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src/hotspot/share/opto/compile.cpp

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  40 #include "gc/shared/barrierSet.hpp"
  41 #include "gc/shared/c2/barrierSetC2.hpp"
  42 #include "jfr/jfrEvents.hpp"
  43 #include "jvm_io.h"
  44 #include "memory/allocation.hpp"
  45 #include "memory/resourceArea.hpp"
  46 #include "opto/addnode.hpp"
  47 #include "opto/block.hpp"
  48 #include "opto/c2compiler.hpp"
  49 #include "opto/callGenerator.hpp"
  50 #include "opto/callnode.hpp"
  51 #include "opto/castnode.hpp"
  52 #include "opto/cfgnode.hpp"
  53 #include "opto/chaitin.hpp"
  54 #include "opto/compile.hpp"
  55 #include "opto/connode.hpp"
  56 #include "opto/convertnode.hpp"
  57 #include "opto/divnode.hpp"
  58 #include "opto/escape.hpp"
  59 #include "opto/idealGraphPrinter.hpp"

  60 #include "opto/locknode.hpp"
  61 #include "opto/loopnode.hpp"
  62 #include "opto/machnode.hpp"
  63 #include "opto/macro.hpp"
  64 #include "opto/matcher.hpp"
  65 #include "opto/mathexactnode.hpp"
  66 #include "opto/memnode.hpp"
  67 #include "opto/mulnode.hpp"
  68 #include "opto/narrowptrnode.hpp"
  69 #include "opto/node.hpp"
  70 #include "opto/opcodes.hpp"
  71 #include "opto/output.hpp"
  72 #include "opto/parse.hpp"
  73 #include "opto/phaseX.hpp"
  74 #include "opto/rootnode.hpp"
  75 #include "opto/runtime.hpp"
  76 #include "opto/stringopts.hpp"
  77 #include "opto/type.hpp"
  78 #include "opto/vector.hpp"
  79 #include "opto/vectornode.hpp"

 385   // as dead to be conservative about the dead node count at any
 386   // given time.
 387   if (!dead->is_Con()) {
 388     record_dead_node(dead->_idx);
 389   }
 390   if (dead->is_macro()) {
 391     remove_macro_node(dead);
 392   }
 393   if (dead->is_expensive()) {
 394     remove_expensive_node(dead);
 395   }
 396   if (dead->is_OpaqueTemplateAssertionPredicate()) {
 397     remove_template_assertion_predicate_opaq(dead);
 398   }
 399   if (dead->is_ParsePredicate()) {
 400     remove_parse_predicate(dead->as_ParsePredicate());
 401   }
 402   if (dead->for_post_loop_opts_igvn()) {
 403     remove_from_post_loop_opts_igvn(dead);
 404   }



 405   if (dead->is_Call()) {
 406     remove_useless_late_inlines(                &_late_inlines, dead);
 407     remove_useless_late_inlines(         &_string_late_inlines, dead);
 408     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 409     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 410 
 411     if (dead->is_CallStaticJava()) {
 412       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 413     }
 414   }
 415   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 416   bs->unregister_potential_barrier_node(dead);
 417 }
 418 
 419 // Disconnect all useless nodes by disconnecting those at the boundary.
 420 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist) {
 421   uint next = 0;
 422   while (next < useful.size()) {
 423     Node *n = useful.at(next++);
 424     if (n->is_SafePoint()) {

 426       // beyond that point.
 427       n->as_SafePoint()->delete_replaced_nodes();
 428     }
 429     // Use raw traversal of out edges since this code removes out edges
 430     int max = n->outcnt();
 431     for (int j = 0; j < max; ++j) {
 432       Node* child = n->raw_out(j);
 433       if (!useful.member(child)) {
 434         assert(!child->is_top() || child != top(),
 435                "If top is cached in Compile object it is in useful list");
 436         // Only need to remove this out-edge to the useless node
 437         n->raw_del_out(j);
 438         --j;
 439         --max;
 440       }
 441     }
 442     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 443       assert(useful.member(n->unique_out()), "do not push a useless node");
 444       worklist.push(n->unique_out());
 445     }



 446   }
 447 
 448   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 449   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 450   remove_useless_nodes(_template_assertion_predicate_opaqs, useful); // remove useless Assertion Predicate opaque nodes
 451   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 452   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass






 453   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 454   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 455 #ifdef ASSERT
 456   if (_modified_nodes != nullptr) {
 457     _modified_nodes->remove_useless_nodes(useful.member_set());
 458   }
 459 #endif
 460 
 461   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 462   bs->eliminate_useless_gc_barriers(useful, this);
 463   // clean up the late inline lists
 464   remove_useless_late_inlines(                &_late_inlines, useful);
 465   remove_useless_late_inlines(         &_string_late_inlines, useful);
 466   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 467   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 468   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 469 }
 470 
 471 // ============================================================================
 472 //------------------------------CompileWrapper---------------------------------

 612 
 613 
 614 Compile::Compile( ciEnv* ci_env, ciMethod* target, int osr_bci,
 615                   Options options, DirectiveSet* directive)
 616                 : Phase(Compiler),
 617                   _compile_id(ci_env->compile_id()),
 618                   _options(options),
 619                   _method(target),
 620                   _entry_bci(osr_bci),
 621                   _ilt(nullptr),
 622                   _stub_function(nullptr),
 623                   _stub_name(nullptr),
 624                   _stub_entry_point(nullptr),
 625                   _max_node_limit(MaxNodeLimit),
 626                   _post_loop_opts_phase(false),
 627                   _allow_macro_nodes(true),
 628                   _inlining_progress(false),
 629                   _inlining_incrementally(false),
 630                   _do_cleanup(false),
 631                   _has_reserved_stack_access(target->has_reserved_stack_access()),

 632 #ifndef PRODUCT
 633                   _igv_idx(0),
 634                   _trace_opto_output(directive->TraceOptoOutputOption),
 635 #endif
 636                   _has_method_handle_invokes(false),
 637                   _clinit_barrier_on_entry(false),
 638                   _stress_seed(0),
 639                   _comp_arena(mtCompiler),
 640                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 641                   _env(ci_env),
 642                   _directive(directive),
 643                   _log(ci_env->log()),
 644                   _first_failure_details(nullptr),
 645                   _intrinsics        (comp_arena(), 0, 0, nullptr),
 646                   _macro_nodes       (comp_arena(), 8, 0, nullptr),
 647                   _parse_predicates  (comp_arena(), 8, 0, nullptr),
 648                   _template_assertion_predicate_opaqs (comp_arena(), 8, 0, nullptr),
 649                   _expensive_nodes   (comp_arena(), 8, 0, nullptr),
 650                   _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),

 651                   _unstable_if_traps (comp_arena(), 8, 0, nullptr),
 652                   _coarsened_locks   (comp_arena(), 8, 0, nullptr),
 653                   _congraph(nullptr),
 654                   NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 655                   _unique(0),
 656                   _dead_node_count(0),
 657                   _dead_node_list(comp_arena()),
 658                   _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 659                   _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 660                   _node_arena(&_node_arena_one),
 661                   _mach_constant_base_node(nullptr),
 662                   _Compile_types(mtCompiler),
 663                   _initial_gvn(nullptr),
 664                   _igvn_worklist(nullptr),
 665                   _types(nullptr),
 666                   _node_hash(nullptr),
 667                   _late_inlines(comp_arena(), 2, 0, nullptr),
 668                   _string_late_inlines(comp_arena(), 2, 0, nullptr),
 669                   _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 670                   _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),

 737 
 738   // GVN that will be run immediately on new nodes
 739   uint estimated_size = method()->code_size()*4+64;
 740   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 741   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 742   _types = new (comp_arena()) Type_Array(comp_arena());
 743   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 744   PhaseGVN gvn;
 745   set_initial_gvn(&gvn);
 746 
 747   print_inlining_init();
 748   { // Scope for timing the parser
 749     TracePhase tp("parse", &timers[_t_parser]);
 750 
 751     // Put top into the hash table ASAP.
 752     initial_gvn()->transform(top());
 753 
 754     // Set up tf(), start(), and find a CallGenerator.
 755     CallGenerator* cg = nullptr;
 756     if (is_osr_compilation()) {
 757       const TypeTuple *domain = StartOSRNode::osr_domain();
 758       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 759       init_tf(TypeFunc::make(domain, range));
 760       StartNode* s = new StartOSRNode(root(), domain);
 761       initial_gvn()->set_type_bottom(s);
 762       verify_start(s);
 763       cg = CallGenerator::for_osr(method(), entry_bci());
 764     } else {
 765       // Normal case.
 766       init_tf(TypeFunc::make(method()));
 767       StartNode* s = new StartNode(root(), tf()->domain());
 768       initial_gvn()->set_type_bottom(s);
 769       verify_start(s);
 770       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 771         // With java.lang.ref.reference.get() we must go through the
 772         // intrinsic - even when get() is the root
 773         // method of the compile - so that, if necessary, the value in
 774         // the referent field of the reference object gets recorded by
 775         // the pre-barrier code.
 776         cg = find_intrinsic(method(), false);
 777       }
 778       if (cg == nullptr) {
 779         float past_uses = method()->interpreter_invocation_count();
 780         float expected_uses = past_uses;
 781         cg = CallGenerator::for_inline(method(), expected_uses);
 782       }
 783     }
 784     if (failing())  return;
 785     if (cg == nullptr) {
 786       const char* reason = InlineTree::check_can_parse(method());
 787       assert(reason != nullptr, "expect reason for parse failure");

 858     print_ideal_ir("print_ideal");
 859   }
 860 #endif
 861 
 862 #ifdef ASSERT
 863   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 864   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 865 #endif
 866 
 867   // Dump compilation data to replay it.
 868   if (directive->DumpReplayOption) {
 869     env()->dump_replay_data(_compile_id);
 870   }
 871   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 872     env()->dump_inline_data(_compile_id);
 873   }
 874 
 875   // Now that we know the size of all the monitors we can add a fixed slot
 876   // for the original deopt pc.
 877   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);










 878   set_fixed_slots(next_slot);
 879 
 880   // Compute when to use implicit null checks. Used by matching trap based
 881   // nodes and NullCheck optimization.
 882   set_allowed_deopt_reasons();
 883 
 884   // Now generate code
 885   Code_Gen();
 886 }
 887 
 888 //------------------------------Compile----------------------------------------
 889 // Compile a runtime stub
 890 Compile::Compile( ciEnv* ci_env,
 891                   TypeFunc_generator generator,
 892                   address stub_function,
 893                   const char *stub_name,
 894                   int is_fancy_jump,
 895                   bool pass_tls,
 896                   bool return_pc,
 897                   DirectiveSet* directive)
 898   : Phase(Compiler),
 899     _compile_id(0),
 900     _options(Options::for_runtime_stub()),
 901     _method(nullptr),
 902     _entry_bci(InvocationEntryBci),
 903     _stub_function(stub_function),
 904     _stub_name(stub_name),
 905     _stub_entry_point(nullptr),
 906     _max_node_limit(MaxNodeLimit),
 907     _post_loop_opts_phase(false),
 908     _allow_macro_nodes(true),
 909     _inlining_progress(false),
 910     _inlining_incrementally(false),
 911     _has_reserved_stack_access(false),

 912 #ifndef PRODUCT
 913     _igv_idx(0),
 914     _trace_opto_output(directive->TraceOptoOutputOption),
 915 #endif
 916     _has_method_handle_invokes(false),
 917     _clinit_barrier_on_entry(false),
 918     _stress_seed(0),
 919     _comp_arena(mtCompiler),
 920     _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 921     _env(ci_env),
 922     _directive(directive),
 923     _log(ci_env->log()),
 924     _first_failure_details(nullptr),
 925     _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 926     _congraph(nullptr),
 927     NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 928     _unique(0),
 929     _dead_node_count(0),
 930     _dead_node_list(comp_arena()),
 931     _node_arena_one(mtCompiler),

1038 
1039   _fixed_slots = 0;
1040   set_has_split_ifs(false);
1041   set_has_loops(false); // first approximation
1042   set_has_stringbuilder(false);
1043   set_has_boxed_value(false);
1044   _trap_can_recompile = false;  // no traps emitted yet
1045   _major_progress = true; // start out assuming good things will happen
1046   set_has_unsafe_access(false);
1047   set_max_vector_size(0);
1048   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1049   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1050   set_decompile_count(0);
1051 
1052 #ifndef PRODUCT
1053   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1054 #endif
1055 
1056   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1057   _loop_opts_cnt = LoopOptsCount;




1058   set_do_inlining(Inline);
1059   set_max_inline_size(MaxInlineSize);
1060   set_freq_inline_size(FreqInlineSize);
1061   set_do_scheduling(OptoScheduling);
1062 
1063   set_do_vector_loop(false);
1064   set_has_monitors(false);
1065   set_has_scoped_access(false);
1066 
1067   if (AllowVectorizeOnDemand) {
1068     if (has_method() && _directive->VectorizeOption) {
1069       set_do_vector_loop(true);
1070       NOT_PRODUCT(if (do_vector_loop() && Verbose) {tty->print("Compile::Init: do vectorized loops (SIMD like) for method %s\n",  method()->name()->as_quoted_ascii());})
1071     } else if (has_method() && method()->name() != nullptr &&
1072                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1073       set_do_vector_loop(true);
1074     }
1075   }
1076   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1077   NOT_PRODUCT(if (use_cmove() && Verbose && has_method()) {tty->print("Compile::Init: use CMove without profitability tests for method %s\n",  method()->name()->as_quoted_ascii());})

1309   // If this method has already thrown a range-check,
1310   // assume it was because we already tried range smearing
1311   // and it failed.
1312   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1313   return !already_trapped;
1314 }
1315 
1316 
1317 //------------------------------flatten_alias_type-----------------------------
1318 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1319   assert(do_aliasing(), "Aliasing should be enabled");
1320   int offset = tj->offset();
1321   TypePtr::PTR ptr = tj->ptr();
1322 
1323   // Known instance (scalarizable allocation) alias only with itself.
1324   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1325                        tj->is_oopptr()->is_known_instance();
1326 
1327   // Process weird unsafe references.
1328   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1329     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");

1330     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1331     tj = TypeOopPtr::BOTTOM;
1332     ptr = tj->ptr();
1333     offset = tj->offset();
1334   }
1335 
1336   // Array pointers need some flattening
1337   const TypeAryPtr* ta = tj->isa_aryptr();
1338   if (ta && ta->is_stable()) {
1339     // Erase stability property for alias analysis.
1340     tj = ta = ta->cast_to_stable(false);
1341   }









1342   if( ta && is_known_inst ) {
1343     if ( offset != Type::OffsetBot &&
1344          offset > arrayOopDesc::length_offset_in_bytes() ) {
1345       offset = Type::OffsetBot; // Flatten constant access into array body only
1346       tj = ta = ta->
1347               remove_speculative()->
1348               cast_to_ptr_type(ptr)->
1349               with_offset(offset);
1350     }
1351   } else if (ta) {
1352     // For arrays indexed by constant indices, we flatten the alias
1353     // space to include all of the array body.  Only the header, klass
1354     // and array length can be accessed un-aliased.


1355     if( offset != Type::OffsetBot ) {
1356       if( ta->const_oop() ) { // MethodData* or Method*
1357         offset = Type::OffsetBot;   // Flatten constant access into array body
1358         tj = ta = ta->
1359                 remove_speculative()->
1360                 cast_to_ptr_type(ptr)->
1361                 cast_to_exactness(false)->
1362                 with_offset(offset);
1363       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1364         // range is OK as-is.
1365         tj = ta = TypeAryPtr::RANGE;
1366       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1367         tj = TypeInstPtr::KLASS; // all klass loads look alike
1368         ta = TypeAryPtr::RANGE; // generic ignored junk
1369         ptr = TypePtr::BotPTR;
1370       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1371         tj = TypeInstPtr::MARK;
1372         ta = TypeAryPtr::RANGE; // generic ignored junk
1373         ptr = TypePtr::BotPTR;
1374       } else {                  // Random constant offset into array body
1375         offset = Type::OffsetBot;   // Flatten constant access into array body
1376         tj = ta = ta->
1377                 remove_speculative()->
1378                 cast_to_ptr_type(ptr)->
1379                 cast_to_exactness(false)->
1380                 with_offset(offset);
1381       }
1382     }
1383     // Arrays of fixed size alias with arrays of unknown size.
1384     if (ta->size() != TypeInt::POS) {
1385       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1386       tj = ta = ta->
1387               remove_speculative()->
1388               cast_to_ptr_type(ptr)->
1389               with_ary(tary)->
1390               cast_to_exactness(false);
1391     }
1392     // Arrays of known objects become arrays of unknown objects.
1393     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1394       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1395       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1396     }
1397     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1398       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1399       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);





1400     }
1401     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1402     // cannot be distinguished by bytecode alone.
1403     if (ta->elem() == TypeInt::BOOL) {
1404       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1405       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1406       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1407     }
1408     // During the 2nd round of IterGVN, NotNull castings are removed.
1409     // Make sure the Bottom and NotNull variants alias the same.
1410     // Also, make sure exact and non-exact variants alias the same.
1411     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != nullptr) {
1412       tj = ta = ta->
1413               remove_speculative()->
1414               cast_to_ptr_type(TypePtr::BotPTR)->
1415               cast_to_exactness(false)->
1416               with_offset(offset);
1417     }
1418   }
1419 
1420   // Oop pointers need some flattening
1421   const TypeInstPtr *to = tj->isa_instptr();
1422   if (to && to != TypeOopPtr::BOTTOM) {
1423     ciInstanceKlass* ik = to->instance_klass();
1424     if( ptr == TypePtr::Constant ) {
1425       if (ik != ciEnv::current()->Class_klass() ||
1426           offset < ik->layout_helper_size_in_bytes()) {

1436     } else if( is_known_inst ) {
1437       tj = to; // Keep NotNull and klass_is_exact for instance type
1438     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1439       // During the 2nd round of IterGVN, NotNull castings are removed.
1440       // Make sure the Bottom and NotNull variants alias the same.
1441       // Also, make sure exact and non-exact variants alias the same.
1442       tj = to = to->
1443               remove_speculative()->
1444               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1445               cast_to_ptr_type(TypePtr::BotPTR)->
1446               cast_to_exactness(false);
1447     }
1448     if (to->speculative() != nullptr) {
1449       tj = to = to->remove_speculative();
1450     }
1451     // Canonicalize the holder of this field
1452     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1453       // First handle header references such as a LoadKlassNode, even if the
1454       // object's klass is unloaded at compile time (4965979).
1455       if (!is_known_inst) { // Do it only for non-instance types
1456         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1457       }
1458     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1459       // Static fields are in the space above the normal instance
1460       // fields in the java.lang.Class instance.
1461       if (ik != ciEnv::current()->Class_klass()) {
1462         to = nullptr;
1463         tj = TypeOopPtr::BOTTOM;
1464         offset = tj->offset();
1465       }
1466     } else {
1467       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1468       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1469       assert(tj->offset() == offset, "no change to offset expected");
1470       bool xk = to->klass_is_exact();
1471       int instance_id = to->instance_id();
1472 
1473       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1474       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1475       // its interfaces are included.
1476       if (xk && ik->equals(canonical_holder)) {
1477         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id), "exact type should be canonical type");
1478       } else {
1479         assert(xk || !is_known_inst, "Known instance should be exact type");
1480         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id);
1481       }
1482     }
1483   }
1484 
1485   // Klass pointers to object array klasses need some flattening
1486   const TypeKlassPtr *tk = tj->isa_klassptr();
1487   if( tk ) {
1488     // If we are referencing a field within a Klass, we need
1489     // to assume the worst case of an Object.  Both exact and
1490     // inexact types must flatten to the same alias class so
1491     // use NotNull as the PTR.
1492     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1493       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1494                                        env()->Object_klass(),
1495                                        offset);
1496     }
1497 
1498     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1499       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1500       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1501         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1502       } else {
1503         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1504       }
1505     }
1506 
1507     // Check for precise loads from the primary supertype array and force them
1508     // to the supertype cache alias index.  Check for generic array loads from
1509     // the primary supertype array and also force them to the supertype cache
1510     // alias index.  Since the same load can reach both, we need to merge
1511     // these 2 disparate memories into the same alias class.  Since the
1512     // primary supertype array is read-only, there's no chance of confusion
1513     // where we bypass an array load and an array store.
1514     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1515     if (offset == Type::OffsetBot ||
1516         (offset >= primary_supers_offset &&
1517          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1518         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1519       offset = in_bytes(Klass::secondary_super_cache_offset());
1520       tj = tk = tk->with_offset(offset);
1521     }
1522   }
1523 
1524   // Flatten all Raw pointers together.
1525   if (tj->base() == Type::RawPtr)
1526     tj = TypeRawPtr::BOTTOM;

1616   intptr_t key = (intptr_t) adr_type;
1617   key ^= key >> logAliasCacheSize;
1618   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1619 }
1620 
1621 
1622 //-----------------------------grow_alias_types--------------------------------
1623 void Compile::grow_alias_types() {
1624   const int old_ats  = _max_alias_types; // how many before?
1625   const int new_ats  = old_ats;          // how many more?
1626   const int grow_ats = old_ats+new_ats;  // how many now?
1627   _max_alias_types = grow_ats;
1628   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1629   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1630   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1631   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1632 }
1633 
1634 
1635 //--------------------------------find_alias_type------------------------------
1636 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1637   if (!do_aliasing()) {
1638     return alias_type(AliasIdxBot);
1639   }
1640 
1641   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1642   if (ace->_adr_type == adr_type) {
1643     return alias_type(ace->_index);



1644   }
1645 
1646   // Handle special cases.
1647   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1648   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1649 
1650   // Do it the slow way.
1651   const TypePtr* flat = flatten_alias_type(adr_type);
1652 
1653 #ifdef ASSERT
1654   {
1655     ResourceMark rm;
1656     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1657            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1658     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1659            Type::str(adr_type));
1660     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1661       const TypeOopPtr* foop = flat->is_oopptr();
1662       // Scalarizable allocations have exact klass always.
1663       bool exact = !foop->klass_is_exact() || foop->is_known_instance();

1673     if (alias_type(i)->adr_type() == flat) {
1674       idx = i;
1675       break;
1676     }
1677   }
1678 
1679   if (idx == AliasIdxTop) {
1680     if (no_create)  return nullptr;
1681     // Grow the array if necessary.
1682     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1683     // Add a new alias type.
1684     idx = _num_alias_types++;
1685     _alias_types[idx]->Init(idx, flat);
1686     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1687     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1688     if (flat->isa_instptr()) {
1689       if (flat->offset() == java_lang_Class::klass_offset()
1690           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1691         alias_type(idx)->set_rewritable(false);
1692     }

1693     if (flat->isa_aryptr()) {
1694 #ifdef ASSERT
1695       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1696       // (T_BYTE has the weakest alignment and size restrictions...)
1697       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1698 #endif

1699       if (flat->offset() == TypePtr::OffsetBot) {
1700         alias_type(idx)->set_element(flat->is_aryptr()->elem());







1701       }
1702     }
1703     if (flat->isa_klassptr()) {
1704       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1705         alias_type(idx)->set_rewritable(false);
1706       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1707         alias_type(idx)->set_rewritable(false);
1708       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1709         alias_type(idx)->set_rewritable(false);
1710       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1711         alias_type(idx)->set_rewritable(false);
1712       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1713         alias_type(idx)->set_rewritable(false);


1714       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1715         alias_type(idx)->set_rewritable(false);
1716     }
1717     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1718     // but the base pointer type is not distinctive enough to identify
1719     // references into JavaThread.)
1720 
1721     // Check for final fields.
1722     const TypeInstPtr* tinst = flat->isa_instptr();
1723     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1724       ciField* field;
1725       if (tinst->const_oop() != nullptr &&
1726           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1727           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1728         // static field
1729         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1730         field = k->get_field_by_offset(tinst->offset(), true);




1731       } else {
1732         ciInstanceKlass *k = tinst->instance_klass();
1733         field = k->get_field_by_offset(tinst->offset(), false);
1734       }
1735       assert(field == nullptr ||
1736              original_field == nullptr ||
1737              (field->holder() == original_field->holder() &&
1738               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1739               field->is_static() == original_field->is_static()), "wrong field?");
1740       // Set field() and is_rewritable() attributes.
1741       if (field != nullptr)  alias_type(idx)->set_field(field);







1742     }
1743   }
1744 
1745   // Fill the cache for next time.
1746   ace->_adr_type = adr_type;
1747   ace->_index    = idx;
1748   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");

1749 
1750   // Might as well try to fill the cache for the flattened version, too.
1751   AliasCacheEntry* face = probe_alias_cache(flat);
1752   if (face->_adr_type == nullptr) {
1753     face->_adr_type = flat;
1754     face->_index    = idx;
1755     assert(alias_type(flat) == alias_type(idx), "flat type must work too");

1756   }
1757 
1758   return alias_type(idx);
1759 }
1760 
1761 
1762 Compile::AliasType* Compile::alias_type(ciField* field) {
1763   const TypeOopPtr* t;
1764   if (field->is_static())
1765     t = TypeInstPtr::make(field->holder()->java_mirror());
1766   else
1767     t = TypeOopPtr::make_from_klass_raw(field->holder());
1768   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1769   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1770   return atp;
1771 }
1772 
1773 
1774 //------------------------------have_alias_type--------------------------------
1775 bool Compile::have_alias_type(const TypePtr* adr_type) {

1855   assert(!C->major_progress(), "not cleared");
1856 
1857   if (_for_post_loop_igvn.length() > 0) {
1858     while (_for_post_loop_igvn.length() > 0) {
1859       Node* n = _for_post_loop_igvn.pop();
1860       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1861       igvn._worklist.push(n);
1862     }
1863     igvn.optimize();
1864     if (failing()) return;
1865     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1866     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1867 
1868     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1869     if (C->major_progress()) {
1870       C->clear_major_progress(); // ensure that major progress is now clear
1871     }
1872   }
1873 }
1874 














































































































































































































































































































































































































1875 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1876   if (OptimizeUnstableIf) {
1877     _unstable_if_traps.append(trap);
1878   }
1879 }
1880 
1881 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1882   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1883     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1884     Node* n = trap->uncommon_trap();
1885     if (!useful.member(n)) {
1886       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1887     }
1888   }
1889 }
1890 
1891 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1892 // or fold-compares case. Return true if succeed or not found.
1893 //
1894 // In rare cases, the found trap has been processed. It is too late to delete it. Return

1930       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1931       Bytecodes::Code c = iter.cur_bc();
1932       Node* lhs = nullptr;
1933       Node* rhs = nullptr;
1934       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
1935         lhs = unc->peek_operand(0);
1936         rhs = unc->peek_operand(1);
1937       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
1938         lhs = unc->peek_operand(0);
1939       }
1940 
1941       ResourceMark rm;
1942       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
1943       assert(live_locals.is_valid(), "broken liveness info");
1944       int len = (int)live_locals.size();
1945 
1946       for (int i = 0; i < len; i++) {
1947         Node* local = unc->local(jvms, i);
1948         // kill local using the liveness of next_bci.
1949         // give up when the local looks like an operand to secure reexecution.
1950         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
1951           uint idx = jvms->locoff() + i;
1952 #ifdef ASSERT
1953           if (PrintOpto && Verbose) {
1954             tty->print("[unstable_if] kill local#%d: ", idx);
1955             local->dump();
1956             tty->cr();
1957           }
1958 #endif
1959           igvn.replace_input_of(unc, idx, top());
1960           modified = true;
1961         }
1962       }
1963     }
1964 
1965     // keep the mondified trap for late query
1966     if (modified) {
1967       trap->set_modified();
1968     } else {
1969       _unstable_if_traps.delete_at(i);
1970     }
1971   }
1972   igvn.optimize();
1973 }
1974 
1975 // StringOpts and late inlining of string methods
1976 void Compile::inline_string_calls(bool parse_time) {
1977   {
1978     // remove useless nodes to make the usage analysis simpler
1979     ResourceMark rm;
1980     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
1981   }
1982 
1983   {
1984     ResourceMark rm;
1985     print_method(PHASE_BEFORE_STRINGOPTS, 3);

2140 
2141   if (_string_late_inlines.length() > 0) {
2142     assert(has_stringbuilder(), "inconsistent");
2143 
2144     inline_string_calls(false);
2145 
2146     if (failing())  return;
2147 
2148     inline_incrementally_cleanup(igvn);
2149   }
2150 
2151   set_inlining_incrementally(false);
2152 }
2153 
2154 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2155   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2156   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2157   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2158   // as if "inlining_incrementally() == true" were set.
2159   assert(inlining_incrementally() == false, "not allowed");
2160   assert(_modified_nodes == nullptr, "not allowed");



2161   assert(_late_inlines.length() > 0, "sanity");
2162 
2163   while (_late_inlines.length() > 0) {
2164     igvn_worklist()->ensure_empty(); // should be done with igvn
2165 
2166     while (inline_incrementally_one()) {
2167       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2168     }
2169     if (failing())  return;
2170 
2171     inline_incrementally_cleanup(igvn);
2172   }

2173 }
2174 
2175 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2176   if (_loop_opts_cnt > 0) {
2177     while (major_progress() && (_loop_opts_cnt > 0)) {
2178       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2179       PhaseIdealLoop::optimize(igvn, mode);
2180       _loop_opts_cnt--;
2181       if (failing())  return false;
2182       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2183     }
2184   }
2185   return true;
2186 }
2187 
2188 // Remove edges from "root" to each SafePoint at a backward branch.
2189 // They were inserted during parsing (see add_safepoint()) to make
2190 // infinite loops without calls or exceptions visible to root, i.e.,
2191 // useful.
2192 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {

2299     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2300   }
2301   assert(!has_vbox_nodes(), "sanity");
2302 
2303   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2304     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2305     igvn_worklist()->ensure_empty(); // should be done with igvn
2306     {
2307       ResourceMark rm;
2308       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2309     }
2310     igvn.reset_from_gvn(initial_gvn());
2311     igvn.optimize();
2312     if (failing()) return;
2313   }
2314 
2315   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2316   // safepoints
2317   remove_root_to_sfpts_edges(igvn);
2318 





2319   if (failing())  return;
2320 
2321   // Perform escape analysis
2322   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2323     if (has_loops()) {
2324       // Cleanup graph (remove dead nodes).
2325       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2326       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2327       if (failing())  return;
2328     }
2329     bool progress;
2330     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2331     do {
2332       ConnectionGraph::do_analysis(this, &igvn);
2333 
2334       if (failing())  return;
2335 
2336       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2337 
2338       // Optimize out fields loads from scalar replaceable allocations.

2422   if (failing())  return;
2423 
2424   // Loop transforms on the ideal graph.  Range Check Elimination,
2425   // peeling, unrolling, etc.
2426   if (!optimize_loops(igvn, LoopOptsDefault)) {
2427     return;
2428   }
2429 
2430   if (failing())  return;
2431 
2432   C->clear_major_progress(); // ensure that major progress is now clear
2433 
2434   process_for_post_loop_opts_igvn(igvn);
2435 
2436   if (failing())  return;
2437 
2438 #ifdef ASSERT
2439   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2440 #endif
2441 








2442   {
2443     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2444     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2445     PhaseMacroExpand  mex(igvn);
2446     if (mex.expand_macro_nodes()) {
2447       assert(failing(), "must bail out w/ explicit message");
2448       return;
2449     }
2450     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2451   }
2452 




2453   {
2454     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2455     if (bs->expand_barriers(this, igvn)) {
2456       assert(failing(), "must bail out w/ explicit message");
2457       return;
2458     }
2459     print_method(PHASE_BARRIER_EXPANSION, 2);
2460   }
2461 
2462   if (C->max_vector_size() > 0) {
2463     C->optimize_logic_cones(igvn);
2464     igvn.optimize();
2465     if (failing()) return;
2466   }
2467 
2468   DEBUG_ONLY( _modified_nodes = nullptr; )

2469 
2470   assert(igvn._worklist.size() == 0, "not empty");
2471 
2472   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2473 
2474   if (_late_inlines.length() > 0) {
2475     // More opportunities to optimize virtual and MH calls.
2476     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2477     process_late_inline_calls_no_inline(igvn);
2478     if (failing())  return;
2479   }
2480  } // (End scope of igvn; run destructor if necessary for asserts.)
2481 
2482  check_no_dead_use();
2483 
2484  process_print_inlining();
2485 
2486  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2487  // to remove hashes to unlock nodes for modifications.
2488  C->node_hash()->clear();
2489 
2490  // A method with only infinite loops has no edges entering loops from root
2491  {
2492    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2493    if (final_graph_reshaping()) {
2494      assert(failing(), "must bail out w/ explicit message");
2495      return;
2496    }
2497  }
2498 
2499  print_method(PHASE_OPTIMIZE_FINISHED, 2);

3766           k->subsume_by(m, this);
3767         }
3768       }
3769     }
3770     break;
3771   }
3772   case Op_CmpUL: {
3773     if (!Matcher::has_match_rule(Op_CmpUL)) {
3774       // No support for unsigned long comparisons
3775       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3776       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3777       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3778       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3779       Node* andl = new AndLNode(orl, remove_sign_mask);
3780       Node* cmp = new CmpLNode(andl, n->in(2));
3781       n->subsume_by(cmp, this);
3782     }
3783     break;
3784   }
3785 #ifdef ASSERT





3786   case Op_ConNKlass: {
3787     const TypePtr* tp = n->as_Type()->type()->make_ptr();
3788     ciKlass* klass = tp->is_klassptr()->exact_klass();
3789     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
3790     break;
3791   }
3792 #endif
3793   default:
3794     assert(!n->is_Call(), "");
3795     assert(!n->is_Mem(), "");
3796     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3797     break;
3798   }
3799 }
3800 
3801 //------------------------------final_graph_reshaping_walk---------------------
3802 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3803 // requires that the walk visits a node's inputs before visiting the node.
3804 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3805   Unique_Node_List sfpt;

4152   }
4153 }
4154 
4155 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4156   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4157 }
4158 
4159 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4160   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4161 }
4162 
4163 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4164   if (holder->is_initialized()) {
4165     return false;
4166   }
4167   if (holder->is_being_initialized()) {
4168     if (accessing_method->holder() == holder) {
4169       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4170       // <init>, or a static method. In all those cases, there was an initialization
4171       // barrier on the holder klass passed.
4172       if (accessing_method->is_static_initializer() ||
4173           accessing_method->is_object_initializer() ||
4174           accessing_method->is_static()) {
4175         return false;
4176       }
4177     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4178       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4179       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4180       // child class can become fully initialized while its parent class is still being initialized.
4181       if (accessing_method->is_static_initializer()) {
4182         return false;
4183       }
4184     }
4185     ciMethod* root = method(); // the root method of compilation
4186     if (root != accessing_method) {
4187       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4188     }
4189   }
4190   return true;
4191 }
4192 
4193 #ifndef PRODUCT
4194 //------------------------------verify_bidirectional_edges---------------------
4195 // For each input edge to a node (ie - for each Use-Def edge), verify that
4196 // there is a corresponding Def-Use edge.
4197 void Compile::verify_bidirectional_edges(Unique_Node_List &visited) {
4198   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4199   uint stack_size = live_nodes() >> 4;
4200   Node_List nstack(MAX2(stack_size, (uint)OptoNodeListSize));
4201   nstack.push(_root);

4217       if (in != nullptr && !in->is_top()) {
4218         // Count instances of `next`
4219         int cnt = 0;
4220         for (uint idx = 0; idx < in->_outcnt; idx++) {
4221           if (in->_out[idx] == n) {
4222             cnt++;
4223           }
4224         }
4225         assert(cnt > 0, "Failed to find Def-Use edge.");
4226         // Check for duplicate edges
4227         // walk the input array downcounting the input edges to n
4228         for (uint j = 0; j < length; j++) {
4229           if (n->in(j) == in) {
4230             cnt--;
4231           }
4232         }
4233         assert(cnt == 0, "Mismatched edge count.");
4234       } else if (in == nullptr) {
4235         assert(i == 0 || i >= n->req() ||
4236                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||

4237                (n->is_Unlock() && i == (n->req() - 1)) ||
4238                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4239               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4240       } else {
4241         assert(in->is_top(), "sanity");
4242         // Nothing to check.
4243       }
4244     }
4245   }
4246 }
4247 
4248 //------------------------------verify_graph_edges---------------------------
4249 // Walk the Graph and verify that there is a one-to-one correspondence
4250 // between Use-Def edges and Def-Use edges in the graph.
4251 void Compile::verify_graph_edges(bool no_dead_code) {
4252   if (VerifyGraphEdges) {
4253     Unique_Node_List visited;
4254 
4255     // Call graph walk to check edges
4256     verify_bidirectional_edges(visited);
4257     if (no_dead_code) {
4258       // Now make sure that no visited node is used by an unvisited node.
4259       bool dead_nodes = false;

4353 // (1) subklass is already limited to a subtype of superklass => always ok
4354 // (2) subklass does not overlap with superklass => always fail
4355 // (3) superklass has NO subtypes and we can check with a simple compare.
4356 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4357   if (skip) {
4358     return SSC_full_test;       // Let caller generate the general case.
4359   }
4360 
4361   if (subk->is_java_subtype_of(superk)) {
4362     return SSC_always_true; // (0) and (1)  this test cannot fail
4363   }
4364 
4365   if (!subk->maybe_java_subtype_of(superk)) {
4366     return SSC_always_false; // (2) true path dead; no dynamic test needed
4367   }
4368 
4369   const Type* superelem = superk;
4370   if (superk->isa_aryklassptr()) {
4371     int ignored;
4372     superelem = superk->is_aryklassptr()->base_element_type(ignored);







4373   }
4374 
4375   if (superelem->isa_instklassptr()) {
4376     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4377     if (!ik->has_subklass()) {
4378       if (!ik->is_final()) {
4379         // Add a dependency if there is a chance of a later subclass.
4380         dependencies()->assert_leaf_type(ik);
4381       }
4382       if (!superk->maybe_java_subtype_of(subk)) {
4383         return SSC_always_false;
4384       }
4385       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4386     }
4387   } else {
4388     // A primitive array type has no subtypes.
4389     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4390   }
4391 
4392   return SSC_full_test;

4952       const Type* t = igvn.type_or_null(n);
4953       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
4954       if (n->is_Type()) {
4955         t = n->as_Type()->type();
4956         assert(t == t->remove_speculative(), "no more speculative types");
4957       }
4958       // Iterate over outs - endless loops is unreachable from below
4959       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4960         Node *m = n->fast_out(i);
4961         if (not_a_node(m)) {
4962           continue;
4963         }
4964         worklist.push(m);
4965       }
4966     }
4967     igvn.check_no_speculative_types();
4968 #endif
4969   }
4970 }
4971 





















4972 // Auxiliary methods to support randomized stressing/fuzzing.
4973 
4974 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
4975   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
4976     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
4977     FLAG_SET_ERGO(StressSeed, _stress_seed);
4978   } else {
4979     _stress_seed = StressSeed;
4980   }
4981   if (_log != nullptr) {
4982     _log->elem("stress_test seed='%u'", _stress_seed);
4983   }
4984 }
4985 
4986 int Compile::random() {
4987   _stress_seed = os::next_random(_stress_seed);
4988   return static_cast<int>(_stress_seed);
4989 }
4990 
4991 // This method can be called the arbitrary number of times, with current count

  40 #include "gc/shared/barrierSet.hpp"
  41 #include "gc/shared/c2/barrierSetC2.hpp"
  42 #include "jfr/jfrEvents.hpp"
  43 #include "jvm_io.h"
  44 #include "memory/allocation.hpp"
  45 #include "memory/resourceArea.hpp"
  46 #include "opto/addnode.hpp"
  47 #include "opto/block.hpp"
  48 #include "opto/c2compiler.hpp"
  49 #include "opto/callGenerator.hpp"
  50 #include "opto/callnode.hpp"
  51 #include "opto/castnode.hpp"
  52 #include "opto/cfgnode.hpp"
  53 #include "opto/chaitin.hpp"
  54 #include "opto/compile.hpp"
  55 #include "opto/connode.hpp"
  56 #include "opto/convertnode.hpp"
  57 #include "opto/divnode.hpp"
  58 #include "opto/escape.hpp"
  59 #include "opto/idealGraphPrinter.hpp"
  60 #include "opto/inlinetypenode.hpp"
  61 #include "opto/locknode.hpp"
  62 #include "opto/loopnode.hpp"
  63 #include "opto/machnode.hpp"
  64 #include "opto/macro.hpp"
  65 #include "opto/matcher.hpp"
  66 #include "opto/mathexactnode.hpp"
  67 #include "opto/memnode.hpp"
  68 #include "opto/mulnode.hpp"
  69 #include "opto/narrowptrnode.hpp"
  70 #include "opto/node.hpp"
  71 #include "opto/opcodes.hpp"
  72 #include "opto/output.hpp"
  73 #include "opto/parse.hpp"
  74 #include "opto/phaseX.hpp"
  75 #include "opto/rootnode.hpp"
  76 #include "opto/runtime.hpp"
  77 #include "opto/stringopts.hpp"
  78 #include "opto/type.hpp"
  79 #include "opto/vector.hpp"
  80 #include "opto/vectornode.hpp"

 386   // as dead to be conservative about the dead node count at any
 387   // given time.
 388   if (!dead->is_Con()) {
 389     record_dead_node(dead->_idx);
 390   }
 391   if (dead->is_macro()) {
 392     remove_macro_node(dead);
 393   }
 394   if (dead->is_expensive()) {
 395     remove_expensive_node(dead);
 396   }
 397   if (dead->is_OpaqueTemplateAssertionPredicate()) {
 398     remove_template_assertion_predicate_opaq(dead);
 399   }
 400   if (dead->is_ParsePredicate()) {
 401     remove_parse_predicate(dead->as_ParsePredicate());
 402   }
 403   if (dead->for_post_loop_opts_igvn()) {
 404     remove_from_post_loop_opts_igvn(dead);
 405   }
 406   if (dead->is_InlineType()) {
 407     remove_inline_type(dead);
 408   }
 409   if (dead->is_Call()) {
 410     remove_useless_late_inlines(                &_late_inlines, dead);
 411     remove_useless_late_inlines(         &_string_late_inlines, dead);
 412     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 413     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 414 
 415     if (dead->is_CallStaticJava()) {
 416       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 417     }
 418   }
 419   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 420   bs->unregister_potential_barrier_node(dead);
 421 }
 422 
 423 // Disconnect all useless nodes by disconnecting those at the boundary.
 424 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist) {
 425   uint next = 0;
 426   while (next < useful.size()) {
 427     Node *n = useful.at(next++);
 428     if (n->is_SafePoint()) {

 430       // beyond that point.
 431       n->as_SafePoint()->delete_replaced_nodes();
 432     }
 433     // Use raw traversal of out edges since this code removes out edges
 434     int max = n->outcnt();
 435     for (int j = 0; j < max; ++j) {
 436       Node* child = n->raw_out(j);
 437       if (!useful.member(child)) {
 438         assert(!child->is_top() || child != top(),
 439                "If top is cached in Compile object it is in useful list");
 440         // Only need to remove this out-edge to the useless node
 441         n->raw_del_out(j);
 442         --j;
 443         --max;
 444       }
 445     }
 446     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 447       assert(useful.member(n->unique_out()), "do not push a useless node");
 448       worklist.push(n->unique_out());
 449     }
 450     if (n->outcnt() == 0) {
 451       worklist.push(n);
 452     }
 453   }
 454 
 455   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 456   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 457   remove_useless_nodes(_template_assertion_predicate_opaqs, useful); // remove useless Assertion Predicate opaque nodes
 458   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 459   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 460   remove_useless_nodes(_inline_type_nodes,  useful); // remove useless inline type nodes
 461 #ifdef ASSERT
 462   if (_modified_nodes != nullptr) {
 463     _modified_nodes->remove_useless_nodes(useful.member_set());
 464   }
 465 #endif
 466   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 467   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 468 #ifdef ASSERT
 469   if (_modified_nodes != nullptr) {
 470     _modified_nodes->remove_useless_nodes(useful.member_set());
 471   }
 472 #endif
 473 
 474   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 475   bs->eliminate_useless_gc_barriers(useful, this);
 476   // clean up the late inline lists
 477   remove_useless_late_inlines(                &_late_inlines, useful);
 478   remove_useless_late_inlines(         &_string_late_inlines, useful);
 479   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 480   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 481   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 482 }
 483 
 484 // ============================================================================
 485 //------------------------------CompileWrapper---------------------------------

 625 
 626 
 627 Compile::Compile( ciEnv* ci_env, ciMethod* target, int osr_bci,
 628                   Options options, DirectiveSet* directive)
 629                 : Phase(Compiler),
 630                   _compile_id(ci_env->compile_id()),
 631                   _options(options),
 632                   _method(target),
 633                   _entry_bci(osr_bci),
 634                   _ilt(nullptr),
 635                   _stub_function(nullptr),
 636                   _stub_name(nullptr),
 637                   _stub_entry_point(nullptr),
 638                   _max_node_limit(MaxNodeLimit),
 639                   _post_loop_opts_phase(false),
 640                   _allow_macro_nodes(true),
 641                   _inlining_progress(false),
 642                   _inlining_incrementally(false),
 643                   _do_cleanup(false),
 644                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 645                   _has_circular_inline_type(false),
 646 #ifndef PRODUCT
 647                   _igv_idx(0),
 648                   _trace_opto_output(directive->TraceOptoOutputOption),
 649 #endif
 650                   _has_method_handle_invokes(false),
 651                   _clinit_barrier_on_entry(false),
 652                   _stress_seed(0),
 653                   _comp_arena(mtCompiler),
 654                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 655                   _env(ci_env),
 656                   _directive(directive),
 657                   _log(ci_env->log()),
 658                   _first_failure_details(nullptr),
 659                   _intrinsics        (comp_arena(), 0, 0, nullptr),
 660                   _macro_nodes       (comp_arena(), 8, 0, nullptr),
 661                   _parse_predicates  (comp_arena(), 8, 0, nullptr),
 662                   _template_assertion_predicate_opaqs (comp_arena(), 8, 0, nullptr),
 663                   _expensive_nodes   (comp_arena(), 8, 0, nullptr),
 664                   _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 665                   _inline_type_nodes (comp_arena(), 8, 0, nullptr),
 666                   _unstable_if_traps (comp_arena(), 8, 0, nullptr),
 667                   _coarsened_locks   (comp_arena(), 8, 0, nullptr),
 668                   _congraph(nullptr),
 669                   NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 670                   _unique(0),
 671                   _dead_node_count(0),
 672                   _dead_node_list(comp_arena()),
 673                   _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 674                   _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 675                   _node_arena(&_node_arena_one),
 676                   _mach_constant_base_node(nullptr),
 677                   _Compile_types(mtCompiler),
 678                   _initial_gvn(nullptr),
 679                   _igvn_worklist(nullptr),
 680                   _types(nullptr),
 681                   _node_hash(nullptr),
 682                   _late_inlines(comp_arena(), 2, 0, nullptr),
 683                   _string_late_inlines(comp_arena(), 2, 0, nullptr),
 684                   _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 685                   _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),

 752 
 753   // GVN that will be run immediately on new nodes
 754   uint estimated_size = method()->code_size()*4+64;
 755   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 756   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 757   _types = new (comp_arena()) Type_Array(comp_arena());
 758   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 759   PhaseGVN gvn;
 760   set_initial_gvn(&gvn);
 761 
 762   print_inlining_init();
 763   { // Scope for timing the parser
 764     TracePhase tp("parse", &timers[_t_parser]);
 765 
 766     // Put top into the hash table ASAP.
 767     initial_gvn()->transform(top());
 768 
 769     // Set up tf(), start(), and find a CallGenerator.
 770     CallGenerator* cg = nullptr;
 771     if (is_osr_compilation()) {
 772       init_tf(TypeFunc::make(method(), /* is_osr_compilation = */ true));
 773       StartNode* s = new StartOSRNode(root(), tf()->domain_sig());


 774       initial_gvn()->set_type_bottom(s);
 775       verify_start(s);
 776       cg = CallGenerator::for_osr(method(), entry_bci());
 777     } else {
 778       // Normal case.
 779       init_tf(TypeFunc::make(method()));
 780       StartNode* s = new StartNode(root(), tf()->domain_cc());
 781       initial_gvn()->set_type_bottom(s);
 782       verify_start(s);
 783       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 784         // With java.lang.ref.reference.get() we must go through the
 785         // intrinsic - even when get() is the root
 786         // method of the compile - so that, if necessary, the value in
 787         // the referent field of the reference object gets recorded by
 788         // the pre-barrier code.
 789         cg = find_intrinsic(method(), false);
 790       }
 791       if (cg == nullptr) {
 792         float past_uses = method()->interpreter_invocation_count();
 793         float expected_uses = past_uses;
 794         cg = CallGenerator::for_inline(method(), expected_uses);
 795       }
 796     }
 797     if (failing())  return;
 798     if (cg == nullptr) {
 799       const char* reason = InlineTree::check_can_parse(method());
 800       assert(reason != nullptr, "expect reason for parse failure");

 871     print_ideal_ir("print_ideal");
 872   }
 873 #endif
 874 
 875 #ifdef ASSERT
 876   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 877   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 878 #endif
 879 
 880   // Dump compilation data to replay it.
 881   if (directive->DumpReplayOption) {
 882     env()->dump_replay_data(_compile_id);
 883   }
 884   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 885     env()->dump_inline_data(_compile_id);
 886   }
 887 
 888   // Now that we know the size of all the monitors we can add a fixed slot
 889   // for the original deopt pc.
 890   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 891   if (needs_stack_repair()) {
 892     // One extra slot for the special stack increment value
 893     next_slot += 2;
 894   }
 895   // TODO 8284443 Only reserve extra slot if needed
 896   if (InlineTypeReturnedAsFields) {
 897     // One extra slot to hold the IsInit information for a nullable
 898     // inline type return if we run out of registers.
 899     next_slot += 2;
 900   }
 901   set_fixed_slots(next_slot);
 902 
 903   // Compute when to use implicit null checks. Used by matching trap based
 904   // nodes and NullCheck optimization.
 905   set_allowed_deopt_reasons();
 906 
 907   // Now generate code
 908   Code_Gen();
 909 }
 910 
 911 //------------------------------Compile----------------------------------------
 912 // Compile a runtime stub
 913 Compile::Compile( ciEnv* ci_env,
 914                   TypeFunc_generator generator,
 915                   address stub_function,
 916                   const char *stub_name,
 917                   int is_fancy_jump,
 918                   bool pass_tls,
 919                   bool return_pc,
 920                   DirectiveSet* directive)
 921   : Phase(Compiler),
 922     _compile_id(0),
 923     _options(Options::for_runtime_stub()),
 924     _method(nullptr),
 925     _entry_bci(InvocationEntryBci),
 926     _stub_function(stub_function),
 927     _stub_name(stub_name),
 928     _stub_entry_point(nullptr),
 929     _max_node_limit(MaxNodeLimit),
 930     _post_loop_opts_phase(false),
 931     _allow_macro_nodes(true),
 932     _inlining_progress(false),
 933     _inlining_incrementally(false),
 934     _has_reserved_stack_access(false),
 935     _has_circular_inline_type(false),
 936 #ifndef PRODUCT
 937     _igv_idx(0),
 938     _trace_opto_output(directive->TraceOptoOutputOption),
 939 #endif
 940     _has_method_handle_invokes(false),
 941     _clinit_barrier_on_entry(false),
 942     _stress_seed(0),
 943     _comp_arena(mtCompiler),
 944     _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 945     _env(ci_env),
 946     _directive(directive),
 947     _log(ci_env->log()),
 948     _first_failure_details(nullptr),
 949     _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 950     _congraph(nullptr),
 951     NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 952     _unique(0),
 953     _dead_node_count(0),
 954     _dead_node_list(comp_arena()),
 955     _node_arena_one(mtCompiler),

1062 
1063   _fixed_slots = 0;
1064   set_has_split_ifs(false);
1065   set_has_loops(false); // first approximation
1066   set_has_stringbuilder(false);
1067   set_has_boxed_value(false);
1068   _trap_can_recompile = false;  // no traps emitted yet
1069   _major_progress = true; // start out assuming good things will happen
1070   set_has_unsafe_access(false);
1071   set_max_vector_size(0);
1072   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1073   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1074   set_decompile_count(0);
1075 
1076 #ifndef PRODUCT
1077   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1078 #endif
1079 
1080   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1081   _loop_opts_cnt = LoopOptsCount;
1082   _has_flat_accesses = false;
1083   _flat_accesses_share_alias = true;
1084   _scalarize_in_safepoints = false;
1085 
1086   set_do_inlining(Inline);
1087   set_max_inline_size(MaxInlineSize);
1088   set_freq_inline_size(FreqInlineSize);
1089   set_do_scheduling(OptoScheduling);
1090 
1091   set_do_vector_loop(false);
1092   set_has_monitors(false);
1093   set_has_scoped_access(false);
1094 
1095   if (AllowVectorizeOnDemand) {
1096     if (has_method() && _directive->VectorizeOption) {
1097       set_do_vector_loop(true);
1098       NOT_PRODUCT(if (do_vector_loop() && Verbose) {tty->print("Compile::Init: do vectorized loops (SIMD like) for method %s\n",  method()->name()->as_quoted_ascii());})
1099     } else if (has_method() && method()->name() != nullptr &&
1100                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1101       set_do_vector_loop(true);
1102     }
1103   }
1104   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1105   NOT_PRODUCT(if (use_cmove() && Verbose && has_method()) {tty->print("Compile::Init: use CMove without profitability tests for method %s\n",  method()->name()->as_quoted_ascii());})

1337   // If this method has already thrown a range-check,
1338   // assume it was because we already tried range smearing
1339   // and it failed.
1340   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1341   return !already_trapped;
1342 }
1343 
1344 
1345 //------------------------------flatten_alias_type-----------------------------
1346 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1347   assert(do_aliasing(), "Aliasing should be enabled");
1348   int offset = tj->offset();
1349   TypePtr::PTR ptr = tj->ptr();
1350 
1351   // Known instance (scalarizable allocation) alias only with itself.
1352   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1353                        tj->is_oopptr()->is_known_instance();
1354 
1355   // Process weird unsafe references.
1356   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1357     bool default_value_load = EnableValhalla && tj->is_instptr()->instance_klass() == ciEnv::current()->Class_klass();
1358     assert(InlineUnsafeOps || StressReflectiveCode || default_value_load, "indeterminate pointers come only from unsafe ops");
1359     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1360     tj = TypeOopPtr::BOTTOM;
1361     ptr = tj->ptr();
1362     offset = tj->offset();
1363   }
1364 
1365   // Array pointers need some flattening
1366   const TypeAryPtr* ta = tj->isa_aryptr();
1367   if (ta && ta->is_stable()) {
1368     // Erase stability property for alias analysis.
1369     tj = ta = ta->cast_to_stable(false);
1370   }
1371   if (ta && ta->is_not_flat()) {
1372     // Erase not flat property for alias analysis.
1373     tj = ta = ta->cast_to_not_flat(false);
1374   }
1375   if (ta && ta->is_not_null_free()) {
1376     // Erase not null free property for alias analysis.
1377     tj = ta = ta->cast_to_not_null_free(false);
1378   }
1379 
1380   if( ta && is_known_inst ) {
1381     if ( offset != Type::OffsetBot &&
1382          offset > arrayOopDesc::length_offset_in_bytes() ) {
1383       offset = Type::OffsetBot; // Flatten constant access into array body only
1384       tj = ta = ta->
1385               remove_speculative()->
1386               cast_to_ptr_type(ptr)->
1387               with_offset(offset);
1388     }
1389   } else if (ta) {
1390     // For arrays indexed by constant indices, we flatten the alias
1391     // space to include all of the array body.  Only the header, klass
1392     // and array length can be accessed un-aliased.
1393     // For flat inline type array, each field has its own slice so
1394     // we must include the field offset.
1395     if( offset != Type::OffsetBot ) {
1396       if( ta->const_oop() ) { // MethodData* or Method*
1397         offset = Type::OffsetBot;   // Flatten constant access into array body
1398         tj = ta = ta->
1399                 remove_speculative()->
1400                 cast_to_ptr_type(ptr)->
1401                 cast_to_exactness(false)->
1402                 with_offset(offset);
1403       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1404         // range is OK as-is.
1405         tj = ta = TypeAryPtr::RANGE;
1406       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1407         tj = TypeInstPtr::KLASS; // all klass loads look alike
1408         ta = TypeAryPtr::RANGE; // generic ignored junk
1409         ptr = TypePtr::BotPTR;
1410       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1411         tj = TypeInstPtr::MARK;
1412         ta = TypeAryPtr::RANGE; // generic ignored junk
1413         ptr = TypePtr::BotPTR;
1414       } else {                  // Random constant offset into array body
1415         offset = Type::OffsetBot;   // Flatten constant access into array body
1416         tj = ta = ta->
1417                 remove_speculative()->
1418                 cast_to_ptr_type(ptr)->
1419                 cast_to_exactness(false)->
1420                 with_offset(offset);
1421       }
1422     }
1423     // Arrays of fixed size alias with arrays of unknown size.
1424     if (ta->size() != TypeInt::POS) {
1425       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1426       tj = ta = ta->
1427               remove_speculative()->
1428               cast_to_ptr_type(ptr)->
1429               with_ary(tary)->
1430               cast_to_exactness(false);
1431     }
1432     // Arrays of known objects become arrays of unknown objects.
1433     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1434       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1435       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,Type::Offset(offset), ta->field_offset());
1436     }
1437     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1438       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1439       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,Type::Offset(offset), ta->field_offset());
1440     }
1441     // Initially all flattened array accesses share a single slice
1442     if (ta->is_flat() && ta->elem() != TypeInstPtr::BOTTOM && _flat_accesses_share_alias) {
1443       const TypeAry* tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size(), /* stable= */ false, /* flat= */ true);
1444       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,Type::Offset(offset), Type::Offset(Type::OffsetBot));
1445     }
1446     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1447     // cannot be distinguished by bytecode alone.
1448     if (ta->elem() == TypeInt::BOOL) {
1449       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1450       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1451       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,Type::Offset(offset), ta->field_offset());
1452     }
1453     // During the 2nd round of IterGVN, NotNull castings are removed.
1454     // Make sure the Bottom and NotNull variants alias the same.
1455     // Also, make sure exact and non-exact variants alias the same.
1456     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != nullptr) {
1457       tj = ta = ta->
1458               remove_speculative()->
1459               cast_to_ptr_type(TypePtr::BotPTR)->
1460               cast_to_exactness(false)->
1461               with_offset(offset);
1462     }
1463   }
1464 
1465   // Oop pointers need some flattening
1466   const TypeInstPtr *to = tj->isa_instptr();
1467   if (to && to != TypeOopPtr::BOTTOM) {
1468     ciInstanceKlass* ik = to->instance_klass();
1469     if( ptr == TypePtr::Constant ) {
1470       if (ik != ciEnv::current()->Class_klass() ||
1471           offset < ik->layout_helper_size_in_bytes()) {

1481     } else if( is_known_inst ) {
1482       tj = to; // Keep NotNull and klass_is_exact for instance type
1483     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1484       // During the 2nd round of IterGVN, NotNull castings are removed.
1485       // Make sure the Bottom and NotNull variants alias the same.
1486       // Also, make sure exact and non-exact variants alias the same.
1487       tj = to = to->
1488               remove_speculative()->
1489               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1490               cast_to_ptr_type(TypePtr::BotPTR)->
1491               cast_to_exactness(false);
1492     }
1493     if (to->speculative() != nullptr) {
1494       tj = to = to->remove_speculative();
1495     }
1496     // Canonicalize the holder of this field
1497     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1498       // First handle header references such as a LoadKlassNode, even if the
1499       // object's klass is unloaded at compile time (4965979).
1500       if (!is_known_inst) { // Do it only for non-instance types
1501         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, Type::Offset(offset));
1502       }
1503     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1504       // Static fields are in the space above the normal instance
1505       // fields in the java.lang.Class instance.
1506       if (ik != ciEnv::current()->Class_klass()) {
1507         to = nullptr;
1508         tj = TypeOopPtr::BOTTOM;
1509         offset = tj->offset();
1510       }
1511     } else {
1512       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1513       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1514       assert(tj->offset() == offset, "no change to offset expected");
1515       bool xk = to->klass_is_exact();
1516       int instance_id = to->instance_id();
1517 
1518       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1519       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1520       // its interfaces are included.
1521       if (xk && ik->equals(canonical_holder)) {
1522         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, Type::Offset(offset), instance_id), "exact type should be canonical type");
1523       } else {
1524         assert(xk || !is_known_inst, "Known instance should be exact type");
1525         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, Type::Offset(offset), instance_id);
1526       }
1527     }
1528   }
1529 
1530   // Klass pointers to object array klasses need some flattening
1531   const TypeKlassPtr *tk = tj->isa_klassptr();
1532   if( tk ) {
1533     // If we are referencing a field within a Klass, we need
1534     // to assume the worst case of an Object.  Both exact and
1535     // inexact types must flatten to the same alias class so
1536     // use NotNull as the PTR.
1537     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1538       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1539                                        env()->Object_klass(),
1540                                        Type::Offset(offset));
1541     }
1542 
1543     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1544       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1545       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1546         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), Type::Offset(offset));
1547       } else {
1548         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, Type::Offset(offset), tk->is_not_flat(), tk->is_not_null_free(), tk->is_null_free());
1549       }
1550     }

1551     // Check for precise loads from the primary supertype array and force them
1552     // to the supertype cache alias index.  Check for generic array loads from
1553     // the primary supertype array and also force them to the supertype cache
1554     // alias index.  Since the same load can reach both, we need to merge
1555     // these 2 disparate memories into the same alias class.  Since the
1556     // primary supertype array is read-only, there's no chance of confusion
1557     // where we bypass an array load and an array store.
1558     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1559     if (offset == Type::OffsetBot ||
1560         (offset >= primary_supers_offset &&
1561          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1562         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1563       offset = in_bytes(Klass::secondary_super_cache_offset());
1564       tj = tk = tk->with_offset(offset);
1565     }
1566   }
1567 
1568   // Flatten all Raw pointers together.
1569   if (tj->base() == Type::RawPtr)
1570     tj = TypeRawPtr::BOTTOM;

1660   intptr_t key = (intptr_t) adr_type;
1661   key ^= key >> logAliasCacheSize;
1662   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1663 }
1664 
1665 
1666 //-----------------------------grow_alias_types--------------------------------
1667 void Compile::grow_alias_types() {
1668   const int old_ats  = _max_alias_types; // how many before?
1669   const int new_ats  = old_ats;          // how many more?
1670   const int grow_ats = old_ats+new_ats;  // how many now?
1671   _max_alias_types = grow_ats;
1672   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1673   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1674   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1675   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1676 }
1677 
1678 
1679 //--------------------------------find_alias_type------------------------------
1680 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field, bool uncached) {
1681   if (!do_aliasing()) {
1682     return alias_type(AliasIdxBot);
1683   }
1684 
1685   AliasCacheEntry* ace = nullptr;
1686   if (!uncached) {
1687     ace = probe_alias_cache(adr_type);
1688     if (ace->_adr_type == adr_type) {
1689       return alias_type(ace->_index);
1690     }
1691   }
1692 
1693   // Handle special cases.
1694   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1695   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1696 
1697   // Do it the slow way.
1698   const TypePtr* flat = flatten_alias_type(adr_type);
1699 
1700 #ifdef ASSERT
1701   {
1702     ResourceMark rm;
1703     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1704            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1705     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1706            Type::str(adr_type));
1707     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1708       const TypeOopPtr* foop = flat->is_oopptr();
1709       // Scalarizable allocations have exact klass always.
1710       bool exact = !foop->klass_is_exact() || foop->is_known_instance();

1720     if (alias_type(i)->adr_type() == flat) {
1721       idx = i;
1722       break;
1723     }
1724   }
1725 
1726   if (idx == AliasIdxTop) {
1727     if (no_create)  return nullptr;
1728     // Grow the array if necessary.
1729     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1730     // Add a new alias type.
1731     idx = _num_alias_types++;
1732     _alias_types[idx]->Init(idx, flat);
1733     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1734     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1735     if (flat->isa_instptr()) {
1736       if (flat->offset() == java_lang_Class::klass_offset()
1737           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1738         alias_type(idx)->set_rewritable(false);
1739     }
1740     ciField* field = nullptr;
1741     if (flat->isa_aryptr()) {
1742 #ifdef ASSERT
1743       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1744       // (T_BYTE has the weakest alignment and size restrictions...)
1745       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1746 #endif
1747       const Type* elemtype = flat->is_aryptr()->elem();
1748       if (flat->offset() == TypePtr::OffsetBot) {
1749         alias_type(idx)->set_element(elemtype);
1750       }
1751       int field_offset = flat->is_aryptr()->field_offset().get();
1752       if (flat->is_flat() &&
1753           field_offset != Type::OffsetBot) {
1754         ciInlineKlass* vk = elemtype->inline_klass();
1755         field_offset += vk->first_field_offset();
1756         field = vk->get_field_by_offset(field_offset, false);
1757       }
1758     }
1759     if (flat->isa_klassptr()) {
1760       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1761         alias_type(idx)->set_rewritable(false);
1762       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1763         alias_type(idx)->set_rewritable(false);
1764       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1765         alias_type(idx)->set_rewritable(false);
1766       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1767         alias_type(idx)->set_rewritable(false);
1768       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1769         alias_type(idx)->set_rewritable(false);
1770       if (flat->offset() == in_bytes(Klass::layout_helper_offset()))
1771         alias_type(idx)->set_rewritable(false);
1772       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1773         alias_type(idx)->set_rewritable(false);
1774     }
1775     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1776     // but the base pointer type is not distinctive enough to identify
1777     // references into JavaThread.)
1778 
1779     // Check for final fields.
1780     const TypeInstPtr* tinst = flat->isa_instptr();
1781     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {

1782       if (tinst->const_oop() != nullptr &&
1783           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1784           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1785         // static field
1786         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1787         field = k->get_field_by_offset(tinst->offset(), true);
1788       } else if (tinst->is_inlinetypeptr()) {
1789         // Inline type field
1790         ciInlineKlass* vk = tinst->inline_klass();
1791         field = vk->get_field_by_offset(tinst->offset(), false);
1792       } else {
1793         ciInstanceKlass *k = tinst->instance_klass();
1794         field = k->get_field_by_offset(tinst->offset(), false);
1795       }
1796     }
1797     assert(field == nullptr ||
1798            original_field == nullptr ||
1799            (field->holder() == original_field->holder() &&
1800             field->offset_in_bytes() == original_field->offset_in_bytes() &&
1801             field->is_static() == original_field->is_static()), "wrong field?");
1802     // Set field() and is_rewritable() attributes.
1803     if (field != nullptr) {
1804       alias_type(idx)->set_field(field);
1805       if (flat->isa_aryptr()) {
1806         // Fields of flat arrays are rewritable although they are declared final
1807         assert(flat->is_flat(), "must be a flat array");
1808         alias_type(idx)->set_rewritable(true);
1809       }
1810     }
1811   }
1812 
1813   // Fill the cache for next time.
1814   if (!uncached) {
1815     ace->_adr_type = adr_type;
1816     ace->_index    = idx;
1817     assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1818 
1819     // Might as well try to fill the cache for the flattened version, too.
1820     AliasCacheEntry* face = probe_alias_cache(flat);
1821     if (face->_adr_type == nullptr) {
1822       face->_adr_type = flat;
1823       face->_index    = idx;
1824       assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1825     }
1826   }
1827 
1828   return alias_type(idx);
1829 }
1830 
1831 
1832 Compile::AliasType* Compile::alias_type(ciField* field) {
1833   const TypeOopPtr* t;
1834   if (field->is_static())
1835     t = TypeInstPtr::make(field->holder()->java_mirror());
1836   else
1837     t = TypeOopPtr::make_from_klass_raw(field->holder());
1838   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1839   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1840   return atp;
1841 }
1842 
1843 
1844 //------------------------------have_alias_type--------------------------------
1845 bool Compile::have_alias_type(const TypePtr* adr_type) {

1925   assert(!C->major_progress(), "not cleared");
1926 
1927   if (_for_post_loop_igvn.length() > 0) {
1928     while (_for_post_loop_igvn.length() > 0) {
1929       Node* n = _for_post_loop_igvn.pop();
1930       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1931       igvn._worklist.push(n);
1932     }
1933     igvn.optimize();
1934     if (failing()) return;
1935     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1936     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1937 
1938     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1939     if (C->major_progress()) {
1940       C->clear_major_progress(); // ensure that major progress is now clear
1941     }
1942   }
1943 }
1944 
1945 void Compile::add_inline_type(Node* n) {
1946   assert(n->is_InlineType(), "unexpected node");
1947   _inline_type_nodes.push(n);
1948 }
1949 
1950 void Compile::remove_inline_type(Node* n) {
1951   assert(n->is_InlineType(), "unexpected node");
1952   if (_inline_type_nodes.contains(n)) {
1953     _inline_type_nodes.remove(n);
1954   }
1955 }
1956 
1957 // Does the return value keep otherwise useless inline type allocations alive?
1958 static bool return_val_keeps_allocations_alive(Node* ret_val) {
1959   ResourceMark rm;
1960   Unique_Node_List wq;
1961   wq.push(ret_val);
1962   bool some_allocations = false;
1963   for (uint i = 0; i < wq.size(); i++) {
1964     Node* n = wq.at(i);
1965     if (n->outcnt() > 1) {
1966       // Some other use for the allocation
1967       return false;
1968     } else if (n->is_InlineType()) {
1969       wq.push(n->in(1));
1970     } else if (n->is_Phi()) {
1971       for (uint j = 1; j < n->req(); j++) {
1972         wq.push(n->in(j));
1973       }
1974     } else if (n->is_CheckCastPP() &&
1975                n->in(1)->is_Proj() &&
1976                n->in(1)->in(0)->is_Allocate()) {
1977       some_allocations = true;
1978     } else if (n->is_CheckCastPP()) {
1979       wq.push(n->in(1));
1980     }
1981   }
1982   return some_allocations;
1983 }
1984 
1985 void Compile::process_inline_types(PhaseIterGVN &igvn, bool remove) {
1986   // Make sure that the return value does not keep an otherwise unused allocation alive
1987   if (tf()->returns_inline_type_as_fields()) {
1988     Node* ret = nullptr;
1989     for (uint i = 1; i < root()->req(); i++) {
1990       Node* in = root()->in(i);
1991       if (in->Opcode() == Op_Return) {
1992         assert(ret == nullptr, "only one return");
1993         ret = in;
1994       }
1995     }
1996     if (ret != nullptr) {
1997       Node* ret_val = ret->in(TypeFunc::Parms);
1998       if (igvn.type(ret_val)->isa_oopptr() &&
1999           return_val_keeps_allocations_alive(ret_val)) {
2000         igvn.replace_input_of(ret, TypeFunc::Parms, InlineTypeNode::tagged_klass(igvn.type(ret_val)->inline_klass(), igvn));
2001         assert(ret_val->outcnt() == 0, "should be dead now");
2002         igvn.remove_dead_node(ret_val);
2003       }
2004     }
2005   }
2006   if (_inline_type_nodes.length() == 0) {
2007     return;
2008   }
2009   // Scalarize inline types in safepoint debug info.
2010   // Delay this until all inlining is over to avoid getting inconsistent debug info.
2011   set_scalarize_in_safepoints(true);
2012   for (int i = _inline_type_nodes.length()-1; i >= 0; i--) {
2013     InlineTypeNode* vt = _inline_type_nodes.at(i)->as_InlineType();
2014     vt->make_scalar_in_safepoints(&igvn);
2015     igvn.record_for_igvn(vt);
2016   }
2017   if (remove) {
2018     // Remove inline type nodes by replacing them with their oop input
2019     while (_inline_type_nodes.length() > 0) {
2020       InlineTypeNode* vt = _inline_type_nodes.pop()->as_InlineType();
2021       if (vt->outcnt() == 0) {
2022         igvn.remove_dead_node(vt);
2023         continue;
2024       }
2025       for (DUIterator i = vt->outs(); vt->has_out(i); i++) {
2026         DEBUG_ONLY(bool must_be_buffered = false);
2027         Node* u = vt->out(i);
2028         // Check if any users are blackholes. If so, rewrite them to use either the
2029         // allocated buffer, or individual components, instead of the inline type node
2030         // that goes away.
2031         if (u->is_Blackhole()) {
2032           BlackholeNode* bh = u->as_Blackhole();
2033 
2034           // Unlink the old input
2035           int idx = bh->find_edge(vt);
2036           assert(idx != -1, "The edge should be there");
2037           bh->del_req(idx);
2038           --i;
2039 
2040           if (vt->is_allocated(&igvn)) {
2041             // Already has the allocated instance, blackhole that
2042             bh->add_req(vt->get_oop());
2043           } else {
2044             // Not allocated yet, blackhole the components
2045             for (uint c = 0; c < vt->field_count(); c++) {
2046               bh->add_req(vt->field_value(c));
2047             }
2048           }
2049 
2050           // Node modified, record for IGVN
2051           igvn.record_for_igvn(bh);
2052         }
2053 #ifdef ASSERT
2054         // Verify that inline type is buffered when replacing by oop
2055         else if (u->is_InlineType()) {
2056           // InlineType uses don't need buffering because they are about to be replaced as well
2057         } else if (u->is_Phi()) {
2058           // TODO 8302217 Remove this once InlineTypeNodes are reliably pushed through
2059         } else {
2060           must_be_buffered = true;
2061         }
2062         if (must_be_buffered && !vt->is_allocated(&igvn)) {
2063           vt->dump(0);
2064           u->dump(0);
2065           assert(false, "Should have been buffered");
2066         }
2067 #endif
2068       }
2069       igvn.replace_node(vt, vt->get_oop());
2070     }
2071   }
2072   igvn.optimize();
2073 }
2074 
2075 void Compile::adjust_flat_array_access_aliases(PhaseIterGVN& igvn) {
2076   if (!_has_flat_accesses) {
2077     return;
2078   }
2079   // Initially, all flat array accesses share the same slice to
2080   // keep dependencies with Object[] array accesses (that could be
2081   // to a flat array) correct. We're done with parsing so we
2082   // now know all flat array accesses in this compile
2083   // unit. Let's move flat array accesses to their own slice,
2084   // one per element field. This should help memory access
2085   // optimizations.
2086   ResourceMark rm;
2087   Unique_Node_List wq;
2088   wq.push(root());
2089 
2090   Node_List mergememnodes;
2091   Node_List memnodes;
2092 
2093   // Alias index currently shared by all flat memory accesses
2094   int index = get_alias_index(TypeAryPtr::INLINES);
2095 
2096   // Find MergeMem nodes and flat array accesses
2097   for (uint i = 0; i < wq.size(); i++) {
2098     Node* n = wq.at(i);
2099     if (n->is_Mem()) {
2100       const TypePtr* adr_type = nullptr;
2101       adr_type = get_adr_type(get_alias_index(n->adr_type()));
2102       if (adr_type == TypeAryPtr::INLINES) {
2103         memnodes.push(n);
2104       }
2105     } else if (n->is_MergeMem()) {
2106       MergeMemNode* mm = n->as_MergeMem();
2107       if (mm->memory_at(index) != mm->base_memory()) {
2108         mergememnodes.push(n);
2109       }
2110     }
2111     for (uint j = 0; j < n->req(); j++) {
2112       Node* m = n->in(j);
2113       if (m != nullptr) {
2114         wq.push(m);
2115       }
2116     }
2117   }
2118 
2119   if (memnodes.size() > 0) {
2120     _flat_accesses_share_alias = false;
2121 
2122     // We are going to change the slice for the flat array
2123     // accesses so we need to clear the cache entries that refer to
2124     // them.
2125     for (uint i = 0; i < AliasCacheSize; i++) {
2126       AliasCacheEntry* ace = &_alias_cache[i];
2127       if (ace->_adr_type != nullptr &&
2128           ace->_adr_type->is_flat()) {
2129         ace->_adr_type = nullptr;
2130         ace->_index = (i != 0) ? 0 : AliasIdxTop; // Make sure the nullptr adr_type resolves to AliasIdxTop
2131       }
2132     }
2133 
2134     // Find what aliases we are going to add
2135     int start_alias = num_alias_types()-1;
2136     int stop_alias = 0;
2137 
2138     for (uint i = 0; i < memnodes.size(); i++) {
2139       Node* m = memnodes.at(i);
2140       const TypePtr* adr_type = nullptr;
2141       adr_type = m->adr_type();
2142 #ifdef ASSERT
2143       m->as_Mem()->set_adr_type(adr_type);
2144 #endif
2145       int idx = get_alias_index(adr_type);
2146       start_alias = MIN2(start_alias, idx);
2147       stop_alias = MAX2(stop_alias, idx);
2148     }
2149 
2150     assert(stop_alias >= start_alias, "should have expanded aliases");
2151 
2152     Node_Stack stack(0);
2153 #ifdef ASSERT
2154     VectorSet seen(Thread::current()->resource_area());
2155 #endif
2156     // Now let's fix the memory graph so each flat array access
2157     // is moved to the right slice. Start from the MergeMem nodes.
2158     uint last = unique();
2159     for (uint i = 0; i < mergememnodes.size(); i++) {
2160       MergeMemNode* current = mergememnodes.at(i)->as_MergeMem();
2161       Node* n = current->memory_at(index);
2162       MergeMemNode* mm = nullptr;
2163       do {
2164         // Follow memory edges through memory accesses, phis and
2165         // narrow membars and push nodes on the stack. Once we hit
2166         // bottom memory, we pop element off the stack one at a
2167         // time, in reverse order, and move them to the right slice
2168         // by changing their memory edges.
2169         if ((n->is_Phi() && n->adr_type() != TypePtr::BOTTOM) || n->is_Mem() || n->adr_type() == TypeAryPtr::INLINES) {
2170           assert(!seen.test_set(n->_idx), "");
2171           // Uses (a load for instance) will need to be moved to the
2172           // right slice as well and will get a new memory state
2173           // that we don't know yet. The use could also be the
2174           // backedge of a loop. We put a place holder node between
2175           // the memory node and its uses. We replace that place
2176           // holder with the correct memory state once we know it,
2177           // i.e. when nodes are popped off the stack. Using the
2178           // place holder make the logic work in the presence of
2179           // loops.
2180           if (n->outcnt() > 1) {
2181             Node* place_holder = nullptr;
2182             assert(!n->has_out_with(Op_Node), "");
2183             for (DUIterator k = n->outs(); n->has_out(k); k++) {
2184               Node* u = n->out(k);
2185               if (u != current && u->_idx < last) {
2186                 bool success = false;
2187                 for (uint l = 0; l < u->req(); l++) {
2188                   if (!stack.is_empty() && u == stack.node() && l == stack.index()) {
2189                     continue;
2190                   }
2191                   Node* in = u->in(l);
2192                   if (in == n) {
2193                     if (place_holder == nullptr) {
2194                       place_holder = new Node(1);
2195                       place_holder->init_req(0, n);
2196                     }
2197                     igvn.replace_input_of(u, l, place_holder);
2198                     success = true;
2199                   }
2200                 }
2201                 if (success) {
2202                   --k;
2203                 }
2204               }
2205             }
2206           }
2207           if (n->is_Phi()) {
2208             stack.push(n, 1);
2209             n = n->in(1);
2210           } else if (n->is_Mem()) {
2211             stack.push(n, n->req());
2212             n = n->in(MemNode::Memory);
2213           } else {
2214             assert(n->is_Proj() && n->in(0)->Opcode() == Op_MemBarCPUOrder, "");
2215             stack.push(n, n->req());
2216             n = n->in(0)->in(TypeFunc::Memory);
2217           }
2218         } else {
2219           assert(n->adr_type() == TypePtr::BOTTOM || (n->Opcode() == Op_Node && n->_idx >= last) || (n->is_Proj() && n->in(0)->is_Initialize()), "");
2220           // Build a new MergeMem node to carry the new memory state
2221           // as we build it. IGVN should fold extraneous MergeMem
2222           // nodes.
2223           mm = MergeMemNode::make(n);
2224           igvn.register_new_node_with_optimizer(mm);
2225           while (stack.size() > 0) {
2226             Node* m = stack.node();
2227             uint idx = stack.index();
2228             if (m->is_Mem()) {
2229               // Move memory node to its new slice
2230               const TypePtr* adr_type = m->adr_type();
2231               int alias = get_alias_index(adr_type);
2232               Node* prev = mm->memory_at(alias);
2233               igvn.replace_input_of(m, MemNode::Memory, prev);
2234               mm->set_memory_at(alias, m);
2235             } else if (m->is_Phi()) {
2236               // We need as many new phis as there are new aliases
2237               igvn.replace_input_of(m, idx, mm);
2238               if (idx == m->req()-1) {
2239                 Node* r = m->in(0);
2240                 for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2241                   const TypePtr* adr_type = get_adr_type(j);
2242                   if (!adr_type->isa_aryptr() || !adr_type->is_flat() || j == (uint)index) {
2243                     continue;
2244                   }
2245                   Node* phi = new PhiNode(r, Type::MEMORY, get_adr_type(j));
2246                   igvn.register_new_node_with_optimizer(phi);
2247                   for (uint k = 1; k < m->req(); k++) {
2248                     phi->init_req(k, m->in(k)->as_MergeMem()->memory_at(j));
2249                   }
2250                   mm->set_memory_at(j, phi);
2251                 }
2252                 Node* base_phi = new PhiNode(r, Type::MEMORY, TypePtr::BOTTOM);
2253                 igvn.register_new_node_with_optimizer(base_phi);
2254                 for (uint k = 1; k < m->req(); k++) {
2255                   base_phi->init_req(k, m->in(k)->as_MergeMem()->base_memory());
2256                 }
2257                 mm->set_base_memory(base_phi);
2258               }
2259             } else {
2260               // This is a MemBarCPUOrder node from
2261               // Parse::array_load()/Parse::array_store(), in the
2262               // branch that handles flat arrays hidden under
2263               // an Object[] array. We also need one new membar per
2264               // new alias to keep the unknown access that the
2265               // membars protect properly ordered with accesses to
2266               // known flat array.
2267               assert(m->is_Proj(), "projection expected");
2268               Node* ctrl = m->in(0)->in(TypeFunc::Control);
2269               igvn.replace_input_of(m->in(0), TypeFunc::Control, top());
2270               for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2271                 const TypePtr* adr_type = get_adr_type(j);
2272                 if (!adr_type->isa_aryptr() || !adr_type->is_flat() || j == (uint)index) {
2273                   continue;
2274                 }
2275                 MemBarNode* mb = new MemBarCPUOrderNode(this, j, nullptr);
2276                 igvn.register_new_node_with_optimizer(mb);
2277                 Node* mem = mm->memory_at(j);
2278                 mb->init_req(TypeFunc::Control, ctrl);
2279                 mb->init_req(TypeFunc::Memory, mem);
2280                 ctrl = new ProjNode(mb, TypeFunc::Control);
2281                 igvn.register_new_node_with_optimizer(ctrl);
2282                 mem = new ProjNode(mb, TypeFunc::Memory);
2283                 igvn.register_new_node_with_optimizer(mem);
2284                 mm->set_memory_at(j, mem);
2285               }
2286               igvn.replace_node(m->in(0)->as_Multi()->proj_out(TypeFunc::Control), ctrl);
2287             }
2288             if (idx < m->req()-1) {
2289               idx += 1;
2290               stack.set_index(idx);
2291               n = m->in(idx);
2292               break;
2293             }
2294             // Take care of place holder nodes
2295             if (m->has_out_with(Op_Node)) {
2296               Node* place_holder = m->find_out_with(Op_Node);
2297               if (place_holder != nullptr) {
2298                 Node* mm_clone = mm->clone();
2299                 igvn.register_new_node_with_optimizer(mm_clone);
2300                 Node* hook = new Node(1);
2301                 hook->init_req(0, mm);
2302                 igvn.replace_node(place_holder, mm_clone);
2303                 hook->destruct(&igvn);
2304               }
2305               assert(!m->has_out_with(Op_Node), "place holder should be gone now");
2306             }
2307             stack.pop();
2308           }
2309         }
2310       } while(stack.size() > 0);
2311       // Fix the memory state at the MergeMem we started from
2312       igvn.rehash_node_delayed(current);
2313       for (uint j = (uint)start_alias; j <= (uint)stop_alias; j++) {
2314         const TypePtr* adr_type = get_adr_type(j);
2315         if (!adr_type->isa_aryptr() || !adr_type->is_flat()) {
2316           continue;
2317         }
2318         current->set_memory_at(j, mm);
2319       }
2320       current->set_memory_at(index, current->base_memory());
2321     }
2322     igvn.optimize();
2323   }
2324   print_method(PHASE_SPLIT_INLINES_ARRAY, 2);
2325 #ifdef ASSERT
2326   if (!_flat_accesses_share_alias) {
2327     wq.clear();
2328     wq.push(root());
2329     for (uint i = 0; i < wq.size(); i++) {
2330       Node* n = wq.at(i);
2331       assert(n->adr_type() != TypeAryPtr::INLINES, "should have been removed from the graph");
2332       for (uint j = 0; j < n->req(); j++) {
2333         Node* m = n->in(j);
2334         if (m != nullptr) {
2335           wq.push(m);
2336         }
2337       }
2338     }
2339   }
2340 #endif
2341 }
2342 
2343 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
2344   if (OptimizeUnstableIf) {
2345     _unstable_if_traps.append(trap);
2346   }
2347 }
2348 
2349 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
2350   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
2351     UnstableIfTrap* trap = _unstable_if_traps.at(i);
2352     Node* n = trap->uncommon_trap();
2353     if (!useful.member(n)) {
2354       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
2355     }
2356   }
2357 }
2358 
2359 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
2360 // or fold-compares case. Return true if succeed or not found.
2361 //
2362 // In rare cases, the found trap has been processed. It is too late to delete it. Return

2398       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
2399       Bytecodes::Code c = iter.cur_bc();
2400       Node* lhs = nullptr;
2401       Node* rhs = nullptr;
2402       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
2403         lhs = unc->peek_operand(0);
2404         rhs = unc->peek_operand(1);
2405       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
2406         lhs = unc->peek_operand(0);
2407       }
2408 
2409       ResourceMark rm;
2410       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
2411       assert(live_locals.is_valid(), "broken liveness info");
2412       int len = (int)live_locals.size();
2413 
2414       for (int i = 0; i < len; i++) {
2415         Node* local = unc->local(jvms, i);
2416         // kill local using the liveness of next_bci.
2417         // give up when the local looks like an operand to secure reexecution.
2418         if (!live_locals.at(i) && !local->is_top() && local != lhs && local != rhs) {
2419           uint idx = jvms->locoff() + i;
2420 #ifdef ASSERT
2421           if (PrintOpto && Verbose) {
2422             tty->print("[unstable_if] kill local#%d: ", idx);
2423             local->dump();
2424             tty->cr();
2425           }
2426 #endif
2427           igvn.replace_input_of(unc, idx, top());
2428           modified = true;
2429         }
2430       }
2431     }
2432 
2433     // keep the modified trap for late query
2434     if (modified) {
2435       trap->set_modified();
2436     } else {
2437       _unstable_if_traps.delete_at(i);
2438     }
2439   }
2440   igvn.optimize();
2441 }
2442 
2443 // StringOpts and late inlining of string methods
2444 void Compile::inline_string_calls(bool parse_time) {
2445   {
2446     // remove useless nodes to make the usage analysis simpler
2447     ResourceMark rm;
2448     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2449   }
2450 
2451   {
2452     ResourceMark rm;
2453     print_method(PHASE_BEFORE_STRINGOPTS, 3);

2608 
2609   if (_string_late_inlines.length() > 0) {
2610     assert(has_stringbuilder(), "inconsistent");
2611 
2612     inline_string_calls(false);
2613 
2614     if (failing())  return;
2615 
2616     inline_incrementally_cleanup(igvn);
2617   }
2618 
2619   set_inlining_incrementally(false);
2620 }
2621 
2622 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2623   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2624   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2625   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2626   // as if "inlining_incrementally() == true" were set.
2627   assert(inlining_incrementally() == false, "not allowed");
2628 #ifdef ASSERT
2629   Unique_Node_List* modified_nodes = _modified_nodes;
2630   _modified_nodes = nullptr;
2631 #endif
2632   assert(_late_inlines.length() > 0, "sanity");
2633 
2634   while (_late_inlines.length() > 0) {
2635     igvn_worklist()->ensure_empty(); // should be done with igvn
2636 
2637     while (inline_incrementally_one()) {
2638       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2639     }
2640     if (failing())  return;
2641 
2642     inline_incrementally_cleanup(igvn);
2643   }
2644   DEBUG_ONLY( _modified_nodes = modified_nodes; )
2645 }
2646 
2647 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2648   if (_loop_opts_cnt > 0) {
2649     while (major_progress() && (_loop_opts_cnt > 0)) {
2650       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2651       PhaseIdealLoop::optimize(igvn, mode);
2652       _loop_opts_cnt--;
2653       if (failing())  return false;
2654       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2655     }
2656   }
2657   return true;
2658 }
2659 
2660 // Remove edges from "root" to each SafePoint at a backward branch.
2661 // They were inserted during parsing (see add_safepoint()) to make
2662 // infinite loops without calls or exceptions visible to root, i.e.,
2663 // useful.
2664 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {

2771     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2772   }
2773   assert(!has_vbox_nodes(), "sanity");
2774 
2775   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2776     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2777     igvn_worklist()->ensure_empty(); // should be done with igvn
2778     {
2779       ResourceMark rm;
2780       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2781     }
2782     igvn.reset_from_gvn(initial_gvn());
2783     igvn.optimize();
2784     if (failing()) return;
2785   }
2786 
2787   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2788   // safepoints
2789   remove_root_to_sfpts_edges(igvn);
2790 
2791   // Process inline type nodes now that all inlining is over
2792   process_inline_types(igvn);
2793 
2794   adjust_flat_array_access_aliases(igvn);
2795 
2796   if (failing())  return;
2797 
2798   // Perform escape analysis
2799   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2800     if (has_loops()) {
2801       // Cleanup graph (remove dead nodes).
2802       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2803       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2804       if (failing())  return;
2805     }
2806     bool progress;
2807     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2808     do {
2809       ConnectionGraph::do_analysis(this, &igvn);
2810 
2811       if (failing())  return;
2812 
2813       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2814 
2815       // Optimize out fields loads from scalar replaceable allocations.

2899   if (failing())  return;
2900 
2901   // Loop transforms on the ideal graph.  Range Check Elimination,
2902   // peeling, unrolling, etc.
2903   if (!optimize_loops(igvn, LoopOptsDefault)) {
2904     return;
2905   }
2906 
2907   if (failing())  return;
2908 
2909   C->clear_major_progress(); // ensure that major progress is now clear
2910 
2911   process_for_post_loop_opts_igvn(igvn);
2912 
2913   if (failing())  return;
2914 
2915 #ifdef ASSERT
2916   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2917 #endif
2918 
2919   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2920 
2921   if (_late_inlines.length() > 0) {
2922     // More opportunities to optimize virtual and MH calls.
2923     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2924     process_late_inline_calls_no_inline(igvn);
2925   }
2926 
2927   {
2928     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2929     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2930     PhaseMacroExpand  mex(igvn);
2931     if (mex.expand_macro_nodes()) {
2932       assert(failing(), "must bail out w/ explicit message");
2933       return;
2934     }
2935     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2936   }
2937 
2938   // Process inline type nodes again and remove them. From here
2939   // on we don't need to keep track of field values anymore.
2940   process_inline_types(igvn, /* remove= */ true);
2941 
2942   {
2943     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2944     if (bs->expand_barriers(this, igvn)) {
2945       assert(failing(), "must bail out w/ explicit message");
2946       return;
2947     }
2948     print_method(PHASE_BARRIER_EXPANSION, 2);
2949   }
2950 
2951   if (C->max_vector_size() > 0) {
2952     C->optimize_logic_cones(igvn);
2953     igvn.optimize();
2954     if (failing()) return;
2955   }
2956 
2957   DEBUG_ONLY( _modified_nodes = nullptr; )
2958   DEBUG_ONLY( _late_inlines.clear(); )
2959 
2960   assert(igvn._worklist.size() == 0, "not empty");









2961  } // (End scope of igvn; run destructor if necessary for asserts.)
2962 
2963  check_no_dead_use();
2964 
2965  process_print_inlining();
2966 
2967  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2968  // to remove hashes to unlock nodes for modifications.
2969  C->node_hash()->clear();
2970 
2971  // A method with only infinite loops has no edges entering loops from root
2972  {
2973    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2974    if (final_graph_reshaping()) {
2975      assert(failing(), "must bail out w/ explicit message");
2976      return;
2977    }
2978  }
2979 
2980  print_method(PHASE_OPTIMIZE_FINISHED, 2);

4247           k->subsume_by(m, this);
4248         }
4249       }
4250     }
4251     break;
4252   }
4253   case Op_CmpUL: {
4254     if (!Matcher::has_match_rule(Op_CmpUL)) {
4255       // No support for unsigned long comparisons
4256       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
4257       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
4258       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
4259       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
4260       Node* andl = new AndLNode(orl, remove_sign_mask);
4261       Node* cmp = new CmpLNode(andl, n->in(2));
4262       n->subsume_by(cmp, this);
4263     }
4264     break;
4265   }
4266 #ifdef ASSERT
4267   case Op_InlineType: {
4268     n->dump(-1);
4269     assert(false, "inline type node was not removed");
4270     break;
4271   }
4272   case Op_ConNKlass: {
4273     const TypePtr* tp = n->as_Type()->type()->make_ptr();
4274     ciKlass* klass = tp->is_klassptr()->exact_klass();
4275     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
4276     break;
4277   }
4278 #endif
4279   default:
4280     assert(!n->is_Call(), "");
4281     assert(!n->is_Mem(), "");
4282     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
4283     break;
4284   }
4285 }
4286 
4287 //------------------------------final_graph_reshaping_walk---------------------
4288 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
4289 // requires that the walk visits a node's inputs before visiting the node.
4290 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
4291   Unique_Node_List sfpt;

4638   }
4639 }
4640 
4641 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4642   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4643 }
4644 
4645 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4646   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4647 }
4648 
4649 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4650   if (holder->is_initialized()) {
4651     return false;
4652   }
4653   if (holder->is_being_initialized()) {
4654     if (accessing_method->holder() == holder) {
4655       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4656       // <init>, or a static method. In all those cases, there was an initialization
4657       // barrier on the holder klass passed.
4658       if (accessing_method->is_class_initializer() ||
4659           accessing_method->is_object_constructor() ||
4660           accessing_method->is_static()) {
4661         return false;
4662       }
4663     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4664       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4665       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4666       // child class can become fully initialized while its parent class is still being initialized.
4667       if (accessing_method->is_class_initializer()) {
4668         return false;
4669       }
4670     }
4671     ciMethod* root = method(); // the root method of compilation
4672     if (root != accessing_method) {
4673       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4674     }
4675   }
4676   return true;
4677 }
4678 
4679 #ifndef PRODUCT
4680 //------------------------------verify_bidirectional_edges---------------------
4681 // For each input edge to a node (ie - for each Use-Def edge), verify that
4682 // there is a corresponding Def-Use edge.
4683 void Compile::verify_bidirectional_edges(Unique_Node_List &visited) {
4684   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4685   uint stack_size = live_nodes() >> 4;
4686   Node_List nstack(MAX2(stack_size, (uint)OptoNodeListSize));
4687   nstack.push(_root);

4703       if (in != nullptr && !in->is_top()) {
4704         // Count instances of `next`
4705         int cnt = 0;
4706         for (uint idx = 0; idx < in->_outcnt; idx++) {
4707           if (in->_out[idx] == n) {
4708             cnt++;
4709           }
4710         }
4711         assert(cnt > 0, "Failed to find Def-Use edge.");
4712         // Check for duplicate edges
4713         // walk the input array downcounting the input edges to n
4714         for (uint j = 0; j < length; j++) {
4715           if (n->in(j) == in) {
4716             cnt--;
4717           }
4718         }
4719         assert(cnt == 0, "Mismatched edge count.");
4720       } else if (in == nullptr) {
4721         assert(i == 0 || i >= n->req() ||
4722                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4723                (n->is_Allocate() && i >= AllocateNode::InlineType) ||
4724                (n->is_Unlock() && i == (n->req() - 1)) ||
4725                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4726               "only region, phi, arraycopy, allocate, unlock or membar nodes have null data edges");
4727       } else {
4728         assert(in->is_top(), "sanity");
4729         // Nothing to check.
4730       }
4731     }
4732   }
4733 }
4734 
4735 //------------------------------verify_graph_edges---------------------------
4736 // Walk the Graph and verify that there is a one-to-one correspondence
4737 // between Use-Def edges and Def-Use edges in the graph.
4738 void Compile::verify_graph_edges(bool no_dead_code) {
4739   if (VerifyGraphEdges) {
4740     Unique_Node_List visited;
4741 
4742     // Call graph walk to check edges
4743     verify_bidirectional_edges(visited);
4744     if (no_dead_code) {
4745       // Now make sure that no visited node is used by an unvisited node.
4746       bool dead_nodes = false;

4840 // (1) subklass is already limited to a subtype of superklass => always ok
4841 // (2) subklass does not overlap with superklass => always fail
4842 // (3) superklass has NO subtypes and we can check with a simple compare.
4843 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4844   if (skip) {
4845     return SSC_full_test;       // Let caller generate the general case.
4846   }
4847 
4848   if (subk->is_java_subtype_of(superk)) {
4849     return SSC_always_true; // (0) and (1)  this test cannot fail
4850   }
4851 
4852   if (!subk->maybe_java_subtype_of(superk)) {
4853     return SSC_always_false; // (2) true path dead; no dynamic test needed
4854   }
4855 
4856   const Type* superelem = superk;
4857   if (superk->isa_aryklassptr()) {
4858     int ignored;
4859     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4860 
4861     // Do not fold the subtype check to an array klass pointer comparison for null-able inline type arrays
4862     // because null-free [LMyValue <: null-able [LMyValue but the klasses are different. Perform a full test.
4863     if (!superk->is_aryklassptr()->is_null_free() && superk->is_aryklassptr()->elem()->isa_instklassptr() &&
4864         superk->is_aryklassptr()->elem()->is_instklassptr()->instance_klass()->is_inlinetype()) {
4865       return SSC_full_test;
4866     }
4867   }
4868 
4869   if (superelem->isa_instklassptr()) {
4870     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4871     if (!ik->has_subklass()) {
4872       if (!ik->is_final()) {
4873         // Add a dependency if there is a chance of a later subclass.
4874         dependencies()->assert_leaf_type(ik);
4875       }
4876       if (!superk->maybe_java_subtype_of(subk)) {
4877         return SSC_always_false;
4878       }
4879       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4880     }
4881   } else {
4882     // A primitive array type has no subtypes.
4883     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4884   }
4885 
4886   return SSC_full_test;

5446       const Type* t = igvn.type_or_null(n);
5447       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
5448       if (n->is_Type()) {
5449         t = n->as_Type()->type();
5450         assert(t == t->remove_speculative(), "no more speculative types");
5451       }
5452       // Iterate over outs - endless loops is unreachable from below
5453       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5454         Node *m = n->fast_out(i);
5455         if (not_a_node(m)) {
5456           continue;
5457         }
5458         worklist.push(m);
5459       }
5460     }
5461     igvn.check_no_speculative_types();
5462 #endif
5463   }
5464 }
5465 
5466 Node* Compile::optimize_acmp(PhaseGVN* phase, Node* a, Node* b) {
5467   const TypeInstPtr* ta = phase->type(a)->isa_instptr();
5468   const TypeInstPtr* tb = phase->type(b)->isa_instptr();
5469   if (!EnableValhalla || ta == nullptr || tb == nullptr ||
5470       ta->is_zero_type() || tb->is_zero_type() ||
5471       !ta->can_be_inline_type() || !tb->can_be_inline_type()) {
5472     // Use old acmp if one operand is null or not an inline type
5473     return new CmpPNode(a, b);
5474   } else if (ta->is_inlinetypeptr() || tb->is_inlinetypeptr()) {
5475     // We know that one operand is an inline type. Therefore,
5476     // new acmp will only return true if both operands are nullptr.
5477     // Check if both operands are null by or'ing the oops.
5478     a = phase->transform(new CastP2XNode(nullptr, a));
5479     b = phase->transform(new CastP2XNode(nullptr, b));
5480     a = phase->transform(new OrXNode(a, b));
5481     return new CmpXNode(a, phase->MakeConX(0));
5482   }
5483   // Use new acmp
5484   return nullptr;
5485 }
5486 
5487 // Auxiliary methods to support randomized stressing/fuzzing.
5488 
5489 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5490   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5491     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5492     FLAG_SET_ERGO(StressSeed, _stress_seed);
5493   } else {
5494     _stress_seed = StressSeed;
5495   }
5496   if (_log != nullptr) {
5497     _log->elem("stress_test seed='%u'", _stress_seed);
5498   }
5499 }
5500 
5501 int Compile::random() {
5502   _stress_seed = os::next_random(_stress_seed);
5503   return static_cast<int>(_stress_seed);
5504 }
5505 
5506 // This method can be called the arbitrary number of times, with current count
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