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