1 /*
   2  * Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/bcEscapeAnalyzer.hpp"
  27 #include "compiler/compileLog.hpp"
  28 #include "libadt/vectset.hpp"
  29 #include "memory/allocation.hpp"
  30 #include "memory/resourceArea.hpp"
  31 #include "opto/c2compiler.hpp"
  32 #include "opto/arraycopynode.hpp"
  33 #include "opto/callnode.hpp"
  34 #include "opto/cfgnode.hpp"
  35 #include "opto/compile.hpp"
  36 #include "opto/escape.hpp"
  37 #include "opto/phaseX.hpp"
  38 #include "opto/movenode.hpp"
  39 #include "opto/rootnode.hpp"
  40 
  41 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
  42   _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
  43   _in_worklist(C->comp_arena()),
  44   _next_pidx(0),
  45   _collecting(true),
  46   _verify(false),
  47   _compile(C),
  48   _igvn(igvn),
  49   _node_map(C->comp_arena()) {
  50   // Add unknown java object.
  51   add_java_object(C->top(), PointsToNode::GlobalEscape);
  52   phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
  53   // Add ConP(#NULL) and ConN(#NULL) nodes.
  54   Node* oop_null = igvn->zerocon(T_OBJECT);
  55   assert(oop_null->_idx < nodes_size(), "should be created already");
  56   add_java_object(oop_null, PointsToNode::NoEscape);
  57   null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
  58   if (UseCompressedOops) {
  59     Node* noop_null = igvn->zerocon(T_NARROWOOP);
  60     assert(noop_null->_idx < nodes_size(), "should be created already");
  61     map_ideal_node(noop_null, null_obj);
  62   }
  63   _pcmp_neq = NULL; // Should be initialized
  64   _pcmp_eq  = NULL;
  65 }
  66 
  67 bool ConnectionGraph::has_candidates(Compile *C) {
  68   // EA brings benefits only when the code has allocations and/or locks which
  69   // are represented by ideal Macro nodes.
  70   int cnt = C->macro_count();
  71   for (int i = 0; i < cnt; i++) {
  72     Node *n = C->macro_node(i);
  73     if (n->is_Allocate())
  74       return true;
  75     if (n->is_Lock()) {
  76       Node* obj = n->as_Lock()->obj_node()->uncast();
  77       if (!(obj->is_Parm() || obj->is_Con()))
  78         return true;
  79     }
  80     if (n->is_CallStaticJava() &&
  81         n->as_CallStaticJava()->is_boxing_method()) {
  82       return true;
  83     }
  84   }
  85   return false;
  86 }
  87 
  88 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
  89   Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
  90   ResourceMark rm;
  91 
  92   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
  93   // to create space for them in ConnectionGraph::_nodes[].
  94   Node* oop_null = igvn->zerocon(T_OBJECT);
  95   Node* noop_null = igvn->zerocon(T_NARROWOOP);
  96   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
  97   // Perform escape analysis
  98   if (congraph->compute_escape()) {
  99     // There are non escaping objects.
 100     C->set_congraph(congraph);
 101   }
 102   // Cleanup.
 103   if (oop_null->outcnt() == 0)
 104     igvn->hash_delete(oop_null);
 105   if (noop_null->outcnt() == 0)
 106     igvn->hash_delete(noop_null);
 107 }
 108 
 109 bool ConnectionGraph::compute_escape() {
 110   Compile* C = _compile;
 111   PhaseGVN* igvn = _igvn;
 112 
 113   // Worklists used by EA.
 114   Unique_Node_List delayed_worklist;
 115   GrowableArray<Node*> alloc_worklist;
 116   GrowableArray<Node*> ptr_cmp_worklist;
 117   GrowableArray<Node*> storestore_worklist;
 118   GrowableArray<ArrayCopyNode*> arraycopy_worklist;
 119   GrowableArray<PointsToNode*>   ptnodes_worklist;
 120   GrowableArray<JavaObjectNode*> java_objects_worklist;
 121   GrowableArray<JavaObjectNode*> non_escaped_worklist;
 122   GrowableArray<FieldNode*>      oop_fields_worklist;
 123   DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
 124 
 125   { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
 126 
 127   // 1. Populate Connection Graph (CG) with PointsTo nodes.
 128   ideal_nodes.map(C->live_nodes(), NULL);  // preallocate space
 129   // Initialize worklist
 130   if (C->root() != NULL) {
 131     ideal_nodes.push(C->root());
 132   }
 133   // Processed ideal nodes are unique on ideal_nodes list
 134   // but several ideal nodes are mapped to the phantom_obj.
 135   // To avoid duplicated entries on the following worklists
 136   // add the phantom_obj only once to them.
 137   ptnodes_worklist.append(phantom_obj);
 138   java_objects_worklist.append(phantom_obj);
 139   for( uint next = 0; next < ideal_nodes.size(); ++next ) {
 140     Node* n = ideal_nodes.at(next);
 141     // Create PointsTo nodes and add them to Connection Graph. Called
 142     // only once per ideal node since ideal_nodes is Unique_Node list.
 143     add_node_to_connection_graph(n, &delayed_worklist);
 144     PointsToNode* ptn = ptnode_adr(n->_idx);
 145     if (ptn != NULL && ptn != phantom_obj) {
 146       ptnodes_worklist.append(ptn);
 147       if (ptn->is_JavaObject()) {
 148         java_objects_worklist.append(ptn->as_JavaObject());
 149         if ((n->is_Allocate() || n->is_CallStaticJava()) &&
 150             (ptn->escape_state() < PointsToNode::GlobalEscape)) {
 151           // Only allocations and java static calls results are interesting.
 152           non_escaped_worklist.append(ptn->as_JavaObject());
 153         }
 154       } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
 155         oop_fields_worklist.append(ptn->as_Field());
 156       }
 157     }
 158     if (n->is_MergeMem()) {
 159       // Collect all MergeMem nodes to add memory slices for
 160       // scalar replaceable objects in split_unique_types().
 161       _mergemem_worklist.append(n->as_MergeMem());
 162     } else if (OptimizePtrCompare && n->is_Cmp() &&
 163                (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
 164       // Collect compare pointers nodes.
 165       ptr_cmp_worklist.append(n);
 166     } else if (n->is_MemBarStoreStore()) {
 167       // Collect all MemBarStoreStore nodes so that depending on the
 168       // escape status of the associated Allocate node some of them
 169       // may be eliminated.
 170       storestore_worklist.append(n);
 171     } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
 172                (n->req() > MemBarNode::Precedent)) {
 173       record_for_optimizer(n);
 174 #ifdef ASSERT
 175     } else if (n->is_AddP()) {
 176       // Collect address nodes for graph verification.
 177       addp_worklist.append(n);
 178 #endif
 179     } else if (n->is_ArrayCopy()) {
 180       // Keep a list of ArrayCopy nodes so if one of its input is non
 181       // escaping, we can record a unique type
 182       arraycopy_worklist.append(n->as_ArrayCopy());
 183     }
 184     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 185       Node* m = n->fast_out(i);   // Get user
 186       ideal_nodes.push(m);
 187     }
 188   }
 189   if (non_escaped_worklist.length() == 0) {
 190     _collecting = false;
 191     return false; // Nothing to do.
 192   }
 193   // Add final simple edges to graph.
 194   while(delayed_worklist.size() > 0) {
 195     Node* n = delayed_worklist.pop();
 196     add_final_edges(n);
 197   }
 198   int ptnodes_length = ptnodes_worklist.length();
 199 
 200 #ifdef ASSERT
 201   if (VerifyConnectionGraph) {
 202     // Verify that no new simple edges could be created and all
 203     // local vars has edges.
 204     _verify = true;
 205     for (int next = 0; next < ptnodes_length; ++next) {
 206       PointsToNode* ptn = ptnodes_worklist.at(next);
 207       add_final_edges(ptn->ideal_node());
 208       if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
 209         ptn->dump();
 210         assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
 211       }
 212     }
 213     _verify = false;
 214   }
 215 #endif
 216   // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
 217   // processing, calls to CI to resolve symbols (types, fields, methods)
 218   // referenced in bytecode. During symbol resolution VM may throw
 219   // an exception which CI cleans and converts to compilation failure.
 220   if (C->failing())  return false;
 221 
 222   // 2. Finish Graph construction by propagating references to all
 223   //    java objects through graph.
 224   if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
 225                                  java_objects_worklist, oop_fields_worklist)) {
 226     // All objects escaped or hit time or iterations limits.
 227     _collecting = false;
 228     return false;
 229   }
 230 
 231   // 3. Adjust scalar_replaceable state of nonescaping objects and push
 232   //    scalar replaceable allocations on alloc_worklist for processing
 233   //    in split_unique_types().
 234   int non_escaped_length = non_escaped_worklist.length();
 235   for (int next = 0; next < non_escaped_length; next++) {
 236     JavaObjectNode* ptn = non_escaped_worklist.at(next);
 237     bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
 238     Node* n = ptn->ideal_node();
 239     if (n->is_Allocate()) {
 240       n->as_Allocate()->_is_non_escaping = noescape;
 241     }
 242     if (n->is_CallStaticJava()) {
 243       n->as_CallStaticJava()->_is_non_escaping = noescape;
 244     }
 245     if (noescape && ptn->scalar_replaceable()) {
 246       adjust_scalar_replaceable_state(ptn);
 247       if (ptn->scalar_replaceable()) {
 248         alloc_worklist.append(ptn->ideal_node());
 249       }
 250     }
 251   }
 252 
 253 #ifdef ASSERT
 254   if (VerifyConnectionGraph) {
 255     // Verify that graph is complete - no new edges could be added or needed.
 256     verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
 257                             java_objects_worklist, addp_worklist);
 258   }
 259   assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
 260   assert(null_obj->escape_state() == PointsToNode::NoEscape &&
 261          null_obj->edge_count() == 0 &&
 262          !null_obj->arraycopy_src() &&
 263          !null_obj->arraycopy_dst(), "sanity");
 264 #endif
 265 
 266   _collecting = false;
 267 
 268   } // TracePhase t3("connectionGraph")
 269 
 270   // 4. Optimize ideal graph based on EA information.
 271   bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
 272   if (has_non_escaping_obj) {
 273     optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
 274   }
 275 
 276 #ifndef PRODUCT
 277   if (PrintEscapeAnalysis) {
 278     dump(ptnodes_worklist); // Dump ConnectionGraph
 279   }
 280 #endif
 281 
 282   bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
 283 #ifdef ASSERT
 284   if (VerifyConnectionGraph) {
 285     int alloc_length = alloc_worklist.length();
 286     for (int next = 0; next < alloc_length; ++next) {
 287       Node* n = alloc_worklist.at(next);
 288       PointsToNode* ptn = ptnode_adr(n->_idx);
 289       assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
 290     }
 291   }
 292 #endif
 293 
 294   // 5. Separate memory graph for scalar replaceable allcations.
 295   if (has_scalar_replaceable_candidates &&
 296       C->AliasLevel() >= 3 && EliminateAllocations) {
 297     // Now use the escape information to create unique types for
 298     // scalar replaceable objects.
 299     split_unique_types(alloc_worklist, arraycopy_worklist);
 300     if (C->failing())  return false;
 301     C->print_method(PHASE_AFTER_EA, 2);
 302 
 303 #ifdef ASSERT
 304   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
 305     tty->print("=== No allocations eliminated for ");
 306     C->method()->print_short_name();
 307     if(!EliminateAllocations) {
 308       tty->print(" since EliminateAllocations is off ===");
 309     } else if(!has_scalar_replaceable_candidates) {
 310       tty->print(" since there are no scalar replaceable candidates ===");
 311     } else if(C->AliasLevel() < 3) {
 312       tty->print(" since AliasLevel < 3 ===");
 313     }
 314     tty->cr();
 315 #endif
 316   }
 317   return has_non_escaping_obj;
 318 }
 319 
 320 // Utility function for nodes that load an object
 321 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 322   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 323   // ThreadLocal has RawPtr type.
 324   const Type* t = _igvn->type(n);
 325   if (t->make_ptr() != NULL) {
 326     Node* adr = n->in(MemNode::Address);
 327 #ifdef ASSERT
 328     if (!adr->is_AddP()) {
 329       assert(_igvn->type(adr)->isa_rawptr(), "sanity");
 330     } else {
 331       assert((ptnode_adr(adr->_idx) == NULL ||
 332               ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
 333     }
 334 #endif
 335     add_local_var_and_edge(n, PointsToNode::NoEscape,
 336                            adr, delayed_worklist);
 337   }
 338 }
 339 
 340 // Populate Connection Graph with PointsTo nodes and create simple
 341 // connection graph edges.
 342 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 343   assert(!_verify, "this method should not be called for verification");
 344   PhaseGVN* igvn = _igvn;
 345   uint n_idx = n->_idx;
 346   PointsToNode* n_ptn = ptnode_adr(n_idx);
 347   if (n_ptn != NULL)
 348     return; // No need to redefine PointsTo node during first iteration.
 349 
 350   if (n->is_Call()) {
 351     // Arguments to allocation and locking don't escape.
 352     if (n->is_AbstractLock()) {
 353       // Put Lock and Unlock nodes on IGVN worklist to process them during
 354       // first IGVN optimization when escape information is still available.
 355       record_for_optimizer(n);
 356     } else if (n->is_Allocate()) {
 357       add_call_node(n->as_Call());
 358       record_for_optimizer(n);
 359     } else {
 360       if (n->is_CallStaticJava()) {
 361         const char* name = n->as_CallStaticJava()->_name;
 362         if (name != NULL && strcmp(name, "uncommon_trap") == 0)
 363           return; // Skip uncommon traps
 364       }
 365       // Don't mark as processed since call's arguments have to be processed.
 366       delayed_worklist->push(n);
 367       // Check if a call returns an object.
 368       if ((n->as_Call()->returns_pointer() &&
 369            n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
 370           (n->is_CallStaticJava() &&
 371            n->as_CallStaticJava()->is_boxing_method())) {
 372         add_call_node(n->as_Call());
 373       } else if (n->as_Call()->tf()->returns_value_type_as_fields()) {
 374         bool returns_oop = false;
 375         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax && !returns_oop; i++) {
 376           ProjNode* pn = n->fast_out(i)->as_Proj();
 377           if (pn->_con >= TypeFunc::Parms && pn->bottom_type()->isa_ptr()) {
 378             returns_oop = true;
 379           }
 380         }
 381         if (returns_oop) {
 382           add_call_node(n->as_Call());
 383         }
 384       }
 385     }
 386     return;
 387   }
 388   // Put this check here to process call arguments since some call nodes
 389   // point to phantom_obj.
 390   if (n_ptn == phantom_obj || n_ptn == null_obj)
 391     return; // Skip predefined nodes.
 392 
 393   int opcode = n->Opcode();
 394   switch (opcode) {
 395     case Op_AddP: {
 396       Node* base = get_addp_base(n);
 397       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 398       // Field nodes are created for all field types. They are used in
 399       // adjust_scalar_replaceable_state() and split_unique_types().
 400       // Note, non-oop fields will have only base edges in Connection
 401       // Graph because such fields are not used for oop loads and stores.
 402       int offset = address_offset(n, igvn);
 403       add_field(n, PointsToNode::NoEscape, offset);
 404       if (ptn_base == NULL) {
 405         delayed_worklist->push(n); // Process it later.
 406       } else {
 407         n_ptn = ptnode_adr(n_idx);
 408         add_base(n_ptn->as_Field(), ptn_base);
 409       }
 410       break;
 411     }
 412     case Op_CastX2P: {
 413       map_ideal_node(n, phantom_obj);
 414       break;
 415     }
 416     case Op_CastPP:
 417     case Op_CheckCastPP:
 418     case Op_EncodeP:
 419     case Op_DecodeN:
 420     case Op_EncodePKlass:
 421     case Op_DecodeNKlass: {
 422       add_local_var_and_edge(n, PointsToNode::NoEscape,
 423                              n->in(1), delayed_worklist);
 424       break;
 425     }
 426     case Op_CMoveP: {
 427       add_local_var(n, PointsToNode::NoEscape);
 428       // Do not add edges during first iteration because some could be
 429       // not defined yet.
 430       delayed_worklist->push(n);
 431       break;
 432     }
 433     case Op_ConP:
 434     case Op_ConN:
 435     case Op_ConNKlass: {
 436       // assume all oop constants globally escape except for null
 437       PointsToNode::EscapeState es;
 438       const Type* t = igvn->type(n);
 439       if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
 440         es = PointsToNode::NoEscape;
 441       } else {
 442         es = PointsToNode::GlobalEscape;
 443       }
 444       add_java_object(n, es);
 445       break;
 446     }
 447     case Op_CreateEx: {
 448       // assume that all exception objects globally escape
 449       map_ideal_node(n, phantom_obj);
 450       break;
 451     }
 452     case Op_LoadKlass:
 453     case Op_LoadNKlass: {
 454       // Unknown class is loaded
 455       map_ideal_node(n, phantom_obj);
 456       break;
 457     }
 458     case Op_LoadP:
 459     case Op_LoadN:
 460     case Op_LoadPLocked: {
 461       add_objload_to_connection_graph(n, delayed_worklist);
 462       break;
 463     }
 464     case Op_Parm: {
 465       map_ideal_node(n, phantom_obj);
 466       break;
 467     }
 468     case Op_PartialSubtypeCheck: {
 469       // Produces Null or notNull and is used in only in CmpP so
 470       // phantom_obj could be used.
 471       map_ideal_node(n, phantom_obj); // Result is unknown
 472       break;
 473     }
 474     case Op_Phi: {
 475       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 476       // ThreadLocal has RawPtr type.
 477       const Type* t = n->as_Phi()->type();
 478       if (t->make_ptr() != NULL) {
 479         add_local_var(n, PointsToNode::NoEscape);
 480         // Do not add edges during first iteration because some could be
 481         // not defined yet.
 482         delayed_worklist->push(n);
 483       }
 484       break;
 485     }
 486     case Op_Proj: {
 487       // we are only interested in the oop result projection from a call
 488       if (n->as_Proj()->_con >= TypeFunc::Parms && n->in(0)->is_Call() &&
 489           (n->in(0)->as_Call()->returns_pointer() || n->bottom_type()->isa_ptr())) {
 490         assert((n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->as_Call()->returns_pointer()) ||
 491                n->in(0)->as_Call()->tf()->returns_value_type_as_fields(), "what kind of oop return is it?");
 492         add_local_var_and_edge(n, PointsToNode::NoEscape,
 493                                n->in(0), delayed_worklist);
 494       }
 495       break;
 496     }
 497     case Op_Rethrow: // Exception object escapes
 498     case Op_Return: {
 499       if (n->req() > TypeFunc::Parms &&
 500           igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 501         // Treat Return value as LocalVar with GlobalEscape escape state.
 502         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 503                                n->in(TypeFunc::Parms), delayed_worklist);
 504       }
 505       break;
 506     }
 507     case Op_CompareAndExchangeP:
 508     case Op_CompareAndExchangeN:
 509     case Op_GetAndSetP:
 510     case Op_GetAndSetN: {
 511       add_objload_to_connection_graph(n, delayed_worklist);
 512       // fallthrough
 513     }
 514     case Op_StoreP:
 515     case Op_StoreN:
 516     case Op_StoreNKlass:
 517     case Op_StorePConditional:
 518     case Op_WeakCompareAndSwapP:
 519     case Op_WeakCompareAndSwapN:
 520     case Op_CompareAndSwapP:
 521     case Op_CompareAndSwapN: {
 522       Node* adr = n->in(MemNode::Address);
 523       const Type *adr_type = igvn->type(adr);
 524       adr_type = adr_type->make_ptr();
 525       if (adr_type == NULL) {
 526         break; // skip dead nodes
 527       }
 528       if (   adr_type->isa_oopptr()
 529           || (   (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
 530               && adr_type == TypeRawPtr::NOTNULL
 531               && adr->in(AddPNode::Address)->is_Proj()
 532               && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 533         delayed_worklist->push(n); // Process it later.
 534 #ifdef ASSERT
 535         assert(adr->is_AddP(), "expecting an AddP");
 536         if (adr_type == TypeRawPtr::NOTNULL) {
 537           // Verify a raw address for a store captured by Initialize node.
 538           int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 539           assert(offs != Type::OffsetBot, "offset must be a constant");
 540         }
 541 #endif
 542       } else {
 543         // Ignore copy the displaced header to the BoxNode (OSR compilation).
 544         if (adr->is_BoxLock())
 545           break;
 546         // Stored value escapes in unsafe access.
 547         if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
 548           // Pointer stores in G1 barriers looks like unsafe access.
 549           // Ignore such stores to be able scalar replace non-escaping
 550           // allocations.
 551           if (UseG1GC && adr->is_AddP()) {
 552             Node* base = get_addp_base(adr);
 553             if (base->Opcode() == Op_LoadP &&
 554                 base->in(MemNode::Address)->is_AddP()) {
 555               adr = base->in(MemNode::Address);
 556               Node* tls = get_addp_base(adr);
 557               if (tls->Opcode() == Op_ThreadLocal) {
 558                 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 559                 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
 560                                      SATBMarkQueue::byte_offset_of_buf())) {
 561                   break; // G1 pre barrier previous oop value store.
 562                 }
 563                 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
 564                                      DirtyCardQueue::byte_offset_of_buf())) {
 565                   break; // G1 post barrier card address store.
 566                 }
 567               }
 568             }
 569           }
 570           delayed_worklist->push(n); // Process unsafe access later.
 571           break;
 572         }
 573 #ifdef ASSERT
 574         n->dump(1);
 575         assert(false, "not unsafe or G1 barrier raw StoreP");
 576 #endif
 577       }
 578       break;
 579     }
 580     case Op_AryEq:
 581     case Op_HasNegatives:
 582     case Op_StrComp:
 583     case Op_StrEquals:
 584     case Op_StrIndexOf:
 585     case Op_StrIndexOfChar:
 586     case Op_StrInflatedCopy:
 587     case Op_StrCompressedCopy:
 588     case Op_EncodeISOArray: {
 589       add_local_var(n, PointsToNode::ArgEscape);
 590       delayed_worklist->push(n); // Process it later.
 591       break;
 592     }
 593     case Op_ThreadLocal: {
 594       add_java_object(n, PointsToNode::ArgEscape);
 595       break;
 596     }
 597     default:
 598       ; // Do nothing for nodes not related to EA.
 599   }
 600   return;
 601 }
 602 
 603 #ifdef ASSERT
 604 #define ELSE_FAIL(name)                               \
 605       /* Should not be called for not pointer type. */  \
 606       n->dump(1);                                       \
 607       assert(false, name);                              \
 608       break;
 609 #else
 610 #define ELSE_FAIL(name) \
 611       break;
 612 #endif
 613 
 614 // Add final simple edges to graph.
 615 void ConnectionGraph::add_final_edges(Node *n) {
 616   PointsToNode* n_ptn = ptnode_adr(n->_idx);
 617 #ifdef ASSERT
 618   if (_verify && n_ptn->is_JavaObject())
 619     return; // This method does not change graph for JavaObject.
 620 #endif
 621 
 622   if (n->is_Call()) {
 623     process_call_arguments(n->as_Call());
 624     return;
 625   }
 626   assert(n->is_Store() || n->is_LoadStore() ||
 627          (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
 628          "node should be registered already");
 629   int opcode = n->Opcode();
 630   switch (opcode) {
 631     case Op_AddP: {
 632       Node* base = get_addp_base(n);
 633       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 634       assert(ptn_base != NULL, "field's base should be registered");
 635       add_base(n_ptn->as_Field(), ptn_base);
 636       break;
 637     }
 638     case Op_CastPP:
 639     case Op_CheckCastPP:
 640     case Op_EncodeP:
 641     case Op_DecodeN:
 642     case Op_EncodePKlass:
 643     case Op_DecodeNKlass: {
 644       add_local_var_and_edge(n, PointsToNode::NoEscape,
 645                              n->in(1), NULL);
 646       break;
 647     }
 648     case Op_CMoveP: {
 649       for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
 650         Node* in = n->in(i);
 651         if (in == NULL)
 652           continue;  // ignore NULL
 653         Node* uncast_in = in->uncast();
 654         if (uncast_in->is_top() || uncast_in == n)
 655           continue;  // ignore top or inputs which go back this node
 656         PointsToNode* ptn = ptnode_adr(in->_idx);
 657         assert(ptn != NULL, "node should be registered");
 658         add_edge(n_ptn, ptn);
 659       }
 660       break;
 661     }
 662     case Op_LoadP:
 663     case Op_LoadN:
 664     case Op_LoadPLocked: {
 665       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 666       // ThreadLocal has RawPtr type.
 667       const Type* t = _igvn->type(n);
 668       if (t->make_ptr() != NULL) {
 669         Node* adr = n->in(MemNode::Address);
 670         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 671         break;
 672       }
 673       ELSE_FAIL("Op_LoadP");
 674     }
 675     case Op_Phi: {
 676       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 677       // ThreadLocal has RawPtr type.
 678       const Type* t = n->as_Phi()->type();
 679       if (t->make_ptr() != NULL) {
 680         for (uint i = 1; i < n->req(); i++) {
 681           Node* in = n->in(i);
 682           if (in == NULL)
 683             continue;  // ignore NULL
 684           Node* uncast_in = in->uncast();
 685           if (uncast_in->is_top() || uncast_in == n)
 686             continue;  // ignore top or inputs which go back this node
 687           PointsToNode* ptn = ptnode_adr(in->_idx);
 688           assert(ptn != NULL, "node should be registered");
 689           add_edge(n_ptn, ptn);
 690         }
 691         break;
 692       }
 693       ELSE_FAIL("Op_Phi");
 694     }
 695     case Op_Proj: {
 696       // we are only interested in the oop result projection from a call
 697       if (n->as_Proj()->_con >= TypeFunc::Parms && n->in(0)->is_Call() &&
 698           (n->in(0)->as_Call()->returns_pointer()|| n->bottom_type()->isa_ptr())) {
 699         assert((n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->as_Call()->returns_pointer()) ||
 700                n->in(0)->as_Call()->tf()->returns_value_type_as_fields(), "what kind of oop return is it?");
 701         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
 702         break;
 703       }
 704       ELSE_FAIL("Op_Proj");
 705     }
 706     case Op_Rethrow: // Exception object escapes
 707     case Op_Return: {
 708       if (n->req() > TypeFunc::Parms &&
 709           _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 710         // Treat Return value as LocalVar with GlobalEscape escape state.
 711         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 712                                n->in(TypeFunc::Parms), NULL);
 713         break;
 714       }
 715       ELSE_FAIL("Op_Return");
 716     }
 717     case Op_StoreP:
 718     case Op_StoreN:
 719     case Op_StoreNKlass:
 720     case Op_StorePConditional:
 721     case Op_CompareAndExchangeP:
 722     case Op_CompareAndExchangeN:
 723     case Op_CompareAndSwapP:
 724     case Op_CompareAndSwapN:
 725     case Op_WeakCompareAndSwapP:
 726     case Op_WeakCompareAndSwapN:
 727     case Op_GetAndSetP:
 728     case Op_GetAndSetN: {
 729       Node* adr = n->in(MemNode::Address);
 730       const Type *adr_type = _igvn->type(adr);
 731       adr_type = adr_type->make_ptr();
 732 #ifdef ASSERT
 733       if (adr_type == NULL) {
 734         n->dump(1);
 735         assert(adr_type != NULL, "dead node should not be on list");
 736         break;
 737       }
 738 #endif
 739       if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
 740           opcode == Op_CompareAndExchangeN || opcode == Op_CompareAndExchangeP) {
 741         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 742       }
 743       if (   adr_type->isa_oopptr()
 744           || (   (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
 745               && adr_type == TypeRawPtr::NOTNULL
 746               && adr->in(AddPNode::Address)->is_Proj()
 747               && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 748         // Point Address to Value
 749         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 750         assert(adr_ptn != NULL &&
 751                adr_ptn->as_Field()->is_oop(), "node should be registered");
 752         Node *val = n->in(MemNode::ValueIn);
 753         PointsToNode* ptn = ptnode_adr(val->_idx);
 754         assert(ptn != NULL, "node should be registered");
 755         add_edge(adr_ptn, ptn);
 756         break;
 757       } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
 758         // Stored value escapes in unsafe access.
 759         Node *val = n->in(MemNode::ValueIn);
 760         PointsToNode* ptn = ptnode_adr(val->_idx);
 761         assert(ptn != NULL, "node should be registered");
 762         set_escape_state(ptn, PointsToNode::GlobalEscape);
 763         // Add edge to object for unsafe access with offset.
 764         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 765         assert(adr_ptn != NULL, "node should be registered");
 766         if (adr_ptn->is_Field()) {
 767           assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
 768           add_edge(adr_ptn, ptn);
 769         }
 770         break;
 771       }
 772       ELSE_FAIL("Op_StoreP");
 773     }
 774     case Op_AryEq:
 775     case Op_HasNegatives:
 776     case Op_StrComp:
 777     case Op_StrEquals:
 778     case Op_StrIndexOf:
 779     case Op_StrIndexOfChar:
 780     case Op_StrInflatedCopy:
 781     case Op_StrCompressedCopy:
 782     case Op_EncodeISOArray: {
 783       // char[]/byte[] arrays passed to string intrinsic do not escape but
 784       // they are not scalar replaceable. Adjust escape state for them.
 785       // Start from in(2) edge since in(1) is memory edge.
 786       for (uint i = 2; i < n->req(); i++) {
 787         Node* adr = n->in(i);
 788         const Type* at = _igvn->type(adr);
 789         if (!adr->is_top() && at->isa_ptr()) {
 790           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
 791                  at->isa_ptr() != NULL, "expecting a pointer");
 792           if (adr->is_AddP()) {
 793             adr = get_addp_base(adr);
 794           }
 795           PointsToNode* ptn = ptnode_adr(adr->_idx);
 796           assert(ptn != NULL, "node should be registered");
 797           add_edge(n_ptn, ptn);
 798         }
 799       }
 800       break;
 801     }
 802     default: {
 803       // This method should be called only for EA specific nodes which may
 804       // miss some edges when they were created.
 805 #ifdef ASSERT
 806       n->dump(1);
 807 #endif
 808       guarantee(false, "unknown node");
 809     }
 810   }
 811   return;
 812 }
 813 
 814 void ConnectionGraph::add_call_node(CallNode* call) {
 815   assert(call->returns_pointer() || call->tf()->returns_value_type_as_fields(), "only for call which returns pointer");
 816   uint call_idx = call->_idx;
 817   if (call->is_Allocate()) {
 818     Node* k = call->in(AllocateNode::KlassNode);
 819     const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
 820     assert(kt != NULL, "TypeKlassPtr  required.");
 821     ciKlass* cik = kt->klass();
 822     PointsToNode::EscapeState es = PointsToNode::NoEscape;
 823     bool scalar_replaceable = true;
 824     if (call->is_AllocateArray()) {
 825       if (!cik->is_array_klass()) { // StressReflectiveCode
 826         es = PointsToNode::GlobalEscape;
 827       } else {
 828         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
 829         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
 830           // Not scalar replaceable if the length is not constant or too big.
 831           scalar_replaceable = false;
 832         }
 833       }
 834     } else {  // Allocate instance
 835       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
 836           cik->is_subclass_of(_compile->env()->Reference_klass()) ||
 837          !cik->is_instance_klass() || // StressReflectiveCode
 838          !cik->as_instance_klass()->can_be_instantiated() ||
 839           cik->as_instance_klass()->has_finalizer()) {
 840         es = PointsToNode::GlobalEscape;
 841       }
 842     }
 843     add_java_object(call, es);
 844     PointsToNode* ptn = ptnode_adr(call_idx);
 845     if (!scalar_replaceable && ptn->scalar_replaceable()) {
 846       ptn->set_scalar_replaceable(false);
 847     }
 848   } else if (call->is_CallStaticJava()) {
 849     // Call nodes could be different types:
 850     //
 851     // 1. CallDynamicJavaNode (what happened during call is unknown):
 852     //
 853     //    - mapped to GlobalEscape JavaObject node if oop is returned;
 854     //
 855     //    - all oop arguments are escaping globally;
 856     //
 857     // 2. CallStaticJavaNode (execute bytecode analysis if possible):
 858     //
 859     //    - the same as CallDynamicJavaNode if can't do bytecode analysis;
 860     //
 861     //    - mapped to GlobalEscape JavaObject node if unknown oop is returned;
 862     //    - mapped to NoEscape JavaObject node if non-escaping object allocated
 863     //      during call is returned;
 864     //    - mapped to ArgEscape LocalVar node pointed to object arguments
 865     //      which are returned and does not escape during call;
 866     //
 867     //    - oop arguments escaping status is defined by bytecode analysis;
 868     //
 869     // For a static call, we know exactly what method is being called.
 870     // Use bytecode estimator to record whether the call's return value escapes.
 871     ciMethod* meth = call->as_CallJava()->method();
 872     if (meth == NULL) {
 873       const char* name = call->as_CallStaticJava()->_name;
 874       assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
 875       // Returns a newly allocated unescaped object.
 876       add_java_object(call, PointsToNode::NoEscape);
 877       ptnode_adr(call_idx)->set_scalar_replaceable(false);
 878     } else if (meth->is_boxing_method()) {
 879       // Returns boxing object
 880       PointsToNode::EscapeState es;
 881       vmIntrinsics::ID intr = meth->intrinsic_id();
 882       if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
 883         // It does not escape if object is always allocated.
 884         es = PointsToNode::NoEscape;
 885       } else {
 886         // It escapes globally if object could be loaded from cache.
 887         es = PointsToNode::GlobalEscape;
 888       }
 889       add_java_object(call, es);
 890     } else {
 891       BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
 892       call_analyzer->copy_dependencies(_compile->dependencies());
 893       if (call_analyzer->is_return_allocated()) {
 894         // Returns a newly allocated unescaped object, simply
 895         // update dependency information.
 896         // Mark it as NoEscape so that objects referenced by
 897         // it's fields will be marked as NoEscape at least.
 898         add_java_object(call, PointsToNode::NoEscape);
 899         ptnode_adr(call_idx)->set_scalar_replaceable(false);
 900       } else {
 901         // Determine whether any arguments are returned.
 902         const TypeTuple* d = call->tf()->domain_cc();
 903         bool ret_arg = false;
 904         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 905           if (d->field_at(i)->isa_ptr() != NULL &&
 906               call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
 907             ret_arg = true;
 908             break;
 909           }
 910         }
 911         if (ret_arg) {
 912           add_local_var(call, PointsToNode::ArgEscape);
 913         } else {
 914           // Returns unknown object.
 915           map_ideal_node(call, phantom_obj);
 916         }
 917       }
 918     }
 919   } else {
 920     // An other type of call, assume the worst case:
 921     // returned value is unknown and globally escapes.
 922     assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
 923     map_ideal_node(call, phantom_obj);
 924   }
 925 }
 926 
 927 void ConnectionGraph::process_call_arguments(CallNode *call) {
 928     bool is_arraycopy = false;
 929     switch (call->Opcode()) {
 930 #ifdef ASSERT
 931     case Op_Allocate:
 932     case Op_AllocateArray:
 933     case Op_Lock:
 934     case Op_Unlock:
 935       assert(false, "should be done already");
 936       break;
 937 #endif
 938     case Op_ArrayCopy:
 939     case Op_CallLeafNoFP:
 940       // Most array copies are ArrayCopy nodes at this point but there
 941       // are still a few direct calls to the copy subroutines (See
 942       // PhaseStringOpts::copy_string())
 943       is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
 944         call->as_CallLeaf()->is_call_to_arraycopystub();
 945       // fall through
 946     case Op_CallLeaf: {
 947       // Stub calls, objects do not escape but they are not scale replaceable.
 948       // Adjust escape state for outgoing arguments.
 949       const TypeTuple * d = call->tf()->domain_sig();
 950       bool src_has_oops = false;
 951       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 952         const Type* at = d->field_at(i);
 953         Node *arg = call->in(i);
 954         if (arg == NULL) {
 955           continue;
 956         }
 957         const Type *aat = _igvn->type(arg);
 958         if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
 959           continue;
 960         if (arg->is_AddP()) {
 961           //
 962           // The inline_native_clone() case when the arraycopy stub is called
 963           // after the allocation before Initialize and CheckCastPP nodes.
 964           // Or normal arraycopy for object arrays case.
 965           //
 966           // Set AddP's base (Allocate) as not scalar replaceable since
 967           // pointer to the base (with offset) is passed as argument.
 968           //
 969           arg = get_addp_base(arg);
 970         }
 971         PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
 972         assert(arg_ptn != NULL, "should be registered");
 973         PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
 974         if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
 975           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
 976                  aat->isa_ptr() != NULL, "expecting an Ptr");
 977           bool arg_has_oops = aat->isa_oopptr() &&
 978                               (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
 979                                (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
 980           if (i == TypeFunc::Parms) {
 981             src_has_oops = arg_has_oops;
 982           }
 983           //
 984           // src or dst could be j.l.Object when other is basic type array:
 985           //
 986           //   arraycopy(char[],0,Object*,0,size);
 987           //   arraycopy(Object*,0,char[],0,size);
 988           //
 989           // Don't add edges in such cases.
 990           //
 991           bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
 992                                        arg_has_oops && (i > TypeFunc::Parms);
 993 #ifdef ASSERT
 994           if (!(is_arraycopy ||
 995                 (call->as_CallLeaf()->_name != NULL &&
 996                  (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
 997                   strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
 998                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
 999                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
1000                   strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
1001                   strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
1002                   strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
1003                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
1004                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
1005                   strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
1006                   strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
1007                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
1008                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
1009                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
1010                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
1011                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
1012                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
1013                   strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1014                   strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1015                   strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1016                   strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1017                   strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1018                   strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1019                  ))) {
1020             call->dump();
1021             fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1022           }
1023 #endif
1024           // Always process arraycopy's destination object since
1025           // we need to add all possible edges to references in
1026           // source object.
1027           if (arg_esc >= PointsToNode::ArgEscape &&
1028               !arg_is_arraycopy_dest) {
1029             continue;
1030           }
1031           PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1032           if (call->is_ArrayCopy()) {
1033             ArrayCopyNode* ac = call->as_ArrayCopy();
1034             if (ac->is_clonebasic() ||
1035                 ac->is_arraycopy_validated() ||
1036                 ac->is_copyof_validated() ||
1037                 ac->is_copyofrange_validated()) {
1038               es = PointsToNode::NoEscape;
1039             }
1040           }
1041           set_escape_state(arg_ptn, es);
1042           if (arg_is_arraycopy_dest) {
1043             Node* src = call->in(TypeFunc::Parms);
1044             if (src->is_AddP()) {
1045               src = get_addp_base(src);
1046             }
1047             PointsToNode* src_ptn = ptnode_adr(src->_idx);
1048             assert(src_ptn != NULL, "should be registered");
1049             if (arg_ptn != src_ptn) {
1050               // Special arraycopy edge:
1051               // A destination object's field can't have the source object
1052               // as base since objects escape states are not related.
1053               // Only escape state of destination object's fields affects
1054               // escape state of fields in source object.
1055               add_arraycopy(call, es, src_ptn, arg_ptn);
1056             }
1057           }
1058         }
1059       }
1060       break;
1061     }
1062     case Op_CallStaticJava: {
1063       // For a static call, we know exactly what method is being called.
1064       // Use bytecode estimator to record the call's escape affects
1065 #ifdef ASSERT
1066       const char* name = call->as_CallStaticJava()->_name;
1067       assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1068 #endif
1069       ciMethod* meth = call->as_CallJava()->method();
1070       if ((meth != NULL) && meth->is_boxing_method()) {
1071         break; // Boxing methods do not modify any oops.
1072       }
1073       BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1074       // fall-through if not a Java method or no analyzer information
1075       if (call_analyzer != NULL) {
1076         PointsToNode* call_ptn = ptnode_adr(call->_idx);
1077         const TypeTuple* d = call->tf()->domain_cc();
1078         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1079           const Type* at = d->field_at(i);
1080           int k = i - TypeFunc::Parms;
1081           Node* arg = call->in(i);
1082           PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1083           if (at->isa_ptr() != NULL &&
1084               call_analyzer->is_arg_returned(k)) {
1085             // The call returns arguments.
1086             if (call_ptn != NULL) { // Is call's result used?
1087               assert(call_ptn->is_LocalVar(), "node should be registered");
1088               assert(arg_ptn != NULL, "node should be registered");
1089               add_edge(call_ptn, arg_ptn);
1090             }
1091           }
1092           if (at->isa_oopptr() != NULL &&
1093               arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1094             if (!call_analyzer->is_arg_stack(k)) {
1095               // The argument global escapes
1096               set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1097             } else {
1098               set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1099               if (!call_analyzer->is_arg_local(k)) {
1100                 // The argument itself doesn't escape, but any fields might
1101                 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1102               }
1103             }
1104           }
1105         }
1106         if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1107           // The call returns arguments.
1108           assert(call_ptn->edge_count() > 0, "sanity");
1109           if (!call_analyzer->is_return_local()) {
1110             // Returns also unknown object.
1111             add_edge(call_ptn, phantom_obj);
1112           }
1113         }
1114         break;
1115       }
1116     }
1117     default: {
1118       // Fall-through here if not a Java method or no analyzer information
1119       // or some other type of call, assume the worst case: all arguments
1120       // globally escape.
1121       const TypeTuple* d = call->tf()->domain_cc();
1122       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1123         const Type* at = d->field_at(i);
1124         if (at->isa_oopptr() != NULL) {
1125           Node* arg = call->in(i);
1126           if (arg->is_AddP()) {
1127             arg = get_addp_base(arg);
1128           }
1129           assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1130           set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1131         }
1132       }
1133     }
1134   }
1135 }
1136 
1137 
1138 // Finish Graph construction.
1139 bool ConnectionGraph::complete_connection_graph(
1140                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1141                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1142                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1143                          GrowableArray<FieldNode*>&      oop_fields_worklist) {
1144   // Normally only 1-3 passes needed to build Connection Graph depending
1145   // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1146   // Set limit to 20 to catch situation when something did go wrong and
1147   // bailout Escape Analysis.
1148   // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1149 #define CG_BUILD_ITER_LIMIT 20
1150 
1151   // Propagate GlobalEscape and ArgEscape escape states and check that
1152   // we still have non-escaping objects. The method pushs on _worklist
1153   // Field nodes which reference phantom_object.
1154   if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1155     return false; // Nothing to do.
1156   }
1157   // Now propagate references to all JavaObject nodes.
1158   int java_objects_length = java_objects_worklist.length();
1159   elapsedTimer time;
1160   bool timeout = false;
1161   int new_edges = 1;
1162   int iterations = 0;
1163   do {
1164     while ((new_edges > 0) &&
1165            (iterations++ < CG_BUILD_ITER_LIMIT)) {
1166       double start_time = time.seconds();
1167       time.start();
1168       new_edges = 0;
1169       // Propagate references to phantom_object for nodes pushed on _worklist
1170       // by find_non_escaped_objects() and find_field_value().
1171       new_edges += add_java_object_edges(phantom_obj, false);
1172       for (int next = 0; next < java_objects_length; ++next) {
1173         JavaObjectNode* ptn = java_objects_worklist.at(next);
1174         new_edges += add_java_object_edges(ptn, true);
1175 
1176 #define SAMPLE_SIZE 4
1177         if ((next % SAMPLE_SIZE) == 0) {
1178           // Each 4 iterations calculate how much time it will take
1179           // to complete graph construction.
1180           time.stop();
1181           // Poll for requests from shutdown mechanism to quiesce compiler
1182           // because Connection graph construction may take long time.
1183           CompileBroker::maybe_block();
1184           double stop_time = time.seconds();
1185           double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1186           double time_until_end = time_per_iter * (double)(java_objects_length - next);
1187           if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1188             timeout = true;
1189             break; // Timeout
1190           }
1191           start_time = stop_time;
1192           time.start();
1193         }
1194 #undef SAMPLE_SIZE
1195 
1196       }
1197       if (timeout) break;
1198       if (new_edges > 0) {
1199         // Update escape states on each iteration if graph was updated.
1200         if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1201           return false; // Nothing to do.
1202         }
1203       }
1204       time.stop();
1205       if (time.seconds() >= EscapeAnalysisTimeout) {
1206         timeout = true;
1207         break;
1208       }
1209     }
1210     if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1211       time.start();
1212       // Find fields which have unknown value.
1213       int fields_length = oop_fields_worklist.length();
1214       for (int next = 0; next < fields_length; next++) {
1215         FieldNode* field = oop_fields_worklist.at(next);
1216         if (field->edge_count() == 0) {
1217           new_edges += find_field_value(field);
1218           // This code may added new edges to phantom_object.
1219           // Need an other cycle to propagate references to phantom_object.
1220         }
1221       }
1222       time.stop();
1223       if (time.seconds() >= EscapeAnalysisTimeout) {
1224         timeout = true;
1225         break;
1226       }
1227     } else {
1228       new_edges = 0; // Bailout
1229     }
1230   } while (new_edges > 0);
1231 
1232   // Bailout if passed limits.
1233   if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1234     Compile* C = _compile;
1235     if (C->log() != NULL) {
1236       C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1237       C->log()->text("%s", timeout ? "time" : "iterations");
1238       C->log()->end_elem(" limit'");
1239     }
1240     assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1241            time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1242     // Possible infinite build_connection_graph loop,
1243     // bailout (no changes to ideal graph were made).
1244     return false;
1245   }
1246 #ifdef ASSERT
1247   if (Verbose && PrintEscapeAnalysis) {
1248     tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1249                   iterations, nodes_size(), ptnodes_worklist.length());
1250   }
1251 #endif
1252 
1253 #undef CG_BUILD_ITER_LIMIT
1254 
1255   // Find fields initialized by NULL for non-escaping Allocations.
1256   int non_escaped_length = non_escaped_worklist.length();
1257   for (int next = 0; next < non_escaped_length; next++) {
1258     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1259     PointsToNode::EscapeState es = ptn->escape_state();
1260     assert(es <= PointsToNode::ArgEscape, "sanity");
1261     if (es == PointsToNode::NoEscape) {
1262       if (find_init_values(ptn, null_obj, _igvn) > 0) {
1263         // Adding references to NULL object does not change escape states
1264         // since it does not escape. Also no fields are added to NULL object.
1265         add_java_object_edges(null_obj, false);
1266       }
1267     }
1268     Node* n = ptn->ideal_node();
1269     if (n->is_Allocate()) {
1270       // The object allocated by this Allocate node will never be
1271       // seen by an other thread. Mark it so that when it is
1272       // expanded no MemBarStoreStore is added.
1273       InitializeNode* ini = n->as_Allocate()->initialization();
1274       if (ini != NULL)
1275         ini->set_does_not_escape();
1276     }
1277   }
1278   return true; // Finished graph construction.
1279 }
1280 
1281 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1282 // and check that we still have non-escaping java objects.
1283 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1284                                                GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1285   GrowableArray<PointsToNode*> escape_worklist;
1286   // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1287   int ptnodes_length = ptnodes_worklist.length();
1288   for (int next = 0; next < ptnodes_length; ++next) {
1289     PointsToNode* ptn = ptnodes_worklist.at(next);
1290     if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1291         ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1292       escape_worklist.push(ptn);
1293     }
1294   }
1295   // Set escape states to referenced nodes (edges list).
1296   while (escape_worklist.length() > 0) {
1297     PointsToNode* ptn = escape_worklist.pop();
1298     PointsToNode::EscapeState es  = ptn->escape_state();
1299     PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1300     if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1301         es >= PointsToNode::ArgEscape) {
1302       // GlobalEscape or ArgEscape state of field means it has unknown value.
1303       if (add_edge(ptn, phantom_obj)) {
1304         // New edge was added
1305         add_field_uses_to_worklist(ptn->as_Field());
1306       }
1307     }
1308     for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1309       PointsToNode* e = i.get();
1310       if (e->is_Arraycopy()) {
1311         assert(ptn->arraycopy_dst(), "sanity");
1312         // Propagate only fields escape state through arraycopy edge.
1313         if (e->fields_escape_state() < field_es) {
1314           set_fields_escape_state(e, field_es);
1315           escape_worklist.push(e);
1316         }
1317       } else if (es >= field_es) {
1318         // fields_escape_state is also set to 'es' if it is less than 'es'.
1319         if (e->escape_state() < es) {
1320           set_escape_state(e, es);
1321           escape_worklist.push(e);
1322         }
1323       } else {
1324         // Propagate field escape state.
1325         bool es_changed = false;
1326         if (e->fields_escape_state() < field_es) {
1327           set_fields_escape_state(e, field_es);
1328           es_changed = true;
1329         }
1330         if ((e->escape_state() < field_es) &&
1331             e->is_Field() && ptn->is_JavaObject() &&
1332             e->as_Field()->is_oop()) {
1333           // Change escape state of referenced fields.
1334           set_escape_state(e, field_es);
1335           es_changed = true;
1336         } else if (e->escape_state() < es) {
1337           set_escape_state(e, es);
1338           es_changed = true;
1339         }
1340         if (es_changed) {
1341           escape_worklist.push(e);
1342         }
1343       }
1344     }
1345   }
1346   // Remove escaped objects from non_escaped list.
1347   for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1348     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1349     if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1350       non_escaped_worklist.delete_at(next);
1351     }
1352     if (ptn->escape_state() == PointsToNode::NoEscape) {
1353       // Find fields in non-escaped allocations which have unknown value.
1354       find_init_values(ptn, phantom_obj, NULL);
1355     }
1356   }
1357   return (non_escaped_worklist.length() > 0);
1358 }
1359 
1360 // Add all references to JavaObject node by walking over all uses.
1361 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1362   int new_edges = 0;
1363   if (populate_worklist) {
1364     // Populate _worklist by uses of jobj's uses.
1365     for (UseIterator i(jobj); i.has_next(); i.next()) {
1366       PointsToNode* use = i.get();
1367       if (use->is_Arraycopy())
1368         continue;
1369       add_uses_to_worklist(use);
1370       if (use->is_Field() && use->as_Field()->is_oop()) {
1371         // Put on worklist all field's uses (loads) and
1372         // related field nodes (same base and offset).
1373         add_field_uses_to_worklist(use->as_Field());
1374       }
1375     }
1376   }
1377   for (int l = 0; l < _worklist.length(); l++) {
1378     PointsToNode* use = _worklist.at(l);
1379     if (PointsToNode::is_base_use(use)) {
1380       // Add reference from jobj to field and from field to jobj (field's base).
1381       use = PointsToNode::get_use_node(use)->as_Field();
1382       if (add_base(use->as_Field(), jobj)) {
1383         new_edges++;
1384       }
1385       continue;
1386     }
1387     assert(!use->is_JavaObject(), "sanity");
1388     if (use->is_Arraycopy()) {
1389       if (jobj == null_obj) // NULL object does not have field edges
1390         continue;
1391       // Added edge from Arraycopy node to arraycopy's source java object
1392       if (add_edge(use, jobj)) {
1393         jobj->set_arraycopy_src();
1394         new_edges++;
1395       }
1396       // and stop here.
1397       continue;
1398     }
1399     if (!add_edge(use, jobj))
1400       continue; // No new edge added, there was such edge already.
1401     new_edges++;
1402     if (use->is_LocalVar()) {
1403       add_uses_to_worklist(use);
1404       if (use->arraycopy_dst()) {
1405         for (EdgeIterator i(use); i.has_next(); i.next()) {
1406           PointsToNode* e = i.get();
1407           if (e->is_Arraycopy()) {
1408             if (jobj == null_obj) // NULL object does not have field edges
1409               continue;
1410             // Add edge from arraycopy's destination java object to Arraycopy node.
1411             if (add_edge(jobj, e)) {
1412               new_edges++;
1413               jobj->set_arraycopy_dst();
1414             }
1415           }
1416         }
1417       }
1418     } else {
1419       // Added new edge to stored in field values.
1420       // Put on worklist all field's uses (loads) and
1421       // related field nodes (same base and offset).
1422       add_field_uses_to_worklist(use->as_Field());
1423     }
1424   }
1425   _worklist.clear();
1426   _in_worklist.Reset();
1427   return new_edges;
1428 }
1429 
1430 // Put on worklist all related field nodes.
1431 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1432   assert(field->is_oop(), "sanity");
1433   int offset = field->offset();
1434   add_uses_to_worklist(field);
1435   // Loop over all bases of this field and push on worklist Field nodes
1436   // with the same offset and base (since they may reference the same field).
1437   for (BaseIterator i(field); i.has_next(); i.next()) {
1438     PointsToNode* base = i.get();
1439     add_fields_to_worklist(field, base);
1440     // Check if the base was source object of arraycopy and go over arraycopy's
1441     // destination objects since values stored to a field of source object are
1442     // accessable by uses (loads) of fields of destination objects.
1443     if (base->arraycopy_src()) {
1444       for (UseIterator j(base); j.has_next(); j.next()) {
1445         PointsToNode* arycp = j.get();
1446         if (arycp->is_Arraycopy()) {
1447           for (UseIterator k(arycp); k.has_next(); k.next()) {
1448             PointsToNode* abase = k.get();
1449             if (abase->arraycopy_dst() && abase != base) {
1450               // Look for the same arraycopy reference.
1451               add_fields_to_worklist(field, abase);
1452             }
1453           }
1454         }
1455       }
1456     }
1457   }
1458 }
1459 
1460 // Put on worklist all related field nodes.
1461 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1462   int offset = field->offset();
1463   if (base->is_LocalVar()) {
1464     for (UseIterator j(base); j.has_next(); j.next()) {
1465       PointsToNode* f = j.get();
1466       if (PointsToNode::is_base_use(f)) { // Field
1467         f = PointsToNode::get_use_node(f);
1468         if (f == field || !f->as_Field()->is_oop())
1469           continue;
1470         int offs = f->as_Field()->offset();
1471         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1472           add_to_worklist(f);
1473         }
1474       }
1475     }
1476   } else {
1477     assert(base->is_JavaObject(), "sanity");
1478     if (// Skip phantom_object since it is only used to indicate that
1479         // this field's content globally escapes.
1480         (base != phantom_obj) &&
1481         // NULL object node does not have fields.
1482         (base != null_obj)) {
1483       for (EdgeIterator i(base); i.has_next(); i.next()) {
1484         PointsToNode* f = i.get();
1485         // Skip arraycopy edge since store to destination object field
1486         // does not update value in source object field.
1487         if (f->is_Arraycopy()) {
1488           assert(base->arraycopy_dst(), "sanity");
1489           continue;
1490         }
1491         if (f == field || !f->as_Field()->is_oop())
1492           continue;
1493         int offs = f->as_Field()->offset();
1494         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1495           add_to_worklist(f);
1496         }
1497       }
1498     }
1499   }
1500 }
1501 
1502 // Find fields which have unknown value.
1503 int ConnectionGraph::find_field_value(FieldNode* field) {
1504   // Escaped fields should have init value already.
1505   assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1506   int new_edges = 0;
1507   for (BaseIterator i(field); i.has_next(); i.next()) {
1508     PointsToNode* base = i.get();
1509     if (base->is_JavaObject()) {
1510       // Skip Allocate's fields which will be processed later.
1511       if (base->ideal_node()->is_Allocate())
1512         return 0;
1513       assert(base == null_obj, "only NULL ptr base expected here");
1514     }
1515   }
1516   if (add_edge(field, phantom_obj)) {
1517     // New edge was added
1518     new_edges++;
1519     add_field_uses_to_worklist(field);
1520   }
1521   return new_edges;
1522 }
1523 
1524 // Find fields initializing values for allocations.
1525 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1526   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1527   int new_edges = 0;
1528   Node* alloc = pta->ideal_node();
1529   if (init_val == phantom_obj) {
1530     // Do nothing for Allocate nodes since its fields values are
1531     // "known" unless they are initialized by arraycopy/clone.
1532     if (alloc->is_Allocate() && !pta->arraycopy_dst())
1533       return 0;
1534     assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1535 #ifdef ASSERT
1536     if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1537       const char* name = alloc->as_CallStaticJava()->_name;
1538       assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1539     }
1540 #endif
1541     // Non-escaped allocation returned from Java or runtime call have
1542     // unknown values in fields.
1543     for (EdgeIterator i(pta); i.has_next(); i.next()) {
1544       PointsToNode* field = i.get();
1545       if (field->is_Field() && field->as_Field()->is_oop()) {
1546         if (add_edge(field, phantom_obj)) {
1547           // New edge was added
1548           new_edges++;
1549           add_field_uses_to_worklist(field->as_Field());
1550         }
1551       }
1552     }
1553     return new_edges;
1554   }
1555   assert(init_val == null_obj, "sanity");
1556   // Do nothing for Call nodes since its fields values are unknown.
1557   if (!alloc->is_Allocate())
1558     return 0;
1559 
1560   InitializeNode* ini = alloc->as_Allocate()->initialization();
1561   bool visited_bottom_offset = false;
1562   GrowableArray<int> offsets_worklist;
1563 
1564   // Check if an oop field's initializing value is recorded and add
1565   // a corresponding NULL if field's value if it is not recorded.
1566   // Connection Graph does not record a default initialization by NULL
1567   // captured by Initialize node.
1568   //
1569   for (EdgeIterator i(pta); i.has_next(); i.next()) {
1570     PointsToNode* field = i.get(); // Field (AddP)
1571     if (!field->is_Field() || !field->as_Field()->is_oop())
1572       continue; // Not oop field
1573     int offset = field->as_Field()->offset();
1574     if (offset == Type::OffsetBot) {
1575       if (!visited_bottom_offset) {
1576         // OffsetBot is used to reference array's element,
1577         // always add reference to NULL to all Field nodes since we don't
1578         // known which element is referenced.
1579         if (add_edge(field, null_obj)) {
1580           // New edge was added
1581           new_edges++;
1582           add_field_uses_to_worklist(field->as_Field());
1583           visited_bottom_offset = true;
1584         }
1585       }
1586     } else {
1587       // Check only oop fields.
1588       const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1589       if (adr_type->isa_rawptr()) {
1590 #ifdef ASSERT
1591         // Raw pointers are used for initializing stores so skip it
1592         // since it should be recorded already
1593         Node* base = get_addp_base(field->ideal_node());
1594         assert(adr_type->isa_rawptr() && base->is_Proj() &&
1595                (base->in(0) == alloc),"unexpected pointer type");
1596 #endif
1597         continue;
1598       }
1599       if (!offsets_worklist.contains(offset)) {
1600         offsets_worklist.append(offset);
1601         Node* value = NULL;
1602         if (ini != NULL) {
1603           // StoreP::memory_type() == T_ADDRESS
1604           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1605           Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1606           // Make sure initializing store has the same type as this AddP.
1607           // This AddP may reference non existing field because it is on a
1608           // dead branch of bimorphic call which is not eliminated yet.
1609           if (store != NULL && store->is_Store() &&
1610               store->as_Store()->memory_type() == ft) {
1611             value = store->in(MemNode::ValueIn);
1612 #ifdef ASSERT
1613             if (VerifyConnectionGraph) {
1614               // Verify that AddP already points to all objects the value points to.
1615               PointsToNode* val = ptnode_adr(value->_idx);
1616               assert((val != NULL), "should be processed already");
1617               PointsToNode* missed_obj = NULL;
1618               if (val->is_JavaObject()) {
1619                 if (!field->points_to(val->as_JavaObject())) {
1620                   missed_obj = val;
1621                 }
1622               } else {
1623                 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1624                   tty->print_cr("----------init store has invalid value -----");
1625                   store->dump();
1626                   val->dump();
1627                   assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1628                 }
1629                 for (EdgeIterator j(val); j.has_next(); j.next()) {
1630                   PointsToNode* obj = j.get();
1631                   if (obj->is_JavaObject()) {
1632                     if (!field->points_to(obj->as_JavaObject())) {
1633                       missed_obj = obj;
1634                       break;
1635                     }
1636                   }
1637                 }
1638               }
1639               if (missed_obj != NULL) {
1640                 tty->print_cr("----------field---------------------------------");
1641                 field->dump();
1642                 tty->print_cr("----------missed referernce to object-----------");
1643                 missed_obj->dump();
1644                 tty->print_cr("----------object referernced by init store -----");
1645                 store->dump();
1646                 val->dump();
1647                 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1648               }
1649             }
1650 #endif
1651           } else {
1652             // There could be initializing stores which follow allocation.
1653             // For example, a volatile field store is not collected
1654             // by Initialize node.
1655             //
1656             // Need to check for dependent loads to separate such stores from
1657             // stores which follow loads. For now, add initial value NULL so
1658             // that compare pointers optimization works correctly.
1659           }
1660         }
1661         if (value == NULL) {
1662           // A field's initializing value was not recorded. Add NULL.
1663           if (add_edge(field, null_obj)) {
1664             // New edge was added
1665             new_edges++;
1666             add_field_uses_to_worklist(field->as_Field());
1667           }
1668         }
1669       }
1670     }
1671   }
1672   return new_edges;
1673 }
1674 
1675 // Adjust scalar_replaceable state after Connection Graph is built.
1676 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1677   // Search for non-escaping objects which are not scalar replaceable
1678   // and mark them to propagate the state to referenced objects.
1679 
1680   // 1. An object is not scalar replaceable if the field into which it is
1681   // stored has unknown offset (stored into unknown element of an array).
1682   //
1683   for (UseIterator i(jobj); i.has_next(); i.next()) {
1684     PointsToNode* use = i.get();
1685     if (use->is_Arraycopy()) {
1686       continue;
1687     }
1688     if (use->is_Field()) {
1689       FieldNode* field = use->as_Field();
1690       assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1691       if (field->offset() == Type::OffsetBot) {
1692         jobj->set_scalar_replaceable(false);
1693         return;
1694       }
1695       // 2. An object is not scalar replaceable if the field into which it is
1696       // stored has multiple bases one of which is null.
1697       if (field->base_count() > 1) {
1698         for (BaseIterator i(field); i.has_next(); i.next()) {
1699           PointsToNode* base = i.get();
1700           if (base == null_obj) {
1701             jobj->set_scalar_replaceable(false);
1702             return;
1703           }
1704         }
1705       }
1706     }
1707     assert(use->is_Field() || use->is_LocalVar(), "sanity");
1708     // 3. An object is not scalar replaceable if it is merged with other objects.
1709     for (EdgeIterator j(use); j.has_next(); j.next()) {
1710       PointsToNode* ptn = j.get();
1711       if (ptn->is_JavaObject() && ptn != jobj) {
1712         // Mark all objects.
1713         jobj->set_scalar_replaceable(false);
1714          ptn->set_scalar_replaceable(false);
1715       }
1716     }
1717     if (!jobj->scalar_replaceable()) {
1718       return;
1719     }
1720   }
1721 
1722   for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1723     if (j.get()->is_Arraycopy()) {
1724       continue;
1725     }
1726 
1727     // Non-escaping object node should point only to field nodes.
1728     FieldNode* field = j.get()->as_Field();
1729     int offset = field->as_Field()->offset();
1730 
1731     // 4. An object is not scalar replaceable if it has a field with unknown
1732     // offset (array's element is accessed in loop).
1733     if (offset == Type::OffsetBot) {
1734       jobj->set_scalar_replaceable(false);
1735       return;
1736     }
1737     // 5. Currently an object is not scalar replaceable if a LoadStore node
1738     // access its field since the field value is unknown after it.
1739     //
1740     Node* n = field->ideal_node();
1741     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1742       if (n->fast_out(i)->is_LoadStore()) {
1743         jobj->set_scalar_replaceable(false);
1744         return;
1745       }
1746     }
1747 
1748     // 6. Or the address may point to more then one object. This may produce
1749     // the false positive result (set not scalar replaceable)
1750     // since the flow-insensitive escape analysis can't separate
1751     // the case when stores overwrite the field's value from the case
1752     // when stores happened on different control branches.
1753     //
1754     // Note: it will disable scalar replacement in some cases:
1755     //
1756     //    Point p[] = new Point[1];
1757     //    p[0] = new Point(); // Will be not scalar replaced
1758     //
1759     // but it will save us from incorrect optimizations in next cases:
1760     //
1761     //    Point p[] = new Point[1];
1762     //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
1763     //
1764     if (field->base_count() > 1) {
1765       for (BaseIterator i(field); i.has_next(); i.next()) {
1766         PointsToNode* base = i.get();
1767         // Don't take into account LocalVar nodes which
1768         // may point to only one object which should be also
1769         // this field's base by now.
1770         if (base->is_JavaObject() && base != jobj) {
1771           // Mark all bases.
1772           jobj->set_scalar_replaceable(false);
1773           base->set_scalar_replaceable(false);
1774         }
1775       }
1776     }
1777   }
1778 }
1779 
1780 #ifdef ASSERT
1781 void ConnectionGraph::verify_connection_graph(
1782                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1783                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1784                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1785                          GrowableArray<Node*>& addp_worklist) {
1786   // Verify that graph is complete - no new edges could be added.
1787   int java_objects_length = java_objects_worklist.length();
1788   int non_escaped_length  = non_escaped_worklist.length();
1789   int new_edges = 0;
1790   for (int next = 0; next < java_objects_length; ++next) {
1791     JavaObjectNode* ptn = java_objects_worklist.at(next);
1792     new_edges += add_java_object_edges(ptn, true);
1793   }
1794   assert(new_edges == 0, "graph was not complete");
1795   // Verify that escape state is final.
1796   int length = non_escaped_worklist.length();
1797   find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1798   assert((non_escaped_length == non_escaped_worklist.length()) &&
1799          (non_escaped_length == length) &&
1800          (_worklist.length() == 0), "escape state was not final");
1801 
1802   // Verify fields information.
1803   int addp_length = addp_worklist.length();
1804   for (int next = 0; next < addp_length; ++next ) {
1805     Node* n = addp_worklist.at(next);
1806     FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1807     if (field->is_oop()) {
1808       // Verify that field has all bases
1809       Node* base = get_addp_base(n);
1810       PointsToNode* ptn = ptnode_adr(base->_idx);
1811       if (ptn->is_JavaObject()) {
1812         assert(field->has_base(ptn->as_JavaObject()), "sanity");
1813       } else {
1814         assert(ptn->is_LocalVar(), "sanity");
1815         for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1816           PointsToNode* e = i.get();
1817           if (e->is_JavaObject()) {
1818             assert(field->has_base(e->as_JavaObject()), "sanity");
1819           }
1820         }
1821       }
1822       // Verify that all fields have initializing values.
1823       if (field->edge_count() == 0) {
1824         tty->print_cr("----------field does not have references----------");
1825         field->dump();
1826         for (BaseIterator i(field); i.has_next(); i.next()) {
1827           PointsToNode* base = i.get();
1828           tty->print_cr("----------field has next base---------------------");
1829           base->dump();
1830           if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1831             tty->print_cr("----------base has fields-------------------------");
1832             for (EdgeIterator j(base); j.has_next(); j.next()) {
1833               j.get()->dump();
1834             }
1835             tty->print_cr("----------base has references---------------------");
1836             for (UseIterator j(base); j.has_next(); j.next()) {
1837               j.get()->dump();
1838             }
1839           }
1840         }
1841         for (UseIterator i(field); i.has_next(); i.next()) {
1842           i.get()->dump();
1843         }
1844         assert(field->edge_count() > 0, "sanity");
1845       }
1846     }
1847   }
1848 }
1849 #endif
1850 
1851 // Optimize ideal graph.
1852 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1853                                            GrowableArray<Node*>& storestore_worklist) {
1854   Compile* C = _compile;
1855   PhaseIterGVN* igvn = _igvn;
1856   if (EliminateLocks) {
1857     // Mark locks before changing ideal graph.
1858     int cnt = C->macro_count();
1859     for( int i=0; i < cnt; i++ ) {
1860       Node *n = C->macro_node(i);
1861       if (n->is_AbstractLock()) { // Lock and Unlock nodes
1862         AbstractLockNode* alock = n->as_AbstractLock();
1863         if (!alock->is_non_esc_obj()) {
1864           if (not_global_escape(alock->obj_node())) {
1865             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1866             // The lock could be marked eliminated by lock coarsening
1867             // code during first IGVN before EA. Replace coarsened flag
1868             // to eliminate all associated locks/unlocks.
1869 #ifdef ASSERT
1870             alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1871 #endif
1872             alock->set_non_esc_obj();
1873           }
1874         }
1875       }
1876     }
1877   }
1878 
1879   if (OptimizePtrCompare) {
1880     // Add ConI(#CC_GT) and ConI(#CC_EQ).
1881     _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1882     _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1883     // Optimize objects compare.
1884     while (ptr_cmp_worklist.length() != 0) {
1885       Node *n = ptr_cmp_worklist.pop();
1886       Node *res = optimize_ptr_compare(n);
1887       if (res != NULL) {
1888 #ifndef PRODUCT
1889         if (PrintOptimizePtrCompare) {
1890           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"));
1891           if (Verbose) {
1892             n->dump(1);
1893           }
1894         }
1895 #endif
1896         igvn->replace_node(n, res);
1897       }
1898     }
1899     // cleanup
1900     if (_pcmp_neq->outcnt() == 0)
1901       igvn->hash_delete(_pcmp_neq);
1902     if (_pcmp_eq->outcnt()  == 0)
1903       igvn->hash_delete(_pcmp_eq);
1904   }
1905 
1906   // For MemBarStoreStore nodes added in library_call.cpp, check
1907   // escape status of associated AllocateNode and optimize out
1908   // MemBarStoreStore node if the allocated object never escapes.
1909   while (storestore_worklist.length() != 0) {
1910     Node *n = storestore_worklist.pop();
1911     MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1912     Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1913     assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1914     if (not_global_escape(alloc)) {
1915       MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1916       mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1917       mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1918       igvn->register_new_node_with_optimizer(mb);
1919       igvn->replace_node(storestore, mb);
1920     }
1921   }
1922 }
1923 
1924 // Optimize objects compare.
1925 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1926   assert(OptimizePtrCompare, "sanity");
1927   PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1928   PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1929   JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1930   JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1931   assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1932   assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1933 
1934   // Check simple cases first.
1935   if (jobj1 != NULL) {
1936     if (jobj1->escape_state() == PointsToNode::NoEscape) {
1937       if (jobj1 == jobj2) {
1938         // Comparing the same not escaping object.
1939         return _pcmp_eq;
1940       }
1941       Node* obj = jobj1->ideal_node();
1942       // Comparing not escaping allocation.
1943       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1944           !ptn2->points_to(jobj1)) {
1945         return _pcmp_neq; // This includes nullness check.
1946       }
1947     }
1948   }
1949   if (jobj2 != NULL) {
1950     if (jobj2->escape_state() == PointsToNode::NoEscape) {
1951       Node* obj = jobj2->ideal_node();
1952       // Comparing not escaping allocation.
1953       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1954           !ptn1->points_to(jobj2)) {
1955         return _pcmp_neq; // This includes nullness check.
1956       }
1957     }
1958   }
1959   if (jobj1 != NULL && jobj1 != phantom_obj &&
1960       jobj2 != NULL && jobj2 != phantom_obj &&
1961       jobj1->ideal_node()->is_Con() &&
1962       jobj2->ideal_node()->is_Con()) {
1963     // Klass or String constants compare. Need to be careful with
1964     // compressed pointers - compare types of ConN and ConP instead of nodes.
1965     const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1966     const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1967     if (t1->make_ptr() == t2->make_ptr()) {
1968       return _pcmp_eq;
1969     } else {
1970       return _pcmp_neq;
1971     }
1972   }
1973   if (ptn1->meet(ptn2)) {
1974     return NULL; // Sets are not disjoint
1975   }
1976 
1977   // Sets are disjoint.
1978   bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1979   bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1980   bool set1_has_null_ptr    = ptn1->points_to(null_obj);
1981   bool set2_has_null_ptr    = ptn2->points_to(null_obj);
1982   if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
1983       (set2_has_unknown_ptr && set1_has_null_ptr)) {
1984     // Check nullness of unknown object.
1985     return NULL;
1986   }
1987 
1988   // Disjointness by itself is not sufficient since
1989   // alias analysis is not complete for escaped objects.
1990   // Disjoint sets are definitely unrelated only when
1991   // at least one set has only not escaping allocations.
1992   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1993     if (ptn1->non_escaping_allocation()) {
1994       return _pcmp_neq;
1995     }
1996   }
1997   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1998     if (ptn2->non_escaping_allocation()) {
1999       return _pcmp_neq;
2000     }
2001   }
2002   return NULL;
2003 }
2004 
2005 // Connection Graph constuction functions.
2006 
2007 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
2008   PointsToNode* ptadr = _nodes.at(n->_idx);
2009   if (ptadr != NULL) {
2010     assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
2011     return;
2012   }
2013   Compile* C = _compile;
2014   ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2015   _nodes.at_put(n->_idx, ptadr);
2016 }
2017 
2018 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2019   PointsToNode* ptadr = _nodes.at(n->_idx);
2020   if (ptadr != NULL) {
2021     assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2022     return;
2023   }
2024   Compile* C = _compile;
2025   ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2026   _nodes.at_put(n->_idx, ptadr);
2027 }
2028 
2029 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2030   PointsToNode* ptadr = _nodes.at(n->_idx);
2031   if (ptadr != NULL) {
2032     assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2033     return;
2034   }
2035   bool unsafe = false;
2036   bool is_oop = is_oop_field(n, offset, &unsafe);
2037   if (unsafe) {
2038     es = PointsToNode::GlobalEscape;
2039   }
2040   Compile* C = _compile;
2041   FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2042   _nodes.at_put(n->_idx, field);
2043 }
2044 
2045 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2046                                     PointsToNode* src, PointsToNode* dst) {
2047   assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2048   assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2049   PointsToNode* ptadr = _nodes.at(n->_idx);
2050   if (ptadr != NULL) {
2051     assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2052     return;
2053   }
2054   Compile* C = _compile;
2055   ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2056   _nodes.at_put(n->_idx, ptadr);
2057   // Add edge from arraycopy node to source object.
2058   (void)add_edge(ptadr, src);
2059   src->set_arraycopy_src();
2060   // Add edge from destination object to arraycopy node.
2061   (void)add_edge(dst, ptadr);
2062   dst->set_arraycopy_dst();
2063 }
2064 
2065 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2066   const Type* adr_type = n->as_AddP()->bottom_type();
2067   int field_offset = adr_type->isa_aryptr() ? adr_type->isa_aryptr()->field_offset().get() : Type::OffsetBot;
2068   BasicType bt = T_INT;
2069   if (offset == Type::OffsetBot && field_offset == Type::OffsetBot) {
2070     // Check only oop fields.
2071     if (!adr_type->isa_aryptr() ||
2072         (adr_type->isa_aryptr()->klass() == NULL) ||
2073          adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2074       // OffsetBot is used to reference array's element. Ignore first AddP.
2075       if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2076         bt = T_OBJECT;
2077       }
2078     }
2079   } else if (offset != oopDesc::klass_offset_in_bytes()) {
2080     if (adr_type->isa_instptr() || adr_type->isa_valuetypeptr()) {
2081       ciField* field = _compile->alias_type(adr_type->is_ptr())->field();
2082       if (field != NULL) {
2083         bt = field->layout_type();
2084       } else {
2085         // Check for unsafe oop field access
2086         if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2087             n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2088             n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2089           bt = T_OBJECT;
2090           (*unsafe) = true;
2091         }
2092       }
2093     } else if (adr_type->isa_aryptr()) {
2094       if (offset == arrayOopDesc::length_offset_in_bytes()) {
2095         // Ignore array length load.
2096       } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2097         // Ignore first AddP.
2098       } else {
2099         const Type* elemtype = adr_type->isa_aryptr()->elem();
2100         if (elemtype->isa_valuetype() && field_offset != Type::OffsetBot) {
2101           ciValueKlass* vk = elemtype->is_valuetype()->value_klass();
2102           field_offset += vk->first_field_offset();
2103           bt = vk->get_field_by_offset(field_offset, false)->layout_type();
2104         } else {
2105           bt = elemtype->array_element_basic_type();
2106         }
2107       }
2108     } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2109       // Allocation initialization, ThreadLocal field access, unsafe access
2110       if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2111           n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2112           n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2113         bt = T_OBJECT;
2114       }
2115     }
2116   }
2117   // TODO enable when using T_VALUETYPEPTR
2118   //assert(bt != T_VALUETYPE, "should not have valuetype here");
2119   return (bt == T_OBJECT || bt == T_VALUETYPE || bt == T_VALUETYPEPTR || bt == T_NARROWOOP || bt == T_ARRAY);
2120 }
2121 
2122 // Returns unique pointed java object or NULL.
2123 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2124   assert(!_collecting, "should not call when contructed graph");
2125   // If the node was created after the escape computation we can't answer.
2126   uint idx = n->_idx;
2127   if (idx >= nodes_size()) {
2128     return NULL;
2129   }
2130   PointsToNode* ptn = ptnode_adr(idx);
2131   if (ptn->is_JavaObject()) {
2132     return ptn->as_JavaObject();
2133   }
2134   assert(ptn->is_LocalVar(), "sanity");
2135   // Check all java objects it points to.
2136   JavaObjectNode* jobj = NULL;
2137   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2138     PointsToNode* e = i.get();
2139     if (e->is_JavaObject()) {
2140       if (jobj == NULL) {
2141         jobj = e->as_JavaObject();
2142       } else if (jobj != e) {
2143         return NULL;
2144       }
2145     }
2146   }
2147   return jobj;
2148 }
2149 
2150 // Return true if this node points only to non-escaping allocations.
2151 bool PointsToNode::non_escaping_allocation() {
2152   if (is_JavaObject()) {
2153     Node* n = ideal_node();
2154     if (n->is_Allocate() || n->is_CallStaticJava()) {
2155       return (escape_state() == PointsToNode::NoEscape);
2156     } else {
2157       return false;
2158     }
2159   }
2160   assert(is_LocalVar(), "sanity");
2161   // Check all java objects it points to.
2162   for (EdgeIterator i(this); i.has_next(); i.next()) {
2163     PointsToNode* e = i.get();
2164     if (e->is_JavaObject()) {
2165       Node* n = e->ideal_node();
2166       if ((e->escape_state() != PointsToNode::NoEscape) ||
2167           !(n->is_Allocate() || n->is_CallStaticJava())) {
2168         return false;
2169       }
2170     }
2171   }
2172   return true;
2173 }
2174 
2175 // Return true if we know the node does not escape globally.
2176 bool ConnectionGraph::not_global_escape(Node *n) {
2177   assert(!_collecting, "should not call during graph construction");
2178   // If the node was created after the escape computation we can't answer.
2179   uint idx = n->_idx;
2180   if (idx >= nodes_size()) {
2181     return false;
2182   }
2183   PointsToNode* ptn = ptnode_adr(idx);
2184   PointsToNode::EscapeState es = ptn->escape_state();
2185   // If we have already computed a value, return it.
2186   if (es >= PointsToNode::GlobalEscape)
2187     return false;
2188   if (ptn->is_JavaObject()) {
2189     return true; // (es < PointsToNode::GlobalEscape);
2190   }
2191   assert(ptn->is_LocalVar(), "sanity");
2192   // Check all java objects it points to.
2193   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2194     if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2195       return false;
2196   }
2197   return true;
2198 }
2199 
2200 
2201 // Helper functions
2202 
2203 // Return true if this node points to specified node or nodes it points to.
2204 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2205   if (is_JavaObject()) {
2206     return (this == ptn);
2207   }
2208   assert(is_LocalVar() || is_Field(), "sanity");
2209   for (EdgeIterator i(this); i.has_next(); i.next()) {
2210     if (i.get() == ptn)
2211       return true;
2212   }
2213   return false;
2214 }
2215 
2216 // Return true if one node points to an other.
2217 bool PointsToNode::meet(PointsToNode* ptn) {
2218   if (this == ptn) {
2219     return true;
2220   } else if (ptn->is_JavaObject()) {
2221     return this->points_to(ptn->as_JavaObject());
2222   } else if (this->is_JavaObject()) {
2223     return ptn->points_to(this->as_JavaObject());
2224   }
2225   assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2226   int ptn_count =  ptn->edge_count();
2227   for (EdgeIterator i(this); i.has_next(); i.next()) {
2228     PointsToNode* this_e = i.get();
2229     for (int j = 0; j < ptn_count; j++) {
2230       if (this_e == ptn->edge(j))
2231         return true;
2232     }
2233   }
2234   return false;
2235 }
2236 
2237 #ifdef ASSERT
2238 // Return true if bases point to this java object.
2239 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2240   for (BaseIterator i(this); i.has_next(); i.next()) {
2241     if (i.get() == jobj)
2242       return true;
2243   }
2244   return false;
2245 }
2246 #endif
2247 
2248 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2249   const Type *adr_type = phase->type(adr);
2250   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2251       adr->in(AddPNode::Address)->is_Proj() &&
2252       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2253     // We are computing a raw address for a store captured by an Initialize
2254     // compute an appropriate address type. AddP cases #3 and #5 (see below).
2255     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2256     assert(offs != Type::OffsetBot ||
2257            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2258            "offset must be a constant or it is initialization of array");
2259     return offs;
2260   }
2261   const TypePtr *t_ptr = adr_type->isa_ptr();
2262   assert(t_ptr != NULL, "must be a pointer type");
2263   return t_ptr->offset();
2264 }
2265 
2266 Node* ConnectionGraph::get_addp_base(Node *addp) {
2267   assert(addp->is_AddP(), "must be AddP");
2268   //
2269   // AddP cases for Base and Address inputs:
2270   // case #1. Direct object's field reference:
2271   //     Allocate
2272   //       |
2273   //     Proj #5 ( oop result )
2274   //       |
2275   //     CheckCastPP (cast to instance type)
2276   //      | |
2277   //     AddP  ( base == address )
2278   //
2279   // case #2. Indirect object's field reference:
2280   //      Phi
2281   //       |
2282   //     CastPP (cast to instance type)
2283   //      | |
2284   //     AddP  ( base == address )
2285   //
2286   // case #3. Raw object's field reference for Initialize node:
2287   //      Allocate
2288   //        |
2289   //      Proj #5 ( oop result )
2290   //  top   |
2291   //     \  |
2292   //     AddP  ( base == top )
2293   //
2294   // case #4. Array's element reference:
2295   //   {CheckCastPP | CastPP}
2296   //     |  | |
2297   //     |  AddP ( array's element offset )
2298   //     |  |
2299   //     AddP ( array's offset )
2300   //
2301   // case #5. Raw object's field reference for arraycopy stub call:
2302   //          The inline_native_clone() case when the arraycopy stub is called
2303   //          after the allocation before Initialize and CheckCastPP nodes.
2304   //      Allocate
2305   //        |
2306   //      Proj #5 ( oop result )
2307   //       | |
2308   //       AddP  ( base == address )
2309   //
2310   // case #6. Constant Pool, ThreadLocal, CastX2P or
2311   //          Raw object's field reference:
2312   //      {ConP, ThreadLocal, CastX2P, raw Load}
2313   //  top   |
2314   //     \  |
2315   //     AddP  ( base == top )
2316   //
2317   // case #7. Klass's field reference.
2318   //      LoadKlass
2319   //       | |
2320   //       AddP  ( base == address )
2321   //
2322   // case #8. narrow Klass's field reference.
2323   //      LoadNKlass
2324   //       |
2325   //      DecodeN
2326   //       | |
2327   //       AddP  ( base == address )
2328   //
2329   // case #9. Mixed unsafe access
2330   //    {instance}
2331   //        |
2332   //      CheckCastPP (raw)
2333   //  top   |
2334   //     \  |
2335   //     AddP  ( base == top )
2336   //
2337   Node *base = addp->in(AddPNode::Base);
2338   if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
2339     base = addp->in(AddPNode::Address);
2340     while (base->is_AddP()) {
2341       // Case #6 (unsafe access) may have several chained AddP nodes.
2342       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2343       base = base->in(AddPNode::Address);
2344     }
2345     if (base->Opcode() == Op_CheckCastPP &&
2346         base->bottom_type()->isa_rawptr() &&
2347         _igvn->type(base->in(1))->isa_oopptr()) {
2348       base = base->in(1); // Case #9
2349     } else {
2350       Node* uncast_base = base->uncast();
2351       int opcode = uncast_base->Opcode();
2352       assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2353              opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2354              (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2355              (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2356     }
2357   }
2358   return base;
2359 }
2360 
2361 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2362   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2363   Node* addp2 = addp->raw_out(0);
2364   if (addp->outcnt() == 1 && addp2->is_AddP() &&
2365       addp2->in(AddPNode::Base) == n &&
2366       addp2->in(AddPNode::Address) == addp) {
2367     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2368     //
2369     // Find array's offset to push it on worklist first and
2370     // as result process an array's element offset first (pushed second)
2371     // to avoid CastPP for the array's offset.
2372     // Otherwise the inserted CastPP (LocalVar) will point to what
2373     // the AddP (Field) points to. Which would be wrong since
2374     // the algorithm expects the CastPP has the same point as
2375     // as AddP's base CheckCastPP (LocalVar).
2376     //
2377     //    ArrayAllocation
2378     //     |
2379     //    CheckCastPP
2380     //     |
2381     //    memProj (from ArrayAllocation CheckCastPP)
2382     //     |  ||
2383     //     |  ||   Int (element index)
2384     //     |  ||    |   ConI (log(element size))
2385     //     |  ||    |   /
2386     //     |  ||   LShift
2387     //     |  ||  /
2388     //     |  AddP (array's element offset)
2389     //     |  |
2390     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
2391     //     | / /
2392     //     AddP (array's offset)
2393     //      |
2394     //     Load/Store (memory operation on array's element)
2395     //
2396     return addp2;
2397   }
2398   return NULL;
2399 }
2400 
2401 //
2402 // Adjust the type and inputs of an AddP which computes the
2403 // address of a field of an instance
2404 //
2405 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2406   PhaseGVN* igvn = _igvn;
2407   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2408   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2409   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2410   if (t == NULL) {
2411     // We are computing a raw address for a store captured by an Initialize
2412     // compute an appropriate address type (cases #3 and #5).
2413     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2414     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2415     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2416     assert(offs != Type::OffsetBot, "offset must be a constant");
2417     t = base_t->add_offset(offs)->is_oopptr();
2418   }
2419   int inst_id = base_t->instance_id();
2420   assert(!t->is_known_instance() || t->instance_id() == inst_id,
2421                              "old type must be non-instance or match new type");
2422 
2423   // The type 't' could be subclass of 'base_t'.
2424   // As result t->offset() could be large then base_t's size and it will
2425   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2426   // constructor verifies correctness of the offset.
2427   //
2428   // It could happened on subclass's branch (from the type profiling
2429   // inlining) which was not eliminated during parsing since the exactness
2430   // of the allocation type was not propagated to the subclass type check.
2431   //
2432   // Or the type 't' could be not related to 'base_t' at all.
2433   // It could happened when CHA type is different from MDO type on a dead path
2434   // (for example, from instanceof check) which is not collapsed during parsing.
2435   //
2436   // Do nothing for such AddP node and don't process its users since
2437   // this code branch will go away.
2438   //
2439   if (!t->is_known_instance() &&
2440       !base_t->klass()->is_subtype_of(t->klass())) {
2441      return false; // bail out
2442   }
2443   const TypePtr* tinst = base_t->add_offset(t->offset());
2444   if (tinst->isa_aryptr() && t->isa_aryptr()) {
2445     // In the case of a flattened value type array, each field has its
2446     // own slice so we need to keep track of the field being accessed.
2447     tinst = tinst->is_aryptr()->with_field_offset(t->is_aryptr()->field_offset().get());
2448   }
2449 
2450   // Do NOT remove the next line: ensure a new alias index is allocated
2451   // for the instance type. Note: C++ will not remove it since the call
2452   // has side effect.
2453   int alias_idx = _compile->get_alias_index(tinst);
2454   igvn->set_type(addp, tinst);
2455   // record the allocation in the node map
2456   set_map(addp, get_map(base->_idx));
2457   // Set addp's Base and Address to 'base'.
2458   Node *abase = addp->in(AddPNode::Base);
2459   Node *adr   = addp->in(AddPNode::Address);
2460   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2461       adr->in(0)->_idx == (uint)inst_id) {
2462     // Skip AddP cases #3 and #5.
2463   } else {
2464     assert(!abase->is_top(), "sanity"); // AddP case #3
2465     if (abase != base) {
2466       igvn->hash_delete(addp);
2467       addp->set_req(AddPNode::Base, base);
2468       if (abase == adr) {
2469         addp->set_req(AddPNode::Address, base);
2470       } else {
2471         // AddP case #4 (adr is array's element offset AddP node)
2472 #ifdef ASSERT
2473         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2474         assert(adr->is_AddP() && atype != NULL &&
2475                atype->instance_id() == inst_id, "array's element offset should be processed first");
2476 #endif
2477       }
2478       igvn->hash_insert(addp);
2479     }
2480   }
2481   // Put on IGVN worklist since at least addp's type was changed above.
2482   record_for_optimizer(addp);
2483   return true;
2484 }
2485 
2486 //
2487 // Create a new version of orig_phi if necessary. Returns either the newly
2488 // created phi or an existing phi.  Sets create_new to indicate whether a new
2489 // phi was created.  Cache the last newly created phi in the node map.
2490 //
2491 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, bool &new_created) {
2492   Compile *C = _compile;
2493   PhaseGVN* igvn = _igvn;
2494   new_created = false;
2495   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2496   // nothing to do if orig_phi is bottom memory or matches alias_idx
2497   if (phi_alias_idx == alias_idx) {
2498     return orig_phi;
2499   }
2500   // Have we recently created a Phi for this alias index?
2501   PhiNode *result = get_map_phi(orig_phi->_idx);
2502   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2503     return result;
2504   }
2505   // Previous check may fail when the same wide memory Phi was split into Phis
2506   // for different memory slices. Search all Phis for this region.
2507   if (result != NULL) {
2508     Node* region = orig_phi->in(0);
2509     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2510       Node* phi = region->fast_out(i);
2511       if (phi->is_Phi() &&
2512           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2513         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2514         return phi->as_Phi();
2515       }
2516     }
2517   }
2518   if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2519     if (C->do_escape_analysis() == true && !C->failing()) {
2520       // Retry compilation without escape analysis.
2521       // If this is the first failure, the sentinel string will "stick"
2522       // to the Compile object, and the C2Compiler will see it and retry.
2523       C->record_failure(C2Compiler::retry_no_escape_analysis());
2524     }
2525     return NULL;
2526   }
2527   orig_phi_worklist.append_if_missing(orig_phi);
2528   const TypePtr *atype = C->get_adr_type(alias_idx);
2529   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2530   C->copy_node_notes_to(result, orig_phi);
2531   igvn->set_type(result, result->bottom_type());
2532   record_for_optimizer(result);
2533   set_map(orig_phi, result);
2534   new_created = true;
2535   return result;
2536 }
2537 
2538 //
2539 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2540 // specified alias index.
2541 //
2542 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist) {
2543   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2544   Compile *C = _compile;
2545   PhaseGVN* igvn = _igvn;
2546   bool new_phi_created;
2547   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2548   if (!new_phi_created) {
2549     return result;
2550   }
2551   GrowableArray<PhiNode *>  phi_list;
2552   GrowableArray<uint>  cur_input;
2553   PhiNode *phi = orig_phi;
2554   uint idx = 1;
2555   bool finished = false;
2556   while(!finished) {
2557     while (idx < phi->req()) {
2558       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2559       if (mem != NULL && mem->is_Phi()) {
2560         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2561         if (new_phi_created) {
2562           // found an phi for which we created a new split, push current one on worklist and begin
2563           // processing new one
2564           phi_list.push(phi);
2565           cur_input.push(idx);
2566           phi = mem->as_Phi();
2567           result = newphi;
2568           idx = 1;
2569           continue;
2570         } else {
2571           mem = newphi;
2572         }
2573       }
2574       if (C->failing()) {
2575         return NULL;
2576       }
2577       result->set_req(idx++, mem);
2578     }
2579 #ifdef ASSERT
2580     // verify that the new Phi has an input for each input of the original
2581     assert( phi->req() == result->req(), "must have same number of inputs.");
2582     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2583 #endif
2584     // Check if all new phi's inputs have specified alias index.
2585     // Otherwise use old phi.
2586     for (uint i = 1; i < phi->req(); i++) {
2587       Node* in = result->in(i);
2588       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2589     }
2590     // we have finished processing a Phi, see if there are any more to do
2591     finished = (phi_list.length() == 0 );
2592     if (!finished) {
2593       phi = phi_list.pop();
2594       idx = cur_input.pop();
2595       PhiNode *prev_result = get_map_phi(phi->_idx);
2596       prev_result->set_req(idx++, result);
2597       result = prev_result;
2598     }
2599   }
2600   return result;
2601 }
2602 
2603 //
2604 // The next methods are derived from methods in MemNode.
2605 //
2606 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2607   Node *mem = mmem;
2608   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2609   // means an array I have not precisely typed yet.  Do not do any
2610   // alias stuff with it any time soon.
2611   if (toop->base() != Type::AnyPtr &&
2612       !(toop->klass() != NULL &&
2613         toop->klass()->is_java_lang_Object() &&
2614         toop->offset() == Type::OffsetBot)) {
2615     mem = mmem->memory_at(alias_idx);
2616     // Update input if it is progress over what we have now
2617   }
2618   return mem;
2619 }
2620 
2621 //
2622 // Move memory users to their memory slices.
2623 //
2624 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis) {
2625   Compile* C = _compile;
2626   PhaseGVN* igvn = _igvn;
2627   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2628   assert(tp != NULL, "ptr type");
2629   int alias_idx = C->get_alias_index(tp);
2630   int general_idx = C->get_general_index(alias_idx);
2631 
2632   // Move users first
2633   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2634     Node* use = n->fast_out(i);
2635     if (use->is_MergeMem()) {
2636       MergeMemNode* mmem = use->as_MergeMem();
2637       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2638       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2639         continue; // Nothing to do
2640       }
2641       // Replace previous general reference to mem node.
2642       uint orig_uniq = C->unique();
2643       Node* m = find_inst_mem(n, general_idx, orig_phis);
2644       assert(orig_uniq == C->unique(), "no new nodes");
2645       mmem->set_memory_at(general_idx, m);
2646       --imax;
2647       --i;
2648     } else if (use->is_MemBar()) {
2649       assert(!use->is_Initialize(), "initializing stores should not be moved");
2650       if (use->req() > MemBarNode::Precedent &&
2651           use->in(MemBarNode::Precedent) == n) {
2652         // Don't move related membars.
2653         record_for_optimizer(use);
2654         continue;
2655       }
2656       tp = use->as_MemBar()->adr_type()->isa_ptr();
2657       if ((tp != NULL && C->get_alias_index(tp) == alias_idx) ||
2658           alias_idx == general_idx) {
2659         continue; // Nothing to do
2660       }
2661       // Move to general memory slice.
2662       uint orig_uniq = C->unique();
2663       Node* m = find_inst_mem(n, general_idx, orig_phis);
2664       assert(orig_uniq == C->unique(), "no new nodes");
2665       igvn->hash_delete(use);
2666       imax -= use->replace_edge(n, m);
2667       igvn->hash_insert(use);
2668       record_for_optimizer(use);
2669       --i;
2670 #ifdef ASSERT
2671     } else if (use->is_Mem()) {
2672       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2673         // Don't move related cardmark.
2674         continue;
2675       }
2676       // Memory nodes should have new memory input.
2677       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2678       assert(tp != NULL, "ptr type");
2679       int idx = C->get_alias_index(tp);
2680       assert(get_map(use->_idx) != NULL || idx == alias_idx,
2681              "Following memory nodes should have new memory input or be on the same memory slice");
2682     } else if (use->is_Phi()) {
2683       // Phi nodes should be split and moved already.
2684       tp = use->as_Phi()->adr_type()->isa_ptr();
2685       assert(tp != NULL, "ptr type");
2686       int idx = C->get_alias_index(tp);
2687       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2688     } else {
2689       use->dump();
2690       assert(false, "should not be here");
2691 #endif
2692     }
2693   }
2694 }
2695 
2696 //
2697 // Search memory chain of "mem" to find a MemNode whose address
2698 // is the specified alias index.
2699 //
2700 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis) {
2701   if (orig_mem == NULL)
2702     return orig_mem;
2703   Compile* C = _compile;
2704   PhaseGVN* igvn = _igvn;
2705   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2706   bool is_instance = (toop != NULL) && toop->is_known_instance();
2707   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2708   Node *prev = NULL;
2709   Node *result = orig_mem;
2710   while (prev != result) {
2711     prev = result;
2712     if (result == start_mem)
2713       break;  // hit one of our sentinels
2714     if (result->is_Mem()) {
2715       const Type *at = igvn->type(result->in(MemNode::Address));
2716       if (at == Type::TOP)
2717         break; // Dead
2718       assert (at->isa_ptr() != NULL, "pointer type required.");
2719       int idx = C->get_alias_index(at->is_ptr());
2720       if (idx == alias_idx)
2721         break; // Found
2722       if (!is_instance && (at->isa_oopptr() == NULL ||
2723                            !at->is_oopptr()->is_known_instance())) {
2724         break; // Do not skip store to general memory slice.
2725       }
2726       result = result->in(MemNode::Memory);
2727     }
2728     if (!is_instance)
2729       continue;  // don't search further for non-instance types
2730     // skip over a call which does not affect this memory slice
2731     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2732       Node *proj_in = result->in(0);
2733       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2734         break;  // hit one of our sentinels
2735       } else if (proj_in->is_Call()) {
2736         // ArrayCopy node processed here as well
2737         CallNode *call = proj_in->as_Call();
2738         if (!call->may_modify(toop, igvn)) {
2739           result = call->in(TypeFunc::Memory);
2740         }
2741       } else if (proj_in->is_Initialize()) {
2742         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2743         // Stop if this is the initialization for the object instance which
2744         // which contains this memory slice, otherwise skip over it.
2745         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2746           result = proj_in->in(TypeFunc::Memory);
2747         }
2748       } else if (proj_in->is_MemBar()) {
2749         if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2750             proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2751             proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2752           // clone
2753           ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2754           if (ac->may_modify(toop, igvn)) {
2755             break;
2756           }
2757         }
2758         result = proj_in->in(TypeFunc::Memory);
2759       }
2760     } else if (result->is_MergeMem()) {
2761       MergeMemNode *mmem = result->as_MergeMem();
2762       result = step_through_mergemem(mmem, alias_idx, toop);
2763       if (result == mmem->base_memory()) {
2764         // Didn't find instance memory, search through general slice recursively.
2765         result = mmem->memory_at(C->get_general_index(alias_idx));
2766         result = find_inst_mem(result, alias_idx, orig_phis);
2767         if (C->failing()) {
2768           return NULL;
2769         }
2770         mmem->set_memory_at(alias_idx, result);
2771       }
2772     } else if (result->is_Phi() &&
2773                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2774       Node *un = result->as_Phi()->unique_input(igvn);
2775       if (un != NULL) {
2776         orig_phis.append_if_missing(result->as_Phi());
2777         result = un;
2778       } else {
2779         break;
2780       }
2781     } else if (result->is_ClearArray()) {
2782       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2783         // Can not bypass initialization of the instance
2784         // we are looking for.
2785         break;
2786       }
2787       // Otherwise skip it (the call updated 'result' value).
2788     } else if (result->Opcode() == Op_SCMemProj) {
2789       Node* mem = result->in(0);
2790       Node* adr = NULL;
2791       if (mem->is_LoadStore()) {
2792         adr = mem->in(MemNode::Address);
2793       } else {
2794         assert(mem->Opcode() == Op_EncodeISOArray ||
2795                mem->Opcode() == Op_StrCompressedCopy, "sanity");
2796         adr = mem->in(3); // Memory edge corresponds to destination array
2797       }
2798       const Type *at = igvn->type(adr);
2799       if (at != Type::TOP) {
2800         assert(at->isa_ptr() != NULL, "pointer type required.");
2801         int idx = C->get_alias_index(at->is_ptr());
2802         if (idx == alias_idx) {
2803           // Assert in debug mode
2804           assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2805           break; // In product mode return SCMemProj node
2806         }
2807       }
2808       result = mem->in(MemNode::Memory);
2809     } else if (result->Opcode() == Op_StrInflatedCopy) {
2810       Node* adr = result->in(3); // Memory edge corresponds to destination array
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 StrInflatedCopy node accesses its field");
2818           break; // In product mode return SCMemProj node
2819         }
2820       }
2821       result = result->in(MemNode::Memory);
2822     }
2823   }
2824   if (result->is_Phi()) {
2825     PhiNode *mphi = result->as_Phi();
2826     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2827     const TypePtr *t = mphi->adr_type();
2828     if (!is_instance) {
2829       // Push all non-instance Phis on the orig_phis worklist to update inputs
2830       // during Phase 4 if needed.
2831       orig_phis.append_if_missing(mphi);
2832     } else if (C->get_alias_index(t) != alias_idx) {
2833       // Create a new Phi with the specified alias index type.
2834       result = split_memory_phi(mphi, alias_idx, orig_phis);
2835     }
2836   }
2837   // the result is either MemNode, PhiNode, InitializeNode.
2838   return result;
2839 }
2840 
2841 //
2842 //  Convert the types of unescaped object to instance types where possible,
2843 //  propagate the new type information through the graph, and update memory
2844 //  edges and MergeMem inputs to reflect the new type.
2845 //
2846 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
2847 //  The processing is done in 4 phases:
2848 //
2849 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
2850 //            types for the CheckCastPP for allocations where possible.
2851 //            Propagate the new types through users as follows:
2852 //               casts and Phi:  push users on alloc_worklist
2853 //               AddP:  cast Base and Address inputs to the instance type
2854 //                      push any AddP users on alloc_worklist and push any memnode
2855 //                      users onto memnode_worklist.
2856 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
2857 //            search the Memory chain for a store with the appropriate type
2858 //            address type.  If a Phi is found, create a new version with
2859 //            the appropriate memory slices from each of the Phi inputs.
2860 //            For stores, process the users as follows:
2861 //               MemNode:  push on memnode_worklist
2862 //               MergeMem: push on mergemem_worklist
2863 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
2864 //            moving the first node encountered of each  instance type to the
2865 //            the input corresponding to its alias index.
2866 //            appropriate memory slice.
2867 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2868 //
2869 // In the following example, the CheckCastPP nodes are the cast of allocation
2870 // results and the allocation of node 29 is unescaped and eligible to be an
2871 // instance type.
2872 //
2873 // We start with:
2874 //
2875 //     7 Parm #memory
2876 //    10  ConI  "12"
2877 //    19  CheckCastPP   "Foo"
2878 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2879 //    29  CheckCastPP   "Foo"
2880 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
2881 //
2882 //    40  StoreP  25   7  20   ... alias_index=4
2883 //    50  StoreP  35  40  30   ... alias_index=4
2884 //    60  StoreP  45  50  20   ... alias_index=4
2885 //    70  LoadP    _  60  30   ... alias_index=4
2886 //    80  Phi     75  50  60   Memory alias_index=4
2887 //    90  LoadP    _  80  30   ... alias_index=4
2888 //   100  LoadP    _  80  20   ... alias_index=4
2889 //
2890 //
2891 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2892 // and creating a new alias index for node 30.  This gives:
2893 //
2894 //     7 Parm #memory
2895 //    10  ConI  "12"
2896 //    19  CheckCastPP   "Foo"
2897 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2898 //    29  CheckCastPP   "Foo"  iid=24
2899 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2900 //
2901 //    40  StoreP  25   7  20   ... alias_index=4
2902 //    50  StoreP  35  40  30   ... alias_index=6
2903 //    60  StoreP  45  50  20   ... alias_index=4
2904 //    70  LoadP    _  60  30   ... alias_index=6
2905 //    80  Phi     75  50  60   Memory alias_index=4
2906 //    90  LoadP    _  80  30   ... alias_index=6
2907 //   100  LoadP    _  80  20   ... alias_index=4
2908 //
2909 // In phase 2, new memory inputs are computed for the loads and stores,
2910 // And a new version of the phi is created.  In phase 4, the inputs to
2911 // node 80 are updated and then the memory nodes are updated with the
2912 // values computed in phase 2.  This results in:
2913 //
2914 //     7 Parm #memory
2915 //    10  ConI  "12"
2916 //    19  CheckCastPP   "Foo"
2917 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2918 //    29  CheckCastPP   "Foo"  iid=24
2919 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2920 //
2921 //    40  StoreP  25  7   20   ... alias_index=4
2922 //    50  StoreP  35  7   30   ... alias_index=6
2923 //    60  StoreP  45  40  20   ... alias_index=4
2924 //    70  LoadP    _  50  30   ... alias_index=6
2925 //    80  Phi     75  40  60   Memory alias_index=4
2926 //   120  Phi     75  50  50   Memory alias_index=6
2927 //    90  LoadP    _ 120  30   ... alias_index=6
2928 //   100  LoadP    _  80  20   ... alias_index=4
2929 //
2930 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2931   GrowableArray<Node *>  memnode_worklist;
2932   GrowableArray<PhiNode *>  orig_phis;
2933   PhaseIterGVN  *igvn = _igvn;
2934   uint new_index_start = (uint) _compile->num_alias_types();
2935   Arena* arena = Thread::current()->resource_area();
2936   VectorSet visited(arena);
2937   ideal_nodes.clear(); // Reset for use with set_map/get_map.
2938   uint unique_old = _compile->unique();
2939 
2940   //  Phase 1:  Process possible allocations from alloc_worklist.
2941   //  Create instance types for the CheckCastPP for allocations where possible.
2942   //
2943   // (Note: don't forget to change the order of the second AddP node on
2944   //  the alloc_worklist if the order of the worklist processing is changed,
2945   //  see the comment in find_second_addp().)
2946   //
2947   while (alloc_worklist.length() != 0) {
2948     Node *n = alloc_worklist.pop();
2949     uint ni = n->_idx;
2950     if (n->is_Call()) {
2951       CallNode *alloc = n->as_Call();
2952       // copy escape information to call node
2953       PointsToNode* ptn = ptnode_adr(alloc->_idx);
2954       PointsToNode::EscapeState es = ptn->escape_state();
2955       // We have an allocation or call which returns a Java object,
2956       // see if it is unescaped.
2957       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2958         continue;
2959       // Find CheckCastPP for the allocate or for the return value of a call
2960       n = alloc->result_cast();
2961       if (n == NULL) {            // No uses except Initialize node
2962         if (alloc->is_Allocate()) {
2963           // Set the scalar_replaceable flag for allocation
2964           // so it could be eliminated if it has no uses.
2965           alloc->as_Allocate()->_is_scalar_replaceable = true;
2966         }
2967         if (alloc->is_CallStaticJava()) {
2968           // Set the scalar_replaceable flag for boxing method
2969           // so it could be eliminated if it has no uses.
2970           alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2971         }
2972         continue;
2973       }
2974       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2975         assert(!alloc->is_Allocate(), "allocation should have unique type");
2976         continue;
2977       }
2978 
2979       // The inline code for Object.clone() casts the allocation result to
2980       // java.lang.Object and then to the actual type of the allocated
2981       // object. Detect this case and use the second cast.
2982       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2983       // the allocation result is cast to java.lang.Object and then
2984       // to the actual Array type.
2985       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2986           && (alloc->is_AllocateArray() ||
2987               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2988         Node *cast2 = NULL;
2989         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2990           Node *use = n->fast_out(i);
2991           if (use->is_CheckCastPP()) {
2992             cast2 = use;
2993             break;
2994           }
2995         }
2996         if (cast2 != NULL) {
2997           n = cast2;
2998         } else {
2999           // Non-scalar replaceable if the allocation type is unknown statically
3000           // (reflection allocation), the object can't be restored during
3001           // deoptimization without precise type.
3002           continue;
3003         }
3004       }
3005 
3006       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
3007       if (t == NULL)
3008         continue;  // not a TypeOopPtr
3009       if (!t->klass_is_exact())
3010         continue; // not an unique type
3011 
3012       if (alloc->is_Allocate()) {
3013         // Set the scalar_replaceable flag for allocation
3014         // so it could be eliminated.
3015         alloc->as_Allocate()->_is_scalar_replaceable = true;
3016       }
3017       if (alloc->is_CallStaticJava()) {
3018         // Set the scalar_replaceable flag for boxing method
3019         // so it could be eliminated.
3020         alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
3021       }
3022       set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
3023       // in order for an object to be scalar-replaceable, it must be:
3024       //   - a direct allocation (not a call returning an object)
3025       //   - non-escaping
3026       //   - eligible to be a unique type
3027       //   - not determined to be ineligible by escape analysis
3028       set_map(alloc, n);
3029       set_map(n, alloc);
3030       const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3031       igvn->hash_delete(n);
3032       igvn->set_type(n,  tinst);
3033       n->raise_bottom_type(tinst);
3034       igvn->hash_insert(n);
3035       record_for_optimizer(n);
3036       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr() || t->isa_valuetypeptr())) {
3037 
3038         // First, put on the worklist all Field edges from Connection Graph
3039         // which is more accurate than putting immediate users from Ideal Graph.
3040         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3041           PointsToNode* tgt = e.get();
3042           if (tgt->is_Arraycopy()) {
3043             continue;
3044           }
3045           Node* use = tgt->ideal_node();
3046           assert(tgt->is_Field() && use->is_AddP(),
3047                  "only AddP nodes are Field edges in CG");
3048           if (use->outcnt() > 0) { // Don't process dead nodes
3049             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3050             if (addp2 != NULL) {
3051               assert(alloc->is_AllocateArray(),"array allocation was expected");
3052               alloc_worklist.append_if_missing(addp2);
3053             }
3054             alloc_worklist.append_if_missing(use);
3055           }
3056         }
3057 
3058         // An allocation may have an Initialize which has raw stores. Scan
3059         // the users of the raw allocation result and push AddP users
3060         // on alloc_worklist.
3061         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
3062         assert (raw_result != NULL, "must have an allocation result");
3063         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3064           Node *use = raw_result->fast_out(i);
3065           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3066             Node* addp2 = find_second_addp(use, raw_result);
3067             if (addp2 != NULL) {
3068               assert(alloc->is_AllocateArray(),"array allocation was expected");
3069               alloc_worklist.append_if_missing(addp2);
3070             }
3071             alloc_worklist.append_if_missing(use);
3072           } else if (use->is_MemBar()) {
3073             memnode_worklist.append_if_missing(use);
3074           }
3075         }
3076       }
3077     } else if (n->is_AddP()) {
3078       JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3079       if (jobj == NULL || jobj == phantom_obj) {
3080 #ifdef ASSERT
3081         ptnode_adr(get_addp_base(n)->_idx)->dump();
3082         ptnode_adr(n->_idx)->dump();
3083         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3084 #endif
3085         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3086         return;
3087       }
3088       Node *base = get_map(jobj->idx());  // CheckCastPP node
3089       if (!split_AddP(n, base)) continue; // wrong type from dead path
3090     } else if (n->is_Phi() ||
3091                n->is_CheckCastPP() ||
3092                n->is_EncodeP() ||
3093                n->is_DecodeN() ||
3094                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3095       if (visited.test_set(n->_idx)) {
3096         assert(n->is_Phi(), "loops only through Phi's");
3097         continue;  // already processed
3098       }
3099       JavaObjectNode* jobj = unique_java_object(n);
3100       if (jobj == NULL || jobj == phantom_obj) {
3101 #ifdef ASSERT
3102         ptnode_adr(n->_idx)->dump();
3103         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3104 #endif
3105         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3106         return;
3107       } else {
3108         Node *val = get_map(jobj->idx());   // CheckCastPP node
3109         TypeNode *tn = n->as_Type();
3110         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3111         assert(tinst != NULL && tinst->is_known_instance() &&
3112                tinst->instance_id() == jobj->idx() , "instance type expected.");
3113 
3114         const Type *tn_type = igvn->type(tn);
3115         const TypeOopPtr *tn_t;
3116         if (tn_type->isa_narrowoop()) {
3117           tn_t = tn_type->make_ptr()->isa_oopptr();
3118         } else {
3119           tn_t = tn_type->isa_oopptr();
3120         }
3121         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3122           if (tn_type->isa_narrowoop()) {
3123             tn_type = tinst->make_narrowoop();
3124           } else {
3125             tn_type = tinst;
3126           }
3127           igvn->hash_delete(tn);
3128           igvn->set_type(tn, tn_type);
3129           tn->set_type(tn_type);
3130           igvn->hash_insert(tn);
3131           record_for_optimizer(n);
3132         } else {
3133           assert(tn_type == TypePtr::NULL_PTR ||
3134                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3135                  "unexpected type");
3136           continue; // Skip dead path with different type
3137         }
3138       }
3139     } else {
3140       debug_only(n->dump();)
3141       assert(false, "EA: unexpected node");
3142       continue;
3143     }
3144     // push allocation's users on appropriate worklist
3145     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3146       Node *use = n->fast_out(i);
3147       if(use->is_Mem() && use->in(MemNode::Address) == n) {
3148         // Load/store to instance's field
3149         memnode_worklist.append_if_missing(use);
3150       } else if (use->is_MemBar()) {
3151         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3152           memnode_worklist.append_if_missing(use);
3153         }
3154       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3155         Node* addp2 = find_second_addp(use, n);
3156         if (addp2 != NULL) {
3157           alloc_worklist.append_if_missing(addp2);
3158         }
3159         alloc_worklist.append_if_missing(use);
3160       } else if (use->is_Phi() ||
3161                  use->is_CheckCastPP() ||
3162                  use->is_EncodeNarrowPtr() ||
3163                  use->is_DecodeNarrowPtr() ||
3164                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3165         alloc_worklist.append_if_missing(use);
3166 #ifdef ASSERT
3167       } else if (use->is_Mem()) {
3168         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3169       } else if (use->is_MergeMem()) {
3170         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3171       } else if (use->is_SafePoint()) {
3172         // Look for MergeMem nodes for calls which reference unique allocation
3173         // (through CheckCastPP nodes) even for debug info.
3174         Node* m = use->in(TypeFunc::Memory);
3175         if (m->is_MergeMem()) {
3176           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3177         }
3178       } else if (use->Opcode() == Op_EncodeISOArray) {
3179         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3180           // EncodeISOArray overwrites destination array
3181           memnode_worklist.append_if_missing(use);
3182         }
3183       } else if (use->Opcode() == Op_Return) {
3184         assert(_compile->tf()->returns_value_type_as_fields(), "must return a value type");
3185         // Get ValueKlass by removing the tag bit from the metadata pointer
3186         Node* klass = use->in(TypeFunc::Parms);
3187         intptr_t ptr = igvn->type(klass)->isa_rawptr()->get_con();
3188         clear_nth_bit(ptr, 0);
3189         assert(Metaspace::contains((void*)ptr), "should be klass");
3190         assert(((ValueKlass*)ptr)->contains_oops(), "returned value type must contain a reference field");
3191       } else {
3192         uint op = use->Opcode();
3193         if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3194             (use->in(MemNode::Memory) == n)) {
3195           // They overwrite memory edge corresponding to destination array,
3196           memnode_worklist.append_if_missing(use);
3197         } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3198               op == Op_CastP2X || op == Op_StoreCM ||
3199               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3200               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3201               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
3202               op == Op_ValueType)) {
3203           n->dump();
3204           use->dump();
3205           assert(false, "EA: missing allocation reference path");
3206         }
3207 #endif
3208       }
3209     }
3210 
3211   }
3212 
3213   // Go over all ArrayCopy nodes and if one of the inputs has a unique
3214   // type, record it in the ArrayCopy node so we know what memory this
3215   // node uses/modified.
3216   for (int next = 0; next < arraycopy_worklist.length(); next++) {
3217     ArrayCopyNode* ac = arraycopy_worklist.at(next);
3218     Node* dest = ac->in(ArrayCopyNode::Dest);
3219     if (dest->is_AddP()) {
3220       dest = get_addp_base(dest);
3221     }
3222     JavaObjectNode* jobj = unique_java_object(dest);
3223     if (jobj != NULL) {
3224       Node *base = get_map(jobj->idx());
3225       if (base != NULL) {
3226         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3227         ac->_dest_type = base_t;
3228       }
3229     }
3230     Node* src = ac->in(ArrayCopyNode::Src);
3231     if (src->is_AddP()) {
3232       src = get_addp_base(src);
3233     }
3234     jobj = unique_java_object(src);
3235     if (jobj != NULL) {
3236       Node* base = get_map(jobj->idx());
3237       if (base != NULL) {
3238         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3239         ac->_src_type = base_t;
3240       }
3241     }
3242   }
3243 
3244   // New alias types were created in split_AddP().
3245   uint new_index_end = (uint) _compile->num_alias_types();
3246   assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3247 
3248   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
3249   //            compute new values for Memory inputs  (the Memory inputs are not
3250   //            actually updated until phase 4.)
3251   if (memnode_worklist.length() == 0)
3252     return;  // nothing to do
3253   while (memnode_worklist.length() != 0) {
3254     Node *n = memnode_worklist.pop();
3255     if (visited.test_set(n->_idx))
3256       continue;
3257     if (n->is_Phi() || n->is_ClearArray()) {
3258       // we don't need to do anything, but the users must be pushed
3259     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3260       // we don't need to do anything, but the users must be pushed
3261       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3262       if (n == NULL)
3263         continue;
3264     } else if (n->Opcode() == Op_StrCompressedCopy ||
3265                n->Opcode() == Op_EncodeISOArray) {
3266       // get the memory projection
3267       n = n->find_out_with(Op_SCMemProj);
3268       assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3269     } else {
3270       assert(n->is_Mem(), "memory node required.");
3271       Node *addr = n->in(MemNode::Address);
3272       const Type *addr_t = igvn->type(addr);
3273       if (addr_t == Type::TOP)
3274         continue;
3275       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3276       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3277       assert ((uint)alias_idx < new_index_end, "wrong alias index");
3278       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3279       if (_compile->failing()) {
3280         return;
3281       }
3282       if (mem != n->in(MemNode::Memory)) {
3283         // We delay the memory edge update since we need old one in
3284         // MergeMem code below when instances memory slices are separated.
3285         set_map(n, mem);
3286       }
3287       if (n->is_Load()) {
3288         continue;  // don't push users
3289       } else if (n->is_LoadStore()) {
3290         // get the memory projection
3291         n = n->find_out_with(Op_SCMemProj);
3292         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3293       }
3294     }
3295     // push user on appropriate worklist
3296     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3297       Node *use = n->fast_out(i);
3298       if (use->is_Phi() || use->is_ClearArray()) {
3299         memnode_worklist.append_if_missing(use);
3300       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3301         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3302           continue;
3303         memnode_worklist.append_if_missing(use);
3304       } else if (use->is_MemBar()) {
3305         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3306           memnode_worklist.append_if_missing(use);
3307         }
3308 #ifdef ASSERT
3309       } else if(use->is_Mem()) {
3310         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3311       } else if (use->is_MergeMem()) {
3312         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3313       } else if (use->Opcode() == Op_EncodeISOArray) {
3314         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3315           // EncodeISOArray overwrites destination array
3316           memnode_worklist.append_if_missing(use);
3317         }
3318       } else {
3319         uint op = use->Opcode();
3320         if ((use->in(MemNode::Memory) == n) &&
3321             (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3322           // They overwrite memory edge corresponding to destination array,
3323           memnode_worklist.append_if_missing(use);
3324         } else if (!(op == Op_StoreCM ||
3325               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3326                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3327               op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3328               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3329               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3330           n->dump();
3331           use->dump();
3332           assert(false, "EA: missing memory path");
3333         }
3334 #endif
3335       }
3336     }
3337   }
3338 
3339   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
3340   //            Walk each memory slice moving the first node encountered of each
3341   //            instance type to the input corresponding to its alias index.
3342   uint length = _mergemem_worklist.length();
3343   for( uint next = 0; next < length; ++next ) {
3344     MergeMemNode* nmm = _mergemem_worklist.at(next);
3345     assert(!visited.test_set(nmm->_idx), "should not be visited before");
3346     // Note: we don't want to use MergeMemStream here because we only want to
3347     // scan inputs which exist at the start, not ones we add during processing.
3348     // Note 2: MergeMem may already contains instance memory slices added
3349     // during find_inst_mem() call when memory nodes were processed above.
3350     igvn->hash_delete(nmm);
3351     uint nslices = MIN2(nmm->req(), new_index_start);
3352     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3353       Node* mem = nmm->in(i);
3354       Node* cur = NULL;
3355       if (mem == NULL || mem->is_top())
3356         continue;
3357       // First, update mergemem by moving memory nodes to corresponding slices
3358       // if their type became more precise since this mergemem was created.
3359       while (mem->is_Mem()) {
3360         const Type *at = igvn->type(mem->in(MemNode::Address));
3361         if (at != Type::TOP) {
3362           assert (at->isa_ptr() != NULL, "pointer type required.");
3363           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3364           if (idx == i) {
3365             if (cur == NULL)
3366               cur = mem;
3367           } else {
3368             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3369               nmm->set_memory_at(idx, mem);
3370             }
3371           }
3372         }
3373         mem = mem->in(MemNode::Memory);
3374       }
3375       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3376       // Find any instance of the current type if we haven't encountered
3377       // already a memory slice of the instance along the memory chain.
3378       for (uint ni = new_index_start; ni < new_index_end; ni++) {
3379         if((uint)_compile->get_general_index(ni) == i) {
3380           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3381           if (nmm->is_empty_memory(m)) {
3382             Node* result = find_inst_mem(mem, ni, orig_phis);
3383             if (_compile->failing()) {
3384               return;
3385             }
3386             nmm->set_memory_at(ni, result);
3387           }
3388         }
3389       }
3390     }
3391     // Find the rest of instances values
3392     for (uint ni = new_index_start; ni < new_index_end; ni++) {
3393       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3394       Node* result = step_through_mergemem(nmm, ni, tinst);
3395       if (result == nmm->base_memory()) {
3396         // Didn't find instance memory, search through general slice recursively.
3397         result = nmm->memory_at(_compile->get_general_index(ni));
3398         result = find_inst_mem(result, ni, orig_phis);
3399         if (_compile->failing()) {
3400           return;
3401         }
3402         nmm->set_memory_at(ni, result);
3403       }
3404     }
3405     igvn->hash_insert(nmm);
3406     record_for_optimizer(nmm);
3407   }
3408 
3409   //  Phase 4:  Update the inputs of non-instance memory Phis and
3410   //            the Memory input of memnodes
3411   // First update the inputs of any non-instance Phi's from
3412   // which we split out an instance Phi.  Note we don't have
3413   // to recursively process Phi's encountered on the input memory
3414   // chains as is done in split_memory_phi() since they will
3415   // also be processed here.
3416   for (int j = 0; j < orig_phis.length(); j++) {
3417     PhiNode *phi = orig_phis.at(j);
3418     int alias_idx = _compile->get_alias_index(phi->adr_type());
3419     igvn->hash_delete(phi);
3420     for (uint i = 1; i < phi->req(); i++) {
3421       Node *mem = phi->in(i);
3422       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3423       if (_compile->failing()) {
3424         return;
3425       }
3426       if (mem != new_mem) {
3427         phi->set_req(i, new_mem);
3428       }
3429     }
3430     igvn->hash_insert(phi);
3431     record_for_optimizer(phi);
3432   }
3433 
3434   // Update the memory inputs of MemNodes with the value we computed
3435   // in Phase 2 and move stores memory users to corresponding memory slices.
3436   // Disable memory split verification code until the fix for 6984348.
3437   // Currently it produces false negative results since it does not cover all cases.
3438 #if 0 // ifdef ASSERT
3439   visited.Reset();
3440   Node_Stack old_mems(arena, _compile->unique() >> 2);
3441 #endif
3442   for (uint i = 0; i < ideal_nodes.size(); i++) {
3443     Node*    n = ideal_nodes.at(i);
3444     Node* nmem = get_map(n->_idx);
3445     assert(nmem != NULL, "sanity");
3446     if (n->is_Mem()) {
3447 #if 0 // ifdef ASSERT
3448       Node* old_mem = n->in(MemNode::Memory);
3449       if (!visited.test_set(old_mem->_idx)) {
3450         old_mems.push(old_mem, old_mem->outcnt());
3451       }
3452 #endif
3453       assert(n->in(MemNode::Memory) != nmem, "sanity");
3454       if (!n->is_Load()) {
3455         // Move memory users of a store first.
3456         move_inst_mem(n, orig_phis);
3457       }
3458       // Now update memory input
3459       igvn->hash_delete(n);
3460       n->set_req(MemNode::Memory, nmem);
3461       igvn->hash_insert(n);
3462       record_for_optimizer(n);
3463     } else {
3464       assert(n->is_Allocate() || n->is_CheckCastPP() ||
3465              n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3466     }
3467   }
3468 #if 0 // ifdef ASSERT
3469   // Verify that memory was split correctly
3470   while (old_mems.is_nonempty()) {
3471     Node* old_mem = old_mems.node();
3472     uint  old_cnt = old_mems.index();
3473     old_mems.pop();
3474     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3475   }
3476 #endif
3477 }
3478 
3479 #ifndef PRODUCT
3480 static const char *node_type_names[] = {
3481   "UnknownType",
3482   "JavaObject",
3483   "LocalVar",
3484   "Field",
3485   "Arraycopy"
3486 };
3487 
3488 static const char *esc_names[] = {
3489   "UnknownEscape",
3490   "NoEscape",
3491   "ArgEscape",
3492   "GlobalEscape"
3493 };
3494 
3495 void PointsToNode::dump(bool print_state) const {
3496   NodeType nt = node_type();
3497   tty->print("%s ", node_type_names[(int) nt]);
3498   if (print_state) {
3499     EscapeState es = escape_state();
3500     EscapeState fields_es = fields_escape_state();
3501     tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3502     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3503       tty->print("NSR ");
3504   }
3505   if (is_Field()) {
3506     FieldNode* f = (FieldNode*)this;
3507     if (f->is_oop())
3508       tty->print("oop ");
3509     if (f->offset() > 0)
3510       tty->print("+%d ", f->offset());
3511     tty->print("(");
3512     for (BaseIterator i(f); i.has_next(); i.next()) {
3513       PointsToNode* b = i.get();
3514       tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3515     }
3516     tty->print(" )");
3517   }
3518   tty->print("[");
3519   for (EdgeIterator i(this); i.has_next(); i.next()) {
3520     PointsToNode* e = i.get();
3521     tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3522   }
3523   tty->print(" [");
3524   for (UseIterator i(this); i.has_next(); i.next()) {
3525     PointsToNode* u = i.get();
3526     bool is_base = false;
3527     if (PointsToNode::is_base_use(u)) {
3528       is_base = true;
3529       u = PointsToNode::get_use_node(u)->as_Field();
3530     }
3531     tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3532   }
3533   tty->print(" ]]  ");
3534   if (_node == NULL)
3535     tty->print_cr("<null>");
3536   else
3537     _node->dump();
3538 }
3539 
3540 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3541   bool first = true;
3542   int ptnodes_length = ptnodes_worklist.length();
3543   for (int i = 0; i < ptnodes_length; i++) {
3544     PointsToNode *ptn = ptnodes_worklist.at(i);
3545     if (ptn == NULL || !ptn->is_JavaObject())
3546       continue;
3547     PointsToNode::EscapeState es = ptn->escape_state();
3548     if ((es != PointsToNode::NoEscape) && !Verbose) {
3549       continue;
3550     }
3551     Node* n = ptn->ideal_node();
3552     if (n->is_Allocate() || (n->is_CallStaticJava() &&
3553                              n->as_CallStaticJava()->is_boxing_method())) {
3554       if (first) {
3555         tty->cr();
3556         tty->print("======== Connection graph for ");
3557         _compile->method()->print_short_name();
3558         tty->cr();
3559         first = false;
3560       }
3561       ptn->dump();
3562       // Print all locals and fields which reference this allocation
3563       for (UseIterator j(ptn); j.has_next(); j.next()) {
3564         PointsToNode* use = j.get();
3565         if (use->is_LocalVar()) {
3566           use->dump(Verbose);
3567         } else if (Verbose) {
3568           use->dump();
3569         }
3570       }
3571       tty->cr();
3572     }
3573   }
3574 }
3575 #endif