1 /*
   2  * Copyright (c) 2005, 2016, 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_oopptr()) {
 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_oopptr())) {
 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_oopptr())) {
 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()) {
2101           assert(field_offset != Type::OffsetBot, "invalid field offset");
2102           ciValueKlass* vk = elemtype->is_valuetype()->value_klass();
2103           field_offset += vk->first_field_offset();
2104           bt = vk->get_field_by_offset(field_offset, false)->layout_type();
2105         } else {
2106           bt = elemtype->array_element_basic_type();
2107         }
2108       }
2109     } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2110       // Allocation initialization, ThreadLocal field access, unsafe access
2111       if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2112           n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2113           n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2114         bt = T_OBJECT;
2115       }
2116     }
2117   }
2118   return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2119 }
2120 
2121 // Returns unique pointed java object or NULL.
2122 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2123   assert(!_collecting, "should not call when contructed graph");
2124   // If the node was created after the escape computation we can't answer.
2125   uint idx = n->_idx;
2126   if (idx >= nodes_size()) {
2127     return NULL;
2128   }
2129   PointsToNode* ptn = ptnode_adr(idx);
2130   if (ptn->is_JavaObject()) {
2131     return ptn->as_JavaObject();
2132   }
2133   assert(ptn->is_LocalVar(), "sanity");
2134   // Check all java objects it points to.
2135   JavaObjectNode* jobj = NULL;
2136   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2137     PointsToNode* e = i.get();
2138     if (e->is_JavaObject()) {
2139       if (jobj == NULL) {
2140         jobj = e->as_JavaObject();
2141       } else if (jobj != e) {
2142         return NULL;
2143       }
2144     }
2145   }
2146   return jobj;
2147 }
2148 
2149 // Return true if this node points only to non-escaping allocations.
2150 bool PointsToNode::non_escaping_allocation() {
2151   if (is_JavaObject()) {
2152     Node* n = ideal_node();
2153     if (n->is_Allocate() || n->is_CallStaticJava()) {
2154       return (escape_state() == PointsToNode::NoEscape);
2155     } else {
2156       return false;
2157     }
2158   }
2159   assert(is_LocalVar(), "sanity");
2160   // Check all java objects it points to.
2161   for (EdgeIterator i(this); i.has_next(); i.next()) {
2162     PointsToNode* e = i.get();
2163     if (e->is_JavaObject()) {
2164       Node* n = e->ideal_node();
2165       if ((e->escape_state() != PointsToNode::NoEscape) ||
2166           !(n->is_Allocate() || n->is_CallStaticJava())) {
2167         return false;
2168       }
2169     }
2170   }
2171   return true;
2172 }
2173 
2174 // Return true if we know the node does not escape globally.
2175 bool ConnectionGraph::not_global_escape(Node *n) {
2176   assert(!_collecting, "should not call during graph construction");
2177   // If the node was created after the escape computation we can't answer.
2178   uint idx = n->_idx;
2179   if (idx >= nodes_size()) {
2180     return false;
2181   }
2182   PointsToNode* ptn = ptnode_adr(idx);
2183   PointsToNode::EscapeState es = ptn->escape_state();
2184   // If we have already computed a value, return it.
2185   if (es >= PointsToNode::GlobalEscape)
2186     return false;
2187   if (ptn->is_JavaObject()) {
2188     return true; // (es < PointsToNode::GlobalEscape);
2189   }
2190   assert(ptn->is_LocalVar(), "sanity");
2191   // Check all java objects it points to.
2192   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2193     if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2194       return false;
2195   }
2196   return true;
2197 }
2198 
2199 
2200 // Helper functions
2201 
2202 // Return true if this node points to specified node or nodes it points to.
2203 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2204   if (is_JavaObject()) {
2205     return (this == ptn);
2206   }
2207   assert(is_LocalVar() || is_Field(), "sanity");
2208   for (EdgeIterator i(this); i.has_next(); i.next()) {
2209     if (i.get() == ptn)
2210       return true;
2211   }
2212   return false;
2213 }
2214 
2215 // Return true if one node points to an other.
2216 bool PointsToNode::meet(PointsToNode* ptn) {
2217   if (this == ptn) {
2218     return true;
2219   } else if (ptn->is_JavaObject()) {
2220     return this->points_to(ptn->as_JavaObject());
2221   } else if (this->is_JavaObject()) {
2222     return ptn->points_to(this->as_JavaObject());
2223   }
2224   assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2225   int ptn_count =  ptn->edge_count();
2226   for (EdgeIterator i(this); i.has_next(); i.next()) {
2227     PointsToNode* this_e = i.get();
2228     for (int j = 0; j < ptn_count; j++) {
2229       if (this_e == ptn->edge(j))
2230         return true;
2231     }
2232   }
2233   return false;
2234 }
2235 
2236 #ifdef ASSERT
2237 // Return true if bases point to this java object.
2238 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2239   for (BaseIterator i(this); i.has_next(); i.next()) {
2240     if (i.get() == jobj)
2241       return true;
2242   }
2243   return false;
2244 }
2245 #endif
2246 
2247 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2248   const Type *adr_type = phase->type(adr);
2249   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2250       adr->in(AddPNode::Address)->is_Proj() &&
2251       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2252     // We are computing a raw address for a store captured by an Initialize
2253     // compute an appropriate address type. AddP cases #3 and #5 (see below).
2254     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2255     assert(offs != Type::OffsetBot ||
2256            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2257            "offset must be a constant or it is initialization of array");
2258     return offs;
2259   }
2260   const TypePtr *t_ptr = adr_type->isa_ptr();
2261   assert(t_ptr != NULL, "must be a pointer type");
2262   return t_ptr->offset();
2263 }
2264 
2265 Node* ConnectionGraph::get_addp_base(Node *addp) {
2266   assert(addp->is_AddP(), "must be AddP");
2267   //
2268   // AddP cases for Base and Address inputs:
2269   // case #1. Direct object's field reference:
2270   //     Allocate
2271   //       |
2272   //     Proj #5 ( oop result )
2273   //       |
2274   //     CheckCastPP (cast to instance type)
2275   //      | |
2276   //     AddP  ( base == address )
2277   //
2278   // case #2. Indirect object's field reference:
2279   //      Phi
2280   //       |
2281   //     CastPP (cast to instance type)
2282   //      | |
2283   //     AddP  ( base == address )
2284   //
2285   // case #3. Raw object's field reference for Initialize node:
2286   //      Allocate
2287   //        |
2288   //      Proj #5 ( oop result )
2289   //  top   |
2290   //     \  |
2291   //     AddP  ( base == top )
2292   //
2293   // case #4. Array's element reference:
2294   //   {CheckCastPP | CastPP}
2295   //     |  | |
2296   //     |  AddP ( array's element offset )
2297   //     |  |
2298   //     AddP ( array's offset )
2299   //
2300   // case #5. Raw object's field reference for arraycopy stub call:
2301   //          The inline_native_clone() case when the arraycopy stub is called
2302   //          after the allocation before Initialize and CheckCastPP nodes.
2303   //      Allocate
2304   //        |
2305   //      Proj #5 ( oop result )
2306   //       | |
2307   //       AddP  ( base == address )
2308   //
2309   // case #6. Constant Pool, ThreadLocal, CastX2P or
2310   //          Raw object's field reference:
2311   //      {ConP, ThreadLocal, CastX2P, raw Load}
2312   //  top   |
2313   //     \  |
2314   //     AddP  ( base == top )
2315   //
2316   // case #7. Klass's field reference.
2317   //      LoadKlass
2318   //       | |
2319   //       AddP  ( base == address )
2320   //
2321   // case #8. narrow Klass's field reference.
2322   //      LoadNKlass
2323   //       |
2324   //      DecodeN
2325   //       | |
2326   //       AddP  ( base == address )
2327   //
2328   Node *base = addp->in(AddPNode::Base);
2329   if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2330     base = addp->in(AddPNode::Address);
2331     while (base->is_AddP()) {
2332       // Case #6 (unsafe access) may have several chained AddP nodes.
2333       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2334       base = base->in(AddPNode::Address);
2335     }
2336     Node* uncast_base = base->uncast();
2337     int opcode = uncast_base->Opcode();
2338     assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2339            opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2340            (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2341            (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2342   }
2343   return base;
2344 }
2345 
2346 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2347   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2348   Node* addp2 = addp->raw_out(0);
2349   if (addp->outcnt() == 1 && addp2->is_AddP() &&
2350       addp2->in(AddPNode::Base) == n &&
2351       addp2->in(AddPNode::Address) == addp) {
2352     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2353     //
2354     // Find array's offset to push it on worklist first and
2355     // as result process an array's element offset first (pushed second)
2356     // to avoid CastPP for the array's offset.
2357     // Otherwise the inserted CastPP (LocalVar) will point to what
2358     // the AddP (Field) points to. Which would be wrong since
2359     // the algorithm expects the CastPP has the same point as
2360     // as AddP's base CheckCastPP (LocalVar).
2361     //
2362     //    ArrayAllocation
2363     //     |
2364     //    CheckCastPP
2365     //     |
2366     //    memProj (from ArrayAllocation CheckCastPP)
2367     //     |  ||
2368     //     |  ||   Int (element index)
2369     //     |  ||    |   ConI (log(element size))
2370     //     |  ||    |   /
2371     //     |  ||   LShift
2372     //     |  ||  /
2373     //     |  AddP (array's element offset)
2374     //     |  |
2375     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
2376     //     | / /
2377     //     AddP (array's offset)
2378     //      |
2379     //     Load/Store (memory operation on array's element)
2380     //
2381     return addp2;
2382   }
2383   return NULL;
2384 }
2385 
2386 //
2387 // Adjust the type and inputs of an AddP which computes the
2388 // address of a field of an instance
2389 //
2390 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2391   PhaseGVN* igvn = _igvn;
2392   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2393   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2394   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2395   if (t == NULL) {
2396     // We are computing a raw address for a store captured by an Initialize
2397     // compute an appropriate address type (cases #3 and #5).
2398     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2399     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2400     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2401     assert(offs != Type::OffsetBot, "offset must be a constant");
2402     t = base_t->add_offset(offs)->is_oopptr();
2403   }
2404   int inst_id = base_t->instance_id();
2405   assert(!t->is_known_instance() || t->instance_id() == inst_id,
2406                              "old type must be non-instance or match new type");
2407 
2408   // The type 't' could be subclass of 'base_t'.
2409   // As result t->offset() could be large then base_t's size and it will
2410   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2411   // constructor verifies correctness of the offset.
2412   //
2413   // It could happened on subclass's branch (from the type profiling
2414   // inlining) which was not eliminated during parsing since the exactness
2415   // of the allocation type was not propagated to the subclass type check.
2416   //
2417   // Or the type 't' could be not related to 'base_t' at all.
2418   // It could happened when CHA type is different from MDO type on a dead path
2419   // (for example, from instanceof check) which is not collapsed during parsing.
2420   //
2421   // Do nothing for such AddP node and don't process its users since
2422   // this code branch will go away.
2423   //
2424   if (!t->is_known_instance() &&
2425       !base_t->klass()->is_subtype_of(t->klass())) {
2426      return false; // bail out
2427   }
2428   const TypePtr* tinst = base_t->add_offset(t->offset());
2429   if (tinst->isa_aryptr() && t->isa_aryptr()) {
2430     // In the case of a flattened value type array, each field has its
2431     // own slice so we need to keep track of the field being accessed.
2432     tinst = tinst->is_aryptr()->with_field_offset(t->is_aryptr()->field_offset().get());
2433   }
2434 
2435   // Do NOT remove the next line: ensure a new alias index is allocated
2436   // for the instance type. Note: C++ will not remove it since the call
2437   // has side effect.
2438   int alias_idx = _compile->get_alias_index(tinst);
2439   igvn->set_type(addp, tinst);
2440   // record the allocation in the node map
2441   set_map(addp, get_map(base->_idx));
2442   // Set addp's Base and Address to 'base'.
2443   Node *abase = addp->in(AddPNode::Base);
2444   Node *adr   = addp->in(AddPNode::Address);
2445   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2446       adr->in(0)->_idx == (uint)inst_id) {
2447     // Skip AddP cases #3 and #5.
2448   } else {
2449     assert(!abase->is_top(), "sanity"); // AddP case #3
2450     if (abase != base) {
2451       igvn->hash_delete(addp);
2452       addp->set_req(AddPNode::Base, base);
2453       if (abase == adr) {
2454         addp->set_req(AddPNode::Address, base);
2455       } else {
2456         // AddP case #4 (adr is array's element offset AddP node)
2457 #ifdef ASSERT
2458         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2459         assert(adr->is_AddP() && atype != NULL &&
2460                atype->instance_id() == inst_id, "array's element offset should be processed first");
2461 #endif
2462       }
2463       igvn->hash_insert(addp);
2464     }
2465   }
2466   // Put on IGVN worklist since at least addp's type was changed above.
2467   record_for_optimizer(addp);
2468   return true;
2469 }
2470 
2471 //
2472 // Create a new version of orig_phi if necessary. Returns either the newly
2473 // created phi or an existing phi.  Sets create_new to indicate whether a new
2474 // phi was created.  Cache the last newly created phi in the node map.
2475 //
2476 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, bool &new_created) {
2477   Compile *C = _compile;
2478   PhaseGVN* igvn = _igvn;
2479   new_created = false;
2480   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2481   // nothing to do if orig_phi is bottom memory or matches alias_idx
2482   if (phi_alias_idx == alias_idx) {
2483     return orig_phi;
2484   }
2485   // Have we recently created a Phi for this alias index?
2486   PhiNode *result = get_map_phi(orig_phi->_idx);
2487   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2488     return result;
2489   }
2490   // Previous check may fail when the same wide memory Phi was split into Phis
2491   // for different memory slices. Search all Phis for this region.
2492   if (result != NULL) {
2493     Node* region = orig_phi->in(0);
2494     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2495       Node* phi = region->fast_out(i);
2496       if (phi->is_Phi() &&
2497           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2498         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2499         return phi->as_Phi();
2500       }
2501     }
2502   }
2503   if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2504     if (C->do_escape_analysis() == true && !C->failing()) {
2505       // Retry compilation without escape analysis.
2506       // If this is the first failure, the sentinel string will "stick"
2507       // to the Compile object, and the C2Compiler will see it and retry.
2508       C->record_failure(C2Compiler::retry_no_escape_analysis());
2509     }
2510     return NULL;
2511   }
2512   orig_phi_worklist.append_if_missing(orig_phi);
2513   const TypePtr *atype = C->get_adr_type(alias_idx);
2514   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2515   C->copy_node_notes_to(result, orig_phi);
2516   igvn->set_type(result, result->bottom_type());
2517   record_for_optimizer(result);
2518   set_map(orig_phi, result);
2519   new_created = true;
2520   return result;
2521 }
2522 
2523 //
2524 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2525 // specified alias index.
2526 //
2527 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist) {
2528   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2529   Compile *C = _compile;
2530   PhaseGVN* igvn = _igvn;
2531   bool new_phi_created;
2532   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2533   if (!new_phi_created) {
2534     return result;
2535   }
2536   GrowableArray<PhiNode *>  phi_list;
2537   GrowableArray<uint>  cur_input;
2538   PhiNode *phi = orig_phi;
2539   uint idx = 1;
2540   bool finished = false;
2541   while(!finished) {
2542     while (idx < phi->req()) {
2543       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2544       if (mem != NULL && mem->is_Phi()) {
2545         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2546         if (new_phi_created) {
2547           // found an phi for which we created a new split, push current one on worklist and begin
2548           // processing new one
2549           phi_list.push(phi);
2550           cur_input.push(idx);
2551           phi = mem->as_Phi();
2552           result = newphi;
2553           idx = 1;
2554           continue;
2555         } else {
2556           mem = newphi;
2557         }
2558       }
2559       if (C->failing()) {
2560         return NULL;
2561       }
2562       result->set_req(idx++, mem);
2563     }
2564 #ifdef ASSERT
2565     // verify that the new Phi has an input for each input of the original
2566     assert( phi->req() == result->req(), "must have same number of inputs.");
2567     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2568 #endif
2569     // Check if all new phi's inputs have specified alias index.
2570     // Otherwise use old phi.
2571     for (uint i = 1; i < phi->req(); i++) {
2572       Node* in = result->in(i);
2573       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2574     }
2575     // we have finished processing a Phi, see if there are any more to do
2576     finished = (phi_list.length() == 0 );
2577     if (!finished) {
2578       phi = phi_list.pop();
2579       idx = cur_input.pop();
2580       PhiNode *prev_result = get_map_phi(phi->_idx);
2581       prev_result->set_req(idx++, result);
2582       result = prev_result;
2583     }
2584   }
2585   return result;
2586 }
2587 
2588 //
2589 // The next methods are derived from methods in MemNode.
2590 //
2591 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2592   Node *mem = mmem;
2593   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2594   // means an array I have not precisely typed yet.  Do not do any
2595   // alias stuff with it any time soon.
2596   if (toop->base() != Type::AnyPtr &&
2597       !(toop->klass() != NULL &&
2598         toop->klass()->is_java_lang_Object() &&
2599         toop->offset() == Type::OffsetBot)) {
2600     mem = mmem->memory_at(alias_idx);
2601     // Update input if it is progress over what we have now
2602   }
2603   return mem;
2604 }
2605 
2606 //
2607 // Move memory users to their memory slices.
2608 //
2609 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis) {
2610   Compile* C = _compile;
2611   PhaseGVN* igvn = _igvn;
2612   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2613   assert(tp != NULL, "ptr type");
2614   int alias_idx = C->get_alias_index(tp);
2615   int general_idx = C->get_general_index(alias_idx);
2616 
2617   // Move users first
2618   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2619     Node* use = n->fast_out(i);
2620     if (use->is_MergeMem()) {
2621       MergeMemNode* mmem = use->as_MergeMem();
2622       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2623       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2624         continue; // Nothing to do
2625       }
2626       // Replace previous general reference to mem node.
2627       uint orig_uniq = C->unique();
2628       Node* m = find_inst_mem(n, general_idx, orig_phis);
2629       assert(orig_uniq == C->unique(), "no new nodes");
2630       mmem->set_memory_at(general_idx, m);
2631       --imax;
2632       --i;
2633     } else if (use->is_MemBar()) {
2634       assert(!use->is_Initialize(), "initializing stores should not be moved");
2635       if (use->req() > MemBarNode::Precedent &&
2636           use->in(MemBarNode::Precedent) == n) {
2637         // Don't move related membars.
2638         record_for_optimizer(use);
2639         continue;
2640       }
2641       tp = use->as_MemBar()->adr_type()->isa_ptr();
2642       if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2643           alias_idx == general_idx) {
2644         continue; // Nothing to do
2645       }
2646       // Move to general memory slice.
2647       uint orig_uniq = C->unique();
2648       Node* m = find_inst_mem(n, general_idx, orig_phis);
2649       assert(orig_uniq == C->unique(), "no new nodes");
2650       igvn->hash_delete(use);
2651       imax -= use->replace_edge(n, m);
2652       igvn->hash_insert(use);
2653       record_for_optimizer(use);
2654       --i;
2655 #ifdef ASSERT
2656     } else if (use->is_Mem()) {
2657       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2658         // Don't move related cardmark.
2659         continue;
2660       }
2661       // Memory nodes should have new memory input.
2662       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2663       assert(tp != NULL, "ptr type");
2664       int idx = C->get_alias_index(tp);
2665       assert(get_map(use->_idx) != NULL || idx == alias_idx,
2666              "Following memory nodes should have new memory input or be on the same memory slice");
2667     } else if (use->is_Phi()) {
2668       // Phi nodes should be split and moved already.
2669       tp = use->as_Phi()->adr_type()->isa_ptr();
2670       assert(tp != NULL, "ptr type");
2671       int idx = C->get_alias_index(tp);
2672       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2673     } else {
2674       use->dump();
2675       assert(false, "should not be here");
2676 #endif
2677     }
2678   }
2679 }
2680 
2681 //
2682 // Search memory chain of "mem" to find a MemNode whose address
2683 // is the specified alias index.
2684 //
2685 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis) {
2686   if (orig_mem == NULL)
2687     return orig_mem;
2688   Compile* C = _compile;
2689   PhaseGVN* igvn = _igvn;
2690   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2691   bool is_instance = (toop != NULL) && toop->is_known_instance();
2692   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2693   Node *prev = NULL;
2694   Node *result = orig_mem;
2695   while (prev != result) {
2696     prev = result;
2697     if (result == start_mem)
2698       break;  // hit one of our sentinels
2699     if (result->is_Mem()) {
2700       const Type *at = igvn->type(result->in(MemNode::Address));
2701       if (at == Type::TOP)
2702         break; // Dead
2703       assert (at->isa_ptr() != NULL, "pointer type required.");
2704       int idx = C->get_alias_index(at->is_ptr());
2705       if (idx == alias_idx)
2706         break; // Found
2707       if (!is_instance && (at->isa_oopptr() == NULL ||
2708                            !at->is_oopptr()->is_known_instance())) {
2709         break; // Do not skip store to general memory slice.
2710       }
2711       result = result->in(MemNode::Memory);
2712     }
2713     if (!is_instance)
2714       continue;  // don't search further for non-instance types
2715     // skip over a call which does not affect this memory slice
2716     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2717       Node *proj_in = result->in(0);
2718       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2719         break;  // hit one of our sentinels
2720       } else if (proj_in->is_Call()) {
2721         // ArrayCopy node processed here as well
2722         CallNode *call = proj_in->as_Call();
2723         if (!call->may_modify(toop, igvn)) {
2724           result = call->in(TypeFunc::Memory);
2725         }
2726       } else if (proj_in->is_Initialize()) {
2727         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2728         // Stop if this is the initialization for the object instance which
2729         // which contains this memory slice, otherwise skip over it.
2730         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2731           result = proj_in->in(TypeFunc::Memory);
2732         }
2733       } else if (proj_in->is_MemBar()) {
2734         if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2735             proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2736             proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2737           // clone
2738           ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2739           if (ac->may_modify(toop, igvn)) {
2740             break;
2741           }
2742         }
2743         result = proj_in->in(TypeFunc::Memory);
2744       }
2745     } else if (result->is_MergeMem()) {
2746       MergeMemNode *mmem = result->as_MergeMem();
2747       result = step_through_mergemem(mmem, alias_idx, toop);
2748       if (result == mmem->base_memory()) {
2749         // Didn't find instance memory, search through general slice recursively.
2750         result = mmem->memory_at(C->get_general_index(alias_idx));
2751         result = find_inst_mem(result, alias_idx, orig_phis);
2752         if (C->failing()) {
2753           return NULL;
2754         }
2755         mmem->set_memory_at(alias_idx, result);
2756       }
2757     } else if (result->is_Phi() &&
2758                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2759       Node *un = result->as_Phi()->unique_input(igvn);
2760       if (un != NULL) {
2761         orig_phis.append_if_missing(result->as_Phi());
2762         result = un;
2763       } else {
2764         break;
2765       }
2766     } else if (result->is_ClearArray()) {
2767       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2768         // Can not bypass initialization of the instance
2769         // we are looking for.
2770         break;
2771       }
2772       // Otherwise skip it (the call updated 'result' value).
2773     } else if (result->Opcode() == Op_SCMemProj) {
2774       Node* mem = result->in(0);
2775       Node* adr = NULL;
2776       if (mem->is_LoadStore()) {
2777         adr = mem->in(MemNode::Address);
2778       } else {
2779         assert(mem->Opcode() == Op_EncodeISOArray ||
2780                mem->Opcode() == Op_StrCompressedCopy, "sanity");
2781         adr = mem->in(3); // Memory edge corresponds to destination array
2782       }
2783       const Type *at = igvn->type(adr);
2784       if (at != Type::TOP) {
2785         assert(at->isa_ptr() != NULL, "pointer type required.");
2786         int idx = C->get_alias_index(at->is_ptr());
2787         if (idx == alias_idx) {
2788           // Assert in debug mode
2789           assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2790           break; // In product mode return SCMemProj node
2791         }
2792       }
2793       result = mem->in(MemNode::Memory);
2794     } else if (result->Opcode() == Op_StrInflatedCopy) {
2795       Node* adr = result->in(3); // Memory edge corresponds to destination array
2796       const Type *at = igvn->type(adr);
2797       if (at != Type::TOP) {
2798         assert(at->isa_ptr() != NULL, "pointer type required.");
2799         int idx = C->get_alias_index(at->is_ptr());
2800         if (idx == alias_idx) {
2801           // Assert in debug mode
2802           assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2803           break; // In product mode return SCMemProj node
2804         }
2805       }
2806       result = result->in(MemNode::Memory);
2807     }
2808   }
2809   if (result->is_Phi()) {
2810     PhiNode *mphi = result->as_Phi();
2811     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2812     const TypePtr *t = mphi->adr_type();
2813     if (!is_instance) {
2814       // Push all non-instance Phis on the orig_phis worklist to update inputs
2815       // during Phase 4 if needed.
2816       orig_phis.append_if_missing(mphi);
2817     } else if (C->get_alias_index(t) != alias_idx) {
2818       // Create a new Phi with the specified alias index type.
2819       result = split_memory_phi(mphi, alias_idx, orig_phis);
2820     }
2821   }
2822   // the result is either MemNode, PhiNode, InitializeNode.
2823   return result;
2824 }
2825 
2826 //
2827 //  Convert the types of unescaped object to instance types where possible,
2828 //  propagate the new type information through the graph, and update memory
2829 //  edges and MergeMem inputs to reflect the new type.
2830 //
2831 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
2832 //  The processing is done in 4 phases:
2833 //
2834 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
2835 //            types for the CheckCastPP for allocations where possible.
2836 //            Propagate the new types through users as follows:
2837 //               casts and Phi:  push users on alloc_worklist
2838 //               AddP:  cast Base and Address inputs to the instance type
2839 //                      push any AddP users on alloc_worklist and push any memnode
2840 //                      users onto memnode_worklist.
2841 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
2842 //            search the Memory chain for a store with the appropriate type
2843 //            address type.  If a Phi is found, create a new version with
2844 //            the appropriate memory slices from each of the Phi inputs.
2845 //            For stores, process the users as follows:
2846 //               MemNode:  push on memnode_worklist
2847 //               MergeMem: push on mergemem_worklist
2848 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
2849 //            moving the first node encountered of each  instance type to the
2850 //            the input corresponding to its alias index.
2851 //            appropriate memory slice.
2852 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2853 //
2854 // In the following example, the CheckCastPP nodes are the cast of allocation
2855 // results and the allocation of node 29 is unescaped and eligible to be an
2856 // instance type.
2857 //
2858 // We start with:
2859 //
2860 //     7 Parm #memory
2861 //    10  ConI  "12"
2862 //    19  CheckCastPP   "Foo"
2863 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2864 //    29  CheckCastPP   "Foo"
2865 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
2866 //
2867 //    40  StoreP  25   7  20   ... alias_index=4
2868 //    50  StoreP  35  40  30   ... alias_index=4
2869 //    60  StoreP  45  50  20   ... alias_index=4
2870 //    70  LoadP    _  60  30   ... alias_index=4
2871 //    80  Phi     75  50  60   Memory alias_index=4
2872 //    90  LoadP    _  80  30   ... alias_index=4
2873 //   100  LoadP    _  80  20   ... alias_index=4
2874 //
2875 //
2876 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2877 // and creating a new alias index for node 30.  This gives:
2878 //
2879 //     7 Parm #memory
2880 //    10  ConI  "12"
2881 //    19  CheckCastPP   "Foo"
2882 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2883 //    29  CheckCastPP   "Foo"  iid=24
2884 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2885 //
2886 //    40  StoreP  25   7  20   ... alias_index=4
2887 //    50  StoreP  35  40  30   ... alias_index=6
2888 //    60  StoreP  45  50  20   ... alias_index=4
2889 //    70  LoadP    _  60  30   ... alias_index=6
2890 //    80  Phi     75  50  60   Memory alias_index=4
2891 //    90  LoadP    _  80  30   ... alias_index=6
2892 //   100  LoadP    _  80  20   ... alias_index=4
2893 //
2894 // In phase 2, new memory inputs are computed for the loads and stores,
2895 // And a new version of the phi is created.  In phase 4, the inputs to
2896 // node 80 are updated and then the memory nodes are updated with the
2897 // values computed in phase 2.  This results in:
2898 //
2899 //     7 Parm #memory
2900 //    10  ConI  "12"
2901 //    19  CheckCastPP   "Foo"
2902 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2903 //    29  CheckCastPP   "Foo"  iid=24
2904 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2905 //
2906 //    40  StoreP  25  7   20   ... alias_index=4
2907 //    50  StoreP  35  7   30   ... alias_index=6
2908 //    60  StoreP  45  40  20   ... alias_index=4
2909 //    70  LoadP    _  50  30   ... alias_index=6
2910 //    80  Phi     75  40  60   Memory alias_index=4
2911 //   120  Phi     75  50  50   Memory alias_index=6
2912 //    90  LoadP    _ 120  30   ... alias_index=6
2913 //   100  LoadP    _  80  20   ... alias_index=4
2914 //
2915 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2916   GrowableArray<Node *>  memnode_worklist;
2917   GrowableArray<PhiNode *>  orig_phis;
2918   PhaseIterGVN  *igvn = _igvn;
2919   uint new_index_start = (uint) _compile->num_alias_types();
2920   Arena* arena = Thread::current()->resource_area();
2921   VectorSet visited(arena);
2922   ideal_nodes.clear(); // Reset for use with set_map/get_map.
2923   uint unique_old = _compile->unique();
2924 
2925   //  Phase 1:  Process possible allocations from alloc_worklist.
2926   //  Create instance types for the CheckCastPP for allocations where possible.
2927   //
2928   // (Note: don't forget to change the order of the second AddP node on
2929   //  the alloc_worklist if the order of the worklist processing is changed,
2930   //  see the comment in find_second_addp().)
2931   //
2932   while (alloc_worklist.length() != 0) {
2933     Node *n = alloc_worklist.pop();
2934     uint ni = n->_idx;
2935     if (n->is_Call()) {
2936       CallNode *alloc = n->as_Call();
2937       // copy escape information to call node
2938       PointsToNode* ptn = ptnode_adr(alloc->_idx);
2939       PointsToNode::EscapeState es = ptn->escape_state();
2940       // We have an allocation or call which returns a Java object,
2941       // see if it is unescaped.
2942       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2943         continue;
2944       // Find CheckCastPP for the allocate or for the return value of a call
2945       n = alloc->result_cast();
2946       if (n == NULL) {            // No uses except Initialize node
2947         if (alloc->is_Allocate()) {
2948           // Set the scalar_replaceable flag for allocation
2949           // so it could be eliminated if it has no uses.
2950           alloc->as_Allocate()->_is_scalar_replaceable = true;
2951         }
2952         if (alloc->is_CallStaticJava()) {
2953           // Set the scalar_replaceable flag for boxing method
2954           // so it could be eliminated if it has no uses.
2955           alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2956         }
2957         continue;
2958       }
2959       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2960         assert(!alloc->is_Allocate(), "allocation should have unique type");
2961         continue;
2962       }
2963 
2964       // The inline code for Object.clone() casts the allocation result to
2965       // java.lang.Object and then to the actual type of the allocated
2966       // object. Detect this case and use the second cast.
2967       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2968       // the allocation result is cast to java.lang.Object and then
2969       // to the actual Array type.
2970       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2971           && (alloc->is_AllocateArray() ||
2972               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2973         Node *cast2 = NULL;
2974         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2975           Node *use = n->fast_out(i);
2976           if (use->is_CheckCastPP()) {
2977             cast2 = use;
2978             break;
2979           }
2980         }
2981         if (cast2 != NULL) {
2982           n = cast2;
2983         } else {
2984           // Non-scalar replaceable if the allocation type is unknown statically
2985           // (reflection allocation), the object can't be restored during
2986           // deoptimization without precise type.
2987           continue;
2988         }
2989       }
2990 
2991       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2992       if (t == NULL)
2993         continue;  // not a TypeOopPtr
2994       if (!t->klass_is_exact())
2995         continue; // not an unique type
2996 
2997       if (alloc->is_Allocate()) {
2998         // Set the scalar_replaceable flag for allocation
2999         // so it could be eliminated.
3000         alloc->as_Allocate()->_is_scalar_replaceable = true;
3001       }
3002       if (alloc->is_CallStaticJava()) {
3003         // Set the scalar_replaceable flag for boxing method
3004         // so it could be eliminated.
3005         alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
3006       }
3007       set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
3008       // in order for an object to be scalar-replaceable, it must be:
3009       //   - a direct allocation (not a call returning an object)
3010       //   - non-escaping
3011       //   - eligible to be a unique type
3012       //   - not determined to be ineligible by escape analysis
3013       set_map(alloc, n);
3014       set_map(n, alloc);
3015       const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3016       igvn->hash_delete(n);
3017       igvn->set_type(n,  tinst);
3018       n->raise_bottom_type(tinst);
3019       igvn->hash_insert(n);
3020       record_for_optimizer(n);
3021       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr() || t->isa_valuetypeptr())) {
3022 
3023         // First, put on the worklist all Field edges from Connection Graph
3024         // which is more accurate than putting immediate users from Ideal Graph.
3025         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3026           PointsToNode* tgt = e.get();
3027           if (tgt->is_Arraycopy()) {
3028             continue;
3029           }
3030           Node* use = tgt->ideal_node();
3031           assert(tgt->is_Field() && use->is_AddP(),
3032                  "only AddP nodes are Field edges in CG");
3033           if (use->outcnt() > 0) { // Don't process dead nodes
3034             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3035             if (addp2 != NULL) {
3036               assert(alloc->is_AllocateArray(),"array allocation was expected");
3037               alloc_worklist.append_if_missing(addp2);
3038             }
3039             alloc_worklist.append_if_missing(use);
3040           }
3041         }
3042 
3043         // An allocation may have an Initialize which has raw stores. Scan
3044         // the users of the raw allocation result and push AddP users
3045         // on alloc_worklist.
3046         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
3047         assert (raw_result != NULL, "must have an allocation result");
3048         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3049           Node *use = raw_result->fast_out(i);
3050           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3051             Node* addp2 = find_second_addp(use, raw_result);
3052             if (addp2 != NULL) {
3053               assert(alloc->is_AllocateArray(),"array allocation was expected");
3054               alloc_worklist.append_if_missing(addp2);
3055             }
3056             alloc_worklist.append_if_missing(use);
3057           } else if (use->is_MemBar()) {
3058             memnode_worklist.append_if_missing(use);
3059           }
3060         }
3061       }
3062     } else if (n->is_AddP()) {
3063       JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3064       if (jobj == NULL || jobj == phantom_obj) {
3065 #ifdef ASSERT
3066         ptnode_adr(get_addp_base(n)->_idx)->dump();
3067         ptnode_adr(n->_idx)->dump();
3068         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3069 #endif
3070         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3071         return;
3072       }
3073       Node *base = get_map(jobj->idx());  // CheckCastPP node
3074       if (!split_AddP(n, base)) continue; // wrong type from dead path
3075     } else if (n->is_Phi() ||
3076                n->is_CheckCastPP() ||
3077                n->is_EncodeP() ||
3078                n->is_DecodeN() ||
3079                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3080       if (visited.test_set(n->_idx)) {
3081         assert(n->is_Phi(), "loops only through Phi's");
3082         continue;  // already processed
3083       }
3084       JavaObjectNode* jobj = unique_java_object(n);
3085       if (jobj == NULL || jobj == phantom_obj) {
3086 #ifdef ASSERT
3087         ptnode_adr(n->_idx)->dump();
3088         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3089 #endif
3090         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3091         return;
3092       } else {
3093         Node *val = get_map(jobj->idx());   // CheckCastPP node
3094         TypeNode *tn = n->as_Type();
3095         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3096         assert(tinst != NULL && tinst->is_known_instance() &&
3097                tinst->instance_id() == jobj->idx() , "instance type expected.");
3098 
3099         const Type *tn_type = igvn->type(tn);
3100         const TypeOopPtr *tn_t;
3101         if (tn_type->isa_narrowoop()) {
3102           tn_t = tn_type->make_ptr()->isa_oopptr();
3103         } else {
3104           tn_t = tn_type->isa_oopptr();
3105         }
3106         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3107           if (tn_type->isa_narrowoop()) {
3108             tn_type = tinst->make_narrowoop();
3109           } else {
3110             tn_type = tinst;
3111           }
3112           igvn->hash_delete(tn);
3113           igvn->set_type(tn, tn_type);
3114           tn->set_type(tn_type);
3115           igvn->hash_insert(tn);
3116           record_for_optimizer(n);
3117         } else {
3118           assert(tn_type == TypePtr::NULL_PTR ||
3119                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3120                  "unexpected type");
3121           continue; // Skip dead path with different type
3122         }
3123       }
3124     } else {
3125       debug_only(n->dump();)
3126       assert(false, "EA: unexpected node");
3127       continue;
3128     }
3129     // push allocation's users on appropriate worklist
3130     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3131       Node *use = n->fast_out(i);
3132       if(use->is_Mem() && use->in(MemNode::Address) == n) {
3133         // Load/store to instance's field
3134         memnode_worklist.append_if_missing(use);
3135       } else if (use->is_MemBar()) {
3136         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3137           memnode_worklist.append_if_missing(use);
3138         }
3139       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3140         Node* addp2 = find_second_addp(use, n);
3141         if (addp2 != NULL) {
3142           alloc_worklist.append_if_missing(addp2);
3143         }
3144         alloc_worklist.append_if_missing(use);
3145       } else if (use->is_Phi() ||
3146                  use->is_CheckCastPP() ||
3147                  use->is_EncodeNarrowPtr() ||
3148                  use->is_DecodeNarrowPtr() ||
3149                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3150         alloc_worklist.append_if_missing(use);
3151 #ifdef ASSERT
3152       } else if (use->is_Mem()) {
3153         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3154       } else if (use->is_MergeMem()) {
3155         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3156       } else if (use->is_SafePoint()) {
3157         // Look for MergeMem nodes for calls which reference unique allocation
3158         // (through CheckCastPP nodes) even for debug info.
3159         Node* m = use->in(TypeFunc::Memory);
3160         if (m->is_MergeMem()) {
3161           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3162         }
3163       } else if (use->Opcode() == Op_EncodeISOArray) {
3164         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3165           // EncodeISOArray overwrites destination array
3166           memnode_worklist.append_if_missing(use);
3167         }






3168       } else {
3169         uint op = use->Opcode();
3170         if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3171             (use->in(MemNode::Memory) == n)) {
3172           // They overwrite memory edge corresponding to destination array,
3173           memnode_worklist.append_if_missing(use);
3174         } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3175               op == Op_CastP2X || op == Op_StoreCM ||
3176               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3177               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3178               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
3179               op == Op_ValueType)) {
3180           n->dump();
3181           use->dump();
3182           assert(false, "EA: missing allocation reference path");
3183         }
3184 #endif
3185       }
3186     }
3187 
3188   }
3189 
3190   // Go over all ArrayCopy nodes and if one of the inputs has a unique
3191   // type, record it in the ArrayCopy node so we know what memory this
3192   // node uses/modified.
3193   for (int next = 0; next < arraycopy_worklist.length(); next++) {
3194     ArrayCopyNode* ac = arraycopy_worklist.at(next);
3195     Node* dest = ac->in(ArrayCopyNode::Dest);
3196     if (dest->is_AddP()) {
3197       dest = get_addp_base(dest);
3198     }
3199     JavaObjectNode* jobj = unique_java_object(dest);
3200     if (jobj != NULL) {
3201       Node *base = get_map(jobj->idx());
3202       if (base != NULL) {
3203         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3204         ac->_dest_type = base_t;
3205       }
3206     }
3207     Node* src = ac->in(ArrayCopyNode::Src);
3208     if (src->is_AddP()) {
3209       src = get_addp_base(src);
3210     }
3211     jobj = unique_java_object(src);
3212     if (jobj != NULL) {
3213       Node* base = get_map(jobj->idx());
3214       if (base != NULL) {
3215         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3216         ac->_src_type = base_t;
3217       }
3218     }
3219   }
3220 
3221   // New alias types were created in split_AddP().
3222   uint new_index_end = (uint) _compile->num_alias_types();
3223   assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3224 
3225   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
3226   //            compute new values for Memory inputs  (the Memory inputs are not
3227   //            actually updated until phase 4.)
3228   if (memnode_worklist.length() == 0)
3229     return;  // nothing to do
3230   while (memnode_worklist.length() != 0) {
3231     Node *n = memnode_worklist.pop();
3232     if (visited.test_set(n->_idx))
3233       continue;
3234     if (n->is_Phi() || n->is_ClearArray()) {
3235       // we don't need to do anything, but the users must be pushed
3236     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3237       // we don't need to do anything, but the users must be pushed
3238       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3239       if (n == NULL)
3240         continue;
3241     } else if (n->Opcode() == Op_StrCompressedCopy ||
3242                n->Opcode() == Op_EncodeISOArray) {
3243       // get the memory projection
3244       n = n->find_out_with(Op_SCMemProj);
3245       assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3246     } else {
3247       assert(n->is_Mem(), "memory node required.");
3248       Node *addr = n->in(MemNode::Address);
3249       const Type *addr_t = igvn->type(addr);
3250       if (addr_t == Type::TOP)
3251         continue;
3252       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3253       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3254       assert ((uint)alias_idx < new_index_end, "wrong alias index");
3255       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3256       if (_compile->failing()) {
3257         return;
3258       }
3259       if (mem != n->in(MemNode::Memory)) {
3260         // We delay the memory edge update since we need old one in
3261         // MergeMem code below when instances memory slices are separated.
3262         set_map(n, mem);
3263       }
3264       if (n->is_Load()) {
3265         continue;  // don't push users
3266       } else if (n->is_LoadStore()) {
3267         // get the memory projection
3268         n = n->find_out_with(Op_SCMemProj);
3269         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3270       }
3271     }
3272     // push user on appropriate worklist
3273     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3274       Node *use = n->fast_out(i);
3275       if (use->is_Phi() || use->is_ClearArray()) {
3276         memnode_worklist.append_if_missing(use);
3277       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3278         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3279           continue;
3280         memnode_worklist.append_if_missing(use);
3281       } else if (use->is_MemBar()) {
3282         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3283           memnode_worklist.append_if_missing(use);
3284         }
3285 #ifdef ASSERT
3286       } else if(use->is_Mem()) {
3287         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3288       } else if (use->is_MergeMem()) {
3289         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3290       } else if (use->Opcode() == Op_EncodeISOArray) {
3291         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3292           // EncodeISOArray overwrites destination array
3293           memnode_worklist.append_if_missing(use);
3294         }
3295       } else {
3296         uint op = use->Opcode();
3297         if ((use->in(MemNode::Memory) == n) &&
3298             (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3299           // They overwrite memory edge corresponding to destination array,
3300           memnode_worklist.append_if_missing(use);
3301         } else if (!(op == Op_StoreCM ||
3302               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3303                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3304               op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3305               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3306               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3307           n->dump();
3308           use->dump();
3309           assert(false, "EA: missing memory path");
3310         }
3311 #endif
3312       }
3313     }
3314   }
3315 
3316   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
3317   //            Walk each memory slice moving the first node encountered of each
3318   //            instance type to the input corresponding to its alias index.
3319   uint length = _mergemem_worklist.length();
3320   for( uint next = 0; next < length; ++next ) {
3321     MergeMemNode* nmm = _mergemem_worklist.at(next);
3322     assert(!visited.test_set(nmm->_idx), "should not be visited before");
3323     // Note: we don't want to use MergeMemStream here because we only want to
3324     // scan inputs which exist at the start, not ones we add during processing.
3325     // Note 2: MergeMem may already contains instance memory slices added
3326     // during find_inst_mem() call when memory nodes were processed above.
3327     igvn->hash_delete(nmm);
3328     uint nslices = MIN2(nmm->req(), new_index_start);
3329     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3330       Node* mem = nmm->in(i);
3331       Node* cur = NULL;
3332       if (mem == NULL || mem->is_top())
3333         continue;
3334       // First, update mergemem by moving memory nodes to corresponding slices
3335       // if their type became more precise since this mergemem was created.
3336       while (mem->is_Mem()) {
3337         const Type *at = igvn->type(mem->in(MemNode::Address));
3338         if (at != Type::TOP) {
3339           assert (at->isa_ptr() != NULL, "pointer type required.");
3340           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3341           if (idx == i) {
3342             if (cur == NULL)
3343               cur = mem;
3344           } else {
3345             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3346               nmm->set_memory_at(idx, mem);
3347             }
3348           }
3349         }
3350         mem = mem->in(MemNode::Memory);
3351       }
3352       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3353       // Find any instance of the current type if we haven't encountered
3354       // already a memory slice of the instance along the memory chain.
3355       for (uint ni = new_index_start; ni < new_index_end; ni++) {
3356         if((uint)_compile->get_general_index(ni) == i) {
3357           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3358           if (nmm->is_empty_memory(m)) {
3359             Node* result = find_inst_mem(mem, ni, orig_phis);
3360             if (_compile->failing()) {
3361               return;
3362             }
3363             nmm->set_memory_at(ni, result);
3364           }
3365         }
3366       }
3367     }
3368     // Find the rest of instances values
3369     for (uint ni = new_index_start; ni < new_index_end; ni++) {
3370       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3371       Node* result = step_through_mergemem(nmm, ni, tinst);
3372       if (result == nmm->base_memory()) {
3373         // Didn't find instance memory, search through general slice recursively.
3374         result = nmm->memory_at(_compile->get_general_index(ni));
3375         result = find_inst_mem(result, ni, orig_phis);
3376         if (_compile->failing()) {
3377           return;
3378         }
3379         nmm->set_memory_at(ni, result);
3380       }
3381     }
3382     igvn->hash_insert(nmm);
3383     record_for_optimizer(nmm);
3384   }
3385 
3386   //  Phase 4:  Update the inputs of non-instance memory Phis and
3387   //            the Memory input of memnodes
3388   // First update the inputs of any non-instance Phi's from
3389   // which we split out an instance Phi.  Note we don't have
3390   // to recursively process Phi's encountered on the input memory
3391   // chains as is done in split_memory_phi() since they will
3392   // also be processed here.
3393   for (int j = 0; j < orig_phis.length(); j++) {
3394     PhiNode *phi = orig_phis.at(j);
3395     int alias_idx = _compile->get_alias_index(phi->adr_type());
3396     igvn->hash_delete(phi);
3397     for (uint i = 1; i < phi->req(); i++) {
3398       Node *mem = phi->in(i);
3399       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3400       if (_compile->failing()) {
3401         return;
3402       }
3403       if (mem != new_mem) {
3404         phi->set_req(i, new_mem);
3405       }
3406     }
3407     igvn->hash_insert(phi);
3408     record_for_optimizer(phi);
3409   }
3410 
3411   // Update the memory inputs of MemNodes with the value we computed
3412   // in Phase 2 and move stores memory users to corresponding memory slices.
3413   // Disable memory split verification code until the fix for 6984348.
3414   // Currently it produces false negative results since it does not cover all cases.
3415 #if 0 // ifdef ASSERT
3416   visited.Reset();
3417   Node_Stack old_mems(arena, _compile->unique() >> 2);
3418 #endif
3419   for (uint i = 0; i < ideal_nodes.size(); i++) {
3420     Node*    n = ideal_nodes.at(i);
3421     Node* nmem = get_map(n->_idx);
3422     assert(nmem != NULL, "sanity");
3423     if (n->is_Mem()) {
3424 #if 0 // ifdef ASSERT
3425       Node* old_mem = n->in(MemNode::Memory);
3426       if (!visited.test_set(old_mem->_idx)) {
3427         old_mems.push(old_mem, old_mem->outcnt());
3428       }
3429 #endif
3430       assert(n->in(MemNode::Memory) != nmem, "sanity");
3431       if (!n->is_Load()) {
3432         // Move memory users of a store first.
3433         move_inst_mem(n, orig_phis);
3434       }
3435       // Now update memory input
3436       igvn->hash_delete(n);
3437       n->set_req(MemNode::Memory, nmem);
3438       igvn->hash_insert(n);
3439       record_for_optimizer(n);
3440     } else {
3441       assert(n->is_Allocate() || n->is_CheckCastPP() ||
3442              n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3443     }
3444   }
3445 #if 0 // ifdef ASSERT
3446   // Verify that memory was split correctly
3447   while (old_mems.is_nonempty()) {
3448     Node* old_mem = old_mems.node();
3449     uint  old_cnt = old_mems.index();
3450     old_mems.pop();
3451     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3452   }
3453 #endif
3454 }
3455 
3456 #ifndef PRODUCT
3457 static const char *node_type_names[] = {
3458   "UnknownType",
3459   "JavaObject",
3460   "LocalVar",
3461   "Field",
3462   "Arraycopy"
3463 };
3464 
3465 static const char *esc_names[] = {
3466   "UnknownEscape",
3467   "NoEscape",
3468   "ArgEscape",
3469   "GlobalEscape"
3470 };
3471 
3472 void PointsToNode::dump(bool print_state) const {
3473   NodeType nt = node_type();
3474   tty->print("%s ", node_type_names[(int) nt]);
3475   if (print_state) {
3476     EscapeState es = escape_state();
3477     EscapeState fields_es = fields_escape_state();
3478     tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3479     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3480       tty->print("NSR ");
3481   }
3482   if (is_Field()) {
3483     FieldNode* f = (FieldNode*)this;
3484     if (f->is_oop())
3485       tty->print("oop ");
3486     if (f->offset() > 0)
3487       tty->print("+%d ", f->offset());
3488     tty->print("(");
3489     for (BaseIterator i(f); i.has_next(); i.next()) {
3490       PointsToNode* b = i.get();
3491       tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3492     }
3493     tty->print(" )");
3494   }
3495   tty->print("[");
3496   for (EdgeIterator i(this); i.has_next(); i.next()) {
3497     PointsToNode* e = i.get();
3498     tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3499   }
3500   tty->print(" [");
3501   for (UseIterator i(this); i.has_next(); i.next()) {
3502     PointsToNode* u = i.get();
3503     bool is_base = false;
3504     if (PointsToNode::is_base_use(u)) {
3505       is_base = true;
3506       u = PointsToNode::get_use_node(u)->as_Field();
3507     }
3508     tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3509   }
3510   tty->print(" ]]  ");
3511   if (_node == NULL)
3512     tty->print_cr("<null>");
3513   else
3514     _node->dump();
3515 }
3516 
3517 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3518   bool first = true;
3519   int ptnodes_length = ptnodes_worklist.length();
3520   for (int i = 0; i < ptnodes_length; i++) {
3521     PointsToNode *ptn = ptnodes_worklist.at(i);
3522     if (ptn == NULL || !ptn->is_JavaObject())
3523       continue;
3524     PointsToNode::EscapeState es = ptn->escape_state();
3525     if ((es != PointsToNode::NoEscape) && !Verbose) {
3526       continue;
3527     }
3528     Node* n = ptn->ideal_node();
3529     if (n->is_Allocate() || (n->is_CallStaticJava() &&
3530                              n->as_CallStaticJava()->is_boxing_method())) {
3531       if (first) {
3532         tty->cr();
3533         tty->print("======== Connection graph for ");
3534         _compile->method()->print_short_name();
3535         tty->cr();
3536         first = false;
3537       }
3538       ptn->dump();
3539       // Print all locals and fields which reference this allocation
3540       for (UseIterator j(ptn); j.has_next(); j.next()) {
3541         PointsToNode* use = j.get();
3542         if (use->is_LocalVar()) {
3543           use->dump(Verbose);
3544         } else if (Verbose) {
3545           use->dump();
3546         }
3547       }
3548       tty->cr();
3549     }
3550   }
3551 }
3552 #endif
--- EOF ---