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