1 /*
   2  * Copyright (c) 2005, 2026, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "ci/bcEscapeAnalyzer.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "gc/shared/barrierSet.hpp"
  28 #include "gc/shared/c2/barrierSetC2.hpp"
  29 #include "libadt/vectset.hpp"
  30 #include "memory/allocation.hpp"
  31 #include "memory/metaspace.hpp"
  32 #include "memory/resourceArea.hpp"
  33 #include "opto/arraycopynode.hpp"
  34 #include "opto/c2compiler.hpp"
  35 #include "opto/callnode.hpp"
  36 #include "opto/castnode.hpp"
  37 #include "opto/cfgnode.hpp"
  38 #include "opto/compile.hpp"
  39 #include "opto/escape.hpp"
  40 #include "opto/inlinetypenode.hpp"
  41 #include "opto/locknode.hpp"
  42 #include "opto/macro.hpp"
  43 #include "opto/movenode.hpp"
  44 #include "opto/narrowptrnode.hpp"
  45 #include "opto/phaseX.hpp"
  46 #include "opto/rootnode.hpp"
  47 #include "utilities/macros.hpp"
  48 
  49 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn, int invocation) :
  50   // If ReduceAllocationMerges is enabled we might call split_through_phi during
  51   // split_unique_types and that will create additional nodes that need to be
  52   // pushed to the ConnectionGraph. The code below bumps the initial capacity of
  53   // _nodes by 10% to account for these additional nodes. If capacity is exceeded
  54   // the array will be reallocated.
  55   _nodes(C->comp_arena(), C->do_reduce_allocation_merges() ? C->unique()*1.10 : C->unique(), C->unique(), nullptr),
  56   _in_worklist(C->comp_arena()),
  57   _next_pidx(0),
  58   _collecting(true),
  59   _verify(false),
  60   _compile(C),
  61   _igvn(igvn),
  62   _invocation(invocation),
  63   _build_iterations(0),
  64   _build_time(0.),
  65   _node_map(C->comp_arena()) {
  66   // Add unknown java object.
  67   add_java_object(C->top(), PointsToNode::GlobalEscape);
  68   phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
  69   set_not_scalar_replaceable(phantom_obj NOT_PRODUCT(COMMA "Phantom object"));
  70   // Add ConP and ConN null oop nodes
  71   Node* oop_null = igvn->zerocon(T_OBJECT);
  72   assert(oop_null->_idx < nodes_size(), "should be created already");
  73   add_java_object(oop_null, PointsToNode::NoEscape);
  74   null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
  75   set_not_scalar_replaceable(null_obj NOT_PRODUCT(COMMA "Null object"));
  76   if (UseCompressedOops) {
  77     Node* noop_null = igvn->zerocon(T_NARROWOOP);
  78     assert(noop_null->_idx < nodes_size(), "should be created already");
  79     map_ideal_node(noop_null, null_obj);
  80   }
  81 }
  82 
  83 bool ConnectionGraph::has_candidates(Compile *C) {
  84   // EA brings benefits only when the code has allocations and/or locks which
  85   // are represented by ideal Macro nodes.
  86   int cnt = C->macro_count();
  87   for (int i = 0; i < cnt; i++) {
  88     Node *n = C->macro_node(i);
  89     if (n->is_Allocate()) {
  90       return true;
  91     }
  92     if (n->is_Lock()) {
  93       Node* obj = n->as_Lock()->obj_node()->uncast();
  94       if (!(obj->is_Parm() || obj->is_Con())) {
  95         return true;
  96       }
  97     }
  98     if (n->is_CallStaticJava() &&
  99         n->as_CallStaticJava()->is_boxing_method()) {
 100       return true;
 101     }
 102   }
 103   return false;
 104 }
 105 
 106 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
 107   Compile::TracePhase tp(Phase::_t_escapeAnalysis);
 108   ResourceMark rm;
 109 
 110   // Add ConP and ConN null oop nodes before ConnectionGraph construction
 111   // to create space for them in ConnectionGraph::_nodes[].
 112   Node* oop_null = igvn->zerocon(T_OBJECT);
 113   Node* noop_null = igvn->zerocon(T_NARROWOOP);
 114   int invocation = 0;
 115   if (C->congraph() != nullptr) {
 116     invocation = C->congraph()->_invocation + 1;
 117   }
 118   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn, invocation);
 119   NOT_PRODUCT(if (C->should_print_igv(/* Any level */ 1)) C->igv_printer()->set_congraph(congraph);)
 120   // Perform escape analysis
 121   if (congraph->compute_escape()) {
 122     // There are non escaping objects.
 123     C->set_congraph(congraph);
 124   }
 125   NOT_PRODUCT(if (C->should_print_igv(/* Any level */ 1)) C->igv_printer()->set_congraph(nullptr);)
 126   // Cleanup.
 127   if (oop_null->outcnt() == 0) {
 128     igvn->hash_delete(oop_null);
 129   }
 130   if (noop_null->outcnt() == 0) {
 131     igvn->hash_delete(noop_null);
 132   }
 133 
 134   C->print_method(PHASE_AFTER_EA, 2);
 135 }
 136 
 137 bool ConnectionGraph::compute_escape() {
 138   Compile* C = _compile;
 139   PhaseGVN* igvn = _igvn;
 140 
 141   // Worklists used by EA.
 142   Unique_Node_List delayed_worklist;
 143   Unique_Node_List reducible_merges;
 144   GrowableArray<Node*> alloc_worklist;
 145   GrowableArray<Node*> ptr_cmp_worklist;
 146   GrowableArray<MemBarStoreStoreNode*> storestore_worklist;
 147   GrowableArray<ArrayCopyNode*>  arraycopy_worklist;
 148   GrowableArray<PointsToNode*>   ptnodes_worklist;
 149   GrowableArray<JavaObjectNode*> java_objects_worklist;
 150   GrowableArray<JavaObjectNode*> non_escaped_allocs_worklist;
 151   GrowableArray<FieldNode*>      oop_fields_worklist;
 152   GrowableArray<SafePointNode*>  sfn_worklist;
 153   GrowableArray<MergeMemNode*>   mergemem_worklist;
 154   DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
 155 
 156   { Compile::TracePhase tp(Phase::_t_connectionGraph);
 157 
 158   // 1. Populate Connection Graph (CG) with PointsTo nodes.
 159   ideal_nodes.map(C->live_nodes(), nullptr);  // preallocate space
 160   // Initialize worklist
 161   if (C->root() != nullptr) {
 162     ideal_nodes.push(C->root());
 163   }
 164   // Processed ideal nodes are unique on ideal_nodes list
 165   // but several ideal nodes are mapped to the phantom_obj.
 166   // To avoid duplicated entries on the following worklists
 167   // add the phantom_obj only once to them.
 168   ptnodes_worklist.append(phantom_obj);
 169   java_objects_worklist.append(phantom_obj);
 170   for( uint next = 0; next < ideal_nodes.size(); ++next ) {
 171     Node* n = ideal_nodes.at(next);
 172     if ((n->Opcode() == Op_LoadX || n->Opcode() == Op_StoreX) &&
 173         !n->in(MemNode::Address)->is_AddP() &&
 174         _igvn->type(n->in(MemNode::Address))->isa_oopptr()) {
 175       // Load/Store at mark work address is at offset 0 so has no AddP which confuses EA
 176       Node* addp = new AddPNode(n->in(MemNode::Address), n->in(MemNode::Address), _igvn->MakeConX(0));
 177       _igvn->register_new_node_with_optimizer(addp);
 178       _igvn->replace_input_of(n, MemNode::Address, addp);
 179       ideal_nodes.push(addp);
 180       _nodes.at_put_grow(addp->_idx, nullptr, nullptr);
 181     }
 182     // Create PointsTo nodes and add them to Connection Graph. Called
 183     // only once per ideal node since ideal_nodes is Unique_Node list.
 184     add_node_to_connection_graph(n, &delayed_worklist);
 185     PointsToNode* ptn = ptnode_adr(n->_idx);
 186     if (ptn != nullptr && ptn != phantom_obj) {
 187       ptnodes_worklist.append(ptn);
 188       if (ptn->is_JavaObject()) {
 189         java_objects_worklist.append(ptn->as_JavaObject());
 190         if ((n->is_Allocate() || n->is_CallStaticJava()) &&
 191             (ptn->escape_state() < PointsToNode::GlobalEscape)) {
 192           // Only allocations and java static calls results are interesting.
 193           non_escaped_allocs_worklist.append(ptn->as_JavaObject());
 194         }
 195       } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
 196         oop_fields_worklist.append(ptn->as_Field());
 197       }
 198     }
 199     // Collect some interesting nodes for further use.
 200     switch (n->Opcode()) {
 201       case Op_MergeMem:
 202         // Collect all MergeMem nodes to add memory slices for
 203         // scalar replaceable objects in split_unique_types().
 204         mergemem_worklist.append(n->as_MergeMem());
 205         break;
 206       case Op_CmpP:
 207       case Op_CmpN:
 208         // Collect compare pointers nodes.
 209         if (OptimizePtrCompare) {
 210           ptr_cmp_worklist.append(n);
 211         }
 212         break;
 213       case Op_MemBarStoreStore:
 214         // Collect all MemBarStoreStore nodes so that depending on the
 215         // escape status of the associated Allocate node some of them
 216         // may be eliminated.
 217         if (!UseStoreStoreForCtor || n->req() > MemBarNode::Precedent) {
 218           storestore_worklist.append(n->as_MemBarStoreStore());
 219         }
 220         // If MemBarStoreStore has a precedent edge add it to the worklist (like MemBarRelease)
 221       case Op_MemBarRelease:
 222         if (n->req() > MemBarNode::Precedent) {
 223           record_for_optimizer(n);
 224         }
 225         break;
 226 #ifdef ASSERT
 227       case Op_AddP:
 228         // Collect address nodes for graph verification.
 229         addp_worklist.append(n);
 230         break;
 231 #endif
 232       case Op_ArrayCopy:
 233         // Keep a list of ArrayCopy nodes so if one of its input is non
 234         // escaping, we can record a unique type
 235         arraycopy_worklist.append(n->as_ArrayCopy());
 236         break;
 237       default:
 238         // not interested now, ignore...
 239         break;
 240     }
 241     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 242       Node* m = n->fast_out(i);   // Get user
 243       ideal_nodes.push(m);
 244     }
 245     if (n->is_SafePoint()) {
 246       sfn_worklist.append(n->as_SafePoint());
 247     }
 248   }
 249 
 250 #ifndef PRODUCT
 251   if (_compile->directive()->TraceEscapeAnalysisOption) {
 252     tty->print("+++++ Initial worklist for ");
 253     _compile->method()->print_name();
 254     tty->print_cr(" (ea_inv=%d)", _invocation);
 255     for (int i = 0; i < ptnodes_worklist.length(); i++) {
 256       PointsToNode* ptn = ptnodes_worklist.at(i);
 257       ptn->dump();
 258     }
 259     tty->print_cr("+++++ Calculating escape states and scalar replaceability");
 260   }
 261 #endif
 262 
 263   if (non_escaped_allocs_worklist.length() == 0) {
 264     _collecting = false;
 265     NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 266     return false; // Nothing to do.
 267   }
 268   // Add final simple edges to graph.
 269   while(delayed_worklist.size() > 0) {
 270     Node* n = delayed_worklist.pop();
 271     add_final_edges(n);
 272   }
 273 
 274 #ifdef ASSERT
 275   if (VerifyConnectionGraph) {
 276     // Verify that no new simple edges could be created and all
 277     // local vars has edges.
 278     _verify = true;
 279     int ptnodes_length = ptnodes_worklist.length();
 280     for (int next = 0; next < ptnodes_length; ++next) {
 281       PointsToNode* ptn = ptnodes_worklist.at(next);
 282       add_final_edges(ptn->ideal_node());
 283       if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
 284         ptn->dump();
 285         assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
 286       }
 287     }
 288     _verify = false;
 289   }
 290 #endif
 291   // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
 292   // processing, calls to CI to resolve symbols (types, fields, methods)
 293   // referenced in bytecode. During symbol resolution VM may throw
 294   // an exception which CI cleans and converts to compilation failure.
 295   if (C->failing()) {
 296     NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 297     return false;
 298   }
 299 
 300   _compile->print_method(PHASE_EA_AFTER_INITIAL_CONGRAPH, 4);
 301 
 302   // 2. Finish Graph construction by propagating references to all
 303   //    java objects through graph.
 304   if (!complete_connection_graph(ptnodes_worklist, non_escaped_allocs_worklist,
 305                                  java_objects_worklist, oop_fields_worklist)) {
 306     // All objects escaped or hit time or iterations limits.
 307     _collecting = false;
 308     NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 309     return false;
 310   }
 311 
 312   _compile->print_method(PHASE_EA_AFTER_COMPLETE_CONGRAPH, 4);
 313 
 314   // 3. Adjust scalar_replaceable state of nonescaping objects and push
 315   //    scalar replaceable allocations on alloc_worklist for processing
 316   //    in split_unique_types().
 317   GrowableArray<JavaObjectNode*> jobj_worklist;
 318   int non_escaped_length = non_escaped_allocs_worklist.length();
 319   bool found_nsr_alloc = false;
 320   for (int next = 0; next < non_escaped_length; next++) {
 321     JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
 322     bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
 323     Node* n = ptn->ideal_node();
 324     if (n->is_Allocate()) {
 325       n->as_Allocate()->_is_non_escaping = noescape;
 326     }
 327     if (noescape && ptn->scalar_replaceable()) {
 328       adjust_scalar_replaceable_state(ptn, reducible_merges);
 329       if (ptn->scalar_replaceable()) {
 330         jobj_worklist.push(ptn);
 331       } else {
 332         found_nsr_alloc = true;
 333       }
 334     }
 335     _compile->print_method(PHASE_EA_ADJUST_SCALAR_REPLACEABLE_ITER, 6, n);
 336   }
 337 
 338   // Propagate NSR (Not Scalar Replaceable) state.
 339   if (found_nsr_alloc) {
 340     find_scalar_replaceable_allocs(jobj_worklist, reducible_merges);
 341   }
 342 
 343   // alloc_worklist will be processed in reverse push order.
 344   // Therefore the reducible Phis will be processed for last and that's what we
 345   // want because by then the scalarizable inputs of the merge will already have
 346   // an unique instance type.
 347   for (uint i = 0; i < reducible_merges.size(); i++ ) {
 348     Node* n = reducible_merges.at(i);
 349     alloc_worklist.append(n);
 350   }
 351 
 352   for (int next = 0; next < jobj_worklist.length(); ++next) {
 353     JavaObjectNode* jobj = jobj_worklist.at(next);
 354     if (jobj->scalar_replaceable()) {
 355       alloc_worklist.append(jobj->ideal_node());
 356     }
 357   }
 358 
 359 #ifdef ASSERT
 360   if (VerifyConnectionGraph) {
 361     // Verify that graph is complete - no new edges could be added or needed.
 362     verify_connection_graph(ptnodes_worklist, non_escaped_allocs_worklist,
 363                             java_objects_worklist, addp_worklist);
 364   }
 365   assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
 366   assert(null_obj->escape_state() == PointsToNode::NoEscape &&
 367          null_obj->edge_count() == 0 &&
 368          !null_obj->arraycopy_src() &&
 369          !null_obj->arraycopy_dst(), "sanity");
 370 #endif
 371 
 372   _collecting = false;
 373 
 374   _compile->print_method(PHASE_EA_AFTER_PROPAGATE_NSR, 4);
 375   } // TracePhase t3("connectionGraph")
 376 
 377   // 4. Optimize ideal graph based on EA information.
 378   bool has_non_escaping_obj = (non_escaped_allocs_worklist.length() > 0);
 379   if (has_non_escaping_obj) {
 380     optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
 381   }
 382 
 383 #ifndef PRODUCT
 384   if (PrintEscapeAnalysis) {
 385     dump(ptnodes_worklist); // Dump ConnectionGraph
 386   }
 387 #endif
 388 
 389 #ifdef ASSERT
 390   if (VerifyConnectionGraph) {
 391     int alloc_length = alloc_worklist.length();
 392     for (int next = 0; next < alloc_length; ++next) {
 393       Node* n = alloc_worklist.at(next);
 394       PointsToNode* ptn = ptnode_adr(n->_idx);
 395       assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
 396     }
 397   }
 398 
 399   if (VerifyReduceAllocationMerges) {
 400     for (uint i = 0; i < reducible_merges.size(); i++ ) {
 401       Node* n = reducible_merges.at(i);
 402       if (!can_reduce_phi(n->as_Phi())) {
 403         TraceReduceAllocationMerges = true;
 404         n->dump(2);
 405         n->dump(-2);
 406         assert(can_reduce_phi(n->as_Phi()), "Sanity: previous reducible Phi is no longer reducible before SUT.");
 407       }
 408     }
 409   }
 410 #endif
 411 
 412   _compile->print_method(PHASE_EA_AFTER_GRAPH_OPTIMIZATION, 4);
 413 
 414   // 5. Separate memory graph for scalar replaceable allcations.
 415   bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
 416   if (has_scalar_replaceable_candidates && EliminateAllocations) {
 417     assert(C->do_aliasing(), "Aliasing should be enabled");
 418     // Now use the escape information to create unique types for
 419     // scalar replaceable objects.
 420     split_unique_types(alloc_worklist, arraycopy_worklist, mergemem_worklist, reducible_merges);
 421     if (C->failing()) {
 422       NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 423       return false;
 424     }
 425 
 426 #ifdef ASSERT
 427   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
 428     tty->print("=== No allocations eliminated for ");
 429     C->method()->print_short_name();
 430     if (!EliminateAllocations) {
 431       tty->print(" since EliminateAllocations is off ===");
 432     } else if(!has_scalar_replaceable_candidates) {
 433       tty->print(" since there are no scalar replaceable candidates ===");
 434     }
 435     tty->cr();
 436 #endif
 437   }
 438 
 439   // 6. Expand flat accesses if the object does not escape. This adds nodes to
 440   // the graph, so it has to be after split_unique_types. This expands atomic
 441   // mismatched accesses (though encapsulated in LoadFlats and StoreFlats) into
 442   // non-mismatched accesses, so it is better before reduce allocation merges.
 443   if (has_non_escaping_obj) {
 444     optimize_flat_accesses(sfn_worklist);
 445   }
 446 
 447   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES, 4);
 448 
 449   // 7. Reduce allocation merges used as debug information. This is done after
 450   // split_unique_types because the methods used to create SafePointScalarObject
 451   // need to traverse the memory graph to find values for object fields. We also
 452   // set to null the scalarized inputs of reducible Phis so that the Allocate
 453   // that they point can be later scalar replaced.
 454   bool delay = _igvn->delay_transform();
 455   _igvn->set_delay_transform(true);
 456   for (uint i = 0; i < reducible_merges.size(); i++) {
 457     Node* n = reducible_merges.at(i);
 458     if (n->outcnt() > 0) {
 459       if (!reduce_phi_on_safepoints(n->as_Phi())) {
 460         NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 461         C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
 462         return false;
 463       }
 464 
 465       // Now we set the scalar replaceable inputs of ophi to null, which is
 466       // the last piece that would prevent it from being scalar replaceable.
 467       reset_scalar_replaceable_entries(n->as_Phi());
 468     }
 469   }
 470   _igvn->set_delay_transform(delay);
 471 
 472   // Annotate at safepoints if they have <= ArgEscape objects in their scope and at
 473   // java calls if they pass ArgEscape objects as parameters.
 474   if (has_non_escaping_obj &&
 475       (C->env()->should_retain_local_variables() ||
 476        C->env()->jvmti_can_get_owned_monitor_info() ||
 477        C->env()->jvmti_can_walk_any_space() ||
 478        DeoptimizeObjectsALot)) {
 479     int sfn_length = sfn_worklist.length();
 480     for (int next = 0; next < sfn_length; next++) {
 481       SafePointNode* sfn = sfn_worklist.at(next);
 482       sfn->set_has_ea_local_in_scope(has_ea_local_in_scope(sfn));
 483       if (sfn->is_CallJava()) {
 484         CallJavaNode* call = sfn->as_CallJava();
 485         call->set_arg_escape(has_arg_escape(call));
 486       }
 487     }
 488   }
 489 
 490   _compile->print_method(PHASE_EA_AFTER_REDUCE_PHI_ON_SAFEPOINTS, 4);
 491 
 492   NOT_PRODUCT(escape_state_statistics(java_objects_worklist);)
 493   return has_non_escaping_obj;
 494 }
 495 
 496 // Check if it's profitable to reduce the Phi passed as parameter.  Returns true
 497 // if at least one scalar replaceable allocation participates in the merge.
 498 bool ConnectionGraph::can_reduce_phi_check_inputs(PhiNode* ophi) const {
 499   bool found_sr_allocate = false;
 500 
 501   for (uint i = 1; i < ophi->req(); i++) {
 502     JavaObjectNode* ptn = unique_java_object(ophi->in(i));
 503     if (ptn != nullptr && ptn->scalar_replaceable()) {
 504       AllocateNode* alloc = ptn->ideal_node()->as_Allocate();
 505 
 506       // Don't handle arrays.
 507       if (alloc->Opcode() != Op_Allocate) {
 508         assert(alloc->Opcode() == Op_AllocateArray, "Unexpected type of allocation.");
 509         continue;
 510       }
 511 
 512       if (PhaseMacroExpand::can_eliminate_allocation(_igvn, alloc, nullptr)) {
 513         found_sr_allocate = true;
 514       } else {
 515         NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("%dth input of Phi %d is SR but can't be eliminated.", i, ophi->_idx);)
 516         ptn->set_scalar_replaceable(false);
 517       }
 518     }
 519   }
 520 
 521   NOT_PRODUCT(if (TraceReduceAllocationMerges && !found_sr_allocate) tty->print_cr("Can NOT reduce Phi %d on invocation %d. No SR Allocate as input.", ophi->_idx, _invocation);)
 522   return found_sr_allocate;
 523 }
 524 
 525 // We can reduce the Cmp if it's a comparison between the Phi and a constant.
 526 // I require the 'other' input to be a constant so that I can move the Cmp
 527 // around safely.
 528 bool ConnectionGraph::can_reduce_cmp(Node* n, Node* cmp) const {
 529   assert(cmp->Opcode() == Op_CmpP || cmp->Opcode() == Op_CmpN, "not expected node: %s", cmp->Name());
 530   Node* left = cmp->in(1);
 531   Node* right = cmp->in(2);
 532 
 533   return (left == n || right == n) &&
 534          (left->is_Con() || right->is_Con()) &&
 535          cmp->outcnt() == 1;
 536 }
 537 
 538 // We are going to check if any of the SafePointScalarMerge entries
 539 // in the SafePoint reference the Phi that we are checking.
 540 bool ConnectionGraph::has_been_reduced(PhiNode* n, SafePointNode* sfpt) const {
 541   JVMState *jvms = sfpt->jvms();
 542 
 543   for (uint i = jvms->debug_start(); i < jvms->debug_end(); i++) {
 544     Node* sfpt_in = sfpt->in(i);
 545     if (sfpt_in->is_SafePointScalarMerge()) {
 546       SafePointScalarMergeNode* smerge = sfpt_in->as_SafePointScalarMerge();
 547       Node* nsr_ptr = sfpt->in(smerge->merge_pointer_idx(jvms));
 548       if (nsr_ptr == n) {
 549         return true;
 550       }
 551     }
 552   }
 553 
 554   return false;
 555 }
 556 
 557 // Check if we are able to untangle the merge. The following patterns are
 558 // supported:
 559 //  - Phi -> SafePoints
 560 //  - Phi -> CmpP/N
 561 //  - Phi -> AddP -> Load
 562 //  - Phi -> CastPP -> SafePoints
 563 //  - Phi -> CastPP -> AddP -> Load
 564 bool ConnectionGraph::can_reduce_check_users(Node* n, uint nesting) const {
 565   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 566     Node* use = n->fast_out(i);
 567 
 568     if (use->is_SafePoint()) {
 569       if (use->is_Call() && use->as_Call()->has_non_debug_use(n)) {
 570         NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. Call has non_debug_use().", n->_idx, _invocation);)
 571         return false;
 572       } else if (has_been_reduced(n->is_Phi() ? n->as_Phi() : n->as_CastPP()->in(1)->as_Phi(), use->as_SafePoint())) {
 573         NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. It has already been reduced.", n->_idx, _invocation);)
 574         return false;
 575       }
 576     } else if (use->is_AddP()) {
 577       Node* addp = use;
 578       for (DUIterator_Fast jmax, j = addp->fast_outs(jmax); j < jmax; j++) {
 579         Node* use_use = addp->fast_out(j);
 580         const Type* load_type = _igvn->type(use_use);
 581 
 582         if (!use_use->is_Load() || !use_use->as_Load()->can_split_through_phi_base(_igvn)) {
 583           NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. AddP user isn't a [splittable] Load(): %s", n->_idx, _invocation, use_use->Name());)
 584           return false;
 585         } else if (load_type->isa_narrowklass() || load_type->isa_klassptr()) {
 586           NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. [Narrow] Klass Load: %s", n->_idx, _invocation, use_use->Name());)
 587           return false;
 588         }
 589       }
 590     } else if (nesting > 0) {
 591       NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. Unsupported user %s at nesting level %d.", n->_idx, _invocation, use->Name(), nesting);)
 592       return false;
 593     } else if (use->is_CastPP()) {
 594       const Type* cast_t = _igvn->type(use);
 595       if (cast_t == nullptr || cast_t->make_ptr()->isa_instptr() == nullptr) {
 596 #ifndef PRODUCT
 597         if (TraceReduceAllocationMerges) {
 598           tty->print_cr("Can NOT reduce Phi %d on invocation %d. CastPP is not to an instance.", n->_idx, _invocation);
 599           use->dump();
 600         }
 601 #endif
 602         return false;
 603       }
 604 
 605       bool is_trivial_control = use->in(0) == nullptr || use->in(0) == n->in(0);
 606       if (!is_trivial_control) {
 607         // If it's not a trivial control then we check if we can reduce the
 608         // CmpP/N used by the If controlling the cast.
 609         if (use->in(0)->is_IfTrue() || use->in(0)->is_IfFalse()) {
 610           Node* iff = use->in(0)->in(0);
 611           // We may have an OpaqueConstantBool node between If and Bool nodes. But we could also have a sub class of IfNode,
 612           // for example, an OuterStripMinedLoopEnd or a Parse Predicate. Bail out in all these cases.
 613           bool can_reduce = (iff->Opcode() == Op_If) && iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp();
 614           if (can_reduce) {
 615             Node* iff_cmp = iff->in(1)->in(1);
 616             int opc = iff_cmp->Opcode();
 617             can_reduce = (opc == Op_CmpP || opc == Op_CmpN) && can_reduce_cmp(n, iff_cmp);
 618           }
 619           if (!can_reduce) {
 620 #ifndef PRODUCT
 621             if (TraceReduceAllocationMerges) {
 622               tty->print_cr("Can NOT reduce Phi %d on invocation %d. CastPP %d doesn't have simple control.", n->_idx, _invocation, use->_idx);
 623               n->dump(5);
 624             }
 625 #endif
 626             return false;
 627           }
 628         }
 629       }
 630 
 631       if (!can_reduce_check_users(use, nesting+1)) {
 632         return false;
 633       }
 634     } else if (use->Opcode() == Op_CmpP || use->Opcode() == Op_CmpN) {
 635       if (!can_reduce_cmp(n, use)) {
 636         NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. CmpP/N %d isn't reducible.", n->_idx, _invocation, use->_idx);)
 637         return false;
 638       }
 639     } else {
 640       NOT_PRODUCT(if (TraceReduceAllocationMerges) tty->print_cr("Can NOT reduce Phi %d on invocation %d. One of the uses is: %d %s", n->_idx, _invocation, use->_idx, use->Name());)
 641       return false;
 642     }
 643   }
 644 
 645   return true;
 646 }
 647 
 648 // Returns true if: 1) It's profitable to reduce the merge, and 2) The Phi is
 649 // only used in some certain code shapes. Check comments in
 650 // 'can_reduce_phi_inputs' and 'can_reduce_phi_users' for more
 651 // details.
 652 bool ConnectionGraph::can_reduce_phi(PhiNode* ophi) const {
 653   // If there was an error attempting to reduce allocation merges for this
 654   // method we might have disabled the compilation and be retrying with RAM
 655   // disabled.
 656   if (!_compile->do_reduce_allocation_merges() || ophi->region()->Opcode() != Op_Region) {
 657     return false;
 658   }
 659 
 660   const Type* phi_t = _igvn->type(ophi);
 661   if (phi_t == nullptr ||
 662       phi_t->make_ptr() == nullptr ||
 663       phi_t->make_ptr()->isa_aryptr() != nullptr) {
 664     return false;
 665   }
 666 
 667   if (!can_reduce_phi_check_inputs(ophi) || !can_reduce_check_users(ophi, /* nesting: */ 0)) {
 668     return false;
 669   }
 670 
 671   NOT_PRODUCT(if (TraceReduceAllocationMerges) { tty->print_cr("Can reduce Phi %d during invocation %d: ", ophi->_idx, _invocation); })
 672   return true;
 673 }
 674 
 675 // This method will return a CmpP/N that we need to use on the If controlling a
 676 // CastPP after it was split. This method is only called on bases that are
 677 // nullable therefore we always need a controlling if for the splitted CastPP.
 678 //
 679 // 'curr_ctrl' is the control of the CastPP that we want to split through phi.
 680 // If the CastPP currently doesn't have a control then the CmpP/N will be
 681 // against the null constant, otherwise it will be against the constant input of
 682 // the existing CmpP/N. It's guaranteed that there will be a CmpP/N in the later
 683 // case because we have constraints on it and because the CastPP has a control
 684 // input.
 685 Node* ConnectionGraph::specialize_cmp(Node* base, Node* curr_ctrl) {
 686   const Type* t = base->bottom_type();
 687   Node* con = nullptr;
 688 
 689   if (curr_ctrl == nullptr || curr_ctrl->is_Region()) {
 690     con = _igvn->zerocon(t->basic_type());
 691   } else {
 692     // can_reduce_check_users() verified graph: true/false -> if -> bool -> cmp
 693     assert(curr_ctrl->in(0)->Opcode() == Op_If, "unexpected node %s", curr_ctrl->in(0)->Name());
 694     Node* bol = curr_ctrl->in(0)->in(1);
 695     assert(bol->is_Bool(), "unexpected node %s", bol->Name());
 696     Node* curr_cmp = bol->in(1);
 697     assert(curr_cmp->Opcode() == Op_CmpP || curr_cmp->Opcode() == Op_CmpN, "unexpected node %s", curr_cmp->Name());
 698     con = curr_cmp->in(1)->is_Con() ? curr_cmp->in(1) : curr_cmp->in(2);
 699   }
 700 
 701   return CmpNode::make(base, con, t->basic_type());
 702 }
 703 
 704 // This method 'specializes' the CastPP passed as parameter to the base passed
 705 // as parameter. Note that the existing CastPP input is a Phi. "Specialize"
 706 // means that the CastPP now will be specific for a given base instead of a Phi.
 707 // An If-Then-Else-Region block is inserted to control the CastPP. The control
 708 // of the CastPP is a copy of the current one (if there is one) or a check
 709 // against null.
 710 //
 711 // Before:
 712 //
 713 //    C1     C2  ... Cn
 714 //     \      |      /
 715 //      \     |     /
 716 //       \    |    /
 717 //        \   |   /
 718 //         \  |  /
 719 //          \ | /
 720 //           \|/
 721 //          Region     B1      B2  ... Bn
 722 //            |          \      |      /
 723 //            |           \     |     /
 724 //            |            \    |    /
 725 //            |             \   |   /
 726 //            |              \  |  /
 727 //            |               \ | /
 728 //            ---------------> Phi
 729 //                              |
 730 //                      X       |
 731 //                      |       |
 732 //                      |       |
 733 //                      ------> CastPP
 734 //
 735 // After (only partial illustration; base = B2, current_control = C2):
 736 //
 737 //                      C2
 738 //                      |
 739 //                      If
 740 //                     / \
 741 //                    /   \
 742 //                   T     F
 743 //                  /\     /
 744 //                 /  \   /
 745 //                /    \ /
 746 //      C1    CastPP   Reg        Cn
 747 //       |              |          |
 748 //       |              |          |
 749 //       |              |          |
 750 //       -------------- | ----------
 751 //                    | | |
 752 //                    Region
 753 //
 754 Node* ConnectionGraph::specialize_castpp(Node* castpp, Node* base, Node* current_control) {
 755   Node* control_successor  = current_control->unique_ctrl_out();
 756   Node* cmp                = _igvn->transform(specialize_cmp(base, castpp->in(0)));
 757   Node* bol                = _igvn->transform(new BoolNode(cmp, BoolTest::ne));
 758   IfNode* if_ne            = _igvn->transform(new IfNode(current_control, bol, PROB_MIN, COUNT_UNKNOWN))->as_If();
 759   Node* not_eq_control     = _igvn->transform(new IfTrueNode(if_ne));
 760   Node* yes_eq_control     = _igvn->transform(new IfFalseNode(if_ne));
 761   Node* end_region         = _igvn->transform(new RegionNode(3));
 762 
 763   // Insert the new if-else-region block into the graph
 764   end_region->set_req(1, not_eq_control);
 765   end_region->set_req(2, yes_eq_control);
 766   control_successor->replace_edge(current_control, end_region, _igvn);
 767 
 768   _igvn->_worklist.push(current_control);
 769   _igvn->_worklist.push(control_successor);
 770 
 771   return _igvn->transform(ConstraintCastNode::make_cast_for_type(not_eq_control, base, _igvn->type(castpp), ConstraintCastNode::DependencyType::NonFloatingNonNarrowing, nullptr));
 772 }
 773 
 774 Node* ConnectionGraph::split_castpp_load_through_phi(Node* curr_addp, Node* curr_load, Node* region, GrowableArray<Node*>* bases_for_loads, GrowableArray<Node *>  &alloc_worklist) {
 775   const Type* load_type = _igvn->type(curr_load);
 776   Node* nsr_value = _igvn->zerocon(load_type->basic_type());
 777   Node* memory = curr_load->in(MemNode::Memory);
 778 
 779   // The data_phi merging the loads needs to be nullable if
 780   // we are loading pointers.
 781   if (load_type->make_ptr() != nullptr) {
 782     if (load_type->isa_narrowoop()) {
 783       load_type = load_type->meet(TypeNarrowOop::NULL_PTR);
 784     } else if (load_type->isa_ptr()) {
 785       load_type = load_type->meet(TypePtr::NULL_PTR);
 786     } else {
 787       assert(false, "Unexpected load ptr type.");
 788     }
 789   }
 790 
 791   Node* data_phi = PhiNode::make(region, nsr_value, load_type);
 792 
 793   for (int i = 1; i < bases_for_loads->length(); i++) {
 794     Node* base = bases_for_loads->at(i);
 795     Node* cmp_region = nullptr;
 796     if (base != nullptr) {
 797       if (base->is_CFG()) { // means that we added a CastPP as child of this CFG node
 798         cmp_region = base->unique_ctrl_out_or_null();
 799         assert(cmp_region != nullptr, "There should be.");
 800         base = base->find_out_with(Op_CastPP);
 801       }
 802 
 803       Node* addr = _igvn->transform(new AddPNode(base, base, curr_addp->in(AddPNode::Offset)));
 804       Node* mem = (memory->is_Phi() && (memory->in(0) == region)) ? memory->in(i) : memory;
 805       Node* load = curr_load->clone();
 806       load->set_req(0, nullptr);
 807       load->set_req(1, mem);
 808       load->set_req(2, addr);
 809 
 810       if (cmp_region != nullptr) { // see comment on previous if
 811         Node* intermediate_phi = PhiNode::make(cmp_region, nsr_value, load_type);
 812         intermediate_phi->set_req(1, _igvn->transform(load));
 813         load = intermediate_phi;
 814       }
 815 
 816       data_phi->set_req(i, _igvn->transform(load));
 817     } else {
 818       // Just use the default, which is already in phi
 819     }
 820   }
 821 
 822   // Takes care of updating CG and split_unique_types worklists due
 823   // to cloned AddP->Load.
 824   updates_after_load_split(data_phi, curr_load, alloc_worklist);
 825 
 826   return _igvn->transform(data_phi);
 827 }
 828 
 829 // This method only reduces CastPP fields loads; SafePoints are handled
 830 // separately. The idea here is basically to clone the CastPP and place copies
 831 // on each input of the Phi, including non-scalar replaceable inputs.
 832 // Experimentation shows that the resulting IR graph is simpler that way than if
 833 // we just split the cast through scalar-replaceable inputs.
 834 //
 835 // The reduction process requires that CastPP's control be one of:
 836 //  1) no control,
 837 //  2) the same region as Ophi, or
 838 //  3) an IfTrue/IfFalse coming from an CmpP/N between Ophi and a constant.
 839 //
 840 // After splitting the CastPP we'll put it under an If-Then-Else-Region control
 841 // flow. If the CastPP originally had an IfTrue/False control input then we'll
 842 // use a similar CmpP/N to control the new If-Then-Else-Region. Otherwise, we'll
 843 // juse use a CmpP/N against the null constant.
 844 //
 845 // The If-Then-Else-Region isn't always needed. For instance, if input to
 846 // splitted cast was not nullable (or if it was the null constant) then we don't
 847 // need (shouldn't) use a CastPP at all.
 848 //
 849 // After the casts are splitted we'll split the AddP->Loads through the Phi and
 850 // connect them to the just split CastPPs.
 851 //
 852 // Before (CastPP control is same as Phi):
 853 //
 854 //          Region     Allocate   Null    Call
 855 //            |             \      |      /
 856 //            |              \     |     /
 857 //            |               \    |    /
 858 //            |                \   |   /
 859 //            |                 \  |  /
 860 //            |                  \ | /
 861 //            ------------------> Phi            # Oop Phi
 862 //            |                    |
 863 //            |                    |
 864 //            |                    |
 865 //            |                    |
 866 //            ----------------> CastPP
 867 //                                 |
 868 //                               AddP
 869 //                                 |
 870 //                               Load
 871 //
 872 // After (Very much simplified):
 873 //
 874 //                         Call  Null
 875 //                            \  /
 876 //                            CmpP
 877 //                             |
 878 //                           Bool#NE
 879 //                             |
 880 //                             If
 881 //                            / \
 882 //                           T   F
 883 //                          / \ /
 884 //                         /   R
 885 //                     CastPP  |
 886 //                       |     |
 887 //                     AddP    |
 888 //                       |     |
 889 //                     Load    |
 890 //                         \   |   0
 891 //            Allocate      \  |  /
 892 //                \          \ | /
 893 //               AddP         Phi
 894 //                  \         /
 895 //                 Load      /
 896 //                    \  0  /
 897 //                     \ | /
 898 //                      \|/
 899 //                      Phi        # "Field" Phi
 900 //
 901 void ConnectionGraph::reduce_phi_on_castpp_field_load(Node* curr_castpp, GrowableArray<Node*> &alloc_worklist) {
 902   Node* ophi = curr_castpp->in(1);
 903   assert(ophi->is_Phi(), "Expected this to be a Phi node.");
 904 
 905   // Identify which base should be used for AddP->Load later when spliting the
 906   // CastPP->Loads through ophi. Three kind of values may be stored in this
 907   // array, depending on the nullability status of the corresponding input in
 908   // ophi.
 909   //
 910   //  - nullptr:    Meaning that the base is actually the null constant and therefore
 911   //                we won't try to load from it.
 912   //
 913   //  - CFG Node:   Meaning that the base is a CastPP that was specialized for
 914   //                this input of Ophi. I.e., we added an If->Then->Else-Region
 915   //                that will 'activate' the CastPp only when the input is not Null.
 916   //
 917   //  - Other Node: Meaning that the base is not nullable and therefore we'll try
 918   //                to load directly from it.
 919   GrowableArray<Node*> bases_for_loads(ophi->req(), ophi->req(), nullptr);
 920 
 921   for (uint i = 1; i < ophi->req(); i++) {
 922     Node* base = ophi->in(i);
 923     const Type* base_t = _igvn->type(base);
 924 
 925     if (base_t->maybe_null()) {
 926       if (base->is_Con()) {
 927         // Nothing todo as bases_for_loads[i] is already null
 928       } else {
 929         Node* new_castpp = specialize_castpp(curr_castpp, base, ophi->in(0)->in(i));
 930         bases_for_loads.at_put(i, new_castpp->in(0)); // Use the ctrl of the new node just as a flag
 931       }
 932     } else {
 933       bases_for_loads.at_put(i, base);
 934     }
 935   }
 936 
 937   // Now let's split the CastPP->Loads through the Phi
 938   for (int i = curr_castpp->outcnt()-1; i >= 0;) {
 939     Node* use = curr_castpp->raw_out(i);
 940     if (use->is_AddP()) {
 941       for (int j = use->outcnt()-1; j >= 0;) {
 942         Node* use_use = use->raw_out(j);
 943         assert(use_use->is_Load(), "Expected this to be a Load node.");
 944 
 945         // We can't make an unconditional load from a nullable input. The
 946         // 'split_castpp_load_through_phi` method will add an
 947         // 'If-Then-Else-Region` around nullable bases and only load from them
 948         // when the input is not null.
 949         Node* phi = split_castpp_load_through_phi(use, use_use, ophi->in(0), &bases_for_loads, alloc_worklist);
 950         _igvn->replace_node(use_use, phi);
 951 
 952         --j;
 953         j = MIN2(j, (int)use->outcnt()-1);
 954       }
 955 
 956       _igvn->remove_dead_node(use);
 957     }
 958     --i;
 959     i = MIN2(i, (int)curr_castpp->outcnt()-1);
 960   }
 961 }
 962 
 963 // This method split a given CmpP/N through the Phi used in one of its inputs.
 964 // As a result we convert a comparison with a pointer to a comparison with an
 965 // integer.
 966 // The only requirement is that one of the inputs of the CmpP/N must be a Phi
 967 // while the other must be a constant.
 968 // The splitting process is basically just cloning the CmpP/N above the input
 969 // Phi.  However, some (most) of the cloned CmpP/Ns won't be requred because we
 970 // can prove at compile time the result of the comparison.
 971 //
 972 // Before:
 973 //
 974 //             in1    in2 ... inN
 975 //              \      |      /
 976 //               \     |     /
 977 //                \    |    /
 978 //                 \   |   /
 979 //                  \  |  /
 980 //                   \ | /
 981 //                    Phi
 982 //                     |   Other
 983 //                     |    /
 984 //                     |   /
 985 //                     |  /
 986 //                    CmpP/N
 987 //
 988 // After:
 989 //
 990 //        in1  Other   in2 Other  inN  Other
 991 //         |    |      |   |      |    |
 992 //         \    |      |   |      |    |
 993 //          \  /       |   /      |    /
 994 //          CmpP/N    CmpP/N     CmpP/N
 995 //          Bool      Bool       Bool
 996 //            \        |        /
 997 //             \       |       /
 998 //              \      |      /
 999 //               \     |     /
1000 //                \    |    /
1001 //                 \   |   /
1002 //                  \  |  /
1003 //                   \ | /
1004 //                    Phi
1005 //                     |
1006 //                     |   Zero
1007 //                     |    /
1008 //                     |   /
1009 //                     |  /
1010 //                     CmpI
1011 //
1012 //
1013 void ConnectionGraph::reduce_phi_on_cmp(Node* cmp) {
1014   Node* ophi = cmp->in(1)->is_Con() ? cmp->in(2) : cmp->in(1);
1015   assert(ophi->is_Phi(), "Expected this to be a Phi node.");
1016 
1017   Node* other = cmp->in(1)->is_Con() ? cmp->in(1) : cmp->in(2);
1018   Node* zero = _igvn->intcon(0);
1019   Node* one = _igvn->intcon(1);
1020   BoolTest::mask mask = cmp->unique_out()->as_Bool()->_test._test;
1021 
1022   // This Phi will merge the result of the Cmps split through the Phi
1023   Node* res_phi = PhiNode::make(ophi->in(0), zero, TypeInt::INT);
1024 
1025   for (uint i=1; i<ophi->req(); i++) {
1026     Node* ophi_input = ophi->in(i);
1027     Node* res_phi_input = nullptr;
1028 
1029     const TypeInt* tcmp = optimize_ptr_compare(ophi_input, other);
1030     if (tcmp->singleton()) {
1031       if ((mask == BoolTest::mask::eq && tcmp == TypeInt::CC_EQ) ||
1032           (mask == BoolTest::mask::ne && tcmp == TypeInt::CC_GT)) {
1033         res_phi_input = one;
1034       } else {
1035         res_phi_input = zero;
1036       }
1037     } else {
1038       Node* ncmp = _igvn->transform(cmp->clone());
1039       ncmp->set_req(1, ophi_input);
1040       ncmp->set_req(2, other);
1041       Node* bol = _igvn->transform(new BoolNode(ncmp, mask));
1042       res_phi_input = bol->as_Bool()->as_int_value(_igvn);
1043     }
1044 
1045     res_phi->set_req(i, res_phi_input);
1046   }
1047 
1048   // This CMP always compares whether the output of "res_phi" is TRUE as far as the "mask".
1049   Node* new_cmp = _igvn->transform(new CmpINode(_igvn->transform(res_phi), (mask == BoolTest::mask::eq) ? one : zero));
1050   _igvn->replace_node(cmp, new_cmp);
1051 }
1052 
1053 // Push the newly created AddP on alloc_worklist and patch
1054 // the connection graph. Note that the changes in the CG below
1055 // won't affect the ES of objects since the new nodes have the
1056 // same status as the old ones.
1057 void ConnectionGraph::updates_after_load_split(Node* data_phi, Node* previous_load, GrowableArray<Node *>  &alloc_worklist) {
1058   assert(data_phi != nullptr, "Output of split_through_phi is null.");
1059   assert(data_phi != previous_load, "Output of split_through_phi is same as input.");
1060   assert(data_phi->is_Phi(), "Output of split_through_phi isn't a Phi.");
1061 
1062   if (data_phi == nullptr || !data_phi->is_Phi()) {
1063     // Make this a retry?
1064     return ;
1065   }
1066 
1067   Node* previous_addp = previous_load->in(MemNode::Address);
1068   FieldNode* fn = ptnode_adr(previous_addp->_idx)->as_Field();
1069   for (uint i = 1; i < data_phi->req(); i++) {
1070     Node* new_load = data_phi->in(i);
1071 
1072     if (new_load->is_Phi()) {
1073       // new_load is currently the "intermediate_phi" from an specialized
1074       // CastPP.
1075       new_load = new_load->in(1);
1076     }
1077 
1078     // "new_load" might actually be a constant, parameter, etc.
1079     if (new_load->is_Load()) {
1080       Node* new_addp = new_load->in(MemNode::Address);
1081 
1082       // If new_load is a Load but not from an AddP, it means that the load is folded into another
1083       // load. And since this load is not from a field, we cannot create a unique type for it.
1084       // For example:
1085       //
1086       //   if (b) {
1087       //       Holder h1 = new Holder();
1088       //       Object o = ...;
1089       //       h.o = o.getClass();
1090       //   } else {
1091       //       Holder h2 = ...;
1092       //   }
1093       //   Holder h = Phi(h1, h2);
1094       //   Object r = h.o;
1095       //
1096       // Then, splitting r through the merge point results in:
1097       //
1098       //   if (b) {
1099       //       Holder h1 = new Holder();
1100       //       Object o = ...;
1101       //       h.o = o.getClass();
1102       //       Object o1 = h.o;
1103       //   } else {
1104       //       Holder h2 = ...;
1105       //       Object o2 = h2.o;
1106       //   }
1107       //   Object r = Phi(o1, o2);
1108       //
1109       // In this case, o1 is folded to o.getClass() which is a Load but not from an AddP, but from
1110       // an OopHandle that is loaded from the Klass of o.
1111       if (!new_addp->is_AddP()) {
1112         continue;
1113       }
1114       Node* base = get_addp_base(new_addp);
1115 
1116       // The base might not be something that we can create an unique
1117       // type for. If that's the case we are done with that input.
1118       PointsToNode* jobj_ptn = unique_java_object(base);
1119       if (jobj_ptn == nullptr || !jobj_ptn->scalar_replaceable()) {
1120         continue;
1121       }
1122 
1123       // Push to alloc_worklist since the base has an unique_type
1124       alloc_worklist.append_if_missing(new_addp);
1125 
1126       // Now let's add the node to the connection graph
1127       _nodes.at_grow(new_addp->_idx, nullptr);
1128       add_field(new_addp, fn->escape_state(), fn->offset());
1129       add_base(ptnode_adr(new_addp->_idx)->as_Field(), ptnode_adr(base->_idx));
1130 
1131       // If the load doesn't load an object then it won't be
1132       // part of the connection graph
1133       PointsToNode* curr_load_ptn = ptnode_adr(previous_load->_idx);
1134       if (curr_load_ptn != nullptr) {
1135         _nodes.at_grow(new_load->_idx, nullptr);
1136         add_local_var(new_load, curr_load_ptn->escape_state());
1137         add_edge(ptnode_adr(new_load->_idx), ptnode_adr(new_addp->_idx)->as_Field());
1138       }
1139     }
1140   }
1141 }
1142 
1143 void ConnectionGraph::reduce_phi_on_field_access(Node* previous_addp, GrowableArray<Node *>  &alloc_worklist) {
1144   // We'll pass this to 'split_through_phi' so that it'll do the split even
1145   // though the load doesn't have an unique instance type.
1146   bool ignore_missing_instance_id = true;
1147 
1148   // All AddPs are present in the connection graph
1149   FieldNode* fn = ptnode_adr(previous_addp->_idx)->as_Field();
1150 
1151   // Iterate over AddP looking for a Load
1152   for (int k = previous_addp->outcnt()-1; k >= 0;) {
1153     Node* previous_load = previous_addp->raw_out(k);
1154     if (previous_load->is_Load()) {
1155       Node* data_phi = previous_load->as_Load()->split_through_phi(_igvn, ignore_missing_instance_id);
1156 
1157       // Takes care of updating CG and split_unique_types worklists due to cloned
1158       // AddP->Load.
1159       updates_after_load_split(data_phi, previous_load, alloc_worklist);
1160 
1161       _igvn->replace_node(previous_load, data_phi);
1162     }
1163     --k;
1164     k = MIN2(k, (int)previous_addp->outcnt()-1);
1165   }
1166 
1167   // Remove the old AddP from the processing list because it's dead now
1168   assert(previous_addp->outcnt() == 0, "AddP should be dead now.");
1169   alloc_worklist.remove_if_existing(previous_addp);
1170 }
1171 
1172 // Create a 'selector' Phi based on the inputs of 'ophi'. If index 'i' of the
1173 // selector is:
1174 //    -> a '-1' constant, the i'th input of the original Phi is NSR.
1175 //    -> a 'x' constant >=0, the i'th input of of original Phi will be SR and
1176 //       the info about the scalarized object will be at index x of ObjectMergeValue::possible_objects
1177 PhiNode* ConnectionGraph::create_selector(PhiNode* ophi) const {
1178   Node* minus_one = _igvn->register_new_node_with_optimizer(ConINode::make(-1));
1179   Node* selector  = _igvn->register_new_node_with_optimizer(PhiNode::make(ophi->region(), minus_one, TypeInt::INT));
1180   uint number_of_sr_objects = 0;
1181   for (uint i = 1; i < ophi->req(); i++) {
1182     Node* base = ophi->in(i);
1183     JavaObjectNode* ptn = unique_java_object(base);
1184 
1185     if (ptn != nullptr && ptn->scalar_replaceable()) {
1186       Node* sr_obj_idx = _igvn->register_new_node_with_optimizer(ConINode::make(number_of_sr_objects));
1187       selector->set_req(i, sr_obj_idx);
1188       number_of_sr_objects++;
1189     }
1190   }
1191 
1192   return selector->as_Phi();
1193 }
1194 
1195 // Returns true if the AddP node 'n' has at least one base that is a reducible
1196 // merge. If the base is a CastPP/CheckCastPP then the input of the cast is
1197 // checked instead.
1198 bool ConnectionGraph::has_reducible_merge_base(AddPNode* n, Unique_Node_List &reducible_merges) {
1199   PointsToNode* ptn = ptnode_adr(n->_idx);
1200   if (ptn == nullptr || !ptn->is_Field() || ptn->as_Field()->base_count() < 2) {
1201     return false;
1202   }
1203 
1204   for (BaseIterator i(ptn->as_Field()); i.has_next(); i.next()) {
1205     Node* base = i.get()->ideal_node();
1206 
1207     if (reducible_merges.member(base)) {
1208       return true;
1209     }
1210 
1211     if (base->is_CastPP() || base->is_CheckCastPP()) {
1212       base = base->in(1);
1213       if (reducible_merges.member(base)) {
1214         return true;
1215       }
1216     }
1217   }
1218 
1219   return false;
1220 }
1221 
1222 // This method will call its helper method to reduce SafePoint nodes that use
1223 // 'ophi' or a casted version of 'ophi'. All SafePoint nodes using the same
1224 // "version" of Phi use the same debug information (regarding the Phi).
1225 // Therefore, I collect all safepoints and patch them all at once.
1226 //
1227 // The safepoints using the Phi node have to be processed before safepoints of
1228 // CastPP nodes. The reason is, when reducing a CastPP we add a reference (the
1229 // NSR merge pointer) to the input of the CastPP (i.e., the Phi) in the
1230 // safepoint. If we process CastPP's safepoints before Phi's safepoints the
1231 // algorithm that process Phi's safepoints will think that the added Phi
1232 // reference is a regular reference.
1233 bool ConnectionGraph::reduce_phi_on_safepoints(PhiNode* ophi) {
1234   PhiNode* selector = create_selector(ophi);
1235   Unique_Node_List safepoints;
1236   Unique_Node_List casts;
1237 
1238   // Just collect the users of the Phis for later processing
1239   // in the needed order.
1240   for (uint i = 0; i < ophi->outcnt(); i++) {
1241     Node* use = ophi->raw_out(i);
1242     if (use->is_SafePoint()) {
1243       safepoints.push(use);
1244     } else if (use->is_CastPP()) {
1245       casts.push(use);
1246     } else {
1247       assert(use->outcnt() == 0, "Only CastPP & SafePoint users should be left.");
1248     }
1249   }
1250 
1251   // Need to process safepoints using the Phi first
1252   if (!reduce_phi_on_safepoints_helper(ophi, nullptr, selector, safepoints)) {
1253     return false;
1254   }
1255 
1256   // Now process CastPP->safepoints
1257   for (uint i = 0; i < casts.size(); i++) {
1258     Node* cast = casts.at(i);
1259     Unique_Node_List cast_sfpts;
1260 
1261     for (DUIterator_Fast jmax, j = cast->fast_outs(jmax); j < jmax; j++) {
1262       Node* use_use = cast->fast_out(j);
1263       if (use_use->is_SafePoint()) {
1264         cast_sfpts.push(use_use);
1265       } else {
1266         assert(use_use->outcnt() == 0, "Only SafePoint users should be left.");
1267       }
1268     }
1269 
1270     if (!reduce_phi_on_safepoints_helper(ophi, cast, selector, cast_sfpts)) {
1271       return false;
1272     }
1273   }
1274 
1275   return true;
1276 }
1277 
1278 // This method will create a SafePointScalarMERGEnode for each SafePoint in
1279 // 'safepoints'. It then will iterate on the inputs of 'ophi' and create a
1280 // SafePointScalarObjectNode for each scalar replaceable input. Each
1281 // SafePointScalarMergeNode may describe multiple scalar replaced objects -
1282 // check detailed description in SafePointScalarMergeNode class header.
1283 bool ConnectionGraph::reduce_phi_on_safepoints_helper(Node* ophi, Node* cast, Node* selector, Unique_Node_List& safepoints) {
1284   PhaseMacroExpand mexp(*_igvn);
1285   Node* original_sfpt_parent =  cast != nullptr ? cast : ophi;
1286   const TypeOopPtr* merge_t = _igvn->type(original_sfpt_parent)->make_oopptr();
1287 
1288   Node* nsr_merge_pointer = ophi;
1289   if (cast != nullptr) {
1290     const Type* new_t = merge_t->meet(TypePtr::NULL_PTR);
1291     nsr_merge_pointer = _igvn->transform(ConstraintCastNode::make_cast_for_type(cast->in(0), cast->in(1), new_t, ConstraintCastNode::DependencyType::FloatingNarrowing, nullptr));
1292   }
1293 
1294   for (uint spi = 0; spi < safepoints.size(); spi++) {
1295     SafePointNode* sfpt = safepoints.at(spi)->as_SafePoint();
1296     JVMState *jvms      = sfpt->jvms();
1297     uint merge_idx      = (sfpt->req() - jvms->scloff());
1298     int debug_start     = jvms->debug_start();
1299 
1300     SafePointScalarMergeNode* smerge = new SafePointScalarMergeNode(merge_t, merge_idx);
1301     smerge->init_req(0, _compile->root());
1302     _igvn->register_new_node_with_optimizer(smerge);
1303 
1304     // The next two inputs are:
1305     //  (1) A copy of the original pointer to NSR objects.
1306     //  (2) A selector, used to decide if we need to rematerialize an object
1307     //      or use the pointer to a NSR object.
1308     // See more details of these fields in the declaration of SafePointScalarMergeNode
1309     sfpt->add_req(nsr_merge_pointer);
1310     sfpt->add_req(selector);
1311 
1312     for (uint i = 1; i < ophi->req(); i++) {
1313       Node* base = ophi->in(i);
1314       JavaObjectNode* ptn = unique_java_object(base);
1315 
1316       // If the base is not scalar replaceable we don't need to register information about
1317       // it at this time.
1318       if (ptn == nullptr || !ptn->scalar_replaceable()) {
1319         continue;
1320       }
1321 
1322       AllocateNode* alloc = ptn->ideal_node()->as_Allocate();
1323       Unique_Node_List value_worklist;
1324 #ifdef ASSERT
1325       const Type* res_type = alloc->result_cast()->bottom_type();
1326       if (res_type->is_inlinetypeptr() && !Compile::current()->has_circular_inline_type()) {
1327         PhiNode* phi = ophi->as_Phi();
1328         assert(!ophi->as_Phi()->can_push_inline_types_down(_igvn), "missed earlier scalarization opportunity");
1329       }
1330 #endif
1331       SafePointScalarObjectNode* sobj = mexp.create_scalarized_object_description(alloc, sfpt, &value_worklist);
1332       if (sobj == nullptr) {
1333         _compile->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1334         return false;
1335       }
1336 
1337       // Now make a pass over the debug information replacing any references
1338       // to the allocated object with "sobj"
1339       Node* ccpp = alloc->result_cast();
1340       sfpt->replace_edges_in_range(ccpp, sobj, debug_start, jvms->debug_end(), _igvn);
1341 
1342       // Register the scalarized object as a candidate for reallocation
1343       smerge->add_req(sobj);
1344 
1345       // Scalarize inline types that were added to the safepoint.
1346       // Don't allow linking a constant oop (if available) for flat array elements
1347       // because Deoptimization::reassign_flat_array_elements needs field values.
1348       const bool allow_oop = !merge_t->is_flat();
1349       for (uint j = 0; j < value_worklist.size(); ++j) {
1350         InlineTypeNode* vt = value_worklist.at(j)->as_InlineType();
1351         vt->make_scalar_in_safepoints(_igvn, allow_oop);
1352       }
1353     }
1354 
1355     // Replaces debug information references to "original_sfpt_parent" in "sfpt" with references to "smerge"
1356     sfpt->replace_edges_in_range(original_sfpt_parent, smerge, debug_start, jvms->debug_end(), _igvn);
1357 
1358     // The call to 'replace_edges_in_range' above might have removed the
1359     // reference to ophi that we need at _merge_pointer_idx. The line below make
1360     // sure the reference is maintained.
1361     sfpt->set_req(smerge->merge_pointer_idx(jvms), nsr_merge_pointer);
1362     _igvn->_worklist.push(sfpt);
1363   }
1364 
1365   return true;
1366 }
1367 
1368 void ConnectionGraph::reduce_phi(PhiNode* ophi, GrowableArray<Node*> &alloc_worklist) {
1369   bool delay = _igvn->delay_transform();
1370   _igvn->set_delay_transform(true);
1371   _igvn->hash_delete(ophi);
1372 
1373   // Copying all users first because some will be removed and others won't.
1374   // Ophi also may acquire some new users as part of Cast reduction.
1375   // CastPPs also need to be processed before CmpPs.
1376   Unique_Node_List castpps;
1377   Unique_Node_List others;
1378   for (DUIterator_Fast imax, i = ophi->fast_outs(imax); i < imax; i++) {
1379     Node* use = ophi->fast_out(i);
1380 
1381     if (use->is_CastPP()) {
1382       castpps.push(use);
1383     } else if (use->is_AddP() || use->is_Cmp()) {
1384       others.push(use);
1385     } else {
1386       // Safepoints to be processed later; other users aren't expected here
1387       assert(use->is_SafePoint(), "Unexpected user of reducible Phi %d -> %d:%s:%d", ophi->_idx, use->_idx, use->Name(), use->outcnt());
1388     }
1389   }
1390 
1391   _compile->print_method(PHASE_EA_BEFORE_PHI_REDUCTION, 5, ophi);
1392 
1393   // CastPPs need to be processed before Cmps because during the process of
1394   // splitting CastPPs we make reference to the inputs of the Cmp that is used
1395   // by the If controlling the CastPP.
1396   for (uint i = 0; i < castpps.size(); i++) {
1397     reduce_phi_on_castpp_field_load(castpps.at(i), alloc_worklist);
1398     _compile->print_method(PHASE_EA_AFTER_PHI_CASTPP_REDUCTION, 6, castpps.at(i));
1399   }
1400 
1401   for (uint i = 0; i < others.size(); i++) {
1402     Node* use = others.at(i);
1403 
1404     if (use->is_AddP()) {
1405       reduce_phi_on_field_access(use, alloc_worklist);
1406       _compile->print_method(PHASE_EA_AFTER_PHI_ADDP_REDUCTION, 6, use);
1407     } else if(use->is_Cmp()) {
1408       reduce_phi_on_cmp(use);
1409       _compile->print_method(PHASE_EA_AFTER_PHI_CMP_REDUCTION, 6, use);
1410     }
1411   }
1412 
1413   _igvn->set_delay_transform(delay);
1414 }
1415 
1416 void ConnectionGraph::reset_scalar_replaceable_entries(PhiNode* ophi) {
1417   Node* null_ptr            = _igvn->makecon(TypePtr::NULL_PTR);
1418   const TypeOopPtr* merge_t = _igvn->type(ophi)->make_oopptr();
1419   const Type* new_t         = merge_t->meet(TypePtr::NULL_PTR);
1420   Node* new_phi             = _igvn->register_new_node_with_optimizer(PhiNode::make(ophi->region(), null_ptr, new_t));
1421 
1422   for (uint i = 1; i < ophi->req(); i++) {
1423     Node* base          = ophi->in(i);
1424     JavaObjectNode* ptn = unique_java_object(base);
1425 
1426     if (ptn != nullptr && ptn->scalar_replaceable()) {
1427       new_phi->set_req(i, null_ptr);
1428     } else {
1429       new_phi->set_req(i, ophi->in(i));
1430     }
1431   }
1432 
1433   for (int i = ophi->outcnt()-1; i >= 0;) {
1434     Node* out = ophi->raw_out(i);
1435 
1436     if (out->is_ConstraintCast()) {
1437       const Type* out_t = _igvn->type(out)->make_ptr();
1438       const Type* out_new_t = out_t->meet(TypePtr::NULL_PTR);
1439       bool change = out_new_t != out_t;
1440 
1441       for (int j = out->outcnt()-1; change && j >= 0; --j) {
1442         Node* out2 = out->raw_out(j);
1443         if (!out2->is_SafePoint()) {
1444           change = false;
1445           break;
1446         }
1447       }
1448 
1449       if (change) {
1450         Node* new_cast = ConstraintCastNode::make_cast_for_type(out->in(0), out->in(1), out_new_t, ConstraintCastNode::DependencyType::NonFloatingNarrowing, nullptr);
1451         _igvn->replace_node(out, new_cast);
1452         _igvn->register_new_node_with_optimizer(new_cast);
1453       }
1454     }
1455 
1456     --i;
1457     i = MIN2(i, (int)ophi->outcnt()-1);
1458   }
1459 
1460   _igvn->replace_node(ophi, new_phi);
1461 }
1462 
1463 void ConnectionGraph::verify_ram_nodes(Compile* C, Node* root) {
1464   if (!C->do_reduce_allocation_merges()) return;
1465 
1466   Unique_Node_List ideal_nodes;
1467   ideal_nodes.map(C->live_nodes(), nullptr);  // preallocate space
1468   ideal_nodes.push(root);
1469 
1470   for (uint next = 0; next < ideal_nodes.size(); ++next) {
1471     Node* n = ideal_nodes.at(next);
1472 
1473     if (n->is_SafePointScalarMerge()) {
1474       SafePointScalarMergeNode* merge = n->as_SafePointScalarMerge();
1475 
1476       // Validate inputs of merge
1477       for (uint i = 1; i < merge->req(); i++) {
1478         if (merge->in(i) != nullptr && !merge->in(i)->is_top() && !merge->in(i)->is_SafePointScalarObject()) {
1479           assert(false, "SafePointScalarMerge inputs should be null/top or SafePointScalarObject.");
1480           C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1481         }
1482       }
1483 
1484       // Validate users of merge
1485       for (DUIterator_Fast imax, i = merge->fast_outs(imax); i < imax; i++) {
1486         Node* sfpt = merge->fast_out(i);
1487         if (sfpt->is_SafePoint()) {
1488           int merge_idx = merge->merge_pointer_idx(sfpt->as_SafePoint()->jvms());
1489 
1490           if (sfpt->in(merge_idx) != nullptr && sfpt->in(merge_idx)->is_SafePointScalarMerge()) {
1491             assert(false, "SafePointScalarMerge nodes can't be nested.");
1492             C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1493           }
1494         } else {
1495           assert(false, "Only safepoints can use SafePointScalarMerge nodes.");
1496           C->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
1497         }
1498       }
1499     }
1500 
1501     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1502       Node* m = n->fast_out(i);
1503       ideal_nodes.push(m);
1504     }
1505   }
1506 }
1507 
1508 // Returns true if there is an object in the scope of sfn that does not escape globally.
1509 bool ConnectionGraph::has_ea_local_in_scope(SafePointNode* sfn) {
1510   Compile* C = _compile;
1511   for (JVMState* jvms = sfn->jvms(); jvms != nullptr; jvms = jvms->caller()) {
1512     if (C->env()->should_retain_local_variables() || C->env()->jvmti_can_walk_any_space() ||
1513         DeoptimizeObjectsALot) {
1514       // Jvmti agents can access locals. Must provide info about local objects at runtime.
1515       int num_locs = jvms->loc_size();
1516       for (int idx = 0; idx < num_locs; idx++) {
1517         Node* l = sfn->local(jvms, idx);
1518         if (not_global_escape(l)) {
1519           return true;
1520         }
1521       }
1522     }
1523     if (C->env()->jvmti_can_get_owned_monitor_info() ||
1524         C->env()->jvmti_can_walk_any_space() || DeoptimizeObjectsALot) {
1525       // Jvmti agents can read monitors. Must provide info about locked objects at runtime.
1526       int num_mon = jvms->nof_monitors();
1527       for (int idx = 0; idx < num_mon; idx++) {
1528         Node* m = sfn->monitor_obj(jvms, idx);
1529         if (m != nullptr && not_global_escape(m)) {
1530           return true;
1531         }
1532       }
1533     }
1534   }
1535   return false;
1536 }
1537 
1538 // Returns true if at least one of the arguments to the call is an object
1539 // that does not escape globally.
1540 bool ConnectionGraph::has_arg_escape(CallJavaNode* call) {
1541   if (call->method() != nullptr) {
1542     uint max_idx = TypeFunc::Parms + call->method()->arg_size();
1543     for (uint idx = TypeFunc::Parms; idx < max_idx; idx++) {
1544       Node* p = call->in(idx);
1545       if (not_global_escape(p)) {
1546         return true;
1547       }
1548     }
1549   } else {
1550     const char* name = call->as_CallStaticJava()->_name;
1551     assert(name != nullptr, "no name");
1552     // no arg escapes through uncommon traps
1553     if (strcmp(name, "uncommon_trap") != 0) {
1554       // process_call_arguments() assumes that all arguments escape globally
1555       const TypeTuple* d = call->tf()->domain_sig();
1556       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1557         const Type* at = d->field_at(i);
1558         if (at->isa_oopptr() != nullptr) {
1559           return true;
1560         }
1561       }
1562     }
1563   }
1564   return false;
1565 }
1566 
1567 
1568 
1569 // Utility function for nodes that load an object
1570 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
1571   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1572   // ThreadLocal has RawPtr type.
1573   const Type* t = _igvn->type(n);
1574   if (t->make_ptr() != nullptr) {
1575     Node* adr = n->in(MemNode::Address);
1576 #ifdef ASSERT
1577     if (!adr->is_AddP()) {
1578       assert(_igvn->type(adr)->isa_rawptr(), "sanity");
1579     } else {
1580       assert((ptnode_adr(adr->_idx) == nullptr ||
1581               ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
1582     }
1583 #endif
1584     add_local_var_and_edge(n, PointsToNode::NoEscape,
1585                            adr, delayed_worklist);
1586   }
1587 }
1588 
1589 // Populate Connection Graph with PointsTo nodes and create simple
1590 // connection graph edges.
1591 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
1592   assert(!_verify, "this method should not be called for verification");
1593   PhaseGVN* igvn = _igvn;
1594   uint n_idx = n->_idx;
1595   PointsToNode* n_ptn = ptnode_adr(n_idx);
1596   if (n_ptn != nullptr) {
1597     return; // No need to redefine PointsTo node during first iteration.
1598   }
1599   int opcode = n->Opcode();
1600   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_to_con_graph(this, igvn, delayed_worklist, n, opcode);
1601   if (gc_handled) {
1602     return; // Ignore node if already handled by GC.
1603   }
1604 
1605   if (n->is_Call()) {
1606     // Arguments to allocation and locking don't escape.
1607     if (n->is_AbstractLock()) {
1608       // Put Lock and Unlock nodes on IGVN worklist to process them during
1609       // first IGVN optimization when escape information is still available.
1610       record_for_optimizer(n);
1611     } else if (n->is_Allocate()) {
1612       add_call_node(n->as_Call());
1613       record_for_optimizer(n);
1614     } else {
1615       if (n->is_CallStaticJava()) {
1616         const char* name = n->as_CallStaticJava()->_name;
1617         if (name != nullptr && strcmp(name, "uncommon_trap") == 0) {
1618           return; // Skip uncommon traps
1619         }
1620       }
1621       // Don't mark as processed since call's arguments have to be processed.
1622       delayed_worklist->push(n);
1623       // Check if a call returns an object.
1624       if ((n->as_Call()->returns_pointer() &&
1625            n->as_Call()->proj_out_or_null(TypeFunc::Parms) != nullptr) ||
1626           (n->is_CallStaticJava() &&
1627            n->as_CallStaticJava()->is_boxing_method())) {
1628         add_call_node(n->as_Call());
1629       } else if (n->as_Call()->tf()->returns_inline_type_as_fields()) {
1630         bool returns_oop = false;
1631         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax && !returns_oop; i++) {
1632           ProjNode* pn = n->fast_out(i)->as_Proj();
1633           if (pn->_con >= TypeFunc::Parms && pn->bottom_type()->isa_ptr()) {
1634             returns_oop = true;
1635           }
1636         }
1637         if (returns_oop) {
1638           add_call_node(n->as_Call());
1639         }
1640       }
1641     }
1642     return;
1643   }
1644   // Put this check here to process call arguments since some call nodes
1645   // point to phantom_obj.
1646   if (n_ptn == phantom_obj || n_ptn == null_obj) {
1647     return; // Skip predefined nodes.
1648   }
1649   switch (opcode) {
1650     case Op_AddP: {
1651       Node* base = get_addp_base(n);
1652       PointsToNode* ptn_base = ptnode_adr(base->_idx);
1653       // Field nodes are created for all field types. They are used in
1654       // adjust_scalar_replaceable_state() and split_unique_types().
1655       // Note, non-oop fields will have only base edges in Connection
1656       // Graph because such fields are not used for oop loads and stores.
1657       int offset = address_offset(n, igvn);
1658       add_field(n, PointsToNode::NoEscape, offset);
1659       if (ptn_base == nullptr) {
1660         delayed_worklist->push(n); // Process it later.
1661       } else {
1662         n_ptn = ptnode_adr(n_idx);
1663         add_base(n_ptn->as_Field(), ptn_base);
1664       }
1665       break;
1666     }
1667     case Op_CastX2P:
1668     case Op_CastI2N: {
1669       map_ideal_node(n, phantom_obj);
1670       break;
1671     }
1672     case Op_InlineType:
1673     case Op_CastPP:
1674     case Op_CheckCastPP:
1675     case Op_EncodeP:
1676     case Op_DecodeN:
1677     case Op_EncodePKlass:
1678     case Op_DecodeNKlass: {
1679       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist);
1680       break;
1681     }
1682     case Op_CMoveP: {
1683       add_local_var(n, PointsToNode::NoEscape);
1684       // Do not add edges during first iteration because some could be
1685       // not defined yet.
1686       delayed_worklist->push(n);
1687       break;
1688     }
1689     case Op_ConP:
1690     case Op_ConN:
1691     case Op_ConNKlass: {
1692       // assume all oop constants globally escape except for null
1693       PointsToNode::EscapeState es;
1694       const Type* t = igvn->type(n);
1695       if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
1696         es = PointsToNode::NoEscape;
1697       } else {
1698         es = PointsToNode::GlobalEscape;
1699       }
1700       PointsToNode* ptn_con = add_java_object(n, es);
1701       set_not_scalar_replaceable(ptn_con NOT_PRODUCT(COMMA "Constant pointer"));
1702       break;
1703     }
1704     case Op_CreateEx: {
1705       // assume that all exception objects globally escape
1706       map_ideal_node(n, phantom_obj);
1707       break;
1708     }
1709     case Op_LoadKlass:
1710     case Op_LoadNKlass: {
1711       // Unknown class is loaded
1712       map_ideal_node(n, phantom_obj);
1713       break;
1714     }
1715     case Op_LoadP:
1716     case Op_LoadN: {
1717       add_objload_to_connection_graph(n, delayed_worklist);
1718       break;
1719     }
1720     case Op_Parm: {
1721       map_ideal_node(n, phantom_obj);
1722       break;
1723     }
1724     case Op_PartialSubtypeCheck: {
1725       // Produces Null or notNull and is used in only in CmpP so
1726       // phantom_obj could be used.
1727       map_ideal_node(n, phantom_obj); // Result is unknown
1728       break;
1729     }
1730     case Op_Phi: {
1731       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1732       // ThreadLocal has RawPtr type.
1733       const Type* t = n->as_Phi()->type();
1734       if (t->make_ptr() != nullptr) {
1735         add_local_var(n, PointsToNode::NoEscape);
1736         // Do not add edges during first iteration because some could be
1737         // not defined yet.
1738         delayed_worklist->push(n);
1739       }
1740       break;
1741     }
1742     case Op_LoadFlat:
1743       // Treat LoadFlat similar to an unknown call that receives nothing and produces its results
1744       map_ideal_node(n, phantom_obj);
1745       break;
1746     case Op_StoreFlat:
1747       // Treat StoreFlat similar to a call that escapes the stored flattened fields
1748       delayed_worklist->push(n);
1749       break;
1750     case Op_Proj: {
1751       // we are only interested in the oop result projection from a call
1752       if (n->as_Proj()->_con >= TypeFunc::Parms && n->in(0)->is_Call() &&
1753           (n->in(0)->as_Call()->returns_pointer() || n->bottom_type()->isa_ptr())) {
1754         assert((n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->as_Call()->returns_pointer()) ||
1755                n->in(0)->as_Call()->tf()->returns_inline_type_as_fields(), "what kind of oop return is it?");
1756         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), delayed_worklist);
1757       } else if (n->as_Proj()->_con >= TypeFunc::Parms && n->in(0)->is_LoadFlat() && igvn->type(n)->isa_ptr()) {
1758         // Treat LoadFlat outputs similar to a call return value
1759         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), delayed_worklist);
1760       }
1761       break;
1762     }
1763     case Op_Rethrow: // Exception object escapes
1764     case Op_Return: {
1765       if (n->req() > TypeFunc::Parms &&
1766           igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
1767         // Treat Return value as LocalVar with GlobalEscape escape state.
1768         add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), delayed_worklist);
1769       }
1770       break;
1771     }
1772     case Op_CompareAndExchangeP:
1773     case Op_CompareAndExchangeN:
1774     case Op_GetAndSetP:
1775     case Op_GetAndSetN: {
1776       add_objload_to_connection_graph(n, delayed_worklist);
1777       // fall-through
1778     }
1779     case Op_StoreP:
1780     case Op_StoreN:
1781     case Op_StoreNKlass:
1782     case Op_WeakCompareAndSwapP:
1783     case Op_WeakCompareAndSwapN:
1784     case Op_CompareAndSwapP:
1785     case Op_CompareAndSwapN: {
1786       add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
1787       break;
1788     }
1789     case Op_AryEq:
1790     case Op_CountPositives:
1791     case Op_StrComp:
1792     case Op_StrEquals:
1793     case Op_StrIndexOf:
1794     case Op_StrIndexOfChar:
1795     case Op_StrInflatedCopy:
1796     case Op_StrCompressedCopy:
1797     case Op_VectorizedHashCode:
1798     case Op_EncodeISOArray: {
1799       add_local_var(n, PointsToNode::ArgEscape);
1800       delayed_worklist->push(n); // Process it later.
1801       break;
1802     }
1803     case Op_ThreadLocal: {
1804       PointsToNode* ptn_thr = add_java_object(n, PointsToNode::ArgEscape);
1805       set_not_scalar_replaceable(ptn_thr NOT_PRODUCT(COMMA "Constant pointer"));
1806       break;
1807     }
1808     case Op_Blackhole: {
1809       // All blackhole pointer arguments are globally escaping.
1810       // Only do this if there is at least one pointer argument.
1811       // Do not add edges during first iteration because some could be
1812       // not defined yet, defer to final step.
1813       for (uint i = 0; i < n->req(); i++) {
1814         Node* in = n->in(i);
1815         if (in != nullptr) {
1816           const Type* at = _igvn->type(in);
1817           if (!at->isa_ptr()) continue;
1818 
1819           add_local_var(n, PointsToNode::GlobalEscape);
1820           delayed_worklist->push(n);
1821           break;
1822         }
1823       }
1824       break;
1825     }
1826     default:
1827       ; // Do nothing for nodes not related to EA.
1828   }
1829   return;
1830 }
1831 
1832 // Add final simple edges to graph.
1833 void ConnectionGraph::add_final_edges(Node *n) {
1834   PointsToNode* n_ptn = ptnode_adr(n->_idx);
1835 #ifdef ASSERT
1836   if (_verify && n_ptn->is_JavaObject())
1837     return; // This method does not change graph for JavaObject.
1838 #endif
1839 
1840   if (n->is_Call()) {
1841     process_call_arguments(n->as_Call());
1842     return;
1843   }
1844   assert(n->is_Store() || n->is_LoadStore() || n->is_StoreFlat() ||
1845          ((n_ptn != nullptr) && (n_ptn->ideal_node() != nullptr)),
1846          "node should be registered already");
1847   int opcode = n->Opcode();
1848   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_final_edges(this, _igvn, n, opcode);
1849   if (gc_handled) {
1850     return; // Ignore node if already handled by GC.
1851   }
1852   switch (opcode) {
1853     case Op_AddP: {
1854       Node* base = get_addp_base(n);
1855       PointsToNode* ptn_base = ptnode_adr(base->_idx);
1856       assert(ptn_base != nullptr, "field's base should be registered");
1857       add_base(n_ptn->as_Field(), ptn_base);
1858       break;
1859     }
1860     case Op_InlineType:
1861     case Op_CastPP:
1862     case Op_CheckCastPP:
1863     case Op_EncodeP:
1864     case Op_DecodeN:
1865     case Op_EncodePKlass:
1866     case Op_DecodeNKlass: {
1867       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), nullptr);
1868       break;
1869     }
1870     case Op_CMoveP: {
1871       for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
1872         Node* in = n->in(i);
1873         if (in == nullptr) {
1874           continue;  // ignore null
1875         }
1876         Node* uncast_in = in->uncast();
1877         if (uncast_in->is_top() || uncast_in == n) {
1878           continue;  // ignore top or inputs which go back this node
1879         }
1880         PointsToNode* ptn = ptnode_adr(in->_idx);
1881         assert(ptn != nullptr, "node should be registered");
1882         add_edge(n_ptn, ptn);
1883       }
1884       break;
1885     }
1886     case Op_LoadP:
1887     case Op_LoadN: {
1888       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1889       // ThreadLocal has RawPtr type.
1890       assert(_igvn->type(n)->make_ptr() != nullptr, "Unexpected node type");
1891       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), nullptr);
1892       break;
1893     }
1894     case Op_Phi: {
1895       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1896       // ThreadLocal has RawPtr type.
1897       assert(n->as_Phi()->type()->make_ptr() != nullptr, "Unexpected node type");
1898       for (uint i = 1; i < n->req(); i++) {
1899         Node* in = n->in(i);
1900         if (in == nullptr) {
1901           continue;  // ignore null
1902         }
1903         Node* uncast_in = in->uncast();
1904         if (uncast_in->is_top() || uncast_in == n) {
1905           continue;  // ignore top or inputs which go back this node
1906         }
1907         PointsToNode* ptn = ptnode_adr(in->_idx);
1908         assert(ptn != nullptr, "node should be registered");
1909         add_edge(n_ptn, ptn);
1910       }
1911       break;
1912     }
1913     case Op_StoreFlat: {
1914       // StoreFlat globally escapes its stored flattened fields
1915       InlineTypeNode* value = n->as_StoreFlat()->value();
1916       ciInlineKlass* vk = _igvn->type(value)->inline_klass();
1917       for (int i = 0; i < vk->nof_nonstatic_fields(); i++) {
1918         ciField* field = vk->nonstatic_field_at(i);
1919         if (field->type()->is_primitive_type()) {
1920           continue;
1921         }
1922 
1923         Node* field_value = value->field_value_by_offset(field->offset_in_bytes(), true);
1924         PointsToNode* field_value_ptn = ptnode_adr(field_value->_idx);
1925         set_escape_state(field_value_ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "store into a flat field"));
1926       }
1927       break;
1928     }
1929     case Op_Proj: {
1930       if (n->in(0)->is_Call()) {
1931         // we are only interested in the oop result projection from a call
1932         assert((n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->as_Call()->returns_pointer()) ||
1933               n->in(0)->as_Call()->tf()->returns_inline_type_as_fields(), "what kind of oop return is it?");
1934         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), nullptr);
1935       } else if (n->in(0)->is_LoadFlat()) {
1936         // Treat LoadFlat outputs similar to a call return value
1937         add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), nullptr);
1938       }
1939       break;
1940     }
1941     case Op_Rethrow: // Exception object escapes
1942     case Op_Return: {
1943       assert(n->req() > TypeFunc::Parms && _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr(),
1944              "Unexpected node type");
1945       // Treat Return value as LocalVar with GlobalEscape escape state.
1946       add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), nullptr);
1947       break;
1948     }
1949     case Op_CompareAndExchangeP:
1950     case Op_CompareAndExchangeN:
1951     case Op_GetAndSetP:
1952     case Op_GetAndSetN:{
1953       assert(_igvn->type(n)->make_ptr() != nullptr, "Unexpected node type");
1954       add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), nullptr);
1955       // fall-through
1956     }
1957     case Op_CompareAndSwapP:
1958     case Op_CompareAndSwapN:
1959     case Op_WeakCompareAndSwapP:
1960     case Op_WeakCompareAndSwapN:
1961     case Op_StoreP:
1962     case Op_StoreN:
1963     case Op_StoreNKlass:{
1964       add_final_edges_unsafe_access(n, opcode);
1965       break;
1966     }
1967     case Op_VectorizedHashCode:
1968     case Op_AryEq:
1969     case Op_CountPositives:
1970     case Op_StrComp:
1971     case Op_StrEquals:
1972     case Op_StrIndexOf:
1973     case Op_StrIndexOfChar:
1974     case Op_StrInflatedCopy:
1975     case Op_StrCompressedCopy:
1976     case Op_EncodeISOArray: {
1977       // char[]/byte[] arrays passed to string intrinsic do not escape but
1978       // they are not scalar replaceable. Adjust escape state for them.
1979       // Start from in(2) edge since in(1) is memory edge.
1980       for (uint i = 2; i < n->req(); i++) {
1981         Node* adr = n->in(i);
1982         const Type* at = _igvn->type(adr);
1983         if (!adr->is_top() && at->isa_ptr()) {
1984           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
1985                  at->isa_ptr() != nullptr, "expecting a pointer");
1986           if (adr->is_AddP()) {
1987             adr = get_addp_base(adr);
1988           }
1989           PointsToNode* ptn = ptnode_adr(adr->_idx);
1990           assert(ptn != nullptr, "node should be registered");
1991           add_edge(n_ptn, ptn);
1992         }
1993       }
1994       break;
1995     }
1996     case Op_Blackhole: {
1997       // All blackhole pointer arguments are globally escaping.
1998       for (uint i = 0; i < n->req(); i++) {
1999         Node* in = n->in(i);
2000         if (in != nullptr) {
2001           const Type* at = _igvn->type(in);
2002           if (!at->isa_ptr()) continue;
2003 
2004           if (in->is_AddP()) {
2005             in = get_addp_base(in);
2006           }
2007 
2008           PointsToNode* ptn = ptnode_adr(in->_idx);
2009           assert(ptn != nullptr, "should be defined already");
2010           set_escape_state(ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "blackhole"));
2011           add_edge(n_ptn, ptn);
2012         }
2013       }
2014       break;
2015     }
2016     default: {
2017       // This method should be called only for EA specific nodes which may
2018       // miss some edges when they were created.
2019 #ifdef ASSERT
2020       n->dump(1);
2021 #endif
2022       guarantee(false, "unknown node");
2023     }
2024   }
2025   return;
2026 }
2027 
2028 void ConnectionGraph::add_to_congraph_unsafe_access(Node* n, uint opcode, Unique_Node_List* delayed_worklist) {
2029   Node* adr = n->in(MemNode::Address);
2030   const Type* adr_type = _igvn->type(adr);
2031   adr_type = adr_type->make_ptr();
2032   if (adr_type == nullptr) {
2033     return; // skip dead nodes
2034   }
2035   if (adr_type->isa_oopptr()
2036       || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
2037           && adr_type == TypeRawPtr::NOTNULL
2038           && is_captured_store_address(adr))) {
2039     delayed_worklist->push(n); // Process it later.
2040 #ifdef ASSERT
2041     assert (adr->is_AddP(), "expecting an AddP");
2042     if (adr_type == TypeRawPtr::NOTNULL) {
2043       // Verify a raw address for a store captured by Initialize node.
2044       int offs = (int) _igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2045       assert(offs != Type::OffsetBot, "offset must be a constant");
2046     }
2047 #endif
2048   } else {
2049     // Ignore copy the displaced header to the BoxNode (OSR compilation).
2050     if (adr->is_BoxLock()) {
2051       return;
2052     }
2053     // Stored value escapes in unsafe access.
2054     if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
2055       delayed_worklist->push(n); // Process unsafe access later.
2056       return;
2057     }
2058 #ifdef ASSERT
2059     n->dump(1);
2060     assert(false, "not unsafe");
2061 #endif
2062   }
2063 }
2064 
2065 bool ConnectionGraph::add_final_edges_unsafe_access(Node* n, uint opcode) {
2066   Node* adr = n->in(MemNode::Address);
2067   const Type *adr_type = _igvn->type(adr);
2068   adr_type = adr_type->make_ptr();
2069 #ifdef ASSERT
2070   if (adr_type == nullptr) {
2071     n->dump(1);
2072     assert(adr_type != nullptr, "dead node should not be on list");
2073     return true;
2074   }
2075 #endif
2076 
2077   if (adr_type->isa_oopptr()
2078       || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
2079            && adr_type == TypeRawPtr::NOTNULL
2080            && is_captured_store_address(adr))) {
2081     // Point Address to Value
2082     PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
2083     assert(adr_ptn != nullptr &&
2084            adr_ptn->as_Field()->is_oop(), "node should be registered");
2085     Node* val = n->in(MemNode::ValueIn);
2086     PointsToNode* ptn = ptnode_adr(val->_idx);
2087     assert(ptn != nullptr, "node should be registered");
2088     add_edge(adr_ptn, ptn);
2089     return true;
2090   } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
2091     // Stored value escapes in unsafe access.
2092     Node* val = n->in(MemNode::ValueIn);
2093     PointsToNode* ptn = ptnode_adr(val->_idx);
2094     assert(ptn != nullptr, "node should be registered");
2095     set_escape_state(ptn, PointsToNode::GlobalEscape NOT_PRODUCT(COMMA "stored at raw address"));
2096     // Add edge to object for unsafe access with offset.
2097     PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
2098     assert(adr_ptn != nullptr, "node should be registered");
2099     if (adr_ptn->is_Field()) {
2100       assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
2101       add_edge(adr_ptn, ptn);
2102     }
2103     return true;
2104   }
2105 #ifdef ASSERT
2106   n->dump(1);
2107   assert(false, "not unsafe");
2108 #endif
2109   return false;
2110 }
2111 
2112 // Iterate over the domains for the scalarized and non scalarized calling conventions: Only move to the next element
2113 // in the non scalarized calling convention once all elements of the scalarized calling convention for that parameter
2114 // have been iterated over. So (ignoring hidden arguments such as the null marker) iterating over:
2115 // value class MyValue {
2116 //   int f1;
2117 //   float f2;
2118 // }
2119 // void m(Object o, MyValue v, int i)
2120 // produces the pairs:
2121 // (Object, Object), (Myvalue, int), (MyValue, float), (int, int)
2122 class DomainIterator : public StackObj {
2123 private:
2124   const TypeTuple* _domain;
2125   const TypeTuple* _domain_cc;
2126   const GrowableArray<SigEntry>* _sig_cc;
2127 
2128   uint _i_domain;
2129   uint _i_domain_cc;
2130   int _i_sig_cc;
2131   uint _depth;
2132 
2133   void next_helper() {
2134     if (_sig_cc == nullptr) {
2135       return;
2136     }
2137     BasicType prev_bt = _i_sig_cc > 0 ? _sig_cc->at(_i_sig_cc-1)._bt : T_ILLEGAL;
2138     while (_i_sig_cc < _sig_cc->length()) {
2139       BasicType bt = _sig_cc->at(_i_sig_cc)._bt;
2140       assert(bt != T_VOID || _sig_cc->at(_i_sig_cc-1)._bt == prev_bt, "");
2141       if (bt == T_METADATA) {
2142         _depth++;
2143       } else if (bt == T_VOID && (prev_bt != T_LONG && prev_bt != T_DOUBLE)) {
2144         _depth--;
2145         if (_depth == 0) {
2146           _i_domain++;
2147         }
2148       } else {
2149         return;
2150       }
2151       prev_bt = bt;
2152       _i_sig_cc++;
2153     }
2154   }
2155 
2156 public:
2157 
2158   DomainIterator(CallJavaNode* call) :
2159     _domain(call->tf()->domain_sig()),
2160     _domain_cc(call->tf()->domain_cc()),
2161     _sig_cc(call->method()->get_sig_cc()),
2162     _i_domain(TypeFunc::Parms),
2163     _i_domain_cc(TypeFunc::Parms),
2164     _i_sig_cc(0),
2165     _depth(0) {
2166     next_helper();
2167   }
2168 
2169   bool has_next() const {
2170     assert(_sig_cc == nullptr || (_i_sig_cc < _sig_cc->length()) == (_i_domain < _domain->cnt()), "should reach end in sync");
2171     assert((_i_domain < _domain->cnt()) == (_i_domain_cc < _domain_cc->cnt()), "should reach end in sync");
2172     return _i_domain < _domain->cnt();
2173   }
2174 
2175   void next() {
2176     assert(_depth != 0 || _domain->field_at(_i_domain) == _domain_cc->field_at(_i_domain_cc), "should produce same non scalarized elements");
2177     _i_sig_cc++;
2178     if (_depth == 0) {
2179       _i_domain++;
2180     }
2181     _i_domain_cc++;
2182     next_helper();
2183   }
2184 
2185   uint i_domain() const {
2186     return _i_domain;
2187   }
2188 
2189   uint i_domain_cc() const {
2190     return _i_domain_cc;
2191   }
2192 
2193   const Type* current_domain() const {
2194     return _domain->field_at(_i_domain);
2195   }
2196 
2197   const Type* current_domain_cc() const {
2198     return _domain_cc->field_at(_i_domain_cc);
2199   }
2200 };
2201 
2202 void ConnectionGraph::add_call_node(CallNode* call) {
2203   assert(call->returns_pointer() || call->tf()->returns_inline_type_as_fields(), "only for call which returns pointer");
2204   uint call_idx = call->_idx;
2205   if (call->is_Allocate()) {
2206     Node* k = call->in(AllocateNode::KlassNode);
2207     const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
2208     assert(kt != nullptr, "TypeKlassPtr  required.");
2209     PointsToNode::EscapeState es = PointsToNode::NoEscape;
2210     bool scalar_replaceable = true;
2211     NOT_PRODUCT(const char* nsr_reason = "");
2212     if (call->is_AllocateArray()) {
2213       if (!kt->isa_aryklassptr()) { // StressReflectiveCode
2214         es = PointsToNode::GlobalEscape;
2215       } else {
2216         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2217         if (length < 0) {
2218           // Not scalar replaceable if the length is not constant.
2219           scalar_replaceable = false;
2220           NOT_PRODUCT(nsr_reason = "has a non-constant length");
2221         } else if (length > EliminateAllocationArraySizeLimit) {
2222           // Not scalar replaceable if the length is too big.
2223           scalar_replaceable = false;
2224           NOT_PRODUCT(nsr_reason = "has a length that is too big");
2225         }
2226       }
2227     } else {  // Allocate instance
2228       if (!kt->isa_instklassptr()) { // StressReflectiveCode
2229         es = PointsToNode::GlobalEscape;
2230       } else {
2231         const TypeInstKlassPtr* ikt = kt->is_instklassptr();
2232         ciInstanceKlass* ik = ikt->klass_is_exact() ? ikt->exact_klass()->as_instance_klass() : ikt->instance_klass();
2233         if (ik->is_subclass_of(_compile->env()->Thread_klass()) ||
2234             ik->is_subclass_of(_compile->env()->Reference_klass()) ||
2235             !ik->can_be_instantiated() ||
2236             ik->has_finalizer()) {
2237           es = PointsToNode::GlobalEscape;
2238         } else {
2239           int nfields = ik->as_instance_klass()->nof_nonstatic_fields();
2240           if (nfields > EliminateAllocationFieldsLimit) {
2241             // Not scalar replaceable if there are too many fields.
2242             scalar_replaceable = false;
2243             NOT_PRODUCT(nsr_reason = "has too many fields");
2244           }
2245         }
2246       }
2247     }
2248     add_java_object(call, es);
2249     PointsToNode* ptn = ptnode_adr(call_idx);
2250     if (!scalar_replaceable && ptn->scalar_replaceable()) {
2251       set_not_scalar_replaceable(ptn NOT_PRODUCT(COMMA nsr_reason));
2252     }
2253   } else if (call->is_CallStaticJava()) {
2254     // Call nodes could be different types:
2255     //
2256     // 1. CallDynamicJavaNode (what happened during call is unknown):
2257     //
2258     //    - mapped to GlobalEscape JavaObject node if oop is returned;
2259     //
2260     //    - all oop arguments are escaping globally;
2261     //
2262     // 2. CallStaticJavaNode (execute bytecode analysis if possible):
2263     //
2264     //    - the same as CallDynamicJavaNode if can't do bytecode analysis;
2265     //
2266     //    - mapped to GlobalEscape JavaObject node if unknown oop is returned;
2267     //    - mapped to NoEscape JavaObject node if non-escaping object allocated
2268     //      during call is returned;
2269     //    - mapped to ArgEscape LocalVar node pointed to object arguments
2270     //      which are returned and does not escape during call;
2271     //
2272     //    - oop arguments escaping status is defined by bytecode analysis;
2273     //
2274     // For a static call, we know exactly what method is being called.
2275     // Use bytecode estimator to record whether the call's return value escapes.
2276     ciMethod* meth = call->as_CallJava()->method();
2277     if (meth == nullptr) {
2278       const char* name = call->as_CallStaticJava()->_name;
2279       assert(call->as_CallStaticJava()->is_call_to_multianewarray_stub() ||
2280              strncmp(name, "load_unknown_inline", 19) == 0 ||
2281              strncmp(name, "store_inline_type_fields_to_buf", 31) == 0, "TODO: add failed case check");
2282       // Returns a newly allocated non-escaped object.
2283       add_java_object(call, PointsToNode::NoEscape);
2284       set_not_scalar_replaceable(ptnode_adr(call_idx) NOT_PRODUCT(COMMA "is result of multinewarray"));
2285     } else if (meth->is_boxing_method()) {
2286       // Returns boxing object
2287       PointsToNode::EscapeState es;
2288       vmIntrinsics::ID intr = meth->intrinsic_id();
2289       if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
2290         // It does not escape if object is always allocated.
2291         es = PointsToNode::NoEscape;
2292       } else {
2293         // It escapes globally if object could be loaded from cache.
2294         es = PointsToNode::GlobalEscape;
2295       }
2296       add_java_object(call, es);
2297       if (es == PointsToNode::GlobalEscape) {
2298         set_not_scalar_replaceable(ptnode_adr(call->_idx) NOT_PRODUCT(COMMA "object can be loaded from boxing cache"));
2299       }
2300     } else {
2301       BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
2302       call_analyzer->copy_dependencies(_compile->dependencies());
2303       if (call_analyzer->is_return_allocated()) {
2304         // Returns a newly allocated non-escaped object, simply
2305         // update dependency information.
2306         // Mark it as NoEscape so that objects referenced by
2307         // it's fields will be marked as NoEscape at least.
2308         add_java_object(call, PointsToNode::NoEscape);
2309         set_not_scalar_replaceable(ptnode_adr(call_idx) NOT_PRODUCT(COMMA "is result of call"));
2310       } else {


2311         bool ret_arg = false;
2312         // Determine whether any arguments are returned.
2313         for (DomainIterator di(call->as_CallJava()); di.has_next(); di.next()) {
2314           uint arg = di.i_domain() - TypeFunc::Parms;
2315           if (di.current_domain_cc()->isa_ptr() != nullptr &&
2316               call_analyzer->is_arg_returned(arg) &&
2317               !meth->is_scalarized_arg(arg)) {
2318             ret_arg = true;
2319             break;
2320           }
2321         }
2322         if (ret_arg) {
2323           add_local_var(call, PointsToNode::ArgEscape);
2324         } else {
2325           // Returns unknown object.
2326           map_ideal_node(call, phantom_obj);
2327         }
2328       }
2329     }
2330   } else {
2331     // An other type of call, assume the worst case:
2332     // returned value is unknown and globally escapes.
2333     assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
2334     map_ideal_node(call, phantom_obj);
2335   }
2336 }
2337 
2338 void ConnectionGraph::process_call_arguments(CallNode *call) {
2339     bool is_arraycopy = false;
2340     switch (call->Opcode()) {
2341 #ifdef ASSERT
2342     case Op_Allocate:
2343     case Op_AllocateArray:
2344     case Op_Lock:
2345     case Op_Unlock:
2346       assert(false, "should be done already");
2347       break;
2348 #endif
2349     case Op_ArrayCopy:
2350     case Op_CallLeafNoFP:
2351       // Most array copies are ArrayCopy nodes at this point but there
2352       // are still a few direct calls to the copy subroutines (See
2353       // PhaseStringOpts::copy_string())
2354       is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
2355         call->as_CallLeaf()->is_call_to_arraycopystub();
2356       // fall through
2357     case Op_CallLeafVector:
2358     case Op_CallLeaf: {
2359       // Stub calls, objects do not escape but they are not scale replaceable.
2360       // Adjust escape state for outgoing arguments.
2361       const TypeTuple * d = call->tf()->domain_sig();
2362       bool src_has_oops = false;
2363       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2364         const Type* at = d->field_at(i);
2365         Node *arg = call->in(i);
2366         if (arg == nullptr) {
2367           continue;
2368         }
2369         const Type *aat = _igvn->type(arg);
2370         if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr()) {
2371           continue;
2372         }
2373         if (arg->is_AddP()) {
2374           //
2375           // The inline_native_clone() case when the arraycopy stub is called
2376           // after the allocation before Initialize and CheckCastPP nodes.
2377           // Or normal arraycopy for object arrays case.
2378           //
2379           // Set AddP's base (Allocate) as not scalar replaceable since
2380           // pointer to the base (with offset) is passed as argument.
2381           //
2382           arg = get_addp_base(arg);
2383         }
2384         PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2385         assert(arg_ptn != nullptr, "should be registered");
2386         PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
2387         if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
2388           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
2389                  aat->isa_ptr() != nullptr, "expecting an Ptr");
2390           bool arg_has_oops = aat->isa_oopptr() &&
2391                               (aat->isa_instptr() ||
2392                                (aat->isa_aryptr() && (aat->isa_aryptr()->elem() == Type::BOTTOM || aat->isa_aryptr()->elem()->make_oopptr() != nullptr)) ||
2393                                (aat->isa_aryptr() && aat->isa_aryptr()->elem() != nullptr &&
2394                                                                aat->isa_aryptr()->is_flat() &&
2395                                                                aat->isa_aryptr()->elem()->inline_klass()->contains_oops()));
2396           if (i == TypeFunc::Parms) {
2397             src_has_oops = arg_has_oops;
2398           }
2399           //
2400           // src or dst could be j.l.Object when other is basic type array:
2401           //
2402           //   arraycopy(char[],0,Object*,0,size);
2403           //   arraycopy(Object*,0,char[],0,size);
2404           //
2405           // Don't add edges in such cases.
2406           //
2407           bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
2408                                        arg_has_oops && (i > TypeFunc::Parms);
2409 #ifdef ASSERT
2410           if (!(is_arraycopy ||
2411                 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(call) ||
2412                 (call->as_CallLeaf()->_name != nullptr &&
2413                  (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
2414                   strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
2415                   strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
2416                   strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
2417                   strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
2418                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
2419                   strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
2420                   strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_encryptAESCrypt") == 0 ||
2421                   strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_decryptAESCrypt") == 0 ||
2422                   strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
2423                   strcmp(call->as_CallLeaf()->_name, "galoisCounterMode_AESCrypt") == 0 ||
2424                   strcmp(call->as_CallLeaf()->_name, "poly1305_processBlocks") == 0 ||
2425                   strcmp(call->as_CallLeaf()->_name, "intpoly_montgomeryMult_P256") == 0 ||
2426                   strcmp(call->as_CallLeaf()->_name, "intpoly_assign") == 0 ||
2427                   strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
2428                   strcmp(call->as_CallLeaf()->_name, "chacha20Block") == 0 ||
2429                   strcmp(call->as_CallLeaf()->_name, "kyberNtt") == 0 ||
2430                   strcmp(call->as_CallLeaf()->_name, "kyberInverseNtt") == 0 ||
2431                   strcmp(call->as_CallLeaf()->_name, "kyberNttMult") == 0 ||
2432                   strcmp(call->as_CallLeaf()->_name, "kyberAddPoly_2") == 0 ||
2433                   strcmp(call->as_CallLeaf()->_name, "kyberAddPoly_3") == 0 ||
2434                   strcmp(call->as_CallLeaf()->_name, "kyber12To16") == 0 ||
2435                   strcmp(call->as_CallLeaf()->_name, "kyberBarrettReduce") == 0 ||
2436                   strcmp(call->as_CallLeaf()->_name, "dilithiumAlmostNtt") == 0 ||
2437                   strcmp(call->as_CallLeaf()->_name, "dilithiumAlmostInverseNtt") == 0 ||
2438                   strcmp(call->as_CallLeaf()->_name, "dilithiumNttMult") == 0 ||
2439                   strcmp(call->as_CallLeaf()->_name, "dilithiumMontMulByConstant") == 0 ||
2440                   strcmp(call->as_CallLeaf()->_name, "dilithiumDecomposePoly") == 0 ||
2441                   strcmp(call->as_CallLeaf()->_name, "encodeBlock") == 0 ||
2442                   strcmp(call->as_CallLeaf()->_name, "decodeBlock") == 0 ||
2443                   strcmp(call->as_CallLeaf()->_name, "md5_implCompress") == 0 ||
2444                   strcmp(call->as_CallLeaf()->_name, "md5_implCompressMB") == 0 ||
2445                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
2446                   strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
2447                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
2448                   strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
2449                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
2450                   strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
2451                   strcmp(call->as_CallLeaf()->_name, "sha3_implCompress") == 0 ||
2452                   strcmp(call->as_CallLeaf()->_name, "double_keccak") == 0 ||
2453                   strcmp(call->as_CallLeaf()->_name, "sha3_implCompressMB") == 0 ||
2454                   strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
2455                   strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
2456                   strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
2457                   strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
2458                   strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
2459                   strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0 ||
2460                   strcmp(call->as_CallLeaf()->_name, "load_unknown_inline") == 0 ||
2461                   strcmp(call->as_CallLeaf()->_name, "store_unknown_inline") == 0 ||
2462                   strcmp(call->as_CallLeaf()->_name, "store_inline_type_fields_to_buf") == 0 ||
2463                   strcmp(call->as_CallLeaf()->_name, "bigIntegerRightShiftWorker") == 0 ||
2464                   strcmp(call->as_CallLeaf()->_name, "bigIntegerLeftShiftWorker") == 0 ||
2465                   strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0 ||
2466                   strcmp(call->as_CallLeaf()->_name, "stringIndexOf") == 0 ||
2467                   strcmp(call->as_CallLeaf()->_name, "arraysort_stub") == 0 ||
2468                   strcmp(call->as_CallLeaf()->_name, "array_partition_stub") == 0 ||
2469                   strcmp(call->as_CallLeaf()->_name, "get_class_id_intrinsic") == 0 ||
2470                   strcmp(call->as_CallLeaf()->_name, "unsafe_setmemory") == 0)
2471                  ))) {
2472             call->dump();
2473             fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
2474           }
2475 #endif
2476           // Always process arraycopy's destination object since
2477           // we need to add all possible edges to references in
2478           // source object.
2479           if (arg_esc >= PointsToNode::ArgEscape &&
2480               !arg_is_arraycopy_dest) {
2481             continue;
2482           }
2483           PointsToNode::EscapeState es = PointsToNode::ArgEscape;
2484           if (call->is_ArrayCopy()) {
2485             ArrayCopyNode* ac = call->as_ArrayCopy();
2486             if (ac->is_clonebasic() ||
2487                 ac->is_arraycopy_validated() ||
2488                 ac->is_copyof_validated() ||
2489                 ac->is_copyofrange_validated()) {
2490               es = PointsToNode::NoEscape;
2491             }
2492           }
2493           set_escape_state(arg_ptn, es NOT_PRODUCT(COMMA trace_arg_escape_message(call)));
2494           if (arg_is_arraycopy_dest) {
2495             Node* src = call->in(TypeFunc::Parms);
2496             if (src->is_AddP()) {
2497               src = get_addp_base(src);
2498             }
2499             PointsToNode* src_ptn = ptnode_adr(src->_idx);
2500             assert(src_ptn != nullptr, "should be registered");
2501             // Special arraycopy edge:
2502             // Only escape state of destination object's fields affects
2503             // escape state of fields in source object.
2504             add_arraycopy(call, es, src_ptn, arg_ptn);
2505           }
2506         }
2507       }
2508       break;
2509     }
2510     case Op_CallStaticJava: {
2511       // For a static call, we know exactly what method is being called.
2512       // Use bytecode estimator to record the call's escape affects
2513 #ifdef ASSERT
2514       const char* name = call->as_CallStaticJava()->_name;
2515       assert((name == nullptr || strcmp(name, "uncommon_trap") != 0), "normal calls only");
2516 #endif
2517       ciMethod* meth = call->as_CallJava()->method();
2518       if ((meth != nullptr) && meth->is_boxing_method()) {
2519         break; // Boxing methods do not modify any oops.
2520       }
2521       BCEscapeAnalyzer* call_analyzer = (meth !=nullptr) ? meth->get_bcea() : nullptr;
2522       // fall-through if not a Java method or no analyzer information
2523       if (call_analyzer != nullptr) {
2524         PointsToNode* call_ptn = ptnode_adr(call->_idx);
2525         for (DomainIterator di(call->as_CallJava()); di.has_next(); di.next()) {
2526           int k = di.i_domain() - TypeFunc::Parms;
2527           const Type* at = di.current_domain_cc();
2528           Node* arg = call->in(di.i_domain_cc());

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


3972 }
3973 
3974 Node* ConnectionGraph::get_addp_base(Node *addp) {
3975   assert(addp->is_AddP(), "must be AddP");
3976   //
3977   // AddP cases for Base and Address inputs:
3978   // case #1. Direct object's field reference:
3979   //     Allocate
3980   //       |
3981   //     Proj #5 ( oop result )
3982   //       |
3983   //     CheckCastPP (cast to instance type)
3984   //      | |
3985   //     AddP  ( base == address )
3986   //
3987   // case #2. Indirect object's field reference:
3988   //      Phi
3989   //       |
3990   //     CastPP (cast to instance type)
3991   //      | |
3992   //     AddP  ( base == address )
3993   //
3994   // case #3. Raw object's field reference for Initialize node.
3995   //          Could have an additional Phi merging multiple allocations.
3996   //      Allocate
3997   //        |
3998   //      Proj #5 ( oop result )
3999   //  top   |
4000   //     \  |
4001   //     AddP  ( base == top )
4002   //
4003   // case #4. Array's element reference:
4004   //   {CheckCastPP | CastPP}
4005   //     |  | |
4006   //     |  AddP ( array's element offset )
4007   //     |  |
4008   //     AddP ( array's offset )
4009   //
4010   // case #5. Raw object's field reference for arraycopy stub call:
4011   //          The inline_native_clone() case when the arraycopy stub is called
4012   //          after the allocation before Initialize and CheckCastPP nodes.
4013   //      Allocate
4014   //        |
4015   //      Proj #5 ( oop result )
4016   //       | |
4017   //       AddP  ( base == address )
4018   //
4019   // case #6. Constant Pool, ThreadLocal, CastX2P, Klass, OSR buffer buf or
4020   //          Raw object's field reference:
4021   //      {ConP, ThreadLocal, CastX2P, raw Load, Parm0}
4022   //  top   |
4023   //     \  |
4024   //     AddP  ( base == top )
4025   //
4026   // case #7. Klass's field reference.
4027   //      LoadKlass
4028   //       | |
4029   //       AddP  ( base == address )
4030   //
4031   // case #8. narrow Klass's field reference.
4032   //      LoadNKlass
4033   //       |
4034   //      DecodeN
4035   //       | |
4036   //       AddP  ( base == address )
4037   //
4038   // case #9. Mixed unsafe access
4039   //    {instance}
4040   //        |
4041   //      CheckCastPP (raw)
4042   //  top   |
4043   //     \  |
4044   //     AddP  ( base == top )
4045   //
4046   // case #10. Klass fetched with
4047   //           LibraryCallKit::load_*_refined_array_klass()
4048   //           which has en extra Phi.
4049   //  LoadKlass   LoadKlass
4050   //       |          |
4051   //     CastPP    CastPP
4052   //          \   /
4053   //           Phi
4054   //      top   |
4055   //         \  |
4056   //         AddP  ( base == top )
4057   //
4058   Node *base = addp->in(AddPNode::Base);
4059   if (base->uncast()->is_top()) { // The AddP case #3, #6, #9, and #10.
4060     base = addp->in(AddPNode::Address);
4061     while (base->is_AddP()) {
4062       // Case #6 (unsafe access) may have several chained AddP nodes.
4063       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
4064       base = base->in(AddPNode::Address);
4065     }
4066     if (base->Opcode() == Op_CheckCastPP &&
4067         base->bottom_type()->isa_rawptr() &&
4068         _igvn->type(base->in(1))->isa_oopptr()) {
4069       base = base->in(1); // Case #9
4070     } else {
4071       // Case #3, #6, and #10
4072       Node* uncast_base = base->uncast();
4073       int opcode = uncast_base->Opcode();
4074       assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
4075              opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
4076              (_igvn->C->is_osr_compilation() && uncast_base->is_Parm() && uncast_base->as_Parm()->_con == TypeFunc::Parms)||
4077              (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != nullptr)) ||
4078              (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_klassptr() != nullptr)) ||
4079              is_captured_store_address(addp) ||
4080              is_load_array_klass_related(uncast_base), "sanity");
4081     }
4082   }
4083   return base;
4084 }
4085 
4086 #ifdef ASSERT
4087 // Case #10
4088 bool ConnectionGraph::is_load_array_klass_related(const Node* uncast_base) {
4089   if (!uncast_base->is_Phi() || uncast_base->req() != 3) {
4090     return false;
4091   }
4092   Node* in1 = uncast_base->in(1);
4093   Node* in2 = uncast_base->in(2);
4094   return in1->uncast()->Opcode() == Op_LoadKlass &&
4095          in2->uncast()->Opcode() == Op_LoadKlass;
4096 }
4097 #endif
4098 
4099 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
4100   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
4101   Node* addp2 = addp->raw_out(0);
4102   if (addp->outcnt() == 1 && addp2->is_AddP() &&
4103       addp2->in(AddPNode::Base) == n &&
4104       addp2->in(AddPNode::Address) == addp) {
4105     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
4106     //
4107     // Find array's offset to push it on worklist first and
4108     // as result process an array's element offset first (pushed second)
4109     // to avoid CastPP for the array's offset.
4110     // Otherwise the inserted CastPP (LocalVar) will point to what
4111     // the AddP (Field) points to. Which would be wrong since
4112     // the algorithm expects the CastPP has the same point as
4113     // as AddP's base CheckCastPP (LocalVar).
4114     //
4115     //    ArrayAllocation
4116     //     |
4117     //    CheckCastPP
4118     //     |
4119     //    memProj (from ArrayAllocation CheckCastPP)
4120     //     |  ||
4121     //     |  ||   Int (element index)
4122     //     |  ||    |   ConI (log(element size))
4123     //     |  ||    |   /
4124     //     |  ||   LShift
4125     //     |  ||  /
4126     //     |  AddP (array's element offset)
4127     //     |  |
4128     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
4129     //     | / /
4130     //     AddP (array's offset)
4131     //      |
4132     //     Load/Store (memory operation on array's element)
4133     //
4134     return addp2;
4135   }
4136   return nullptr;
4137 }
4138 
4139 //
4140 // Adjust the type and inputs of an AddP which computes the
4141 // address of a field of an instance
4142 //
4143 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
4144   PhaseGVN* igvn = _igvn;
4145   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
4146   assert(base_t != nullptr && base_t->is_known_instance(), "expecting instance oopptr");
4147   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
4148   if (t == nullptr) {
4149     // We are computing a raw address for a store captured by an Initialize
4150     // compute an appropriate address type (cases #3 and #5).
4151     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
4152     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
4153     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
4154     assert(offs != Type::OffsetBot, "offset must be a constant");
4155     if (base_t->isa_aryptr() != nullptr) {
4156       // In the case of a flat inline type array, each field has its
4157       // own slice so we need to extract the field being accessed from
4158       // the address computation
4159       t = base_t->isa_aryptr()->add_field_offset_and_offset(offs)->is_oopptr();
4160     } else {
4161       t = base_t->add_offset(offs)->is_oopptr();
4162     }
4163   }
4164   int inst_id = base_t->instance_id();
4165   assert(!t->is_known_instance() || t->instance_id() == inst_id,
4166                              "old type must be non-instance or match new type");
4167 
4168   // The type 't' could be subclass of 'base_t'.
4169   // As result t->offset() could be large then base_t's size and it will
4170   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
4171   // constructor verifies correctness of the offset.
4172   //
4173   // It could happened on subclass's branch (from the type profiling
4174   // inlining) which was not eliminated during parsing since the exactness
4175   // of the allocation type was not propagated to the subclass type check.
4176   //
4177   // Or the type 't' could be not related to 'base_t' at all.
4178   // It could happen when CHA type is different from MDO type on a dead path
4179   // (for example, from instanceof check) which is not collapsed during parsing.
4180   //
4181   // Do nothing for such AddP node and don't process its users since
4182   // this code branch will go away.
4183   //
4184   if (!t->is_known_instance() &&
4185       !base_t->maybe_java_subtype_of(t)) {
4186      return false; // bail out
4187   }
4188   const TypePtr* tinst = base_t->add_offset(t->offset());
4189   if (tinst->isa_aryptr() && t->isa_aryptr()) {
4190     // In the case of a flat inline type array, each field has its
4191     // own slice so we need to keep track of the field being accessed.
4192     tinst = tinst->is_aryptr()->with_field_offset(t->is_aryptr()->field_offset().get());
4193     // Keep array properties (not flat/null-free)
4194     tinst = tinst->is_aryptr()->update_properties(t->is_aryptr());
4195     if (tinst == nullptr) {
4196       return false; // Skip dead path with inconsistent properties
4197     }
4198   }
4199 
4200   // Do NOT remove the next line: ensure a new alias index is allocated
4201   // for the instance type. Note: C++ will not remove it since the call
4202   // has side effect.
4203   int alias_idx = _compile->get_alias_index(tinst);
4204   igvn->set_type(addp, tinst);
4205   // record the allocation in the node map
4206   set_map(addp, get_map(base->_idx));
4207   // Set addp's Base and Address to 'base'.
4208   Node *abase = addp->in(AddPNode::Base);
4209   Node *adr   = addp->in(AddPNode::Address);
4210   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
4211       adr->in(0)->_idx == (uint)inst_id) {
4212     // Skip AddP cases #3 and #5.
4213   } else {
4214     assert(!abase->is_top(), "sanity"); // AddP case #3
4215     if (abase != base) {
4216       igvn->hash_delete(addp);
4217       addp->set_req(AddPNode::Base, base);
4218       if (abase == adr) {
4219         addp->set_req(AddPNode::Address, base);
4220       } else {
4221         // AddP case #4 (adr is array's element offset AddP node)
4222 #ifdef ASSERT
4223         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
4224         assert(adr->is_AddP() && atype != nullptr &&
4225                atype->instance_id() == inst_id, "array's element offset should be processed first");
4226 #endif
4227       }
4228       igvn->hash_insert(addp);
4229     }
4230   }
4231   // Put on IGVN worklist since at least addp's type was changed above.
4232   record_for_optimizer(addp);
4233   return true;
4234 }
4235 
4236 //
4237 // Create a new version of orig_phi if necessary. Returns either the newly
4238 // created phi or an existing phi.  Sets create_new to indicate whether a new
4239 // phi was created.  Cache the last newly created phi in the node map.
4240 //
4241 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, bool &new_created) {
4242   Compile *C = _compile;
4243   PhaseGVN* igvn = _igvn;
4244   new_created = false;
4245   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
4246   // nothing to do if orig_phi is bottom memory or matches alias_idx
4247   if (phi_alias_idx == alias_idx) {
4248     return orig_phi;
4249   }
4250   // Have we recently created a Phi for this alias index?
4251   PhiNode *result = get_map_phi(orig_phi->_idx);
4252   if (result != nullptr && C->get_alias_index(result->adr_type()) == alias_idx) {
4253     return result;
4254   }
4255   // Previous check may fail when the same wide memory Phi was split into Phis
4256   // for different memory slices. Search all Phis for this region.
4257   if (result != nullptr) {
4258     Node* region = orig_phi->in(0);
4259     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
4260       Node* phi = region->fast_out(i);
4261       if (phi->is_Phi() &&
4262           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
4263         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
4264         return phi->as_Phi();
4265       }
4266     }
4267   }
4268   if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
4269     if (C->do_escape_analysis() == true && !C->failing()) {
4270       // Retry compilation without escape analysis.
4271       // If this is the first failure, the sentinel string will "stick"
4272       // to the Compile object, and the C2Compiler will see it and retry.
4273       C->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4274     }
4275     return nullptr;
4276   }
4277   orig_phi_worklist.append_if_missing(orig_phi);
4278   const TypePtr *atype = C->get_adr_type(alias_idx);
4279   result = PhiNode::make(orig_phi->in(0), nullptr, Type::MEMORY, atype);
4280   C->copy_node_notes_to(result, orig_phi);
4281   igvn->set_type(result, result->bottom_type());
4282   record_for_optimizer(result);
4283   set_map(orig_phi, result);
4284   new_created = true;
4285   return result;
4286 }
4287 
4288 //
4289 // Return a new version of Memory Phi "orig_phi" with the inputs having the
4290 // specified alias index.
4291 //
4292 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, uint rec_depth) {
4293   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
4294   Compile *C = _compile;
4295   PhaseGVN* igvn = _igvn;
4296   bool new_phi_created;
4297   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
4298   if (!new_phi_created) {
4299     return result;
4300   }
4301   GrowableArray<PhiNode *>  phi_list;
4302   GrowableArray<uint>  cur_input;
4303   PhiNode *phi = orig_phi;
4304   uint idx = 1;
4305   bool finished = false;
4306   while(!finished) {
4307     while (idx < phi->req()) {
4308       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, rec_depth + 1);
4309       if (mem != nullptr && mem->is_Phi()) {
4310         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
4311         if (new_phi_created) {
4312           // found an phi for which we created a new split, push current one on worklist and begin
4313           // processing new one
4314           phi_list.push(phi);
4315           cur_input.push(idx);
4316           phi = mem->as_Phi();
4317           result = newphi;
4318           idx = 1;
4319           continue;
4320         } else {
4321           mem = newphi;
4322         }
4323       }
4324       if (C->failing()) {
4325         return nullptr;
4326       }
4327       result->set_req(idx++, mem);
4328     }
4329 #ifdef ASSERT
4330     // verify that the new Phi has an input for each input of the original
4331     assert( phi->req() == result->req(), "must have same number of inputs.");
4332     assert( result->in(0) != nullptr && result->in(0) == phi->in(0), "regions must match");
4333 #endif
4334     // Check if all new phi's inputs have specified alias index.
4335     // Otherwise use old phi.
4336     for (uint i = 1; i < phi->req(); i++) {
4337       Node* in = result->in(i);
4338       assert((phi->in(i) == nullptr) == (in == nullptr), "inputs must correspond.");
4339     }
4340     // we have finished processing a Phi, see if there are any more to do
4341     finished = (phi_list.length() == 0 );
4342     if (!finished) {
4343       phi = phi_list.pop();
4344       idx = cur_input.pop();
4345       PhiNode *prev_result = get_map_phi(phi->_idx);
4346       prev_result->set_req(idx++, result);
4347       result = prev_result;
4348     }
4349   }
4350   return result;
4351 }
4352 
4353 //
4354 // The next methods are derived from methods in MemNode.
4355 //
4356 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
4357   Node *mem = mmem;
4358   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
4359   // means an array I have not precisely typed yet.  Do not do any
4360   // alias stuff with it any time soon.
4361   if (toop->base() != Type::AnyPtr &&
4362       !(toop->isa_instptr() &&
4363         toop->is_instptr()->instance_klass()->is_java_lang_Object() &&
4364         toop->offset() == Type::OffsetBot)) {
4365     mem = mmem->memory_at(alias_idx);
4366     // Update input if it is progress over what we have now
4367   }
4368   return mem;
4369 }
4370 
4371 //
4372 // Move memory users to their memory slices.
4373 //
4374 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis) {
4375   Compile* C = _compile;
4376   PhaseGVN* igvn = _igvn;
4377   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
4378   assert(tp != nullptr, "ptr type");
4379   int alias_idx = C->get_alias_index(tp);
4380   int general_idx = C->get_general_index(alias_idx);
4381 
4382   // Move users first
4383   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4384     Node* use = n->fast_out(i);
4385     if (use->is_MergeMem()) {
4386       MergeMemNode* mmem = use->as_MergeMem();
4387       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
4388       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
4389         continue; // Nothing to do
4390       }
4391       // Replace previous general reference to mem node.
4392       uint orig_uniq = C->unique();
4393       Node* m = find_inst_mem(n, general_idx, orig_phis);
4394       assert(orig_uniq == C->unique(), "no new nodes");
4395       mmem->set_memory_at(general_idx, m);
4396       --imax;
4397       --i;
4398     } else if (use->is_MemBar()) {
4399       assert(!use->is_Initialize(), "initializing stores should not be moved");
4400       if (use->req() > MemBarNode::Precedent &&
4401           use->in(MemBarNode::Precedent) == n) {
4402         // Don't move related membars.
4403         record_for_optimizer(use);
4404         continue;
4405       }
4406       tp = use->as_MemBar()->adr_type()->isa_ptr();
4407       if ((tp != nullptr && C->get_alias_index(tp) == alias_idx) ||
4408           alias_idx == general_idx) {
4409         continue; // Nothing to do
4410       }
4411       // Move to general memory slice.
4412       uint orig_uniq = C->unique();
4413       Node* m = find_inst_mem(n, general_idx, orig_phis);
4414       assert(orig_uniq == C->unique(), "no new nodes");
4415       igvn->hash_delete(use);
4416       imax -= use->replace_edge(n, m, igvn);
4417       igvn->hash_insert(use);
4418       record_for_optimizer(use);
4419       --i;
4420 #ifdef ASSERT
4421     } else if (use->is_Mem()) {
4422       // Memory nodes should have new memory input.
4423       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
4424       assert(tp != nullptr, "ptr type");
4425       int idx = C->get_alias_index(tp);
4426       assert(get_map(use->_idx) != nullptr || idx == alias_idx,
4427              "Following memory nodes should have new memory input or be on the same memory slice");
4428     } else if (use->is_Phi()) {
4429       // Phi nodes should be split and moved already.
4430       tp = use->as_Phi()->adr_type()->isa_ptr();
4431       assert(tp != nullptr, "ptr type");
4432       int idx = C->get_alias_index(tp);
4433       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
4434     } else {
4435       use->dump();
4436       assert(false, "should not be here");
4437 #endif
4438     }
4439   }
4440 }
4441 
4442 //
4443 // Search memory chain of "mem" to find a MemNode whose address
4444 // is the specified alias index.
4445 //
4446 #define FIND_INST_MEM_RECURSION_DEPTH_LIMIT 1000
4447 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, uint rec_depth) {
4448   if (rec_depth > FIND_INST_MEM_RECURSION_DEPTH_LIMIT) {
4449     _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4450     return nullptr;
4451   }
4452   if (orig_mem == nullptr) {
4453     return orig_mem;
4454   }
4455   Compile* C = _compile;
4456   PhaseGVN* igvn = _igvn;
4457   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
4458   bool is_instance = (toop != nullptr) && toop->is_known_instance();
4459   Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
4460   Node *prev = nullptr;
4461   Node *result = orig_mem;
4462   while (prev != result) {
4463     prev = result;
4464     if (result == start_mem) {
4465       break;  // hit one of our sentinels
4466     }
4467     if (result->is_Mem()) {
4468       const Type *at = igvn->type(result->in(MemNode::Address));
4469       if (at == Type::TOP) {
4470         break; // Dead
4471       }
4472       assert (at->isa_ptr() != nullptr, "pointer type required.");
4473       int idx = C->get_alias_index(at->is_ptr());
4474       if (idx == alias_idx) {
4475         break; // Found
4476       }
4477       if (!is_instance && (at->isa_oopptr() == nullptr ||
4478                            !at->is_oopptr()->is_known_instance())) {
4479         break; // Do not skip store to general memory slice.
4480       }
4481       result = result->in(MemNode::Memory);
4482     }
4483     if (!is_instance) {
4484       continue;  // don't search further for non-instance types
4485     }
4486     // skip over a call which does not affect this memory slice
4487     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
4488       Node *proj_in = result->in(0);
4489       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
4490         break;  // hit one of our sentinels
4491       } else if (proj_in->is_Call()) {
4492         // ArrayCopy node processed here as well
4493         CallNode *call = proj_in->as_Call();
4494         if (!call->may_modify(toop, igvn)) {
4495           result = call->in(TypeFunc::Memory);
4496         }
4497       } else if (proj_in->is_Initialize()) {
4498         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
4499         // Stop if this is the initialization for the object instance which
4500         // which contains this memory slice, otherwise skip over it.
4501         if (alloc == nullptr || alloc->_idx != (uint)toop->instance_id()) {
4502           result = proj_in->in(TypeFunc::Memory);
4503         } else if (C->get_alias_index(result->adr_type()) != alias_idx) {
4504           assert(C->get_general_index(alias_idx) == C->get_alias_index(result->adr_type()), "should be projection for the same field/array element");
4505           result = get_map(result->_idx);
4506           assert(result != nullptr, "new projection should have been allocated");
4507           break;
4508         }
4509       } else if (proj_in->is_MemBar()) {
4510         // Check if there is an array copy for a clone
4511         // Step over GC barrier when ReduceInitialCardMarks is disabled
4512         BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
4513         Node* control_proj_ac = bs->step_over_gc_barrier(proj_in->in(0));
4514 
4515         if (control_proj_ac->is_Proj() && control_proj_ac->in(0)->is_ArrayCopy()) {
4516           // Stop if it is a clone
4517           ArrayCopyNode* ac = control_proj_ac->in(0)->as_ArrayCopy();
4518           if (ac->may_modify(toop, igvn)) {
4519             break;
4520           }
4521         }
4522         result = proj_in->in(TypeFunc::Memory);
4523       }
4524     } else if (result->is_MergeMem()) {
4525       MergeMemNode *mmem = result->as_MergeMem();
4526       result = step_through_mergemem(mmem, alias_idx, toop);
4527       if (result == mmem->base_memory()) {
4528         // Didn't find instance memory, search through general slice recursively.
4529         result = mmem->memory_at(C->get_general_index(alias_idx));
4530         result = find_inst_mem(result, alias_idx, orig_phis, rec_depth + 1);
4531         if (C->failing()) {
4532           return nullptr;
4533         }
4534         mmem->set_memory_at(alias_idx, result);
4535       }
4536     } else if (result->is_Phi() &&
4537                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
4538       Node *un = result->as_Phi()->unique_input(igvn);
4539       if (un != nullptr) {
4540         orig_phis.append_if_missing(result->as_Phi());
4541         result = un;
4542       } else {
4543         break;
4544       }
4545     } else if (result->is_ClearArray()) {
4546       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
4547         // Can not bypass initialization of the instance
4548         // we are looking for.
4549         break;
4550       }
4551       // Otherwise skip it (the call updated 'result' value).
4552     } else if (result->Opcode() == Op_SCMemProj) {
4553       Node* mem = result->in(0);
4554       Node* adr = nullptr;
4555       if (mem->is_LoadStore()) {
4556         adr = mem->in(MemNode::Address);
4557       } else {
4558         assert(mem->Opcode() == Op_EncodeISOArray ||
4559                mem->Opcode() == Op_StrCompressedCopy, "sanity");
4560         adr = mem->in(3); // Memory edge corresponds to destination array
4561       }
4562       const Type *at = igvn->type(adr);
4563       if (at != Type::TOP) {
4564         assert(at->isa_ptr() != nullptr, "pointer type required.");
4565         int idx = C->get_alias_index(at->is_ptr());
4566         if (idx == alias_idx) {
4567           // Assert in debug mode
4568           assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
4569           break; // In product mode return SCMemProj node
4570         }
4571       }
4572       result = mem->in(MemNode::Memory);
4573     } else if (result->Opcode() == Op_StrInflatedCopy) {
4574       Node* adr = result->in(3); // Memory edge corresponds to destination array
4575       const Type *at = igvn->type(adr);
4576       if (at != Type::TOP) {
4577         assert(at->isa_ptr() != nullptr, "pointer type required.");
4578         int idx = C->get_alias_index(at->is_ptr());
4579         if (idx == alias_idx) {
4580           // Assert in debug mode
4581           assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
4582           break; // In product mode return SCMemProj node
4583         }
4584       }
4585       result = result->in(MemNode::Memory);
4586     }
4587   }
4588   if (result->is_Phi()) {
4589     PhiNode *mphi = result->as_Phi();
4590     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
4591     const TypePtr *t = mphi->adr_type();
4592     if (!is_instance) {
4593       // Push all non-instance Phis on the orig_phis worklist to update inputs
4594       // during Phase 4 if needed.
4595       orig_phis.append_if_missing(mphi);
4596     } else if (C->get_alias_index(t) != alias_idx) {
4597       // Create a new Phi with the specified alias index type.
4598       result = split_memory_phi(mphi, alias_idx, orig_phis, rec_depth + 1);
4599     }
4600   }
4601   // the result is either MemNode, PhiNode, InitializeNode.
4602   return result;
4603 }
4604 
4605 //
4606 //  Convert the types of non-escaped object to instance types where possible,
4607 //  propagate the new type information through the graph, and update memory
4608 //  edges and MergeMem inputs to reflect the new type.
4609 //
4610 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
4611 //  The processing is done in 4 phases:
4612 //
4613 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
4614 //            types for the CheckCastPP for allocations where possible.
4615 //            Propagate the new types through users as follows:
4616 //               casts and Phi:  push users on alloc_worklist
4617 //               AddP:  cast Base and Address inputs to the instance type
4618 //                      push any AddP users on alloc_worklist and push any memnode
4619 //                      users onto memnode_worklist.
4620 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
4621 //            search the Memory chain for a store with the appropriate type
4622 //            address type.  If a Phi is found, create a new version with
4623 //            the appropriate memory slices from each of the Phi inputs.
4624 //            For stores, process the users as follows:
4625 //               MemNode:  push on memnode_worklist
4626 //               MergeMem: push on mergemem_worklist
4627 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
4628 //            moving the first node encountered of each  instance type to the
4629 //            the input corresponding to its alias index.
4630 //            appropriate memory slice.
4631 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
4632 //
4633 // In the following example, the CheckCastPP nodes are the cast of allocation
4634 // results and the allocation of node 29 is non-escaped and eligible to be an
4635 // instance type.
4636 //
4637 // We start with:
4638 //
4639 //     7 Parm #memory
4640 //    10  ConI  "12"
4641 //    19  CheckCastPP   "Foo"
4642 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4643 //    29  CheckCastPP   "Foo"
4644 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
4645 //
4646 //    40  StoreP  25   7  20   ... alias_index=4
4647 //    50  StoreP  35  40  30   ... alias_index=4
4648 //    60  StoreP  45  50  20   ... alias_index=4
4649 //    70  LoadP    _  60  30   ... alias_index=4
4650 //    80  Phi     75  50  60   Memory alias_index=4
4651 //    90  LoadP    _  80  30   ... alias_index=4
4652 //   100  LoadP    _  80  20   ... alias_index=4
4653 //
4654 //
4655 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
4656 // and creating a new alias index for node 30.  This gives:
4657 //
4658 //     7 Parm #memory
4659 //    10  ConI  "12"
4660 //    19  CheckCastPP   "Foo"
4661 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4662 //    29  CheckCastPP   "Foo"  iid=24
4663 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
4664 //
4665 //    40  StoreP  25   7  20   ... alias_index=4
4666 //    50  StoreP  35  40  30   ... alias_index=6
4667 //    60  StoreP  45  50  20   ... alias_index=4
4668 //    70  LoadP    _  60  30   ... alias_index=6
4669 //    80  Phi     75  50  60   Memory alias_index=4
4670 //    90  LoadP    _  80  30   ... alias_index=6
4671 //   100  LoadP    _  80  20   ... alias_index=4
4672 //
4673 // In phase 2, new memory inputs are computed for the loads and stores,
4674 // And a new version of the phi is created.  In phase 4, the inputs to
4675 // node 80 are updated and then the memory nodes are updated with the
4676 // values computed in phase 2.  This results in:
4677 //
4678 //     7 Parm #memory
4679 //    10  ConI  "12"
4680 //    19  CheckCastPP   "Foo"
4681 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
4682 //    29  CheckCastPP   "Foo"  iid=24
4683 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
4684 //
4685 //    40  StoreP  25  7   20   ... alias_index=4
4686 //    50  StoreP  35  7   30   ... alias_index=6
4687 //    60  StoreP  45  40  20   ... alias_index=4
4688 //    70  LoadP    _  50  30   ... alias_index=6
4689 //    80  Phi     75  40  60   Memory alias_index=4
4690 //   120  Phi     75  50  50   Memory alias_index=6
4691 //    90  LoadP    _ 120  30   ... alias_index=6
4692 //   100  LoadP    _  80  20   ... alias_index=4
4693 //
4694 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist,
4695                                          GrowableArray<ArrayCopyNode*> &arraycopy_worklist,
4696                                          GrowableArray<MergeMemNode*> &mergemem_worklist,
4697                                          Unique_Node_List &reducible_merges) {
4698   DEBUG_ONLY(Unique_Node_List reduced_merges;)
4699   GrowableArray<Node *>  memnode_worklist;
4700   GrowableArray<PhiNode *>  orig_phis;
4701   PhaseIterGVN  *igvn = _igvn;
4702   uint new_index_start = (uint) _compile->num_alias_types();
4703   VectorSet visited;
4704   ideal_nodes.clear(); // Reset for use with set_map/get_map.
4705 
4706   //  Phase 1:  Process possible allocations from alloc_worklist.
4707   //  Create instance types for the CheckCastPP for allocations where possible.
4708   //
4709   // (Note: don't forget to change the order of the second AddP node on
4710   //  the alloc_worklist if the order of the worklist processing is changed,
4711   //  see the comment in find_second_addp().)
4712   //
4713   while (alloc_worklist.length() != 0) {
4714     Node *n = alloc_worklist.pop();
4715     uint ni = n->_idx;
4716     if (n->is_Call()) {
4717       CallNode *alloc = n->as_Call();
4718       // copy escape information to call node
4719       PointsToNode* ptn = ptnode_adr(alloc->_idx);
4720       PointsToNode::EscapeState es = ptn->escape_state();
4721       // We have an allocation or call which returns a Java object,
4722       // see if it is non-escaped.
4723       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable()) {
4724         continue;
4725       }
4726       // Find CheckCastPP for the allocate or for the return value of a call
4727       n = alloc->result_cast();
4728       if (n == nullptr) {            // No uses except Initialize node
4729         if (alloc->is_Allocate()) {
4730           // Set the scalar_replaceable flag for allocation
4731           // so it could be eliminated if it has no uses.
4732           alloc->as_Allocate()->_is_scalar_replaceable = true;
4733         }
4734         continue;
4735       }
4736       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
4737         // we could reach here for allocate case if one init is associated with many allocs.
4738         if (alloc->is_Allocate()) {
4739           alloc->as_Allocate()->_is_scalar_replaceable = false;
4740         }
4741         continue;
4742       }
4743 
4744       // The inline code for Object.clone() casts the allocation result to
4745       // java.lang.Object and then to the actual type of the allocated
4746       // object. Detect this case and use the second cast.
4747       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
4748       // the allocation result is cast to java.lang.Object and then
4749       // to the actual Array type.
4750       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
4751           && (alloc->is_AllocateArray() ||
4752               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeInstKlassPtr::OBJECT)) {
4753         Node *cast2 = nullptr;
4754         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4755           Node *use = n->fast_out(i);
4756           if (use->is_CheckCastPP()) {
4757             cast2 = use;
4758             break;
4759           }
4760         }
4761         if (cast2 != nullptr) {
4762           n = cast2;
4763         } else {
4764           // Non-scalar replaceable if the allocation type is unknown statically
4765           // (reflection allocation), the object can't be restored during
4766           // deoptimization without precise type.
4767           continue;
4768         }
4769       }
4770 
4771       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
4772       if (t == nullptr) {
4773         continue;  // not a TypeOopPtr
4774       }
4775       if (!t->klass_is_exact()) {
4776         continue; // not an unique type
4777       }
4778       if (alloc->is_Allocate()) {
4779         // Set the scalar_replaceable flag for allocation
4780         // so it could be eliminated.
4781         alloc->as_Allocate()->_is_scalar_replaceable = true;
4782       }
4783       set_escape_state(ptnode_adr(n->_idx), es NOT_PRODUCT(COMMA trace_propagate_message(ptn))); // CheckCastPP escape state
4784       // in order for an object to be scalar-replaceable, it must be:
4785       //   - a direct allocation (not a call returning an object)
4786       //   - non-escaping
4787       //   - eligible to be a unique type
4788       //   - not determined to be ineligible by escape analysis
4789       set_map(alloc, n);
4790       set_map(n, alloc);
4791       const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
4792       igvn->hash_delete(n);
4793       igvn->set_type(n,  tinst);
4794       n->raise_bottom_type(tinst);
4795       igvn->hash_insert(n);
4796       record_for_optimizer(n);
4797       // Allocate an alias index for the header fields. Accesses to
4798       // the header emitted during macro expansion wouldn't have
4799       // correct memory state otherwise.
4800       _compile->get_alias_index(tinst->add_offset(oopDesc::mark_offset_in_bytes()));
4801       _compile->get_alias_index(tinst->add_offset(oopDesc::klass_offset_in_bytes()));
4802       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
4803         // Add a new NarrowMem projection for each existing NarrowMem projection with new adr type
4804         InitializeNode* init = alloc->as_Allocate()->initialization();
4805         assert(init != nullptr, "can't find Initialization node for this Allocate node");
4806         auto process_narrow_proj = [&](NarrowMemProjNode* proj) {
4807           const TypePtr* adr_type = proj->adr_type();
4808           const TypePtr* new_adr_type = tinst->with_offset(adr_type->offset());
4809           if (adr_type->isa_aryptr()) {
4810             // In the case of a flat inline type array, each field has its own slice so we need a
4811             // NarrowMemProj for each field of the flat array elements
4812             new_adr_type = new_adr_type->is_aryptr()->with_field_offset(adr_type->is_aryptr()->field_offset().get());
4813           }
4814           if (adr_type != new_adr_type && !init->already_has_narrow_mem_proj_with_adr_type(new_adr_type)) {
4815             DEBUG_ONLY( uint alias_idx = _compile->get_alias_index(new_adr_type); )
4816             assert(_compile->get_general_index(alias_idx) == _compile->get_alias_index(adr_type), "new adr type should be narrowed down from existing adr type");
4817             NarrowMemProjNode* new_proj = new NarrowMemProjNode(init, new_adr_type);
4818             igvn->set_type(new_proj, new_proj->bottom_type());
4819             record_for_optimizer(new_proj);
4820             set_map(proj, new_proj); // record it so ConnectionGraph::find_inst_mem() can find it
4821           }
4822         };
4823         init->for_each_narrow_mem_proj_with_new_uses(process_narrow_proj);
4824 
4825         // First, put on the worklist all Field edges from Connection Graph
4826         // which is more accurate than putting immediate users from Ideal Graph.
4827         for (EdgeIterator e(ptn); e.has_next(); e.next()) {
4828           PointsToNode* tgt = e.get();
4829           if (tgt->is_Arraycopy()) {
4830             continue;
4831           }
4832           Node* use = tgt->ideal_node();
4833           assert(tgt->is_Field() && use->is_AddP(),
4834                  "only AddP nodes are Field edges in CG");
4835           if (use->outcnt() > 0) { // Don't process dead nodes
4836             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
4837             if (addp2 != nullptr) {
4838               assert(alloc->is_AllocateArray(),"array allocation was expected");
4839               alloc_worklist.append_if_missing(addp2);
4840             }
4841             alloc_worklist.append_if_missing(use);
4842           }
4843         }
4844 
4845         // An allocation may have an Initialize which has raw stores. Scan
4846         // the users of the raw allocation result and push AddP users
4847         // on alloc_worklist.
4848         Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
4849         assert (raw_result != nullptr, "must have an allocation result");
4850         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
4851           Node *use = raw_result->fast_out(i);
4852           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
4853             Node* addp2 = find_second_addp(use, raw_result);
4854             if (addp2 != nullptr) {
4855               assert(alloc->is_AllocateArray(),"array allocation was expected");
4856               alloc_worklist.append_if_missing(addp2);
4857             }
4858             alloc_worklist.append_if_missing(use);
4859           } else if (use->is_MemBar()) {
4860             memnode_worklist.append_if_missing(use);
4861           }
4862         }
4863       }
4864     } else if (n->is_AddP()) {
4865       if (has_reducible_merge_base(n->as_AddP(), reducible_merges)) {
4866         // This AddP will go away when we reduce the Phi
4867         continue;
4868       }
4869       Node* addp_base = get_addp_base(n);
4870       JavaObjectNode* jobj = unique_java_object(addp_base);
4871       if (jobj == nullptr || jobj == phantom_obj) {
4872 #ifdef ASSERT
4873         ptnode_adr(get_addp_base(n)->_idx)->dump();
4874         ptnode_adr(n->_idx)->dump();
4875         assert(jobj != nullptr && jobj != phantom_obj, "escaped allocation");
4876 #endif
4877         _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4878         return;
4879       }
4880       Node *base = get_map(jobj->idx());  // CheckCastPP node
4881       if (!split_AddP(n, base)) continue; // wrong type from dead path
4882     } else if (n->is_Phi() ||
4883                n->is_CheckCastPP() ||
4884                n->is_EncodeP() ||
4885                n->is_DecodeN() ||
4886                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
4887       if (visited.test_set(n->_idx)) {
4888         assert(n->is_Phi(), "loops only through Phi's");
4889         continue;  // already processed
4890       }
4891       // Reducible Phi's will be removed from the graph after split_unique_types
4892       // finishes. For now we just try to split out the SR inputs of the merge.
4893       Node* parent = n->in(1);
4894       if (reducible_merges.member(n)) {
4895         reduce_phi(n->as_Phi(), alloc_worklist);
4896 #ifdef ASSERT
4897         if (VerifyReduceAllocationMerges) {
4898           reduced_merges.push(n);
4899         }
4900 #endif
4901         continue;
4902       } else if (reducible_merges.member(parent)) {
4903         // 'n' is an user of a reducible merge (a Phi). It will be simplified as
4904         // part of reduce_merge.
4905         continue;
4906       }
4907       JavaObjectNode* jobj = unique_java_object(n);
4908       if (jobj == nullptr || jobj == phantom_obj) {
4909 #ifdef ASSERT
4910         ptnode_adr(n->_idx)->dump();
4911         assert(jobj != nullptr && jobj != phantom_obj, "escaped allocation");
4912 #endif
4913         _compile->record_failure(_invocation > 0 ? C2Compiler::retry_no_iterative_escape_analysis() : C2Compiler::retry_no_escape_analysis());
4914         return;
4915       } else {
4916         Node *val = get_map(jobj->idx());   // CheckCastPP node
4917         TypeNode *tn = n->as_Type();
4918         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
4919         assert(tinst != nullptr && tinst->is_known_instance() &&
4920                tinst->instance_id() == jobj->idx() , "instance type expected.");
4921 
4922         const Type *tn_type = igvn->type(tn);
4923         const TypeOopPtr *tn_t;
4924         if (tn_type->isa_narrowoop()) {
4925           tn_t = tn_type->make_ptr()->isa_oopptr();
4926         } else {
4927           tn_t = tn_type->isa_oopptr();
4928         }
4929         if (tn_t != nullptr && tinst->maybe_java_subtype_of(tn_t)) {
4930           if (tn_t->isa_aryptr()) {
4931             // Keep array properties (not flat/null-free)
4932             tinst = tinst->is_aryptr()->update_properties(tn_t->is_aryptr());
4933             if (tinst == nullptr) {
4934               continue; // Skip dead path with inconsistent properties
4935             }
4936           }
4937           if (tn_type->isa_narrowoop()) {
4938             tn_type = tinst->make_narrowoop();
4939           } else {
4940             tn_type = tinst;
4941           }
4942           igvn->hash_delete(tn);
4943           igvn->set_type(tn, tn_type);
4944           tn->set_type(tn_type);
4945           igvn->hash_insert(tn);
4946           record_for_optimizer(n);
4947         } else {
4948           assert(tn_type == TypePtr::NULL_PTR ||
4949                  (tn_t != nullptr && !tinst->maybe_java_subtype_of(tn_t)),
4950                  "unexpected type");
4951           continue; // Skip dead path with different type
4952         }
4953       }
4954     } else {
4955       DEBUG_ONLY(n->dump();)
4956       assert(false, "EA: unexpected node");
4957       continue;
4958     }
4959     // push allocation's users on appropriate worklist
4960     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4961       Node *use = n->fast_out(i);
4962       if (use->is_Mem() && use->in(MemNode::Address) == n) {
4963         // Load/store to instance's field
4964         memnode_worklist.append_if_missing(use);
4965       } else if (use->is_MemBar()) {
4966         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
4967           memnode_worklist.append_if_missing(use);
4968         }
4969       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
4970         Node* addp2 = find_second_addp(use, n);
4971         if (addp2 != nullptr) {
4972           alloc_worklist.append_if_missing(addp2);
4973         }
4974         alloc_worklist.append_if_missing(use);
4975       } else if (use->is_Phi() ||
4976                  use->is_CheckCastPP() ||
4977                  use->is_EncodeNarrowPtr() ||
4978                  use->is_DecodeNarrowPtr() ||
4979                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
4980         alloc_worklist.append_if_missing(use);
4981 #ifdef ASSERT
4982       } else if (use->is_Mem()) {
4983         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
4984       } else if (use->is_MergeMem()) {
4985         assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
4986       } else if (use->is_SafePoint()) {
4987         // Look for MergeMem nodes for calls which reference unique allocation
4988         // (through CheckCastPP nodes) even for debug info.
4989         Node* m = use->in(TypeFunc::Memory);
4990         if (m->is_MergeMem()) {
4991           assert(mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
4992         }
4993       } else if (use->Opcode() == Op_EncodeISOArray) {
4994         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
4995           // EncodeISOArray overwrites destination array
4996           memnode_worklist.append_if_missing(use);
4997         }
4998       } else if (use->Opcode() == Op_Return) {
4999         // Allocation is referenced by field of returned inline type
5000         assert(_compile->tf()->returns_inline_type_as_fields(), "EA: unexpected reference by ReturnNode");
5001       } else {
5002         uint op = use->Opcode();
5003         if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
5004             (use->in(MemNode::Memory) == n)) {
5005           // They overwrite memory edge corresponding to destination array,
5006           memnode_worklist.append_if_missing(use);
5007         } else if (!(op == Op_CmpP || op == Op_Conv2B ||
5008               op == Op_CastP2X ||
5009               op == Op_FastLock || op == Op_AryEq ||
5010               op == Op_StrComp || op == Op_CountPositives ||
5011               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
5012               op == Op_StrEquals || op == Op_VectorizedHashCode ||
5013               op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
5014               op == Op_SubTypeCheck || op == Op_InlineType || op == Op_FlatArrayCheck ||
5015               op == Op_ReinterpretS2HF ||
5016               BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
5017           n->dump();
5018           use->dump();
5019           assert(false, "EA: missing allocation reference path");
5020         }
5021 #endif
5022       }
5023     }
5024 
5025   }
5026 
5027 #ifdef ASSERT
5028   if (VerifyReduceAllocationMerges) {
5029     for (uint i = 0; i < reducible_merges.size(); i++) {
5030       Node* phi = reducible_merges.at(i);
5031 
5032       if (!reduced_merges.member(phi)) {
5033         phi->dump(2);
5034         phi->dump(-2);
5035         assert(false, "This reducible merge wasn't reduced.");
5036       }
5037 
5038       // At this point reducible Phis shouldn't have AddP users anymore; only SafePoints or Casts.
5039       for (DUIterator_Fast jmax, j = phi->fast_outs(jmax); j < jmax; j++) {
5040         Node* use = phi->fast_out(j);
5041         if (!use->is_SafePoint() && !use->is_CastPP()) {
5042           phi->dump(2);
5043           phi->dump(-2);
5044           assert(false, "Unexpected user of reducible Phi -> %d:%s:%d", use->_idx, use->Name(), use->outcnt());
5045         }
5046       }
5047     }
5048   }
5049 #endif
5050 
5051   // Go over all ArrayCopy nodes and if one of the inputs has a unique
5052   // type, record it in the ArrayCopy node so we know what memory this
5053   // node uses/modified.
5054   for (int next = 0; next < arraycopy_worklist.length(); next++) {
5055     ArrayCopyNode* ac = arraycopy_worklist.at(next);
5056     Node* dest = ac->in(ArrayCopyNode::Dest);
5057     if (dest->is_AddP()) {
5058       dest = get_addp_base(dest);
5059     }
5060     JavaObjectNode* jobj = unique_java_object(dest);
5061     if (jobj != nullptr) {
5062       Node *base = get_map(jobj->idx());
5063       if (base != nullptr) {
5064         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
5065         ac->_dest_type = base_t;
5066       }
5067     }
5068     Node* src = ac->in(ArrayCopyNode::Src);
5069     if (src->is_AddP()) {
5070       src = get_addp_base(src);
5071     }
5072     jobj = unique_java_object(src);
5073     if (jobj != nullptr) {
5074       Node* base = get_map(jobj->idx());
5075       if (base != nullptr) {
5076         const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
5077         ac->_src_type = base_t;
5078       }
5079     }
5080   }
5081 
5082   // New alias types were created in split_AddP().
5083   uint new_index_end = (uint) _compile->num_alias_types();
5084 
5085   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_1, 5);
5086 
5087   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
5088   //            compute new values for Memory inputs  (the Memory inputs are not
5089   //            actually updated until phase 4.)
5090   if (memnode_worklist.length() == 0)
5091     return;  // nothing to do
5092   while (memnode_worklist.length() != 0) {
5093     Node *n = memnode_worklist.pop();
5094     if (visited.test_set(n->_idx)) {
5095       continue;
5096     }
5097     if (n->is_Phi() || n->is_ClearArray()) {
5098       // we don't need to do anything, but the users must be pushed
5099     } else if (n->is_MemBar()) { // MemBar nodes
5100       if (!n->is_Initialize()) { // memory projections for Initialize pushed below (so we get to all their uses)
5101         // we don't need to do anything, but the users must be pushed
5102         n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
5103         if (n == nullptr) {
5104           continue;
5105         }
5106       }
5107     } else if (n->is_CallLeaf()) {
5108       // Runtime calls with narrow memory input (no MergeMem node)
5109       // get the memory projection
5110       n = n->as_Call()->proj_out_or_null(TypeFunc::Memory);
5111       if (n == nullptr) {
5112         continue;
5113       }
5114     } else if (n->Opcode() == Op_StrInflatedCopy) {
5115       // Check direct uses of StrInflatedCopy.
5116       // It is memory type Node - no special SCMemProj node.
5117     } else if (n->Opcode() == Op_StrCompressedCopy ||
5118                n->Opcode() == Op_EncodeISOArray) {
5119       // get the memory projection
5120       n = n->find_out_with(Op_SCMemProj);
5121       assert(n != nullptr && n->Opcode() == Op_SCMemProj, "memory projection required");
5122     } else if (n->is_CallLeaf() && n->as_CallLeaf()->_name != nullptr &&
5123                strcmp(n->as_CallLeaf()->_name, "store_unknown_inline") == 0) {
5124       n = n->as_CallLeaf()->proj_out(TypeFunc::Memory);
5125     } else if (n->is_Proj()) {
5126       assert(n->in(0)->is_Initialize(), "we only push memory projections for Initialize");
5127     } else {
5128 #ifdef ASSERT
5129       if (!n->is_Mem()) {
5130         n->dump();
5131       }
5132       assert(n->is_Mem(), "memory node required.");
5133 #endif
5134       Node *addr = n->in(MemNode::Address);
5135       const Type *addr_t = igvn->type(addr);
5136       if (addr_t == Type::TOP) {
5137         continue;
5138       }
5139       assert (addr_t->isa_ptr() != nullptr, "pointer type required.");
5140       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
5141       assert ((uint)alias_idx < new_index_end, "wrong alias index");
5142       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
5143       if (_compile->failing()) {
5144         return;
5145       }
5146       if (mem != n->in(MemNode::Memory)) {
5147         // We delay the memory edge update since we need old one in
5148         // MergeMem code below when instances memory slices are separated.
5149         set_map(n, mem);
5150       }
5151       if (n->is_Load()) {
5152         continue;  // don't push users
5153       } else if (n->is_LoadStore()) {
5154         // get the memory projection
5155         n = n->find_out_with(Op_SCMemProj);
5156         assert(n != nullptr && n->Opcode() == Op_SCMemProj, "memory projection required");
5157       }
5158     }
5159     // push user on appropriate worklist
5160     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5161       Node *use = n->fast_out(i);
5162       if (use->is_Phi() || use->is_ClearArray()) {
5163         memnode_worklist.append_if_missing(use);
5164       } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
5165         memnode_worklist.append_if_missing(use);
5166       } else if (use->is_MemBar() || use->is_CallLeaf()) {
5167         if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
5168           memnode_worklist.append_if_missing(use);
5169         }
5170       } else if (use->is_Proj()) {
5171         assert(n->is_Initialize(), "We only push projections of Initialize");
5172         if (use->as_Proj()->_con == TypeFunc::Memory) { // Ignore precedent edge
5173           memnode_worklist.append_if_missing(use);
5174         }
5175 #ifdef ASSERT
5176       } else if (use->is_Mem()) {
5177         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
5178       } else if (use->is_MergeMem()) {
5179         assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
5180       } else if (use->Opcode() == Op_EncodeISOArray) {
5181         if (use->in(MemNode::Memory) == n || use->in(3) == n) {
5182           // EncodeISOArray overwrites destination array
5183           memnode_worklist.append_if_missing(use);
5184         }
5185       } else if (use->is_CallLeaf() && use->as_CallLeaf()->_name != nullptr &&
5186                  strcmp(use->as_CallLeaf()->_name, "store_unknown_inline") == 0) {
5187         // store_unknown_inline overwrites destination array
5188         memnode_worklist.append_if_missing(use);
5189       } else {
5190         uint op = use->Opcode();
5191         if ((use->in(MemNode::Memory) == n) &&
5192             (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
5193           // They overwrite memory edge corresponding to destination array,
5194           memnode_worklist.append_if_missing(use);
5195         } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
5196               op == Op_AryEq || op == Op_StrComp || op == Op_CountPositives ||
5197               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy || op == Op_VectorizedHashCode ||
5198               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar || op == Op_FlatArrayCheck)) {
5199           n->dump();
5200           use->dump();
5201           assert(false, "EA: missing memory path");
5202         }
5203 #endif
5204       }
5205     }
5206   }
5207 
5208   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
5209   //            Walk each memory slice moving the first node encountered of each
5210   //            instance type to the input corresponding to its alias index.
5211   uint length = mergemem_worklist.length();
5212   for( uint next = 0; next < length; ++next ) {
5213     MergeMemNode* nmm = mergemem_worklist.at(next);
5214     assert(!visited.test_set(nmm->_idx), "should not be visited before");
5215     // Note: we don't want to use MergeMemStream here because we only want to
5216     // scan inputs which exist at the start, not ones we add during processing.
5217     // Note 2: MergeMem may already contains instance memory slices added
5218     // during find_inst_mem() call when memory nodes were processed above.
5219     igvn->hash_delete(nmm);
5220     uint nslices = MIN2(nmm->req(), new_index_start);
5221     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
5222       Node* mem = nmm->in(i);
5223       Node* cur = nullptr;
5224       if (mem == nullptr || mem->is_top()) {
5225         continue;
5226       }
5227       // First, update mergemem by moving memory nodes to corresponding slices
5228       // if their type became more precise since this mergemem was created.
5229       while (mem->is_Mem()) {
5230         const Type* at = igvn->type(mem->in(MemNode::Address));
5231         if (at != Type::TOP) {
5232           assert (at->isa_ptr() != nullptr, "pointer type required.");
5233           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
5234           if (idx == i) {
5235             if (cur == nullptr) {
5236               cur = mem;
5237             }
5238           } else {
5239             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
5240               nmm->set_memory_at(idx, mem);
5241             }
5242           }
5243         }
5244         mem = mem->in(MemNode::Memory);
5245       }
5246       nmm->set_memory_at(i, (cur != nullptr) ? cur : mem);
5247       // Find any instance of the current type if we haven't encountered
5248       // already a memory slice of the instance along the memory chain.
5249       for (uint ni = new_index_start; ni < new_index_end; ni++) {
5250         if((uint)_compile->get_general_index(ni) == i) {
5251           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
5252           if (nmm->is_empty_memory(m)) {
5253             Node* result = find_inst_mem(mem, ni, orig_phis);
5254             if (_compile->failing()) {
5255               return;
5256             }
5257             nmm->set_memory_at(ni, result);
5258           }
5259         }
5260       }
5261     }
5262     // Find the rest of instances values
5263     for (uint ni = new_index_start; ni < new_index_end; ni++) {
5264       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
5265       Node* result = step_through_mergemem(nmm, ni, tinst);
5266       if (result == nmm->base_memory()) {
5267         // Didn't find instance memory, search through general slice recursively.
5268         result = nmm->memory_at(_compile->get_general_index(ni));
5269         result = find_inst_mem(result, ni, orig_phis);
5270         if (_compile->failing()) {
5271           return;
5272         }
5273         nmm->set_memory_at(ni, result);
5274       }
5275     }
5276 
5277     // If we have crossed the 3/4 point of max node limit it's too risky
5278     // to continue with EA/SR because we might hit the max node limit.
5279     if (_compile->live_nodes() >= _compile->max_node_limit() * 0.75) {
5280       if (_compile->do_reduce_allocation_merges()) {
5281         _compile->record_failure(C2Compiler::retry_no_reduce_allocation_merges());
5282       } else if (_invocation > 0) {
5283         _compile->record_failure(C2Compiler::retry_no_iterative_escape_analysis());
5284       } else {
5285         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
5286       }
5287       return;
5288     }
5289 
5290     igvn->hash_insert(nmm);
5291     record_for_optimizer(nmm);
5292   }
5293 
5294   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_3, 5);
5295 
5296   //  Phase 4:  Update the inputs of non-instance memory Phis and
5297   //            the Memory input of memnodes
5298   // First update the inputs of any non-instance Phi's from
5299   // which we split out an instance Phi.  Note we don't have
5300   // to recursively process Phi's encountered on the input memory
5301   // chains as is done in split_memory_phi() since they will
5302   // also be processed here.
5303   for (int j = 0; j < orig_phis.length(); j++) {
5304     PhiNode *phi = orig_phis.at(j);
5305     int alias_idx = _compile->get_alias_index(phi->adr_type());
5306     igvn->hash_delete(phi);
5307     for (uint i = 1; i < phi->req(); i++) {
5308       Node *mem = phi->in(i);
5309       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
5310       if (_compile->failing()) {
5311         return;
5312       }
5313       if (mem != new_mem) {
5314         phi->set_req(i, new_mem);
5315       }
5316     }
5317     igvn->hash_insert(phi);
5318     record_for_optimizer(phi);
5319   }
5320 
5321   // Update the memory inputs of MemNodes with the value we computed
5322   // in Phase 2 and move stores memory users to corresponding memory slices.
5323   // Disable memory split verification code until the fix for 6984348.
5324   // Currently it produces false negative results since it does not cover all cases.
5325 #if 0 // ifdef ASSERT
5326   visited.Reset();
5327   Node_Stack old_mems(arena, _compile->unique() >> 2);
5328 #endif
5329   for (uint i = 0; i < ideal_nodes.size(); i++) {
5330     Node*    n = ideal_nodes.at(i);
5331     Node* nmem = get_map(n->_idx);
5332     assert(nmem != nullptr, "sanity");
5333     if (n->is_Mem()) {
5334 #if 0 // ifdef ASSERT
5335       Node* old_mem = n->in(MemNode::Memory);
5336       if (!visited.test_set(old_mem->_idx)) {
5337         old_mems.push(old_mem, old_mem->outcnt());
5338       }
5339 #endif
5340       assert(n->in(MemNode::Memory) != nmem, "sanity");
5341       if (!n->is_Load()) {
5342         // Move memory users of a store first.
5343         move_inst_mem(n, orig_phis);
5344       }
5345       // Now update memory input
5346       igvn->hash_delete(n);
5347       n->set_req(MemNode::Memory, nmem);
5348       igvn->hash_insert(n);
5349       record_for_optimizer(n);
5350     } else {
5351       assert(n->is_Allocate() || n->is_CheckCastPP() ||
5352              n->is_AddP() || n->is_Phi() || n->is_NarrowMemProj(), "unknown node used for set_map()");
5353     }
5354   }
5355 #if 0 // ifdef ASSERT
5356   // Verify that memory was split correctly
5357   while (old_mems.is_nonempty()) {
5358     Node* old_mem = old_mems.node();
5359     uint  old_cnt = old_mems.index();
5360     old_mems.pop();
5361     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
5362   }
5363 #endif
5364   _compile->print_method(PHASE_EA_AFTER_SPLIT_UNIQUE_TYPES_4, 5);
5365 }
5366 
5367 #ifndef PRODUCT
5368 int ConnectionGraph::_no_escape_counter = 0;
5369 int ConnectionGraph::_arg_escape_counter = 0;
5370 int ConnectionGraph::_global_escape_counter = 0;
5371 
5372 static const char *node_type_names[] = {
5373   "UnknownType",
5374   "JavaObject",
5375   "LocalVar",
5376   "Field",
5377   "Arraycopy"
5378 };
5379 
5380 static const char *esc_names[] = {
5381   "UnknownEscape",
5382   "NoEscape",
5383   "ArgEscape",
5384   "GlobalEscape"
5385 };
5386 
5387 const char* PointsToNode::esc_name() const {
5388   return esc_names[(int)escape_state()];
5389 }
5390 
5391 void PointsToNode::dump_header(bool print_state, outputStream* out) const {
5392   NodeType nt = node_type();
5393   out->print("%s(%d) ", node_type_names[(int) nt], _pidx);
5394   if (print_state) {
5395     EscapeState es = escape_state();
5396     EscapeState fields_es = fields_escape_state();
5397     out->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
5398     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable()) {
5399       out->print("NSR ");
5400     }
5401   }
5402 }
5403 
5404 void PointsToNode::dump(bool print_state, outputStream* out, bool newline) const {
5405   dump_header(print_state, out);
5406   if (is_Field()) {
5407     FieldNode* f = (FieldNode*)this;
5408     if (f->is_oop()) {
5409       out->print("oop ");
5410     }
5411     if (f->offset() > 0) {
5412       out->print("+%d ", f->offset());
5413     }
5414     out->print("(");
5415     for (BaseIterator i(f); i.has_next(); i.next()) {
5416       PointsToNode* b = i.get();
5417       out->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
5418     }
5419     out->print(" )");
5420   }
5421   out->print("[");
5422   for (EdgeIterator i(this); i.has_next(); i.next()) {
5423     PointsToNode* e = i.get();
5424     out->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
5425   }
5426   out->print(" [");
5427   for (UseIterator i(this); i.has_next(); i.next()) {
5428     PointsToNode* u = i.get();
5429     bool is_base = false;
5430     if (PointsToNode::is_base_use(u)) {
5431       is_base = true;
5432       u = PointsToNode::get_use_node(u)->as_Field();
5433     }
5434     out->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
5435   }
5436   out->print(" ]]  ");
5437   if (_node == nullptr) {
5438     out->print("<null>%s", newline ? "\n" : "");
5439   } else {
5440     _node->dump(newline ? "\n" : "", false, out);
5441   }
5442 }
5443 
5444 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
5445   bool first = true;
5446   int ptnodes_length = ptnodes_worklist.length();
5447   for (int i = 0; i < ptnodes_length; i++) {
5448     PointsToNode *ptn = ptnodes_worklist.at(i);
5449     if (ptn == nullptr || !ptn->is_JavaObject()) {
5450       continue;
5451     }
5452     PointsToNode::EscapeState es = ptn->escape_state();
5453     if ((es != PointsToNode::NoEscape) && !Verbose) {
5454       continue;
5455     }
5456     Node* n = ptn->ideal_node();
5457     if (n->is_Allocate() || (n->is_CallStaticJava() &&
5458                              n->as_CallStaticJava()->is_boxing_method())) {
5459       if (first) {
5460         tty->cr();
5461         tty->print("======== Connection graph for ");
5462         _compile->method()->print_short_name();
5463         tty->cr();
5464         tty->print_cr("invocation #%d: %d iterations and %f sec to build connection graph with %d nodes and worklist size %d",
5465                       _invocation, _build_iterations, _build_time, nodes_size(), ptnodes_worklist.length());
5466         tty->cr();
5467         first = false;
5468       }
5469       ptn->dump();
5470       // Print all locals and fields which reference this allocation
5471       for (UseIterator j(ptn); j.has_next(); j.next()) {
5472         PointsToNode* use = j.get();
5473         if (use->is_LocalVar()) {
5474           use->dump(Verbose);
5475         } else if (Verbose) {
5476           use->dump();
5477         }
5478       }
5479       tty->cr();
5480     }
5481   }
5482 }
5483 
5484 void ConnectionGraph::print_statistics() {
5485   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));
5486 }
5487 
5488 void ConnectionGraph::escape_state_statistics(GrowableArray<JavaObjectNode*>& java_objects_worklist) {
5489   if (!PrintOptoStatistics || (_invocation > 0)) { // Collect data only for the first invocation
5490     return;
5491   }
5492   for (int next = 0; next < java_objects_worklist.length(); ++next) {
5493     JavaObjectNode* ptn = java_objects_worklist.at(next);
5494     if (ptn->ideal_node()->is_Allocate()) {
5495       if (ptn->escape_state() == PointsToNode::NoEscape) {
5496         AtomicAccess::inc(&ConnectionGraph::_no_escape_counter);
5497       } else if (ptn->escape_state() == PointsToNode::ArgEscape) {
5498         AtomicAccess::inc(&ConnectionGraph::_arg_escape_counter);
5499       } else if (ptn->escape_state() == PointsToNode::GlobalEscape) {
5500         AtomicAccess::inc(&ConnectionGraph::_global_escape_counter);
5501       } else {
5502         assert(false, "Unexpected Escape State");
5503       }
5504     }
5505   }
5506 }
5507 
5508 void ConnectionGraph::trace_es_update_helper(PointsToNode* ptn, PointsToNode::EscapeState es, bool fields, const char* reason) const {
5509   if (_compile->directive()->TraceEscapeAnalysisOption) {
5510     assert(ptn != nullptr, "should not be null");
5511     assert(reason != nullptr, "should not be null");
5512     ptn->dump_header(true);
5513     PointsToNode::EscapeState new_es = fields ? ptn->escape_state() : es;
5514     PointsToNode::EscapeState new_fields_es = fields ? es : ptn->fields_escape_state();
5515     tty->print_cr("-> %s(%s) %s", esc_names[(int)new_es], esc_names[(int)new_fields_es], reason);
5516   }
5517 }
5518 
5519 const char* ConnectionGraph::trace_propagate_message(PointsToNode* from) const {
5520   if (_compile->directive()->TraceEscapeAnalysisOption) {
5521     stringStream ss;
5522     ss.print("propagated from: ");
5523     from->dump(true, &ss, false);
5524     return ss.as_string();
5525   } else {
5526     return nullptr;
5527   }
5528 }
5529 
5530 const char* ConnectionGraph::trace_arg_escape_message(CallNode* call) const {
5531   if (_compile->directive()->TraceEscapeAnalysisOption) {
5532     stringStream ss;
5533     ss.print("escapes as arg to:");
5534     call->dump("", false, &ss);
5535     return ss.as_string();
5536   } else {
5537     return nullptr;
5538   }
5539 }
5540 
5541 const char* ConnectionGraph::trace_merged_message(PointsToNode* other) const {
5542   if (_compile->directive()->TraceEscapeAnalysisOption) {
5543     stringStream ss;
5544     ss.print("is merged with other object: ");
5545     other->dump_header(true, &ss);
5546     return ss.as_string();
5547   } else {
5548     return nullptr;
5549   }
5550 }
5551 
5552 #endif
5553 
5554 void ConnectionGraph::record_for_optimizer(Node *n) {
5555   _igvn->_worklist.push(n);
5556   _igvn->add_users_to_worklist(n);
5557 }
--- EOF ---