; // Boxing methods do not modify any oops.
1057       }
1058       BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1059       // fall-through if not a Java method or no analyzer information
1060       if (call_analyzer != NULL) {
1061         PointsToNode* call_ptn = ptnode_adr(call->_idx);
1062         const TypeTuple* d = call->tf()->domain_sig();
1063         int extra = 0;
1064         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1065           const Type* at = d->field_at(i);
1066           if (at->isa_valuetypeptr()) {
1067             extra += at->is_valuetypeptr()->value_type()->value_klass()->field_count() - 1;
1068             continue;
1069           }
1070           int k = i - TypeFunc::Parms;
1071           Node* arg = call->in(i + extra);
1072           PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1073           if (at->isa_ptr() != NULL &&
1074               call_analyzer->is_arg_returned(k)) {
1075             // The call returns arguments.
1076             if (call_ptn != NULL) { // Is call's result used?
1077               assert(call_ptn->is_LocalVar(), "node should be registered");
1078               assert(arg_ptn != NULL, "node should be registered");
1079               add_edge(call_ptn, arg_ptn);
1080             }
1081           }
1082           if (at->isa_oopptr() != NULL &&
1083               arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1084             if (!call_analyzer->is_arg_stack(k)) {
1085               // The argument global escapes
1086               set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1087             } else {
1088               set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1089               if (!call_analyzer->is_arg_local(k)) {
1090                 // The argument itself doesn't escape, but any fields might
1091                 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1092               }
1093             }
1094           }
1095         }
1096         if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1097           // The call returns arguments.
1098           assert(call_ptn->edge_count() > 0, "sanity");
1099           if (!call_analyzer->is_return_local()) {
1100             // Returns also unknown object.
1101             add_edge(call_ptn, phantom_obj);
1102           }
1103         }
1104         break;
1105       }
1106     }
1107     default: {
1108       // Fall-through here if not a Java method or no analyzer information
1109       // or some other type of call, assume the worst case: all arguments
1110       // globally escape.
1111       const TypeTuple* d = call->tf()->domain_sig();
1112       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1113         const Type* at = d->field_at(i);
1114         if (at->isa_oopptr() != NULL) {
1115           Node* arg = call->in(i);
1116           if (arg->is_AddP()) {
1117             arg = get_addp_base(arg);
1118           }
1119           assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1120           set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1121         }
1122       }
1123     }
1124   }
1125 }
1126 
1127 
1128 // Finish Graph construction.
1129 bool ConnectionGraph::complete_connection_graph(
1130                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1131                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1132                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1133                          GrowableArray<FieldNode*>&      oop_fields_worklist) {
1134   // Normally only 1-3 passes needed to build Connection Graph depending
1135   // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1136   // Set limit to 20 to catch situation when something did go wrong and
1137   // bailout Escape Analysis.
1138   // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1139 #define CG_BUILD_ITER_LIMIT 20
1140 
1141   // Propagate GlobalEscape and ArgEscape escape states and check that
1142   // we still have non-escaping objects. The method pushs on _worklist
1143   // Field nodes which reference phantom_object.
1144   if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1145     return false; // Nothing to do.
1146   }
1147   // Now propagate references to all JavaObject nodes.
1148   int java_objects_length = java_objects_worklist.length();
1149   elapsedTimer time;
1150   bool timeout = false;
1151   int new_edges = 1;
1152   int iterations = 0;
1153   do {
1154     while ((new_edges > 0) &&
1155            (iterations++ < CG_BUILD_ITER_LIMIT)) {
1156       double start_time = time.seconds();
1157       time.start();
1158       new_edges = 0;
1159       // Propagate references to phantom_object for nodes pushed on _worklist
1160       // by find_non_escaped_objects() and find_field_value().
1161       new_edges += add_java_object_edges(phantom_obj, false);
1162       for (int next = 0; next < java_objects_length; ++next) {
1163         JavaObjectNode* ptn = java_objects_worklist.at(next);
1164         new_edges += add_java_object_edges(ptn, true);
1165 
1166 #define SAMPLE_SIZE 4
1167         if ((next % SAMPLE_SIZE) == 0) {
1168           // Each 4 iterations calculate how much time it will take
1169           // to complete graph construction.
1170           time.stop();
1171           // Poll for requests from shutdown mechanism to quiesce compiler
1172           // because Connection graph construction may take long time.
1173           CompileBroker::maybe_block();
1174           double stop_time = time.seconds();
1175           double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1176           double time_until_end = time_per_iter * (double)(java_objects_length - next);
1177           if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1178             timeout = true;
1179             break; // Timeout
1180           }
1181           start_time = stop_time;
1182           time.start();
1183         }
1184 #undef SAMPLE_SIZE
1185 
1186       }
1187       if (timeout) break;
1188       if (new_edges > 0) {
1189         // Update escape states on each iteration if graph was updated.
1190         if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1191           return false; // Nothing to do.
1192         }
1193       }
1194       time.stop();
1195       if (time.seconds() >= EscapeAnalysisTimeout) {
1196         timeout = true;
1197         break;
1198       }
1199     }
1200     if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1201       time.start();
1202       // Find fields which have unknown value.
1203       int fields_length = oop_fields_worklist.length();
1204       for (int next = 0; next < fields_length; next++) {
1205         FieldNode* field = oop_fields_worklist.at(next);
1206         if (field->edge_count() == 0) {
1207           new_edges += find_field_value(field);
1208           // This code may added new edges to phantom_object.
1209           // Need an other cycle to propagate references to phantom_object.
1210         }
1211       }
1212       time.stop();
1213       if (time.seconds() >= EscapeAnalysisTimeout) {
1214         timeout = true;
1215         break;
1216       }
1217     } else {
1218       new_edges = 0; // Bailout
1219     }
1220   } while (new_edges > 0);
1221 
1222   // Bailout if passed limits.
1223   if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1224     Compile* C = _compile;
1225     if (C->log() != NULL) {
1226       C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1227       C->log()->text("%s", timeout ? "time" : "iterations");
1228       C->log()->end_elem(" limit'");
1229     }
1230     assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1231            time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1232     // Possible infinite build_connection_graph loop,
1233     // bailout (no changes to ideal graph were made).
1234     return false;
1235   }
1236 #ifdef ASSERT
1237   if (Verbose && PrintEscapeAnalysis) {
1238     tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1239                   iterations, nodes_size(), ptnodes_worklist.length());
1240   }
1241 #endif
1242 
1243 #undef CG_BUILD_ITER_LIMIT
1244 
1245   // Find fields initialized by NULL for non-escaping Allocations.
1246   int non_escaped_length = non_escaped_worklist.length();
1247   for (int next = 0; next < non_escaped_length; next++) {
1248     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1249     PointsToNode::EscapeState es = ptn->escape_state();
1250     assert(es <= PointsToNode::ArgEscape, "sanity");
1251     if (es == PointsToNode::NoEscape) {
1252       if (find_init_values(ptn, null_obj, _igvn) > 0) {
1253         // Adding references to NULL object does not change escape states
1254         // since it does not escape. Also no fields are added to NULL object.
1255         add_java_object_edges(null_obj, false);
1256       }
1257     }
1258     Node* n = ptn->ideal_node();
1259     if (n->is_Allocate()) {
1260       // The object allocated by this Allocate node will never be
1261       // seen by an other thread. Mark it so that when it is
1262       // expanded no MemBarStoreStore is added.
1263       InitializeNode* ini = n->as_Allocate()->initialization();
1264       if (ini != NULL)
1265         ini->set_does_not_escape();
1266     }
1267   }
1268   return true; // Finished graph construction.
1269 }
1270 
1271 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1272 // and check that we still have non-escaping java objects.
1273 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1274                                                GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1275   GrowableArray<PointsToNode*> escape_worklist;
1276   // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1277   int ptnodes_length = ptnodes_worklist.length();
1278   for (int next = 0; next < ptnodes_length; ++next) {
1279     PointsToNode* ptn = ptnodes_worklist.at(next);
1280     if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1281         ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1282       escape_worklist.push(ptn);
1283     }
1284   }
1285   // Set escape states to referenced nodes (edges list).
1286   while (escape_worklist.length() > 0) {
1287     PointsToNode* ptn = escape_worklist.pop();
1288     PointsToNode::EscapeState es  = ptn->escape_state();
1289     PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1290     if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1291         es >= PointsToNode::ArgEscape) {
1292       // GlobalEscape or ArgEscape state of field means it has unknown value.
1293       if (add_edge(ptn, phantom_obj)) {
1294         // New edge was added
1295         add_field_uses_to_worklist(ptn->as_Field());
1296       }
1297     }
1298     for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1299       PointsToNode* e = i.get();
1300       if (e->is_Arraycopy()) {
1301         assert(ptn->arraycopy_dst(), "sanity");
1302         // Propagate only fields escape state through arraycopy edge.
1303         if (e->fields_escape_state() < field_es) {
1304           set_fields_escape_state(e, field_es);
1305           escape_worklist.push(e);
1306         }
1307       } else if (es >= field_es) {
1308         // fields_escape_state is also set to 'es' if it is less than 'es'.
1309         if (e->escape_state() < es) {
1310           set_escape_state(e, es);
1311           escape_worklist.push(e);
1312         }
1313       } else {
1314         // Propagate field escape state.
1315         bool es_changed = false;
1316         if (e->fields_escape_state() < field_es) {
1317           set_fields_escape_state(e, field_es);
1318           es_changed = true;
1319         }
1320         if ((e->escape_state() < field_es) &&
1321             e->is_Field() && ptn->is_JavaObject() &&
1322             e->as_Field()->is_oop()) {
1323           // Change escape state of referenced fields.
1324           set_escape_state(e, field_es);
1325           es_changed = true;
1326         } else if (e->escape_state() < es) {
1327           set_escape_state(e, es);
1328           es_changed = true;
1329         }
1330         if (es_changed) {
1331           escape_worklist.push(e);
1332         }
1333       }
1334     }
1335   }
1336   // Remove escaped objects from non_escaped list.
1337   for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1338     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1339     if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1340       non_escaped_worklist.delete_at(next);
1341     }
1342     if (ptn->escape_state() == PointsToNode::NoEscape) {
1343       // Find fields in non-escaped allocations which have unknown value.
1344       find_init_values(ptn, phantom_obj, NULL);
1345     }
1346   }
1347   return (non_escaped_worklist.length() > 0);
1348 }
1349 
1350 // Add all references to JavaObject node by walking over all uses.
1351 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1352   int new_edges = 0;
1353   if (populate_worklist) {
1354     // Populate _worklist by uses of jobj's uses.
1355     for (UseIterator i(jobj); i.has_next(); i.next()) {
1356       PointsToNode* use = i.get();
1357       if (use->is_Arraycopy())
1358         continue;
1359       add_uses_to_worklist(use);
1360       if (use->is_Field() && use->as_Field()->is_oop()) {
1361         // Put on worklist all field's uses (loads) and
1362         // related field nodes (same base and offset).
1363         add_field_uses_to_worklist(use->as_Field());
1364       }
1365     }
1366   }
1367   for (int l = 0; l < _worklist.length(); l++) {
1368     PointsToNode* use = _worklist.at(l);
1369     if (PointsToNode::is_base_use(use)) {
1370       // Add reference from jobj to field and from field to jobj (field's base).
1371       use = PointsToNode::get_use_node(use)->as_Field();
1372       if (add_base(use->as_Field(), jobj)) {
1373         new_edges++;
1374       }
1375       continue;
1376     }
1377     assert(!use->is_JavaObject(), "sanity");
1378     if (use->is_Arraycopy()) {
1379       if (jobj == null_obj) // NULL object does not have field edges
1380         continue;
1381       // Added edge from Arraycopy node to arraycopy's source java object
1382       if (add_edge(use, jobj)) {
1383         jobj->set_arraycopy_src();
1384         new_edges++;
1385       }
1386       // and stop here.
1387       continue;
1388     }
1389     if (!add_edge(use, jobj))
1390       continue; // No new edge added, there was such edge already.
1391     new_edges++;
1392     if (use->is_LocalVar()) {
1393       add_uses_to_worklist(use);
1394       if (use->arraycopy_dst()) {
1395         for (EdgeIterator i(use); i.has_next(); i.next()) {
1396           PointsToNode* e = i.get();
1397           if (e->is_Arraycopy()) {
1398             if (jobj == null_obj) // NULL object does not have field edges
1399               continue;
1400             // Add edge from arraycopy's destination java object to Arraycopy node.
1401             if (add_edge(jobj, e)) {
1402               new_edges++;
1403               jobj->set_arraycopy_dst();
1404             }
1405           }
1406         }
1407       }
1408     } else {
1409       // Added new edge to stored in field values.
1410       // Put on worklist all field's uses (loads) and
1411       // related field nodes (same base and offset).
1412       add_field_uses_to_worklist(use->as_Field());
1413     }
1414   }
1415   _worklist.clear();
1416   _in_worklist.Reset();
1417   return new_edges;
1418 }
1419 
1420 // Put on worklist all related field nodes.
1421 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1422   assert(field->is_oop(), "sanity");
1423   int offset = field->offset();
1424   add_uses_to_worklist(field);
1425   // Loop over all bases of this field and push on worklist Field nodes
1426   // with the same offset and base (since they may reference the same field).
1427   for (BaseIterator i(field); i.has_next(); i.next()) {
1428     PointsToNode* base = i.get();
1429     add_fields_to_worklist(field, base);
1430     // Check if the base was source object of arraycopy and go over arraycopy's
1431     // destination objects since values stored to a field of source object are
1432     // accessable by uses (loads) of fields of destination objects.
1433     if (base->arraycopy_src()) {
1434       for (UseIterator j(base); j.has_next(); j.next()) {
1435         PointsToNode* arycp = j.get();
1436         if (arycp->is_Arraycopy()) {
1437           for (UseIterator k(arycp); k.has_next(); k.next()) {
1438             PointsToNode* abase = k.get();
1439             if (abase->arraycopy_dst() && abase != base) {
1440               // Look for the same arraycopy reference.
1441               add_fields_to_worklist(field, abase);
1442             }
1443           }
1444         }
1445       }
1446     }
1447   }
1448 }
1449 
1450 // Put on worklist all related field nodes.
1451 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1452   int offset = field->offset();
1453   if (base->is_LocalVar()) {
1454     for (UseIterator j(base); j.has_next(); j.next()) {
1455       PointsToNode* f = j.get();
1456       if (PointsToNode::is_base_use(f)) { // Field
1457         f = PointsToNode::get_use_node(f);
1458         if (f == field || !f->as_Field()->is_oop())
1459           continue;
1460         int offs = f->as_Field()->offset();
1461         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1462           add_to_worklist(f);
1463         }
1464       }
1465     }
1466   } else {
1467     assert(base->is_JavaObject(), "sanity");
1468     if (// Skip phantom_object since it is only used to indicate that
1469         // this field's content globally escapes.
1470         (base != phantom_obj) &&
1471         // NULL object node does not have fields.
1472         (base != null_obj)) {
1473       for (EdgeIterator i(base); i.has_next(); i.next()) {
1474         PointsToNode* f = i.get();
1475         // Skip arraycopy edge since store to destination object field
1476         // does not update value in source object field.
1477         if (f->is_Arraycopy()) {
1478           assert(base->arraycopy_dst(), "sanity");
1479           continue;
1480         }
1481         if (f == field || !f->as_Field()->is_oop())
1482           continue;
1483         int offs = f->as_Field()->offset();
1484         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1485           add_to_worklist(f);
1486         }
1487       }
1488     }
1489   }
1490 }
1491 
1492 // Find fields which have unknown value.
1493 int ConnectionGraph::find_field_value(FieldNode* field) {
1494   // Escaped fields should have init value already.
1495   assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1496   int new_edges = 0;
1497   for (BaseIterator i(field); i.has_next(); i.next()) {
1498     PointsToNode* base = i.get();
1499     if (base->is_JavaObject()) {
1500       // Skip Allocate's fields which will be processed later.
1501       if (base->ideal_node()->is_Allocate())
1502         return 0;
1503       assert(base == null_obj, "only NULL ptr base expected here");
1504     }
1505   }
1506   if (add_edge(field, phantom_obj)) {
1507     // New edge was added
1508     new_edges++;
1509     add_field_uses_to_worklist(field);
1510   }
1511   return new_edges;
1512 }
1513 
1514 // Find fields initializing values for allocations.
1515 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1516   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1517   int new_edges = 0;
1518   Node* alloc = pta->ideal_node();
1519   if (init_val == phantom_obj) {
1520     // Do nothing for Allocate nodes since its fields values are
1521     // "known" unless they are initialized by arraycopy/clone.
1522     if (alloc->is_Allocate() && !pta->arraycopy_dst())
1523       return 0;
1524     assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1525 #ifdef ASSERT
1526     if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1527       const char* name = alloc->as_CallStaticJava()->_name;
1528       assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1529     }
1530 #endif
1531     // Non-escaped allocation returned from Java or runtime call have
1532     // unknown values in fields.
1533     for (EdgeIterator i(pta); i.has_next(); i.next()) {
1534       PointsToNode* field = i.get();
1535       if (field->is_Field() && field->as_Field()->is_oop()) {
1536         if (add_edge(field, phantom_obj)) {
1537           // New edge was added
1538           new_edges++;
1539           add_field_uses_to_worklist(field->as_Field());
1540         }
1541       }
1542     }
1543     return new_edges;
1544   }
1545   assert(init_val == null_obj, "sanity");
1546   // Do nothing for Call nodes since its fields values are unknown.
1547   if (!alloc->is_Allocate())
1548     return 0;
1549 
1550   InitializeNode* ini = alloc->as_Allocate()->initialization();
1551   bool visited_bottom_offset = false;
1552   GrowableArray<int> offsets_worklist;
1553 
1554   // Check if an oop field's initializing value is recorded and add
1555   // a corresponding NULL if field's value if it is not recorded.
1556   // Connection Graph does not record a default initialization by NULL
1557   // captured by Initialize node.
1558   //
1559   for (EdgeIterator i(pta); i.has_next(); i.next()) {
1560     PointsToNode* field = i.get(); // Field (AddP)
1561     if (!field->is_Field() || !field->as_Field()->is_oop())
1562       continue; // Not oop field
1563     int offset = field->as_Field()->offset();
1564     if (offset == Type::OffsetBot) {
1565       if (!visited_bottom_offset) {
1566         // OffsetBot is used to reference array's element,
1567         // always add reference to NULL to all Field nodes since we don't
1568         // known which element is referenced.
1569         if (add_edge(field, null_obj)) {
1570           // New edge was added
1571           new_edges++;
1572           add_field_uses_to_worklist(field->as_Field());
1573           visited_bottom_offset = true;
1574         }
1575       }
1576     } else {
1577       // Check only oop fields.
1578       const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1579       if (adr_type->isa_rawptr()) {
1580 #ifdef ASSERT
1581         // Raw pointers are used for initializing stores so skip it
1582         // since it should be recorded already
1583         Node* base = get_addp_base(field->ideal_node());
1584         assert(adr_type->isa_rawptr() && base->is_Proj() &&
1585                (base->in(0) == alloc),"unexpected pointer type");
1586 #endif
1587         continue;
1588       }
1589       if (!offsets_worklist.contains(offset)) {
1590         offsets_worklist.append(offset);
1591         Node* value = NULL;
1592         if (ini != NULL) {
1593           // StoreP::memory_type() == T_ADDRESS
1594           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1595           Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1596           // Make sure initializing store has the same type as this AddP.
1597           // This AddP may reference non existing field because it is on a
1598           // dead branch of bimorphic call which is not eliminated yet.
1599           if (store != NULL && store->is_Store() &&
1600               store->as_Store()->memory_type() == ft) {
1601             value = store->in(MemNode::ValueIn);
1602 #ifdef ASSERT
1603             if (VerifyConnectionGraph) {
1604               // Verify that AddP already points to all objects the value points to.
1605               PointsToNode* val = ptnode_adr(value->_idx);
1606               assert((val != NULL), "should be processed already");
1607               PointsToNode* missed_obj = NULL;
1608               if (val->is_JavaObject()) {
1609                 if (!field->points_to(val->as_JavaObject())) {
1610                   missed_obj = val;
1611                 }
1612               } else {
1613                 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1614                   tty->print_cr("----------init store has invalid value -----");
1615                   store->dump();
1616                   val->dump();
1617                   assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1618                 }
1619                 for (EdgeIterator j(val); j.has_next(); j.next()) {
1620                   PointsToNode* obj = j.get();
1621                   if (obj->is_JavaObject()) {
1622                     if (!field->points_to(obj->as_JavaObject())) {
1623                       missed_obj = obj;
1624                       break;
1625                     }
1626                   }
1627                 }
1628               }
1629               if (missed_obj != NULL) {
1630                 tty->print_cr("----------field---------------------------------");
1631                 field->dump();
1632                 tty->print_cr("----------missed referernce to object-----------");
1633                 missed_obj->dump();
1634                 tty->print_cr("----------object referernced by init store -----");
1635                 store->dump();
1636                 val->dump();
1637                 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1638               }
1639             }
1640 #endif
1641           } else {
1642             // There could be initializing stores which follow allocation.
1643             // For example, a volatile field store is not collected
1644             // by Initialize node.
1645             //
1646             // Need to check for dependent loads to separate such stores from
1647             // stores which follow loads. For now, add initial value NULL so
1648             // that compare pointers optimization works correctly.
1649           }
1650         }
1651         if (value == NULL) {
1652           // A field's initializing value was not recorded. Add NULL.
1653           if (add_edge(field, null_obj)) {
1654             // New edge was added
1655             new_edges++;
1656             add_field_uses_to_worklist(field->as_Field());
1657           }
1658         }
1659       }
1660     }
1661   }
1662   return new_edges;
1663 }
1664 
1665 // Adjust scalar_replaceable state after Connection Graph is built.
1666 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1667   // Search for non-escaping objects which are not scalar replaceable
1668   // and mark them to propagate the state to referenced objects.
1669 
1670   // 1. An object is not scalar replaceable if the field into which it is
1671   // stored has unknown offset (stored into unknown element of an array).
1672   //
1673   for (UseIterator i(jobj); i.has_next(); i.next()) {
1674     PointsToNode* use = i.get();
1675     if (use->is_Arraycopy()) {
1676       continue;
1677     }
1678     if (use->is_Field()) {
1679       FieldNode* field = use->as_Field();
1680       assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1681       if (field->offset() == Type::OffsetBot) {
1682         jobj->set_scalar_replaceable(false);
1683         return;
1684       }
1685       // 2. An object is not scalar replaceable if the field into which it is
1686       // stored has multiple bases one of which is null.
1687       if (field->base_count() > 1) {
1688         for (BaseIterator i(field); i.has_next(); i.next()) {
1689           PointsToNode* base = i.get();
1690           if (base == null_obj) {
1691             jobj->set_scalar_replaceable(false);
1692             return;
1693           }
1694         }
1695       }
1696     }
1697     assert(use->is_Field() || use->is_LocalVar(), "sanity");
1698     // 3. An object is not scalar replaceable if it is merged with other objects.
1699     for (EdgeIterator j(use); j.has_next(); j.next()) {
1700       PointsToNode* ptn = j.get();
1701       if (ptn->is_JavaObject() && ptn != jobj) {
1702         // Mark all objects.
1703         jobj->set_scalar_replaceable(false);
1704          ptn->set_scalar_replaceable(false);
1705       }
1706     }
1707     if (!jobj->scalar_replaceable()) {
1708       return;
1709     }
1710   }
1711 
1712   for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1713     if (j.get()->is_Arraycopy()) {
1714       continue;
1715     }
1716 
1717     // Non-escaping object node should point only to field nodes.
1718     FieldNode* field = j.get()->as_Field();
1719     int offset = field->as_Field()->offset();
1720 
1721     // 4. An object is not scalar replaceable if it has a field with unknown
1722     // offset (array's element is accessed in loop).
1723     if (offset == Type::OffsetBot) {
1724       jobj->set_scalar_replaceable(false);
1725       return;
1726     }
1727     // 5. Currently an object is not scalar replaceable if a LoadStore node
1728     // access its field since the field value is unknown after it.
1729     //
1730     Node* n = field->ideal_node();
1731     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1732       if (n->fast_out(i)->is_LoadStore()) {
1733         jobj->set_scalar_replaceable(false);
1734         return;
1735       }
1736     }
1737 
1738     // 6. Or the address may point to more then one object. This may produce
1739     // the false positive result (set not scalar replaceable)
1740     // since the flow-insensitive escape analysis can't separate
1741     // the case when stores overwrite the field's value from the case
1742     // when stores happened on different control branches.
1743     //
1744     // Note: it will disable scalar replacement in some cases:
1745     //
1746     //    Point p[] = new Point[1];
1747     //    p[0] = new Point(); // Will be not scalar replaced
1748     //
1749     // but it will save us from incorrect optimizations in next cases:
1750     //
1751     //    Point p[] = new Point[1];
1752     //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
1753     //
1754     if (field->base_count() > 1) {
1755       for (BaseIterator i(field); i.has_next(); i.next()) {
1756         PointsToNode* base = i.get();
1757         // Don't take into account LocalVar nodes which
1758         // may point to only one object which should be also
1759         // this field's base by now.
1760         if (base->is_JavaObject() && base != jobj) {
1761           // Mark all bases.
1762           jobj->set_scalar_replaceable(false);
1763           base->set_scalar_replaceable(false);
1764         }
1765       }
1766     }
1767   }
1768 }
1769 
1770 #ifdef ASSERT
1771 void ConnectionGraph::verify_connection_graph(
1772                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1773                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1774                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1775                          GrowableArray<Node*>& addp_worklist) {
1776   // Verify that graph is complete - no new edges could be added.
1777   int java_objects_length = java_objects_worklist.length();
1778   int non_escaped_length  = non_escaped_worklist.length();
1779   int new_edges = 0;
1780   for (int next = 0; next < java_objects_length; ++next) {
1781     JavaObjectNode* ptn = java_objects_worklist.at(next);
1782     new_edges += add_java_object_edges(ptn, true);
1783   }
1784   assert(new_edges == 0, "graph was not complete");
1785   // Verify that escape state is final.
1786   int length = non_escaped_worklist.length();
1787   find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1788   assert((non_escaped_length == non_escaped_worklist.length()) &&
1789          (non_escaped_length == length) &&
1790          (_worklist.length() == 0), "escape state was not final");
1791 
1792   // Verify fields information.
1793   int addp_length = addp_worklist.length();
1794   for (int next = 0; next < addp_length; ++next ) {
1795     Node* n = addp_worklist.at(next);
1796     FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1797     if (field->is_oop()) {
1798       // Verify that field has all bases
1799       Node* base = get_addp_base(n);
1800       PointsToNode* ptn = ptnode_adr(base->_idx);
1801       if (ptn->is_JavaObject()) {
1802         assert(field->has_base(ptn->as_JavaObject()), "sanity");
1803       } else {
1804         assert(ptn->is_LocalVar(), "sanity");
1805         for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1806           PointsToNode* e = i.get();
1807           if (e->is_JavaObject()) {
1808             assert(field->has_base(e->as_JavaObject()), "sanity");
1809           }
1810         }
1811       }
1812       // Verify that all fields have initializing values.
1813       if (field->edge_count() == 0) {
1814         tty->print_cr("----------field does not have references----------");
1815         field->dump();
1816         for (BaseIterator i(field); i.has_next(); i.next()) {
1817           PointsToNode* base = i.get();
1818           tty->print_cr("----------field has next base---------------------");
1819           base->dump();
1820           if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1821             tty->print_cr("----------base has fields-------------------------");
1822             for (EdgeIterator j(base); j.has_next(); j.next()) {
1823               j.get()->dump();
1824             }
1825             tty->print_cr("----------base has references---------------------");
1826             for (UseIterator j(base); j.has_next(); j.next()) {
1827               j.get()->dump();
1828             }
1829           }
1830         }
1831         for (UseIterator i(field); i.has_next(); i.next()) {
1832           i.get()->dump();
1833         }
1834         assert(field->edge_count() > 0, "sanity");
1835       }
1836     }
1837   }
1838 }
1839 #endif
1840 
1841 // Optimize ideal graph.
1842 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1843                                            GrowableArray<Node*>& storestore_worklist) {
1844   Compile* C = _compile;
1845   PhaseIterGVN* igvn = _igvn;
1846   if (EliminateLocks) {
1847     // Mark locks before changing ideal graph.
1848     int cnt = C->macro_count();
1849     for( int i=0; i < cnt; i++ ) {
1850       Node *n = C->macro_node(i);
1851       if (n->is_AbstractLock()) { // Lock and Unlock nodes
1852         AbstractLockNode* alock = n->as_AbstractLock();
1853         if (!alock->is_non_esc_obj()) {
1854           if (not_global_escape(alock->obj_node())) {
1855             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1856             // The lock could be marked eliminated by lock coarsening
1857             // code during first IGVN before EA. Replace coarsened flag
1858             // to eliminate all associated locks/unlocks.
1859 #ifdef ASSERT
1860             alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1861 #endif
1862             alock->set_non_esc_obj();
1863           }
1864         }
1865       }
1866     }
1867   }
1868 
1869   if (OptimizePtrCompare) {
1870     // Add ConI(#CC_GT) and ConI(#CC_EQ).
1871     _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1872     _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1873     // Optimize objects compare.
1874     while (ptr_cmp_worklist.length() != 0) {
1875       Node *n = ptr_cmp_worklist.pop();
1876       Node *res = optimize_ptr_compare(n);
1877       if (res != NULL) {
1878 #ifndef PRODUCT
1879         if (PrintOptimizePtrCompare) {
1880           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"));
1881           if (Verbose) {
1882             n->dump(1);
1883           }
1884         }
1885 #endif
1886         igvn->replace_node(n, res);
1887       }
1888     }
1889     // cleanup
1890     if (_pcmp_neq->outcnt() == 0)
1891       igvn->hash_delete(_pcmp_neq);
1892     if (_pcmp_eq->outcnt()  == 0)
1893       igvn->hash_delete(_pcmp_eq);
1894   }
1895 
1896   // For MemBarStoreStore nodes added in library_call.cpp, check
1897   // escape status of associated AllocateNode and optimize out
1898   // MemBarStoreStore node if the allocated object never escapes.
1899   while (storestore_worklist.length() != 0) {
1900     Node *n = storestore_worklist.pop();
1901     MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1902     Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1903     assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1904     if (not_global_escape(alloc)) {
1905       MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1906       mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1907       mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1908       igvn->register_new_node_with_optimizer(mb);
1909       igvn->replace_node(storestore, mb);
1910     }
1911   }
1912 }
1913 
1914 // Optimize objects compare.
1915 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1916   assert(OptimizePtrCompare, "sanity");
1917   PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1918   PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1919   JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1920   JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1921   assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1922   assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1923 
1924   // Check simple cases first.
1925   if (jobj1 != NULL) {
1926     if (jobj1->escape_state() == PointsToNode::NoEscape) {
1927       if (jobj1 == jobj2) {
1928         // Comparing the same not escaping object.
1929         return _pcmp_eq;
1930       }
1931       Node* obj = jobj1->ideal_node();
1932       // Comparing not escaping allocation.
1933       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1934           !ptn2->points_to(jobj1)) {
1935         return _pcmp_neq; // This includes nullness check.
1936       }
1937     }
1938   }
1939   if (jobj2 != NULL) {
1940     if (jobj2->escape_state() == PointsToNode::NoEscape) {
1941       Node* obj = jobj2->ideal_node();
1942       // Comparing not escaping allocation.
1943       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1944           !ptn1->points_to(jobj2)) {
1945         return _pcmp_neq; // This includes nullness check.
1946       }
1947     }
1948   }
1949   if (jobj1 != NULL && jobj1 != phantom_obj &&
1950       jobj2 != NULL && jobj2 != phantom_obj &&
1951       jobj1->ideal_node()->is_Con() &&
1952       jobj2->ideal_node()->is_Con()) {
1953     // Klass or String constants compare. Need to be careful with
1954     // compressed pointers - compare types of ConN and ConP instead of nodes.
1955     const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1956     const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1957     if (t1->make_ptr() == t2->make_ptr()) {
1958       return _pcmp_eq;
1959     } else {
1960       return _pcmp_neq;
1961     }
1962   }
1963   if (ptn1->meet(ptn2)) {
1964     return NULL; // Sets are not disjoint
1965   }
1966 
1967   // Sets are disjoint.
1968   bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1969   bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1970   bool set1_has_null_ptr    = ptn1->points_to(null_obj);
1971   bool set2_has_null_ptr    = ptn2->points_to(null_obj);
1972   if (set1_has_unknown_ptr && set2_has_null_ptr ||
1973       set2_has_unknown_ptr && set1_has_null_ptr) {
1974     // Check nullness of unknown object.
1975     return NULL;
1976   }
1977 
1978   // Disjointness by itself is not sufficient since
1979   // alias analysis is not complete for escaped objects.
1980   // Disjoint sets are definitely unrelated only when
1981   // at least one set has only not escaping allocations.
1982   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1983     if (ptn1->non_escaping_allocation()) {
1984       return _pcmp_neq;
1985     }
1986   }
1987   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1988     if (ptn2->non_escaping_allocation()) {
1989       return _pcmp_neq;
1990     }
1991   }
1992   return NULL;
1993 }
1994 
1995 // Connection Graph constuction functions.
1996 
1997 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1998   PointsToNode* ptadr = _nodes.at(n->_idx);
1999   if (ptadr != NULL) {
2000     assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
2001     return;
2002   }
2003   Compile* C = _compile;
2004   ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2005   _nodes.at_put(n->_idx, ptadr);
2006 }
2007 
2008 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2009   PointsToNode* ptadr = _nodes.at(n->_idx);
2010   if (ptadr != NULL) {
2011     assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2012     return;
2013   }
2014   Compile* C = _compile;
2015   ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2016   _nodes.at_put(n->_idx, ptadr);
2017 }
2018 
2019 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2020   PointsToNode* ptadr = _nodes.at(n->_idx);
2021   if (ptadr != NULL) {
2022     assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2023     return;
2024   }
2025   bool unsafe = false;
2026   bool is_oop = is_oop_field(n, offset, &unsafe);
2027   if (unsafe) {
2028     es = PointsToNode::GlobalEscape;
2029   }
2030   Compile* C = _compile;
2031   FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2032   _nodes.at_put(n->_idx, field);
2033 }
2034 
2035 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2036                                     PointsToNode* src, PointsToNode* dst) {
2037   assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2038   assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2039   PointsToNode* ptadr = _nodes.at(n->_idx);
2040   if (ptadr != NULL) {
2041     assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2042     return;
2043   }
2044   Compile* C = _compile;
2045   ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2046   _nodes.at_put(n->_idx, ptadr);
2047   // Add edge from arraycopy node to source object.
2048   (void)add_edge(ptadr, src);
2049   src->set_arraycopy_src();
2050   // Add edge from destination object to arraycopy node.
2051   (void)add_edge(dst, ptadr);
2052   dst->set_arraycopy_dst();
2053 }
2054 
2055 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2056   const Type* adr_type = n->as_AddP()->bottom_type();
2057   BasicType bt = T_INT;
2058   if (offset == Type::OffsetBot) {
2059     // Check only oop fields.
2060     if (!adr_type->isa_aryptr() ||
2061         (adr_type->isa_aryptr()->klass() == NULL) ||
2062          adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2063       // OffsetBot is used to reference array's element. Ignore first AddP.
2064       if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2065         bt = T_OBJECT;
2066       }
2067     }
2068   } else if (offset != oopDesc::klass_offset_in_bytes()) {
2069     if (adr_type->isa_instptr() || adr_type->isa_valuetypeptr()) {
2070       ciField* field = _compile->alias_type(adr_type->is_ptr())->field();
2071       if (field != NULL) {
2072         bt = field->layout_type();
2073       } else {
2074         // Check for unsafe oop field access
2075         if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2076             n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2077             n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2078           bt = T_OBJECT;
2079           (*unsafe) = true;
2080         }
2081       }
2082     } else if (adr_type->isa_aryptr()) {
2083       if (offset == arrayOopDesc::length_offset_in_bytes()) {
2084         // Ignore array length load.
2085       } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2086         // Ignore first AddP.
2087       } else {
2088         const Type* elemtype = adr_type->isa_aryptr()->elem();
2089         bt = elemtype->array_element_basic_type();
2090       }
2091     } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2092       // Allocation initialization, ThreadLocal field access, unsafe access
2093       if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2094           n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2095           n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2096         bt = T_OBJECT;
2097       }
2098     }
2099   }
2100   return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2101 }
2102 
2103 // Returns unique pointed java object or NULL.
2104 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2105   assert(!_collecting, "should not call when contructed graph");
2106   // If the node was created after the escape computation we can't answer.
2107   uint idx = n->_idx;
2108   if (idx >= nodes_size()) {
2109     return NULL;
2110   }
2111   PointsToNode* ptn = ptnode_adr(idx);
2112   if (ptn->is_JavaObject()) {
2113     return ptn->as_JavaObject();
2114   }
2115   assert(ptn->is_LocalVar(), "sanity");
2116   // Check all java objects it points to.
2117   JavaObjectNode* jobj = NULL;
2118   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2119     PointsToNode* e = i.get();
2120     if (e->is_JavaObject()) {
2121       if (jobj == NULL) {
2122         jobj = e->as_JavaObject();
2123       } else if (jobj != e) {
2124         return NULL;
2125       }
2126     }
2127   }
2128   return jobj;
2129 }
2130 
2131 // Return true if this node points only to non-escaping allocations.
2132 bool PointsToNode::non_escaping_allocation() {
2133   if (is_JavaObject()) {
2134     Node* n = ideal_node();
2135     if (n->is_Allocate() || n->is_CallStaticJava()) {
2136       return (escape_state() == PointsToNode::NoEscape);
2137     } else {
2138       return false;
2139     }
2140   }
2141   assert(is_LocalVar(), "sanity");
2142   // Check all java objects it points to.
2143   for (EdgeIterator i(this); i.has_next(); i.next()) {
2144     PointsToNode* e = i.get();
2145     if (e->is_JavaObject()) {
2146       Node* n = e->ideal_node();
2147       if ((e->escape_state() != PointsToNode::NoEscape) ||
2148           !(n->is_Allocate() || n->is_CallStaticJava())) {
2149         return false;
2150       }
2151     }
2152   }
2153   return true;
2154 }
2155 
2156 // Return true if we know the node does not escape globally.
2157 bool ConnectionGraph::not_global_escape(Node *n) {
2158   assert(!_collecting, "should not call during graph construction");
2159   // If the node was created after the escape computation we can't answer.
2160   uint idx = n->_idx;
2161   if (idx >= nodes_size()) {
2162     return false;
2163   }
2164   PointsToNode* ptn = ptnode_adr(idx);
2165   PointsToNode::EscapeState es = ptn->escape_state();
2166   // If we have already computed a value, return it.
2167   if (es >= PointsToNode::GlobalEscape)
2168     return false;
2169   if (ptn->is_JavaObject()) {
2170     return true; // (es < PointsToNode::GlobalEscape);
2171   }
2172   assert(ptn->is_LocalVar(), "sanity");
2173   // Check all java objects it points to.
2174   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2175     if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2176       return false;
2177   }
2178   return true;
2179 }
2180 
2181 
2182 // Helper functions
2183 
2184 // Return true if this node points to specified node or nodes it points to.
2185 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2186   if (is_JavaObject()) {
2187     return (this == ptn);
2188   }
2189   assert(is_LocalVar() || is_Field(), "sanity");
2190   for (EdgeIterator i(this); i.has_next(); i.next()) {
2191     if (i.get() == ptn)
2192       return true;
2193   }
2194   return false;
2195 }
2196 
2197 // Return true if one node points to an other.
2198 bool PointsToNode::meet(PointsToNode* ptn) {
2199   if (this == ptn) {
2200     return true;
2201   } else if (ptn->is_JavaObject()) {
2202     return this->points_to(ptn->as_JavaObject());
2203   } else if (this->is_JavaObject()) {
2204     return ptn->points_to(this->as_JavaObject());
2205   }
2206   assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2207   int ptn_count =  ptn->edge_count();
2208   for (EdgeIterator i(this); i.has_next(); i.next()) {
2209     PointsToNode* this_e = i.get();
2210     for (int j = 0; j < ptn_count; j++) {
2211       if (this_e == ptn->edge(j))
2212         return true;
2213     }
2214   }
2215   return false;
2216 }
2217 
2218 #ifdef ASSERT
2219 // Return true if bases point to this java object.
2220 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2221   for (BaseIterator i(this); i.has_next(); i.next()) {
2222     if (i.get() == jobj)
2223       return true;
2224   }
2225   return false;
2226 }
2227 #endif
2228 
2229 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2230   const Type *adr_type = phase->type(adr);
2231   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2232       adr->in(AddPNode::Address)->is_Proj() &&
2233       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2234     // We are computing a raw address for a store captured by an Initialize
2235     // compute an appropriate address type. AddP cases #3 and #5 (see below).
2236     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2237     assert(offs != Type::OffsetBot ||
2238            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2239            "offset must be a constant or it is initialization of array");
2240     return offs;
2241   }
2242   const TypePtr *t_ptr = adr_type->isa_ptr();
2243   assert(t_ptr != NULL, "must be a pointer type");
2244   return t_ptr->offset();
2245 }
2246 
2247 Node* ConnectionGraph::get_addp_base(Node *addp) {
2248   assert(addp->is_AddP(), "must be AddP");
2249   //
2250   // AddP cases for Base and Address inputs:
2251   // case #1. Direct object's field reference:
2252   //     Allocate
2253   //       |
2254   //     Proj #5 ( oop result )
2255   //       |
2256   //     CheckCastPP (cast to instance type)
2257   //      | |
2258   //     AddP  ( base == address )
2259   //
2260   // case #2. Indirect object's field reference:
2261   //      Phi
2262   //       |
2263   //     CastPP (cast to instance type)
2264   //      | |
2265   //     AddP  ( base == address )
2266   //
2267   // case #3. Raw object's field reference for Initialize node:
2268   //      Allocate
2269   //        |
2270   //      Proj #5 ( oop result )
2271   //  top   |
2272   //     \  |
2273   //     AddP  ( base == top )
2274   //
2275   // case #4. Array's element reference:
2276   //   {CheckCastPP | CastPP}
2277   //     |  | |
2278   //     |  AddP ( array's element offset )
2279   //     |  |
2280   //     AddP ( array's offset )
2281   //
2282   // case #5. Raw object's field reference for arraycopy stub call:
2283   //          The inline_native_clone() case when the arraycopy stub is called
2284   //          after the allocation before Initialize and CheckCastPP nodes.
2285   //      Allocate
2286   //        |
2287   //      Proj #5 ( oop result )
2288   //       | |
2289   //       AddP  ( base == address )
2290   //
2291   // case #6. Constant Pool, ThreadLocal, CastX2P or
2292   //          Raw object's field reference:
2293   //      {ConP, ThreadLocal, CastX2P, raw Load}
2294   //  top   |
2295   //     \  |
2296   //     AddP  ( base == top )
2297   //
2298   // case #7. Klass's field reference.
2299   //      LoadKlass
2300   //       | |
2301   //       AddP  ( base == address )
2302   //
2303   // case #8. narrow Klass's field reference.
2304   //      LoadNKlass
2305   //       |
2306   //      DecodeN
2307   //       | |
2308   //       AddP  ( base == address )
2309   //
2310   Node *base = addp->in(AddPNode::Base);
2311   if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2312     base = addp->in(AddPNode::Address);
2313     while (base->is_AddP()) {
2314       // Case #6 (unsafe access) may have several chained AddP nodes.
2315       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2316       base = base->in(AddPNode::Address);
2317     }
2318     Node* uncast_base = base->uncast();
2319     int opcode = uncast_base->Opcode();
2320     assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2321            opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2322            (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2323            (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2324   }
2325   return base;
2326 }
2327 
2328 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2329   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2330   Node* addp2 = addp->raw_out(0);
2331   if (addp->outcnt() == 1 && addp2->is_AddP() &&
2332       addp2->in(AddPNode::Base) == n &&
2333       addp2->in(AddPNode::Address) == addp) {
2334     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2335     //
2336     // Find array's offset to push it on worklist first and
2337     // as result process an array's element offset first (pushed second)
2338     // to avoid CastPP for the array's offset.
2339     // Otherwise the inserted CastPP (LocalVar) will point to what
2340     // the AddP (Field) points to. Which would be wrong since
2341     // the algorithm expects the CastPP has the same point as
2342     // as AddP's base CheckCastPP (LocalVar).
2343     //
2344     //    ArrayAllocation
2345     //     |
2346     //    CheckCastPP
2347     //     |
2348     //    memProj (from ArrayAllocation CheckCastPP)
2349     //     |  ||
2350     //     |  ||   Int (element index)
2351     //     |  ||    |   ConI (log(element size))
2352     //     |  ||    |   /
2353     //     |  ||   LShift
2354     //     |  ||  /
2355     //     |  AddP (array's element offset)
2356     //     |  |
2357     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
2358     //     | / /
2359     //     AddP (array's offset)
2360     //      |
2361     //     Load/Store (memory operation on array's element)
2362     //
2363     return addp2;
2364   }
2365   return NULL;
2366 }
2367 
2368 //
2369 // Adjust the type and inputs of an AddP which computes the
2370 // address of a field of an instance
2371 //
2372 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2373   PhaseGVN* igvn = _igvn;
2374   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2375   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2376   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2377   if (t == NULL) {
2378     // We are computing a raw address for a store captured by an Initialize
2379     // compute an appropriate address type (cases #3 and #5).
2380     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2381     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2382     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2383     assert(offs != Type::OffsetBot, "offset must be a constant");
2384     t = base_t->add_offset(offs)->is_oopptr();
2385   }
2386   int inst_id = base_t->instance_id();
2387   assert(!t->is_known_instance() || t->instance_id() == inst_id,
2388                              "old type must be non-instance or match new type");
2389 
2390   // The type 't' could be subclass of 'base_t'.
2391   // As result t->offset() could be large then base_t's size and it will
2392   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2393   // constructor verifies correctness of the offset.
2394   //
2395   // It could happened on subclass's branch (from the type profiling
2396   // inlining) which was not eliminated during parsing since the exactness
2397   // of the allocation type was not propagated to the subclass type check.
2398   //
2399   // Or the type 't' could be not related to 'base_t' at all.
2400   // It could happened when CHA type is different from MDO type on a dead path
2401   // (for example, from instanceof check) which is not collapsed during parsing.
2402   //
2403   // Do nothing for such AddP node and don't process its users since
2404   // this code branch will go away.
2405   //
2406   if (!t->is_known_instance() &&
2407       !base_t->klass()->is_subtype_of(t->klass())) {
2408      return false; // bail out
2409   }
2410   const TypePtr* tinst = base_t->add_offset(t->offset());
2411   if (tinst->isa_aryptr() && t->isa_aryptr()) {
2412     // In the case of a flattened value type array, each field has its
2413     // own slice so we need to keep track of the field being accessed.
2414     tinst = tinst->is_aryptr()->with_field_offset(t->is_aryptr()->field_offset());
2415   }
2416 
2417   // Do NOT remove the next line: ensure a new alias index is allocated
2418   // for the instance type. Note: C++ will not remove it since the call
2419   // has side effect.
2420   int alias_idx = _compile->get_alias_index(tinst);
2421   igvn->set_type(addp, tinst);
2422   // record the allocation in the node map
2423   set_map(addp, get_map(base->_idx));
2424   // Set addp's Base and Address to 'base'.
2425   Node *abase = addp->in(AddPNode::Base);
2426   Node *adr   = addp->in(AddPNode::Address);
2427   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2428       adr->in(0)->_idx == (uint)inst_id) {
2429     // Skip AddP cases #3 and #5.
2430   } else {
2431     assert(!abase->is_top(), "sanity"); // AddP case #3
2432     if (abase != base) {
2433       igvn->hash_delete(addp);
2434       addp->set_req(AddPNode::Base, base);
2435       if (abase == adr) {
2436         addp->set_req(AddPNode::Address, base);
2437       } else {
2438         // AddP case #4 (adr is array's element offset AddP node)
2439 #ifdef ASSERT
2440         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2441         assert(adr->is_AddP() && atype != NULL &&
2442                atype->instance_id() == inst_id, "array's element offset should be processed first");
2443 #endif
2444       }
2445       igvn->hash_insert(addp);
2446     }
2447   }
2448   // Put on IGVN worklist since at least addp's type was changed above.
2449   record_for_optimizer(addp);
2450   return true;
2451 }
2452 
2453 //
2454 // Create a new version of orig_phi if necessary. Returns either the newly
2455 // created phi or an existing phi.  Sets create_new to indicate whether a new
2456 // phi was created.  Cache the last newly created phi in the node map.
2457 //
2458 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, bool &new_created) {
2459   Compile *C = _compile;
2460   PhaseGVN* igvn = _igvn;
2461   new_created = false;
2462   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2463   // nothing to do if orig_phi is bottom memory or matches alias_idx
2464   if (phi_alias_idx == alias_idx) {
2465     return orig_phi;
2466   }
2467   // Have we recently created a Phi for this alias index?
2468   PhiNode *result = get_map_phi(orig_phi->_idx);
2469   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2470     return result;
2471   }
2472   // Previous check may fail when the same wide memory Phi was split into Phis
2473   // for different memory slices. Search all Phis for this region.
2474   if (result != NULL) {
2475     Node* region = orig_phi->in(0);
2476     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2477       Node* phi = region->fast_out(i);
2478       if (phi->is_Phi() &&
2479           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2480         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2481         return phi->as_Phi();
2482       }
2483     }
2484   }
2485   if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2486     if (C->do_escape_analysis() == true && !C->failing()) {
2487       // Retry compilation without escape analysis.
2488       // If this is the first failure, the sentinel string will "stick"
2489       // to the Compile object, and the C2Compiler will see it and retry.
2490       C->record_failure(C2Compiler::retry_no_escape_analysis());
2491     }
2492     return NULL;
2493   }
2494   orig_phi_worklist.append_if_missing(orig_phi);
2495   const TypePtr *atype = C->get_adr_type(alias_idx);
2496   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2497   C->copy_node_notes_to(result, orig_phi);
2498   igvn->set_type(result, result->bottom_type());
2499   record_for_optimizer(result);
2500   set_map(orig_phi, result);
2501   new_created = true;
2502   return result;
2503 }
2504 
2505 //
2506 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2507 // specified alias index.
2508 //
2509 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist) {
2510   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2511   Compile *C = _compile;
2512   PhaseGVN* igvn = _igvn;
2513   bool new_phi_created;
2514   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2515   if (!new_phi_created) {
2516     return result;
2517   }
2518   GrowableArray<PhiNode *>  phi_list;
2519   GrowableArray<uint>  cur_input;
2520   PhiNode *phi = orig_phi;
2521   uint idx = 1;
2522   bool finished = false;
2523   while(!finished) {
2524     while (idx < phi->req()) {
2525       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2526       if (mem != NULL && mem->is_Phi()) {
2527         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2528         if (new_phi_created) {
2529           // found an phi for which we created a new split, push current one on worklist and begin
2530           // processing new one
2531           phi_list.push(phi);
2532           cur_input.push(idx);
2533           phi = mem->as_Phi();
2534           result = newphi;
2535           idx = 1;
2536           continue;
2537         } else {
2538           mem = newphi;
2539         }
2540       }
2541       if (C->failing()) {
2542         return NULL;
2543       }
2544       result->set_req(idx++, mem);
2545     }
2546 #ifdef ASSERT
2547     // verify that the new Phi has an input for each input of the original
2548     assert( phi->req() == result->req(), "must have same number of inputs.");
2549     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2550 #endif
2551     // Check if all new phi's inputs have specified alias index.
2552     // Otherwise use old phi.
2553     for (uint i = 1; i < phi->req(); i++) {
2554       Node* in = result->in(i);
2555       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2556     }
2557     // we have finished processing a Phi, see if there are any more to do
2558     finished = (phi_list.length() == 0 );
2559     if (!finished) {
2560       phi = phi_list.pop();
2561       idx = cur_input.pop();
2562       PhiNode *prev_result = get_map_phi(phi->_idx);
2563       prev_result->set_req(idx++, result);
2564       result = prev_result;
2565     }
2566   }
2567   return result;
2568 }
2569 
2570 //
2571 // The next methods are derived from methods in MemNode.
2572 //
2573 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2574   Node *mem = mmem;
2575   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2576   // means an array I have not precisely typed yet.  Do not do any
2577   // alias stuff with it any time soon.
2578   if (toop->base() != Type::AnyPtr &&
2579       !(toop->klass() != NULL &&
2580         toop->klass()->is_java_lang_Object() &&
2581         toop->offset() == Type::OffsetBot)) {
2582     mem = mmem->memory_at(alias_idx);
2583     // Update input if it is progress over what we have now
2584   }
2585   return mem;
2586 }
2587 
2588 //
2589 // Move memory users to their memory slices.
2590 //
2591 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis) {
2592   Compile* C = _compile;
2593   PhaseGVN* igvn = _igvn;
2594   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2595   assert(tp != NULL, "ptr type");
2596   int alias_idx = C->get_alias_index(tp);
2597   int general_idx = C->get_general_index(alias_idx);
2598 
2599   // Move users first
2600   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2601     Node* use = n->fast_out(i);
2602     if (use->is_MergeMem()) {
2603       MergeMemNode* mmem = use->as_MergeMem();
2604       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2605       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2606         continue; // Nothing to do
2607       }
2608       // Replace previous general reference to mem node.
2609       uint orig_uniq = C->unique();
2610       Node* m = find_inst_mem(n, general_idx, orig_phis);
2611       assert(orig_uniq == C->unique(), "no new nodes");
2612       mmem->set_memory_at(general_idx, m);
2613       --imax;
2614       --i;
2615     } else if (use->is_MemBar()) {
2616       assert(!use->is_Initialize(), "initializing stores should not be moved");
2617       if (use->req() > MemBarNode::Precedent &&
2618           use->in(MemBarNode::Precedent) == n) {
2619         // Don't move related membars.
2620         record_for_optimizer(use);
2621         continue;
2622       }
2623       tp = use->as_MemBar()->adr_type()->isa_ptr();
2624       if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2625           alias_idx == general_idx) {
2626         continue; // Nothing to do
2627       }
2628       // Move to general memory slice.
2629       uint orig_uniq = C->unique();
2630       Node* m = find_inst_mem(n, general_idx, orig_phis);
2631       assert(orig_uniq == C->unique(), "no new nodes");
2632       igvn->hash_delete(use);
2633       imax -= use->replace_edge(n, m);
2634       igvn->hash_insert(use);
2635       record_for_optimizer(use);
2636       --i;
2637 #ifdef ASSERT
2638     } else if (use->is_Mem()) {
2639       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2640         // Don't move related cardmark.
2641         continue;
2642       }
2643       // Memory nodes should have new memory input.
2644       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2645       assert(tp != NULL, "ptr type");
2646       int idx = C->get_alias_index(tp);
2647       assert(get_map(use->_idx) != NULL || idx == alias_idx,
2648              "Following memory nodes should have new memory input or be on the same memory slice");
2649     } else if (use->is_Phi()) {
2650       // Phi nodes should be split and moved already.
2651       tp = use->as_Phi()->adr_type()->isa_ptr();
2652       assert(tp != NULL, "ptr type");
2653       int idx = C->get_alias_index(tp);
2654       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2655     } else {
2656       use->dump();
2657       assert(false, "should not be here");
2658 #endif
2659     }
2660   }
2661 }
2662 
2663 //
2664 // Search memory chain of "mem" to find a MemNode whose address
2665 // is the specified alias index.
2666 //
2667 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis) {
2668   if (orig_mem == NULL)
2669     return orig_mem;
2670   Compile* C = _compile;
2671   PhaseGVN* igvn = _igvn;
2672   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2673   bool is_instance = (toop != NULL) && toop->is_known_instance();
2674   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2675   Node *prev = NULL;
2676   Node *result = orig_mem;
2677   while (prev != result) {
2678     prev = result;
2679     if (result == start_mem)
2680       break;  // hit one of our sentinels
2681     if (result->is_Mem()) {
2682       const Type *at = igvn->type(result->in(MemNode::Address));
2683       if (at == Type::TOP)
2684         break; // Dead
2685       assert (at->isa_ptr() != NULL, "pointer type required.");
2686       int idx = C->get_alias_index(at->is_ptr());
2687       if (idx == alias_idx)
2688         break; // Found
2689       if (!is_instance && (at->isa_oopptr() == NULL ||
2690                            !at->is_oopptr()->is_known_instance())) {
2691         break; // Do not skip store to general memory slice.
2692       }
2693       result = result->in(MemNode::Memory);
2694     }
2695     if (!is_instance)
2696       continue;  // don't search further for non-instance types
2697     // skip over a call which does not affect this memory slice
2698     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2699       Node *proj_in = result->in(0);
2700       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2701         break;  // hit one of our sentinels
2702       } else if (proj_in->is_Call()) {
2703         // ArrayCopy node processed here as well
2704         CallNode *call = proj_in->as_Call();
2705         if (!call->may_modify(toop, igvn)) {
2706           result = call->in(TypeFunc::Memory);
2707         }
2708       } else if (proj_in->is_Initialize()) {
2709         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2710         // Stop if this is the initialization for the object instance which
2711         // which contains this memory slice, otherwise skip over it.
2712         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2713           result = proj_in->in(TypeFunc::Memory);
2714         }
2715       } else if (proj_in->is_MemBar()) {
2716         if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2717             proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2718             proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2719           // clone
2720           ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2721           if (ac->may_modify(toop, igvn)) {
2722             break;
2723           }
2724         }
2725         result = proj_in->in(TypeFunc::Memory);
2726       }
2727     } else if (result->is_MergeMem()) {
2728       MergeMemNode *mmem = result->as_MergeMem();
2729       result = step_through_mergemem(mmem, alias_idx, toop);
2730       if (result == mmem->base_memory()) {
2731         // Didn't find instance memory, search through general slice recursively.
2732         result = mmem->memory_at(C->get_general_index(alias_idx));
2733         result = find_inst_mem(result, alias_idx, orig_phis);
2734         if (C->failing()) {
2735           return NULL;
2736         }
2737         mmem->set_memory_at(alias_idx, result);
2738       }
2739     } else if (result->is_Phi() &&
2740                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2741       Node *un = result->as_Phi()->unique_input(igvn);
2742       if (un != NULL) {
2743         orig_phis.append_if_missing(result->as_Phi());
2744         result = un;
2745       } else {
2746         break;
2747       }
2748     } else if (result->is_ClearArray()) {
2749       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2750         // Can not bypass initialization of the instance
2751         // we are looking for.
2752         break;
2753       }
2754       // Otherwise skip it (the call updated 'result' value).
2755     } else if (result->Opcode() == Op_SCMemProj) {
2756       Node* mem = result->in(0);
2757       Node* adr = NULL;
2758       if (mem->is_LoadStore()) {
2759         adr = mem->in(MemNode::Address);
2760       } else {
2761         assert(mem->Opcode() == Op_EncodeISOArray ||
2762                mem->Opcode() == Op_StrCompressedCopy, "sanity");
2763         adr = mem->in(3); // Memory edge corresponds to destination array
2764       }
2765       const Type *at = igvn->type(adr);
2766       if (at != Type::TOP) {
2767         assert(at->isa_ptr() != NULL, "pointer type required.");
2768         int idx = C->get_alias_index(at->is_ptr());
2769         if (idx == alias_idx) {
2770           // Assert in debug mode
2771           assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2772           break; // In product mode return SCMemProj node
2773         }
2774       }
2775       result = mem->in(MemNode::Memory);
2776     } else if (result->Opcode() == Op_StrInflatedCopy) {
2777       Node* adr = result->in(3); // Memory edge corresponds to destination array
2778       const Type *at = igvn->type(adr);
2779       if (at != Type::TOP) {
2780         assert(at->isa_ptr() != NULL, "pointer type required.");
2781         int idx = C->get_alias_index(at->is_ptr());
2782         if (idx == alias_idx) {
2783           // Assert in debug mode
2784           assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2785           break; // In product mode return SCMemProj node
2786         }
2787       }
2788       result = result->in(MemNode::Memory);
2789     }
2790   }
2791   if (result->is_Phi()) {
2792     PhiNode *mphi = result->as_Phi();
2793     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2794     const TypePtr *t = mphi->adr_type();
2795     if (!is_instance) {
2796       // Push all non-instance Phis on the orig_phis worklist to update inputs
2797       // during Phase 4 if needed.
2798       orig_phis.append_if_missing(mphi);
2799     } else if (C->get_alias_index(t) != alias_idx) {
2800       // Create a new Phi with the specified alias index type.
2801       result = split_memory_phi(mphi, alias_idx, orig_phis);
2802     }
2803   }
2804   // the result is either MemNode, PhiNode, InitializeNode.
2805   return result;
2806 }
2807 
2808 //
2809 //  Convert the types of unescaped object to instance types where possible,
2810 //  propagate the new type information through the graph, and update memory
2811 //  edges and MergeMem inputs to reflect the new type.
2812 //
2813 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
2814 //  The processing is done in 4 phases:
2815 //
2816 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
2817 //            types for the CheckCastPP for allocations where possible.
2818 //            Propagate the new types through users as follows:
2819 //               casts and Phi:  push users on alloc_worklist
2820 //               AddP:  cast Base and Address inputs to the instance type
2821 //                      push any AddP users on alloc_worklist and push any memnode
2822 //                      users onto memnode_worklist.
2823 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
2824 //            search the Memory chain for a store with the appropriate type
2825 //            address type.  If a Phi is found, create a new version with
2826 //            the appropriate memory slices from each of the Phi inputs.
2827 //            For stores, process the users as follows:
2828 //               MemNode:  push on memnode_worklist
2829 //               MergeMem: push on mergemem_worklist
2830 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
2831 //            moving the first node encountered of each  instance type to the
2832 //            the input corresponding to its alias index.
2833 //            appropriate memory slice.
2834 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2835 //
2836 // In the following example, the CheckCastPP nodes are the cast of allocation
2837 // results and the allocation of node 29 is unescaped and eligible to be an
2838 // instance type.
2839 //
2840 // We start with:
2841 //
2842 //     7 Parm #memory
2843 //    10  ConI  "12"
2844 //    19  CheckCastPP   "Foo"
2845 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2846 //    29  CheckCastPP   "Foo"
2847 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
2848 //
2849 //    40  StoreP  25   7  20   ... alias_index=4
2850 //    50  StoreP  35  40  30   ... alias_index=4
2851 //    60  StoreP  45  50  20   ... alias_index=4
2852 //    70  LoadP    _  60  30   ... alias_index=4
2853 //    80  Phi     75  50  60   Memory alias_index=4
2854 //    90  LoadP    _  80  30   ... alias_index=4
2855 //   100  LoadP    _  80  20   ... alias_index=4
2856 //
2857 //
2858 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2859 // and creating a new alias index for node 30.  This gives:
2860 //
2861 //     7 Parm #memory
2862 //    10  ConI  "12"
2863 //    19  CheckCastPP   "Foo"
2864 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2865 //    29  CheckCastPP   "Foo"  iid=24
2866 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2867 //
2868 //    40  StoreP  25   7  20   ... alias_index=4
2869 //    50  StoreP  35  40  30   ... alias_index=6
2870 //    60  StoreP  45  50  20   ... alias_index=4
2871 //    70  LoadP    _  60  30   ... alias_index=6
2872 //    80  Phi     75  50  60   Memory alias_index=4
2873 //    90  LoadP    _  80  30   ... alias_index=6
2874 //   100  LoadP    _  80  20   ... alias_index=4
2875 //
2876 // In phase 2, new memory inputs are computed for the loads and stores,
2877 // And a new version of the phi is created.  In phase 4, the inputs to
2878 // node 80 are updated and then the memory nodes are updated with the
2879 // values computed in phase 2.  This results in:
2880 //
2881 //     7 Parm #memory
2882 //    10  ConI  "12"
2883 //    19  CheckCastPP   "Foo"
2884 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2885 //    29  CheckCastPP   "Foo"  iid=24
2886 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2887 //
2888 //    40  StoreP  25  7   20   ... alias_index=4
2889 //    50  StoreP  35  7   30   ... alias_index=6
2890 //    60  StoreP  45  40  20   ... alias_index=4
2891 //    70  LoadP    _  50  30   ... alias_index=6
2892 //    80  Phi     75  40  60   Memory alias_index=4
2893 //   120  Phi     75  50  50   Memory alias_index=6
2894 //    90  LoadP    _ 120  30   ... alias_index=6
2895 //   100  LoadP    _  80  20   ... alias_index=4
2896 //
2897 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2898   GrowableArray<Node *>  memnode_worklist;
2899   GrowableArray<PhiNode *>  orig_phis;
2900   PhaseIterGVN  *igvn = _igvn;
2901   uint new_index_start = (uint) _compile->num_alias_types();
2902   Arena* arena = Thread::current()->resource_area();
2903   VectorSet visited(arena);
2904   ideal_nodes.clear(); // Reset for use with set_map/get_map.
2905   uint unique_old = _compile->unique();
2906 
2907   //  Phase 1:  Process possible allocations from alloc_worklist.
2908   //  Create instance types for the CheckCastPP for allocations where possible.
2909   //
2910   // (Note: don't forget to change the order of the second AddP node on
2911   //  the alloc_worklist if the order of the worklist processing is changed,
2912   //  see the comment in find_second_addp().)
2913   //
2914   while (alloc_worklist.length() != 0) {
2915     Node *n = alloc_worklist.pop();
2916     uint ni = n->_idx;
2917     if (n->is_Call()) {
2918       CallNode *alloc = n->as_Call();
2919       // copy escape information to call node
2920       PointsToNode* ptn = ptnode_adr(alloc->_idx);
2921       PointsToNode::EscapeState es = ptn->escape_state();
2922       // We have an allocation or call which returns a Java object,
2923       // see if it is unescaped.
2924       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2925         continue;
2926       // Find CheckCastPP for the allocate or for the return value of a call
2927       n = alloc->result_cast();
2928       if (n == NULL) {            // No uses except Initialize node
2929         if (alloc->is_Allocate()) {
2930           // Set the scalar_replaceable flag for allocation
2931           // so it could be eliminated if it has no uses.
2932           alloc->as_Allocate()->_is_scalar_replaceable = true;
2933         }
2934         if (alloc->is_CallStaticJava()) {
2935           // Set the scalar_replaceable flag for boxing method
2936           // so it could be eliminated if it has no uses.
2937           alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2938         }
2939         continue;
2940       }
2941       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2942         assert(!alloc->is_Allocate(), "allocation should have unique type");
2943         continue;
2944       }
2945 
2946       // The inline code for Object.clone() casts the allocation result to
2947       // java.lang.Object and then to the actual type of the allocated
2948       // object. Detect this case and use the second cast.
2949       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2950       // the allocation result is cast to java.lang.Object and then
2951       // to the actual Array type.
2952       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2953           && (alloc->is_AllocateArray() ||
2954               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2955         Node *cast2 = NULL;
2956         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2957           Node *use = n->fast_out(i);
2958           if (use->is_CheckCastPP()) {
2959             cast2 = use;
2960             break;
2961           }
2962         }
2963         if (cast2 != NULL) {
2964           n = cast2;
2965         } else {
2966           // Non-scalar replaceable if the allocation type is unknown statically
2967           // (reflection allocation), the object can't be restored during
2968           // deoptimization without precise type.
2969           continue;
2970         }
2971       }
2972 
2973       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2974       if (t == NULL)
2975         continue;  // not a TypeOopPtr
2976       if (!t->klass_is_exact())
2977         continue; // not an unique type
2978 
2979       if (alloc->is_Allocate()) {
2980         // Set the scalar_replaceable flag for allocation
2981         // so it could be eliminated.
2982         alloc->as_Allocate()->_is_scalar_replaceable = true;
2983       }
2984       if (alloc->is_CallStaticJava()) {
2985         // Set the scalar_replaceable flag for boxing method
2986         // so it could be eliminated.
2987         alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2988       }
2989       set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2990       // in order for an object to be scalar-replaceable, it must be:
2991       //   - a direct allocation (not a call returning an object)
2992       //   - non-escaping
2993       //   - eligible to be a unique type
2994       //   - not determined to be ineligible by escape analysis
2995       set_map(alloc, n);
2996       set_map(n, alloc);
2997       const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
2998       igvn->hash_delete(n);
2999       igvn->set_type(n,  tinst);
3000       n->raise_bottom_type(tinst);
3001       igvn->hash_insert(n);
3002       record_for_optimizer(n);
3003       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr() || t->isa_valuetypeptr())) {
3004 
3005         // First, put on the worklist all Field edges from Connection Graph
3006         // which is more accurate than putting immediate users from Ideal Graph.
3007         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3008           PointsToNode* tgt = e.get();
3009           if (tgt->is_Arraycopy()) {
3010             continue;
3011           }
3012           Node* use = tgt->ideal_node();
3013           assert(tgt->is_Field() && use->is_AddP(),
3014                  "only AddP nodes are Field edges in CG");
3015           if (use->outcnt() > 0) { // Don't process dead nodes
3016             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3017             if (addp2 != NULL) {
3018               assert(alloc->is_AllocateArray(),"array allocation was expected");
3019               alloc_worklist.append_if_missing(addp2);
3020             }
3021             alloc_worklist.append_if_missing(use);
3022           }
3023         }
3024 
3025         // An allocation may have an Initialize which has raw stores. Scan
3026         // the users of the raw allocation result and push AddP users
3027         // on alloc_worklist.
3028         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
3029         assert (raw_result != NULL, "must have an allocation result");
3030         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3031           Node *use = raw_result->fast_out(i);
3032           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3033             Node* addp2 = find_second_addp(use, raw_result);
3034             if (addp2 != NULL) {
3035               assert(alloc->is_AllocateArray(),"array allocation was expected");
3036               alloc_worklist.append_if_missing(addp2);
3037             }
3038             alloc_worklist.append_if_missing(use);
3039           } else if (use->is_MemBar()) {
3040             memnode_worklist.append_if_missing(use);
3041           }
3042         }
3043       }
3044     } else if (n->is_AddP()) {
3045       JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3046       if (jobj == NULL || jobj == phantom_obj) {
3047 #ifdef ASSERT
3048         ptnode_adr(get_addp_base(n)->_idx)->dump();
3049         ptnode_adr(n->_idx)->dump();
3050         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3051 #endif
3052         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3053         return;
3054       }
3055       Node *base = get_map(jobj->idx());  // CheckCastPP node
3056       if (!split_AddP(n, base)) continue; // wrong type from dead path
3057     } else if (n->is_Phi() ||
3058                n->is_CheckCastPP() ||
3059                n->is_EncodeP() ||
3060                n->is_DecodeN() ||
3061                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3062       if (visited.test_set(n->_idx)) {
3063         assert(n->is_Phi(), "loops only through Phi's");
3064         continue;  // already processed
3065       }
3066       JavaObjectNode* jobj = unique_java_object(n);
3067       if (jobj == NULL || jobj == phantom_obj) {
3068 #ifdef ASSERT
3069         ptnode_adr(n->_idx)->dump();
3070         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3071 #endif
3072         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3073         return;
3074       } else {
3075         Node *val = get_map(jobj->idx());   // CheckCastPP node
3076         TypeNode *tn = n->as_Type();
3077         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3078         assert(tinst != NULL && tinst->is_known_instance() &&
3079                tinst->instance_id() == jobj->idx() , "instance type expected.");
3080 
3081         const Type *tn_type = igvn->type(tn);
3082         const TypeOopPtr *tn_t;
3083         if (tn_type->isa_narrowoop()) {
3084           tn_t = tn_type->make_ptr()->isa_oopptr();
3085         } else {
3086           tn_t = tn_type->isa_oopptr();
3087         }
3088         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3089           if (tn_type->isa_narrowoop()) {
3090             tn_type = tinst->make_narrowoop();
3091           } else {
3092             tn_type = tinst;
3093           }
3094           igvn->hash_delete(tn);
3095           igvn->set_type(tn, tn_type);
3096           tn->set_type(tn_type);
3097           igvn->hash_insert(tn);
3098           record_for_optimizer(n);
3099         } else {
3100           assert(tn_type == TypePtr::NULL_PTR ||
3101                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3102                  "unexpected type");
3103           continue; // Skip dead path with different type
3104         }
3105       }
3106     } else {
3107       debug_only(n->dump();)
3108       assert(false, "EA: unexpected node");
3109       continue;
3110     }
3111     // push allocation's users on appropriate worklist
3112     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3113       Node *use = n->fast_out(i);
3114       if(use->is_Mem() && use->in(MemNode::Address) == n) {
3115         // Load/store to instance's field
3116         memnode_worklist.append_if_missing(use);
3117       } else if (use->is_MemBar()) {
3118         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3119           memnode_worklist.append_if_missing(use);
3120         }
3121       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3122         Node* addp2 = find_second_addp(use, n);
3123         if (addp2 != NULL) {
3124           alloc_worklist.append_if_missing(addp2);
3125         }
3126         alloc_worklist.append_if_missing(use);
3127       } else if (use->is_Phi() ||
3128                  use->is_CheckCastPP() ||
3129                  use->is_EncodeNarrowPtr() ||
3130                  use->is_DecodeNarrowPtr() ||
3131                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3132         alloc_worklist.append_if_missing(use);
3133 #ifdef ASSERT
3134       } else if (use->is_Mem()) {
3135         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3136       } else if (use->is_MergeMem()) {
3137         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3138       } else if (use->is_SafePoint()) {
3139         // Look for MergeMem nodes for calls which reference unique allocation
3140         // (through CheckCastPP nodes) even for debug info.
3141         Node* m = use->in(TypeFunc::Memory);
3142         if (m->is_MergeMem()) {
3143           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3144         }
3145       } else if (use->Opcode() == Op_EncodeISOArray) {
3146         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3147           // EncodeISOArray overwrites destination array
3148           memnode_worklist.append_if_missing(use);
3149         }
3150       } else {
3151         uint op = use->Opcode();
3152         if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3153             (use->in(MemNode::Memory) == n)) {
3154           // They overwrite memory edge corresponding to destination array,
3155           memnode_worklist.append_if_missing(use);
3156         } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3157               op == Op_CastP2X || op == Op_StoreCM ||
3158               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3159               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3160               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
3161               op == Op_ValueType)) {
3162           n->dump();
3163           use->dump();
3164           assert(false, "EA: missing allocation reference path");
3165         }
3166 #endif
3167       }
3168     }
3169 
3170   }
3171 
3172   // Go over all ArrayCopy nodes and if one of the inputs has a unique
3173   // type, record it in the ArrayCopy node so we know what memory this
3174   // node uses/modified.
3175   for (int next = 0; next < arraycopy_worklist.length(); next++) {
3176     ArrayCopyNode* ac = arraycopy_worklist.at(next);
3177     Node* dest = ac->in(ArrayCopyNode::Dest);
3178     if (dest->is_AddP()) {
3179       dest = get_addp_base(dest);
3180     }
3181     JavaObjectNode* jobj = unique_java_object(dest);
3182     if (jobj != NULL) {
3183       Node *base = get_map(jobj->idx());
3184       if (base != NULL) {
3185         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3186         ac->_dest_type = base_t;
3187       }
3188     }
3189     Node* src = ac->in(ArrayCopyNode::Src);
3190     if (src->is_AddP()) {
3191       src = get_addp_base(src);
3192     }
3193     jobj = unique_java_object(src);
3194     if (jobj != NULL) {
3195       Node* base = get_map(jobj->idx());
3196       if (base != NULL) {
3197         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3198         ac->_src_type = base_t;
3199       }
3200     }
3201   }
3202 
3203   // New alias types were created in split_AddP().
3204   uint new_index_end = (uint) _compile->num_alias_types();
3205   assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3206 
3207   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
3208   //            compute new values for Memory inputs  (the Memory inputs are not
3209   //            actually updated until phase 4.)
3210   if (memnode_worklist.length() == 0)
3211     return;  // nothing to do
3212   while (memnode_worklist.length() != 0) {
3213     Node *n = memnode_worklist.pop();
3214     if (visited.test_set(n->_idx))
3215       continue;
3216     if (n->is_Phi() || n->is_ClearArray()) {
3217       // we don't need to do anything, but the users must be pushed
3218     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3219       // we don't need to do anything, but the users must be pushed
3220       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3221       if (n == NULL)
3222         continue;
3223     } else if (n->Opcode() == Op_StrCompressedCopy ||
3224                n->Opcode() == Op_EncodeISOArray) {
3225       // get the memory projection
3226       n = n->find_out_with(Op_SCMemProj);
3227       assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3228     } else {
3229       assert(n->is_Mem(), "memory node required.");
3230       Node *addr = n->in(MemNode::Address);
3231       const Type *addr_t = igvn->type(addr);
3232       if (addr_t == Type::TOP)
3233         continue;
3234       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3235       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3236       assert ((uint)alias_idx < new_index_end, "wrong alias index");
3237       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3238       if (_compile->failing()) {
3239         return;
3240       }
3241       if (mem != n->in(MemNode::Memory)) {
3242         // We delay the memory edge update since we need old one in
3243         // MergeMem code below when instances memory slices are separated.
3244         set_map(n, mem);
3245       }
3246       if (n->is_Load()) {
3247         continue;  // don't push users
3248       } else if (n->is_LoadStore()) {
3249         // get the memory projection
3250         n = n->find_out_with(Op_SCMemProj);
3251         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3252       }
3253     }
3254     // push user on appropriate worklist
3255     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3256       Node *use = n->fast_out(i);
3257       if (use->is_Phi() || use->is_ClearArray()) {
3258         memnode_worklist.append_if_missing(use);
3259       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3260         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3261           continue;
3262         memnode_worklist.append_if_missing(use);
3263       } else if (use->is_MemBar()) {
3264         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3265           memnode_worklist.append_if_missing(use);
3266         }
3267 #ifdef ASSERT
3268       } else if(use->is_Mem()) {
3269         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3270       } else if (use->is_MergeMem()) {
3271         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3272       } else if (use->Opcode() == Op_EncodeISOArray) {
3273         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3274           // EncodeISOArray overwrites destination array
3275           memnode_worklist.append_if_missing(use);
3276         }
3277       } else {
3278         uint op = use->Opcode();
3279         if ((use->in(MemNode::Memory) == n) &&
3280             (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3281           // They overwrite memory edge corresponding to destination array,
3282           memnode_worklist.append_if_missing(use);
3283         } else if (!(op == Op_StoreCM ||
3284               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3285                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3286               op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3287               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3288               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3289           n->dump();
3290           use->dump();
3291           assert(false, "EA: missing memory path");
3292         }
3293 #endif
3294       }
3295     }
3296   }
3297 
3298   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
3299   //            Walk each memory slice moving the first node encountered of each
3300   //            instance type to the input corresponding to its alias index.
3301   uint length = _mergemem_worklist.length();
3302   for( uint next = 0; next < length; ++next ) {
3303     MergeMemNode* nmm = _mergemem_worklist.at(next);
3304     assert(!visited.test_set(nmm->_idx), "should not be visited before");
3305     // Note: we don't want to use MergeMemStream here because we only want to
3306     // scan inputs which exist at the start, not ones we add during processing.
3307     // Note 2: MergeMem may already contains instance memory slices added
3308     // during find_inst_mem() call when memory nodes were processed above.
3309     igvn->hash_delete(nmm);
3310     uint nslices = MIN2(nmm->req(), new_index_start);
3311     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3312       Node* mem = nmm->in(i);
3313       Node* cur = NULL;
3314       if (mem == NULL || mem->is_top())
3315         continue;
3316       // First, update mergemem by moving memory nodes to corresponding slices
3317       // if their type became more precise since this mergemem was created.
3318       while (mem->is_Mem()) {
3319         const Type *at = igvn->type(mem->in(MemNode::Address));
3320         if (at != Type::TOP) {
3321           assert (at->isa_ptr() != NULL, "pointer type required.");
3322           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3323           if (idx == i) {
3324             if (cur == NULL)
3325               cur = mem;
3326           } else {
3327             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3328               nmm->set_memory_at(idx, mem);
3329             }
3330           }
3331         }
3332         mem = mem->in(MemNode::Memory);
3333       }
3334       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3335       // Find any instance of the current type if we haven't encountered
3336       // already a memory slice of the instance along the memory chain.
3337       for (uint ni = new_index_start; ni < new_index_end; ni++) {
3338         if((uint)_compile->get_general_index(ni) == i) {
3339           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3340           if (nmm->is_empty_memory(m)) {
3341             Node* result = find_inst_mem(mem, ni, orig_phis);
3342             if (_compile->failing()) {
3343               return;
3344             }
3345             nmm->set_memory_at(ni, result);
3346           }
3347         }
3348       }
3349     }
3350     // Find the rest of instances values
3351     for (uint ni = new_index_start; ni < new_index_end; ni++) {
3352       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3353       Node* result = step_through_mergemem(nmm, ni, tinst);
3354       if (result == nmm->base_memory()) {
3355         // Didn't find instance memory, search through general slice recursively.
3356         result = nmm->memory_at(_compile->get_general_index(ni));
3357         result = find_inst_mem(result, ni, orig_phis);
3358         if (_compile->failing()) {
3359           return;
3360         }
3361         nmm->set_memory_at(ni, result);
3362       }
3363     }
3364     igvn->hash_insert(nmm);
3365     record_for_optimizer(nmm);
3366   }
3367 
3368   //  Phase 4:  Update the inputs of non-instance memory Phis and
3369   //            the Memory input of memnodes
3370   // First update the inputs of any non-instance Phi's from
3371   // which we split out an instance Phi.  Note we don't have
3372   // to recursively process Phi's encountered on the input memory
3373   // chains as is done in split_memory_phi() since they will
3374   // also be processed here.
3375   for (int j = 0; j < orig_phis.length(); j++) {
3376     PhiNode *phi = orig_phis.at(j);
3377     int alias_idx = _compile->get_alias_index(phi->adr_type());
3378     igvn->hash_delete(phi);
3379     for (uint i = 1; i < phi->req(); i++) {
3380       Node *mem = phi->in(i);
3381       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3382       if (_compile->failing()) {
3383         return;
3384       }
3385       if (mem != new_mem) {
3386         phi->set_req(i, new_mem);
3387       }
3388     }
3389     igvn->hash_insert(phi);
3390     record_for_optimizer(phi);
3391   }
3392 
3393   // Update the memory inputs of MemNodes with the value we computed
3394   // in Phase 2 and move stores memory users to corresponding memory slices.
3395   // Disable memory split verification code until the fix for 6984348.
3396   // Currently it produces false negative results since it does not cover all cases.
3397 #if 0 // ifdef ASSERT
3398   visited.Reset();
3399   Node_Stack old_mems(arena, _compile->unique() >> 2);
3400 #endif
3401   for (uint i = 0; i < ideal_nodes.size(); i++) {
3402     Node*    n = ideal_nodes.at(i);
3403     Node* nmem = get_map(n->_idx);
3404     assert(nmem != NULL, "sanity");
3405     if (n->is_Mem()) {
3406 #if 0 // ifdef ASSERT
3407       Node* old_mem = n->in(MemNode::Memory);
3408       if (!visited.test_set(old_mem->_idx)) {
3409         old_mems.push(old_mem, old_mem->outcnt());
3410       }
3411 #endif
3412       assert(n->in(MemNode::Memory) != nmem, "sanity");
3413       if (!n->is_Load()) {
3414         // Move memory users of a store first.
3415         move_inst_mem(n, orig_phis);
3416       }
3417       // Now update memory input
3418       igvn->hash_delete(n);
3419       n->set_req(MemNode::Memory, nmem);
3420       igvn->hash_insert(n);
3421       record_for_optimizer(n);
3422     } else {
3423       assert(n->is_Allocate() || n->is_CheckCastPP() ||
3424              n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3425     }
3426   }
3427 #if 0 // ifdef ASSERT
3428   // Verify that memory was split correctly
3429   while (old_mems.is_nonempty()) {
3430     Node* old_mem = old_mems.node();
3431     uint  old_cnt = old_mems.index();
3432     old_mems.pop();
3433     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3434   }
3435 #endif
3436 }
3437 
3438 #ifndef PRODUCT
3439 static const char *node_type_names[] = {
3440   "UnknownType",
3441   "JavaObject",
3442   "LocalVar",
3443   "Field",
3444   "Arraycopy"
3445 };
3446 
3447 static const char *esc_names[] = {
3448   "UnknownEscape",
3449   "NoEscape",
3450   "ArgEscape",
3451   "GlobalEscape"
3452 };
3453 
3454 void PointsToNode::dump(bool print_state) const {
3455   NodeType nt = node_type();
3456   tty->print("%s ", node_type_names[(int) nt]);
3457   if (print_state) {
3458     EscapeState es = escape_state();
3459     EscapeState fields_es = fields_escape_state();
3460     tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3461     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3462       tty->print("NSR ");
3463   }
3464   if (is_Field()) {
3465     FieldNode* f = (FieldNode*)this;
3466     if (f->is_oop())
3467       tty->print("oop ");
3468     if (f->offset() > 0)
3469       tty->print("+%d ", f->offset());
3470     tty->print("(");
3471     for (BaseIterator i(f); i.has_next(); i.next()) {
3472       PointsToNode* b = i.get();
3473       tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3474     }
3475     tty->print(" )");
3476   }
3477   tty->print("[");
3478   for (EdgeIterator i(this); i.has_next(); i.next()) {
3479     PointsToNode* e = i.get();
3480     tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3481   }
3482   tty->print(" [");
3483   for (UseIterator i(this); i.has_next(); i.next()) {
3484     PointsToNode* u = i.get();
3485     bool is_base = false;
3486     if (PointsToNode::is_base_use(u)) {
3487       is_base = true;
3488       u = PointsToNode::get_use_node(u)->as_Field();
3489     }
3490     tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3491   }
3492   tty->print(" ]]  ");
3493   if (_node == NULL)
3494     tty->print_cr("<null>");
3495   else
3496     _node->dump();
3497 }
3498 
3499 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3500   bool first = true;
3501   int ptnodes_length = ptnodes_worklist.length();
3502   for (int i = 0; i < ptnodes_length; i++) {
3503     PointsToNode *ptn = ptnodes_worklist.at(i);
3504     if (ptn == NULL || !ptn->is_JavaObject())
3505       continue;
3506     PointsToNode::EscapeState es = ptn->escape_state();
3507     if ((es != PointsToNode::NoEscape) && !Verbose) {
3508       continue;
3509     }
3510     Node* n = ptn->ideal_node();
3511     if (n->is_Allocate() || (n->is_CallStaticJava() &&
3512                              n->as_CallStaticJava()->is_boxing_method())) {
3513       if (first) {
3514         tty->cr();
3515         tty->print("======== Connection graph for ");
3516         _compile->method()->print_short_name();
3517         tty->cr();
3518         first = false;
3519       }
3520       ptn->dump();
3521       // Print all locals and fields which reference this allocation
3522       for (UseIterator j(ptn); j.has_next(); j.next()) {
3523         PointsToNode* use = j.get();
3524         if (use->is_LocalVar()) {
3525           use->dump(Verbose);
3526         } else if (Verbose) {
3527           use->dump();
3528         }
3529       }
3530       tty->cr();
3531     }
3532   }
3533 }
3534 #endif