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 = AddPNode::make_with_base(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(PhiNode* phi, 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 == phi || right == phi) &&
 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* phi, 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 == phi) {
 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   assert((n->is_Phi() && nesting == 0) || (n->is_CastPP() && nesting > 0),
 566          "invalid node class %s and nesting %d combination", n->Name(), nesting);
 567   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 568     Node* use = n->fast_out(i);
 569 
 570     if (use->is_SafePoint()) {
 571       if (use->is_Call() && use->as_Call()->has_non_debug_use(n)) {
 572         NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. Call has non_debug_use().", n->_idx, _invocation);)
 573         return false;
 574       } else if (has_been_reduced(n->is_Phi() ? n->as_Phi() : n->as_CastPP()->in(1)->as_Phi(), use->as_SafePoint())) {
 575         NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. It has already been reduced.", n->_idx, _invocation);)
 576         return false;
 577       }
 578     } else if (use->is_AddP()) {
 579       Node* addp = use;
 580       for (DUIterator_Fast jmax, j = addp->fast_outs(jmax); j < jmax; j++) {
 581         Node* use_use = addp->fast_out(j);
 582         const Type* load_type = _igvn->type(use_use);
 583 
 584         if (!use_use->is_Load() || !use_use->as_Load()->can_split_through_phi_base(_igvn)) {
 585           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());)
 586           return false;
 587         } else if (load_type->isa_narrowklass() || load_type->isa_klassptr()) {
 588           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());)
 589           return false;
 590         }
 591       }
 592     } else if (nesting > 0) {
 593       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);)
 594       return false;
 595     } else if (use->is_CastPP()) {
 596       const Type* cast_t = _igvn->type(use);
 597       if (cast_t == nullptr || cast_t->make_ptr()->isa_instptr() == nullptr) {
 598 #ifndef PRODUCT
 599         if (TraceReduceAllocationMerges) {
 600           tty->print_cr("Can NOT reduce Phi %d on invocation %d. CastPP is not to an instance.", n->_idx, _invocation);
 601           use->dump();
 602         }
 603 #endif
 604         return false;
 605       }
 606 
 607       if (!can_reduce_phi_at_castpp(n->as_Phi(), use->as_CastPP())) {
 608 #ifdef ASSERT
 609         if (TraceReduceAllocationMerges) {
 610           tty->print_cr("Can NOT reduce Phi %d on invocation %d. CastPP %d doesn't have simple control.", n->_idx, _invocation, use->_idx);
 611           n->dump(5);
 612         }
 613 #endif
 614         return false;
 615       }
 616 
 617       if (!can_reduce_check_users(use, nesting+1)) {
 618         return false;
 619       }
 620     } else if (use->Opcode() == Op_CmpP || use->Opcode() == Op_CmpN) {
 621       if (!can_reduce_cmp(n->as_Phi(), use)) {
 622         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);)
 623         return false;
 624       }
 625     } else {
 626       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());)
 627       return false;
 628     }
 629   }
 630 
 631   return true;
 632 }
 633 
 634 // Returns true if the CastPP's control is simple enough to reduce the Phi:
 635 //  1) no control,
 636 //  2) control is the same Region as the Phi, or
 637 //  3) an IfTrue/IfFalse coming from an CmpP/N between the phi and a constant.
 638 bool ConnectionGraph::can_reduce_phi_at_castpp(PhiNode* phi, CastPPNode* castpp) const {
 639   if (castpp->in(0) == nullptr || castpp->in(0) == phi->in(0)) {
 640     return true;
 641   }
 642   // If it's not a trivial control then we check if we can reduce the
 643   // CmpP/N used by the If controlling the cast.
 644   if (!(castpp->in(0)->is_IfTrue() || castpp->in(0)->is_IfFalse())) {
 645     return false; // Only If control is considered
 646   } else {
 647     Node* iff = castpp->in(0)->in(0);
 648     // We may have an OpaqueConstantBool node between If and Bool nodes. But we could also have a sub class of IfNode,
 649     // for example, an OuterStripMinedLoopEnd or a Parse Predicate. Bail out in all these cases.
 650     if (iff->Opcode() == Op_If && iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
 651       Node* iff_cmp  = iff->in(1)->in(1);
 652       int opc = iff_cmp->Opcode();
 653       if ((opc == Op_CmpP || opc == Op_CmpN) && can_reduce_cmp(phi, iff_cmp)) {
 654         return true;
 655       }
 656     }
 657   }
 658   return false;
 659 }
 660 
 661 // Returns true if: 1) It's profitable to reduce the merge, and 2) The Phi is
 662 // only used in some certain code shapes. Check comments in
 663 // 'can_reduce_phi_inputs' and 'can_reduce_phi_users' for more
 664 // details.
 665 bool ConnectionGraph::can_reduce_phi(PhiNode* ophi) const {
 666   // If there was an error attempting to reduce allocation merges for this
 667   // method we might have disabled the compilation and be retrying with RAM
 668   // disabled.
 669   if (!_compile->do_reduce_allocation_merges() || ophi->region()->Opcode() != Op_Region) {
 670     return false;
 671   }
 672 
 673   const Type* phi_t = _igvn->type(ophi);
 674   if (phi_t == nullptr ||
 675       phi_t->make_ptr() == nullptr ||
 676       phi_t->make_ptr()->isa_aryptr() != nullptr) {
 677     return false;
 678   }
 679 
 680   if (!can_reduce_phi_check_inputs(ophi) || !can_reduce_check_users(ophi, /* nesting: */ 0)) {
 681     return false;
 682   }
 683 
 684   NOT_PRODUCT(if (TraceReduceAllocationMerges) { tty->print_cr("Can reduce Phi %d during invocation %d: ", ophi->_idx, _invocation); })
 685   return true;
 686 }
 687 
 688 // This method will return a CmpP/N that we need to use on the If controlling a
 689 // CastPP after it was split. This method is only called on bases that are
 690 // nullable therefore we always need a controlling if for the splitted CastPP.
 691 //
 692 // 'curr_ctrl' is the control of the CastPP that we want to split through phi.
 693 // If the CastPP currently doesn't have a control then the CmpP/N will be
 694 // against the null constant, otherwise it will be against the constant input of
 695 // the existing CmpP/N. It's guaranteed that there will be a CmpP/N in the later
 696 // case because we have constraints on it and because the CastPP has a control
 697 // input.
 698 Node* ConnectionGraph::specialize_cmp(Node* base, Node* curr_ctrl) {
 699   const Type* t = base->bottom_type();
 700   Node* con = nullptr;
 701 
 702   if (curr_ctrl == nullptr || curr_ctrl->is_Region()) {
 703     con = _igvn->zerocon(t->basic_type());
 704   } else {
 705     // can_reduce_check_users() verified graph: true/false -> if -> bool -> cmp
 706     assert(curr_ctrl->in(0)->Opcode() == Op_If, "unexpected node %s", curr_ctrl->in(0)->Name());
 707     Node* bol = curr_ctrl->in(0)->in(1);
 708     assert(bol->is_Bool(), "unexpected node %s", bol->Name());
 709     Node* curr_cmp = bol->in(1);
 710     assert(curr_cmp->Opcode() == Op_CmpP || curr_cmp->Opcode() == Op_CmpN, "unexpected node %s", curr_cmp->Name());
 711     con = curr_cmp->in(1)->is_Con() ? curr_cmp->in(1) : curr_cmp->in(2);
 712   }
 713 
 714   return CmpNode::make(base, con, t->basic_type());
 715 }
 716 
 717 // This method 'specializes' the CastPP passed as parameter to the base passed
 718 // as parameter. Note that the existing CastPP input is a Phi. "Specialize"
 719 // means that the CastPP now will be specific for a given base instead of a Phi.
 720 // An If-Then-Else-Region block is inserted to control the CastPP. The control
 721 // of the CastPP is a copy of the current one (if there is one) or a check
 722 // against null.
 723 //
 724 // Before:
 725 //
 726 //    C1     C2  ... Cn
 727 //     \      |      /
 728 //      \     |     /
 729 //       \    |    /
 730 //        \   |   /
 731 //         \  |  /
 732 //          \ | /
 733 //           \|/
 734 //          Region     B1      B2  ... Bn
 735 //            |          \      |      /
 736 //            |           \     |     /
 737 //            |            \    |    /
 738 //            |             \   |   /
 739 //            |              \  |  /
 740 //            |               \ | /
 741 //            ---------------> Phi
 742 //                              |
 743 //                      X       |
 744 //                      |       |
 745 //                      |       |
 746 //                      ------> CastPP
 747 //
 748 // After (only partial illustration; base = B2, current_control = C2):
 749 //
 750 //                      C2
 751 //                      |
 752 //                      If
 753 //                     / \
 754 //                    /   \
 755 //                   T     F
 756 //                  /\     /
 757 //                 /  \   /
 758 //                /    \ /
 759 //      C1    CastPP   Reg        Cn
 760 //       |              |          |
 761 //       |              |          |
 762 //       |              |          |
 763 //       -------------- | ----------
 764 //                    | | |
 765 //                    Region
 766 //
 767 Node* ConnectionGraph::specialize_castpp(Node* castpp, Node* base, Node* current_control) {
 768   Node* control_successor  = current_control->unique_ctrl_out();
 769   Node* cmp                = _igvn->transform(specialize_cmp(base, castpp->in(0)));
 770   Node* bol                = _igvn->transform(new BoolNode(cmp, BoolTest::ne));
 771   IfNode* if_ne            = _igvn->transform(new IfNode(current_control, bol, PROB_MIN, COUNT_UNKNOWN))->as_If();
 772   Node* not_eq_control     = _igvn->transform(new IfTrueNode(if_ne));
 773   Node* yes_eq_control     = _igvn->transform(new IfFalseNode(if_ne));
 774   Node* end_region         = _igvn->transform(new RegionNode(3));
 775 
 776   // Insert the new if-else-region block into the graph
 777   end_region->set_req(1, not_eq_control);
 778   end_region->set_req(2, yes_eq_control);
 779   control_successor->replace_edge(current_control, end_region, _igvn);
 780 
 781   _igvn->_worklist.push(current_control);
 782   _igvn->_worklist.push(control_successor);
 783 
 784   return _igvn->transform(ConstraintCastNode::make_cast_for_type(not_eq_control, base, _igvn->type(castpp), ConstraintCastNode::DependencyType::NonFloatingNonNarrowing, nullptr));
 785 }
 786 
 787 Node* ConnectionGraph::split_castpp_load_through_phi(Node* curr_addp, Node* curr_load, Node* region, GrowableArray<Node*>* bases_for_loads, GrowableArray<Node *>  &alloc_worklist) {
 788   const Type* load_type = _igvn->type(curr_load);
 789   Node* nsr_value = _igvn->zerocon(load_type->basic_type());
 790   Node* memory = curr_load->in(MemNode::Memory);
 791 
 792   // The data_phi merging the loads needs to be nullable if
 793   // we are loading pointers.
 794   if (load_type->make_ptr() != nullptr) {
 795     if (load_type->isa_narrowoop()) {
 796       load_type = load_type->meet(TypeNarrowOop::NULL_PTR);
 797     } else if (load_type->isa_ptr()) {
 798       load_type = load_type->meet(TypePtr::NULL_PTR);
 799     } else {
 800       assert(false, "Unexpected load ptr type.");
 801     }
 802   }
 803 
 804   Node* data_phi = PhiNode::make(region, nsr_value, load_type);
 805 
 806   for (int i = 1; i < bases_for_loads->length(); i++) {
 807     Node* base = bases_for_loads->at(i);
 808     Node* cmp_region = nullptr;
 809     if (base != nullptr) {
 810       if (base->is_CFG()) { // means that we added a CastPP as child of this CFG node
 811         cmp_region = base->unique_ctrl_out_or_null();
 812         assert(cmp_region != nullptr, "There should be.");
 813         base = base->find_out_with(Op_CastPP);
 814       }
 815 
 816       Node* addr = _igvn->transform(AddPNode::make_with_base(base, curr_addp->in(AddPNode::Offset)));
 817       Node* mem = (memory->is_Phi() && (memory->in(0) == region)) ? memory->in(i) : memory;
 818       Node* load = curr_load->clone();
 819       load->set_req(0, nullptr);
 820       load->set_req(1, mem);
 821       load->set_req(2, addr);
 822 
 823       if (cmp_region != nullptr) { // see comment on previous if
 824         Node* intermediate_phi = PhiNode::make(cmp_region, nsr_value, load_type);
 825         intermediate_phi->set_req(1, _igvn->transform(load));
 826         load = intermediate_phi;
 827       }
 828 
 829       data_phi->set_req(i, _igvn->transform(load));
 830     } else {
 831       // Just use the default, which is already in phi
 832     }
 833   }
 834 
 835   // Takes care of updating CG and split_unique_types worklists due
 836   // to cloned AddP->Load.
 837   updates_after_load_split(data_phi, curr_load, alloc_worklist);
 838 
 839   return _igvn->transform(data_phi);
 840 }
 841 
 842 // This method only reduces CastPP fields loads; SafePoints are handled
 843 // separately. The idea here is basically to clone the CastPP and place copies
 844 // on each input of the Phi, including non-scalar replaceable inputs.
 845 // Experimentation shows that the resulting IR graph is simpler that way than if
 846 // we just split the cast through scalar-replaceable inputs.
 847 //
 848 // The reduction process requires that CastPP's control be one of:
 849 //  1) no control,
 850 //  2) the same region as Ophi, or
 851 //  3) an IfTrue/IfFalse coming from an CmpP/N between Ophi and a constant.
 852 //
 853 // After splitting the CastPP we'll put it under an If-Then-Else-Region control
 854 // flow. If the CastPP originally had an IfTrue/False control input then we'll
 855 // use a similar CmpP/N to control the new If-Then-Else-Region. Otherwise, we'll
 856 // juse use a CmpP/N against the null constant.
 857 //
 858 // The If-Then-Else-Region isn't always needed. For instance, if input to
 859 // splitted cast was not nullable (or if it was the null constant) then we don't
 860 // need (shouldn't) use a CastPP at all.
 861 //
 862 // After the casts are splitted we'll split the AddP->Loads through the Phi and
 863 // connect them to the just split CastPPs.
 864 //
 865 // Before (CastPP control is same as Phi):
 866 //
 867 //          Region     Allocate   Null    Call
 868 //            |             \      |      /
 869 //            |              \     |     /
 870 //            |               \    |    /
 871 //            |                \   |   /
 872 //            |                 \  |  /
 873 //            |                  \ | /
 874 //            ------------------> Phi            # Oop Phi
 875 //            |                    |
 876 //            |                    |
 877 //            |                    |
 878 //            |                    |
 879 //            ----------------> CastPP
 880 //                                 |
 881 //                               AddP
 882 //                                 |
 883 //                               Load
 884 //
 885 // After (Very much simplified):
 886 //
 887 //                         Call  Null
 888 //                            \  /
 889 //                            CmpP
 890 //                             |
 891 //                           Bool#NE
 892 //                             |
 893 //                             If
 894 //                            / \
 895 //                           T   F
 896 //                          / \ /
 897 //                         /   R
 898 //                     CastPP  |
 899 //                       |     |
 900 //                     AddP    |
 901 //                       |     |
 902 //                     Load    |
 903 //                         \   |   0
 904 //            Allocate      \  |  /
 905 //                \          \ | /
 906 //               AddP         Phi
 907 //                  \         /
 908 //                 Load      /
 909 //                    \  0  /
 910 //                     \ | /
 911 //                      \|/
 912 //                      Phi        # "Field" Phi
 913 //
 914 void ConnectionGraph::reduce_phi_on_castpp_field_load(CastPPNode* curr_castpp, GrowableArray<Node*> &alloc_worklist) {
 915   PhiNode* ophi = curr_castpp->in(1)->as_Phi();
 916   precond(can_reduce_phi_at_castpp(ophi, curr_castpp));
 917 
 918   // Identify which base should be used for AddP->Load later when spliting the
 919   // CastPP->Loads through ophi. Three kind of values may be stored in this
 920   // array, depending on the nullability status of the corresponding input in
 921   // ophi.
 922   //
 923   //  - nullptr:    Meaning that the base is actually the null constant and therefore
 924   //                we won't try to load from it.
 925   //
 926   //  - CFG Node:   Meaning that the base is a CastPP that was specialized for
 927   //                this input of Ophi. I.e., we added an If->Then->Else-Region
 928   //                that will 'activate' the CastPp only when the input is not Null.
 929   //
 930   //  - Other Node: Meaning that the base is not nullable and therefore we'll try
 931   //                to load directly from it.
 932   GrowableArray<Node*> bases_for_loads(ophi->req(), ophi->req(), nullptr);
 933 
 934   for (uint i = 1; i < ophi->req(); i++) {
 935     Node* base = ophi->in(i);
 936     const Type* base_t = _igvn->type(base);
 937 
 938     if (base_t->maybe_null()) {
 939       if (base->is_Con()) {
 940         // Nothing todo as bases_for_loads[i] is already null
 941       } else {
 942         Node* new_castpp = specialize_castpp(curr_castpp, base, ophi->in(0)->in(i));
 943         bases_for_loads.at_put(i, new_castpp->in(0)); // Use the ctrl of the new node just as a flag
 944       }
 945     } else {
 946       bases_for_loads.at_put(i, base);
 947     }
 948   }
 949 
 950   // Now let's split the CastPP->Loads through the Phi
 951   for (int i = curr_castpp->outcnt()-1; i >= 0;) {
 952     Node* use = curr_castpp->raw_out(i);
 953     if (use->is_AddP()) {
 954       for (int j = use->outcnt()-1; j >= 0;) {
 955         Node* use_use = use->raw_out(j);
 956         assert(use_use->is_Load(), "Expected this to be a Load node.");
 957 
 958         // We can't make an unconditional load from a nullable input. The
 959         // 'split_castpp_load_through_phi` method will add an
 960         // 'If-Then-Else-Region` around nullable bases and only load from them
 961         // when the input is not null.
 962         Node* phi = split_castpp_load_through_phi(use, use_use, ophi->in(0), &bases_for_loads, alloc_worklist);
 963         _igvn->replace_node(use_use, phi);
 964 
 965         --j;
 966         j = MIN2(j, (int)use->outcnt()-1);
 967       }
 968 
 969       _igvn->remove_dead_node(use, PhaseIterGVN::NodeOrigin::Graph);
 970     }
 971     --i;
 972     i = MIN2(i, (int)curr_castpp->outcnt()-1);
 973   }
 974 }
 975 
 976 // This method split a given CmpP/N through the Phi used in one of its inputs.
 977 // As a result we convert a comparison with a pointer to a comparison with an
 978 // integer.
 979 // The only requirement is that one of the inputs of the CmpP/N must be a Phi
 980 // while the other must be a constant.
 981 // The splitting process is basically just cloning the CmpP/N above the input
 982 // Phi.  However, some (most) of the cloned CmpP/Ns won't be requred because we
 983 // can prove at compile time the result of the comparison.
 984 //
 985 // Before:
 986 //
 987 //             in1    in2 ... inN
 988 //              \      |      /
 989 //               \     |     /
 990 //                \    |    /
 991 //                 \   |   /
 992 //                  \  |  /
 993 //                   \ | /
 994 //                    Phi
 995 //                     |   Other
 996 //                     |    /
 997 //                     |   /
 998 //                     |  /
 999 //                    CmpP/N
1000 //
1001 // After:
1002 //
1003 //        in1  Other   in2 Other  inN  Other
1004 //         |    |      |   |      |    |
1005 //         \    |      |   |      |    |
1006 //          \  /       |   /      |    /
1007 //          CmpP/N    CmpP/N     CmpP/N
1008 //          Bool      Bool       Bool
1009 //            \        |        /
1010 //             \       |       /
1011 //              \      |      /
1012 //               \     |     /
1013 //                \    |    /
1014 //                 \   |   /
1015 //                  \  |  /
1016 //                   \ | /
1017 //                    Phi
1018 //                     |
1019 //                     |   Zero
1020 //                     |    /
1021 //                     |   /
1022 //                     |  /
1023 //                     CmpI
1024 //
1025 //
1026 void ConnectionGraph::reduce_phi_on_cmp(Node* cmp) {
1027   Node* ophi = cmp->in(1)->is_Con() ? cmp->in(2) : cmp->in(1);
1028   assert(ophi->is_Phi(), "Expected this to be a Phi node.");
1029 
1030   Node* other = cmp->in(1)->is_Con() ? cmp->in(1) : cmp->in(2);
1031   Node* zero = _igvn->intcon(0);
1032   Node* one = _igvn->intcon(1);
1033   BoolTest::mask mask = cmp->unique_out()->as_Bool()->_test._test;
1034 
1035   // This Phi will merge the result of the Cmps split through the Phi
1036   Node* res_phi = PhiNode::make(ophi->in(0), zero, TypeInt::INT);
1037 
1038   for (uint i=1; i<ophi->req(); i++) {
1039     Node* ophi_input = ophi->in(i);
1040     Node* res_phi_input = nullptr;
1041 
1042     const TypeInt* tcmp = optimize_ptr_compare(ophi_input, other);
1043     if (tcmp->singleton()) {
1044       if ((mask == BoolTest::mask::eq && tcmp == TypeInt::CC_EQ) ||
1045           (mask == BoolTest::mask::ne && tcmp == TypeInt::CC_GT)) {
1046         res_phi_input = one;
1047       } else {
1048         res_phi_input = zero;
1049       }
1050     } else {
1051       Node* ncmp = _igvn->transform(cmp->clone());
1052       ncmp->set_req(1, ophi_input);
1053       ncmp->set_req(2, other);
1054       Node* bol = _igvn->transform(new BoolNode(ncmp, mask));
1055       res_phi_input = bol->as_Bool()->as_int_value(_igvn);
1056     }
1057 
1058     res_phi->set_req(i, res_phi_input);
1059   }
1060 
1061   // This CMP always compares whether the output of "res_phi" is TRUE as far as the "mask".
1062   Node* new_cmp = _igvn->transform(new CmpINode(_igvn->transform(res_phi), (mask == BoolTest::mask::eq) ? one : zero));
1063   _igvn->replace_node(cmp, new_cmp);
1064 }
1065 
1066 // Push the newly created AddP on alloc_worklist and patch
1067 // the connection graph. Note that the changes in the CG below
1068 // won't affect the ES of objects since the new nodes have the
1069 // same status as the old ones.
1070 void ConnectionGraph::updates_after_load_split(Node* data_phi, Node* previous_load, GrowableArray<Node *>  &alloc_worklist) {
1071   assert(data_phi != nullptr, "Output of split_through_phi is null.");
1072   assert(data_phi != previous_load, "Output of split_through_phi is same as input.");
1073   assert(data_phi->is_Phi(), "Output of split_through_phi isn't a Phi.");
1074 
1075   if (data_phi == nullptr || !data_phi->is_Phi()) {
1076     // Make this a retry?
1077     return ;
1078   }
1079 
1080   Node* previous_addp = previous_load->in(MemNode::Address);
1081   FieldNode* fn = ptnode_adr(previous_addp->_idx)->as_Field();
1082   for (uint i = 1; i < data_phi->req(); i++) {
1083     Node* new_load = data_phi->in(i);
1084 
1085     if (new_load->is_Phi()) {
1086       // new_load is currently the "intermediate_phi" from an specialized
1087       // CastPP.
1088       new_load = new_load->in(1);
1089     }
1090 
1091     // "new_load" might actually be a constant, parameter, etc.
1092     if (new_load->is_Load()) {
1093       Node* new_addp = new_load->in(MemNode::Address);
1094 
1095       // If new_load is a Load but not from an AddP, it means that the load is folded into another
1096       // load. And since this load is not from a field, we cannot create a unique type for it.
1097       // For example:
1098       //
1099       //   if (b) {
1100       //       Holder h1 = new Holder();
1101       //       Object o = ...;
1102       //       h.o = o.getClass();
1103       //   } else {
1104       //       Holder h2 = ...;
1105       //   }
1106       //   Holder h = Phi(h1, h2);
1107       //   Object r = h.o;
1108       //
1109       // Then, splitting r through the merge point results in:
1110       //
1111       //   if (b) {
1112       //       Holder h1 = new Holder();
1113       //       Object o = ...;
1114       //       h.o = o.getClass();
1115       //       Object o1 = h.o;
1116       //   } else {
1117       //       Holder h2 = ...;
1118       //       Object o2 = h2.o;
1119       //   }
1120       //   Object r = Phi(o1, o2);
1121       //
1122       // In this case, o1 is folded to o.getClass() which is a Load but not from an AddP, but from
1123       // an OopHandle that is loaded from the Klass of o.
1124       if (!new_addp->is_AddP()) {
1125         continue;
1126       }
1127       Node* base = get_addp_base(new_addp);
1128 
1129       // The base might not be something that we can create an unique
1130       // type for. If that's the case we are done with that input.
1131       PointsToNode* jobj_ptn = unique_java_object(base);
1132       if (jobj_ptn == nullptr || !jobj_ptn->scalar_replaceable()) {
1133         continue;
1134       }
1135 
1136       // Push to alloc_worklist since the base has an unique_type
1137       alloc_worklist.append_if_missing(new_addp);
1138 
1139       // Now let's add the node to the connection graph
1140       _nodes.at_grow(new_addp->_idx, nullptr);
1141       add_field(new_addp, fn->escape_state(), fn->offset());
1142       add_base(ptnode_adr(new_addp->_idx)->as_Field(), ptnode_adr(base->_idx));
1143 
1144       // If the load doesn't load an object then it won't be
1145       // part of the connection graph
1146       PointsToNode* curr_load_ptn = ptnode_adr(previous_load->_idx);
1147       if (curr_load_ptn != nullptr) {
1148         _nodes.at_grow(new_load->_idx, nullptr);
1149         add_local_var(new_load, curr_load_ptn->escape_state());
1150         add_edge(ptnode_adr(new_load->_idx), ptnode_adr(new_addp->_idx)->as_Field());
1151       }
1152     }
1153   }
1154 }
1155 
1156 void ConnectionGraph::reduce_phi_on_field_access(Node* previous_addp, GrowableArray<Node *>  &alloc_worklist) {
1157   // We'll pass this to 'split_through_phi' so that it'll do the split even
1158   // though the load doesn't have an unique instance type.
1159   bool ignore_missing_instance_id = true;
1160 
1161   // All AddPs are present in the connection graph
1162   FieldNode* fn = ptnode_adr(previous_addp->_idx)->as_Field();
1163 
1164   // Iterate over AddP looking for a Load
1165   for (int k = previous_addp->outcnt()-1; k >= 0;) {
1166     Node* previous_load = previous_addp->raw_out(k);
1167     if (previous_load->is_Load()) {
1168       Node* data_phi = previous_load->as_Load()->split_through_phi(_igvn, ignore_missing_instance_id);
1169 
1170       // Takes care of updating CG and split_unique_types worklists due to cloned
1171       // AddP->Load.
1172       updates_after_load_split(data_phi, previous_load, alloc_worklist);
1173 
1174       _igvn->replace_node(previous_load, data_phi);
1175     }
1176     --k;
1177     k = MIN2(k, (int)previous_addp->outcnt()-1);
1178   }
1179 
1180   // Remove the old AddP from the processing list because it's dead now
1181   assert(previous_addp->outcnt() == 0, "AddP should be dead now.");
1182   alloc_worklist.remove_if_existing(previous_addp);
1183 }
1184 
1185 // Create a 'selector' Phi based on the inputs of 'ophi'. If index 'i' of the
1186 // selector is:
1187 //    -> a '-1' constant, the i'th input of the original Phi is NSR.
1188 //    -> a 'x' constant >=0, the i'th input of of original Phi will be SR and
1189 //       the info about the scalarized object will be at index x of ObjectMergeValue::possible_objects
1190 PhiNode* ConnectionGraph::create_selector(PhiNode* ophi) const {
1191   Node* minus_one = _igvn->register_new_node_with_optimizer(ConINode::make(-1));
1192   Node* selector  = _igvn->register_new_node_with_optimizer(PhiNode::make(ophi->region(), minus_one, TypeInt::INT));
1193   uint number_of_sr_objects = 0;
1194   for (uint i = 1; i < ophi->req(); i++) {
1195     Node* base = ophi->in(i);
1196     JavaObjectNode* ptn = unique_java_object(base);
1197 
1198     if (ptn != nullptr && ptn->scalar_replaceable()) {
1199       Node* sr_obj_idx = _igvn->register_new_node_with_optimizer(ConINode::make(number_of_sr_objects));
1200       selector->set_req(i, sr_obj_idx);
1201       number_of_sr_objects++;
1202     }
1203   }
1204 
1205   return selector->as_Phi();
1206 }
1207 
1208 // Returns true if the AddP node 'n' has at least one base that is a reducible
1209 // merge. If the base is a CastPP/CheckCastPP then the input of the cast is
1210 // checked instead.
1211 bool ConnectionGraph::has_reducible_merge_base(AddPNode* n, Unique_Node_List &reducible_merges) {
1212   PointsToNode* ptn = ptnode_adr(n->_idx);
1213   if (ptn == nullptr || !ptn->is_Field() || ptn->as_Field()->base_count() < 2) {
1214     return false;
1215   }
1216 
1217   for (BaseIterator i(ptn->as_Field()); i.has_next(); i.next()) {
1218     Node* base = i.get()->ideal_node();
1219 
1220     if (reducible_merges.member(base)) {
1221       return true;
1222     }
1223 
1224     if (base->is_CastPP() || base->is_CheckCastPP()) {
1225       base = base->in(1);
1226       if (reducible_merges.member(base)) {
1227         return true;
1228       }
1229     }
1230   }
1231 
1232   return false;
1233 }
1234 
1235 // This method will call its helper method to reduce SafePoint nodes that use
1236 // 'ophi' or a casted version of 'ophi'. All SafePoint nodes using the same
1237 // "version" of Phi use the same debug information (regarding the Phi).
1238 // Therefore, I collect all safepoints and patch them all at once.
1239 //
1240 // The safepoints using the Phi node have to be processed before safepoints of
1241 // CastPP nodes. The reason is, when reducing a CastPP we add a reference (the
1242 // NSR merge pointer) to the input of the CastPP (i.e., the Phi) in the
1243 // safepoint. If we process CastPP's safepoints before Phi's safepoints the
1244 // algorithm that process Phi's safepoints will think that the added Phi
1245 // reference is a regular reference.
1246 bool ConnectionGraph::reduce_phi_on_safepoints(PhiNode* ophi) {
1247   PhiNode* selector = create_selector(ophi);
1248   Unique_Node_List safepoints;
1249   Unique_Node_List casts;
1250 
1251   // Just collect the users of the Phis for later processing
1252   // in the needed order.
1253   for (uint i = 0; i < ophi->outcnt(); i++) {
1254     Node* use = ophi->raw_out(i);
1255     if (use->is_SafePoint()) {
1256       safepoints.push(use);
1257     } else if (use->is_CastPP()) {
1258       casts.push(use);
1259     } else {
1260       assert(use->outcnt() == 0, "Only CastPP & SafePoint users should be left.");
1261     }
1262   }
1263 
1264   // Need to process safepoints using the Phi first
1265   if (!reduce_phi_on_safepoints_helper(ophi, nullptr, selector, safepoints)) {
1266     return false;
1267   }
1268 
1269   // Now process CastPP->safepoints
1270   for (uint i = 0; i < casts.size(); i++) {
1271     Node* cast = casts.at(i);
1272     Unique_Node_List cast_sfpts;
1273 
1274     for (DUIterator_Fast jmax, j = cast->fast_outs(jmax); j < jmax; j++) {
1275       Node* use_use = cast->fast_out(j);
1276       if (use_use->is_SafePoint()) {
1277         cast_sfpts.push(use_use);
1278       } else {
1279         assert(use_use->outcnt() == 0, "Only SafePoint users should be left.");
1280       }
1281     }
1282 
1283     if (!reduce_phi_on_safepoints_helper(ophi, cast, selector, cast_sfpts)) {
1284       return false;
1285     }
1286   }
1287 
1288   return true;
1289 }
1290 
1291 // This method will create a SafePointScalarMERGEnode for each SafePoint in
1292 // 'safepoints'. It then will iterate on the inputs of 'ophi' and create a
1293 // SafePointScalarObjectNode for each scalar replaceable input. Each
1294 // SafePointScalarMergeNode may describe multiple scalar replaced objects -
1295 // check detailed description in SafePointScalarMergeNode class header.
1296 bool ConnectionGraph::reduce_phi_on_safepoints_helper(Node* ophi, Node* cast, Node* selector, Unique_Node_List& safepoints) {
1297   PhaseMacroExpand mexp(*_igvn);
1298   Node* original_sfpt_parent =  cast != nullptr ? cast : ophi;
1299   const TypeOopPtr* merge_t = _igvn->type(original_sfpt_parent)->make_oopptr();
1300 
1301   Node* nsr_merge_pointer = ophi;
1302   if (cast != nullptr) {
1303     const Type* new_t = merge_t->meet(TypePtr::NULL_PTR);
1304     nsr_merge_pointer = _igvn->transform(ConstraintCastNode::make_cast_for_type(cast->in(0), cast->in(1), new_t, ConstraintCastNode::DependencyType::FloatingNarrowing, nullptr));
1305   }
1306 
1307   for (uint spi = 0; spi < safepoints.size(); spi++) {
1308     SafePointNode* sfpt = safepoints.at(spi)->as_SafePoint();
1309 
1310     SafePointNode::NodeEdgeTempStorage non_debug_edges_worklist(*_igvn);
1311 
1312     // All sfpt inputs are implicitly included into debug info during the scalarization process below.
1313     // Keep non-debug inputs separately, so they stay non-debug.
1314     sfpt->remove_non_debug_edges(non_debug_edges_worklist);
1315 
1316     JVMState* jvms  = sfpt->jvms();
1317     uint merge_idx  = (sfpt->req() - jvms->scloff());
1318     int debug_start = jvms->debug_start();
1319 
1320     SafePointScalarMergeNode* smerge = new SafePointScalarMergeNode(merge_t, merge_idx);
1321     smerge->init_req(0, _compile->root());
1322     _igvn->register_new_node_with_optimizer(smerge);
1323 
1324     assert(sfpt->jvms()->endoff() == sfpt->req(), "no extra edges past debug info allowed");
1325 
1326     // The next two inputs are:
1327     //  (1) A copy of the original pointer to NSR objects.
1328     //  (2) A selector, used to decide if we need to rematerialize an object
1329     //      or use the pointer to a NSR object.
1330     // See more details of these fields in the declaration of SafePointScalarMergeNode.
1331     // It is safe to include them into debug info straight away since create_scalarized_object_description()
1332     // will include all newly added inputs into debug info anyway.
1333     sfpt->add_req(nsr_merge_pointer);
1334     sfpt->add_req(selector);
1335     sfpt->jvms()->set_endoff(sfpt->req());
1336 
1337     for (uint i = 1; i < ophi->req(); i++) {
1338       Node* base = ophi->in(i);
1339       JavaObjectNode* ptn = unique_java_object(base);
1340 
1341       // If the base is not scalar replaceable we don't need to register information about
1342       // it at this time.
1343       if (ptn == nullptr || !ptn->scalar_replaceable()) {
1344         continue;
1345       }
1346 
1347       AllocateNode* alloc = ptn->ideal_node()->as_Allocate();
1348       Unique_Node_List value_worklist;
1349 #ifdef ASSERT
1350       const Type* res_type = alloc->result_cast()->bottom_type();
1351       if (res_type->is_inlinetypeptr() && !Compile::current()->has_circular_inline_type()) {
1352         assert(!ophi->as_Phi()->can_push_inline_types_down(_igvn), "missed earlier scalarization opportunity");
1353       }
1354 #endif
1355       SafePointScalarObjectNode* sobj = mexp.create_scalarized_object_description(alloc, sfpt, &value_worklist);
1356       if (sobj == nullptr) {
1357         _compile->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1358         sfpt->restore_non_debug_edges(non_debug_edges_worklist);
1359         return false; // non-recoverable failure; recompile
1360       }
1361 
1362       // Now make a pass over the debug information replacing any references
1363       // to the allocated object with "sobj"
1364       Node* ccpp = alloc->result_cast();
1365       sfpt->replace_edges_in_range(ccpp, sobj, debug_start, jvms->debug_end(), _igvn);
1366       non_debug_edges_worklist.remove_edge_if_present(ccpp); // drop scalarized input from non-debug info
1367 
1368       // Register the scalarized object as a candidate for reallocation
1369       smerge->add_req(sobj);
1370 
1371       // Scalarize inline types that were added to the safepoint.
1372       // Don't allow linking a constant oop (if available) for flat array elements
1373       // because Deoptimization::reassign_flat_array_elements needs field values.
1374       const bool allow_oop = !merge_t->is_flat();
1375       for (uint j = 0; j < value_worklist.size(); ++j) {
1376         InlineTypeNode* vt = value_worklist.at(j)->as_InlineType();
1377         vt->make_scalar_in_safepoints(_igvn, allow_oop);
1378       }
1379     }
1380 
1381     // Replaces debug information references to "original_sfpt_parent" in "sfpt" with references to "smerge"
1382     sfpt->replace_edges_in_range(original_sfpt_parent, smerge, debug_start, jvms->debug_end(), _igvn);
1383     non_debug_edges_worklist.remove_edge_if_present(original_sfpt_parent); // drop scalarized input from non-debug info
1384 
1385     // The call to 'replace_edges_in_range' above might have removed the
1386     // reference to ophi that we need at _merge_pointer_idx. The line below make
1387     // sure the reference is maintained.
1388     sfpt->set_req(smerge->merge_pointer_idx(jvms), nsr_merge_pointer);
1389 
1390     sfpt->restore_non_debug_edges(non_debug_edges_worklist);
1391 
1392     _igvn->_worklist.push(sfpt);
1393   }
1394 
1395   return true;
1396 }
1397 
1398 void ConnectionGraph::reduce_phi(PhiNode* ophi, GrowableArray<Node*> &alloc_worklist) {
1399   bool delay = _igvn->delay_transform();
1400   _igvn->set_delay_transform(true);
1401   _igvn->hash_delete(ophi);
1402 
1403   // Copying all users first because some will be removed and others won't.
1404   // Ophi also may acquire some new users as part of Cast reduction.
1405   // CastPPs also need to be processed before CmpPs.
1406   Unique_Node_List castpps;
1407   Unique_Node_List others;
1408   for (DUIterator_Fast imax, i = ophi->fast_outs(imax); i < imax; i++) {
1409     Node* use = ophi->fast_out(i);
1410 
1411     if (use->is_CastPP()) {
1412       castpps.push(use);
1413     } else if (use->is_AddP() || use->is_Cmp()) {
1414       others.push(use);
1415     } else {
1416       // Safepoints to be processed later; other users aren't expected here
1417       assert(use->is_SafePoint(), "Unexpected user of reducible Phi %d -> %d:%s:%d", ophi->_idx, use->_idx, use->Name(), use->outcnt());
1418     }
1419   }
1420 
1421   _compile->print_method(PHASE_EA_BEFORE_PHI_REDUCTION, 5, ophi);
1422 
1423   // CastPPs need to be processed before Cmps because during the process of
1424   // splitting CastPPs we make reference to the inputs of the Cmp that is used
1425   // by the If controlling the CastPP.
1426   for (uint i = 0; i < castpps.size(); i++) {
1427     reduce_phi_on_castpp_field_load(castpps.at(i)->as_CastPP(), alloc_worklist);
1428     _compile->print_method(PHASE_EA_AFTER_PHI_CASTPP_REDUCTION, 6, castpps.at(i));
1429   }
1430 
1431   for (uint i = 0; i < others.size(); i++) {
1432     Node* use = others.at(i);
1433 
1434     if (use->is_AddP()) {
1435       reduce_phi_on_field_access(use, alloc_worklist);
1436       _compile->print_method(PHASE_EA_AFTER_PHI_ADDP_REDUCTION, 6, use);
1437     } else if(use->is_Cmp()) {
1438       reduce_phi_on_cmp(use);
1439       _compile->print_method(PHASE_EA_AFTER_PHI_CMP_REDUCTION, 6, use);
1440     }
1441   }
1442 
1443   _igvn->set_delay_transform(delay);
1444 }
1445 
1446 void ConnectionGraph::reset_scalar_replaceable_entries(PhiNode* ophi) {
1447   Node* null_ptr            = _igvn->makecon(TypePtr::NULL_PTR);
1448   const TypeOopPtr* merge_t = _igvn->type(ophi)->make_oopptr();
1449   const Type* new_t         = merge_t->meet(TypePtr::NULL_PTR);
1450   Node* new_phi             = _igvn->register_new_node_with_optimizer(PhiNode::make(ophi->region(), null_ptr, new_t));
1451 
1452   for (uint i = 1; i < ophi->req(); i++) {
1453     Node* base          = ophi->in(i);
1454     JavaObjectNode* ptn = unique_java_object(base);
1455 
1456     if (ptn != nullptr && ptn->scalar_replaceable()) {
1457       new_phi->set_req(i, null_ptr);
1458     } else {
1459       new_phi->set_req(i, ophi->in(i));
1460     }
1461   }
1462 
1463   for (int i = ophi->outcnt()-1; i >= 0;) {
1464     Node* out = ophi->raw_out(i);
1465 
1466     if (out->is_ConstraintCast()) {
1467       const Type* out_t = _igvn->type(out)->make_ptr();
1468       const Type* out_new_t = out_t->meet(TypePtr::NULL_PTR);
1469       bool change = out_new_t != out_t;
1470 
1471       for (int j = out->outcnt()-1; change && j >= 0; --j) {
1472         Node* out2 = out->raw_out(j);
1473         if (!out2->is_SafePoint()) {
1474           change = false;
1475           break;
1476         }
1477       }
1478 
1479       if (change) {
1480         Node* new_cast = ConstraintCastNode::make_cast_for_type(out->in(0), out->in(1), out_new_t, ConstraintCastNode::DependencyType::NonFloatingNarrowing, nullptr);
1481         _igvn->replace_node(out, new_cast);
1482         _igvn->register_new_node_with_optimizer(new_cast);
1483       }
1484     }
1485 
1486     --i;
1487     i = MIN2(i, (int)ophi->outcnt()-1);
1488   }
1489 
1490   _igvn->replace_node(ophi, new_phi);
1491 }
1492 
1493 void ConnectionGraph::verify_ram_nodes(Compile* C, Node* root) {
1494   if (!C->do_reduce_allocation_merges()) return;
1495 
1496   Unique_Node_List ideal_nodes;
1497   ideal_nodes.map(C->live_nodes(), nullptr);  // preallocate space
1498   ideal_nodes.push(root);
1499 
1500   for (uint next = 0; next < ideal_nodes.size(); ++next) {
1501     Node* n = ideal_nodes.at(next);
1502 
1503     if (n->is_SafePointScalarMerge()) {
1504       SafePointScalarMergeNode* merge = n->as_SafePointScalarMerge();
1505 
1506       // Validate inputs of merge
1507       for (uint i = 1; i < merge->req(); i++) {
1508         if (merge->in(i) != nullptr && !merge->in(i)->is_top() && !merge->in(i)->is_SafePointScalarObject()) {
1509           assert(false, "SafePointScalarMerge inputs should be null/top or SafePointScalarObject.");
1510           C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1511         }
1512       }
1513 
1514       // Validate users of merge
1515       for (DUIterator_Fast imax, i = merge->fast_outs(imax); i < imax; i++) {
1516         Node* sfpt = merge->fast_out(i);
1517         if (sfpt->is_SafePoint()) {
1518           int merge_idx = merge->merge_pointer_idx(sfpt->as_SafePoint()->jvms());
1519 
1520           if (sfpt->in(merge_idx) != nullptr && sfpt->in(merge_idx)->is_SafePointScalarMerge()) {
1521             assert(false, "SafePointScalarMerge nodes can't be nested.");
1522             C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1523           }
1524         } else {
1525           assert(false, "Only safepoints can use SafePointScalarMerge nodes.");
1526           C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1527         }
1528       }
1529     }
1530 
1531     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1532       Node* m = n->fast_out(i);
1533       ideal_nodes.push(m);
1534     }
1535   }
1536 }
1537 
1538 // Returns true if there is an object in the scope of sfn that does not escape globally.
1539 bool ConnectionGraph::has_ea_local_in_scope(SafePointNode* sfn) {
1540   Compile* C = _compile;
1541   for (JVMState* jvms = sfn->jvms(); jvms != nullptr; jvms = jvms->caller()) {
1542     if (C->env()->should_retain_local_variables() || C->env()->jvmti_can_walk_any_space() ||
1543         DeoptimizeObjectsALot) {
1544       // Jvmti agents can access locals. Must provide info about local objects at runtime.
1545       int num_locs = jvms->loc_size();
1546       for (int idx = 0; idx < num_locs; idx++) {
1547         Node* l = sfn->local(jvms, idx);
1548         if (not_global_escape(l)) {
1549           return true;
1550         }
1551       }
1552     }
1553     if (C->env()->jvmti_can_get_owned_monitor_info() ||
1554         C->env()->jvmti_can_walk_any_space() || DeoptimizeObjectsALot) {
1555       // Jvmti agents can read monitors. Must provide info about locked objects at runtime.
1556       int num_mon = jvms->nof_monitors();
1557       for (int idx = 0; idx < num_mon; idx++) {
1558         Node* m = sfn->monitor_obj(jvms, idx);
1559         if (m != nullptr && not_global_escape(m)) {
1560           return true;
1561         }
1562       }
1563     }
1564   }
1565   return false;
1566 }
1567 
1568 // Returns true if at least one of the arguments to the call is an object
1569 // that does not escape globally.
1570 bool ConnectionGraph::has_arg_escape(CallJavaNode* call) {
1571   if (call->method() != nullptr) {
1572     uint max_idx = TypeFunc::Parms + call->method()->arg_size();
1573     for (uint idx = TypeFunc::Parms; idx < max_idx; idx++) {
1574       Node* p = call->in(idx);
1575       if (not_global_escape(p)) {
1576         return true;
1577       }
1578     }
1579   } else {
1580     const char* name = call->as_CallStaticJava()->_name;
1581     assert(name != nullptr, "no name");
1582     // no arg escapes through uncommon traps
1583     if (strcmp(name, "uncommon_trap") != 0) {
1584       // process_call_arguments() assumes that all arguments escape globally
1585       const TypeTuple* d = call->tf()->domain_sig();
1586       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1587         const Type* at = d->field_at(i);
1588         if (at->isa_oopptr() != nullptr) {
1589           return true;
1590         }
1591       }
1592     }
1593   }
1594   return false;
1595 }
1596 
1597 
1598 
1599 // Utility function for nodes that load an object
1600 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
1601   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1602   // ThreadLocal has RawPtr type.
1603   const Type* t = _igvn->type(n);
1604   if (t->make_ptr() != nullptr) {
1605     Node* adr = n->in(MemNode::Address);
1606 #ifdef ASSERT
1607     if (!adr->is_AddP()) {
1608       assert(_igvn->type(adr)->isa_rawptr(), "sanity");
1609     } else {
1610       assert((ptnode_adr(adr->_idx) == nullptr ||
1611               ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
1612     }
1613 #endif
1614     add_local_var_and_edge(n, PointsToNode::NoEscape,
1615                            adr, delayed_worklist);
1616   }
1617 }
1618 
1619 void ConnectionGraph::add_proj(Node* n, Unique_Node_List* delayed_worklist) {
1620   if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() && n->in(0)->as_Call()->returns_pointer()) {
1621     add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), delayed_worklist);
1622   } else if (n->in(0)->is_LoadFlat()) {
1623     // Treat LoadFlat outputs similar to a call return value
1624     add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), delayed_worklist);
1625   } else if (n->as_Proj()->_con >= TypeFunc::Parms && n->in(0)->is_Call() && n->bottom_type()->isa_ptr()) {
1626     CallNode* call = n->in(0)->as_Call();
1627     assert(call->tf()->returns_inline_type_as_fields(), "");
1628     if (n->as_Proj()->_con == TypeFunc::Parms || !returns_an_argument(call)) {
1629       // either:
1630       // - not an argument returned
1631       // - the returned buffer for a returned scalarized argument
1632       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), delayed_worklist);
1633     } else {
1634       add_local_var(n, PointsToNode::NoEscape);
1635     }
1636   }
1637 }
1638 
1639 // Populate Connection Graph with PointsTo nodes and create simple
1640 // connection graph edges.
1641 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
1642   assert(!_verify, "this method should not be called for verification");
1643   PhaseGVN* igvn = _igvn;
1644   uint n_idx = n->_idx;
1645   PointsToNode* n_ptn = ptnode_adr(n_idx);
1646   if (n_ptn != nullptr) {
1647     return; // No need to redefine PointsTo node during first iteration.
1648   }
1649   int opcode = n->Opcode();
1650   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_to_con_graph(this, igvn, delayed_worklist, n, opcode);
1651   if (gc_handled) {
1652     return; // Ignore node if already handled by GC.
1653   }
1654 
1655   if (n->is_Call()) {
1656     // Arguments to allocation and locking don't escape.
1657     if (n->is_AbstractLock()) {
1658       // Put Lock and Unlock nodes on IGVN worklist to process them during
1659       // first IGVN optimization when escape information is still available.
1660       record_for_optimizer(n);
1661     } else if (n->is_Allocate()) {
1662       add_call_node(n->as_Call());
1663       record_for_optimizer(n);
1664     } else {
1665       if (n->is_CallStaticJava()) {
1666         const char* name = n->as_CallStaticJava()->_name;
1667         if (name != nullptr && strcmp(name, "uncommon_trap") == 0) {
1668           return; // Skip uncommon traps
1669         }
1670       }
1671       // Don't mark as processed since call's arguments have to be processed.
1672       delayed_worklist->push(n);
1673       // Check if a call returns an object.
1674       if ((n->as_Call()->returns_pointer() &&
1675            n->as_Call()->proj_out_or_null(TypeFunc::Parms) != nullptr) ||
1676           (n->is_CallStaticJava() &&
1677            n->as_CallStaticJava()->is_boxing_method())) {
1678         add_call_node(n->as_Call());
1679       } else if (n->as_Call()->tf()->returns_inline_type_as_fields()) {
1680         bool returns_oop = false;
1681         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax && !returns_oop; i++) {
1682           ProjNode* pn = n->fast_out(i)->as_Proj();
1683           if (pn->_con >= TypeFunc::Parms && pn->bottom_type()->isa_ptr()) {
1684             returns_oop = true;
1685           }
1686         }
1687         if (returns_oop) {
1688           add_call_node(n->as_Call());
1689         }
1690       }
1691     }
1692     return;
1693   }
1694   // Put this check here to process call arguments since some call nodes
1695   // point to phantom_obj.
1696   if (n_ptn == phantom_obj || n_ptn == null_obj) {
1697     return; // Skip predefined nodes.
1698   }
1699   switch (opcode) {
1700     case Op_AddP: {
1701       Node* base = get_addp_base(n);
1702       PointsToNode* ptn_base = ptnode_adr(base->_idx);
1703       // Field nodes are created for all field types. They are used in
1704       // adjust_scalar_replaceable_state() and split_unique_types().
1705       // Note, non-oop fields will have only base edges in Connection
1706       // Graph because such fields are not used for oop loads and stores.
1707       int offset = address_offset(n, igvn);
1708       add_field(n, PointsToNode::NoEscape, offset);
1709       if (ptn_base == nullptr) {
1710         delayed_worklist->push(n); // Process it later.
1711       } else {
1712         n_ptn = ptnode_adr(n_idx);
1713         add_base(n_ptn->as_Field(), ptn_base);
1714       }
1715       break;
1716     }
1717     case Op_CastX2P:
1718     case Op_CastI2N: {
1719       map_ideal_node(n, phantom_obj);
1720       break;
1721     }
1722     case Op_InlineType:
1723     case Op_CastPP:
1724     case Op_CheckCastPP:
1725     case Op_EncodeP:
1726     case Op_DecodeN:
1727     case Op_EncodePKlass:
1728     case Op_DecodeNKlass: {
1729       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist);
1730       break;
1731     }
1732     case Op_CMoveP: {
1733       add_local_var(n, PointsToNode::NoEscape);
1734       // Do not add edges during first iteration because some could be
1735       // not defined yet.
1736       delayed_worklist->push(n);
1737       break;
1738     }
1739     case Op_ConP:
1740     case Op_ConN:
1741     case Op_ConNKlass: {
1742       // assume all oop constants globally escape except for null
1743       PointsToNode::EscapeState es;
1744       const Type* t = igvn->type(n);
1745       if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
1746         es = PointsToNode::NoEscape;
1747       } else {
1748         es = PointsToNode::GlobalEscape;
1749       }
1750       PointsToNode* ptn_con = add_java_object(n, es);
1751       set_not_scalar_replaceable(ptn_con NOT_PRODUCT(COMMA "Constant pointer"));
1752       break;
1753     }
1754     case Op_CreateEx: {
1755       // assume that all exception objects globally escape
1756       map_ideal_node(n, phantom_obj);
1757       break;
1758     }
1759     case Op_LoadKlass:
1760     case Op_LoadNKlass: {
1761       // Unknown class is loaded
1762       map_ideal_node(n, phantom_obj);
1763       break;
1764     }
1765     case Op_LoadP:
1766     case Op_LoadN: {
1767       add_objload_to_connection_graph(n, delayed_worklist);
1768       break;
1769     }
1770     case Op_Parm: {
1771       map_ideal_node(n, phantom_obj);
1772       break;
1773     }
1774     case Op_PartialSubtypeCheck: {
1775       // Produces Null or notNull and is used in only in CmpP so
1776       // phantom_obj could be used.
1777       map_ideal_node(n, phantom_obj); // Result is unknown
1778       break;
1779     }
1780     case Op_Phi: {
1781       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1782       // ThreadLocal has RawPtr type.
1783       const Type* t = n->as_Phi()->type();
1784       if (t->make_ptr() != nullptr) {
1785         add_local_var(n, PointsToNode::NoEscape);
1786         // Do not add edges during first iteration because some could be
1787         // not defined yet.
1788         delayed_worklist->push(n);
1789       }
1790       break;
1791     }
1792     case Op_LoadFlat:
1793       // Treat LoadFlat similar to an unknown call that receives nothing and produces its results
1794       map_ideal_node(n, phantom_obj);
1795       break;
1796     case Op_StoreFlat:
1797       // Treat StoreFlat similar to a call that escapes the stored flattened fields
1798       delayed_worklist->push(n);
1799       break;
1800     case Op_Proj: {
1801       // we are only interested in the oop result projection from a call
1802       add_proj(n, delayed_worklist);



1803       break;
1804     }
1805     case Op_Rethrow: // Exception object escapes
1806     case Op_Return: {
1807       if (n->req() > TypeFunc::Parms &&
1808           igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
1809         // Treat Return value as LocalVar with GlobalEscape escape state.
1810         add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), delayed_worklist);
1811       }
1812       break;
1813     }
1814     case Op_CompareAndExchangeP:
1815     case Op_CompareAndExchangeN:
1816     case Op_GetAndSetP:
1817     case Op_GetAndSetN: {
1818       add_objload_to_connection_graph(n, delayed_worklist);
1819       // fall-through
1820     }
1821     case Op_StoreP:
1822     case Op_StoreN:
1823     case Op_StoreNKlass:
1824     case Op_WeakCompareAndSwapP:
1825     case Op_WeakCompareAndSwapN:
1826     case Op_CompareAndSwapP:
1827     case Op_CompareAndSwapN: {
1828       add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
1829       break;
1830     }
1831     case Op_AryEq:
1832     case Op_CountPositives:
1833     case Op_StrComp:
1834     case Op_StrEquals:
1835     case Op_StrIndexOf:
1836     case Op_StrIndexOfChar:
1837     case Op_StrInflatedCopy:
1838     case Op_StrCompressedCopy:
1839     case Op_VectorizedHashCode:
1840     case Op_EncodeISOArray: {
1841       add_local_var(n, PointsToNode::ArgEscape);
1842       delayed_worklist->push(n); // Process it later.
1843       break;
1844     }
1845     case Op_ThreadLocal: {
1846       PointsToNode* ptn_thr = add_java_object(n, PointsToNode::ArgEscape);
1847       set_not_scalar_replaceable(ptn_thr NOT_PRODUCT(COMMA "Constant pointer"));
1848       break;
1849     }
1850     case Op_Blackhole: {
1851       // All blackhole pointer arguments are globally escaping.
1852       // Only do this if there is at least one pointer argument.
1853       // Do not add edges during first iteration because some could be
1854       // not defined yet, defer to final step.
1855       for (uint i = 0; i < n->req(); i++) {
1856         Node* in = n->in(i);
1857         if (in != nullptr) {
1858           const Type* at = _igvn->type(in);
1859           if (!at->isa_ptr()) continue;
1860 
1861           add_local_var(n, PointsToNode::GlobalEscape);
1862           delayed_worklist->push(n);
1863           break;
1864         }
1865       }
1866       break;
1867     }
1868     default:
1869       ; // Do nothing for nodes not related to EA.
1870   }
1871   return;
1872 }
1873 
1874 // Add final simple edges to graph.
1875 void ConnectionGraph::add_final_edges(Node *n) {
1876   PointsToNode* n_ptn = ptnode_adr(n->_idx);
1877 #ifdef ASSERT
1878   if (_verify && n_ptn->is_JavaObject())
1879     return; // This method does not change graph for JavaObject.
1880 #endif
1881 
1882   if (n->is_Call()) {
1883     process_call_arguments(n->as_Call());
1884     return;
1885   }
1886   assert(n->is_Store() || n->is_LoadStore() || n->is_StoreFlat() ||
1887          ((n_ptn != nullptr) && (n_ptn->ideal_node() != nullptr)),
1888          "node should be registered already");
1889   int opcode = n->Opcode();
1890   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_final_edges(this, _igvn, n, opcode);
1891   if (gc_handled) {
1892     return; // Ignore node if already handled by GC.
1893   }
1894   switch (opcode) {
1895     case Op_AddP: {
1896       Node* base = get_addp_base(n);
1897       PointsToNode* ptn_base = ptnode_adr(base->_idx);
1898       assert(ptn_base != nullptr, "field's base should be registered");
1899       add_base(n_ptn->as_Field(), ptn_base);
1900       break;
1901     }
1902     case Op_InlineType:
1903     case Op_CastPP:
1904     case Op_CheckCastPP:
1905     case Op_EncodeP:
1906     case Op_DecodeN:
1907     case Op_EncodePKlass:
1908     case Op_DecodeNKlass: {
1909       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), nullptr);
1910       break;
1911     }
1912     case Op_CMoveP: {
1913       for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
1914         Node* in = n->in(i);
1915         if (in == nullptr) {
1916           continue;  // ignore null
1917         }
1918         Node* uncast_in = in->uncast();
1919         if (uncast_in->is_top() || uncast_in == n) {
1920           continue;  // ignore top or inputs which go back this node
1921         }
1922         PointsToNode* ptn = ptnode_adr(in->_idx);
1923         assert(ptn != nullptr, "node should be registered");
1924         add_edge(n_ptn, ptn);
1925       }
1926       break;
1927     }
1928     case Op_LoadP:
1929     case Op_LoadN: {
1930       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1931       // ThreadLocal has RawPtr type.
1932       assert(_igvn->type(n)->make_ptr() != nullptr, "Unexpected node type");
1933       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), nullptr);
1934       break;
1935     }
1936     case Op_Phi: {
1937       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1938       // ThreadLocal has RawPtr type.
1939       assert(n->as_Phi()->type()->make_ptr() != nullptr, "Unexpected node type");
1940       for (uint i = 1; i < n->req(); i++) {
1941         Node* in = n->in(i);
1942         if (in == nullptr) {
1943           continue;  // ignore null
1944         }
1945         Node* uncast_in = in->uncast();
1946         if (uncast_in->is_top() || uncast_in == n) {
1947           continue;  // ignore top or inputs which go back this node
1948         }
1949         PointsToNode* ptn = ptnode_adr(in->_idx);
1950         assert(ptn != nullptr, "node should be registered");
1951         add_edge(n_ptn, ptn);
1952       }
1953       break;
1954     }
1955     case Op_StoreFlat: {
1956       // StoreFlat globally escapes its stored flattened fields
1957       InlineTypeNode* value = n->as_StoreFlat()->value();
1958       ciInlineKlass* vk = _igvn->type(value)->inline_klass();
1959       for (int i = 0; i < vk->nof_nonstatic_fields(); i++) {
1960         ciField* field = vk->nonstatic_field_at(i);
1961         if (field->type()->is_primitive_type()) {
1962           continue;
1963         }
1964 
1965         Node* field_value = value->field_value_by_offset(field->offset_in_bytes(), true);
1966         PointsToNode* field_value_ptn = ptnode_adr(field_value->_idx);
1967         set_escape_state(field_value_ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "store into a flat field"));
1968       }
1969       break;
1970     }
1971     case Op_Proj: {
1972       add_proj(n, nullptr);



1973       break;
1974     }
1975     case Op_Rethrow: // Exception object escapes
1976     case Op_Return: {
1977       assert(n->req() > TypeFunc::Parms && _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr(),
1978              "Unexpected node type");
1979       // Treat Return value as LocalVar with GlobalEscape escape state.
1980       add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), nullptr);
1981       break;
1982     }
1983     case Op_CompareAndExchangeP:
1984     case Op_CompareAndExchangeN:
1985     case Op_GetAndSetP:
1986     case Op_GetAndSetN:{
1987       assert(_igvn->type(n)->make_ptr() != nullptr, "Unexpected node type");
1988       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), nullptr);
1989       // fall-through
1990     }
1991     case Op_CompareAndSwapP:
1992     case Op_CompareAndSwapN:
1993     case Op_WeakCompareAndSwapP:
1994     case Op_WeakCompareAndSwapN:
1995     case Op_StoreP:
1996     case Op_StoreN:
1997     case Op_StoreNKlass:{
1998       add_final_edges_unsafe_access(n, opcode);
1999       break;
2000     }
2001     case Op_VectorizedHashCode:
2002     case Op_AryEq:
2003     case Op_CountPositives:
2004     case Op_StrComp:
2005     case Op_StrEquals:
2006     case Op_StrIndexOf:
2007     case Op_StrIndexOfChar:
2008     case Op_StrInflatedCopy:
2009     case Op_StrCompressedCopy:
2010     case Op_EncodeISOArray: {
2011       // char[]/byte[] arrays passed to string intrinsic do not escape but
2012       // they are not scalar replaceable. Adjust escape state for them.
2013       // Start from in(2) edge since in(1) is memory edge.
2014       for (uint i = 2; i < n->req(); i++) {
2015         Node* adr = n->in(i);
2016         const Type* at = _igvn->type(adr);
2017         if (!adr->is_top() && at->isa_ptr()) {
2018           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
2019                  at->isa_ptr() != nullptr, "expecting a pointer");
2020           if (adr->is_AddP()) {
2021             adr = get_addp_base(adr);
2022           }
2023           PointsToNode* ptn = ptnode_adr(adr->_idx);
2024           assert(ptn != nullptr, "node should be registered");
2025           add_edge(n_ptn, ptn);
2026         }
2027       }
2028       break;
2029     }
2030     case Op_Blackhole: {
2031       // All blackhole pointer arguments are globally escaping.
2032       for (uint i = 0; i < n->req(); i++) {
2033         Node* in = n->in(i);
2034         if (in != nullptr) {
2035           const Type* at = _igvn->type(in);
2036           if (!at->isa_ptr()) continue;
2037 
2038           if (in->is_AddP()) {
2039             in = get_addp_base(in);
2040           }
2041 
2042           PointsToNode* ptn = ptnode_adr(in->_idx);
2043           assert(ptn != nullptr, "should be defined already");
2044           set_escape_state(ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "blackhole"));
2045           add_edge(n_ptn, ptn);
2046         }
2047       }
2048       break;
2049     }
2050     default: {
2051       // This method should be called only for EA specific nodes which may
2052       // miss some edges when they were created.
2053 #ifdef ASSERT
2054       n->dump(1);
2055 #endif
2056       guarantee(false, "unknown node");
2057     }
2058   }
2059   return;
2060 }
2061 
2062 void ConnectionGraph::add_to_congraph_unsafe_access(Node* n, uint opcode, Unique_Node_List* delayed_worklist) {
2063   Node* adr = n->in(MemNode::Address);
2064   const Type* adr_type = _igvn->type(adr);
2065   adr_type = adr_type->make_ptr();
2066   if (adr_type == nullptr) {
2067     return; // skip dead nodes
2068   }
2069   if (adr_type->isa_oopptr()
2070       || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
2071           && adr_type == TypeRawPtr::NOTNULL
2072           && is_captured_store_address(adr))) {
2073     delayed_worklist->push(n); // Process it later.
2074 #ifdef ASSERT
2075     assert (adr->is_AddP(), "expecting an AddP");
2076     if (adr_type == TypeRawPtr::NOTNULL) {
2077       // Verify a raw address for a store captured by Initialize node.
2078       int offs = (int) _igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2079       assert(offs != Type::OffsetBot, "offset must be a constant");
2080     }
2081 #endif
2082   } else {
2083     // Ignore copy the displaced header to the BoxNode (OSR compilation).
2084     if (adr->is_BoxLock()) {
2085       return;
2086     }
2087     // Stored value escapes in unsafe access.
2088     if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
2089       delayed_worklist->push(n); // Process unsafe access later.
2090       return;
2091     }
2092 #ifdef ASSERT
2093     n->dump(1);
2094     assert(false, "not unsafe");
2095 #endif
2096   }
2097 }
2098 
2099 bool ConnectionGraph::add_final_edges_unsafe_access(Node* n, uint opcode) {
2100   Node* adr = n->in(MemNode::Address);
2101   const Type *adr_type = _igvn->type(adr);
2102   adr_type = adr_type->make_ptr();
2103 #ifdef ASSERT
2104   if (adr_type == nullptr) {
2105     n->dump(1);
2106     assert(adr_type != nullptr, "dead node should not be on list");
2107     return true;
2108   }
2109 #endif
2110 
2111   if (adr_type->isa_oopptr()
2112       || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
2113            && adr_type == TypeRawPtr::NOTNULL
2114            && is_captured_store_address(adr))) {
2115     // Point Address to Value
2116     PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
2117     assert(adr_ptn != nullptr &&
2118            adr_ptn->as_Field()->is_oop(), "node should be registered");
2119     Node* val = n->in(MemNode::ValueIn);
2120     PointsToNode* ptn = ptnode_adr(val->_idx);
2121     assert(ptn != nullptr, "node should be registered");
2122     add_edge(adr_ptn, ptn);
2123     return true;
2124   } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
2125     // Stored value escapes in unsafe access.
2126     Node* val = n->in(MemNode::ValueIn);
2127     PointsToNode* ptn = ptnode_adr(val->_idx);
2128     assert(ptn != nullptr, "node should be registered");
2129     set_escape_state(ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "stored at raw address"));
2130     // Add edge to object for unsafe access with offset.
2131     PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
2132     assert(adr_ptn != nullptr, "node should be registered");
2133     if (adr_ptn->is_Field()) {
2134       assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
2135       add_edge(adr_ptn, ptn);
2136     }
2137     return true;
2138   }
2139 #ifdef ASSERT
2140   n->dump(1);
2141   assert(false, "not unsafe");
2142 #endif
2143   return false;
2144 }
2145 
2146 // Iterate over the domains for the scalarized and non scalarized calling conventions: Only move to the next element
2147 // in the non scalarized calling convention once all elements of the scalarized calling convention for that parameter
2148 // have been iterated over. So (ignoring hidden arguments such as the null marker) iterating over:
2149 // value class MyValue {
2150 //   int f1;
2151 //   float f2;
2152 // }
2153 // void m(Object o, MyValue v, int i)
2154 // produces the pairs:
2155 // (Object, Object), (Myvalue, int), (MyValue, float), (int, int)
2156 class DomainIterator : public StackObj {
2157 private:
2158   const TypeTuple* _domain;
2159   const TypeTuple* _domain_cc;
2160   const GrowableArray<SigEntry>* _sig_cc;
2161 
2162   uint _i_domain;
2163   uint _i_domain_cc;
2164   int _i_sig_cc;
2165   uint _depth;
2166   uint _first_field_pos;
2167   const bool _is_static;
2168 
2169   void next_helper() {
2170     if (_sig_cc == nullptr) {
2171       return;
2172     }
2173     BasicType prev_bt = _i_sig_cc > 0 ? _sig_cc->at(_i_sig_cc-1)._bt : T_ILLEGAL;
2174     BasicType prev_prev_bt = _i_sig_cc > 1 ? _sig_cc->at(_i_sig_cc-2)._bt : T_ILLEGAL;
2175     while (_i_sig_cc < _sig_cc->length()) {
2176       BasicType bt = _sig_cc->at(_i_sig_cc)._bt;
2177       assert(bt != T_VOID || _sig_cc->at(_i_sig_cc-1)._bt == prev_bt, "incorrect prev bt");
2178       if (bt == T_METADATA) {
2179         if (_depth == 0) {
2180           _first_field_pos = _i_domain_cc;
2181         }
2182         _depth++;
2183       } else if (bt == T_VOID && (prev_bt != T_LONG && prev_bt != T_DOUBLE)) {
2184         _depth--;
2185         if (_depth == 0) {
2186           _i_domain++;
2187         }
2188       } else if (bt == T_OBJECT && prev_bt == T_METADATA && (_is_static || _i_domain > 0) && _sig_cc->at(_i_sig_cc)._offset == 0) {
2189         assert(_sig_cc->at(_i_sig_cc)._vt_oop, "buffer expected right after T_METADATA");
2190         assert(_depth == 1, "only root value has buffer");
2191         _i_domain_cc++;
2192         _first_field_pos = _i_domain_cc;
2193       } else if (bt == T_BOOLEAN && prev_prev_bt == T_METADATA && (_is_static || _i_domain > 0) && _sig_cc->at(_i_sig_cc)._offset == -1) {
2194         assert(_sig_cc->at(_i_sig_cc)._null_marker, "null marker expected right after T_METADATA");
2195         assert(_depth == 1, "only root value null marker");
2196         _i_domain_cc++;
2197         _first_field_pos = _i_domain_cc;
2198       } else {
2199         return;
2200       }
2201       prev_prev_bt = prev_bt;
2202       prev_bt = bt;
2203       _i_sig_cc++;
2204     }
2205   }
2206 
2207 public:
2208 
2209   DomainIterator(CallJavaNode* call) :
2210     _domain(call->tf()->domain_sig()),
2211     _domain_cc(call->tf()->domain_cc()),
2212     _sig_cc(call->method()->get_sig_cc()),
2213     _i_domain(TypeFunc::Parms),
2214     _i_domain_cc(TypeFunc::Parms),
2215     _i_sig_cc(0),
2216     _depth(0),
2217     _first_field_pos(0),
2218     _is_static(call->method()->is_static()) {
2219     next_helper();
2220   }
2221 
2222   bool has_next() const {
2223     assert(_sig_cc == nullptr || (_i_sig_cc < _sig_cc->length()) == (_i_domain < _domain->cnt()), "should reach end in sync");
2224     assert((_i_domain < _domain->cnt()) == (_i_domain_cc < _domain_cc->cnt()), "should reach end in sync");
2225     return _i_domain < _domain->cnt();
2226   }
2227 
2228   void next() {
2229     assert(_depth != 0 || _domain->field_at(_i_domain) == _domain_cc->field_at(_i_domain_cc), "should produce same non scalarized elements");
2230     _i_sig_cc++;
2231     if (_depth == 0) {
2232       _i_domain++;
2233     }
2234     _i_domain_cc++;
2235     next_helper();
2236   }
2237 
2238   uint i_domain() const {
2239     return _i_domain;
2240   }
2241 
2242   uint i_domain_cc() const {
2243     return _i_domain_cc;
2244   }
2245 
2246   const Type* current_domain() const {
2247     return _domain->field_at(_i_domain);
2248   }
2249 
2250   const Type* current_domain_cc() const {
2251     return _domain_cc->field_at(_i_domain_cc);
2252   }
2253 
2254   uint first_field_pos() const {
2255     assert(_first_field_pos >= TypeFunc::Parms, "not yet updated?");
2256     return _first_field_pos;
2257   }
2258 };
2259 
2260 // Determine whether any arguments are returned.
2261 bool ConnectionGraph::returns_an_argument(CallNode* call) {
2262   ciMethod* meth = call->as_CallJava()->method();
2263   BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
2264   if (call_analyzer == nullptr) {
2265     return false;
2266   }
2267 
2268   const TypeTuple* d = call->tf()->domain_sig();
2269   bool ret_arg = false;
2270   for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2271     if (d->field_at(i)->isa_ptr() != nullptr &&
2272         call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2273       if (meth->is_scalarized_arg(i - TypeFunc::Parms) && !compatible_return(call->as_CallJava(), i)) {
2274         return false;
2275       }
2276       if (call->tf()->returns_inline_type_as_fields() != meth->is_scalarized_arg(i - TypeFunc::Parms)) {
2277         return false;
2278       }
2279       ret_arg = true;
2280     }
2281   }
2282   return ret_arg;
2283 }
2284 
2285 void ConnectionGraph::add_call_node(CallNode* call) {
2286   assert(call->returns_pointer() || call->tf()->returns_inline_type_as_fields(), "only for call which returns pointer");
2287   uint call_idx = call->_idx;
2288   if (call->is_Allocate()) {
2289     Node* k = call->in(AllocateNode::KlassNode);
2290     const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
2291     assert(kt != nullptr, "TypeKlassPtr  required.");
2292     PointsToNode::EscapeState es = PointsToNode::NoEscape;
2293     bool scalar_replaceable = true;
2294     NOT_PRODUCT(const char* nsr_reason = "");
2295     if (call->is_AllocateArray()) {
2296       if (!kt->isa_aryklassptr()) { // StressReflectiveCode
2297         es = PointsToNode::GlobalEscape;
2298       } else {
2299         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2300         if (length < 0) {
2301           // Not scalar replaceable if the length is not constant.
2302           scalar_replaceable = false;
2303           NOT_PRODUCT(nsr_reason = "has a non-constant length");
2304         } else if (length > EliminateAllocationArraySizeLimit) {
2305           // Not scalar replaceable if the length is too big.
2306           scalar_replaceable = false;
2307           NOT_PRODUCT(nsr_reason = "has a length that is too big");
2308         }
2309       }
2310     } else {  // Allocate instance
2311       if (!kt->isa_instklassptr()) { // StressReflectiveCode
2312         es = PointsToNode::GlobalEscape;
2313       } else {
2314         const TypeInstKlassPtr* ikt = kt->is_instklassptr();
2315         ciInstanceKlass* ik = ikt->klass_is_exact() ? ikt->exact_klass()->as_instance_klass() : ikt->instance_klass();
2316         if (ik->is_subclass_of(_compile->env()->Thread_klass()) ||
2317             ik->is_subclass_of(_compile->env()->Reference_klass()) ||
2318             !ik->can_be_instantiated() ||
2319             ik->has_finalizer()) {
2320           es = PointsToNode::GlobalEscape;
2321         } else {
2322           int nfields = ik->as_instance_klass()->nof_nonstatic_fields();
2323           if (nfields > EliminateAllocationFieldsLimit) {
2324             // Not scalar replaceable if there are too many fields.
2325             scalar_replaceable = false;
2326             NOT_PRODUCT(nsr_reason = "has too many fields");
2327           }
2328         }
2329       }
2330     }
2331     add_java_object(call, es);
2332     PointsToNode* ptn = ptnode_adr(call_idx);
2333     if (!scalar_replaceable && ptn->scalar_replaceable()) {
2334       set_not_scalar_replaceable(ptn NOT_PRODUCT(COMMA nsr_reason));
2335     }
2336   } else if (call->is_CallStaticJava()) {
2337     // Call nodes could be different types:
2338     //
2339     // 1. CallDynamicJavaNode (what happened during call is unknown):
2340     //
2341     //    - mapped to GlobalEscape JavaObject node if oop is returned;
2342     //
2343     //    - all oop arguments are escaping globally;
2344     //
2345     // 2. CallStaticJavaNode (execute bytecode analysis if possible):
2346     //
2347     //    - the same as CallDynamicJavaNode if can't do bytecode analysis;
2348     //
2349     //    - mapped to GlobalEscape JavaObject node if unknown oop is returned;
2350     //    - mapped to NoEscape JavaObject node if non-escaping object allocated
2351     //      during call is returned;
2352     //    - mapped to ArgEscape LocalVar node pointed to object arguments
2353     //      which are returned and does not escape during call;
2354     //
2355     //    - oop arguments escaping status is defined by bytecode analysis;
2356     //
2357     // For a static call, we know exactly what method is being called.
2358     // Use bytecode estimator to record whether the call's return value escapes.
2359     ciMethod* meth = call->as_CallJava()->method();
2360     if (meth == nullptr) {
2361       const char* name = call->as_CallStaticJava()->_name;
2362       assert(call->as_CallStaticJava()->is_call_to_multianewarray_stub() ||
2363              strncmp(name, "load_unknown_inline", 19) == 0 ||
2364              strncmp(name, "store_inline_type_fields_to_buf", 31) == 0, "TODO: add failed case check");
2365       // Returns a newly allocated non-escaped object.
2366       add_java_object(call, PointsToNode::NoEscape);
2367       set_not_scalar_replaceable(ptnode_adr(call_idx) NOT_PRODUCT(COMMA "is result of multinewarray"));
2368     } else if (meth->is_boxing_method()) {
2369       // Returns boxing object
2370       PointsToNode::EscapeState es;
2371       vmIntrinsics::ID intr = meth->intrinsic_id();
2372       if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
2373         // It does not escape if object is always allocated.
2374         es = PointsToNode::NoEscape;
2375       } else {
2376         // It escapes globally if object could be loaded from cache.
2377         es = PointsToNode::GlobalEscape;
2378       }
2379       add_java_object(call, es);
2380       if (es == PointsToNode::GlobalEscape) {
2381         set_not_scalar_replaceable(ptnode_adr(call->_idx) NOT_PRODUCT(COMMA "object can be loaded from boxing cache"));
2382       }
2383     } else {
2384       BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
2385       call_analyzer->copy_dependencies(_compile->dependencies());
2386       if (call_analyzer->is_return_allocated()) {
2387         // Returns a newly allocated non-escaped object, simply
2388         // update dependency information.
2389         // Mark it as NoEscape so that objects referenced by
2390         // it's fields will be marked as NoEscape at least.
2391         add_java_object(call, PointsToNode::NoEscape);
2392         set_not_scalar_replaceable(ptnode_adr(call_idx) NOT_PRODUCT(COMMA "is result of call"));
2393       } else {
2394         // For non scalarized argument/return: add_proj() adds an edge between the return projection and the call,
2395         // process_call_arguments() adds an edge between the call and the argument
2396         // For scalarized argument/return: process_call_arguments() adds an edge between a call projection for a field
2397         // and the argument input to the call for that field. An edge is added between the projection for the returned
2398         // buffer and the call.
2399         if (returns_an_argument(call) && !call->tf()->returns_inline_type_as_fields()) {
2400           // returns non scalarized argument




2401           add_local_var(call, PointsToNode::ArgEscape);
2402         } else {
2403           // Returns unknown object or scalarized argument being returned
2404           map_ideal_node(call, phantom_obj);
2405         }
2406       }
2407     }
2408   } else {
2409     // An other type of call, assume the worst case:
2410     // returned value is unknown and globally escapes.
2411     assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
2412     map_ideal_node(call, phantom_obj);
2413   }
2414 }
2415 
2416 // Check that the return type is compatible with the type of the argument being returned i.e. that there's no cast that
2417 // fails in the method
2418 bool ConnectionGraph::compatible_return(CallJavaNode* call, uint k) {
2419   return call->tf()->domain_sig()->field_at(k)->is_instptr()->instance_klass() == call->tf()->range_sig()->field_at(TypeFunc::Parms)->is_instptr()->instance_klass();
2420 }
2421 
2422 void ConnectionGraph::process_call_arguments(CallNode *call) {
2423     bool is_arraycopy = false;
2424     switch (call->Opcode()) {
2425 #ifdef ASSERT
2426     case Op_Allocate:
2427     case Op_AllocateArray:
2428     case Op_Lock:
2429     case Op_Unlock:
2430       assert(false, "should be done already");
2431       break;
2432 #endif
2433     case Op_ArrayCopy:
2434     case Op_CallLeafNoFP:
2435       // Most array copies are ArrayCopy nodes at this point but there
2436       // are still a few direct calls to the copy subroutines (See
2437       // PhaseStringOpts::copy_string())
2438       is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
2439         call->as_CallLeaf()->is_call_to_arraycopystub();
2440       // fall through
2441     case Op_CallLeafVector:
2442     case Op_CallLeaf: {
2443       // Stub calls, objects do not escape but they are not scale replaceable.
2444       // Adjust escape state for outgoing arguments.
2445       const TypeTuple * d = call->tf()->domain_sig();
2446       bool src_has_oops = false;
2447       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2448         const Type* at = d->field_at(i);
2449         Node *arg = call->in(i);
2450         if (arg == nullptr) {
2451           continue;
2452         }
2453         const Type *aat = _igvn->type(arg);
2454         if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr()) {
2455           continue;
2456         }
2457         if (arg->is_AddP()) {
2458           //
2459           // The inline_native_clone() case when the arraycopy stub is called
2460           // after the allocation before Initialize and CheckCastPP nodes.
2461           // Or normal arraycopy for object arrays case.
2462           //
2463           // Set AddP's base (Allocate) as not scalar replaceable since
2464           // pointer to the base (with offset) is passed as argument.
2465           //
2466           arg = get_addp_base(arg);
2467         }
2468         PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2469         assert(arg_ptn != nullptr, "should be registered");
2470         PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
2471         if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
2472           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
2473                  aat->isa_ptr() != nullptr, "expecting an Ptr");
2474           bool arg_has_oops = aat->isa_oopptr() &&
2475                               (aat->isa_instptr() ||
2476                                (aat->isa_aryptr() && (aat->isa_aryptr()->elem() == Type::BOTTOM || aat->isa_aryptr()->elem()->make_oopptr() != nullptr)) ||
2477                                (aat->isa_aryptr() && aat->isa_aryptr()->elem() != nullptr &&
2478                                                                aat->isa_aryptr()->is_flat() &&
2479                                                                aat->isa_aryptr()->elem()->inline_klass()->contains_oops()));
2480           if (i == TypeFunc::Parms) {
2481             src_has_oops = arg_has_oops;
2482           }
2483           //
2484           // src or dst could be j.l.Object when other is basic type array:
2485           //
2486           //   arraycopy(char[],0,Object*,0,size);
2487           //   arraycopy(Object*,0,char[],0,size);
2488           //
2489           // Don't add edges in such cases.
2490           //
2491           bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
2492                                        arg_has_oops && (i > TypeFunc::Parms);
2493 #ifdef ASSERT
2494           if (!(is_arraycopy ||
2495                 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(call) ||
2496                 (call->as_CallLeaf()->_name != nullptr &&
2497                  (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
2498                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
2499                   strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
2500                   strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
2501                   strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
2502                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
2503                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
2504                   strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_encryptAESCrypt") == 0 ||
2505                   strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_decryptAESCrypt") == 0 ||
2506                   strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
2507                   strcmp(call->as_CallLeaf()->_name, "galoisCounterMode_AESCrypt") == 0 ||
2508                   strcmp(call->as_CallLeaf()->_name, "poly1305_processBlocks") == 0 ||
2509                   strcmp(call->as_CallLeaf()->_name, "intpoly_montgomeryMult_P256") == 0 ||
2510                   strcmp(call->as_CallLeaf()->_name, "intpoly_assign") == 0 ||
2511                   strcmp(call->as_CallLeaf()->_name, "intpoly_mult_25519") == 0 ||
2512                   strcmp(call->as_CallLeaf()->_name, "intpoly_square_25519") == 0 ||
2513                   strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
2514                   strcmp(call->as_CallLeaf()->_name, "chacha20Block") == 0 ||
2515                   strcmp(call->as_CallLeaf()->_name, "kyberNtt") == 0 ||
2516                   strcmp(call->as_CallLeaf()->_name, "kyberInverseNtt") == 0 ||
2517                   strcmp(call->as_CallLeaf()->_name, "kyberNttMult") == 0 ||
2518                   strcmp(call->as_CallLeaf()->_name, "kyberAddPoly_2") == 0 ||
2519                   strcmp(call->as_CallLeaf()->_name, "kyberAddPoly_3") == 0 ||
2520                   strcmp(call->as_CallLeaf()->_name, "kyber12To16") == 0 ||
2521                   strcmp(call->as_CallLeaf()->_name, "kyberBarrettReduce") == 0 ||
2522                   strcmp(call->as_CallLeaf()->_name, "dilithiumAlmostNtt") == 0 ||
2523                   strcmp(call->as_CallLeaf()->_name, "dilithiumAlmostInverseNtt") == 0 ||
2524                   strcmp(call->as_CallLeaf()->_name, "dilithiumNttMult") == 0 ||
2525                   strcmp(call->as_CallLeaf()->_name, "dilithiumMontMulByConstant") == 0 ||
2526                   strcmp(call->as_CallLeaf()->_name, "dilithiumDecomposePoly") == 0 ||
2527                   strcmp(call->as_CallLeaf()->_name, "encodeBlock") == 0 ||
2528                   strcmp(call->as_CallLeaf()->_name, "decodeBlock") == 0 ||
2529                   strcmp(call->as_CallLeaf()->_name, "md5_implCompress") == 0 ||
2530                   strcmp(call->as_CallLeaf()->_name, "md5_implCompressMB") == 0 ||
2531                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
2532                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
2533                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
2534                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
2535                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
2536                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
2537                   strcmp(call->as_CallLeaf()->_name, "sha3_implCompress") == 0 ||
2538                   strcmp(call->as_CallLeaf()->_name, "double_keccak") == 0 ||
2539                   strcmp(call->as_CallLeaf()->_name, "quad_keccak") == 0 ||
2540                   strcmp(call->as_CallLeaf()->_name, "sha3_implCompressMB") == 0 ||
2541                   strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
2542                   strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
2543                   strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
2544                   strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
2545                   strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
2546                   strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0 ||
2547                   strcmp(call->as_CallLeaf()->_name, "load_unknown_inline") == 0 ||
2548                   strcmp(call->as_CallLeaf()->_name, "store_unknown_inline") == 0 ||
2549                   strcmp(call->as_CallLeaf()->_name, "store_inline_type_fields_to_buf") == 0 ||
2550                   strcmp(call->as_CallLeaf()->_name, "bigIntegerRightShiftWorker") == 0 ||
2551                   strcmp(call->as_CallLeaf()->_name, "bigIntegerLeftShiftWorker") == 0 ||
2552                   strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0 ||
2553                   strcmp(call->as_CallLeaf()->_name, "stringIndexOf") == 0 ||
2554                   strcmp(call->as_CallLeaf()->_name, "arraysort_stub") == 0 ||
2555                   strcmp(call->as_CallLeaf()->_name, "array_partition_stub") == 0 ||
2556                   strcmp(call->as_CallLeaf()->_name, "get_class_id_intrinsic") == 0 ||
2557                   strcmp(call->as_CallLeaf()->_name, "unsafe_setmemory") == 0)
2558                  ))) {
2559             call->dump();
2560             fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
2561           }
2562 #endif
2563           // Always process arraycopy's destination object since
2564           // we need to add all possible edges to references in
2565           // source object.
2566           if (arg_esc >= PointsToNode::ArgEscape &&
2567               !arg_is_arraycopy_dest) {
2568             continue;
2569           }
2570           PointsToNode::EscapeState es = PointsToNode::ArgEscape;
2571           if (call->is_ArrayCopy()) {
2572             ArrayCopyNode* ac = call->as_ArrayCopy();
2573             if (ac->is_clonebasic() ||
2574                 ac->is_arraycopy_validated() ||
2575                 ac->is_copyof_validated() ||
2576                 ac->is_copyofrange_validated()) {
2577               es = PointsToNode::NoEscape;
2578             }
2579           }
2580           set_escape_state(arg_ptn, es NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2581           if (arg_is_arraycopy_dest) {
2582             Node* src = call->in(TypeFunc::Parms);
2583             if (src->is_AddP()) {
2584               src = get_addp_base(src);
2585             }
2586             PointsToNode* src_ptn = ptnode_adr(src->_idx);
2587             assert(src_ptn != nullptr, "should be registered");
2588             // Special arraycopy edge:
2589             // Only escape state of destination object's fields affects
2590             // escape state of fields in source object.
2591             add_arraycopy(call, es, src_ptn, arg_ptn);
2592           }
2593         }
2594       }
2595       break;
2596     }
2597     case Op_CallStaticJava: {
2598       // For a static call, we know exactly what method is being called.
2599       // Use bytecode estimator to record the call's escape affects
2600 #ifdef ASSERT
2601       const char* name = call->as_CallStaticJava()->_name;
2602       assert((name == nullptr || strcmp(name, "uncommon_trap") != 0), "normal calls only");
2603 #endif
2604       ciMethod* meth = call->as_CallJava()->method();
2605       if ((meth != nullptr) && meth->is_boxing_method()) {
2606         break; // Boxing methods do not modify any oops.
2607       }
2608       BCEscapeAnalyzer* call_analyzer = (meth !=nullptr) ? meth->get_bcea() : nullptr;
2609       // fall-through if not a Java method or no analyzer information
2610       if (call_analyzer != nullptr) {
2611         PointsToNode* call_ptn = ptnode_adr(call->_idx);
2612         bool ret_arg = returns_an_argument(call);
2613         for (DomainIterator di(call->as_CallJava()); di.has_next(); di.next()) {
2614           int k = di.i_domain() - TypeFunc::Parms;
2615           const Type* at = di.current_domain_cc();
2616           Node* arg = call->in(di.i_domain_cc());
2617           PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2618           assert(!call_analyzer->is_arg_returned(k) || !meth->is_scalarized_arg(k) ||
2619                  !compatible_return(call->as_CallJava(), di.i_domain()) ||
2620                  call->proj_out_or_null(di.i_domain_cc() - di.first_field_pos() + TypeFunc::Parms + 1) == nullptr ||
2621                  _igvn->type(call->proj_out_or_null(di.i_domain_cc() - di.first_field_pos() + TypeFunc::Parms + 1)) == at,
2622                  "scalarized return and scalarized argument should match");
2623           if (at->isa_ptr() != nullptr && call_analyzer->is_arg_returned(k) && ret_arg) {
2624             // The call returns arguments.
2625             if (meth->is_scalarized_arg(k)) {
2626               ProjNode* res_proj = call->proj_out_or_null(di.i_domain_cc() - di.first_field_pos() + TypeFunc::Parms + 1);
2627               if (res_proj != nullptr) {
2628                 assert(_igvn->type(res_proj)->isa_ptr(), "scalarized return and scalarized argument should match");
2629                 if (res_proj->_con != TypeFunc::Parms) {
2630                   // add an edge between the result projection for a field and the argument projection for the same argument field
2631                   PointsToNode* proj_ptn = ptnode_adr(res_proj->_idx);
2632                   add_edge(proj_ptn, arg_ptn);
2633                   if (!call_analyzer->is_return_local()) {
2634                     add_edge(proj_ptn, phantom_obj);
2635                   }
2636                 }
2637               }
2638             } else if (call_ptn != nullptr) { // Is call's result used?
2639               assert(call_ptn->is_LocalVar(), "node should be registered");
2640               assert(arg_ptn != nullptr, "node should be registered");
2641               add_edge(call_ptn, arg_ptn);
2642             }
2643           }
2644           if (at->isa_oopptr() != nullptr &&
2645               arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
2646             if (!call_analyzer->is_arg_stack(k)) {
2647               // The argument global escapes
2648               set_escape_state(arg_ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2649             } else {
2650               set_escape_state(arg_ptn, PointsToNode::ArgEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2651               if (!call_analyzer->is_arg_local(k)) {
2652                 // The argument itself doesn't escape, but any fields might
2653                 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2654               }
2655             }
2656           }
2657         }
2658         if (call_ptn != nullptr && call_ptn->is_LocalVar()) {
2659           // The call returns arguments.
2660           assert(call_ptn->edge_count() > 0, "sanity");
2661           if (!call_analyzer->is_return_local()) {
2662             // Returns also unknown object.
2663             add_edge(call_ptn, phantom_obj);
2664           }
2665         }
2666         break;
2667       }
2668     }
2669     default: {
2670       // Fall-through here if not a Java method or no analyzer information
2671       // or some other type of call, assume the worst case: all arguments
2672       // globally escape.
2673       const TypeTuple* d = call->tf()->domain_cc();
2674       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2675         const Type* at = d->field_at(i);
2676         if (at->isa_oopptr() != nullptr) {
2677           Node* arg = call->in(i);
2678           if (arg->is_AddP()) {
2679             arg = get_addp_base(arg);
2680           }
2681           assert(ptnode_adr(arg->_idx) != nullptr, "should be defined already");
2682           set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2683         }
2684       }
2685     }
2686   }
2687 }
2688 
2689 
2690 // Finish Graph construction.
2691 bool ConnectionGraph::complete_connection_graph(
2692                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
2693                          GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist,
2694                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
2695                          GrowableArray<FieldNode*>&      oop_fields_worklist) {
2696   // Normally only 1-3 passes needed to build Connection Graph depending
2697   // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
2698   // Set limit to 20 to catch situation when something did go wrong and
2699   // bailout Escape Analysis.
2700   // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
2701 #define GRAPH_BUILD_ITER_LIMIT 20
2702 
2703   // Propagate GlobalEscape and ArgEscape escape states and check that
2704   // we still have non-escaping objects. The method pushs on _worklist
2705   // Field nodes which reference phantom_object.
2706   if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist)) {
2707     return false; // Nothing to do.
2708   }
2709   // Now propagate references to all JavaObject nodes.
2710   int java_objects_length = java_objects_worklist.length();
2711   elapsedTimer build_time;
2712   build_time.start();
2713   elapsedTimer time;
2714   bool timeout = false;
2715   int new_edges = 1;
2716   int iterations = 0;
2717   do {
2718     while ((new_edges > 0) &&
2719            (iterations++ < GRAPH_BUILD_ITER_LIMIT)) {
2720       double start_time = time.seconds();
2721       time.start();
2722       new_edges = 0;
2723       // Propagate references to phantom_object for nodes pushed on _worklist
2724       // by find_non_escaped_objects() and find_field_value().
2725       new_edges += add_java_object_edges(phantom_obj, false);
2726       for (int next = 0; next < java_objects_length; ++next) {
2727         JavaObjectNode* ptn = java_objects_worklist.at(next);
2728         new_edges += add_java_object_edges(ptn, true);
2729 
2730 #define SAMPLE_SIZE 4
2731         if ((next % SAMPLE_SIZE) == 0) {
2732           // Each 4 iterations calculate how much time it will take
2733           // to complete graph construction.
2734           time.stop();
2735           // Poll for requests from shutdown mechanism to quiesce compiler
2736           // because Connection graph construction may take long time.
2737           CompileBroker::maybe_block();
2738           double stop_time = time.seconds();
2739           double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
2740           double time_until_end = time_per_iter * (double)(java_objects_length - next);
2741           if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
2742             timeout = true;
2743             break; // Timeout
2744           }
2745           start_time = stop_time;
2746           time.start();
2747         }
2748 #undef SAMPLE_SIZE
2749 
2750       }
2751       if (timeout) break;
2752       if (new_edges > 0) {
2753         // Update escape states on each iteration if graph was updated.
2754         if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist)) {
2755           return false; // Nothing to do.
2756         }
2757       }
2758       time.stop();
2759       if (time.seconds() >= EscapeAnalysisTimeout) {
2760         timeout = true;
2761         break;
2762       }
2763       _compile->print_method(PHASE_EA_COMPLETE_CONNECTION_GRAPH_ITER, 5);
2764     }
2765     if ((iterations < GRAPH_BUILD_ITER_LIMIT) && !timeout) {
2766       time.start();
2767       // Find fields which have unknown value.
2768       int fields_length = oop_fields_worklist.length();
2769       for (int next = 0; next < fields_length; next++) {
2770         FieldNode* field = oop_fields_worklist.at(next);
2771         if (field->edge_count() == 0) {
2772           new_edges += find_field_value(field);
2773           // This code may added new edges to phantom_object.
2774           // Need an other cycle to propagate references to phantom_object.
2775         }
2776       }
2777       time.stop();
2778       if (time.seconds() >= EscapeAnalysisTimeout) {
2779         timeout = true;
2780         break;
2781       }
2782     } else {
2783       new_edges = 0; // Bailout
2784     }
2785   } while (new_edges > 0);
2786 
2787   build_time.stop();
2788   _build_time = build_time.seconds();
2789   _build_iterations = iterations;
2790 
2791   // Bailout if passed limits.
2792   if ((iterations >= GRAPH_BUILD_ITER_LIMIT) || timeout) {
2793     Compile* C = _compile;
2794     if (C->log() != nullptr) {
2795       C->log()->begin_elem("connectionGraph_bailout reason='reached ");
2796       C->log()->text("%s", timeout ? "time" : "iterations");
2797       C->log()->end_elem(" limit'");
2798     }
2799     assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build during invocation %d (%f sec, %d iterations) with %d nodes and worklist size %d",
2800            _invocation, _build_time, _build_iterations, nodes_size(), ptnodes_worklist.length());
2801     // Possible infinite build_connection_graph loop,
2802     // bailout (no changes to ideal graph were made).
2803     return false;
2804   }
2805 
2806 #undef GRAPH_BUILD_ITER_LIMIT
2807 
2808   // Find fields initialized by null for non-escaping Allocations.
2809   int non_escaped_length = non_escaped_allocs_worklist.length();
2810   for (int next = 0; next < non_escaped_length; next++) {
2811     JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
2812     PointsToNode::EscapeState es = ptn->escape_state();
2813     assert(es <= PointsToNode::ArgEscape, "sanity");
2814     if (es == PointsToNode::NoEscape) {
2815       if (find_init_values_null(ptn, _igvn) > 0) {
2816         // Adding references to null object does not change escape states
2817         // since it does not escape. Also no fields are added to null object.
2818         add_java_object_edges(null_obj, false);
2819       }
2820     }
2821     Node* n = ptn->ideal_node();
2822     if (n->is_Allocate()) {
2823       // The object allocated by this Allocate node will never be
2824       // seen by an other thread. Mark it so that when it is
2825       // expanded no MemBarStoreStore is added.
2826       InitializeNode* ini = n->as_Allocate()->initialization();
2827       if (ini != nullptr)
2828         ini->set_does_not_escape();
2829     }
2830   }
2831   return true; // Finished graph construction.
2832 }
2833 
2834 // Propagate GlobalEscape and ArgEscape escape states to all nodes
2835 // and check that we still have non-escaping java objects.
2836 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
2837                                                GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist,
2838                                                bool print_method) {
2839   GrowableArray<PointsToNode*> escape_worklist;
2840   // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
2841   int ptnodes_length = ptnodes_worklist.length();
2842   for (int next = 0; next < ptnodes_length; ++next) {
2843     PointsToNode* ptn = ptnodes_worklist.at(next);
2844     if (ptn->escape_state() >= PointsToNode::ArgEscape ||
2845         ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
2846       escape_worklist.push(ptn);
2847     }
2848   }
2849   // Set escape states to referenced nodes (edges list).
2850   while (escape_worklist.length() > 0) {
2851     PointsToNode* ptn = escape_worklist.pop();
2852     PointsToNode::EscapeState es  = ptn->escape_state();
2853     PointsToNode::EscapeState field_es = ptn->fields_escape_state();
2854     if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
2855         es >= PointsToNode::ArgEscape) {
2856       // GlobalEscape or ArgEscape state of field means it has unknown value.
2857       if (add_edge(ptn, phantom_obj)) {
2858         // New edge was added
2859         add_field_uses_to_worklist(ptn->as_Field());
2860       }
2861     }
2862     for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2863       PointsToNode* e = i.get();
2864       if (e->is_Arraycopy()) {
2865         assert(ptn->arraycopy_dst(), "sanity");
2866         // Propagate only fields escape state through arraycopy edge.
2867         if (e->fields_escape_state() < field_es) {
2868           set_fields_escape_state(e, field_es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2869           escape_worklist.push(e);
2870         }
2871       } else if (es >= field_es) {
2872         // fields_escape_state is also set to 'es' if it is less than 'es'.
2873         if (e->escape_state() < es) {
2874           set_escape_state(e, es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2875           escape_worklist.push(e);
2876         }
2877       } else {
2878         // Propagate field escape state.
2879         bool es_changed = false;
2880         if (e->fields_escape_state() < field_es) {
2881           set_fields_escape_state(e, field_es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2882           es_changed = true;
2883         }
2884         if ((e->escape_state() < field_es) &&
2885             e->is_Field() && ptn->is_JavaObject() &&
2886             e->as_Field()->is_oop()) {
2887           // Change escape state of referenced fields.
2888           set_escape_state(e, field_es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2889           es_changed = true;
2890         } else if (e->escape_state() < es) {
2891           set_escape_state(e, es NOT_PRODUCT(COMMA trace_propagate_message(ptn)));
2892           es_changed = true;
2893         }
2894         if (es_changed) {
2895           escape_worklist.push(e);
2896         }
2897       }
2898       if (print_method) {
2899         _compile->print_method(PHASE_EA_CONNECTION_GRAPH_PROPAGATE_ITER, 6, e->ideal_node());
2900       }
2901     }
2902   }
2903   // Remove escaped objects from non_escaped list.
2904   for (int next = non_escaped_allocs_worklist.length()-1; next >= 0 ; --next) {
2905     JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
2906     if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
2907       non_escaped_allocs_worklist.delete_at(next);
2908     }
2909     if (ptn->escape_state() == PointsToNode::NoEscape) {
2910       // Find fields in non-escaped allocations which have unknown value.
2911       find_init_values_phantom(ptn);
2912     }
2913   }
2914   return (non_escaped_allocs_worklist.length() > 0);
2915 }
2916 
2917 // Add all references to JavaObject node by walking over all uses.
2918 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
2919   int new_edges = 0;
2920   if (populate_worklist) {
2921     // Populate _worklist by uses of jobj's uses.
2922     for (UseIterator i(jobj); i.has_next(); i.next()) {
2923       PointsToNode* use = i.get();
2924       if (use->is_Arraycopy()) {
2925         continue;
2926       }
2927       add_uses_to_worklist(use);
2928       if (use->is_Field() && use->as_Field()->is_oop()) {
2929         // Put on worklist all field's uses (loads) and
2930         // related field nodes (same base and offset).
2931         add_field_uses_to_worklist(use->as_Field());
2932       }
2933     }
2934   }
2935   for (int l = 0; l < _worklist.length(); l++) {
2936     PointsToNode* use = _worklist.at(l);
2937     if (PointsToNode::is_base_use(use)) {
2938       // Add reference from jobj to field and from field to jobj (field's base).
2939       use = PointsToNode::get_use_node(use)->as_Field();
2940       if (add_base(use->as_Field(), jobj)) {
2941         new_edges++;
2942       }
2943       continue;
2944     }
2945     assert(!use->is_JavaObject(), "sanity");
2946     if (use->is_Arraycopy()) {
2947       if (jobj == null_obj) { // null object does not have field edges
2948         continue;
2949       }
2950       // Added edge from Arraycopy node to arraycopy's source java object
2951       if (add_edge(use, jobj)) {
2952         jobj->set_arraycopy_src();
2953         new_edges++;
2954       }
2955       // and stop here.
2956       continue;
2957     }
2958     if (!add_edge(use, jobj)) {
2959       continue; // No new edge added, there was such edge already.
2960     }
2961     new_edges++;
2962     if (use->is_LocalVar()) {
2963       add_uses_to_worklist(use);
2964       if (use->arraycopy_dst()) {
2965         for (EdgeIterator i(use); i.has_next(); i.next()) {
2966           PointsToNode* e = i.get();
2967           if (e->is_Arraycopy()) {
2968             if (jobj == null_obj) { // null object does not have field edges
2969               continue;
2970             }
2971             // Add edge from arraycopy's destination java object to Arraycopy node.
2972             if (add_edge(jobj, e)) {
2973               new_edges++;
2974               jobj->set_arraycopy_dst();
2975             }
2976           }
2977         }
2978       }
2979     } else {
2980       // Added new edge to stored in field values.
2981       // Put on worklist all field's uses (loads) and
2982       // related field nodes (same base and offset).
2983       add_field_uses_to_worklist(use->as_Field());
2984     }
2985   }
2986   _worklist.clear();
2987   _in_worklist.reset();
2988   return new_edges;
2989 }
2990 
2991 // Put on worklist all related field nodes.
2992 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
2993   assert(field->is_oop(), "sanity");
2994   int offset = field->offset();
2995   add_uses_to_worklist(field);
2996   // Loop over all bases of this field and push on worklist Field nodes
2997   // with the same offset and base (since they may reference the same field).
2998   for (BaseIterator i(field); i.has_next(); i.next()) {
2999     PointsToNode* base = i.get();
3000     add_fields_to_worklist(field, base);
3001     // Check if the base was source object of arraycopy and go over arraycopy's
3002     // destination objects since values stored to a field of source object are
3003     // accessible by uses (loads) of fields of destination objects.
3004     if (base->arraycopy_src()) {
3005       for (UseIterator j(base); j.has_next(); j.next()) {
3006         PointsToNode* arycp = j.get();
3007         if (arycp->is_Arraycopy()) {
3008           for (UseIterator k(arycp); k.has_next(); k.next()) {
3009             PointsToNode* abase = k.get();
3010             if (abase->arraycopy_dst() && abase != base) {
3011               // Look for the same arraycopy reference.
3012               add_fields_to_worklist(field, abase);
3013             }
3014           }
3015         }
3016       }
3017     }
3018   }
3019 }
3020 
3021 // Put on worklist all related field nodes.
3022 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
3023   int offset = field->offset();
3024   if (base->is_LocalVar()) {
3025     for (UseIterator j(base); j.has_next(); j.next()) {
3026       PointsToNode* f = j.get();
3027       if (PointsToNode::is_base_use(f)) { // Field
3028         f = PointsToNode::get_use_node(f);
3029         if (f == field || !f->as_Field()->is_oop()) {
3030           continue;
3031         }
3032         int offs = f->as_Field()->offset();
3033         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
3034           add_to_worklist(f);
3035         }
3036       }
3037     }
3038   } else {
3039     assert(base->is_JavaObject(), "sanity");
3040     if (// Skip phantom_object since it is only used to indicate that
3041         // this field's content globally escapes.
3042         (base != phantom_obj) &&
3043         // null object node does not have fields.
3044         (base != null_obj)) {
3045       for (EdgeIterator i(base); i.has_next(); i.next()) {
3046         PointsToNode* f = i.get();
3047         // Skip arraycopy edge since store to destination object field
3048         // does not update value in source object field.
3049         if (f->is_Arraycopy()) {
3050           assert(base->arraycopy_dst(), "sanity");
3051           continue;
3052         }
3053         if (f == field || !f->as_Field()->is_oop()) {
3054           continue;
3055         }
3056         int offs = f->as_Field()->offset();
3057         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
3058           add_to_worklist(f);
3059         }
3060       }
3061     }
3062   }
3063 }
3064 
3065 // Find fields which have unknown value.
3066 int ConnectionGraph::find_field_value(FieldNode* field) {
3067   // Escaped fields should have init value already.
3068   assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
3069   int new_edges = 0;
3070   for (BaseIterator i(field); i.has_next(); i.next()) {
3071     PointsToNode* base = i.get();
3072     if (base->is_JavaObject()) {
3073       // Skip Allocate's fields which will be processed later.
3074       if (base->ideal_node()->is_Allocate()) {
3075         return 0;
3076       }
3077       assert(base == null_obj, "only null ptr base expected here");
3078     }
3079   }
3080   if (add_edge(field, phantom_obj)) {
3081     // New edge was added
3082     new_edges++;
3083     add_field_uses_to_worklist(field);
3084   }
3085   return new_edges;
3086 }
3087 
3088 // Find fields initializing values for allocations.
3089 int ConnectionGraph::find_init_values_phantom(JavaObjectNode* pta) {
3090   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
3091   PointsToNode* init_val = phantom_obj;
3092   Node* alloc = pta->ideal_node();
3093 
3094   // Do nothing for Allocate nodes since its fields values are
3095   // "known" unless they are initialized by arraycopy/clone.
3096   if (alloc->is_Allocate() && !pta->arraycopy_dst()) {
3097     if (alloc->as_Allocate()->in(AllocateNode::InitValue) != nullptr) {
3098       // Null-free inline type arrays are initialized with an init value instead of null
3099       init_val = ptnode_adr(alloc->as_Allocate()->in(AllocateNode::InitValue)->_idx);
3100       assert(init_val != nullptr, "init value should be registered");
3101     } else {
3102       return 0;
3103     }
3104   }
3105   // Non-escaped allocation returned from Java or runtime call has unknown values in fields.
3106   assert(pta->arraycopy_dst() || alloc->is_CallStaticJava() || init_val != phantom_obj, "sanity");
3107 #ifdef ASSERT
3108   if (alloc->is_CallStaticJava() && alloc->as_CallStaticJava()->method() == nullptr) {
3109     const char* name = alloc->as_CallStaticJava()->_name;
3110     assert(alloc->as_CallStaticJava()->is_call_to_multianewarray_stub() ||
3111            strncmp(name, "load_unknown_inline", 19) == 0 ||
3112            strncmp(name, "store_inline_type_fields_to_buf", 31) == 0, "sanity");
3113   }
3114 #endif
3115   // Non-escaped allocation returned from Java or runtime call have unknown values in fields.
3116   int new_edges = 0;
3117   for (EdgeIterator i(pta); i.has_next(); i.next()) {
3118     PointsToNode* field = i.get();
3119     if (field->is_Field() && field->as_Field()->is_oop()) {
3120       if (add_edge(field, init_val)) {
3121         // New edge was added
3122         new_edges++;
3123         add_field_uses_to_worklist(field->as_Field());
3124       }
3125     }
3126   }
3127   return new_edges;
3128 }
3129 
3130 // Find fields initializing values for allocations.
3131 int ConnectionGraph::find_init_values_null(JavaObjectNode* pta, PhaseValues* phase) {
3132   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
3133   Node* alloc = pta->ideal_node();
3134   // Do nothing for Call nodes since its fields values are unknown.
3135   if (!alloc->is_Allocate() || alloc->as_Allocate()->in(AllocateNode::InitValue) != nullptr) {
3136     return 0;
3137   }
3138   InitializeNode* ini = alloc->as_Allocate()->initialization();
3139   bool visited_bottom_offset = false;
3140   GrowableArray<int> offsets_worklist;
3141   int new_edges = 0;
3142 
3143   // Check if an oop field's initializing value is recorded and add
3144   // a corresponding null if field's value if it is not recorded.
3145   // Connection Graph does not record a default initialization by null
3146   // captured by Initialize node.
3147   //
3148   for (EdgeIterator i(pta); i.has_next(); i.next()) {
3149     PointsToNode* field = i.get(); // Field (AddP)
3150     if (!field->is_Field() || !field->as_Field()->is_oop()) {
3151       continue; // Not oop field
3152     }
3153     int offset = field->as_Field()->offset();
3154     if (offset == Type::OffsetBot) {
3155       if (!visited_bottom_offset) {
3156         // OffsetBot is used to reference array's element,
3157         // always add reference to null to all Field nodes since we don't
3158         // known which element is referenced.
3159         if (add_edge(field, null_obj)) {
3160           // New edge was added
3161           new_edges++;
3162           add_field_uses_to_worklist(field->as_Field());
3163           visited_bottom_offset = true;
3164         }
3165       }
3166     } else {
3167       // Check only oop fields.
3168       const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
3169       if (adr_type->isa_rawptr()) {
3170 #ifdef ASSERT
3171         // Raw pointers are used for initializing stores so skip it
3172         // since it should be recorded already
3173         Node* base = get_addp_base(field->ideal_node());
3174         assert(adr_type->isa_rawptr() && is_captured_store_address(field->ideal_node()), "unexpected pointer type");
3175 #endif
3176         continue;
3177       }
3178       if (!offsets_worklist.contains(offset)) {
3179         offsets_worklist.append(offset);
3180         Node* value = nullptr;
3181         if (ini != nullptr) {
3182           // StoreP::value_basic_type() == T_ADDRESS
3183           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
3184           Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
3185           // Make sure initializing store has the same type as this AddP.
3186           // This AddP may reference non existing field because it is on a
3187           // dead branch of bimorphic call which is not eliminated yet.
3188           if (store != nullptr && store->is_Store() &&
3189               store->as_Store()->value_basic_type() == ft) {
3190             value = store->in(MemNode::ValueIn);
3191 #ifdef ASSERT
3192             if (VerifyConnectionGraph) {
3193               // Verify that AddP already points to all objects the value points to.
3194               PointsToNode* val = ptnode_adr(value->_idx);
3195               assert((val != nullptr), "should be processed already");
3196               PointsToNode* missed_obj = nullptr;
3197               if (val->is_JavaObject()) {
3198                 if (!field->points_to(val->as_JavaObject())) {
3199                   missed_obj = val;
3200                 }
3201               } else {
3202                 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
3203                   tty->print_cr("----------init store has invalid value -----");
3204                   store->dump();
3205                   val->dump();
3206                   assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
3207                 }
3208                 for (EdgeIterator j(val); j.has_next(); j.next()) {
3209                   PointsToNode* obj = j.get();
3210                   if (obj->is_JavaObject()) {
3211                     if (!field->points_to(obj->as_JavaObject())) {
3212                       missed_obj = obj;
3213                       break;
3214                     }
3215                   }
3216                 }
3217               }
3218               if (missed_obj != nullptr) {
3219                 tty->print_cr("----------field---------------------------------");
3220                 field->dump();
3221                 tty->print_cr("----------missed reference to object------------");
3222                 missed_obj->dump();
3223                 tty->print_cr("----------object referenced by init store-------");
3224                 store->dump();
3225                 val->dump();
3226                 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
3227               }
3228             }
3229 #endif
3230           } else {
3231             // There could be initializing stores which follow allocation.
3232             // For example, a volatile field store is not collected
3233             // by Initialize node.
3234             //
3235             // Need to check for dependent loads to separate such stores from
3236             // stores which follow loads. For now, add initial value null so
3237             // that compare pointers optimization works correctly.
3238           }
3239         }
3240         if (value == nullptr) {
3241           // A field's initializing value was not recorded. Add null.
3242           if (add_edge(field, null_obj)) {
3243             // New edge was added
3244             new_edges++;
3245             add_field_uses_to_worklist(field->as_Field());
3246           }
3247         }
3248       }
3249     }
3250   }
3251   return new_edges;
3252 }
3253 
3254 // Adjust scalar_replaceable state after Connection Graph is built.
3255 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj, Unique_Node_List &reducible_merges) {
3256   // A Phi 'x' is a _candidate_ to be reducible if 'can_reduce_phi(x)'
3257   // returns true. If one of the constraints in this method set 'jobj' to NSR
3258   // then the candidate Phi is discarded. If the Phi has another SR 'jobj' as
3259   // input, 'adjust_scalar_replaceable_state' will eventually be called with
3260   // that other object and the Phi will become a reducible Phi.
3261   // There could be multiple merges involving the same jobj.
3262   Unique_Node_List candidates;
3263 
3264   // Search for non-escaping objects which are not scalar replaceable
3265   // and mark them to propagate the state to referenced objects.
3266 
3267   for (UseIterator i(jobj); i.has_next(); i.next()) {
3268     PointsToNode* use = i.get();
3269     if (use->is_Arraycopy()) {
3270       continue;
3271     }
3272     if (use->is_Field()) {
3273       FieldNode* field = use->as_Field();
3274       assert(field->is_oop() && field->scalar_replaceable(), "sanity");
3275       // 1. An object is not scalar replaceable if the field into which it is
3276       // stored has unknown offset (stored into unknown element of an array).
3277       if (field->offset() == Type::OffsetBot) {
3278         set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored at unknown offset"));
3279         return;
3280       }
3281       for (BaseIterator i(field); i.has_next(); i.next()) {
3282         PointsToNode* base = i.get();
3283         // 2. An object is not scalar replaceable if the field into which it is
3284         // stored has multiple bases one of which is null.
3285         if ((base == null_obj) && (field->base_count() > 1)) {
3286           set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored into field with potentially null base"));
3287           return;
3288         }
3289         // 2.5. An object is not scalar replaceable if the field into which it is
3290         // stored has NSR base.
3291         if (!base->scalar_replaceable()) {
3292           set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored into field with NSR base"));
3293           return;
3294         }
3295       }
3296     }
3297     assert(use->is_Field() || use->is_LocalVar(), "sanity");
3298     // 3. An object is not scalar replaceable if it is merged with other objects
3299     // and we can't remove the merge
3300     for (EdgeIterator j(use); j.has_next(); j.next()) {
3301       PointsToNode* ptn = j.get();
3302       if (ptn->is_JavaObject() && ptn != jobj) {
3303         Node* use_n = use->ideal_node();
3304 
3305         // These other local vars may point to multiple objects through a Phi
3306         // In this case we skip them and see if we can reduce the Phi.
3307         if (use_n->is_CastPP() || use_n->is_CheckCastPP()) {
3308           use_n = use_n->in(1);
3309         }
3310 
3311         // If it's already a candidate or confirmed reducible merge we can skip verification
3312         if (candidates.member(use_n) || reducible_merges.member(use_n)) {
3313           continue;
3314         }
3315 
3316         if (use_n->is_Phi() && can_reduce_phi(use_n->as_Phi())) {
3317           candidates.push(use_n);
3318         } else {
3319           // Mark all objects as NSR if we can't remove the merge
3320           set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA trace_merged_message(ptn)));
3321           set_not_scalar_replaceable(ptn NOT_PRODUCT(COMMA trace_merged_message(jobj)));
3322         }
3323       }
3324     }
3325     if (!jobj->scalar_replaceable()) {
3326       return;
3327     }
3328   }
3329 
3330   for (EdgeIterator j(jobj); j.has_next(); j.next()) {
3331     if (j.get()->is_Arraycopy()) {
3332       continue;
3333     }
3334 
3335     // Non-escaping object node should point only to field nodes.
3336     FieldNode* field = j.get()->as_Field();
3337     int offset = field->as_Field()->offset();
3338 
3339     // 4. An object is not scalar replaceable if it has a field with unknown
3340     // offset (array's element is accessed in loop).
3341     if (offset == Type::OffsetBot) {
3342       set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "has field with unknown offset"));
3343       return;
3344     }
3345     // 5. Currently an object is not scalar replaceable if a LoadStore node
3346     // access its field since the field value is unknown after it.
3347     //
3348     Node* n = field->ideal_node();
3349 
3350     // Test for an unsafe access that was parsed as maybe off heap
3351     // (with a CheckCastPP to raw memory).
3352     assert(n->is_AddP(), "expect an address computation");
3353     if (n->in(AddPNode::Base)->is_top() &&
3354         n->in(AddPNode::Address)->Opcode() == Op_CheckCastPP) {
3355       assert(n->in(AddPNode::Address)->bottom_type()->isa_rawptr(), "raw address so raw cast expected");
3356       assert(_igvn->type(n->in(AddPNode::Address)->in(1))->isa_oopptr(), "cast pattern at unsafe access expected");
3357       set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is used as base of mixed unsafe access"));
3358       return;
3359     }
3360 
3361     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3362       Node* u = n->fast_out(i);
3363       if (u->is_LoadStore() || (u->is_Mem() && u->as_Mem()->is_mismatched_access())) {
3364         set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is used in LoadStore or mismatched access"));
3365         return;
3366       }
3367     }
3368 
3369     // 6. Or the address may point to more then one object. This may produce
3370     // the false positive result (set not scalar replaceable)
3371     // since the flow-insensitive escape analysis can't separate
3372     // the case when stores overwrite the field's value from the case
3373     // when stores happened on different control branches.
3374     //
3375     // Note: it will disable scalar replacement in some cases:
3376     //
3377     //    Point p[] = new Point[1];
3378     //    p[0] = new Point(); // Will be not scalar replaced
3379     //
3380     // but it will save us from incorrect optimizations in next cases:
3381     //
3382     //    Point p[] = new Point[1];
3383     //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
3384     //
3385     if (field->base_count() > 1 && candidates.size() == 0) {
3386       if (has_non_reducible_merge(field, reducible_merges)) {
3387         for (BaseIterator i(field); i.has_next(); i.next()) {
3388           PointsToNode* base = i.get();
3389           // Don't take into account LocalVar nodes which
3390           // may point to only one object which should be also
3391           // this field's base by now.
3392           if (base->is_JavaObject() && base != jobj) {
3393             // Mark all bases.
3394             set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "may point to more than one object"));
3395             set_not_scalar_replaceable(base NOT_PRODUCT(COMMA "may point to more than one object"));
3396           }
3397         }
3398 
3399         if (!jobj->scalar_replaceable()) {
3400           return;
3401         }
3402       }
3403     }
3404   }
3405 
3406   // The candidate is truly a reducible merge only if none of the other
3407   // constraints ruled it as NSR. There could be multiple merges involving the
3408   // same jobj.
3409   assert(jobj->scalar_replaceable(), "sanity");
3410   for (uint i = 0; i < candidates.size(); i++ ) {
3411     Node* candidate = candidates.at(i);
3412     reducible_merges.push(candidate);
3413   }
3414 }
3415 
3416 bool ConnectionGraph::has_non_reducible_merge(FieldNode* field, Unique_Node_List& reducible_merges) {
3417   for (BaseIterator i(field); i.has_next(); i.next()) {
3418     Node* base = i.get()->ideal_node();
3419     if (base->is_Phi() && !reducible_merges.member(base)) {
3420       return true;
3421     }
3422   }
3423   return false;
3424 }
3425 
3426 void ConnectionGraph::revisit_reducible_phi_status(JavaObjectNode* jobj, Unique_Node_List& reducible_merges) {
3427   assert(jobj != nullptr && !jobj->scalar_replaceable(), "jobj should be set as NSR before calling this function.");
3428 
3429   // Look for 'phis' that refer to 'jobj' as the last
3430   // remaining scalar replaceable input.
3431   uint reducible_merges_cnt = reducible_merges.size();
3432   for (uint i = 0; i < reducible_merges_cnt; i++) {
3433     Node* phi = reducible_merges.at(i);
3434 
3435     // This 'Phi' will be a 'good' if it still points to
3436     // at least one scalar replaceable object. Note that 'obj'
3437     // was/should be marked as NSR before calling this function.
3438     bool good_phi = false;
3439 
3440     for (uint j = 1; j < phi->req(); j++) {
3441       JavaObjectNode* phi_in_obj = unique_java_object(phi->in(j));
3442       if (phi_in_obj != nullptr && phi_in_obj->scalar_replaceable()) {
3443         good_phi = true;
3444         break;
3445       }
3446     }
3447 
3448     if (!good_phi) {
3449       NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Phi %d became non-reducible after node %d became NSR.", phi->_idx, jobj->ideal_node()->_idx);)
3450       reducible_merges.remove(i);
3451 
3452       // Decrement the index because the 'remove' call above actually
3453       // moves the last entry of the list to position 'i'.
3454       i--;
3455 
3456       reducible_merges_cnt--;
3457     }
3458   }
3459 }
3460 
3461 // Propagate NSR (Not scalar replaceable) state.
3462 void ConnectionGraph::find_scalar_replaceable_allocs(GrowableArray<JavaObjectNode*>& jobj_worklist, Unique_Node_List &reducible_merges) {
3463   int jobj_length = jobj_worklist.length();
3464   bool found_nsr_alloc = true;
3465   while (found_nsr_alloc) {
3466     found_nsr_alloc = false;
3467     for (int next = 0; next < jobj_length; ++next) {
3468       JavaObjectNode* jobj = jobj_worklist.at(next);
3469       for (UseIterator i(jobj); (jobj->scalar_replaceable() && i.has_next()); i.next()) {
3470         PointsToNode* use = i.get();
3471         if (use->is_Field()) {
3472           FieldNode* field = use->as_Field();
3473           assert(field->is_oop() && field->scalar_replaceable(), "sanity");
3474           assert(field->offset() != Type::OffsetBot, "sanity");
3475           for (BaseIterator i(field); i.has_next(); i.next()) {
3476             PointsToNode* base = i.get();
3477             // An object is not scalar replaceable if the field into which
3478             // it is stored has NSR base.
3479             if ((base != null_obj) && !base->scalar_replaceable()) {
3480               set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is stored into field with NSR base"));
3481               // Any merge that had only 'jobj' as scalar-replaceable will now be non-reducible,
3482               // because there is no point in reducing a Phi that won't improve the number of SR
3483               // objects.
3484               revisit_reducible_phi_status(jobj, reducible_merges);
3485               found_nsr_alloc = true;
3486               break;
3487             }
3488           }
3489         } else if (use->is_LocalVar()) {
3490           Node* phi = use->ideal_node();
3491           if (phi->Opcode() == Op_Phi && reducible_merges.member(phi) && !can_reduce_phi(phi->as_Phi())) {
3492             set_not_scalar_replaceable(jobj NOT_PRODUCT(COMMA "is merged in a non-reducible phi"));
3493             reducible_merges.yank(phi);
3494             found_nsr_alloc = true;
3495             break;
3496           }
3497         }
3498         _compile->print_method(PHASE_EA_PROPAGATE_NSR_ITER, 5, jobj->ideal_node());
3499       }
3500     }
3501   }
3502 }
3503 
3504 #ifdef ASSERT
3505 void ConnectionGraph::verify_connection_graph(
3506                          GrowableArray<PointsToNode*>&   ptnodes_worklist,
3507                          GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist,
3508                          GrowableArray<JavaObjectNode*>& java_objects_worklist,
3509                          GrowableArray<Node*>& addp_worklist) {
3510   // Verify that graph is complete - no new edges could be added.
3511   int java_objects_length = java_objects_worklist.length();
3512   int non_escaped_length  = non_escaped_allocs_worklist.length();
3513   int new_edges = 0;
3514   for (int next = 0; next < java_objects_length; ++next) {
3515     JavaObjectNode* ptn = java_objects_worklist.at(next);
3516     new_edges += add_java_object_edges(ptn, true);
3517   }
3518   assert(new_edges == 0, "graph was not complete");
3519   // Verify that escape state is final.
3520   int length = non_escaped_allocs_worklist.length();
3521   find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist, /*print_method=*/ false);
3522   assert((non_escaped_length == non_escaped_allocs_worklist.length()) &&
3523          (non_escaped_length == length) &&
3524          (_worklist.length() == 0), "escape state was not final");
3525 
3526   // Verify fields information.
3527   int addp_length = addp_worklist.length();
3528   for (int next = 0; next < addp_length; ++next ) {
3529     Node* n = addp_worklist.at(next);
3530     FieldNode* field = ptnode_adr(n->_idx)->as_Field();
3531     if (field->is_oop()) {
3532       // Verify that field has all bases
3533       Node* base = get_addp_base(n);
3534       PointsToNode* ptn = ptnode_adr(base->_idx);
3535       if (ptn->is_JavaObject()) {
3536         assert(field->has_base(ptn->as_JavaObject()), "sanity");
3537       } else {
3538         assert(ptn->is_LocalVar(), "sanity");
3539         for (EdgeIterator i(ptn); i.has_next(); i.next()) {
3540           PointsToNode* e = i.get();
3541           if (e->is_JavaObject()) {
3542             assert(field->has_base(e->as_JavaObject()), "sanity");
3543           }
3544         }
3545       }
3546       // Verify that all fields have initializing values.
3547       if (field->edge_count() == 0) {
3548         tty->print_cr("----------field does not have references----------");
3549         field->dump();
3550         for (BaseIterator i(field); i.has_next(); i.next()) {
3551           PointsToNode* base = i.get();
3552           tty->print_cr("----------field has next base---------------------");
3553           base->dump();
3554           if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
3555             tty->print_cr("----------base has fields-------------------------");
3556             for (EdgeIterator j(base); j.has_next(); j.next()) {
3557               j.get()->dump();
3558             }
3559             tty->print_cr("----------base has references---------------------");
3560             for (UseIterator j(base); j.has_next(); j.next()) {
3561               j.get()->dump();
3562             }
3563           }
3564         }
3565         for (UseIterator i(field); i.has_next(); i.next()) {
3566           i.get()->dump();
3567         }
3568         assert(field->edge_count() > 0, "sanity");
3569       }
3570     }
3571   }
3572 }
3573 #endif
3574 
3575 // Optimize ideal graph.
3576 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
3577                                            GrowableArray<MemBarStoreStoreNode*>& storestore_worklist) {
3578   Compile* C = _compile;
3579   PhaseIterGVN* igvn = _igvn;
3580   if (EliminateLocks) {
3581     // Mark locks before changing ideal graph.
3582     int cnt = C->macro_count();
3583     for (int i = 0; i < cnt; i++) {
3584       Node *n = C->macro_node(i);
3585       if (n->is_AbstractLock()) { // Lock and Unlock nodes
3586         AbstractLockNode* alock = n->as_AbstractLock();
3587         if (!alock->is_non_esc_obj()) {
3588           const Type* obj_type = igvn->type(alock->obj_node());
3589           if (can_eliminate_lock(alock) && !obj_type->is_inlinetypeptr()) {
3590             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
3591             // The lock could be marked eliminated by lock coarsening
3592             // code during first IGVN before EA. Replace coarsened flag
3593             // to eliminate all associated locks/unlocks.
3594 #ifdef ASSERT
3595             alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
3596 #endif
3597             alock->set_non_esc_obj();
3598           }
3599         }
3600       }
3601     }
3602   }
3603 
3604   if (OptimizePtrCompare) {
3605     for (int i = 0; i < ptr_cmp_worklist.length(); i++) {
3606       Node *n = ptr_cmp_worklist.at(i);
3607       assert(n->Opcode() == Op_CmpN || n->Opcode() == Op_CmpP, "must be");
3608       const TypeInt* tcmp = optimize_ptr_compare(n->in(1), n->in(2));
3609       if (tcmp->singleton()) {
3610         Node* cmp = igvn->makecon(tcmp);
3611 #ifndef PRODUCT
3612         if (PrintOptimizePtrCompare) {
3613           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"));
3614           if (Verbose) {
3615             n->dump(1);
3616           }
3617         }
3618 #endif
3619         igvn->replace_node(n, cmp);
3620       }
3621     }
3622   }
3623 
3624   // For MemBarStoreStore nodes added in library_call.cpp, check
3625   // escape status of associated AllocateNode and optimize out
3626   // MemBarStoreStore node if the allocated object never escapes.
3627   for (int i = 0; i < storestore_worklist.length(); i++) {
3628     Node* storestore = storestore_worklist.at(i);
3629     Node* alloc = storestore->in(MemBarNode::Precedent)->in(0);
3630     if (alloc->is_Allocate() && not_global_escape(alloc)) {
3631       if (alloc->in(AllocateNode::InlineType) != nullptr) {
3632         // Non-escaping inline type buffer allocations don't require a membar
3633         storestore->as_MemBar()->remove(_igvn);
3634       } else {
3635         MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
3636         mb->init_req(TypeFunc::Memory,  storestore->in(TypeFunc::Memory));
3637         mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
3638         igvn->register_new_node_with_optimizer(mb);
3639         igvn->replace_node(storestore, mb);
3640       }
3641     }
3642   }
3643 }
3644 
3645 // Atomic flat accesses on non-escaping objects can be optimized to non-atomic accesses
3646 void ConnectionGraph::optimize_flat_accesses(GrowableArray<SafePointNode*>& sfn_worklist) {
3647   PhaseIterGVN& igvn = *_igvn;
3648   bool delay = igvn.delay_transform();
3649   igvn.set_delay_transform(true);
3650   igvn.C->for_each_flat_access([&](Node* n) {
3651     Node* base = n->is_LoadFlat() ? n->as_LoadFlat()->base() : n->as_StoreFlat()->base();
3652     if (!not_global_escape(base)) {
3653       return;
3654     }
3655 
3656     bool expanded;
3657     if (n->is_LoadFlat()) {
3658       expanded = n->as_LoadFlat()->expand_non_atomic(igvn);
3659     } else {
3660       expanded = n->as_StoreFlat()->expand_non_atomic(igvn);
3661     }
3662     if (expanded) {
3663       sfn_worklist.remove(n->as_SafePoint());
3664       igvn.C->remove_flat_access(n);
3665     }
3666   });
3667   igvn.set_delay_transform(delay);
3668 }
3669 
3670 // Optimize objects compare.
3671 const TypeInt* ConnectionGraph::optimize_ptr_compare(Node* left, Node* right) {
3672   const TypeInt* UNKNOWN = TypeInt::CC;    // [-1, 0,1]
3673   if (!OptimizePtrCompare) {
3674     return UNKNOWN;
3675   }
3676   const TypeInt* EQ = TypeInt::CC_EQ; // [0] == ZERO
3677   const TypeInt* NE = TypeInt::CC_GT; // [1] == ONE
3678 
3679   PointsToNode* ptn1 = ptnode_adr(left->_idx);
3680   PointsToNode* ptn2 = ptnode_adr(right->_idx);
3681   JavaObjectNode* jobj1 = unique_java_object(left);
3682   JavaObjectNode* jobj2 = unique_java_object(right);
3683 
3684   // The use of this method during allocation merge reduction may cause 'left'
3685   // or 'right' be something (e.g., a Phi) that isn't in the connection graph or
3686   // that doesn't reference an unique java object.
3687   if (ptn1 == nullptr || ptn2 == nullptr ||
3688       jobj1 == nullptr || jobj2 == nullptr) {
3689     return UNKNOWN;
3690   }
3691 
3692   assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
3693   assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
3694 
3695   // Check simple cases first.
3696   if (jobj1 != nullptr) {
3697     if (jobj1->escape_state() == PointsToNode::NoEscape) {
3698       if (jobj1 == jobj2) {
3699         // Comparing the same not escaping object.
3700         return EQ;
3701       }
3702       Node* obj = jobj1->ideal_node();
3703       // Comparing not escaping allocation.
3704       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
3705           !ptn2->points_to(jobj1)) {
3706         return NE; // This includes nullness check.
3707       }
3708     }
3709   }
3710   if (jobj2 != nullptr) {
3711     if (jobj2->escape_state() == PointsToNode::NoEscape) {
3712       Node* obj = jobj2->ideal_node();
3713       // Comparing not escaping allocation.
3714       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
3715           !ptn1->points_to(jobj2)) {
3716         return NE; // This includes nullness check.
3717       }
3718     }
3719   }
3720   if (jobj1 != nullptr && jobj1 != phantom_obj &&
3721       jobj2 != nullptr && jobj2 != phantom_obj &&
3722       jobj1->ideal_node()->is_Con() &&
3723       jobj2->ideal_node()->is_Con()) {
3724     // Klass or String constants compare. Need to be careful with
3725     // compressed pointers - compare types of ConN and ConP instead of nodes.
3726     const Type* t1 = jobj1->ideal_node()->get_ptr_type();
3727     const Type* t2 = jobj2->ideal_node()->get_ptr_type();
3728     if (t1->make_ptr() == t2->make_ptr()) {
3729       return EQ;
3730     } else {
3731       return NE;
3732     }
3733   }
3734   if (ptn1->meet(ptn2)) {
3735     return UNKNOWN; // Sets are not disjoint
3736   }
3737 
3738   // Sets are disjoint.
3739   bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
3740   bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
3741   bool set1_has_null_ptr    = ptn1->points_to(null_obj);
3742   bool set2_has_null_ptr    = ptn2->points_to(null_obj);
3743   if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
3744       (set2_has_unknown_ptr && set1_has_null_ptr)) {
3745     // Check nullness of unknown object.
3746     return UNKNOWN;
3747   }
3748 
3749   // Disjointness by itself is not sufficient since
3750   // alias analysis is not complete for escaped objects.
3751   // Disjoint sets are definitely unrelated only when
3752   // at least one set has only not escaping allocations.
3753   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
3754     if (ptn1->non_escaping_allocation()) {
3755       return NE;
3756     }
3757   }
3758   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
3759     if (ptn2->non_escaping_allocation()) {
3760       return NE;
3761     }
3762   }
3763   return UNKNOWN;
3764 }
3765 
3766 // Connection Graph construction functions.
3767 
3768 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
3769   PointsToNode* ptadr = _nodes.at(n->_idx);
3770   if (ptadr != nullptr) {
3771     assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
3772     return;
3773   }
3774   Compile* C = _compile;
3775   ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
3776   map_ideal_node(n, ptadr);
3777 }
3778 
3779 PointsToNode* ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
3780   PointsToNode* ptadr = _nodes.at(n->_idx);
3781   if (ptadr != nullptr) {
3782     assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
3783     return ptadr;
3784   }
3785   Compile* C = _compile;
3786   ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
3787   map_ideal_node(n, ptadr);
3788   return ptadr;
3789 }
3790 
3791 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
3792   PointsToNode* ptadr = _nodes.at(n->_idx);
3793   if (ptadr != nullptr) {
3794     assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
3795     return;
3796   }
3797   bool unsafe = false;
3798   bool is_oop = is_oop_field(n, offset, &unsafe);
3799   if (unsafe) {
3800     es = PointsToNode::GlobalEscape;
3801   }
3802   Compile* C = _compile;
3803   FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
3804   map_ideal_node(n, field);
3805 }
3806 
3807 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
3808                                     PointsToNode* src, PointsToNode* dst) {
3809   assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
3810   assert((src != null_obj) && (dst != null_obj), "not for ConP null");
3811   PointsToNode* ptadr = _nodes.at(n->_idx);
3812   if (ptadr != nullptr) {
3813     assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
3814     return;
3815   }
3816   Compile* C = _compile;
3817   ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
3818   map_ideal_node(n, ptadr);
3819   // Add edge from arraycopy node to source object.
3820   (void)add_edge(ptadr, src);
3821   src->set_arraycopy_src();
3822   // Add edge from destination object to arraycopy node.
3823   (void)add_edge(dst, ptadr);
3824   dst->set_arraycopy_dst();
3825 }
3826 
3827 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
3828   const Type* adr_type = n->as_AddP()->bottom_type();
3829   int field_offset = adr_type->isa_aryptr() ? adr_type->isa_aryptr()->field_offset().get() : Type::OffsetBot;
3830   BasicType bt = T_INT;
3831   if (offset == Type::OffsetBot && field_offset == Type::OffsetBot) {
3832     // Check only oop fields.
3833     if (!adr_type->isa_aryptr() ||
3834         adr_type->isa_aryptr()->elem() == Type::BOTTOM ||
3835         adr_type->isa_aryptr()->elem()->make_oopptr() != nullptr) {
3836       // OffsetBot is used to reference array's element. Ignore first AddP.
3837       if (find_second_addp(n, n->in(AddPNode::Base)) == nullptr) {
3838         bt = T_OBJECT;
3839       }
3840     }
3841   } else if (offset != oopDesc::klass_offset_in_bytes()) {
3842     if (adr_type->isa_instptr()) {
3843       ciField* field = _compile->alias_type(adr_type->is_ptr())->field();
3844       if (field != nullptr) {
3845         bt = field->layout_type();
3846       } else {
3847         // Check for unsafe oop field access
3848         if (has_oop_node_outs(n)) {
3849           bt = T_OBJECT;
3850           (*unsafe) = true;
3851         }
3852       }
3853     } else if (adr_type->isa_aryptr()) {
3854       if (offset == arrayOopDesc::length_offset_in_bytes()) {
3855         // Ignore array length load.
3856       } else if (find_second_addp(n, n->in(AddPNode::Base)) != nullptr) {
3857         // Ignore first AddP.
3858       } else {
3859         const Type* elemtype = adr_type->is_aryptr()->elem();
3860         if (adr_type->is_aryptr()->is_flat() && field_offset != Type::OffsetBot) {
3861           ciInlineKlass* vk = elemtype->inline_klass();
3862           field_offset += vk->payload_offset();
3863           ciField* field = vk->get_field_by_offset(field_offset, false);
3864           if (field != nullptr) {
3865             bt = field->layout_type();
3866           } else {
3867             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);
3868             bt = T_BOOLEAN;
3869           }
3870         } else {
3871           bt = elemtype->array_element_basic_type();
3872         }
3873       }
3874     } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
3875       // Allocation initialization, ThreadLocal field access, unsafe access
3876       if (has_oop_node_outs(n)) {
3877         bt = T_OBJECT;
3878       }
3879     }
3880   }
3881   // Note: T_NARROWOOP is not classed as a real reference type
3882   bool res = (is_reference_type(bt) || bt == T_NARROWOOP);
3883   assert(!has_oop_node_outs(n) || res, "sanity: AddP has oop outs, needs to be treated as oop field");
3884   return res;
3885 }
3886 
3887 bool ConnectionGraph::has_oop_node_outs(Node* n) {
3888   return n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
3889          n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
3890          n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
3891          BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n);
3892 }
3893 
3894 // Returns unique pointed java object or null.
3895 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) const {
3896   // If the node was created after the escape computation we can't answer.
3897   uint idx = n->_idx;
3898   if (idx >= nodes_size()) {
3899     return nullptr;
3900   }
3901   PointsToNode* ptn = ptnode_adr(idx);
3902   if (ptn == nullptr) {
3903     return nullptr;
3904   }
3905   if (ptn->is_JavaObject()) {
3906     return ptn->as_JavaObject();
3907   }
3908   assert(ptn->is_LocalVar(), "sanity");
3909   // Check all java objects it points to.
3910   JavaObjectNode* jobj = nullptr;
3911   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
3912     PointsToNode* e = i.get();
3913     if (e->is_JavaObject()) {
3914       if (jobj == nullptr) {
3915         jobj = e->as_JavaObject();
3916       } else if (jobj != e) {
3917         return nullptr;
3918       }
3919     }
3920   }
3921   return jobj;
3922 }
3923 
3924 // Return true if this node points only to non-escaping allocations.
3925 bool PointsToNode::non_escaping_allocation() {
3926   if (is_JavaObject()) {
3927     Node* n = ideal_node();
3928     if (n->is_Allocate() || n->is_CallStaticJava()) {
3929       return (escape_state() == PointsToNode::NoEscape);
3930     } else {
3931       return false;
3932     }
3933   }
3934   assert(is_LocalVar(), "sanity");
3935   // Check all java objects it points to.
3936   for (EdgeIterator i(this); i.has_next(); i.next()) {
3937     PointsToNode* e = i.get();
3938     if (e->is_JavaObject()) {
3939       Node* n = e->ideal_node();
3940       if ((e->escape_state() != PointsToNode::NoEscape) ||
3941           !(n->is_Allocate() || n->is_CallStaticJava())) {
3942         return false;
3943       }
3944     }
3945   }
3946   return true;
3947 }
3948 
3949 // Return true if we know the node does not escape globally.
3950 bool ConnectionGraph::not_global_escape(Node *n) {
3951   assert(!_collecting, "should not call during graph construction");
3952   // If the node was created after the escape computation we can't answer.
3953   uint idx = n->_idx;
3954   if (idx >= nodes_size()) {
3955     return false;
3956   }
3957   PointsToNode* ptn = ptnode_adr(idx);
3958   if (ptn == nullptr) {
3959     return false; // not in congraph (e.g. ConI)
3960   }
3961   PointsToNode::EscapeState es = ptn->escape_state();
3962   // If we have already computed a value, return it.
3963   if (es >= PointsToNode::GlobalEscape) {
3964     return false;
3965   }
3966   if (ptn->is_JavaObject()) {
3967     return true; // (es < PointsToNode::GlobalEscape);
3968   }
3969   assert(ptn->is_LocalVar(), "sanity");
3970   // Check all java objects it points to.
3971   for (EdgeIterator i(ptn); i.has_next(); i.next()) {
3972     if (i.get()->escape_state() >= PointsToNode::GlobalEscape) {
3973       return false;
3974     }
3975   }
3976   return true;
3977 }
3978 
3979 // Return true if locked object does not escape globally
3980 // and locked code region (identified by BoxLockNode) is balanced:
3981 // all compiled code paths have corresponding Lock/Unlock pairs.
3982 bool ConnectionGraph::can_eliminate_lock(AbstractLockNode* alock) {
3983   if (alock->is_balanced() && not_global_escape(alock->obj_node())) {
3984     if (EliminateNestedLocks) {
3985       // We can mark whole locking region as Local only when only
3986       // one object is used for locking.
3987       alock->box_node()->as_BoxLock()->set_local();
3988     }
3989     return true;
3990   }
3991   return false;
3992 }
3993 
3994 // Helper functions
3995 
3996 // Return true if this node points to specified node or nodes it points to.
3997 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
3998   if (is_JavaObject()) {
3999     return (this == ptn);
4000   }
4001   assert(is_LocalVar() || is_Field(), "sanity");
4002   for (EdgeIterator i(this); i.has_next(); i.next()) {
4003     if (i.get() == ptn) {
4004       return true;
4005     }
4006   }
4007   return false;
4008 }
4009 
4010 // Return true if one node points to an other.
4011 bool PointsToNode::meet(PointsToNode* ptn) {
4012   if (this == ptn) {
4013     return true;
4014   } else if (ptn->is_JavaObject()) {
4015     return this->points_to(ptn->as_JavaObject());
4016   } else if (this->is_JavaObject()) {
4017     return ptn->points_to(this->as_JavaObject());
4018   }
4019   assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
4020   int ptn_count =  ptn->edge_count();
4021   for (EdgeIterator i(this); i.has_next(); i.next()) {
4022     PointsToNode* this_e = i.get();
4023     for (int j = 0; j < ptn_count; j++) {
4024       if (this_e == ptn->edge(j)) {
4025         return true;
4026       }
4027     }
4028   }
4029   return false;
4030 }
4031 
4032 #ifdef ASSERT
4033 // Return true if bases point to this java object.
4034 bool FieldNode::has_base(JavaObjectNode* jobj) const {
4035   for (BaseIterator i(this); i.has_next(); i.next()) {
4036     if (i.get() == jobj) {
4037       return true;
4038     }
4039   }
4040   return false;
4041 }
4042 #endif
4043 
4044 bool ConnectionGraph::is_captured_store_address(Node* addp) {
4045   // Handle simple case first.
4046   assert(_igvn->type(addp)->isa_oopptr() == nullptr, "should be raw access");
4047   if (addp->in(AddPNode::Address)->is_Proj() && addp->in(AddPNode::Address)->in(0)->is_Allocate()) {
4048     return true;
4049   } else if (addp->in(AddPNode::Address)->is_Phi()) {
4050     for (DUIterator_Fast imax, i = addp->fast_outs(imax); i < imax; i++) {
4051       Node* addp_use = addp->fast_out(i);
4052       if (addp_use->is_Store()) {
4053         for (DUIterator_Fast jmax, j = addp_use->fast_outs(jmax); j < jmax; j++) {
4054           if (addp_use->fast_out(j)->is_Initialize()) {
4055             return true;
4056           }
4057         }
4058       }
4059     }
4060   }
4061   return false;
4062 }
4063 
4064 int ConnectionGraph::address_offset(Node* adr, PhaseValues* phase) {
4065   const Type *adr_type = phase->type(adr);
4066   if (adr->is_AddP() && adr_type->isa_oopptr() == nullptr && is_captured_store_address(adr)) {
4067     // We are computing a raw address for a store captured by an Initialize
4068     // compute an appropriate address type. AddP cases #3 and #5 (see below).
4069     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
4070     assert(offs != Type::OffsetBot ||
4071            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
4072            "offset must be a constant or it is initialization of array");
4073     return offs;
4074   }
4075   return adr_type->is_ptr()->flat_offset();


4076 }
4077 
4078 Node* ConnectionGraph::get_addp_base(Node *addp) {
4079   assert(addp->is_AddP(), "must be AddP");
4080   //
4081   // AddP cases for Base and Address inputs:
4082   // case #1. Direct object's field reference:
4083   //     Allocate
4084   //       |
4085   //     Proj #5 ( oop result )
4086   //       |
4087   //     CheckCastPP (cast to instance type)
4088   //      | |
4089   //     AddP  ( base == address )
4090   //
4091   // case #2. Indirect object's field reference:
4092   //      Phi
4093   //       |
4094   //     CastPP (cast to instance type)
4095   //      | |
4096   //     AddP  ( base == address )
4097   //
4098   // case #3. Raw object's field reference for Initialize node.
4099   //          Could have an additional Phi merging multiple allocations.
4100   //      Allocate
4101   //        |
4102   //      Proj #5 ( oop result )
4103   //  top   |
4104   //     \  |
4105   //     AddP  ( base == top )
4106   //
4107   // case #4. Array's element reference:
4108   //   {CheckCastPP | CastPP}
4109   //     |  | |
4110   //     |  AddP ( array's element offset )
4111   //     |  |
4112   //     AddP ( array's offset )
4113   //
4114   // case #5. Raw object's field reference for arraycopy stub call:
4115   //          The inline_native_clone() case when the arraycopy stub is called
4116   //          after the allocation before Initialize and CheckCastPP nodes.
4117   //      Allocate
4118   //        |
4119   //      Proj #5 ( oop result )
4120   //       | |
4121   //       AddP  ( base == address )
4122   //
4123   // case #6. Constant Pool, ThreadLocal, CastX2P, Klass, OSR buffer buf or
4124   //          Raw object's field reference:
4125   //      {ConP, ThreadLocal, CastX2P, raw Load, Parm0}
4126   //  top   |
4127   //     \  |
4128   //     AddP  ( base == top )
4129   //
4130   // case #7. Klass's field reference.
4131   //      LoadKlass
4132   //       | |
4133   //       AddP  ( base == address )
4134   //
4135   // case #8. narrow Klass's field reference.
4136   //      LoadNKlass
4137   //       |
4138   //      DecodeN
4139   //       | |
4140   //       AddP  ( base == address )
4141   //
4142   // case #9. Mixed unsafe access
4143   //    {instance}
4144   //        |
4145   //      CheckCastPP (raw)
4146   //  top   |
4147   //     \  |
4148   //     AddP  ( base == top )
4149   //
4150   // case #10. Klass fetched with
4151   //           LibraryCallKit::load_*_refined_array_klass()
4152   //           which has en extra Phi.
4153   //  LoadKlass   LoadKlass
4154   //       |          |
4155   //     CastPP    CastPP
4156   //          \   /
4157   //           Phi
4158   //      top   |
4159   //         \  |
4160   //         AddP  ( base == top )
4161   //
4162   Node *base = addp->in(AddPNode::Base);
4163   if (base->uncast()->is_top()) { // The AddP case #3, #6, #9, and #10.
4164     base = addp->in(AddPNode::Address);
4165     while (base->is_AddP()) {
4166       // Case #6 (unsafe access) may have several chained AddP nodes.
4167       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
4168       base = base->in(AddPNode::Address);
4169     }
4170     if (base->Opcode() == Op_CheckCastPP &&
4171         base->bottom_type()->isa_rawptr() &&
4172         _igvn->type(base->in(1))->isa_oopptr()) {
4173       base = base->in(1); // Case #9
4174     } else {
4175       // Case #3, #6, and #10
4176       Node* uncast_base = base->uncast();
4177       int opcode = uncast_base->Opcode();
4178       assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
4179              opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
4180              (_igvn->C->is_osr_compilation() && uncast_base->is_Parm() && uncast_base->as_Parm()->_con == TypeFunc::Parms)||
4181              (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != nullptr)) ||
4182              (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_klassptr() != nullptr)) ||
4183              is_captured_store_address(addp) ||
4184              is_load_array_klass_related(uncast_base), "sanity");
4185     }
4186   }
4187   return base;
4188 }
4189 
4190 #ifdef ASSERT
4191 // Case #10
4192 bool ConnectionGraph::is_load_array_klass_related(const Node* uncast_base) {
4193   if (!uncast_base->is_Phi() || uncast_base->req() != 3) {
4194     return false;
4195   }
4196   Node* in1 = uncast_base->in(1);
4197   Node* in2 = uncast_base->in(2);
4198   return in1->uncast()->Opcode() == Op_LoadKlass &&
4199          in2->uncast()->Opcode() == Op_LoadKlass;
4200 }
4201 #endif
4202 
4203 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
4204   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
4205   Node* addp2 = addp->raw_out(0);
4206   if (addp->outcnt() == 1 && addp2->is_AddP() &&
4207       addp2->in(AddPNode::Base) == n &&
4208       addp2->in(AddPNode::Address) == addp) {
4209     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
4210     //
4211     // Find array's offset to push it on worklist first and
4212     // as result process an array's element offset first (pushed second)
4213     // to avoid CastPP for the array's offset.
4214     // Otherwise the inserted CastPP (LocalVar) will point to what
4215     // the AddP (Field) points to. Which would be wrong since
4216     // the algorithm expects the CastPP has the same point as
4217     // as AddP's base CheckCastPP (LocalVar).
4218     //
4219     //    ArrayAllocation
4220     //     |
4221     //    CheckCastPP
4222     //     |
4223     //    memProj (from ArrayAllocation CheckCastPP)
4224     //     |  ||
4225     //     |  ||   Int (element index)
4226     //     |  ||    |   ConI (log(element size))
4227     //     |  ||    |   /
4228     //     |  ||   LShift
4229     //     |  ||  /
4230     //     |  AddP (array's element offset)
4231     //     |  |
4232     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
4233     //     | / /
4234     //     AddP (array's offset)
4235     //      |
4236     //     Load/Store (memory operation on array's element)
4237     //
4238     return addp2;
4239   }
4240   return nullptr;
4241 }
4242 
4243 //
4244 // Adjust the type and inputs of an AddP which computes the
4245 // address of a field of an instance
4246 //
4247 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
4248   PhaseGVN* igvn = _igvn;
4249   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
4250   assert(base_t != nullptr && base_t->is_known_instance(), "expecting instance oopptr");
4251   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
4252   if (t == nullptr) {
4253     // We are computing a raw address for a store captured by an Initialize
4254     // compute an appropriate address type (cases #3 and #5).
4255     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
4256     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
4257     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
4258     assert(offs != Type::OffsetBot, "offset must be a constant");
4259     if (base_t->isa_aryptr() != nullptr) {
4260       // In the case of a flat inline type array, each field has its
4261       // own slice so we need to extract the field being accessed from
4262       // the address computation
4263       t = base_t->isa_aryptr()->add_field_offset_and_offset(offs)->is_oopptr();
4264     } else {
4265       t = base_t->add_offset(offs)->is_oopptr();
4266     }
4267   }
4268   int inst_id = base_t->instance_id();
4269   assert(!t->is_known_instance() || t->instance_id() == inst_id,
4270                              "old type must be non-instance or match new type");
4271 
4272   // The type 't' could be subclass of 'base_t'.
4273   // As result t->offset() could be large then base_t's size and it will
4274   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
4275   // constructor verifies correctness of the offset.
4276   //
4277   // It could happened on subclass's branch (from the type profiling
4278   // inlining) which was not eliminated during parsing since the exactness
4279   // of the allocation type was not propagated to the subclass type check.
4280   //
4281   // Or the type 't' could be not related to 'base_t' at all.
4282   // It could happen when CHA type is different from MDO type on a dead path
4283   // (for example, from instanceof check) which is not collapsed during parsing.
4284   //
4285   // Do nothing for such AddP node and don't process its users since
4286   // this code branch will go away.
4287   //
4288   if (!t->is_known_instance() &&
4289       !base_t->maybe_java_subtype_of(t)) {
4290      return false; // bail out
4291   }
4292   const TypePtr* tinst = base_t->add_offset(t->offset());
4293   if (tinst->isa_aryptr() && t->isa_aryptr()) {
4294     // In the case of a flat inline type array, each field has its
4295     // own slice so we need to keep track of the field being accessed.
4296     tinst = tinst->is_aryptr()->with_field_offset(t->is_aryptr()->field_offset().get());
4297     // Keep array properties (not flat/null-free)
4298     tinst = tinst->is_aryptr()->update_properties(t->is_aryptr());
4299     if (tinst == nullptr) {
4300       return false; // Skip dead path with inconsistent properties
4301     }
4302   }
4303 
4304   // Do NOT remove the next line: ensure a new alias index is allocated
4305   // for the instance type. Note: C++ will not remove it since the call
4306   // has side effect.
4307   int alias_idx = _compile->get_alias_index(tinst);
4308   igvn->set_type(addp, tinst);
4309   // record the allocation in the node map
4310   set_map(addp, get_map(base->_idx));
4311   // Set addp's Base and Address to 'base'.
4312   Node *abase = addp->in(AddPNode::Base);
4313   Node *adr   = addp->in(AddPNode::Address);
4314   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
4315       adr->in(0)->_idx == (uint)inst_id) {
4316     // Skip AddP cases #3 and #5.
4317   } else {
4318     assert(!abase->is_top(), "sanity"); // AddP case #3
4319     if (abase != base) {
4320       igvn->hash_delete(addp);
4321       addp->set_req(AddPNode::Base, base);
4322       if (abase == adr) {
4323         addp->set_req(AddPNode::Address, base);
4324       } else {
4325         // AddP case #4 (adr is array's element offset AddP node)
4326 #ifdef ASSERT
4327         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
4328         assert(adr->is_AddP() && atype != nullptr &&
4329                atype->instance_id() == inst_id, "array's element offset should be processed first");
4330 #endif
4331       }
4332       igvn->hash_insert(addp);
4333     }
4334   }
4335   // Put on IGVN worklist since at least addp's type was changed above.
4336   record_for_optimizer(addp);
4337   return true;
4338 }
4339 
4340 //
4341 // Create a new version of orig_phi if necessary. Returns either the newly
4342 // created phi or an existing phi.  Sets create_new to indicate whether a new
4343 // phi was created.  Cache the last newly created phi in the node map.
4344 //
4345 PhiNode* ConnectionGraph::create_split_phi(PhiNode* orig_phi, int alias_idx, Unique_Node_List& orig_phi_worklist, bool& new_created) {
4346   Compile *C = _compile;
4347   PhaseGVN* igvn = _igvn;
4348   new_created = false;
4349   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
4350   // nothing to do if orig_phi is bottom memory or matches alias_idx
4351   if (phi_alias_idx == alias_idx) {
4352     return orig_phi;
4353   }
4354   // Have we recently created a Phi for this alias index?
4355   PhiNode *result = get_map_phi(orig_phi->_idx);
4356   if (result != nullptr && C->get_alias_index(result->adr_type()) == alias_idx) {
4357     return result;
4358   }
4359   // Previous check may fail when the same wide memory Phi was split into Phis
4360   // for different memory slices. Search all Phis for this region.
4361   if (result != nullptr) {
4362     Node* region = orig_phi->in(0);
4363     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
4364       Node* phi = region->fast_out(i);
4365       if (phi->is_Phi() &&
4366           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
4367         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
4368         return phi->as_Phi();
4369       }
4370     }
4371   }
4372   if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
4373     if (C->do_escape_analysis() == true && !C->failing()) {
4374       // Retry compilation without escape analysis.
4375       // If this is the first failure, the sentinel string will "stick"
4376       // to the Compile object, and the C2Compiler will see it and retry.
4377       C->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4378     }
4379     return nullptr;
4380   }
4381   orig_phi_worklist.push(orig_phi);
4382   const TypePtr *atype = C->get_adr_type(alias_idx);
4383   result = PhiNode::make(orig_phi->in(0), nullptr, Type::MEMORY, atype);
4384   C->copy_node_notes_to(result, orig_phi);
4385   igvn->set_type(result, result->bottom_type());
4386   record_for_optimizer(result);
4387   set_map(orig_phi, result);
4388   new_created = true;
4389   return result;
4390 }
4391 
4392 //
4393 // Return a new version of Memory Phi "orig_phi" with the inputs having the
4394 // specified alias index.
4395 //
4396 PhiNode* ConnectionGraph::split_memory_phi(PhiNode* orig_phi, int alias_idx, Unique_Node_List& orig_phi_worklist, uint rec_depth) {
4397   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
4398   Compile *C = _compile;
4399   PhaseGVN* igvn = _igvn;
4400   bool new_phi_created;
4401   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
4402   if (!new_phi_created) {
4403     return result;
4404   }
4405   Unique_Node_List phi_list;
4406   GrowableArray<uint>  cur_input;
4407   PhiNode *phi = orig_phi;
4408   uint idx = 1;
4409   bool finished = false;
4410   while(!finished) {
4411     while (idx < phi->req()) {
4412       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, rec_depth + 1);
4413       if (mem != nullptr && mem->is_Phi()) {
4414         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
4415         if (new_phi_created) {
4416           // found an phi for which we created a new split, push current one on worklist and begin
4417           // processing new one
4418           phi_list.push(phi);
4419           cur_input.push(idx);
4420           phi = mem->as_Phi();
4421           result = newphi;
4422           idx = 1;
4423           continue;
4424         } else {
4425           mem = newphi;
4426         }
4427       }
4428       if (C->failing()) {
4429         return nullptr;
4430       }
4431       result->set_req(idx++, mem);
4432     }
4433 #ifdef ASSERT
4434     // verify that the new Phi has an input for each input of the original
4435     assert( phi->req() == result->req(), "must have same number of inputs.");
4436     assert( result->in(0) != nullptr && result->in(0) == phi->in(0), "regions must match");
4437 #endif
4438     // Check if all new phi's inputs have specified alias index.
4439     // Otherwise use old phi.
4440     for (uint i = 1; i < phi->req(); i++) {
4441       Node* in = result->in(i);
4442       assert((phi->in(i) == nullptr) == (in == nullptr), "inputs must correspond.");
4443     }
4444     // we have finished processing a Phi, see if there are any more to do
4445     finished = (phi_list.size() == 0);
4446     if (!finished) {
4447       phi = phi_list.pop()->as_Phi();
4448       idx = cur_input.pop();
4449       PhiNode *prev_result = get_map_phi(phi->_idx);
4450       prev_result->set_req(idx++, result);
4451       result = prev_result;
4452     }
4453   }
4454   return result;
4455 }
4456 
4457 //
4458 // The next methods are derived from methods in MemNode.
4459 //
4460 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
4461   Node *mem = mmem;
4462   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
4463   // means an array I have not precisely typed yet.  Do not do any
4464   // alias stuff with it any time soon.
4465   if (toop->base() != Type::AnyPtr &&
4466       !(toop->isa_instptr() &&
4467         toop->is_instptr()->instance_klass()->is_java_lang_Object() &&
4468         toop->offset() == Type::OffsetBot)) {
4469     mem = mmem->memory_at(alias_idx);
4470     // Update input if it is progress over what we have now
4471   }
4472   return mem;
4473 }
4474 
4475 //
4476 // Move memory users to their memory slices.
4477 //
4478 void ConnectionGraph::move_inst_mem(Node* n, Unique_Node_List& orig_phis) {
4479   Compile* C = _compile;
4480   PhaseGVN* igvn = _igvn;
4481   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
4482   assert(tp != nullptr, "ptr type");
4483   int alias_idx = C->get_alias_index(tp);
4484   int general_idx = C->get_general_index(alias_idx);
4485 
4486   // Move users first
4487   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4488     Node* use = n->fast_out(i);
4489     if (use->is_MergeMem()) {
4490       MergeMemNode* mmem = use->as_MergeMem();
4491       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
4492       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
4493         continue; // Nothing to do
4494       }
4495       // Replace previous general reference to mem node.
4496       uint orig_uniq = C->unique();
4497       Node* m = find_inst_mem(n, general_idx, orig_phis);
4498       assert(orig_uniq == C->unique(), "no new nodes");
4499       mmem->set_memory_at(general_idx, m);
4500       --imax;
4501       --i;
4502     } else if (use->is_MemBar()) {
4503       assert(!use->is_Initialize(), "initializing stores should not be moved");
4504       if (use->req() > MemBarNode::Precedent &&
4505           use->in(MemBarNode::Precedent) == n) {
4506         // Don't move related membars.
4507         record_for_optimizer(use);
4508         continue;
4509       }
4510       tp = use->as_MemBar()->adr_type()->isa_ptr();
4511       if ((tp != nullptr && C->get_alias_index(tp) == alias_idx) ||
4512           alias_idx == general_idx) {
4513         continue; // Nothing to do
4514       }
4515       // Move to general memory slice.
4516       uint orig_uniq = C->unique();
4517       Node* m = find_inst_mem(n, general_idx, orig_phis);
4518       assert(orig_uniq == C->unique(), "no new nodes");
4519       igvn->hash_delete(use);
4520       imax -= use->replace_edge(n, m, igvn);
4521       igvn->hash_insert(use);
4522       record_for_optimizer(use);
4523       --i;
4524 #ifdef ASSERT
4525     } else if (use->is_Mem()) {
4526       // Memory nodes should have new memory input.
4527       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
4528       assert(tp != nullptr, "ptr type");
4529       int idx = C->get_alias_index(tp);
4530       assert(get_map(use->_idx) != nullptr || idx == alias_idx,
4531              "Following memory nodes should have new memory input or be on the same memory slice");
4532     } else if (use->is_Phi()) {
4533       // Phi nodes should be split and moved already.
4534       tp = use->as_Phi()->adr_type()->isa_ptr();
4535       assert(tp != nullptr, "ptr type");
4536       int idx = C->get_alias_index(tp);
4537       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
4538     } else {
4539       use->dump();
4540       assert(false, "should not be here");
4541 #endif
4542     }
4543   }
4544 }
4545 
4546 //
4547 // Search memory chain of "mem" to find a MemNode whose address
4548 // is the specified alias index.
4549 //
4550 #define FIND_INST_MEM_RECURSION_DEPTH_LIMIT 1000
4551 Node* ConnectionGraph::find_inst_mem(Node* orig_mem, int alias_idx, Unique_Node_List& orig_phis, uint rec_depth) {
4552   if (rec_depth > FIND_INST_MEM_RECURSION_DEPTH_LIMIT) {
4553     _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4554     return nullptr;
4555   }
4556   if (orig_mem == nullptr) {
4557     return orig_mem;
4558   }
4559   Compile* C = _compile;
4560   PhaseGVN* igvn = _igvn;
4561   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
4562   bool is_instance = (toop != nullptr) && toop->is_known_instance();
4563   Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
4564   Node *prev = nullptr;
4565   Node *result = orig_mem;
4566   while (prev != result) {
4567     prev = result;
4568     if (result == start_mem) {
4569       break;  // hit one of our sentinels
4570     }
4571     if (result->is_Mem()) {
4572       const Type *at = igvn->type(result->in(MemNode::Address));
4573       if (at == Type::TOP) {
4574         break; // Dead
4575       }
4576       assert (at->isa_ptr() != nullptr, "pointer type required.");
4577       int idx = C->get_alias_index(at->is_ptr());
4578       if (idx == alias_idx) {
4579         break; // Found
4580       }
4581       if (!is_instance && (at->isa_oopptr() == nullptr ||
4582                            !at->is_oopptr()->is_known_instance())) {
4583         break; // Do not skip store to general memory slice.
4584       }
4585       result = result->in(MemNode::Memory);
4586     }
4587     if (!is_instance) {
4588       continue;  // don't search further for non-instance types
4589     }
4590     // skip over a call which does not affect this memory slice
4591     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
4592       Node *proj_in = result->in(0);
4593       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
4594         break;  // hit one of our sentinels
4595       } else if (proj_in->is_Call()) {
4596         // ArrayCopy node processed here as well
4597         CallNode *call = proj_in->as_Call();
4598         if (!call->may_modify(toop, igvn)) {
4599           result = call->in(TypeFunc::Memory);
4600         }
4601       } else if (proj_in->is_Initialize()) {
4602         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
4603         // Stop if this is the initialization for the object instance which
4604         // which contains this memory slice, otherwise skip over it.
4605         if (alloc == nullptr || alloc->_idx != (uint)toop->instance_id()) {
4606           result = proj_in->in(TypeFunc::Memory);
4607         } else if (C->get_alias_index(result->adr_type()) != alias_idx) {
4608           assert(C->get_general_index(alias_idx) == C->get_alias_index(result->adr_type()), "should be projection for the same field/array element");
4609           result = get_map(result->_idx);
4610           assert(result != nullptr, "new projection should have been allocated");
4611           break;
4612         }
4613       } else if (proj_in->is_MemBar()) {
4614         // Check if there is an array copy for a clone
4615         // Step over GC barrier when ReduceInitialCardMarks is disabled
4616         BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
4617         Node* control_proj_ac = bs->step_over_gc_barrier(proj_in->in(0));
4618 
4619         if (control_proj_ac->is_Proj() && control_proj_ac->in(0)->is_ArrayCopy()) {
4620           // Stop if it is a clone
4621           ArrayCopyNode* ac = control_proj_ac->in(0)->as_ArrayCopy();
4622           if (ac->may_modify(toop, igvn)) {
4623             break;
4624           }
4625         }
4626         result = proj_in->in(TypeFunc::Memory);
4627       } else if (proj_in->is_LoadFlat()) {
4628         result = proj_in->in(TypeFunc::Memory);
4629       }
4630     } else if (result->is_MergeMem()) {
4631       MergeMemNode *mmem = result->as_MergeMem();
4632       result = step_through_mergemem(mmem, alias_idx, toop);
4633       if (result == mmem->base_memory()) {
4634         // Didn't find instance memory, search through general slice recursively.
4635         result = mmem->memory_at(C->get_general_index(alias_idx));
4636         result = find_inst_mem(result, alias_idx, orig_phis, rec_depth + 1);
4637         if (C->failing()) {
4638           return nullptr;
4639         }
4640         mmem->set_memory_at(alias_idx, result);
4641       }
4642     } else if (result->is_Phi() &&
4643                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
4644       Node *un = result->as_Phi()->unique_input(igvn);
4645       if (un != nullptr) {
4646         orig_phis.push(result);
4647         result = un;
4648       } else {
4649         break;
4650       }
4651     } else if (result->is_ClearArray()) {
4652       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
4653         // Can not bypass initialization of the instance
4654         // we are looking for.
4655         break;
4656       }
4657       // Otherwise skip it (the call updated 'result' value).
4658     } else if (result->Opcode() == Op_SCMemProj) {
4659       Node* mem = result->in(0);
4660       Node* adr = nullptr;
4661       if (mem->is_LoadStore()) {
4662         adr = mem->in(MemNode::Address);
4663       } else {
4664         assert(mem->Opcode() == Op_EncodeISOArray ||
4665                mem->Opcode() == Op_StrCompressedCopy, "sanity");
4666         adr = mem->in(3); // Memory edge corresponds to destination array
4667       }
4668       const Type *at = igvn->type(adr);
4669       if (at != Type::TOP) {
4670         assert(at->isa_ptr() != nullptr, "pointer type required.");
4671         int idx = C->get_alias_index(at->is_ptr());
4672         if (idx == alias_idx) {
4673           // Assert in debug mode
4674           assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
4675           break; // In product mode return SCMemProj node
4676         }
4677       }
4678       result = mem->in(MemNode::Memory);
4679     } else if (result->Opcode() == Op_StrInflatedCopy) {
4680       Node* adr = result->in(3); // Memory edge corresponds to destination array
4681       const Type *at = igvn->type(adr);
4682       if (at != Type::TOP) {
4683         assert(at->isa_ptr() != nullptr, "pointer type required.");
4684         int idx = C->get_alias_index(at->is_ptr());
4685         if (idx == alias_idx) {
4686           // Assert in debug mode
4687           assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
4688           break; // In product mode return SCMemProj node
4689         }
4690       }
4691       result = result->in(MemNode::Memory);
4692     }
4693   }
4694   if (result->is_Phi()) {
4695     PhiNode *mphi = result->as_Phi();
4696     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
4697     const TypePtr *t = mphi->adr_type();
4698     if (!is_instance) {
4699       // Push all non-instance Phis on the orig_phis worklist to update inputs
4700       // during Phase 4 if needed.
4701       orig_phis.push(mphi);
4702     } else if (C->get_alias_index(t) != alias_idx) {
4703       // Create a new Phi with the specified alias index type.
4704       result = split_memory_phi(mphi, alias_idx, orig_phis, rec_depth + 1);
4705     }
4706   }
4707   // the result is either MemNode, PhiNode, InitializeNode.
4708   return result;
4709 }
4710 
4711 //
4712 //  Convert the types of non-escaped object to instance types where possible,
4713 //  propagate the new type information through the graph, and update memory
4714 //  edges and MergeMem inputs to reflect the new type.
4715 //
4716 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
4717 //  The processing is done in 4 phases:
4718 //
4719 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
4720 //            types for the CheckCastPP for allocations where possible.
4721 //            Propagate the new types through users as follows:
4722 //               casts and Phi:  push users on alloc_worklist
4723 //               AddP:  cast Base and Address inputs to the instance type
4724 //                      push any AddP users on alloc_worklist and push any memnode
4725 //                      users onto memnode_worklist.
4726 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
4727 //            search the Memory chain for a store with the appropriate type
4728 //            address type.  If a Phi is found, create a new version with
4729 //            the appropriate memory slices from each of the Phi inputs.
4730 //            For stores, process the users as follows:
4731 //               MemNode:  push on memnode_worklist
4732 //               MergeMem: push on mergemem_worklist
4733 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
4734 //            moving the first node encountered of each  instance type to the
4735 //            the input corresponding to its alias index.
4736 //            appropriate memory slice.
4737 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
4738 //
4739 // In the following example, the CheckCastPP nodes are the cast of allocation
4740 // results and the allocation of node 29 is non-escaped and eligible to be an
4741 // instance type.
4742 //
4743 // We start with:
4744 //
4745 //     7 Parm #memory
4746 //    10  ConI  "12"
4747 //    19  CheckCastPP   "Foo"
4748 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4749 //    29  CheckCastPP   "Foo"
4750 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
4751 //
4752 //    40  StoreP  25   7  20   ... alias_index=4
4753 //    50  StoreP  35  40  30   ... alias_index=4
4754 //    60  StoreP  45  50  20   ... alias_index=4
4755 //    70  LoadP    _  60  30   ... alias_index=4
4756 //    80  Phi     75  50  60   Memory alias_index=4
4757 //    90  LoadP    _  80  30   ... alias_index=4
4758 //   100  LoadP    _  80  20   ... alias_index=4
4759 //
4760 //
4761 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
4762 // and creating a new alias index for node 30.  This gives:
4763 //
4764 //     7 Parm #memory
4765 //    10  ConI  "12"
4766 //    19  CheckCastPP   "Foo"
4767 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4768 //    29  CheckCastPP   "Foo"  iid=24
4769 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
4770 //
4771 //    40  StoreP  25   7  20   ... alias_index=4
4772 //    50  StoreP  35  40  30   ... alias_index=6
4773 //    60  StoreP  45  50  20   ... alias_index=4
4774 //    70  LoadP    _  60  30   ... alias_index=6
4775 //    80  Phi     75  50  60   Memory alias_index=4
4776 //    90  LoadP    _  80  30   ... alias_index=6
4777 //   100  LoadP    _  80  20   ... alias_index=4
4778 //
4779 // In phase 2, new memory inputs are computed for the loads and stores,
4780 // And a new version of the phi is created.  In phase 4, the inputs to
4781 // node 80 are updated and then the memory nodes are updated with the
4782 // values computed in phase 2.  This results in:
4783 //
4784 //     7 Parm #memory
4785 //    10  ConI  "12"
4786 //    19  CheckCastPP   "Foo"
4787 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4788 //    29  CheckCastPP   "Foo"  iid=24
4789 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
4790 //
4791 //    40  StoreP  25  7   20   ... alias_index=4
4792 //    50  StoreP  35  7   30   ... alias_index=6
4793 //    60  StoreP  45  40  20   ... alias_index=4
4794 //    70  LoadP    _  50  30   ... alias_index=6
4795 //    80  Phi     75  40  60   Memory alias_index=4
4796 //   120  Phi     75  50  50   Memory alias_index=6
4797 //    90  LoadP    _ 120  30   ... alias_index=6
4798 //   100  LoadP    _  80  20   ... alias_index=4
4799 //
4800 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist,
4801                                          GrowableArray<ArrayCopyNode*> &arraycopy_worklist,
4802                                          GrowableArray<MergeMemNode*> &mergemem_worklist,
4803                                          Unique_Node_List &reducible_merges) {
4804   DEBUG_ONLY(Unique_Node_List reduced_merges;)
4805   Unique_Node_List memnode_worklist;
4806   Unique_Node_List orig_phis;
4807   PhaseIterGVN  *igvn = _igvn;
4808   uint new_index_start = (uint) _compile->num_alias_types();
4809   VectorSet visited;
4810   ideal_nodes.clear(); // Reset for use with set_map/get_map.
4811 
4812   //  Phase 1:  Process possible allocations from alloc_worklist.
4813   //  Create instance types for the CheckCastPP for allocations where possible.
4814   //
4815   // (Note: don't forget to change the order of the second AddP node on
4816   //  the alloc_worklist if the order of the worklist processing is changed,
4817   //  see the comment in find_second_addp().)
4818   //
4819   while (alloc_worklist.length() != 0) {
4820     Node *n = alloc_worklist.pop();
4821     uint ni = n->_idx;
4822     if (n->is_Call()) {
4823       CallNode *alloc = n->as_Call();
4824       // copy escape information to call node
4825       PointsToNode* ptn = ptnode_adr(alloc->_idx);
4826       PointsToNode::EscapeState es = ptn->escape_state();
4827       // We have an allocation or call which returns a Java object,
4828       // see if it is non-escaped.
4829       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable()) {
4830         continue;
4831       }
4832       // Find CheckCastPP for the allocate or for the return value of a call
4833       n = alloc->result_cast();
4834       if (n == nullptr) {            // No uses except Initialize node
4835         if (alloc->is_Allocate()) {
4836           // Set the scalar_replaceable flag for allocation
4837           // so it could be eliminated if it has no uses.
4838           alloc->as_Allocate()->_is_scalar_replaceable = true;
4839         }
4840         continue;
4841       }
4842       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
4843         // we could reach here for allocate case if one init is associated with many allocs.
4844         if (alloc->is_Allocate()) {
4845           alloc->as_Allocate()->_is_scalar_replaceable = false;
4846         }
4847         continue;
4848       }
4849 
4850       // The inline code for Object.clone() casts the allocation result to
4851       // java.lang.Object and then to the actual type of the allocated
4852       // object. Detect this case and use the second cast.
4853       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
4854       // the allocation result is cast to java.lang.Object and then
4855       // to the actual Array type.
4856       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
4857           && (alloc->is_AllocateArray() ||
4858               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeInstKlassPtr::OBJECT)) {
4859         Node *cast2 = nullptr;
4860         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4861           Node *use = n->fast_out(i);
4862           if (use->is_CheckCastPP()) {
4863             cast2 = use;
4864             break;
4865           }
4866         }
4867         if (cast2 != nullptr) {
4868           n = cast2;
4869         } else {
4870           // Non-scalar replaceable if the allocation type is unknown statically
4871           // (reflection allocation), the object can't be restored during
4872           // deoptimization without precise type.
4873           continue;
4874         }
4875       }
4876 
4877       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
4878       if (t == nullptr) {
4879         continue;  // not a TypeOopPtr
4880       }
4881       if (!t->klass_is_exact()) {
4882         continue; // not an unique type
4883       }
4884       if (alloc->is_Allocate()) {
4885         // Set the scalar_replaceable flag for allocation
4886         // so it could be eliminated.
4887         alloc->as_Allocate()->_is_scalar_replaceable = true;
4888       }
4889       set_escape_state(ptnode_adr(n->_idx), es NOT_PRODUCT(COMMA trace_propagate_message(ptn))); // CheckCastPP escape state
4890       // in order for an object to be scalar-replaceable, it must be:
4891       //   - a direct allocation (not a call returning an object)
4892       //   - non-escaping
4893       //   - eligible to be a unique type
4894       //   - not determined to be ineligible by escape analysis
4895       set_map(alloc, n);
4896       set_map(n, alloc);
4897       const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
4898       igvn->hash_delete(n);
4899       igvn->set_type(n,  tinst);
4900       n->raise_bottom_type(tinst);
4901       igvn->hash_insert(n);
4902       record_for_optimizer(n);
4903       // Allocate an alias index for the header fields. Accesses to
4904       // the header emitted during macro expansion wouldn't have
4905       // correct memory state otherwise.
4906       _compile->get_alias_index(tinst->add_offset(oopDesc::mark_offset_in_bytes()));
4907       _compile->get_alias_index(tinst->add_offset(oopDesc::klass_offset_in_bytes()));
4908       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
4909         // Add a new NarrowMem projection for each existing NarrowMem projection with new adr type
4910         InitializeNode* init = alloc->as_Allocate()->initialization();
4911         assert(init != nullptr, "can't find Initialization node for this Allocate node");
4912         auto process_narrow_proj = [&](NarrowMemProjNode* proj) {
4913           const TypePtr* adr_type = proj->adr_type();
4914           const TypePtr* new_adr_type = tinst->with_offset(adr_type->offset());
4915           if (adr_type->isa_aryptr()) {
4916             // In the case of a flat inline type array, each field has its own slice so we need a
4917             // NarrowMemProj for each field of the flat array elements
4918             new_adr_type = new_adr_type->is_aryptr()->with_field_offset(adr_type->is_aryptr()->field_offset().get());
4919           }
4920           if (adr_type != new_adr_type && !init->already_has_narrow_mem_proj_with_adr_type(new_adr_type)) {
4921             // Do NOT remove the next line: ensure a new alias index is allocated for the instance type.
4922             uint alias_idx = _compile->get_alias_index(new_adr_type);
4923             assert(_compile->get_general_index(alias_idx) == _compile->get_alias_index(adr_type), "new adr type should be narrowed down from existing adr type");
4924             NarrowMemProjNode* new_proj = new NarrowMemProjNode(init, new_adr_type);
4925             igvn->set_type(new_proj, new_proj->bottom_type());
4926             record_for_optimizer(new_proj);
4927             set_map(proj, new_proj); // record it so ConnectionGraph::find_inst_mem() can find it
4928           }
4929         };
4930         init->for_each_narrow_mem_proj_with_new_uses(process_narrow_proj);
4931 
4932         // First, put on the worklist all Field edges from Connection Graph
4933         // which is more accurate than putting immediate users from Ideal Graph.
4934         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
4935           PointsToNode* tgt = e.get();
4936           if (tgt->is_Arraycopy()) {
4937             continue;
4938           }
4939           Node* use = tgt->ideal_node();
4940           assert(tgt->is_Field() && use->is_AddP(),
4941                  "only AddP nodes are Field edges in CG");
4942           if (use->outcnt() > 0) { // Don't process dead nodes
4943             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
4944             if (addp2 != nullptr) {
4945               assert(alloc->is_AllocateArray(),"array allocation was expected");
4946               alloc_worklist.append_if_missing(addp2);
4947             }
4948             alloc_worklist.append_if_missing(use);
4949           }
4950         }
4951 
4952         // An allocation may have an Initialize which has raw stores. Scan
4953         // the users of the raw allocation result and push AddP users
4954         // on alloc_worklist.
4955         Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
4956         assert (raw_result != nullptr, "must have an allocation result");
4957         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
4958           Node *use = raw_result->fast_out(i);
4959           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
4960             Node* addp2 = find_second_addp(use, raw_result);
4961             if (addp2 != nullptr) {
4962               assert(alloc->is_AllocateArray(),"array allocation was expected");
4963               alloc_worklist.append_if_missing(addp2);
4964             }
4965             alloc_worklist.append_if_missing(use);
4966           } else if (use->is_MemBar()) {
4967             memnode_worklist.push(use);
4968           }
4969         }
4970       }
4971     } else if (n->is_AddP()) {
4972       if (has_reducible_merge_base(n->as_AddP(), reducible_merges)) {
4973         // This AddP will go away when we reduce the Phi
4974         continue;
4975       }
4976       Node* addp_base = get_addp_base(n);
4977       JavaObjectNode* jobj = unique_java_object(addp_base);
4978       if (jobj == nullptr || jobj == phantom_obj) {
4979 #ifdef ASSERT
4980         ptnode_adr(get_addp_base(n)->_idx)->dump();
4981         ptnode_adr(n->_idx)->dump();
4982         assert(jobj != nullptr && jobj != phantom_obj, "escaped allocation");
4983 #endif
4984         _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4985         return;
4986       }
4987       Node *base = get_map(jobj->idx());  // CheckCastPP node
4988       if (!split_AddP(n, base)) continue; // wrong type from dead path
4989     } else if (n->is_Phi() ||
4990                n->is_CheckCastPP() ||
4991                n->is_EncodeP() ||
4992                n->is_DecodeN() ||
4993                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
4994       if (visited.test_set(n->_idx)) {
4995         assert(n->is_Phi(), "loops only through Phi's");
4996         continue;  // already processed
4997       }
4998       // Reducible Phi's will be removed from the graph after split_unique_types
4999       // finishes. For now we just try to split out the SR inputs of the merge.
5000       Node* parent = n->in(1);
5001       if (reducible_merges.member(n)) {
5002         reduce_phi(n->as_Phi(), alloc_worklist);
5003 #ifdef ASSERT
5004         if (VerifyReduceAllocationMerges) {
5005           reduced_merges.push(n);
5006         }
5007 #endif
5008         continue;
5009       } else if (reducible_merges.member(parent)) {
5010         // 'n' is an user of a reducible merge (a Phi). It will be simplified as
5011         // part of reduce_merge.
5012         continue;
5013       }
5014       JavaObjectNode* jobj = unique_java_object(n);
5015       if (jobj == nullptr || jobj == phantom_obj) {
5016 #ifdef ASSERT
5017         ptnode_adr(n->_idx)->dump();
5018         assert(jobj != nullptr && jobj != phantom_obj, "escaped allocation");
5019 #endif
5020         _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
5021         return;
5022       } else {
5023         Node *val = get_map(jobj->idx());   // CheckCastPP node
5024         TypeNode *tn = n->as_Type();
5025         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
5026         assert(tinst != nullptr && tinst->is_known_instance() &&
5027                tinst->instance_id() == jobj->idx() , "instance type expected.");
5028 
5029         const Type *tn_type = igvn->type(tn);
5030         const TypeOopPtr *tn_t;
5031         if (tn_type->isa_narrowoop()) {
5032           tn_t = tn_type->make_ptr()->isa_oopptr();
5033         } else {
5034           tn_t = tn_type->isa_oopptr();
5035         }
5036         if (tn_t != nullptr && tinst->maybe_java_subtype_of(tn_t)) {
5037           if (tn_t->isa_aryptr()) {
5038             // Keep array properties (not flat/null-free)
5039             tinst = tinst->is_aryptr()->update_properties(tn_t->is_aryptr());
5040             if (tinst == nullptr) {
5041               continue; // Skip dead path with inconsistent properties
5042             }
5043           }
5044           if (tn_type->isa_narrowoop()) {
5045             tn_type = tinst->make_narrowoop();
5046           } else {
5047             tn_type = tinst;
5048           }
5049           igvn->hash_delete(tn);
5050           igvn->set_type(tn, tn_type);
5051           tn->set_type(tn_type);
5052           igvn->hash_insert(tn);
5053           record_for_optimizer(n);
5054         } else {
5055           assert(tn_type == TypePtr::NULL_PTR ||
5056                  (tn_t != nullptr && !tinst->maybe_java_subtype_of(tn_t)),
5057                  "unexpected type");
5058           continue; // Skip dead path with different type
5059         }
5060       }
5061     } else {
5062       DEBUG_ONLY(n->dump();)
5063       assert(false, "EA: unexpected node");
5064       continue;
5065     }
5066     // push allocation's users on appropriate worklist
5067     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5068       Node *use = n->fast_out(i);
5069       if (use->is_Mem() && use->in(MemNode::Address) == n) {
5070         // Load/store to instance's field
5071         memnode_worklist.push(use);
5072       } else if (use->is_MemBar()) {
5073         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
5074           memnode_worklist.push(use);
5075         }
5076       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
5077         Node* addp2 = find_second_addp(use, n);
5078         if (addp2 != nullptr) {
5079           alloc_worklist.append_if_missing(addp2);
5080         }
5081         alloc_worklist.append_if_missing(use);
5082       } else if (use->is_Phi() ||
5083                  use->is_CheckCastPP() ||
5084                  use->is_EncodeNarrowPtr() ||
5085                  use->is_DecodeNarrowPtr() ||
5086                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
5087         alloc_worklist.append_if_missing(use);
5088 #ifdef ASSERT
5089       } else if (use->is_Mem()) {
5090         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
5091       } else if (use->is_MergeMem()) {
5092         assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
5093       } else if (use->is_SafePoint()) {
5094         // Look for MergeMem nodes for calls which reference unique allocation
5095         // (through CheckCastPP nodes) even for debug info.
5096         Node* m = use->in(TypeFunc::Memory);
5097         if (m->is_MergeMem()) {
5098           assert(mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
5099         }
5100       } else if (use->Opcode() == Op_EncodeISOArray) {
5101         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
5102           // EncodeISOArray overwrites destination array
5103           memnode_worklist.push(use);
5104         }
5105       } else if (use->Opcode() == Op_Return) {
5106         // Allocation is referenced by field of returned inline type
5107         assert(_compile->tf()->returns_inline_type_as_fields(), "EA: unexpected reference by ReturnNode");
5108       } else {
5109         uint op = use->Opcode();
5110         if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
5111             (use->in(MemNode::Memory) == n)) {
5112           // They overwrite memory edge corresponding to destination array,
5113           memnode_worklist.push(use);
5114         } else if (!(op == Op_CmpP || op == Op_Conv2B ||
5115               op == Op_CastP2X ||
5116               op == Op_FastLock || op == Op_AryEq ||
5117               op == Op_StrComp || op == Op_CountPositives ||
5118               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
5119               op == Op_StrEquals || op == Op_VectorizedHashCode ||
5120               op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
5121               op == Op_SubTypeCheck || op == Op_InlineType || op == Op_FlatArrayCheck ||
5122               op == Op_ReinterpretS2HF ||
5123               op == Op_ReachabilityFence ||
5124               BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
5125           n->dump();
5126           use->dump();
5127           assert(false, "EA: missing allocation reference path");
5128         }
5129 #endif
5130       }
5131     }
5132 
5133   }
5134 
5135 #ifdef ASSERT
5136   if (VerifyReduceAllocationMerges) {
5137     for (uint i = 0; i < reducible_merges.size(); i++) {
5138       Node* phi = reducible_merges.at(i);
5139 
5140       if (!reduced_merges.member(phi)) {
5141         phi->dump(2);
5142         phi->dump(-2);
5143         assert(false, "This reducible merge wasn't reduced.");
5144       }
5145 
5146       // At this point reducible Phis shouldn't have AddP users anymore; only SafePoints or Casts.
5147       for (DUIterator_Fast jmax, j = phi->fast_outs(jmax); j < jmax; j++) {
5148         Node* use = phi->fast_out(j);
5149         if (!use->is_SafePoint() && !use->is_CastPP()) {
5150           phi->dump(2);
5151           phi->dump(-2);
5152           assert(false, "Unexpected user of reducible Phi -> %d:%s:%d", use->_idx, use->Name(), use->outcnt());
5153         }
5154       }
5155     }
5156   }
5157 #endif
5158 
5159   // Go over all ArrayCopy nodes and if one of the inputs has a unique
5160   // type, record it in the ArrayCopy node so we know what memory this
5161   // node uses/modified.
5162   for (int next = 0; next < arraycopy_worklist.length(); next++) {
5163     ArrayCopyNode* ac = arraycopy_worklist.at(next);
5164     Node* dest = ac->in(ArrayCopyNode::Dest);
5165     if (dest->is_AddP()) {
5166       dest = get_addp_base(dest);
5167     }
5168     JavaObjectNode* jobj = unique_java_object(dest);
5169     if (jobj != nullptr) {
5170       Node *base = get_map(jobj->idx());
5171       if (base != nullptr) {
5172         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
5173         ac->_dest_type = base_t;
5174       }
5175     }
5176     Node* src = ac->in(ArrayCopyNode::Src);
5177     if (src->is_AddP()) {
5178       src = get_addp_base(src);
5179     }
5180     jobj = unique_java_object(src);
5181     if (jobj != nullptr) {
5182       Node* base = get_map(jobj->idx());
5183       if (base != nullptr) {
5184         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
5185         ac->_src_type = base_t;
5186       }
5187     }
5188   }
5189 
5190   // New alias types were created in split_AddP().
5191   uint new_index_end = (uint) _compile->num_alias_types();
5192 
5193   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_1, 5);
5194 
5195   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
5196   //            compute new values for Memory inputs  (the Memory inputs are not
5197   //            actually updated until phase 4.)
5198   if (memnode_worklist.size() == 0) {
5199     return;  // nothing to do
5200   }
5201   while (memnode_worklist.size() != 0) {
5202     Node *n = memnode_worklist.pop();
5203     if (visited.test_set(n->_idx)) {
5204       continue;
5205     }
5206     if (n->is_Phi()) {
5207       if ((uint) _compile->get_alias_index(n->adr_type()) < new_index_start) {
5208         // Push memory phis on the orig_phis worklist to update
5209         // during Phase 4 if needed.
5210         orig_phis.push(n);
5211       }
5212     } else if (n->is_ClearArray()) {
5213      // we don't need to do anything, but the users must be pushed
5214     } else if (n->is_MemBar()) { // MemBar nodes
5215       if (!n->is_Initialize()) { // memory projections for Initialize pushed below (so we get to all their uses)
5216         // we don't need to do anything, but the users must be pushed
5217         n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
5218         if (n == nullptr) {
5219           continue;
5220         }
5221       }
5222     } else if (n->is_CallLeaf()) {
5223       // Runtime calls with narrow memory input (no MergeMem node)
5224       // get the memory projection
5225       n = n->as_Call()->proj_out_or_null(TypeFunc::Memory);
5226       if (n == nullptr) {
5227         continue;
5228       }
5229     } else if (n->Opcode() == Op_StrInflatedCopy) {
5230       // Check direct uses of StrInflatedCopy.
5231       // It is memory type Node - no special SCMemProj node.
5232     } else if (n->Opcode() == Op_StrCompressedCopy ||
5233                n->Opcode() == Op_EncodeISOArray) {
5234       // get the memory projection
5235       n = n->find_out_with(Op_SCMemProj);
5236       assert(n != nullptr && n->Opcode() == Op_SCMemProj, "memory projection required");
5237     } else if (n->is_CallLeaf() && n->as_CallLeaf()->_name != nullptr &&
5238                strcmp(n->as_CallLeaf()->_name, "store_unknown_inline") == 0) {
5239       n = n->as_CallLeaf()->proj_out(TypeFunc::Memory);
5240     } else if (n->is_Proj()) {
5241       assert(n->in(0)->is_Initialize(), "we only push memory projections for Initialize");
5242     } else {
5243 #ifdef ASSERT
5244       if (!n->is_Mem()) {
5245         n->dump();
5246       }
5247       assert(n->is_Mem(), "memory node required.");
5248 #endif
5249       Node *addr = n->in(MemNode::Address);
5250       const Type *addr_t = igvn->type(addr);
5251       if (addr_t == Type::TOP) {
5252         continue;
5253       }
5254       assert (addr_t->isa_ptr() != nullptr, "pointer type required.");
5255       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
5256       assert ((uint)alias_idx < new_index_end, "wrong alias index");
5257       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
5258       if (_compile->failing()) {
5259         return;
5260       }
5261       if (mem != n->in(MemNode::Memory)) {
5262         // We delay the memory edge update since we need old one in
5263         // MergeMem code below when instances memory slices are separated.
5264         set_map(n, mem);
5265       }
5266       if (n->is_Load()) {
5267         continue;  // don't push users
5268       } else if (n->is_LoadStore()) {
5269         // get the memory projection
5270         n = n->find_out_with(Op_SCMemProj);
5271         assert(n != nullptr && n->Opcode() == Op_SCMemProj, "memory projection required");
5272       }
5273     }
5274     // push user on appropriate worklist
5275     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5276       Node *use = n->fast_out(i);
5277       if (use->is_Phi() || use->is_ClearArray()) {
5278         memnode_worklist.push(use);
5279       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
5280         memnode_worklist.push(use);
5281       } else if (use->is_MemBar() || use->is_CallLeaf()) {
5282         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
5283           memnode_worklist.push(use);
5284         }
5285       } else if (use->is_Proj()) {
5286         assert(n->is_Initialize(), "We only push projections of Initialize");
5287         if (use->as_Proj()->_con == TypeFunc::Memory) { // Ignore precedent edge
5288           memnode_worklist.push(use);
5289         }
5290 #ifdef ASSERT
5291       } else if (use->is_Mem()) {
5292         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
5293       } else if (use->is_MergeMem()) {
5294         assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
5295       } else if (use->Opcode() == Op_EncodeISOArray) {
5296         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
5297           // EncodeISOArray overwrites destination array
5298           memnode_worklist.push(use);
5299         }
5300       } else if (use->is_CallLeaf() && use->as_CallLeaf()->_name != nullptr &&
5301                  strcmp(use->as_CallLeaf()->_name, "store_unknown_inline") == 0) {
5302         // store_unknown_inline overwrites destination array
5303         memnode_worklist.push(use);
5304       } else {
5305         uint op = use->Opcode();
5306         if ((use->in(MemNode::Memory) == n) &&
5307             (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
5308           // They overwrite memory edge corresponding to destination array,
5309           memnode_worklist.push(use);
5310         } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
5311               op == Op_AryEq || op == Op_StrComp || op == Op_CountPositives ||
5312               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy || op == Op_VectorizedHashCode ||
5313               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar || op == Op_FlatArrayCheck)) {
5314           n->dump();
5315           use->dump();
5316           assert(false, "EA: missing memory path");
5317         }
5318 #endif
5319       }
5320     }
5321   }
5322 
5323   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
5324   //            Walk each memory slice moving the first node encountered of each
5325   //            instance type to the input corresponding to its alias index.
5326   uint length = mergemem_worklist.length();
5327   for( uint next = 0; next < length; ++next ) {
5328     MergeMemNode* nmm = mergemem_worklist.at(next);
5329     assert(!visited.test_set(nmm->_idx), "should not be visited before");
5330     // Note: we don't want to use MergeMemStream here because we only want to
5331     // scan inputs which exist at the start, not ones we add during processing.
5332     // Note 2: MergeMem may already contains instance memory slices added
5333     // during find_inst_mem() call when memory nodes were processed above.
5334     igvn->hash_delete(nmm);
5335     uint nslices = MIN2(nmm->req(), new_index_start);
5336     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
5337       Node* mem = nmm->in(i);
5338       Node* cur = nullptr;
5339       if (mem == nullptr || mem->is_top()) {
5340         continue;
5341       }
5342       // First, update mergemem by moving memory nodes to corresponding slices
5343       // if their type became more precise since this mergemem was created.
5344       while (mem->is_Mem()) {
5345         const Type* at = igvn->type(mem->in(MemNode::Address));
5346         if (at != Type::TOP) {
5347           assert (at->isa_ptr() != nullptr, "pointer type required.");
5348           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
5349           if (idx == i) {
5350             if (cur == nullptr) {
5351               cur = mem;
5352             }
5353           } else {
5354             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
5355               nmm->set_memory_at(idx, mem);
5356             }
5357           }
5358         }
5359         mem = mem->in(MemNode::Memory);
5360       }
5361       nmm->set_memory_at(i, (cur != nullptr) ? cur : mem);
5362       // Find any instance of the current type if we haven't encountered
5363       // already a memory slice of the instance along the memory chain.
5364       for (uint ni = new_index_start; ni < new_index_end; ni++) {
5365         if((uint)_compile->get_general_index(ni) == i) {
5366           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
5367           if (nmm->is_empty_memory(m)) {
5368             Node* result = find_inst_mem(mem, ni, orig_phis);
5369             if (_compile->failing()) {
5370               return;
5371             }
5372             nmm->set_memory_at(ni, result);
5373           }
5374         }
5375       }
5376     }
5377     // Find the rest of instances values
5378     for (uint ni = new_index_start; ni < new_index_end; ni++) {
5379       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
5380       Node* result = step_through_mergemem(nmm, ni, tinst);
5381       if (result == nmm->base_memory()) {
5382         // Didn't find instance memory, search through general slice recursively.
5383         result = nmm->memory_at(_compile->get_general_index(ni));
5384         result = find_inst_mem(result, ni, orig_phis);
5385         if (_compile->failing()) {
5386           return;
5387         }
5388         nmm->set_memory_at(ni, result);
5389       }
5390     }
5391 
5392     // If we have crossed the 3/4 point of max node limit it's too risky
5393     // to continue with EA/SR because we might hit the max node limit.
5394     if (_compile->live_nodes() >= _compile->max_node_limit() * 0.75) {
5395       if (_compile->do_reduce_allocation_merges()) {
5396         _compile->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
5397       } else if (_invocation > 0) {
5398         _compile->record_failure(C2Compiler::retry_no_iterative_escape_analysis());
5399       } else {
5400         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
5401       }
5402       return;
5403     }
5404 
5405     igvn->hash_insert(nmm);
5406     record_for_optimizer(nmm);
5407   }
5408 
5409   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_3, 5);
5410 
5411   //  Phase 4:  Update the inputs of non-instance memory Phis and
5412   //            the Memory input of memnodes
5413   // First update the inputs of any non-instance Phi's from
5414   // which we split out an instance Phi.  Note we don't have
5415   // to recursively process Phi's encountered on the input memory
5416   // chains as is done in split_memory_phi() since they will
5417   // also be processed here.
5418   for (uint j = 0; j < orig_phis.size(); j++) {
5419     PhiNode* phi = orig_phis.at(j)->as_Phi();
5420     int alias_idx = _compile->get_alias_index(phi->adr_type());
5421     igvn->hash_delete(phi);
5422     for (uint i = 1; i < phi->req(); i++) {
5423       Node *mem = phi->in(i);
5424       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
5425       if (_compile->failing()) {
5426         return;
5427       }
5428       if (mem != new_mem) {
5429         phi->set_req(i, new_mem);
5430       }
5431     }
5432     igvn->hash_insert(phi);
5433     record_for_optimizer(phi);
5434   }
5435 
5436   // Update the memory inputs of MemNodes with the value we computed
5437   // in Phase 2 and move stores memory users to corresponding memory slices.
5438   // Disable memory split verification code until the fix for 6984348.
5439   // Currently it produces false negative results since it does not cover all cases.
5440 #if 0 // ifdef ASSERT
5441   visited.Reset();
5442   Node_Stack old_mems(arena, _compile->unique() >> 2);
5443 #endif
5444   for (uint i = 0; i < ideal_nodes.size(); i++) {
5445     Node*    n = ideal_nodes.at(i);
5446     Node* nmem = get_map(n->_idx);
5447     assert(nmem != nullptr, "sanity");
5448     if (n->is_Mem()) {
5449 #if 0 // ifdef ASSERT
5450       Node* old_mem = n->in(MemNode::Memory);
5451       if (!visited.test_set(old_mem->_idx)) {
5452         old_mems.push(old_mem, old_mem->outcnt());
5453       }
5454 #endif
5455       assert(n->in(MemNode::Memory) != nmem, "sanity");
5456       if (!n->is_Load()) {
5457         // Move memory users of a store first.
5458         move_inst_mem(n, orig_phis);
5459       }
5460       // Now update memory input
5461       igvn->hash_delete(n);
5462       n->set_req(MemNode::Memory, nmem);
5463       igvn->hash_insert(n);
5464       record_for_optimizer(n);
5465     } else {
5466       assert(n->is_Allocate() || n->is_CheckCastPP() ||
5467              n->is_AddP() || n->is_Phi() || n->is_NarrowMemProj(), "unknown node used for set_map()");
5468     }
5469   }
5470 #if 0 // ifdef ASSERT
5471   // Verify that memory was split correctly
5472   while (old_mems.is_nonempty()) {
5473     Node* old_mem = old_mems.node();
5474     uint  old_cnt = old_mems.index();
5475     old_mems.pop();
5476     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
5477   }
5478 #endif
5479   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_4, 5);
5480 }
5481 
5482 #ifndef PRODUCT
5483 int ConnectionGraph::_no_escape_counter = 0;
5484 int ConnectionGraph::_arg_escape_counter = 0;
5485 int ConnectionGraph::_global_escape_counter = 0;
5486 
5487 static const char *node_type_names[] = {
5488   "UnknownType",
5489   "JavaObject",
5490   "LocalVar",
5491   "Field",
5492   "Arraycopy"
5493 };
5494 
5495 static const char *esc_names[] = {
5496   "UnknownEscape",
5497   "NoEscape",
5498   "ArgEscape",
5499   "GlobalEscape"
5500 };
5501 
5502 const char* PointsToNode::esc_name() const {
5503   return esc_names[(int)escape_state()];
5504 }
5505 
5506 void PointsToNode::dump_header(bool print_state, outputStream* out) const {
5507   NodeType nt = node_type();
5508   out->print("%s(%d) ", node_type_names[(int) nt], _pidx);
5509   if (print_state) {
5510     EscapeState es = escape_state();
5511     EscapeState fields_es = fields_escape_state();
5512     out->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
5513     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable()) {
5514       out->print("NSR ");
5515     }
5516   }
5517 }
5518 
5519 void PointsToNode::dump(bool print_state, outputStream* out, bool newline) const {
5520   dump_header(print_state, out);
5521   if (is_Field()) {
5522     FieldNode* f = (FieldNode*)this;
5523     if (f->is_oop()) {
5524       out->print("oop ");
5525     }
5526     if (f->offset() > 0) {
5527       out->print("+%d ", f->offset());
5528     }
5529     out->print("(");
5530     for (BaseIterator i(f); i.has_next(); i.next()) {
5531       PointsToNode* b = i.get();
5532       out->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
5533     }
5534     out->print(" )");
5535   }
5536   out->print("[");
5537   for (EdgeIterator i(this); i.has_next(); i.next()) {
5538     PointsToNode* e = i.get();
5539     out->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
5540   }
5541   out->print(" [");
5542   for (UseIterator i(this); i.has_next(); i.next()) {
5543     PointsToNode* u = i.get();
5544     bool is_base = false;
5545     if (PointsToNode::is_base_use(u)) {
5546       is_base = true;
5547       u = PointsToNode::get_use_node(u)->as_Field();
5548     }
5549     out->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
5550   }
5551   out->print(" ]]  ");
5552   if (_node == nullptr) {
5553     out->print("<null>%s", newline ? "\n" : "");
5554   } else {
5555     _node->dump(newline ? "\n" : "", false, out);
5556   }
5557 }
5558 
5559 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
5560   bool first = true;
5561   int ptnodes_length = ptnodes_worklist.length();
5562   for (int i = 0; i < ptnodes_length; i++) {
5563     PointsToNode *ptn = ptnodes_worklist.at(i);
5564     if (ptn == nullptr || !ptn->is_JavaObject()) {
5565       continue;
5566     }
5567     PointsToNode::EscapeState es = ptn->escape_state();
5568     if ((es != PointsToNode::NoEscape) && !Verbose) {
5569       continue;
5570     }
5571     Node* n = ptn->ideal_node();
5572     if (n->is_Allocate() || (n->is_CallStaticJava() &&
5573                              n->as_CallStaticJava()->is_boxing_method())) {
5574       if (first) {
5575         tty->cr();
5576         tty->print("======== Connection graph for ");
5577         _compile->method()->print_short_name();
5578         tty->cr();
5579         tty->print_cr("invocation #%d: %d iterations and %f sec to build connection graph with %d nodes and worklist size %d",
5580                       _invocation, _build_iterations, _build_time, nodes_size(), ptnodes_worklist.length());
5581         tty->cr();
5582         first = false;
5583       }
5584       ptn->dump();
5585       // Print all locals and fields which reference this allocation
5586       for (UseIterator j(ptn); j.has_next(); j.next()) {
5587         PointsToNode* use = j.get();
5588         if (use->is_LocalVar()) {
5589           use->dump(Verbose);
5590         } else if (Verbose) {
5591           use->dump();
5592         }
5593       }
5594       tty->cr();
5595     }
5596   }
5597 }
5598 
5599 void ConnectionGraph::print_statistics() {
5600   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));
5601 }
5602 
5603 void ConnectionGraph::escape_state_statistics(GrowableArray<JavaObjectNode*>& java_objects_worklist) {
5604   if (!PrintOptoStatistics || (_invocation > 0)) { // Collect data only for the first invocation
5605     return;
5606   }
5607   for (int next = 0; next < java_objects_worklist.length(); ++next) {
5608     JavaObjectNode* ptn = java_objects_worklist.at(next);
5609     if (ptn->ideal_node()->is_Allocate()) {
5610       if (ptn->escape_state() == PointsToNode::NoEscape) {
5611         AtomicAccess::inc(&ConnectionGraph::_no_escape_counter);
5612       } else if (ptn->escape_state() == PointsToNode::ArgEscape) {
5613         AtomicAccess::inc(&ConnectionGraph::_arg_escape_counter);
5614       } else if (ptn->escape_state() == PointsToNode::GlobalEscape) {
5615         AtomicAccess::inc(&ConnectionGraph::_global_escape_counter);
5616       } else {
5617         assert(false, "Unexpected Escape State");
5618       }
5619     }
5620   }
5621 }
5622 
5623 void ConnectionGraph::trace_es_update_helper(PointsToNode* ptn, PointsToNode::EscapeState es, bool fields, const char* reason) const {
5624   if (_compile->directive()->TraceEscapeAnalysisOption) {
5625     assert(ptn != nullptr, "should not be null");
5626     assert(reason != nullptr, "should not be null");
5627     ptn->dump_header(true);
5628     PointsToNode::EscapeState new_es = fields ? ptn->escape_state() : es;
5629     PointsToNode::EscapeState new_fields_es = fields ? es : ptn->fields_escape_state();
5630     tty->print_cr("-> %s(%s) %s", esc_names[(int)new_es], esc_names[(int)new_fields_es], reason);
5631   }
5632 }
5633 
5634 const char* ConnectionGraph::trace_propagate_message(PointsToNode* from) const {
5635   if (_compile->directive()->TraceEscapeAnalysisOption) {
5636     stringStream ss;
5637     ss.print("propagated from: ");
5638     from->dump(true, &ss, false);
5639     return ss.as_string();
5640   } else {
5641     return nullptr;
5642   }
5643 }
5644 
5645 const char* ConnectionGraph::trace_arg_escape_message(CallNode* call) const {
5646   if (_compile->directive()->TraceEscapeAnalysisOption) {
5647     stringStream ss;
5648     ss.print("escapes as arg to:");
5649     call->dump("", false, &ss);
5650     return ss.as_string();
5651   } else {
5652     return nullptr;
5653   }
5654 }
5655 
5656 const char* ConnectionGraph::trace_merged_message(PointsToNode* other) const {
5657   if (_compile->directive()->TraceEscapeAnalysisOption) {
5658     stringStream ss;
5659     ss.print("is merged with other object: ");
5660     other->dump_header(true, &ss);
5661     return ss.as_string();
5662   } else {
5663     return nullptr;
5664   }
5665 }
5666 
5667 #endif
5668 
5669 void ConnectionGraph::record_for_optimizer(Node *n) {
5670   _igvn->_worklist.push(n);
5671   _igvn->add_users_to_worklist(n);
5672 }
--- EOF ---