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


4074 }
4075 
4076 Node* ConnectionGraph::get_addp_base(Node *addp) {
4077   assert(addp->is_AddP(), "must be AddP");
4078   //
4079   // AddP cases for Base and Address inputs:
4080   // case #1. Direct object's field reference:
4081   //     Allocate
4082   //       |
4083   //     Proj #5 ( oop result )
4084   //       |
4085   //     CheckCastPP (cast to instance type)
4086   //      | |
4087   //     AddP  ( base == address )
4088   //
4089   // case #2. Indirect object's field reference:
4090   //      Phi
4091   //       |
4092   //     CastPP (cast to instance type)
4093   //      | |
4094   //     AddP  ( base == address )
4095   //
4096   // case #3. Raw object's field reference for Initialize node.
4097   //          Could have an additional Phi merging multiple allocations.
4098   //      Allocate
4099   //        |
4100   //      Proj #5 ( oop result )
4101   //  top   |
4102   //     \  |
4103   //     AddP  ( base == top )
4104   //
4105   // case #4. Array's element reference:
4106   //   {CheckCastPP | CastPP}
4107   //     |  | |
4108   //     |  AddP ( array's element offset )
4109   //     |  |
4110   //     AddP ( array's offset )
4111   //
4112   // case #5. Raw object's field reference for arraycopy stub call:
4113   //          The inline_native_clone() case when the arraycopy stub is called
4114   //          after the allocation before Initialize and CheckCastPP nodes.
4115   //      Allocate
4116   //        |
4117   //      Proj #5 ( oop result )
4118   //       | |
4119   //       AddP  ( base == address )
4120   //
4121   // case #6. Constant Pool, ThreadLocal, CastX2P, Klass, OSR buffer buf or
4122   //          Raw object's field reference:
4123   //      {ConP, ThreadLocal, CastX2P, raw Load, Parm0}
4124   //  top   |
4125   //     \  |
4126   //     AddP  ( base == top )
4127   //
4128   // case #7. Klass's field reference.
4129   //      LoadKlass
4130   //       | |
4131   //       AddP  ( base == address )
4132   //
4133   // case #8. narrow Klass's field reference.
4134   //      LoadNKlass
4135   //       |
4136   //      DecodeN
4137   //       | |
4138   //       AddP  ( base == address )
4139   //
4140   // case #9. Mixed unsafe access
4141   //    {instance}
4142   //        |
4143   //      CheckCastPP (raw)
4144   //  top   |
4145   //     \  |
4146   //     AddP  ( base == top )
4147   //
4148   // case #10. Klass fetched with
4149   //           LibraryCallKit::load_*_refined_array_klass()
4150   //           which has en extra Phi.
4151   //  LoadKlass   LoadKlass
4152   //       |          |
4153   //     CastPP    CastPP
4154   //          \   /
4155   //           Phi
4156   //      top   |
4157   //         \  |
4158   //         AddP  ( base == top )
4159   //
4160   Node *base = addp->in(AddPNode::Base);
4161   if (base->uncast()->is_top()) { // The AddP case #3, #6, #9, and #10.
4162     base = addp->in(AddPNode::Address);
4163     while (base->is_AddP()) {
4164       // Case #6 (unsafe access) may have several chained AddP nodes.
4165       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
4166       base = base->in(AddPNode::Address);
4167     }
4168     if (base->Opcode() == Op_CheckCastPP &&
4169         base->bottom_type()->isa_rawptr() &&
4170         _igvn->type(base->in(1))->isa_oopptr()) {
4171       base = base->in(1); // Case #9
4172     } else {
4173       // Case #3, #6, and #10
4174       Node* uncast_base = base->uncast();
4175       int opcode = uncast_base->Opcode();
4176       assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
4177              opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
4178              (_igvn->C->is_osr_compilation() && uncast_base->is_Parm() && uncast_base->as_Parm()->_con == TypeFunc::Parms)||
4179              (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != nullptr)) ||
4180              (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_klassptr() != nullptr)) ||
4181              is_captured_store_address(addp) ||
4182              is_load_array_klass_related(uncast_base), "sanity");
4183     }
4184   }
4185   return base;
4186 }
4187 
4188 #ifdef ASSERT
4189 // Case #10
4190 bool ConnectionGraph::is_load_array_klass_related(const Node* uncast_base) {
4191   if (!uncast_base->is_Phi() || uncast_base->req() != 3) {
4192     return false;
4193   }
4194   Node* in1 = uncast_base->in(1);
4195   Node* in2 = uncast_base->in(2);
4196   return in1->uncast()->Opcode() == Op_LoadKlass &&
4197          in2->uncast()->Opcode() == Op_LoadKlass;
4198 }
4199 #endif
4200 
4201 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
4202   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
4203   Node* addp2 = addp->raw_out(0);
4204   if (addp->outcnt() == 1 && addp2->is_AddP() &&
4205       addp2->in(AddPNode::Base) == n &&
4206       addp2->in(AddPNode::Address) == addp) {
4207     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
4208     //
4209     // Find array's offset to push it on worklist first and
4210     // as result process an array's element offset first (pushed second)
4211     // to avoid CastPP for the array's offset.
4212     // Otherwise the inserted CastPP (LocalVar) will point to what
4213     // the AddP (Field) points to. Which would be wrong since
4214     // the algorithm expects the CastPP has the same point as
4215     // as AddP's base CheckCastPP (LocalVar).
4216     //
4217     //    ArrayAllocation
4218     //     |
4219     //    CheckCastPP
4220     //     |
4221     //    memProj (from ArrayAllocation CheckCastPP)
4222     //     |  ||
4223     //     |  ||   Int (element index)
4224     //     |  ||    |   ConI (log(element size))
4225     //     |  ||    |   /
4226     //     |  ||   LShift
4227     //     |  ||  /
4228     //     |  AddP (array's element offset)
4229     //     |  |
4230     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
4231     //     | / /
4232     //     AddP (array's offset)
4233     //      |
4234     //     Load/Store (memory operation on array's element)
4235     //
4236     return addp2;
4237   }
4238   return nullptr;
4239 }
4240 
4241 //
4242 // Adjust the type and inputs of an AddP which computes the
4243 // address of a field of an instance
4244 //
4245 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
4246   PhaseGVN* igvn = _igvn;
4247   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
4248   assert(base_t != nullptr && base_t->is_known_instance(), "expecting instance oopptr");
4249   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
4250   if (t == nullptr) {
4251     // We are computing a raw address for a store captured by an Initialize
4252     // compute an appropriate address type (cases #3 and #5).
4253     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
4254     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
4255     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
4256     assert(offs != Type::OffsetBot, "offset must be a constant");
4257     if (base_t->isa_aryptr() != nullptr) {
4258       // In the case of a flat inline type array, each field has its
4259       // own slice so we need to extract the field being accessed from
4260       // the address computation
4261       t = base_t->isa_aryptr()->add_field_offset_and_offset(offs)->is_oopptr();
4262     } else {
4263       t = base_t->add_offset(offs)->is_oopptr();
4264     }
4265   }
4266   int inst_id = base_t->instance_id();
4267   assert(!t->is_known_instance() || t->instance_id() == inst_id,
4268                              "old type must be non-instance or match new type");
4269 
4270   // The type 't' could be subclass of 'base_t'.
4271   // As result t->offset() could be large then base_t's size and it will
4272   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
4273   // constructor verifies correctness of the offset.
4274   //
4275   // It could happened on subclass's branch (from the type profiling
4276   // inlining) which was not eliminated during parsing since the exactness
4277   // of the allocation type was not propagated to the subclass type check.
4278   //
4279   // Or the type 't' could be not related to 'base_t' at all.
4280   // It could happen when CHA type is different from MDO type on a dead path
4281   // (for example, from instanceof check) which is not collapsed during parsing.
4282   //
4283   // Do nothing for such AddP node and don't process its users since
4284   // this code branch will go away.
4285   //
4286   if (!t->is_known_instance() &&
4287       !base_t->maybe_java_subtype_of(t)) {
4288      return false; // bail out
4289   }
4290   const TypePtr* tinst = base_t->add_offset(t->offset());
4291   if (tinst->isa_aryptr() && t->isa_aryptr()) {
4292     // In the case of a flat inline type array, each field has its
4293     // own slice so we need to keep track of the field being accessed.
4294     tinst = tinst->is_aryptr()->with_field_offset(t->is_aryptr()->field_offset().get());
4295     // Keep array properties (not flat/null-free)
4296     tinst = tinst->is_aryptr()->update_properties(t->is_aryptr());
4297     if (tinst == nullptr) {
4298       return false; // Skip dead path with inconsistent properties
4299     }
4300   }
4301 
4302   // Do NOT remove the next line: ensure a new alias index is allocated
4303   // for the instance type. Note: C++ will not remove it since the call
4304   // has side effect.
4305   int alias_idx = _compile->get_alias_index(tinst);
4306   igvn->set_type(addp, tinst);
4307   // record the allocation in the node map
4308   set_map(addp, get_map(base->_idx));
4309   // Set addp's Base and Address to 'base'.
4310   Node *abase = addp->in(AddPNode::Base);
4311   Node *adr   = addp->in(AddPNode::Address);
4312   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
4313       adr->in(0)->_idx == (uint)inst_id) {
4314     // Skip AddP cases #3 and #5.
4315   } else {
4316     assert(!abase->is_top(), "sanity"); // AddP case #3
4317     if (abase != base) {
4318       igvn->hash_delete(addp);
4319       addp->set_req(AddPNode::Base, base);
4320       if (abase == adr) {
4321         addp->set_req(AddPNode::Address, base);
4322       } else {
4323         // AddP case #4 (adr is array's element offset AddP node)
4324 #ifdef ASSERT
4325         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
4326         assert(adr->is_AddP() && atype != nullptr &&
4327                atype->instance_id() == inst_id, "array's element offset should be processed first");
4328 #endif
4329       }
4330       igvn->hash_insert(addp);
4331     }
4332   }
4333   // Put on IGVN worklist since at least addp's type was changed above.
4334   record_for_optimizer(addp);
4335   return true;
4336 }
4337 
4338 //
4339 // Create a new version of orig_phi if necessary. Returns either the newly
4340 // created phi or an existing phi.  Sets create_new to indicate whether a new
4341 // phi was created.  Cache the last newly created phi in the node map.
4342 //
4343 PhiNode* ConnectionGraph::create_split_phi(PhiNode* orig_phi, int alias_idx, Unique_Node_List& orig_phi_worklist, bool& new_created) {
4344   Compile *C = _compile;
4345   PhaseGVN* igvn = _igvn;
4346   new_created = false;
4347   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
4348   // nothing to do if orig_phi is bottom memory or matches alias_idx
4349   if (phi_alias_idx == alias_idx) {
4350     return orig_phi;
4351   }
4352   // Have we recently created a Phi for this alias index?
4353   PhiNode *result = get_map_phi(orig_phi->_idx);
4354   if (result != nullptr && C->get_alias_index(result->adr_type()) == alias_idx) {
4355     return result;
4356   }
4357   // Previous check may fail when the same wide memory Phi was split into Phis
4358   // for different memory slices. Search all Phis for this region.
4359   if (result != nullptr) {
4360     Node* region = orig_phi->in(0);
4361     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
4362       Node* phi = region->fast_out(i);
4363       if (phi->is_Phi() &&
4364           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
4365         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
4366         return phi->as_Phi();
4367       }
4368     }
4369   }
4370   if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
4371     if (C->do_escape_analysis() == true && !C->failing()) {
4372       // Retry compilation without escape analysis.
4373       // If this is the first failure, the sentinel string will "stick"
4374       // to the Compile object, and the C2Compiler will see it and retry.
4375       C->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4376     }
4377     return nullptr;
4378   }
4379   orig_phi_worklist.push(orig_phi);
4380   const TypePtr *atype = C->get_adr_type(alias_idx);
4381   result = PhiNode::make(orig_phi->in(0), nullptr, Type::MEMORY, atype);
4382   C->copy_node_notes_to(result, orig_phi);
4383   igvn->set_type(result, result->bottom_type());
4384   record_for_optimizer(result);
4385   set_map(orig_phi, result);
4386   new_created = true;
4387   return result;
4388 }
4389 
4390 //
4391 // Return a new version of Memory Phi "orig_phi" with the inputs having the
4392 // specified alias index.
4393 //
4394 PhiNode* ConnectionGraph::split_memory_phi(PhiNode* orig_phi, int alias_idx, Unique_Node_List& orig_phi_worklist, uint rec_depth) {
4395   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
4396   Compile *C = _compile;
4397   PhaseGVN* igvn = _igvn;
4398   bool new_phi_created;
4399   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
4400   if (!new_phi_created) {
4401     return result;
4402   }
4403   Unique_Node_List phi_list;
4404   GrowableArray<uint>  cur_input;
4405   PhiNode *phi = orig_phi;
4406   uint idx = 1;
4407   bool finished = false;
4408   while(!finished) {
4409     while (idx < phi->req()) {
4410       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, rec_depth + 1);
4411       if (mem != nullptr && mem->is_Phi()) {
4412         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
4413         if (new_phi_created) {
4414           // found an phi for which we created a new split, push current one on worklist and begin
4415           // processing new one
4416           phi_list.push(phi);
4417           cur_input.push(idx);
4418           phi = mem->as_Phi();
4419           result = newphi;
4420           idx = 1;
4421           continue;
4422         } else {
4423           mem = newphi;
4424         }
4425       }
4426       if (C->failing()) {
4427         return nullptr;
4428       }
4429       result->set_req(idx++, mem);
4430     }
4431 #ifdef ASSERT
4432     // verify that the new Phi has an input for each input of the original
4433     assert( phi->req() == result->req(), "must have same number of inputs.");
4434     assert( result->in(0) != nullptr && result->in(0) == phi->in(0), "regions must match");
4435 #endif
4436     // Check if all new phi's inputs have specified alias index.
4437     // Otherwise use old phi.
4438     for (uint i = 1; i < phi->req(); i++) {
4439       Node* in = result->in(i);
4440       assert((phi->in(i) == nullptr) == (in == nullptr), "inputs must correspond.");
4441     }
4442     // we have finished processing a Phi, see if there are any more to do
4443     finished = (phi_list.size() == 0);
4444     if (!finished) {
4445       phi = phi_list.pop()->as_Phi();
4446       idx = cur_input.pop();
4447       PhiNode *prev_result = get_map_phi(phi->_idx);
4448       prev_result->set_req(idx++, result);
4449       result = prev_result;
4450     }
4451   }
4452   return result;
4453 }
4454 
4455 //
4456 // The next methods are derived from methods in MemNode.
4457 //
4458 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
4459   Node *mem = mmem;
4460   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
4461   // means an array I have not precisely typed yet.  Do not do any
4462   // alias stuff with it any time soon.
4463   if (toop->base() != Type::AnyPtr &&
4464       !(toop->isa_instptr() &&
4465         toop->is_instptr()->instance_klass()->is_java_lang_Object() &&
4466         toop->offset() == Type::OffsetBot)) {
4467     mem = mmem->memory_at(alias_idx);
4468     // Update input if it is progress over what we have now
4469   }
4470   return mem;
4471 }
4472 
4473 //
4474 // Move memory users to their memory slices.
4475 //
4476 void ConnectionGraph::move_inst_mem(Node* n, Unique_Node_List& orig_phis) {
4477   Compile* C = _compile;
4478   PhaseGVN* igvn = _igvn;
4479   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
4480   assert(tp != nullptr, "ptr type");
4481   int alias_idx = C->get_alias_index(tp);
4482   int general_idx = C->get_general_index(alias_idx);
4483 
4484   // Move users first
4485   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4486     Node* use = n->fast_out(i);
4487     if (use->is_MergeMem()) {
4488       MergeMemNode* mmem = use->as_MergeMem();
4489       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
4490       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
4491         continue; // Nothing to do
4492       }
4493       // Replace previous general reference to mem node.
4494       uint orig_uniq = C->unique();
4495       Node* m = find_inst_mem(n, general_idx, orig_phis);
4496       assert(orig_uniq == C->unique(), "no new nodes");
4497       mmem->set_memory_at(general_idx, m);
4498       --imax;
4499       --i;
4500     } else if (use->is_MemBar()) {
4501       assert(!use->is_Initialize(), "initializing stores should not be moved");
4502       if (use->req() > MemBarNode::Precedent &&
4503           use->in(MemBarNode::Precedent) == n) {
4504         // Don't move related membars.
4505         record_for_optimizer(use);
4506         continue;
4507       }
4508       tp = use->as_MemBar()->adr_type()->isa_ptr();
4509       if ((tp != nullptr && C->get_alias_index(tp) == alias_idx) ||
4510           alias_idx == general_idx) {
4511         continue; // Nothing to do
4512       }
4513       // Move to general memory slice.
4514       uint orig_uniq = C->unique();
4515       Node* m = find_inst_mem(n, general_idx, orig_phis);
4516       assert(orig_uniq == C->unique(), "no new nodes");
4517       igvn->hash_delete(use);
4518       imax -= use->replace_edge(n, m, igvn);
4519       igvn->hash_insert(use);
4520       record_for_optimizer(use);
4521       --i;
4522 #ifdef ASSERT
4523     } else if (use->is_Mem()) {
4524       // Memory nodes should have new memory input.
4525       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
4526       assert(tp != nullptr, "ptr type");
4527       int idx = C->get_alias_index(tp);
4528       assert(get_map(use->_idx) != nullptr || idx == alias_idx,
4529              "Following memory nodes should have new memory input or be on the same memory slice");
4530     } else if (use->is_Phi()) {
4531       // Phi nodes should be split and moved already.
4532       tp = use->as_Phi()->adr_type()->isa_ptr();
4533       assert(tp != nullptr, "ptr type");
4534       int idx = C->get_alias_index(tp);
4535       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
4536     } else {
4537       use->dump();
4538       assert(false, "should not be here");
4539 #endif
4540     }
4541   }
4542 }
4543 
4544 //
4545 // Search memory chain of "mem" to find a MemNode whose address
4546 // is the specified alias index.
4547 //
4548 #define FIND_INST_MEM_RECURSION_DEPTH_LIMIT 1000
4549 Node* ConnectionGraph::find_inst_mem(Node* orig_mem, int alias_idx, Unique_Node_List& orig_phis, uint rec_depth) {
4550   if (rec_depth > FIND_INST_MEM_RECURSION_DEPTH_LIMIT) {
4551     _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4552     return nullptr;
4553   }
4554   if (orig_mem == nullptr) {
4555     return orig_mem;
4556   }
4557   Compile* C = _compile;
4558   PhaseGVN* igvn = _igvn;
4559   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
4560   bool is_instance = (toop != nullptr) && toop->is_known_instance();
4561   Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
4562   Node *prev = nullptr;
4563   Node *result = orig_mem;
4564   while (prev != result) {
4565     prev = result;
4566     if (result == start_mem) {
4567       break;  // hit one of our sentinels
4568     }
4569     if (result->is_Mem()) {
4570       const Type *at = igvn->type(result->in(MemNode::Address));
4571       if (at == Type::TOP) {
4572         break; // Dead
4573       }
4574       assert (at->isa_ptr() != nullptr, "pointer type required.");
4575       int idx = C->get_alias_index(at->is_ptr());
4576       if (idx == alias_idx) {
4577         break; // Found
4578       }
4579       if (!is_instance && (at->isa_oopptr() == nullptr ||
4580                            !at->is_oopptr()->is_known_instance())) {
4581         break; // Do not skip store to general memory slice.
4582       }
4583       result = result->in(MemNode::Memory);
4584     }
4585     if (!is_instance) {
4586       continue;  // don't search further for non-instance types
4587     }
4588     // skip over a call which does not affect this memory slice
4589     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
4590       Node *proj_in = result->in(0);
4591       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
4592         break;  // hit one of our sentinels
4593       } else if (proj_in->is_Call()) {
4594         // ArrayCopy node processed here as well
4595         CallNode *call = proj_in->as_Call();
4596         if (!call->may_modify(toop, igvn)) {
4597           result = call->in(TypeFunc::Memory);
4598         }
4599       } else if (proj_in->is_Initialize()) {
4600         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
4601         // Stop if this is the initialization for the object instance which
4602         // which contains this memory slice, otherwise skip over it.
4603         if (alloc == nullptr || alloc->_idx != (uint)toop->instance_id()) {
4604           result = proj_in->in(TypeFunc::Memory);
4605         } else if (C->get_alias_index(result->adr_type()) != alias_idx) {
4606           assert(C->get_general_index(alias_idx) == C->get_alias_index(result->adr_type()), "should be projection for the same field/array element");
4607           result = get_map(result->_idx);
4608           assert(result != nullptr, "new projection should have been allocated");
4609           break;
4610         }
4611       } else if (proj_in->is_MemBar()) {
4612         // Check if there is an array copy for a clone
4613         // Step over GC barrier when ReduceInitialCardMarks is disabled
4614         BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
4615         Node* control_proj_ac = bs->step_over_gc_barrier(proj_in->in(0));
4616 
4617         if (control_proj_ac->is_Proj() && control_proj_ac->in(0)->is_ArrayCopy()) {
4618           // Stop if it is a clone
4619           ArrayCopyNode* ac = control_proj_ac->in(0)->as_ArrayCopy();
4620           if (ac->may_modify(toop, igvn)) {
4621             break;
4622           }
4623         }
4624         result = proj_in->in(TypeFunc::Memory);
4625       } else if (proj_in->is_LoadFlat()) {
4626         result = proj_in->in(TypeFunc::Memory);
4627       }
4628     } else if (result->is_MergeMem()) {
4629       MergeMemNode *mmem = result->as_MergeMem();
4630       result = step_through_mergemem(mmem, alias_idx, toop);
4631       if (result == mmem->base_memory()) {
4632         // Didn't find instance memory, search through general slice recursively.
4633         result = mmem->memory_at(C->get_general_index(alias_idx));
4634         result = find_inst_mem(result, alias_idx, orig_phis, rec_depth + 1);
4635         if (C->failing()) {
4636           return nullptr;
4637         }
4638         mmem->set_memory_at(alias_idx, result);
4639       }
4640     } else if (result->is_Phi() &&
4641                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
4642       Node *un = result->as_Phi()->unique_input(igvn);
4643       if (un != nullptr) {
4644         orig_phis.push(result);
4645         result = un;
4646       } else {
4647         break;
4648       }
4649     } else if (result->is_ClearArray()) {
4650       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
4651         // Can not bypass initialization of the instance
4652         // we are looking for.
4653         break;
4654       }
4655       // Otherwise skip it (the call updated 'result' value).
4656     } else if (result->Opcode() == Op_SCMemProj) {
4657       Node* mem = result->in(0);
4658       Node* adr = nullptr;
4659       if (mem->is_LoadStore()) {
4660         adr = mem->in(MemNode::Address);
4661       } else {
4662         assert(mem->Opcode() == Op_EncodeISOArray ||
4663                mem->Opcode() == Op_StrCompressedCopy, "sanity");
4664         adr = mem->in(3); // Memory edge corresponds to destination array
4665       }
4666       const Type *at = igvn->type(adr);
4667       if (at != Type::TOP) {
4668         assert(at->isa_ptr() != nullptr, "pointer type required.");
4669         int idx = C->get_alias_index(at->is_ptr());
4670         if (idx == alias_idx) {
4671           // Assert in debug mode
4672           assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
4673           break; // In product mode return SCMemProj node
4674         }
4675       }
4676       result = mem->in(MemNode::Memory);
4677     } else if (result->Opcode() == Op_StrInflatedCopy) {
4678       Node* adr = result->in(3); // Memory edge corresponds to destination array
4679       const Type *at = igvn->type(adr);
4680       if (at != Type::TOP) {
4681         assert(at->isa_ptr() != nullptr, "pointer type required.");
4682         int idx = C->get_alias_index(at->is_ptr());
4683         if (idx == alias_idx) {
4684           // Assert in debug mode
4685           assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
4686           break; // In product mode return SCMemProj node
4687         }
4688       }
4689       result = result->in(MemNode::Memory);
4690     }
4691   }
4692   if (result->is_Phi()) {
4693     PhiNode *mphi = result->as_Phi();
4694     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
4695     const TypePtr *t = mphi->adr_type();
4696     if (!is_instance) {
4697       // Push all non-instance Phis on the orig_phis worklist to update inputs
4698       // during Phase 4 if needed.
4699       orig_phis.push(mphi);
4700     } else if (C->get_alias_index(t) != alias_idx) {
4701       // Create a new Phi with the specified alias index type.
4702       result = split_memory_phi(mphi, alias_idx, orig_phis, rec_depth + 1);
4703     }
4704   }
4705   // the result is either MemNode, PhiNode, InitializeNode.
4706   return result;
4707 }
4708 
4709 //
4710 //  Convert the types of non-escaped object to instance types where possible,
4711 //  propagate the new type information through the graph, and update memory
4712 //  edges and MergeMem inputs to reflect the new type.
4713 //
4714 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
4715 //  The processing is done in 4 phases:
4716 //
4717 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
4718 //            types for the CheckCastPP for allocations where possible.
4719 //            Propagate the new types through users as follows:
4720 //               casts and Phi:  push users on alloc_worklist
4721 //               AddP:  cast Base and Address inputs to the instance type
4722 //                      push any AddP users on alloc_worklist and push any memnode
4723 //                      users onto memnode_worklist.
4724 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
4725 //            search the Memory chain for a store with the appropriate type
4726 //            address type.  If a Phi is found, create a new version with
4727 //            the appropriate memory slices from each of the Phi inputs.
4728 //            For stores, process the users as follows:
4729 //               MemNode:  push on memnode_worklist
4730 //               MergeMem: push on mergemem_worklist
4731 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
4732 //            moving the first node encountered of each  instance type to the
4733 //            the input corresponding to its alias index.
4734 //            appropriate memory slice.
4735 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
4736 //
4737 // In the following example, the CheckCastPP nodes are the cast of allocation
4738 // results and the allocation of node 29 is non-escaped and eligible to be an
4739 // instance type.
4740 //
4741 // We start with:
4742 //
4743 //     7 Parm #memory
4744 //    10  ConI  "12"
4745 //    19  CheckCastPP   "Foo"
4746 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4747 //    29  CheckCastPP   "Foo"
4748 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
4749 //
4750 //    40  StoreP  25   7  20   ... alias_index=4
4751 //    50  StoreP  35  40  30   ... alias_index=4
4752 //    60  StoreP  45  50  20   ... alias_index=4
4753 //    70  LoadP    _  60  30   ... alias_index=4
4754 //    80  Phi     75  50  60   Memory alias_index=4
4755 //    90  LoadP    _  80  30   ... alias_index=4
4756 //   100  LoadP    _  80  20   ... alias_index=4
4757 //
4758 //
4759 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
4760 // and creating a new alias index for node 30.  This gives:
4761 //
4762 //     7 Parm #memory
4763 //    10  ConI  "12"
4764 //    19  CheckCastPP   "Foo"
4765 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4766 //    29  CheckCastPP   "Foo"  iid=24
4767 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
4768 //
4769 //    40  StoreP  25   7  20   ... alias_index=4
4770 //    50  StoreP  35  40  30   ... alias_index=6
4771 //    60  StoreP  45  50  20   ... alias_index=4
4772 //    70  LoadP    _  60  30   ... alias_index=6
4773 //    80  Phi     75  50  60   Memory alias_index=4
4774 //    90  LoadP    _  80  30   ... alias_index=6
4775 //   100  LoadP    _  80  20   ... alias_index=4
4776 //
4777 // In phase 2, new memory inputs are computed for the loads and stores,
4778 // And a new version of the phi is created.  In phase 4, the inputs to
4779 // node 80 are updated and then the memory nodes are updated with the
4780 // values computed in phase 2.  This results in:
4781 //
4782 //     7 Parm #memory
4783 //    10  ConI  "12"
4784 //    19  CheckCastPP   "Foo"
4785 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4786 //    29  CheckCastPP   "Foo"  iid=24
4787 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
4788 //
4789 //    40  StoreP  25  7   20   ... alias_index=4
4790 //    50  StoreP  35  7   30   ... alias_index=6
4791 //    60  StoreP  45  40  20   ... alias_index=4
4792 //    70  LoadP    _  50  30   ... alias_index=6
4793 //    80  Phi     75  40  60   Memory alias_index=4
4794 //   120  Phi     75  50  50   Memory alias_index=6
4795 //    90  LoadP    _ 120  30   ... alias_index=6
4796 //   100  LoadP    _  80  20   ... alias_index=4
4797 //
4798 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist,
4799                                          GrowableArray<ArrayCopyNode*> &arraycopy_worklist,
4800                                          GrowableArray<MergeMemNode*> &mergemem_worklist,
4801                                          Unique_Node_List &reducible_merges) {
4802   DEBUG_ONLY(Unique_Node_List reduced_merges;)
4803   Unique_Node_List memnode_worklist;
4804   Unique_Node_List orig_phis;
4805   PhaseIterGVN  *igvn = _igvn;
4806   uint new_index_start = (uint) _compile->num_alias_types();
4807   VectorSet visited;
4808   ideal_nodes.clear(); // Reset for use with set_map/get_map.
4809 
4810   //  Phase 1:  Process possible allocations from alloc_worklist.
4811   //  Create instance types for the CheckCastPP for allocations where possible.
4812   //
4813   // (Note: don't forget to change the order of the second AddP node on
4814   //  the alloc_worklist if the order of the worklist processing is changed,
4815   //  see the comment in find_second_addp().)
4816   //
4817   while (alloc_worklist.length() != 0) {
4818     Node *n = alloc_worklist.pop();
4819     uint ni = n->_idx;
4820     if (n->is_Call()) {
4821       CallNode *alloc = n->as_Call();
4822       // copy escape information to call node
4823       PointsToNode* ptn = ptnode_adr(alloc->_idx);
4824       PointsToNode::EscapeState es = ptn->escape_state();
4825       // We have an allocation or call which returns a Java object,
4826       // see if it is non-escaped.
4827       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable()) {
4828         continue;
4829       }
4830       // Find CheckCastPP for the allocate or for the return value of a call
4831       n = alloc->result_cast();
4832       if (n == nullptr) {            // No uses except Initialize node
4833         if (alloc->is_Allocate()) {
4834           // Set the scalar_replaceable flag for allocation
4835           // so it could be eliminated if it has no uses.
4836           alloc->as_Allocate()->_is_scalar_replaceable = true;
4837         }
4838         continue;
4839       }
4840       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
4841         // we could reach here for allocate case if one init is associated with many allocs.
4842         if (alloc->is_Allocate()) {
4843           alloc->as_Allocate()->_is_scalar_replaceable = false;
4844         }
4845         continue;
4846       }
4847 
4848       // The inline code for Object.clone() casts the allocation result to
4849       // java.lang.Object and then to the actual type of the allocated
4850       // object. Detect this case and use the second cast.
4851       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
4852       // the allocation result is cast to java.lang.Object and then
4853       // to the actual Array type.
4854       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
4855           && (alloc->is_AllocateArray() ||
4856               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeInstKlassPtr::OBJECT)) {
4857         Node *cast2 = nullptr;
4858         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4859           Node *use = n->fast_out(i);
4860           if (use->is_CheckCastPP()) {
4861             cast2 = use;
4862             break;
4863           }
4864         }
4865         if (cast2 != nullptr) {
4866           n = cast2;
4867         } else {
4868           // Non-scalar replaceable if the allocation type is unknown statically
4869           // (reflection allocation), the object can't be restored during
4870           // deoptimization without precise type.
4871           continue;
4872         }
4873       }
4874 
4875       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
4876       if (t == nullptr) {
4877         continue;  // not a TypeOopPtr
4878       }
4879       if (!t->klass_is_exact()) {
4880         continue; // not an unique type
4881       }
4882       if (alloc->is_Allocate()) {
4883         // Set the scalar_replaceable flag for allocation
4884         // so it could be eliminated.
4885         alloc->as_Allocate()->_is_scalar_replaceable = true;
4886       }
4887       set_escape_state(ptnode_adr(n->_idx), es NOT_PRODUCT(COMMA trace_propagate_message(ptn))); // CheckCastPP escape state
4888       // in order for an object to be scalar-replaceable, it must be:
4889       //   - a direct allocation (not a call returning an object)
4890       //   - non-escaping
4891       //   - eligible to be a unique type
4892       //   - not determined to be ineligible by escape analysis
4893       set_map(alloc, n);
4894       set_map(n, alloc);
4895       const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
4896       igvn->hash_delete(n);
4897       igvn->set_type(n,  tinst);
4898       n->raise_bottom_type(tinst);
4899       igvn->hash_insert(n);
4900       record_for_optimizer(n);
4901       // Allocate an alias index for the header fields. Accesses to
4902       // the header emitted during macro expansion wouldn't have
4903       // correct memory state otherwise.
4904       _compile->get_alias_index(tinst->add_offset(oopDesc::mark_offset_in_bytes()));
4905       _compile->get_alias_index(tinst->add_offset(oopDesc::klass_offset_in_bytes()));
4906       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
4907         // Add a new NarrowMem projection for each existing NarrowMem projection with new adr type
4908         InitializeNode* init = alloc->as_Allocate()->initialization();
4909         assert(init != nullptr, "can't find Initialization node for this Allocate node");
4910         auto process_narrow_proj = [&](NarrowMemProjNode* proj) {
4911           const TypePtr* adr_type = proj->adr_type();
4912           const TypePtr* new_adr_type = tinst->with_offset(adr_type->offset());
4913           if (adr_type->isa_aryptr()) {
4914             // In the case of a flat inline type array, each field has its own slice so we need a
4915             // NarrowMemProj for each field of the flat array elements
4916             new_adr_type = new_adr_type->is_aryptr()->with_field_offset(adr_type->is_aryptr()->field_offset().get());
4917           }
4918           if (adr_type != new_adr_type && !init->already_has_narrow_mem_proj_with_adr_type(new_adr_type)) {
4919             // Do NOT remove the next line: ensure a new alias index is allocated for the instance type.
4920             uint alias_idx = _compile->get_alias_index(new_adr_type);
4921             assert(_compile->get_general_index(alias_idx) == _compile->get_alias_index(adr_type), "new adr type should be narrowed down from existing adr type");
4922             NarrowMemProjNode* new_proj = new NarrowMemProjNode(init, new_adr_type);
4923             igvn->set_type(new_proj, new_proj->bottom_type());
4924             record_for_optimizer(new_proj);
4925             set_map(proj, new_proj); // record it so ConnectionGraph::find_inst_mem() can find it
4926           }
4927         };
4928         init->for_each_narrow_mem_proj_with_new_uses(process_narrow_proj);
4929 
4930         // First, put on the worklist all Field edges from Connection Graph
4931         // which is more accurate than putting immediate users from Ideal Graph.
4932         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
4933           PointsToNode* tgt = e.get();
4934           if (tgt->is_Arraycopy()) {
4935             continue;
4936           }
4937           Node* use = tgt->ideal_node();
4938           assert(tgt->is_Field() && use->is_AddP(),
4939                  "only AddP nodes are Field edges in CG");
4940           if (use->outcnt() > 0) { // Don't process dead nodes
4941             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
4942             if (addp2 != nullptr) {
4943               assert(alloc->is_AllocateArray(),"array allocation was expected");
4944               alloc_worklist.append_if_missing(addp2);
4945             }
4946             alloc_worklist.append_if_missing(use);
4947           }
4948         }
4949 
4950         // An allocation may have an Initialize which has raw stores. Scan
4951         // the users of the raw allocation result and push AddP users
4952         // on alloc_worklist.
4953         Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
4954         assert (raw_result != nullptr, "must have an allocation result");
4955         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
4956           Node *use = raw_result->fast_out(i);
4957           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
4958             Node* addp2 = find_second_addp(use, raw_result);
4959             if (addp2 != nullptr) {
4960               assert(alloc->is_AllocateArray(),"array allocation was expected");
4961               alloc_worklist.append_if_missing(addp2);
4962             }
4963             alloc_worklist.append_if_missing(use);
4964           } else if (use->is_MemBar()) {
4965             memnode_worklist.push(use);
4966           }
4967         }
4968       }
4969     } else if (n->is_AddP()) {
4970       if (has_reducible_merge_base(n->as_AddP(), reducible_merges)) {
4971         // This AddP will go away when we reduce the Phi
4972         continue;
4973       }
4974       Node* addp_base = get_addp_base(n);
4975       JavaObjectNode* jobj = unique_java_object(addp_base);
4976       if (jobj == nullptr || jobj == phantom_obj) {
4977 #ifdef ASSERT
4978         ptnode_adr(get_addp_base(n)->_idx)->dump();
4979         ptnode_adr(n->_idx)->dump();
4980         assert(jobj != nullptr && jobj != phantom_obj, "escaped allocation");
4981 #endif
4982         _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4983         return;
4984       }
4985       Node *base = get_map(jobj->idx());  // CheckCastPP node
4986       if (!split_AddP(n, base)) continue; // wrong type from dead path
4987     } else if (n->is_Phi() ||
4988                n->is_CheckCastPP() ||
4989                n->is_EncodeP() ||
4990                n->is_DecodeN() ||
4991                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
4992       if (visited.test_set(n->_idx)) {
4993         assert(n->is_Phi(), "loops only through Phi's");
4994         continue;  // already processed
4995       }
4996       // Reducible Phi's will be removed from the graph after split_unique_types
4997       // finishes. For now we just try to split out the SR inputs of the merge.
4998       Node* parent = n->in(1);
4999       if (reducible_merges.member(n)) {
5000         reduce_phi(n->as_Phi(), alloc_worklist);
5001 #ifdef ASSERT
5002         if (VerifyReduceAllocationMerges) {
5003           reduced_merges.push(n);
5004         }
5005 #endif
5006         continue;
5007       } else if (reducible_merges.member(parent)) {
5008         // 'n' is an user of a reducible merge (a Phi). It will be simplified as
5009         // part of reduce_merge.
5010         continue;
5011       }
5012       JavaObjectNode* jobj = unique_java_object(n);
5013       if (jobj == nullptr || jobj == phantom_obj) {
5014 #ifdef ASSERT
5015         ptnode_adr(n->_idx)->dump();
5016         assert(jobj != nullptr && jobj != phantom_obj, "escaped allocation");
5017 #endif
5018         _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
5019         return;
5020       } else {
5021         Node *val = get_map(jobj->idx());   // CheckCastPP node
5022         TypeNode *tn = n->as_Type();
5023         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
5024         assert(tinst != nullptr && tinst->is_known_instance() &&
5025                tinst->instance_id() == jobj->idx() , "instance type expected.");
5026 
5027         const Type *tn_type = igvn->type(tn);
5028         const TypeOopPtr *tn_t;
5029         if (tn_type->isa_narrowoop()) {
5030           tn_t = tn_type->make_ptr()->isa_oopptr();
5031         } else {
5032           tn_t = tn_type->isa_oopptr();
5033         }
5034         if (tn_t != nullptr && tinst->maybe_java_subtype_of(tn_t)) {
5035           if (tn_t->isa_aryptr()) {
5036             // Keep array properties (not flat/null-free)
5037             tinst = tinst->is_aryptr()->update_properties(tn_t->is_aryptr());
5038             if (tinst == nullptr) {
5039               continue; // Skip dead path with inconsistent properties
5040             }
5041           }
5042           if (tn_type->isa_narrowoop()) {
5043             tn_type = tinst->make_narrowoop();
5044           } else {
5045             tn_type = tinst;
5046           }
5047           igvn->hash_delete(tn);
5048           igvn->set_type(tn, tn_type);
5049           tn->set_type(tn_type);
5050           igvn->hash_insert(tn);
5051           record_for_optimizer(n);
5052         } else {
5053           assert(tn_type == TypePtr::NULL_PTR ||
5054                  (tn_t != nullptr && !tinst->maybe_java_subtype_of(tn_t)),
5055                  "unexpected type");
5056           continue; // Skip dead path with different type
5057         }
5058       }
5059     } else {
5060       DEBUG_ONLY(n->dump();)
5061       assert(false, "EA: unexpected node");
5062       continue;
5063     }
5064     // push allocation's users on appropriate worklist
5065     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5066       Node *use = n->fast_out(i);
5067       if (use->is_Mem() && use->in(MemNode::Address) == n) {
5068         // Load/store to instance's field
5069         memnode_worklist.push(use);
5070       } else if (use->is_MemBar()) {
5071         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
5072           memnode_worklist.push(use);
5073         }
5074       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
5075         Node* addp2 = find_second_addp(use, n);
5076         if (addp2 != nullptr) {
5077           alloc_worklist.append_if_missing(addp2);
5078         }
5079         alloc_worklist.append_if_missing(use);
5080       } else if (use->is_Phi() ||
5081                  use->is_CheckCastPP() ||
5082                  use->is_EncodeNarrowPtr() ||
5083                  use->is_DecodeNarrowPtr() ||
5084                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
5085         alloc_worklist.append_if_missing(use);
5086 #ifdef ASSERT
5087       } else if (use->is_Mem()) {
5088         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
5089       } else if (use->is_MergeMem()) {
5090         assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
5091       } else if (use->is_SafePoint()) {
5092         // Look for MergeMem nodes for calls which reference unique allocation
5093         // (through CheckCastPP nodes) even for debug info.
5094         Node* m = use->in(TypeFunc::Memory);
5095         if (m->is_MergeMem()) {
5096           assert(mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
5097         }
5098       } else if (use->Opcode() == Op_EncodeISOArray) {
5099         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
5100           // EncodeISOArray overwrites destination array
5101           memnode_worklist.push(use);
5102         }
5103       } else if (use->Opcode() == Op_Return) {
5104         // Allocation is referenced by field of returned inline type
5105         assert(_compile->tf()->returns_inline_type_as_fields(), "EA: unexpected reference by ReturnNode");
5106       } else {
5107         uint op = use->Opcode();
5108         if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
5109             (use->in(MemNode::Memory) == n)) {
5110           // They overwrite memory edge corresponding to destination array,
5111           memnode_worklist.push(use);
5112         } else if (!(op == Op_CmpP || op == Op_Conv2B ||
5113               op == Op_CastP2X ||
5114               op == Op_FastLock || op == Op_AryEq ||
5115               op == Op_StrComp || op == Op_CountPositives ||
5116               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
5117               op == Op_StrEquals || op == Op_VectorizedHashCode ||
5118               op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
5119               op == Op_SubTypeCheck || op == Op_InlineType || op == Op_FlatArrayCheck ||
5120               op == Op_ReinterpretS2HF ||
5121               op == Op_ReachabilityFence ||
5122               BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
5123           n->dump();
5124           use->dump();
5125           assert(false, "EA: missing allocation reference path");
5126         }
5127 #endif
5128       }
5129     }
5130 
5131   }
5132 
5133 #ifdef ASSERT
5134   if (VerifyReduceAllocationMerges) {
5135     for (uint i = 0; i < reducible_merges.size(); i++) {
5136       Node* phi = reducible_merges.at(i);
5137 
5138       if (!reduced_merges.member(phi)) {
5139         phi->dump(2);
5140         phi->dump(-2);
5141         assert(false, "This reducible merge wasn't reduced.");
5142       }
5143 
5144       // At this point reducible Phis shouldn't have AddP users anymore; only SafePoints or Casts.
5145       for (DUIterator_Fast jmax, j = phi->fast_outs(jmax); j < jmax; j++) {
5146         Node* use = phi->fast_out(j);
5147         if (!use->is_SafePoint() && !use->is_CastPP()) {
5148           phi->dump(2);
5149           phi->dump(-2);
5150           assert(false, "Unexpected user of reducible Phi -> %d:%s:%d", use->_idx, use->Name(), use->outcnt());
5151         }
5152       }
5153     }
5154   }
5155 #endif
5156 
5157   // Go over all ArrayCopy nodes and if one of the inputs has a unique
5158   // type, record it in the ArrayCopy node so we know what memory this
5159   // node uses/modified.
5160   for (int next = 0; next < arraycopy_worklist.length(); next++) {
5161     ArrayCopyNode* ac = arraycopy_worklist.at(next);
5162     Node* dest = ac->in(ArrayCopyNode::Dest);
5163     if (dest->is_AddP()) {
5164       dest = get_addp_base(dest);
5165     }
5166     JavaObjectNode* jobj = unique_java_object(dest);
5167     if (jobj != nullptr) {
5168       Node *base = get_map(jobj->idx());
5169       if (base != nullptr) {
5170         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
5171         ac->_dest_type = base_t;
5172       }
5173     }
5174     Node* src = ac->in(ArrayCopyNode::Src);
5175     if (src->is_AddP()) {
5176       src = get_addp_base(src);
5177     }
5178     jobj = unique_java_object(src);
5179     if (jobj != nullptr) {
5180       Node* base = get_map(jobj->idx());
5181       if (base != nullptr) {
5182         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
5183         ac->_src_type = base_t;
5184       }
5185     }
5186   }
5187 
5188   // New alias types were created in split_AddP().
5189   uint new_index_end = (uint) _compile->num_alias_types();
5190 
5191   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_1, 5);
5192 
5193   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
5194   //            compute new values for Memory inputs  (the Memory inputs are not
5195   //            actually updated until phase 4.)
5196   if (memnode_worklist.size() == 0) {
5197     return;  // nothing to do
5198   }
5199   while (memnode_worklist.size() != 0) {
5200     Node *n = memnode_worklist.pop();
5201     if (visited.test_set(n->_idx)) {
5202       continue;
5203     }
5204     if (n->is_Phi()) {
5205       if ((uint) _compile->get_alias_index(n->adr_type()) < new_index_start) {
5206         // Push memory phis on the orig_phis worklist to update
5207         // during Phase 4 if needed.
5208         orig_phis.push(n);
5209       }
5210     } else if (n->is_ClearArray()) {
5211      // we don't need to do anything, but the users must be pushed
5212     } else if (n->is_MemBar()) { // MemBar nodes
5213       if (!n->is_Initialize()) { // memory projections for Initialize pushed below (so we get to all their uses)
5214         // we don't need to do anything, but the users must be pushed
5215         n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
5216         if (n == nullptr) {
5217           continue;
5218         }
5219       }
5220     } else if (n->is_CallLeaf()) {
5221       // Runtime calls with narrow memory input (no MergeMem node)
5222       // get the memory projection
5223       n = n->as_Call()->proj_out_or_null(TypeFunc::Memory);
5224       if (n == nullptr) {
5225         continue;
5226       }
5227     } else if (n->Opcode() == Op_StrInflatedCopy) {
5228       // Check direct uses of StrInflatedCopy.
5229       // It is memory type Node - no special SCMemProj node.
5230     } else if (n->Opcode() == Op_StrCompressedCopy ||
5231                n->Opcode() == Op_EncodeISOArray) {
5232       // get the memory projection
5233       n = n->find_out_with(Op_SCMemProj);
5234       assert(n != nullptr && n->Opcode() == Op_SCMemProj, "memory projection required");
5235     } else if (n->is_CallLeaf() && n->as_CallLeaf()->_name != nullptr &&
5236                strcmp(n->as_CallLeaf()->_name, "store_unknown_inline") == 0) {
5237       n = n->as_CallLeaf()->proj_out(TypeFunc::Memory);
5238     } else if (n->is_Proj()) {
5239       assert(n->in(0)->is_Initialize(), "we only push memory projections for Initialize");
5240     } else {
5241 #ifdef ASSERT
5242       if (!n->is_Mem()) {
5243         n->dump();
5244       }
5245       assert(n->is_Mem(), "memory node required.");
5246 #endif
5247       Node *addr = n->in(MemNode::Address);
5248       const Type *addr_t = igvn->type(addr);
5249       if (addr_t == Type::TOP) {
5250         continue;
5251       }
5252       assert (addr_t->isa_ptr() != nullptr, "pointer type required.");
5253       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
5254       assert ((uint)alias_idx < new_index_end, "wrong alias index");
5255       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
5256       if (_compile->failing()) {
5257         return;
5258       }
5259       if (mem != n->in(MemNode::Memory)) {
5260         // We delay the memory edge update since we need old one in
5261         // MergeMem code below when instances memory slices are separated.
5262         set_map(n, mem);
5263       }
5264       if (n->is_Load()) {
5265         continue;  // don't push users
5266       } else if (n->is_LoadStore()) {
5267         // get the memory projection
5268         n = n->find_out_with(Op_SCMemProj);
5269         assert(n != nullptr && n->Opcode() == Op_SCMemProj, "memory projection required");
5270       }
5271     }
5272     // push user on appropriate worklist
5273     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5274       Node *use = n->fast_out(i);
5275       if (use->is_Phi() || use->is_ClearArray()) {
5276         memnode_worklist.push(use);
5277       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
5278         memnode_worklist.push(use);
5279       } else if (use->is_MemBar() || use->is_CallLeaf()) {
5280         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
5281           memnode_worklist.push(use);
5282         }
5283       } else if (use->is_Proj()) {
5284         assert(n->is_Initialize(), "We only push projections of Initialize");
5285         if (use->as_Proj()->_con == TypeFunc::Memory) { // Ignore precedent edge
5286           memnode_worklist.push(use);
5287         }
5288 #ifdef ASSERT
5289       } else if (use->is_Mem()) {
5290         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
5291       } else if (use->is_MergeMem()) {
5292         assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
5293       } else if (use->Opcode() == Op_EncodeISOArray) {
5294         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
5295           // EncodeISOArray overwrites destination array
5296           memnode_worklist.push(use);
5297         }
5298       } else if (use->is_CallLeaf() && use->as_CallLeaf()->_name != nullptr &&
5299                  strcmp(use->as_CallLeaf()->_name, "store_unknown_inline") == 0) {
5300         // store_unknown_inline overwrites destination array
5301         memnode_worklist.push(use);
5302       } else {
5303         uint op = use->Opcode();
5304         if ((use->in(MemNode::Memory) == n) &&
5305             (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
5306           // They overwrite memory edge corresponding to destination array,
5307           memnode_worklist.push(use);
5308         } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
5309               op == Op_AryEq || op == Op_StrComp || op == Op_CountPositives ||
5310               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy || op == Op_VectorizedHashCode ||
5311               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar || op == Op_FlatArrayCheck)) {
5312           n->dump();
5313           use->dump();
5314           assert(false, "EA: missing memory path");
5315         }
5316 #endif
5317       }
5318     }
5319   }
5320 
5321   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
5322   //            Walk each memory slice moving the first node encountered of each
5323   //            instance type to the input corresponding to its alias index.
5324   uint length = mergemem_worklist.length();
5325   for( uint next = 0; next < length; ++next ) {
5326     MergeMemNode* nmm = mergemem_worklist.at(next);
5327     assert(!visited.test_set(nmm->_idx), "should not be visited before");
5328     // Note: we don't want to use MergeMemStream here because we only want to
5329     // scan inputs which exist at the start, not ones we add during processing.
5330     // Note 2: MergeMem may already contains instance memory slices added
5331     // during find_inst_mem() call when memory nodes were processed above.
5332     igvn->hash_delete(nmm);
5333     uint nslices = MIN2(nmm->req(), new_index_start);
5334     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
5335       Node* mem = nmm->in(i);
5336       Node* cur = nullptr;
5337       if (mem == nullptr || mem->is_top()) {
5338         continue;
5339       }
5340       // First, update mergemem by moving memory nodes to corresponding slices
5341       // if their type became more precise since this mergemem was created.
5342       while (mem->is_Mem()) {
5343         const Type* at = igvn->type(mem->in(MemNode::Address));
5344         if (at != Type::TOP) {
5345           assert (at->isa_ptr() != nullptr, "pointer type required.");
5346           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
5347           if (idx == i) {
5348             if (cur == nullptr) {
5349               cur = mem;
5350             }
5351           } else {
5352             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
5353               nmm->set_memory_at(idx, mem);
5354             }
5355           }
5356         }
5357         mem = mem->in(MemNode::Memory);
5358       }
5359       nmm->set_memory_at(i, (cur != nullptr) ? cur : mem);
5360       // Find any instance of the current type if we haven't encountered
5361       // already a memory slice of the instance along the memory chain.
5362       for (uint ni = new_index_start; ni < new_index_end; ni++) {
5363         if((uint)_compile->get_general_index(ni) == i) {
5364           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
5365           if (nmm->is_empty_memory(m)) {
5366             Node* result = find_inst_mem(mem, ni, orig_phis);
5367             if (_compile->failing()) {
5368               return;
5369             }
5370             nmm->set_memory_at(ni, result);
5371           }
5372         }
5373       }
5374     }
5375     // Find the rest of instances values
5376     for (uint ni = new_index_start; ni < new_index_end; ni++) {
5377       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
5378       Node* result = step_through_mergemem(nmm, ni, tinst);
5379       if (result == nmm->base_memory()) {
5380         // Didn't find instance memory, search through general slice recursively.
5381         result = nmm->memory_at(_compile->get_general_index(ni));
5382         result = find_inst_mem(result, ni, orig_phis);
5383         if (_compile->failing()) {
5384           return;
5385         }
5386         nmm->set_memory_at(ni, result);
5387       }
5388     }
5389 
5390     // If we have crossed the 3/4 point of max node limit it's too risky
5391     // to continue with EA/SR because we might hit the max node limit.
5392     if (_compile->live_nodes() >= _compile->max_node_limit() * 0.75) {
5393       if (_compile->do_reduce_allocation_merges()) {
5394         _compile->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
5395       } else if (_invocation > 0) {
5396         _compile->record_failure(C2Compiler::retry_no_iterative_escape_analysis());
5397       } else {
5398         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
5399       }
5400       return;
5401     }
5402 
5403     igvn->hash_insert(nmm);
5404     record_for_optimizer(nmm);
5405   }
5406 
5407   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_3, 5);
5408 
5409   //  Phase 4:  Update the inputs of non-instance memory Phis and
5410   //            the Memory input of memnodes
5411   // First update the inputs of any non-instance Phi's from
5412   // which we split out an instance Phi.  Note we don't have
5413   // to recursively process Phi's encountered on the input memory
5414   // chains as is done in split_memory_phi() since they will
5415   // also be processed here.
5416   for (uint j = 0; j < orig_phis.size(); j++) {
5417     PhiNode* phi = orig_phis.at(j)->as_Phi();
5418     int alias_idx = _compile->get_alias_index(phi->adr_type());
5419     igvn->hash_delete(phi);
5420     for (uint i = 1; i < phi->req(); i++) {
5421       Node *mem = phi->in(i);
5422       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
5423       if (_compile->failing()) {
5424         return;
5425       }
5426       if (mem != new_mem) {
5427         phi->set_req(i, new_mem);
5428       }
5429     }
5430     igvn->hash_insert(phi);
5431     record_for_optimizer(phi);
5432   }
5433 
5434   // Update the memory inputs of MemNodes with the value we computed
5435   // in Phase 2 and move stores memory users to corresponding memory slices.
5436   // Disable memory split verification code until the fix for 6984348.
5437   // Currently it produces false negative results since it does not cover all cases.
5438 #if 0 // ifdef ASSERT
5439   visited.Reset();
5440   Node_Stack old_mems(arena, _compile->unique() >> 2);
5441 #endif
5442   for (uint i = 0; i < ideal_nodes.size(); i++) {
5443     Node*    n = ideal_nodes.at(i);
5444     Node* nmem = get_map(n->_idx);
5445     assert(nmem != nullptr, "sanity");
5446     if (n->is_Mem()) {
5447 #if 0 // ifdef ASSERT
5448       Node* old_mem = n->in(MemNode::Memory);
5449       if (!visited.test_set(old_mem->_idx)) {
5450         old_mems.push(old_mem, old_mem->outcnt());
5451       }
5452 #endif
5453       assert(n->in(MemNode::Memory) != nmem, "sanity");
5454       if (!n->is_Load()) {
5455         // Move memory users of a store first.
5456         move_inst_mem(n, orig_phis);
5457       }
5458       // Now update memory input
5459       igvn->hash_delete(n);
5460       n->set_req(MemNode::Memory, nmem);
5461       igvn->hash_insert(n);
5462       record_for_optimizer(n);
5463     } else {
5464       assert(n->is_Allocate() || n->is_CheckCastPP() ||
5465              n->is_AddP() || n->is_Phi() || n->is_NarrowMemProj(), "unknown node used for set_map()");
5466     }
5467   }
5468 #if 0 // ifdef ASSERT
5469   // Verify that memory was split correctly
5470   while (old_mems.is_nonempty()) {
5471     Node* old_mem = old_mems.node();
5472     uint  old_cnt = old_mems.index();
5473     old_mems.pop();
5474     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
5475   }
5476 #endif
5477   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_4, 5);
5478 }
5479 
5480 #ifndef PRODUCT
5481 int ConnectionGraph::_no_escape_counter = 0;
5482 int ConnectionGraph::_arg_escape_counter = 0;
5483 int ConnectionGraph::_global_escape_counter = 0;
5484 
5485 static const char *node_type_names[] = {
5486   "UnknownType",
5487   "JavaObject",
5488   "LocalVar",
5489   "Field",
5490   "Arraycopy"
5491 };
5492 
5493 static const char *esc_names[] = {
5494   "UnknownEscape",
5495   "NoEscape",
5496   "ArgEscape",
5497   "GlobalEscape"
5498 };
5499 
5500 const char* PointsToNode::esc_name() const {
5501   return esc_names[(int)escape_state()];
5502 }
5503 
5504 void PointsToNode::dump_header(bool print_state, outputStream* out) const {
5505   NodeType nt = node_type();
5506   out->print("%s(%d) ", node_type_names[(int) nt], _pidx);
5507   if (print_state) {
5508     EscapeState es = escape_state();
5509     EscapeState fields_es = fields_escape_state();
5510     out->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
5511     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable()) {
5512       out->print("NSR ");
5513     }
5514   }
5515 }
5516 
5517 void PointsToNode::dump(bool print_state, outputStream* out, bool newline) const {
5518   dump_header(print_state, out);
5519   if (is_Field()) {
5520     FieldNode* f = (FieldNode*)this;
5521     if (f->is_oop()) {
5522       out->print("oop ");
5523     }
5524     if (f->offset() > 0) {
5525       out->print("+%d ", f->offset());
5526     }
5527     out->print("(");
5528     for (BaseIterator i(f); i.has_next(); i.next()) {
5529       PointsToNode* b = i.get();
5530       out->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
5531     }
5532     out->print(" )");
5533   }
5534   out->print("[");
5535   for (EdgeIterator i(this); i.has_next(); i.next()) {
5536     PointsToNode* e = i.get();
5537     out->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
5538   }
5539   out->print(" [");
5540   for (UseIterator i(this); i.has_next(); i.next()) {
5541     PointsToNode* u = i.get();
5542     bool is_base = false;
5543     if (PointsToNode::is_base_use(u)) {
5544       is_base = true;
5545       u = PointsToNode::get_use_node(u)->as_Field();
5546     }
5547     out->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
5548   }
5549   out->print(" ]]  ");
5550   if (_node == nullptr) {
5551     out->print("<null>%s", newline ? "\n" : "");
5552   } else {
5553     _node->dump(newline ? "\n" : "", false, out);
5554   }
5555 }
5556 
5557 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
5558   bool first = true;
5559   int ptnodes_length = ptnodes_worklist.length();
5560   for (int i = 0; i < ptnodes_length; i++) {
5561     PointsToNode *ptn = ptnodes_worklist.at(i);
5562     if (ptn == nullptr || !ptn->is_JavaObject()) {
5563       continue;
5564     }
5565     PointsToNode::EscapeState es = ptn->escape_state();
5566     if ((es != PointsToNode::NoEscape) && !Verbose) {
5567       continue;
5568     }
5569     Node* n = ptn->ideal_node();
5570     if (n->is_Allocate() || (n->is_CallStaticJava() &&
5571                              n->as_CallStaticJava()->is_boxing_method())) {
5572       if (first) {
5573         tty->cr();
5574         tty->print("======== Connection graph for ");
5575         _compile->method()->print_short_name();
5576         tty->cr();
5577         tty->print_cr("invocation #%d: %d iterations and %f sec to build connection graph with %d nodes and worklist size %d",
5578                       _invocation, _build_iterations, _build_time, nodes_size(), ptnodes_worklist.length());
5579         tty->cr();
5580         first = false;
5581       }
5582       ptn->dump();
5583       // Print all locals and fields which reference this allocation
5584       for (UseIterator j(ptn); j.has_next(); j.next()) {
5585         PointsToNode* use = j.get();
5586         if (use->is_LocalVar()) {
5587           use->dump(Verbose);
5588         } else if (Verbose) {
5589           use->dump();
5590         }
5591       }
5592       tty->cr();
5593     }
5594   }
5595 }
5596 
5597 void ConnectionGraph::print_statistics() {
5598   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));
5599 }
5600 
5601 void ConnectionGraph::escape_state_statistics(GrowableArray<JavaObjectNode*>& java_objects_worklist) {
5602   if (!PrintOptoStatistics || (_invocation > 0)) { // Collect data only for the first invocation
5603     return;
5604   }
5605   for (int next = 0; next < java_objects_worklist.length(); ++next) {
5606     JavaObjectNode* ptn = java_objects_worklist.at(next);
5607     if (ptn->ideal_node()->is_Allocate()) {
5608       if (ptn->escape_state() == PointsToNode::NoEscape) {
5609         AtomicAccess::inc(&ConnectionGraph::_no_escape_counter);
5610       } else if (ptn->escape_state() == PointsToNode::ArgEscape) {
5611         AtomicAccess::inc(&ConnectionGraph::_arg_escape_counter);
5612       } else if (ptn->escape_state() == PointsToNode::GlobalEscape) {
5613         AtomicAccess::inc(&ConnectionGraph::_global_escape_counter);
5614       } else {
5615         assert(false, "Unexpected Escape State");
5616       }
5617     }
5618   }
5619 }
5620 
5621 void ConnectionGraph::trace_es_update_helper(PointsToNode* ptn, PointsToNode::EscapeState es, bool fields, const char* reason) const {
5622   if (_compile->directive()->TraceEscapeAnalysisOption) {
5623     assert(ptn != nullptr, "should not be null");
5624     assert(reason != nullptr, "should not be null");
5625     ptn->dump_header(true);
5626     PointsToNode::EscapeState new_es = fields ? ptn->escape_state() : es;
5627     PointsToNode::EscapeState new_fields_es = fields ? es : ptn->fields_escape_state();
5628     tty->print_cr("-> %s(%s) %s", esc_names[(int)new_es], esc_names[(int)new_fields_es], reason);
5629   }
5630 }
5631 
5632 const char* ConnectionGraph::trace_propagate_message(PointsToNode* from) const {
5633   if (_compile->directive()->TraceEscapeAnalysisOption) {
5634     stringStream ss;
5635     ss.print("propagated from: ");
5636     from->dump(true, &ss, false);
5637     return ss.as_string();
5638   } else {
5639     return nullptr;
5640   }
5641 }
5642 
5643 const char* ConnectionGraph::trace_arg_escape_message(CallNode* call) const {
5644   if (_compile->directive()->TraceEscapeAnalysisOption) {
5645     stringStream ss;
5646     ss.print("escapes as arg to:");
5647     call->dump("", false, &ss);
5648     return ss.as_string();
5649   } else {
5650     return nullptr;
5651   }
5652 }
5653 
5654 const char* ConnectionGraph::trace_merged_message(PointsToNode* other) const {
5655   if (_compile->directive()->TraceEscapeAnalysisOption) {
5656     stringStream ss;
5657     ss.print("is merged with other object: ");
5658     other->dump_header(true, &ss);
5659     return ss.as_string();
5660   } else {
5661     return nullptr;
5662   }
5663 }
5664 
5665 #endif
5666 
5667 void ConnectionGraph::record_for_optimizer(Node *n) {
5668   _igvn->_worklist.push(n);
5669   _igvn->add_users_to_worklist(n);
5670 }
--- EOF ---