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