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   // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
 210   // processing, calls to CI to resolve symbols (types, fields, methods)
 211   // referenced in bytecode. During symbol resolution VM may throw
 212   // an exception which CI cleans and converts to compilation failure.
 213   if (C->failing())  return false;
 214 
 215   // 2. Finish Graph construction by propagating references to all
 216   //    java objects through graph.
 217   if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
 218                                  java_objects_worklist, oop_fields_worklist)) {
 219     // All objects escaped or hit time or iterations limits.
 220     _collecting = false;
 221     return false;
 222   }
 223 
 224   // 3. Adjust scalar_replaceable state of nonescaping objects and push
 225   //    scalar replaceable allocations on alloc_worklist for processing
 226   //    in split_unique_types().
 227   int non_escaped_length = non_escaped_worklist.length();
 228   for (int next = 0; next < non_escaped_length; next++) {
 229     JavaObjectNode* ptn = non_escaped_worklist.at(next);
 230     bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
 231     Node* n = ptn->ideal_node();
 232     if (n->is_Allocate()) {
 233       n->as_Allocate()->_is_non_escaping = noescape;
 234     }
 235     if (n->is_CallStaticJava()) {
 236       n->as_CallStaticJava()->_is_non_escaping = noescape;
 237     }
 238     if (noescape && ptn->scalar_replaceable()) {
 239       adjust_scalar_replaceable_state(ptn);
 240       if (ptn->scalar_replaceable()) {
 241         alloc_worklist.append(ptn->ideal_node());
 242       }
 243     }
 244   }
 245 
 246 #ifdef ASSERT
 247   if (VerifyConnectionGraph) {
 248     // Verify that graph is complete - no new edges could be added or needed.
 249     verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
 250                             java_objects_worklist, addp_worklist);
 251   }
 252   assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
 253   assert(null_obj->escape_state() == PointsToNode::NoEscape &&
 254          null_obj->edge_count() == 0 &&
 255          !null_obj->arraycopy_src() &&
 256          !null_obj->arraycopy_dst(), "sanity");
 257 #endif
 258 
 259   _collecting = false;
 260 
 261   } // TracePhase t3("connectionGraph")
 262 
 263   // 4. Optimize ideal graph based on EA information.
 264   bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
 265   if (has_non_escaping_obj) {
 266     optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
 267   }
 268 
 269 #ifndef PRODUCT
 270   if (PrintEscapeAnalysis) {
 271     dump(ptnodes_worklist); // Dump ConnectionGraph
 272   }
 273 #endif
 274 
 275   bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
 276 #ifdef ASSERT
 277   if (VerifyConnectionGraph) {
 278     int alloc_length = alloc_worklist.length();
 279     for (int next = 0; next < alloc_length; ++next) {
 280       Node* n = alloc_worklist.at(next);
 281       PointsToNode* ptn = ptnode_adr(n->_idx);
 282       assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
 283     }
 284   }
 285 #endif
 286 
 287   // 5. Separate memory graph for scalar replaceable allcations.
 288   if (has_scalar_replaceable_candidates &&
 289       C->AliasLevel() >= 3 && EliminateAllocations) {
 290     // Now use the escape information to create unique types for
 291     // scalar replaceable objects.
 292     split_unique_types(alloc_worklist);
 293     if (C->failing())  return false;
 294     C->print_method(PHASE_AFTER_EA, 2);
 295 
 296 #ifdef ASSERT
 297   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
 298     tty->print("=== No allocations eliminated for ");
 299     C->method()->print_short_name();
 300     if(!EliminateAllocations) {
 301       tty->print(" since EliminateAllocations is off ===");
 302     } else if(!has_scalar_replaceable_candidates) {
 303       tty->print(" since there are no scalar replaceable candidates ===");
 304     } else if(C->AliasLevel() < 3) {
 305       tty->print(" since AliasLevel < 3 ===");
 306     }
 307     tty->cr();
 308 #endif
 309   }
 310   return has_non_escaping_obj;
 311 }
 312 
 313 // Utility function for nodes that load an object
 314 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 315   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 316   // ThreadLocal has RawPtr type.
 317   const Type* t = _igvn->type(n);
 318   if (t->make_ptr() != NULL) {
 319     Node* adr = n->in(MemNode::Address);
 320 #ifdef ASSERT
 321     if (!adr->is_AddP()) {
 322       assert(_igvn->type(adr)->isa_rawptr(), "sanity");
 323     } else {
 324       assert((ptnode_adr(adr->_idx) == NULL ||
 325               ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
 326     }
 327 #endif
 328     add_local_var_and_edge(n, PointsToNode::NoEscape,
 329                            adr, delayed_worklist);
 330   }
 331 }
 332 
 333 // Populate Connection Graph with PointsTo nodes and create simple
 334 // connection graph edges.
 335 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 336   assert(!_verify, "this method sould not be called for verification");
 337   PhaseGVN* igvn = _igvn;
 338   uint n_idx = n->_idx;
 339   PointsToNode* n_ptn = ptnode_adr(n_idx);
 340   if (n_ptn != NULL)
 341     return; // No need to redefine PointsTo node during first iteration.
 342 
 343   if (n->is_Call()) {
 344     // Arguments to allocation and locking don't escape.
 345     if (n->is_AbstractLock()) {
 346       // Put Lock and Unlock nodes on IGVN worklist to process them during
 347       // first IGVN optimization when escape information is still available.
 348       record_for_optimizer(n);
 349     } else if (n->is_Allocate()) {
 350       add_call_node(n->as_Call());
 351       record_for_optimizer(n);
 352     } else {
 353       if (n->is_CallStaticJava()) {
 354         const char* name = n->as_CallStaticJava()->_name;
 355         if (name != NULL && strcmp(name, "uncommon_trap") == 0)
 356           return; // Skip uncommon traps
 357       }
 358       // Don't mark as processed since call's arguments have to be processed.
 359       delayed_worklist->push(n);
 360       // Check if a call returns an object.
 361       if ((n->as_Call()->returns_pointer() &&
 362            n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
 363           (n->is_CallStaticJava() &&
 364            n->as_CallStaticJava()->is_boxing_method())) {
 365         add_call_node(n->as_Call());
 366       }
 367     }
 368     return;
 369   }
 370   // Put this check here to process call arguments since some call nodes
 371   // point to phantom_obj.
 372   if (n_ptn == phantom_obj || n_ptn == null_obj)
 373     return; // Skip predefined nodes.
 374 
 375   int opcode = n->Opcode();
 376   switch (opcode) {
 377     case Op_AddP: {
 378       Node* base = get_addp_base(n);
 379       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 380       // Field nodes are created for all field types. They are used in
 381       // adjust_scalar_replaceable_state() and split_unique_types().
 382       // Note, non-oop fields will have only base edges in Connection
 383       // Graph because such fields are not used for oop loads and stores.
 384       int offset = address_offset(n, igvn);
 385       add_field(n, PointsToNode::NoEscape, offset);
 386       if (ptn_base == NULL) {
 387         delayed_worklist->push(n); // Process it later.
 388       } else {
 389         n_ptn = ptnode_adr(n_idx);
 390         add_base(n_ptn->as_Field(), ptn_base);
 391       }
 392       break;
 393     }
 394     case Op_CastX2P: {
 395       map_ideal_node(n, phantom_obj);
 396       break;
 397     }
 398     case Op_CastPP:
 399     case Op_CheckCastPP:
 400     case Op_EncodeP:
 401     case Op_DecodeN:
 402     case Op_EncodePKlass:
 403     case Op_DecodeNKlass: {
 404       add_local_var_and_edge(n, PointsToNode::NoEscape,
 405                              n->in(1), delayed_worklist);
 406       break;
 407     }
 408     case Op_CMoveP: {
 409       add_local_var(n, PointsToNode::NoEscape);
 410       // Do not add edges during first iteration because some could be
 411       // not defined yet.
 412       delayed_worklist->push(n);
 413       break;
 414     }
 415     case Op_ConP:
 416     case Op_ConN:
 417     case Op_ConNKlass: {
 418       // assume all oop constants globally escape except for null
 419       PointsToNode::EscapeState es;
 420       const Type* t = igvn->type(n);
 421       if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
 422         es = PointsToNode::NoEscape;
 423       } else {
 424         es = PointsToNode::GlobalEscape;
 425       }
 426       add_java_object(n, es);
 427       break;
 428     }
 429     case Op_CreateEx: {
 430       // assume that all exception objects globally escape
 431       map_ideal_node(n, phantom_obj);
 432       break;
 433     }
 434     case Op_LoadKlass:
 435     case Op_LoadNKlass: {
 436       // Unknown class is loaded
 437       map_ideal_node(n, phantom_obj);
 438       break;
 439     }
 440     case Op_LoadP:
 441     case Op_LoadN:
 442     case Op_LoadPLocked: {
 443       add_objload_to_connection_graph(n, delayed_worklist);
 444       break;
 445     }
 446     case Op_Parm: {
 447       map_ideal_node(n, phantom_obj);
 448       break;
 449     }
 450     case Op_PartialSubtypeCheck: {
 451       // Produces Null or notNull and is used in only in CmpP so
 452       // phantom_obj could be used.
 453       map_ideal_node(n, phantom_obj); // Result is unknown
 454       break;
 455     }
 456     case Op_Phi: {
 457       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 458       // ThreadLocal has RawPtr type.
 459       const Type* t = n->as_Phi()->type();
 460       if (t->make_ptr() != NULL) {
 461         add_local_var(n, PointsToNode::NoEscape);
 462         // Do not add edges during first iteration because some could be
 463         // not defined yet.
 464         delayed_worklist->push(n);
 465       }
 466       break;
 467     }
 468     case Op_Proj: {
 469       // we are only interested in the oop result projection from a call
 470       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
 471           n->in(0)->as_Call()->returns_pointer()) {
 472         add_local_var_and_edge(n, PointsToNode::NoEscape,
 473                                n->in(0), delayed_worklist);
 474       }
 475       break;
 476     }
 477     case Op_Rethrow: // Exception object escapes
 478     case Op_Return: {
 479       if (n->req() > TypeFunc::Parms &&
 480           igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 481         // Treat Return value as LocalVar with GlobalEscape escape state.
 482         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 483                                n->in(TypeFunc::Parms), delayed_worklist);
 484       }
 485       break;
 486     }
 487     case Op_GetAndSetP:
 488     case Op_GetAndSetN: {
 489       add_objload_to_connection_graph(n, delayed_worklist);
 490       // fallthrough
 491     }
 492     case Op_StoreP:
 493     case Op_StoreN:
 494     case Op_StoreNKlass:
 495     case Op_StorePConditional:
 496     case Op_CompareAndSwapP:
 497     case Op_CompareAndSwapN: {
 498       Node* adr = n->in(MemNode::Address);
 499       const Type *adr_type = igvn->type(adr);
 500       adr_type = adr_type->make_ptr();
 501       if (adr_type == NULL) {
 502         break; // skip dead nodes
 503       }
 504       if (adr_type->isa_oopptr() ||
 505           (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
 506                         (adr_type == TypeRawPtr::NOTNULL &&
 507                          adr->in(AddPNode::Address)->is_Proj() &&
 508                          adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 509         delayed_worklist->push(n); // Process it later.
 510 #ifdef ASSERT
 511         assert(adr->is_AddP(), "expecting an AddP");
 512         if (adr_type == TypeRawPtr::NOTNULL) {
 513           // Verify a raw address for a store captured by Initialize node.
 514           int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 515           assert(offs != Type::OffsetBot, "offset must be a constant");
 516         }
 517 #endif
 518       } else {
 519         // Ignore copy the displaced header to the BoxNode (OSR compilation).
 520         if (adr->is_BoxLock())
 521           break;
 522         // Stored value escapes in unsafe access.
 523         if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
 524           // Pointer stores in G1 barriers looks like unsafe access.
 525           // Ignore such stores to be able scalar replace non-escaping
 526           // allocations.
 527           if (UseG1GC && adr->is_AddP()) {
 528             Node* base = get_addp_base(adr);
 529             if (base->Opcode() == Op_LoadP &&
 530                 base->in(MemNode::Address)->is_AddP()) {
 531               adr = base->in(MemNode::Address);
 532               Node* tls = get_addp_base(adr);
 533               if (tls->Opcode() == Op_ThreadLocal) {
 534                 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 535                 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
 536                                      PtrQueue::byte_offset_of_buf())) {
 537                   break; // G1 pre barier previous oop value store.
 538                 }
 539                 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
 540                                      PtrQueue::byte_offset_of_buf())) {
 541                   break; // G1 post barier card address store.
 542                 }
 543               }
 544             }
 545           }
 546           delayed_worklist->push(n); // Process unsafe access later.
 547           break;
 548         }
 549 #ifdef ASSERT
 550         n->dump(1);
 551         assert(false, "not unsafe or G1 barrier raw StoreP");
 552 #endif
 553       }
 554       break;
 555     }
 556     case Op_AryEq:
 557     case Op_StrComp:
 558     case Op_StrEquals:
 559     case Op_StrIndexOf:
 560     case Op_EncodeISOArray: {
 561       add_local_var(n, PointsToNode::ArgEscape);
 562       delayed_worklist->push(n); // Process it later.
 563       break;
 564     }
 565     case Op_ThreadLocal: {
 566       add_java_object(n, PointsToNode::ArgEscape);
 567       break;
 568     }
 569     default:
 570       ; // Do nothing for nodes not related to EA.
 571   }
 572   return;
 573 }
 574 
 575 #ifdef ASSERT
 576 #define ELSE_FAIL(name)                               \
 577       /* Should not be called for not pointer type. */  \
 578       n->dump(1);                                       \
 579       assert(false, name);                              \
 580       break;
 581 #else
 582 #define ELSE_FAIL(name) \
 583       break;
 584 #endif
 585 
 586 // Add final simple edges to graph.
 587 void ConnectionGraph::add_final_edges(Node *n) {
 588   PointsToNode* n_ptn = ptnode_adr(n->_idx);
 589 #ifdef ASSERT
 590   if (_verify && n_ptn->is_JavaObject())
 591     return; // This method does not change graph for JavaObject.
 592 #endif
 593 
 594   if (n->is_Call()) {
 595     process_call_arguments(n->as_Call());
 596     return;
 597   }
 598   assert(n->is_Store() || n->is_LoadStore() ||
 599          (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
 600          "node should be registered already");
 601   int opcode = n->Opcode();
 602   switch (opcode) {
 603     case Op_AddP: {
 604       Node* base = get_addp_base(n);
 605       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 606       assert(ptn_base != NULL, "field's base should be registered");
 607       add_base(n_ptn->as_Field(), ptn_base);
 608       break;
 609     }
 610     case Op_CastPP:
 611     case Op_CheckCastPP:
 612     case Op_EncodeP:
 613     case Op_DecodeN:
 614     case Op_EncodePKlass:
 615     case Op_DecodeNKlass: {
 616       add_local_var_and_edge(n, PointsToNode::NoEscape,
 617                              n->in(1), NULL);
 618       break;
 619     }
 620     case Op_CMoveP: {
 621       for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
 622         Node* in = n->in(i);
 623         if (in == NULL)
 624           continue;  // ignore NULL
 625         Node* uncast_in = in->uncast();
 626         if (uncast_in->is_top() || uncast_in == n)
 627           continue;  // ignore top or inputs which go back this node
 628         PointsToNode* ptn = ptnode_adr(in->_idx);
 629         assert(ptn != NULL, "node should be registered");
 630         add_edge(n_ptn, ptn);
 631       }
 632       break;
 633     }
 634     case Op_LoadP:
 635     case Op_LoadN:
 636     case Op_LoadPLocked: {
 637       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 638       // ThreadLocal has RawPtr type.
 639       const Type* t = _igvn->type(n);
 640       if (t->make_ptr() != NULL) {
 641         Node* adr = n->in(MemNode::Address);
 642         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 643         break;
 644       }
 645       ELSE_FAIL("Op_LoadP");
 646     }
 647     case Op_Phi: {
 648       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 649       // ThreadLocal has RawPtr type.
 650       const Type* t = n->as_Phi()->type();
 651       if (t->make_ptr() != NULL) {
 652         for (uint i = 1; i < n->req(); i++) {
 653           Node* in = n->in(i);
 654           if (in == NULL)
 655             continue;  // ignore NULL
 656           Node* uncast_in = in->uncast();
 657           if (uncast_in->is_top() || uncast_in == n)
 658             continue;  // ignore top or inputs which go back this node
 659           PointsToNode* ptn = ptnode_adr(in->_idx);
 660           assert(ptn != NULL, "node should be registered");
 661           add_edge(n_ptn, ptn);
 662         }
 663         break;
 664       }
 665       ELSE_FAIL("Op_Phi");
 666     }
 667     case Op_Proj: {
 668       // we are only interested in the oop result projection from a call
 669       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
 670           n->in(0)->as_Call()->returns_pointer()) {
 671         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
 672         break;
 673       }
 674       ELSE_FAIL("Op_Proj");
 675     }
 676     case Op_Rethrow: // Exception object escapes
 677     case Op_Return: {
 678       if (n->req() > TypeFunc::Parms &&
 679           _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 680         // Treat Return value as LocalVar with GlobalEscape escape state.
 681         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 682                                n->in(TypeFunc::Parms), NULL);
 683         break;
 684       }
 685       ELSE_FAIL("Op_Return");
 686     }
 687     case Op_StoreP:
 688     case Op_StoreN:
 689     case Op_StoreNKlass:
 690     case Op_StorePConditional:
 691     case Op_CompareAndSwapP:
 692     case Op_CompareAndSwapN:
 693     case Op_GetAndSetP:
 694     case Op_GetAndSetN: {
 695       Node* adr = n->in(MemNode::Address);
 696       const Type *adr_type = _igvn->type(adr);
 697       adr_type = adr_type->make_ptr();
 698 #ifdef ASSERT
 699       if (adr_type == NULL) {
 700         n->dump(1);
 701         assert(adr_type != NULL, "dead node should not be on list");
 702         break;
 703       }
 704 #endif
 705       if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
 706         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 707       }
 708       if (adr_type->isa_oopptr() ||
 709           (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
 710                         (adr_type == TypeRawPtr::NOTNULL &&
 711                          adr->in(AddPNode::Address)->is_Proj() &&
 712                          adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 713         // Point Address to Value
 714         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 715         assert(adr_ptn != NULL &&
 716                adr_ptn->as_Field()->is_oop(), "node should be registered");
 717         Node *val = n->in(MemNode::ValueIn);
 718         PointsToNode* ptn = ptnode_adr(val->_idx);
 719         assert(ptn != NULL, "node should be registered");
 720         add_edge(adr_ptn, ptn);
 721         break;
 722       } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
 723         // Stored value escapes in unsafe access.
 724         Node *val = n->in(MemNode::ValueIn);
 725         PointsToNode* ptn = ptnode_adr(val->_idx);
 726         assert(ptn != NULL, "node should be registered");
 727         set_escape_state(ptn, PointsToNode::GlobalEscape);
 728         // Add edge to object for unsafe access with offset.
 729         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 730         assert(adr_ptn != NULL, "node should be registered");
 731         if (adr_ptn->is_Field()) {
 732           assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
 733           add_edge(adr_ptn, ptn);
 734         }
 735         break;
 736       }
 737       ELSE_FAIL("Op_StoreP");
 738     }
 739     case Op_AryEq:
 740     case Op_StrComp:
 741     case Op_StrEquals:
 742     case Op_StrIndexOf:
 743     case Op_EncodeISOArray: {
 744       // char[] arrays passed to string intrinsic do not escape but
 745       // they are not scalar replaceable. Adjust escape state for them.
 746       // Start from in(2) edge since in(1) is memory edge.
 747       for (uint i = 2; i < n->req(); i++) {
 748         Node* adr = n->in(i);
 749         const Type* at = _igvn->type(adr);
 750         if (!adr->is_top() && at->isa_ptr()) {
 751           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
 752                  at->isa_ptr() != NULL, "expecting a pointer");
 753           if (adr->is_AddP()) {
 754             adr = get_addp_base(adr);
 755           }
 756           PointsToNode* ptn = ptnode_adr(adr->_idx);
 757           assert(ptn != NULL, "node should be registered");
 758           add_edge(n_ptn, ptn);
 759         }
 760       }
 761       break;
 762     }
 763     default: {
 764       // This method should be called only for EA specific nodes which may
 765       // miss some edges when they were created.
 766 #ifdef ASSERT
 767       n->dump(1);
 768 #endif
 769       guarantee(false, "unknown node");
 770     }
 771   }
 772   return;
 773 }
 774 
 775 void ConnectionGraph::add_call_node(CallNode* call) {
 776   assert(call->returns_pointer(), "only for call which returns pointer");
 777   uint call_idx = call->_idx;
 778   if (call->is_Allocate()) {
 779     Node* k = call->in(AllocateNode::KlassNode);
 780     const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
 781     assert(kt != NULL, "TypeKlassPtr  required.");
 782     ciKlass* cik = kt->klass();
 783     PointsToNode::EscapeState es = PointsToNode::NoEscape;
 784     bool scalar_replaceable = true;
 785     if (call->is_AllocateArray()) {
 786       if (!cik->is_array_klass()) { // StressReflectiveCode
 787         es = PointsToNode::GlobalEscape;
 788       } else {
 789         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
 790         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
 791           // Not scalar replaceable if the length is not constant or too big.
 792           scalar_replaceable = false;
 793         }
 794       }
 795     } else {  // Allocate instance
 796       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
 797           cik->is_subclass_of(_compile->env()->Reference_klass()) ||
 798          !cik->is_instance_klass() || // StressReflectiveCode
 799           cik->as_instance_klass()->has_finalizer()) {
 800         es = PointsToNode::GlobalEscape;
 801       }
 802     }
 803     add_java_object(call, es);
 804     PointsToNode* ptn = ptnode_adr(call_idx);
 805     if (!scalar_replaceable && ptn->scalar_replaceable()) {
 806       ptn->set_scalar_replaceable(false);
 807     }
 808   } else if (call->is_CallStaticJava()) {
 809     // Call nodes could be different types:
 810     //
 811     // 1. CallDynamicJavaNode (what happened during call is unknown):
 812     //
 813     //    - mapped to GlobalEscape JavaObject node if oop is returned;
 814     //
 815     //    - all oop arguments are escaping globally;
 816     //
 817     // 2. CallStaticJavaNode (execute bytecode analysis if possible):
 818     //
 819     //    - the same as CallDynamicJavaNode if can't do bytecode analysis;
 820     //
 821     //    - mapped to GlobalEscape JavaObject node if unknown oop is returned;
 822     //    - mapped to NoEscape JavaObject node if non-escaping object allocated
 823     //      during call is returned;
 824     //    - mapped to ArgEscape LocalVar node pointed to object arguments
 825     //      which are returned and does not escape during call;
 826     //
 827     //    - oop arguments escaping status is defined by bytecode analysis;
 828     //
 829     // For a static call, we know exactly what method is being called.
 830     // Use bytecode estimator to record whether the call's return value escapes.
 831     ciMethod* meth = call->as_CallJava()->method();
 832     if (meth == NULL) {
 833       const char* name = call->as_CallStaticJava()->_name;
 834       assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
 835       // Returns a newly allocated unescaped object.
 836       add_java_object(call, PointsToNode::NoEscape);
 837       ptnode_adr(call_idx)->set_scalar_replaceable(false);
 838     } else if (meth->is_boxing_method()) {
 839       // Returns boxing object
 840       PointsToNode::EscapeState es;
 841       vmIntrinsics::ID intr = meth->intrinsic_id();
 842       if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
 843         // It does not escape if object is always allocated.
 844         es = PointsToNode::NoEscape;
 845       } else {
 846         // It escapes globally if object could be loaded from cache.
 847         es = PointsToNode::GlobalEscape;
 848       }
 849       add_java_object(call, es);
 850     } else {
 851       BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
 852       call_analyzer->copy_dependencies(_compile->dependencies());
 853       if (call_analyzer->is_return_allocated()) {
 854         // Returns a newly allocated unescaped object, simply
 855         // update dependency information.
 856         // Mark it as NoEscape so that objects referenced by
 857         // it's fields will be marked as NoEscape at least.
 858         add_java_object(call, PointsToNode::NoEscape);
 859         ptnode_adr(call_idx)->set_scalar_replaceable(false);
 860       } else {
 861         // Determine whether any arguments are returned.
 862         const TypeTuple* d = call->tf()->domain();
 863         bool ret_arg = false;
 864         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 865           if (d->field_at(i)->isa_ptr() != NULL &&
 866               call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
 867             ret_arg = true;
 868             break;
 869           }
 870         }
 871         if (ret_arg) {
 872           add_local_var(call, PointsToNode::ArgEscape);
 873         } else {
 874           // Returns unknown object.
 875           map_ideal_node(call, phantom_obj);
 876         }
 877       }
 878     }
 879   } else {
 880     // An other type of call, assume the worst case:
 881     // returned value is unknown and globally escapes.
 882     assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
 883     map_ideal_node(call, phantom_obj);
 884   }
 885 }
 886 
 887 void ConnectionGraph::process_call_arguments(CallNode *call) {
 888     bool is_arraycopy = false;
 889     switch (call->Opcode()) {
 890 #ifdef ASSERT
 891     case Op_Allocate:
 892     case Op_AllocateArray:
 893     case Op_Lock:
 894     case Op_Unlock:
 895       assert(false, "should be done already");
 896       break;
 897 #endif
 898     case Op_ArrayCopy:
 899     case Op_CallLeafNoFP:
 900       // Most array copies are ArrayCopy nodes at this point but there
 901       // are still a few direct calls to the copy subroutines (See
 902       // PhaseStringOpts::copy_string())
 903       is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
 904         (call->as_CallLeaf()->_name != NULL &&
 905          strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
 906       // fall through
 907     case Op_CallLeaf: {
 908       // Stub calls, objects do not escape but they are not scale replaceable.
 909       // Adjust escape state for outgoing arguments.
 910       const TypeTuple * d = call->tf()->domain();
 911       bool src_has_oops = false;
 912       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 913         const Type* at = d->field_at(i);
 914         Node *arg = call->in(i);
 915         if (arg == NULL) {
 916           continue;
 917         }
 918         const Type *aat = _igvn->type(arg);
 919         if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
 920           continue;
 921         if (arg->is_AddP()) {
 922           //
 923           // The inline_native_clone() case when the arraycopy stub is called
 924           // after the allocation before Initialize and CheckCastPP nodes.
 925           // Or normal arraycopy for object arrays case.
 926           //
 927           // Set AddP's base (Allocate) as not scalar replaceable since
 928           // pointer to the base (with offset) is passed as argument.
 929           //
 930           arg = get_addp_base(arg);
 931         }
 932         PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
 933         assert(arg_ptn != NULL, "should be registered");
 934         PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
 935         if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
 936           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
 937                  aat->isa_ptr() != NULL, "expecting an Ptr");
 938           bool arg_has_oops = aat->isa_oopptr() &&
 939                               (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
 940                                (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
 941           if (i == TypeFunc::Parms) {
 942             src_has_oops = arg_has_oops;
 943           }
 944           //
 945           // src or dst could be j.l.Object when other is basic type array:
 946           //
 947           //   arraycopy(char[],0,Object*,0,size);
 948           //   arraycopy(Object*,0,char[],0,size);
 949           //
 950           // Don't add edges in such cases.
 951           //
 952           bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
 953                                        arg_has_oops && (i > TypeFunc::Parms);
 954 #ifdef ASSERT
 955           if (!(is_arraycopy ||
 956                 (call->as_CallLeaf()->_name != NULL &&
 957                  (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
 958                   strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
 959                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
 960                   strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
 961                   strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
 962                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
 963                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
 964                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
 965                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
 966                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
 967                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
 968                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
 969                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
 970                   strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0)
 971                   ))) {
 972             call->dump();
 973             fatal(err_msg_res("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name));
 974           }
 975 #endif
 976           // Always process arraycopy's destination object since
 977           // we need to add all possible edges to references in
 978           // source object.
 979           if (arg_esc >= PointsToNode::ArgEscape &&
 980               !arg_is_arraycopy_dest) {
 981             continue;
 982           }
 983           set_escape_state(arg_ptn, PointsToNode::ArgEscape);
 984           if (arg_is_arraycopy_dest) {
 985             Node* src = call->in(TypeFunc::Parms);
 986             if (src->is_AddP()) {
 987               src = get_addp_base(src);
 988             }
 989             PointsToNode* src_ptn = ptnode_adr(src->_idx);
 990             assert(src_ptn != NULL, "should be registered");
 991             if (arg_ptn != src_ptn) {
 992               // Special arraycopy edge:
 993               // A destination object's field can't have the source object
 994               // as base since objects escape states are not related.
 995               // Only escape state of destination object's fields affects
 996               // escape state of fields in source object.
 997               add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
 998             }
 999           }
1000         }
1001       }
1002       break;
1003     }
1004     case Op_CallStaticJava: {
1005       // For a static call, we know exactly what method is being called.
1006       // Use bytecode estimator to record the call's escape affects
1007 #ifdef ASSERT
1008       const char* name = call->as_CallStaticJava()->_name;
1009       assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1010 #endif
1011       ciMethod* meth = call->as_CallJava()->method();
1012       if ((meth != NULL) && meth->is_boxing_method()) {
1013         break; // Boxing methods do not modify any oops.
1014       }
1015       BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1016       // fall-through if not a Java method or no analyzer information
1017       if (call_analyzer != NULL) {
1018         PointsToNode* call_ptn = ptnode_adr(call->_idx);
1019         const TypeTuple* d = call->tf()->domain();
1020         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1021           const Type* at = d->field_at(i);
1022           int k = i - TypeFunc::Parms;
1023           Node* arg = call->in(i);
1024           PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1025           if (at->isa_ptr() != NULL &&
1026               call_analyzer->is_arg_returned(k)) {
1027             // The call returns arguments.
1028             if (call_ptn != NULL) { // Is call's result used?
1029               assert(call_ptn->is_LocalVar(), "node should be registered");
1030               assert(arg_ptn != NULL, "node should be registered");
1031               add_edge(call_ptn, arg_ptn);
1032             }
1033           }
1034           if (at->isa_oopptr() != NULL &&
1035               arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1036             if (!call_analyzer->is_arg_stack(k)) {
1037               // The argument global escapes
1038               set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1039             } else {
1040               set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1041               if (!call_analyzer->is_arg_local(k)) {
1042                 // The argument itself doesn't escape, but any fields might
1043                 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1044               }
1045             }
1046           }
1047         }
1048         if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1049           // The call returns arguments.
1050           assert(call_ptn->edge_count() > 0, "sanity");
1051           if (!call_analyzer->is_return_local()) {
1052             // Returns also unknown object.
1053             add_edge(call_ptn, phantom_obj);
1054           }
1055         }
1056         break;
1057       }
1058     }
1059     default: {
1060       // Fall-through here if not a Java method or no analyzer information
1061       // or some other type of call, assume the worst case: all arguments
1062       // globally escape.
1063       const TypeTuple* d = call->tf()->domain();
1064       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1065         const Type* at = d->field_at(i);
1066         if (at->isa_oopptr() != NULL) {
1067           Node* arg = call->in(i);
1068           if (arg->is_AddP()) {
1069             arg = get_addp_base(arg);
1070           }
1071           assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1072           set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1073         }
1074       }
1075     }
1076   }
1077 }
1078 
1079 
1080 // Finish Graph construction.
1081 bool ConnectionGraph::complete_connection_graph(
1082                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1083                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1084                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1085                          GrowableArray<FieldNode*>&      oop_fields_worklist) {
1086   // Normally only 1-3 passes needed to build Connection Graph depending
1087   // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1088   // Set limit to 20 to catch situation when something did go wrong and
1089   // bailout Escape Analysis.
1090   // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1091 #define CG_BUILD_ITER_LIMIT 20
1092 
1093   // Propagate GlobalEscape and ArgEscape escape states and check that
1094   // we still have non-escaping objects. The method pushs on _worklist
1095   // Field nodes which reference phantom_object.
1096   if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1097     return false; // Nothing to do.
1098   }
1099   // Now propagate references to all JavaObject nodes.
1100   int java_objects_length = java_objects_worklist.length();
1101   elapsedTimer time;
1102   bool timeout = false;
1103   int new_edges = 1;
1104   int iterations = 0;
1105   do {
1106     while ((new_edges > 0) &&
1107            (iterations++ < CG_BUILD_ITER_LIMIT)) {
1108       double start_time = time.seconds();
1109       time.start();
1110       new_edges = 0;
1111       // Propagate references to phantom_object for nodes pushed on _worklist
1112       // by find_non_escaped_objects() and find_field_value().
1113       new_edges += add_java_object_edges(phantom_obj, false);
1114       for (int next = 0; next < java_objects_length; ++next) {
1115         JavaObjectNode* ptn = java_objects_worklist.at(next);
1116         new_edges += add_java_object_edges(ptn, true);
1117 
1118 #define SAMPLE_SIZE 4
1119         if ((next % SAMPLE_SIZE) == 0) {
1120           // Each 4 iterations calculate how much time it will take
1121           // to complete graph construction.
1122           time.stop();
1123           // Poll for requests from shutdown mechanism to quiesce compiler
1124           // because Connection graph construction may take long time.
1125           CompileBroker::maybe_block();
1126           double stop_time = time.seconds();
1127           double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1128           double time_until_end = time_per_iter * (double)(java_objects_length - next);
1129           if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1130             timeout = true;
1131             break; // Timeout
1132           }
1133           start_time = stop_time;
1134           time.start();
1135         }
1136 #undef SAMPLE_SIZE
1137 
1138       }
1139       if (timeout) break;
1140       if (new_edges > 0) {
1141         // Update escape states on each iteration if graph was updated.
1142         if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1143           return false; // Nothing to do.
1144         }
1145       }
1146       time.stop();
1147       if (time.seconds() >= EscapeAnalysisTimeout) {
1148         timeout = true;
1149         break;
1150       }
1151     }
1152     if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1153       time.start();
1154       // Find fields which have unknown value.
1155       int fields_length = oop_fields_worklist.length();
1156       for (int next = 0; next < fields_length; next++) {
1157         FieldNode* field = oop_fields_worklist.at(next);
1158         if (field->edge_count() == 0) {
1159           new_edges += find_field_value(field);
1160           // This code may added new edges to phantom_object.
1161           // Need an other cycle to propagate references to phantom_object.
1162         }
1163       }
1164       time.stop();
1165       if (time.seconds() >= EscapeAnalysisTimeout) {
1166         timeout = true;
1167         break;
1168       }
1169     } else {
1170       new_edges = 0; // Bailout
1171     }
1172   } while (new_edges > 0);
1173 
1174   // Bailout if passed limits.
1175   if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1176     Compile* C = _compile;
1177     if (C->log() != NULL) {
1178       C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1179       C->log()->text("%s", timeout ? "time" : "iterations");
1180       C->log()->end_elem(" limit'");
1181     }
1182     assert(ExitEscapeAnalysisOnTimeout, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1183            time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1184     // Possible infinite build_connection_graph loop,
1185     // bailout (no changes to ideal graph were made).
1186     return false;
1187   }
1188 #ifdef ASSERT
1189   if (Verbose && PrintEscapeAnalysis) {
1190     tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1191                   iterations, nodes_size(), ptnodes_worklist.length());
1192   }
1193 #endif
1194 
1195 #undef CG_BUILD_ITER_LIMIT
1196 
1197   // Find fields initialized by NULL for non-escaping Allocations.
1198   int non_escaped_length = non_escaped_worklist.length();
1199   for (int next = 0; next < non_escaped_length; next++) {
1200     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1201     PointsToNode::EscapeState es = ptn->escape_state();
1202     assert(es <= PointsToNode::ArgEscape, "sanity");
1203     if (es == PointsToNode::NoEscape) {
1204       if (find_init_values(ptn, null_obj, _igvn) > 0) {
1205         // Adding references to NULL object does not change escape states
1206         // since it does not escape. Also no fields are added to NULL object.
1207         add_java_object_edges(null_obj, false);
1208       }
1209     }
1210     Node* n = ptn->ideal_node();
1211     if (n->is_Allocate()) {
1212       // The object allocated by this Allocate node will never be
1213       // seen by an other thread. Mark it so that when it is
1214       // expanded no MemBarStoreStore is added.
1215       InitializeNode* ini = n->as_Allocate()->initialization();
1216       if (ini != NULL)
1217         ini->set_does_not_escape();
1218     }
1219   }
1220   return true; // Finished graph construction.
1221 }
1222 
1223 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1224 // and check that we still have non-escaping java objects.
1225 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1226                                                GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1227   GrowableArray<PointsToNode*> escape_worklist;
1228   // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1229   int ptnodes_length = ptnodes_worklist.length();
1230   for (int next = 0; next < ptnodes_length; ++next) {
1231     PointsToNode* ptn = ptnodes_worklist.at(next);
1232     if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1233         ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1234       escape_worklist.push(ptn);
1235     }
1236   }
1237   // Set escape states to referenced nodes (edges list).
1238   while (escape_worklist.length() > 0) {
1239     PointsToNode* ptn = escape_worklist.pop();
1240     PointsToNode::EscapeState es  = ptn->escape_state();
1241     PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1242     if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1243         es >= PointsToNode::ArgEscape) {
1244       // GlobalEscape or ArgEscape state of field means it has unknown value.
1245       if (add_edge(ptn, phantom_obj)) {
1246         // New edge was added
1247         add_field_uses_to_worklist(ptn->as_Field());
1248       }
1249     }
1250     for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1251       PointsToNode* e = i.get();
1252       if (e->is_Arraycopy()) {
1253         assert(ptn->arraycopy_dst(), "sanity");
1254         // Propagate only fields escape state through arraycopy edge.
1255         if (e->fields_escape_state() < field_es) {
1256           set_fields_escape_state(e, field_es);
1257           escape_worklist.push(e);
1258         }
1259       } else if (es >= field_es) {
1260         // fields_escape_state is also set to 'es' if it is less than 'es'.
1261         if (e->escape_state() < es) {
1262           set_escape_state(e, es);
1263           escape_worklist.push(e);
1264         }
1265       } else {
1266         // Propagate field escape state.
1267         bool es_changed = false;
1268         if (e->fields_escape_state() < field_es) {
1269           set_fields_escape_state(e, field_es);
1270           es_changed = true;
1271         }
1272         if ((e->escape_state() < field_es) &&
1273             e->is_Field() && ptn->is_JavaObject() &&
1274             e->as_Field()->is_oop()) {
1275           // Change escape state of referenced fileds.
1276           set_escape_state(e, field_es);
1277           es_changed = true;;
1278         } else if (e->escape_state() < es) {
1279           set_escape_state(e, es);
1280           es_changed = true;;
1281         }
1282         if (es_changed) {
1283           escape_worklist.push(e);
1284         }
1285       }
1286     }
1287   }
1288   // Remove escaped objects from non_escaped list.
1289   for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1290     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1291     if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1292       non_escaped_worklist.delete_at(next);
1293     }
1294     if (ptn->escape_state() == PointsToNode::NoEscape) {
1295       // Find fields in non-escaped allocations which have unknown value.
1296       find_init_values(ptn, phantom_obj, NULL);
1297     }
1298   }
1299   return (non_escaped_worklist.length() > 0);
1300 }
1301 
1302 // Add all references to JavaObject node by walking over all uses.
1303 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1304   int new_edges = 0;
1305   if (populate_worklist) {
1306     // Populate _worklist by uses of jobj's uses.
1307     for (UseIterator i(jobj); i.has_next(); i.next()) {
1308       PointsToNode* use = i.get();
1309       if (use->is_Arraycopy())
1310         continue;
1311       add_uses_to_worklist(use);
1312       if (use->is_Field() && use->as_Field()->is_oop()) {
1313         // Put on worklist all field's uses (loads) and
1314         // related field nodes (same base and offset).
1315         add_field_uses_to_worklist(use->as_Field());
1316       }
1317     }
1318   }
1319   for (int l = 0; l < _worklist.length(); l++) {
1320     PointsToNode* use = _worklist.at(l);
1321     if (PointsToNode::is_base_use(use)) {
1322       // Add reference from jobj to field and from field to jobj (field's base).
1323       use = PointsToNode::get_use_node(use)->as_Field();
1324       if (add_base(use->as_Field(), jobj)) {
1325         new_edges++;
1326       }
1327       continue;
1328     }
1329     assert(!use->is_JavaObject(), "sanity");
1330     if (use->is_Arraycopy()) {
1331       if (jobj == null_obj) // NULL object does not have field edges
1332         continue;
1333       // Added edge from Arraycopy node to arraycopy's source java object
1334       if (add_edge(use, jobj)) {
1335         jobj->set_arraycopy_src();
1336         new_edges++;
1337       }
1338       // and stop here.
1339       continue;
1340     }
1341     if (!add_edge(use, jobj))
1342       continue; // No new edge added, there was such edge already.
1343     new_edges++;
1344     if (use->is_LocalVar()) {
1345       add_uses_to_worklist(use);
1346       if (use->arraycopy_dst()) {
1347         for (EdgeIterator i(use); i.has_next(); i.next()) {
1348           PointsToNode* e = i.get();
1349           if (e->is_Arraycopy()) {
1350             if (jobj == null_obj) // NULL object does not have field edges
1351               continue;
1352             // Add edge from arraycopy's destination java object to Arraycopy node.
1353             if (add_edge(jobj, e)) {
1354               new_edges++;
1355               jobj->set_arraycopy_dst();
1356             }
1357           }
1358         }
1359       }
1360     } else {
1361       // Added new edge to stored in field values.
1362       // Put on worklist all field's uses (loads) and
1363       // related field nodes (same base and offset).
1364       add_field_uses_to_worklist(use->as_Field());
1365     }
1366   }
1367   _worklist.clear();
1368   _in_worklist.Reset();
1369   return new_edges;
1370 }
1371 
1372 // Put on worklist all related field nodes.
1373 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1374   assert(field->is_oop(), "sanity");
1375   int offset = field->offset();
1376   add_uses_to_worklist(field);
1377   // Loop over all bases of this field and push on worklist Field nodes
1378   // with the same offset and base (since they may reference the same field).
1379   for (BaseIterator i(field); i.has_next(); i.next()) {
1380     PointsToNode* base = i.get();
1381     add_fields_to_worklist(field, base);
1382     // Check if the base was source object of arraycopy and go over arraycopy's
1383     // destination objects since values stored to a field of source object are
1384     // accessable by uses (loads) of fields of destination objects.
1385     if (base->arraycopy_src()) {
1386       for (UseIterator j(base); j.has_next(); j.next()) {
1387         PointsToNode* arycp = j.get();
1388         if (arycp->is_Arraycopy()) {
1389           for (UseIterator k(arycp); k.has_next(); k.next()) {
1390             PointsToNode* abase = k.get();
1391             if (abase->arraycopy_dst() && abase != base) {
1392               // Look for the same arracopy reference.
1393               add_fields_to_worklist(field, abase);
1394             }
1395           }
1396         }
1397       }
1398     }
1399   }
1400 }
1401 
1402 // Put on worklist all related field nodes.
1403 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1404   int offset = field->offset();
1405   if (base->is_LocalVar()) {
1406     for (UseIterator j(base); j.has_next(); j.next()) {
1407       PointsToNode* f = j.get();
1408       if (PointsToNode::is_base_use(f)) { // Field
1409         f = PointsToNode::get_use_node(f);
1410         if (f == field || !f->as_Field()->is_oop())
1411           continue;
1412         int offs = f->as_Field()->offset();
1413         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1414           add_to_worklist(f);
1415         }
1416       }
1417     }
1418   } else {
1419     assert(base->is_JavaObject(), "sanity");
1420     if (// Skip phantom_object since it is only used to indicate that
1421         // this field's content globally escapes.
1422         (base != phantom_obj) &&
1423         // NULL object node does not have fields.
1424         (base != null_obj)) {
1425       for (EdgeIterator i(base); i.has_next(); i.next()) {
1426         PointsToNode* f = i.get();
1427         // Skip arraycopy edge since store to destination object field
1428         // does not update value in source object field.
1429         if (f->is_Arraycopy()) {
1430           assert(base->arraycopy_dst(), "sanity");
1431           continue;
1432         }
1433         if (f == field || !f->as_Field()->is_oop())
1434           continue;
1435         int offs = f->as_Field()->offset();
1436         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1437           add_to_worklist(f);
1438         }
1439       }
1440     }
1441   }
1442 }
1443 
1444 // Find fields which have unknown value.
1445 int ConnectionGraph::find_field_value(FieldNode* field) {
1446   // Escaped fields should have init value already.
1447   assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1448   int new_edges = 0;
1449   for (BaseIterator i(field); i.has_next(); i.next()) {
1450     PointsToNode* base = i.get();
1451     if (base->is_JavaObject()) {
1452       // Skip Allocate's fields which will be processed later.
1453       if (base->ideal_node()->is_Allocate())
1454         return 0;
1455       assert(base == null_obj, "only NULL ptr base expected here");
1456     }
1457   }
1458   if (add_edge(field, phantom_obj)) {
1459     // New edge was added
1460     new_edges++;
1461     add_field_uses_to_worklist(field);
1462   }
1463   return new_edges;
1464 }
1465 
1466 // Find fields initializing values for allocations.
1467 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1468   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1469   int new_edges = 0;
1470   Node* alloc = pta->ideal_node();
1471   if (init_val == phantom_obj) {
1472     // Do nothing for Allocate nodes since its fields values are "known".
1473     if (alloc->is_Allocate())
1474       return 0;
1475     assert(alloc->as_CallStaticJava(), "sanity");
1476 #ifdef ASSERT
1477     if (alloc->as_CallStaticJava()->method() == NULL) {
1478       const char* name = alloc->as_CallStaticJava()->_name;
1479       assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1480     }
1481 #endif
1482     // Non-escaped allocation returned from Java or runtime call have
1483     // unknown values in fields.
1484     for (EdgeIterator i(pta); i.has_next(); i.next()) {
1485       PointsToNode* field = i.get();
1486       if (field->is_Field() && field->as_Field()->is_oop()) {
1487         if (add_edge(field, phantom_obj)) {
1488           // New edge was added
1489           new_edges++;
1490           add_field_uses_to_worklist(field->as_Field());
1491         }
1492       }
1493     }
1494     return new_edges;
1495   }
1496   assert(init_val == null_obj, "sanity");
1497   // Do nothing for Call nodes since its fields values are unknown.
1498   if (!alloc->is_Allocate())
1499     return 0;
1500 
1501   InitializeNode* ini = alloc->as_Allocate()->initialization();
1502   bool visited_bottom_offset = false;
1503   GrowableArray<int> offsets_worklist;
1504 
1505   // Check if an oop field's initializing value is recorded and add
1506   // a corresponding NULL if field's value if it is not recorded.
1507   // Connection Graph does not record a default initialization by NULL
1508   // captured by Initialize node.
1509   //
1510   for (EdgeIterator i(pta); i.has_next(); i.next()) {
1511     PointsToNode* field = i.get(); // Field (AddP)
1512     if (!field->is_Field() || !field->as_Field()->is_oop())
1513       continue; // Not oop field
1514     int offset = field->as_Field()->offset();
1515     if (offset == Type::OffsetBot) {
1516       if (!visited_bottom_offset) {
1517         // OffsetBot is used to reference array's element,
1518         // always add reference to NULL to all Field nodes since we don't
1519         // known which element is referenced.
1520         if (add_edge(field, null_obj)) {
1521           // New edge was added
1522           new_edges++;
1523           add_field_uses_to_worklist(field->as_Field());
1524           visited_bottom_offset = true;
1525         }
1526       }
1527     } else {
1528       // Check only oop fields.
1529       const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1530       if (adr_type->isa_rawptr()) {
1531 #ifdef ASSERT
1532         // Raw pointers are used for initializing stores so skip it
1533         // since it should be recorded already
1534         Node* base = get_addp_base(field->ideal_node());
1535         assert(adr_type->isa_rawptr() && base->is_Proj() &&
1536                (base->in(0) == alloc),"unexpected pointer type");
1537 #endif
1538         continue;
1539       }
1540       if (!offsets_worklist.contains(offset)) {
1541         offsets_worklist.append(offset);
1542         Node* value = NULL;
1543         if (ini != NULL) {
1544           // StoreP::memory_type() == T_ADDRESS
1545           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1546           Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1547           // Make sure initializing store has the same type as this AddP.
1548           // This AddP may reference non existing field because it is on a
1549           // dead branch of bimorphic call which is not eliminated yet.
1550           if (store != NULL && store->is_Store() &&
1551               store->as_Store()->memory_type() == ft) {
1552             value = store->in(MemNode::ValueIn);
1553 #ifdef ASSERT
1554             if (VerifyConnectionGraph) {
1555               // Verify that AddP already points to all objects the value points to.
1556               PointsToNode* val = ptnode_adr(value->_idx);
1557               assert((val != NULL), "should be processed already");
1558               PointsToNode* missed_obj = NULL;
1559               if (val->is_JavaObject()) {
1560                 if (!field->points_to(val->as_JavaObject())) {
1561                   missed_obj = val;
1562                 }
1563               } else {
1564                 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1565                   tty->print_cr("----------init store has invalid value -----");
1566                   store->dump();
1567                   val->dump();
1568                   assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1569                 }
1570                 for (EdgeIterator j(val); j.has_next(); j.next()) {
1571                   PointsToNode* obj = j.get();
1572                   if (obj->is_JavaObject()) {
1573                     if (!field->points_to(obj->as_JavaObject())) {
1574                       missed_obj = obj;
1575                       break;
1576                     }
1577                   }
1578                 }
1579               }
1580               if (missed_obj != NULL) {
1581                 tty->print_cr("----------field---------------------------------");
1582                 field->dump();
1583                 tty->print_cr("----------missed referernce to object-----------");
1584                 missed_obj->dump();
1585                 tty->print_cr("----------object referernced by init store -----");
1586                 store->dump();
1587                 val->dump();
1588                 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1589               }
1590             }
1591 #endif
1592           } else {
1593             // There could be initializing stores which follow allocation.
1594             // For example, a volatile field store is not collected
1595             // by Initialize node.
1596             //
1597             // Need to check for dependent loads to separate such stores from
1598             // stores which follow loads. For now, add initial value NULL so
1599             // that compare pointers optimization works correctly.
1600           }
1601         }
1602         if (value == NULL) {
1603           // A field's initializing value was not recorded. Add NULL.
1604           if (add_edge(field, null_obj)) {
1605             // New edge was added
1606             new_edges++;
1607             add_field_uses_to_worklist(field->as_Field());
1608           }
1609         }
1610       }
1611     }
1612   }
1613   return new_edges;
1614 }
1615 
1616 // Adjust scalar_replaceable state after Connection Graph is built.
1617 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1618   // Search for non-escaping objects which are not scalar replaceable
1619   // and mark them to propagate the state to referenced objects.
1620 
1621   // 1. An object is not scalar replaceable if the field into which it is
1622   // stored has unknown offset (stored into unknown element of an array).
1623   //
1624   for (UseIterator i(jobj); i.has_next(); i.next()) {
1625     PointsToNode* use = i.get();
1626     assert(!use->is_Arraycopy(), "sanity");
1627     if (use->is_Field()) {
1628       FieldNode* field = use->as_Field();
1629       assert(field->is_oop() && field->scalar_replaceable() &&
1630              field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1631       if (field->offset() == Type::OffsetBot) {
1632         jobj->set_scalar_replaceable(false);
1633         return;
1634       }
1635       // 2. An object is not scalar replaceable if the field into which it is
1636       // stored has multiple bases one of which is null.
1637       if (field->base_count() > 1) {
1638         for (BaseIterator i(field); i.has_next(); i.next()) {
1639           PointsToNode* base = i.get();
1640           if (base == null_obj) {
1641             jobj->set_scalar_replaceable(false);
1642             return;
1643           }
1644         }
1645       }
1646     }
1647     assert(use->is_Field() || use->is_LocalVar(), "sanity");
1648     // 3. An object is not scalar replaceable if it is merged with other objects.
1649     for (EdgeIterator j(use); j.has_next(); j.next()) {
1650       PointsToNode* ptn = j.get();
1651       if (ptn->is_JavaObject() && ptn != jobj) {
1652         // Mark all objects.
1653         jobj->set_scalar_replaceable(false);
1654          ptn->set_scalar_replaceable(false);
1655       }
1656     }
1657     if (!jobj->scalar_replaceable()) {
1658       return;
1659     }
1660   }
1661 
1662   for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1663     // Non-escaping object node should point only to field nodes.
1664     FieldNode* field = j.get()->as_Field();
1665     int offset = field->as_Field()->offset();
1666 
1667     // 4. An object is not scalar replaceable if it has a field with unknown
1668     // offset (array's element is accessed in loop).
1669     if (offset == Type::OffsetBot) {
1670       jobj->set_scalar_replaceable(false);
1671       return;
1672     }
1673     // 5. Currently an object is not scalar replaceable if a LoadStore node
1674     // access its field since the field value is unknown after it.
1675     //
1676     Node* n = field->ideal_node();
1677     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1678       if (n->fast_out(i)->is_LoadStore()) {
1679         jobj->set_scalar_replaceable(false);
1680         return;
1681       }
1682     }
1683 
1684     // 6. Or the address may point to more then one object. This may produce
1685     // the false positive result (set not scalar replaceable)
1686     // since the flow-insensitive escape analysis can't separate
1687     // the case when stores overwrite the field's value from the case
1688     // when stores happened on different control branches.
1689     //
1690     // Note: it will disable scalar replacement in some cases:
1691     //
1692     //    Point p[] = new Point[1];
1693     //    p[0] = new Point(); // Will be not scalar replaced
1694     //
1695     // but it will save us from incorrect optimizations in next cases:
1696     //
1697     //    Point p[] = new Point[1];
1698     //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
1699     //
1700     if (field->base_count() > 1) {
1701       for (BaseIterator i(field); i.has_next(); i.next()) {
1702         PointsToNode* base = i.get();
1703         // Don't take into account LocalVar nodes which
1704         // may point to only one object which should be also
1705         // this field's base by now.
1706         if (base->is_JavaObject() && base != jobj) {
1707           // Mark all bases.
1708           jobj->set_scalar_replaceable(false);
1709           base->set_scalar_replaceable(false);
1710         }
1711       }
1712     }
1713   }
1714 }
1715 
1716 #ifdef ASSERT
1717 void ConnectionGraph::verify_connection_graph(
1718                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1719                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1720                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1721                          GrowableArray<Node*>& addp_worklist) {
1722   // Verify that graph is complete - no new edges could be added.
1723   int java_objects_length = java_objects_worklist.length();
1724   int non_escaped_length  = non_escaped_worklist.length();
1725   int new_edges = 0;
1726   for (int next = 0; next < java_objects_length; ++next) {
1727     JavaObjectNode* ptn = java_objects_worklist.at(next);
1728     new_edges += add_java_object_edges(ptn, true);
1729   }
1730   assert(new_edges == 0, "graph was not complete");
1731   // Verify that escape state is final.
1732   int length = non_escaped_worklist.length();
1733   find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1734   assert((non_escaped_length == non_escaped_worklist.length()) &&
1735          (non_escaped_length == length) &&
1736          (_worklist.length() == 0), "escape state was not final");
1737 
1738   // Verify fields information.
1739   int addp_length = addp_worklist.length();
1740   for (int next = 0; next < addp_length; ++next ) {
1741     Node* n = addp_worklist.at(next);
1742     FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1743     if (field->is_oop()) {
1744       // Verify that field has all bases
1745       Node* base = get_addp_base(n);
1746       PointsToNode* ptn = ptnode_adr(base->_idx);
1747       if (ptn->is_JavaObject()) {
1748         assert(field->has_base(ptn->as_JavaObject()), "sanity");
1749       } else {
1750         assert(ptn->is_LocalVar(), "sanity");
1751         for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1752           PointsToNode* e = i.get();
1753           if (e->is_JavaObject()) {
1754             assert(field->has_base(e->as_JavaObject()), "sanity");
1755           }
1756         }
1757       }
1758       // Verify that all fields have initializing values.
1759       if (field->edge_count() == 0) {
1760         tty->print_cr("----------field does not have references----------");
1761         field->dump();
1762         for (BaseIterator i(field); i.has_next(); i.next()) {
1763           PointsToNode* base = i.get();
1764           tty->print_cr("----------field has next base---------------------");
1765           base->dump();
1766           if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1767             tty->print_cr("----------base has fields-------------------------");
1768             for (EdgeIterator j(base); j.has_next(); j.next()) {
1769               j.get()->dump();
1770             }
1771             tty->print_cr("----------base has references---------------------");
1772             for (UseIterator j(base); j.has_next(); j.next()) {
1773               j.get()->dump();
1774             }
1775           }
1776         }
1777         for (UseIterator i(field); i.has_next(); i.next()) {
1778           i.get()->dump();
1779         }
1780         assert(field->edge_count() > 0, "sanity");
1781       }
1782     }
1783   }
1784 }
1785 #endif
1786 
1787 // Optimize ideal graph.
1788 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1789                                            GrowableArray<Node*>& storestore_worklist) {
1790   Compile* C = _compile;
1791   PhaseIterGVN* igvn = _igvn;
1792   if (EliminateLocks) {
1793     // Mark locks before changing ideal graph.
1794     int cnt = C->macro_count();
1795     for( int i=0; i < cnt; i++ ) {
1796       Node *n = C->macro_node(i);
1797       if (n->is_AbstractLock()) { // Lock and Unlock nodes
1798         AbstractLockNode* alock = n->as_AbstractLock();
1799         if (!alock->is_non_esc_obj()) {
1800           if (not_global_escape(alock->obj_node())) {
1801             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1802             // The lock could be marked eliminated by lock coarsening
1803             // code during first IGVN before EA. Replace coarsened flag
1804             // to eliminate all associated locks/unlocks.



1805             alock->set_non_esc_obj();
1806           }
1807         }
1808       }
1809     }
1810   }
1811 
1812   if (OptimizePtrCompare) {
1813     // Add ConI(#CC_GT) and ConI(#CC_EQ).
1814     _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1815     _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1816     // Optimize objects compare.
1817     while (ptr_cmp_worklist.length() != 0) {
1818       Node *n = ptr_cmp_worklist.pop();
1819       Node *res = optimize_ptr_compare(n);
1820       if (res != NULL) {
1821 #ifndef PRODUCT
1822         if (PrintOptimizePtrCompare) {
1823           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"));
1824           if (Verbose) {
1825             n->dump(1);
1826           }
1827         }
1828 #endif
1829         igvn->replace_node(n, res);
1830       }
1831     }
1832     // cleanup
1833     if (_pcmp_neq->outcnt() == 0)
1834       igvn->hash_delete(_pcmp_neq);
1835     if (_pcmp_eq->outcnt()  == 0)
1836       igvn->hash_delete(_pcmp_eq);
1837   }
1838 
1839   // For MemBarStoreStore nodes added in library_call.cpp, check
1840   // escape status of associated AllocateNode and optimize out
1841   // MemBarStoreStore node if the allocated object never escapes.
1842   while (storestore_worklist.length() != 0) {
1843     Node *n = storestore_worklist.pop();
1844     MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1845     Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1846     assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1847     if (not_global_escape(alloc)) {
1848       MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1849       mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1850       mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1851       igvn->register_new_node_with_optimizer(mb);
1852       igvn->replace_node(storestore, mb);
1853     }
1854   }
1855 }
1856 
1857 // Optimize objects compare.
1858 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1859   assert(OptimizePtrCompare, "sanity");
1860   PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1861   PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1862   JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1863   JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1864   assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1865   assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1866 
1867   // Check simple cases first.
1868   if (jobj1 != NULL) {
1869     if (jobj1->escape_state() == PointsToNode::NoEscape) {
1870       if (jobj1 == jobj2) {
1871         // Comparing the same not escaping object.
1872         return _pcmp_eq;
1873       }
1874       Node* obj = jobj1->ideal_node();
1875       // Comparing not escaping allocation.
1876       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1877           !ptn2->points_to(jobj1)) {
1878         return _pcmp_neq; // This includes nullness check.
1879       }
1880     }
1881   }
1882   if (jobj2 != NULL) {
1883     if (jobj2->escape_state() == PointsToNode::NoEscape) {
1884       Node* obj = jobj2->ideal_node();
1885       // Comparing not escaping allocation.
1886       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1887           !ptn1->points_to(jobj2)) {
1888         return _pcmp_neq; // This includes nullness check.
1889       }
1890     }
1891   }
1892   if (jobj1 != NULL && jobj1 != phantom_obj &&
1893       jobj2 != NULL && jobj2 != phantom_obj &&
1894       jobj1->ideal_node()->is_Con() &&
1895       jobj2->ideal_node()->is_Con()) {
1896     // Klass or String constants compare. Need to be careful with
1897     // compressed pointers - compare types of ConN and ConP instead of nodes.
1898     const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1899     const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1900     if (t1->make_ptr() == t2->make_ptr()) {
1901       return _pcmp_eq;
1902     } else {
1903       return _pcmp_neq;
1904     }
1905   }
1906   if (ptn1->meet(ptn2)) {
1907     return NULL; // Sets are not disjoint
1908   }
1909 
1910   // Sets are disjoint.
1911   bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1912   bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1913   bool set1_has_null_ptr    = ptn1->points_to(null_obj);
1914   bool set2_has_null_ptr    = ptn2->points_to(null_obj);
1915   if (set1_has_unknown_ptr && set2_has_null_ptr ||
1916       set2_has_unknown_ptr && set1_has_null_ptr) {
1917     // Check nullness of unknown object.
1918     return NULL;
1919   }
1920 
1921   // Disjointness by itself is not sufficient since
1922   // alias analysis is not complete for escaped objects.
1923   // Disjoint sets are definitely unrelated only when
1924   // at least one set has only not escaping allocations.
1925   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1926     if (ptn1->non_escaping_allocation()) {
1927       return _pcmp_neq;
1928     }
1929   }
1930   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1931     if (ptn2->non_escaping_allocation()) {
1932       return _pcmp_neq;
1933     }
1934   }
1935   return NULL;
1936 }
1937 
1938 // Connection Graph constuction functions.
1939 
1940 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1941   PointsToNode* ptadr = _nodes.at(n->_idx);
1942   if (ptadr != NULL) {
1943     assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1944     return;
1945   }
1946   Compile* C = _compile;
1947   ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
1948   _nodes.at_put(n->_idx, ptadr);
1949 }
1950 
1951 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1952   PointsToNode* ptadr = _nodes.at(n->_idx);
1953   if (ptadr != NULL) {
1954     assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1955     return;
1956   }
1957   Compile* C = _compile;
1958   ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
1959   _nodes.at_put(n->_idx, ptadr);
1960 }
1961 
1962 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1963   PointsToNode* ptadr = _nodes.at(n->_idx);
1964   if (ptadr != NULL) {
1965     assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1966     return;
1967   }
1968   bool unsafe = false;
1969   bool is_oop = is_oop_field(n, offset, &unsafe);
1970   if (unsafe) {
1971     es = PointsToNode::GlobalEscape;
1972   }
1973   Compile* C = _compile;
1974   FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
1975   _nodes.at_put(n->_idx, field);
1976 }
1977 
1978 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1979                                     PointsToNode* src, PointsToNode* dst) {
1980   assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1981   assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1982   PointsToNode* ptadr = _nodes.at(n->_idx);
1983   if (ptadr != NULL) {
1984     assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1985     return;
1986   }
1987   Compile* C = _compile;
1988   ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
1989   _nodes.at_put(n->_idx, ptadr);
1990   // Add edge from arraycopy node to source object.
1991   (void)add_edge(ptadr, src);
1992   src->set_arraycopy_src();
1993   // Add edge from destination object to arraycopy node.
1994   (void)add_edge(dst, ptadr);
1995   dst->set_arraycopy_dst();
1996 }
1997 
1998 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1999   const Type* adr_type = n->as_AddP()->bottom_type();
2000   BasicType bt = T_INT;
2001   if (offset == Type::OffsetBot) {
2002     // Check only oop fields.
2003     if (!adr_type->isa_aryptr() ||
2004         (adr_type->isa_aryptr()->klass() == NULL) ||
2005          adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2006       // OffsetBot is used to reference array's element. Ignore first AddP.
2007       if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2008         bt = T_OBJECT;
2009       }
2010     }
2011   } else if (offset != oopDesc::klass_offset_in_bytes()) {
2012     if (adr_type->isa_instptr()) {
2013       ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2014       if (field != NULL) {
2015         bt = field->layout_type();
2016       } else {
2017         // Check for unsafe oop field access
2018         if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN)) {
2019           bt = T_OBJECT;
2020           (*unsafe) = true;
2021         }
2022       }
2023     } else if (adr_type->isa_aryptr()) {
2024       if (offset == arrayOopDesc::length_offset_in_bytes()) {
2025         // Ignore array length load.
2026       } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2027         // Ignore first AddP.
2028       } else {
2029         const Type* elemtype = adr_type->isa_aryptr()->elem();
2030         bt = elemtype->array_element_basic_type();
2031       }
2032     } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2033       // Allocation initialization, ThreadLocal field access, unsafe access
2034       if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN)) {
2035         bt = T_OBJECT;
2036       }
2037     }
2038   }
2039   return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2040 }
2041 
2042 // Returns unique pointed java object or NULL.
2043 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2044   assert(!_collecting, "should not call when contructed graph");
2045   // If the node was created after the escape computation we can't answer.
2046   uint idx = n->_idx;
2047   if (idx >= nodes_size()) {
2048     return NULL;
2049   }
2050   PointsToNode* ptn = ptnode_adr(idx);
2051   if (ptn->is_JavaObject()) {
2052     return ptn->as_JavaObject();
2053   }
2054   assert(ptn->is_LocalVar(), "sanity");
2055   // Check all java objects it points to.
2056   JavaObjectNode* jobj = NULL;
2057   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2058     PointsToNode* e = i.get();
2059     if (e->is_JavaObject()) {
2060       if (jobj == NULL) {
2061         jobj = e->as_JavaObject();
2062       } else if (jobj != e) {
2063         return NULL;
2064       }
2065     }
2066   }
2067   return jobj;
2068 }
2069 
2070 // Return true if this node points only to non-escaping allocations.
2071 bool PointsToNode::non_escaping_allocation() {
2072   if (is_JavaObject()) {
2073     Node* n = ideal_node();
2074     if (n->is_Allocate() || n->is_CallStaticJava()) {
2075       return (escape_state() == PointsToNode::NoEscape);
2076     } else {
2077       return false;
2078     }
2079   }
2080   assert(is_LocalVar(), "sanity");
2081   // Check all java objects it points to.
2082   for (EdgeIterator i(this); i.has_next(); i.next()) {
2083     PointsToNode* e = i.get();
2084     if (e->is_JavaObject()) {
2085       Node* n = e->ideal_node();
2086       if ((e->escape_state() != PointsToNode::NoEscape) ||
2087           !(n->is_Allocate() || n->is_CallStaticJava())) {
2088         return false;
2089       }
2090     }
2091   }
2092   return true;
2093 }
2094 
2095 // Return true if we know the node does not escape globally.
2096 bool ConnectionGraph::not_global_escape(Node *n) {
2097   assert(!_collecting, "should not call during graph construction");
2098   // If the node was created after the escape computation we can't answer.
2099   uint idx = n->_idx;
2100   if (idx >= nodes_size()) {
2101     return false;
2102   }
2103   PointsToNode* ptn = ptnode_adr(idx);
2104   PointsToNode::EscapeState es = ptn->escape_state();
2105   // If we have already computed a value, return it.
2106   if (es >= PointsToNode::GlobalEscape)
2107     return false;
2108   if (ptn->is_JavaObject()) {
2109     return true; // (es < PointsToNode::GlobalEscape);
2110   }
2111   assert(ptn->is_LocalVar(), "sanity");
2112   // Check all java objects it points to.
2113   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2114     if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2115       return false;
2116   }
2117   return true;
2118 }
2119 
2120 
2121 // Helper functions
2122 
2123 // Return true if this node points to specified node or nodes it points to.
2124 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2125   if (is_JavaObject()) {
2126     return (this == ptn);
2127   }
2128   assert(is_LocalVar() || is_Field(), "sanity");
2129   for (EdgeIterator i(this); i.has_next(); i.next()) {
2130     if (i.get() == ptn)
2131       return true;
2132   }
2133   return false;
2134 }
2135 
2136 // Return true if one node points to an other.
2137 bool PointsToNode::meet(PointsToNode* ptn) {
2138   if (this == ptn) {
2139     return true;
2140   } else if (ptn->is_JavaObject()) {
2141     return this->points_to(ptn->as_JavaObject());
2142   } else if (this->is_JavaObject()) {
2143     return ptn->points_to(this->as_JavaObject());
2144   }
2145   assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2146   int ptn_count =  ptn->edge_count();
2147   for (EdgeIterator i(this); i.has_next(); i.next()) {
2148     PointsToNode* this_e = i.get();
2149     for (int j = 0; j < ptn_count; j++) {
2150       if (this_e == ptn->edge(j))
2151         return true;
2152     }
2153   }
2154   return false;
2155 }
2156 
2157 #ifdef ASSERT
2158 // Return true if bases point to this java object.
2159 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2160   for (BaseIterator i(this); i.has_next(); i.next()) {
2161     if (i.get() == jobj)
2162       return true;
2163   }
2164   return false;
2165 }
2166 #endif
2167 
2168 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2169   const Type *adr_type = phase->type(adr);
2170   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2171       adr->in(AddPNode::Address)->is_Proj() &&
2172       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2173     // We are computing a raw address for a store captured by an Initialize
2174     // compute an appropriate address type. AddP cases #3 and #5 (see below).
2175     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2176     assert(offs != Type::OffsetBot ||
2177            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2178            "offset must be a constant or it is initialization of array");
2179     return offs;
2180   }
2181   const TypePtr *t_ptr = adr_type->isa_ptr();
2182   assert(t_ptr != NULL, "must be a pointer type");
2183   return t_ptr->offset();
2184 }
2185 
2186 Node* ConnectionGraph::get_addp_base(Node *addp) {
2187   assert(addp->is_AddP(), "must be AddP");
2188   //
2189   // AddP cases for Base and Address inputs:
2190   // case #1. Direct object's field reference:
2191   //     Allocate
2192   //       |
2193   //     Proj #5 ( oop result )
2194   //       |
2195   //     CheckCastPP (cast to instance type)
2196   //      | |
2197   //     AddP  ( base == address )
2198   //
2199   // case #2. Indirect object's field reference:
2200   //      Phi
2201   //       |
2202   //     CastPP (cast to instance type)
2203   //      | |
2204   //     AddP  ( base == address )
2205   //
2206   // case #3. Raw object's field reference for Initialize node:
2207   //      Allocate
2208   //        |
2209   //      Proj #5 ( oop result )
2210   //  top   |
2211   //     \  |
2212   //     AddP  ( base == top )
2213   //
2214   // case #4. Array's element reference:
2215   //   {CheckCastPP | CastPP}
2216   //     |  | |
2217   //     |  AddP ( array's element offset )
2218   //     |  |
2219   //     AddP ( array's offset )
2220   //
2221   // case #5. Raw object's field reference for arraycopy stub call:
2222   //          The inline_native_clone() case when the arraycopy stub is called
2223   //          after the allocation before Initialize and CheckCastPP nodes.
2224   //      Allocate
2225   //        |
2226   //      Proj #5 ( oop result )
2227   //       | |
2228   //       AddP  ( base == address )
2229   //
2230   // case #6. Constant Pool, ThreadLocal, CastX2P or
2231   //          Raw object's field reference:
2232   //      {ConP, ThreadLocal, CastX2P, raw Load}
2233   //  top   |
2234   //     \  |
2235   //     AddP  ( base == top )
2236   //
2237   // case #7. Klass's field reference.
2238   //      LoadKlass
2239   //       | |
2240   //       AddP  ( base == address )
2241   //
2242   // case #8. narrow Klass's field reference.
2243   //      LoadNKlass
2244   //       |
2245   //      DecodeN
2246   //       | |
2247   //       AddP  ( base == address )
2248   //
2249   Node *base = addp->in(AddPNode::Base);
2250   if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2251     base = addp->in(AddPNode::Address);
2252     while (base->is_AddP()) {
2253       // Case #6 (unsafe access) may have several chained AddP nodes.
2254       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2255       base = base->in(AddPNode::Address);
2256     }
2257     Node* uncast_base = base->uncast();
2258     int opcode = uncast_base->Opcode();
2259     assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2260            opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2261            (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2262            (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2263   }
2264   return base;
2265 }
2266 
2267 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2268   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2269   Node* addp2 = addp->raw_out(0);
2270   if (addp->outcnt() == 1 && addp2->is_AddP() &&
2271       addp2->in(AddPNode::Base) == n &&
2272       addp2->in(AddPNode::Address) == addp) {
2273     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2274     //
2275     // Find array's offset to push it on worklist first and
2276     // as result process an array's element offset first (pushed second)
2277     // to avoid CastPP for the array's offset.
2278     // Otherwise the inserted CastPP (LocalVar) will point to what
2279     // the AddP (Field) points to. Which would be wrong since
2280     // the algorithm expects the CastPP has the same point as
2281     // as AddP's base CheckCastPP (LocalVar).
2282     //
2283     //    ArrayAllocation
2284     //     |
2285     //    CheckCastPP
2286     //     |
2287     //    memProj (from ArrayAllocation CheckCastPP)
2288     //     |  ||
2289     //     |  ||   Int (element index)
2290     //     |  ||    |   ConI (log(element size))
2291     //     |  ||    |   /
2292     //     |  ||   LShift
2293     //     |  ||  /
2294     //     |  AddP (array's element offset)
2295     //     |  |
2296     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
2297     //     | / /
2298     //     AddP (array's offset)
2299     //      |
2300     //     Load/Store (memory operation on array's element)
2301     //
2302     return addp2;
2303   }
2304   return NULL;
2305 }
2306 
2307 //
2308 // Adjust the type and inputs of an AddP which computes the
2309 // address of a field of an instance
2310 //
2311 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2312   PhaseGVN* igvn = _igvn;
2313   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2314   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2315   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2316   if (t == NULL) {
2317     // We are computing a raw address for a store captured by an Initialize
2318     // compute an appropriate address type (cases #3 and #5).
2319     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2320     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2321     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2322     assert(offs != Type::OffsetBot, "offset must be a constant");
2323     t = base_t->add_offset(offs)->is_oopptr();
2324   }
2325   int inst_id =  base_t->instance_id();
2326   assert(!t->is_known_instance() || t->instance_id() == inst_id,
2327                              "old type must be non-instance or match new type");
2328 
2329   // The type 't' could be subclass of 'base_t'.
2330   // As result t->offset() could be large then base_t's size and it will
2331   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2332   // constructor verifies correctness of the offset.
2333   //
2334   // It could happened on subclass's branch (from the type profiling
2335   // inlining) which was not eliminated during parsing since the exactness
2336   // of the allocation type was not propagated to the subclass type check.
2337   //
2338   // Or the type 't' could be not related to 'base_t' at all.
2339   // It could happened when CHA type is different from MDO type on a dead path
2340   // (for example, from instanceof check) which is not collapsed during parsing.
2341   //
2342   // Do nothing for such AddP node and don't process its users since
2343   // this code branch will go away.
2344   //
2345   if (!t->is_known_instance() &&
2346       !base_t->klass()->is_subtype_of(t->klass())) {
2347      return false; // bail out
2348   }
2349   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2350   // Do NOT remove the next line: ensure a new alias index is allocated
2351   // for the instance type. Note: C++ will not remove it since the call
2352   // has side effect.
2353   int alias_idx = _compile->get_alias_index(tinst);
2354   igvn->set_type(addp, tinst);
2355   // record the allocation in the node map
2356   set_map(addp, get_map(base->_idx));
2357   // Set addp's Base and Address to 'base'.
2358   Node *abase = addp->in(AddPNode::Base);
2359   Node *adr   = addp->in(AddPNode::Address);
2360   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2361       adr->in(0)->_idx == (uint)inst_id) {
2362     // Skip AddP cases #3 and #5.
2363   } else {
2364     assert(!abase->is_top(), "sanity"); // AddP case #3
2365     if (abase != base) {
2366       igvn->hash_delete(addp);
2367       addp->set_req(AddPNode::Base, base);
2368       if (abase == adr) {
2369         addp->set_req(AddPNode::Address, base);
2370       } else {
2371         // AddP case #4 (adr is array's element offset AddP node)
2372 #ifdef ASSERT
2373         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2374         assert(adr->is_AddP() && atype != NULL &&
2375                atype->instance_id() == inst_id, "array's element offset should be processed first");
2376 #endif
2377       }
2378       igvn->hash_insert(addp);
2379     }
2380   }
2381   // Put on IGVN worklist since at least addp's type was changed above.
2382   record_for_optimizer(addp);
2383   return true;
2384 }
2385 
2386 //
2387 // Create a new version of orig_phi if necessary. Returns either the newly
2388 // created phi or an existing phi.  Sets create_new to indicate whether a new
2389 // phi was created.  Cache the last newly created phi in the node map.
2390 //
2391 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, bool &new_created) {
2392   Compile *C = _compile;
2393   PhaseGVN* igvn = _igvn;
2394   new_created = false;
2395   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2396   // nothing to do if orig_phi is bottom memory or matches alias_idx
2397   if (phi_alias_idx == alias_idx) {
2398     return orig_phi;
2399   }
2400   // Have we recently created a Phi for this alias index?
2401   PhiNode *result = get_map_phi(orig_phi->_idx);
2402   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2403     return result;
2404   }
2405   // Previous check may fail when the same wide memory Phi was split into Phis
2406   // for different memory slices. Search all Phis for this region.
2407   if (result != NULL) {
2408     Node* region = orig_phi->in(0);
2409     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2410       Node* phi = region->fast_out(i);
2411       if (phi->is_Phi() &&
2412           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2413         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2414         return phi->as_Phi();
2415       }
2416     }
2417   }
2418   if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2419     if (C->do_escape_analysis() == true && !C->failing()) {
2420       // Retry compilation without escape analysis.
2421       // If this is the first failure, the sentinel string will "stick"
2422       // to the Compile object, and the C2Compiler will see it and retry.
2423       C->record_failure(C2Compiler::retry_no_escape_analysis());
2424     }
2425     return NULL;
2426   }
2427   orig_phi_worklist.append_if_missing(orig_phi);
2428   const TypePtr *atype = C->get_adr_type(alias_idx);
2429   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2430   C->copy_node_notes_to(result, orig_phi);
2431   igvn->set_type(result, result->bottom_type());
2432   record_for_optimizer(result);
2433   set_map(orig_phi, result);
2434   new_created = true;
2435   return result;
2436 }
2437 
2438 //
2439 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2440 // specified alias index.
2441 //
2442 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist) {
2443   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2444   Compile *C = _compile;
2445   PhaseGVN* igvn = _igvn;
2446   bool new_phi_created;
2447   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2448   if (!new_phi_created) {
2449     return result;
2450   }
2451   GrowableArray<PhiNode *>  phi_list;
2452   GrowableArray<uint>  cur_input;
2453   PhiNode *phi = orig_phi;
2454   uint idx = 1;
2455   bool finished = false;
2456   while(!finished) {
2457     while (idx < phi->req()) {
2458       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2459       if (mem != NULL && mem->is_Phi()) {
2460         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2461         if (new_phi_created) {
2462           // found an phi for which we created a new split, push current one on worklist and begin
2463           // processing new one
2464           phi_list.push(phi);
2465           cur_input.push(idx);
2466           phi = mem->as_Phi();
2467           result = newphi;
2468           idx = 1;
2469           continue;
2470         } else {
2471           mem = newphi;
2472         }
2473       }
2474       if (C->failing()) {
2475         return NULL;
2476       }
2477       result->set_req(idx++, mem);
2478     }
2479 #ifdef ASSERT
2480     // verify that the new Phi has an input for each input of the original
2481     assert( phi->req() == result->req(), "must have same number of inputs.");
2482     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2483 #endif
2484     // Check if all new phi's inputs have specified alias index.
2485     // Otherwise use old phi.
2486     for (uint i = 1; i < phi->req(); i++) {
2487       Node* in = result->in(i);
2488       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2489     }
2490     // we have finished processing a Phi, see if there are any more to do
2491     finished = (phi_list.length() == 0 );
2492     if (!finished) {
2493       phi = phi_list.pop();
2494       idx = cur_input.pop();
2495       PhiNode *prev_result = get_map_phi(phi->_idx);
2496       prev_result->set_req(idx++, result);
2497       result = prev_result;
2498     }
2499   }
2500   return result;
2501 }
2502 
2503 //
2504 // The next methods are derived from methods in MemNode.
2505 //
2506 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2507   Node *mem = mmem;
2508   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2509   // means an array I have not precisely typed yet.  Do not do any
2510   // alias stuff with it any time soon.
2511   if (toop->base() != Type::AnyPtr &&
2512       !(toop->klass() != NULL &&
2513         toop->klass()->is_java_lang_Object() &&
2514         toop->offset() == Type::OffsetBot)) {
2515     mem = mmem->memory_at(alias_idx);
2516     // Update input if it is progress over what we have now
2517   }
2518   return mem;
2519 }
2520 
2521 //
2522 // Move memory users to their memory slices.
2523 //
2524 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis) {
2525   Compile* C = _compile;
2526   PhaseGVN* igvn = _igvn;
2527   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2528   assert(tp != NULL, "ptr type");
2529   int alias_idx = C->get_alias_index(tp);
2530   int general_idx = C->get_general_index(alias_idx);
2531 
2532   // Move users first
2533   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2534     Node* use = n->fast_out(i);
2535     if (use->is_MergeMem()) {
2536       MergeMemNode* mmem = use->as_MergeMem();
2537       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2538       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2539         continue; // Nothing to do
2540       }
2541       // Replace previous general reference to mem node.
2542       uint orig_uniq = C->unique();
2543       Node* m = find_inst_mem(n, general_idx, orig_phis);
2544       assert(orig_uniq == C->unique(), "no new nodes");
2545       mmem->set_memory_at(general_idx, m);
2546       --imax;
2547       --i;
2548     } else if (use->is_MemBar()) {
2549       assert(!use->is_Initialize(), "initializing stores should not be moved");
2550       if (use->req() > MemBarNode::Precedent &&
2551           use->in(MemBarNode::Precedent) == n) {
2552         // Don't move related membars.
2553         record_for_optimizer(use);
2554         continue;
2555       }
2556       tp = use->as_MemBar()->adr_type()->isa_ptr();
2557       if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2558           alias_idx == general_idx) {
2559         continue; // Nothing to do
2560       }
2561       // Move to general memory slice.
2562       uint orig_uniq = C->unique();
2563       Node* m = find_inst_mem(n, general_idx, orig_phis);
2564       assert(orig_uniq == C->unique(), "no new nodes");
2565       igvn->hash_delete(use);
2566       imax -= use->replace_edge(n, m);
2567       igvn->hash_insert(use);
2568       record_for_optimizer(use);
2569       --i;
2570 #ifdef ASSERT
2571     } else if (use->is_Mem()) {
2572       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2573         // Don't move related cardmark.
2574         continue;
2575       }
2576       // Memory nodes should have new memory input.
2577       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2578       assert(tp != NULL, "ptr type");
2579       int idx = C->get_alias_index(tp);
2580       assert(get_map(use->_idx) != NULL || idx == alias_idx,
2581              "Following memory nodes should have new memory input or be on the same memory slice");
2582     } else if (use->is_Phi()) {
2583       // Phi nodes should be split and moved already.
2584       tp = use->as_Phi()->adr_type()->isa_ptr();
2585       assert(tp != NULL, "ptr type");
2586       int idx = C->get_alias_index(tp);
2587       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2588     } else {
2589       use->dump();
2590       assert(false, "should not be here");
2591 #endif
2592     }
2593   }
2594 }
2595 
2596 //
2597 // Search memory chain of "mem" to find a MemNode whose address
2598 // is the specified alias index.
2599 //
2600 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis) {
2601   if (orig_mem == NULL)
2602     return orig_mem;
2603   Compile* C = _compile;
2604   PhaseGVN* igvn = _igvn;
2605   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2606   bool is_instance = (toop != NULL) && toop->is_known_instance();
2607   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2608   Node *prev = NULL;
2609   Node *result = orig_mem;
2610   while (prev != result) {
2611     prev = result;
2612     if (result == start_mem)
2613       break;  // hit one of our sentinels
2614     if (result->is_Mem()) {
2615       const Type *at = igvn->type(result->in(MemNode::Address));
2616       if (at == Type::TOP)
2617         break; // Dead
2618       assert (at->isa_ptr() != NULL, "pointer type required.");
2619       int idx = C->get_alias_index(at->is_ptr());
2620       if (idx == alias_idx)
2621         break; // Found
2622       if (!is_instance && (at->isa_oopptr() == NULL ||
2623                            !at->is_oopptr()->is_known_instance())) {
2624         break; // Do not skip store to general memory slice.
2625       }
2626       result = result->in(MemNode::Memory);
2627     }
2628     if (!is_instance)
2629       continue;  // don't search further for non-instance types
2630     // skip over a call which does not affect this memory slice
2631     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2632       Node *proj_in = result->in(0);
2633       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2634         break;  // hit one of our sentinels
2635       } else if (proj_in->is_Call()) {
2636         CallNode *call = proj_in->as_Call();
2637         if (!call->may_modify(toop, igvn)) {
2638           result = call->in(TypeFunc::Memory);
2639         }
2640       } else if (proj_in->is_Initialize()) {
2641         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2642         // Stop if this is the initialization for the object instance which
2643         // which contains this memory slice, otherwise skip over it.
2644         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2645           result = proj_in->in(TypeFunc::Memory);
2646         }
2647       } else if (proj_in->is_MemBar()) {
2648         result = proj_in->in(TypeFunc::Memory);
2649       }
2650     } else if (result->is_MergeMem()) {
2651       MergeMemNode *mmem = result->as_MergeMem();
2652       result = step_through_mergemem(mmem, alias_idx, toop);
2653       if (result == mmem->base_memory()) {
2654         // Didn't find instance memory, search through general slice recursively.
2655         result = mmem->memory_at(C->get_general_index(alias_idx));
2656         result = find_inst_mem(result, alias_idx, orig_phis);
2657         if (C->failing()) {
2658           return NULL;
2659         }
2660         mmem->set_memory_at(alias_idx, result);
2661       }
2662     } else if (result->is_Phi() &&
2663                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2664       Node *un = result->as_Phi()->unique_input(igvn);
2665       if (un != NULL) {
2666         orig_phis.append_if_missing(result->as_Phi());
2667         result = un;
2668       } else {
2669         break;
2670       }
2671     } else if (result->is_ClearArray()) {
2672       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2673         // Can not bypass initialization of the instance
2674         // we are looking for.
2675         break;
2676       }
2677       // Otherwise skip it (the call updated 'result' value).
2678     } else if (result->Opcode() == Op_SCMemProj) {
2679       Node* mem = result->in(0);
2680       Node* adr = NULL;
2681       if (mem->is_LoadStore()) {
2682         adr = mem->in(MemNode::Address);
2683       } else {
2684         assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
2685         adr = mem->in(3); // Memory edge corresponds to destination array
2686       }
2687       const Type *at = igvn->type(adr);
2688       if (at != Type::TOP) {
2689         assert (at->isa_ptr() != NULL, "pointer type required.");
2690         int idx = C->get_alias_index(at->is_ptr());
2691         assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2692         break;
2693       }
2694       result = mem->in(MemNode::Memory);
2695     }
2696   }
2697   if (result->is_Phi()) {
2698     PhiNode *mphi = result->as_Phi();
2699     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2700     const TypePtr *t = mphi->adr_type();
2701     if (!is_instance) {
2702       // Push all non-instance Phis on the orig_phis worklist to update inputs
2703       // during Phase 4 if needed.
2704       orig_phis.append_if_missing(mphi);
2705     } else if (C->get_alias_index(t) != alias_idx) {
2706       // Create a new Phi with the specified alias index type.
2707       result = split_memory_phi(mphi, alias_idx, orig_phis);
2708     }
2709   }
2710   // the result is either MemNode, PhiNode, InitializeNode.
2711   return result;
2712 }
2713 
2714 //
2715 //  Convert the types of unescaped object to instance types where possible,
2716 //  propagate the new type information through the graph, and update memory
2717 //  edges and MergeMem inputs to reflect the new type.
2718 //
2719 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
2720 //  The processing is done in 4 phases:
2721 //
2722 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
2723 //            types for the CheckCastPP for allocations where possible.
2724 //            Propagate the the new types through users as follows:
2725 //               casts and Phi:  push users on alloc_worklist
2726 //               AddP:  cast Base and Address inputs to the instance type
2727 //                      push any AddP users on alloc_worklist and push any memnode
2728 //                      users onto memnode_worklist.
2729 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
2730 //            search the Memory chain for a store with the appropriate type
2731 //            address type.  If a Phi is found, create a new version with
2732 //            the appropriate memory slices from each of the Phi inputs.
2733 //            For stores, process the users as follows:
2734 //               MemNode:  push on memnode_worklist
2735 //               MergeMem: push on mergemem_worklist
2736 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
2737 //            moving the first node encountered of each  instance type to the
2738 //            the input corresponding to its alias index.
2739 //            appropriate memory slice.
2740 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2741 //
2742 // In the following example, the CheckCastPP nodes are the cast of allocation
2743 // results and the allocation of node 29 is unescaped and eligible to be an
2744 // instance type.
2745 //
2746 // We start with:
2747 //
2748 //     7 Parm #memory
2749 //    10  ConI  "12"
2750 //    19  CheckCastPP   "Foo"
2751 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2752 //    29  CheckCastPP   "Foo"
2753 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
2754 //
2755 //    40  StoreP  25   7  20   ... alias_index=4
2756 //    50  StoreP  35  40  30   ... alias_index=4
2757 //    60  StoreP  45  50  20   ... alias_index=4
2758 //    70  LoadP    _  60  30   ... alias_index=4
2759 //    80  Phi     75  50  60   Memory alias_index=4
2760 //    90  LoadP    _  80  30   ... alias_index=4
2761 //   100  LoadP    _  80  20   ... alias_index=4
2762 //
2763 //
2764 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2765 // and creating a new alias index for node 30.  This gives:
2766 //
2767 //     7 Parm #memory
2768 //    10  ConI  "12"
2769 //    19  CheckCastPP   "Foo"
2770 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2771 //    29  CheckCastPP   "Foo"  iid=24
2772 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2773 //
2774 //    40  StoreP  25   7  20   ... alias_index=4
2775 //    50  StoreP  35  40  30   ... alias_index=6
2776 //    60  StoreP  45  50  20   ... alias_index=4
2777 //    70  LoadP    _  60  30   ... alias_index=6
2778 //    80  Phi     75  50  60   Memory alias_index=4
2779 //    90  LoadP    _  80  30   ... alias_index=6
2780 //   100  LoadP    _  80  20   ... alias_index=4
2781 //
2782 // In phase 2, new memory inputs are computed for the loads and stores,
2783 // And a new version of the phi is created.  In phase 4, the inputs to
2784 // node 80 are updated and then the memory nodes are updated with the
2785 // values computed in phase 2.  This results in:
2786 //
2787 //     7 Parm #memory
2788 //    10  ConI  "12"
2789 //    19  CheckCastPP   "Foo"
2790 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2791 //    29  CheckCastPP   "Foo"  iid=24
2792 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2793 //
2794 //    40  StoreP  25  7   20   ... alias_index=4
2795 //    50  StoreP  35  7   30   ... alias_index=6
2796 //    60  StoreP  45  40  20   ... alias_index=4
2797 //    70  LoadP    _  50  30   ... alias_index=6
2798 //    80  Phi     75  40  60   Memory alias_index=4
2799 //   120  Phi     75  50  50   Memory alias_index=6
2800 //    90  LoadP    _ 120  30   ... alias_index=6
2801 //   100  LoadP    _  80  20   ... alias_index=4
2802 //
2803 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
2804   GrowableArray<Node *>  memnode_worklist;
2805   GrowableArray<PhiNode *>  orig_phis;
2806   PhaseIterGVN  *igvn = _igvn;
2807   uint new_index_start = (uint) _compile->num_alias_types();
2808   Arena* arena = Thread::current()->resource_area();
2809   VectorSet visited(arena);
2810   ideal_nodes.clear(); // Reset for use with set_map/get_map.
2811   uint unique_old = _compile->unique();
2812 
2813   //  Phase 1:  Process possible allocations from alloc_worklist.
2814   //  Create instance types for the CheckCastPP for allocations where possible.
2815   //
2816   // (Note: don't forget to change the order of the second AddP node on
2817   //  the alloc_worklist if the order of the worklist processing is changed,
2818   //  see the comment in find_second_addp().)
2819   //
2820   while (alloc_worklist.length() != 0) {
2821     Node *n = alloc_worklist.pop();
2822     uint ni = n->_idx;
2823     if (n->is_Call()) {
2824       CallNode *alloc = n->as_Call();
2825       // copy escape information to call node
2826       PointsToNode* ptn = ptnode_adr(alloc->_idx);
2827       PointsToNode::EscapeState es = ptn->escape_state();
2828       // We have an allocation or call which returns a Java object,
2829       // see if it is unescaped.
2830       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2831         continue;
2832       // Find CheckCastPP for the allocate or for the return value of a call
2833       n = alloc->result_cast();
2834       if (n == NULL) {            // No uses except Initialize node
2835         if (alloc->is_Allocate()) {
2836           // Set the scalar_replaceable flag for allocation
2837           // so it could be eliminated if it has no uses.
2838           alloc->as_Allocate()->_is_scalar_replaceable = true;
2839         }
2840         if (alloc->is_CallStaticJava()) {
2841           // Set the scalar_replaceable flag for boxing method
2842           // so it could be eliminated if it has no uses.
2843           alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2844         }
2845         continue;
2846       }
2847       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2848         assert(!alloc->is_Allocate(), "allocation should have unique type");
2849         continue;
2850       }
2851 
2852       // The inline code for Object.clone() casts the allocation result to
2853       // java.lang.Object and then to the actual type of the allocated
2854       // object. Detect this case and use the second cast.
2855       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2856       // the allocation result is cast to java.lang.Object and then
2857       // to the actual Array type.
2858       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2859           && (alloc->is_AllocateArray() ||
2860               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2861         Node *cast2 = NULL;
2862         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2863           Node *use = n->fast_out(i);
2864           if (use->is_CheckCastPP()) {
2865             cast2 = use;
2866             break;
2867           }
2868         }
2869         if (cast2 != NULL) {
2870           n = cast2;
2871         } else {
2872           // Non-scalar replaceable if the allocation type is unknown statically
2873           // (reflection allocation), the object can't be restored during
2874           // deoptimization without precise type.
2875           continue;
2876         }
2877       }
2878 
2879       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2880       if (t == NULL)
2881         continue;  // not a TypeOopPtr
2882       if (!t->klass_is_exact())
2883         continue; // not an unique type
2884 
2885       if (alloc->is_Allocate()) {
2886         // Set the scalar_replaceable flag for allocation
2887         // so it could be eliminated.
2888         alloc->as_Allocate()->_is_scalar_replaceable = true;
2889       }
2890       if (alloc->is_CallStaticJava()) {
2891         // Set the scalar_replaceable flag for boxing method
2892         // so it could be eliminated.
2893         alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2894       }
2895       set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2896       // in order for an object to be scalar-replaceable, it must be:
2897       //   - a direct allocation (not a call returning an object)
2898       //   - non-escaping
2899       //   - eligible to be a unique type
2900       //   - not determined to be ineligible by escape analysis
2901       set_map(alloc, n);
2902       set_map(n, alloc);
2903       const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
2904       igvn->hash_delete(n);
2905       igvn->set_type(n,  tinst);
2906       n->raise_bottom_type(tinst);
2907       igvn->hash_insert(n);
2908       record_for_optimizer(n);
2909       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2910 
2911         // First, put on the worklist all Field edges from Connection Graph
2912         // which is more accurate then putting immediate users from Ideal Graph.
2913         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2914           PointsToNode* tgt = e.get();
2915           Node* use = tgt->ideal_node();
2916           assert(tgt->is_Field() && use->is_AddP(),
2917                  "only AddP nodes are Field edges in CG");
2918           if (use->outcnt() > 0) { // Don't process dead nodes
2919             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2920             if (addp2 != NULL) {
2921               assert(alloc->is_AllocateArray(),"array allocation was expected");
2922               alloc_worklist.append_if_missing(addp2);
2923             }
2924             alloc_worklist.append_if_missing(use);
2925           }
2926         }
2927 
2928         // An allocation may have an Initialize which has raw stores. Scan
2929         // the users of the raw allocation result and push AddP users
2930         // on alloc_worklist.
2931         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2932         assert (raw_result != NULL, "must have an allocation result");
2933         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2934           Node *use = raw_result->fast_out(i);
2935           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2936             Node* addp2 = find_second_addp(use, raw_result);
2937             if (addp2 != NULL) {
2938               assert(alloc->is_AllocateArray(),"array allocation was expected");
2939               alloc_worklist.append_if_missing(addp2);
2940             }
2941             alloc_worklist.append_if_missing(use);
2942           } else if (use->is_MemBar()) {
2943             memnode_worklist.append_if_missing(use);
2944           }
2945         }
2946       }
2947     } else if (n->is_AddP()) {
2948       JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2949       if (jobj == NULL || jobj == phantom_obj) {
2950 #ifdef ASSERT
2951         ptnode_adr(get_addp_base(n)->_idx)->dump();
2952         ptnode_adr(n->_idx)->dump();
2953         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2954 #endif
2955         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2956         return;
2957       }
2958       Node *base = get_map(jobj->idx());  // CheckCastPP node
2959       if (!split_AddP(n, base)) continue; // wrong type from dead path
2960     } else if (n->is_Phi() ||
2961                n->is_CheckCastPP() ||
2962                n->is_EncodeP() ||
2963                n->is_DecodeN() ||
2964                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2965       if (visited.test_set(n->_idx)) {
2966         assert(n->is_Phi(), "loops only through Phi's");
2967         continue;  // already processed
2968       }
2969       JavaObjectNode* jobj = unique_java_object(n);
2970       if (jobj == NULL || jobj == phantom_obj) {
2971 #ifdef ASSERT
2972         ptnode_adr(n->_idx)->dump();
2973         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2974 #endif
2975         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2976         return;
2977       } else {
2978         Node *val = get_map(jobj->idx());   // CheckCastPP node
2979         TypeNode *tn = n->as_Type();
2980         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2981         assert(tinst != NULL && tinst->is_known_instance() &&
2982                tinst->instance_id() == jobj->idx() , "instance type expected.");
2983 
2984         const Type *tn_type = igvn->type(tn);
2985         const TypeOopPtr *tn_t;
2986         if (tn_type->isa_narrowoop()) {
2987           tn_t = tn_type->make_ptr()->isa_oopptr();
2988         } else {
2989           tn_t = tn_type->isa_oopptr();
2990         }
2991         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2992           if (tn_type->isa_narrowoop()) {
2993             tn_type = tinst->make_narrowoop();
2994           } else {
2995             tn_type = tinst;
2996           }
2997           igvn->hash_delete(tn);
2998           igvn->set_type(tn, tn_type);
2999           tn->set_type(tn_type);
3000           igvn->hash_insert(tn);
3001           record_for_optimizer(n);
3002         } else {
3003           assert(tn_type == TypePtr::NULL_PTR ||
3004                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3005                  "unexpected type");
3006           continue; // Skip dead path with different type
3007         }
3008       }
3009     } else {
3010       debug_only(n->dump();)
3011       assert(false, "EA: unexpected node");
3012       continue;
3013     }
3014     // push allocation's users on appropriate worklist
3015     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3016       Node *use = n->fast_out(i);
3017       if(use->is_Mem() && use->in(MemNode::Address) == n) {
3018         // Load/store to instance's field
3019         memnode_worklist.append_if_missing(use);
3020       } else if (use->is_MemBar()) {
3021         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3022           memnode_worklist.append_if_missing(use);
3023         }
3024       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3025         Node* addp2 = find_second_addp(use, n);
3026         if (addp2 != NULL) {
3027           alloc_worklist.append_if_missing(addp2);
3028         }
3029         alloc_worklist.append_if_missing(use);
3030       } else if (use->is_Phi() ||
3031                  use->is_CheckCastPP() ||
3032                  use->is_EncodeNarrowPtr() ||
3033                  use->is_DecodeNarrowPtr() ||
3034                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3035         alloc_worklist.append_if_missing(use);
3036 #ifdef ASSERT
3037       } else if (use->is_Mem()) {
3038         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3039       } else if (use->is_MergeMem()) {
3040         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3041       } else if (use->is_SafePoint()) {
3042         // Look for MergeMem nodes for calls which reference unique allocation
3043         // (through CheckCastPP nodes) even for debug info.
3044         Node* m = use->in(TypeFunc::Memory);
3045         if (m->is_MergeMem()) {
3046           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3047         }
3048       } else if (use->Opcode() == Op_EncodeISOArray) {
3049         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3050           // EncodeISOArray overwrites destination array
3051           memnode_worklist.append_if_missing(use);
3052         }
3053       } else {
3054         uint op = use->Opcode();
3055         if (!(op == Op_CmpP || op == Op_Conv2B ||
3056               op == Op_CastP2X || op == Op_StoreCM ||
3057               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
3058               op == Op_StrEquals || op == Op_StrIndexOf)) {
3059           n->dump();
3060           use->dump();
3061           assert(false, "EA: missing allocation reference path");
3062         }
3063 #endif
3064       }
3065     }
3066 
3067   }
3068   // New alias types were created in split_AddP().
3069   uint new_index_end = (uint) _compile->num_alias_types();
3070   assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3071 
3072   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
3073   //            compute new values for Memory inputs  (the Memory inputs are not
3074   //            actually updated until phase 4.)
3075   if (memnode_worklist.length() == 0)
3076     return;  // nothing to do
3077   while (memnode_worklist.length() != 0) {
3078     Node *n = memnode_worklist.pop();
3079     if (visited.test_set(n->_idx))
3080       continue;
3081     if (n->is_Phi() || n->is_ClearArray()) {
3082       // we don't need to do anything, but the users must be pushed
3083     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3084       // we don't need to do anything, but the users must be pushed
3085       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3086       if (n == NULL)
3087         continue;
3088     } else if (n->Opcode() == Op_EncodeISOArray) {
3089       // get the memory projection
3090       n = n->find_out_with(Op_SCMemProj);
3091       assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3092     } else {
3093       assert(n->is_Mem(), "memory node required.");
3094       Node *addr = n->in(MemNode::Address);
3095       const Type *addr_t = igvn->type(addr);
3096       if (addr_t == Type::TOP)
3097         continue;
3098       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3099       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3100       assert ((uint)alias_idx < new_index_end, "wrong alias index");
3101       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3102       if (_compile->failing()) {
3103         return;
3104       }
3105       if (mem != n->in(MemNode::Memory)) {
3106         // We delay the memory edge update since we need old one in
3107         // MergeMem code below when instances memory slices are separated.
3108         set_map(n, mem);
3109       }
3110       if (n->is_Load()) {
3111         continue;  // don't push users
3112       } else if (n->is_LoadStore()) {
3113         // get the memory projection
3114         n = n->find_out_with(Op_SCMemProj);
3115         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3116       }
3117     }
3118     // push user on appropriate worklist
3119     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3120       Node *use = n->fast_out(i);
3121       if (use->is_Phi() || use->is_ClearArray()) {
3122         memnode_worklist.append_if_missing(use);
3123       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3124         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3125           continue;
3126         memnode_worklist.append_if_missing(use);
3127       } else if (use->is_MemBar()) {
3128         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3129           memnode_worklist.append_if_missing(use);
3130         }
3131 #ifdef ASSERT
3132       } else if(use->is_Mem()) {
3133         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3134       } else if (use->is_MergeMem()) {
3135         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3136       } else if (use->Opcode() == Op_EncodeISOArray) {
3137         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3138           // EncodeISOArray overwrites destination array
3139           memnode_worklist.append_if_missing(use);
3140         }
3141       } else {
3142         uint op = use->Opcode();
3143         if (!(op == Op_StoreCM ||
3144               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3145                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3146               op == Op_AryEq || op == Op_StrComp ||
3147               op == Op_StrEquals || op == Op_StrIndexOf)) {
3148           n->dump();
3149           use->dump();
3150           assert(false, "EA: missing memory path");
3151         }
3152 #endif
3153       }
3154     }
3155   }
3156 
3157   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
3158   //            Walk each memory slice moving the first node encountered of each
3159   //            instance type to the the input corresponding to its alias index.
3160   uint length = _mergemem_worklist.length();
3161   for( uint next = 0; next < length; ++next ) {
3162     MergeMemNode* nmm = _mergemem_worklist.at(next);
3163     assert(!visited.test_set(nmm->_idx), "should not be visited before");
3164     // Note: we don't want to use MergeMemStream here because we only want to
3165     // scan inputs which exist at the start, not ones we add during processing.
3166     // Note 2: MergeMem may already contains instance memory slices added
3167     // during find_inst_mem() call when memory nodes were processed above.
3168     igvn->hash_delete(nmm);
3169     uint nslices = nmm->req();
3170     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3171       Node* mem = nmm->in(i);
3172       Node* cur = NULL;
3173       if (mem == NULL || mem->is_top())
3174         continue;
3175       // First, update mergemem by moving memory nodes to corresponding slices
3176       // if their type became more precise since this mergemem was created.
3177       while (mem->is_Mem()) {
3178         const Type *at = igvn->type(mem->in(MemNode::Address));
3179         if (at != Type::TOP) {
3180           assert (at->isa_ptr() != NULL, "pointer type required.");
3181           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3182           if (idx == i) {
3183             if (cur == NULL)
3184               cur = mem;
3185           } else {
3186             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3187               nmm->set_memory_at(idx, mem);
3188             }
3189           }
3190         }
3191         mem = mem->in(MemNode::Memory);
3192       }
3193       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3194       // Find any instance of the current type if we haven't encountered
3195       // already a memory slice of the instance along the memory chain.
3196       for (uint ni = new_index_start; ni < new_index_end; ni++) {
3197         if((uint)_compile->get_general_index(ni) == i) {
3198           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3199           if (nmm->is_empty_memory(m)) {
3200             Node* result = find_inst_mem(mem, ni, orig_phis);
3201             if (_compile->failing()) {
3202               return;
3203             }
3204             nmm->set_memory_at(ni, result);
3205           }
3206         }
3207       }
3208     }
3209     // Find the rest of instances values
3210     for (uint ni = new_index_start; ni < new_index_end; ni++) {
3211       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3212       Node* result = step_through_mergemem(nmm, ni, tinst);
3213       if (result == nmm->base_memory()) {
3214         // Didn't find instance memory, search through general slice recursively.
3215         result = nmm->memory_at(_compile->get_general_index(ni));
3216         result = find_inst_mem(result, ni, orig_phis);
3217         if (_compile->failing()) {
3218           return;
3219         }
3220         nmm->set_memory_at(ni, result);
3221       }
3222     }
3223     igvn->hash_insert(nmm);
3224     record_for_optimizer(nmm);
3225   }
3226 
3227   //  Phase 4:  Update the inputs of non-instance memory Phis and
3228   //            the Memory input of memnodes
3229   // First update the inputs of any non-instance Phi's from
3230   // which we split out an instance Phi.  Note we don't have
3231   // to recursively process Phi's encounted on the input memory
3232   // chains as is done in split_memory_phi() since they  will
3233   // also be processed here.
3234   for (int j = 0; j < orig_phis.length(); j++) {
3235     PhiNode *phi = orig_phis.at(j);
3236     int alias_idx = _compile->get_alias_index(phi->adr_type());
3237     igvn->hash_delete(phi);
3238     for (uint i = 1; i < phi->req(); i++) {
3239       Node *mem = phi->in(i);
3240       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3241       if (_compile->failing()) {
3242         return;
3243       }
3244       if (mem != new_mem) {
3245         phi->set_req(i, new_mem);
3246       }
3247     }
3248     igvn->hash_insert(phi);
3249     record_for_optimizer(phi);
3250   }
3251 
3252   // Update the memory inputs of MemNodes with the value we computed
3253   // in Phase 2 and move stores memory users to corresponding memory slices.
3254   // Disable memory split verification code until the fix for 6984348.
3255   // Currently it produces false negative results since it does not cover all cases.
3256 #if 0 // ifdef ASSERT
3257   visited.Reset();
3258   Node_Stack old_mems(arena, _compile->unique() >> 2);
3259 #endif
3260   for (uint i = 0; i < ideal_nodes.size(); i++) {
3261     Node*    n = ideal_nodes.at(i);
3262     Node* nmem = get_map(n->_idx);
3263     assert(nmem != NULL, "sanity");
3264     if (n->is_Mem()) {
3265 #if 0 // ifdef ASSERT
3266       Node* old_mem = n->in(MemNode::Memory);
3267       if (!visited.test_set(old_mem->_idx)) {
3268         old_mems.push(old_mem, old_mem->outcnt());
3269       }
3270 #endif
3271       assert(n->in(MemNode::Memory) != nmem, "sanity");
3272       if (!n->is_Load()) {
3273         // Move memory users of a store first.
3274         move_inst_mem(n, orig_phis);
3275       }
3276       // Now update memory input
3277       igvn->hash_delete(n);
3278       n->set_req(MemNode::Memory, nmem);
3279       igvn->hash_insert(n);
3280       record_for_optimizer(n);
3281     } else {
3282       assert(n->is_Allocate() || n->is_CheckCastPP() ||
3283              n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3284     }
3285   }
3286 #if 0 // ifdef ASSERT
3287   // Verify that memory was split correctly
3288   while (old_mems.is_nonempty()) {
3289     Node* old_mem = old_mems.node();
3290     uint  old_cnt = old_mems.index();
3291     old_mems.pop();
3292     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3293   }
3294 #endif
3295 }
3296 
3297 #ifndef PRODUCT
3298 static const char *node_type_names[] = {
3299   "UnknownType",
3300   "JavaObject",
3301   "LocalVar",
3302   "Field",
3303   "Arraycopy"
3304 };
3305 
3306 static const char *esc_names[] = {
3307   "UnknownEscape",
3308   "NoEscape",
3309   "ArgEscape",
3310   "GlobalEscape"
3311 };
3312 
3313 void PointsToNode::dump(bool print_state) const {
3314   NodeType nt = node_type();
3315   tty->print("%s ", node_type_names[(int) nt]);
3316   if (print_state) {
3317     EscapeState es = escape_state();
3318     EscapeState fields_es = fields_escape_state();
3319     tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3320     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3321       tty->print("NSR ");
3322   }
3323   if (is_Field()) {
3324     FieldNode* f = (FieldNode*)this;
3325     if (f->is_oop())
3326       tty->print("oop ");
3327     if (f->offset() > 0)
3328       tty->print("+%d ", f->offset());
3329     tty->print("(");
3330     for (BaseIterator i(f); i.has_next(); i.next()) {
3331       PointsToNode* b = i.get();
3332       tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3333     }
3334     tty->print(" )");
3335   }
3336   tty->print("[");
3337   for (EdgeIterator i(this); i.has_next(); i.next()) {
3338     PointsToNode* e = i.get();
3339     tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3340   }
3341   tty->print(" [");
3342   for (UseIterator i(this); i.has_next(); i.next()) {
3343     PointsToNode* u = i.get();
3344     bool is_base = false;
3345     if (PointsToNode::is_base_use(u)) {
3346       is_base = true;
3347       u = PointsToNode::get_use_node(u)->as_Field();
3348     }
3349     tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3350   }
3351   tty->print(" ]]  ");
3352   if (_node == NULL)
3353     tty->print_cr("<null>");
3354   else
3355     _node->dump();
3356 }
3357 
3358 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3359   bool first = true;
3360   int ptnodes_length = ptnodes_worklist.length();
3361   for (int i = 0; i < ptnodes_length; i++) {
3362     PointsToNode *ptn = ptnodes_worklist.at(i);
3363     if (ptn == NULL || !ptn->is_JavaObject())
3364       continue;
3365     PointsToNode::EscapeState es = ptn->escape_state();
3366     if ((es != PointsToNode::NoEscape) && !Verbose) {
3367       continue;
3368     }
3369     Node* n = ptn->ideal_node();
3370     if (n->is_Allocate() || (n->is_CallStaticJava() &&
3371                              n->as_CallStaticJava()->is_boxing_method())) {
3372       if (first) {
3373         tty->cr();
3374         tty->print("======== Connection graph for ");
3375         _compile->method()->print_short_name();
3376         tty->cr();
3377         first = false;
3378       }
3379       ptn->dump();
3380       // Print all locals and fields which reference this allocation
3381       for (UseIterator j(ptn); j.has_next(); j.next()) {
3382         PointsToNode* use = j.get();
3383         if (use->is_LocalVar()) {
3384           use->dump(Verbose);
3385         } else if (Verbose) {
3386           use->dump();
3387         }
3388       }
3389       tty->cr();
3390     }
3391   }
3392 }
3393 #endif
--- EOF ---