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