1 /*
   2  * Copyright (c) 2005, 2018, 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 "gc/shared/c2/barrierSetC2.hpp"
  29 #include "libadt/vectset.hpp"
  30 #include "memory/allocation.hpp"
  31 #include "memory/resourceArea.hpp"
  32 #include "opto/c2compiler.hpp"
  33 #include "opto/arraycopynode.hpp"
  34 #include "opto/callnode.hpp"
  35 #include "opto/cfgnode.hpp"
  36 #include "opto/compile.hpp"
  37 #include "opto/escape.hpp"
  38 #include "opto/phaseX.hpp"
  39 #include "opto/movenode.hpp"
  40 #include "opto/rootnode.hpp"
  41 #include "utilities/macros.hpp"
  42 #if INCLUDE_G1GC
  43 #include "gc/g1/g1ThreadLocalData.hpp"
  44 #endif // INCLUDE_G1GC
  45 #if INCLUDE_ZGC
  46 #include "gc/z/c2/zBarrierSetC2.hpp"
  47 #endif
  48 
  49 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
  50   _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
  51   _in_worklist(C->comp_arena()),
  52   _next_pidx(0),
  53   _collecting(true),
  54   _verify(false),
  55   _compile(C),
  56   _igvn(igvn),
  57   _node_map(C->comp_arena()) {
  58   // Add unknown java object.
  59   add_java_object(C->top(), PointsToNode::GlobalEscape);
  60   phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
  61   // Add ConP(#NULL) and ConN(#NULL) nodes.
  62   Node* oop_null = igvn->zerocon(T_OBJECT);
  63   assert(oop_null->_idx < nodes_size(), "should be created already");
  64   add_java_object(oop_null, PointsToNode::NoEscape);
  65   null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
  66   if (UseCompressedOops) {
  67     Node* noop_null = igvn->zerocon(T_NARROWOOP);
  68     assert(noop_null->_idx < nodes_size(), "should be created already");
  69     map_ideal_node(noop_null, null_obj);
  70   }
  71   _pcmp_neq = NULL; // Should be initialized
  72   _pcmp_eq  = NULL;
  73 }
  74 
  75 bool ConnectionGraph::has_candidates(Compile *C) {
  76   // EA brings benefits only when the code has allocations and/or locks which
  77   // are represented by ideal Macro nodes.
  78   int cnt = C->macro_count();
  79   for (int i = 0; i < cnt; i++) {
  80     Node *n = C->macro_node(i);
  81     if (n->is_Allocate())
  82       return true;
  83     if (n->is_Lock()) {
  84       Node* obj = n->as_Lock()->obj_node()->uncast();
  85       if (!(obj->is_Parm() || obj->is_Con()))
  86         return true;
  87     }
  88     if (n->is_CallStaticJava() &&
  89         n->as_CallStaticJava()->is_boxing_method()) {
  90       return true;
  91     }
  92   }
  93   return false;
  94 }
  95 
  96 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
  97   Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
  98   ResourceMark rm;
  99 
 100   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
 101   // to create space for them in ConnectionGraph::_nodes[].
 102   Node* oop_null = igvn->zerocon(T_OBJECT);
 103   Node* noop_null = igvn->zerocon(T_NARROWOOP);
 104   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
 105   // Perform escape analysis
 106   if (congraph->compute_escape()) {
 107     // There are non escaping objects.
 108     C->set_congraph(congraph);
 109   }
 110   // Cleanup.
 111   if (oop_null->outcnt() == 0)
 112     igvn->hash_delete(oop_null);
 113   if (noop_null->outcnt() == 0)
 114     igvn->hash_delete(noop_null);
 115 }
 116 
 117 bool ConnectionGraph::compute_escape() {
 118   Compile* C = _compile;
 119   PhaseGVN* igvn = _igvn;
 120 
 121   // Worklists used by EA.
 122   Unique_Node_List delayed_worklist;
 123   GrowableArray<Node*> alloc_worklist;
 124   GrowableArray<Node*> ptr_cmp_worklist;
 125   GrowableArray<Node*> storestore_worklist;
 126   GrowableArray<ArrayCopyNode*> arraycopy_worklist;
 127   GrowableArray<PointsToNode*>   ptnodes_worklist;
 128   GrowableArray<JavaObjectNode*> java_objects_worklist;
 129   GrowableArray<JavaObjectNode*> non_escaped_worklist;
 130   GrowableArray<FieldNode*>      oop_fields_worklist;
 131   DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
 132 
 133   { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
 134 
 135   // 1. Populate Connection Graph (CG) with PointsTo nodes.
 136   ideal_nodes.map(C->live_nodes(), NULL);  // preallocate space
 137   // Initialize worklist
 138   if (C->root() != NULL) {
 139     ideal_nodes.push(C->root());
 140   }
 141   // Processed ideal nodes are unique on ideal_nodes list
 142   // but several ideal nodes are mapped to the phantom_obj.
 143   // To avoid duplicated entries on the following worklists
 144   // add the phantom_obj only once to them.
 145   ptnodes_worklist.append(phantom_obj);
 146   java_objects_worklist.append(phantom_obj);
 147   for( uint next = 0; next < ideal_nodes.size(); ++next ) {
 148     Node* n = ideal_nodes.at(next);
 149     // Create PointsTo nodes and add them to Connection Graph. Called
 150     // only once per ideal node since ideal_nodes is Unique_Node list.
 151     add_node_to_connection_graph(n, &delayed_worklist);
 152     PointsToNode* ptn = ptnode_adr(n->_idx);
 153     if (ptn != NULL && ptn != phantom_obj) {
 154       ptnodes_worklist.append(ptn);
 155       if (ptn->is_JavaObject()) {
 156         java_objects_worklist.append(ptn->as_JavaObject());
 157         if ((n->is_Allocate() || n->is_CallStaticJava()) &&
 158             (ptn->escape_state() < PointsToNode::GlobalEscape)) {
 159           // Only allocations and java static calls results are interesting.
 160           non_escaped_worklist.append(ptn->as_JavaObject());
 161         }
 162       } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
 163         oop_fields_worklist.append(ptn->as_Field());
 164       }
 165     }
 166     if (n->is_MergeMem()) {
 167       // Collect all MergeMem nodes to add memory slices for
 168       // scalar replaceable objects in split_unique_types().
 169       _mergemem_worklist.append(n->as_MergeMem());
 170     } else if (OptimizePtrCompare && n->is_Cmp() &&
 171                (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
 172       // Collect compare pointers nodes.
 173       ptr_cmp_worklist.append(n);
 174     } else if (n->is_MemBarStoreStore()) {
 175       // Collect all MemBarStoreStore nodes so that depending on the
 176       // escape status of the associated Allocate node some of them
 177       // may be eliminated.
 178       storestore_worklist.append(n);
 179     } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
 180                (n->req() > MemBarNode::Precedent)) {
 181       record_for_optimizer(n);
 182 #ifdef ASSERT
 183     } else if (n->is_AddP()) {
 184       // Collect address nodes for graph verification.
 185       addp_worklist.append(n);
 186 #endif
 187     } else if (n->is_ArrayCopy()) {
 188       // Keep a list of ArrayCopy nodes so if one of its input is non
 189       // escaping, we can record a unique type
 190       arraycopy_worklist.append(n->as_ArrayCopy());
 191     }
 192     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 193       Node* m = n->fast_out(i);   // Get user
 194       ideal_nodes.push(m);
 195     }
 196   }
 197   if (non_escaped_worklist.length() == 0) {
 198     _collecting = false;
 199     return false; // Nothing to do.
 200   }
 201   // Add final simple edges to graph.
 202   while(delayed_worklist.size() > 0) {
 203     Node* n = delayed_worklist.pop();
 204     add_final_edges(n);
 205   }
 206   int ptnodes_length = ptnodes_worklist.length();
 207 
 208 #ifdef ASSERT
 209   if (VerifyConnectionGraph) {
 210     // Verify that no new simple edges could be created and all
 211     // local vars has edges.
 212     _verify = true;
 213     for (int next = 0; next < ptnodes_length; ++next) {
 214       PointsToNode* ptn = ptnodes_worklist.at(next);
 215       add_final_edges(ptn->ideal_node());
 216       if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
 217         ptn->dump();
 218         assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
 219       }
 220     }
 221     _verify = false;
 222   }
 223 #endif
 224   // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
 225   // processing, calls to CI to resolve symbols (types, fields, methods)
 226   // referenced in bytecode. During symbol resolution VM may throw
 227   // an exception which CI cleans and converts to compilation failure.
 228   if (C->failing())  return false;
 229 
 230   // 2. Finish Graph construction by propagating references to all
 231   //    java objects through graph.
 232   if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
 233                                  java_objects_worklist, oop_fields_worklist)) {
 234     // All objects escaped or hit time or iterations limits.
 235     _collecting = false;
 236     return false;
 237   }
 238 
 239   // 3. Adjust scalar_replaceable state of nonescaping objects and push
 240   //    scalar replaceable allocations on alloc_worklist for processing
 241   //    in split_unique_types().
 242   int non_escaped_length = non_escaped_worklist.length();
 243   for (int next = 0; next < non_escaped_length; next++) {
 244     JavaObjectNode* ptn = non_escaped_worklist.at(next);
 245     bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
 246     Node* n = ptn->ideal_node();
 247     if (n->is_Allocate()) {
 248       n->as_Allocate()->_is_non_escaping = noescape;
 249     }
 250     if (n->is_CallStaticJava()) {
 251       n->as_CallStaticJava()->_is_non_escaping = noescape;
 252     }
 253     if (noescape && ptn->scalar_replaceable()) {
 254       adjust_scalar_replaceable_state(ptn);
 255       if (ptn->scalar_replaceable()) {
 256         alloc_worklist.append(ptn->ideal_node());
 257       }
 258     }
 259   }
 260 
 261 #ifdef ASSERT
 262   if (VerifyConnectionGraph) {
 263     // Verify that graph is complete - no new edges could be added or needed.
 264     verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
 265                             java_objects_worklist, addp_worklist);
 266   }
 267   assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
 268   assert(null_obj->escape_state() == PointsToNode::NoEscape &&
 269          null_obj->edge_count() == 0 &&
 270          !null_obj->arraycopy_src() &&
 271          !null_obj->arraycopy_dst(), "sanity");
 272 #endif
 273 
 274   _collecting = false;
 275 
 276   } // TracePhase t3("connectionGraph")
 277 
 278   // 4. Optimize ideal graph based on EA information.
 279   bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
 280   if (has_non_escaping_obj) {
 281     optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
 282   }
 283 
 284 #ifndef PRODUCT
 285   if (PrintEscapeAnalysis) {
 286     dump(ptnodes_worklist); // Dump ConnectionGraph
 287   }
 288 #endif
 289 
 290   bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
 291 #ifdef ASSERT
 292   if (VerifyConnectionGraph) {
 293     int alloc_length = alloc_worklist.length();
 294     for (int next = 0; next < alloc_length; ++next) {
 295       Node* n = alloc_worklist.at(next);
 296       PointsToNode* ptn = ptnode_adr(n->_idx);
 297       assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
 298     }
 299   }
 300 #endif
 301 
 302   // 5. Separate memory graph for scalar replaceable allcations.
 303   if (has_scalar_replaceable_candidates &&
 304       C->AliasLevel() >= 3 && EliminateAllocations) {
 305     // Now use the escape information to create unique types for
 306     // scalar replaceable objects.
 307     split_unique_types(alloc_worklist, arraycopy_worklist);
 308     if (C->failing())  return false;
 309     C->print_method(PHASE_AFTER_EA, 2);
 310 
 311 #ifdef ASSERT
 312   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
 313     tty->print("=== No allocations eliminated for ");
 314     C->method()->print_short_name();
 315     if(!EliminateAllocations) {
 316       tty->print(" since EliminateAllocations is off ===");
 317     } else if(!has_scalar_replaceable_candidates) {
 318       tty->print(" since there are no scalar replaceable candidates ===");
 319     } else if(C->AliasLevel() < 3) {
 320       tty->print(" since AliasLevel < 3 ===");
 321     }
 322     tty->cr();
 323 #endif
 324   }
 325   return has_non_escaping_obj;
 326 }
 327 
 328 // Utility function for nodes that load an object
 329 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 330   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 331   // ThreadLocal has RawPtr type.
 332   const Type* t = _igvn->type(n);
 333   if (t->make_ptr() != NULL) {
 334     Node* adr = n->in(MemNode::Address);
 335 #ifdef ASSERT
 336     if (!adr->is_AddP()) {
 337       assert(_igvn->type(adr)->isa_rawptr(), "sanity");
 338     } else {
 339       assert((ptnode_adr(adr->_idx) == NULL ||
 340               ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
 341     }
 342 #endif
 343     add_local_var_and_edge(n, PointsToNode::NoEscape,
 344                            adr, delayed_worklist);
 345   }
 346 }
 347 
 348 // Populate Connection Graph with PointsTo nodes and create simple
 349 // connection graph edges.
 350 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 351   assert(!_verify, "this method should not be called for verification");
 352   PhaseGVN* igvn = _igvn;
 353   uint n_idx = n->_idx;
 354   PointsToNode* n_ptn = ptnode_adr(n_idx);
 355   if (n_ptn != NULL)
 356     return; // No need to redefine PointsTo node during first iteration.
 357 
 358   if (n->is_Call()) {
 359     // Arguments to allocation and locking don't escape.
 360     if (n->is_AbstractLock()) {
 361       // Put Lock and Unlock nodes on IGVN worklist to process them during
 362       // first IGVN optimization when escape information is still available.
 363       record_for_optimizer(n);
 364     } else if (n->is_Allocate()) {
 365       add_call_node(n->as_Call());
 366       record_for_optimizer(n);
 367     } else {
 368       if (n->is_CallStaticJava()) {
 369         const char* name = n->as_CallStaticJava()->_name;
 370         if (name != NULL && strcmp(name, "uncommon_trap") == 0)
 371           return; // Skip uncommon traps
 372       }
 373       // Don't mark as processed since call's arguments have to be processed.
 374       delayed_worklist->push(n);
 375       // Check if a call returns an object.
 376       if ((n->as_Call()->returns_pointer() &&
 377            n->as_Call()->proj_out_or_null(TypeFunc::Parms) != NULL) ||
 378           (n->is_CallStaticJava() &&
 379            n->as_CallStaticJava()->is_boxing_method())) {
 380         add_call_node(n->as_Call());
 381       }
 382     }
 383     return;
 384   }
 385   // Put this check here to process call arguments since some call nodes
 386   // point to phantom_obj.
 387   if (n_ptn == phantom_obj || n_ptn == null_obj)
 388     return; // Skip predefined nodes.
 389 
 390   int opcode = n->Opcode();
 391   switch (opcode) {
 392     case Op_AddP: {
 393       Node* base = get_addp_base(n);
 394       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 395       // Field nodes are created for all field types. They are used in
 396       // adjust_scalar_replaceable_state() and split_unique_types().
 397       // Note, non-oop fields will have only base edges in Connection
 398       // Graph because such fields are not used for oop loads and stores.
 399       int offset = address_offset(n, igvn);
 400       add_field(n, PointsToNode::NoEscape, offset);
 401       if (ptn_base == NULL) {
 402         delayed_worklist->push(n); // Process it later.
 403       } else {
 404         n_ptn = ptnode_adr(n_idx);
 405         add_base(n_ptn->as_Field(), ptn_base);
 406       }
 407       break;
 408     }
 409     case Op_CastX2P: {
 410       map_ideal_node(n, phantom_obj);
 411       break;
 412     }
 413     case Op_CastPP:
 414     case Op_CheckCastPP:
 415     case Op_EncodeP:
 416     case Op_DecodeN:
 417     case Op_EncodePKlass:
 418     case Op_DecodeNKlass: {
 419       add_local_var_and_edge(n, PointsToNode::NoEscape,
 420                              n->in(1), delayed_worklist);
 421       break;
 422     }
 423     case Op_CMoveP: {
 424       add_local_var(n, PointsToNode::NoEscape);
 425       // Do not add edges during first iteration because some could be
 426       // not defined yet.
 427       delayed_worklist->push(n);
 428       break;
 429     }
 430     case Op_ConP:
 431     case Op_ConN:
 432     case Op_ConNKlass: {
 433       // assume all oop constants globally escape except for null
 434       PointsToNode::EscapeState es;
 435       const Type* t = igvn->type(n);
 436       if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
 437         es = PointsToNode::NoEscape;
 438       } else {
 439         es = PointsToNode::GlobalEscape;
 440       }
 441       add_java_object(n, es);
 442       break;
 443     }
 444     case Op_CreateEx: {
 445       // assume that all exception objects globally escape
 446       map_ideal_node(n, phantom_obj);
 447       break;
 448     }
 449     case Op_LoadKlass:
 450     case Op_LoadNKlass: {
 451       // Unknown class is loaded
 452       map_ideal_node(n, phantom_obj);
 453       break;
 454     }
 455     case Op_LoadP:
 456 #if INCLUDE_ZGC
 457     case Op_LoadBarrierSlowReg:
 458     case Op_LoadBarrierWeakSlowReg:
 459 #endif
 460     case Op_LoadN:
 461     case Op_LoadPLocked: {
 462       add_objload_to_connection_graph(n, delayed_worklist);
 463       break;
 464     }
 465     case Op_Parm: {
 466       map_ideal_node(n, phantom_obj);
 467       break;
 468     }
 469     case Op_PartialSubtypeCheck: {
 470       // Produces Null or notNull and is used in only in CmpP so
 471       // phantom_obj could be used.
 472       map_ideal_node(n, phantom_obj); // Result is unknown
 473       break;
 474     }
 475     case Op_Phi: {
 476       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 477       // ThreadLocal has RawPtr type.
 478       const Type* t = n->as_Phi()->type();
 479       if (t->make_ptr() != NULL) {
 480         add_local_var(n, PointsToNode::NoEscape);
 481         // Do not add edges during first iteration because some could be
 482         // not defined yet.
 483         delayed_worklist->push(n);
 484       }
 485       break;
 486     }
 487     case Op_Proj: {
 488       // we are only interested in the oop result projection from a call
 489       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
 490           n->in(0)->as_Call()->returns_pointer()) {
 491         add_local_var_and_edge(n, PointsToNode::NoEscape,
 492                                n->in(0), delayed_worklist);
 493       }
 494 #if INCLUDE_ZGC
 495       else if (UseZGC) {
 496         if (n->as_Proj()->_con == LoadBarrierNode::Oop && n->in(0)->is_LoadBarrier()) {
 497           add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0)->in(LoadBarrierNode::Oop), delayed_worklist);
 498         }
 499       }
 500 #endif
 501       break;
 502     }
 503     case Op_Rethrow: // Exception object escapes
 504     case Op_Return: {
 505       if (n->req() > TypeFunc::Parms &&
 506           igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 507         // Treat Return value as LocalVar with GlobalEscape escape state.
 508         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 509                                n->in(TypeFunc::Parms), delayed_worklist);
 510       }
 511       break;
 512     }
 513     case Op_CompareAndExchangeP:
 514     case Op_CompareAndExchangeN:
 515     case Op_GetAndSetP:
 516     case Op_GetAndSetN: {
 517       add_objload_to_connection_graph(n, delayed_worklist);
 518       // fallthrough
 519     }
 520     case Op_StoreP:
 521     case Op_StoreN:
 522     case Op_StoreNKlass:
 523     case Op_StorePConditional:
 524     case Op_WeakCompareAndSwapP:
 525     case Op_WeakCompareAndSwapN:
 526     case Op_CompareAndSwapP:
 527     case Op_CompareAndSwapN: {
 528       Node* adr = n->in(MemNode::Address);
 529       const Type *adr_type = igvn->type(adr);
 530       adr_type = adr_type->make_ptr();
 531       if (adr_type == NULL) {
 532         break; // skip dead nodes
 533       }
 534       if (   adr_type->isa_oopptr()
 535           || (   (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
 536               && adr_type == TypeRawPtr::NOTNULL
 537               && adr->in(AddPNode::Address)->is_Proj()
 538               && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 539         delayed_worklist->push(n); // Process it later.
 540 #ifdef ASSERT
 541         assert(adr->is_AddP(), "expecting an AddP");
 542         if (adr_type == TypeRawPtr::NOTNULL) {
 543           // Verify a raw address for a store captured by Initialize node.
 544           int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 545           assert(offs != Type::OffsetBot, "offset must be a constant");
 546         }
 547 #endif
 548       } else {
 549         // Ignore copy the displaced header to the BoxNode (OSR compilation).
 550         if (adr->is_BoxLock())
 551           break;
 552         // Stored value escapes in unsafe access.
 553         if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
 554           // Pointer stores in G1 barriers looks like unsafe access.
 555           // Ignore such stores to be able scalar replace non-escaping
 556           // allocations.
 557 #if INCLUDE_G1GC
 558           if (UseG1GC && adr->is_AddP()) {
 559             Node* base = get_addp_base(adr);
 560             if (base->Opcode() == Op_LoadP &&
 561                 base->in(MemNode::Address)->is_AddP()) {
 562               adr = base->in(MemNode::Address);
 563               Node* tls = get_addp_base(adr);
 564               if (tls->Opcode() == Op_ThreadLocal) {
 565                 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 566                 if (offs == in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset())) {
 567                   break; // G1 pre barrier previous oop value store.
 568                 }
 569                 if (offs == in_bytes(G1ThreadLocalData::dirty_card_queue_buffer_offset())) {
 570                   break; // G1 post barrier card address store.
 571                 }
 572               }
 573             }
 574           }
 575 #endif
 576           delayed_worklist->push(n); // Process unsafe access later.
 577           break;
 578         }
 579 #ifdef ASSERT
 580         n->dump(1);
 581         assert(false, "not unsafe or G1 barrier raw StoreP");
 582 #endif
 583       }
 584       break;
 585     }
 586     case Op_AryEq:
 587     case Op_HasNegatives:
 588     case Op_StrComp:
 589     case Op_StrEquals:
 590     case Op_StrIndexOf:
 591     case Op_StrIndexOfChar:
 592     case Op_StrInflatedCopy:
 593     case Op_StrCompressedCopy:
 594     case Op_EncodeISOArray: {
 595       add_local_var(n, PointsToNode::ArgEscape);
 596       delayed_worklist->push(n); // Process it later.
 597       break;
 598     }
 599     case Op_ThreadLocal: {
 600       add_java_object(n, PointsToNode::ArgEscape);
 601       break;
 602     }
 603     default:
 604       ; // Do nothing for nodes not related to EA.
 605   }
 606   return;
 607 }
 608 
 609 #ifdef ASSERT
 610 #define ELSE_FAIL(name)                               \
 611       /* Should not be called for not pointer type. */  \
 612       n->dump(1);                                       \
 613       assert(false, name);                              \
 614       break;
 615 #else
 616 #define ELSE_FAIL(name) \
 617       break;
 618 #endif
 619 
 620 // Add final simple edges to graph.
 621 void ConnectionGraph::add_final_edges(Node *n) {
 622   PointsToNode* n_ptn = ptnode_adr(n->_idx);
 623 #ifdef ASSERT
 624   if (_verify && n_ptn->is_JavaObject())
 625     return; // This method does not change graph for JavaObject.
 626 #endif
 627 
 628   if (n->is_Call()) {
 629     process_call_arguments(n->as_Call());
 630     return;
 631   }
 632   assert(n->is_Store() || n->is_LoadStore() ||
 633          (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
 634          "node should be registered already");
 635   int opcode = n->Opcode();
 636   switch (opcode) {
 637     case Op_AddP: {
 638       Node* base = get_addp_base(n);
 639       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 640       assert(ptn_base != NULL, "field's base should be registered");
 641       add_base(n_ptn->as_Field(), ptn_base);
 642       break;
 643     }
 644     case Op_CastPP:
 645     case Op_CheckCastPP:
 646     case Op_EncodeP:
 647     case Op_DecodeN:
 648     case Op_EncodePKlass:
 649     case Op_DecodeNKlass: {
 650       add_local_var_and_edge(n, PointsToNode::NoEscape,
 651                              n->in(1), NULL);
 652       break;
 653     }
 654     case Op_CMoveP: {
 655       for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
 656         Node* in = n->in(i);
 657         if (in == NULL)
 658           continue;  // ignore NULL
 659         Node* uncast_in = in->uncast();
 660         if (uncast_in->is_top() || uncast_in == n)
 661           continue;  // ignore top or inputs which go back this node
 662         PointsToNode* ptn = ptnode_adr(in->_idx);
 663         assert(ptn != NULL, "node should be registered");
 664         add_edge(n_ptn, ptn);
 665       }
 666       break;
 667     }
 668     case Op_LoadP:
 669 #if INCLUDE_ZGC
 670     case Op_LoadBarrierSlowReg:
 671     case Op_LoadBarrierWeakSlowReg:
 672 #endif
 673     case Op_LoadN:
 674     case Op_LoadPLocked: {
 675       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 676       // ThreadLocal has RawPtr type.
 677       const Type* t = _igvn->type(n);
 678       if (t->make_ptr() != NULL) {
 679         Node* adr = n->in(MemNode::Address);
 680         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 681         break;
 682       }
 683       ELSE_FAIL("Op_LoadP");
 684     }
 685     case Op_Phi: {
 686       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 687       // ThreadLocal has RawPtr type.
 688       const Type* t = n->as_Phi()->type();
 689       if (t->make_ptr() != NULL) {
 690         for (uint i = 1; i < n->req(); i++) {
 691           Node* in = n->in(i);
 692           if (in == NULL)
 693             continue;  // ignore NULL
 694           Node* uncast_in = in->uncast();
 695           if (uncast_in->is_top() || uncast_in == n)
 696             continue;  // ignore top or inputs which go back this node
 697           PointsToNode* ptn = ptnode_adr(in->_idx);
 698           assert(ptn != NULL, "node should be registered");
 699           add_edge(n_ptn, ptn);
 700         }
 701         break;
 702       }
 703       ELSE_FAIL("Op_Phi");
 704     }
 705     case Op_Proj: {
 706       // we are only interested in the oop result projection from a call
 707       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
 708           n->in(0)->as_Call()->returns_pointer()) {
 709         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
 710         break;
 711       }
 712 #if INCLUDE_ZGC
 713       else if (UseZGC) {
 714         if (n->as_Proj()->_con == LoadBarrierNode::Oop && n->in(0)->is_LoadBarrier()) {
 715           add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0)->in(LoadBarrierNode::Oop), NULL);
 716           break;
 717         }
 718       }
 719 #endif
 720       ELSE_FAIL("Op_Proj");
 721     }
 722     case Op_Rethrow: // Exception object escapes
 723     case Op_Return: {
 724       if (n->req() > TypeFunc::Parms &&
 725           _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 726         // Treat Return value as LocalVar with GlobalEscape escape state.
 727         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 728                                n->in(TypeFunc::Parms), NULL);
 729         break;
 730       }
 731       ELSE_FAIL("Op_Return");
 732     }
 733     case Op_StoreP:
 734     case Op_StoreN:
 735     case Op_StoreNKlass:
 736     case Op_StorePConditional:
 737     case Op_CompareAndExchangeP:
 738     case Op_CompareAndExchangeN:
 739     case Op_CompareAndSwapP:
 740     case Op_CompareAndSwapN:
 741     case Op_WeakCompareAndSwapP:
 742     case Op_WeakCompareAndSwapN:
 743     case Op_GetAndSetP:
 744     case Op_GetAndSetN: {
 745       Node* adr = n->in(MemNode::Address);
 746       const Type *adr_type = _igvn->type(adr);
 747       adr_type = adr_type->make_ptr();
 748 #ifdef ASSERT
 749       if (adr_type == NULL) {
 750         n->dump(1);
 751         assert(adr_type != NULL, "dead node should not be on list");
 752         break;
 753       }
 754 #endif
 755       if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
 756           opcode == Op_CompareAndExchangeN || opcode == Op_CompareAndExchangeP) {
 757         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 758       }
 759       if (   adr_type->isa_oopptr()
 760           || (   (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
 761               && adr_type == TypeRawPtr::NOTNULL
 762               && adr->in(AddPNode::Address)->is_Proj()
 763               && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 764         // Point Address to Value
 765         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 766         assert(adr_ptn != NULL &&
 767                adr_ptn->as_Field()->is_oop(), "node should be registered");
 768         Node *val = n->in(MemNode::ValueIn);
 769         PointsToNode* ptn = ptnode_adr(val->_idx);
 770         assert(ptn != NULL, "node should be registered");
 771         add_edge(adr_ptn, ptn);
 772         break;
 773       } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
 774         // Stored value escapes in unsafe access.
 775         Node *val = n->in(MemNode::ValueIn);
 776         PointsToNode* ptn = ptnode_adr(val->_idx);
 777         assert(ptn != NULL, "node should be registered");
 778         set_escape_state(ptn, PointsToNode::GlobalEscape);
 779         // Add edge to object for unsafe access with offset.
 780         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 781         assert(adr_ptn != NULL, "node should be registered");
 782         if (adr_ptn->is_Field()) {
 783           assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
 784           add_edge(adr_ptn, ptn);
 785         }
 786         break;
 787       }
 788       ELSE_FAIL("Op_StoreP");
 789     }
 790     case Op_AryEq:
 791     case Op_HasNegatives:
 792     case Op_StrComp:
 793     case Op_StrEquals:
 794     case Op_StrIndexOf:
 795     case Op_StrIndexOfChar:
 796     case Op_StrInflatedCopy:
 797     case Op_StrCompressedCopy:
 798     case Op_EncodeISOArray: {
 799       // char[]/byte[] arrays passed to string intrinsic do not escape but
 800       // they are not scalar replaceable. Adjust escape state for them.
 801       // Start from in(2) edge since in(1) is memory edge.
 802       for (uint i = 2; i < n->req(); i++) {
 803         Node* adr = n->in(i);
 804         const Type* at = _igvn->type(adr);
 805         if (!adr->is_top() && at->isa_ptr()) {
 806           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
 807                  at->isa_ptr() != NULL, "expecting a pointer");
 808           if (adr->is_AddP()) {
 809             adr = get_addp_base(adr);
 810           }
 811           PointsToNode* ptn = ptnode_adr(adr->_idx);
 812           assert(ptn != NULL, "node should be registered");
 813           add_edge(n_ptn, ptn);
 814         }
 815       }
 816       break;
 817     }
 818     default: {
 819       // This method should be called only for EA specific nodes which may
 820       // miss some edges when they were created.
 821 #ifdef ASSERT
 822       n->dump(1);
 823 #endif
 824       guarantee(false, "unknown node");
 825     }
 826   }
 827   return;
 828 }
 829 
 830 void ConnectionGraph::add_call_node(CallNode* call) {
 831   assert(call->returns_pointer(), "only for call which returns pointer");
 832   uint call_idx = call->_idx;
 833   if (call->is_Allocate()) {
 834     Node* k = call->in(AllocateNode::KlassNode);
 835     const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
 836     assert(kt != NULL, "TypeKlassPtr  required.");
 837     ciKlass* cik = kt->klass();
 838     PointsToNode::EscapeState es = PointsToNode::NoEscape;
 839     bool scalar_replaceable = true;
 840     if (call->is_AllocateArray()) {
 841       if (!cik->is_array_klass()) { // StressReflectiveCode
 842         es = PointsToNode::GlobalEscape;
 843       } else {
 844         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
 845         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
 846           // Not scalar replaceable if the length is not constant or too big.
 847           scalar_replaceable = false;
 848         }
 849       }
 850     } else {  // Allocate instance
 851       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
 852           cik->is_subclass_of(_compile->env()->Reference_klass()) ||
 853          !cik->is_instance_klass() || // StressReflectiveCode
 854          !cik->as_instance_klass()->can_be_instantiated() ||
 855           cik->as_instance_klass()->has_finalizer()) {
 856         es = PointsToNode::GlobalEscape;
 857       }
 858     }
 859     add_java_object(call, es);
 860     PointsToNode* ptn = ptnode_adr(call_idx);
 861     if (!scalar_replaceable && ptn->scalar_replaceable()) {
 862       ptn->set_scalar_replaceable(false);
 863     }
 864   } else if (call->is_CallStaticJava()) {
 865     // Call nodes could be different types:
 866     //
 867     // 1. CallDynamicJavaNode (what happened during call is unknown):
 868     //
 869     //    - mapped to GlobalEscape JavaObject node if oop is returned;
 870     //
 871     //    - all oop arguments are escaping globally;
 872     //
 873     // 2. CallStaticJavaNode (execute bytecode analysis if possible):
 874     //
 875     //    - the same as CallDynamicJavaNode if can't do bytecode analysis;
 876     //
 877     //    - mapped to GlobalEscape JavaObject node if unknown oop is returned;
 878     //    - mapped to NoEscape JavaObject node if non-escaping object allocated
 879     //      during call is returned;
 880     //    - mapped to ArgEscape LocalVar node pointed to object arguments
 881     //      which are returned and does not escape during call;
 882     //
 883     //    - oop arguments escaping status is defined by bytecode analysis;
 884     //
 885     // For a static call, we know exactly what method is being called.
 886     // Use bytecode estimator to record whether the call's return value escapes.
 887     ciMethod* meth = call->as_CallJava()->method();
 888     if (meth == NULL) {
 889       const char* name = call->as_CallStaticJava()->_name;
 890       assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
 891       // Returns a newly allocated unescaped object.
 892       add_java_object(call, PointsToNode::NoEscape);
 893       ptnode_adr(call_idx)->set_scalar_replaceable(false);
 894     } else if (meth->is_boxing_method()) {
 895       // Returns boxing object
 896       PointsToNode::EscapeState es;
 897       vmIntrinsics::ID intr = meth->intrinsic_id();
 898       if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
 899         // It does not escape if object is always allocated.
 900         es = PointsToNode::NoEscape;
 901       } else {
 902         // It escapes globally if object could be loaded from cache.
 903         es = PointsToNode::GlobalEscape;
 904       }
 905       add_java_object(call, es);
 906     } else {
 907       BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
 908       call_analyzer->copy_dependencies(_compile->dependencies());
 909       if (call_analyzer->is_return_allocated()) {
 910         // Returns a newly allocated unescaped object, simply
 911         // update dependency information.
 912         // Mark it as NoEscape so that objects referenced by
 913         // it's fields will be marked as NoEscape at least.
 914         add_java_object(call, PointsToNode::NoEscape);
 915         ptnode_adr(call_idx)->set_scalar_replaceable(false);
 916       } else {
 917         // Determine whether any arguments are returned.
 918         const TypeTuple* d = call->tf()->domain();
 919         bool ret_arg = false;
 920         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 921           if (d->field_at(i)->isa_ptr() != NULL &&
 922               call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
 923             ret_arg = true;
 924             break;
 925           }
 926         }
 927         if (ret_arg) {
 928           add_local_var(call, PointsToNode::ArgEscape);
 929         } else {
 930           // Returns unknown object.
 931           map_ideal_node(call, phantom_obj);
 932         }
 933       }
 934     }
 935   } else {
 936     // An other type of call, assume the worst case:
 937     // returned value is unknown and globally escapes.
 938     assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
 939     map_ideal_node(call, phantom_obj);
 940   }
 941 }
 942 
 943 void ConnectionGraph::process_call_arguments(CallNode *call) {
 944     bool is_arraycopy = false;
 945     switch (call->Opcode()) {
 946 #ifdef ASSERT
 947     case Op_Allocate:
 948     case Op_AllocateArray:
 949     case Op_Lock:
 950     case Op_Unlock:
 951       assert(false, "should be done already");
 952       break;
 953 #endif
 954     case Op_ArrayCopy:
 955     case Op_CallLeafNoFP:
 956       // Most array copies are ArrayCopy nodes at this point but there
 957       // are still a few direct calls to the copy subroutines (See
 958       // PhaseStringOpts::copy_string())
 959       is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
 960         call->as_CallLeaf()->is_call_to_arraycopystub();
 961       // fall through
 962     case Op_CallLeaf: {
 963       // Stub calls, objects do not escape but they are not scale replaceable.
 964       // Adjust escape state for outgoing arguments.
 965       const TypeTuple * d = call->tf()->domain();
 966       bool src_has_oops = false;
 967       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 968         const Type* at = d->field_at(i);
 969         Node *arg = call->in(i);
 970         if (arg == NULL) {
 971           continue;
 972         }
 973         const Type *aat = _igvn->type(arg);
 974         if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
 975           continue;
 976         if (arg->is_AddP()) {
 977           //
 978           // The inline_native_clone() case when the arraycopy stub is called
 979           // after the allocation before Initialize and CheckCastPP nodes.
 980           // Or normal arraycopy for object arrays case.
 981           //
 982           // Set AddP's base (Allocate) as not scalar replaceable since
 983           // pointer to the base (with offset) is passed as argument.
 984           //
 985           arg = get_addp_base(arg);
 986         }
 987         PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
 988         assert(arg_ptn != NULL, "should be registered");
 989         PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
 990         if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
 991           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
 992                  aat->isa_ptr() != NULL, "expecting an Ptr");
 993           bool arg_has_oops = aat->isa_oopptr() &&
 994                               (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
 995                                (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
 996           if (i == TypeFunc::Parms) {
 997             src_has_oops = arg_has_oops;
 998           }
 999           //
1000           // src or dst could be j.l.Object when other is basic type array:
1001           //
1002           //   arraycopy(char[],0,Object*,0,size);
1003           //   arraycopy(Object*,0,char[],0,size);
1004           //
1005           // Don't add edges in such cases.
1006           //
1007           bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
1008                                        arg_has_oops && (i > TypeFunc::Parms);
1009 #ifdef ASSERT
1010           if (!(is_arraycopy ||
1011                 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(call) ||
1012                 (call->as_CallLeaf()->_name != NULL &&
1013                  (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
1014                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
1015                   strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
1016                   strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
1017                   strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
1018                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
1019                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
1020                   strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
1021                   strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
1022                   strcmp(call->as_CallLeaf()->_name, "encodeBlock") == 0 ||
1023                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
1024                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
1025                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
1026                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
1027                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
1028                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
1029                   strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1030                   strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1031                   strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1032                   strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1033                   strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1034                   strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1035                  ))) {
1036             call->dump();
1037             fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1038           }
1039 #endif
1040           // Always process arraycopy's destination object since
1041           // we need to add all possible edges to references in
1042           // source object.
1043           if (arg_esc >= PointsToNode::ArgEscape &&
1044               !arg_is_arraycopy_dest) {
1045             continue;
1046           }
1047           PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1048           if (call->is_ArrayCopy()) {
1049             ArrayCopyNode* ac = call->as_ArrayCopy();
1050             if (ac->is_clonebasic() ||
1051                 ac->is_arraycopy_validated() ||
1052                 ac->is_copyof_validated() ||
1053                 ac->is_copyofrange_validated()) {
1054               es = PointsToNode::NoEscape;
1055             }
1056           }
1057           set_escape_state(arg_ptn, es);
1058           if (arg_is_arraycopy_dest) {
1059             Node* src = call->in(TypeFunc::Parms);
1060             if (src->is_AddP()) {
1061               src = get_addp_base(src);
1062             }
1063             PointsToNode* src_ptn = ptnode_adr(src->_idx);
1064             assert(src_ptn != NULL, "should be registered");
1065             if (arg_ptn != src_ptn) {
1066               // Special arraycopy edge:
1067               // A destination object's field can't have the source object
1068               // as base since objects escape states are not related.
1069               // Only escape state of destination object's fields affects
1070               // escape state of fields in source object.
1071               add_arraycopy(call, es, src_ptn, arg_ptn);
1072             }
1073           }
1074         }
1075       }
1076       break;
1077     }
1078     case Op_CallStaticJava: {
1079       // For a static call, we know exactly what method is being called.
1080       // Use bytecode estimator to record the call's escape affects
1081 #ifdef ASSERT
1082       const char* name = call->as_CallStaticJava()->_name;
1083       assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1084 #endif
1085       ciMethod* meth = call->as_CallJava()->method();
1086       if ((meth != NULL) && meth->is_boxing_method()) {
1087         break; // Boxing methods do not modify any oops.
1088       }
1089       BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1090       // fall-through if not a Java method or no analyzer information
1091       if (call_analyzer != NULL) {
1092         PointsToNode* call_ptn = ptnode_adr(call->_idx);
1093         const TypeTuple* d = call->tf()->domain();
1094         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1095           const Type* at = d->field_at(i);
1096           int k = i - TypeFunc::Parms;
1097           Node* arg = call->in(i);
1098           PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1099           if (at->isa_ptr() != NULL &&
1100               call_analyzer->is_arg_returned(k)) {
1101             // The call returns arguments.
1102             if (call_ptn != NULL) { // Is call's result used?
1103               assert(call_ptn->is_LocalVar(), "node should be registered");
1104               assert(arg_ptn != NULL, "node should be registered");
1105               add_edge(call_ptn, arg_ptn);
1106             }
1107           }
1108           if (at->isa_oopptr() != NULL &&
1109               arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1110             if (!call_analyzer->is_arg_stack(k)) {
1111               // The argument global escapes
1112               set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1113             } else {
1114               set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1115               if (!call_analyzer->is_arg_local(k)) {
1116                 // The argument itself doesn't escape, but any fields might
1117                 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1118               }
1119             }
1120           }
1121         }
1122         if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1123           // The call returns arguments.
1124           assert(call_ptn->edge_count() > 0, "sanity");
1125           if (!call_analyzer->is_return_local()) {
1126             // Returns also unknown object.
1127             add_edge(call_ptn, phantom_obj);
1128           }
1129         }
1130         break;
1131       }
1132     }
1133     default: {
1134       // Fall-through here if not a Java method or no analyzer information
1135       // or some other type of call, assume the worst case: all arguments
1136       // globally escape.
1137       const TypeTuple* d = call->tf()->domain();
1138       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1139         const Type* at = d->field_at(i);
1140         if (at->isa_oopptr() != NULL) {
1141           Node* arg = call->in(i);
1142           if (arg->is_AddP()) {
1143             arg = get_addp_base(arg);
1144           }
1145           assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1146           set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1147         }
1148       }
1149     }
1150   }
1151 }
1152 
1153 
1154 // Finish Graph construction.
1155 bool ConnectionGraph::complete_connection_graph(
1156                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1157                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1158                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1159                          GrowableArray<FieldNode*>&      oop_fields_worklist) {
1160   // Normally only 1-3 passes needed to build Connection Graph depending
1161   // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1162   // Set limit to 20 to catch situation when something did go wrong and
1163   // bailout Escape Analysis.
1164   // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1165 #define CG_BUILD_ITER_LIMIT 20
1166 
1167   // Propagate GlobalEscape and ArgEscape escape states and check that
1168   // we still have non-escaping objects. The method pushs on _worklist
1169   // Field nodes which reference phantom_object.
1170   if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1171     return false; // Nothing to do.
1172   }
1173   // Now propagate references to all JavaObject nodes.
1174   int java_objects_length = java_objects_worklist.length();
1175   elapsedTimer time;
1176   bool timeout = false;
1177   int new_edges = 1;
1178   int iterations = 0;
1179   do {
1180     while ((new_edges > 0) &&
1181            (iterations++ < CG_BUILD_ITER_LIMIT)) {
1182       double start_time = time.seconds();
1183       time.start();
1184       new_edges = 0;
1185       // Propagate references to phantom_object for nodes pushed on _worklist
1186       // by find_non_escaped_objects() and find_field_value().
1187       new_edges += add_java_object_edges(phantom_obj, false);
1188       for (int next = 0; next < java_objects_length; ++next) {
1189         JavaObjectNode* ptn = java_objects_worklist.at(next);
1190         new_edges += add_java_object_edges(ptn, true);
1191 
1192 #define SAMPLE_SIZE 4
1193         if ((next % SAMPLE_SIZE) == 0) {
1194           // Each 4 iterations calculate how much time it will take
1195           // to complete graph construction.
1196           time.stop();
1197           // Poll for requests from shutdown mechanism to quiesce compiler
1198           // because Connection graph construction may take long time.
1199           CompileBroker::maybe_block();
1200           double stop_time = time.seconds();
1201           double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1202           double time_until_end = time_per_iter * (double)(java_objects_length - next);
1203           if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1204             timeout = true;
1205             break; // Timeout
1206           }
1207           start_time = stop_time;
1208           time.start();
1209         }
1210 #undef SAMPLE_SIZE
1211 
1212       }
1213       if (timeout) break;
1214       if (new_edges > 0) {
1215         // Update escape states on each iteration if graph was updated.
1216         if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1217           return false; // Nothing to do.
1218         }
1219       }
1220       time.stop();
1221       if (time.seconds() >= EscapeAnalysisTimeout) {
1222         timeout = true;
1223         break;
1224       }
1225     }
1226     if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1227       time.start();
1228       // Find fields which have unknown value.
1229       int fields_length = oop_fields_worklist.length();
1230       for (int next = 0; next < fields_length; next++) {
1231         FieldNode* field = oop_fields_worklist.at(next);
1232         if (field->edge_count() == 0) {
1233           new_edges += find_field_value(field);
1234           // This code may added new edges to phantom_object.
1235           // Need an other cycle to propagate references to phantom_object.
1236         }
1237       }
1238       time.stop();
1239       if (time.seconds() >= EscapeAnalysisTimeout) {
1240         timeout = true;
1241         break;
1242       }
1243     } else {
1244       new_edges = 0; // Bailout
1245     }
1246   } while (new_edges > 0);
1247 
1248   // Bailout if passed limits.
1249   if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1250     Compile* C = _compile;
1251     if (C->log() != NULL) {
1252       C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1253       C->log()->text("%s", timeout ? "time" : "iterations");
1254       C->log()->end_elem(" limit'");
1255     }
1256     assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1257            time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1258     // Possible infinite build_connection_graph loop,
1259     // bailout (no changes to ideal graph were made).
1260     return false;
1261   }
1262 #ifdef ASSERT
1263   if (Verbose && PrintEscapeAnalysis) {
1264     tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1265                   iterations, nodes_size(), ptnodes_worklist.length());
1266   }
1267 #endif
1268 
1269 #undef CG_BUILD_ITER_LIMIT
1270 
1271   // Find fields initialized by NULL for non-escaping Allocations.
1272   int non_escaped_length = non_escaped_worklist.length();
1273   for (int next = 0; next < non_escaped_length; next++) {
1274     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1275     PointsToNode::EscapeState es = ptn->escape_state();
1276     assert(es <= PointsToNode::ArgEscape, "sanity");
1277     if (es == PointsToNode::NoEscape) {
1278       if (find_init_values(ptn, null_obj, _igvn) > 0) {
1279         // Adding references to NULL object does not change escape states
1280         // since it does not escape. Also no fields are added to NULL object.
1281         add_java_object_edges(null_obj, false);
1282       }
1283     }
1284     Node* n = ptn->ideal_node();
1285     if (n->is_Allocate()) {
1286       // The object allocated by this Allocate node will never be
1287       // seen by an other thread. Mark it so that when it is
1288       // expanded no MemBarStoreStore is added.
1289       InitializeNode* ini = n->as_Allocate()->initialization();
1290       if (ini != NULL)
1291         ini->set_does_not_escape();
1292     }
1293   }
1294   return true; // Finished graph construction.
1295 }
1296 
1297 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1298 // and check that we still have non-escaping java objects.
1299 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1300                                                GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1301   GrowableArray<PointsToNode*> escape_worklist;
1302   // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1303   int ptnodes_length = ptnodes_worklist.length();
1304   for (int next = 0; next < ptnodes_length; ++next) {
1305     PointsToNode* ptn = ptnodes_worklist.at(next);
1306     if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1307         ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1308       escape_worklist.push(ptn);
1309     }
1310   }
1311   // Set escape states to referenced nodes (edges list).
1312   while (escape_worklist.length() > 0) {
1313     PointsToNode* ptn = escape_worklist.pop();
1314     PointsToNode::EscapeState es  = ptn->escape_state();
1315     PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1316     if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1317         es >= PointsToNode::ArgEscape) {
1318       // GlobalEscape or ArgEscape state of field means it has unknown value.
1319       if (add_edge(ptn, phantom_obj)) {
1320         // New edge was added
1321         add_field_uses_to_worklist(ptn->as_Field());
1322       }
1323     }
1324     for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1325       PointsToNode* e = i.get();
1326       if (e->is_Arraycopy()) {
1327         assert(ptn->arraycopy_dst(), "sanity");
1328         // Propagate only fields escape state through arraycopy edge.
1329         if (e->fields_escape_state() < field_es) {
1330           set_fields_escape_state(e, field_es);
1331           escape_worklist.push(e);
1332         }
1333       } else if (es >= field_es) {
1334         // fields_escape_state is also set to 'es' if it is less than 'es'.
1335         if (e->escape_state() < es) {
1336           set_escape_state(e, es);
1337           escape_worklist.push(e);
1338         }
1339       } else {
1340         // Propagate field escape state.
1341         bool es_changed = false;
1342         if (e->fields_escape_state() < field_es) {
1343           set_fields_escape_state(e, field_es);
1344           es_changed = true;
1345         }
1346         if ((e->escape_state() < field_es) &&
1347             e->is_Field() && ptn->is_JavaObject() &&
1348             e->as_Field()->is_oop()) {
1349           // Change escape state of referenced fields.
1350           set_escape_state(e, field_es);
1351           es_changed = true;
1352         } else if (e->escape_state() < es) {
1353           set_escape_state(e, es);
1354           es_changed = true;
1355         }
1356         if (es_changed) {
1357           escape_worklist.push(e);
1358         }
1359       }
1360     }
1361   }
1362   // Remove escaped objects from non_escaped list.
1363   for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1364     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1365     if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1366       non_escaped_worklist.delete_at(next);
1367     }
1368     if (ptn->escape_state() == PointsToNode::NoEscape) {
1369       // Find fields in non-escaped allocations which have unknown value.
1370       find_init_values(ptn, phantom_obj, NULL);
1371     }
1372   }
1373   return (non_escaped_worklist.length() > 0);
1374 }
1375 
1376 // Add all references to JavaObject node by walking over all uses.
1377 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1378   int new_edges = 0;
1379   if (populate_worklist) {
1380     // Populate _worklist by uses of jobj's uses.
1381     for (UseIterator i(jobj); i.has_next(); i.next()) {
1382       PointsToNode* use = i.get();
1383       if (use->is_Arraycopy())
1384         continue;
1385       add_uses_to_worklist(use);
1386       if (use->is_Field() && use->as_Field()->is_oop()) {
1387         // Put on worklist all field's uses (loads) and
1388         // related field nodes (same base and offset).
1389         add_field_uses_to_worklist(use->as_Field());
1390       }
1391     }
1392   }
1393   for (int l = 0; l < _worklist.length(); l++) {
1394     PointsToNode* use = _worklist.at(l);
1395     if (PointsToNode::is_base_use(use)) {
1396       // Add reference from jobj to field and from field to jobj (field's base).
1397       use = PointsToNode::get_use_node(use)->as_Field();
1398       if (add_base(use->as_Field(), jobj)) {
1399         new_edges++;
1400       }
1401       continue;
1402     }
1403     assert(!use->is_JavaObject(), "sanity");
1404     if (use->is_Arraycopy()) {
1405       if (jobj == null_obj) // NULL object does not have field edges
1406         continue;
1407       // Added edge from Arraycopy node to arraycopy's source java object
1408       if (add_edge(use, jobj)) {
1409         jobj->set_arraycopy_src();
1410         new_edges++;
1411       }
1412       // and stop here.
1413       continue;
1414     }
1415     if (!add_edge(use, jobj))
1416       continue; // No new edge added, there was such edge already.
1417     new_edges++;
1418     if (use->is_LocalVar()) {
1419       add_uses_to_worklist(use);
1420       if (use->arraycopy_dst()) {
1421         for (EdgeIterator i(use); i.has_next(); i.next()) {
1422           PointsToNode* e = i.get();
1423           if (e->is_Arraycopy()) {
1424             if (jobj == null_obj) // NULL object does not have field edges
1425               continue;
1426             // Add edge from arraycopy's destination java object to Arraycopy node.
1427             if (add_edge(jobj, e)) {
1428               new_edges++;
1429               jobj->set_arraycopy_dst();
1430             }
1431           }
1432         }
1433       }
1434     } else {
1435       // Added new edge to stored in field values.
1436       // Put on worklist all field's uses (loads) and
1437       // related field nodes (same base and offset).
1438       add_field_uses_to_worklist(use->as_Field());
1439     }
1440   }
1441   _worklist.clear();
1442   _in_worklist.Reset();
1443   return new_edges;
1444 }
1445 
1446 // Put on worklist all related field nodes.
1447 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1448   assert(field->is_oop(), "sanity");
1449   int offset = field->offset();
1450   add_uses_to_worklist(field);
1451   // Loop over all bases of this field and push on worklist Field nodes
1452   // with the same offset and base (since they may reference the same field).
1453   for (BaseIterator i(field); i.has_next(); i.next()) {
1454     PointsToNode* base = i.get();
1455     add_fields_to_worklist(field, base);
1456     // Check if the base was source object of arraycopy and go over arraycopy's
1457     // destination objects since values stored to a field of source object are
1458     // accessable by uses (loads) of fields of destination objects.
1459     if (base->arraycopy_src()) {
1460       for (UseIterator j(base); j.has_next(); j.next()) {
1461         PointsToNode* arycp = j.get();
1462         if (arycp->is_Arraycopy()) {
1463           for (UseIterator k(arycp); k.has_next(); k.next()) {
1464             PointsToNode* abase = k.get();
1465             if (abase->arraycopy_dst() && abase != base) {
1466               // Look for the same arraycopy reference.
1467               add_fields_to_worklist(field, abase);
1468             }
1469           }
1470         }
1471       }
1472     }
1473   }
1474 }
1475 
1476 // Put on worklist all related field nodes.
1477 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1478   int offset = field->offset();
1479   if (base->is_LocalVar()) {
1480     for (UseIterator j(base); j.has_next(); j.next()) {
1481       PointsToNode* f = j.get();
1482       if (PointsToNode::is_base_use(f)) { // Field
1483         f = PointsToNode::get_use_node(f);
1484         if (f == field || !f->as_Field()->is_oop())
1485           continue;
1486         int offs = f->as_Field()->offset();
1487         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1488           add_to_worklist(f);
1489         }
1490       }
1491     }
1492   } else {
1493     assert(base->is_JavaObject(), "sanity");
1494     if (// Skip phantom_object since it is only used to indicate that
1495         // this field's content globally escapes.
1496         (base != phantom_obj) &&
1497         // NULL object node does not have fields.
1498         (base != null_obj)) {
1499       for (EdgeIterator i(base); i.has_next(); i.next()) {
1500         PointsToNode* f = i.get();
1501         // Skip arraycopy edge since store to destination object field
1502         // does not update value in source object field.
1503         if (f->is_Arraycopy()) {
1504           assert(base->arraycopy_dst(), "sanity");
1505           continue;
1506         }
1507         if (f == field || !f->as_Field()->is_oop())
1508           continue;
1509         int offs = f->as_Field()->offset();
1510         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1511           add_to_worklist(f);
1512         }
1513       }
1514     }
1515   }
1516 }
1517 
1518 // Find fields which have unknown value.
1519 int ConnectionGraph::find_field_value(FieldNode* field) {
1520   // Escaped fields should have init value already.
1521   assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1522   int new_edges = 0;
1523   for (BaseIterator i(field); i.has_next(); i.next()) {
1524     PointsToNode* base = i.get();
1525     if (base->is_JavaObject()) {
1526       // Skip Allocate's fields which will be processed later.
1527       if (base->ideal_node()->is_Allocate())
1528         return 0;
1529       assert(base == null_obj, "only NULL ptr base expected here");
1530     }
1531   }
1532   if (add_edge(field, phantom_obj)) {
1533     // New edge was added
1534     new_edges++;
1535     add_field_uses_to_worklist(field);
1536   }
1537   return new_edges;
1538 }
1539 
1540 // Find fields initializing values for allocations.
1541 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1542   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1543   int new_edges = 0;
1544   Node* alloc = pta->ideal_node();
1545   if (init_val == phantom_obj) {
1546     // Do nothing for Allocate nodes since its fields values are
1547     // "known" unless they are initialized by arraycopy/clone.
1548     if (alloc->is_Allocate() && !pta->arraycopy_dst())
1549       return 0;
1550     assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1551 #ifdef ASSERT
1552     if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1553       const char* name = alloc->as_CallStaticJava()->_name;
1554       assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1555     }
1556 #endif
1557     // Non-escaped allocation returned from Java or runtime call have
1558     // unknown values in fields.
1559     for (EdgeIterator i(pta); i.has_next(); i.next()) {
1560       PointsToNode* field = i.get();
1561       if (field->is_Field() && field->as_Field()->is_oop()) {
1562         if (add_edge(field, phantom_obj)) {
1563           // New edge was added
1564           new_edges++;
1565           add_field_uses_to_worklist(field->as_Field());
1566         }
1567       }
1568     }
1569     return new_edges;
1570   }
1571   assert(init_val == null_obj, "sanity");
1572   // Do nothing for Call nodes since its fields values are unknown.
1573   if (!alloc->is_Allocate())
1574     return 0;
1575 
1576   InitializeNode* ini = alloc->as_Allocate()->initialization();
1577   bool visited_bottom_offset = false;
1578   GrowableArray<int> offsets_worklist;
1579 
1580   // Check if an oop field's initializing value is recorded and add
1581   // a corresponding NULL if field's value if it is not recorded.
1582   // Connection Graph does not record a default initialization by NULL
1583   // captured by Initialize node.
1584   //
1585   for (EdgeIterator i(pta); i.has_next(); i.next()) {
1586     PointsToNode* field = i.get(); // Field (AddP)
1587     if (!field->is_Field() || !field->as_Field()->is_oop())
1588       continue; // Not oop field
1589     int offset = field->as_Field()->offset();
1590     if (offset == Type::OffsetBot) {
1591       if (!visited_bottom_offset) {
1592         // OffsetBot is used to reference array's element,
1593         // always add reference to NULL to all Field nodes since we don't
1594         // known which element is referenced.
1595         if (add_edge(field, null_obj)) {
1596           // New edge was added
1597           new_edges++;
1598           add_field_uses_to_worklist(field->as_Field());
1599           visited_bottom_offset = true;
1600         }
1601       }
1602     } else {
1603       // Check only oop fields.
1604       const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1605       if (adr_type->isa_rawptr()) {
1606 #ifdef ASSERT
1607         // Raw pointers are used for initializing stores so skip it
1608         // since it should be recorded already
1609         Node* base = get_addp_base(field->ideal_node());
1610         assert(adr_type->isa_rawptr() && base->is_Proj() &&
1611                (base->in(0) == alloc),"unexpected pointer type");
1612 #endif
1613         continue;
1614       }
1615       if (!offsets_worklist.contains(offset)) {
1616         offsets_worklist.append(offset);
1617         Node* value = NULL;
1618         if (ini != NULL) {
1619           // StoreP::memory_type() == T_ADDRESS
1620           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1621           Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1622           // Make sure initializing store has the same type as this AddP.
1623           // This AddP may reference non existing field because it is on a
1624           // dead branch of bimorphic call which is not eliminated yet.
1625           if (store != NULL && store->is_Store() &&
1626               store->as_Store()->memory_type() == ft) {
1627             value = store->in(MemNode::ValueIn);
1628 #ifdef ASSERT
1629             if (VerifyConnectionGraph) {
1630               // Verify that AddP already points to all objects the value points to.
1631               PointsToNode* val = ptnode_adr(value->_idx);
1632               assert((val != NULL), "should be processed already");
1633               PointsToNode* missed_obj = NULL;
1634               if (val->is_JavaObject()) {
1635                 if (!field->points_to(val->as_JavaObject())) {
1636                   missed_obj = val;
1637                 }
1638               } else {
1639                 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1640                   tty->print_cr("----------init store has invalid value -----");
1641                   store->dump();
1642                   val->dump();
1643                   assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1644                 }
1645                 for (EdgeIterator j(val); j.has_next(); j.next()) {
1646                   PointsToNode* obj = j.get();
1647                   if (obj->is_JavaObject()) {
1648                     if (!field->points_to(obj->as_JavaObject())) {
1649                       missed_obj = obj;
1650                       break;
1651                     }
1652                   }
1653                 }
1654               }
1655               if (missed_obj != NULL) {
1656                 tty->print_cr("----------field---------------------------------");
1657                 field->dump();
1658                 tty->print_cr("----------missed referernce to object-----------");
1659                 missed_obj->dump();
1660                 tty->print_cr("----------object referernced by init store -----");
1661                 store->dump();
1662                 val->dump();
1663                 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1664               }
1665             }
1666 #endif
1667           } else {
1668             // There could be initializing stores which follow allocation.
1669             // For example, a volatile field store is not collected
1670             // by Initialize node.
1671             //
1672             // Need to check for dependent loads to separate such stores from
1673             // stores which follow loads. For now, add initial value NULL so
1674             // that compare pointers optimization works correctly.
1675           }
1676         }
1677         if (value == NULL) {
1678           // A field's initializing value was not recorded. Add NULL.
1679           if (add_edge(field, null_obj)) {
1680             // New edge was added
1681             new_edges++;
1682             add_field_uses_to_worklist(field->as_Field());
1683           }
1684         }
1685       }
1686     }
1687   }
1688   return new_edges;
1689 }
1690 
1691 // Adjust scalar_replaceable state after Connection Graph is built.
1692 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1693   // Search for non-escaping objects which are not scalar replaceable
1694   // and mark them to propagate the state to referenced objects.
1695 
1696   // 1. An object is not scalar replaceable if the field into which it is
1697   // stored has unknown offset (stored into unknown element of an array).
1698   //
1699   for (UseIterator i(jobj); i.has_next(); i.next()) {
1700     PointsToNode* use = i.get();
1701     if (use->is_Arraycopy()) {
1702       continue;
1703     }
1704     if (use->is_Field()) {
1705       FieldNode* field = use->as_Field();
1706       assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1707       if (field->offset() == Type::OffsetBot) {
1708         jobj->set_scalar_replaceable(false);
1709         return;
1710       }
1711       // 2. An object is not scalar replaceable if the field into which it is
1712       // stored has multiple bases one of which is null.
1713       if (field->base_count() > 1) {
1714         for (BaseIterator i(field); i.has_next(); i.next()) {
1715           PointsToNode* base = i.get();
1716           if (base == null_obj) {
1717             jobj->set_scalar_replaceable(false);
1718             return;
1719           }
1720         }
1721       }
1722     }
1723     assert(use->is_Field() || use->is_LocalVar(), "sanity");
1724     // 3. An object is not scalar replaceable if it is merged with other objects.
1725     for (EdgeIterator j(use); j.has_next(); j.next()) {
1726       PointsToNode* ptn = j.get();
1727       if (ptn->is_JavaObject() && ptn != jobj) {
1728         // Mark all objects.
1729         jobj->set_scalar_replaceable(false);
1730          ptn->set_scalar_replaceable(false);
1731       }
1732     }
1733     if (!jobj->scalar_replaceable()) {
1734       return;
1735     }
1736   }
1737 
1738   for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1739     if (j.get()->is_Arraycopy()) {
1740       continue;
1741     }
1742 
1743     // Non-escaping object node should point only to field nodes.
1744     FieldNode* field = j.get()->as_Field();
1745     int offset = field->as_Field()->offset();
1746 
1747     // 4. An object is not scalar replaceable if it has a field with unknown
1748     // offset (array's element is accessed in loop).
1749     if (offset == Type::OffsetBot) {
1750       jobj->set_scalar_replaceable(false);
1751       return;
1752     }
1753     // 5. Currently an object is not scalar replaceable if a LoadStore node
1754     // access its field since the field value is unknown after it.
1755     //
1756     Node* n = field->ideal_node();
1757 
1758     // Test for an unsafe access that was parsed as maybe off heap
1759     // (with a CheckCastPP to raw memory).
1760     assert(n->is_AddP(), "expect an address computation");
1761     if (n->in(AddPNode::Base)->is_top() &&
1762         n->in(AddPNode::Address)->Opcode() == Op_CheckCastPP) {
1763       assert(n->in(AddPNode::Address)->bottom_type()->isa_rawptr(), "raw address so raw cast expected");
1764       assert(_igvn->type(n->in(AddPNode::Address)->in(1))->isa_oopptr(), "cast pattern at unsafe access expected");
1765       jobj->set_scalar_replaceable(false);
1766       return;
1767     }
1768 
1769     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1770       if (n->fast_out(i)->is_LoadStore()) {
1771         jobj->set_scalar_replaceable(false);
1772         return;
1773       }
1774     }
1775 
1776     // 6. Or the address may point to more then one object. This may produce
1777     // the false positive result (set not scalar replaceable)
1778     // since the flow-insensitive escape analysis can't separate
1779     // the case when stores overwrite the field's value from the case
1780     // when stores happened on different control branches.
1781     //
1782     // Note: it will disable scalar replacement in some cases:
1783     //
1784     //    Point p[] = new Point[1];
1785     //    p[0] = new Point(); // Will be not scalar replaced
1786     //
1787     // but it will save us from incorrect optimizations in next cases:
1788     //
1789     //    Point p[] = new Point[1];
1790     //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
1791     //
1792     if (field->base_count() > 1) {
1793       for (BaseIterator i(field); i.has_next(); i.next()) {
1794         PointsToNode* base = i.get();
1795         // Don't take into account LocalVar nodes which
1796         // may point to only one object which should be also
1797         // this field's base by now.
1798         if (base->is_JavaObject() && base != jobj) {
1799           // Mark all bases.
1800           jobj->set_scalar_replaceable(false);
1801           base->set_scalar_replaceable(false);
1802         }
1803       }
1804     }
1805   }
1806 }
1807 
1808 #ifdef ASSERT
1809 void ConnectionGraph::verify_connection_graph(
1810                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1811                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1812                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1813                          GrowableArray<Node*>& addp_worklist) {
1814   // Verify that graph is complete - no new edges could be added.
1815   int java_objects_length = java_objects_worklist.length();
1816   int non_escaped_length  = non_escaped_worklist.length();
1817   int new_edges = 0;
1818   for (int next = 0; next < java_objects_length; ++next) {
1819     JavaObjectNode* ptn = java_objects_worklist.at(next);
1820     new_edges += add_java_object_edges(ptn, true);
1821   }
1822   assert(new_edges == 0, "graph was not complete");
1823   // Verify that escape state is final.
1824   int length = non_escaped_worklist.length();
1825   find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1826   assert((non_escaped_length == non_escaped_worklist.length()) &&
1827          (non_escaped_length == length) &&
1828          (_worklist.length() == 0), "escape state was not final");
1829 
1830   // Verify fields information.
1831   int addp_length = addp_worklist.length();
1832   for (int next = 0; next < addp_length; ++next ) {
1833     Node* n = addp_worklist.at(next);
1834     FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1835     if (field->is_oop()) {
1836       // Verify that field has all bases
1837       Node* base = get_addp_base(n);
1838       PointsToNode* ptn = ptnode_adr(base->_idx);
1839       if (ptn->is_JavaObject()) {
1840         assert(field->has_base(ptn->as_JavaObject()), "sanity");
1841       } else {
1842         assert(ptn->is_LocalVar(), "sanity");
1843         for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1844           PointsToNode* e = i.get();
1845           if (e->is_JavaObject()) {
1846             assert(field->has_base(e->as_JavaObject()), "sanity");
1847           }
1848         }
1849       }
1850       // Verify that all fields have initializing values.
1851       if (field->edge_count() == 0) {
1852         tty->print_cr("----------field does not have references----------");
1853         field->dump();
1854         for (BaseIterator i(field); i.has_next(); i.next()) {
1855           PointsToNode* base = i.get();
1856           tty->print_cr("----------field has next base---------------------");
1857           base->dump();
1858           if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1859             tty->print_cr("----------base has fields-------------------------");
1860             for (EdgeIterator j(base); j.has_next(); j.next()) {
1861               j.get()->dump();
1862             }
1863             tty->print_cr("----------base has references---------------------");
1864             for (UseIterator j(base); j.has_next(); j.next()) {
1865               j.get()->dump();
1866             }
1867           }
1868         }
1869         for (UseIterator i(field); i.has_next(); i.next()) {
1870           i.get()->dump();
1871         }
1872         assert(field->edge_count() > 0, "sanity");
1873       }
1874     }
1875   }
1876 }
1877 #endif
1878 
1879 // Optimize ideal graph.
1880 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1881                                            GrowableArray<Node*>& storestore_worklist) {
1882   Compile* C = _compile;
1883   PhaseIterGVN* igvn = _igvn;
1884   if (EliminateLocks) {
1885     // Mark locks before changing ideal graph.
1886     int cnt = C->macro_count();
1887     for( int i=0; i < cnt; i++ ) {
1888       Node *n = C->macro_node(i);
1889       if (n->is_AbstractLock()) { // Lock and Unlock nodes
1890         AbstractLockNode* alock = n->as_AbstractLock();
1891         if (!alock->is_non_esc_obj()) {
1892           if (not_global_escape(alock->obj_node())) {
1893             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1894             // The lock could be marked eliminated by lock coarsening
1895             // code during first IGVN before EA. Replace coarsened flag
1896             // to eliminate all associated locks/unlocks.
1897 #ifdef ASSERT
1898             alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1899 #endif
1900             alock->set_non_esc_obj();
1901           }
1902         }
1903       }
1904     }
1905   }
1906 
1907   if (OptimizePtrCompare) {
1908     // Add ConI(#CC_GT) and ConI(#CC_EQ).
1909     _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1910     _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1911     // Optimize objects compare.
1912     while (ptr_cmp_worklist.length() != 0) {
1913       Node *n = ptr_cmp_worklist.pop();
1914       Node *res = optimize_ptr_compare(n);
1915       if (res != NULL) {
1916 #ifndef PRODUCT
1917         if (PrintOptimizePtrCompare) {
1918           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"));
1919           if (Verbose) {
1920             n->dump(1);
1921           }
1922         }
1923 #endif
1924         igvn->replace_node(n, res);
1925       }
1926     }
1927     // cleanup
1928     if (_pcmp_neq->outcnt() == 0)
1929       igvn->hash_delete(_pcmp_neq);
1930     if (_pcmp_eq->outcnt()  == 0)
1931       igvn->hash_delete(_pcmp_eq);
1932   }
1933 
1934   // For MemBarStoreStore nodes added in library_call.cpp, check
1935   // escape status of associated AllocateNode and optimize out
1936   // MemBarStoreStore node if the allocated object never escapes.
1937   while (storestore_worklist.length() != 0) {
1938     Node *n = storestore_worklist.pop();
1939     MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1940     Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1941     assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1942     if (not_global_escape(alloc)) {
1943       MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1944       mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1945       mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1946       igvn->register_new_node_with_optimizer(mb);
1947       igvn->replace_node(storestore, mb);
1948     }
1949   }
1950 }
1951 
1952 // Optimize objects compare.
1953 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1954   assert(OptimizePtrCompare, "sanity");
1955   PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1956   PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1957   JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1958   JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1959   assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1960   assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1961 
1962   // Check simple cases first.
1963   if (jobj1 != NULL) {
1964     if (jobj1->escape_state() == PointsToNode::NoEscape) {
1965       if (jobj1 == jobj2) {
1966         // Comparing the same not escaping object.
1967         return _pcmp_eq;
1968       }
1969       Node* obj = jobj1->ideal_node();
1970       // Comparing not escaping allocation.
1971       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1972           !ptn2->points_to(jobj1)) {
1973         return _pcmp_neq; // This includes nullness check.
1974       }
1975     }
1976   }
1977   if (jobj2 != NULL) {
1978     if (jobj2->escape_state() == PointsToNode::NoEscape) {
1979       Node* obj = jobj2->ideal_node();
1980       // Comparing not escaping allocation.
1981       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1982           !ptn1->points_to(jobj2)) {
1983         return _pcmp_neq; // This includes nullness check.
1984       }
1985     }
1986   }
1987   if (jobj1 != NULL && jobj1 != phantom_obj &&
1988       jobj2 != NULL && jobj2 != phantom_obj &&
1989       jobj1->ideal_node()->is_Con() &&
1990       jobj2->ideal_node()->is_Con()) {
1991     // Klass or String constants compare. Need to be careful with
1992     // compressed pointers - compare types of ConN and ConP instead of nodes.
1993     const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1994     const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1995     if (t1->make_ptr() == t2->make_ptr()) {
1996       return _pcmp_eq;
1997     } else {
1998       return _pcmp_neq;
1999     }
2000   }
2001   if (ptn1->meet(ptn2)) {
2002     return NULL; // Sets are not disjoint
2003   }
2004 
2005   // Sets are disjoint.
2006   bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
2007   bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
2008   bool set1_has_null_ptr    = ptn1->points_to(null_obj);
2009   bool set2_has_null_ptr    = ptn2->points_to(null_obj);
2010   if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
2011       (set2_has_unknown_ptr && set1_has_null_ptr)) {
2012     // Check nullness of unknown object.
2013     return NULL;
2014   }
2015 
2016   // Disjointness by itself is not sufficient since
2017   // alias analysis is not complete for escaped objects.
2018   // Disjoint sets are definitely unrelated only when
2019   // at least one set has only not escaping allocations.
2020   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
2021     if (ptn1->non_escaping_allocation()) {
2022       return _pcmp_neq;
2023     }
2024   }
2025   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
2026     if (ptn2->non_escaping_allocation()) {
2027       return _pcmp_neq;
2028     }
2029   }
2030   return NULL;
2031 }
2032 
2033 // Connection Graph constuction functions.
2034 
2035 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
2036   PointsToNode* ptadr = _nodes.at(n->_idx);
2037   if (ptadr != NULL) {
2038     assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
2039     return;
2040   }
2041   Compile* C = _compile;
2042   ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2043   _nodes.at_put(n->_idx, ptadr);
2044 }
2045 
2046 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2047   PointsToNode* ptadr = _nodes.at(n->_idx);
2048   if (ptadr != NULL) {
2049     assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2050     return;
2051   }
2052   Compile* C = _compile;
2053   ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2054   _nodes.at_put(n->_idx, ptadr);
2055 }
2056 
2057 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2058   PointsToNode* ptadr = _nodes.at(n->_idx);
2059   if (ptadr != NULL) {
2060     assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2061     return;
2062   }
2063   bool unsafe = false;
2064   bool is_oop = is_oop_field(n, offset, &unsafe);
2065   if (unsafe) {
2066     es = PointsToNode::GlobalEscape;
2067   }
2068   Compile* C = _compile;
2069   FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2070   _nodes.at_put(n->_idx, field);
2071 }
2072 
2073 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2074                                     PointsToNode* src, PointsToNode* dst) {
2075   assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2076   assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2077   PointsToNode* ptadr = _nodes.at(n->_idx);
2078   if (ptadr != NULL) {
2079     assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2080     return;
2081   }
2082   Compile* C = _compile;
2083   ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2084   _nodes.at_put(n->_idx, ptadr);
2085   // Add edge from arraycopy node to source object.
2086   (void)add_edge(ptadr, src);
2087   src->set_arraycopy_src();
2088   // Add edge from destination object to arraycopy node.
2089   (void)add_edge(dst, ptadr);
2090   dst->set_arraycopy_dst();
2091 }
2092 
2093 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2094   const Type* adr_type = n->as_AddP()->bottom_type();
2095   BasicType bt = T_INT;
2096   if (offset == Type::OffsetBot) {
2097     // Check only oop fields.
2098     if (!adr_type->isa_aryptr() ||
2099         (adr_type->isa_aryptr()->klass() == NULL) ||
2100          adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2101       // OffsetBot is used to reference array's element. Ignore first AddP.
2102       if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2103         bt = T_OBJECT;
2104       }
2105     }
2106   } else if (offset != oopDesc::klass_offset_in_bytes()) {
2107     if (adr_type->isa_instptr()) {
2108       ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2109       if (field != NULL) {
2110         bt = field->layout_type();
2111       } else {
2112         // Check for unsafe oop field access
2113         if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2114             n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2115             n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2116           bt = T_OBJECT;
2117           (*unsafe) = true;
2118         }
2119       }
2120     } else if (adr_type->isa_aryptr()) {
2121       if (offset == arrayOopDesc::length_offset_in_bytes()) {
2122         // Ignore array length load.
2123       } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2124         // Ignore first AddP.
2125       } else {
2126         const Type* elemtype = adr_type->isa_aryptr()->elem();
2127         bt = elemtype->array_element_basic_type();
2128       }
2129     } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2130       // Allocation initialization, ThreadLocal field access, unsafe access
2131       if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2132           n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2133           n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2134         bt = T_OBJECT;
2135       }
2136     }
2137   }
2138   return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2139 }
2140 
2141 // Returns unique pointed java object or NULL.
2142 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2143   assert(!_collecting, "should not call when contructed graph");
2144   // If the node was created after the escape computation we can't answer.
2145   uint idx = n->_idx;
2146   if (idx >= nodes_size()) {
2147     return NULL;
2148   }
2149   PointsToNode* ptn = ptnode_adr(idx);
2150   if (ptn->is_JavaObject()) {
2151     return ptn->as_JavaObject();
2152   }
2153   assert(ptn->is_LocalVar(), "sanity");
2154   // Check all java objects it points to.
2155   JavaObjectNode* jobj = NULL;
2156   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2157     PointsToNode* e = i.get();
2158     if (e->is_JavaObject()) {
2159       if (jobj == NULL) {
2160         jobj = e->as_JavaObject();
2161       } else if (jobj != e) {
2162         return NULL;
2163       }
2164     }
2165   }
2166   return jobj;
2167 }
2168 
2169 // Return true if this node points only to non-escaping allocations.
2170 bool PointsToNode::non_escaping_allocation() {
2171   if (is_JavaObject()) {
2172     Node* n = ideal_node();
2173     if (n->is_Allocate() || n->is_CallStaticJava()) {
2174       return (escape_state() == PointsToNode::NoEscape);
2175     } else {
2176       return false;
2177     }
2178   }
2179   assert(is_LocalVar(), "sanity");
2180   // Check all java objects it points to.
2181   for (EdgeIterator i(this); i.has_next(); i.next()) {
2182     PointsToNode* e = i.get();
2183     if (e->is_JavaObject()) {
2184       Node* n = e->ideal_node();
2185       if ((e->escape_state() != PointsToNode::NoEscape) ||
2186           !(n->is_Allocate() || n->is_CallStaticJava())) {
2187         return false;
2188       }
2189     }
2190   }
2191   return true;
2192 }
2193 
2194 // Return true if we know the node does not escape globally.
2195 bool ConnectionGraph::not_global_escape(Node *n) {
2196   assert(!_collecting, "should not call during graph construction");
2197   // If the node was created after the escape computation we can't answer.
2198   uint idx = n->_idx;
2199   if (idx >= nodes_size()) {
2200     return false;
2201   }
2202   PointsToNode* ptn = ptnode_adr(idx);
2203   PointsToNode::EscapeState es = ptn->escape_state();
2204   // If we have already computed a value, return it.
2205   if (es >= PointsToNode::GlobalEscape)
2206     return false;
2207   if (ptn->is_JavaObject()) {
2208     return true; // (es < PointsToNode::GlobalEscape);
2209   }
2210   assert(ptn->is_LocalVar(), "sanity");
2211   // Check all java objects it points to.
2212   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2213     if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2214       return false;
2215   }
2216   return true;
2217 }
2218 
2219 
2220 // Helper functions
2221 
2222 // Return true if this node points to specified node or nodes it points to.
2223 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2224   if (is_JavaObject()) {
2225     return (this == ptn);
2226   }
2227   assert(is_LocalVar() || is_Field(), "sanity");
2228   for (EdgeIterator i(this); i.has_next(); i.next()) {
2229     if (i.get() == ptn)
2230       return true;
2231   }
2232   return false;
2233 }
2234 
2235 // Return true if one node points to an other.
2236 bool PointsToNode::meet(PointsToNode* ptn) {
2237   if (this == ptn) {
2238     return true;
2239   } else if (ptn->is_JavaObject()) {
2240     return this->points_to(ptn->as_JavaObject());
2241   } else if (this->is_JavaObject()) {
2242     return ptn->points_to(this->as_JavaObject());
2243   }
2244   assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2245   int ptn_count =  ptn->edge_count();
2246   for (EdgeIterator i(this); i.has_next(); i.next()) {
2247     PointsToNode* this_e = i.get();
2248     for (int j = 0; j < ptn_count; j++) {
2249       if (this_e == ptn->edge(j))
2250         return true;
2251     }
2252   }
2253   return false;
2254 }
2255 
2256 #ifdef ASSERT
2257 // Return true if bases point to this java object.
2258 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2259   for (BaseIterator i(this); i.has_next(); i.next()) {
2260     if (i.get() == jobj)
2261       return true;
2262   }
2263   return false;
2264 }
2265 #endif
2266 
2267 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2268   const Type *adr_type = phase->type(adr);
2269   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2270       adr->in(AddPNode::Address)->is_Proj() &&
2271       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2272     // We are computing a raw address for a store captured by an Initialize
2273     // compute an appropriate address type. AddP cases #3 and #5 (see below).
2274     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2275     assert(offs != Type::OffsetBot ||
2276            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2277            "offset must be a constant or it is initialization of array");
2278     return offs;
2279   }
2280   const TypePtr *t_ptr = adr_type->isa_ptr();
2281   assert(t_ptr != NULL, "must be a pointer type");
2282   return t_ptr->offset();
2283 }
2284 
2285 Node* ConnectionGraph::get_addp_base(Node *addp) {
2286   assert(addp->is_AddP(), "must be AddP");
2287   //
2288   // AddP cases for Base and Address inputs:
2289   // case #1. Direct object's field reference:
2290   //     Allocate
2291   //       |
2292   //     Proj #5 ( oop result )
2293   //       |
2294   //     CheckCastPP (cast to instance type)
2295   //      | |
2296   //     AddP  ( base == address )
2297   //
2298   // case #2. Indirect object's field reference:
2299   //      Phi
2300   //       |
2301   //     CastPP (cast to instance type)
2302   //      | |
2303   //     AddP  ( base == address )
2304   //
2305   // case #3. Raw object's field reference for Initialize node:
2306   //      Allocate
2307   //        |
2308   //      Proj #5 ( oop result )
2309   //  top   |
2310   //     \  |
2311   //     AddP  ( base == top )
2312   //
2313   // case #4. Array's element reference:
2314   //   {CheckCastPP | CastPP}
2315   //     |  | |
2316   //     |  AddP ( array's element offset )
2317   //     |  |
2318   //     AddP ( array's offset )
2319   //
2320   // case #5. Raw object's field reference for arraycopy stub call:
2321   //          The inline_native_clone() case when the arraycopy stub is called
2322   //          after the allocation before Initialize and CheckCastPP nodes.
2323   //      Allocate
2324   //        |
2325   //      Proj #5 ( oop result )
2326   //       | |
2327   //       AddP  ( base == address )
2328   //
2329   // case #6. Constant Pool, ThreadLocal, CastX2P or
2330   //          Raw object's field reference:
2331   //      {ConP, ThreadLocal, CastX2P, raw Load}
2332   //  top   |
2333   //     \  |
2334   //     AddP  ( base == top )
2335   //
2336   // case #7. Klass's field reference.
2337   //      LoadKlass
2338   //       | |
2339   //       AddP  ( base == address )
2340   //
2341   // case #8. narrow Klass's field reference.
2342   //      LoadNKlass
2343   //       |
2344   //      DecodeN
2345   //       | |
2346   //       AddP  ( base == address )
2347   //
2348   // case #9. Mixed unsafe access
2349   //    {instance}
2350   //        |
2351   //      CheckCastPP (raw)
2352   //  top   |
2353   //     \  |
2354   //     AddP  ( base == top )
2355   //
2356   Node *base = addp->in(AddPNode::Base);
2357   if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
2358     base = addp->in(AddPNode::Address);
2359     while (base->is_AddP()) {
2360       // Case #6 (unsafe access) may have several chained AddP nodes.
2361       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2362       base = base->in(AddPNode::Address);
2363     }
2364     if (base->Opcode() == Op_CheckCastPP &&
2365         base->bottom_type()->isa_rawptr() &&
2366         _igvn->type(base->in(1))->isa_oopptr()) {
2367       base = base->in(1); // Case #9
2368     } else {
2369       Node* uncast_base = base->uncast();
2370       int opcode = uncast_base->Opcode();
2371       assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2372              opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2373              (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2374              (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2375     }
2376   }
2377   return base;
2378 }
2379 
2380 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2381   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2382   Node* addp2 = addp->raw_out(0);
2383   if (addp->outcnt() == 1 && addp2->is_AddP() &&
2384       addp2->in(AddPNode::Base) == n &&
2385       addp2->in(AddPNode::Address) == addp) {
2386     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2387     //
2388     // Find array's offset to push it on worklist first and
2389     // as result process an array's element offset first (pushed second)
2390     // to avoid CastPP for the array's offset.
2391     // Otherwise the inserted CastPP (LocalVar) will point to what
2392     // the AddP (Field) points to. Which would be wrong since
2393     // the algorithm expects the CastPP has the same point as
2394     // as AddP's base CheckCastPP (LocalVar).
2395     //
2396     //    ArrayAllocation
2397     //     |
2398     //    CheckCastPP
2399     //     |
2400     //    memProj (from ArrayAllocation CheckCastPP)
2401     //     |  ||
2402     //     |  ||   Int (element index)
2403     //     |  ||    |   ConI (log(element size))
2404     //     |  ||    |   /
2405     //     |  ||   LShift
2406     //     |  ||  /
2407     //     |  AddP (array's element offset)
2408     //     |  |
2409     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
2410     //     | / /
2411     //     AddP (array's offset)
2412     //      |
2413     //     Load/Store (memory operation on array's element)
2414     //
2415     return addp2;
2416   }
2417   return NULL;
2418 }
2419 
2420 //
2421 // Adjust the type and inputs of an AddP which computes the
2422 // address of a field of an instance
2423 //
2424 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2425   PhaseGVN* igvn = _igvn;
2426   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2427   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2428   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2429   if (t == NULL) {
2430     // We are computing a raw address for a store captured by an Initialize
2431     // compute an appropriate address type (cases #3 and #5).
2432     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2433     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2434     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2435     assert(offs != Type::OffsetBot, "offset must be a constant");
2436     t = base_t->add_offset(offs)->is_oopptr();
2437   }
2438   int inst_id =  base_t->instance_id();
2439   assert(!t->is_known_instance() || t->instance_id() == inst_id,
2440                              "old type must be non-instance or match new type");
2441 
2442   // The type 't' could be subclass of 'base_t'.
2443   // As result t->offset() could be large then base_t's size and it will
2444   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2445   // constructor verifies correctness of the offset.
2446   //
2447   // It could happened on subclass's branch (from the type profiling
2448   // inlining) which was not eliminated during parsing since the exactness
2449   // of the allocation type was not propagated to the subclass type check.
2450   //
2451   // Or the type 't' could be not related to 'base_t' at all.
2452   // It could happened when CHA type is different from MDO type on a dead path
2453   // (for example, from instanceof check) which is not collapsed during parsing.
2454   //
2455   // Do nothing for such AddP node and don't process its users since
2456   // this code branch will go away.
2457   //
2458   if (!t->is_known_instance() &&
2459       !base_t->klass()->is_subtype_of(t->klass())) {
2460      return false; // bail out
2461   }
2462   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2463   // Do NOT remove the next line: ensure a new alias index is allocated
2464   // for the instance type. Note: C++ will not remove it since the call
2465   // has side effect.
2466   int alias_idx = _compile->get_alias_index(tinst);
2467   igvn->set_type(addp, tinst);
2468   // record the allocation in the node map
2469   set_map(addp, get_map(base->_idx));
2470   // Set addp's Base and Address to 'base'.
2471   Node *abase = addp->in(AddPNode::Base);
2472   Node *adr   = addp->in(AddPNode::Address);
2473   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2474       adr->in(0)->_idx == (uint)inst_id) {
2475     // Skip AddP cases #3 and #5.
2476   } else {
2477     assert(!abase->is_top(), "sanity"); // AddP case #3
2478     if (abase != base) {
2479       igvn->hash_delete(addp);
2480       addp->set_req(AddPNode::Base, base);
2481       if (abase == adr) {
2482         addp->set_req(AddPNode::Address, base);
2483       } else {
2484         // AddP case #4 (adr is array's element offset AddP node)
2485 #ifdef ASSERT
2486         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2487         assert(adr->is_AddP() && atype != NULL &&
2488                atype->instance_id() == inst_id, "array's element offset should be processed first");
2489 #endif
2490       }
2491       igvn->hash_insert(addp);
2492     }
2493   }
2494   // Put on IGVN worklist since at least addp's type was changed above.
2495   record_for_optimizer(addp);
2496   return true;
2497 }
2498 
2499 //
2500 // Create a new version of orig_phi if necessary. Returns either the newly
2501 // created phi or an existing phi.  Sets create_new to indicate whether a new
2502 // phi was created.  Cache the last newly created phi in the node map.
2503 //
2504 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, bool &new_created) {
2505   Compile *C = _compile;
2506   PhaseGVN* igvn = _igvn;
2507   new_created = false;
2508   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2509   // nothing to do if orig_phi is bottom memory or matches alias_idx
2510   if (phi_alias_idx == alias_idx) {
2511     return orig_phi;
2512   }
2513   // Have we recently created a Phi for this alias index?
2514   PhiNode *result = get_map_phi(orig_phi->_idx);
2515   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2516     return result;
2517   }
2518   // Previous check may fail when the same wide memory Phi was split into Phis
2519   // for different memory slices. Search all Phis for this region.
2520   if (result != NULL) {
2521     Node* region = orig_phi->in(0);
2522     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2523       Node* phi = region->fast_out(i);
2524       if (phi->is_Phi() &&
2525           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2526         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2527         return phi->as_Phi();
2528       }
2529     }
2530   }
2531   if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2532     if (C->do_escape_analysis() == true && !C->failing()) {
2533       // Retry compilation without escape analysis.
2534       // If this is the first failure, the sentinel string will "stick"
2535       // to the Compile object, and the C2Compiler will see it and retry.
2536       C->record_failure(C2Compiler::retry_no_escape_analysis());
2537     }
2538     return NULL;
2539   }
2540   orig_phi_worklist.append_if_missing(orig_phi);
2541   const TypePtr *atype = C->get_adr_type(alias_idx);
2542   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2543   C->copy_node_notes_to(result, orig_phi);
2544   igvn->set_type(result, result->bottom_type());
2545   record_for_optimizer(result);
2546   set_map(orig_phi, result);
2547   new_created = true;
2548   return result;
2549 }
2550 
2551 //
2552 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2553 // specified alias index.
2554 //
2555 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist) {
2556   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2557   Compile *C = _compile;
2558   PhaseGVN* igvn = _igvn;
2559   bool new_phi_created;
2560   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2561   if (!new_phi_created) {
2562     return result;
2563   }
2564   GrowableArray<PhiNode *>  phi_list;
2565   GrowableArray<uint>  cur_input;
2566   PhiNode *phi = orig_phi;
2567   uint idx = 1;
2568   bool finished = false;
2569   while(!finished) {
2570     while (idx < phi->req()) {
2571       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2572       if (mem != NULL && mem->is_Phi()) {
2573         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2574         if (new_phi_created) {
2575           // found an phi for which we created a new split, push current one on worklist and begin
2576           // processing new one
2577           phi_list.push(phi);
2578           cur_input.push(idx);
2579           phi = mem->as_Phi();
2580           result = newphi;
2581           idx = 1;
2582           continue;
2583         } else {
2584           mem = newphi;
2585         }
2586       }
2587       if (C->failing()) {
2588         return NULL;
2589       }
2590       result->set_req(idx++, mem);
2591     }
2592 #ifdef ASSERT
2593     // verify that the new Phi has an input for each input of the original
2594     assert( phi->req() == result->req(), "must have same number of inputs.");
2595     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2596 #endif
2597     // Check if all new phi's inputs have specified alias index.
2598     // Otherwise use old phi.
2599     for (uint i = 1; i < phi->req(); i++) {
2600       Node* in = result->in(i);
2601       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2602     }
2603     // we have finished processing a Phi, see if there are any more to do
2604     finished = (phi_list.length() == 0 );
2605     if (!finished) {
2606       phi = phi_list.pop();
2607       idx = cur_input.pop();
2608       PhiNode *prev_result = get_map_phi(phi->_idx);
2609       prev_result->set_req(idx++, result);
2610       result = prev_result;
2611     }
2612   }
2613   return result;
2614 }
2615 
2616 //
2617 // The next methods are derived from methods in MemNode.
2618 //
2619 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2620   Node *mem = mmem;
2621   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2622   // means an array I have not precisely typed yet.  Do not do any
2623   // alias stuff with it any time soon.
2624   if (toop->base() != Type::AnyPtr &&
2625       !(toop->klass() != NULL &&
2626         toop->klass()->is_java_lang_Object() &&
2627         toop->offset() == Type::OffsetBot)) {
2628     mem = mmem->memory_at(alias_idx);
2629     // Update input if it is progress over what we have now
2630   }
2631   return mem;
2632 }
2633 
2634 //
2635 // Move memory users to their memory slices.
2636 //
2637 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis) {
2638   Compile* C = _compile;
2639   PhaseGVN* igvn = _igvn;
2640   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2641   assert(tp != NULL, "ptr type");
2642   int alias_idx = C->get_alias_index(tp);
2643   int general_idx = C->get_general_index(alias_idx);
2644 
2645   // Move users first
2646   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2647     Node* use = n->fast_out(i);
2648     if (use->is_MergeMem()) {
2649       MergeMemNode* mmem = use->as_MergeMem();
2650       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2651       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2652         continue; // Nothing to do
2653       }
2654       // Replace previous general reference to mem node.
2655       uint orig_uniq = C->unique();
2656       Node* m = find_inst_mem(n, general_idx, orig_phis);
2657       assert(orig_uniq == C->unique(), "no new nodes");
2658       mmem->set_memory_at(general_idx, m);
2659       --imax;
2660       --i;
2661     } else if (use->is_MemBar()) {
2662       assert(!use->is_Initialize(), "initializing stores should not be moved");
2663       if (use->req() > MemBarNode::Precedent &&
2664           use->in(MemBarNode::Precedent) == n) {
2665         // Don't move related membars.
2666         record_for_optimizer(use);
2667         continue;
2668       }
2669       tp = use->as_MemBar()->adr_type()->isa_ptr();
2670       if ((tp != NULL && C->get_alias_index(tp) == alias_idx) ||
2671           alias_idx == general_idx) {
2672         continue; // Nothing to do
2673       }
2674       // Move to general memory slice.
2675       uint orig_uniq = C->unique();
2676       Node* m = find_inst_mem(n, general_idx, orig_phis);
2677       assert(orig_uniq == C->unique(), "no new nodes");
2678       igvn->hash_delete(use);
2679       imax -= use->replace_edge(n, m);
2680       igvn->hash_insert(use);
2681       record_for_optimizer(use);
2682       --i;
2683 #ifdef ASSERT
2684     } else if (use->is_Mem()) {
2685       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2686         // Don't move related cardmark.
2687         continue;
2688       }
2689       // Memory nodes should have new memory input.
2690       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2691       assert(tp != NULL, "ptr type");
2692       int idx = C->get_alias_index(tp);
2693       assert(get_map(use->_idx) != NULL || idx == alias_idx,
2694              "Following memory nodes should have new memory input or be on the same memory slice");
2695     } else if (use->is_Phi()) {
2696       // Phi nodes should be split and moved already.
2697       tp = use->as_Phi()->adr_type()->isa_ptr();
2698       assert(tp != NULL, "ptr type");
2699       int idx = C->get_alias_index(tp);
2700       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2701     } else {
2702       use->dump();
2703       assert(false, "should not be here");
2704 #endif
2705     }
2706   }
2707 }
2708 
2709 //
2710 // Search memory chain of "mem" to find a MemNode whose address
2711 // is the specified alias index.
2712 //
2713 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis) {
2714   if (orig_mem == NULL)
2715     return orig_mem;
2716   Compile* C = _compile;
2717   PhaseGVN* igvn = _igvn;
2718   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2719   bool is_instance = (toop != NULL) && toop->is_known_instance();
2720   Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
2721   Node *prev = NULL;
2722   Node *result = orig_mem;
2723   while (prev != result) {
2724     prev = result;
2725     if (result == start_mem)
2726       break;  // hit one of our sentinels
2727     if (result->is_Mem()) {
2728       const Type *at = igvn->type(result->in(MemNode::Address));
2729       if (at == Type::TOP)
2730         break; // Dead
2731       assert (at->isa_ptr() != NULL, "pointer type required.");
2732       int idx = C->get_alias_index(at->is_ptr());
2733       if (idx == alias_idx)
2734         break; // Found
2735       if (!is_instance && (at->isa_oopptr() == NULL ||
2736                            !at->is_oopptr()->is_known_instance())) {
2737         break; // Do not skip store to general memory slice.
2738       }
2739       result = result->in(MemNode::Memory);
2740     }
2741     if (!is_instance)
2742       continue;  // don't search further for non-instance types
2743     // skip over a call which does not affect this memory slice
2744     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2745       Node *proj_in = result->in(0);
2746       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2747         break;  // hit one of our sentinels
2748       } else if (proj_in->is_Call()) {
2749         // ArrayCopy node processed here as well
2750         CallNode *call = proj_in->as_Call();
2751         if (!call->may_modify(toop, igvn)) {
2752           result = call->in(TypeFunc::Memory);
2753         }
2754       } else if (proj_in->is_Initialize()) {
2755         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2756         // Stop if this is the initialization for the object instance which
2757         // which contains this memory slice, otherwise skip over it.
2758         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2759           result = proj_in->in(TypeFunc::Memory);
2760         }
2761       } else if (proj_in->is_MemBar()) {
2762         if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2763             proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2764             proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2765           // clone
2766           ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2767           if (ac->may_modify(toop, igvn)) {
2768             break;
2769           }
2770         }
2771         result = proj_in->in(TypeFunc::Memory);
2772       }
2773     } else if (result->is_MergeMem()) {
2774       MergeMemNode *mmem = result->as_MergeMem();
2775       result = step_through_mergemem(mmem, alias_idx, toop);
2776       if (result == mmem->base_memory()) {
2777         // Didn't find instance memory, search through general slice recursively.
2778         result = mmem->memory_at(C->get_general_index(alias_idx));
2779         result = find_inst_mem(result, alias_idx, orig_phis);
2780         if (C->failing()) {
2781           return NULL;
2782         }
2783         mmem->set_memory_at(alias_idx, result);
2784       }
2785     } else if (result->is_Phi() &&
2786                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2787       Node *un = result->as_Phi()->unique_input(igvn);
2788       if (un != NULL) {
2789         orig_phis.append_if_missing(result->as_Phi());
2790         result = un;
2791       } else {
2792         break;
2793       }
2794     } else if (result->is_ClearArray()) {
2795       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2796         // Can not bypass initialization of the instance
2797         // we are looking for.
2798         break;
2799       }
2800       // Otherwise skip it (the call updated 'result' value).
2801     } else if (result->Opcode() == Op_SCMemProj) {
2802       Node* mem = result->in(0);
2803       Node* adr = NULL;
2804       if (mem->is_LoadStore()) {
2805         adr = mem->in(MemNode::Address);
2806       } else {
2807         assert(mem->Opcode() == Op_EncodeISOArray ||
2808                mem->Opcode() == Op_StrCompressedCopy, "sanity");
2809         adr = mem->in(3); // Memory edge corresponds to destination array
2810       }
2811       const Type *at = igvn->type(adr);
2812       if (at != Type::TOP) {
2813         assert(at->isa_ptr() != NULL, "pointer type required.");
2814         int idx = C->get_alias_index(at->is_ptr());
2815         if (idx == alias_idx) {
2816           // Assert in debug mode
2817           assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2818           break; // In product mode return SCMemProj node
2819         }
2820       }
2821       result = mem->in(MemNode::Memory);
2822     } else if (result->Opcode() == Op_StrInflatedCopy) {
2823       Node* adr = result->in(3); // Memory edge corresponds to destination array
2824       const Type *at = igvn->type(adr);
2825       if (at != Type::TOP) {
2826         assert(at->isa_ptr() != NULL, "pointer type required.");
2827         int idx = C->get_alias_index(at->is_ptr());
2828         if (idx == alias_idx) {
2829           // Assert in debug mode
2830           assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2831           break; // In product mode return SCMemProj node
2832         }
2833       }
2834       result = result->in(MemNode::Memory);
2835     }
2836   }
2837   if (result->is_Phi()) {
2838     PhiNode *mphi = result->as_Phi();
2839     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2840     const TypePtr *t = mphi->adr_type();
2841     if (!is_instance) {
2842       // Push all non-instance Phis on the orig_phis worklist to update inputs
2843       // during Phase 4 if needed.
2844       orig_phis.append_if_missing(mphi);
2845     } else if (C->get_alias_index(t) != alias_idx) {
2846       // Create a new Phi with the specified alias index type.
2847       result = split_memory_phi(mphi, alias_idx, orig_phis);
2848     }
2849   }
2850   // the result is either MemNode, PhiNode, InitializeNode.
2851   return result;
2852 }
2853 
2854 //
2855 //  Convert the types of unescaped object to instance types where possible,
2856 //  propagate the new type information through the graph, and update memory
2857 //  edges and MergeMem inputs to reflect the new type.
2858 //
2859 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
2860 //  The processing is done in 4 phases:
2861 //
2862 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
2863 //            types for the CheckCastPP for allocations where possible.
2864 //            Propagate the new types through users as follows:
2865 //               casts and Phi:  push users on alloc_worklist
2866 //               AddP:  cast Base and Address inputs to the instance type
2867 //                      push any AddP users on alloc_worklist and push any memnode
2868 //                      users onto memnode_worklist.
2869 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
2870 //            search the Memory chain for a store with the appropriate type
2871 //            address type.  If a Phi is found, create a new version with
2872 //            the appropriate memory slices from each of the Phi inputs.
2873 //            For stores, process the users as follows:
2874 //               MemNode:  push on memnode_worklist
2875 //               MergeMem: push on mergemem_worklist
2876 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
2877 //            moving the first node encountered of each  instance type to the
2878 //            the input corresponding to its alias index.
2879 //            appropriate memory slice.
2880 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2881 //
2882 // In the following example, the CheckCastPP nodes are the cast of allocation
2883 // results and the allocation of node 29 is unescaped and eligible to be an
2884 // instance type.
2885 //
2886 // We start with:
2887 //
2888 //     7 Parm #memory
2889 //    10  ConI  "12"
2890 //    19  CheckCastPP   "Foo"
2891 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2892 //    29  CheckCastPP   "Foo"
2893 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
2894 //
2895 //    40  StoreP  25   7  20   ... alias_index=4
2896 //    50  StoreP  35  40  30   ... alias_index=4
2897 //    60  StoreP  45  50  20   ... alias_index=4
2898 //    70  LoadP    _  60  30   ... alias_index=4
2899 //    80  Phi     75  50  60   Memory alias_index=4
2900 //    90  LoadP    _  80  30   ... alias_index=4
2901 //   100  LoadP    _  80  20   ... alias_index=4
2902 //
2903 //
2904 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2905 // and creating a new alias index for node 30.  This gives:
2906 //
2907 //     7 Parm #memory
2908 //    10  ConI  "12"
2909 //    19  CheckCastPP   "Foo"
2910 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2911 //    29  CheckCastPP   "Foo"  iid=24
2912 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2913 //
2914 //    40  StoreP  25   7  20   ... alias_index=4
2915 //    50  StoreP  35  40  30   ... alias_index=6
2916 //    60  StoreP  45  50  20   ... alias_index=4
2917 //    70  LoadP    _  60  30   ... alias_index=6
2918 //    80  Phi     75  50  60   Memory alias_index=4
2919 //    90  LoadP    _  80  30   ... alias_index=6
2920 //   100  LoadP    _  80  20   ... alias_index=4
2921 //
2922 // In phase 2, new memory inputs are computed for the loads and stores,
2923 // And a new version of the phi is created.  In phase 4, the inputs to
2924 // node 80 are updated and then the memory nodes are updated with the
2925 // values computed in phase 2.  This results in:
2926 //
2927 //     7 Parm #memory
2928 //    10  ConI  "12"
2929 //    19  CheckCastPP   "Foo"
2930 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2931 //    29  CheckCastPP   "Foo"  iid=24
2932 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2933 //
2934 //    40  StoreP  25  7   20   ... alias_index=4
2935 //    50  StoreP  35  7   30   ... alias_index=6
2936 //    60  StoreP  45  40  20   ... alias_index=4
2937 //    70  LoadP    _  50  30   ... alias_index=6
2938 //    80  Phi     75  40  60   Memory alias_index=4
2939 //   120  Phi     75  50  50   Memory alias_index=6
2940 //    90  LoadP    _ 120  30   ... alias_index=6
2941 //   100  LoadP    _  80  20   ... alias_index=4
2942 //
2943 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2944   GrowableArray<Node *>  memnode_worklist;
2945   GrowableArray<PhiNode *>  orig_phis;
2946   PhaseIterGVN  *igvn = _igvn;
2947   uint new_index_start = (uint) _compile->num_alias_types();
2948   Arena* arena = Thread::current()->resource_area();
2949   VectorSet visited(arena);
2950   ideal_nodes.clear(); // Reset for use with set_map/get_map.
2951   uint unique_old = _compile->unique();
2952 
2953   //  Phase 1:  Process possible allocations from alloc_worklist.
2954   //  Create instance types for the CheckCastPP for allocations where possible.
2955   //
2956   // (Note: don't forget to change the order of the second AddP node on
2957   //  the alloc_worklist if the order of the worklist processing is changed,
2958   //  see the comment in find_second_addp().)
2959   //
2960   while (alloc_worklist.length() != 0) {
2961     Node *n = alloc_worklist.pop();
2962     uint ni = n->_idx;
2963     if (n->is_Call()) {
2964       CallNode *alloc = n->as_Call();
2965       // copy escape information to call node
2966       PointsToNode* ptn = ptnode_adr(alloc->_idx);
2967       PointsToNode::EscapeState es = ptn->escape_state();
2968       // We have an allocation or call which returns a Java object,
2969       // see if it is unescaped.
2970       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2971         continue;
2972       // Find CheckCastPP for the allocate or for the return value of a call
2973       n = alloc->result_cast();
2974       if (n == NULL) {            // No uses except Initialize node
2975         if (alloc->is_Allocate()) {
2976           // Set the scalar_replaceable flag for allocation
2977           // so it could be eliminated if it has no uses.
2978           alloc->as_Allocate()->_is_scalar_replaceable = true;
2979         }
2980         if (alloc->is_CallStaticJava()) {
2981           // Set the scalar_replaceable flag for boxing method
2982           // so it could be eliminated if it has no uses.
2983           alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2984         }
2985         continue;
2986       }
2987       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2988         assert(!alloc->is_Allocate(), "allocation should have unique type");
2989         continue;
2990       }
2991 
2992       // The inline code for Object.clone() casts the allocation result to
2993       // java.lang.Object and then to the actual type of the allocated
2994       // object. Detect this case and use the second cast.
2995       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2996       // the allocation result is cast to java.lang.Object and then
2997       // to the actual Array type.
2998       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2999           && (alloc->is_AllocateArray() ||
3000               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
3001         Node *cast2 = NULL;
3002         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3003           Node *use = n->fast_out(i);
3004           if (use->is_CheckCastPP()) {
3005             cast2 = use;
3006             break;
3007           }
3008         }
3009         if (cast2 != NULL) {
3010           n = cast2;
3011         } else {
3012           // Non-scalar replaceable if the allocation type is unknown statically
3013           // (reflection allocation), the object can't be restored during
3014           // deoptimization without precise type.
3015           continue;
3016         }
3017       }
3018 
3019       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
3020       if (t == NULL)
3021         continue;  // not a TypeOopPtr
3022       if (!t->klass_is_exact())
3023         continue; // not an unique type
3024 
3025       if (alloc->is_Allocate()) {
3026         // Set the scalar_replaceable flag for allocation
3027         // so it could be eliminated.
3028         alloc->as_Allocate()->_is_scalar_replaceable = true;
3029       }
3030       if (alloc->is_CallStaticJava()) {
3031         // Set the scalar_replaceable flag for boxing method
3032         // so it could be eliminated.
3033         alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
3034       }
3035       set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
3036       // in order for an object to be scalar-replaceable, it must be:
3037       //   - a direct allocation (not a call returning an object)
3038       //   - non-escaping
3039       //   - eligible to be a unique type
3040       //   - not determined to be ineligible by escape analysis
3041       set_map(alloc, n);
3042       set_map(n, alloc);
3043       const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3044       igvn->hash_delete(n);
3045       igvn->set_type(n,  tinst);
3046       n->raise_bottom_type(tinst);
3047       igvn->hash_insert(n);
3048       record_for_optimizer(n);
3049       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
3050 
3051         // First, put on the worklist all Field edges from Connection Graph
3052         // which is more accurate than putting immediate users from Ideal Graph.
3053         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3054           PointsToNode* tgt = e.get();
3055           if (tgt->is_Arraycopy()) {
3056             continue;
3057           }
3058           Node* use = tgt->ideal_node();
3059           assert(tgt->is_Field() && use->is_AddP(),
3060                  "only AddP nodes are Field edges in CG");
3061           if (use->outcnt() > 0) { // Don't process dead nodes
3062             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3063             if (addp2 != NULL) {
3064               assert(alloc->is_AllocateArray(),"array allocation was expected");
3065               alloc_worklist.append_if_missing(addp2);
3066             }
3067             alloc_worklist.append_if_missing(use);
3068           }
3069         }
3070 
3071         // An allocation may have an Initialize which has raw stores. Scan
3072         // the users of the raw allocation result and push AddP users
3073         // on alloc_worklist.
3074         Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
3075         assert (raw_result != NULL, "must have an allocation result");
3076         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3077           Node *use = raw_result->fast_out(i);
3078           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3079             Node* addp2 = find_second_addp(use, raw_result);
3080             if (addp2 != NULL) {
3081               assert(alloc->is_AllocateArray(),"array allocation was expected");
3082               alloc_worklist.append_if_missing(addp2);
3083             }
3084             alloc_worklist.append_if_missing(use);
3085           } else if (use->is_MemBar()) {
3086             memnode_worklist.append_if_missing(use);
3087           }
3088         }
3089       }
3090     } else if (n->is_AddP()) {
3091       JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3092       if (jobj == NULL || jobj == phantom_obj) {
3093 #ifdef ASSERT
3094         ptnode_adr(get_addp_base(n)->_idx)->dump();
3095         ptnode_adr(n->_idx)->dump();
3096         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3097 #endif
3098         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3099         return;
3100       }
3101       Node *base = get_map(jobj->idx());  // CheckCastPP node
3102       if (!split_AddP(n, base)) continue; // wrong type from dead path
3103     } else if (n->is_Phi() ||
3104                n->is_CheckCastPP() ||
3105                n->is_EncodeP() ||
3106                n->is_DecodeN() ||
3107                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3108       if (visited.test_set(n->_idx)) {
3109         assert(n->is_Phi(), "loops only through Phi's");
3110         continue;  // already processed
3111       }
3112       JavaObjectNode* jobj = unique_java_object(n);
3113       if (jobj == NULL || jobj == phantom_obj) {
3114 #ifdef ASSERT
3115         ptnode_adr(n->_idx)->dump();
3116         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3117 #endif
3118         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3119         return;
3120       } else {
3121         Node *val = get_map(jobj->idx());   // CheckCastPP node
3122         TypeNode *tn = n->as_Type();
3123         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3124         assert(tinst != NULL && tinst->is_known_instance() &&
3125                tinst->instance_id() == jobj->idx() , "instance type expected.");
3126 
3127         const Type *tn_type = igvn->type(tn);
3128         const TypeOopPtr *tn_t;
3129         if (tn_type->isa_narrowoop()) {
3130           tn_t = tn_type->make_ptr()->isa_oopptr();
3131         } else {
3132           tn_t = tn_type->isa_oopptr();
3133         }
3134         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3135           if (tn_type->isa_narrowoop()) {
3136             tn_type = tinst->make_narrowoop();
3137           } else {
3138             tn_type = tinst;
3139           }
3140           igvn->hash_delete(tn);
3141           igvn->set_type(tn, tn_type);
3142           tn->set_type(tn_type);
3143           igvn->hash_insert(tn);
3144           record_for_optimizer(n);
3145         } else {
3146           assert(tn_type == TypePtr::NULL_PTR ||
3147                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3148                  "unexpected type");
3149           continue; // Skip dead path with different type
3150         }
3151       }
3152     } else {
3153       debug_only(n->dump();)
3154       assert(false, "EA: unexpected node");
3155       continue;
3156     }
3157     // push allocation's users on appropriate worklist
3158     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3159       Node *use = n->fast_out(i);
3160       if(use->is_Mem() && use->in(MemNode::Address) == n) {
3161         // Load/store to instance's field
3162         memnode_worklist.append_if_missing(use);
3163       } else if (use->is_MemBar()) {
3164         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3165           memnode_worklist.append_if_missing(use);
3166         }
3167       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3168         Node* addp2 = find_second_addp(use, n);
3169         if (addp2 != NULL) {
3170           alloc_worklist.append_if_missing(addp2);
3171         }
3172         alloc_worklist.append_if_missing(use);
3173       } else if (use->is_Phi() ||
3174                  use->is_CheckCastPP() ||
3175                  use->is_EncodeNarrowPtr() ||
3176                  use->is_DecodeNarrowPtr() ||
3177                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3178         alloc_worklist.append_if_missing(use);
3179 #ifdef ASSERT
3180       } else if (use->is_Mem()) {
3181         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3182       } else if (use->is_MergeMem()) {
3183         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3184       } else if (use->is_SafePoint()) {
3185         // Look for MergeMem nodes for calls which reference unique allocation
3186         // (through CheckCastPP nodes) even for debug info.
3187         Node* m = use->in(TypeFunc::Memory);
3188         if (m->is_MergeMem()) {
3189           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3190         }
3191       } else if (use->Opcode() == Op_EncodeISOArray) {
3192         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3193           // EncodeISOArray overwrites destination array
3194           memnode_worklist.append_if_missing(use);
3195         }
3196       } else {
3197         uint op = use->Opcode();
3198         if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3199             (use->in(MemNode::Memory) == n)) {
3200           // They overwrite memory edge corresponding to destination array,
3201           memnode_worklist.append_if_missing(use);
3202         } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3203               op == Op_CastP2X || op == Op_StoreCM ||
3204               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3205               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3206               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
3207               BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
3208           n->dump();
3209           use->dump();
3210           assert(false, "EA: missing allocation reference path");
3211         }
3212 #endif
3213       }
3214     }
3215 
3216   }
3217 
3218   // Go over all ArrayCopy nodes and if one of the inputs has a unique
3219   // type, record it in the ArrayCopy node so we know what memory this
3220   // node uses/modified.
3221   for (int next = 0; next < arraycopy_worklist.length(); next++) {
3222     ArrayCopyNode* ac = arraycopy_worklist.at(next);
3223     Node* dest = ac->in(ArrayCopyNode::Dest);
3224     if (dest->is_AddP()) {
3225       dest = get_addp_base(dest);
3226     }
3227     JavaObjectNode* jobj = unique_java_object(dest);
3228     if (jobj != NULL) {
3229       Node *base = get_map(jobj->idx());
3230       if (base != NULL) {
3231         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3232         ac->_dest_type = base_t;
3233       }
3234     }
3235     Node* src = ac->in(ArrayCopyNode::Src);
3236     if (src->is_AddP()) {
3237       src = get_addp_base(src);
3238     }
3239     jobj = unique_java_object(src);
3240     if (jobj != NULL) {
3241       Node* base = get_map(jobj->idx());
3242       if (base != NULL) {
3243         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3244         ac->_src_type = base_t;
3245       }
3246     }
3247   }
3248 
3249   // New alias types were created in split_AddP().
3250   uint new_index_end = (uint) _compile->num_alias_types();
3251   assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3252 
3253   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
3254   //            compute new values for Memory inputs  (the Memory inputs are not
3255   //            actually updated until phase 4.)
3256   if (memnode_worklist.length() == 0)
3257     return;  // nothing to do
3258   while (memnode_worklist.length() != 0) {
3259     Node *n = memnode_worklist.pop();
3260     if (visited.test_set(n->_idx))
3261       continue;
3262     if (n->is_Phi() || n->is_ClearArray()) {
3263       // we don't need to do anything, but the users must be pushed
3264     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3265       // we don't need to do anything, but the users must be pushed
3266       n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
3267       if (n == NULL)
3268         continue;
3269     } else if (n->Opcode() == Op_StrCompressedCopy ||
3270                n->Opcode() == Op_EncodeISOArray) {
3271       // get the memory projection
3272       n = n->find_out_with(Op_SCMemProj);
3273       assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3274     } else {
3275       assert(n->is_Mem(), "memory node required.");
3276       Node *addr = n->in(MemNode::Address);
3277       const Type *addr_t = igvn->type(addr);
3278       if (addr_t == Type::TOP)
3279         continue;
3280       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3281       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3282       assert ((uint)alias_idx < new_index_end, "wrong alias index");
3283       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3284       if (_compile->failing()) {
3285         return;
3286       }
3287       if (mem != n->in(MemNode::Memory)) {
3288         // We delay the memory edge update since we need old one in
3289         // MergeMem code below when instances memory slices are separated.
3290         set_map(n, mem);
3291       }
3292       if (n->is_Load()) {
3293         continue;  // don't push users
3294       } else if (n->is_LoadStore()) {
3295         // get the memory projection
3296         n = n->find_out_with(Op_SCMemProj);
3297         assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3298       }
3299     }
3300     // push user on appropriate worklist
3301     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3302       Node *use = n->fast_out(i);
3303       if (use->is_Phi() || use->is_ClearArray()) {
3304         memnode_worklist.append_if_missing(use);
3305       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3306         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3307           continue;
3308         memnode_worklist.append_if_missing(use);
3309       } else if (use->is_MemBar()) {
3310         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3311           memnode_worklist.append_if_missing(use);
3312         }
3313 #ifdef ASSERT
3314       } else if(use->is_Mem()) {
3315         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3316       } else if (use->is_MergeMem()) {
3317         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3318       } else if (use->Opcode() == Op_EncodeISOArray) {
3319         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3320           // EncodeISOArray overwrites destination array
3321           memnode_worklist.append_if_missing(use);
3322         }
3323       } else {
3324         uint op = use->Opcode();
3325         if ((use->in(MemNode::Memory) == n) &&
3326             (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3327           // They overwrite memory edge corresponding to destination array,
3328           memnode_worklist.append_if_missing(use);
3329         } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
3330               op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3331               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3332               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3333           n->dump();
3334           use->dump();
3335           assert(false, "EA: missing memory path");
3336         }
3337 #endif
3338       }
3339     }
3340   }
3341 
3342   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
3343   //            Walk each memory slice moving the first node encountered of each
3344   //            instance type to the the input corresponding to its alias index.
3345   uint length = _mergemem_worklist.length();
3346   for( uint next = 0; next < length; ++next ) {
3347     MergeMemNode* nmm = _mergemem_worklist.at(next);
3348     assert(!visited.test_set(nmm->_idx), "should not be visited before");
3349     // Note: we don't want to use MergeMemStream here because we only want to
3350     // scan inputs which exist at the start, not ones we add during processing.
3351     // Note 2: MergeMem may already contains instance memory slices added
3352     // during find_inst_mem() call when memory nodes were processed above.
3353     igvn->hash_delete(nmm);
3354     uint nslices = MIN2(nmm->req(), new_index_start);
3355     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3356       Node* mem = nmm->in(i);
3357       Node* cur = NULL;
3358       if (mem == NULL || mem->is_top())
3359         continue;
3360       // First, update mergemem by moving memory nodes to corresponding slices
3361       // if their type became more precise since this mergemem was created.
3362       while (mem->is_Mem()) {
3363         const Type *at = igvn->type(mem->in(MemNode::Address));
3364         if (at != Type::TOP) {
3365           assert (at->isa_ptr() != NULL, "pointer type required.");
3366           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3367           if (idx == i) {
3368             if (cur == NULL)
3369               cur = mem;
3370           } else {
3371             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3372               nmm->set_memory_at(idx, mem);
3373             }
3374           }
3375         }
3376         mem = mem->in(MemNode::Memory);
3377       }
3378       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3379       // Find any instance of the current type if we haven't encountered
3380       // already a memory slice of the instance along the memory chain.
3381       for (uint ni = new_index_start; ni < new_index_end; ni++) {
3382         if((uint)_compile->get_general_index(ni) == i) {
3383           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3384           if (nmm->is_empty_memory(m)) {
3385             Node* result = find_inst_mem(mem, ni, orig_phis);
3386             if (_compile->failing()) {
3387               return;
3388             }
3389             nmm->set_memory_at(ni, result);
3390           }
3391         }
3392       }
3393     }
3394     // Find the rest of instances values
3395     for (uint ni = new_index_start; ni < new_index_end; ni++) {
3396       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3397       Node* result = step_through_mergemem(nmm, ni, tinst);
3398       if (result == nmm->base_memory()) {
3399         // Didn't find instance memory, search through general slice recursively.
3400         result = nmm->memory_at(_compile->get_general_index(ni));
3401         result = find_inst_mem(result, ni, orig_phis);
3402         if (_compile->failing()) {
3403           return;
3404         }
3405         nmm->set_memory_at(ni, result);
3406       }
3407     }
3408     igvn->hash_insert(nmm);
3409     record_for_optimizer(nmm);
3410   }
3411 
3412   //  Phase 4:  Update the inputs of non-instance memory Phis and
3413   //            the Memory input of memnodes
3414   // First update the inputs of any non-instance Phi's from
3415   // which we split out an instance Phi.  Note we don't have
3416   // to recursively process Phi's encounted on the input memory
3417   // chains as is done in split_memory_phi() since they  will
3418   // also be processed here.
3419   for (int j = 0; j < orig_phis.length(); j++) {
3420     PhiNode *phi = orig_phis.at(j);
3421     int alias_idx = _compile->get_alias_index(phi->adr_type());
3422     igvn->hash_delete(phi);
3423     for (uint i = 1; i < phi->req(); i++) {
3424       Node *mem = phi->in(i);
3425       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3426       if (_compile->failing()) {
3427         return;
3428       }
3429       if (mem != new_mem) {
3430         phi->set_req(i, new_mem);
3431       }
3432     }
3433     igvn->hash_insert(phi);
3434     record_for_optimizer(phi);
3435   }
3436 
3437   // Update the memory inputs of MemNodes with the value we computed
3438   // in Phase 2 and move stores memory users to corresponding memory slices.
3439   // Disable memory split verification code until the fix for 6984348.
3440   // Currently it produces false negative results since it does not cover all cases.
3441 #if 0 // ifdef ASSERT
3442   visited.Reset();
3443   Node_Stack old_mems(arena, _compile->unique() >> 2);
3444 #endif
3445   for (uint i = 0; i < ideal_nodes.size(); i++) {
3446     Node*    n = ideal_nodes.at(i);
3447     Node* nmem = get_map(n->_idx);
3448     assert(nmem != NULL, "sanity");
3449     if (n->is_Mem()) {
3450 #if 0 // ifdef ASSERT
3451       Node* old_mem = n->in(MemNode::Memory);
3452       if (!visited.test_set(old_mem->_idx)) {
3453         old_mems.push(old_mem, old_mem->outcnt());
3454       }
3455 #endif
3456       assert(n->in(MemNode::Memory) != nmem, "sanity");
3457       if (!n->is_Load()) {
3458         // Move memory users of a store first.
3459         move_inst_mem(n, orig_phis);
3460       }
3461       // Now update memory input
3462       igvn->hash_delete(n);
3463       n->set_req(MemNode::Memory, nmem);
3464       igvn->hash_insert(n);
3465       record_for_optimizer(n);
3466     } else {
3467       assert(n->is_Allocate() || n->is_CheckCastPP() ||
3468              n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3469     }
3470   }
3471 #if 0 // ifdef ASSERT
3472   // Verify that memory was split correctly
3473   while (old_mems.is_nonempty()) {
3474     Node* old_mem = old_mems.node();
3475     uint  old_cnt = old_mems.index();
3476     old_mems.pop();
3477     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3478   }
3479 #endif
3480 }
3481 
3482 #ifndef PRODUCT
3483 static const char *node_type_names[] = {
3484   "UnknownType",
3485   "JavaObject",
3486   "LocalVar",
3487   "Field",
3488   "Arraycopy"
3489 };
3490 
3491 static const char *esc_names[] = {
3492   "UnknownEscape",
3493   "NoEscape",
3494   "ArgEscape",
3495   "GlobalEscape"
3496 };
3497 
3498 void PointsToNode::dump(bool print_state) const {
3499   NodeType nt = node_type();
3500   tty->print("%s ", node_type_names[(int) nt]);
3501   if (print_state) {
3502     EscapeState es = escape_state();
3503     EscapeState fields_es = fields_escape_state();
3504     tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3505     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3506       tty->print("NSR ");
3507   }
3508   if (is_Field()) {
3509     FieldNode* f = (FieldNode*)this;
3510     if (f->is_oop())
3511       tty->print("oop ");
3512     if (f->offset() > 0)
3513       tty->print("+%d ", f->offset());
3514     tty->print("(");
3515     for (BaseIterator i(f); i.has_next(); i.next()) {
3516       PointsToNode* b = i.get();
3517       tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3518     }
3519     tty->print(" )");
3520   }
3521   tty->print("[");
3522   for (EdgeIterator i(this); i.has_next(); i.next()) {
3523     PointsToNode* e = i.get();
3524     tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3525   }
3526   tty->print(" [");
3527   for (UseIterator i(this); i.has_next(); i.next()) {
3528     PointsToNode* u = i.get();
3529     bool is_base = false;
3530     if (PointsToNode::is_base_use(u)) {
3531       is_base = true;
3532       u = PointsToNode::get_use_node(u)->as_Field();
3533     }
3534     tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3535   }
3536   tty->print(" ]]  ");
3537   if (_node == NULL)
3538     tty->print_cr("<null>");
3539   else
3540     _node->dump();
3541 }
3542 
3543 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3544   bool first = true;
3545   int ptnodes_length = ptnodes_worklist.length();
3546   for (int i = 0; i < ptnodes_length; i++) {
3547     PointsToNode *ptn = ptnodes_worklist.at(i);
3548     if (ptn == NULL || !ptn->is_JavaObject())
3549       continue;
3550     PointsToNode::EscapeState es = ptn->escape_state();
3551     if ((es != PointsToNode::NoEscape) && !Verbose) {
3552       continue;
3553     }
3554     Node* n = ptn->ideal_node();
3555     if (n->is_Allocate() || (n->is_CallStaticJava() &&
3556                              n->as_CallStaticJava()->is_boxing_method())) {
3557       if (first) {
3558         tty->cr();
3559         tty->print("======== Connection graph for ");
3560         _compile->method()->print_short_name();
3561         tty->cr();
3562         first = false;
3563       }
3564       ptn->dump();
3565       // Print all locals and fields which reference this allocation
3566       for (UseIterator j(ptn); j.has_next(); j.next()) {
3567         PointsToNode* use = j.get();
3568         if (use->is_LocalVar()) {
3569           use->dump(Verbose);
3570         } else if (Verbose) {
3571           use->dump();
3572         }
3573       }
3574       tty->cr();
3575     }
3576   }
3577 }
3578 #endif