1 /*
   2  * Copyright (c) 2005, 2026, 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 "ci/bcEscapeAnalyzer.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "gc/shared/barrierSet.hpp"
  28 #include "gc/shared/c2/barrierSetC2.hpp"
  29 #include "libadt/vectset.hpp"
  30 #include "memory/allocation.hpp"
  31 #include "memory/metaspace.hpp"
  32 #include "memory/resourceArea.hpp"
  33 #include "opto/arraycopynode.hpp"
  34 #include "opto/c2compiler.hpp"
  35 #include "opto/callnode.hpp"
  36 #include "opto/castnode.hpp"
  37 #include "opto/cfgnode.hpp"
  38 #include "opto/compile.hpp"
  39 #include "opto/escape.hpp"
  40 #include "opto/inlinetypenode.hpp"
  41 #include "opto/locknode.hpp"
  42 #include "opto/macro.hpp"
  43 #include "opto/movenode.hpp"
  44 #include "opto/narrowptrnode.hpp"
  45 #include "opto/phaseX.hpp"
  46 #include "opto/rootnode.hpp"
  47 #include "utilities/macros.hpp"
  48 
  49 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn, int invocation) :
  50   // If ReduceAllocationMerges is enabled we might call split_through_phi during
  51   // split_unique_types and that will create additional nodes that need to be
  52   // pushed to the ConnectionGraph. The code below bumps the initial capacity of
  53   // _nodes by 10% to account for these additional nodes. If capacity is exceeded
  54   // the array will be reallocated.
  55   _nodes(C->comp_arena(), C->do_reduce_allocation_merges() ? C->unique()*1.10 : C->unique(), C->unique(), nullptr),
  56   _in_worklist(C->comp_arena()),
  57   _next_pidx(0),
  58   _collecting(true),
  59   _verify(false),
  60   _compile(C),
  61   _igvn(igvn),
  62   _invocation(invocation),
  63   _build_iterations(0),
  64   _build_time(0.),
  65   _node_map(C->comp_arena()) {
  66   // Add unknown java object.
  67   add_java_object(C->top(), PointsToNode::GlobalEscape);
  68   phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
  69   set_not_scalar_replaceable(phantom_obj NOT_PRODUCT(COMMA "Phantom object"));
  70   // Add ConP and ConN null oop nodes
  71   Node* oop_null = igvn->zerocon(T_OBJECT);
  72   assert(oop_null->_idx < nodes_size(), "should be created already");
  73   add_java_object(oop_null, PointsToNode::NoEscape);
  74   null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
  75   set_not_scalar_replaceable(null_obj NOT_PRODUCT(COMMA "Null object"));
  76   if (UseCompressedOops) {
  77     Node* noop_null = igvn->zerocon(T_NARROWOOP);
  78     assert(noop_null->_idx < nodes_size(), "should be created already");
  79     map_ideal_node(noop_null, null_obj);
  80   }
  81 }
  82 
  83 bool ConnectionGraph::has_candidates(Compile *C) {
  84   // EA brings benefits only when the code has allocations and/or locks which
  85   // are represented by ideal Macro nodes.
  86   int cnt = C->macro_count();
  87   for (int i = 0; i < cnt; i++) {
  88     Node *n = C->macro_node(i);
  89     if (n->is_Allocate()) {
  90       return true;
  91     }
  92     if (n->is_Lock()) {
  93       Node* obj = n->as_Lock()->obj_node()->uncast();
  94       if (!(obj->is_Parm() || obj->is_Con())) {
  95         return true;
  96       }
  97     }
  98     if (n->is_CallStaticJava() &&
  99         n->as_CallStaticJava()->is_boxing_method()) {
 100       return true;
 101     }
 102   }
 103   return false;
 104 }
 105 
 106 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
 107   Compile::TracePhase tp(Phase::_t_escapeAnalysis);
 108   ResourceMark rm;
 109 
 110   // Add ConP and ConN null oop nodes before ConnectionGraph construction
 111   // to create space for them in ConnectionGraph::_nodes[].
 112   Node* oop_null = igvn->zerocon(T_OBJECT);
 113   Node* noop_null = igvn->zerocon(T_NARROWOOP);
 114   int invocation = 0;
 115   if (C->congraph() != nullptr) {
 116     invocation = C->congraph()->_invocation + 1;
 117   }
 118   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn, invocation);
 119   NOT_PRODUCT(if (C->should_print_igv(/* Any level */ 1)) C->igv_printer()->set_congraph(congraph);)
 120   // Perform escape analysis
 121   if (congraph->compute_escape()) {
 122     // There are non escaping objects.
 123     C->set_congraph(congraph);
 124   }
 125   NOT_PRODUCT(if (C->should_print_igv(/* Any level */ 1)) C->igv_printer()->set_congraph(nullptr);)
 126   // Cleanup.
 127   if (oop_null->outcnt() == 0) {
 128     igvn->hash_delete(oop_null);
 129   }
 130   if (noop_null->outcnt() == 0) {
 131     igvn->hash_delete(noop_null);
 132   }
 133 
 134   C->print_method(PHASE_AFTER_EA, 2);
 135 }
 136 
 137 bool ConnectionGraph::compute_escape() {
 138   Compile* C = _compile;
 139   PhaseGVN* igvn = _igvn;
 140 
 141   // Worklists used by EA.
 142   Unique_Node_List delayed_worklist;
 143   Unique_Node_List reducible_merges;
 144   GrowableArray<Node*> alloc_worklist;
 145   GrowableArray<Node*> ptr_cmp_worklist;
 146   GrowableArray<MemBarStoreStoreNode*> storestore_worklist;
 147   GrowableArray<ArrayCopyNode*>  arraycopy_worklist;
 148   GrowableArray<PointsToNode*>   ptnodes_worklist;
 149   GrowableArray<JavaObjectNode*> java_objects_worklist;
 150   GrowableArray<JavaObjectNode*> non_escaped_allocs_worklist;
 151   GrowableArray<FieldNode*>      oop_fields_worklist;
 152   GrowableArray<SafePointNode*>  sfn_worklist;
 153   GrowableArray<MergeMemNode*>   mergemem_worklist;
 154   DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
 155 
 156   { Compile::TracePhase tp(Phase::_t_connectionGraph);
 157 
 158   // 1. Populate Connection Graph (CG) with PointsTo nodes.
 159   ideal_nodes.map(C->live_nodes(), nullptr);  // preallocate space
 160   // Initialize worklist
 161   if (C->root() != nullptr) {
 162     ideal_nodes.push(C->root());
 163   }
 164   // Processed ideal nodes are unique on ideal_nodes list
 165   // but several ideal nodes are mapped to the phantom_obj.
 166   // To avoid duplicated entries on the following worklists
 167   // add the phantom_obj only once to them.
 168   ptnodes_worklist.append(phantom_obj);
 169   java_objects_worklist.append(phantom_obj);
 170   for( uint next = 0; next < ideal_nodes.size(); ++next ) {
 171     Node* n = ideal_nodes.at(next);
 172     if ((n->Opcode() == Op_LoadX || n->Opcode() == Op_StoreX) &&
 173         !n->in(MemNode::Address)->is_AddP() &&
 174         _igvn->type(n->in(MemNode::Address))->isa_oopptr()) {
 175       // Load/Store at mark work address is at offset 0 so has no AddP which confuses EA
 176       Node* addp = new AddPNode(n->in(MemNode::Address), n->in(MemNode::Address), _igvn->MakeConX(0));
 177       _igvn->register_new_node_with_optimizer(addp);
 178       _igvn->replace_input_of(n, MemNode::Address, addp);
 179       ideal_nodes.push(addp);
 180       _nodes.at_put_grow(addp->_idx, nullptr, nullptr);
 181     }
 182     // Create PointsTo nodes and add them to Connection Graph. Called
 183     // only once per ideal node since ideal_nodes is Unique_Node list.
 184     add_node_to_connection_graph(n, &delayed_worklist);
 185     PointsToNode* ptn = ptnode_adr(n->_idx);
 186     if (ptn != nullptr && ptn != phantom_obj) {
 187       ptnodes_worklist.append(ptn);
 188       if (ptn->is_JavaObject()) {
 189         java_objects_worklist.append(ptn->as_JavaObject());
 190         if ((n->is_Allocate() || n->is_CallStaticJava()) &&
 191             (ptn->escape_state() < PointsToNode::GlobalEscape)) {
 192           // Only allocations and java static calls results are interesting.
 193           non_escaped_allocs_worklist.append(ptn->as_JavaObject());
 194         }
 195       } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
 196         oop_fields_worklist.append(ptn->as_Field());
 197       }
 198     }
 199     // Collect some interesting nodes for further use.
 200     switch (n->Opcode()) {
 201       case Op_MergeMem:
 202         // Collect all MergeMem nodes to add memory slices for
 203         // scalar replaceable objects in split_unique_types().
 204         mergemem_worklist.append(n->as_MergeMem());
 205         break;
 206       case Op_CmpP:
 207       case Op_CmpN:
 208         // Collect compare pointers nodes.
 209         if (OptimizePtrCompare) {
 210           ptr_cmp_worklist.append(n);
 211         }
 212         break;
 213       case Op_MemBarStoreStore:
 214         // Collect all MemBarStoreStore nodes so that depending on the
 215         // escape status of the associated Allocate node some of them
 216         // may be eliminated.
 217         if (!UseStoreStoreForCtor || n->req() > MemBarNode::Precedent) {
 218           storestore_worklist.append(n->as_MemBarStoreStore());
 219         }
 220         // If MemBarStoreStore has a precedent edge add it to the worklist (like MemBarRelease)
 221       case Op_MemBarRelease:
 222         if (n->req() > MemBarNode::Precedent) {
 223           record_for_optimizer(n);
 224         }
 225         break;
 226 #ifdef ASSERT
 227       case Op_AddP:
 228         // Collect address nodes for graph verification.
 229         addp_worklist.append(n);
 230         break;
 231 #endif
 232       case Op_ArrayCopy:
 233         // Keep a list of ArrayCopy nodes so if one of its input is non
 234         // escaping, we can record a unique type
 235         arraycopy_worklist.append(n->as_ArrayCopy());
 236         break;
 237       default:
 238         // not interested now, ignore...
 239         break;
 240     }
 241     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 242       Node* m = n->fast_out(i);   // Get user
 243       ideal_nodes.push(m);
 244     }
 245     if (n->is_SafePoint()) {
 246       sfn_worklist.append(n->as_SafePoint());
 247     }
 248   }
 249 
 250 #ifndef PRODUCT
 251   if (_compile->directive()->TraceEscapeAnalysisOption) {
 252     tty->print("+++++ Initial worklist for ");
 253     _compile->method()->print_name();
 254     tty->print_cr(" (ea_inv=%d)", _invocation);
 255     for (int i = 0; i < ptnodes_worklist.length(); i++) {
 256       PointsToNode* ptn = ptnodes_worklist.at(i);
 257       ptn->dump();
 258     }
 259     tty->print_cr("+++++ Calculating escape states and scalar replaceability");
 260   }
 261 #endif
 262 
 263   if (non_escaped_allocs_worklist.length() == 0) {
 264     _collecting = false;
 265     NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 266     return false; // Nothing to do.
 267   }
 268   // Add final simple edges to graph.
 269   while(delayed_worklist.size() > 0) {
 270     Node* n = delayed_worklist.pop();
 271     add_final_edges(n);
 272   }
 273 
 274 #ifdef ASSERT
 275   if (VerifyConnectionGraph) {
 276     // Verify that no new simple edges could be created and all
 277     // local vars has edges.
 278     _verify = true;
 279     int ptnodes_length = ptnodes_worklist.length();
 280     for (int next = 0; next < ptnodes_length; ++next) {
 281       PointsToNode* ptn = ptnodes_worklist.at(next);
 282       add_final_edges(ptn->ideal_node());
 283       if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
 284         ptn->dump();
 285         assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
 286       }
 287     }
 288     _verify = false;
 289   }
 290 #endif
 291   // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
 292   // processing, calls to CI to resolve symbols (types, fields, methods)
 293   // referenced in bytecode. During symbol resolution VM may throw
 294   // an exception which CI cleans and converts to compilation failure.
 295   if (C->failing()) {
 296     NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 297     return false;
 298   }
 299 
 300   _compile->print_method(PHASE_EA_AFTER_INITIAL_CONGRAPH, 4);
 301 
 302   // 2. Finish Graph construction by propagating references to all
 303   //    java objects through graph.
 304   if (!complete_connection_graph(ptnodes_worklist, non_escaped_allocs_worklist,
 305                                  java_objects_worklist, oop_fields_worklist)) {
 306     // All objects escaped or hit time or iterations limits.
 307     _collecting = false;
 308     NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 309     return false;
 310   }
 311 
 312   _compile->print_method(PHASE_EA_AFTER_COMPLETE_CONGRAPH, 4);
 313 
 314   // 3. Adjust scalar_replaceable state of nonescaping objects and push
 315   //    scalar replaceable allocations on alloc_worklist for processing
 316   //    in split_unique_types().
 317   GrowableArray<JavaObjectNode*> jobj_worklist;
 318   int non_escaped_length = non_escaped_allocs_worklist.length();
 319   bool found_nsr_alloc = false;
 320   for (int next = 0; next < non_escaped_length; next++) {
 321     JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
 322     bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
 323     Node* n = ptn->ideal_node();
 324     if (n->is_Allocate()) {
 325       n->as_Allocate()->_is_non_escaping = noescape;
 326     }
 327     if (noescape && ptn->scalar_replaceable()) {
 328       adjust_scalar_replaceable_state(ptn, reducible_merges);
 329       if (ptn->scalar_replaceable()) {
 330         jobj_worklist.push(ptn);
 331       } else {
 332         found_nsr_alloc = true;
 333       }
 334     }
 335     _compile->print_method(PHASE_EA_ADJUST_SCALAR_REPLACEABLE_ITER, 6, n);
 336   }
 337 
 338   // Propagate NSR (Not Scalar Replaceable) state.
 339   if (found_nsr_alloc) {
 340     find_scalar_replaceable_allocs(jobj_worklist, reducible_merges);
 341   }
 342 
 343   // alloc_worklist will be processed in reverse push order.
 344   // Therefore the reducible Phis will be processed for last and that's what we
 345   // want because by then the scalarizable inputs of the merge will already have
 346   // an unique instance type.
 347   for (uint i = 0; i < reducible_merges.size(); i++ ) {
 348     Node* n = reducible_merges.at(i);
 349     alloc_worklist.append(n);
 350   }
 351 
 352   for (int next = 0; next < jobj_worklist.length(); ++next) {
 353     JavaObjectNode* jobj = jobj_worklist.at(next);
 354     if (jobj->scalar_replaceable()) {
 355       alloc_worklist.append(jobj->ideal_node());
 356     }
 357   }
 358 
 359 #ifdef ASSERT
 360   if (VerifyConnectionGraph) {
 361     // Verify that graph is complete - no new edges could be added or needed.
 362     verify_connection_graph(ptnodes_worklist, non_escaped_allocs_worklist,
 363                             java_objects_worklist, addp_worklist);
 364   }
 365   assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
 366   assert(null_obj->escape_state() == PointsToNode::NoEscape &&
 367          null_obj->edge_count() == 0 &&
 368          !null_obj->arraycopy_src() &&
 369          !null_obj->arraycopy_dst(), "sanity");
 370 #endif
 371 
 372   _collecting = false;
 373 
 374   _compile->print_method(PHASE_EA_AFTER_PROPAGATE_NSR, 4);
 375   } // TracePhase t3("connectionGraph")
 376 
 377   // 4. Optimize ideal graph based on EA information.
 378   bool has_non_escaping_obj = (non_escaped_allocs_worklist.length() > 0);
 379   if (has_non_escaping_obj) {
 380     optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
 381   }
 382 
 383 #ifndef PRODUCT
 384   if (PrintEscapeAnalysis) {
 385     dump(ptnodes_worklist); // Dump ConnectionGraph
 386   }
 387 #endif
 388 
 389 #ifdef ASSERT
 390   if (VerifyConnectionGraph) {
 391     int alloc_length = alloc_worklist.length();
 392     for (int next = 0; next < alloc_length; ++next) {
 393       Node* n = alloc_worklist.at(next);
 394       PointsToNode* ptn = ptnode_adr(n->_idx);
 395       assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
 396     }
 397   }
 398 
 399   if (VerifyReduceAllocationMerges) {
 400     for (uint i = 0; i < reducible_merges.size(); i++ ) {
 401       Node* n = reducible_merges.at(i);
 402       if (!can_reduce_phi(n->as_Phi())) {
 403         TraceReduceAllocationMerges = true;
 404         n->dump(2);
 405         n->dump(-2);
 406         assert(can_reduce_phi(n->as_Phi()), "Sanity: previous reducible Phi is no longer reducible before SUT.");
 407       }
 408     }
 409   }
 410 #endif
 411 
 412   _compile->print_method(PHASE_EA_AFTER_GRAPH_OPTIMIZATION, 4);
 413 
 414   // 5. Separate memory graph for scalar replaceable allcations.
 415   bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
 416   if (has_scalar_replaceable_candidates && EliminateAllocations) {
 417     assert(C->do_aliasing(), "Aliasing should be enabled");
 418     // Now use the escape information to create unique types for
 419     // scalar replaceable objects.
 420     split_unique_types(alloc_worklist, arraycopy_worklist, mergemem_worklist, reducible_merges);
 421     if (C->failing()) {
 422       NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 423       return false;
 424     }
 425 
 426 #ifdef ASSERT
 427   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
 428     tty->print("=== No allocations eliminated for ");
 429     C->method()->print_short_name();
 430     if (!EliminateAllocations) {
 431       tty->print(" since EliminateAllocations is off ===");
 432     } else if(!has_scalar_replaceable_candidates) {
 433       tty->print(" since there are no scalar replaceable candidates ===");
 434     }
 435     tty->cr();
 436 #endif
 437   }
 438 
 439   // 6. Expand flat accesses if the object does not escape. This adds nodes to
 440   // the graph, so it has to be after split_unique_types. This expands atomic
 441   // mismatched accesses (though encapsulated in LoadFlats and StoreFlats) into
 442   // non-mismatched accesses, so it is better before reduce allocation merges.
 443   if (has_non_escaping_obj) {
 444     optimize_flat_accesses(sfn_worklist);
 445   }
 446 
 447   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES, 4);
 448 
 449   // 7. Reduce allocation merges used as debug information. This is done after
 450   // split_unique_types because the methods used to create SafePointScalarObject
 451   // need to traverse the memory graph to find values for object fields. We also
 452   // set to null the scalarized inputs of reducible Phis so that the Allocate
 453   // that they point can be later scalar replaced.
 454   bool delay = _igvn->delay_transform();
 455   _igvn->set_delay_transform(true);
 456   for (uint i = 0; i < reducible_merges.size(); i++) {
 457     Node* n = reducible_merges.at(i);
 458     if (n->outcnt() > 0) {
 459       if (!reduce_phi_on_safepoints(n->as_Phi())) {
 460         NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 461         C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
 462         return false;
 463       }
 464 
 465       // Now we set the scalar replaceable inputs of ophi to null, which is
 466       // the last piece that would prevent it from being scalar replaceable.
 467       reset_scalar_replaceable_entries(n->as_Phi());
 468     }
 469   }
 470   _igvn->set_delay_transform(delay);
 471 
 472   // Annotate at safepoints if they have <= ArgEscape objects in their scope and at
 473   // java calls if they pass ArgEscape objects as parameters.
 474   if (has_non_escaping_obj &&
 475       (C->env()->should_retain_local_variables() ||
 476        C->env()->jvmti_can_get_owned_monitor_info() ||
 477        C->env()->jvmti_can_walk_any_space() ||
 478        DeoptimizeObjectsALot)) {
 479     int sfn_length = sfn_worklist.length();
 480     for (int next = 0; next < sfn_length; next++) {
 481       SafePointNode* sfn = sfn_worklist.at(next);
 482       sfn->set_has_ea_local_in_scope(has_ea_local_in_scope(sfn));
 483       if (sfn->is_CallJava()) {
 484         CallJavaNode* call = sfn->as_CallJava();
 485         call->set_arg_escape(has_arg_escape(call));
 486       }
 487     }
 488   }
 489 
 490   _compile->print_method(PHASE_EA_AFTER_REDUCE_PHI_ON_SAFEPOINTS, 4);
 491 
 492   NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 493   return has_non_escaping_obj;
 494 }
 495 
 496 // Check if it's profitable to reduce the Phi passed as parameter.  Returns true
 497 // if at least one scalar replaceable allocation participates in the merge.
 498 bool ConnectionGraph::can_reduce_phi_check_inputs(PhiNode* ophi) const {
 499   bool found_sr_allocate = false;
 500 
 501   for (uint i = 1; i < ophi->req(); i++) {
 502     JavaObjectNode* ptn = unique_java_object(ophi->in(i));
 503     if (ptn != nullptr && ptn->scalar_replaceable()) {
 504       AllocateNode* alloc = ptn->ideal_node()->as_Allocate();
 505 
 506       // Don't handle arrays.
 507       if (alloc->Opcode() != Op_Allocate) {
 508         assert(alloc->Opcode() == Op_AllocateArray, "Unexpected type of allocation.");
 509         continue;
 510       }
 511 
 512       if (PhaseMacroExpand::can_eliminate_allocation(_igvn, alloc, nullptr)) {
 513         found_sr_allocate = true;
 514       } else {
 515         NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("%dth input of Phi %d is SR but can't be eliminated.", i, ophi->_idx);)
 516         ptn->set_scalar_replaceable(false);
 517       }
 518     }
 519   }
 520 
 521   NOT_PRODUCT(if (TraceReduceAllocationMerges && !found_sr_allocate) tty->print_cr("Can NOT reduce Phi %d on invocation %d. No SR Allocate as input.", ophi->_idx, _invocation);)
 522   return found_sr_allocate;
 523 }
 524 
 525 // We can reduce the Cmp if it's a comparison between the Phi and a constant.
 526 // I require the 'other' input to be a constant so that I can move the Cmp
 527 // around safely.
 528 bool ConnectionGraph::can_reduce_cmp(Node* n, Node* cmp) const {
 529   assert(cmp->Opcode() == Op_CmpP || cmp->Opcode() == Op_CmpN, "not expected node: %s", cmp->Name());
 530   Node* left = cmp->in(1);
 531   Node* right = cmp->in(2);
 532 
 533   return (left == n || right == n) &&
 534          (left->is_Con() || right->is_Con()) &&
 535          cmp->outcnt() == 1;
 536 }
 537 
 538 // We are going to check if any of the SafePointScalarMerge entries
 539 // in the SafePoint reference the Phi that we are checking.
 540 bool ConnectionGraph::has_been_reduced(PhiNode* n, SafePointNode* sfpt) const {
 541   JVMState *jvms = sfpt->jvms();
 542 
 543   for (uint i = jvms->debug_start(); i < jvms->debug_end(); i++) {
 544     Node* sfpt_in = sfpt->in(i);
 545     if (sfpt_in->is_SafePointScalarMerge()) {
 546       SafePointScalarMergeNode* smerge = sfpt_in->as_SafePointScalarMerge();
 547       Node* nsr_ptr = sfpt->in(smerge->merge_pointer_idx(jvms));
 548       if (nsr_ptr == n) {
 549         return true;
 550       }
 551     }
 552   }
 553 
 554   return false;
 555 }
 556 
 557 // Check if we are able to untangle the merge. The following patterns are
 558 // supported:
 559 //  - Phi -> SafePoints
 560 //  - Phi -> CmpP/N
 561 //  - Phi -> AddP -> Load
 562 //  - Phi -> CastPP -> SafePoints
 563 //  - Phi -> CastPP -> AddP -> Load
 564 bool ConnectionGraph::can_reduce_check_users(Node* n, uint nesting) const {
 565   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 566     Node* use = n->fast_out(i);
 567 
 568     if (use->is_SafePoint()) {
 569       if (use->is_Call() && use->as_Call()->has_non_debug_use(n)) {
 570         NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. Call has non_debug_use().", n->_idx, _invocation);)
 571         return false;
 572       } else if (has_been_reduced(n->is_Phi() ? n->as_Phi() : n->as_CastPP()->in(1)->as_Phi(), use->as_SafePoint())) {
 573         NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. It has already been reduced.", n->_idx, _invocation);)
 574         return false;
 575       }
 576     } else if (use->is_AddP()) {
 577       Node* addp = use;
 578       for (DUIterator_Fast jmax, j = addp->fast_outs(jmax); j < jmax; j++) {
 579         Node* use_use = addp->fast_out(j);
 580         const Type* load_type = _igvn->type(use_use);
 581 
 582         if (!use_use->is_Load() || !use_use->as_Load()->can_split_through_phi_base(_igvn)) {
 583           NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. AddP user isn't a [splittable] Load(): %s", n->_idx, _invocation, use_use->Name());)
 584           return false;
 585         } else if (load_type->isa_narrowklass() || load_type->isa_klassptr()) {
 586           NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. [Narrow] Klass Load: %s", n->_idx, _invocation, use_use->Name());)
 587           return false;
 588         }
 589       }
 590     } else if (nesting > 0) {
 591       NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. Unsupported user %s at nesting level %d.", n->_idx, _invocation, use->Name(), nesting);)
 592       return false;
 593     } else if (use->is_CastPP()) {
 594       const Type* cast_t = _igvn->type(use);
 595       if (cast_t == nullptr || cast_t->make_ptr()->isa_instptr() == nullptr) {
 596 #ifndef PRODUCT
 597         if (TraceReduceAllocationMerges) {
 598           tty->print_cr("Can NOT reduce Phi %d on invocation %d. CastPP is not to an instance.", n->_idx, _invocation);
 599           use->dump();
 600         }
 601 #endif
 602         return false;
 603       }
 604 
 605       bool is_trivial_control = use->in(0) == nullptr || use->in(0) == n->in(0);
 606       if (!is_trivial_control) {
 607         // If it's not a trivial control then we check if we can reduce the
 608         // CmpP/N used by the If controlling the cast.
 609         if (use->in(0)->is_IfTrue() || use->in(0)->is_IfFalse()) {
 610           Node* iff = use->in(0)->in(0);
 611           // We may have an OpaqueNotNull node between If and Bool nodes. But we could also have a sub class of IfNode,
 612           // for example, an OuterStripMinedLoopEnd or a Parse Predicate. Bail out in all these cases.
 613           bool can_reduce = (iff->Opcode() == Op_If) && iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp();
 614           if (can_reduce) {
 615             Node* iff_cmp = iff->in(1)->in(1);
 616             int opc = iff_cmp->Opcode();
 617             can_reduce = (opc == Op_CmpP || opc == Op_CmpN) && can_reduce_cmp(n, iff_cmp);
 618           }
 619           if (!can_reduce) {
 620 #ifndef PRODUCT
 621             if (TraceReduceAllocationMerges) {
 622               tty->print_cr("Can NOT reduce Phi %d on invocation %d. CastPP %d doesn't have simple control.", n->_idx, _invocation, use->_idx);
 623               n->dump(5);
 624             }
 625 #endif
 626             return false;
 627           }
 628         }
 629       }
 630 
 631       if (!can_reduce_check_users(use, nesting+1)) {
 632         return false;
 633       }
 634     } else if (use->Opcode() == Op_CmpP || use->Opcode() == Op_CmpN) {
 635       if (!can_reduce_cmp(n, use)) {
 636         NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. CmpP/N %d isn't reducible.", n->_idx, _invocation, use->_idx);)
 637         return false;
 638       }
 639     } else {
 640       NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. One of the uses is: %d %s", n->_idx, _invocation, use->_idx, use->Name());)
 641       return false;
 642     }
 643   }
 644 
 645   return true;
 646 }
 647 
 648 // Returns true if: 1) It's profitable to reduce the merge, and 2) The Phi is
 649 // only used in some certain code shapes. Check comments in
 650 // 'can_reduce_phi_inputs' and 'can_reduce_phi_users' for more
 651 // details.
 652 bool ConnectionGraph::can_reduce_phi(PhiNode* ophi) const {
 653   // If there was an error attempting to reduce allocation merges for this
 654   // method we might have disabled the compilation and be retrying with RAM
 655   // disabled.
 656   if (!_compile->do_reduce_allocation_merges() || ophi->region()->Opcode() != Op_Region) {
 657     return false;
 658   }
 659 
 660   const Type* phi_t = _igvn->type(ophi);
 661   if (phi_t == nullptr ||
 662       phi_t->make_ptr() == nullptr ||
 663       phi_t->make_ptr()->isa_aryptr() != nullptr) {
 664     return false;
 665   }
 666 
 667   if (!can_reduce_phi_check_inputs(ophi) || !can_reduce_check_users(ophi, /* nesting: */ 0)) {
 668     return false;
 669   }
 670 
 671   NOT_PRODUCT(if (TraceReduceAllocationMerges) { tty->print_cr("Can reduce Phi %d during invocation %d: ", ophi->_idx, _invocation); })
 672   return true;
 673 }
 674 
 675 // This method will return a CmpP/N that we need to use on the If controlling a
 676 // CastPP after it was split. This method is only called on bases that are
 677 // nullable therefore we always need a controlling if for the splitted CastPP.
 678 //
 679 // 'curr_ctrl' is the control of the CastPP that we want to split through phi.
 680 // If the CastPP currently doesn't have a control then the CmpP/N will be
 681 // against the null constant, otherwise it will be against the constant input of
 682 // the existing CmpP/N. It's guaranteed that there will be a CmpP/N in the later
 683 // case because we have constraints on it and because the CastPP has a control
 684 // input.
 685 Node* ConnectionGraph::specialize_cmp(Node* base, Node* curr_ctrl) {
 686   const Type* t = base->bottom_type();
 687   Node* con = nullptr;
 688 
 689   if (curr_ctrl == nullptr || curr_ctrl->is_Region()) {
 690     con = _igvn->zerocon(t->basic_type());
 691   } else {
 692     // can_reduce_check_users() verified graph: true/false -> if -> bool -> cmp
 693     assert(curr_ctrl->in(0)->Opcode() == Op_If, "unexpected node %s", curr_ctrl->in(0)->Name());
 694     Node* bol = curr_ctrl->in(0)->in(1);
 695     assert(bol->is_Bool(), "unexpected node %s", bol->Name());
 696     Node* curr_cmp = bol->in(1);
 697     assert(curr_cmp->Opcode() == Op_CmpP || curr_cmp->Opcode() == Op_CmpN, "unexpected node %s", curr_cmp->Name());
 698     con = curr_cmp->in(1)->is_Con() ? curr_cmp->in(1) : curr_cmp->in(2);
 699   }
 700 
 701   return CmpNode::make(base, con, t->basic_type());
 702 }
 703 
 704 // This method 'specializes' the CastPP passed as parameter to the base passed
 705 // as parameter. Note that the existing CastPP input is a Phi. "Specialize"
 706 // means that the CastPP now will be specific for a given base instead of a Phi.
 707 // An If-Then-Else-Region block is inserted to control the CastPP. The control
 708 // of the CastPP is a copy of the current one (if there is one) or a check
 709 // against null.
 710 //
 711 // Before:
 712 //
 713 //    C1     C2  ... Cn
 714 //     \      |      /
 715 //      \     |     /
 716 //       \    |    /
 717 //        \   |   /
 718 //         \  |  /
 719 //          \ | /
 720 //           \|/
 721 //          Region     B1      B2  ... Bn
 722 //            |          \      |      /
 723 //            |           \     |     /
 724 //            |            \    |    /
 725 //            |             \   |   /
 726 //            |              \  |  /
 727 //            |               \ | /
 728 //            ---------------> Phi
 729 //                              |
 730 //                      X       |
 731 //                      |       |
 732 //                      |       |
 733 //                      ------> CastPP
 734 //
 735 // After (only partial illustration; base = B2, current_control = C2):
 736 //
 737 //                      C2
 738 //                      |
 739 //                      If
 740 //                     / \
 741 //                    /   \
 742 //                   T     F
 743 //                  /\     /
 744 //                 /  \   /
 745 //                /    \ /
 746 //      C1    CastPP   Reg        Cn
 747 //       |              |          |
 748 //       |              |          |
 749 //       |              |          |
 750 //       -------------- | ----------
 751 //                    | | |
 752 //                    Region
 753 //
 754 Node* ConnectionGraph::specialize_castpp(Node* castpp, Node* base, Node* current_control) {
 755   Node* control_successor  = current_control->unique_ctrl_out();
 756   Node* cmp                = _igvn->transform(specialize_cmp(base, castpp->in(0)));
 757   Node* bol                = _igvn->transform(new BoolNode(cmp, BoolTest::ne));
 758   IfNode* if_ne            = _igvn->transform(new IfNode(current_control, bol, PROB_MIN, COUNT_UNKNOWN))->as_If();
 759   Node* not_eq_control     = _igvn->transform(new IfTrueNode(if_ne));
 760   Node* yes_eq_control     = _igvn->transform(new IfFalseNode(if_ne));
 761   Node* end_region         = _igvn->transform(new RegionNode(3));
 762 
 763   // Insert the new if-else-region block into the graph
 764   end_region->set_req(1, not_eq_control);
 765   end_region->set_req(2, yes_eq_control);
 766   control_successor->replace_edge(current_control, end_region, _igvn);
 767 
 768   _igvn->_worklist.push(current_control);
 769   _igvn->_worklist.push(control_successor);
 770 
 771   return _igvn->transform(ConstraintCastNode::make_cast_for_type(not_eq_control, base, _igvn->type(castpp), ConstraintCastNode::DependencyType::NonFloatingNonNarrowing, nullptr));
 772 }
 773 
 774 Node* ConnectionGraph::split_castpp_load_through_phi(Node* curr_addp, Node* curr_load, Node* region, GrowableArray<Node*>* bases_for_loads, GrowableArray<Node *>  &alloc_worklist) {
 775   const Type* load_type = _igvn->type(curr_load);
 776   Node* nsr_value = _igvn->zerocon(load_type->basic_type());
 777   Node* memory = curr_load->in(MemNode::Memory);
 778 
 779   // The data_phi merging the loads needs to be nullable if
 780   // we are loading pointers.
 781   if (load_type->make_ptr() != nullptr) {
 782     if (load_type->isa_narrowoop()) {
 783       load_type = load_type->meet(TypeNarrowOop::NULL_PTR);
 784     } else if (load_type->isa_ptr()) {
 785       load_type = load_type->meet(TypePtr::NULL_PTR);
 786     } else {
 787       assert(false, "Unexpected load ptr type.");
 788     }
 789   }
 790 
 791   Node* data_phi = PhiNode::make(region, nsr_value, load_type);
 792 
 793   for (int i = 1; i < bases_for_loads->length(); i++) {
 794     Node* base = bases_for_loads->at(i);
 795     Node* cmp_region = nullptr;
 796     if (base != nullptr) {
 797       if (base->is_CFG()) { // means that we added a CastPP as child of this CFG node
 798         cmp_region = base->unique_ctrl_out_or_null();
 799         assert(cmp_region != nullptr, "There should be.");
 800         base = base->find_out_with(Op_CastPP);
 801       }
 802 
 803       Node* addr = _igvn->transform(new AddPNode(base, base, curr_addp->in(AddPNode::Offset)));
 804       Node* mem = (memory->is_Phi() && (memory->in(0) == region)) ? memory->in(i) : memory;
 805       Node* load = curr_load->clone();
 806       load->set_req(0, nullptr);
 807       load->set_req(1, mem);
 808       load->set_req(2, addr);
 809 
 810       if (cmp_region != nullptr) { // see comment on previous if
 811         Node* intermediate_phi = PhiNode::make(cmp_region, nsr_value, load_type);
 812         intermediate_phi->set_req(1, _igvn->transform(load));
 813         load = intermediate_phi;
 814       }
 815 
 816       data_phi->set_req(i, _igvn->transform(load));
 817     } else {
 818       // Just use the default, which is already in phi
 819     }
 820   }
 821 
 822   // Takes care of updating CG and split_unique_types worklists due
 823   // to cloned AddP->Load.
 824   updates_after_load_split(data_phi, curr_load, alloc_worklist);
 825 
 826   return _igvn->transform(data_phi);
 827 }
 828 
 829 // This method only reduces CastPP fields loads; SafePoints are handled
 830 // separately. The idea here is basically to clone the CastPP and place copies
 831 // on each input of the Phi, including non-scalar replaceable inputs.
 832 // Experimentation shows that the resulting IR graph is simpler that way than if
 833 // we just split the cast through scalar-replaceable inputs.
 834 //
 835 // The reduction process requires that CastPP's control be one of:
 836 //  1) no control,
 837 //  2) the same region as Ophi, or
 838 //  3) an IfTrue/IfFalse coming from an CmpP/N between Ophi and a constant.
 839 //
 840 // After splitting the CastPP we'll put it under an If-Then-Else-Region control
 841 // flow. If the CastPP originally had an IfTrue/False control input then we'll
 842 // use a similar CmpP/N to control the new If-Then-Else-Region. Otherwise, we'll
 843 // juse use a CmpP/N against the null constant.
 844 //
 845 // The If-Then-Else-Region isn't always needed. For instance, if input to
 846 // splitted cast was not nullable (or if it was the null constant) then we don't
 847 // need (shouldn't) use a CastPP at all.
 848 //
 849 // After the casts are splitted we'll split the AddP->Loads through the Phi and
 850 // connect them to the just split CastPPs.
 851 //
 852 // Before (CastPP control is same as Phi):
 853 //
 854 //          Region     Allocate   Null    Call
 855 //            |             \      |      /
 856 //            |              \     |     /
 857 //            |               \    |    /
 858 //            |                \   |   /
 859 //            |                 \  |  /
 860 //            |                  \ | /
 861 //            ------------------> Phi            # Oop Phi
 862 //            |                    |
 863 //            |                    |
 864 //            |                    |
 865 //            |                    |
 866 //            ----------------> CastPP
 867 //                                 |
 868 //                               AddP
 869 //                                 |
 870 //                               Load
 871 //
 872 // After (Very much simplified):
 873 //
 874 //                         Call  Null
 875 //                            \  /
 876 //                            CmpP
 877 //                             |
 878 //                           Bool#NE
 879 //                             |
 880 //                             If
 881 //                            / \
 882 //                           T   F
 883 //                          / \ /
 884 //                         /   R
 885 //                     CastPP  |
 886 //                       |     |
 887 //                     AddP    |
 888 //                       |     |
 889 //                     Load    |
 890 //                         \   |   0
 891 //            Allocate      \  |  /
 892 //                \          \ | /
 893 //               AddP         Phi
 894 //                  \         /
 895 //                 Load      /
 896 //                    \  0  /
 897 //                     \ | /
 898 //                      \|/
 899 //                      Phi        # "Field" Phi
 900 //
 901 void ConnectionGraph::reduce_phi_on_castpp_field_load(Node* curr_castpp, GrowableArray<Node*> &alloc_worklist) {
 902   Node* ophi = curr_castpp->in(1);
 903   assert(ophi->is_Phi(), "Expected this to be a Phi node.");
 904 
 905   // Identify which base should be used for AddP->Load later when spliting the
 906   // CastPP->Loads through ophi. Three kind of values may be stored in this
 907   // array, depending on the nullability status of the corresponding input in
 908   // ophi.
 909   //
 910   //  - nullptr:    Meaning that the base is actually the null constant and therefore
 911   //                we won't try to load from it.
 912   //
 913   //  - CFG Node:   Meaning that the base is a CastPP that was specialized for
 914   //                this input of Ophi. I.e., we added an If->Then->Else-Region
 915   //                that will 'activate' the CastPp only when the input is not Null.
 916   //
 917   //  - Other Node: Meaning that the base is not nullable and therefore we'll try
 918   //                to load directly from it.
 919   GrowableArray<Node*> bases_for_loads(ophi->req(), ophi->req(), nullptr);
 920 
 921   for (uint i = 1; i < ophi->req(); i++) {
 922     Node* base = ophi->in(i);
 923     const Type* base_t = _igvn->type(base);
 924 
 925     if (base_t->maybe_null()) {
 926       if (base->is_Con()) {
 927         // Nothing todo as bases_for_loads[i] is already null
 928       } else {
 929         Node* new_castpp = specialize_castpp(curr_castpp, base, ophi->in(0)->in(i));
 930         bases_for_loads.at_put(i, new_castpp->in(0)); // Use the ctrl of the new node just as a flag
 931       }
 932     } else {
 933       bases_for_loads.at_put(i, base);
 934     }
 935   }
 936 
 937   // Now let's split the CastPP->Loads through the Phi
 938   for (int i = curr_castpp->outcnt()-1; i >= 0;) {
 939     Node* use = curr_castpp->raw_out(i);
 940     if (use->is_AddP()) {
 941       for (int j = use->outcnt()-1; j >= 0;) {
 942         Node* use_use = use->raw_out(j);
 943         assert(use_use->is_Load(), "Expected this to be a Load node.");
 944 
 945         // We can't make an unconditional load from a nullable input. The
 946         // 'split_castpp_load_through_phi` method will add an
 947         // 'If-Then-Else-Region` around nullable bases and only load from them
 948         // when the input is not null.
 949         Node* phi = split_castpp_load_through_phi(use, use_use, ophi->in(0), &bases_for_loads, alloc_worklist);
 950         _igvn->replace_node(use_use, phi);
 951 
 952         --j;
 953         j = MIN2(j, (int)use->outcnt()-1);
 954       }
 955 
 956       _igvn->remove_dead_node(use);
 957     }
 958     --i;
 959     i = MIN2(i, (int)curr_castpp->outcnt()-1);
 960   }
 961 }
 962 
 963 // This method split a given CmpP/N through the Phi used in one of its inputs.
 964 // As a result we convert a comparison with a pointer to a comparison with an
 965 // integer.
 966 // The only requirement is that one of the inputs of the CmpP/N must be a Phi
 967 // while the other must be a constant.
 968 // The splitting process is basically just cloning the CmpP/N above the input
 969 // Phi.  However, some (most) of the cloned CmpP/Ns won't be requred because we
 970 // can prove at compile time the result of the comparison.
 971 //
 972 // Before:
 973 //
 974 //             in1    in2 ... inN
 975 //              \      |      /
 976 //               \     |     /
 977 //                \    |    /
 978 //                 \   |   /
 979 //                  \  |  /
 980 //                   \ | /
 981 //                    Phi
 982 //                     |   Other
 983 //                     |    /
 984 //                     |   /
 985 //                     |  /
 986 //                    CmpP/N
 987 //
 988 // After:
 989 //
 990 //        in1  Other   in2 Other  inN  Other
 991 //         |    |      |   |      |    |
 992 //         \    |      |   |      |    |
 993 //          \  /       |   /      |    /
 994 //          CmpP/N    CmpP/N     CmpP/N
 995 //          Bool      Bool       Bool
 996 //            \        |        /
 997 //             \       |       /
 998 //              \      |      /
 999 //               \     |     /
1000 //                \    |    /
1001 //                 \   |   /
1002 //                  \  |  /
1003 //                   \ | /
1004 //                    Phi
1005 //                     |
1006 //                     |   Zero
1007 //                     |    /
1008 //                     |   /
1009 //                     |  /
1010 //                     CmpI
1011 //
1012 //
1013 void ConnectionGraph::reduce_phi_on_cmp(Node* cmp) {
1014   Node* ophi = cmp->in(1)->is_Con() ? cmp->in(2) : cmp->in(1);
1015   assert(ophi->is_Phi(), "Expected this to be a Phi node.");
1016 
1017   Node* other = cmp->in(1)->is_Con() ? cmp->in(1) : cmp->in(2);
1018   Node* zero = _igvn->intcon(0);
1019   Node* one = _igvn->intcon(1);
1020   BoolTest::mask mask = cmp->unique_out()->as_Bool()->_test._test;
1021 
1022   // This Phi will merge the result of the Cmps split through the Phi
1023   Node* res_phi = PhiNode::make(ophi->in(0), zero, TypeInt::INT);
1024 
1025   for (uint i=1; i<ophi->req(); i++) {
1026     Node* ophi_input = ophi->in(i);
1027     Node* res_phi_input = nullptr;
1028 
1029     const TypeInt* tcmp = optimize_ptr_compare(ophi_input, other);
1030     if (tcmp->singleton()) {
1031       if ((mask == BoolTest::mask::eq && tcmp == TypeInt::CC_EQ) ||
1032           (mask == BoolTest::mask::ne && tcmp == TypeInt::CC_GT)) {
1033         res_phi_input = one;
1034       } else {
1035         res_phi_input = zero;
1036       }
1037     } else {
1038       Node* ncmp = _igvn->transform(cmp->clone());
1039       ncmp->set_req(1, ophi_input);
1040       ncmp->set_req(2, other);
1041       Node* bol = _igvn->transform(new BoolNode(ncmp, mask));
1042       res_phi_input = bol->as_Bool()->as_int_value(_igvn);
1043     }
1044 
1045     res_phi->set_req(i, res_phi_input);
1046   }
1047 
1048   // This CMP always compares whether the output of "res_phi" is TRUE as far as the "mask".
1049   Node* new_cmp = _igvn->transform(new CmpINode(_igvn->transform(res_phi), (mask == BoolTest::mask::eq) ? one : zero));
1050   _igvn->replace_node(cmp, new_cmp);
1051 }
1052 
1053 // Push the newly created AddP on alloc_worklist and patch
1054 // the connection graph. Note that the changes in the CG below
1055 // won't affect the ES of objects since the new nodes have the
1056 // same status as the old ones.
1057 void ConnectionGraph::updates_after_load_split(Node* data_phi, Node* previous_load, GrowableArray<Node *>  &alloc_worklist) {
1058   assert(data_phi != nullptr, "Output of split_through_phi is null.");
1059   assert(data_phi != previous_load, "Output of split_through_phi is same as input.");
1060   assert(data_phi->is_Phi(), "Output of split_through_phi isn't a Phi.");
1061 
1062   if (data_phi == nullptr || !data_phi->is_Phi()) {
1063     // Make this a retry?
1064     return ;
1065   }
1066 
1067   Node* previous_addp = previous_load->in(MemNode::Address);
1068   FieldNode* fn = ptnode_adr(previous_addp->_idx)->as_Field();
1069   for (uint i = 1; i < data_phi->req(); i++) {
1070     Node* new_load = data_phi->in(i);
1071 
1072     if (new_load->is_Phi()) {
1073       // new_load is currently the "intermediate_phi" from an specialized
1074       // CastPP.
1075       new_load = new_load->in(1);
1076     }
1077 
1078     // "new_load" might actually be a constant, parameter, etc.
1079     if (new_load->is_Load()) {
1080       Node* new_addp = new_load->in(MemNode::Address);
1081 
1082       // If new_load is a Load but not from an AddP, it means that the load is folded into another
1083       // load. And since this load is not from a field, we cannot create a unique type for it.
1084       // For example:
1085       //
1086       //   if (b) {
1087       //       Holder h1 = new Holder();
1088       //       Object o = ...;
1089       //       h.o = o.getClass();
1090       //   } else {
1091       //       Holder h2 = ...;
1092       //   }
1093       //   Holder h = Phi(h1, h2);
1094       //   Object r = h.o;
1095       //
1096       // Then, splitting r through the merge point results in:
1097       //
1098       //   if (b) {
1099       //       Holder h1 = new Holder();
1100       //       Object o = ...;
1101       //       h.o = o.getClass();
1102       //       Object o1 = h.o;
1103       //   } else {
1104       //       Holder h2 = ...;
1105       //       Object o2 = h2.o;
1106       //   }
1107       //   Object r = Phi(o1, o2);
1108       //
1109       // In this case, o1 is folded to o.getClass() which is a Load but not from an AddP, but from
1110       // an OopHandle that is loaded from the Klass of o.
1111       if (!new_addp->is_AddP()) {
1112         continue;
1113       }
1114       Node* base = get_addp_base(new_addp);
1115 
1116       // The base might not be something that we can create an unique
1117       // type for. If that's the case we are done with that input.
1118       PointsToNode* jobj_ptn = unique_java_object(base);
1119       if (jobj_ptn == nullptr || !jobj_ptn->scalar_replaceable()) {
1120         continue;
1121       }
1122 
1123       // Push to alloc_worklist since the base has an unique_type
1124       alloc_worklist.append_if_missing(new_addp);
1125 
1126       // Now let's add the node to the connection graph
1127       _nodes.at_grow(new_addp->_idx, nullptr);
1128       add_field(new_addp, fn->escape_state(), fn->offset());
1129       add_base(ptnode_adr(new_addp->_idx)->as_Field(), ptnode_adr(base->_idx));
1130 
1131       // If the load doesn't load an object then it won't be
1132       // part of the connection graph
1133       PointsToNode* curr_load_ptn = ptnode_adr(previous_load->_idx);
1134       if (curr_load_ptn != nullptr) {
1135         _nodes.at_grow(new_load->_idx, nullptr);
1136         add_local_var(new_load, curr_load_ptn->escape_state());
1137         add_edge(ptnode_adr(new_load->_idx), ptnode_adr(new_addp->_idx)->as_Field());
1138       }
1139     }
1140   }
1141 }
1142 
1143 void ConnectionGraph::reduce_phi_on_field_access(Node* previous_addp, GrowableArray<Node *>  &alloc_worklist) {
1144   // We'll pass this to 'split_through_phi' so that it'll do the split even
1145   // though the load doesn't have an unique instance type.
1146   bool ignore_missing_instance_id = true;
1147 
1148   // All AddPs are present in the connection graph
1149   FieldNode* fn = ptnode_adr(previous_addp->_idx)->as_Field();
1150 
1151   // Iterate over AddP looking for a Load
1152   for (int k = previous_addp->outcnt()-1; k >= 0;) {
1153     Node* previous_load = previous_addp->raw_out(k);
1154     if (previous_load->is_Load()) {
1155       Node* data_phi = previous_load->as_Load()->split_through_phi(_igvn, ignore_missing_instance_id);
1156 
1157       // Takes care of updating CG and split_unique_types worklists due to cloned
1158       // AddP->Load.
1159       updates_after_load_split(data_phi, previous_load, alloc_worklist);
1160 
1161       _igvn->replace_node(previous_load, data_phi);
1162     }
1163     --k;
1164     k = MIN2(k, (int)previous_addp->outcnt()-1);
1165   }
1166 
1167   // Remove the old AddP from the processing list because it's dead now
1168   assert(previous_addp->outcnt() == 0, "AddP should be dead now.");
1169   alloc_worklist.remove_if_existing(previous_addp);
1170 }
1171 
1172 // Create a 'selector' Phi based on the inputs of 'ophi'. If index 'i' of the
1173 // selector is:
1174 //    -> a '-1' constant, the i'th input of the original Phi is NSR.
1175 //    -> a 'x' constant >=0, the i'th input of of original Phi will be SR and
1176 //       the info about the scalarized object will be at index x of ObjectMergeValue::possible_objects
1177 PhiNode* ConnectionGraph::create_selector(PhiNode* ophi) const {
1178   Node* minus_one = _igvn->register_new_node_with_optimizer(ConINode::make(-1));
1179   Node* selector  = _igvn->register_new_node_with_optimizer(PhiNode::make(ophi->region(), minus_one, TypeInt::INT));
1180   uint number_of_sr_objects = 0;
1181   for (uint i = 1; i < ophi->req(); i++) {
1182     Node* base = ophi->in(i);
1183     JavaObjectNode* ptn = unique_java_object(base);
1184 
1185     if (ptn != nullptr && ptn->scalar_replaceable()) {
1186       Node* sr_obj_idx = _igvn->register_new_node_with_optimizer(ConINode::make(number_of_sr_objects));
1187       selector->set_req(i, sr_obj_idx);
1188       number_of_sr_objects++;
1189     }
1190   }
1191 
1192   return selector->as_Phi();
1193 }
1194 
1195 // Returns true if the AddP node 'n' has at least one base that is a reducible
1196 // merge. If the base is a CastPP/CheckCastPP then the input of the cast is
1197 // checked instead.
1198 bool ConnectionGraph::has_reducible_merge_base(AddPNode* n, Unique_Node_List &reducible_merges) {
1199   PointsToNode* ptn = ptnode_adr(n->_idx);
1200   if (ptn == nullptr || !ptn->is_Field() || ptn->as_Field()->base_count() < 2) {
1201     return false;
1202   }
1203 
1204   for (BaseIterator i(ptn->as_Field()); i.has_next(); i.next()) {
1205     Node* base = i.get()->ideal_node();
1206 
1207     if (reducible_merges.member(base)) {
1208       return true;
1209     }
1210 
1211     if (base->is_CastPP() || base->is_CheckCastPP()) {
1212       base = base->in(1);
1213       if (reducible_merges.member(base)) {
1214         return true;
1215       }
1216     }
1217   }
1218 
1219   return false;
1220 }
1221 
1222 // This method will call its helper method to reduce SafePoint nodes that use
1223 // 'ophi' or a casted version of 'ophi'. All SafePoint nodes using the same
1224 // "version" of Phi use the same debug information (regarding the Phi).
1225 // Therefore, I collect all safepoints and patch them all at once.
1226 //
1227 // The safepoints using the Phi node have to be processed before safepoints of
1228 // CastPP nodes. The reason is, when reducing a CastPP we add a reference (the
1229 // NSR merge pointer) to the input of the CastPP (i.e., the Phi) in the
1230 // safepoint. If we process CastPP's safepoints before Phi's safepoints the
1231 // algorithm that process Phi's safepoints will think that the added Phi
1232 // reference is a regular reference.
1233 bool ConnectionGraph::reduce_phi_on_safepoints(PhiNode* ophi) {
1234   PhiNode* selector = create_selector(ophi);
1235   Unique_Node_List safepoints;
1236   Unique_Node_List casts;
1237 
1238   // Just collect the users of the Phis for later processing
1239   // in the needed order.
1240   for (uint i = 0; i < ophi->outcnt(); i++) {
1241     Node* use = ophi->raw_out(i);
1242     if (use->is_SafePoint()) {
1243       safepoints.push(use);
1244     } else if (use->is_CastPP()) {
1245       casts.push(use);
1246     } else {
1247       assert(use->outcnt() == 0, "Only CastPP & SafePoint users should be left.");
1248     }
1249   }
1250 
1251   // Need to process safepoints using the Phi first
1252   if (!reduce_phi_on_safepoints_helper(ophi, nullptr, selector, safepoints)) {
1253     return false;
1254   }
1255 
1256   // Now process CastPP->safepoints
1257   for (uint i = 0; i < casts.size(); i++) {
1258     Node* cast = casts.at(i);
1259     Unique_Node_List cast_sfpts;
1260 
1261     for (DUIterator_Fast jmax, j = cast->fast_outs(jmax); j < jmax; j++) {
1262       Node* use_use = cast->fast_out(j);
1263       if (use_use->is_SafePoint()) {
1264         cast_sfpts.push(use_use);
1265       } else {
1266         assert(use_use->outcnt() == 0, "Only SafePoint users should be left.");
1267       }
1268     }
1269 
1270     if (!reduce_phi_on_safepoints_helper(ophi, cast, selector, cast_sfpts)) {
1271       return false;
1272     }
1273   }
1274 
1275   return true;
1276 }
1277 
1278 // This method will create a SafePointScalarMERGEnode for each SafePoint in
1279 // 'safepoints'. It then will iterate on the inputs of 'ophi' and create a
1280 // SafePointScalarObjectNode for each scalar replaceable input. Each
1281 // SafePointScalarMergeNode may describe multiple scalar replaced objects -
1282 // check detailed description in SafePointScalarMergeNode class header.
1283 bool ConnectionGraph::reduce_phi_on_safepoints_helper(Node* ophi, Node* cast, Node* selector, Unique_Node_List& safepoints) {
1284   PhaseMacroExpand mexp(*_igvn);
1285   Node* original_sfpt_parent =  cast != nullptr ? cast : ophi;
1286   const TypeOopPtr* merge_t = _igvn->type(original_sfpt_parent)->make_oopptr();
1287 
1288   Node* nsr_merge_pointer = ophi;
1289   if (cast != nullptr) {
1290     const Type* new_t = merge_t->meet(TypePtr::NULL_PTR);
1291     nsr_merge_pointer = _igvn->transform(ConstraintCastNode::make_cast_for_type(cast->in(0), cast->in(1), new_t, ConstraintCastNode::DependencyType::FloatingNarrowing, nullptr));
1292   }
1293 
1294   for (uint spi = 0; spi < safepoints.size(); spi++) {
1295     SafePointNode* sfpt = safepoints.at(spi)->as_SafePoint();
1296     JVMState *jvms      = sfpt->jvms();
1297     uint merge_idx      = (sfpt->req() - jvms->scloff());
1298     int debug_start     = jvms->debug_start();
1299 
1300     SafePointScalarMergeNode* smerge = new SafePointScalarMergeNode(merge_t, merge_idx);
1301     smerge->init_req(0, _compile->root());
1302     _igvn->register_new_node_with_optimizer(smerge);
1303 
1304     // The next two inputs are:
1305     //  (1) A copy of the original pointer to NSR objects.
1306     //  (2) A selector, used to decide if we need to rematerialize an object
1307     //      or use the pointer to a NSR object.
1308     // See more details of these fields in the declaration of SafePointScalarMergeNode
1309     sfpt->add_req(nsr_merge_pointer);
1310     sfpt->add_req(selector);
1311 
1312     for (uint i = 1; i < ophi->req(); i++) {
1313       Node* base = ophi->in(i);
1314       JavaObjectNode* ptn = unique_java_object(base);
1315 
1316       // If the base is not scalar replaceable we don't need to register information about
1317       // it at this time.
1318       if (ptn == nullptr || !ptn->scalar_replaceable()) {
1319         continue;
1320       }
1321 
1322       AllocateNode* alloc = ptn->ideal_node()->as_Allocate();
1323       Unique_Node_List value_worklist;
1324 #ifdef ASSERT
1325       const Type* res_type = alloc->result_cast()->bottom_type();
1326       if (res_type->is_inlinetypeptr() && !Compile::current()->has_circular_inline_type()) {
1327         PhiNode* phi = ophi->as_Phi();
1328         assert(!ophi->as_Phi()->can_push_inline_types_down(_igvn), "missed earlier scalarization opportunity");
1329       }
1330 #endif
1331       SafePointScalarObjectNode* sobj = mexp.create_scalarized_object_description(alloc, sfpt, &value_worklist);
1332       if (sobj == nullptr) {
1333         _compile->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1334         return false;
1335       }
1336 
1337       // Now make a pass over the debug information replacing any references
1338       // to the allocated object with "sobj"
1339       Node* ccpp = alloc->result_cast();
1340       sfpt->replace_edges_in_range(ccpp, sobj, debug_start, jvms->debug_end(), _igvn);
1341 
1342       // Register the scalarized object as a candidate for reallocation
1343       smerge->add_req(sobj);
1344 
1345       // Scalarize inline types that were added to the safepoint.
1346       // Don't allow linking a constant oop (if available) for flat array elements
1347       // because Deoptimization::reassign_flat_array_elements needs field values.
1348       const bool allow_oop = !merge_t->is_flat();
1349       for (uint j = 0; j < value_worklist.size(); ++j) {
1350         InlineTypeNode* vt = value_worklist.at(j)->as_InlineType();
1351         vt->make_scalar_in_safepoints(_igvn, allow_oop);
1352       }
1353     }
1354 
1355     // Replaces debug information references to "original_sfpt_parent" in "sfpt" with references to "smerge"
1356     sfpt->replace_edges_in_range(original_sfpt_parent, smerge, debug_start, jvms->debug_end(), _igvn);
1357 
1358     // The call to 'replace_edges_in_range' above might have removed the
1359     // reference to ophi that we need at _merge_pointer_idx. The line below make
1360     // sure the reference is maintained.
1361     sfpt->set_req(smerge->merge_pointer_idx(jvms), nsr_merge_pointer);
1362     _igvn->_worklist.push(sfpt);
1363   }
1364 
1365   return true;
1366 }
1367 
1368 void ConnectionGraph::reduce_phi(PhiNode* ophi, GrowableArray<Node*> &alloc_worklist) {
1369   bool delay = _igvn->delay_transform();
1370   _igvn->set_delay_transform(true);
1371   _igvn->hash_delete(ophi);
1372 
1373   // Copying all users first because some will be removed and others won't.
1374   // Ophi also may acquire some new users as part of Cast reduction.
1375   // CastPPs also need to be processed before CmpPs.
1376   Unique_Node_List castpps;
1377   Unique_Node_List others;
1378   for (DUIterator_Fast imax, i = ophi->fast_outs(imax); i < imax; i++) {
1379     Node* use = ophi->fast_out(i);
1380 
1381     if (use->is_CastPP()) {
1382       castpps.push(use);
1383     } else if (use->is_AddP() || use->is_Cmp()) {
1384       others.push(use);
1385     } else {
1386       // Safepoints to be processed later; other users aren't expected here
1387       assert(use->is_SafePoint(), "Unexpected user of reducible Phi %d -> %d:%s:%d", ophi->_idx, use->_idx, use->Name(), use->outcnt());
1388     }
1389   }
1390 
1391   _compile->print_method(PHASE_EA_BEFORE_PHI_REDUCTION, 5, ophi);
1392 
1393   // CastPPs need to be processed before Cmps because during the process of
1394   // splitting CastPPs we make reference to the inputs of the Cmp that is used
1395   // by the If controlling the CastPP.
1396   for (uint i = 0; i < castpps.size(); i++) {
1397     reduce_phi_on_castpp_field_load(castpps.at(i), alloc_worklist);
1398     _compile->print_method(PHASE_EA_AFTER_PHI_CASTPP_REDUCTION, 6, castpps.at(i));
1399   }
1400 
1401   for (uint i = 0; i < others.size(); i++) {
1402     Node* use = others.at(i);
1403 
1404     if (use->is_AddP()) {
1405       reduce_phi_on_field_access(use, alloc_worklist);
1406       _compile->print_method(PHASE_EA_AFTER_PHI_ADDP_REDUCTION, 6, use);
1407     } else if(use->is_Cmp()) {
1408       reduce_phi_on_cmp(use);
1409       _compile->print_method(PHASE_EA_AFTER_PHI_CMP_REDUCTION, 6, use);
1410     }
1411   }
1412 
1413   _igvn->set_delay_transform(delay);
1414 }
1415 
1416 void ConnectionGraph::reset_scalar_replaceable_entries(PhiNode* ophi) {
1417   Node* null_ptr            = _igvn->makecon(TypePtr::NULL_PTR);
1418   const TypeOopPtr* merge_t = _igvn->type(ophi)->make_oopptr();
1419   const Type* new_t         = merge_t->meet(TypePtr::NULL_PTR);
1420   Node* new_phi             = _igvn->register_new_node_with_optimizer(PhiNode::make(ophi->region(), null_ptr, new_t));
1421 
1422   for (uint i = 1; i < ophi->req(); i++) {
1423     Node* base          = ophi->in(i);
1424     JavaObjectNode* ptn = unique_java_object(base);
1425 
1426     if (ptn != nullptr && ptn->scalar_replaceable()) {
1427       new_phi->set_req(i, null_ptr);
1428     } else {
1429       new_phi->set_req(i, ophi->in(i));
1430     }
1431   }
1432 
1433   for (int i = ophi->outcnt()-1; i >= 0;) {
1434     Node* out = ophi->raw_out(i);
1435 
1436     if (out->is_ConstraintCast()) {
1437       const Type* out_t = _igvn->type(out)->make_ptr();
1438       const Type* out_new_t = out_t->meet(TypePtr::NULL_PTR);
1439       bool change = out_new_t != out_t;
1440 
1441       for (int j = out->outcnt()-1; change && j >= 0; --j) {
1442         Node* out2 = out->raw_out(j);
1443         if (!out2->is_SafePoint()) {
1444           change = false;
1445           break;
1446         }
1447       }
1448 
1449       if (change) {
1450         Node* new_cast = ConstraintCastNode::make_cast_for_type(out->in(0), out->in(1), out_new_t, ConstraintCastNode::DependencyType::NonFloatingNarrowing, nullptr);
1451         _igvn->replace_node(out, new_cast);
1452         _igvn->register_new_node_with_optimizer(new_cast);
1453       }
1454     }
1455 
1456     --i;
1457     i = MIN2(i, (int)ophi->outcnt()-1);
1458   }
1459 
1460   _igvn->replace_node(ophi, new_phi);
1461 }
1462 
1463 void ConnectionGraph::verify_ram_nodes(Compile* C, Node* root) {
1464   if (!C->do_reduce_allocation_merges()) return;
1465 
1466   Unique_Node_List ideal_nodes;
1467   ideal_nodes.map(C->live_nodes(), nullptr);  // preallocate space
1468   ideal_nodes.push(root);
1469 
1470   for (uint next = 0; next < ideal_nodes.size(); ++next) {
1471     Node* n = ideal_nodes.at(next);
1472 
1473     if (n->is_SafePointScalarMerge()) {
1474       SafePointScalarMergeNode* merge = n->as_SafePointScalarMerge();
1475 
1476       // Validate inputs of merge
1477       for (uint i = 1; i < merge->req(); i++) {
1478         if (merge->in(i) != nullptr && !merge->in(i)->is_top() && !merge->in(i)->is_SafePointScalarObject()) {
1479           assert(false, "SafePointScalarMerge inputs should be null/top or SafePointScalarObject.");
1480           C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1481         }
1482       }
1483 
1484       // Validate users of merge
1485       for (DUIterator_Fast imax, i = merge->fast_outs(imax); i < imax; i++) {
1486         Node* sfpt = merge->fast_out(i);
1487         if (sfpt->is_SafePoint()) {
1488           int merge_idx = merge->merge_pointer_idx(sfpt->as_SafePoint()->jvms());
1489 
1490           if (sfpt->in(merge_idx) != nullptr && sfpt->in(merge_idx)->is_SafePointScalarMerge()) {
1491             assert(false, "SafePointScalarMerge nodes can't be nested.");
1492             C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1493           }
1494         } else {
1495           assert(false, "Only safepoints can use SafePointScalarMerge nodes.");
1496           C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1497         }
1498       }
1499     }
1500 
1501     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1502       Node* m = n->fast_out(i);
1503       ideal_nodes.push(m);
1504     }
1505   }
1506 }
1507 
1508 // Returns true if there is an object in the scope of sfn that does not escape globally.
1509 bool ConnectionGraph::has_ea_local_in_scope(SafePointNode* sfn) {
1510   Compile* C = _compile;
1511   for (JVMState* jvms = sfn->jvms(); jvms != nullptr; jvms = jvms->caller()) {
1512     if (C->env()->should_retain_local_variables() || C->env()->jvmti_can_walk_any_space() ||
1513         DeoptimizeObjectsALot) {
1514       // Jvmti agents can access locals. Must provide info about local objects at runtime.
1515       int num_locs = jvms->loc_size();
1516       for (int idx = 0; idx < num_locs; idx++) {
1517         Node* l = sfn->local(jvms, idx);
1518         if (not_global_escape(l)) {
1519           return true;
1520         }
1521       }
1522     }
1523     if (C->env()->jvmti_can_get_owned_monitor_info() ||
1524         C->env()->jvmti_can_walk_any_space() || DeoptimizeObjectsALot) {
1525       // Jvmti agents can read monitors. Must provide info about locked objects at runtime.
1526       int num_mon = jvms->nof_monitors();
1527       for (int idx = 0; idx < num_mon; idx++) {
1528         Node* m = sfn->monitor_obj(jvms, idx);
1529         if (m != nullptr && not_global_escape(m)) {
1530           return true;
1531         }
1532       }
1533     }
1534   }
1535   return false;
1536 }
1537 
1538 // Returns true if at least one of the arguments to the call is an object
1539 // that does not escape globally.
1540 bool ConnectionGraph::has_arg_escape(CallJavaNode* call) {
1541   if (call->method() != nullptr) {
1542     uint max_idx = TypeFunc::Parms + call->method()->arg_size();
1543     for (uint idx = TypeFunc::Parms; idx < max_idx; idx++) {
1544       Node* p = call->in(idx);
1545       if (not_global_escape(p)) {
1546         return true;
1547       }
1548     }
1549   } else {
1550     const char* name = call->as_CallStaticJava()->_name;
1551     assert(name != nullptr, "no name");
1552     // no arg escapes through uncommon traps
1553     if (strcmp(name, "uncommon_trap") != 0) {
1554       // process_call_arguments() assumes that all arguments escape globally
1555       const TypeTuple* d = call->tf()->domain_sig();
1556       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1557         const Type* at = d->field_at(i);
1558         if (at->isa_oopptr() != nullptr) {
1559           return true;
1560         }
1561       }
1562     }
1563   }
1564   return false;
1565 }
1566 
1567 
1568 
1569 // Utility function for nodes that load an object
1570 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
1571   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1572   // ThreadLocal has RawPtr type.
1573   const Type* t = _igvn->type(n);
1574   if (t->make_ptr() != nullptr) {
1575     Node* adr = n->in(MemNode::Address);
1576 #ifdef ASSERT
1577     if (!adr->is_AddP()) {
1578       assert(_igvn->type(adr)->isa_rawptr(), "sanity");
1579     } else {
1580       assert((ptnode_adr(adr->_idx) == nullptr ||
1581               ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
1582     }
1583 #endif
1584     add_local_var_and_edge(n, PointsToNode::NoEscape,
1585                            adr, delayed_worklist);
1586   }
1587 }
1588 
1589 // Populate Connection Graph with PointsTo nodes and create simple
1590 // connection graph edges.
1591 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
1592   assert(!_verify, "this method should not be called for verification");
1593   PhaseGVN* igvn = _igvn;
1594   uint n_idx = n->_idx;
1595   PointsToNode* n_ptn = ptnode_adr(n_idx);
1596   if (n_ptn != nullptr) {
1597     return; // No need to redefine PointsTo node during first iteration.
1598   }
1599   int opcode = n->Opcode();
1600   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_to_con_graph(this, igvn, delayed_worklist, n, opcode);
1601   if (gc_handled) {
1602     return; // Ignore node if already handled by GC.
1603   }
1604 
1605   if (n->is_Call()) {
1606     // Arguments to allocation and locking don't escape.
1607     if (n->is_AbstractLock()) {
1608       // Put Lock and Unlock nodes on IGVN worklist to process them during
1609       // first IGVN optimization when escape information is still available.
1610       record_for_optimizer(n);
1611     } else if (n->is_Allocate()) {
1612       add_call_node(n->as_Call());
1613       record_for_optimizer(n);
1614     } else {
1615       if (n->is_CallStaticJava()) {
1616         const char* name = n->as_CallStaticJava()->_name;
1617         if (name != nullptr && strcmp(name, "uncommon_trap") == 0) {
1618           return; // Skip uncommon traps
1619         }
1620       }
1621       // Don't mark as processed since call's arguments have to be processed.
1622       delayed_worklist->push(n);
1623       // Check if a call returns an object.
1624       if ((n->as_Call()->returns_pointer() &&
1625            n->as_Call()->proj_out_or_null(TypeFunc::Parms) != nullptr) ||
1626           (n->is_CallStaticJava() &&
1627            n->as_CallStaticJava()->is_boxing_method())) {
1628         add_call_node(n->as_Call());
1629       } else if (n->as_Call()->tf()->returns_inline_type_as_fields()) {
1630         bool returns_oop = false;
1631         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax && !returns_oop; i++) {
1632           ProjNode* pn = n->fast_out(i)->as_Proj();
1633           if (pn->_con >= TypeFunc::Parms && pn->bottom_type()->isa_ptr()) {
1634             returns_oop = true;
1635           }
1636         }
1637         if (returns_oop) {
1638           add_call_node(n->as_Call());
1639         }
1640       }
1641     }
1642     return;
1643   }
1644   // Put this check here to process call arguments since some call nodes
1645   // point to phantom_obj.
1646   if (n_ptn == phantom_obj || n_ptn == null_obj) {
1647     return; // Skip predefined nodes.
1648   }
1649   switch (opcode) {
1650     case Op_AddP: {
1651       Node* base = get_addp_base(n);
1652       PointsToNode* ptn_base = ptnode_adr(base->_idx);
1653       // Field nodes are created for all field types. They are used in
1654       // adjust_scalar_replaceable_state() and split_unique_types().
1655       // Note, non-oop fields will have only base edges in Connection
1656       // Graph because such fields are not used for oop loads and stores.
1657       int offset = address_offset(n, igvn);
1658       add_field(n, PointsToNode::NoEscape, offset);
1659       if (ptn_base == nullptr) {
1660         delayed_worklist->push(n); // Process it later.
1661       } else {
1662         n_ptn = ptnode_adr(n_idx);
1663         add_base(n_ptn->as_Field(), ptn_base);
1664       }
1665       break;
1666     }
1667     case Op_CastX2P:
1668     case Op_CastI2N: {
1669       map_ideal_node(n, phantom_obj);
1670       break;
1671     }
1672     case Op_InlineType:
1673     case Op_CastPP:
1674     case Op_CheckCastPP:
1675     case Op_EncodeP:
1676     case Op_DecodeN:
1677     case Op_EncodePKlass:
1678     case Op_DecodeNKlass: {
1679       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist);
1680       break;
1681     }
1682     case Op_CMoveP: {
1683       add_local_var(n, PointsToNode::NoEscape);
1684       // Do not add edges during first iteration because some could be
1685       // not defined yet.
1686       delayed_worklist->push(n);
1687       break;
1688     }
1689     case Op_ConP:
1690     case Op_ConN:
1691     case Op_ConNKlass: {
1692       // assume all oop constants globally escape except for null
1693       PointsToNode::EscapeState es;
1694       const Type* t = igvn->type(n);
1695       if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
1696         es = PointsToNode::NoEscape;
1697       } else {
1698         es = PointsToNode::GlobalEscape;
1699       }
1700       PointsToNode* ptn_con = add_java_object(n, es);
1701       set_not_scalar_replaceable(ptn_con NOT_PRODUCT(COMMA "Constant pointer"));
1702       break;
1703     }
1704     case Op_CreateEx: {
1705       // assume that all exception objects globally escape
1706       map_ideal_node(n, phantom_obj);
1707       break;
1708     }
1709     case Op_LoadKlass:
1710     case Op_LoadNKlass: {
1711       // Unknown class is loaded
1712       map_ideal_node(n, phantom_obj);
1713       break;
1714     }
1715     case Op_LoadP:
1716     case Op_LoadN: {
1717       add_objload_to_connection_graph(n, delayed_worklist);
1718       break;
1719     }
1720     case Op_Parm: {
1721       map_ideal_node(n, phantom_obj);
1722       break;
1723     }
1724     case Op_PartialSubtypeCheck: {
1725       // Produces Null or notNull and is used in only in CmpP so
1726       // phantom_obj could be used.
1727       map_ideal_node(n, phantom_obj); // Result is unknown
1728       break;
1729     }
1730     case Op_Phi: {
1731       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1732       // ThreadLocal has RawPtr type.
1733       const Type* t = n->as_Phi()->type();
1734       if (t->make_ptr() != nullptr) {
1735         add_local_var(n, PointsToNode::NoEscape);
1736         // Do not add edges during first iteration because some could be
1737         // not defined yet.
1738         delayed_worklist->push(n);
1739       }
1740       break;
1741     }
1742     case Op_LoadFlat:
1743       // Treat LoadFlat similar to an unknown call that receives nothing and produces its results
1744       map_ideal_node(n, phantom_obj);
1745       break;
1746     case Op_StoreFlat:
1747       // Treat StoreFlat similar to a call that escapes the stored flattened fields
1748       delayed_worklist->push(n);
1749       break;
1750     case Op_Proj: {
1751       // we are only interested in the oop result projection from a call
1752       if (n->as_Proj()->_con >= TypeFunc::Parms && n->in(0)->is_Call() &&
1753           (n->in(0)->as_Call()->returns_pointer() || n->bottom_type()->isa_ptr())) {
1754         assert((n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->as_Call()->returns_pointer()) ||
1755                n->in(0)->as_Call()->tf()->returns_inline_type_as_fields(), "what kind of oop return is it?");
1756         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), delayed_worklist);
1757       } else if (n->as_Proj()->_con >= TypeFunc::Parms && n->in(0)->is_LoadFlat() && igvn->type(n)->isa_ptr()) {
1758         // Treat LoadFlat outputs similar to a call return value
1759         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), delayed_worklist);
1760       }
1761       break;
1762     }
1763     case Op_Rethrow: // Exception object escapes
1764     case Op_Return: {
1765       if (n->req() > TypeFunc::Parms &&
1766           igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
1767         // Treat Return value as LocalVar with GlobalEscape escape state.
1768         add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), delayed_worklist);
1769       }
1770       break;
1771     }
1772     case Op_CompareAndExchangeP:
1773     case Op_CompareAndExchangeN:
1774     case Op_GetAndSetP:
1775     case Op_GetAndSetN: {
1776       add_objload_to_connection_graph(n, delayed_worklist);
1777       // fall-through
1778     }
1779     case Op_StoreP:
1780     case Op_StoreN:
1781     case Op_StoreNKlass:
1782     case Op_WeakCompareAndSwapP:
1783     case Op_WeakCompareAndSwapN:
1784     case Op_CompareAndSwapP:
1785     case Op_CompareAndSwapN: {
1786       add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
1787       break;
1788     }
1789     case Op_AryEq:
1790     case Op_CountPositives:
1791     case Op_StrComp:
1792     case Op_StrEquals:
1793     case Op_StrIndexOf:
1794     case Op_StrIndexOfChar:
1795     case Op_StrInflatedCopy:
1796     case Op_StrCompressedCopy:
1797     case Op_VectorizedHashCode:
1798     case Op_EncodeISOArray: {
1799       add_local_var(n, PointsToNode::ArgEscape);
1800       delayed_worklist->push(n); // Process it later.
1801       break;
1802     }
1803     case Op_ThreadLocal: {
1804       PointsToNode* ptn_thr = add_java_object(n, PointsToNode::ArgEscape);
1805       set_not_scalar_replaceable(ptn_thr NOT_PRODUCT(COMMA "Constant pointer"));
1806       break;
1807     }
1808     case Op_Blackhole: {
1809       // All blackhole pointer arguments are globally escaping.
1810       // Only do this if there is at least one pointer argument.
1811       // Do not add edges during first iteration because some could be
1812       // not defined yet, defer to final step.
1813       for (uint i = 0; i < n->req(); i++) {
1814         Node* in = n->in(i);
1815         if (in != nullptr) {
1816           const Type* at = _igvn->type(in);
1817           if (!at->isa_ptr()) continue;
1818 
1819           add_local_var(n, PointsToNode::GlobalEscape);
1820           delayed_worklist->push(n);
1821           break;
1822         }
1823       }
1824       break;
1825     }
1826     default:
1827       ; // Do nothing for nodes not related to EA.
1828   }
1829   return;
1830 }
1831 
1832 // Add final simple edges to graph.
1833 void ConnectionGraph::add_final_edges(Node *n) {
1834   PointsToNode* n_ptn = ptnode_adr(n->_idx);
1835 #ifdef ASSERT
1836   if (_verify && n_ptn->is_JavaObject())
1837     return; // This method does not change graph for JavaObject.
1838 #endif
1839 
1840   if (n->is_Call()) {
1841     process_call_arguments(n->as_Call());
1842     return;
1843   }
1844   assert(n->is_Store() || n->is_LoadStore() || n->is_StoreFlat() ||
1845          ((n_ptn != nullptr) && (n_ptn->ideal_node() != nullptr)),
1846          "node should be registered already");
1847   int opcode = n->Opcode();
1848   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_final_edges(this, _igvn, n, opcode);
1849   if (gc_handled) {
1850     return; // Ignore node if already handled by GC.
1851   }
1852   switch (opcode) {
1853     case Op_AddP: {
1854       Node* base = get_addp_base(n);
1855       PointsToNode* ptn_base = ptnode_adr(base->_idx);
1856       assert(ptn_base != nullptr, "field's base should be registered");
1857       add_base(n_ptn->as_Field(), ptn_base);
1858       break;
1859     }
1860     case Op_InlineType:
1861     case Op_CastPP:
1862     case Op_CheckCastPP:
1863     case Op_EncodeP:
1864     case Op_DecodeN:
1865     case Op_EncodePKlass:
1866     case Op_DecodeNKlass: {
1867       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), nullptr);
1868       break;
1869     }
1870     case Op_CMoveP: {
1871       for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
1872         Node* in = n->in(i);
1873         if (in == nullptr) {
1874           continue;  // ignore null
1875         }
1876         Node* uncast_in = in->uncast();
1877         if (uncast_in->is_top() || uncast_in == n) {
1878           continue;  // ignore top or inputs which go back this node
1879         }
1880         PointsToNode* ptn = ptnode_adr(in->_idx);
1881         assert(ptn != nullptr, "node should be registered");
1882         add_edge(n_ptn, ptn);
1883       }
1884       break;
1885     }
1886     case Op_LoadP:
1887     case Op_LoadN: {
1888       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1889       // ThreadLocal has RawPtr type.
1890       assert(_igvn->type(n)->make_ptr() != nullptr, "Unexpected node type");
1891       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), nullptr);
1892       break;
1893     }
1894     case Op_Phi: {
1895       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1896       // ThreadLocal has RawPtr type.
1897       assert(n->as_Phi()->type()->make_ptr() != nullptr, "Unexpected node type");
1898       for (uint i = 1; i < n->req(); i++) {
1899         Node* in = n->in(i);
1900         if (in == nullptr) {
1901           continue;  // ignore null
1902         }
1903         Node* uncast_in = in->uncast();
1904         if (uncast_in->is_top() || uncast_in == n) {
1905           continue;  // ignore top or inputs which go back this node
1906         }
1907         PointsToNode* ptn = ptnode_adr(in->_idx);
1908         assert(ptn != nullptr, "node should be registered");
1909         add_edge(n_ptn, ptn);
1910       }
1911       break;
1912     }
1913     case Op_StoreFlat: {
1914       // StoreFlat globally escapes its stored flattened fields
1915       InlineTypeNode* value = n->as_StoreFlat()->value();
1916       ciInlineKlass* vk = _igvn->type(value)->inline_klass();
1917       for (int i = 0; i < vk->nof_nonstatic_fields(); i++) {
1918         ciField* field = vk->nonstatic_field_at(i);
1919         if (field->type()->is_primitive_type()) {
1920           continue;
1921         }
1922 
1923         Node* field_value = value->field_value_by_offset(field->offset_in_bytes(), true);
1924         PointsToNode* field_value_ptn = ptnode_adr(field_value->_idx);
1925         set_escape_state(field_value_ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "store into a flat field"));
1926       }
1927       break;
1928     }
1929     case Op_Proj: {
1930       if (n->in(0)->is_Call()) {
1931         // we are only interested in the oop result projection from a call
1932         assert((n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->as_Call()->returns_pointer()) ||
1933               n->in(0)->as_Call()->tf()->returns_inline_type_as_fields(), "what kind of oop return is it?");
1934         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), nullptr);
1935       } else if (n->in(0)->is_LoadFlat()) {
1936         // Treat LoadFlat outputs similar to a call return value
1937         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), nullptr);
1938       }
1939       break;
1940     }
1941     case Op_Rethrow: // Exception object escapes
1942     case Op_Return: {
1943       assert(n->req() > TypeFunc::Parms && _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr(),
1944              "Unexpected node type");
1945       // Treat Return value as LocalVar with GlobalEscape escape state.
1946       add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), nullptr);
1947       break;
1948     }
1949     case Op_CompareAndExchangeP:
1950     case Op_CompareAndExchangeN:
1951     case Op_GetAndSetP:
1952     case Op_GetAndSetN:{
1953       assert(_igvn->type(n)->make_ptr() != nullptr, "Unexpected node type");
1954       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), nullptr);
1955       // fall-through
1956     }
1957     case Op_CompareAndSwapP:
1958     case Op_CompareAndSwapN:
1959     case Op_WeakCompareAndSwapP:
1960     case Op_WeakCompareAndSwapN:
1961     case Op_StoreP:
1962     case Op_StoreN:
1963     case Op_StoreNKlass:{
1964       add_final_edges_unsafe_access(n, opcode);
1965       break;
1966     }
1967     case Op_VectorizedHashCode:
1968     case Op_AryEq:
1969     case Op_CountPositives:
1970     case Op_StrComp:
1971     case Op_StrEquals:
1972     case Op_StrIndexOf:
1973     case Op_StrIndexOfChar:
1974     case Op_StrInflatedCopy:
1975     case Op_StrCompressedCopy:
1976     case Op_EncodeISOArray: {
1977       // char[]/byte[] arrays passed to string intrinsic do not escape but
1978       // they are not scalar replaceable. Adjust escape state for them.
1979       // Start from in(2) edge since in(1) is memory edge.
1980       for (uint i = 2; i < n->req(); i++) {
1981         Node* adr = n->in(i);
1982         const Type* at = _igvn->type(adr);
1983         if (!adr->is_top() && at->isa_ptr()) {
1984           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
1985                  at->isa_ptr() != nullptr, "expecting a pointer");
1986           if (adr->is_AddP()) {
1987             adr = get_addp_base(adr);
1988           }
1989           PointsToNode* ptn = ptnode_adr(adr->_idx);
1990           assert(ptn != nullptr, "node should be registered");
1991           add_edge(n_ptn, ptn);
1992         }
1993       }
1994       break;
1995     }
1996     case Op_Blackhole: {
1997       // All blackhole pointer arguments are globally escaping.
1998       for (uint i = 0; i < n->req(); i++) {
1999         Node* in = n->in(i);
2000         if (in != nullptr) {
2001           const Type* at = _igvn->type(in);
2002           if (!at->isa_ptr()) continue;
2003 
2004           if (in->is_AddP()) {
2005             in = get_addp_base(in);
2006           }
2007 
2008           PointsToNode* ptn = ptnode_adr(in->_idx);
2009           assert(ptn != nullptr, "should be defined already");
2010           set_escape_state(ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "blackhole"));
2011           add_edge(n_ptn, ptn);
2012         }
2013       }
2014       break;
2015     }
2016     default: {
2017       // This method should be called only for EA specific nodes which may
2018       // miss some edges when they were created.
2019 #ifdef ASSERT
2020       n->dump(1);
2021 #endif
2022       guarantee(false, "unknown node");
2023     }
2024   }
2025   return;
2026 }
2027 
2028 void ConnectionGraph::add_to_congraph_unsafe_access(Node* n, uint opcode, Unique_Node_List* delayed_worklist) {
2029   Node* adr = n->in(MemNode::Address);
2030   const Type* adr_type = _igvn->type(adr);
2031   adr_type = adr_type->make_ptr();
2032   if (adr_type == nullptr) {
2033     return; // skip dead nodes
2034   }
2035   if (adr_type->isa_oopptr()
2036       || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
2037           && adr_type == TypeRawPtr::NOTNULL
2038           && is_captured_store_address(adr))) {
2039     delayed_worklist->push(n); // Process it later.
2040 #ifdef ASSERT
2041     assert (adr->is_AddP(), "expecting an AddP");
2042     if (adr_type == TypeRawPtr::NOTNULL) {
2043       // Verify a raw address for a store captured by Initialize node.
2044       int offs = (int) _igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2045       assert(offs != Type::OffsetBot, "offset must be a constant");
2046     }
2047 #endif
2048   } else {
2049     // Ignore copy the displaced header to the BoxNode (OSR compilation).
2050     if (adr->is_BoxLock()) {
2051       return;
2052     }
2053     // Stored value escapes in unsafe access.
2054     if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
2055       delayed_worklist->push(n); // Process unsafe access later.
2056       return;
2057     }
2058 #ifdef ASSERT
2059     n->dump(1);
2060     assert(false, "not unsafe");
2061 #endif
2062   }
2063 }
2064 
2065 bool ConnectionGraph::add_final_edges_unsafe_access(Node* n, uint opcode) {
2066   Node* adr = n->in(MemNode::Address);
2067   const Type *adr_type = _igvn->type(adr);
2068   adr_type = adr_type->make_ptr();
2069 #ifdef ASSERT
2070   if (adr_type == nullptr) {
2071     n->dump(1);
2072     assert(adr_type != nullptr, "dead node should not be on list");
2073     return true;
2074   }
2075 #endif
2076 
2077   if (adr_type->isa_oopptr()
2078       || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
2079            && adr_type == TypeRawPtr::NOTNULL
2080            && is_captured_store_address(adr))) {
2081     // Point Address to Value
2082     PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
2083     assert(adr_ptn != nullptr &&
2084            adr_ptn->as_Field()->is_oop(), "node should be registered");
2085     Node* val = n->in(MemNode::ValueIn);
2086     PointsToNode* ptn = ptnode_adr(val->_idx);
2087     assert(ptn != nullptr, "node should be registered");
2088     add_edge(adr_ptn, ptn);
2089     return true;
2090   } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
2091     // Stored value escapes in unsafe access.
2092     Node* val = n->in(MemNode::ValueIn);
2093     PointsToNode* ptn = ptnode_adr(val->_idx);
2094     assert(ptn != nullptr, "node should be registered");
2095     set_escape_state(ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "stored at raw address"));
2096     // Add edge to object for unsafe access with offset.
2097     PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
2098     assert(adr_ptn != nullptr, "node should be registered");
2099     if (adr_ptn->is_Field()) {
2100       assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
2101       add_edge(adr_ptn, ptn);
2102     }
2103     return true;
2104   }
2105 #ifdef ASSERT
2106   n->dump(1);
2107   assert(false, "not unsafe");
2108 #endif
2109   return false;
2110 }
2111 
2112 void ConnectionGraph::add_call_node(CallNode* call) {
2113   assert(call->returns_pointer() || call->tf()->returns_inline_type_as_fields(), "only for call which returns pointer");
2114   uint call_idx = call->_idx;
2115   if (call->is_Allocate()) {
2116     Node* k = call->in(AllocateNode::KlassNode);
2117     const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
2118     assert(kt != nullptr, "TypeKlassPtr  required.");
2119     PointsToNode::EscapeState es = PointsToNode::NoEscape;
2120     bool scalar_replaceable = true;
2121     NOT_PRODUCT(const char* nsr_reason = "");
2122     if (call->is_AllocateArray()) {
2123       if (!kt->isa_aryklassptr()) { // StressReflectiveCode
2124         es = PointsToNode::GlobalEscape;
2125       } else {
2126         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2127         if (length < 0) {
2128           // Not scalar replaceable if the length is not constant.
2129           scalar_replaceable = false;
2130           NOT_PRODUCT(nsr_reason = "has a non-constant length");
2131         } else if (length > EliminateAllocationArraySizeLimit) {
2132           // Not scalar replaceable if the length is too big.
2133           scalar_replaceable = false;
2134           NOT_PRODUCT(nsr_reason = "has a length that is too big");
2135         }
2136       }
2137     } else {  // Allocate instance
2138       if (!kt->isa_instklassptr()) { // StressReflectiveCode
2139         es = PointsToNode::GlobalEscape;
2140       } else {
2141         const TypeInstKlassPtr* ikt = kt->is_instklassptr();
2142         ciInstanceKlass* ik = ikt->klass_is_exact() ? ikt->exact_klass()->as_instance_klass() : ikt->instance_klass();
2143         if (ik->is_subclass_of(_compile->env()->Thread_klass()) ||
2144             ik->is_subclass_of(_compile->env()->Reference_klass()) ||
2145             !ik->can_be_instantiated() ||
2146             ik->has_finalizer()) {
2147           es = PointsToNode::GlobalEscape;
2148         } else {
2149           int nfields = ik->as_instance_klass()->nof_nonstatic_fields();
2150           if (nfields > EliminateAllocationFieldsLimit) {
2151             // Not scalar replaceable if there are too many fields.
2152             scalar_replaceable = false;
2153             NOT_PRODUCT(nsr_reason = "has too many fields");
2154           }
2155         }
2156       }
2157     }
2158     add_java_object(call, es);
2159     PointsToNode* ptn = ptnode_adr(call_idx);
2160     if (!scalar_replaceable && ptn->scalar_replaceable()) {
2161       set_not_scalar_replaceable(ptn NOT_PRODUCT(COMMA nsr_reason));
2162     }
2163   } else if (call->is_CallStaticJava()) {
2164     // Call nodes could be different types:
2165     //
2166     // 1. CallDynamicJavaNode (what happened during call is unknown):
2167     //
2168     //    - mapped to GlobalEscape JavaObject node if oop is returned;
2169     //
2170     //    - all oop arguments are escaping globally;
2171     //
2172     // 2. CallStaticJavaNode (execute bytecode analysis if possible):
2173     //
2174     //    - the same as CallDynamicJavaNode if can't do bytecode analysis;
2175     //
2176     //    - mapped to GlobalEscape JavaObject node if unknown oop is returned;
2177     //    - mapped to NoEscape JavaObject node if non-escaping object allocated
2178     //      during call is returned;
2179     //    - mapped to ArgEscape LocalVar node pointed to object arguments
2180     //      which are returned and does not escape during call;
2181     //
2182     //    - oop arguments escaping status is defined by bytecode analysis;
2183     //
2184     // For a static call, we know exactly what method is being called.
2185     // Use bytecode estimator to record whether the call's return value escapes.
2186     ciMethod* meth = call->as_CallJava()->method();
2187     if (meth == nullptr) {
2188       const char* name = call->as_CallStaticJava()->_name;
2189       assert(call->as_CallStaticJava()->is_call_to_multianewarray_stub() ||
2190              strncmp(name, "load_unknown_inline", 19) == 0 ||
2191              strncmp(name, "store_inline_type_fields_to_buf", 31) == 0, "TODO: add failed case check");
2192       // Returns a newly allocated non-escaped object.
2193       add_java_object(call, PointsToNode::NoEscape);
2194       set_not_scalar_replaceable(ptnode_adr(call_idx) NOT_PRODUCT(COMMA "is result of multinewarray"));
2195     } else if (meth->is_boxing_method()) {
2196       // Returns boxing object
2197       PointsToNode::EscapeState es;
2198       vmIntrinsics::ID intr = meth->intrinsic_id();
2199       if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
2200         // It does not escape if object is always allocated.
2201         es = PointsToNode::NoEscape;
2202       } else {
2203         // It escapes globally if object could be loaded from cache.
2204         es = PointsToNode::GlobalEscape;
2205       }
2206       add_java_object(call, es);
2207       if (es == PointsToNode::GlobalEscape) {
2208         set_not_scalar_replaceable(ptnode_adr(call->_idx) NOT_PRODUCT(COMMA "object can be loaded from boxing cache"));
2209       }
2210     } else {
2211       BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
2212       call_analyzer->copy_dependencies(_compile->dependencies());
2213       if (call_analyzer->is_return_allocated()) {
2214         // Returns a newly allocated non-escaped object, simply
2215         // update dependency information.
2216         // Mark it as NoEscape so that objects referenced by
2217         // it's fields will be marked as NoEscape at least.
2218         add_java_object(call, PointsToNode::NoEscape);
2219         set_not_scalar_replaceable(ptnode_adr(call_idx) NOT_PRODUCT(COMMA "is result of call"));
2220       } else {
2221         // Determine whether any arguments are returned.
2222         const TypeTuple* d = call->tf()->domain_cc();
2223         bool ret_arg = false;
2224         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2225           if (d->field_at(i)->isa_ptr() != nullptr &&
2226               call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2227             ret_arg = true;
2228             break;
2229           }
2230         }
2231         if (ret_arg) {
2232           add_local_var(call, PointsToNode::ArgEscape);
2233         } else {
2234           // Returns unknown object.
2235           map_ideal_node(call, phantom_obj);
2236         }
2237       }
2238     }
2239   } else {
2240     // An other type of call, assume the worst case:
2241     // returned value is unknown and globally escapes.
2242     assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
2243     map_ideal_node(call, phantom_obj);
2244   }
2245 }
2246 
2247 void ConnectionGraph::process_call_arguments(CallNode *call) {
2248     bool is_arraycopy = false;
2249     switch (call->Opcode()) {
2250 #ifdef ASSERT
2251     case Op_Allocate:
2252     case Op_AllocateArray:
2253     case Op_Lock:
2254     case Op_Unlock:
2255       assert(false, "should be done already");
2256       break;
2257 #endif
2258     case Op_ArrayCopy:
2259     case Op_CallLeafNoFP:
2260       // Most array copies are ArrayCopy nodes at this point but there
2261       // are still a few direct calls to the copy subroutines (See
2262       // PhaseStringOpts::copy_string())
2263       is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
2264         call->as_CallLeaf()->is_call_to_arraycopystub();
2265       // fall through
2266     case Op_CallLeafVector:
2267     case Op_CallLeaf: {
2268       // Stub calls, objects do not escape but they are not scale replaceable.
2269       // Adjust escape state for outgoing arguments.
2270       const TypeTuple * d = call->tf()->domain_sig();
2271       bool src_has_oops = false;
2272       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2273         const Type* at = d->field_at(i);
2274         Node *arg = call->in(i);
2275         if (arg == nullptr) {
2276           continue;
2277         }
2278         const Type *aat = _igvn->type(arg);
2279         if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr()) {
2280           continue;
2281         }
2282         if (arg->is_AddP()) {
2283           //
2284           // The inline_native_clone() case when the arraycopy stub is called
2285           // after the allocation before Initialize and CheckCastPP nodes.
2286           // Or normal arraycopy for object arrays case.
2287           //
2288           // Set AddP's base (Allocate) as not scalar replaceable since
2289           // pointer to the base (with offset) is passed as argument.
2290           //
2291           arg = get_addp_base(arg);
2292         }
2293         PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2294         assert(arg_ptn != nullptr, "should be registered");
2295         PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
2296         if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
2297           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
2298                  aat->isa_ptr() != nullptr, "expecting an Ptr");
2299           bool arg_has_oops = aat->isa_oopptr() &&
2300                               (aat->isa_instptr() ||
2301                                (aat->isa_aryptr() && (aat->isa_aryptr()->elem() == Type::BOTTOM || aat->isa_aryptr()->elem()->make_oopptr() != nullptr)) ||
2302                                (aat->isa_aryptr() && aat->isa_aryptr()->elem() != nullptr &&
2303                                                                aat->isa_aryptr()->is_flat() &&
2304                                                                aat->isa_aryptr()->elem()->inline_klass()->contains_oops()));
2305           if (i == TypeFunc::Parms) {
2306             src_has_oops = arg_has_oops;
2307           }
2308           //
2309           // src or dst could be j.l.Object when other is basic type array:
2310           //
2311           //   arraycopy(char[],0,Object*,0,size);
2312           //   arraycopy(Object*,0,char[],0,size);
2313           //
2314           // Don't add edges in such cases.
2315           //
2316           bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
2317                                        arg_has_oops && (i > TypeFunc::Parms);
2318 #ifdef ASSERT
2319           if (!(is_arraycopy ||
2320                 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(call) ||
2321                 (call->as_CallLeaf()->_name != nullptr &&
2322                  (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
2323                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
2324                   strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
2325                   strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
2326                   strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
2327                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
2328                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
2329                   strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_encryptAESCrypt") == 0 ||
2330                   strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_decryptAESCrypt") == 0 ||
2331                   strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
2332                   strcmp(call->as_CallLeaf()->_name, "galoisCounterMode_AESCrypt") == 0 ||
2333                   strcmp(call->as_CallLeaf()->_name, "poly1305_processBlocks") == 0 ||
2334                   strcmp(call->as_CallLeaf()->_name, "intpoly_montgomeryMult_P256") == 0 ||
2335                   strcmp(call->as_CallLeaf()->_name, "intpoly_assign") == 0 ||
2336                   strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
2337                   strcmp(call->as_CallLeaf()->_name, "chacha20Block") == 0 ||
2338                   strcmp(call->as_CallLeaf()->_name, "kyberNtt") == 0 ||
2339                   strcmp(call->as_CallLeaf()->_name, "kyberInverseNtt") == 0 ||
2340                   strcmp(call->as_CallLeaf()->_name, "kyberNttMult") == 0 ||
2341                   strcmp(call->as_CallLeaf()->_name, "kyberAddPoly_2") == 0 ||
2342                   strcmp(call->as_CallLeaf()->_name, "kyberAddPoly_3") == 0 ||
2343                   strcmp(call->as_CallLeaf()->_name, "kyber12To16") == 0 ||
2344                   strcmp(call->as_CallLeaf()->_name, "kyberBarrettReduce") == 0 ||
2345                   strcmp(call->as_CallLeaf()->_name, "dilithiumAlmostNtt") == 0 ||
2346                   strcmp(call->as_CallLeaf()->_name, "dilithiumAlmostInverseNtt") == 0 ||
2347                   strcmp(call->as_CallLeaf()->_name, "dilithiumNttMult") == 0 ||
2348                   strcmp(call->as_CallLeaf()->_name, "dilithiumMontMulByConstant") == 0 ||
2349                   strcmp(call->as_CallLeaf()->_name, "dilithiumDecomposePoly") == 0 ||
2350                   strcmp(call->as_CallLeaf()->_name, "encodeBlock") == 0 ||
2351                   strcmp(call->as_CallLeaf()->_name, "decodeBlock") == 0 ||
2352                   strcmp(call->as_CallLeaf()->_name, "md5_implCompress") == 0 ||
2353                   strcmp(call->as_CallLeaf()->_name, "md5_implCompressMB") == 0 ||
2354                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
2355                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
2356                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
2357                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
2358                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
2359                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
2360                   strcmp(call->as_CallLeaf()->_name, "sha3_implCompress") == 0 ||
2361                   strcmp(call->as_CallLeaf()->_name, "double_keccak") == 0 ||
2362                   strcmp(call->as_CallLeaf()->_name, "sha3_implCompressMB") == 0 ||
2363                   strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
2364                   strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
2365                   strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
2366                   strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
2367                   strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
2368                   strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0 ||
2369                   strcmp(call->as_CallLeaf()->_name, "load_unknown_inline") == 0 ||
2370                   strcmp(call->as_CallLeaf()->_name, "store_unknown_inline") == 0 ||
2371                   strcmp(call->as_CallLeaf()->_name, "store_inline_type_fields_to_buf") == 0 ||
2372                   strcmp(call->as_CallLeaf()->_name, "bigIntegerRightShiftWorker") == 0 ||
2373                   strcmp(call->as_CallLeaf()->_name, "bigIntegerLeftShiftWorker") == 0 ||
2374                   strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0 ||
2375                   strcmp(call->as_CallLeaf()->_name, "stringIndexOf") == 0 ||
2376                   strcmp(call->as_CallLeaf()->_name, "arraysort_stub") == 0 ||
2377                   strcmp(call->as_CallLeaf()->_name, "array_partition_stub") == 0 ||
2378                   strcmp(call->as_CallLeaf()->_name, "get_class_id_intrinsic") == 0 ||
2379                   strcmp(call->as_CallLeaf()->_name, "unsafe_setmemory") == 0)
2380                  ))) {
2381             call->dump();
2382             fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
2383           }
2384 #endif
2385           // Always process arraycopy's destination object since
2386           // we need to add all possible edges to references in
2387           // source object.
2388           if (arg_esc >= PointsToNode::ArgEscape &&
2389               !arg_is_arraycopy_dest) {
2390             continue;
2391           }
2392           PointsToNode::EscapeState es = PointsToNode::ArgEscape;
2393           if (call->is_ArrayCopy()) {
2394             ArrayCopyNode* ac = call->as_ArrayCopy();
2395             if (ac->is_clonebasic() ||
2396                 ac->is_arraycopy_validated() ||
2397                 ac->is_copyof_validated() ||
2398                 ac->is_copyofrange_validated()) {
2399               es = PointsToNode::NoEscape;
2400             }
2401           }
2402           set_escape_state(arg_ptn, es NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2403           if (arg_is_arraycopy_dest) {
2404             Node* src = call->in(TypeFunc::Parms);
2405             if (src->is_AddP()) {
2406               src = get_addp_base(src);
2407             }
2408             PointsToNode* src_ptn = ptnode_adr(src->_idx);
2409             assert(src_ptn != nullptr, "should be registered");
2410             // Special arraycopy edge:
2411             // Only escape state of destination object's fields affects
2412             // escape state of fields in source object.
2413             add_arraycopy(call, es, src_ptn, arg_ptn);
2414           }
2415         }
2416       }
2417       break;
2418     }
2419     case Op_CallStaticJava: {
2420       // For a static call, we know exactly what method is being called.
2421       // Use bytecode estimator to record the call's escape affects
2422 #ifdef ASSERT
2423       const char* name = call->as_CallStaticJava()->_name;
2424       assert((name == nullptr || strcmp(name, "uncommon_trap") != 0), "normal calls only");
2425 #endif
2426       ciMethod* meth = call->as_CallJava()->method();
2427       if ((meth != nullptr) && meth->is_boxing_method()) {
2428         break; // Boxing methods do not modify any oops.
2429       }
2430       BCEscapeAnalyzer* call_analyzer = (meth !=nullptr) ? meth->get_bcea() : nullptr;
2431       // fall-through if not a Java method or no analyzer information
2432       if (call_analyzer != nullptr) {
2433         PointsToNode* call_ptn = ptnode_adr(call->_idx);
2434         const TypeTuple* d = call->tf()->domain_cc();
2435         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2436           const Type* at = d->field_at(i);
2437           int k = i - TypeFunc::Parms;
2438           Node* arg = call->in(i);
2439           PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2440           if (at->isa_ptr() != nullptr &&
2441               call_analyzer->is_arg_returned(k)) {
2442             // The call returns arguments.
2443             if (call_ptn != nullptr) { // Is call's result used?
2444               assert(call_ptn->is_LocalVar(), "node should be registered");
2445               assert(arg_ptn != nullptr, "node should be registered");
2446               add_edge(call_ptn, arg_ptn);
2447             }
2448           }
2449           if (at->isa_oopptr() != nullptr &&
2450               arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
2451             if (!call_analyzer->is_arg_stack(k)) {
2452               // The argument global escapes
2453               set_escape_state(arg_ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2454             } else {
2455               set_escape_state(arg_ptn, PointsToNode::ArgEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2456               if (!call_analyzer->is_arg_local(k)) {
2457                 // The argument itself doesn't escape, but any fields might
2458                 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2459               }
2460             }
2461           }
2462         }
2463         if (call_ptn != nullptr && call_ptn->is_LocalVar()) {
2464           // The call returns arguments.
2465           assert(call_ptn->edge_count() > 0, "sanity");
2466           if (!call_analyzer->is_return_local()) {
2467             // Returns also unknown object.
2468             add_edge(call_ptn, phantom_obj);
2469           }
2470         }
2471         break;
2472       }
2473     }
2474     default: {
2475       // Fall-through here if not a Java method or no analyzer information
2476       // or some other type of call, assume the worst case: all arguments
2477       // globally escape.
2478       const TypeTuple* d = call->tf()->domain_cc();
2479       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2480         const Type* at = d->field_at(i);
2481         if (at->isa_oopptr() != nullptr) {
2482           Node* arg = call->in(i);
2483           if (arg->is_AddP()) {
2484             arg = get_addp_base(arg);
2485           }
2486           assert(ptnode_adr(arg->_idx) != nullptr, "should be defined already");
2487           set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2488         }
2489       }
2490     }
2491   }
2492 }
2493 
2494 
2495 // Finish Graph construction.
2496 bool ConnectionGraph::complete_connection_graph(
2497                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
2498                          GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist,
2499                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
2500                          GrowableArray<FieldNode*>&      oop_fields_worklist) {
2501   // Normally only 1-3 passes needed to build Connection Graph depending
2502   // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
2503   // Set limit to 20 to catch situation when something did go wrong and
2504   // bailout Escape Analysis.
2505   // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
2506 #define GRAPH_BUILD_ITER_LIMIT 20
2507 
2508   // Propagate GlobalEscape and ArgEscape escape states and check that
2509   // we still have non-escaping objects. The method pushs on _worklist
2510   // Field nodes which reference phantom_object.
2511   if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist)) {
2512     return false; // Nothing to do.
2513   }
2514   // Now propagate references to all JavaObject nodes.
2515   int java_objects_length = java_objects_worklist.length();
2516   elapsedTimer build_time;
2517   build_time.start();
2518   elapsedTimer time;
2519   bool timeout = false;
2520   int new_edges = 1;
2521   int iterations = 0;
2522   do {
2523     while ((new_edges > 0) &&
2524            (iterations++ < GRAPH_BUILD_ITER_LIMIT)) {
2525       double start_time = time.seconds();
2526       time.start();
2527       new_edges = 0;
2528       // Propagate references to phantom_object for nodes pushed on _worklist
2529       // by find_non_escaped_objects() and find_field_value().
2530       new_edges += add_java_object_edges(phantom_obj, false);
2531       for (int next = 0; next < java_objects_length; ++next) {
2532         JavaObjectNode* ptn = java_objects_worklist.at(next);
2533         new_edges += add_java_object_edges(ptn, true);
2534 
2535 #define SAMPLE_SIZE 4
2536         if ((next % SAMPLE_SIZE) == 0) {
2537           // Each 4 iterations calculate how much time it will take
2538           // to complete graph construction.
2539           time.stop();
2540           // Poll for requests from shutdown mechanism to quiesce compiler
2541           // because Connection graph construction may take long time.
2542           CompileBroker::maybe_block();
2543           double stop_time = time.seconds();
2544           double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
2545           double time_until_end = time_per_iter * (double)(java_objects_length - next);
2546           if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
2547             timeout = true;
2548             break; // Timeout
2549           }
2550           start_time = stop_time;
2551           time.start();
2552         }
2553 #undef SAMPLE_SIZE
2554 
2555       }
2556       if (timeout) break;
2557       if (new_edges > 0) {
2558         // Update escape states on each iteration if graph was updated.
2559         if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist)) {
2560           return false; // Nothing to do.
2561         }
2562       }
2563       time.stop();
2564       if (time.seconds() >= EscapeAnalysisTimeout) {
2565         timeout = true;
2566         break;
2567       }
2568       _compile->print_method(PHASE_EA_COMPLETE_CONNECTION_GRAPH_ITER, 5);
2569     }
2570     if ((iterations < GRAPH_BUILD_ITER_LIMIT) && !timeout) {
2571       time.start();
2572       // Find fields which have unknown value.
2573       int fields_length = oop_fields_worklist.length();
2574       for (int next = 0; next < fields_length; next++) {
2575         FieldNode* field = oop_fields_worklist.at(next);
2576         if (field->edge_count() == 0) {
2577           new_edges += find_field_value(field);
2578           // This code may added new edges to phantom_object.
2579           // Need an other cycle to propagate references to phantom_object.
2580         }
2581       }
2582       time.stop();
2583       if (time.seconds() >= EscapeAnalysisTimeout) {
2584         timeout = true;
2585         break;
2586       }
2587     } else {
2588       new_edges = 0; // Bailout
2589     }
2590   } while (new_edges > 0);
2591 
2592   build_time.stop();
2593   _build_time = build_time.seconds();
2594   _build_iterations = iterations;
2595 
2596   // Bailout if passed limits.
2597   if ((iterations >= GRAPH_BUILD_ITER_LIMIT) || timeout) {
2598     Compile* C = _compile;
2599     if (C->log() != nullptr) {
2600       C->log()->begin_elem("connectionGraph_bailout reason='reached ");
2601       C->log()->text("%s", timeout ? "time" : "iterations");
2602       C->log()->end_elem(" limit'");
2603     }
2604     assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build during invocation %d (%f sec, %d iterations) with %d nodes and worklist size %d",
2605            _invocation, _build_time, _build_iterations, nodes_size(), ptnodes_worklist.length());
2606     // Possible infinite build_connection_graph loop,
2607     // bailout (no changes to ideal graph were made).
2608     return false;
2609   }
2610 
2611 #undef GRAPH_BUILD_ITER_LIMIT
2612 
2613   // Find fields initialized by null for non-escaping Allocations.
2614   int non_escaped_length = non_escaped_allocs_worklist.length();
2615   for (int next = 0; next < non_escaped_length; next++) {
2616     JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
2617     PointsToNode::EscapeState es = ptn->escape_state();
2618     assert(es <= PointsToNode::ArgEscape, "sanity");
2619     if (es == PointsToNode::NoEscape) {
2620       if (find_init_values_null(ptn, _igvn) > 0) {
2621         // Adding references to null object does not change escape states
2622         // since it does not escape. Also no fields are added to null object.
2623         add_java_object_edges(null_obj, false);
2624       }
2625     }
2626     Node* n = ptn->ideal_node();
2627     if (n->is_Allocate()) {
2628       // The object allocated by this Allocate node will never be
2629       // seen by an other thread. Mark it so that when it is
2630       // expanded no MemBarStoreStore is added.
2631       InitializeNode* ini = n->as_Allocate()->initialization();
2632       if (ini != nullptr)
2633         ini->set_does_not_escape();
2634     }
2635   }
2636   return true; // Finished graph construction.
2637 }
2638 
2639 // Propagate GlobalEscape and ArgEscape escape states to all nodes
2640 // and check that we still have non-escaping java objects.
2641 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
2642                                                GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist,
2643                                                bool print_method) {
2644   GrowableArray<PointsToNode*> escape_worklist;
2645   // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
2646   int ptnodes_length = ptnodes_worklist.length();
2647   for (int next = 0; next < ptnodes_length; ++next) {
2648     PointsToNode* ptn = ptnodes_worklist.at(next);
2649     if (ptn->escape_state() >= PointsToNode::ArgEscape ||
2650         ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
2651       escape_worklist.push(ptn);
2652     }
2653   }
2654   // Set escape states to referenced nodes (edges list).
2655   while (escape_worklist.length() > 0) {
2656     PointsToNode* ptn = escape_worklist.pop();
2657     PointsToNode::EscapeState es  = ptn->escape_state();
2658     PointsToNode::EscapeState field_es = ptn->fields_escape_state();
2659     if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
2660         es >= PointsToNode::ArgEscape) {
2661       // GlobalEscape or ArgEscape state of field means it has unknown value.
2662       if (add_edge(ptn, phantom_obj)) {
2663         // New edge was added
2664         add_field_uses_to_worklist(ptn->as_Field());
2665       }
2666     }
2667     for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2668       PointsToNode* e = i.get();
2669       if (e->is_Arraycopy()) {
2670         assert(ptn->arraycopy_dst(), "sanity");
2671         // Propagate only fields escape state through arraycopy edge.
2672         if (e->fields_escape_state() < field_es) {
2673           set_fields_escape_state(e, field_es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2674           escape_worklist.push(e);
2675         }
2676       } else if (es >= field_es) {
2677         // fields_escape_state is also set to 'es' if it is less than 'es'.
2678         if (e->escape_state() < es) {
2679           set_escape_state(e, es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2680           escape_worklist.push(e);
2681         }
2682       } else {
2683         // Propagate field escape state.
2684         bool es_changed = false;
2685         if (e->fields_escape_state() < field_es) {
2686           set_fields_escape_state(e, field_es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2687           es_changed = true;
2688         }
2689         if ((e->escape_state() < field_es) &&
2690             e->is_Field() && ptn->is_JavaObject() &&
2691             e->as_Field()->is_oop()) {
2692           // Change escape state of referenced fields.
2693           set_escape_state(e, field_es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2694           es_changed = true;
2695         } else if (e->escape_state() < es) {
2696           set_escape_state(e, es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2697           es_changed = true;
2698         }
2699         if (es_changed) {
2700           escape_worklist.push(e);
2701         }
2702       }
2703       if (print_method) {
2704         _compile->print_method(PHASE_EA_CONNECTION_GRAPH_PROPAGATE_ITER, 6, e->ideal_node());
2705       }
2706     }
2707   }
2708   // Remove escaped objects from non_escaped list.
2709   for (int next = non_escaped_allocs_worklist.length()-1; next >= 0 ; --next) {
2710     JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
2711     if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
2712       non_escaped_allocs_worklist.delete_at(next);
2713     }
2714     if (ptn->escape_state() == PointsToNode::NoEscape) {
2715       // Find fields in non-escaped allocations which have unknown value.
2716       find_init_values_phantom(ptn);
2717     }
2718   }
2719   return (non_escaped_allocs_worklist.length() > 0);
2720 }
2721 
2722 // Add all references to JavaObject node by walking over all uses.
2723 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
2724   int new_edges = 0;
2725   if (populate_worklist) {
2726     // Populate _worklist by uses of jobj's uses.
2727     for (UseIterator i(jobj); i.has_next(); i.next()) {
2728       PointsToNode* use = i.get();
2729       if (use->is_Arraycopy()) {
2730         continue;
2731       }
2732       add_uses_to_worklist(use);
2733       if (use->is_Field() && use->as_Field()->is_oop()) {
2734         // Put on worklist all field's uses (loads) and
2735         // related field nodes (same base and offset).
2736         add_field_uses_to_worklist(use->as_Field());
2737       }
2738     }
2739   }
2740   for (int l = 0; l < _worklist.length(); l++) {
2741     PointsToNode* use = _worklist.at(l);
2742     if (PointsToNode::is_base_use(use)) {
2743       // Add reference from jobj to field and from field to jobj (field's base).
2744       use = PointsToNode::get_use_node(use)->as_Field();
2745       if (add_base(use->as_Field(), jobj)) {
2746         new_edges++;
2747       }
2748       continue;
2749     }
2750     assert(!use->is_JavaObject(), "sanity");
2751     if (use->is_Arraycopy()) {
2752       if (jobj == null_obj) { // null object does not have field edges
2753         continue;
2754       }
2755       // Added edge from Arraycopy node to arraycopy's source java object
2756       if (add_edge(use, jobj)) {
2757         jobj->set_arraycopy_src();
2758         new_edges++;
2759       }
2760       // and stop here.
2761       continue;
2762     }
2763     if (!add_edge(use, jobj)) {
2764       continue; // No new edge added, there was such edge already.
2765     }
2766     new_edges++;
2767     if (use->is_LocalVar()) {
2768       add_uses_to_worklist(use);
2769       if (use->arraycopy_dst()) {
2770         for (EdgeIterator i(use); i.has_next(); i.next()) {
2771           PointsToNode* e = i.get();
2772           if (e->is_Arraycopy()) {
2773             if (jobj == null_obj) { // null object does not have field edges
2774               continue;
2775             }
2776             // Add edge from arraycopy's destination java object to Arraycopy node.
2777             if (add_edge(jobj, e)) {
2778               new_edges++;
2779               jobj->set_arraycopy_dst();
2780             }
2781           }
2782         }
2783       }
2784     } else {
2785       // Added new edge to stored in field values.
2786       // Put on worklist all field's uses (loads) and
2787       // related field nodes (same base and offset).
2788       add_field_uses_to_worklist(use->as_Field());
2789     }
2790   }
2791   _worklist.clear();
2792   _in_worklist.reset();
2793   return new_edges;
2794 }
2795 
2796 // Put on worklist all related field nodes.
2797 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
2798   assert(field->is_oop(), "sanity");
2799   int offset = field->offset();
2800   add_uses_to_worklist(field);
2801   // Loop over all bases of this field and push on worklist Field nodes
2802   // with the same offset and base (since they may reference the same field).
2803   for (BaseIterator i(field); i.has_next(); i.next()) {
2804     PointsToNode* base = i.get();
2805     add_fields_to_worklist(field, base);
2806     // Check if the base was source object of arraycopy and go over arraycopy's
2807     // destination objects since values stored to a field of source object are
2808     // accessible by uses (loads) of fields of destination objects.
2809     if (base->arraycopy_src()) {
2810       for (UseIterator j(base); j.has_next(); j.next()) {
2811         PointsToNode* arycp = j.get();
2812         if (arycp->is_Arraycopy()) {
2813           for (UseIterator k(arycp); k.has_next(); k.next()) {
2814             PointsToNode* abase = k.get();
2815             if (abase->arraycopy_dst() && abase != base) {
2816               // Look for the same arraycopy reference.
2817               add_fields_to_worklist(field, abase);
2818             }
2819           }
2820         }
2821       }
2822     }
2823   }
2824 }
2825 
2826 // Put on worklist all related field nodes.
2827 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
2828   int offset = field->offset();
2829   if (base->is_LocalVar()) {
2830     for (UseIterator j(base); j.has_next(); j.next()) {
2831       PointsToNode* f = j.get();
2832       if (PointsToNode::is_base_use(f)) { // Field
2833         f = PointsToNode::get_use_node(f);
2834         if (f == field || !f->as_Field()->is_oop()) {
2835           continue;
2836         }
2837         int offs = f->as_Field()->offset();
2838         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
2839           add_to_worklist(f);
2840         }
2841       }
2842     }
2843   } else {
2844     assert(base->is_JavaObject(), "sanity");
2845     if (// Skip phantom_object since it is only used to indicate that
2846         // this field's content globally escapes.
2847         (base != phantom_obj) &&
2848         // null object node does not have fields.
2849         (base != null_obj)) {
2850       for (EdgeIterator i(base); i.has_next(); i.next()) {
2851         PointsToNode* f = i.get();
2852         // Skip arraycopy edge since store to destination object field
2853         // does not update value in source object field.
2854         if (f->is_Arraycopy()) {
2855           assert(base->arraycopy_dst(), "sanity");
2856           continue;
2857         }
2858         if (f == field || !f->as_Field()->is_oop()) {
2859           continue;
2860         }
2861         int offs = f->as_Field()->offset();
2862         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
2863           add_to_worklist(f);
2864         }
2865       }
2866     }
2867   }
2868 }
2869 
2870 // Find fields which have unknown value.
2871 int ConnectionGraph::find_field_value(FieldNode* field) {
2872   // Escaped fields should have init value already.
2873   assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
2874   int new_edges = 0;
2875   for (BaseIterator i(field); i.has_next(); i.next()) {
2876     PointsToNode* base = i.get();
2877     if (base->is_JavaObject()) {
2878       // Skip Allocate's fields which will be processed later.
2879       if (base->ideal_node()->is_Allocate()) {
2880         return 0;
2881       }
2882       assert(base == null_obj, "only null ptr base expected here");
2883     }
2884   }
2885   if (add_edge(field, phantom_obj)) {
2886     // New edge was added
2887     new_edges++;
2888     add_field_uses_to_worklist(field);
2889   }
2890   return new_edges;
2891 }
2892 
2893 // Find fields initializing values for allocations.
2894 int ConnectionGraph::find_init_values_phantom(JavaObjectNode* pta) {
2895   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
2896   PointsToNode* init_val = phantom_obj;
2897   Node* alloc = pta->ideal_node();
2898 
2899   // Do nothing for Allocate nodes since its fields values are
2900   // "known" unless they are initialized by arraycopy/clone.
2901   if (alloc->is_Allocate() && !pta->arraycopy_dst()) {
2902     if (alloc->as_Allocate()->in(AllocateNode::InitValue) != nullptr) {
2903       // Null-free inline type arrays are initialized with an init value instead of null
2904       init_val = ptnode_adr(alloc->as_Allocate()->in(AllocateNode::InitValue)->_idx);
2905       assert(init_val != nullptr, "init value should be registered");
2906     } else {
2907       return 0;
2908     }
2909   }
2910   // Non-escaped allocation returned from Java or runtime call has unknown values in fields.
2911   assert(pta->arraycopy_dst() || alloc->is_CallStaticJava() || init_val != phantom_obj, "sanity");
2912 #ifdef ASSERT
2913   if (alloc->is_CallStaticJava() && alloc->as_CallStaticJava()->method() == nullptr) {
2914     const char* name = alloc->as_CallStaticJava()->_name;
2915     assert(alloc->as_CallStaticJava()->is_call_to_multianewarray_stub() ||
2916            strncmp(name, "load_unknown_inline", 19) == 0 ||
2917            strncmp(name, "store_inline_type_fields_to_buf", 31) == 0, "sanity");
2918   }
2919 #endif
2920   // Non-escaped allocation returned from Java or runtime call have unknown values in fields.
2921   int new_edges = 0;
2922   for (EdgeIterator i(pta); i.has_next(); i.next()) {
2923     PointsToNode* field = i.get();
2924     if (field->is_Field() && field->as_Field()->is_oop()) {
2925       if (add_edge(field, init_val)) {
2926         // New edge was added
2927         new_edges++;
2928         add_field_uses_to_worklist(field->as_Field());
2929       }
2930     }
2931   }
2932   return new_edges;
2933 }
2934 
2935 // Find fields initializing values for allocations.
2936 int ConnectionGraph::find_init_values_null(JavaObjectNode* pta, PhaseValues* phase) {
2937   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
2938   Node* alloc = pta->ideal_node();
2939   // Do nothing for Call nodes since its fields values are unknown.
2940   if (!alloc->is_Allocate() || alloc->as_Allocate()->in(AllocateNode::InitValue) != nullptr) {
2941     return 0;
2942   }
2943   InitializeNode* ini = alloc->as_Allocate()->initialization();
2944   bool visited_bottom_offset = false;
2945   GrowableArray<int> offsets_worklist;
2946   int new_edges = 0;
2947 
2948   // Check if an oop field's initializing value is recorded and add
2949   // a corresponding null if field's value if it is not recorded.
2950   // Connection Graph does not record a default initialization by null
2951   // captured by Initialize node.
2952   //
2953   for (EdgeIterator i(pta); i.has_next(); i.next()) {
2954     PointsToNode* field = i.get(); // Field (AddP)
2955     if (!field->is_Field() || !field->as_Field()->is_oop()) {
2956       continue; // Not oop field
2957     }
2958     int offset = field->as_Field()->offset();
2959     if (offset == Type::OffsetBot) {
2960       if (!visited_bottom_offset) {
2961         // OffsetBot is used to reference array's element,
2962         // always add reference to null to all Field nodes since we don't
2963         // known which element is referenced.
2964         if (add_edge(field, null_obj)) {
2965           // New edge was added
2966           new_edges++;
2967           add_field_uses_to_worklist(field->as_Field());
2968           visited_bottom_offset = true;
2969         }
2970       }
2971     } else {
2972       // Check only oop fields.
2973       const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
2974       if (adr_type->isa_rawptr()) {
2975 #ifdef ASSERT
2976         // Raw pointers are used for initializing stores so skip it
2977         // since it should be recorded already
2978         Node* base = get_addp_base(field->ideal_node());
2979         assert(adr_type->isa_rawptr() && is_captured_store_address(field->ideal_node()), "unexpected pointer type");
2980 #endif
2981         continue;
2982       }
2983       if (!offsets_worklist.contains(offset)) {
2984         offsets_worklist.append(offset);
2985         Node* value = nullptr;
2986         if (ini != nullptr) {
2987           // StoreP::value_basic_type() == T_ADDRESS
2988           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
2989           Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
2990           // Make sure initializing store has the same type as this AddP.
2991           // This AddP may reference non existing field because it is on a
2992           // dead branch of bimorphic call which is not eliminated yet.
2993           if (store != nullptr && store->is_Store() &&
2994               store->as_Store()->value_basic_type() == ft) {
2995             value = store->in(MemNode::ValueIn);
2996 #ifdef ASSERT
2997             if (VerifyConnectionGraph) {
2998               // Verify that AddP already points to all objects the value points to.
2999               PointsToNode* val = ptnode_adr(value->_idx);
3000               assert((val != nullptr), "should be processed already");
3001               PointsToNode* missed_obj = nullptr;
3002               if (val->is_JavaObject()) {
3003                 if (!field->points_to(val->as_JavaObject())) {
3004                   missed_obj = val;
3005                 }
3006               } else {
3007                 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
3008                   tty->print_cr("----------init store has invalid value -----");
3009                   store->dump();
3010                   val->dump();
3011                   assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
3012                 }
3013                 for (EdgeIterator j(val); j.has_next(); j.next()) {
3014                   PointsToNode* obj = j.get();
3015                   if (obj->is_JavaObject()) {
3016                     if (!field->points_to(obj->as_JavaObject())) {
3017                       missed_obj = obj;
3018                       break;
3019                     }
3020                   }
3021                 }
3022               }
3023               if (missed_obj != nullptr) {
3024                 tty->print_cr("----------field---------------------------------");
3025                 field->dump();
3026                 tty->print_cr("----------missed reference to object------------");
3027                 missed_obj->dump();
3028                 tty->print_cr("----------object referenced by init store-------");
3029                 store->dump();
3030                 val->dump();
3031                 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
3032               }
3033             }
3034 #endif
3035           } else {
3036             // There could be initializing stores which follow allocation.
3037             // For example, a volatile field store is not collected
3038             // by Initialize node.
3039             //
3040             // Need to check for dependent loads to separate such stores from
3041             // stores which follow loads. For now, add initial value null so
3042             // that compare pointers optimization works correctly.
3043           }
3044         }
3045         if (value == nullptr) {
3046           // A field's initializing value was not recorded. Add null.
3047           if (add_edge(field, null_obj)) {
3048             // New edge was added
3049             new_edges++;
3050             add_field_uses_to_worklist(field->as_Field());
3051           }
3052         }
3053       }
3054     }
3055   }
3056   return new_edges;
3057 }
3058 
3059 // Adjust scalar_replaceable state after Connection Graph is built.
3060 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj, Unique_Node_List &reducible_merges) {
3061   // A Phi 'x' is a _candidate_ to be reducible if 'can_reduce_phi(x)'
3062   // returns true. If one of the constraints in this method set 'jobj' to NSR
3063   // then the candidate Phi is discarded. If the Phi has another SR 'jobj' as
3064   // input, 'adjust_scalar_replaceable_state' will eventually be called with
3065   // that other object and the Phi will become a reducible Phi.
3066   // There could be multiple merges involving the same jobj.
3067   Unique_Node_List candidates;
3068 
3069   // Search for non-escaping objects which are not scalar replaceable
3070   // and mark them to propagate the state to referenced objects.
3071 
3072   for (UseIterator i(jobj); i.has_next(); i.next()) {
3073     PointsToNode* use = i.get();
3074     if (use->is_Arraycopy()) {
3075       continue;
3076     }
3077     if (use->is_Field()) {
3078       FieldNode* field = use->as_Field();
3079       assert(field->is_oop() && field->scalar_replaceable(), "sanity");
3080       // 1. An object is not scalar replaceable if the field into which it is
3081       // stored has unknown offset (stored into unknown element of an array).
3082       if (field->offset() == Type::OffsetBot) {
3083         set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored at unknown offset"));
3084         return;
3085       }
3086       for (BaseIterator i(field); i.has_next(); i.next()) {
3087         PointsToNode* base = i.get();
3088         // 2. An object is not scalar replaceable if the field into which it is
3089         // stored has multiple bases one of which is null.
3090         if ((base == null_obj) && (field->base_count() > 1)) {
3091           set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored into field with potentially null base"));
3092           return;
3093         }
3094         // 2.5. An object is not scalar replaceable if the field into which it is
3095         // stored has NSR base.
3096         if (!base->scalar_replaceable()) {
3097           set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored into field with NSR base"));
3098           return;
3099         }
3100       }
3101     }
3102     assert(use->is_Field() || use->is_LocalVar(), "sanity");
3103     // 3. An object is not scalar replaceable if it is merged with other objects
3104     // and we can't remove the merge
3105     for (EdgeIterator j(use); j.has_next(); j.next()) {
3106       PointsToNode* ptn = j.get();
3107       if (ptn->is_JavaObject() && ptn != jobj) {
3108         Node* use_n = use->ideal_node();
3109 
3110         // These other local vars may point to multiple objects through a Phi
3111         // In this case we skip them and see if we can reduce the Phi.
3112         if (use_n->is_CastPP() || use_n->is_CheckCastPP()) {
3113           use_n = use_n->in(1);
3114         }
3115 
3116         // If it's already a candidate or confirmed reducible merge we can skip verification
3117         if (candidates.member(use_n) || reducible_merges.member(use_n)) {
3118           continue;
3119         }
3120 
3121         if (use_n->is_Phi() && can_reduce_phi(use_n->as_Phi())) {
3122           candidates.push(use_n);
3123         } else {
3124           // Mark all objects as NSR if we can't remove the merge
3125           set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA trace_merged_message(ptn)));
3126           set_not_scalar_replaceable(ptn NOT_PRODUCT(COMMA trace_merged_message(jobj)));
3127         }
3128       }
3129     }
3130     if (!jobj->scalar_replaceable()) {
3131       return;
3132     }
3133   }
3134 
3135   for (EdgeIterator j(jobj); j.has_next(); j.next()) {
3136     if (j.get()->is_Arraycopy()) {
3137       continue;
3138     }
3139 
3140     // Non-escaping object node should point only to field nodes.
3141     FieldNode* field = j.get()->as_Field();
3142     int offset = field->as_Field()->offset();
3143 
3144     // 4. An object is not scalar replaceable if it has a field with unknown
3145     // offset (array's element is accessed in loop).
3146     if (offset == Type::OffsetBot) {
3147       set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "has field with unknown offset"));
3148       return;
3149     }
3150     // 5. Currently an object is not scalar replaceable if a LoadStore node
3151     // access its field since the field value is unknown after it.
3152     //
3153     Node* n = field->ideal_node();
3154 
3155     // Test for an unsafe access that was parsed as maybe off heap
3156     // (with a CheckCastPP to raw memory).
3157     assert(n->is_AddP(), "expect an address computation");
3158     if (n->in(AddPNode::Base)->is_top() &&
3159         n->in(AddPNode::Address)->Opcode() == Op_CheckCastPP) {
3160       assert(n->in(AddPNode::Address)->bottom_type()->isa_rawptr(), "raw address so raw cast expected");
3161       assert(_igvn->type(n->in(AddPNode::Address)->in(1))->isa_oopptr(), "cast pattern at unsafe access expected");
3162       set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is used as base of mixed unsafe access"));
3163       return;
3164     }
3165 
3166     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3167       Node* u = n->fast_out(i);
3168       if (u->is_LoadStore() || (u->is_Mem() && u->as_Mem()->is_mismatched_access())) {
3169         set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is used in LoadStore or mismatched access"));
3170         return;
3171       }
3172     }
3173 
3174     // 6. Or the address may point to more then one object. This may produce
3175     // the false positive result (set not scalar replaceable)
3176     // since the flow-insensitive escape analysis can't separate
3177     // the case when stores overwrite the field's value from the case
3178     // when stores happened on different control branches.
3179     //
3180     // Note: it will disable scalar replacement in some cases:
3181     //
3182     //    Point p[] = new Point[1];
3183     //    p[0] = new Point(); // Will be not scalar replaced
3184     //
3185     // but it will save us from incorrect optimizations in next cases:
3186     //
3187     //    Point p[] = new Point[1];
3188     //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
3189     //
3190     if (field->base_count() > 1 && candidates.size() == 0) {
3191       if (has_non_reducible_merge(field, reducible_merges)) {
3192         for (BaseIterator i(field); i.has_next(); i.next()) {
3193           PointsToNode* base = i.get();
3194           // Don't take into account LocalVar nodes which
3195           // may point to only one object which should be also
3196           // this field's base by now.
3197           if (base->is_JavaObject() && base != jobj) {
3198             // Mark all bases.
3199             set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "may point to more than one object"));
3200             set_not_scalar_replaceable(base NOT_PRODUCT(COMMA "may point to more than one object"));
3201           }
3202         }
3203 
3204         if (!jobj->scalar_replaceable()) {
3205           return;
3206         }
3207       }
3208     }
3209   }
3210 
3211   // The candidate is truly a reducible merge only if none of the other
3212   // constraints ruled it as NSR. There could be multiple merges involving the
3213   // same jobj.
3214   assert(jobj->scalar_replaceable(), "sanity");
3215   for (uint i = 0; i < candidates.size(); i++ ) {
3216     Node* candidate = candidates.at(i);
3217     reducible_merges.push(candidate);
3218   }
3219 }
3220 
3221 bool ConnectionGraph::has_non_reducible_merge(FieldNode* field, Unique_Node_List& reducible_merges) {
3222   for (BaseIterator i(field); i.has_next(); i.next()) {
3223     Node* base = i.get()->ideal_node();
3224     if (base->is_Phi() && !reducible_merges.member(base)) {
3225       return true;
3226     }
3227   }
3228   return false;
3229 }
3230 
3231 void ConnectionGraph::revisit_reducible_phi_status(JavaObjectNode* jobj, Unique_Node_List& reducible_merges) {
3232   assert(jobj != nullptr && !jobj->scalar_replaceable(), "jobj should be set as NSR before calling this function.");
3233 
3234   // Look for 'phis' that refer to 'jobj' as the last
3235   // remaining scalar replaceable input.
3236   uint reducible_merges_cnt = reducible_merges.size();
3237   for (uint i = 0; i < reducible_merges_cnt; i++) {
3238     Node* phi = reducible_merges.at(i);
3239 
3240     // This 'Phi' will be a 'good' if it still points to
3241     // at least one scalar replaceable object. Note that 'obj'
3242     // was/should be marked as NSR before calling this function.
3243     bool good_phi = false;
3244 
3245     for (uint j = 1; j < phi->req(); j++) {
3246       JavaObjectNode* phi_in_obj = unique_java_object(phi->in(j));
3247       if (phi_in_obj != nullptr && phi_in_obj->scalar_replaceable()) {
3248         good_phi = true;
3249         break;
3250       }
3251     }
3252 
3253     if (!good_phi) {
3254       NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Phi %d became non-reducible after node %d became NSR.", phi->_idx, jobj->ideal_node()->_idx);)
3255       reducible_merges.remove(i);
3256 
3257       // Decrement the index because the 'remove' call above actually
3258       // moves the last entry of the list to position 'i'.
3259       i--;
3260 
3261       reducible_merges_cnt--;
3262     }
3263   }
3264 }
3265 
3266 // Propagate NSR (Not scalar replaceable) state.
3267 void ConnectionGraph::find_scalar_replaceable_allocs(GrowableArray<JavaObjectNode*>& jobj_worklist, Unique_Node_List &reducible_merges) {
3268   int jobj_length = jobj_worklist.length();
3269   bool found_nsr_alloc = true;
3270   while (found_nsr_alloc) {
3271     found_nsr_alloc = false;
3272     for (int next = 0; next < jobj_length; ++next) {
3273       JavaObjectNode* jobj = jobj_worklist.at(next);
3274       for (UseIterator i(jobj); (jobj->scalar_replaceable() && i.has_next()); i.next()) {
3275         PointsToNode* use = i.get();
3276         if (use->is_Field()) {
3277           FieldNode* field = use->as_Field();
3278           assert(field->is_oop() && field->scalar_replaceable(), "sanity");
3279           assert(field->offset() != Type::OffsetBot, "sanity");
3280           for (BaseIterator i(field); i.has_next(); i.next()) {
3281             PointsToNode* base = i.get();
3282             // An object is not scalar replaceable if the field into which
3283             // it is stored has NSR base.
3284             if ((base != null_obj) && !base->scalar_replaceable()) {
3285               set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored into field with NSR base"));
3286               // Any merge that had only 'jobj' as scalar-replaceable will now be non-reducible,
3287               // because there is no point in reducing a Phi that won't improve the number of SR
3288               // objects.
3289               revisit_reducible_phi_status(jobj, reducible_merges);
3290               found_nsr_alloc = true;
3291               break;
3292             }
3293           }
3294         } else if (use->is_LocalVar()) {
3295           Node* phi = use->ideal_node();
3296           if (phi->Opcode() == Op_Phi && reducible_merges.member(phi) && !can_reduce_phi(phi->as_Phi())) {
3297             set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is merged in a non-reducible phi"));
3298             reducible_merges.yank(phi);
3299             found_nsr_alloc = true;
3300             break;
3301           }
3302         }
3303         _compile->print_method(PHASE_EA_PROPAGATE_NSR_ITER, 5, jobj->ideal_node());
3304       }
3305     }
3306   }
3307 }
3308 
3309 #ifdef ASSERT
3310 void ConnectionGraph::verify_connection_graph(
3311                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
3312                          GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist,
3313                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
3314                          GrowableArray<Node*>& addp_worklist) {
3315   // Verify that graph is complete - no new edges could be added.
3316   int java_objects_length = java_objects_worklist.length();
3317   int non_escaped_length  = non_escaped_allocs_worklist.length();
3318   int new_edges = 0;
3319   for (int next = 0; next < java_objects_length; ++next) {
3320     JavaObjectNode* ptn = java_objects_worklist.at(next);
3321     new_edges += add_java_object_edges(ptn, true);
3322   }
3323   assert(new_edges == 0, "graph was not complete");
3324   // Verify that escape state is final.
3325   int length = non_escaped_allocs_worklist.length();
3326   find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist, /*print_method=*/ false);
3327   assert((non_escaped_length == non_escaped_allocs_worklist.length()) &&
3328          (non_escaped_length == length) &&
3329          (_worklist.length() == 0), "escape state was not final");
3330 
3331   // Verify fields information.
3332   int addp_length = addp_worklist.length();
3333   for (int next = 0; next < addp_length; ++next ) {
3334     Node* n = addp_worklist.at(next);
3335     FieldNode* field = ptnode_adr(n->_idx)->as_Field();
3336     if (field->is_oop()) {
3337       // Verify that field has all bases
3338       Node* base = get_addp_base(n);
3339       PointsToNode* ptn = ptnode_adr(base->_idx);
3340       if (ptn->is_JavaObject()) {
3341         assert(field->has_base(ptn->as_JavaObject()), "sanity");
3342       } else {
3343         assert(ptn->is_LocalVar(), "sanity");
3344         for (EdgeIterator i(ptn); i.has_next(); i.next()) {
3345           PointsToNode* e = i.get();
3346           if (e->is_JavaObject()) {
3347             assert(field->has_base(e->as_JavaObject()), "sanity");
3348           }
3349         }
3350       }
3351       // Verify that all fields have initializing values.
3352       if (field->edge_count() == 0) {
3353         tty->print_cr("----------field does not have references----------");
3354         field->dump();
3355         for (BaseIterator i(field); i.has_next(); i.next()) {
3356           PointsToNode* base = i.get();
3357           tty->print_cr("----------field has next base---------------------");
3358           base->dump();
3359           if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
3360             tty->print_cr("----------base has fields-------------------------");
3361             for (EdgeIterator j(base); j.has_next(); j.next()) {
3362               j.get()->dump();
3363             }
3364             tty->print_cr("----------base has references---------------------");
3365             for (UseIterator j(base); j.has_next(); j.next()) {
3366               j.get()->dump();
3367             }
3368           }
3369         }
3370         for (UseIterator i(field); i.has_next(); i.next()) {
3371           i.get()->dump();
3372         }
3373         assert(field->edge_count() > 0, "sanity");
3374       }
3375     }
3376   }
3377 }
3378 #endif
3379 
3380 // Optimize ideal graph.
3381 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
3382                                            GrowableArray<MemBarStoreStoreNode*>& storestore_worklist) {
3383   Compile* C = _compile;
3384   PhaseIterGVN* igvn = _igvn;
3385   if (EliminateLocks) {
3386     // Mark locks before changing ideal graph.
3387     int cnt = C->macro_count();
3388     for (int i = 0; i < cnt; i++) {
3389       Node *n = C->macro_node(i);
3390       if (n->is_AbstractLock()) { // Lock and Unlock nodes
3391         AbstractLockNode* alock = n->as_AbstractLock();
3392         if (!alock->is_non_esc_obj()) {
3393           const Type* obj_type = igvn->type(alock->obj_node());
3394           if (can_eliminate_lock(alock) && !obj_type->is_inlinetypeptr()) {
3395             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
3396             // The lock could be marked eliminated by lock coarsening
3397             // code during first IGVN before EA. Replace coarsened flag
3398             // to eliminate all associated locks/unlocks.
3399 #ifdef ASSERT
3400             alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
3401 #endif
3402             alock->set_non_esc_obj();
3403           }
3404         }
3405       }
3406     }
3407   }
3408 
3409   if (OptimizePtrCompare) {
3410     for (int i = 0; i < ptr_cmp_worklist.length(); i++) {
3411       Node *n = ptr_cmp_worklist.at(i);
3412       assert(n->Opcode() == Op_CmpN || n->Opcode() == Op_CmpP, "must be");
3413       const TypeInt* tcmp = optimize_ptr_compare(n->in(1), n->in(2));
3414       if (tcmp->singleton()) {
3415         Node* cmp = igvn->makecon(tcmp);
3416 #ifndef PRODUCT
3417         if (PrintOptimizePtrCompare) {
3418           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, (tcmp == TypeInt::CC_EQ ? "EQ" : "NotEQ"));
3419           if (Verbose) {
3420             n->dump(1);
3421           }
3422         }
3423 #endif
3424         igvn->replace_node(n, cmp);
3425       }
3426     }
3427   }
3428 
3429   // For MemBarStoreStore nodes added in library_call.cpp, check
3430   // escape status of associated AllocateNode and optimize out
3431   // MemBarStoreStore node if the allocated object never escapes.
3432   for (int i = 0; i < storestore_worklist.length(); i++) {
3433     Node* storestore = storestore_worklist.at(i);
3434     Node* alloc = storestore->in(MemBarNode::Precedent)->in(0);
3435     if (alloc->is_Allocate() && not_global_escape(alloc)) {
3436       if (alloc->in(AllocateNode::InlineType) != nullptr) {
3437         // Non-escaping inline type buffer allocations don't require a membar
3438         storestore->as_MemBar()->remove(_igvn);
3439       } else {
3440         MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
3441         mb->init_req(TypeFunc::Memory,  storestore->in(TypeFunc::Memory));
3442         mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
3443         igvn->register_new_node_with_optimizer(mb);
3444         igvn->replace_node(storestore, mb);
3445       }
3446     }
3447   }
3448 }
3449 
3450 // Atomic flat accesses on non-escaping objects can be optimized to non-atomic accesses
3451 void ConnectionGraph::optimize_flat_accesses(GrowableArray<SafePointNode*>& sfn_worklist) {
3452   PhaseIterGVN& igvn = *_igvn;
3453   bool delay = igvn.delay_transform();
3454   igvn.set_delay_transform(true);
3455   igvn.C->for_each_flat_access([&](Node* n) {
3456     Node* base = n->is_LoadFlat() ? n->as_LoadFlat()->base() : n->as_StoreFlat()->base();
3457     if (!not_global_escape(base)) {
3458       return;
3459     }
3460 
3461     bool expanded;
3462     if (n->is_LoadFlat()) {
3463       expanded = n->as_LoadFlat()->expand_non_atomic(igvn);
3464     } else {
3465       expanded = n->as_StoreFlat()->expand_non_atomic(igvn);
3466     }
3467     if (expanded) {
3468       sfn_worklist.remove(n->as_SafePoint());
3469       igvn.C->remove_flat_access(n);
3470     }
3471   });
3472   igvn.set_delay_transform(delay);
3473 }
3474 
3475 // Optimize objects compare.
3476 const TypeInt* ConnectionGraph::optimize_ptr_compare(Node* left, Node* right) {
3477   const TypeInt* UNKNOWN = TypeInt::CC;    // [-1, 0,1]
3478   if (!OptimizePtrCompare) {
3479     return UNKNOWN;
3480   }
3481   const TypeInt* EQ = TypeInt::CC_EQ; // [0] == ZERO
3482   const TypeInt* NE = TypeInt::CC_GT; // [1] == ONE
3483 
3484   PointsToNode* ptn1 = ptnode_adr(left->_idx);
3485   PointsToNode* ptn2 = ptnode_adr(right->_idx);
3486   JavaObjectNode* jobj1 = unique_java_object(left);
3487   JavaObjectNode* jobj2 = unique_java_object(right);
3488 
3489   // The use of this method during allocation merge reduction may cause 'left'
3490   // or 'right' be something (e.g., a Phi) that isn't in the connection graph or
3491   // that doesn't reference an unique java object.
3492   if (ptn1 == nullptr || ptn2 == nullptr ||
3493       jobj1 == nullptr || jobj2 == nullptr) {
3494     return UNKNOWN;
3495   }
3496 
3497   assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
3498   assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
3499 
3500   // Check simple cases first.
3501   if (jobj1 != nullptr) {
3502     if (jobj1->escape_state() == PointsToNode::NoEscape) {
3503       if (jobj1 == jobj2) {
3504         // Comparing the same not escaping object.
3505         return EQ;
3506       }
3507       Node* obj = jobj1->ideal_node();
3508       // Comparing not escaping allocation.
3509       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
3510           !ptn2->points_to(jobj1)) {
3511         return NE; // This includes nullness check.
3512       }
3513     }
3514   }
3515   if (jobj2 != nullptr) {
3516     if (jobj2->escape_state() == PointsToNode::NoEscape) {
3517       Node* obj = jobj2->ideal_node();
3518       // Comparing not escaping allocation.
3519       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
3520           !ptn1->points_to(jobj2)) {
3521         return NE; // This includes nullness check.
3522       }
3523     }
3524   }
3525   if (jobj1 != nullptr && jobj1 != phantom_obj &&
3526       jobj2 != nullptr && jobj2 != phantom_obj &&
3527       jobj1->ideal_node()->is_Con() &&
3528       jobj2->ideal_node()->is_Con()) {
3529     // Klass or String constants compare. Need to be careful with
3530     // compressed pointers - compare types of ConN and ConP instead of nodes.
3531     const Type* t1 = jobj1->ideal_node()->get_ptr_type();
3532     const Type* t2 = jobj2->ideal_node()->get_ptr_type();
3533     if (t1->make_ptr() == t2->make_ptr()) {
3534       return EQ;
3535     } else {
3536       return NE;
3537     }
3538   }
3539   if (ptn1->meet(ptn2)) {
3540     return UNKNOWN; // Sets are not disjoint
3541   }
3542 
3543   // Sets are disjoint.
3544   bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
3545   bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
3546   bool set1_has_null_ptr    = ptn1->points_to(null_obj);
3547   bool set2_has_null_ptr    = ptn2->points_to(null_obj);
3548   if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
3549       (set2_has_unknown_ptr && set1_has_null_ptr)) {
3550     // Check nullness of unknown object.
3551     return UNKNOWN;
3552   }
3553 
3554   // Disjointness by itself is not sufficient since
3555   // alias analysis is not complete for escaped objects.
3556   // Disjoint sets are definitely unrelated only when
3557   // at least one set has only not escaping allocations.
3558   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
3559     if (ptn1->non_escaping_allocation()) {
3560       return NE;
3561     }
3562   }
3563   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
3564     if (ptn2->non_escaping_allocation()) {
3565       return NE;
3566     }
3567   }
3568   return UNKNOWN;
3569 }
3570 
3571 // Connection Graph construction functions.
3572 
3573 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
3574   PointsToNode* ptadr = _nodes.at(n->_idx);
3575   if (ptadr != nullptr) {
3576     assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
3577     return;
3578   }
3579   Compile* C = _compile;
3580   ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
3581   map_ideal_node(n, ptadr);
3582 }
3583 
3584 PointsToNode* ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
3585   PointsToNode* ptadr = _nodes.at(n->_idx);
3586   if (ptadr != nullptr) {
3587     assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
3588     return ptadr;
3589   }
3590   Compile* C = _compile;
3591   ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
3592   map_ideal_node(n, ptadr);
3593   return ptadr;
3594 }
3595 
3596 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
3597   PointsToNode* ptadr = _nodes.at(n->_idx);
3598   if (ptadr != nullptr) {
3599     assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
3600     return;
3601   }
3602   bool unsafe = false;
3603   bool is_oop = is_oop_field(n, offset, &unsafe);
3604   if (unsafe) {
3605     es = PointsToNode::GlobalEscape;
3606   }
3607   Compile* C = _compile;
3608   FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
3609   map_ideal_node(n, field);
3610 }
3611 
3612 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
3613                                     PointsToNode* src, PointsToNode* dst) {
3614   assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
3615   assert((src != null_obj) && (dst != null_obj), "not for ConP null");
3616   PointsToNode* ptadr = _nodes.at(n->_idx);
3617   if (ptadr != nullptr) {
3618     assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
3619     return;
3620   }
3621   Compile* C = _compile;
3622   ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
3623   map_ideal_node(n, ptadr);
3624   // Add edge from arraycopy node to source object.
3625   (void)add_edge(ptadr, src);
3626   src->set_arraycopy_src();
3627   // Add edge from destination object to arraycopy node.
3628   (void)add_edge(dst, ptadr);
3629   dst->set_arraycopy_dst();
3630 }
3631 
3632 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
3633   const Type* adr_type = n->as_AddP()->bottom_type();
3634   int field_offset = adr_type->isa_aryptr() ? adr_type->isa_aryptr()->field_offset().get() : Type::OffsetBot;
3635   BasicType bt = T_INT;
3636   if (offset == Type::OffsetBot && field_offset == Type::OffsetBot) {
3637     // Check only oop fields.
3638     if (!adr_type->isa_aryptr() ||
3639         adr_type->isa_aryptr()->elem() == Type::BOTTOM ||
3640         adr_type->isa_aryptr()->elem()->make_oopptr() != nullptr) {
3641       // OffsetBot is used to reference array's element. Ignore first AddP.
3642       if (find_second_addp(n, n->in(AddPNode::Base)) == nullptr) {
3643         bt = T_OBJECT;
3644       }
3645     }
3646   } else if (offset != oopDesc::klass_offset_in_bytes()) {
3647     if (adr_type->isa_instptr()) {
3648       ciField* field = _compile->alias_type(adr_type->is_ptr())->field();
3649       if (field != nullptr) {
3650         bt = field->layout_type();
3651       } else {
3652         // Check for unsafe oop field access
3653         if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
3654             n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
3655             n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
3656             BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
3657           bt = T_OBJECT;
3658           (*unsafe) = true;
3659         }
3660       }
3661     } else if (adr_type->isa_aryptr()) {
3662       if (offset == arrayOopDesc::length_offset_in_bytes()) {
3663         // Ignore array length load.
3664       } else if (find_second_addp(n, n->in(AddPNode::Base)) != nullptr) {
3665         // Ignore first AddP.
3666       } else {
3667         const Type* elemtype = adr_type->is_aryptr()->elem();
3668         if (adr_type->is_aryptr()->is_flat() && field_offset != Type::OffsetBot) {
3669           ciInlineKlass* vk = elemtype->inline_klass();
3670           field_offset += vk->payload_offset();
3671           ciField* field = vk->get_field_by_offset(field_offset, false);
3672           if (field != nullptr) {
3673             bt = field->layout_type();
3674           } else {
3675             assert(field_offset == vk->payload_offset() + vk->null_marker_offset_in_payload(), "no field or null marker of %s at offset %d", vk->name()->as_utf8(), field_offset);
3676             bt = T_BOOLEAN;
3677           }
3678         } else {
3679           bt = elemtype->array_element_basic_type();
3680         }
3681       }
3682     } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
3683       // Allocation initialization, ThreadLocal field access, unsafe access
3684       if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
3685           n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
3686           n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
3687           BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
3688         bt = T_OBJECT;
3689       }
3690     }
3691   }
3692   // Note: T_NARROWOOP is not classed as a real reference type
3693   return (is_reference_type(bt) || bt == T_NARROWOOP);
3694 }
3695 
3696 // Returns unique pointed java object or null.
3697 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) const {
3698   // If the node was created after the escape computation we can't answer.
3699   uint idx = n->_idx;
3700   if (idx >= nodes_size()) {
3701     return nullptr;
3702   }
3703   PointsToNode* ptn = ptnode_adr(idx);
3704   if (ptn == nullptr) {
3705     return nullptr;
3706   }
3707   if (ptn->is_JavaObject()) {
3708     return ptn->as_JavaObject();
3709   }
3710   assert(ptn->is_LocalVar(), "sanity");
3711   // Check all java objects it points to.
3712   JavaObjectNode* jobj = nullptr;
3713   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
3714     PointsToNode* e = i.get();
3715     if (e->is_JavaObject()) {
3716       if (jobj == nullptr) {
3717         jobj = e->as_JavaObject();
3718       } else if (jobj != e) {
3719         return nullptr;
3720       }
3721     }
3722   }
3723   return jobj;
3724 }
3725 
3726 // Return true if this node points only to non-escaping allocations.
3727 bool PointsToNode::non_escaping_allocation() {
3728   if (is_JavaObject()) {
3729     Node* n = ideal_node();
3730     if (n->is_Allocate() || n->is_CallStaticJava()) {
3731       return (escape_state() == PointsToNode::NoEscape);
3732     } else {
3733       return false;
3734     }
3735   }
3736   assert(is_LocalVar(), "sanity");
3737   // Check all java objects it points to.
3738   for (EdgeIterator i(this); i.has_next(); i.next()) {
3739     PointsToNode* e = i.get();
3740     if (e->is_JavaObject()) {
3741       Node* n = e->ideal_node();
3742       if ((e->escape_state() != PointsToNode::NoEscape) ||
3743           !(n->is_Allocate() || n->is_CallStaticJava())) {
3744         return false;
3745       }
3746     }
3747   }
3748   return true;
3749 }
3750 
3751 // Return true if we know the node does not escape globally.
3752 bool ConnectionGraph::not_global_escape(Node *n) {
3753   assert(!_collecting, "should not call during graph construction");
3754   // If the node was created after the escape computation we can't answer.
3755   uint idx = n->_idx;
3756   if (idx >= nodes_size()) {
3757     return false;
3758   }
3759   PointsToNode* ptn = ptnode_adr(idx);
3760   if (ptn == nullptr) {
3761     return false; // not in congraph (e.g. ConI)
3762   }
3763   PointsToNode::EscapeState es = ptn->escape_state();
3764   // If we have already computed a value, return it.
3765   if (es >= PointsToNode::GlobalEscape) {
3766     return false;
3767   }
3768   if (ptn->is_JavaObject()) {
3769     return true; // (es < PointsToNode::GlobalEscape);
3770   }
3771   assert(ptn->is_LocalVar(), "sanity");
3772   // Check all java objects it points to.
3773   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
3774     if (i.get()->escape_state() >= PointsToNode::GlobalEscape) {
3775       return false;
3776     }
3777   }
3778   return true;
3779 }
3780 
3781 // Return true if locked object does not escape globally
3782 // and locked code region (identified by BoxLockNode) is balanced:
3783 // all compiled code paths have corresponding Lock/Unlock pairs.
3784 bool ConnectionGraph::can_eliminate_lock(AbstractLockNode* alock) {
3785   if (alock->is_balanced() && not_global_escape(alock->obj_node())) {
3786     if (EliminateNestedLocks) {
3787       // We can mark whole locking region as Local only when only
3788       // one object is used for locking.
3789       alock->box_node()->as_BoxLock()->set_local();
3790     }
3791     return true;
3792   }
3793   return false;
3794 }
3795 
3796 // Helper functions
3797 
3798 // Return true if this node points to specified node or nodes it points to.
3799 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
3800   if (is_JavaObject()) {
3801     return (this == ptn);
3802   }
3803   assert(is_LocalVar() || is_Field(), "sanity");
3804   for (EdgeIterator i(this); i.has_next(); i.next()) {
3805     if (i.get() == ptn) {
3806       return true;
3807     }
3808   }
3809   return false;
3810 }
3811 
3812 // Return true if one node points to an other.
3813 bool PointsToNode::meet(PointsToNode* ptn) {
3814   if (this == ptn) {
3815     return true;
3816   } else if (ptn->is_JavaObject()) {
3817     return this->points_to(ptn->as_JavaObject());
3818   } else if (this->is_JavaObject()) {
3819     return ptn->points_to(this->as_JavaObject());
3820   }
3821   assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
3822   int ptn_count =  ptn->edge_count();
3823   for (EdgeIterator i(this); i.has_next(); i.next()) {
3824     PointsToNode* this_e = i.get();
3825     for (int j = 0; j < ptn_count; j++) {
3826       if (this_e == ptn->edge(j)) {
3827         return true;
3828       }
3829     }
3830   }
3831   return false;
3832 }
3833 
3834 #ifdef ASSERT
3835 // Return true if bases point to this java object.
3836 bool FieldNode::has_base(JavaObjectNode* jobj) const {
3837   for (BaseIterator i(this); i.has_next(); i.next()) {
3838     if (i.get() == jobj) {
3839       return true;
3840     }
3841   }
3842   return false;
3843 }
3844 #endif
3845 
3846 bool ConnectionGraph::is_captured_store_address(Node* addp) {
3847   // Handle simple case first.
3848   assert(_igvn->type(addp)->isa_oopptr() == nullptr, "should be raw access");
3849   if (addp->in(AddPNode::Address)->is_Proj() && addp->in(AddPNode::Address)->in(0)->is_Allocate()) {
3850     return true;
3851   } else if (addp->in(AddPNode::Address)->is_Phi()) {
3852     for (DUIterator_Fast imax, i = addp->fast_outs(imax); i < imax; i++) {
3853       Node* addp_use = addp->fast_out(i);
3854       if (addp_use->is_Store()) {
3855         for (DUIterator_Fast jmax, j = addp_use->fast_outs(jmax); j < jmax; j++) {
3856           if (addp_use->fast_out(j)->is_Initialize()) {
3857             return true;
3858           }
3859         }
3860       }
3861     }
3862   }
3863   return false;
3864 }
3865 
3866 int ConnectionGraph::address_offset(Node* adr, PhaseValues* phase) {
3867   const Type *adr_type = phase->type(adr);
3868   if (adr->is_AddP() && adr_type->isa_oopptr() == nullptr && is_captured_store_address(adr)) {
3869     // We are computing a raw address for a store captured by an Initialize
3870     // compute an appropriate address type. AddP cases #3 and #5 (see below).
3871     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
3872     assert(offs != Type::OffsetBot ||
3873            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
3874            "offset must be a constant or it is initialization of array");
3875     return offs;
3876   }
3877   return adr_type->is_ptr()->flat_offset();
3878 }
3879 
3880 Node* ConnectionGraph::get_addp_base(Node *addp) {
3881   assert(addp->is_AddP(), "must be AddP");
3882   //
3883   // AddP cases for Base and Address inputs:
3884   // case #1. Direct object's field reference:
3885   //     Allocate
3886   //       |
3887   //     Proj #5 ( oop result )
3888   //       |
3889   //     CheckCastPP (cast to instance type)
3890   //      | |
3891   //     AddP  ( base == address )
3892   //
3893   // case #2. Indirect object's field reference:
3894   //      Phi
3895   //       |
3896   //     CastPP (cast to instance type)
3897   //      | |
3898   //     AddP  ( base == address )
3899   //
3900   // case #3. Raw object's field reference for Initialize node:
3901   //      Allocate
3902   //        |
3903   //      Proj #5 ( oop result )
3904   //  top   |
3905   //     \  |
3906   //     AddP  ( base == top )
3907   //
3908   // case #4. Array's element reference:
3909   //   {CheckCastPP | CastPP}
3910   //     |  | |
3911   //     |  AddP ( array's element offset )
3912   //     |  |
3913   //     AddP ( array's offset )
3914   //
3915   // case #5. Raw object's field reference for arraycopy stub call:
3916   //          The inline_native_clone() case when the arraycopy stub is called
3917   //          after the allocation before Initialize and CheckCastPP nodes.
3918   //      Allocate
3919   //        |
3920   //      Proj #5 ( oop result )
3921   //       | |
3922   //       AddP  ( base == address )
3923   //
3924   // case #6. Constant Pool, ThreadLocal, CastX2P or
3925   //          Raw object's field reference:
3926   //      {ConP, ThreadLocal, CastX2P, raw Load}
3927   //  top   |
3928   //     \  |
3929   //     AddP  ( base == top )
3930   //
3931   // case #7. Klass's field reference.
3932   //      LoadKlass
3933   //       | |
3934   //       AddP  ( base == address )
3935   //
3936   // case #8. narrow Klass's field reference.
3937   //      LoadNKlass
3938   //       |
3939   //      DecodeN
3940   //       | |
3941   //       AddP  ( base == address )
3942   //
3943   // case #9. Mixed unsafe access
3944   //    {instance}
3945   //        |
3946   //      CheckCastPP (raw)
3947   //  top   |
3948   //     \  |
3949   //     AddP  ( base == top )
3950   //
3951   Node *base = addp->in(AddPNode::Base);
3952   if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
3953     base = addp->in(AddPNode::Address);
3954     while (base->is_AddP()) {
3955       // Case #6 (unsafe access) may have several chained AddP nodes.
3956       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
3957       base = base->in(AddPNode::Address);
3958     }
3959     if (base->Opcode() == Op_CheckCastPP &&
3960         base->bottom_type()->isa_rawptr() &&
3961         _igvn->type(base->in(1))->isa_oopptr()) {
3962       base = base->in(1); // Case #9
3963     } else {
3964       Node* uncast_base = base->uncast();
3965       int opcode = uncast_base->Opcode();
3966       assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
3967              opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
3968              (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != nullptr)) ||
3969              is_captured_store_address(addp), "sanity");
3970     }
3971   }
3972   return base;
3973 }
3974 
3975 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
3976   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
3977   Node* addp2 = addp->raw_out(0);
3978   if (addp->outcnt() == 1 && addp2->is_AddP() &&
3979       addp2->in(AddPNode::Base) == n &&
3980       addp2->in(AddPNode::Address) == addp) {
3981     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
3982     //
3983     // Find array's offset to push it on worklist first and
3984     // as result process an array's element offset first (pushed second)
3985     // to avoid CastPP for the array's offset.
3986     // Otherwise the inserted CastPP (LocalVar) will point to what
3987     // the AddP (Field) points to. Which would be wrong since
3988     // the algorithm expects the CastPP has the same point as
3989     // as AddP's base CheckCastPP (LocalVar).
3990     //
3991     //    ArrayAllocation
3992     //     |
3993     //    CheckCastPP
3994     //     |
3995     //    memProj (from ArrayAllocation CheckCastPP)
3996     //     |  ||
3997     //     |  ||   Int (element index)
3998     //     |  ||    |   ConI (log(element size))
3999     //     |  ||    |   /
4000     //     |  ||   LShift
4001     //     |  ||  /
4002     //     |  AddP (array's element offset)
4003     //     |  |
4004     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
4005     //     | / /
4006     //     AddP (array's offset)
4007     //      |
4008     //     Load/Store (memory operation on array's element)
4009     //
4010     return addp2;
4011   }
4012   return nullptr;
4013 }
4014 
4015 //
4016 // Adjust the type and inputs of an AddP which computes the
4017 // address of a field of an instance
4018 //
4019 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
4020   PhaseGVN* igvn = _igvn;
4021   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
4022   assert(base_t != nullptr && base_t->is_known_instance(), "expecting instance oopptr");
4023   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
4024   if (t == nullptr) {
4025     // We are computing a raw address for a store captured by an Initialize
4026     // compute an appropriate address type (cases #3 and #5).
4027     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
4028     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
4029     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
4030     assert(offs != Type::OffsetBot, "offset must be a constant");
4031     if (base_t->isa_aryptr() != nullptr) {
4032       // In the case of a flat inline type array, each field has its
4033       // own slice so we need to extract the field being accessed from
4034       // the address computation
4035       t = base_t->isa_aryptr()->add_field_offset_and_offset(offs)->is_oopptr();
4036     } else {
4037       t = base_t->add_offset(offs)->is_oopptr();
4038     }
4039   }
4040   int inst_id = base_t->instance_id();
4041   assert(!t->is_known_instance() || t->instance_id() == inst_id,
4042                              "old type must be non-instance or match new type");
4043 
4044   // The type 't' could be subclass of 'base_t'.
4045   // As result t->offset() could be large then base_t's size and it will
4046   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
4047   // constructor verifies correctness of the offset.
4048   //
4049   // It could happened on subclass's branch (from the type profiling
4050   // inlining) which was not eliminated during parsing since the exactness
4051   // of the allocation type was not propagated to the subclass type check.
4052   //
4053   // Or the type 't' could be not related to 'base_t' at all.
4054   // It could happen when CHA type is different from MDO type on a dead path
4055   // (for example, from instanceof check) which is not collapsed during parsing.
4056   //
4057   // Do nothing for such AddP node and don't process its users since
4058   // this code branch will go away.
4059   //
4060   if (!t->is_known_instance() &&
4061       !base_t->maybe_java_subtype_of(t)) {
4062      return false; // bail out
4063   }
4064   const TypePtr* tinst = base_t->add_offset(t->offset());
4065   if (tinst->isa_aryptr() && t->isa_aryptr()) {
4066     // In the case of a flat inline type array, each field has its
4067     // own slice so we need to keep track of the field being accessed.
4068     tinst = tinst->is_aryptr()->with_field_offset(t->is_aryptr()->field_offset().get());
4069     // Keep array properties (not flat/null-free)
4070     tinst = tinst->is_aryptr()->update_properties(t->is_aryptr());
4071     if (tinst == nullptr) {
4072       return false; // Skip dead path with inconsistent properties
4073     }
4074   }
4075 
4076   // Do NOT remove the next line: ensure a new alias index is allocated
4077   // for the instance type. Note: C++ will not remove it since the call
4078   // has side effect.
4079   int alias_idx = _compile->get_alias_index(tinst);
4080   igvn->set_type(addp, tinst);
4081   // record the allocation in the node map
4082   set_map(addp, get_map(base->_idx));
4083   // Set addp's Base and Address to 'base'.
4084   Node *abase = addp->in(AddPNode::Base);
4085   Node *adr   = addp->in(AddPNode::Address);
4086   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
4087       adr->in(0)->_idx == (uint)inst_id) {
4088     // Skip AddP cases #3 and #5.
4089   } else {
4090     assert(!abase->is_top(), "sanity"); // AddP case #3
4091     if (abase != base) {
4092       igvn->hash_delete(addp);
4093       addp->set_req(AddPNode::Base, base);
4094       if (abase == adr) {
4095         addp->set_req(AddPNode::Address, base);
4096       } else {
4097         // AddP case #4 (adr is array's element offset AddP node)
4098 #ifdef ASSERT
4099         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
4100         assert(adr->is_AddP() && atype != nullptr &&
4101                atype->instance_id() == inst_id, "array's element offset should be processed first");
4102 #endif
4103       }
4104       igvn->hash_insert(addp);
4105     }
4106   }
4107   // Put on IGVN worklist since at least addp's type was changed above.
4108   record_for_optimizer(addp);
4109   return true;
4110 }
4111 
4112 //
4113 // Create a new version of orig_phi if necessary. Returns either the newly
4114 // created phi or an existing phi.  Sets create_new to indicate whether a new
4115 // phi was created.  Cache the last newly created phi in the node map.
4116 //
4117 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, bool &new_created) {
4118   Compile *C = _compile;
4119   PhaseGVN* igvn = _igvn;
4120   new_created = false;
4121   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
4122   // nothing to do if orig_phi is bottom memory or matches alias_idx
4123   if (phi_alias_idx == alias_idx) {
4124     return orig_phi;
4125   }
4126   // Have we recently created a Phi for this alias index?
4127   PhiNode *result = get_map_phi(orig_phi->_idx);
4128   if (result != nullptr && C->get_alias_index(result->adr_type()) == alias_idx) {
4129     return result;
4130   }
4131   // Previous check may fail when the same wide memory Phi was split into Phis
4132   // for different memory slices. Search all Phis for this region.
4133   if (result != nullptr) {
4134     Node* region = orig_phi->in(0);
4135     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
4136       Node* phi = region->fast_out(i);
4137       if (phi->is_Phi() &&
4138           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
4139         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
4140         return phi->as_Phi();
4141       }
4142     }
4143   }
4144   if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
4145     if (C->do_escape_analysis() == true && !C->failing()) {
4146       // Retry compilation without escape analysis.
4147       // If this is the first failure, the sentinel string will "stick"
4148       // to the Compile object, and the C2Compiler will see it and retry.
4149       C->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4150     }
4151     return nullptr;
4152   }
4153   orig_phi_worklist.append_if_missing(orig_phi);
4154   const TypePtr *atype = C->get_adr_type(alias_idx);
4155   result = PhiNode::make(orig_phi->in(0), nullptr, Type::MEMORY, atype);
4156   C->copy_node_notes_to(result, orig_phi);
4157   igvn->set_type(result, result->bottom_type());
4158   record_for_optimizer(result);
4159   set_map(orig_phi, result);
4160   new_created = true;
4161   return result;
4162 }
4163 
4164 //
4165 // Return a new version of Memory Phi "orig_phi" with the inputs having the
4166 // specified alias index.
4167 //
4168 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, uint rec_depth) {
4169   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
4170   Compile *C = _compile;
4171   PhaseGVN* igvn = _igvn;
4172   bool new_phi_created;
4173   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
4174   if (!new_phi_created) {
4175     return result;
4176   }
4177   GrowableArray<PhiNode *>  phi_list;
4178   GrowableArray<uint>  cur_input;
4179   PhiNode *phi = orig_phi;
4180   uint idx = 1;
4181   bool finished = false;
4182   while(!finished) {
4183     while (idx < phi->req()) {
4184       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, rec_depth + 1);
4185       if (mem != nullptr && mem->is_Phi()) {
4186         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
4187         if (new_phi_created) {
4188           // found an phi for which we created a new split, push current one on worklist and begin
4189           // processing new one
4190           phi_list.push(phi);
4191           cur_input.push(idx);
4192           phi = mem->as_Phi();
4193           result = newphi;
4194           idx = 1;
4195           continue;
4196         } else {
4197           mem = newphi;
4198         }
4199       }
4200       if (C->failing()) {
4201         return nullptr;
4202       }
4203       result->set_req(idx++, mem);
4204     }
4205 #ifdef ASSERT
4206     // verify that the new Phi has an input for each input of the original
4207     assert( phi->req() == result->req(), "must have same number of inputs.");
4208     assert( result->in(0) != nullptr && result->in(0) == phi->in(0), "regions must match");
4209 #endif
4210     // Check if all new phi's inputs have specified alias index.
4211     // Otherwise use old phi.
4212     for (uint i = 1; i < phi->req(); i++) {
4213       Node* in = result->in(i);
4214       assert((phi->in(i) == nullptr) == (in == nullptr), "inputs must correspond.");
4215     }
4216     // we have finished processing a Phi, see if there are any more to do
4217     finished = (phi_list.length() == 0 );
4218     if (!finished) {
4219       phi = phi_list.pop();
4220       idx = cur_input.pop();
4221       PhiNode *prev_result = get_map_phi(phi->_idx);
4222       prev_result->set_req(idx++, result);
4223       result = prev_result;
4224     }
4225   }
4226   return result;
4227 }
4228 
4229 //
4230 // The next methods are derived from methods in MemNode.
4231 //
4232 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
4233   Node *mem = mmem;
4234   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
4235   // means an array I have not precisely typed yet.  Do not do any
4236   // alias stuff with it any time soon.
4237   if (toop->base() != Type::AnyPtr &&
4238       !(toop->isa_instptr() &&
4239         toop->is_instptr()->instance_klass()->is_java_lang_Object() &&
4240         toop->offset() == Type::OffsetBot)) {
4241     mem = mmem->memory_at(alias_idx);
4242     // Update input if it is progress over what we have now
4243   }
4244   return mem;
4245 }
4246 
4247 //
4248 // Move memory users to their memory slices.
4249 //
4250 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis) {
4251   Compile* C = _compile;
4252   PhaseGVN* igvn = _igvn;
4253   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
4254   assert(tp != nullptr, "ptr type");
4255   int alias_idx = C->get_alias_index(tp);
4256   int general_idx = C->get_general_index(alias_idx);
4257 
4258   // Move users first
4259   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4260     Node* use = n->fast_out(i);
4261     if (use->is_MergeMem()) {
4262       MergeMemNode* mmem = use->as_MergeMem();
4263       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
4264       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
4265         continue; // Nothing to do
4266       }
4267       // Replace previous general reference to mem node.
4268       uint orig_uniq = C->unique();
4269       Node* m = find_inst_mem(n, general_idx, orig_phis);
4270       assert(orig_uniq == C->unique(), "no new nodes");
4271       mmem->set_memory_at(general_idx, m);
4272       --imax;
4273       --i;
4274     } else if (use->is_MemBar()) {
4275       assert(!use->is_Initialize(), "initializing stores should not be moved");
4276       if (use->req() > MemBarNode::Precedent &&
4277           use->in(MemBarNode::Precedent) == n) {
4278         // Don't move related membars.
4279         record_for_optimizer(use);
4280         continue;
4281       }
4282       tp = use->as_MemBar()->adr_type()->isa_ptr();
4283       if ((tp != nullptr && C->get_alias_index(tp) == alias_idx) ||
4284           alias_idx == general_idx) {
4285         continue; // Nothing to do
4286       }
4287       // Move to general memory slice.
4288       uint orig_uniq = C->unique();
4289       Node* m = find_inst_mem(n, general_idx, orig_phis);
4290       assert(orig_uniq == C->unique(), "no new nodes");
4291       igvn->hash_delete(use);
4292       imax -= use->replace_edge(n, m, igvn);
4293       igvn->hash_insert(use);
4294       record_for_optimizer(use);
4295       --i;
4296 #ifdef ASSERT
4297     } else if (use->is_Mem()) {
4298       // Memory nodes should have new memory input.
4299       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
4300       assert(tp != nullptr, "ptr type");
4301       int idx = C->get_alias_index(tp);
4302       assert(get_map(use->_idx) != nullptr || idx == alias_idx,
4303              "Following memory nodes should have new memory input or be on the same memory slice");
4304     } else if (use->is_Phi()) {
4305       // Phi nodes should be split and moved already.
4306       tp = use->as_Phi()->adr_type()->isa_ptr();
4307       assert(tp != nullptr, "ptr type");
4308       int idx = C->get_alias_index(tp);
4309       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
4310     } else {
4311       use->dump();
4312       assert(false, "should not be here");
4313 #endif
4314     }
4315   }
4316 }
4317 
4318 //
4319 // Search memory chain of "mem" to find a MemNode whose address
4320 // is the specified alias index.
4321 //
4322 #define FIND_INST_MEM_RECURSION_DEPTH_LIMIT 1000
4323 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, uint rec_depth) {
4324   if (rec_depth > FIND_INST_MEM_RECURSION_DEPTH_LIMIT) {
4325     _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4326     return nullptr;
4327   }
4328   if (orig_mem == nullptr) {
4329     return orig_mem;
4330   }
4331   Compile* C = _compile;
4332   PhaseGVN* igvn = _igvn;
4333   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
4334   bool is_instance = (toop != nullptr) && toop->is_known_instance();
4335   Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
4336   Node *prev = nullptr;
4337   Node *result = orig_mem;
4338   while (prev != result) {
4339     prev = result;
4340     if (result == start_mem) {
4341       break;  // hit one of our sentinels
4342     }
4343     if (result->is_Mem()) {
4344       const Type *at = igvn->type(result->in(MemNode::Address));
4345       if (at == Type::TOP) {
4346         break; // Dead
4347       }
4348       assert (at->isa_ptr() != nullptr, "pointer type required.");
4349       int idx = C->get_alias_index(at->is_ptr());
4350       if (idx == alias_idx) {
4351         break; // Found
4352       }
4353       if (!is_instance && (at->isa_oopptr() == nullptr ||
4354                            !at->is_oopptr()->is_known_instance())) {
4355         break; // Do not skip store to general memory slice.
4356       }
4357       result = result->in(MemNode::Memory);
4358     }
4359     if (!is_instance) {
4360       continue;  // don't search further for non-instance types
4361     }
4362     // skip over a call which does not affect this memory slice
4363     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
4364       Node *proj_in = result->in(0);
4365       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
4366         break;  // hit one of our sentinels
4367       } else if (proj_in->is_Call()) {
4368         // ArrayCopy node processed here as well
4369         CallNode *call = proj_in->as_Call();
4370         if (!call->may_modify(toop, igvn)) {
4371           result = call->in(TypeFunc::Memory);
4372         }
4373       } else if (proj_in->is_Initialize()) {
4374         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
4375         // Stop if this is the initialization for the object instance which
4376         // which contains this memory slice, otherwise skip over it.
4377         if (alloc == nullptr || alloc->_idx != (uint)toop->instance_id()) {
4378           result = proj_in->in(TypeFunc::Memory);
4379         } else if (C->get_alias_index(result->adr_type()) != alias_idx) {
4380           assert(C->get_general_index(alias_idx) == C->get_alias_index(result->adr_type()), "should be projection for the same field/array element");
4381           result = get_map(result->_idx);
4382           assert(result != nullptr, "new projection should have been allocated");
4383           break;
4384         }
4385       } else if (proj_in->is_MemBar()) {
4386         // Check if there is an array copy for a clone
4387         // Step over GC barrier when ReduceInitialCardMarks is disabled
4388         BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
4389         Node* control_proj_ac = bs->step_over_gc_barrier(proj_in->in(0));
4390 
4391         if (control_proj_ac->is_Proj() && control_proj_ac->in(0)->is_ArrayCopy()) {
4392           // Stop if it is a clone
4393           ArrayCopyNode* ac = control_proj_ac->in(0)->as_ArrayCopy();
4394           if (ac->may_modify(toop, igvn)) {
4395             break;
4396           }
4397         }
4398         result = proj_in->in(TypeFunc::Memory);
4399       }
4400     } else if (result->is_MergeMem()) {
4401       MergeMemNode *mmem = result->as_MergeMem();
4402       result = step_through_mergemem(mmem, alias_idx, toop);
4403       if (result == mmem->base_memory()) {
4404         // Didn't find instance memory, search through general slice recursively.
4405         result = mmem->memory_at(C->get_general_index(alias_idx));
4406         result = find_inst_mem(result, alias_idx, orig_phis, rec_depth + 1);
4407         if (C->failing()) {
4408           return nullptr;
4409         }
4410         mmem->set_memory_at(alias_idx, result);
4411       }
4412     } else if (result->is_Phi() &&
4413                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
4414       Node *un = result->as_Phi()->unique_input(igvn);
4415       if (un != nullptr) {
4416         orig_phis.append_if_missing(result->as_Phi());
4417         result = un;
4418       } else {
4419         break;
4420       }
4421     } else if (result->is_ClearArray()) {
4422       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
4423         // Can not bypass initialization of the instance
4424         // we are looking for.
4425         break;
4426       }
4427       // Otherwise skip it (the call updated 'result' value).
4428     } else if (result->Opcode() == Op_SCMemProj) {
4429       Node* mem = result->in(0);
4430       Node* adr = nullptr;
4431       if (mem->is_LoadStore()) {
4432         adr = mem->in(MemNode::Address);
4433       } else {
4434         assert(mem->Opcode() == Op_EncodeISOArray ||
4435                mem->Opcode() == Op_StrCompressedCopy, "sanity");
4436         adr = mem->in(3); // Memory edge corresponds to destination array
4437       }
4438       const Type *at = igvn->type(adr);
4439       if (at != Type::TOP) {
4440         assert(at->isa_ptr() != nullptr, "pointer type required.");
4441         int idx = C->get_alias_index(at->is_ptr());
4442         if (idx == alias_idx) {
4443           // Assert in debug mode
4444           assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
4445           break; // In product mode return SCMemProj node
4446         }
4447       }
4448       result = mem->in(MemNode::Memory);
4449     } else if (result->Opcode() == Op_StrInflatedCopy) {
4450       Node* adr = result->in(3); // Memory edge corresponds to destination array
4451       const Type *at = igvn->type(adr);
4452       if (at != Type::TOP) {
4453         assert(at->isa_ptr() != nullptr, "pointer type required.");
4454         int idx = C->get_alias_index(at->is_ptr());
4455         if (idx == alias_idx) {
4456           // Assert in debug mode
4457           assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
4458           break; // In product mode return SCMemProj node
4459         }
4460       }
4461       result = result->in(MemNode::Memory);
4462     }
4463   }
4464   if (result->is_Phi()) {
4465     PhiNode *mphi = result->as_Phi();
4466     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
4467     const TypePtr *t = mphi->adr_type();
4468     if (!is_instance) {
4469       // Push all non-instance Phis on the orig_phis worklist to update inputs
4470       // during Phase 4 if needed.
4471       orig_phis.append_if_missing(mphi);
4472     } else if (C->get_alias_index(t) != alias_idx) {
4473       // Create a new Phi with the specified alias index type.
4474       result = split_memory_phi(mphi, alias_idx, orig_phis, rec_depth + 1);
4475     }
4476   }
4477   // the result is either MemNode, PhiNode, InitializeNode.
4478   return result;
4479 }
4480 
4481 //
4482 //  Convert the types of non-escaped object to instance types where possible,
4483 //  propagate the new type information through the graph, and update memory
4484 //  edges and MergeMem inputs to reflect the new type.
4485 //
4486 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
4487 //  The processing is done in 4 phases:
4488 //
4489 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
4490 //            types for the CheckCastPP for allocations where possible.
4491 //            Propagate the new types through users as follows:
4492 //               casts and Phi:  push users on alloc_worklist
4493 //               AddP:  cast Base and Address inputs to the instance type
4494 //                      push any AddP users on alloc_worklist and push any memnode
4495 //                      users onto memnode_worklist.
4496 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
4497 //            search the Memory chain for a store with the appropriate type
4498 //            address type.  If a Phi is found, create a new version with
4499 //            the appropriate memory slices from each of the Phi inputs.
4500 //            For stores, process the users as follows:
4501 //               MemNode:  push on memnode_worklist
4502 //               MergeMem: push on mergemem_worklist
4503 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
4504 //            moving the first node encountered of each  instance type to the
4505 //            the input corresponding to its alias index.
4506 //            appropriate memory slice.
4507 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
4508 //
4509 // In the following example, the CheckCastPP nodes are the cast of allocation
4510 // results and the allocation of node 29 is non-escaped and eligible to be an
4511 // instance type.
4512 //
4513 // We start with:
4514 //
4515 //     7 Parm #memory
4516 //    10  ConI  "12"
4517 //    19  CheckCastPP   "Foo"
4518 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4519 //    29  CheckCastPP   "Foo"
4520 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
4521 //
4522 //    40  StoreP  25   7  20   ... alias_index=4
4523 //    50  StoreP  35  40  30   ... alias_index=4
4524 //    60  StoreP  45  50  20   ... alias_index=4
4525 //    70  LoadP    _  60  30   ... alias_index=4
4526 //    80  Phi     75  50  60   Memory alias_index=4
4527 //    90  LoadP    _  80  30   ... alias_index=4
4528 //   100  LoadP    _  80  20   ... alias_index=4
4529 //
4530 //
4531 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
4532 // and creating a new alias index for node 30.  This gives:
4533 //
4534 //     7 Parm #memory
4535 //    10  ConI  "12"
4536 //    19  CheckCastPP   "Foo"
4537 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4538 //    29  CheckCastPP   "Foo"  iid=24
4539 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
4540 //
4541 //    40  StoreP  25   7  20   ... alias_index=4
4542 //    50  StoreP  35  40  30   ... alias_index=6
4543 //    60  StoreP  45  50  20   ... alias_index=4
4544 //    70  LoadP    _  60  30   ... alias_index=6
4545 //    80  Phi     75  50  60   Memory alias_index=4
4546 //    90  LoadP    _  80  30   ... alias_index=6
4547 //   100  LoadP    _  80  20   ... alias_index=4
4548 //
4549 // In phase 2, new memory inputs are computed for the loads and stores,
4550 // And a new version of the phi is created.  In phase 4, the inputs to
4551 // node 80 are updated and then the memory nodes are updated with the
4552 // values computed in phase 2.  This results in:
4553 //
4554 //     7 Parm #memory
4555 //    10  ConI  "12"
4556 //    19  CheckCastPP   "Foo"
4557 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4558 //    29  CheckCastPP   "Foo"  iid=24
4559 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
4560 //
4561 //    40  StoreP  25  7   20   ... alias_index=4
4562 //    50  StoreP  35  7   30   ... alias_index=6
4563 //    60  StoreP  45  40  20   ... alias_index=4
4564 //    70  LoadP    _  50  30   ... alias_index=6
4565 //    80  Phi     75  40  60   Memory alias_index=4
4566 //   120  Phi     75  50  50   Memory alias_index=6
4567 //    90  LoadP    _ 120  30   ... alias_index=6
4568 //   100  LoadP    _  80  20   ... alias_index=4
4569 //
4570 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist,
4571                                          GrowableArray<ArrayCopyNode*> &arraycopy_worklist,
4572                                          GrowableArray<MergeMemNode*> &mergemem_worklist,
4573                                          Unique_Node_List &reducible_merges) {
4574   DEBUG_ONLY(Unique_Node_List reduced_merges;)
4575   GrowableArray<Node *>  memnode_worklist;
4576   GrowableArray<PhiNode *>  orig_phis;
4577   PhaseIterGVN  *igvn = _igvn;
4578   uint new_index_start = (uint) _compile->num_alias_types();
4579   VectorSet visited;
4580   ideal_nodes.clear(); // Reset for use with set_map/get_map.
4581   uint unique_old = _compile->unique();
4582 
4583   //  Phase 1:  Process possible allocations from alloc_worklist.
4584   //  Create instance types for the CheckCastPP for allocations where possible.
4585   //
4586   // (Note: don't forget to change the order of the second AddP node on
4587   //  the alloc_worklist if the order of the worklist processing is changed,
4588   //  see the comment in find_second_addp().)
4589   //
4590   while (alloc_worklist.length() != 0) {
4591     Node *n = alloc_worklist.pop();
4592     uint ni = n->_idx;
4593     if (n->is_Call()) {
4594       CallNode *alloc = n->as_Call();
4595       // copy escape information to call node
4596       PointsToNode* ptn = ptnode_adr(alloc->_idx);
4597       PointsToNode::EscapeState es = ptn->escape_state();
4598       // We have an allocation or call which returns a Java object,
4599       // see if it is non-escaped.
4600       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable()) {
4601         continue;
4602       }
4603       // Find CheckCastPP for the allocate or for the return value of a call
4604       n = alloc->result_cast();
4605       if (n == nullptr) {            // No uses except Initialize node
4606         if (alloc->is_Allocate()) {
4607           // Set the scalar_replaceable flag for allocation
4608           // so it could be eliminated if it has no uses.
4609           alloc->as_Allocate()->_is_scalar_replaceable = true;
4610         }
4611         continue;
4612       }
4613       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
4614         // we could reach here for allocate case if one init is associated with many allocs.
4615         if (alloc->is_Allocate()) {
4616           alloc->as_Allocate()->_is_scalar_replaceable = false;
4617         }
4618         continue;
4619       }
4620 
4621       // The inline code for Object.clone() casts the allocation result to
4622       // java.lang.Object and then to the actual type of the allocated
4623       // object. Detect this case and use the second cast.
4624       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
4625       // the allocation result is cast to java.lang.Object and then
4626       // to the actual Array type.
4627       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
4628           && (alloc->is_AllocateArray() ||
4629               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeInstKlassPtr::OBJECT)) {
4630         Node *cast2 = nullptr;
4631         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4632           Node *use = n->fast_out(i);
4633           if (use->is_CheckCastPP()) {
4634             cast2 = use;
4635             break;
4636           }
4637         }
4638         if (cast2 != nullptr) {
4639           n = cast2;
4640         } else {
4641           // Non-scalar replaceable if the allocation type is unknown statically
4642           // (reflection allocation), the object can't be restored during
4643           // deoptimization without precise type.
4644           continue;
4645         }
4646       }
4647 
4648       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
4649       if (t == nullptr) {
4650         continue;  // not a TypeOopPtr
4651       }
4652       if (!t->klass_is_exact()) {
4653         continue; // not an unique type
4654       }
4655       if (alloc->is_Allocate()) {
4656         // Set the scalar_replaceable flag for allocation
4657         // so it could be eliminated.
4658         alloc->as_Allocate()->_is_scalar_replaceable = true;
4659       }
4660       set_escape_state(ptnode_adr(n->_idx), es NOT_PRODUCT(COMMA trace_propagate_message(ptn))); // CheckCastPP escape state
4661       // in order for an object to be scalar-replaceable, it must be:
4662       //   - a direct allocation (not a call returning an object)
4663       //   - non-escaping
4664       //   - eligible to be a unique type
4665       //   - not determined to be ineligible by escape analysis
4666       set_map(alloc, n);
4667       set_map(n, alloc);
4668       const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
4669       igvn->hash_delete(n);
4670       igvn->set_type(n,  tinst);
4671       n->raise_bottom_type(tinst);
4672       igvn->hash_insert(n);
4673       record_for_optimizer(n);
4674       // Allocate an alias index for the header fields. Accesses to
4675       // the header emitted during macro expansion wouldn't have
4676       // correct memory state otherwise.
4677       _compile->get_alias_index(tinst->add_offset(oopDesc::mark_offset_in_bytes()));
4678       _compile->get_alias_index(tinst->add_offset(oopDesc::klass_offset_in_bytes()));
4679       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
4680         // Add a new NarrowMem projection for each existing NarrowMem projection with new adr type
4681         InitializeNode* init = alloc->as_Allocate()->initialization();
4682         assert(init != nullptr, "can't find Initialization node for this Allocate node");
4683         auto process_narrow_proj = [&](NarrowMemProjNode* proj) {
4684           const TypePtr* adr_type = proj->adr_type();
4685           const TypePtr* new_adr_type = tinst->with_offset(adr_type->offset());
4686           if (adr_type->isa_aryptr()) {
4687             // In the case of a flat inline type array, each field has its own slice so we need a
4688             // NarrowMemProj for each field of the flat array elements
4689             new_adr_type = new_adr_type->is_aryptr()->with_field_offset(adr_type->is_aryptr()->field_offset().get());
4690           }
4691           if (adr_type != new_adr_type && !init->already_has_narrow_mem_proj_with_adr_type(new_adr_type)) {
4692             DEBUG_ONLY( uint alias_idx = _compile->get_alias_index(new_adr_type); )
4693             assert(_compile->get_general_index(alias_idx) == _compile->get_alias_index(adr_type), "new adr type should be narrowed down from existing adr type");
4694             NarrowMemProjNode* new_proj = new NarrowMemProjNode(init, new_adr_type);
4695             igvn->set_type(new_proj, new_proj->bottom_type());
4696             record_for_optimizer(new_proj);
4697             set_map(proj, new_proj); // record it so ConnectionGraph::find_inst_mem() can find it
4698           }
4699         };
4700         init->for_each_narrow_mem_proj_with_new_uses(process_narrow_proj);
4701 
4702         // First, put on the worklist all Field edges from Connection Graph
4703         // which is more accurate than putting immediate users from Ideal Graph.
4704         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
4705           PointsToNode* tgt = e.get();
4706           if (tgt->is_Arraycopy()) {
4707             continue;
4708           }
4709           Node* use = tgt->ideal_node();
4710           assert(tgt->is_Field() && use->is_AddP(),
4711                  "only AddP nodes are Field edges in CG");
4712           if (use->outcnt() > 0) { // Don't process dead nodes
4713             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
4714             if (addp2 != nullptr) {
4715               assert(alloc->is_AllocateArray(),"array allocation was expected");
4716               alloc_worklist.append_if_missing(addp2);
4717             }
4718             alloc_worklist.append_if_missing(use);
4719           }
4720         }
4721 
4722         // An allocation may have an Initialize which has raw stores. Scan
4723         // the users of the raw allocation result and push AddP users
4724         // on alloc_worklist.
4725         Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
4726         assert (raw_result != nullptr, "must have an allocation result");
4727         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
4728           Node *use = raw_result->fast_out(i);
4729           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
4730             Node* addp2 = find_second_addp(use, raw_result);
4731             if (addp2 != nullptr) {
4732               assert(alloc->is_AllocateArray(),"array allocation was expected");
4733               alloc_worklist.append_if_missing(addp2);
4734             }
4735             alloc_worklist.append_if_missing(use);
4736           } else if (use->is_MemBar()) {
4737             memnode_worklist.append_if_missing(use);
4738           }
4739         }
4740       }
4741     } else if (n->is_AddP()) {
4742       if (has_reducible_merge_base(n->as_AddP(), reducible_merges)) {
4743         // This AddP will go away when we reduce the Phi
4744         continue;
4745       }
4746       Node* addp_base = get_addp_base(n);
4747       JavaObjectNode* jobj = unique_java_object(addp_base);
4748       if (jobj == nullptr || jobj == phantom_obj) {
4749 #ifdef ASSERT
4750         ptnode_adr(get_addp_base(n)->_idx)->dump();
4751         ptnode_adr(n->_idx)->dump();
4752         assert(jobj != nullptr && jobj != phantom_obj, "escaped allocation");
4753 #endif
4754         _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4755         return;
4756       }
4757       Node *base = get_map(jobj->idx());  // CheckCastPP node
4758       if (!split_AddP(n, base)) continue; // wrong type from dead path
4759     } else if (n->is_Phi() ||
4760                n->is_CheckCastPP() ||
4761                n->is_EncodeP() ||
4762                n->is_DecodeN() ||
4763                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
4764       if (visited.test_set(n->_idx)) {
4765         assert(n->is_Phi(), "loops only through Phi's");
4766         continue;  // already processed
4767       }
4768       // Reducible Phi's will be removed from the graph after split_unique_types
4769       // finishes. For now we just try to split out the SR inputs of the merge.
4770       Node* parent = n->in(1);
4771       if (reducible_merges.member(n)) {
4772         reduce_phi(n->as_Phi(), alloc_worklist);
4773 #ifdef ASSERT
4774         if (VerifyReduceAllocationMerges) {
4775           reduced_merges.push(n);
4776         }
4777 #endif
4778         continue;
4779       } else if (reducible_merges.member(parent)) {
4780         // 'n' is an user of a reducible merge (a Phi). It will be simplified as
4781         // part of reduce_merge.
4782         continue;
4783       }
4784       JavaObjectNode* jobj = unique_java_object(n);
4785       if (jobj == nullptr || jobj == phantom_obj) {
4786 #ifdef ASSERT
4787         ptnode_adr(n->_idx)->dump();
4788         assert(jobj != nullptr && jobj != phantom_obj, "escaped allocation");
4789 #endif
4790         _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4791         return;
4792       } else {
4793         Node *val = get_map(jobj->idx());   // CheckCastPP node
4794         TypeNode *tn = n->as_Type();
4795         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
4796         assert(tinst != nullptr && tinst->is_known_instance() &&
4797                tinst->instance_id() == jobj->idx() , "instance type expected.");
4798 
4799         const Type *tn_type = igvn->type(tn);
4800         const TypeOopPtr *tn_t;
4801         if (tn_type->isa_narrowoop()) {
4802           tn_t = tn_type->make_ptr()->isa_oopptr();
4803         } else {
4804           tn_t = tn_type->isa_oopptr();
4805         }
4806         if (tn_t != nullptr && tinst->maybe_java_subtype_of(tn_t)) {
4807           if (tn_t->isa_aryptr()) {
4808             // Keep array properties (not flat/null-free)
4809             tinst = tinst->is_aryptr()->update_properties(tn_t->is_aryptr());
4810             if (tinst == nullptr) {
4811               continue; // Skip dead path with inconsistent properties
4812             }
4813           }
4814           if (tn_type->isa_narrowoop()) {
4815             tn_type = tinst->make_narrowoop();
4816           } else {
4817             tn_type = tinst;
4818           }
4819           igvn->hash_delete(tn);
4820           igvn->set_type(tn, tn_type);
4821           tn->set_type(tn_type);
4822           igvn->hash_insert(tn);
4823           record_for_optimizer(n);
4824         } else {
4825           assert(tn_type == TypePtr::NULL_PTR ||
4826                  (tn_t != nullptr && !tinst->maybe_java_subtype_of(tn_t)),
4827                  "unexpected type");
4828           continue; // Skip dead path with different type
4829         }
4830       }
4831     } else {
4832       DEBUG_ONLY(n->dump();)
4833       assert(false, "EA: unexpected node");
4834       continue;
4835     }
4836     // push allocation's users on appropriate worklist
4837     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4838       Node *use = n->fast_out(i);
4839       if (use->is_Mem() && use->in(MemNode::Address) == n) {
4840         // Load/store to instance's field
4841         memnode_worklist.append_if_missing(use);
4842       } else if (use->is_MemBar()) {
4843         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
4844           memnode_worklist.append_if_missing(use);
4845         }
4846       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
4847         Node* addp2 = find_second_addp(use, n);
4848         if (addp2 != nullptr) {
4849           alloc_worklist.append_if_missing(addp2);
4850         }
4851         alloc_worklist.append_if_missing(use);
4852       } else if (use->is_Phi() ||
4853                  use->is_CheckCastPP() ||
4854                  use->is_EncodeNarrowPtr() ||
4855                  use->is_DecodeNarrowPtr() ||
4856                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
4857         alloc_worklist.append_if_missing(use);
4858 #ifdef ASSERT
4859       } else if (use->is_Mem()) {
4860         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
4861       } else if (use->is_MergeMem()) {
4862         assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
4863       } else if (use->is_SafePoint()) {
4864         // Look for MergeMem nodes for calls which reference unique allocation
4865         // (through CheckCastPP nodes) even for debug info.
4866         Node* m = use->in(TypeFunc::Memory);
4867         if (m->is_MergeMem()) {
4868           assert(mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
4869         }
4870       } else if (use->Opcode() == Op_EncodeISOArray) {
4871         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
4872           // EncodeISOArray overwrites destination array
4873           memnode_worklist.append_if_missing(use);
4874         }
4875       } else if (use->Opcode() == Op_Return) {
4876         // Allocation is referenced by field of returned inline type
4877         assert(_compile->tf()->returns_inline_type_as_fields(), "EA: unexpected reference by ReturnNode");
4878       } else {
4879         uint op = use->Opcode();
4880         if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
4881             (use->in(MemNode::Memory) == n)) {
4882           // They overwrite memory edge corresponding to destination array,
4883           memnode_worklist.append_if_missing(use);
4884         } else if (!(op == Op_CmpP || op == Op_Conv2B ||
4885               op == Op_CastP2X ||
4886               op == Op_FastLock || op == Op_AryEq ||
4887               op == Op_StrComp || op == Op_CountPositives ||
4888               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
4889               op == Op_StrEquals || op == Op_VectorizedHashCode ||
4890               op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
4891               op == Op_SubTypeCheck || op == Op_InlineType || op == Op_FlatArrayCheck ||
4892               op == Op_ReinterpretS2HF ||
4893               BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
4894           n->dump();
4895           use->dump();
4896           assert(false, "EA: missing allocation reference path");
4897         }
4898 #endif
4899       }
4900     }
4901 
4902   }
4903 
4904 #ifdef ASSERT
4905   if (VerifyReduceAllocationMerges) {
4906     for (uint i = 0; i < reducible_merges.size(); i++) {
4907       Node* phi = reducible_merges.at(i);
4908 
4909       if (!reduced_merges.member(phi)) {
4910         phi->dump(2);
4911         phi->dump(-2);
4912         assert(false, "This reducible merge wasn't reduced.");
4913       }
4914 
4915       // At this point reducible Phis shouldn't have AddP users anymore; only SafePoints or Casts.
4916       for (DUIterator_Fast jmax, j = phi->fast_outs(jmax); j < jmax; j++) {
4917         Node* use = phi->fast_out(j);
4918         if (!use->is_SafePoint() && !use->is_CastPP()) {
4919           phi->dump(2);
4920           phi->dump(-2);
4921           assert(false, "Unexpected user of reducible Phi -> %d:%s:%d", use->_idx, use->Name(), use->outcnt());
4922         }
4923       }
4924     }
4925   }
4926 #endif
4927 
4928   // Go over all ArrayCopy nodes and if one of the inputs has a unique
4929   // type, record it in the ArrayCopy node so we know what memory this
4930   // node uses/modified.
4931   for (int next = 0; next < arraycopy_worklist.length(); next++) {
4932     ArrayCopyNode* ac = arraycopy_worklist.at(next);
4933     Node* dest = ac->in(ArrayCopyNode::Dest);
4934     if (dest->is_AddP()) {
4935       dest = get_addp_base(dest);
4936     }
4937     JavaObjectNode* jobj = unique_java_object(dest);
4938     if (jobj != nullptr) {
4939       Node *base = get_map(jobj->idx());
4940       if (base != nullptr) {
4941         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
4942         ac->_dest_type = base_t;
4943       }
4944     }
4945     Node* src = ac->in(ArrayCopyNode::Src);
4946     if (src->is_AddP()) {
4947       src = get_addp_base(src);
4948     }
4949     jobj = unique_java_object(src);
4950     if (jobj != nullptr) {
4951       Node* base = get_map(jobj->idx());
4952       if (base != nullptr) {
4953         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
4954         ac->_src_type = base_t;
4955       }
4956     }
4957   }
4958 
4959   // New alias types were created in split_AddP().
4960   uint new_index_end = (uint) _compile->num_alias_types();
4961 
4962   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_1, 5);
4963 
4964   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
4965   //            compute new values for Memory inputs  (the Memory inputs are not
4966   //            actually updated until phase 4.)
4967   if (memnode_worklist.length() == 0)
4968     return;  // nothing to do
4969   while (memnode_worklist.length() != 0) {
4970     Node *n = memnode_worklist.pop();
4971     if (visited.test_set(n->_idx)) {
4972       continue;
4973     }
4974     if (n->is_Phi() || n->is_ClearArray()) {
4975       // we don't need to do anything, but the users must be pushed
4976     } else if (n->is_MemBar()) { // MemBar nodes
4977       if (!n->is_Initialize()) { // memory projections for Initialize pushed below (so we get to all their uses)
4978         // we don't need to do anything, but the users must be pushed
4979         n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
4980         if (n == nullptr) {
4981           continue;
4982         }
4983       }
4984     } else if (n->is_CallLeaf()) {
4985       // Runtime calls with narrow memory input (no MergeMem node)
4986       // get the memory projection
4987       n = n->as_Call()->proj_out_or_null(TypeFunc::Memory);
4988       if (n == nullptr) {
4989         continue;
4990       }
4991     } else if (n->Opcode() == Op_StrInflatedCopy) {
4992       // Check direct uses of StrInflatedCopy.
4993       // It is memory type Node - no special SCMemProj node.
4994     } else if (n->Opcode() == Op_StrCompressedCopy ||
4995                n->Opcode() == Op_EncodeISOArray) {
4996       // get the memory projection
4997       n = n->find_out_with(Op_SCMemProj);
4998       assert(n != nullptr && n->Opcode() == Op_SCMemProj, "memory projection required");
4999     } else if (n->is_CallLeaf() && n->as_CallLeaf()->_name != nullptr &&
5000                strcmp(n->as_CallLeaf()->_name, "store_unknown_inline") == 0) {
5001       n = n->as_CallLeaf()->proj_out(TypeFunc::Memory);
5002     } else if (n->is_Proj()) {
5003       assert(n->in(0)->is_Initialize(), "we only push memory projections for Initialize");
5004     } else {
5005 #ifdef ASSERT
5006       if (!n->is_Mem()) {
5007         n->dump();
5008       }
5009       assert(n->is_Mem(), "memory node required.");
5010 #endif
5011       Node *addr = n->in(MemNode::Address);
5012       const Type *addr_t = igvn->type(addr);
5013       if (addr_t == Type::TOP) {
5014         continue;
5015       }
5016       assert (addr_t->isa_ptr() != nullptr, "pointer type required.");
5017       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
5018       assert ((uint)alias_idx < new_index_end, "wrong alias index");
5019       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
5020       if (_compile->failing()) {
5021         return;
5022       }
5023       if (mem != n->in(MemNode::Memory)) {
5024         // We delay the memory edge update since we need old one in
5025         // MergeMem code below when instances memory slices are separated.
5026         set_map(n, mem);
5027       }
5028       if (n->is_Load()) {
5029         continue;  // don't push users
5030       } else if (n->is_LoadStore()) {
5031         // get the memory projection
5032         n = n->find_out_with(Op_SCMemProj);
5033         assert(n != nullptr && n->Opcode() == Op_SCMemProj, "memory projection required");
5034       }
5035     }
5036     // push user on appropriate worklist
5037     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5038       Node *use = n->fast_out(i);
5039       if (use->is_Phi() || use->is_ClearArray()) {
5040         memnode_worklist.append_if_missing(use);
5041       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
5042         memnode_worklist.append_if_missing(use);
5043       } else if (use->is_MemBar() || use->is_CallLeaf()) {
5044         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
5045           memnode_worklist.append_if_missing(use);
5046         }
5047       } else if (use->is_Proj()) {
5048         assert(n->is_Initialize(), "We only push projections of Initialize");
5049         if (use->as_Proj()->_con == TypeFunc::Memory) { // Ignore precedent edge
5050           memnode_worklist.append_if_missing(use);
5051         }
5052 #ifdef ASSERT
5053       } else if (use->is_Mem()) {
5054         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
5055       } else if (use->is_MergeMem()) {
5056         assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
5057       } else if (use->Opcode() == Op_EncodeISOArray) {
5058         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
5059           // EncodeISOArray overwrites destination array
5060           memnode_worklist.append_if_missing(use);
5061         }
5062       } else if (use->is_CallLeaf() && use->as_CallLeaf()->_name != nullptr &&
5063                  strcmp(use->as_CallLeaf()->_name, "store_unknown_inline") == 0) {
5064         // store_unknown_inline overwrites destination array
5065         memnode_worklist.append_if_missing(use);
5066       } else {
5067         uint op = use->Opcode();
5068         if ((use->in(MemNode::Memory) == n) &&
5069             (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
5070           // They overwrite memory edge corresponding to destination array,
5071           memnode_worklist.append_if_missing(use);
5072         } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
5073               op == Op_AryEq || op == Op_StrComp || op == Op_CountPositives ||
5074               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy || op == Op_VectorizedHashCode ||
5075               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar || op == Op_FlatArrayCheck)) {
5076           n->dump();
5077           use->dump();
5078           assert(false, "EA: missing memory path");
5079         }
5080 #endif
5081       }
5082     }
5083   }
5084 
5085   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
5086   //            Walk each memory slice moving the first node encountered of each
5087   //            instance type to the input corresponding to its alias index.
5088   uint length = mergemem_worklist.length();
5089   for( uint next = 0; next < length; ++next ) {
5090     MergeMemNode* nmm = mergemem_worklist.at(next);
5091     assert(!visited.test_set(nmm->_idx), "should not be visited before");
5092     // Note: we don't want to use MergeMemStream here because we only want to
5093     // scan inputs which exist at the start, not ones we add during processing.
5094     // Note 2: MergeMem may already contains instance memory slices added
5095     // during find_inst_mem() call when memory nodes were processed above.
5096     igvn->hash_delete(nmm);
5097     uint nslices = MIN2(nmm->req(), new_index_start);
5098     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
5099       Node* mem = nmm->in(i);
5100       Node* cur = nullptr;
5101       if (mem == nullptr || mem->is_top()) {
5102         continue;
5103       }
5104       // First, update mergemem by moving memory nodes to corresponding slices
5105       // if their type became more precise since this mergemem was created.
5106       while (mem->is_Mem()) {
5107         const Type* at = igvn->type(mem->in(MemNode::Address));
5108         if (at != Type::TOP) {
5109           assert (at->isa_ptr() != nullptr, "pointer type required.");
5110           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
5111           if (idx == i) {
5112             if (cur == nullptr) {
5113               cur = mem;
5114             }
5115           } else {
5116             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
5117               nmm->set_memory_at(idx, mem);
5118             }
5119           }
5120         }
5121         mem = mem->in(MemNode::Memory);
5122       }
5123       nmm->set_memory_at(i, (cur != nullptr) ? cur : mem);
5124       // Find any instance of the current type if we haven't encountered
5125       // already a memory slice of the instance along the memory chain.
5126       for (uint ni = new_index_start; ni < new_index_end; ni++) {
5127         if((uint)_compile->get_general_index(ni) == i) {
5128           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
5129           if (nmm->is_empty_memory(m)) {
5130             Node* result = find_inst_mem(mem, ni, orig_phis);
5131             if (_compile->failing()) {
5132               return;
5133             }
5134             nmm->set_memory_at(ni, result);
5135           }
5136         }
5137       }
5138     }
5139     // Find the rest of instances values
5140     for (uint ni = new_index_start; ni < new_index_end; ni++) {
5141       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
5142       Node* result = step_through_mergemem(nmm, ni, tinst);
5143       if (result == nmm->base_memory()) {
5144         // Didn't find instance memory, search through general slice recursively.
5145         result = nmm->memory_at(_compile->get_general_index(ni));
5146         result = find_inst_mem(result, ni, orig_phis);
5147         if (_compile->failing()) {
5148           return;
5149         }
5150         nmm->set_memory_at(ni, result);
5151       }
5152     }
5153 
5154     // If we have crossed the 3/4 point of max node limit it's too risky
5155     // to continue with EA/SR because we might hit the max node limit.
5156     if (_compile->live_nodes() >= _compile->max_node_limit() * 0.75) {
5157       if (_compile->do_reduce_allocation_merges()) {
5158         _compile->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
5159       } else if (_invocation > 0) {
5160         _compile->record_failure(C2Compiler::retry_no_iterative_escape_analysis());
5161       } else {
5162         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
5163       }
5164       return;
5165     }
5166 
5167     igvn->hash_insert(nmm);
5168     record_for_optimizer(nmm);
5169   }
5170 
5171   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_3, 5);
5172 
5173   //  Phase 4:  Update the inputs of non-instance memory Phis and
5174   //            the Memory input of memnodes
5175   // First update the inputs of any non-instance Phi's from
5176   // which we split out an instance Phi.  Note we don't have
5177   // to recursively process Phi's encountered on the input memory
5178   // chains as is done in split_memory_phi() since they will
5179   // also be processed here.
5180   for (int j = 0; j < orig_phis.length(); j++) {
5181     PhiNode *phi = orig_phis.at(j);
5182     int alias_idx = _compile->get_alias_index(phi->adr_type());
5183     igvn->hash_delete(phi);
5184     for (uint i = 1; i < phi->req(); i++) {
5185       Node *mem = phi->in(i);
5186       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
5187       if (_compile->failing()) {
5188         return;
5189       }
5190       if (mem != new_mem) {
5191         phi->set_req(i, new_mem);
5192       }
5193     }
5194     igvn->hash_insert(phi);
5195     record_for_optimizer(phi);
5196   }
5197 
5198   // Update the memory inputs of MemNodes with the value we computed
5199   // in Phase 2 and move stores memory users to corresponding memory slices.
5200   // Disable memory split verification code until the fix for 6984348.
5201   // Currently it produces false negative results since it does not cover all cases.
5202 #if 0 // ifdef ASSERT
5203   visited.Reset();
5204   Node_Stack old_mems(arena, _compile->unique() >> 2);
5205 #endif
5206   for (uint i = 0; i < ideal_nodes.size(); i++) {
5207     Node*    n = ideal_nodes.at(i);
5208     Node* nmem = get_map(n->_idx);
5209     assert(nmem != nullptr, "sanity");
5210     if (n->is_Mem()) {
5211 #if 0 // ifdef ASSERT
5212       Node* old_mem = n->in(MemNode::Memory);
5213       if (!visited.test_set(old_mem->_idx)) {
5214         old_mems.push(old_mem, old_mem->outcnt());
5215       }
5216 #endif
5217       assert(n->in(MemNode::Memory) != nmem, "sanity");
5218       if (!n->is_Load()) {
5219         // Move memory users of a store first.
5220         move_inst_mem(n, orig_phis);
5221       }
5222       // Now update memory input
5223       igvn->hash_delete(n);
5224       n->set_req(MemNode::Memory, nmem);
5225       igvn->hash_insert(n);
5226       record_for_optimizer(n);
5227     } else {
5228       assert(n->is_Allocate() || n->is_CheckCastPP() ||
5229              n->is_AddP() || n->is_Phi() || n->is_NarrowMemProj(), "unknown node used for set_map()");
5230     }
5231   }
5232 #if 0 // ifdef ASSERT
5233   // Verify that memory was split correctly
5234   while (old_mems.is_nonempty()) {
5235     Node* old_mem = old_mems.node();
5236     uint  old_cnt = old_mems.index();
5237     old_mems.pop();
5238     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
5239   }
5240 #endif
5241   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_4, 5);
5242 }
5243 
5244 #ifndef PRODUCT
5245 int ConnectionGraph::_no_escape_counter = 0;
5246 int ConnectionGraph::_arg_escape_counter = 0;
5247 int ConnectionGraph::_global_escape_counter = 0;
5248 
5249 static const char *node_type_names[] = {
5250   "UnknownType",
5251   "JavaObject",
5252   "LocalVar",
5253   "Field",
5254   "Arraycopy"
5255 };
5256 
5257 static const char *esc_names[] = {
5258   "UnknownEscape",
5259   "NoEscape",
5260   "ArgEscape",
5261   "GlobalEscape"
5262 };
5263 
5264 const char* PointsToNode::esc_name() const {
5265   return esc_names[(int)escape_state()];
5266 }
5267 
5268 void PointsToNode::dump_header(bool print_state, outputStream* out) const {
5269   NodeType nt = node_type();
5270   out->print("%s(%d) ", node_type_names[(int) nt], _pidx);
5271   if (print_state) {
5272     EscapeState es = escape_state();
5273     EscapeState fields_es = fields_escape_state();
5274     out->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
5275     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable()) {
5276       out->print("NSR ");
5277     }
5278   }
5279 }
5280 
5281 void PointsToNode::dump(bool print_state, outputStream* out, bool newline) const {
5282   dump_header(print_state, out);
5283   if (is_Field()) {
5284     FieldNode* f = (FieldNode*)this;
5285     if (f->is_oop()) {
5286       out->print("oop ");
5287     }
5288     if (f->offset() > 0) {
5289       out->print("+%d ", f->offset());
5290     }
5291     out->print("(");
5292     for (BaseIterator i(f); i.has_next(); i.next()) {
5293       PointsToNode* b = i.get();
5294       out->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
5295     }
5296     out->print(" )");
5297   }
5298   out->print("[");
5299   for (EdgeIterator i(this); i.has_next(); i.next()) {
5300     PointsToNode* e = i.get();
5301     out->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
5302   }
5303   out->print(" [");
5304   for (UseIterator i(this); i.has_next(); i.next()) {
5305     PointsToNode* u = i.get();
5306     bool is_base = false;
5307     if (PointsToNode::is_base_use(u)) {
5308       is_base = true;
5309       u = PointsToNode::get_use_node(u)->as_Field();
5310     }
5311     out->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
5312   }
5313   out->print(" ]]  ");
5314   if (_node == nullptr) {
5315     out->print("<null>%s", newline ? "\n" : "");
5316   } else {
5317     _node->dump(newline ? "\n" : "", false, out);
5318   }
5319 }
5320 
5321 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
5322   bool first = true;
5323   int ptnodes_length = ptnodes_worklist.length();
5324   for (int i = 0; i < ptnodes_length; i++) {
5325     PointsToNode *ptn = ptnodes_worklist.at(i);
5326     if (ptn == nullptr || !ptn->is_JavaObject()) {
5327       continue;
5328     }
5329     PointsToNode::EscapeState es = ptn->escape_state();
5330     if ((es != PointsToNode::NoEscape) && !Verbose) {
5331       continue;
5332     }
5333     Node* n = ptn->ideal_node();
5334     if (n->is_Allocate() || (n->is_CallStaticJava() &&
5335                              n->as_CallStaticJava()->is_boxing_method())) {
5336       if (first) {
5337         tty->cr();
5338         tty->print("======== Connection graph for ");
5339         _compile->method()->print_short_name();
5340         tty->cr();
5341         tty->print_cr("invocation #%d: %d iterations and %f sec to build connection graph with %d nodes and worklist size %d",
5342                       _invocation, _build_iterations, _build_time, nodes_size(), ptnodes_worklist.length());
5343         tty->cr();
5344         first = false;
5345       }
5346       ptn->dump();
5347       // Print all locals and fields which reference this allocation
5348       for (UseIterator j(ptn); j.has_next(); j.next()) {
5349         PointsToNode* use = j.get();
5350         if (use->is_LocalVar()) {
5351           use->dump(Verbose);
5352         } else if (Verbose) {
5353           use->dump();
5354         }
5355       }
5356       tty->cr();
5357     }
5358   }
5359 }
5360 
5361 void ConnectionGraph::print_statistics() {
5362   tty->print_cr("No escape = %d, Arg escape = %d, Global escape = %d", AtomicAccess::load(&_no_escape_counter), AtomicAccess::load(&_arg_escape_counter), AtomicAccess::load(&_global_escape_counter));
5363 }
5364 
5365 void ConnectionGraph::escape_state_statistics(GrowableArray<JavaObjectNode*>& java_objects_worklist) {
5366   if (!PrintOptoStatistics || (_invocation > 0)) { // Collect data only for the first invocation
5367     return;
5368   }
5369   for (int next = 0; next < java_objects_worklist.length(); ++next) {
5370     JavaObjectNode* ptn = java_objects_worklist.at(next);
5371     if (ptn->ideal_node()->is_Allocate()) {
5372       if (ptn->escape_state() == PointsToNode::NoEscape) {
5373         AtomicAccess::inc(&ConnectionGraph::_no_escape_counter);
5374       } else if (ptn->escape_state() == PointsToNode::ArgEscape) {
5375         AtomicAccess::inc(&ConnectionGraph::_arg_escape_counter);
5376       } else if (ptn->escape_state() == PointsToNode::GlobalEscape) {
5377         AtomicAccess::inc(&ConnectionGraph::_global_escape_counter);
5378       } else {
5379         assert(false, "Unexpected Escape State");
5380       }
5381     }
5382   }
5383 }
5384 
5385 void ConnectionGraph::trace_es_update_helper(PointsToNode* ptn, PointsToNode::EscapeState es, bool fields, const char* reason) const {
5386   if (_compile->directive()->TraceEscapeAnalysisOption) {
5387     assert(ptn != nullptr, "should not be null");
5388     assert(reason != nullptr, "should not be null");
5389     ptn->dump_header(true);
5390     PointsToNode::EscapeState new_es = fields ? ptn->escape_state() : es;
5391     PointsToNode::EscapeState new_fields_es = fields ? es : ptn->fields_escape_state();
5392     tty->print_cr("-> %s(%s) %s", esc_names[(int)new_es], esc_names[(int)new_fields_es], reason);
5393   }
5394 }
5395 
5396 const char* ConnectionGraph::trace_propagate_message(PointsToNode* from) const {
5397   if (_compile->directive()->TraceEscapeAnalysisOption) {
5398     stringStream ss;
5399     ss.print("propagated from: ");
5400     from->dump(true, &ss, false);
5401     return ss.as_string();
5402   } else {
5403     return nullptr;
5404   }
5405 }
5406 
5407 const char* ConnectionGraph::trace_arg_escape_message(CallNode* call) const {
5408   if (_compile->directive()->TraceEscapeAnalysisOption) {
5409     stringStream ss;
5410     ss.print("escapes as arg to:");
5411     call->dump("", false, &ss);
5412     return ss.as_string();
5413   } else {
5414     return nullptr;
5415   }
5416 }
5417 
5418 const char* ConnectionGraph::trace_merged_message(PointsToNode* other) const {
5419   if (_compile->directive()->TraceEscapeAnalysisOption) {
5420     stringStream ss;
5421     ss.print("is merged with other object: ");
5422     other->dump_header(true, &ss);
5423     return ss.as_string();
5424   } else {
5425     return nullptr;
5426   }
5427 }
5428 
5429 #endif
5430 
5431 void ConnectionGraph::record_for_optimizer(Node *n) {
5432   _igvn->_worklist.push(n);
5433   _igvn->add_users_to_worklist(n);
5434 }