1 /*
   2  * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/bcEscapeAnalyzer.hpp"
  27 #include "compiler/compileLog.hpp"
  28 #include "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 #include "opto/subnode.hpp"
  41 
  42 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
  43   _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
  44   _in_worklist(C->comp_arena()),
  45   _next_pidx(0),
  46   _collecting(true),
  47   _verify(false),
  48   _compile(C),
  49   _igvn(igvn),
  50   _node_map(C->comp_arena()) {
  51   // Add unknown java object.
  52   add_java_object(C->top(), PointsToNode::GlobalEscape);
  53   phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
  54   // Add ConP(#NULL) and ConN(#NULL) nodes.
  55   Node* oop_null = igvn->zerocon(T_OBJECT);
  56   assert(oop_null->_idx < nodes_size(), "should be created already");
  57   add_java_object(oop_null, PointsToNode::NoEscape);
  58   null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
  59   if (UseCompressedOops) {
  60     Node* noop_null = igvn->zerocon(T_NARROWOOP);
  61     assert(noop_null->_idx < nodes_size(), "should be created already");
  62     map_ideal_node(noop_null, null_obj);
  63   }
  64   _pcmp_neq = NULL; // Should be initialized
  65   _pcmp_eq  = NULL;
  66 }
  67 
  68 bool ConnectionGraph::has_candidates(Compile *C) {
  69   // EA brings benefits only when the code has allocations and/or locks which
  70   // are represented by ideal Macro nodes.
  71   int cnt = C->macro_count();
  72   for (int i = 0; i < cnt; i++) {
  73     Node *n = C->macro_node(i);
  74     if (n->is_Allocate())
  75       return true;
  76     if (n->is_Lock()) {
  77       Node* obj = n->as_Lock()->obj_node()->uncast();
  78       if (!(obj->is_Parm() || obj->is_Con()))
  79         return true;
  80     }
  81     if (n->is_CallStaticJava() &&
  82         n->as_CallStaticJava()->is_boxing_method()) {
  83       return true;
  84     }
  85   }
  86   return false;
  87 }
  88 
  89 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
  90   Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
  91   ResourceMark rm;
  92 
  93   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
  94   // to create space for them in ConnectionGraph::_nodes[].
  95   Node* oop_null = igvn->zerocon(T_OBJECT);
  96   Node* noop_null = igvn->zerocon(T_NARROWOOP);
  97   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
  98   // Perform escape analysis
  99   if (congraph->compute_escape()) {
 100     // There are non escaping objects.
 101     C->set_congraph(congraph);
 102   }
 103   // Cleanup.
 104   if (oop_null->outcnt() == 0)
 105     igvn->hash_delete(oop_null);
 106   if (noop_null->outcnt() == 0)
 107     igvn->hash_delete(noop_null);
 108 }
 109 
 110 bool ConnectionGraph::compute_escape() {
 111   Compile* C = _compile;
 112   PhaseGVN* igvn = _igvn;
 113 
 114   // Worklists used by EA.
 115   Unique_Node_List delayed_worklist;
 116   GrowableArray<Node*> alloc_worklist;
 117   GrowableArray<Node*> ptr_cmp_worklist;
 118   GrowableArray<Node*> storestore_worklist;
 119   GrowableArray<ArrayCopyNode*> arraycopy_worklist;
 120   GrowableArray<PointsToNode*>   ptnodes_worklist;
 121   GrowableArray<JavaObjectNode*> java_objects_worklist;
 122   GrowableArray<JavaObjectNode*> non_escaped_worklist;
 123   GrowableArray<FieldNode*>      oop_fields_worklist;
 124   DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
 125 
 126   { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
 127 
 128   // 1. Populate Connection Graph (CG) with PointsTo nodes.
 129   ideal_nodes.map(C->live_nodes(), NULL);  // preallocate space
 130   // Initialize worklist
 131   if (C->root() != NULL) {
 132     ideal_nodes.push(C->root());
 133   }
 134   // Processed ideal nodes are unique on ideal_nodes list
 135   // but several ideal nodes are mapped to the phantom_obj.
 136   // To avoid duplicated entries on the following worklists
 137   // add the phantom_obj only once to them.
 138   ptnodes_worklist.append(phantom_obj);
 139   java_objects_worklist.append(phantom_obj);
 140   for( uint next = 0; next < ideal_nodes.size(); ++next ) {
 141     Node* n = ideal_nodes.at(next);
 142     // Create PointsTo nodes and add them to Connection Graph. Called
 143     // only once per ideal node since ideal_nodes is Unique_Node list.
 144     add_node_to_connection_graph(n, &delayed_worklist);
 145     PointsToNode* ptn = ptnode_adr(n->_idx);
 146     if (ptn != NULL && ptn != phantom_obj) {
 147       ptnodes_worklist.append(ptn);
 148       if (ptn->is_JavaObject()) {
 149         java_objects_worklist.append(ptn->as_JavaObject());
 150         if ((n->is_Allocate() || n->is_CallStaticJava()) &&
 151             (ptn->escape_state() < PointsToNode::GlobalEscape)) {
 152           // Only allocations and java static calls results are interesting.
 153           non_escaped_worklist.append(ptn->as_JavaObject());
 154         }
 155       } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
 156         oop_fields_worklist.append(ptn->as_Field());
 157       }
 158     }
 159     if (n->is_MergeMem()) {
 160       // Collect all MergeMem nodes to add memory slices for
 161       // scalar replaceable objects in split_unique_types().
 162       _mergemem_worklist.append(n->as_MergeMem());
 163     } else if (OptimizePtrCompare && n->is_Cmp() &&
 164                ((n->Opcode() == Op_CmpP && !(((CmpPNode*)n)->has_perturbed_operand() != NULL)) ||
 165                  n->Opcode() == Op_CmpN)) {
 166       // Collect compare pointers nodes.
 167       ptr_cmp_worklist.append(n);
 168     } else if (n->is_MemBarStoreStore()) {
 169       // Collect all MemBarStoreStore nodes so that depending on the
 170       // escape status of the associated Allocate node some of them
 171       // may be eliminated.
 172       storestore_worklist.append(n);
 173     } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
 174                (n->req() > MemBarNode::Precedent)) {
 175       record_for_optimizer(n);
 176 #ifdef ASSERT
 177     } else if (n->is_AddP()) {
 178       // Collect address nodes for graph verification.
 179       addp_worklist.append(n);
 180 #endif
 181     } else if (n->is_ArrayCopy()) {
 182       // Keep a list of ArrayCopy nodes so if one of its input is non
 183       // escaping, we can record a unique type
 184       arraycopy_worklist.append(n->as_ArrayCopy());
 185     }
 186     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 187       Node* m = n->fast_out(i);   // Get user
 188       ideal_nodes.push(m);
 189     }
 190   }
 191   if (non_escaped_worklist.length() == 0) {
 192     _collecting = false;
 193     return false; // Nothing to do.
 194   }
 195   // Add final simple edges to graph.
 196   while(delayed_worklist.size() > 0) {
 197     Node* n = delayed_worklist.pop();
 198     add_final_edges(n);
 199   }
 200   int ptnodes_length = ptnodes_worklist.length();
 201 
 202 #ifdef ASSERT
 203   if (VerifyConnectionGraph) {
 204     // Verify that no new simple edges could be created and all
 205     // local vars has edges.
 206     _verify = true;
 207     for (int next = 0; next < ptnodes_length; ++next) {
 208       PointsToNode* ptn = ptnodes_worklist.at(next);
 209       add_final_edges(ptn->ideal_node());
 210       if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
 211         ptn->dump();
 212         assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
 213       }
 214     }
 215     _verify = false;
 216   }
 217 #endif
 218   // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
 219   // processing, calls to CI to resolve symbols (types, fields, methods)
 220   // referenced in bytecode. During symbol resolution VM may throw
 221   // an exception which CI cleans and converts to compilation failure.
 222   if (C->failing())  return false;
 223 
 224   // 2. Finish Graph construction by propagating references to all
 225   //    java objects through graph.
 226   if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
 227                                  java_objects_worklist, oop_fields_worklist)) {
 228     // All objects escaped or hit time or iterations limits.
 229     _collecting = false;
 230     return false;
 231   }
 232 
 233   // 3. Adjust scalar_replaceable state of nonescaping objects and push
 234   //    scalar replaceable allocations on alloc_worklist for processing
 235   //    in split_unique_types().
 236   int non_escaped_length = non_escaped_worklist.length();
 237   for (int next = 0; next < non_escaped_length; next++) {
 238     JavaObjectNode* ptn = non_escaped_worklist.at(next);
 239     bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
 240     Node* n = ptn->ideal_node();
 241     if (n->is_Allocate()) {
 242       n->as_Allocate()->_is_non_escaping = noescape;
 243     }
 244     if (n->is_CallStaticJava()) {
 245       n->as_CallStaticJava()->_is_non_escaping = noescape;
 246     }
 247     if (noescape && ptn->scalar_replaceable()) {
 248       adjust_scalar_replaceable_state(ptn);
 249       if (ptn->scalar_replaceable()) {
 250         alloc_worklist.append(ptn->ideal_node());
 251       }
 252     }
 253   }
 254 
 255 #ifdef ASSERT
 256   if (VerifyConnectionGraph) {
 257     // Verify that graph is complete - no new edges could be added or needed.
 258     verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
 259                             java_objects_worklist, addp_worklist);
 260   }
 261   assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
 262   assert(null_obj->escape_state() == PointsToNode::NoEscape &&
 263          null_obj->edge_count() == 0 &&
 264          !null_obj->arraycopy_src() &&
 265          !null_obj->arraycopy_dst(), "sanity");
 266 #endif
 267 
 268   _collecting = false;
 269 
 270   } // TracePhase t3("connectionGraph")
 271 
 272   // 4. Optimize ideal graph based on EA information.
 273   bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
 274   if (has_non_escaping_obj) {
 275     optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
 276   }
 277 
 278 #ifndef PRODUCT
 279   if (PrintEscapeAnalysis) {
 280     dump(ptnodes_worklist); // Dump ConnectionGraph
 281   }
 282 #endif
 283 
 284   bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
 285 #ifdef ASSERT
 286   if (VerifyConnectionGraph) {
 287     int alloc_length = alloc_worklist.length();
 288     for (int next = 0; next < alloc_length; ++next) {
 289       Node* n = alloc_worklist.at(next);
 290       PointsToNode* ptn = ptnode_adr(n->_idx);
 291       assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
 292     }
 293   }
 294 #endif
 295 
 296   // 5. Separate memory graph for scalar replaceable allcations.
 297   if (has_scalar_replaceable_candidates &&
 298       C->AliasLevel() >= 3 && EliminateAllocations) {
 299     // Now use the escape information to create unique types for
 300     // scalar replaceable objects.
 301     split_unique_types(alloc_worklist, arraycopy_worklist);
 302     if (C->failing())  return false;
 303     C->print_method(PHASE_AFTER_EA, 2);
 304 
 305 #ifdef ASSERT
 306   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
 307     tty->print("=== No allocations eliminated for ");
 308     C->method()->print_short_name();
 309     if(!EliminateAllocations) {
 310       tty->print(" since EliminateAllocations is off ===");
 311     } else if(!has_scalar_replaceable_candidates) {
 312       tty->print(" since there are no scalar replaceable candidates ===");
 313     } else if(C->AliasLevel() < 3) {
 314       tty->print(" since AliasLevel < 3 ===");
 315     }
 316     tty->cr();
 317 #endif
 318   }
 319   return has_non_escaping_obj;
 320 }
 321 
 322 // Utility function for nodes that load an object
 323 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 324   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 325   // ThreadLocal has RawPtr type.
 326   const Type* t = _igvn->type(n);
 327   if (t->make_ptr() != NULL) {
 328     Node* adr = n->in(MemNode::Address);
 329 #ifdef ASSERT
 330     if (!adr->is_AddP()) {
 331       assert(_igvn->type(adr)->isa_rawptr(), "sanity");
 332     } else {
 333       assert((ptnode_adr(adr->_idx) == NULL ||
 334               ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
 335     }
 336 #endif
 337     add_local_var_and_edge(n, PointsToNode::NoEscape,
 338                            adr, delayed_worklist);
 339   }
 340 }
 341 
 342 // Populate Connection Graph with PointsTo nodes and create simple
 343 // connection graph edges.
 344 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
 345   assert(!_verify, "this method should not be called for verification");
 346   PhaseGVN* igvn = _igvn;
 347   uint n_idx = n->_idx;
 348   PointsToNode* n_ptn = ptnode_adr(n_idx);
 349   if (n_ptn != NULL)
 350     return; // No need to redefine PointsTo node during first iteration.
 351 
 352   if (n->is_Call()) {
 353     // Arguments to allocation and locking don't escape.
 354     if (n->is_AbstractLock()) {
 355       // Put Lock and Unlock nodes on IGVN worklist to process them during
 356       // first IGVN optimization when escape information is still available.
 357       record_for_optimizer(n);
 358     } else if (n->is_Allocate()) {
 359       add_call_node(n->as_Call());
 360       record_for_optimizer(n);
 361     } else {
 362       if (n->is_CallStaticJava()) {
 363         const char* name = n->as_CallStaticJava()->_name;
 364         if (name != NULL && strcmp(name, "uncommon_trap") == 0)
 365           return; // Skip uncommon traps
 366       }
 367       // Don't mark as processed since call's arguments have to be processed.
 368       delayed_worklist->push(n);
 369       // Check if a call returns an object.
 370       if ((n->as_Call()->returns_pointer() &&
 371            n->as_Call()->proj_out_or_null(TypeFunc::Parms) != NULL) ||
 372           (n->is_CallStaticJava() &&
 373            n->as_CallStaticJava()->is_boxing_method())) {
 374         add_call_node(n->as_Call());
 375       }
 376     }
 377     return;
 378   }
 379   // Put this check here to process call arguments since some call nodes
 380   // point to phantom_obj.
 381   if (n_ptn == phantom_obj || n_ptn == null_obj)
 382     return; // Skip predefined nodes.
 383 
 384   int opcode = n->Opcode();
 385   switch (opcode) {
 386     case Op_AddP: {
 387       Node* base = get_addp_base(n);
 388       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 389       // Field nodes are created for all field types. They are used in
 390       // adjust_scalar_replaceable_state() and split_unique_types().
 391       // Note, non-oop fields will have only base edges in Connection
 392       // Graph because such fields are not used for oop loads and stores.
 393       int offset = address_offset(n, igvn);
 394       add_field(n, PointsToNode::NoEscape, offset);
 395       if (ptn_base == NULL) {
 396         delayed_worklist->push(n); // Process it later.
 397       } else {
 398         n_ptn = ptnode_adr(n_idx);
 399         add_base(n_ptn->as_Field(), ptn_base);
 400       }
 401       break;
 402     }
 403     case Op_CastX2P: {
 404       map_ideal_node(n, phantom_obj);
 405       break;
 406     }
 407     case Op_CastPP:
 408     case Op_CheckCastPP:
 409     case Op_EncodeP:
 410     case Op_DecodeN:
 411     case Op_EncodePKlass:
 412     case Op_DecodeNKlass: {
 413       add_local_var_and_edge(n, PointsToNode::NoEscape,
 414                              n->in(1), delayed_worklist);
 415       break;
 416     }
 417     case Op_CMoveP: {
 418       add_local_var(n, PointsToNode::NoEscape);
 419       // Do not add edges during first iteration because some could be
 420       // not defined yet.
 421       delayed_worklist->push(n);
 422       break;
 423     }
 424     case Op_ConP:
 425     case Op_ConN:
 426     case Op_ConNKlass: {
 427       // assume all oop constants globally escape except for null
 428       PointsToNode::EscapeState es;
 429       const Type* t = igvn->type(n);
 430       if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
 431         es = PointsToNode::NoEscape;
 432       } else {
 433         es = PointsToNode::GlobalEscape;
 434       }
 435       add_java_object(n, es);
 436       break;
 437     }
 438     case Op_CreateEx: {
 439       // assume that all exception objects globally escape
 440       map_ideal_node(n, phantom_obj);
 441       break;
 442     }
 443     case Op_LoadKlass:
 444     case Op_LoadNKlass: {
 445       // Unknown class is loaded
 446       map_ideal_node(n, phantom_obj);
 447       break;
 448     }
 449     case Op_LoadP:
 450     case Op_LoadN:
 451     case Op_LoadPLocked: {
 452       add_objload_to_connection_graph(n, delayed_worklist);
 453       break;
 454     }
 455     case Op_Parm: {
 456       map_ideal_node(n, phantom_obj);
 457       break;
 458     }
 459     case Op_PartialSubtypeCheck: {
 460       // Produces Null or notNull and is used in only in CmpP so
 461       // phantom_obj could be used.
 462       map_ideal_node(n, phantom_obj); // Result is unknown
 463       break;
 464     }
 465     case Op_Phi: {
 466       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 467       // ThreadLocal has RawPtr type.
 468       const Type* t = n->as_Phi()->type();
 469       if (t->make_ptr() != NULL) {
 470         add_local_var(n, PointsToNode::NoEscape);
 471         // Do not add edges during first iteration because some could be
 472         // not defined yet.
 473         delayed_worklist->push(n);
 474       }
 475       break;
 476     }
 477     case Op_Proj: {
 478       // we are only interested in the oop result projection from a call
 479       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
 480           n->in(0)->as_Call()->returns_pointer()) {
 481         add_local_var_and_edge(n, PointsToNode::NoEscape,
 482                                n->in(0), delayed_worklist);
 483       }
 484       break;
 485     }
 486     case Op_Rethrow: // Exception object escapes
 487     case Op_Return: {
 488       if (n->req() > TypeFunc::Parms &&
 489           igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 490         // Treat Return value as LocalVar with GlobalEscape escape state.
 491         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 492                                n->in(TypeFunc::Parms), delayed_worklist);
 493       }
 494       break;
 495     }
 496     case Op_CompareAndExchangeP:
 497     case Op_CompareAndExchangeN:
 498     case Op_GetAndSetP:
 499     case Op_GetAndSetN: {
 500       add_objload_to_connection_graph(n, delayed_worklist);
 501       // fallthrough
 502     }
 503     case Op_StoreP:
 504     case Op_StoreN:
 505     case Op_StoreNKlass:
 506     case Op_StorePConditional:
 507     case Op_WeakCompareAndSwapP:
 508     case Op_WeakCompareAndSwapN:
 509     case Op_CompareAndSwapP:
 510     case Op_CompareAndSwapN: {
 511       Node* adr = n->in(MemNode::Address);
 512       const Type *adr_type = igvn->type(adr);
 513       adr_type = adr_type->make_ptr();
 514       if (adr_type == NULL) {
 515         break; // skip dead nodes
 516       }
 517       if (   adr_type->isa_oopptr()
 518           || (   (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
 519               && adr_type == TypeRawPtr::NOTNULL
 520               && adr->in(AddPNode::Address)->is_Proj()
 521               && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 522         delayed_worklist->push(n); // Process it later.
 523 #ifdef ASSERT
 524         assert(adr->is_AddP(), "expecting an AddP");
 525         if (adr_type == TypeRawPtr::NOTNULL) {
 526           // Verify a raw address for a store captured by Initialize node.
 527           int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 528           assert(offs != Type::OffsetBot, "offset must be a constant");
 529         }
 530 #endif
 531       } else {
 532         // Ignore copy the displaced header to the BoxNode (OSR compilation).
 533         if (adr->is_BoxLock())
 534           break;
 535         // Stored value escapes in unsafe access.
 536         if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
 537           // Pointer stores in G1 barriers looks like unsafe access.
 538           // Ignore such stores to be able scalar replace non-escaping
 539           // allocations.
 540           if (UseG1GC && adr->is_AddP()) {
 541             Node* base = get_addp_base(adr);
 542             if (base->Opcode() == Op_LoadP &&
 543                 base->in(MemNode::Address)->is_AddP()) {
 544               adr = base->in(MemNode::Address);
 545               Node* tls = get_addp_base(adr);
 546               if (tls->Opcode() == Op_ThreadLocal) {
 547                 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 548                 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
 549                                      SATBMarkQueue::byte_offset_of_buf())) {
 550                   break; // G1 pre barrier previous oop value store.
 551                 }
 552                 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
 553                                      DirtyCardQueue::byte_offset_of_buf())) {
 554                   break; // G1 post barrier card address store.
 555                 }
 556               }
 557             }
 558           }
 559           delayed_worklist->push(n); // Process unsafe access later.
 560           break;
 561         }
 562 #ifdef ASSERT
 563         n->dump(1);
 564         assert(false, "not unsafe or G1 barrier raw StoreP");
 565 #endif
 566       }
 567       break;
 568     }
 569     case Op_AryEq:
 570     case Op_HasNegatives:
 571     case Op_StrComp:
 572     case Op_StrEquals:
 573     case Op_StrIndexOf:
 574     case Op_StrIndexOfChar:
 575     case Op_StrInflatedCopy:
 576     case Op_StrCompressedCopy:
 577     case Op_EncodeISOArray: {
 578       add_local_var(n, PointsToNode::ArgEscape);
 579       delayed_worklist->push(n); // Process it later.
 580       break;
 581     }
 582     case Op_ThreadLocal: {
 583       add_java_object(n, PointsToNode::ArgEscape);
 584       break;
 585     }
 586     default:
 587       ; // Do nothing for nodes not related to EA.
 588   }
 589   return;
 590 }
 591 
 592 #ifdef ASSERT
 593 #define ELSE_FAIL(name)                               \
 594       /* Should not be called for not pointer type. */  \
 595       n->dump(1);                                       \
 596       assert(false, name);                              \
 597       break;
 598 #else
 599 #define ELSE_FAIL(name) \
 600       break;
 601 #endif
 602 
 603 // Add final simple edges to graph.
 604 void ConnectionGraph::add_final_edges(Node *n) {
 605   PointsToNode* n_ptn = ptnode_adr(n->_idx);
 606 #ifdef ASSERT
 607   if (_verify && n_ptn->is_JavaObject())
 608     return; // This method does not change graph for JavaObject.
 609 #endif
 610 
 611   if (n->is_Call()) {
 612     process_call_arguments(n->as_Call());
 613     return;
 614   }
 615   assert(n->is_Store() || n->is_LoadStore() ||
 616          (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
 617          "node should be registered already");
 618   int opcode = n->Opcode();
 619   switch (opcode) {
 620     case Op_AddP: {
 621       Node* base = get_addp_base(n);
 622       PointsToNode* ptn_base = ptnode_adr(base->_idx);
 623       assert(ptn_base != NULL, "field's base should be registered");
 624       add_base(n_ptn->as_Field(), ptn_base);
 625       break;
 626     }
 627     case Op_CastPP:
 628     case Op_CheckCastPP:
 629     case Op_EncodeP:
 630     case Op_DecodeN:
 631     case Op_EncodePKlass:
 632     case Op_DecodeNKlass: {
 633       add_local_var_and_edge(n, PointsToNode::NoEscape,
 634                              n->in(1), NULL);
 635       break;
 636     }
 637     case Op_CMoveP: {
 638       for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
 639         Node* in = n->in(i);
 640         if (in == NULL)
 641           continue;  // ignore NULL
 642         Node* uncast_in = in->uncast();
 643         if (uncast_in->is_top() || uncast_in == n)
 644           continue;  // ignore top or inputs which go back this node
 645         PointsToNode* ptn = ptnode_adr(in->_idx);
 646         assert(ptn != NULL, "node should be registered");
 647         add_edge(n_ptn, ptn);
 648       }
 649       break;
 650     }
 651     case Op_LoadP:
 652     case Op_LoadN:
 653     case Op_LoadPLocked: {
 654       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 655       // ThreadLocal has RawPtr type.
 656       const Type* t = _igvn->type(n);
 657       if (t->make_ptr() != NULL) {
 658         Node* adr = n->in(MemNode::Address);
 659         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 660         break;
 661       }
 662       ELSE_FAIL("Op_LoadP");
 663     }
 664     case Op_Phi: {
 665       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
 666       // ThreadLocal has RawPtr type.
 667       const Type* t = n->as_Phi()->type();
 668       if (t->make_ptr() != NULL) {
 669         for (uint i = 1; i < n->req(); i++) {
 670           Node* in = n->in(i);
 671           if (in == NULL)
 672             continue;  // ignore NULL
 673           Node* uncast_in = in->uncast();
 674           if (uncast_in->is_top() || uncast_in == n)
 675             continue;  // ignore top or inputs which go back this node
 676           PointsToNode* ptn = ptnode_adr(in->_idx);
 677           assert(ptn != NULL, "node should be registered");
 678           add_edge(n_ptn, ptn);
 679         }
 680         break;
 681       }
 682       ELSE_FAIL("Op_Phi");
 683     }
 684     case Op_Proj: {
 685       // we are only interested in the oop result projection from a call
 686       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
 687           n->in(0)->as_Call()->returns_pointer()) {
 688         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
 689         break;
 690       }
 691       ELSE_FAIL("Op_Proj");
 692     }
 693     case Op_Rethrow: // Exception object escapes
 694     case Op_Return: {
 695       if (n->req() > TypeFunc::Parms &&
 696           _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
 697         // Treat Return value as LocalVar with GlobalEscape escape state.
 698         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
 699                                n->in(TypeFunc::Parms), NULL);
 700         break;
 701       }
 702       ELSE_FAIL("Op_Return");
 703     }
 704     case Op_StoreP:
 705     case Op_StoreN:
 706     case Op_StoreNKlass:
 707     case Op_StorePConditional:
 708     case Op_CompareAndExchangeP:
 709     case Op_CompareAndExchangeN:
 710     case Op_CompareAndSwapP:
 711     case Op_CompareAndSwapN:
 712     case Op_WeakCompareAndSwapP:
 713     case Op_WeakCompareAndSwapN:
 714     case Op_GetAndSetP:
 715     case Op_GetAndSetN: {
 716       Node* adr = n->in(MemNode::Address);
 717       const Type *adr_type = _igvn->type(adr);
 718       adr_type = adr_type->make_ptr();
 719 #ifdef ASSERT
 720       if (adr_type == NULL) {
 721         n->dump(1);
 722         assert(adr_type != NULL, "dead node should not be on list");
 723         break;
 724       }
 725 #endif
 726       if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
 727           opcode == Op_CompareAndExchangeN || opcode == Op_CompareAndExchangeP) {
 728         add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
 729       }
 730       if (   adr_type->isa_oopptr()
 731           || (   (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
 732               && adr_type == TypeRawPtr::NOTNULL
 733               && adr->in(AddPNode::Address)->is_Proj()
 734               && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
 735         // Point Address to Value
 736         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 737         assert(adr_ptn != NULL &&
 738                adr_ptn->as_Field()->is_oop(), "node should be registered");
 739         Node *val = n->in(MemNode::ValueIn);
 740         PointsToNode* ptn = ptnode_adr(val->_idx);
 741         assert(ptn != NULL, "node should be registered");
 742         add_edge(adr_ptn, ptn);
 743         break;
 744       } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
 745         // Stored value escapes in unsafe access.
 746         Node *val = n->in(MemNode::ValueIn);
 747         PointsToNode* ptn = ptnode_adr(val->_idx);
 748         assert(ptn != NULL, "node should be registered");
 749         set_escape_state(ptn, PointsToNode::GlobalEscape);
 750         // Add edge to object for unsafe access with offset.
 751         PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
 752         assert(adr_ptn != NULL, "node should be registered");
 753         if (adr_ptn->is_Field()) {
 754           assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
 755           add_edge(adr_ptn, ptn);
 756         }
 757         break;
 758       }
 759       ELSE_FAIL("Op_StoreP");
 760     }
 761     case Op_AryEq:
 762     case Op_HasNegatives:
 763     case Op_StrComp:
 764     case Op_StrEquals:
 765     case Op_StrIndexOf:
 766     case Op_StrIndexOfChar:
 767     case Op_StrInflatedCopy:
 768     case Op_StrCompressedCopy:
 769     case Op_EncodeISOArray: {
 770       // char[]/byte[] arrays passed to string intrinsic do not escape but
 771       // they are not scalar replaceable. Adjust escape state for them.
 772       // Start from in(2) edge since in(1) is memory edge.
 773       for (uint i = 2; i < n->req(); i++) {
 774         Node* adr = n->in(i);
 775         const Type* at = _igvn->type(adr);
 776         if (!adr->is_top() && at->isa_ptr()) {
 777           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
 778                  at->isa_ptr() != NULL, "expecting a pointer");
 779           if (adr->is_AddP()) {
 780             adr = get_addp_base(adr);
 781           }
 782           PointsToNode* ptn = ptnode_adr(adr->_idx);
 783           assert(ptn != NULL, "node should be registered");
 784           add_edge(n_ptn, ptn);
 785         }
 786       }
 787       break;
 788     }
 789     default: {
 790       // This method should be called only for EA specific nodes which may
 791       // miss some edges when they were created.
 792 #ifdef ASSERT
 793       n->dump(1);
 794 #endif
 795       guarantee(false, "unknown node");
 796     }
 797   }
 798   return;
 799 }
 800 
 801 void ConnectionGraph::add_call_node(CallNode* call) {
 802   assert(call->returns_pointer(), "only for call which returns pointer");
 803   uint call_idx = call->_idx;
 804   if (call->is_Allocate()) {
 805     Node* k = call->in(AllocateNode::KlassNode);
 806     const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
 807     assert(kt != NULL, "TypeKlassPtr  required.");
 808     ciKlass* cik = kt->klass();
 809     PointsToNode::EscapeState es = PointsToNode::NoEscape;
 810     bool scalar_replaceable = true;
 811     if (call->is_AllocateArray()) {
 812       if (!cik->is_array_klass()) { // StressReflectiveCode
 813         es = PointsToNode::GlobalEscape;
 814       } else {
 815         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
 816         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
 817           // Not scalar replaceable if the length is not constant or too big.
 818           scalar_replaceable = false;
 819         }
 820       }
 821     } else {  // Allocate instance
 822       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
 823           cik->is_subclass_of(_compile->env()->Reference_klass()) ||
 824          !cik->is_instance_klass() || // StressReflectiveCode
 825          !cik->as_instance_klass()->can_be_instantiated() ||
 826           cik->as_instance_klass()->has_finalizer()) {
 827         es = PointsToNode::GlobalEscape;
 828       }
 829     }
 830     add_java_object(call, es);
 831     PointsToNode* ptn = ptnode_adr(call_idx);
 832     if (!scalar_replaceable && ptn->scalar_replaceable()) {
 833       ptn->set_scalar_replaceable(false);
 834     }
 835   } else if (call->is_CallStaticJava()) {
 836     // Call nodes could be different types:
 837     //
 838     // 1. CallDynamicJavaNode (what happened during call is unknown):
 839     //
 840     //    - mapped to GlobalEscape JavaObject node if oop is returned;
 841     //
 842     //    - all oop arguments are escaping globally;
 843     //
 844     // 2. CallStaticJavaNode (execute bytecode analysis if possible):
 845     //
 846     //    - the same as CallDynamicJavaNode if can't do bytecode analysis;
 847     //
 848     //    - mapped to GlobalEscape JavaObject node if unknown oop is returned;
 849     //    - mapped to NoEscape JavaObject node if non-escaping object allocated
 850     //      during call is returned;
 851     //    - mapped to ArgEscape LocalVar node pointed to object arguments
 852     //      which are returned and does not escape during call;
 853     //
 854     //    - oop arguments escaping status is defined by bytecode analysis;
 855     //
 856     // For a static call, we know exactly what method is being called.
 857     // Use bytecode estimator to record whether the call's return value escapes.
 858     ciMethod* meth = call->as_CallJava()->method();
 859     if (meth == NULL) {
 860       const char* name = call->as_CallStaticJava()->_name;
 861       assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
 862       // Returns a newly allocated unescaped object.
 863       add_java_object(call, PointsToNode::NoEscape);
 864       ptnode_adr(call_idx)->set_scalar_replaceable(false);
 865     } else if (meth->is_boxing_method()) {
 866       // Returns boxing object
 867       PointsToNode::EscapeState es;
 868       vmIntrinsics::ID intr = meth->intrinsic_id();
 869       if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
 870         // It does not escape if object is always allocated.
 871         es = PointsToNode::NoEscape;
 872       } else {
 873         // It escapes globally if object could be loaded from cache.
 874         es = PointsToNode::GlobalEscape;
 875       }
 876       add_java_object(call, es);
 877     } else {
 878       BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
 879       call_analyzer->copy_dependencies(_compile->dependencies());
 880       if (call_analyzer->is_return_allocated()) {
 881         // Returns a newly allocated unescaped object, simply
 882         // update dependency information.
 883         // Mark it as NoEscape so that objects referenced by
 884         // it's fields will be marked as NoEscape at least.
 885         add_java_object(call, PointsToNode::NoEscape);
 886         ptnode_adr(call_idx)->set_scalar_replaceable(false);
 887       } else {
 888         // Determine whether any arguments are returned.
 889         const TypeTuple* d = call->tf()->domain();
 890         bool ret_arg = false;
 891         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 892           if (d->field_at(i)->isa_ptr() != NULL &&
 893               call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
 894             ret_arg = true;
 895             break;
 896           }
 897         }
 898         if (ret_arg) {
 899           add_local_var(call, PointsToNode::ArgEscape);
 900         } else {
 901           // Returns unknown object.
 902           map_ideal_node(call, phantom_obj);
 903         }
 904       }
 905     }
 906   } else {
 907     // An other type of call, assume the worst case:
 908     // returned value is unknown and globally escapes.
 909     assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
 910     map_ideal_node(call, phantom_obj);
 911   }
 912 }
 913 
 914 void ConnectionGraph::process_call_arguments(CallNode *call) {
 915     bool is_arraycopy = false;
 916     switch (call->Opcode()) {
 917 #ifdef ASSERT
 918     case Op_Allocate:
 919     case Op_AllocateArray:
 920     case Op_Lock:
 921     case Op_Unlock:
 922       assert(false, "should be done already");
 923       break;
 924 #endif
 925     case Op_ArrayCopy:
 926     case Op_CallLeafNoFP:
 927       // Most array copies are ArrayCopy nodes at this point but there
 928       // are still a few direct calls to the copy subroutines (See
 929       // PhaseStringOpts::copy_string())
 930       is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
 931         call->as_CallLeaf()->is_call_to_arraycopystub();
 932       // fall through
 933     case Op_CallLeaf: {
 934       // Stub calls, objects do not escape but they are not scale replaceable.
 935       // Adjust escape state for outgoing arguments.
 936       const TypeTuple * d = call->tf()->domain();
 937       bool src_has_oops = false;
 938       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
 939         const Type* at = d->field_at(i);
 940         Node *arg = call->in(i);
 941         if (arg == NULL) {
 942           continue;
 943         }
 944         const Type *aat = _igvn->type(arg);
 945         if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
 946           continue;
 947         if (arg->is_AddP()) {
 948           //
 949           // The inline_native_clone() case when the arraycopy stub is called
 950           // after the allocation before Initialize and CheckCastPP nodes.
 951           // Or normal arraycopy for object arrays case.
 952           //
 953           // Set AddP's base (Allocate) as not scalar replaceable since
 954           // pointer to the base (with offset) is passed as argument.
 955           //
 956           arg = get_addp_base(arg);
 957         }
 958         PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
 959         assert(arg_ptn != NULL, "should be registered");
 960         PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
 961         if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
 962           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
 963                  aat->isa_ptr() != NULL, "expecting an Ptr");
 964           bool arg_has_oops = aat->isa_oopptr() &&
 965                               (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
 966                                (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
 967           if (i == TypeFunc::Parms) {
 968             src_has_oops = arg_has_oops;
 969           }
 970           //
 971           // src or dst could be j.l.Object when other is basic type array:
 972           //
 973           //   arraycopy(char[],0,Object*,0,size);
 974           //   arraycopy(Object*,0,char[],0,size);
 975           //
 976           // Don't add edges in such cases.
 977           //
 978           bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
 979                                        arg_has_oops && (i > TypeFunc::Parms);
 980 #ifdef ASSERT
 981           if (!(is_arraycopy ||
 982                 (call->as_CallLeaf()->_name != NULL &&
 983                  (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
 984                   strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
 985                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
 986                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
 987                   strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
 988                   strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
 989                   strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
 990                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
 991                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
 992                   strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
 993                   strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
 994                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
 995                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
 996                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
 997                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
 998                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
 999                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
1000                   strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1001                   strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1002                   strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1003                   strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1004                   strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1005                   strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1006                  ))) {
1007             call->dump();
1008             fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1009           }
1010 #endif
1011           // Always process arraycopy's destination object since
1012           // we need to add all possible edges to references in
1013           // source object.
1014           if (arg_esc >= PointsToNode::ArgEscape &&
1015               !arg_is_arraycopy_dest) {
1016             continue;
1017           }
1018           PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1019           if (call->is_ArrayCopy()) {
1020             ArrayCopyNode* ac = call->as_ArrayCopy();
1021             if (ac->is_clonebasic() ||
1022                 ac->is_arraycopy_validated() ||
1023                 ac->is_copyof_validated() ||
1024                 ac->is_copyofrange_validated()) {
1025               es = PointsToNode::NoEscape;
1026             }
1027           }
1028           set_escape_state(arg_ptn, es);
1029           if (arg_is_arraycopy_dest) {
1030             Node* src = call->in(TypeFunc::Parms);
1031             if (src->is_AddP()) {
1032               src = get_addp_base(src);
1033             }
1034             PointsToNode* src_ptn = ptnode_adr(src->_idx);
1035             assert(src_ptn != NULL, "should be registered");
1036             if (arg_ptn != src_ptn) {
1037               // Special arraycopy edge:
1038               // A destination object's field can't have the source object
1039               // as base since objects escape states are not related.
1040               // Only escape state of destination object's fields affects
1041               // escape state of fields in source object.
1042               add_arraycopy(call, es, src_ptn, arg_ptn);
1043             }
1044           }
1045         }
1046       }
1047       break;
1048     }
1049     case Op_CallStaticJava: {
1050       // For a static call, we know exactly what method is being called.
1051       // Use bytecode estimator to record the call's escape affects
1052 #ifdef ASSERT
1053       const char* name = call->as_CallStaticJava()->_name;
1054       assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1055 #endif
1056       ciMethod* meth = call->as_CallJava()->method();
1057       if ((meth != NULL) && meth->is_boxing_method()) {
1058         break; // Boxing methods do not modify any oops.
1059       }
1060       BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1061       // fall-through if not a Java method or no analyzer information
1062       if (call_analyzer != NULL) {
1063         PointsToNode* call_ptn = ptnode_adr(call->_idx);
1064         const TypeTuple* d = call->tf()->domain();
1065         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1066           const Type* at = d->field_at(i);
1067           int k = i - TypeFunc::Parms;
1068           Node* arg = call->in(i);
1069           PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1070           if (at->isa_ptr() != NULL &&
1071               call_analyzer->is_arg_returned(k)) {
1072             // The call returns arguments.
1073             if (call_ptn != NULL) { // Is call's result used?
1074               assert(call_ptn->is_LocalVar(), "node should be registered");
1075               assert(arg_ptn != NULL, "node should be registered");
1076               add_edge(call_ptn, arg_ptn);
1077             }
1078           }
1079           if (at->isa_oopptr() != NULL &&
1080               arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1081             if (!call_analyzer->is_arg_stack(k)) {
1082               // The argument global escapes
1083               set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1084             } else {
1085               set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1086               if (!call_analyzer->is_arg_local(k)) {
1087                 // The argument itself doesn't escape, but any fields might
1088                 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1089               }
1090             }
1091           }
1092         }
1093         if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1094           // The call returns arguments.
1095           assert(call_ptn->edge_count() > 0, "sanity");
1096           if (!call_analyzer->is_return_local()) {
1097             // Returns also unknown object.
1098             add_edge(call_ptn, phantom_obj);
1099           }
1100         }
1101         break;
1102       }
1103     }
1104     default: {
1105       // Fall-through here if not a Java method or no analyzer information
1106       // or some other type of call, assume the worst case: all arguments
1107       // globally escape.
1108       const TypeTuple* d = call->tf()->domain();
1109       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1110         const Type* at = d->field_at(i);
1111         if (at->isa_oopptr() != NULL) {
1112           Node* arg = call->in(i);
1113           if (arg->is_AddP()) {
1114             arg = get_addp_base(arg);
1115           }
1116           assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1117           set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1118         }
1119       }
1120     }
1121   }
1122 }
1123 
1124 
1125 // Finish Graph construction.
1126 bool ConnectionGraph::complete_connection_graph(
1127                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1128                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1129                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1130                          GrowableArray<FieldNode*>&      oop_fields_worklist) {
1131   // Normally only 1-3 passes needed to build Connection Graph depending
1132   // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1133   // Set limit to 20 to catch situation when something did go wrong and
1134   // bailout Escape Analysis.
1135   // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1136 #define CG_BUILD_ITER_LIMIT 20
1137 
1138   // Propagate GlobalEscape and ArgEscape escape states and check that
1139   // we still have non-escaping objects. The method pushs on _worklist
1140   // Field nodes which reference phantom_object.
1141   if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1142     return false; // Nothing to do.
1143   }
1144   // Now propagate references to all JavaObject nodes.
1145   int java_objects_length = java_objects_worklist.length();
1146   elapsedTimer time;
1147   bool timeout = false;
1148   int new_edges = 1;
1149   int iterations = 0;
1150   do {
1151     while ((new_edges > 0) &&
1152            (iterations++ < CG_BUILD_ITER_LIMIT)) {
1153       double start_time = time.seconds();
1154       time.start();
1155       new_edges = 0;
1156       // Propagate references to phantom_object for nodes pushed on _worklist
1157       // by find_non_escaped_objects() and find_field_value().
1158       new_edges += add_java_object_edges(phantom_obj, false);
1159       for (int next = 0; next < java_objects_length; ++next) {
1160         JavaObjectNode* ptn = java_objects_worklist.at(next);
1161         new_edges += add_java_object_edges(ptn, true);
1162 
1163 #define SAMPLE_SIZE 4
1164         if ((next % SAMPLE_SIZE) == 0) {
1165           // Each 4 iterations calculate how much time it will take
1166           // to complete graph construction.
1167           time.stop();
1168           // Poll for requests from shutdown mechanism to quiesce compiler
1169           // because Connection graph construction may take long time.
1170           CompileBroker::maybe_block();
1171           double stop_time = time.seconds();
1172           double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1173           double time_until_end = time_per_iter * (double)(java_objects_length - next);
1174           if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1175             timeout = true;
1176             break; // Timeout
1177           }
1178           start_time = stop_time;
1179           time.start();
1180         }
1181 #undef SAMPLE_SIZE
1182 
1183       }
1184       if (timeout) break;
1185       if (new_edges > 0) {
1186         // Update escape states on each iteration if graph was updated.
1187         if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1188           return false; // Nothing to do.
1189         }
1190       }
1191       time.stop();
1192       if (time.seconds() >= EscapeAnalysisTimeout) {
1193         timeout = true;
1194         break;
1195       }
1196     }
1197     if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1198       time.start();
1199       // Find fields which have unknown value.
1200       int fields_length = oop_fields_worklist.length();
1201       for (int next = 0; next < fields_length; next++) {
1202         FieldNode* field = oop_fields_worklist.at(next);
1203         if (field->edge_count() == 0) {
1204           new_edges += find_field_value(field);
1205           // This code may added new edges to phantom_object.
1206           // Need an other cycle to propagate references to phantom_object.
1207         }
1208       }
1209       time.stop();
1210       if (time.seconds() >= EscapeAnalysisTimeout) {
1211         timeout = true;
1212         break;
1213       }
1214     } else {
1215       new_edges = 0; // Bailout
1216     }
1217   } while (new_edges > 0);
1218 
1219   // Bailout if passed limits.
1220   if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1221     Compile* C = _compile;
1222     if (C->log() != NULL) {
1223       C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1224       C->log()->text("%s", timeout ? "time" : "iterations");
1225       C->log()->end_elem(" limit'");
1226     }
1227     assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1228            time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1229     // Possible infinite build_connection_graph loop,
1230     // bailout (no changes to ideal graph were made).
1231     return false;
1232   }
1233 #ifdef ASSERT
1234   if (Verbose && PrintEscapeAnalysis) {
1235     tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1236                   iterations, nodes_size(), ptnodes_worklist.length());
1237   }
1238 #endif
1239 
1240 #undef CG_BUILD_ITER_LIMIT
1241 
1242   // Find fields initialized by NULL for non-escaping Allocations.
1243   int non_escaped_length = non_escaped_worklist.length();
1244   for (int next = 0; next < non_escaped_length; next++) {
1245     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1246     PointsToNode::EscapeState es = ptn->escape_state();
1247     assert(es <= PointsToNode::ArgEscape, "sanity");
1248     if (es == PointsToNode::NoEscape) {
1249       if (find_init_values(ptn, null_obj, _igvn) > 0) {
1250         // Adding references to NULL object does not change escape states
1251         // since it does not escape. Also no fields are added to NULL object.
1252         add_java_object_edges(null_obj, false);
1253       }
1254     }
1255     Node* n = ptn->ideal_node();
1256     if (n->is_Allocate()) {
1257       // The object allocated by this Allocate node will never be
1258       // seen by an other thread. Mark it so that when it is
1259       // expanded no MemBarStoreStore is added.
1260       InitializeNode* ini = n->as_Allocate()->initialization();
1261       if (ini != NULL)
1262         ini->set_does_not_escape();
1263     }
1264   }
1265   return true; // Finished graph construction.
1266 }
1267 
1268 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1269 // and check that we still have non-escaping java objects.
1270 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1271                                                GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1272   GrowableArray<PointsToNode*> escape_worklist;
1273   // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1274   int ptnodes_length = ptnodes_worklist.length();
1275   for (int next = 0; next < ptnodes_length; ++next) {
1276     PointsToNode* ptn = ptnodes_worklist.at(next);
1277     if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1278         ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1279       escape_worklist.push(ptn);
1280     }
1281   }
1282   // Set escape states to referenced nodes (edges list).
1283   while (escape_worklist.length() > 0) {
1284     PointsToNode* ptn = escape_worklist.pop();
1285     PointsToNode::EscapeState es  = ptn->escape_state();
1286     PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1287     if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1288         es >= PointsToNode::ArgEscape) {
1289       // GlobalEscape or ArgEscape state of field means it has unknown value.
1290       if (add_edge(ptn, phantom_obj)) {
1291         // New edge was added
1292         add_field_uses_to_worklist(ptn->as_Field());
1293       }
1294     }
1295     for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1296       PointsToNode* e = i.get();
1297       if (e->is_Arraycopy()) {
1298         assert(ptn->arraycopy_dst(), "sanity");
1299         // Propagate only fields escape state through arraycopy edge.
1300         if (e->fields_escape_state() < field_es) {
1301           set_fields_escape_state(e, field_es);
1302           escape_worklist.push(e);
1303         }
1304       } else if (es >= field_es) {
1305         // fields_escape_state is also set to 'es' if it is less than 'es'.
1306         if (e->escape_state() < es) {
1307           set_escape_state(e, es);
1308           escape_worklist.push(e);
1309         }
1310       } else {
1311         // Propagate field escape state.
1312         bool es_changed = false;
1313         if (e->fields_escape_state() < field_es) {
1314           set_fields_escape_state(e, field_es);
1315           es_changed = true;
1316         }
1317         if ((e->escape_state() < field_es) &&
1318             e->is_Field() && ptn->is_JavaObject() &&
1319             e->as_Field()->is_oop()) {
1320           // Change escape state of referenced fields.
1321           set_escape_state(e, field_es);
1322           es_changed = true;
1323         } else if (e->escape_state() < es) {
1324           set_escape_state(e, es);
1325           es_changed = true;
1326         }
1327         if (es_changed) {
1328           escape_worklist.push(e);
1329         }
1330       }
1331     }
1332   }
1333   // Remove escaped objects from non_escaped list.
1334   for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1335     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1336     if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1337       non_escaped_worklist.delete_at(next);
1338     }
1339     if (ptn->escape_state() == PointsToNode::NoEscape) {
1340       // Find fields in non-escaped allocations which have unknown value.
1341       find_init_values(ptn, phantom_obj, NULL);
1342     }
1343   }
1344   return (non_escaped_worklist.length() > 0);
1345 }
1346 
1347 // Add all references to JavaObject node by walking over all uses.
1348 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1349   int new_edges = 0;
1350   if (populate_worklist) {
1351     // Populate _worklist by uses of jobj's uses.
1352     for (UseIterator i(jobj); i.has_next(); i.next()) {
1353       PointsToNode* use = i.get();
1354       if (use->is_Arraycopy())
1355         continue;
1356       add_uses_to_worklist(use);
1357       if (use->is_Field() && use->as_Field()->is_oop()) {
1358         // Put on worklist all field's uses (loads) and
1359         // related field nodes (same base and offset).
1360         add_field_uses_to_worklist(use->as_Field());
1361       }
1362     }
1363   }
1364   for (int l = 0; l < _worklist.length(); l++) {
1365     PointsToNode* use = _worklist.at(l);
1366     if (PointsToNode::is_base_use(use)) {
1367       // Add reference from jobj to field and from field to jobj (field's base).
1368       use = PointsToNode::get_use_node(use)->as_Field();
1369       if (add_base(use->as_Field(), jobj)) {
1370         new_edges++;
1371       }
1372       continue;
1373     }
1374     assert(!use->is_JavaObject(), "sanity");
1375     if (use->is_Arraycopy()) {
1376       if (jobj == null_obj) // NULL object does not have field edges
1377         continue;
1378       // Added edge from Arraycopy node to arraycopy's source java object
1379       if (add_edge(use, jobj)) {
1380         jobj->set_arraycopy_src();
1381         new_edges++;
1382       }
1383       // and stop here.
1384       continue;
1385     }
1386     if (!add_edge(use, jobj))
1387       continue; // No new edge added, there was such edge already.
1388     new_edges++;
1389     if (use->is_LocalVar()) {
1390       add_uses_to_worklist(use);
1391       if (use->arraycopy_dst()) {
1392         for (EdgeIterator i(use); i.has_next(); i.next()) {
1393           PointsToNode* e = i.get();
1394           if (e->is_Arraycopy()) {
1395             if (jobj == null_obj) // NULL object does not have field edges
1396               continue;
1397             // Add edge from arraycopy's destination java object to Arraycopy node.
1398             if (add_edge(jobj, e)) {
1399               new_edges++;
1400               jobj->set_arraycopy_dst();
1401             }
1402           }
1403         }
1404       }
1405     } else {
1406       // Added new edge to stored in field values.
1407       // Put on worklist all field's uses (loads) and
1408       // related field nodes (same base and offset).
1409       add_field_uses_to_worklist(use->as_Field());
1410     }
1411   }
1412   _worklist.clear();
1413   _in_worklist.Reset();
1414   return new_edges;
1415 }
1416 
1417 // Put on worklist all related field nodes.
1418 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1419   assert(field->is_oop(), "sanity");
1420   int offset = field->offset();
1421   add_uses_to_worklist(field);
1422   // Loop over all bases of this field and push on worklist Field nodes
1423   // with the same offset and base (since they may reference the same field).
1424   for (BaseIterator i(field); i.has_next(); i.next()) {
1425     PointsToNode* base = i.get();
1426     add_fields_to_worklist(field, base);
1427     // Check if the base was source object of arraycopy and go over arraycopy's
1428     // destination objects since values stored to a field of source object are
1429     // accessable by uses (loads) of fields of destination objects.
1430     if (base->arraycopy_src()) {
1431       for (UseIterator j(base); j.has_next(); j.next()) {
1432         PointsToNode* arycp = j.get();
1433         if (arycp->is_Arraycopy()) {
1434           for (UseIterator k(arycp); k.has_next(); k.next()) {
1435             PointsToNode* abase = k.get();
1436             if (abase->arraycopy_dst() && abase != base) {
1437               // Look for the same arraycopy reference.
1438               add_fields_to_worklist(field, abase);
1439             }
1440           }
1441         }
1442       }
1443     }
1444   }
1445 }
1446 
1447 // Put on worklist all related field nodes.
1448 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1449   int offset = field->offset();
1450   if (base->is_LocalVar()) {
1451     for (UseIterator j(base); j.has_next(); j.next()) {
1452       PointsToNode* f = j.get();
1453       if (PointsToNode::is_base_use(f)) { // Field
1454         f = PointsToNode::get_use_node(f);
1455         if (f == field || !f->as_Field()->is_oop())
1456           continue;
1457         int offs = f->as_Field()->offset();
1458         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1459           add_to_worklist(f);
1460         }
1461       }
1462     }
1463   } else {
1464     assert(base->is_JavaObject(), "sanity");
1465     if (// Skip phantom_object since it is only used to indicate that
1466         // this field's content globally escapes.
1467         (base != phantom_obj) &&
1468         // NULL object node does not have fields.
1469         (base != null_obj)) {
1470       for (EdgeIterator i(base); i.has_next(); i.next()) {
1471         PointsToNode* f = i.get();
1472         // Skip arraycopy edge since store to destination object field
1473         // does not update value in source object field.
1474         if (f->is_Arraycopy()) {
1475           assert(base->arraycopy_dst(), "sanity");
1476           continue;
1477         }
1478         if (f == field || !f->as_Field()->is_oop())
1479           continue;
1480         int offs = f->as_Field()->offset();
1481         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1482           add_to_worklist(f);
1483         }
1484       }
1485     }
1486   }
1487 }
1488 
1489 // Find fields which have unknown value.
1490 int ConnectionGraph::find_field_value(FieldNode* field) {
1491   // Escaped fields should have init value already.
1492   assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1493   int new_edges = 0;
1494   for (BaseIterator i(field); i.has_next(); i.next()) {
1495     PointsToNode* base = i.get();
1496     if (base->is_JavaObject()) {
1497       // Skip Allocate's fields which will be processed later.
1498       if (base->ideal_node()->is_Allocate())
1499         return 0;
1500       assert(base == null_obj, "only NULL ptr base expected here");
1501     }
1502   }
1503   if (add_edge(field, phantom_obj)) {
1504     // New edge was added
1505     new_edges++;
1506     add_field_uses_to_worklist(field);
1507   }
1508   return new_edges;
1509 }
1510 
1511 // Find fields initializing values for allocations.
1512 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1513   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1514   int new_edges = 0;
1515   Node* alloc = pta->ideal_node();
1516   if (init_val == phantom_obj) {
1517     // Do nothing for Allocate nodes since its fields values are
1518     // "known" unless they are initialized by arraycopy/clone.
1519     if (alloc->is_Allocate() && !pta->arraycopy_dst())
1520       return 0;
1521     assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1522 #ifdef ASSERT
1523     if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1524       const char* name = alloc->as_CallStaticJava()->_name;
1525       assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1526     }
1527 #endif
1528     // Non-escaped allocation returned from Java or runtime call have
1529     // unknown values in fields.
1530     for (EdgeIterator i(pta); i.has_next(); i.next()) {
1531       PointsToNode* field = i.get();
1532       if (field->is_Field() && field->as_Field()->is_oop()) {
1533         if (add_edge(field, phantom_obj)) {
1534           // New edge was added
1535           new_edges++;
1536           add_field_uses_to_worklist(field->as_Field());
1537         }
1538       }
1539     }
1540     return new_edges;
1541   }
1542   assert(init_val == null_obj, "sanity");
1543   // Do nothing for Call nodes since its fields values are unknown.
1544   if (!alloc->is_Allocate())
1545     return 0;
1546 
1547   InitializeNode* ini = alloc->as_Allocate()->initialization();
1548   bool visited_bottom_offset = false;
1549   GrowableArray<int> offsets_worklist;
1550 
1551   // Check if an oop field's initializing value is recorded and add
1552   // a corresponding NULL if field's value if it is not recorded.
1553   // Connection Graph does not record a default initialization by NULL
1554   // captured by Initialize node.
1555   //
1556   for (EdgeIterator i(pta); i.has_next(); i.next()) {
1557     PointsToNode* field = i.get(); // Field (AddP)
1558     if (!field->is_Field() || !field->as_Field()->is_oop())
1559       continue; // Not oop field
1560     int offset = field->as_Field()->offset();
1561     if (offset == Type::OffsetBot) {
1562       if (!visited_bottom_offset) {
1563         // OffsetBot is used to reference array's element,
1564         // always add reference to NULL to all Field nodes since we don't
1565         // known which element is referenced.
1566         if (add_edge(field, null_obj)) {
1567           // New edge was added
1568           new_edges++;
1569           add_field_uses_to_worklist(field->as_Field());
1570           visited_bottom_offset = true;
1571         }
1572       }
1573     } else {
1574       // Check only oop fields.
1575       const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1576       if (adr_type->isa_rawptr()) {
1577 #ifdef ASSERT
1578         // Raw pointers are used for initializing stores so skip it
1579         // since it should be recorded already
1580         Node* base = get_addp_base(field->ideal_node());
1581         assert(adr_type->isa_rawptr() && base->is_Proj() &&
1582                (base->in(0) == alloc),"unexpected pointer type");
1583 #endif
1584         continue;
1585       }
1586       if (!offsets_worklist.contains(offset)) {
1587         offsets_worklist.append(offset);
1588         Node* value = NULL;
1589         if (ini != NULL) {
1590           // StoreP::memory_type() == T_ADDRESS
1591           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1592           Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1593           // Make sure initializing store has the same type as this AddP.
1594           // This AddP may reference non existing field because it is on a
1595           // dead branch of bimorphic call which is not eliminated yet.
1596           if (store != NULL && store->is_Store() &&
1597               store->as_Store()->memory_type() == ft) {
1598             value = store->in(MemNode::ValueIn);
1599 #ifdef ASSERT
1600             if (VerifyConnectionGraph) {
1601               // Verify that AddP already points to all objects the value points to.
1602               PointsToNode* val = ptnode_adr(value->_idx);
1603               assert((val != NULL), "should be processed already");
1604               PointsToNode* missed_obj = NULL;
1605               if (val->is_JavaObject()) {
1606                 if (!field->points_to(val->as_JavaObject())) {
1607                   missed_obj = val;
1608                 }
1609               } else {
1610                 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1611                   tty->print_cr("----------init store has invalid value -----");
1612                   store->dump();
1613                   val->dump();
1614                   assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1615                 }
1616                 for (EdgeIterator j(val); j.has_next(); j.next()) {
1617                   PointsToNode* obj = j.get();
1618                   if (obj->is_JavaObject()) {
1619                     if (!field->points_to(obj->as_JavaObject())) {
1620                       missed_obj = obj;
1621                       break;
1622                     }
1623                   }
1624                 }
1625               }
1626               if (missed_obj != NULL) {
1627                 tty->print_cr("----------field---------------------------------");
1628                 field->dump();
1629                 tty->print_cr("----------missed referernce to object-----------");
1630                 missed_obj->dump();
1631                 tty->print_cr("----------object referernced by init store -----");
1632                 store->dump();
1633                 val->dump();
1634                 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1635               }
1636             }
1637 #endif
1638           } else {
1639             // There could be initializing stores which follow allocation.
1640             // For example, a volatile field store is not collected
1641             // by Initialize node.
1642             //
1643             // Need to check for dependent loads to separate such stores from
1644             // stores which follow loads. For now, add initial value NULL so
1645             // that compare pointers optimization works correctly.
1646           }
1647         }
1648         if (value == NULL) {
1649           // A field's initializing value was not recorded. Add NULL.
1650           if (add_edge(field, null_obj)) {
1651             // New edge was added
1652             new_edges++;
1653             add_field_uses_to_worklist(field->as_Field());
1654           }
1655         }
1656       }
1657     }
1658   }
1659   return new_edges;
1660 }
1661 
1662 // Adjust scalar_replaceable state after Connection Graph is built.
1663 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1664   // Search for non-escaping objects which are not scalar replaceable
1665   // and mark them to propagate the state to referenced objects.
1666 
1667   // 1. An object is not scalar replaceable if the field into which it is
1668   // stored has unknown offset (stored into unknown element of an array).
1669   //
1670   for (UseIterator i(jobj); i.has_next(); i.next()) {
1671     PointsToNode* use = i.get();
1672     if (use->is_Arraycopy()) {
1673       continue;
1674     }
1675     if (use->is_Field()) {
1676       FieldNode* field = use->as_Field();
1677       assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1678       if (field->offset() == Type::OffsetBot) {
1679         jobj->set_scalar_replaceable(false);
1680         return;
1681       }
1682       // 2. An object is not scalar replaceable if the field into which it is
1683       // stored has multiple bases one of which is null.
1684       if (field->base_count() > 1) {
1685         for (BaseIterator i(field); i.has_next(); i.next()) {
1686           PointsToNode* base = i.get();
1687           if (base == null_obj) {
1688             jobj->set_scalar_replaceable(false);
1689             return;
1690           }
1691         }
1692       }
1693     }
1694     assert(use->is_Field() || use->is_LocalVar(), "sanity");
1695     // 3. An object is not scalar replaceable if it is merged with other objects.
1696     for (EdgeIterator j(use); j.has_next(); j.next()) {
1697       PointsToNode* ptn = j.get();
1698       if (ptn->is_JavaObject() && ptn != jobj) {
1699         // Mark all objects.
1700         jobj->set_scalar_replaceable(false);
1701          ptn->set_scalar_replaceable(false);
1702       }
1703     }
1704     if (!jobj->scalar_replaceable()) {
1705       return;
1706     }
1707   }
1708 
1709   for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1710     if (j.get()->is_Arraycopy()) {
1711       continue;
1712     }
1713 
1714     // Non-escaping object node should point only to field nodes.
1715     FieldNode* field = j.get()->as_Field();
1716     int offset = field->as_Field()->offset();
1717 
1718     // 4. An object is not scalar replaceable if it has a field with unknown
1719     // offset (array's element is accessed in loop).
1720     if (offset == Type::OffsetBot) {
1721       jobj->set_scalar_replaceable(false);
1722       return;
1723     }
1724     // 5. Currently an object is not scalar replaceable if a LoadStore node
1725     // access its field since the field value is unknown after it.
1726     //
1727     Node* n = field->ideal_node();
1728     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1729       if (n->fast_out(i)->is_LoadStore()) {
1730         jobj->set_scalar_replaceable(false);
1731         return;
1732       }
1733     }
1734 
1735     // 6. Or the address may point to more then one object. This may produce
1736     // the false positive result (set not scalar replaceable)
1737     // since the flow-insensitive escape analysis can't separate
1738     // the case when stores overwrite the field's value from the case
1739     // when stores happened on different control branches.
1740     //
1741     // Note: it will disable scalar replacement in some cases:
1742     //
1743     //    Point p[] = new Point[1];
1744     //    p[0] = new Point(); // Will be not scalar replaced
1745     //
1746     // but it will save us from incorrect optimizations in next cases:
1747     //
1748     //    Point p[] = new Point[1];
1749     //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
1750     //
1751     if (field->base_count() > 1) {
1752       for (BaseIterator i(field); i.has_next(); i.next()) {
1753         PointsToNode* base = i.get();
1754         // Don't take into account LocalVar nodes which
1755         // may point to only one object which should be also
1756         // this field's base by now.
1757         if (base->is_JavaObject() && base != jobj) {
1758           // Mark all bases.
1759           jobj->set_scalar_replaceable(false);
1760           base->set_scalar_replaceable(false);
1761         }
1762       }
1763     }
1764   }
1765 }
1766 
1767 #ifdef ASSERT
1768 void ConnectionGraph::verify_connection_graph(
1769                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
1770                          GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1771                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
1772                          GrowableArray<Node*>& addp_worklist) {
1773   // Verify that graph is complete - no new edges could be added.
1774   int java_objects_length = java_objects_worklist.length();
1775   int non_escaped_length  = non_escaped_worklist.length();
1776   int new_edges = 0;
1777   for (int next = 0; next < java_objects_length; ++next) {
1778     JavaObjectNode* ptn = java_objects_worklist.at(next);
1779     new_edges += add_java_object_edges(ptn, true);
1780   }
1781   assert(new_edges == 0, "graph was not complete");
1782   // Verify that escape state is final.
1783   int length = non_escaped_worklist.length();
1784   find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1785   assert((non_escaped_length == non_escaped_worklist.length()) &&
1786          (non_escaped_length == length) &&
1787          (_worklist.length() == 0), "escape state was not final");
1788 
1789   // Verify fields information.
1790   int addp_length = addp_worklist.length();
1791   for (int next = 0; next < addp_length; ++next ) {
1792     Node* n = addp_worklist.at(next);
1793     FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1794     if (field->is_oop()) {
1795       // Verify that field has all bases
1796       Node* base = get_addp_base(n);
1797       PointsToNode* ptn = ptnode_adr(base->_idx);
1798       if (ptn->is_JavaObject()) {
1799         assert(field->has_base(ptn->as_JavaObject()), "sanity");
1800       } else {
1801         assert(ptn->is_LocalVar(), "sanity");
1802         for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1803           PointsToNode* e = i.get();
1804           if (e->is_JavaObject()) {
1805             assert(field->has_base(e->as_JavaObject()), "sanity");
1806           }
1807         }
1808       }
1809       // Verify that all fields have initializing values.
1810       if (field->edge_count() == 0) {
1811         tty->print_cr("----------field does not have references----------");
1812         field->dump();
1813         for (BaseIterator i(field); i.has_next(); i.next()) {
1814           PointsToNode* base = i.get();
1815           tty->print_cr("----------field has next base---------------------");
1816           base->dump();
1817           if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1818             tty->print_cr("----------base has fields-------------------------");
1819             for (EdgeIterator j(base); j.has_next(); j.next()) {
1820               j.get()->dump();
1821             }
1822             tty->print_cr("----------base has references---------------------");
1823             for (UseIterator j(base); j.has_next(); j.next()) {
1824               j.get()->dump();
1825             }
1826           }
1827         }
1828         for (UseIterator i(field); i.has_next(); i.next()) {
1829           i.get()->dump();
1830         }
1831         assert(field->edge_count() > 0, "sanity");
1832       }
1833     }
1834   }
1835 }
1836 #endif
1837 
1838 // Optimize ideal graph.
1839 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1840                                            GrowableArray<Node*>& storestore_worklist) {
1841   Compile* C = _compile;
1842   PhaseIterGVN* igvn = _igvn;
1843   if (EliminateLocks) {
1844     // Mark locks before changing ideal graph.
1845     int cnt = C->macro_count();
1846     for( int i=0; i < cnt; i++ ) {
1847       Node *n = C->macro_node(i);
1848       if (n->is_AbstractLock()) { // Lock and Unlock nodes
1849         AbstractLockNode* alock = n->as_AbstractLock();
1850         if (!alock->is_non_esc_obj()) {
1851           if (not_global_escape(alock->obj_node())) {
1852             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1853             // The lock could be marked eliminated by lock coarsening
1854             // code during first IGVN before EA. Replace coarsened flag
1855             // to eliminate all associated locks/unlocks.
1856 #ifdef ASSERT
1857             alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1858 #endif
1859             alock->set_non_esc_obj();
1860           }
1861         }
1862       }
1863     }
1864   }
1865 
1866   if (OptimizePtrCompare) {
1867     // Add ConI(#CC_GT) and ConI(#CC_EQ).
1868     _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1869     _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1870     // Optimize objects compare.
1871     while (ptr_cmp_worklist.length() != 0) {
1872       Node *n = ptr_cmp_worklist.pop();
1873       Node *res = optimize_ptr_compare(n);
1874       if (res != NULL) {
1875 #ifndef PRODUCT
1876         if (PrintOptimizePtrCompare) {
1877           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"));
1878           if (Verbose) {
1879             n->dump(1);
1880           }
1881         }
1882 #endif
1883         igvn->replace_node(n, res);
1884       }
1885     }
1886     // cleanup
1887     if (_pcmp_neq->outcnt() == 0)
1888       igvn->hash_delete(_pcmp_neq);
1889     if (_pcmp_eq->outcnt()  == 0)
1890       igvn->hash_delete(_pcmp_eq);
1891   }
1892 
1893   // For MemBarStoreStore nodes added in library_call.cpp, check
1894   // escape status of associated AllocateNode and optimize out
1895   // MemBarStoreStore node if the allocated object never escapes.
1896   while (storestore_worklist.length() != 0) {
1897     Node *n = storestore_worklist.pop();
1898     MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1899     Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1900     assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1901     if (not_global_escape(alloc)) {
1902       MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1903       mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1904       mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1905       igvn->register_new_node_with_optimizer(mb);
1906       igvn->replace_node(storestore, mb);
1907     }
1908   }
1909 }
1910 
1911 // Optimize objects compare.
1912 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1913   assert(OptimizePtrCompare, "sanity");
1914   PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1915   PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1916   JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1917   JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1918   assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1919   assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1920 
1921   // Check simple cases first.
1922   if (jobj1 != NULL) {
1923     if (jobj1->escape_state() == PointsToNode::NoEscape) {
1924       if (jobj1 == jobj2) {
1925         // Comparing the same not escaping object.
1926         return _pcmp_eq;
1927       }
1928       Node* obj = jobj1->ideal_node();
1929       // Comparing not escaping allocation.
1930       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1931           !ptn2->points_to(jobj1)) {
1932         return _pcmp_neq; // This includes nullness check.
1933       }
1934     }
1935   }
1936   if (jobj2 != NULL) {
1937     if (jobj2->escape_state() == PointsToNode::NoEscape) {
1938       Node* obj = jobj2->ideal_node();
1939       // Comparing not escaping allocation.
1940       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1941           !ptn1->points_to(jobj2)) {
1942         return _pcmp_neq; // This includes nullness check.
1943       }
1944     }
1945   }
1946   if (jobj1 != NULL && jobj1 != phantom_obj &&
1947       jobj2 != NULL && jobj2 != phantom_obj &&
1948       jobj1->ideal_node()->is_Con() &&
1949       jobj2->ideal_node()->is_Con()) {
1950     // Klass or String constants compare. Need to be careful with
1951     // compressed pointers - compare types of ConN and ConP instead of nodes.
1952     const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1953     const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1954     if (t1->make_ptr() == t2->make_ptr()) {
1955       return _pcmp_eq;
1956     } else {
1957       return _pcmp_neq;
1958     }
1959   }
1960   if (ptn1->meet(ptn2)) {
1961     return NULL; // Sets are not disjoint
1962   }
1963 
1964   // Sets are disjoint.
1965   bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1966   bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1967   bool set1_has_null_ptr    = ptn1->points_to(null_obj);
1968   bool set2_has_null_ptr    = ptn2->points_to(null_obj);
1969   if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
1970       (set2_has_unknown_ptr && set1_has_null_ptr)) {
1971     // Check nullness of unknown object.
1972     return NULL;
1973   }
1974 
1975   // Disjointness by itself is not sufficient since
1976   // alias analysis is not complete for escaped objects.
1977   // Disjoint sets are definitely unrelated only when
1978   // at least one set has only not escaping allocations.
1979   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1980     if (ptn1->non_escaping_allocation()) {
1981       return _pcmp_neq;
1982     }
1983   }
1984   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1985     if (ptn2->non_escaping_allocation()) {
1986       return _pcmp_neq;
1987     }
1988   }
1989   return NULL;
1990 }
1991 
1992 // Connection Graph constuction functions.
1993 
1994 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1995   PointsToNode* ptadr = _nodes.at(n->_idx);
1996   if (ptadr != NULL) {
1997     assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1998     return;
1999   }
2000   Compile* C = _compile;
2001   ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2002   _nodes.at_put(n->_idx, ptadr);
2003 }
2004 
2005 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2006   PointsToNode* ptadr = _nodes.at(n->_idx);
2007   if (ptadr != NULL) {
2008     assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2009     return;
2010   }
2011   Compile* C = _compile;
2012   ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2013   _nodes.at_put(n->_idx, ptadr);
2014 }
2015 
2016 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2017   PointsToNode* ptadr = _nodes.at(n->_idx);
2018   if (ptadr != NULL) {
2019     assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2020     return;
2021   }
2022   bool unsafe = false;
2023   bool is_oop = is_oop_field(n, offset, &unsafe);
2024   if (unsafe) {
2025     es = PointsToNode::GlobalEscape;
2026   }
2027   Compile* C = _compile;
2028   FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2029   _nodes.at_put(n->_idx, field);
2030 }
2031 
2032 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2033                                     PointsToNode* src, PointsToNode* dst) {
2034   assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2035   assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2036   PointsToNode* ptadr = _nodes.at(n->_idx);
2037   if (ptadr != NULL) {
2038     assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2039     return;
2040   }
2041   Compile* C = _compile;
2042   ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2043   _nodes.at_put(n->_idx, ptadr);
2044   // Add edge from arraycopy node to source object.
2045   (void)add_edge(ptadr, src);
2046   src->set_arraycopy_src();
2047   // Add edge from destination object to arraycopy node.
2048   (void)add_edge(dst, ptadr);
2049   dst->set_arraycopy_dst();
2050 }
2051 
2052 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2053   const Type* adr_type = n->as_AddP()->bottom_type();
2054   BasicType bt = T_INT;
2055   if (offset == Type::OffsetBot) {
2056     // Check only oop fields.
2057     if (!adr_type->isa_aryptr() ||
2058         (adr_type->isa_aryptr()->klass() == NULL) ||
2059          adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2060       // OffsetBot is used to reference array's element. Ignore first AddP.
2061       if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2062         bt = T_OBJECT;
2063       }
2064     }
2065   } else if (offset != oopDesc::klass_offset_in_bytes()) {
2066     if (adr_type->isa_instptr()) {
2067       ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2068       if (field != NULL) {
2069         bt = field->layout_type();
2070       } else {
2071         // Check for unsafe oop field access
2072         if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2073             n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2074             n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2075           bt = T_OBJECT;
2076           (*unsafe) = true;
2077         }
2078       }
2079     } else if (adr_type->isa_aryptr()) {
2080       if (offset == arrayOopDesc::length_offset_in_bytes()) {
2081         // Ignore array length load.
2082       } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2083         // Ignore first AddP.
2084       } else {
2085         const Type* elemtype = adr_type->isa_aryptr()->elem();
2086         bt = elemtype->array_element_basic_type();
2087       }
2088     } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2089       // Allocation initialization, ThreadLocal field access, unsafe access
2090       if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2091           n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2092           n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2093         bt = T_OBJECT;
2094       }
2095     }
2096   }
2097   return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2098 }
2099 
2100 // Returns unique pointed java object or NULL.
2101 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2102   assert(!_collecting, "should not call when contructed graph");
2103   // If the node was created after the escape computation we can't answer.
2104   uint idx = n->_idx;
2105   if (idx >= nodes_size()) {
2106     return NULL;
2107   }
2108   PointsToNode* ptn = ptnode_adr(idx);
2109   if (ptn->is_JavaObject()) {
2110     return ptn->as_JavaObject();
2111   }
2112   assert(ptn->is_LocalVar(), "sanity");
2113   // Check all java objects it points to.
2114   JavaObjectNode* jobj = NULL;
2115   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2116     PointsToNode* e = i.get();
2117     if (e->is_JavaObject()) {
2118       if (jobj == NULL) {
2119         jobj = e->as_JavaObject();
2120       } else if (jobj != e) {
2121         return NULL;
2122       }
2123     }
2124   }
2125   return jobj;
2126 }
2127 
2128 // Return true if this node points only to non-escaping allocations.
2129 bool PointsToNode::non_escaping_allocation() {
2130   if (is_JavaObject()) {
2131     Node* n = ideal_node();
2132     if (n->is_Allocate() || n->is_CallStaticJava()) {
2133       return (escape_state() == PointsToNode::NoEscape);
2134     } else {
2135       return false;
2136     }
2137   }
2138   assert(is_LocalVar(), "sanity");
2139   // Check all java objects it points to.
2140   for (EdgeIterator i(this); i.has_next(); i.next()) {
2141     PointsToNode* e = i.get();
2142     if (e->is_JavaObject()) {
2143       Node* n = e->ideal_node();
2144       if ((e->escape_state() != PointsToNode::NoEscape) ||
2145           !(n->is_Allocate() || n->is_CallStaticJava())) {
2146         return false;
2147       }
2148     }
2149   }
2150   return true;
2151 }
2152 
2153 // Return true if we know the node does not escape globally.
2154 bool ConnectionGraph::not_global_escape(Node *n) {
2155   assert(!_collecting, "should not call during graph construction");
2156   // If the node was created after the escape computation we can't answer.
2157   uint idx = n->_idx;
2158   if (idx >= nodes_size()) {
2159     return false;
2160   }
2161   PointsToNode* ptn = ptnode_adr(idx);
2162   PointsToNode::EscapeState es = ptn->escape_state();
2163   // If we have already computed a value, return it.
2164   if (es >= PointsToNode::GlobalEscape)
2165     return false;
2166   if (ptn->is_JavaObject()) {
2167     return true; // (es < PointsToNode::GlobalEscape);
2168   }
2169   assert(ptn->is_LocalVar(), "sanity");
2170   // Check all java objects it points to.
2171   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2172     if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2173       return false;
2174   }
2175   return true;
2176 }
2177 
2178 
2179 // Helper functions
2180 
2181 // Return true if this node points to specified node or nodes it points to.
2182 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2183   if (is_JavaObject()) {
2184     return (this == ptn);
2185   }
2186   assert(is_LocalVar() || is_Field(), "sanity");
2187   for (EdgeIterator i(this); i.has_next(); i.next()) {
2188     if (i.get() == ptn)
2189       return true;
2190   }
2191   return false;
2192 }
2193 
2194 // Return true if one node points to an other.
2195 bool PointsToNode::meet(PointsToNode* ptn) {
2196   if (this == ptn) {
2197     return true;
2198   } else if (ptn->is_JavaObject()) {
2199     return this->points_to(ptn->as_JavaObject());
2200   } else if (this->is_JavaObject()) {
2201     return ptn->points_to(this->as_JavaObject());
2202   }
2203   assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2204   int ptn_count =  ptn->edge_count();
2205   for (EdgeIterator i(this); i.has_next(); i.next()) {
2206     PointsToNode* this_e = i.get();
2207     for (int j = 0; j < ptn_count; j++) {
2208       if (this_e == ptn->edge(j))
2209         return true;
2210     }
2211   }
2212   return false;
2213 }
2214 
2215 #ifdef ASSERT
2216 // Return true if bases point to this java object.
2217 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2218   for (BaseIterator i(this); i.has_next(); i.next()) {
2219     if (i.get() == jobj)
2220       return true;
2221   }
2222   return false;
2223 }
2224 #endif
2225 
2226 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2227   const Type *adr_type = phase->type(adr);
2228   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2229       adr->in(AddPNode::Address)->is_Proj() &&
2230       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2231     // We are computing a raw address for a store captured by an Initialize
2232     // compute an appropriate address type. AddP cases #3 and #5 (see below).
2233     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2234     assert(offs != Type::OffsetBot ||
2235            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2236            "offset must be a constant or it is initialization of array");
2237     return offs;
2238   }
2239   const TypePtr *t_ptr = adr_type->isa_ptr();
2240   assert(t_ptr != NULL, "must be a pointer type");
2241   return t_ptr->offset();
2242 }
2243 
2244 Node* ConnectionGraph::get_addp_base(Node *addp) {
2245   assert(addp->is_AddP(), "must be AddP");
2246   //
2247   // AddP cases for Base and Address inputs:
2248   // case #1. Direct object's field reference:
2249   //     Allocate
2250   //       |
2251   //     Proj #5 ( oop result )
2252   //       |
2253   //     CheckCastPP (cast to instance type)
2254   //      | |
2255   //     AddP  ( base == address )
2256   //
2257   // case #2. Indirect object's field reference:
2258   //      Phi
2259   //       |
2260   //     CastPP (cast to instance type)
2261   //      | |
2262   //     AddP  ( base == address )
2263   //
2264   // case #3. Raw object's field reference for Initialize node:
2265   //      Allocate
2266   //        |
2267   //      Proj #5 ( oop result )
2268   //  top   |
2269   //     \  |
2270   //     AddP  ( base == top )
2271   //
2272   // case #4. Array's element reference:
2273   //   {CheckCastPP | CastPP}
2274   //     |  | |
2275   //     |  AddP ( array's element offset )
2276   //     |  |
2277   //     AddP ( array's offset )
2278   //
2279   // case #5. Raw object's field reference for arraycopy stub call:
2280   //          The inline_native_clone() case when the arraycopy stub is called
2281   //          after the allocation before Initialize and CheckCastPP nodes.
2282   //      Allocate
2283   //        |
2284   //      Proj #5 ( oop result )
2285   //       | |
2286   //       AddP  ( base == address )
2287   //
2288   // case #6. Constant Pool, ThreadLocal, CastX2P or
2289   //          Raw object's field reference:
2290   //      {ConP, ThreadLocal, CastX2P, raw Load}
2291   //  top   |
2292   //     \  |
2293   //     AddP  ( base == top )
2294   //
2295   // case #7. Klass's field reference.
2296   //      LoadKlass
2297   //       | |
2298   //       AddP  ( base == address )
2299   //
2300   // case #8. narrow Klass's field reference.
2301   //      LoadNKlass
2302   //       |
2303   //      DecodeN
2304   //       | |
2305   //       AddP  ( base == address )
2306   //
2307   // case #9. Mixed unsafe access
2308   //    {instance}
2309   //        |
2310   //      CheckCastPP (raw)
2311   //  top   |
2312   //     \  |
2313   //     AddP  ( base == top )
2314   //
2315   Node *base = addp->in(AddPNode::Base);
2316   if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
2317     base = addp->in(AddPNode::Address);
2318     while (base->is_AddP()) {
2319       // Case #6 (unsafe access) may have several chained AddP nodes.
2320       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2321       base = base->in(AddPNode::Address);
2322     }
2323     if (base->Opcode() == Op_CheckCastPP &&
2324         base->bottom_type()->isa_rawptr() &&
2325         _igvn->type(base->in(1))->isa_oopptr()) {
2326       base = base->in(1); // Case #9
2327     } else {
2328       Node* uncast_base = base->uncast();
2329       int opcode = uncast_base->Opcode();
2330       assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2331              opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2332              (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2333              (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2334     }
2335   }
2336   return base;
2337 }
2338 
2339 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2340   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2341   Node* addp2 = addp->raw_out(0);
2342   if (addp->outcnt() == 1 && addp2->is_AddP() &&
2343       addp2->in(AddPNode::Base) == n &&
2344       addp2->in(AddPNode::Address) == addp) {
2345     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2346     //
2347     // Find array's offset to push it on worklist first and
2348     // as result process an array's element offset first (pushed second)
2349     // to avoid CastPP for the array's offset.
2350     // Otherwise the inserted CastPP (LocalVar) will point to what
2351     // the AddP (Field) points to. Which would be wrong since
2352     // the algorithm expects the CastPP has the same point as
2353     // as AddP's base CheckCastPP (LocalVar).
2354     //
2355     //    ArrayAllocation
2356     //     |
2357     //    CheckCastPP
2358     //     |
2359     //    memProj (from ArrayAllocation CheckCastPP)
2360     //     |  ||
2361     //     |  ||   Int (element index)
2362     //     |  ||    |   ConI (log(element size))
2363     //     |  ||    |   /
2364     //     |  ||   LShift
2365     //     |  ||  /
2366     //     |  AddP (array's element offset)
2367     //     |  |
2368     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
2369     //     | / /
2370     //     AddP (array's offset)
2371     //      |
2372     //     Load/Store (memory operation on array's element)
2373     //
2374     return addp2;
2375   }
2376   return NULL;
2377 }
2378 
2379 //
2380 // Adjust the type and inputs of an AddP which computes the
2381 // address of a field of an instance
2382 //
2383 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2384   PhaseGVN* igvn = _igvn;
2385   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2386   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2387   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2388   if (t == NULL) {
2389     // We are computing a raw address for a store captured by an Initialize
2390     // compute an appropriate address type (cases #3 and #5).
2391     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2392     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2393     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2394     assert(offs != Type::OffsetBot, "offset must be a constant");
2395     t = base_t->add_offset(offs)->is_oopptr();
2396   }
2397   int inst_id =  base_t->instance_id();
2398   assert(!t->is_known_instance() || t->instance_id() == inst_id,
2399                              "old type must be non-instance or match new type");
2400 
2401   // The type 't' could be subclass of 'base_t'.
2402   // As result t->offset() could be large then base_t's size and it will
2403   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2404   // constructor verifies correctness of the offset.
2405   //
2406   // It could happened on subclass's branch (from the type profiling
2407   // inlining) which was not eliminated during parsing since the exactness
2408   // of the allocation type was not propagated to the subclass type check.
2409   //
2410   // Or the type 't' could be not related to 'base_t' at all.
2411   // It could happened when CHA type is different from MDO type on a dead path
2412   // (for example, from instanceof check) which is not collapsed during parsing.
2413   //
2414   // Do nothing for such AddP node and don't process its users since
2415   // this code branch will go away.
2416   //
2417   if (!t->is_known_instance() &&
2418       !base_t->klass()->is_subtype_of(t->klass())) {
2419      return false; // bail out
2420   }
2421   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2422   // Do NOT remove the next line: ensure a new alias index is allocated
2423   // for the instance type. Note: C++ will not remove it since the call
2424   // has side effect.
2425   int alias_idx = _compile->get_alias_index(tinst);
2426   igvn->set_type(addp, tinst);
2427   // record the allocation in the node map
2428   set_map(addp, get_map(base->_idx));
2429   // Set addp's Base and Address to 'base'.
2430   Node *abase = addp->in(AddPNode::Base);
2431   Node *adr   = addp->in(AddPNode::Address);
2432   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2433       adr->in(0)->_idx == (uint)inst_id) {
2434     // Skip AddP cases #3 and #5.
2435   } else {
2436     assert(!abase->is_top(), "sanity"); // AddP case #3
2437     if (abase != base) {
2438       igvn->hash_delete(addp);
2439       addp->set_req(AddPNode::Base, base);
2440       if (abase == adr) {
2441         addp->set_req(AddPNode::Address, base);
2442       } else {
2443         // AddP case #4 (adr is array's element offset AddP node)
2444 #ifdef ASSERT
2445         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2446         assert(adr->is_AddP() && atype != NULL &&
2447                atype->instance_id() == inst_id, "array's element offset should be processed first");
2448 #endif
2449       }
2450       igvn->hash_insert(addp);
2451     }
2452   }
2453   // Put on IGVN worklist since at least addp's type was changed above.
2454   record_for_optimizer(addp);
2455   return true;
2456 }
2457 
2458 //
2459 // Create a new version of orig_phi if necessary. Returns either the newly
2460 // created phi or an existing phi.  Sets create_new to indicate whether a new
2461 // phi was created.  Cache the last newly created phi in the node map.
2462 //
2463 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, bool &new_created) {
2464   Compile *C = _compile;
2465   PhaseGVN* igvn = _igvn;
2466   new_created = false;
2467   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2468   // nothing to do if orig_phi is bottom memory or matches alias_idx
2469   if (phi_alias_idx == alias_idx) {
2470     return orig_phi;
2471   }
2472   // Have we recently created a Phi for this alias index?
2473   PhiNode *result = get_map_phi(orig_phi->_idx);
2474   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2475     return result;
2476   }
2477   // Previous check may fail when the same wide memory Phi was split into Phis
2478   // for different memory slices. Search all Phis for this region.
2479   if (result != NULL) {
2480     Node* region = orig_phi->in(0);
2481     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2482       Node* phi = region->fast_out(i);
2483       if (phi->is_Phi() &&
2484           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2485         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2486         return phi->as_Phi();
2487       }
2488     }
2489   }
2490   if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2491     if (C->do_escape_analysis() == true && !C->failing()) {
2492       // Retry compilation without escape analysis.
2493       // If this is the first failure, the sentinel string will "stick"
2494       // to the Compile object, and the C2Compiler will see it and retry.
2495       C->record_failure(C2Compiler::retry_no_escape_analysis());
2496     }
2497     return NULL;
2498   }
2499   orig_phi_worklist.append_if_missing(orig_phi);
2500   const TypePtr *atype = C->get_adr_type(alias_idx);
2501   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2502   C->copy_node_notes_to(result, orig_phi);
2503   igvn->set_type(result, result->bottom_type());
2504   record_for_optimizer(result);
2505   set_map(orig_phi, result);
2506   new_created = true;
2507   return result;
2508 }
2509 
2510 //
2511 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2512 // specified alias index.
2513 //
2514 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist) {
2515   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2516   Compile *C = _compile;
2517   PhaseGVN* igvn = _igvn;
2518   bool new_phi_created;
2519   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2520   if (!new_phi_created) {
2521     return result;
2522   }
2523   GrowableArray<PhiNode *>  phi_list;
2524   GrowableArray<uint>  cur_input;
2525   PhiNode *phi = orig_phi;
2526   uint idx = 1;
2527   bool finished = false;
2528   while(!finished) {
2529     while (idx < phi->req()) {
2530       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2531       if (mem != NULL && mem->is_Phi()) {
2532         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2533         if (new_phi_created) {
2534           // found an phi for which we created a new split, push current one on worklist and begin
2535           // processing new one
2536           phi_list.push(phi);
2537           cur_input.push(idx);
2538           phi = mem->as_Phi();
2539           result = newphi;
2540           idx = 1;
2541           continue;
2542         } else {
2543           mem = newphi;
2544         }
2545       }
2546       if (C->failing()) {
2547         return NULL;
2548       }
2549       result->set_req(idx++, mem);
2550     }
2551 #ifdef ASSERT
2552     // verify that the new Phi has an input for each input of the original
2553     assert( phi->req() == result->req(), "must have same number of inputs.");
2554     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2555 #endif
2556     // Check if all new phi's inputs have specified alias index.
2557     // Otherwise use old phi.
2558     for (uint i = 1; i < phi->req(); i++) {
2559       Node* in = result->in(i);
2560       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2561     }
2562     // we have finished processing a Phi, see if there are any more to do
2563     finished = (phi_list.length() == 0 );
2564     if (!finished) {
2565       phi = phi_list.pop();
2566       idx = cur_input.pop();
2567       PhiNode *prev_result = get_map_phi(phi->_idx);
2568       prev_result->set_req(idx++, result);
2569       result = prev_result;
2570     }
2571   }
2572   return result;
2573 }
2574 
2575 //
2576 // The next methods are derived from methods in MemNode.
2577 //
2578 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2579   Node *mem = mmem;
2580   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2581   // means an array I have not precisely typed yet.  Do not do any
2582   // alias stuff with it any time soon.
2583   if (toop->base() != Type::AnyPtr &&
2584       !(toop->klass() != NULL &&
2585         toop->klass()->is_java_lang_Object() &&
2586         toop->offset() == Type::OffsetBot)) {
2587     mem = mmem->memory_at(alias_idx);
2588     // Update input if it is progress over what we have now
2589   }
2590   return mem;
2591 }
2592 
2593 //
2594 // Move memory users to their memory slices.
2595 //
2596 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis) {
2597   Compile* C = _compile;
2598   PhaseGVN* igvn = _igvn;
2599   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2600   assert(tp != NULL, "ptr type");
2601   int alias_idx = C->get_alias_index(tp);
2602   int general_idx = C->get_general_index(alias_idx);
2603 
2604   // Move users first
2605   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2606     Node* use = n->fast_out(i);
2607     if (use->is_MergeMem()) {
2608       MergeMemNode* mmem = use->as_MergeMem();
2609       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2610       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2611         continue; // Nothing to do
2612       }
2613       // Replace previous general reference to mem node.
2614       uint orig_uniq = C->unique();
2615       Node* m = find_inst_mem(n, general_idx, orig_phis);
2616       assert(orig_uniq == C->unique(), "no new nodes");
2617       mmem->set_memory_at(general_idx, m);
2618       --imax;
2619       --i;
2620     } else if (use->is_MemBar()) {
2621       assert(!use->is_Initialize(), "initializing stores should not be moved");
2622       if (use->req() > MemBarNode::Precedent &&
2623           use->in(MemBarNode::Precedent) == n) {
2624         // Don't move related membars.
2625         record_for_optimizer(use);
2626         continue;
2627       }
2628       tp = use->as_MemBar()->adr_type()->isa_ptr();
2629       if ((tp != NULL && C->get_alias_index(tp) == alias_idx) ||
2630           alias_idx == general_idx) {
2631         continue; // Nothing to do
2632       }
2633       // Move to general memory slice.
2634       uint orig_uniq = C->unique();
2635       Node* m = find_inst_mem(n, general_idx, orig_phis);
2636       assert(orig_uniq == C->unique(), "no new nodes");
2637       igvn->hash_delete(use);
2638       imax -= use->replace_edge(n, m);
2639       igvn->hash_insert(use);
2640       record_for_optimizer(use);
2641       --i;
2642 #ifdef ASSERT
2643     } else if (use->is_Mem()) {
2644       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2645         // Don't move related cardmark.
2646         continue;
2647       }
2648       // Memory nodes should have new memory input.
2649       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2650       assert(tp != NULL, "ptr type");
2651       int idx = C->get_alias_index(tp);
2652       assert(get_map(use->_idx) != NULL || idx == alias_idx,
2653              "Following memory nodes should have new memory input or be on the same memory slice");
2654     } else if (use->is_Phi()) {
2655       // Phi nodes should be split and moved already.
2656       tp = use->as_Phi()->adr_type()->isa_ptr();
2657       assert(tp != NULL, "ptr type");
2658       int idx = C->get_alias_index(tp);
2659       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2660     } else {
2661       use->dump();
2662       assert(false, "should not be here");
2663 #endif
2664     }
2665   }
2666 }
2667 
2668 //
2669 // Search memory chain of "mem" to find a MemNode whose address
2670 // is the specified alias index.
2671 //
2672 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis) {
2673   if (orig_mem == NULL)
2674     return orig_mem;
2675   Compile* C = _compile;
2676   PhaseGVN* igvn = _igvn;
2677   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2678   bool is_instance = (toop != NULL) && toop->is_known_instance();
2679   Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
2680   Node *prev = NULL;
2681   Node *result = orig_mem;
2682   while (prev != result) {
2683     prev = result;
2684     if (result == start_mem)
2685       break;  // hit one of our sentinels
2686     if (result->is_Mem()) {
2687       const Type *at = igvn->type(result->in(MemNode::Address));
2688       if (at == Type::TOP)
2689         break; // Dead
2690       assert (at->isa_ptr() != NULL, "pointer type required.");
2691       int idx = C->get_alias_index(at->is_ptr());
2692       if (idx == alias_idx)
2693         break; // Found
2694       if (!is_instance && (at->isa_oopptr() == NULL ||
2695                            !at->is_oopptr()->is_known_instance())) {
2696         break; // Do not skip store to general memory slice.
2697       }
2698       result = result->in(MemNode::Memory);
2699     }
2700     if (!is_instance)
2701       continue;  // don't search further for non-instance types
2702     // skip over a call which does not affect this memory slice
2703     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2704       Node *proj_in = result->in(0);
2705       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2706         break;  // hit one of our sentinels
2707       } else if (proj_in->is_Call()) {
2708         // ArrayCopy node processed here as well
2709         CallNode *call = proj_in->as_Call();
2710         if (!call->may_modify(toop, igvn)) {
2711           result = call->in(TypeFunc::Memory);
2712         }
2713       } else if (proj_in->is_Initialize()) {
2714         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2715         // Stop if this is the initialization for the object instance which
2716         // which contains this memory slice, otherwise skip over it.
2717         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2718           result = proj_in->in(TypeFunc::Memory);
2719         }
2720       } else if (proj_in->is_MemBar()) {
2721         if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2722             proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2723             proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2724           // clone
2725           ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2726           if (ac->may_modify(toop, igvn)) {
2727             break;
2728           }
2729         }
2730         result = proj_in->in(TypeFunc::Memory);
2731       }
2732     } else if (result->is_MergeMem()) {
2733       MergeMemNode *mmem = result->as_MergeMem();
2734       result = step_through_mergemem(mmem, alias_idx, toop);
2735       if (result == mmem->base_memory()) {
2736         // Didn't find instance memory, search through general slice recursively.
2737         result = mmem->memory_at(C->get_general_index(alias_idx));
2738         result = find_inst_mem(result, alias_idx, orig_phis);
2739         if (C->failing()) {
2740           return NULL;
2741         }
2742         mmem->set_memory_at(alias_idx, result);
2743       }
2744     } else if (result->is_Phi() &&
2745                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2746       Node *un = result->as_Phi()->unique_input(igvn);
2747       if (un != NULL) {
2748         orig_phis.append_if_missing(result->as_Phi());
2749         result = un;
2750       } else {
2751         break;
2752       }
2753     } else if (result->is_ClearArray()) {
2754       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2755         // Can not bypass initialization of the instance
2756         // we are looking for.
2757         break;
2758       }
2759       // Otherwise skip it (the call updated 'result' value).
2760     } else if (result->Opcode() == Op_SCMemProj) {
2761       Node* mem = result->in(0);
2762       Node* adr = NULL;
2763       if (mem->is_LoadStore()) {
2764         adr = mem->in(MemNode::Address);
2765       } else {
2766         assert(mem->Opcode() == Op_EncodeISOArray ||
2767                mem->Opcode() == Op_StrCompressedCopy, "sanity");
2768         adr = mem->in(3); // Memory edge corresponds to destination array
2769       }
2770       const Type *at = igvn->type(adr);
2771       if (at != Type::TOP) {
2772         assert(at->isa_ptr() != NULL, "pointer type required.");
2773         int idx = C->get_alias_index(at->is_ptr());
2774         if (idx == alias_idx) {
2775           // Assert in debug mode
2776           assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2777           break; // In product mode return SCMemProj node
2778         }
2779       }
2780       result = mem->in(MemNode::Memory);
2781     } else if (result->Opcode() == Op_StrInflatedCopy) {
2782       Node* adr = result->in(3); // Memory edge corresponds to destination array
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 StrInflatedCopy node accesses its field");
2790           break; // In product mode return SCMemProj node
2791         }
2792       }
2793       result = result->in(MemNode::Memory);
2794     }
2795   }
2796   if (result->is_Phi()) {
2797     PhiNode *mphi = result->as_Phi();
2798     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2799     const TypePtr *t = mphi->adr_type();
2800     if (!is_instance) {
2801       // Push all non-instance Phis on the orig_phis worklist to update inputs
2802       // during Phase 4 if needed.
2803       orig_phis.append_if_missing(mphi);
2804     } else if (C->get_alias_index(t) != alias_idx) {
2805       // Create a new Phi with the specified alias index type.
2806       result = split_memory_phi(mphi, alias_idx, orig_phis);
2807     }
2808   }
2809   // the result is either MemNode, PhiNode, InitializeNode.
2810   return result;
2811 }
2812 
2813 //
2814 //  Convert the types of unescaped object to instance types where possible,
2815 //  propagate the new type information through the graph, and update memory
2816 //  edges and MergeMem inputs to reflect the new type.
2817 //
2818 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
2819 //  The processing is done in 4 phases:
2820 //
2821 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
2822 //            types for the CheckCastPP for allocations where possible.
2823 //            Propagate the new types through users as follows:
2824 //               casts and Phi:  push users on alloc_worklist
2825 //               AddP:  cast Base and Address inputs to the instance type
2826 //                      push any AddP users on alloc_worklist and push any memnode
2827 //                      users onto memnode_worklist.
2828 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
2829 //            search the Memory chain for a store with the appropriate type
2830 //            address type.  If a Phi is found, create a new version with
2831 //            the appropriate memory slices from each of the Phi inputs.
2832 //            For stores, process the users as follows:
2833 //               MemNode:  push on memnode_worklist
2834 //               MergeMem: push on mergemem_worklist
2835 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
2836 //            moving the first node encountered of each  instance type to the
2837 //            the input corresponding to its alias index.
2838 //            appropriate memory slice.
2839 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2840 //
2841 // In the following example, the CheckCastPP nodes are the cast of allocation
2842 // results and the allocation of node 29 is unescaped and eligible to be an
2843 // instance type.
2844 //
2845 // We start with:
2846 //
2847 //     7 Parm #memory
2848 //    10  ConI  "12"
2849 //    19  CheckCastPP   "Foo"
2850 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2851 //    29  CheckCastPP   "Foo"
2852 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
2853 //
2854 //    40  StoreP  25   7  20   ... alias_index=4
2855 //    50  StoreP  35  40  30   ... alias_index=4
2856 //    60  StoreP  45  50  20   ... alias_index=4
2857 //    70  LoadP    _  60  30   ... alias_index=4
2858 //    80  Phi     75  50  60   Memory alias_index=4
2859 //    90  LoadP    _  80  30   ... alias_index=4
2860 //   100  LoadP    _  80  20   ... alias_index=4
2861 //
2862 //
2863 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2864 // and creating a new alias index for node 30.  This gives:
2865 //
2866 //     7 Parm #memory
2867 //    10  ConI  "12"
2868 //    19  CheckCastPP   "Foo"
2869 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2870 //    29  CheckCastPP   "Foo"  iid=24
2871 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2872 //
2873 //    40  StoreP  25   7  20   ... alias_index=4
2874 //    50  StoreP  35  40  30   ... alias_index=6
2875 //    60  StoreP  45  50  20   ... alias_index=4
2876 //    70  LoadP    _  60  30   ... alias_index=6
2877 //    80  Phi     75  50  60   Memory alias_index=4
2878 //    90  LoadP    _  80  30   ... alias_index=6
2879 //   100  LoadP    _  80  20   ... alias_index=4
2880 //
2881 // In phase 2, new memory inputs are computed for the loads and stores,
2882 // And a new version of the phi is created.  In phase 4, the inputs to
2883 // node 80 are updated and then the memory nodes are updated with the
2884 // values computed in phase 2.  This results in:
2885 //
2886 //     7 Parm #memory
2887 //    10  ConI  "12"
2888 //    19  CheckCastPP   "Foo"
2889 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
2890 //    29  CheckCastPP   "Foo"  iid=24
2891 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
2892 //
2893 //    40  StoreP  25  7   20   ... alias_index=4
2894 //    50  StoreP  35  7   30   ... alias_index=6
2895 //    60  StoreP  45  40  20   ... alias_index=4
2896 //    70  LoadP    _  50  30   ... alias_index=6
2897 //    80  Phi     75  40  60   Memory alias_index=4
2898 //   120  Phi     75  50  50   Memory alias_index=6
2899 //    90  LoadP    _ 120  30   ... alias_index=6
2900 //   100  LoadP    _  80  20   ... alias_index=4
2901 //
2902 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2903   GrowableArray<Node *>  memnode_worklist;
2904   GrowableArray<PhiNode *>  orig_phis;
2905   PhaseIterGVN  *igvn = _igvn;
2906   uint new_index_start = (uint) _compile->num_alias_types();
2907   Arena* arena = Thread::current()->resource_area();
2908   VectorSet visited(arena);
2909   ideal_nodes.clear(); // Reset for use with set_map/get_map.
2910   uint unique_old = _compile->unique();
2911 
2912   //  Phase 1:  Process possible allocations from alloc_worklist.
2913   //  Create instance types for the CheckCastPP for allocations where possible.
2914   //
2915   // (Note: don't forget to change the order of the second AddP node on
2916   //  the alloc_worklist if the order of the worklist processing is changed,
2917   //  see the comment in find_second_addp().)
2918   //
2919   while (alloc_worklist.length() != 0) {
2920     Node *n = alloc_worklist.pop();
2921     uint ni = n->_idx;
2922     if (n->is_Call()) {
2923       CallNode *alloc = n->as_Call();
2924       // copy escape information to call node
2925       PointsToNode* ptn = ptnode_adr(alloc->_idx);
2926       PointsToNode::EscapeState es = ptn->escape_state();
2927       // We have an allocation or call which returns a Java object,
2928       // see if it is unescaped.
2929       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2930         continue;
2931       // Find CheckCastPP for the allocate or for the return value of a call
2932       n = alloc->result_cast();
2933       if (n == NULL) {            // No uses except Initialize node
2934         if (alloc->is_Allocate()) {
2935           // Set the scalar_replaceable flag for allocation
2936           // so it could be eliminated if it has no uses.
2937           alloc->as_Allocate()->_is_scalar_replaceable = true;
2938         }
2939         if (alloc->is_CallStaticJava()) {
2940           // Set the scalar_replaceable flag for boxing method
2941           // so it could be eliminated if it has no uses.
2942           alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2943         }
2944         continue;
2945       }
2946       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2947         assert(!alloc->is_Allocate(), "allocation should have unique type");
2948         continue;
2949       }
2950 
2951       // The inline code for Object.clone() casts the allocation result to
2952       // java.lang.Object and then to the actual type of the allocated
2953       // object. Detect this case and use the second cast.
2954       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2955       // the allocation result is cast to java.lang.Object and then
2956       // to the actual Array type.
2957       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2958           && (alloc->is_AllocateArray() ||
2959               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2960         Node *cast2 = NULL;
2961         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2962           Node *use = n->fast_out(i);
2963           if (use->is_CheckCastPP()) {
2964             cast2 = use;
2965             break;
2966           }
2967         }
2968         if (cast2 != NULL) {
2969           n = cast2;
2970         } else {
2971           // Non-scalar replaceable if the allocation type is unknown statically
2972           // (reflection allocation), the object can't be restored during
2973           // deoptimization without precise type.
2974           continue;
2975         }
2976       }
2977 
2978       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2979       if (t == NULL)
2980         continue;  // not a TypeOopPtr
2981       if (!t->klass_is_exact())
2982         continue; // not an unique type
2983 
2984       if (alloc->is_Allocate()) {
2985         // Set the scalar_replaceable flag for allocation
2986         // so it could be eliminated.
2987         alloc->as_Allocate()->_is_scalar_replaceable = true;
2988       }
2989       if (alloc->is_CallStaticJava()) {
2990         // Set the scalar_replaceable flag for boxing method
2991         // so it could be eliminated.
2992         alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2993       }
2994       set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2995       // in order for an object to be scalar-replaceable, it must be:
2996       //   - a direct allocation (not a call returning an object)
2997       //   - non-escaping
2998       //   - eligible to be a unique type
2999       //   - not determined to be ineligible by escape analysis
3000       set_map(alloc, n);
3001       set_map(n, alloc);
3002       const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3003       igvn->hash_delete(n);
3004       igvn->set_type(n,  tinst);
3005       n->raise_bottom_type(tinst);
3006       igvn->hash_insert(n);
3007       record_for_optimizer(n);
3008       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
3009 
3010         // First, put on the worklist all Field edges from Connection Graph
3011         // which is more accurate than putting immediate users from Ideal Graph.
3012         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3013           PointsToNode* tgt = e.get();
3014           if (tgt->is_Arraycopy()) {
3015             continue;
3016           }
3017           Node* use = tgt->ideal_node();
3018           assert(tgt->is_Field() && use->is_AddP(),
3019                  "only AddP nodes are Field edges in CG");
3020           if (use->outcnt() > 0) { // Don't process dead nodes
3021             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3022             if (addp2 != NULL) {
3023               assert(alloc->is_AllocateArray(),"array allocation was expected");
3024               alloc_worklist.append_if_missing(addp2);
3025             }
3026             alloc_worklist.append_if_missing(use);
3027           }
3028         }
3029 
3030         // An allocation may have an Initialize which has raw stores. Scan
3031         // the users of the raw allocation result and push AddP users
3032         // on alloc_worklist.
3033         Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
3034         assert (raw_result != NULL, "must have an allocation result");
3035         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3036           Node *use = raw_result->fast_out(i);
3037           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3038             Node* addp2 = find_second_addp(use, raw_result);
3039             if (addp2 != NULL) {
3040               assert(alloc->is_AllocateArray(),"array allocation was expected");
3041               alloc_worklist.append_if_missing(addp2);
3042             }
3043             alloc_worklist.append_if_missing(use);
3044           } else if (use->is_MemBar()) {
3045             memnode_worklist.append_if_missing(use);
3046           }
3047         }
3048       }
3049     } else if (n->is_AddP()) {
3050       JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3051       if (jobj == NULL || jobj == phantom_obj) {
3052 #ifdef ASSERT
3053         ptnode_adr(get_addp_base(n)->_idx)->dump();
3054         ptnode_adr(n->_idx)->dump();
3055         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3056 #endif
3057         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3058         return;
3059       }
3060       Node *base = get_map(jobj->idx());  // CheckCastPP node
3061       if (!split_AddP(n, base)) continue; // wrong type from dead path
3062     } else if (n->is_Phi() ||
3063                n->is_CheckCastPP() ||
3064                n->is_EncodeP() ||
3065                n->is_DecodeN() ||
3066                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3067       if (visited.test_set(n->_idx)) {
3068         assert(n->is_Phi(), "loops only through Phi's");
3069         continue;  // already processed
3070       }
3071       JavaObjectNode* jobj = unique_java_object(n);
3072       if (jobj == NULL || jobj == phantom_obj) {
3073 #ifdef ASSERT
3074         ptnode_adr(n->_idx)->dump();
3075         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3076 #endif
3077         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3078         return;
3079       } else {
3080         Node *val = get_map(jobj->idx());   // CheckCastPP node
3081         TypeNode *tn = n->as_Type();
3082         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3083         assert(tinst != NULL && tinst->is_known_instance() &&
3084                tinst->instance_id() == jobj->idx() , "instance type expected.");
3085 
3086         const Type *tn_type = igvn->type(tn);
3087         const TypeOopPtr *tn_t;
3088         if (tn_type->isa_narrowoop()) {
3089           tn_t = tn_type->make_ptr()->isa_oopptr();
3090         } else {
3091           tn_t = tn_type->isa_oopptr();
3092         }
3093         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3094           if (tn_type->isa_narrowoop()) {
3095             tn_type = tinst->make_narrowoop();
3096           } else {
3097             tn_type = tinst;
3098           }
3099           igvn->hash_delete(tn);
3100           igvn->set_type(tn, tn_type);
3101           tn->set_type(tn_type);
3102           igvn->hash_insert(tn);
3103           record_for_optimizer(n);
3104         } else {
3105           assert(tn_type == TypePtr::NULL_PTR ||
3106                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3107                  "unexpected type");
3108           continue; // Skip dead path with different type
3109         }
3110       }
3111     } else {
3112       debug_only(n->dump();)
3113       assert(false, "EA: unexpected node");
3114       continue;
3115     }
3116     // push allocation's users on appropriate worklist
3117     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3118       Node *use = n->fast_out(i);
3119       if(use->is_Mem() && use->in(MemNode::Address) == n) {
3120         // Load/store to instance's field
3121         memnode_worklist.append_if_missing(use);
3122       } else if (use->is_MemBar()) {
3123         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3124           memnode_worklist.append_if_missing(use);
3125         }
3126       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3127         Node* addp2 = find_second_addp(use, n);
3128         if (addp2 != NULL) {
3129           alloc_worklist.append_if_missing(addp2);
3130         }
3131         alloc_worklist.append_if_missing(use);
3132       } else if (use->is_Phi() ||
3133                  use->is_CheckCastPP() ||
3134                  use->is_EncodeNarrowPtr() ||
3135                  use->is_DecodeNarrowPtr() ||
3136                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3137         alloc_worklist.append_if_missing(use);
3138 #ifdef ASSERT
3139       } else if (use->is_Mem()) {
3140         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3141       } else if (use->is_MergeMem()) {
3142         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3143       } else if (use->is_SafePoint()) {
3144         // Look for MergeMem nodes for calls which reference unique allocation
3145         // (through CheckCastPP nodes) even for debug info.
3146         Node* m = use->in(TypeFunc::Memory);
3147         if (m->is_MergeMem()) {
3148           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3149         }
3150       } else if (use->Opcode() == Op_EncodeISOArray) {
3151         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3152           // EncodeISOArray overwrites destination array
3153           memnode_worklist.append_if_missing(use);
3154         }
3155       } else {
3156         uint op = use->Opcode();
3157         if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3158             (use->in(MemNode::Memory) == n)) {
3159           // They overwrite memory edge corresponding to destination array,
3160           memnode_worklist.append_if_missing(use);
3161         } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3162               op == Op_CastP2X || op == Op_StoreCM ||
3163               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3164               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3165               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3166           n->dump();
3167           use->dump();
3168           assert(false, "EA: missing allocation reference path");
3169         }
3170 #endif
3171       }
3172     }
3173 
3174   }
3175 
3176   // Go over all ArrayCopy nodes and if one of the inputs has a unique
3177   // type, record it in the ArrayCopy node so we know what memory this
3178   // node uses/modified.
3179   for (int next = 0; next < arraycopy_worklist.length(); next++) {
3180     ArrayCopyNode* ac = arraycopy_worklist.at(next);
3181     Node* dest = ac->in(ArrayCopyNode::Dest);
3182     if (dest->is_AddP()) {
3183       dest = get_addp_base(dest);
3184     }
3185     JavaObjectNode* jobj = unique_java_object(dest);
3186     if (jobj != NULL) {
3187       Node *base = get_map(jobj->idx());
3188       if (base != NULL) {
3189         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3190         ac->_dest_type = base_t;
3191       }
3192     }
3193     Node* src = ac->in(ArrayCopyNode::Src);
3194     if (src->is_AddP()) {
3195       src = get_addp_base(src);
3196     }
3197     jobj = unique_java_object(src);
3198     if (jobj != NULL) {
3199       Node* base = get_map(jobj->idx());
3200       if (base != NULL) {
3201         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3202         ac->_src_type = base_t;
3203       }
3204     }
3205   }
3206 
3207   // New alias types were created in split_AddP().
3208   uint new_index_end = (uint) _compile->num_alias_types();
3209   assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3210 
3211   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
3212   //            compute new values for Memory inputs  (the Memory inputs are not
3213   //            actually updated until phase 4.)
3214   if (memnode_worklist.length() == 0)
3215     return;  // nothing to do
3216   while (memnode_worklist.length() != 0) {
3217     Node *n = memnode_worklist.pop();
3218     if (visited.test_set(n->_idx))
3219       continue;
3220     if (n->is_Phi() || n->is_ClearArray()) {
3221       // we don't need to do anything, but the users must be pushed
3222     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3223       // we don't need to do anything, but the users must be pushed
3224       n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
3225       if (n == NULL)
3226         continue;
3227     } else if (n->Opcode() == Op_StrCompressedCopy ||
3228                n->Opcode() == Op_EncodeISOArray) {
3229       // get the memory projection
3230       n = n->find_out_with(Op_SCMemProj);
3231       assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3232     } else {
3233       assert(n->is_Mem(), "memory node required.");
3234       Node *addr = n->in(MemNode::Address);
3235       const Type *addr_t = igvn->type(addr);
3236       if (addr_t == Type::TOP)
3237         continue;
3238       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3239       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3240       assert ((uint)alias_idx < new_index_end, "wrong alias index");
3241       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3242       if (_compile->failing()) {
3243         return;
3244       }
3245       if (mem != n->in(MemNode::Memory)) {
3246         // We delay the memory edge update since we need old one in
3247         // MergeMem code below when instances memory slices are separated.
3248         set_map(n, mem);
3249       }
3250       if (n->is_Load()) {
3251         continue;  // don't push users
3252       } else if (n->is_LoadStore()) {
3253         // get the memory projection
3254         n = n->find_out_with(Op_SCMemProj);
3255         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3256       }
3257     }
3258     // push user on appropriate worklist
3259     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3260       Node *use = n->fast_out(i);
3261       if (use->is_Phi() || use->is_ClearArray()) {
3262         memnode_worklist.append_if_missing(use);
3263       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3264         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3265           continue;
3266         memnode_worklist.append_if_missing(use);
3267       } else if (use->is_MemBar()) {
3268         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3269           memnode_worklist.append_if_missing(use);
3270         }
3271 #ifdef ASSERT
3272       } else if(use->is_Mem()) {
3273         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3274       } else if (use->is_MergeMem()) {
3275         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3276       } else if (use->Opcode() == Op_EncodeISOArray) {
3277         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3278           // EncodeISOArray overwrites destination array
3279           memnode_worklist.append_if_missing(use);
3280         }
3281       } else {
3282         uint op = use->Opcode();
3283         if ((use->in(MemNode::Memory) == n) &&
3284             (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3285           // They overwrite memory edge corresponding to destination array,
3286           memnode_worklist.append_if_missing(use);
3287         } else if (!(op == Op_StoreCM ||
3288               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3289                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3290               op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3291               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3292               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3293           n->dump();
3294           use->dump();
3295           assert(false, "EA: missing memory path");
3296         }
3297 #endif
3298       }
3299     }
3300   }
3301 
3302   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
3303   //            Walk each memory slice moving the first node encountered of each
3304   //            instance type to the the input corresponding to its alias index.
3305   uint length = _mergemem_worklist.length();
3306   for( uint next = 0; next < length; ++next ) {
3307     MergeMemNode* nmm = _mergemem_worklist.at(next);
3308     assert(!visited.test_set(nmm->_idx), "should not be visited before");
3309     // Note: we don't want to use MergeMemStream here because we only want to
3310     // scan inputs which exist at the start, not ones we add during processing.
3311     // Note 2: MergeMem may already contains instance memory slices added
3312     // during find_inst_mem() call when memory nodes were processed above.
3313     igvn->hash_delete(nmm);
3314     uint nslices = MIN2(nmm->req(), new_index_start);
3315     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3316       Node* mem = nmm->in(i);
3317       Node* cur = NULL;
3318       if (mem == NULL || mem->is_top())
3319         continue;
3320       // First, update mergemem by moving memory nodes to corresponding slices
3321       // if their type became more precise since this mergemem was created.
3322       while (mem->is_Mem()) {
3323         const Type *at = igvn->type(mem->in(MemNode::Address));
3324         if (at != Type::TOP) {
3325           assert (at->isa_ptr() != NULL, "pointer type required.");
3326           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3327           if (idx == i) {
3328             if (cur == NULL)
3329               cur = mem;
3330           } else {
3331             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3332               nmm->set_memory_at(idx, mem);
3333             }
3334           }
3335         }
3336         mem = mem->in(MemNode::Memory);
3337       }
3338       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3339       // Find any instance of the current type if we haven't encountered
3340       // already a memory slice of the instance along the memory chain.
3341       for (uint ni = new_index_start; ni < new_index_end; ni++) {
3342         if((uint)_compile->get_general_index(ni) == i) {
3343           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3344           if (nmm->is_empty_memory(m)) {
3345             Node* result = find_inst_mem(mem, ni, orig_phis);
3346             if (_compile->failing()) {
3347               return;
3348             }
3349             nmm->set_memory_at(ni, result);
3350           }
3351         }
3352       }
3353     }
3354     // Find the rest of instances values
3355     for (uint ni = new_index_start; ni < new_index_end; ni++) {
3356       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3357       Node* result = step_through_mergemem(nmm, ni, tinst);
3358       if (result == nmm->base_memory()) {
3359         // Didn't find instance memory, search through general slice recursively.
3360         result = nmm->memory_at(_compile->get_general_index(ni));
3361         result = find_inst_mem(result, ni, orig_phis);
3362         if (_compile->failing()) {
3363           return;
3364         }
3365         nmm->set_memory_at(ni, result);
3366       }
3367     }
3368     igvn->hash_insert(nmm);
3369     record_for_optimizer(nmm);
3370   }
3371 
3372   //  Phase 4:  Update the inputs of non-instance memory Phis and
3373   //            the Memory input of memnodes
3374   // First update the inputs of any non-instance Phi's from
3375   // which we split out an instance Phi.  Note we don't have
3376   // to recursively process Phi's encounted on the input memory
3377   // chains as is done in split_memory_phi() since they  will
3378   // also be processed here.
3379   for (int j = 0; j < orig_phis.length(); j++) {
3380     PhiNode *phi = orig_phis.at(j);
3381     int alias_idx = _compile->get_alias_index(phi->adr_type());
3382     igvn->hash_delete(phi);
3383     for (uint i = 1; i < phi->req(); i++) {
3384       Node *mem = phi->in(i);
3385       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3386       if (_compile->failing()) {
3387         return;
3388       }
3389       if (mem != new_mem) {
3390         phi->set_req(i, new_mem);
3391       }
3392     }
3393     igvn->hash_insert(phi);
3394     record_for_optimizer(phi);
3395   }
3396 
3397   // Update the memory inputs of MemNodes with the value we computed
3398   // in Phase 2 and move stores memory users to corresponding memory slices.
3399   // Disable memory split verification code until the fix for 6984348.
3400   // Currently it produces false negative results since it does not cover all cases.
3401 #if 0 // ifdef ASSERT
3402   visited.Reset();
3403   Node_Stack old_mems(arena, _compile->unique() >> 2);
3404 #endif
3405   for (uint i = 0; i < ideal_nodes.size(); i++) {
3406     Node*    n = ideal_nodes.at(i);
3407     Node* nmem = get_map(n->_idx);
3408     assert(nmem != NULL, "sanity");
3409     if (n->is_Mem()) {
3410 #if 0 // ifdef ASSERT
3411       Node* old_mem = n->in(MemNode::Memory);
3412       if (!visited.test_set(old_mem->_idx)) {
3413         old_mems.push(old_mem, old_mem->outcnt());
3414       }
3415 #endif
3416       assert(n->in(MemNode::Memory) != nmem, "sanity");
3417       if (!n->is_Load()) {
3418         // Move memory users of a store first.
3419         move_inst_mem(n, orig_phis);
3420       }
3421       // Now update memory input
3422       igvn->hash_delete(n);
3423       n->set_req(MemNode::Memory, nmem);
3424       igvn->hash_insert(n);
3425       record_for_optimizer(n);
3426     } else {
3427       assert(n->is_Allocate() || n->is_CheckCastPP() ||
3428              n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3429     }
3430   }
3431 #if 0 // ifdef ASSERT
3432   // Verify that memory was split correctly
3433   while (old_mems.is_nonempty()) {
3434     Node* old_mem = old_mems.node();
3435     uint  old_cnt = old_mems.index();
3436     old_mems.pop();
3437     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3438   }
3439 #endif
3440 }
3441 
3442 #ifndef PRODUCT
3443 static const char *node_type_names[] = {
3444   "UnknownType",
3445   "JavaObject",
3446   "LocalVar",
3447   "Field",
3448   "Arraycopy"
3449 };
3450 
3451 static const char *esc_names[] = {
3452   "UnknownEscape",
3453   "NoEscape",
3454   "ArgEscape",
3455   "GlobalEscape"
3456 };
3457 
3458 void PointsToNode::dump(bool print_state) const {
3459   NodeType nt = node_type();
3460   tty->print("%s ", node_type_names[(int) nt]);
3461   if (print_state) {
3462     EscapeState es = escape_state();
3463     EscapeState fields_es = fields_escape_state();
3464     tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3465     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3466       tty->print("NSR ");
3467   }
3468   if (is_Field()) {
3469     FieldNode* f = (FieldNode*)this;
3470     if (f->is_oop())
3471       tty->print("oop ");
3472     if (f->offset() > 0)
3473       tty->print("+%d ", f->offset());
3474     tty->print("(");
3475     for (BaseIterator i(f); i.has_next(); i.next()) {
3476       PointsToNode* b = i.get();
3477       tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3478     }
3479     tty->print(" )");
3480   }
3481   tty->print("[");
3482   for (EdgeIterator i(this); i.has_next(); i.next()) {
3483     PointsToNode* e = i.get();
3484     tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3485   }
3486   tty->print(" [");
3487   for (UseIterator i(this); i.has_next(); i.next()) {
3488     PointsToNode* u = i.get();
3489     bool is_base = false;
3490     if (PointsToNode::is_base_use(u)) {
3491       is_base = true;
3492       u = PointsToNode::get_use_node(u)->as_Field();
3493     }
3494     tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3495   }
3496   tty->print(" ]]  ");
3497   if (_node == NULL)
3498     tty->print_cr("<null>");
3499   else
3500     _node->dump();
3501 }
3502 
3503 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3504   bool first = true;
3505   int ptnodes_length = ptnodes_worklist.length();
3506   for (int i = 0; i < ptnodes_length; i++) {
3507     PointsToNode *ptn = ptnodes_worklist.at(i);
3508     if (ptn == NULL || !ptn->is_JavaObject())
3509       continue;
3510     PointsToNode::EscapeState es = ptn->escape_state();
3511     if ((es != PointsToNode::NoEscape) && !Verbose) {
3512       continue;
3513     }
3514     Node* n = ptn->ideal_node();
3515     if (n->is_Allocate() || (n->is_CallStaticJava() &&
3516                              n->as_CallStaticJava()->is_boxing_method())) {
3517       if (first) {
3518         tty->cr();
3519         tty->print("======== Connection graph for ");
3520         _compile->method()->print_short_name();
3521         tty->cr();
3522         first = false;
3523       }
3524       ptn->dump();
3525       // Print all locals and fields which reference this allocation
3526       for (UseIterator j(ptn); j.has_next(); j.next()) {
3527         PointsToNode* use = j.get();
3528         if (use->is_LocalVar()) {
3529           use->dump(Verbose);
3530         } else if (Verbose) {
3531           use->dump();
3532         }
3533       }
3534       tty->cr();
3535     }
3536   }
3537 }
3538 #endif