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