1 /*
   2  * Copyright (c) 2005, 2013, 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/callnode.hpp"
  32 #include "opto/cfgnode.hpp"
  33 #include "opto/compile.hpp"
  34 #include "opto/escape.hpp"
  35 #include "opto/phaseX.hpp"
  36 #include "opto/rootnode.hpp"
  37 
  38 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
  39   _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
  40   _collecting(true),
  41   _verify(false),
  42   _compile(C),
  43   _igvn(igvn),
  44   _node_map(C->comp_arena()) {
  45   // Add unknown java object.
  46   add_java_object(C->top(), PointsToNode::GlobalEscape);
  47   phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
  48   // Add ConP(#NULL) and ConN(#NULL) nodes.
  49   Node* oop_null = igvn->zerocon(T_OBJECT);
  50   assert(oop_null->_idx < nodes_size(), "should be created already");
  51   add_java_object(oop_null, PointsToNode::NoEscape);
  52   null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
  53   if (UseCompressedOops) {
  54     Node* noop_null = igvn->zerocon(T_NARROWOOP);
  55     assert(noop_null->_idx < nodes_size(), "should be created already");
  56     map_ideal_node(noop_null, null_obj);
  57   }
  58   _pcmp_neq = NULL; // Should be initialized
  59   _pcmp_eq  = NULL;
  60 }
  61 
  62 bool ConnectionGraph::has_candidates(Compile *C) {
  63   // EA brings benefits only when the code has allocations and/or locks which
  64   // are represented by ideal Macro nodes.
  65   int cnt = C->macro_count();
  66   for (int i = 0; i < cnt; i++) {
  67     Node *n = C->macro_node(i);
  68     if (n->is_Allocate())
  69       return true;
  70     if (n->is_Lock()) {
  71       Node* obj = n->as_Lock()->obj_node()->uncast();
  72       if (!(obj->is_Parm() || obj->is_Con()))
  73         return true;
  74     }
  75     if (n->is_CallStaticJava() &&
  76         n->as_CallStaticJava()->is_boxing_method()) {
  77       return true;
  78     }
  79   }
  80   return false;
  81 }
  82 
  83 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
  84   Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
  85   ResourceMark rm;
  86 
  87   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
  88   // to create space for them in ConnectionGraph::_nodes[].
  89   Node* oop_null = igvn->zerocon(T_OBJECT);
  90   Node* noop_null = igvn->zerocon(T_NARROWOOP);
  91   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
  92   // Perform escape analysis
  93   if (congraph->compute_escape()) {
  94     // There are non escaping objects.
  95     C->set_congraph(congraph);
  96   }
  97   // Cleanup.
  98   if (oop_null->outcnt() == 0)
  99     igvn->hash_delete(oop_null);
 100   if (noop_null->outcnt() == 0)
 101     igvn->hash_delete(noop_null);
 102 }
 103 
 104 bool ConnectionGraph::compute_escape() {
 105   Compile* C = _compile;
 106   PhaseGVN* igvn = _igvn;
 107 
 108   // Worklists used by EA.
 109   Unique_Node_List delayed_worklist;
 110   GrowableArray<Node*> alloc_worklist;
 111   GrowableArray<Node*> ptr_cmp_worklist;
 112   GrowableArray<Node*> storestore_worklist;
 113   GrowableArray<PointsToNode*>   ptnodes_worklist;
 114   GrowableArray<JavaObjectNode*> java_objects_worklist;
 115   GrowableArray<JavaObjectNode*> non_escaped_worklist;
 116   GrowableArray<FieldNode*>      oop_fields_worklist;
 117   DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
 118 
 119   { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true);
 120 
 121   // 1. Populate Connection Graph (CG) with PointsTo nodes.
 122   ideal_nodes.map(C->live_nodes(), NULL);  // preallocate space
 123   // Initialize worklist
 124   if (C->root() != NULL) {
 125     ideal_nodes.push(C->root());
 126   }
 127   for( uint next = 0; next < ideal_nodes.size(); ++next ) {
 128     Node* n = ideal_nodes.at(next);
 129     // Create PointsTo nodes and add them to Connection Graph. Called
 130     // only once per ideal node since ideal_nodes is Unique_Node list.
 131     add_node_to_connection_graph(n, &delayed_worklist);
 132     PointsToNode* ptn = ptnode_adr(n->_idx);
 133     if (ptn != NULL) {
 134       ptnodes_worklist.append(ptn);
 135       if (ptn->is_JavaObject()) {
 136         java_objects_worklist.append(ptn->as_JavaObject());
 137         if ((n->is_Allocate() || n->is_CallStaticJava()) &&
 138             (ptn->escape_state() < PointsToNode::GlobalEscape)) {
 139           // Only allocations and java static calls results are interesting.
 140           non_escaped_worklist.append(ptn->as_JavaObject());
 141         }
 142       } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
 143         oop_fields_worklist.append(ptn->as_Field());
 144       }
 145     }
 146     if (n->is_MergeMem()) {
 147       // Collect all MergeMem nodes to add memory slices for
 148       // scalar replaceable objects in split_unique_types().
 149       _mergemem_worklist.append(n->as_MergeMem());
 150     } else if (OptimizePtrCompare && n->is_Cmp() &&
 151                (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
 152       // Collect compare pointers nodes.
 153       ptr_cmp_worklist.append(n);
 154     } else if (n->is_MemBarStoreStore()) {
 155       // Collect all MemBarStoreStore nodes so that depending on the
 156       // escape status of the associated Allocate node some of them
 157       // may be eliminated.
 158       storestore_worklist.append(n);
 159     } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
 160                (n->req() > MemBarNode::Precedent)) {
 161       record_for_optimizer(n);
 162 #ifdef ASSERT
 163     } else if (n->is_AddP()) {
 164       // Collect address nodes for graph verification.
 165       addp_worklist.append(n);
 166 #endif
 167     }
 168     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 169       Node* m = n->fast_out(i);   // Get user
 170       ideal_nodes.push(m);
 171     }
 172   }
 173   if (non_escaped_worklist.length() == 0) {
 174     _collecting = false;
 175     return false; // Nothing to do.
 176   }
 177   // Add final simple edges to graph.
 178   while(delayed_worklist.size() > 0) {
 179     Node* n = delayed_worklist.pop();
 180     add_final_edges(n);
 181   }
 182   int ptnodes_length = ptnodes_worklist.length();
 183 
 184 #ifdef ASSERT
 185   if (VerifyConnectionGraph) {
 186     // Verify that no new simple edges could be created and all
 187     // local vars has edges.
 188     _verify = true;
 189     for (int next = 0; next < ptnodes_length; ++next) {
 190       PointsToNode* ptn = ptnodes_worklist.at(next);
 191       add_final_edges(ptn->ideal_node());
 192       if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
 193         ptn->dump();
 194         assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
 195       }
 196     }
 197     _verify = false;
 198   }
 199 #endif
 200 
 201   // 2. Finish Graph construction by propagating references to all
 202   //    java objects through graph.
 203   if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
 204                                  java_objects_worklist, oop_fields_worklist)) {
 205     // All objects escaped or hit time or iterations limits.
 206     _collecting = false;
 207     return false;
 208   }
 209 
 210   // 3. Adjust scalar_replaceable state of nonescaping objects and push
 211   //    scalar replaceable allocations on alloc_worklist for processing
 212   //    in split_unique_types().
 213   int non_escaped_length = non_escaped_worklist.length();
 214   for (int next = 0; next < non_escaped_length; next++) {
 215     JavaObjectNode* ptn = non_escaped_worklist.at(next);
 216     bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
 217     Node* n = ptn->ideal_node();
 218     if (n->is_Allocate()) {
 219       n->as_Allocate()->_is_non_escaping = noescape;
 220     }
 221     if (n->is_CallStaticJava()) {
 222       n->as_CallStaticJava()->_is_non_escaping = noescape;
 223     }
 224     if (noescape && ptn->scalar_replaceable()) {
 225       adjust_scalar_replaceable_state(ptn);
 226       if (ptn->scalar_replaceable()) {
 227         alloc_worklist.append(ptn->ideal_node());
 228       }
 229     }
 230   }
 231 
 232 #ifdef ASSERT
 233   if (VerifyConnectionGraph) {
 234     // Verify that graph is complete - no new edges could be added or needed.
 235     verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
 236                             java_objects_worklist, addp_worklist);
 237   }
 238   assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
 239   assert(null_obj->escape_state() == PointsToNode::NoEscape &&
 240          null_obj->edge_count() == 0 &&
 241          !null_obj->arraycopy_src() &&
 242          !null_obj->arraycopy_dst(), "sanity");
 243 #endif
 244 
 245   _collecting = false;
 246 
 247   } // TracePhase t3("connectionGraph")
 248 
 249   // 4. Optimize ideal graph based on EA information.
 250   bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
 251   if (has_non_escaping_obj) {
 252     optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
 253   }
 254 
 255 #ifndef PRODUCT
 256   if (PrintEscapeAnalysis) {
 257     dump(ptnodes_worklist); // Dump ConnectionGraph
 258   }
 259 #endif
 260 
 261   bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
 262 #ifdef ASSERT
 263   if (VerifyConnectionGraph) {
 264     int alloc_length = alloc_worklist.length();
 265     for (int next = 0; next < alloc_length; ++next) {
 266       Node* n = alloc_worklist.at(next);
 267       PointsToNode* ptn = ptnode_adr(n->_idx);
 268       assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
 269     }
 270   }
 271 #endif
 272 
 273   // 5. Separate memory graph for scalar replaceable allcations.
 274   if (has_scalar_replaceable_candidates &&
 275       C->AliasLevel() >= 3 && EliminateAllocations) {
 276     // Now use the escape information to create unique types for
 277     // scalar replaceable objects.
 278     split_unique_types(alloc_worklist);
 279     if (C->failing())  return false;
 280     C->print_method(PHASE_AFTER_EA, 2);
 281 
 282 #ifdef ASSERT
 283   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
 284     tty->print("=== No allocations eliminated for ");
 285     C->method()->print_short_name();
 286     if(!EliminateAllocations) {
 287       tty->print(" since EliminateAllocations is off ===");
 288     } else if(!has_scalar_replaceable_candidates) {
 289       tty->print(" since there are no scalar replaceable candidates ===");
 290     } else if(C->AliasLevel() < 3) {
 291       tty->print(" since AliasLevel < 3 ===");
 292     }
 293     tty->cr();
 294 #endif
 295   }
 296   return has_non_escaping_obj;
 297 }
 298 
 299 // Utility function for nodes that load an object
 300 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 301   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 302   // ThreadLocal has RawPtr type.
 303   const Type* t = _igvn->type(n);
 304   if (t->make_ptr() != NULL) {
 305     Node* adr = n->in(MemNode::Address);
 306 #ifdef ASSERT
 307     if (!adr->is_AddP()) {
 308       assert(_igvn->type(adr)->isa_rawptr(), "sanity");
 309     } else {
 310       assert((ptnode_adr(adr->_idx) == NULL ||
 311               ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
 312     }
 313 #endif
 314     add_local_var_and_edge(n, PointsToNode::NoEscape,
 315                            adr, delayed_worklist);
 316   }
 317 }
 318 
 319 // Populate Connection Graph with PointsTo nodes and create simple
 320 // connection graph edges.
 321 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 322   assert(!_verify, "this method sould not be called for verification");
 323   PhaseGVN* igvn = _igvn;
 324   uint n_idx = n->_idx;
 325   PointsToNode* n_ptn = ptnode_adr(n_idx);
 326   if (n_ptn != NULL)
 327     return; // No need to redefine PointsTo node during first iteration.
 328 
 329   if (n->is_Call()) {
 330     // Arguments to allocation and locking don't escape.
 331     if (n->is_AbstractLock()) {
 332       // Put Lock and Unlock nodes on IGVN worklist to process them during
 333       // first IGVN optimization when escape information is still available.
 334       record_for_optimizer(n);
 335     } else if (n->is_Allocate()) {
 336       add_call_node(n->as_Call());
 337       record_for_optimizer(n);
 338     } else {
 339       if (n->is_CallStaticJava()) {
 340         const char* name = n->as_CallStaticJava()->_name;
 341         if (name != NULL && strcmp(name, "uncommon_trap") == 0)
 342           return; // Skip uncommon traps
 343       }
 344       // Don't mark as processed since call's arguments have to be processed.
 345       delayed_worklist->push(n);
 346       // Check if a call returns an object.
 347       if ((n->as_Call()->returns_pointer() &&
 348            n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
 349           (n->is_CallStaticJava() &&
 350            n->as_CallStaticJava()->is_boxing_method())) {
 351         add_call_node(n->as_Call());
 352       }
 353     }
 354     return;
 355   }
 356   // Put this check here to process call arguments since some call nodes
 357   // point to phantom_obj.
 358   if (n_ptn == phantom_obj || n_ptn == null_obj)
 359     return; // Skip predefined nodes.
 360 
 361   int opcode = n->Opcode();
 362   switch (opcode) {
 363     case Op_AddP: {
 364       Node* base = get_addp_base(n);
 365       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 366       // Field nodes are created for all field types. They are used in
 367       // adjust_scalar_replaceable_state() and split_unique_types().
 368       // Note, non-oop fields will have only base edges in Connection
 369       // Graph because such fields are not used for oop loads and stores.
 370       int offset = address_offset(n, igvn);
 371       add_field(n, PointsToNode::NoEscape, offset);
 372       if (ptn_base == NULL) {
 373         delayed_worklist->push(n); // Process it later.
 374       } else {
 375         n_ptn = ptnode_adr(n_idx);
 376         add_base(n_ptn->as_Field(), ptn_base);
 377       }
 378       break;
 379     }
 380     case Op_CastX2P: {
 381       map_ideal_node(n, phantom_obj);
 382       break;
 383     }
 384     case Op_CastPP:
 385     case Op_CheckCastPP:
 386     case Op_EncodeP:
 387     case Op_DecodeN:
 388     case Op_EncodePKlass:
 389     case Op_DecodeNKlass: {
 390       add_local_var_and_edge(n, PointsToNode::NoEscape,
 391                              n->in(1), delayed_worklist);
 392       break;
 393     }
 394     case Op_CMoveP: {
 395       add_local_var(n, PointsToNode::NoEscape);
 396       // Do not add edges during first iteration because some could be
 397       // not defined yet.
 398       delayed_worklist->push(n);
 399       break;
 400     }
 401     case Op_ConP:
 402     case Op_ConN:
 403     case Op_ConNKlass: {
 404       // assume all oop constants globally escape except for null
 405       PointsToNode::EscapeState es;
 406       const Type* t = igvn->type(n);
 407       if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
 408         es = PointsToNode::NoEscape;
 409       } else {
 410         es = PointsToNode::GlobalEscape;
 411       }
 412       add_java_object(n, es);
 413       break;
 414     }
 415     case Op_CreateEx: {
 416       // assume that all exception objects globally escape
 417       add_java_object(n, PointsToNode::GlobalEscape);
 418       break;
 419     }
 420     case Op_LoadKlass:
 421     case Op_LoadNKlass: {
 422       // Unknown class is loaded
 423       map_ideal_node(n, phantom_obj);
 424       break;
 425     }
 426     case Op_LoadP:
 427     case Op_LoadN:
 428     case Op_LoadPLocked: {
 429       add_objload_to_connection_graph(n, delayed_worklist);
 430       break;
 431     }
 432     case Op_Parm: {
 433       map_ideal_node(n, phantom_obj);
 434       break;
 435     }
 436     case Op_PartialSubtypeCheck: {
 437       // Produces Null or notNull and is used in only in CmpP so
 438       // phantom_obj could be used.
 439       map_ideal_node(n, phantom_obj); // Result is unknown
 440       break;
 441     }
 442     case Op_Phi: {
 443       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 444       // ThreadLocal has RawPtr type.
 445       const Type* t = n->as_Phi()->type();
 446       if (t->make_ptr() != NULL) {
 447         add_local_var(n, PointsToNode::NoEscape);
 448         // Do not add edges during first iteration because some could be
 449         // not defined yet.
 450         delayed_worklist->push(n);
 451       }
 452       break;
 453     }
 454     case Op_Proj: {
 455       // we are only interested in the oop result projection from a call
 456       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
 457           n->in(0)->as_Call()->returns_pointer()) {
 458         add_local_var_and_edge(n, PointsToNode::NoEscape,
 459                                n->in(0), delayed_worklist);
 460       }
 461       break;
 462     }
 463     case Op_Rethrow: // Exception object escapes
 464     case Op_Return: {
 465       if (n->req() > TypeFunc::Parms &&
 466           igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 467         // Treat Return value as LocalVar with GlobalEscape escape state.
 468         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 469                                n->in(TypeFunc::Parms), delayed_worklist);
 470       }
 471       break;
 472     }
 473     case Op_GetAndSetP:
 474     case Op_GetAndSetN: {
 475       add_objload_to_connection_graph(n, delayed_worklist);
 476       // fallthrough
 477     }
 478     case Op_StoreP:
 479     case Op_StoreN:
 480     case Op_StoreNKlass:
 481     case Op_StorePConditional:
 482     case Op_CompareAndSwapP:
 483     case Op_CompareAndSwapN: {
 484       Node* adr = n->in(MemNode::Address);
 485       const Type *adr_type = igvn->type(adr);
 486       adr_type = adr_type->make_ptr();
 487       if (adr_type == NULL) {
 488         break; // skip dead nodes
 489       }
 490       if (adr_type->isa_oopptr() ||
 491           (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
 492                         (adr_type == TypeRawPtr::NOTNULL &&
 493                          adr->in(AddPNode::Address)->is_Proj() &&
 494                          adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 495         delayed_worklist->push(n); // Process it later.
 496 #ifdef ASSERT
 497         assert(adr->is_AddP(), "expecting an AddP");
 498         if (adr_type == TypeRawPtr::NOTNULL) {
 499           // Verify a raw address for a store captured by Initialize node.
 500           int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 501           assert(offs != Type::OffsetBot, "offset must be a constant");
 502         }
 503 #endif
 504       } else {
 505         // Ignore copy the displaced header to the BoxNode (OSR compilation).
 506         if (adr->is_BoxLock())
 507           break;
 508         // Stored value escapes in unsafe access.
 509         if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
 510           // Pointer stores in G1 barriers looks like unsafe access.
 511           // Ignore such stores to be able scalar replace non-escaping
 512           // allocations.
 513           if (UseG1GC && adr->is_AddP()) {
 514             Node* base = get_addp_base(adr);
 515             if (base->Opcode() == Op_LoadP &&
 516                 base->in(MemNode::Address)->is_AddP()) {
 517               adr = base->in(MemNode::Address);
 518               Node* tls = get_addp_base(adr);
 519               if (tls->Opcode() == Op_ThreadLocal) {
 520                 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 521                 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
 522                                      PtrQueue::byte_offset_of_buf())) {
 523                   break; // G1 pre barier previous oop value store.
 524                 }
 525                 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
 526                                      PtrQueue::byte_offset_of_buf())) {
 527                   break; // G1 post barier card address store.
 528                 }
 529               }
 530             }
 531           }
 532           delayed_worklist->push(n); // Process unsafe access later.
 533           break;
 534         }
 535 #ifdef ASSERT
 536         n->dump(1);
 537         assert(false, "not unsafe or G1 barrier raw StoreP");
 538 #endif
 539       }
 540       break;
 541     }
 542     case Op_AryEq:
 543     case Op_StrComp:
 544     case Op_StrEquals:
 545     case Op_StrIndexOf:
 546     case Op_EncodeISOArray: {
 547       add_local_var(n, PointsToNode::ArgEscape);
 548       delayed_worklist->push(n); // Process it later.
 549       break;
 550     }
 551     case Op_ThreadLocal: {
 552       add_java_object(n, PointsToNode::ArgEscape);
 553       break;
 554     }
 555     default:
 556       ; // Do nothing for nodes not related to EA.
 557   }
 558   return;
 559 }
 560 
 561 #ifdef ASSERT
 562 #define ELSE_FAIL(name)                               \
 563       /* Should not be called for not pointer type. */  \
 564       n->dump(1);                                       \
 565       assert(false, name);                              \
 566       break;
 567 #else
 568 #define ELSE_FAIL(name) \
 569       break;
 570 #endif
 571 
 572 // Add final simple edges to graph.
 573 void ConnectionGraph::add_final_edges(Node *n) {
 574   PointsToNode* n_ptn = ptnode_adr(n->_idx);
 575 #ifdef ASSERT
 576   if (_verify && n_ptn->is_JavaObject())
 577     return; // This method does not change graph for JavaObject.
 578 #endif
 579 
 580   if (n->is_Call()) {
 581     process_call_arguments(n->as_Call());
 582     return;
 583   }
 584   assert(n->is_Store() || n->is_LoadStore() ||
 585          (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
 586          "node should be registered already");
 587   int opcode = n->Opcode();
 588   switch (opcode) {
 589     case Op_AddP: {
 590       Node* base = get_addp_base(n);
 591       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 592       assert(ptn_base != NULL, "field's base should be registered");
 593       add_base(n_ptn->as_Field(), ptn_base);
 594       break;
 595     }
 596     case Op_CastPP:
 597     case Op_CheckCastPP:
 598     case Op_EncodeP:
 599     case Op_DecodeN:
 600     case Op_EncodePKlass:
 601     case Op_DecodeNKlass: {
 602       add_local_var_and_edge(n, PointsToNode::NoEscape,
 603                              n->in(1), NULL);
 604       break;
 605     }
 606     case Op_CMoveP: {
 607       for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
 608         Node* in = n->in(i);
 609         if (in == NULL)
 610           continue;  // ignore NULL
 611         Node* uncast_in = in->uncast();
 612         if (uncast_in->is_top() || uncast_in == n)
 613           continue;  // ignore top or inputs which go back this node
 614         PointsToNode* ptn = ptnode_adr(in->_idx);
 615         assert(ptn != NULL, "node should be registered");
 616         add_edge(n_ptn, ptn);
 617       }
 618       break;
 619     }
 620     case Op_LoadP:
 621     case Op_LoadN:
 622     case Op_LoadPLocked: {
 623       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 624       // ThreadLocal has RawPtr type.
 625       const Type* t = _igvn->type(n);
 626       if (t->make_ptr() != NULL) {
 627         Node* adr = n->in(MemNode::Address);
 628         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 629         break;
 630       }
 631       ELSE_FAIL("Op_LoadP");
 632     }
 633     case Op_Phi: {
 634       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 635       // ThreadLocal has RawPtr type.
 636       const Type* t = n->as_Phi()->type();
 637       if (t->make_ptr() != NULL) {
 638         for (uint i = 1; i < n->req(); i++) {
 639           Node* in = n->in(i);
 640           if (in == NULL)
 641             continue;  // ignore NULL
 642           Node* uncast_in = in->uncast();
 643           if (uncast_in->is_top() || uncast_in == n)
 644             continue;  // ignore top or inputs which go back this node
 645           PointsToNode* ptn = ptnode_adr(in->_idx);
 646           assert(ptn != NULL, "node should be registered");
 647           add_edge(n_ptn, ptn);
 648         }
 649         break;
 650       }
 651       ELSE_FAIL("Op_Phi");
 652     }
 653     case Op_Proj: {
 654       // we are only interested in the oop result projection from a call
 655       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
 656           n->in(0)->as_Call()->returns_pointer()) {
 657         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
 658         break;
 659       }
 660       ELSE_FAIL("Op_Proj");
 661     }
 662     case Op_Rethrow: // Exception object escapes
 663     case Op_Return: {
 664       if (n->req() > TypeFunc::Parms &&
 665           _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 666         // Treat Return value as LocalVar with GlobalEscape escape state.
 667         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 668                                n->in(TypeFunc::Parms), NULL);
 669         break;
 670       }
 671       ELSE_FAIL("Op_Return");
 672     }
 673     case Op_StoreP:
 674     case Op_StoreN:
 675     case Op_StoreNKlass:
 676     case Op_StorePConditional:
 677     case Op_CompareAndSwapP:
 678     case Op_CompareAndSwapN:
 679     case Op_GetAndSetP:
 680     case Op_GetAndSetN: {
 681       Node* adr = n->in(MemNode::Address);
 682       const Type *adr_type = _igvn->type(adr);
 683       adr_type = adr_type->make_ptr();
 684 #ifdef ASSERT
 685       if (adr_type == NULL) {
 686         n->dump(1);
 687         assert(adr_type != NULL, "dead node should not be on list");
 688         break;
 689       }
 690 #endif
 691       if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
 692         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 693       }
 694       if (adr_type->isa_oopptr() ||
 695           (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
 696                         (adr_type == TypeRawPtr::NOTNULL &&
 697                          adr->in(AddPNode::Address)->is_Proj() &&
 698                          adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 699         // Point Address to Value
 700         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 701         assert(adr_ptn != NULL &&
 702                adr_ptn->as_Field()->is_oop(), "node should be registered");
 703         Node *val = n->in(MemNode::ValueIn);
 704         PointsToNode* ptn = ptnode_adr(val->_idx);
 705         assert(ptn != NULL, "node should be registered");
 706         add_edge(adr_ptn, ptn);
 707         break;
 708       } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
 709         // Stored value escapes in unsafe access.
 710         Node *val = n->in(MemNode::ValueIn);
 711         PointsToNode* ptn = ptnode_adr(val->_idx);
 712         assert(ptn != NULL, "node should be registered");
 713         ptn->set_escape_state(PointsToNode::GlobalEscape);
 714         // Add edge to object for unsafe access with offset.
 715         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 716         assert(adr_ptn != NULL, "node should be registered");
 717         if (adr_ptn->is_Field()) {
 718           assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
 719           add_edge(adr_ptn, ptn);
 720         }
 721         break;
 722       }
 723       ELSE_FAIL("Op_StoreP");
 724     }
 725     case Op_AryEq:
 726     case Op_StrComp:
 727     case Op_StrEquals:
 728     case Op_StrIndexOf:
 729     case Op_EncodeISOArray: {
 730       // char[] arrays passed to string intrinsic do not escape but
 731       // they are not scalar replaceable. Adjust escape state for them.
 732       // Start from in(2) edge since in(1) is memory edge.
 733       for (uint i = 2; i < n->req(); i++) {
 734         Node* adr = n->in(i);
 735         const Type* at = _igvn->type(adr);
 736         if (!adr->is_top() && at->isa_ptr()) {
 737           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
 738                  at->isa_ptr() != NULL, "expecting a pointer");
 739           if (adr->is_AddP()) {
 740             adr = get_addp_base(adr);
 741           }
 742           PointsToNode* ptn = ptnode_adr(adr->_idx);
 743           assert(ptn != NULL, "node should be registered");
 744           add_edge(n_ptn, ptn);
 745         }
 746       }
 747       break;
 748     }
 749     default: {
 750       // This method should be called only for EA specific nodes which may
 751       // miss some edges when they were created.
 752 #ifdef ASSERT
 753       n->dump(1);
 754 #endif
 755       guarantee(false, "unknown node");
 756     }
 757   }
 758   return;
 759 }
 760 
 761 void ConnectionGraph::add_call_node(CallNode* call) {
 762   assert(call->returns_pointer(), "only for call which returns pointer");
 763   uint call_idx = call->_idx;
 764   if (call->is_Allocate()) {
 765     Node* k = call->in(AllocateNode::KlassNode);
 766     const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
 767     assert(kt != NULL, "TypeKlassPtr  required.");
 768     ciKlass* cik = kt->klass();
 769     PointsToNode::EscapeState es = PointsToNode::NoEscape;
 770     bool scalar_replaceable = true;
 771     if (call->is_AllocateArray()) {
 772       if (!cik->is_array_klass()) { // StressReflectiveCode
 773         es = PointsToNode::GlobalEscape;
 774       } else {
 775         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
 776         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
 777           // Not scalar replaceable if the length is not constant or too big.
 778           scalar_replaceable = false;
 779         }
 780       }
 781     } else {  // Allocate instance
 782       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
 783           cik->is_subclass_of(_compile->env()->Reference_klass()) ||
 784          !cik->is_instance_klass() || // StressReflectiveCode
 785           cik->as_instance_klass()->has_finalizer()) {
 786         es = PointsToNode::GlobalEscape;
 787       }
 788     }
 789     add_java_object(call, es);
 790     PointsToNode* ptn = ptnode_adr(call_idx);
 791     if (!scalar_replaceable && ptn->scalar_replaceable()) {
 792       ptn->set_scalar_replaceable(false);
 793     }
 794   } else if (call->is_CallStaticJava()) {
 795     // Call nodes could be different types:
 796     //
 797     // 1. CallDynamicJavaNode (what happened during call is unknown):
 798     //
 799     //    - mapped to GlobalEscape JavaObject node if oop is returned;
 800     //
 801     //    - all oop arguments are escaping globally;
 802     //
 803     // 2. CallStaticJavaNode (execute bytecode analysis if possible):
 804     //
 805     //    - the same as CallDynamicJavaNode if can't do bytecode analysis;
 806     //
 807     //    - mapped to GlobalEscape JavaObject node if unknown oop is returned;
 808     //    - mapped to NoEscape JavaObject node if non-escaping object allocated
 809     //      during call is returned;
 810     //    - mapped to ArgEscape LocalVar node pointed to object arguments
 811     //      which are returned and does not escape during call;
 812     //
 813     //    - oop arguments escaping status is defined by bytecode analysis;
 814     //
 815     // For a static call, we know exactly what method is being called.
 816     // Use bytecode estimator to record whether the call's return value escapes.
 817     ciMethod* meth = call->as_CallJava()->method();
 818     if (meth == NULL) {
 819       const char* name = call->as_CallStaticJava()->_name;
 820       assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
 821       // Returns a newly allocated unescaped object.
 822       add_java_object(call, PointsToNode::NoEscape);
 823       ptnode_adr(call_idx)->set_scalar_replaceable(false);
 824     } else if (meth->is_boxing_method()) {
 825       // Returns boxing object
 826       PointsToNode::EscapeState es;
 827       vmIntrinsics::ID intr = meth->intrinsic_id();
 828       if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
 829         // It does not escape if object is always allocated.
 830         es = PointsToNode::NoEscape;
 831       } else {
 832         // It escapes globally if object could be loaded from cache.
 833         es = PointsToNode::GlobalEscape;
 834       }
 835       add_java_object(call, es);
 836     } else {
 837       BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
 838       call_analyzer->copy_dependencies(_compile->dependencies());
 839       if (call_analyzer->is_return_allocated()) {
 840         // Returns a newly allocated unescaped object, simply
 841         // update dependency information.
 842         // Mark it as NoEscape so that objects referenced by
 843         // it's fields will be marked as NoEscape at least.
 844         add_java_object(call, PointsToNode::NoEscape);
 845         ptnode_adr(call_idx)->set_scalar_replaceable(false);
 846       } else {
 847         // Determine whether any arguments are returned.
 848         const TypeTuple* d = call->tf()->domain();
 849         bool ret_arg = false;
 850         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 851           if (d->field_at(i)->isa_ptr() != NULL &&
 852               call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
 853             ret_arg = true;
 854             break;
 855           }
 856         }
 857         if (ret_arg) {
 858           add_local_var(call, PointsToNode::ArgEscape);
 859         } else {
 860           // Returns unknown object.
 861           map_ideal_node(call, phantom_obj);
 862         }
 863       }
 864     }
 865   } else {
 866     // An other type of call, assume the worst case:
 867     // returned value is unknown and globally escapes.
 868     assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
 869     map_ideal_node(call, phantom_obj);
 870   }
 871 }
 872 
 873 void ConnectionGraph::process_call_arguments(CallNode *call) {
 874     bool is_arraycopy = false;
 875     switch (call->Opcode()) {
 876 #ifdef ASSERT
 877     case Op_Allocate:
 878     case Op_AllocateArray:
 879     case Op_Lock:
 880     case Op_Unlock:
 881       assert(false, "should be done already");
 882       break;
 883 #endif
 884     case Op_CallLeafNoFP:
 885       is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
 886                       strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
 887       // fall through
 888     case Op_CallLeaf: {
 889       // Stub calls, objects do not escape but they are not scale replaceable.
 890       // Adjust escape state for outgoing arguments.
 891       const TypeTuple * d = call->tf()->domain();
 892       bool src_has_oops = false;
 893       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 894         const Type* at = d->field_at(i);
 895         Node *arg = call->in(i);
 896         const Type *aat = _igvn->type(arg);
 897         if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
 898           continue;
 899         if (arg->is_AddP()) {
 900           //
 901           // The inline_native_clone() case when the arraycopy stub is called
 902           // after the allocation before Initialize and CheckCastPP nodes.
 903           // Or normal arraycopy for object arrays case.
 904           //
 905           // Set AddP's base (Allocate) as not scalar replaceable since
 906           // pointer to the base (with offset) is passed as argument.
 907           //
 908           arg = get_addp_base(arg);
 909         }
 910         PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
 911         assert(arg_ptn != NULL, "should be registered");
 912         PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
 913         if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
 914           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
 915                  aat->isa_ptr() != NULL, "expecting an Ptr");
 916           bool arg_has_oops = aat->isa_oopptr() &&
 917                               (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
 918                                (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
 919           if (i == TypeFunc::Parms) {
 920             src_has_oops = arg_has_oops;
 921           }
 922           //
 923           // src or dst could be j.l.Object when other is basic type array:
 924           //
 925           //   arraycopy(char[],0,Object*,0,size);
 926           //   arraycopy(Object*,0,char[],0,size);
 927           //
 928           // Don't add edges in such cases.
 929           //
 930           bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
 931                                        arg_has_oops && (i > TypeFunc::Parms);
 932 #ifdef ASSERT
 933           if (!(is_arraycopy ||
 934                 (call->as_CallLeaf()->_name != NULL &&
 935                  (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
 936                   strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
 937                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
 938                   strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
 939                   strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
 940                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
 941                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0)
 942                   ))) {
 943             call->dump();
 944             fatal(err_msg_res("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name));
 945           }
 946 #endif
 947           // Always process arraycopy's destination object since
 948           // we need to add all possible edges to references in
 949           // source object.
 950           if (arg_esc >= PointsToNode::ArgEscape &&
 951               !arg_is_arraycopy_dest) {
 952             continue;
 953           }
 954           set_escape_state(arg_ptn, PointsToNode::ArgEscape);
 955           if (arg_is_arraycopy_dest) {
 956             Node* src = call->in(TypeFunc::Parms);
 957             if (src->is_AddP()) {
 958               src = get_addp_base(src);
 959             }
 960             PointsToNode* src_ptn = ptnode_adr(src->_idx);
 961             assert(src_ptn != NULL, "should be registered");
 962             if (arg_ptn != src_ptn) {
 963               // Special arraycopy edge:
 964               // A destination object's field can't have the source object
 965               // as base since objects escape states are not related.
 966               // Only escape state of destination object's fields affects
 967               // escape state of fields in source object.
 968               add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
 969             }
 970           }
 971         }
 972       }
 973       break;
 974     }
 975     case Op_CallStaticJava: {
 976       // For a static call, we know exactly what method is being called.
 977       // Use bytecode estimator to record the call's escape affects
 978 #ifdef ASSERT
 979       const char* name = call->as_CallStaticJava()->_name;
 980       assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
 981 #endif
 982       ciMethod* meth = call->as_CallJava()->method();
 983       if ((meth != NULL) && meth->is_boxing_method()) {
 984         break; // Boxing methods do not modify any oops.
 985       }
 986       BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
 987       // fall-through if not a Java method or no analyzer information
 988       if (call_analyzer != NULL) {
 989         PointsToNode* call_ptn = ptnode_adr(call->_idx);
 990         const TypeTuple* d = call->tf()->domain();
 991         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 992           const Type* at = d->field_at(i);
 993           int k = i - TypeFunc::Parms;
 994           Node* arg = call->in(i);
 995           PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
 996           if (at->isa_ptr() != NULL &&
 997               call_analyzer->is_arg_returned(k)) {
 998             // The call returns arguments.
 999             if (call_ptn != NULL) { // Is call's result used?
1000               assert(call_ptn->is_LocalVar(), "node should be registered");
1001               assert(arg_ptn != NULL, "node should be registered");
1002               add_edge(call_ptn, arg_ptn);
1003             }
1004           }
1005           if (at->isa_oopptr() != NULL &&
1006               arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1007             if (!call_analyzer->is_arg_stack(k)) {
1008               // The argument global escapes
1009               set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1010             } else {
1011               set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1012               if (!call_analyzer->is_arg_local(k)) {
1013                 // The argument itself doesn't escape, but any fields might
1014                 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1015               }
1016             }
1017           }
1018         }
1019         if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1020           // The call returns arguments.
1021           assert(call_ptn->edge_count() > 0, "sanity");
1022           if (!call_analyzer->is_return_local()) {
1023             // Returns also unknown object.
1024             add_edge(call_ptn, phantom_obj);
1025           }
1026         }
1027         break;
1028       }
1029     }
1030     default: {
1031       // Fall-through here if not a Java method or no analyzer information
1032       // or some other type of call, assume the worst case: all arguments
1033       // globally escape.
1034       const TypeTuple* d = call->tf()->domain();
1035       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1036         const Type* at = d->field_at(i);
1037         if (at->isa_oopptr() != NULL) {
1038           Node* arg = call->in(i);
1039           if (arg->is_AddP()) {
1040             arg = get_addp_base(arg);
1041           }
1042           assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1043           set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1044         }
1045       }
1046     }
1047   }
1048 }
1049 
1050 
1051 // Finish Graph construction.
1052 bool ConnectionGraph::complete_connection_graph(
1053                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1054                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1055                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1056                          GrowableArray<FieldNode*>&      oop_fields_worklist) {
1057   // Normally only 1-3 passes needed to build Connection Graph depending
1058   // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1059   // Set limit to 20 to catch situation when something did go wrong and
1060   // bailout Escape Analysis.
1061   // Also limit build time to 30 sec (60 in debug VM).
1062 #define CG_BUILD_ITER_LIMIT 20
1063 #ifdef ASSERT
1064 #define CG_BUILD_TIME_LIMIT 60.0
1065 #else
1066 #define CG_BUILD_TIME_LIMIT 30.0
1067 #endif
1068 
1069   // Propagate GlobalEscape and ArgEscape escape states and check that
1070   // we still have non-escaping objects. The method pushs on _worklist
1071   // Field nodes which reference phantom_object.
1072   if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1073     return false; // Nothing to do.
1074   }
1075   // Now propagate references to all JavaObject nodes.
1076   int java_objects_length = java_objects_worklist.length();
1077   elapsedTimer time;
1078   int new_edges = 1;
1079   int iterations = 0;
1080   do {
1081     while ((new_edges > 0) &&
1082           (iterations++   < CG_BUILD_ITER_LIMIT) &&
1083           (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1084       time.start();
1085       new_edges = 0;
1086       // Propagate references to phantom_object for nodes pushed on _worklist
1087       // by find_non_escaped_objects() and find_field_value().
1088       new_edges += add_java_object_edges(phantom_obj, false);
1089       for (int next = 0; next < java_objects_length; ++next) {
1090         JavaObjectNode* ptn = java_objects_worklist.at(next);
1091         new_edges += add_java_object_edges(ptn, true);
1092       }
1093       if (new_edges > 0) {
1094         // Update escape states on each iteration if graph was updated.
1095         if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1096           return false; // Nothing to do.
1097         }
1098       }
1099       time.stop();
1100     }
1101     if ((iterations     < CG_BUILD_ITER_LIMIT) &&
1102         (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1103       time.start();
1104       // Find fields which have unknown value.
1105       int fields_length = oop_fields_worklist.length();
1106       for (int next = 0; next < fields_length; next++) {
1107         FieldNode* field = oop_fields_worklist.at(next);
1108         if (field->edge_count() == 0) {
1109           new_edges += find_field_value(field);
1110           // This code may added new edges to phantom_object.
1111           // Need an other cycle to propagate references to phantom_object.
1112         }
1113       }
1114       time.stop();
1115     } else {
1116       new_edges = 0; // Bailout
1117     }
1118   } while (new_edges > 0);
1119 
1120   // Bailout if passed limits.
1121   if ((iterations     >= CG_BUILD_ITER_LIMIT) ||
1122       (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1123     Compile* C = _compile;
1124     if (C->log() != NULL) {
1125       C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1126       C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time");
1127       C->log()->end_elem(" limit'");
1128     }
1129     assert(ExitEscapeAnalysisOnTimeout, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1130            time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1131     // Possible infinite build_connection_graph loop,
1132     // bailout (no changes to ideal graph were made).
1133     return false;
1134   }
1135 #ifdef ASSERT
1136   if (Verbose && PrintEscapeAnalysis) {
1137     tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1138                   iterations, nodes_size(), ptnodes_worklist.length());
1139   }
1140 #endif
1141 
1142 #undef CG_BUILD_ITER_LIMIT
1143 #undef CG_BUILD_TIME_LIMIT
1144 
1145   // Find fields initialized by NULL for non-escaping Allocations.
1146   int non_escaped_length = non_escaped_worklist.length();
1147   for (int next = 0; next < non_escaped_length; next++) {
1148     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1149     PointsToNode::EscapeState es = ptn->escape_state();
1150     assert(es <= PointsToNode::ArgEscape, "sanity");
1151     if (es == PointsToNode::NoEscape) {
1152       if (find_init_values(ptn, null_obj, _igvn) > 0) {
1153         // Adding references to NULL object does not change escape states
1154         // since it does not escape. Also no fields are added to NULL object.
1155         add_java_object_edges(null_obj, false);
1156       }
1157     }
1158     Node* n = ptn->ideal_node();
1159     if (n->is_Allocate()) {
1160       // The object allocated by this Allocate node will never be
1161       // seen by an other thread. Mark it so that when it is
1162       // expanded no MemBarStoreStore is added.
1163       InitializeNode* ini = n->as_Allocate()->initialization();
1164       if (ini != NULL)
1165         ini->set_does_not_escape();
1166     }
1167   }
1168   return true; // Finished graph construction.
1169 }
1170 
1171 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1172 // and check that we still have non-escaping java objects.
1173 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1174                                                GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1175   GrowableArray<PointsToNode*> escape_worklist;
1176   // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1177   int ptnodes_length = ptnodes_worklist.length();
1178   for (int next = 0; next < ptnodes_length; ++next) {
1179     PointsToNode* ptn = ptnodes_worklist.at(next);
1180     if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1181         ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1182       escape_worklist.push(ptn);
1183     }
1184   }
1185   // Set escape states to referenced nodes (edges list).
1186   while (escape_worklist.length() > 0) {
1187     PointsToNode* ptn = escape_worklist.pop();
1188     PointsToNode::EscapeState es  = ptn->escape_state();
1189     PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1190     if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1191         es >= PointsToNode::ArgEscape) {
1192       // GlobalEscape or ArgEscape state of field means it has unknown value.
1193       if (add_edge(ptn, phantom_obj)) {
1194         // New edge was added
1195         add_field_uses_to_worklist(ptn->as_Field());
1196       }
1197     }
1198     for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1199       PointsToNode* e = i.get();
1200       if (e->is_Arraycopy()) {
1201         assert(ptn->arraycopy_dst(), "sanity");
1202         // Propagate only fields escape state through arraycopy edge.
1203         if (e->fields_escape_state() < field_es) {
1204           set_fields_escape_state(e, field_es);
1205           escape_worklist.push(e);
1206         }
1207       } else if (es >= field_es) {
1208         // fields_escape_state is also set to 'es' if it is less than 'es'.
1209         if (e->escape_state() < es) {
1210           set_escape_state(e, es);
1211           escape_worklist.push(e);
1212         }
1213       } else {
1214         // Propagate field escape state.
1215         bool es_changed = false;
1216         if (e->fields_escape_state() < field_es) {
1217           set_fields_escape_state(e, field_es);
1218           es_changed = true;
1219         }
1220         if ((e->escape_state() < field_es) &&
1221             e->is_Field() && ptn->is_JavaObject() &&
1222             e->as_Field()->is_oop()) {
1223           // Change escape state of referenced fileds.
1224           set_escape_state(e, field_es);
1225           es_changed = true;;
1226         } else if (e->escape_state() < es) {
1227           set_escape_state(e, es);
1228           es_changed = true;;
1229         }
1230         if (es_changed) {
1231           escape_worklist.push(e);
1232         }
1233       }
1234     }
1235   }
1236   // Remove escaped objects from non_escaped list.
1237   for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1238     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1239     if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1240       non_escaped_worklist.delete_at(next);
1241     }
1242     if (ptn->escape_state() == PointsToNode::NoEscape) {
1243       // Find fields in non-escaped allocations which have unknown value.
1244       find_init_values(ptn, phantom_obj, NULL);
1245     }
1246   }
1247   return (non_escaped_worklist.length() > 0);
1248 }
1249 
1250 // Add all references to JavaObject node by walking over all uses.
1251 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1252   int new_edges = 0;
1253   if (populate_worklist) {
1254     // Populate _worklist by uses of jobj's uses.
1255     for (UseIterator i(jobj); i.has_next(); i.next()) {
1256       PointsToNode* use = i.get();
1257       if (use->is_Arraycopy())
1258         continue;
1259       add_uses_to_worklist(use);
1260       if (use->is_Field() && use->as_Field()->is_oop()) {
1261         // Put on worklist all field's uses (loads) and
1262         // related field nodes (same base and offset).
1263         add_field_uses_to_worklist(use->as_Field());
1264       }
1265     }
1266   }
1267   while(_worklist.length() > 0) {
1268     PointsToNode* use = _worklist.pop();
1269     if (PointsToNode::is_base_use(use)) {
1270       // Add reference from jobj to field and from field to jobj (field's base).
1271       use = PointsToNode::get_use_node(use)->as_Field();
1272       if (add_base(use->as_Field(), jobj)) {
1273         new_edges++;
1274       }
1275       continue;
1276     }
1277     assert(!use->is_JavaObject(), "sanity");
1278     if (use->is_Arraycopy()) {
1279       if (jobj == null_obj) // NULL object does not have field edges
1280         continue;
1281       // Added edge from Arraycopy node to arraycopy's source java object
1282       if (add_edge(use, jobj)) {
1283         jobj->set_arraycopy_src();
1284         new_edges++;
1285       }
1286       // and stop here.
1287       continue;
1288     }
1289     if (!add_edge(use, jobj))
1290       continue; // No new edge added, there was such edge already.
1291     new_edges++;
1292     if (use->is_LocalVar()) {
1293       add_uses_to_worklist(use);
1294       if (use->arraycopy_dst()) {
1295         for (EdgeIterator i(use); i.has_next(); i.next()) {
1296           PointsToNode* e = i.get();
1297           if (e->is_Arraycopy()) {
1298             if (jobj == null_obj) // NULL object does not have field edges
1299               continue;
1300             // Add edge from arraycopy's destination java object to Arraycopy node.
1301             if (add_edge(jobj, e)) {
1302               new_edges++;
1303               jobj->set_arraycopy_dst();
1304             }
1305           }
1306         }
1307       }
1308     } else {
1309       // Added new edge to stored in field values.
1310       // Put on worklist all field's uses (loads) and
1311       // related field nodes (same base and offset).
1312       add_field_uses_to_worklist(use->as_Field());
1313     }
1314   }
1315   return new_edges;
1316 }
1317 
1318 // Put on worklist all related field nodes.
1319 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1320   assert(field->is_oop(), "sanity");
1321   int offset = field->offset();
1322   add_uses_to_worklist(field);
1323   // Loop over all bases of this field and push on worklist Field nodes
1324   // with the same offset and base (since they may reference the same field).
1325   for (BaseIterator i(field); i.has_next(); i.next()) {
1326     PointsToNode* base = i.get();
1327     add_fields_to_worklist(field, base);
1328     // Check if the base was source object of arraycopy and go over arraycopy's
1329     // destination objects since values stored to a field of source object are
1330     // accessable by uses (loads) of fields of destination objects.
1331     if (base->arraycopy_src()) {
1332       for (UseIterator j(base); j.has_next(); j.next()) {
1333         PointsToNode* arycp = j.get();
1334         if (arycp->is_Arraycopy()) {
1335           for (UseIterator k(arycp); k.has_next(); k.next()) {
1336             PointsToNode* abase = k.get();
1337             if (abase->arraycopy_dst() && abase != base) {
1338               // Look for the same arracopy reference.
1339               add_fields_to_worklist(field, abase);
1340             }
1341           }
1342         }
1343       }
1344     }
1345   }
1346 }
1347 
1348 // Put on worklist all related field nodes.
1349 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1350   int offset = field->offset();
1351   if (base->is_LocalVar()) {
1352     for (UseIterator j(base); j.has_next(); j.next()) {
1353       PointsToNode* f = j.get();
1354       if (PointsToNode::is_base_use(f)) { // Field
1355         f = PointsToNode::get_use_node(f);
1356         if (f == field || !f->as_Field()->is_oop())
1357           continue;
1358         int offs = f->as_Field()->offset();
1359         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1360           add_to_worklist(f);
1361         }
1362       }
1363     }
1364   } else {
1365     assert(base->is_JavaObject(), "sanity");
1366     if (// Skip phantom_object since it is only used to indicate that
1367         // this field's content globally escapes.
1368         (base != phantom_obj) &&
1369         // NULL object node does not have fields.
1370         (base != null_obj)) {
1371       for (EdgeIterator i(base); i.has_next(); i.next()) {
1372         PointsToNode* f = i.get();
1373         // Skip arraycopy edge since store to destination object field
1374         // does not update value in source object field.
1375         if (f->is_Arraycopy()) {
1376           assert(base->arraycopy_dst(), "sanity");
1377           continue;
1378         }
1379         if (f == field || !f->as_Field()->is_oop())
1380           continue;
1381         int offs = f->as_Field()->offset();
1382         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1383           add_to_worklist(f);
1384         }
1385       }
1386     }
1387   }
1388 }
1389 
1390 // Find fields which have unknown value.
1391 int ConnectionGraph::find_field_value(FieldNode* field) {
1392   // Escaped fields should have init value already.
1393   assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1394   int new_edges = 0;
1395   for (BaseIterator i(field); i.has_next(); i.next()) {
1396     PointsToNode* base = i.get();
1397     if (base->is_JavaObject()) {
1398       // Skip Allocate's fields which will be processed later.
1399       if (base->ideal_node()->is_Allocate())
1400         return 0;
1401       assert(base == null_obj, "only NULL ptr base expected here");
1402     }
1403   }
1404   if (add_edge(field, phantom_obj)) {
1405     // New edge was added
1406     new_edges++;
1407     add_field_uses_to_worklist(field);
1408   }
1409   return new_edges;
1410 }
1411 
1412 // Find fields initializing values for allocations.
1413 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1414   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1415   int new_edges = 0;
1416   Node* alloc = pta->ideal_node();
1417   if (init_val == phantom_obj) {
1418     // Do nothing for Allocate nodes since its fields values are "known".
1419     if (alloc->is_Allocate())
1420       return 0;
1421     assert(alloc->as_CallStaticJava(), "sanity");
1422 #ifdef ASSERT
1423     if (alloc->as_CallStaticJava()->method() == NULL) {
1424       const char* name = alloc->as_CallStaticJava()->_name;
1425       assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1426     }
1427 #endif
1428     // Non-escaped allocation returned from Java or runtime call have
1429     // unknown values in fields.
1430     for (EdgeIterator i(pta); i.has_next(); i.next()) {
1431       PointsToNode* field = i.get();
1432       if (field->is_Field() && field->as_Field()->is_oop()) {
1433         if (add_edge(field, phantom_obj)) {
1434           // New edge was added
1435           new_edges++;
1436           add_field_uses_to_worklist(field->as_Field());
1437         }
1438       }
1439     }
1440     return new_edges;
1441   }
1442   assert(init_val == null_obj, "sanity");
1443   // Do nothing for Call nodes since its fields values are unknown.
1444   if (!alloc->is_Allocate())
1445     return 0;
1446 
1447   InitializeNode* ini = alloc->as_Allocate()->initialization();
1448   Compile* C = _compile;
1449   bool visited_bottom_offset = false;
1450   GrowableArray<int> offsets_worklist;
1451 
1452   // Check if an oop field's initializing value is recorded and add
1453   // a corresponding NULL if field's value if it is not recorded.
1454   // Connection Graph does not record a default initialization by NULL
1455   // captured by Initialize node.
1456   //
1457   for (EdgeIterator i(pta); i.has_next(); i.next()) {
1458     PointsToNode* field = i.get(); // Field (AddP)
1459     if (!field->is_Field() || !field->as_Field()->is_oop())
1460       continue; // Not oop field
1461     int offset = field->as_Field()->offset();
1462     if (offset == Type::OffsetBot) {
1463       if (!visited_bottom_offset) {
1464         // OffsetBot is used to reference array's element,
1465         // always add reference to NULL to all Field nodes since we don't
1466         // known which element is referenced.
1467         if (add_edge(field, null_obj)) {
1468           // New edge was added
1469           new_edges++;
1470           add_field_uses_to_worklist(field->as_Field());
1471           visited_bottom_offset = true;
1472         }
1473       }
1474     } else {
1475       // Check only oop fields.
1476       const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1477       if (adr_type->isa_rawptr()) {
1478 #ifdef ASSERT
1479         // Raw pointers are used for initializing stores so skip it
1480         // since it should be recorded already
1481         Node* base = get_addp_base(field->ideal_node());
1482         assert(adr_type->isa_rawptr() && base->is_Proj() &&
1483                (base->in(0) == alloc),"unexpected pointer type");
1484 #endif
1485         continue;
1486       }
1487       if (!offsets_worklist.contains(offset)) {
1488         offsets_worklist.append(offset);
1489         Node* value = NULL;
1490         if (ini != NULL) {
1491           // StoreP::memory_type() == T_ADDRESS
1492           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1493           Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1494           // Make sure initializing store has the same type as this AddP.
1495           // This AddP may reference non existing field because it is on a
1496           // dead branch of bimorphic call which is not eliminated yet.
1497           if (store != NULL && store->is_Store() &&
1498               store->as_Store()->memory_type() == ft) {
1499             value = store->in(MemNode::ValueIn);
1500 #ifdef ASSERT
1501             if (VerifyConnectionGraph) {
1502               // Verify that AddP already points to all objects the value points to.
1503               PointsToNode* val = ptnode_adr(value->_idx);
1504               assert((val != NULL), "should be processed already");
1505               PointsToNode* missed_obj = NULL;
1506               if (val->is_JavaObject()) {
1507                 if (!field->points_to(val->as_JavaObject())) {
1508                   missed_obj = val;
1509                 }
1510               } else {
1511                 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1512                   tty->print_cr("----------init store has invalid value -----");
1513                   store->dump();
1514                   val->dump();
1515                   assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1516                 }
1517                 for (EdgeIterator j(val); j.has_next(); j.next()) {
1518                   PointsToNode* obj = j.get();
1519                   if (obj->is_JavaObject()) {
1520                     if (!field->points_to(obj->as_JavaObject())) {
1521                       missed_obj = obj;
1522                       break;
1523                     }
1524                   }
1525                 }
1526               }
1527               if (missed_obj != NULL) {
1528                 tty->print_cr("----------field---------------------------------");
1529                 field->dump();
1530                 tty->print_cr("----------missed referernce to object-----------");
1531                 missed_obj->dump();
1532                 tty->print_cr("----------object referernced by init store -----");
1533                 store->dump();
1534                 val->dump();
1535                 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1536               }
1537             }
1538 #endif
1539           } else {
1540             // There could be initializing stores which follow allocation.
1541             // For example, a volatile field store is not collected
1542             // by Initialize node.
1543             //
1544             // Need to check for dependent loads to separate such stores from
1545             // stores which follow loads. For now, add initial value NULL so
1546             // that compare pointers optimization works correctly.
1547           }
1548         }
1549         if (value == NULL) {
1550           // A field's initializing value was not recorded. Add NULL.
1551           if (add_edge(field, null_obj)) {
1552             // New edge was added
1553             new_edges++;
1554             add_field_uses_to_worklist(field->as_Field());
1555           }
1556         }
1557       }
1558     }
1559   }
1560   return new_edges;
1561 }
1562 
1563 // Adjust scalar_replaceable state after Connection Graph is built.
1564 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1565   // Search for non-escaping objects which are not scalar replaceable
1566   // and mark them to propagate the state to referenced objects.
1567 
1568   // 1. An object is not scalar replaceable if the field into which it is
1569   // stored has unknown offset (stored into unknown element of an array).
1570   //
1571   for (UseIterator i(jobj); i.has_next(); i.next()) {
1572     PointsToNode* use = i.get();
1573     assert(!use->is_Arraycopy(), "sanity");
1574     if (use->is_Field()) {
1575       FieldNode* field = use->as_Field();
1576       assert(field->is_oop() && field->scalar_replaceable() &&
1577              field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1578       if (field->offset() == Type::OffsetBot) {
1579         jobj->set_scalar_replaceable(false);
1580         return;
1581       }
1582     }
1583     assert(use->is_Field() || use->is_LocalVar(), "sanity");
1584     // 2. An object is not scalar replaceable if it is merged with other objects.
1585     for (EdgeIterator j(use); j.has_next(); j.next()) {
1586       PointsToNode* ptn = j.get();
1587       if (ptn->is_JavaObject() && ptn != jobj) {
1588         // Mark all objects.
1589         jobj->set_scalar_replaceable(false);
1590          ptn->set_scalar_replaceable(false);
1591       }
1592     }
1593     if (!jobj->scalar_replaceable()) {
1594       return;
1595     }
1596   }
1597 
1598   for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1599     // Non-escaping object node should point only to field nodes.
1600     FieldNode* field = j.get()->as_Field();
1601     int offset = field->as_Field()->offset();
1602 
1603     // 3. An object is not scalar replaceable if it has a field with unknown
1604     // offset (array's element is accessed in loop).
1605     if (offset == Type::OffsetBot) {
1606       jobj->set_scalar_replaceable(false);
1607       return;
1608     }
1609     // 4. Currently an object is not scalar replaceable if a LoadStore node
1610     // access its field since the field value is unknown after it.
1611     //
1612     Node* n = field->ideal_node();
1613     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1614       if (n->fast_out(i)->is_LoadStore()) {
1615         jobj->set_scalar_replaceable(false);
1616         return;
1617       }
1618     }
1619 
1620     // 5. Or the address may point to more then one object. This may produce
1621     // the false positive result (set not scalar replaceable)
1622     // since the flow-insensitive escape analysis can't separate
1623     // the case when stores overwrite the field's value from the case
1624     // when stores happened on different control branches.
1625     //
1626     // Note: it will disable scalar replacement in some cases:
1627     //
1628     //    Point p[] = new Point[1];
1629     //    p[0] = new Point(); // Will be not scalar replaced
1630     //
1631     // but it will save us from incorrect optimizations in next cases:
1632     //
1633     //    Point p[] = new Point[1];
1634     //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
1635     //
1636     if (field->base_count() > 1) {
1637       for (BaseIterator i(field); i.has_next(); i.next()) {
1638         PointsToNode* base = i.get();
1639         // Don't take into account LocalVar nodes which
1640         // may point to only one object which should be also
1641         // this field's base by now.
1642         if (base->is_JavaObject() && base != jobj) {
1643           // Mark all bases.
1644           jobj->set_scalar_replaceable(false);
1645           base->set_scalar_replaceable(false);
1646         }
1647       }
1648     }
1649   }
1650 }
1651 
1652 #ifdef ASSERT
1653 void ConnectionGraph::verify_connection_graph(
1654                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1655                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1656                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1657                          GrowableArray<Node*>& addp_worklist) {
1658   // Verify that graph is complete - no new edges could be added.
1659   int java_objects_length = java_objects_worklist.length();
1660   int non_escaped_length  = non_escaped_worklist.length();
1661   int new_edges = 0;
1662   for (int next = 0; next < java_objects_length; ++next) {
1663     JavaObjectNode* ptn = java_objects_worklist.at(next);
1664     new_edges += add_java_object_edges(ptn, true);
1665   }
1666   assert(new_edges == 0, "graph was not complete");
1667   // Verify that escape state is final.
1668   int length = non_escaped_worklist.length();
1669   find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1670   assert((non_escaped_length == non_escaped_worklist.length()) &&
1671          (non_escaped_length == length) &&
1672          (_worklist.length() == 0), "escape state was not final");
1673 
1674   // Verify fields information.
1675   int addp_length = addp_worklist.length();
1676   for (int next = 0; next < addp_length; ++next ) {
1677     Node* n = addp_worklist.at(next);
1678     FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1679     if (field->is_oop()) {
1680       // Verify that field has all bases
1681       Node* base = get_addp_base(n);
1682       PointsToNode* ptn = ptnode_adr(base->_idx);
1683       if (ptn->is_JavaObject()) {
1684         assert(field->has_base(ptn->as_JavaObject()), "sanity");
1685       } else {
1686         assert(ptn->is_LocalVar(), "sanity");
1687         for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1688           PointsToNode* e = i.get();
1689           if (e->is_JavaObject()) {
1690             assert(field->has_base(e->as_JavaObject()), "sanity");
1691           }
1692         }
1693       }
1694       // Verify that all fields have initializing values.
1695       if (field->edge_count() == 0) {
1696         tty->print_cr("----------field does not have references----------");
1697         field->dump();
1698         for (BaseIterator i(field); i.has_next(); i.next()) {
1699           PointsToNode* base = i.get();
1700           tty->print_cr("----------field has next base---------------------");
1701           base->dump();
1702           if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1703             tty->print_cr("----------base has fields-------------------------");
1704             for (EdgeIterator j(base); j.has_next(); j.next()) {
1705               j.get()->dump();
1706             }
1707             tty->print_cr("----------base has references---------------------");
1708             for (UseIterator j(base); j.has_next(); j.next()) {
1709               j.get()->dump();
1710             }
1711           }
1712         }
1713         for (UseIterator i(field); i.has_next(); i.next()) {
1714           i.get()->dump();
1715         }
1716         assert(field->edge_count() > 0, "sanity");
1717       }
1718     }
1719   }
1720 }
1721 #endif
1722 
1723 // Optimize ideal graph.
1724 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1725                                            GrowableArray<Node*>& storestore_worklist) {
1726   Compile* C = _compile;
1727   PhaseIterGVN* igvn = _igvn;
1728   if (EliminateLocks) {
1729     // Mark locks before changing ideal graph.
1730     int cnt = C->macro_count();
1731     for( int i=0; i < cnt; i++ ) {
1732       Node *n = C->macro_node(i);
1733       if (n->is_AbstractLock()) { // Lock and Unlock nodes
1734         AbstractLockNode* alock = n->as_AbstractLock();
1735         if (!alock->is_non_esc_obj()) {
1736           if (not_global_escape(alock->obj_node())) {
1737             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1738             // The lock could be marked eliminated by lock coarsening
1739             // code during first IGVN before EA. Replace coarsened flag
1740             // to eliminate all associated locks/unlocks.
1741             alock->set_non_esc_obj();
1742           }
1743         }
1744       }
1745     }
1746   }
1747 
1748   if (OptimizePtrCompare) {
1749     // Add ConI(#CC_GT) and ConI(#CC_EQ).
1750     _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1751     _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1752     // Optimize objects compare.
1753     while (ptr_cmp_worklist.length() != 0) {
1754       Node *n = ptr_cmp_worklist.pop();
1755       Node *res = optimize_ptr_compare(n);
1756       if (res != NULL) {
1757 #ifndef PRODUCT
1758         if (PrintOptimizePtrCompare) {
1759           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"));
1760           if (Verbose) {
1761             n->dump(1);
1762           }
1763         }
1764 #endif
1765         igvn->replace_node(n, res);
1766       }
1767     }
1768     // cleanup
1769     if (_pcmp_neq->outcnt() == 0)
1770       igvn->hash_delete(_pcmp_neq);
1771     if (_pcmp_eq->outcnt()  == 0)
1772       igvn->hash_delete(_pcmp_eq);
1773   }
1774 
1775   // For MemBarStoreStore nodes added in library_call.cpp, check
1776   // escape status of associated AllocateNode and optimize out
1777   // MemBarStoreStore node if the allocated object never escapes.
1778   while (storestore_worklist.length() != 0) {
1779     Node *n = storestore_worklist.pop();
1780     MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1781     Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1782     assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1783     if (not_global_escape(alloc)) {
1784       MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1785       mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1786       mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1787       igvn->register_new_node_with_optimizer(mb);
1788       igvn->replace_node(storestore, mb);
1789     }
1790   }
1791 }
1792 
1793 // Optimize objects compare.
1794 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1795   assert(OptimizePtrCompare, "sanity");
1796   PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1797   PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1798   JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1799   JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1800   assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1801   assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1802 
1803   // Check simple cases first.
1804   if (jobj1 != NULL) {
1805     if (jobj1->escape_state() == PointsToNode::NoEscape) {
1806       if (jobj1 == jobj2) {
1807         // Comparing the same not escaping object.
1808         return _pcmp_eq;
1809       }
1810       Node* obj = jobj1->ideal_node();
1811       // Comparing not escaping allocation.
1812       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1813           !ptn2->points_to(jobj1)) {
1814         return _pcmp_neq; // This includes nullness check.
1815       }
1816     }
1817   }
1818   if (jobj2 != NULL) {
1819     if (jobj2->escape_state() == PointsToNode::NoEscape) {
1820       Node* obj = jobj2->ideal_node();
1821       // Comparing not escaping allocation.
1822       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1823           !ptn1->points_to(jobj2)) {
1824         return _pcmp_neq; // This includes nullness check.
1825       }
1826     }
1827   }
1828   if (jobj1 != NULL && jobj1 != phantom_obj &&
1829       jobj2 != NULL && jobj2 != phantom_obj &&
1830       jobj1->ideal_node()->is_Con() &&
1831       jobj2->ideal_node()->is_Con()) {
1832     // Klass or String constants compare. Need to be careful with
1833     // compressed pointers - compare types of ConN and ConP instead of nodes.
1834     const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1835     const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1836     if (t1->make_ptr() == t2->make_ptr()) {
1837       return _pcmp_eq;
1838     } else {
1839       return _pcmp_neq;
1840     }
1841   }
1842   if (ptn1->meet(ptn2)) {
1843     return NULL; // Sets are not disjoint
1844   }
1845 
1846   // Sets are disjoint.
1847   bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1848   bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1849   bool set1_has_null_ptr    = ptn1->points_to(null_obj);
1850   bool set2_has_null_ptr    = ptn2->points_to(null_obj);
1851   if (set1_has_unknown_ptr && set2_has_null_ptr ||
1852       set2_has_unknown_ptr && set1_has_null_ptr) {
1853     // Check nullness of unknown object.
1854     return NULL;
1855   }
1856 
1857   // Disjointness by itself is not sufficient since
1858   // alias analysis is not complete for escaped objects.
1859   // Disjoint sets are definitely unrelated only when
1860   // at least one set has only not escaping allocations.
1861   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1862     if (ptn1->non_escaping_allocation()) {
1863       return _pcmp_neq;
1864     }
1865   }
1866   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1867     if (ptn2->non_escaping_allocation()) {
1868       return _pcmp_neq;
1869     }
1870   }
1871   return NULL;
1872 }
1873 
1874 // Connection Graph constuction functions.
1875 
1876 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1877   PointsToNode* ptadr = _nodes.at(n->_idx);
1878   if (ptadr != NULL) {
1879     assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1880     return;
1881   }
1882   Compile* C = _compile;
1883   ptadr = new (C->comp_arena()) LocalVarNode(C, n, es);
1884   _nodes.at_put(n->_idx, ptadr);
1885 }
1886 
1887 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1888   PointsToNode* ptadr = _nodes.at(n->_idx);
1889   if (ptadr != NULL) {
1890     assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1891     return;
1892   }
1893   Compile* C = _compile;
1894   ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es);
1895   _nodes.at_put(n->_idx, ptadr);
1896 }
1897 
1898 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1899   PointsToNode* ptadr = _nodes.at(n->_idx);
1900   if (ptadr != NULL) {
1901     assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1902     return;
1903   }
1904   bool unsafe = false;
1905   bool is_oop = is_oop_field(n, offset, &unsafe);
1906   if (unsafe) {
1907     es = PointsToNode::GlobalEscape;
1908   }
1909   Compile* C = _compile;
1910   FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop);
1911   _nodes.at_put(n->_idx, field);
1912 }
1913 
1914 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1915                                     PointsToNode* src, PointsToNode* dst) {
1916   assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1917   assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1918   PointsToNode* ptadr = _nodes.at(n->_idx);
1919   if (ptadr != NULL) {
1920     assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1921     return;
1922   }
1923   Compile* C = _compile;
1924   ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es);
1925   _nodes.at_put(n->_idx, ptadr);
1926   // Add edge from arraycopy node to source object.
1927   (void)add_edge(ptadr, src);
1928   src->set_arraycopy_src();
1929   // Add edge from destination object to arraycopy node.
1930   (void)add_edge(dst, ptadr);
1931   dst->set_arraycopy_dst();
1932 }
1933 
1934 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1935   const Type* adr_type = n->as_AddP()->bottom_type();
1936   BasicType bt = T_INT;
1937   if (offset == Type::OffsetBot) {
1938     // Check only oop fields.
1939     if (!adr_type->isa_aryptr() ||
1940         (adr_type->isa_aryptr()->klass() == NULL) ||
1941          adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1942       // OffsetBot is used to reference array's element. Ignore first AddP.
1943       if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
1944         bt = T_OBJECT;
1945       }
1946     }
1947   } else if (offset != oopDesc::klass_offset_in_bytes()) {
1948     if (adr_type->isa_instptr()) {
1949       ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
1950       if (field != NULL) {
1951         bt = field->layout_type();
1952       } else {
1953         // Check for unsafe oop field access
1954         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1955           int opcode = n->fast_out(i)->Opcode();
1956           if (opcode == Op_StoreP || opcode == Op_LoadP ||
1957               opcode == Op_StoreN || opcode == Op_LoadN) {
1958             bt = T_OBJECT;
1959             (*unsafe) = true;
1960             break;
1961           }
1962         }
1963       }
1964     } else if (adr_type->isa_aryptr()) {
1965       if (offset == arrayOopDesc::length_offset_in_bytes()) {
1966         // Ignore array length load.
1967       } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
1968         // Ignore first AddP.
1969       } else {
1970         const Type* elemtype = adr_type->isa_aryptr()->elem();
1971         bt = elemtype->array_element_basic_type();
1972       }
1973     } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
1974       // Allocation initialization, ThreadLocal field access, unsafe access
1975       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1976         int opcode = n->fast_out(i)->Opcode();
1977         if (opcode == Op_StoreP || opcode == Op_LoadP ||
1978             opcode == Op_StoreN || opcode == Op_LoadN) {
1979           bt = T_OBJECT;
1980           break;
1981         }
1982       }
1983     }
1984   }
1985   return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
1986 }
1987 
1988 // Returns unique pointed java object or NULL.
1989 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
1990   assert(!_collecting, "should not call when contructed graph");
1991   // If the node was created after the escape computation we can't answer.
1992   uint idx = n->_idx;
1993   if (idx >= nodes_size()) {
1994     return NULL;
1995   }
1996   PointsToNode* ptn = ptnode_adr(idx);
1997   if (ptn->is_JavaObject()) {
1998     return ptn->as_JavaObject();
1999   }
2000   assert(ptn->is_LocalVar(), "sanity");
2001   // Check all java objects it points to.
2002   JavaObjectNode* jobj = NULL;
2003   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2004     PointsToNode* e = i.get();
2005     if (e->is_JavaObject()) {
2006       if (jobj == NULL) {
2007         jobj = e->as_JavaObject();
2008       } else if (jobj != e) {
2009         return NULL;
2010       }
2011     }
2012   }
2013   return jobj;
2014 }
2015 
2016 // Return true if this node points only to non-escaping allocations.
2017 bool PointsToNode::non_escaping_allocation() {
2018   if (is_JavaObject()) {
2019     Node* n = ideal_node();
2020     if (n->is_Allocate() || n->is_CallStaticJava()) {
2021       return (escape_state() == PointsToNode::NoEscape);
2022     } else {
2023       return false;
2024     }
2025   }
2026   assert(is_LocalVar(), "sanity");
2027   // Check all java objects it points to.
2028   for (EdgeIterator i(this); i.has_next(); i.next()) {
2029     PointsToNode* e = i.get();
2030     if (e->is_JavaObject()) {
2031       Node* n = e->ideal_node();
2032       if ((e->escape_state() != PointsToNode::NoEscape) ||
2033           !(n->is_Allocate() || n->is_CallStaticJava())) {
2034         return false;
2035       }
2036     }
2037   }
2038   return true;
2039 }
2040 
2041 // Return true if we know the node does not escape globally.
2042 bool ConnectionGraph::not_global_escape(Node *n) {
2043   assert(!_collecting, "should not call during graph construction");
2044   // If the node was created after the escape computation we can't answer.
2045   uint idx = n->_idx;
2046   if (idx >= nodes_size()) {
2047     return false;
2048   }
2049   PointsToNode* ptn = ptnode_adr(idx);
2050   PointsToNode::EscapeState es = ptn->escape_state();
2051   // If we have already computed a value, return it.
2052   if (es >= PointsToNode::GlobalEscape)
2053     return false;
2054   if (ptn->is_JavaObject()) {
2055     return true; // (es < PointsToNode::GlobalEscape);
2056   }
2057   assert(ptn->is_LocalVar(), "sanity");
2058   // Check all java objects it points to.
2059   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2060     if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2061       return false;
2062   }
2063   return true;
2064 }
2065 
2066 
2067 // Helper functions
2068 
2069 // Return true if this node points to specified node or nodes it points to.
2070 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2071   if (is_JavaObject()) {
2072     return (this == ptn);
2073   }
2074   assert(is_LocalVar() || is_Field(), "sanity");
2075   for (EdgeIterator i(this); i.has_next(); i.next()) {
2076     if (i.get() == ptn)
2077       return true;
2078   }
2079   return false;
2080 }
2081 
2082 // Return true if one node points to an other.
2083 bool PointsToNode::meet(PointsToNode* ptn) {
2084   if (this == ptn) {
2085     return true;
2086   } else if (ptn->is_JavaObject()) {
2087     return this->points_to(ptn->as_JavaObject());
2088   } else if (this->is_JavaObject()) {
2089     return ptn->points_to(this->as_JavaObject());
2090   }
2091   assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2092   int ptn_count =  ptn->edge_count();
2093   for (EdgeIterator i(this); i.has_next(); i.next()) {
2094     PointsToNode* this_e = i.get();
2095     for (int j = 0; j < ptn_count; j++) {
2096       if (this_e == ptn->edge(j))
2097         return true;
2098     }
2099   }
2100   return false;
2101 }
2102 
2103 #ifdef ASSERT
2104 // Return true if bases point to this java object.
2105 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2106   for (BaseIterator i(this); i.has_next(); i.next()) {
2107     if (i.get() == jobj)
2108       return true;
2109   }
2110   return false;
2111 }
2112 #endif
2113 
2114 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2115   const Type *adr_type = phase->type(adr);
2116   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2117       adr->in(AddPNode::Address)->is_Proj() &&
2118       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2119     // We are computing a raw address for a store captured by an Initialize
2120     // compute an appropriate address type. AddP cases #3 and #5 (see below).
2121     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2122     assert(offs != Type::OffsetBot ||
2123            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2124            "offset must be a constant or it is initialization of array");
2125     return offs;
2126   }
2127   const TypePtr *t_ptr = adr_type->isa_ptr();
2128   assert(t_ptr != NULL, "must be a pointer type");
2129   return t_ptr->offset();
2130 }
2131 
2132 Node* ConnectionGraph::get_addp_base(Node *addp) {
2133   assert(addp->is_AddP(), "must be AddP");
2134   //
2135   // AddP cases for Base and Address inputs:
2136   // case #1. Direct object's field reference:
2137   //     Allocate
2138   //       |
2139   //     Proj #5 ( oop result )
2140   //       |
2141   //     CheckCastPP (cast to instance type)
2142   //      | |
2143   //     AddP  ( base == address )
2144   //
2145   // case #2. Indirect object's field reference:
2146   //      Phi
2147   //       |
2148   //     CastPP (cast to instance type)
2149   //      | |
2150   //     AddP  ( base == address )
2151   //
2152   // case #3. Raw object's field reference for Initialize node:
2153   //      Allocate
2154   //        |
2155   //      Proj #5 ( oop result )
2156   //  top   |
2157   //     \  |
2158   //     AddP  ( base == top )
2159   //
2160   // case #4. Array's element reference:
2161   //   {CheckCastPP | CastPP}
2162   //     |  | |
2163   //     |  AddP ( array's element offset )
2164   //     |  |
2165   //     AddP ( array's offset )
2166   //
2167   // case #5. Raw object's field reference for arraycopy stub call:
2168   //          The inline_native_clone() case when the arraycopy stub is called
2169   //          after the allocation before Initialize and CheckCastPP nodes.
2170   //      Allocate
2171   //        |
2172   //      Proj #5 ( oop result )
2173   //       | |
2174   //       AddP  ( base == address )
2175   //
2176   // case #6. Constant Pool, ThreadLocal, CastX2P or
2177   //          Raw object's field reference:
2178   //      {ConP, ThreadLocal, CastX2P, raw Load}
2179   //  top   |
2180   //     \  |
2181   //     AddP  ( base == top )
2182   //
2183   // case #7. Klass's field reference.
2184   //      LoadKlass
2185   //       | |
2186   //       AddP  ( base == address )
2187   //
2188   // case #8. narrow Klass's field reference.
2189   //      LoadNKlass
2190   //       |
2191   //      DecodeN
2192   //       | |
2193   //       AddP  ( base == address )
2194   //
2195   Node *base = addp->in(AddPNode::Base);
2196   if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2197     base = addp->in(AddPNode::Address);
2198     while (base->is_AddP()) {
2199       // Case #6 (unsafe access) may have several chained AddP nodes.
2200       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2201       base = base->in(AddPNode::Address);
2202     }
2203     Node* uncast_base = base->uncast();
2204     int opcode = uncast_base->Opcode();
2205     assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2206            opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2207            (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2208            (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2209   }
2210   return base;
2211 }
2212 
2213 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2214   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2215   Node* addp2 = addp->raw_out(0);
2216   if (addp->outcnt() == 1 && addp2->is_AddP() &&
2217       addp2->in(AddPNode::Base) == n &&
2218       addp2->in(AddPNode::Address) == addp) {
2219     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2220     //
2221     // Find array's offset to push it on worklist first and
2222     // as result process an array's element offset first (pushed second)
2223     // to avoid CastPP for the array's offset.
2224     // Otherwise the inserted CastPP (LocalVar) will point to what
2225     // the AddP (Field) points to. Which would be wrong since
2226     // the algorithm expects the CastPP has the same point as
2227     // as AddP's base CheckCastPP (LocalVar).
2228     //
2229     //    ArrayAllocation
2230     //     |
2231     //    CheckCastPP
2232     //     |
2233     //    memProj (from ArrayAllocation CheckCastPP)
2234     //     |  ||
2235     //     |  ||   Int (element index)
2236     //     |  ||    |   ConI (log(element size))
2237     //     |  ||    |   /
2238     //     |  ||   LShift
2239     //     |  ||  /
2240     //     |  AddP (array's element offset)
2241     //     |  |
2242     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
2243     //     | / /
2244     //     AddP (array's offset)
2245     //      |
2246     //     Load/Store (memory operation on array's element)
2247     //
2248     return addp2;
2249   }
2250   return NULL;
2251 }
2252 
2253 //
2254 // Adjust the type and inputs of an AddP which computes the
2255 // address of a field of an instance
2256 //
2257 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2258   PhaseGVN* igvn = _igvn;
2259   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2260   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2261   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2262   if (t == NULL) {
2263     // We are computing a raw address for a store captured by an Initialize
2264     // compute an appropriate address type (cases #3 and #5).
2265     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2266     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2267     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2268     assert(offs != Type::OffsetBot, "offset must be a constant");
2269     t = base_t->add_offset(offs)->is_oopptr();
2270   }
2271   int inst_id =  base_t->instance_id();
2272   assert(!t->is_known_instance() || t->instance_id() == inst_id,
2273                              "old type must be non-instance or match new type");
2274 
2275   // The type 't' could be subclass of 'base_t'.
2276   // As result t->offset() could be large then base_t's size and it will
2277   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2278   // constructor verifies correctness of the offset.
2279   //
2280   // It could happened on subclass's branch (from the type profiling
2281   // inlining) which was not eliminated during parsing since the exactness
2282   // of the allocation type was not propagated to the subclass type check.
2283   //
2284   // Or the type 't' could be not related to 'base_t' at all.
2285   // It could happened when CHA type is different from MDO type on a dead path
2286   // (for example, from instanceof check) which is not collapsed during parsing.
2287   //
2288   // Do nothing for such AddP node and don't process its users since
2289   // this code branch will go away.
2290   //
2291   if (!t->is_known_instance() &&
2292       !base_t->klass()->is_subtype_of(t->klass())) {
2293      return false; // bail out
2294   }
2295   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2296   // Do NOT remove the next line: ensure a new alias index is allocated
2297   // for the instance type. Note: C++ will not remove it since the call
2298   // has side effect.
2299   int alias_idx = _compile->get_alias_index(tinst);
2300   igvn->set_type(addp, tinst);
2301   // record the allocation in the node map
2302   set_map(addp, get_map(base->_idx));
2303   // Set addp's Base and Address to 'base'.
2304   Node *abase = addp->in(AddPNode::Base);
2305   Node *adr   = addp->in(AddPNode::Address);
2306   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2307       adr->in(0)->_idx == (uint)inst_id) {
2308     // Skip AddP cases #3 and #5.
2309   } else {
2310     assert(!abase->is_top(), "sanity"); // AddP case #3
2311     if (abase != base) {
2312       igvn->hash_delete(addp);
2313       addp->set_req(AddPNode::Base, base);
2314       if (abase == adr) {
2315         addp->set_req(AddPNode::Address, base);
2316       } else {
2317         // AddP case #4 (adr is array's element offset AddP node)
2318 #ifdef ASSERT
2319         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2320         assert(adr->is_AddP() && atype != NULL &&
2321                atype->instance_id() == inst_id, "array's element offset should be processed first");
2322 #endif
2323       }
2324       igvn->hash_insert(addp);
2325     }
2326   }
2327   // Put on IGVN worklist since at least addp's type was changed above.
2328   record_for_optimizer(addp);
2329   return true;
2330 }
2331 
2332 //
2333 // Create a new version of orig_phi if necessary. Returns either the newly
2334 // created phi or an existing phi.  Sets create_new to indicate whether a new
2335 // phi was created.  Cache the last newly created phi in the node map.
2336 //
2337 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, bool &new_created) {
2338   Compile *C = _compile;
2339   PhaseGVN* igvn = _igvn;
2340   new_created = false;
2341   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2342   // nothing to do if orig_phi is bottom memory or matches alias_idx
2343   if (phi_alias_idx == alias_idx) {
2344     return orig_phi;
2345   }
2346   // Have we recently created a Phi for this alias index?
2347   PhiNode *result = get_map_phi(orig_phi->_idx);
2348   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2349     return result;
2350   }
2351   // Previous check may fail when the same wide memory Phi was split into Phis
2352   // for different memory slices. Search all Phis for this region.
2353   if (result != NULL) {
2354     Node* region = orig_phi->in(0);
2355     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2356       Node* phi = region->fast_out(i);
2357       if (phi->is_Phi() &&
2358           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2359         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2360         return phi->as_Phi();
2361       }
2362     }
2363   }
2364   if ((int) (C->live_nodes() + 2*NodeLimitFudgeFactor) > MaxNodeLimit) {
2365     if (C->do_escape_analysis() == true && !C->failing()) {
2366       // Retry compilation without escape analysis.
2367       // If this is the first failure, the sentinel string will "stick"
2368       // to the Compile object, and the C2Compiler will see it and retry.
2369       C->record_failure(C2Compiler::retry_no_escape_analysis());
2370     }
2371     return NULL;
2372   }
2373   orig_phi_worklist.append_if_missing(orig_phi);
2374   const TypePtr *atype = C->get_adr_type(alias_idx);
2375   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2376   C->copy_node_notes_to(result, orig_phi);
2377   igvn->set_type(result, result->bottom_type());
2378   record_for_optimizer(result);
2379   set_map(orig_phi, result);
2380   new_created = true;
2381   return result;
2382 }
2383 
2384 //
2385 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2386 // specified alias index.
2387 //
2388 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist) {
2389   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2390   Compile *C = _compile;
2391   PhaseGVN* igvn = _igvn;
2392   bool new_phi_created;
2393   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2394   if (!new_phi_created) {
2395     return result;
2396   }
2397   GrowableArray<PhiNode *>  phi_list;
2398   GrowableArray<uint>  cur_input;
2399   PhiNode *phi = orig_phi;
2400   uint idx = 1;
2401   bool finished = false;
2402   while(!finished) {
2403     while (idx < phi->req()) {
2404       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2405       if (mem != NULL && mem->is_Phi()) {
2406         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2407         if (new_phi_created) {
2408           // found an phi for which we created a new split, push current one on worklist and begin
2409           // processing new one
2410           phi_list.push(phi);
2411           cur_input.push(idx);
2412           phi = mem->as_Phi();
2413           result = newphi;
2414           idx = 1;
2415           continue;
2416         } else {
2417           mem = newphi;
2418         }
2419       }
2420       if (C->failing()) {
2421         return NULL;
2422       }
2423       result->set_req(idx++, mem);
2424     }
2425 #ifdef ASSERT
2426     // verify that the new Phi has an input for each input of the original
2427     assert( phi->req() == result->req(), "must have same number of inputs.");
2428     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2429 #endif
2430     // Check if all new phi's inputs have specified alias index.
2431     // Otherwise use old phi.
2432     for (uint i = 1; i < phi->req(); i++) {
2433       Node* in = result->in(i);
2434       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2435     }
2436     // we have finished processing a Phi, see if there are any more to do
2437     finished = (phi_list.length() == 0 );
2438     if (!finished) {
2439       phi = phi_list.pop();
2440       idx = cur_input.pop();
2441       PhiNode *prev_result = get_map_phi(phi->_idx);
2442       prev_result->set_req(idx++, result);
2443       result = prev_result;
2444     }
2445   }
2446   return result;
2447 }
2448 
2449 //
2450 // The next methods are derived from methods in MemNode.
2451 //
2452 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2453   Node *mem = mmem;
2454   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2455   // means an array I have not precisely typed yet.  Do not do any
2456   // alias stuff with it any time soon.
2457   if (toop->base() != Type::AnyPtr &&
2458       !(toop->klass() != NULL &&
2459         toop->klass()->is_java_lang_Object() &&
2460         toop->offset() == Type::OffsetBot)) {
2461     mem = mmem->memory_at(alias_idx);
2462     // Update input if it is progress over what we have now
2463   }
2464   return mem;
2465 }
2466 
2467 //
2468 // Move memory users to their memory slices.
2469 //
2470 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis) {
2471   Compile* C = _compile;
2472   PhaseGVN* igvn = _igvn;
2473   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2474   assert(tp != NULL, "ptr type");
2475   int alias_idx = C->get_alias_index(tp);
2476   int general_idx = C->get_general_index(alias_idx);
2477 
2478   // Move users first
2479   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2480     Node* use = n->fast_out(i);
2481     if (use->is_MergeMem()) {
2482       MergeMemNode* mmem = use->as_MergeMem();
2483       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2484       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2485         continue; // Nothing to do
2486       }
2487       // Replace previous general reference to mem node.
2488       uint orig_uniq = C->unique();
2489       Node* m = find_inst_mem(n, general_idx, orig_phis);
2490       assert(orig_uniq == C->unique(), "no new nodes");
2491       mmem->set_memory_at(general_idx, m);
2492       --imax;
2493       --i;
2494     } else if (use->is_MemBar()) {
2495       assert(!use->is_Initialize(), "initializing stores should not be moved");
2496       if (use->req() > MemBarNode::Precedent &&
2497           use->in(MemBarNode::Precedent) == n) {
2498         // Don't move related membars.
2499         record_for_optimizer(use);
2500         continue;
2501       }
2502       tp = use->as_MemBar()->adr_type()->isa_ptr();
2503       if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2504           alias_idx == general_idx) {
2505         continue; // Nothing to do
2506       }
2507       // Move to general memory slice.
2508       uint orig_uniq = C->unique();
2509       Node* m = find_inst_mem(n, general_idx, orig_phis);
2510       assert(orig_uniq == C->unique(), "no new nodes");
2511       igvn->hash_delete(use);
2512       imax -= use->replace_edge(n, m);
2513       igvn->hash_insert(use);
2514       record_for_optimizer(use);
2515       --i;
2516 #ifdef ASSERT
2517     } else if (use->is_Mem()) {
2518       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2519         // Don't move related cardmark.
2520         continue;
2521       }
2522       // Memory nodes should have new memory input.
2523       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2524       assert(tp != NULL, "ptr type");
2525       int idx = C->get_alias_index(tp);
2526       assert(get_map(use->_idx) != NULL || idx == alias_idx,
2527              "Following memory nodes should have new memory input or be on the same memory slice");
2528     } else if (use->is_Phi()) {
2529       // Phi nodes should be split and moved already.
2530       tp = use->as_Phi()->adr_type()->isa_ptr();
2531       assert(tp != NULL, "ptr type");
2532       int idx = C->get_alias_index(tp);
2533       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2534     } else {
2535       use->dump();
2536       assert(false, "should not be here");
2537 #endif
2538     }
2539   }
2540 }
2541 
2542 //
2543 // Search memory chain of "mem" to find a MemNode whose address
2544 // is the specified alias index.
2545 //
2546 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis) {
2547   if (orig_mem == NULL)
2548     return orig_mem;
2549   Compile* C = _compile;
2550   PhaseGVN* igvn = _igvn;
2551   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2552   bool is_instance = (toop != NULL) && toop->is_known_instance();
2553   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2554   Node *prev = NULL;
2555   Node *result = orig_mem;
2556   while (prev != result) {
2557     prev = result;
2558     if (result == start_mem)
2559       break;  // hit one of our sentinels
2560     if (result->is_Mem()) {
2561       const Type *at = igvn->type(result->in(MemNode::Address));
2562       if (at == Type::TOP)
2563         break; // Dead
2564       assert (at->isa_ptr() != NULL, "pointer type required.");
2565       int idx = C->get_alias_index(at->is_ptr());
2566       if (idx == alias_idx)
2567         break; // Found
2568       if (!is_instance && (at->isa_oopptr() == NULL ||
2569                            !at->is_oopptr()->is_known_instance())) {
2570         break; // Do not skip store to general memory slice.
2571       }
2572       result = result->in(MemNode::Memory);
2573     }
2574     if (!is_instance)
2575       continue;  // don't search further for non-instance types
2576     // skip over a call which does not affect this memory slice
2577     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2578       Node *proj_in = result->in(0);
2579       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2580         break;  // hit one of our sentinels
2581       } else if (proj_in->is_Call()) {
2582         CallNode *call = proj_in->as_Call();
2583         if (!call->may_modify(toop, igvn)) {
2584           result = call->in(TypeFunc::Memory);
2585         }
2586       } else if (proj_in->is_Initialize()) {
2587         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2588         // Stop if this is the initialization for the object instance which
2589         // which contains this memory slice, otherwise skip over it.
2590         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2591           result = proj_in->in(TypeFunc::Memory);
2592         }
2593       } else if (proj_in->is_MemBar()) {
2594         result = proj_in->in(TypeFunc::Memory);
2595       }
2596     } else if (result->is_MergeMem()) {
2597       MergeMemNode *mmem = result->as_MergeMem();
2598       result = step_through_mergemem(mmem, alias_idx, toop);
2599       if (result == mmem->base_memory()) {
2600         // Didn't find instance memory, search through general slice recursively.
2601         result = mmem->memory_at(C->get_general_index(alias_idx));
2602         result = find_inst_mem(result, alias_idx, orig_phis);
2603         if (C->failing()) {
2604           return NULL;
2605         }
2606         mmem->set_memory_at(alias_idx, result);
2607       }
2608     } else if (result->is_Phi() &&
2609                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2610       Node *un = result->as_Phi()->unique_input(igvn);
2611       if (un != NULL) {
2612         orig_phis.append_if_missing(result->as_Phi());
2613         result = un;
2614       } else {
2615         break;
2616       }
2617     } else if (result->is_ClearArray()) {
2618       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2619         // Can not bypass initialization of the instance
2620         // we are looking for.
2621         break;
2622       }
2623       // Otherwise skip it (the call updated 'result' value).
2624     } else if (result->Opcode() == Op_SCMemProj) {
2625       Node* mem = result->in(0);
2626       Node* adr = NULL;
2627       if (mem->is_LoadStore()) {
2628         adr = mem->in(MemNode::Address);
2629       } else {
2630         assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
2631         adr = mem->in(3); // Memory edge corresponds to destination array
2632       }
2633       const Type *at = igvn->type(adr);
2634       if (at != Type::TOP) {
2635         assert (at->isa_ptr() != NULL, "pointer type required.");
2636         int idx = C->get_alias_index(at->is_ptr());
2637         assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2638         break;
2639       }
2640       result = mem->in(MemNode::Memory);
2641     }
2642   }
2643   if (result->is_Phi()) {
2644     PhiNode *mphi = result->as_Phi();
2645     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2646     const TypePtr *t = mphi->adr_type();
2647     if (!is_instance) {
2648       // Push all non-instance Phis on the orig_phis worklist to update inputs
2649       // during Phase 4 if needed.
2650       orig_phis.append_if_missing(mphi);
2651     } else if (C->get_alias_index(t) != alias_idx) {
2652       // Create a new Phi with the specified alias index type.
2653       result = split_memory_phi(mphi, alias_idx, orig_phis);
2654     }
2655   }
2656   // the result is either MemNode, PhiNode, InitializeNode.
2657   return result;
2658 }
2659 
2660 //
2661 //  Convert the types of unescaped object to instance types where possible,
2662 //  propagate the new type information through the graph, and update memory
2663 //  edges and MergeMem inputs to reflect the new type.
2664 //
2665 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
2666 //  The processing is done in 4 phases:
2667 //
2668 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
2669 //            types for the CheckCastPP for allocations where possible.
2670 //            Propagate the the new types through users as follows:
2671 //               casts and Phi:  push users on alloc_worklist
2672 //               AddP:  cast Base and Address inputs to the instance type
2673 //                      push any AddP users on alloc_worklist and push any memnode
2674 //                      users onto memnode_worklist.
2675 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
2676 //            search the Memory chain for a store with the appropriate type
2677 //            address type.  If a Phi is found, create a new version with
2678 //            the appropriate memory slices from each of the Phi inputs.
2679 //            For stores, process the users as follows:
2680 //               MemNode:  push on memnode_worklist
2681 //               MergeMem: push on mergemem_worklist
2682 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
2683 //            moving the first node encountered of each  instance type to the
2684 //            the input corresponding to its alias index.
2685 //            appropriate memory slice.
2686 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2687 //
2688 // In the following example, the CheckCastPP nodes are the cast of allocation
2689 // results and the allocation of node 29 is unescaped and eligible to be an
2690 // instance type.
2691 //
2692 // We start with:
2693 //
2694 //     7 Parm #memory
2695 //    10  ConI  "12"
2696 //    19  CheckCastPP   "Foo"
2697 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2698 //    29  CheckCastPP   "Foo"
2699 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
2700 //
2701 //    40  StoreP  25   7  20   ... alias_index=4
2702 //    50  StoreP  35  40  30   ... alias_index=4
2703 //    60  StoreP  45  50  20   ... alias_index=4
2704 //    70  LoadP    _  60  30   ... alias_index=4
2705 //    80  Phi     75  50  60   Memory alias_index=4
2706 //    90  LoadP    _  80  30   ... alias_index=4
2707 //   100  LoadP    _  80  20   ... alias_index=4
2708 //
2709 //
2710 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2711 // and creating a new alias index for node 30.  This gives:
2712 //
2713 //     7 Parm #memory
2714 //    10  ConI  "12"
2715 //    19  CheckCastPP   "Foo"
2716 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2717 //    29  CheckCastPP   "Foo"  iid=24
2718 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2719 //
2720 //    40  StoreP  25   7  20   ... alias_index=4
2721 //    50  StoreP  35  40  30   ... alias_index=6
2722 //    60  StoreP  45  50  20   ... alias_index=4
2723 //    70  LoadP    _  60  30   ... alias_index=6
2724 //    80  Phi     75  50  60   Memory alias_index=4
2725 //    90  LoadP    _  80  30   ... alias_index=6
2726 //   100  LoadP    _  80  20   ... alias_index=4
2727 //
2728 // In phase 2, new memory inputs are computed for the loads and stores,
2729 // And a new version of the phi is created.  In phase 4, the inputs to
2730 // node 80 are updated and then the memory nodes are updated with the
2731 // values computed in phase 2.  This results in:
2732 //
2733 //     7 Parm #memory
2734 //    10  ConI  "12"
2735 //    19  CheckCastPP   "Foo"
2736 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2737 //    29  CheckCastPP   "Foo"  iid=24
2738 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2739 //
2740 //    40  StoreP  25  7   20   ... alias_index=4
2741 //    50  StoreP  35  7   30   ... alias_index=6
2742 //    60  StoreP  45  40  20   ... alias_index=4
2743 //    70  LoadP    _  50  30   ... alias_index=6
2744 //    80  Phi     75  40  60   Memory alias_index=4
2745 //   120  Phi     75  50  50   Memory alias_index=6
2746 //    90  LoadP    _ 120  30   ... alias_index=6
2747 //   100  LoadP    _  80  20   ... alias_index=4
2748 //
2749 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
2750   GrowableArray<Node *>  memnode_worklist;
2751   GrowableArray<PhiNode *>  orig_phis;
2752   PhaseIterGVN  *igvn = _igvn;
2753   uint new_index_start = (uint) _compile->num_alias_types();
2754   Arena* arena = Thread::current()->resource_area();
2755   VectorSet visited(arena);
2756   ideal_nodes.clear(); // Reset for use with set_map/get_map.
2757   uint unique_old = _compile->unique();
2758 
2759   //  Phase 1:  Process possible allocations from alloc_worklist.
2760   //  Create instance types for the CheckCastPP for allocations where possible.
2761   //
2762   // (Note: don't forget to change the order of the second AddP node on
2763   //  the alloc_worklist if the order of the worklist processing is changed,
2764   //  see the comment in find_second_addp().)
2765   //
2766   while (alloc_worklist.length() != 0) {
2767     Node *n = alloc_worklist.pop();
2768     uint ni = n->_idx;
2769     if (n->is_Call()) {
2770       CallNode *alloc = n->as_Call();
2771       // copy escape information to call node
2772       PointsToNode* ptn = ptnode_adr(alloc->_idx);
2773       PointsToNode::EscapeState es = ptn->escape_state();
2774       // We have an allocation or call which returns a Java object,
2775       // see if it is unescaped.
2776       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2777         continue;
2778       // Find CheckCastPP for the allocate or for the return value of a call
2779       n = alloc->result_cast();
2780       if (n == NULL) {            // No uses except Initialize node
2781         if (alloc->is_Allocate()) {
2782           // Set the scalar_replaceable flag for allocation
2783           // so it could be eliminated if it has no uses.
2784           alloc->as_Allocate()->_is_scalar_replaceable = true;
2785         }
2786         if (alloc->is_CallStaticJava()) {
2787           // Set the scalar_replaceable flag for boxing method
2788           // so it could be eliminated if it has no uses.
2789           alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2790         }
2791         continue;
2792       }
2793       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2794         assert(!alloc->is_Allocate(), "allocation should have unique type");
2795         continue;
2796       }
2797 
2798       // The inline code for Object.clone() casts the allocation result to
2799       // java.lang.Object and then to the actual type of the allocated
2800       // object. Detect this case and use the second cast.
2801       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2802       // the allocation result is cast to java.lang.Object and then
2803       // to the actual Array type.
2804       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2805           && (alloc->is_AllocateArray() ||
2806               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2807         Node *cast2 = NULL;
2808         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2809           Node *use = n->fast_out(i);
2810           if (use->is_CheckCastPP()) {
2811             cast2 = use;
2812             break;
2813           }
2814         }
2815         if (cast2 != NULL) {
2816           n = cast2;
2817         } else {
2818           // Non-scalar replaceable if the allocation type is unknown statically
2819           // (reflection allocation), the object can't be restored during
2820           // deoptimization without precise type.
2821           continue;
2822         }
2823       }
2824       if (alloc->is_Allocate()) {
2825         // Set the scalar_replaceable flag for allocation
2826         // so it could be eliminated.
2827         alloc->as_Allocate()->_is_scalar_replaceable = true;
2828       }
2829       if (alloc->is_CallStaticJava()) {
2830         // Set the scalar_replaceable flag for boxing method
2831         // so it could be eliminated.
2832         alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2833       }
2834       set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2835       // in order for an object to be scalar-replaceable, it must be:
2836       //   - a direct allocation (not a call returning an object)
2837       //   - non-escaping
2838       //   - eligible to be a unique type
2839       //   - not determined to be ineligible by escape analysis
2840       set_map(alloc, n);
2841       set_map(n, alloc);
2842       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2843       if (t == NULL)
2844         continue;  // not a TypeOopPtr
2845       const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
2846       igvn->hash_delete(n);
2847       igvn->set_type(n,  tinst);
2848       n->raise_bottom_type(tinst);
2849       igvn->hash_insert(n);
2850       record_for_optimizer(n);
2851       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2852 
2853         // First, put on the worklist all Field edges from Connection Graph
2854         // which is more accurate then putting immediate users from Ideal Graph.
2855         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2856           PointsToNode* tgt = e.get();
2857           Node* use = tgt->ideal_node();
2858           assert(tgt->is_Field() && use->is_AddP(),
2859                  "only AddP nodes are Field edges in CG");
2860           if (use->outcnt() > 0) { // Don't process dead nodes
2861             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2862             if (addp2 != NULL) {
2863               assert(alloc->is_AllocateArray(),"array allocation was expected");
2864               alloc_worklist.append_if_missing(addp2);
2865             }
2866             alloc_worklist.append_if_missing(use);
2867           }
2868         }
2869 
2870         // An allocation may have an Initialize which has raw stores. Scan
2871         // the users of the raw allocation result and push AddP users
2872         // on alloc_worklist.
2873         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2874         assert (raw_result != NULL, "must have an allocation result");
2875         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2876           Node *use = raw_result->fast_out(i);
2877           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2878             Node* addp2 = find_second_addp(use, raw_result);
2879             if (addp2 != NULL) {
2880               assert(alloc->is_AllocateArray(),"array allocation was expected");
2881               alloc_worklist.append_if_missing(addp2);
2882             }
2883             alloc_worklist.append_if_missing(use);
2884           } else if (use->is_MemBar()) {
2885             memnode_worklist.append_if_missing(use);
2886           }
2887         }
2888       }
2889     } else if (n->is_AddP()) {
2890       JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2891       if (jobj == NULL || jobj == phantom_obj) {
2892 #ifdef ASSERT
2893         ptnode_adr(get_addp_base(n)->_idx)->dump();
2894         ptnode_adr(n->_idx)->dump();
2895         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2896 #endif
2897         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2898         return;
2899       }
2900       Node *base = get_map(jobj->idx());  // CheckCastPP node
2901       if (!split_AddP(n, base)) continue; // wrong type from dead path
2902     } else if (n->is_Phi() ||
2903                n->is_CheckCastPP() ||
2904                n->is_EncodeP() ||
2905                n->is_DecodeN() ||
2906                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2907       if (visited.test_set(n->_idx)) {
2908         assert(n->is_Phi(), "loops only through Phi's");
2909         continue;  // already processed
2910       }
2911       JavaObjectNode* jobj = unique_java_object(n);
2912       if (jobj == NULL || jobj == phantom_obj) {
2913 #ifdef ASSERT
2914         ptnode_adr(n->_idx)->dump();
2915         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2916 #endif
2917         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2918         return;
2919       } else {
2920         Node *val = get_map(jobj->idx());   // CheckCastPP node
2921         TypeNode *tn = n->as_Type();
2922         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2923         assert(tinst != NULL && tinst->is_known_instance() &&
2924                tinst->instance_id() == jobj->idx() , "instance type expected.");
2925 
2926         const Type *tn_type = igvn->type(tn);
2927         const TypeOopPtr *tn_t;
2928         if (tn_type->isa_narrowoop()) {
2929           tn_t = tn_type->make_ptr()->isa_oopptr();
2930         } else {
2931           tn_t = tn_type->isa_oopptr();
2932         }
2933         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2934           if (tn_type->isa_narrowoop()) {
2935             tn_type = tinst->make_narrowoop();
2936           } else {
2937             tn_type = tinst;
2938           }
2939           igvn->hash_delete(tn);
2940           igvn->set_type(tn, tn_type);
2941           tn->set_type(tn_type);
2942           igvn->hash_insert(tn);
2943           record_for_optimizer(n);
2944         } else {
2945           assert(tn_type == TypePtr::NULL_PTR ||
2946                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
2947                  "unexpected type");
2948           continue; // Skip dead path with different type
2949         }
2950       }
2951     } else {
2952       debug_only(n->dump();)
2953       assert(false, "EA: unexpected node");
2954       continue;
2955     }
2956     // push allocation's users on appropriate worklist
2957     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2958       Node *use = n->fast_out(i);
2959       if(use->is_Mem() && use->in(MemNode::Address) == n) {
2960         // Load/store to instance's field
2961         memnode_worklist.append_if_missing(use);
2962       } else if (use->is_MemBar()) {
2963         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
2964           memnode_worklist.append_if_missing(use);
2965         }
2966       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
2967         Node* addp2 = find_second_addp(use, n);
2968         if (addp2 != NULL) {
2969           alloc_worklist.append_if_missing(addp2);
2970         }
2971         alloc_worklist.append_if_missing(use);
2972       } else if (use->is_Phi() ||
2973                  use->is_CheckCastPP() ||
2974                  use->is_EncodeNarrowPtr() ||
2975                  use->is_DecodeNarrowPtr() ||
2976                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
2977         alloc_worklist.append_if_missing(use);
2978 #ifdef ASSERT
2979       } else if (use->is_Mem()) {
2980         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
2981       } else if (use->is_MergeMem()) {
2982         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2983       } else if (use->is_SafePoint()) {
2984         // Look for MergeMem nodes for calls which reference unique allocation
2985         // (through CheckCastPP nodes) even for debug info.
2986         Node* m = use->in(TypeFunc::Memory);
2987         if (m->is_MergeMem()) {
2988           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2989         }
2990       } else if (use->Opcode() == Op_EncodeISOArray) {
2991         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
2992           // EncodeISOArray overwrites destination array
2993           memnode_worklist.append_if_missing(use);
2994         }
2995       } else {
2996         uint op = use->Opcode();
2997         if (!(op == Op_CmpP || op == Op_Conv2B ||
2998               op == Op_CastP2X || op == Op_StoreCM ||
2999               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
3000               op == Op_StrEquals || op == Op_StrIndexOf)) {
3001           n->dump();
3002           use->dump();
3003           assert(false, "EA: missing allocation reference path");
3004         }
3005 #endif
3006       }
3007     }
3008 
3009   }
3010   // New alias types were created in split_AddP().
3011   uint new_index_end = (uint) _compile->num_alias_types();
3012   assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3013 
3014   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
3015   //            compute new values for Memory inputs  (the Memory inputs are not
3016   //            actually updated until phase 4.)
3017   if (memnode_worklist.length() == 0)
3018     return;  // nothing to do
3019   while (memnode_worklist.length() != 0) {
3020     Node *n = memnode_worklist.pop();
3021     if (visited.test_set(n->_idx))
3022       continue;
3023     if (n->is_Phi() || n->is_ClearArray()) {
3024       // we don't need to do anything, but the users must be pushed
3025     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3026       // we don't need to do anything, but the users must be pushed
3027       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3028       if (n == NULL)
3029         continue;
3030     } else if (n->Opcode() == Op_EncodeISOArray) {
3031       // get the memory projection
3032       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3033         Node *use = n->fast_out(i);
3034         if (use->Opcode() == Op_SCMemProj) {
3035           n = use;
3036           break;
3037         }
3038       }
3039       assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3040     } else {
3041       assert(n->is_Mem(), "memory node required.");
3042       Node *addr = n->in(MemNode::Address);
3043       const Type *addr_t = igvn->type(addr);
3044       if (addr_t == Type::TOP)
3045         continue;
3046       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3047       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3048       assert ((uint)alias_idx < new_index_end, "wrong alias index");
3049       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3050       if (_compile->failing()) {
3051         return;
3052       }
3053       if (mem != n->in(MemNode::Memory)) {
3054         // We delay the memory edge update since we need old one in
3055         // MergeMem code below when instances memory slices are separated.
3056         set_map(n, mem);
3057       }
3058       if (n->is_Load()) {
3059         continue;  // don't push users
3060       } else if (n->is_LoadStore()) {
3061         // get the memory projection
3062         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3063           Node *use = n->fast_out(i);
3064           if (use->Opcode() == Op_SCMemProj) {
3065             n = use;
3066             break;
3067           }
3068         }
3069         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3070       }
3071     }
3072     // push user on appropriate worklist
3073     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3074       Node *use = n->fast_out(i);
3075       if (use->is_Phi() || use->is_ClearArray()) {
3076         memnode_worklist.append_if_missing(use);
3077       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3078         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3079           continue;
3080         memnode_worklist.append_if_missing(use);
3081       } else if (use->is_MemBar()) {
3082         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3083           memnode_worklist.append_if_missing(use);
3084         }
3085 #ifdef ASSERT
3086       } else if(use->is_Mem()) {
3087         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3088       } else if (use->is_MergeMem()) {
3089         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3090       } else if (use->Opcode() == Op_EncodeISOArray) {
3091         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3092           // EncodeISOArray overwrites destination array
3093           memnode_worklist.append_if_missing(use);
3094         }
3095       } else {
3096         uint op = use->Opcode();
3097         if (!(op == Op_StoreCM ||
3098               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3099                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3100               op == Op_AryEq || op == Op_StrComp ||
3101               op == Op_StrEquals || op == Op_StrIndexOf)) {
3102           n->dump();
3103           use->dump();
3104           assert(false, "EA: missing memory path");
3105         }
3106 #endif
3107       }
3108     }
3109   }
3110 
3111   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
3112   //            Walk each memory slice moving the first node encountered of each
3113   //            instance type to the the input corresponding to its alias index.
3114   uint length = _mergemem_worklist.length();
3115   for( uint next = 0; next < length; ++next ) {
3116     MergeMemNode* nmm = _mergemem_worklist.at(next);
3117     assert(!visited.test_set(nmm->_idx), "should not be visited before");
3118     // Note: we don't want to use MergeMemStream here because we only want to
3119     // scan inputs which exist at the start, not ones we add during processing.
3120     // Note 2: MergeMem may already contains instance memory slices added
3121     // during find_inst_mem() call when memory nodes were processed above.
3122     igvn->hash_delete(nmm);
3123     uint nslices = nmm->req();
3124     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3125       Node* mem = nmm->in(i);
3126       Node* cur = NULL;
3127       if (mem == NULL || mem->is_top())
3128         continue;
3129       // First, update mergemem by moving memory nodes to corresponding slices
3130       // if their type became more precise since this mergemem was created.
3131       while (mem->is_Mem()) {
3132         const Type *at = igvn->type(mem->in(MemNode::Address));
3133         if (at != Type::TOP) {
3134           assert (at->isa_ptr() != NULL, "pointer type required.");
3135           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3136           if (idx == i) {
3137             if (cur == NULL)
3138               cur = mem;
3139           } else {
3140             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3141               nmm->set_memory_at(idx, mem);
3142             }
3143           }
3144         }
3145         mem = mem->in(MemNode::Memory);
3146       }
3147       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3148       // Find any instance of the current type if we haven't encountered
3149       // already a memory slice of the instance along the memory chain.
3150       for (uint ni = new_index_start; ni < new_index_end; ni++) {
3151         if((uint)_compile->get_general_index(ni) == i) {
3152           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3153           if (nmm->is_empty_memory(m)) {
3154             Node* result = find_inst_mem(mem, ni, orig_phis);
3155             if (_compile->failing()) {
3156               return;
3157             }
3158             nmm->set_memory_at(ni, result);
3159           }
3160         }
3161       }
3162     }
3163     // Find the rest of instances values
3164     for (uint ni = new_index_start; ni < new_index_end; ni++) {
3165       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3166       Node* result = step_through_mergemem(nmm, ni, tinst);
3167       if (result == nmm->base_memory()) {
3168         // Didn't find instance memory, search through general slice recursively.
3169         result = nmm->memory_at(_compile->get_general_index(ni));
3170         result = find_inst_mem(result, ni, orig_phis);
3171         if (_compile->failing()) {
3172           return;
3173         }
3174         nmm->set_memory_at(ni, result);
3175       }
3176     }
3177     igvn->hash_insert(nmm);
3178     record_for_optimizer(nmm);
3179   }
3180 
3181   //  Phase 4:  Update the inputs of non-instance memory Phis and
3182   //            the Memory input of memnodes
3183   // First update the inputs of any non-instance Phi's from
3184   // which we split out an instance Phi.  Note we don't have
3185   // to recursively process Phi's encounted on the input memory
3186   // chains as is done in split_memory_phi() since they  will
3187   // also be processed here.
3188   for (int j = 0; j < orig_phis.length(); j++) {
3189     PhiNode *phi = orig_phis.at(j);
3190     int alias_idx = _compile->get_alias_index(phi->adr_type());
3191     igvn->hash_delete(phi);
3192     for (uint i = 1; i < phi->req(); i++) {
3193       Node *mem = phi->in(i);
3194       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3195       if (_compile->failing()) {
3196         return;
3197       }
3198       if (mem != new_mem) {
3199         phi->set_req(i, new_mem);
3200       }
3201     }
3202     igvn->hash_insert(phi);
3203     record_for_optimizer(phi);
3204   }
3205 
3206   // Update the memory inputs of MemNodes with the value we computed
3207   // in Phase 2 and move stores memory users to corresponding memory slices.
3208   // Disable memory split verification code until the fix for 6984348.
3209   // Currently it produces false negative results since it does not cover all cases.
3210 #if 0 // ifdef ASSERT
3211   visited.Reset();
3212   Node_Stack old_mems(arena, _compile->unique() >> 2);
3213 #endif
3214   for (uint i = 0; i < ideal_nodes.size(); i++) {
3215     Node*    n = ideal_nodes.at(i);
3216     Node* nmem = get_map(n->_idx);
3217     assert(nmem != NULL, "sanity");
3218     if (n->is_Mem()) {
3219 #if 0 // ifdef ASSERT
3220       Node* old_mem = n->in(MemNode::Memory);
3221       if (!visited.test_set(old_mem->_idx)) {
3222         old_mems.push(old_mem, old_mem->outcnt());
3223       }
3224 #endif
3225       assert(n->in(MemNode::Memory) != nmem, "sanity");
3226       if (!n->is_Load()) {
3227         // Move memory users of a store first.
3228         move_inst_mem(n, orig_phis);
3229       }
3230       // Now update memory input
3231       igvn->hash_delete(n);
3232       n->set_req(MemNode::Memory, nmem);
3233       igvn->hash_insert(n);
3234       record_for_optimizer(n);
3235     } else {
3236       assert(n->is_Allocate() || n->is_CheckCastPP() ||
3237              n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3238     }
3239   }
3240 #if 0 // ifdef ASSERT
3241   // Verify that memory was split correctly
3242   while (old_mems.is_nonempty()) {
3243     Node* old_mem = old_mems.node();
3244     uint  old_cnt = old_mems.index();
3245     old_mems.pop();
3246     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3247   }
3248 #endif
3249 }
3250 
3251 #ifndef PRODUCT
3252 static const char *node_type_names[] = {
3253   "UnknownType",
3254   "JavaObject",
3255   "LocalVar",
3256   "Field",
3257   "Arraycopy"
3258 };
3259 
3260 static const char *esc_names[] = {
3261   "UnknownEscape",
3262   "NoEscape",
3263   "ArgEscape",
3264   "GlobalEscape"
3265 };
3266 
3267 void PointsToNode::dump(bool print_state) const {
3268   NodeType nt = node_type();
3269   tty->print("%s ", node_type_names[(int) nt]);
3270   if (print_state) {
3271     EscapeState es = escape_state();
3272     EscapeState fields_es = fields_escape_state();
3273     tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3274     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3275       tty->print("NSR ");
3276   }
3277   if (is_Field()) {
3278     FieldNode* f = (FieldNode*)this;
3279     if (f->is_oop())
3280       tty->print("oop ");
3281     if (f->offset() > 0)
3282       tty->print("+%d ", f->offset());
3283     tty->print("(");
3284     for (BaseIterator i(f); i.has_next(); i.next()) {
3285       PointsToNode* b = i.get();
3286       tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3287     }
3288     tty->print(" )");
3289   }
3290   tty->print("[");
3291   for (EdgeIterator i(this); i.has_next(); i.next()) {
3292     PointsToNode* e = i.get();
3293     tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3294   }
3295   tty->print(" [");
3296   for (UseIterator i(this); i.has_next(); i.next()) {
3297     PointsToNode* u = i.get();
3298     bool is_base = false;
3299     if (PointsToNode::is_base_use(u)) {
3300       is_base = true;
3301       u = PointsToNode::get_use_node(u)->as_Field();
3302     }
3303     tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3304   }
3305   tty->print(" ]]  ");
3306   if (_node == NULL)
3307     tty->print_cr("<null>");
3308   else
3309     _node->dump();
3310 }
3311 
3312 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3313   bool first = true;
3314   int ptnodes_length = ptnodes_worklist.length();
3315   for (int i = 0; i < ptnodes_length; i++) {
3316     PointsToNode *ptn = ptnodes_worklist.at(i);
3317     if (ptn == NULL || !ptn->is_JavaObject())
3318       continue;
3319     PointsToNode::EscapeState es = ptn->escape_state();
3320     if ((es != PointsToNode::NoEscape) && !Verbose) {
3321       continue;
3322     }
3323     Node* n = ptn->ideal_node();
3324     if (n->is_Allocate() || (n->is_CallStaticJava() &&
3325                              n->as_CallStaticJava()->is_boxing_method())) {
3326       if (first) {
3327         tty->cr();
3328         tty->print("======== Connection graph for ");
3329         _compile->method()->print_short_name();
3330         tty->cr();
3331         first = false;
3332       }
3333       ptn->dump();
3334       // Print all locals and fields which reference this allocation
3335       for (UseIterator j(ptn); j.has_next(); j.next()) {
3336         PointsToNode* use = j.get();
3337         if (use->is_LocalVar()) {
3338           use->dump(Verbose);
3339         } else if (Verbose) {
3340           use->dump();
3341         }
3342       }
3343       tty->cr();
3344     }
3345   }
3346 }
3347 #endif