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src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.cpp

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rev 54386 : 8221766: Load-reference barriers for Shenandoah


  26 #include "gc/shenandoah/shenandoahHeap.hpp"
  27 #include "gc/shenandoah/shenandoahHeuristics.hpp"
  28 #include "gc/shenandoah/shenandoahRuntime.hpp"
  29 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
  30 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
  31 #include "gc/shenandoah/c2/shenandoahSupport.hpp"
  32 #include "opto/arraycopynode.hpp"
  33 #include "opto/escape.hpp"
  34 #include "opto/graphKit.hpp"
  35 #include "opto/idealKit.hpp"
  36 #include "opto/macro.hpp"
  37 #include "opto/movenode.hpp"
  38 #include "opto/narrowptrnode.hpp"
  39 #include "opto/rootnode.hpp"
  40 
  41 ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() {
  42   return reinterpret_cast<ShenandoahBarrierSetC2*>(BarrierSet::barrier_set()->barrier_set_c2());
  43 }
  44 
  45 ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena)
  46   : _shenandoah_barriers(new (comp_arena) GrowableArray<ShenandoahWriteBarrierNode*>(comp_arena, 8,  0, NULL)) {

  47 }
  48 
  49 int ShenandoahBarrierSetC2State::shenandoah_barriers_count() const {
  50   return _shenandoah_barriers->length();
  51 }
  52 
  53 ShenandoahWriteBarrierNode* ShenandoahBarrierSetC2State::shenandoah_barrier(int idx) const {
  54   return _shenandoah_barriers->at(idx);
  55 }
  56 
  57 void ShenandoahBarrierSetC2State::add_shenandoah_barrier(ShenandoahWriteBarrierNode * n) {
  58   assert(!_shenandoah_barriers->contains(n), "duplicate entry in barrier list");
  59   _shenandoah_barriers->append(n);
  60 }
  61 
  62 void ShenandoahBarrierSetC2State::remove_shenandoah_barrier(ShenandoahWriteBarrierNode * n) {
  63   if (_shenandoah_barriers->contains(n)) {
  64     _shenandoah_barriers->remove(n);
  65   }
  66 }
  67 
  68 #define __ kit->
  69 
  70 Node* ShenandoahBarrierSetC2::shenandoah_read_barrier(GraphKit* kit, Node* obj) const {
  71   if (ShenandoahReadBarrier) {
  72     obj = shenandoah_read_barrier_impl(kit, obj, false, true, true);
  73   }
  74   return obj;
  75 }
  76 
  77 Node* ShenandoahBarrierSetC2::shenandoah_storeval_barrier(GraphKit* kit, Node* obj) const {
  78   if (ShenandoahStoreValEnqueueBarrier) {
  79     obj = shenandoah_write_barrier(kit, obj);
  80     obj = shenandoah_enqueue_barrier(kit, obj);
  81   }
  82   if (ShenandoahStoreValReadBarrier) {
  83     obj = shenandoah_read_barrier_impl(kit, obj, true, false, false);
  84   }
  85   return obj;
  86 }
  87 
  88 Node* ShenandoahBarrierSetC2::shenandoah_read_barrier_impl(GraphKit* kit, Node* obj, bool use_ctrl, bool use_mem, bool allow_fromspace) const {
  89   const Type* obj_type = obj->bottom_type();
  90   if (obj_type->higher_equal(TypePtr::NULL_PTR)) {
  91     return obj;
  92   }
  93   const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(obj_type);
  94   Node* mem = use_mem ? __ memory(adr_type) : __ immutable_memory();
  95 
  96   if (! ShenandoahBarrierNode::needs_barrier(&__ gvn(), NULL, obj, mem, allow_fromspace)) {
  97     // We know it is null, no barrier needed.
  98     return obj;
  99   }
 100 
 101   if (obj_type->meet(TypePtr::NULL_PTR) == obj_type->remove_speculative()) {
 102 
 103     // We don't know if it's null or not. Need null-check.
 104     enum { _not_null_path = 1, _null_path, PATH_LIMIT };
 105     RegionNode* region = new RegionNode(PATH_LIMIT);
 106     Node*       phi    = new PhiNode(region, obj_type);
 107     Node* null_ctrl = __ top();
 108     Node* not_null_obj = __ null_check_oop(obj, &null_ctrl);
 109 
 110     region->init_req(_null_path, null_ctrl);
 111     phi   ->init_req(_null_path, __ zerocon(T_OBJECT));
 112 
 113     Node* ctrl = use_ctrl ? __ control() : NULL;
 114     ShenandoahReadBarrierNode* rb = new ShenandoahReadBarrierNode(ctrl, mem, not_null_obj, allow_fromspace);
 115     Node* n = __ gvn().transform(rb);
 116 
 117     region->init_req(_not_null_path, __ control());
 118     phi   ->init_req(_not_null_path, n);
 119 
 120     __ set_control(__ gvn().transform(region));
 121     __ record_for_igvn(region);
 122     return __ gvn().transform(phi);
 123 
 124   } else {
 125     // We know it is not null. Simple barrier is sufficient.
 126     Node* ctrl = use_ctrl ? __ control() : NULL;
 127     ShenandoahReadBarrierNode* rb = new ShenandoahReadBarrierNode(ctrl, mem, obj, allow_fromspace);
 128     Node* n = __ gvn().transform(rb);
 129     __ record_for_igvn(n);
 130     return n;
 131   }
 132 }
 133 
 134 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier_helper(GraphKit* kit, Node* obj, const TypePtr* adr_type) const {
 135   ShenandoahWriteBarrierNode* wb = new ShenandoahWriteBarrierNode(kit->C, kit->control(), kit->memory(adr_type), obj);
 136   Node* n = __ gvn().transform(wb);
 137   if (n == wb) { // New barrier needs memory projection.
 138     Node* proj = __ gvn().transform(new ShenandoahWBMemProjNode(n));
 139     __ set_memory(proj, adr_type);
 140   }
 141   return n;
 142 }
 143 
 144 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier(GraphKit* kit, Node* obj) const {
 145   if (ShenandoahWriteBarrier) {
 146     obj = shenandoah_write_barrier_impl(kit, obj);
 147   }
 148   return obj;
 149 }
 150 
 151 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier_impl(GraphKit* kit, Node* obj) const {
 152   if (! ShenandoahBarrierNode::needs_barrier(&__ gvn(), NULL, obj, NULL, true)) {
 153     return obj;
 154   }
 155   const Type* obj_type = obj->bottom_type();
 156   const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(obj_type);
 157   Node* n = shenandoah_write_barrier_helper(kit, obj, adr_type);
 158   __ record_for_igvn(n);
 159   return n;
 160 }
 161 
 162 bool ShenandoahBarrierSetC2::satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr,
 163                                                          BasicType bt, uint adr_idx) const {
 164   intptr_t offset = 0;
 165   Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
 166   AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
 167 
 168   if (offset == Type::OffsetBot) {
 169     return false; // cannot unalias unless there are precise offsets
 170   }
 171 
 172   if (alloc == NULL) {
 173     return false; // No allocation found
 174   }
 175 
 176   intptr_t size_in_bytes = type2aelembytes(bt);
 177 
 178   Node* mem = __ memory(adr_idx); // start searching here...
 179 
 180   for (int cnt = 0; cnt < 50; cnt++) {


 287   Node* no_base = __ top();
 288   Node* zero  = __ ConI(0);
 289   Node* zeroX = __ ConX(0);
 290 
 291   float likely  = PROB_LIKELY(0.999);
 292   float unlikely  = PROB_UNLIKELY(0.999);
 293 
 294   // Offsets into the thread
 295   const int index_offset   = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset());
 296   const int buffer_offset  = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset());
 297 
 298   // Now the actual pointers into the thread
 299   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
 300   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
 301 
 302   // Now some of the values
 303   Node* marking;
 304   Node* gc_state = __ AddP(no_base, tls, __ ConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset())));
 305   Node* ld = __ load(__ ctrl(), gc_state, TypeInt::BYTE, T_BYTE, Compile::AliasIdxRaw);
 306   marking = __ AndI(ld, __ ConI(ShenandoahHeap::MARKING));
 307   assert(ShenandoahWriteBarrierNode::is_gc_state_load(ld), "Should match the shape");
 308 
 309   // if (!marking)
 310   __ if_then(marking, BoolTest::ne, zero, unlikely); {
 311     BasicType index_bt = TypeX_X->basic_type();
 312     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
 313     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
 314 
 315     if (do_load) {
 316       // load original value
 317       // alias_idx correct??
 318       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
 319     }
 320 
 321     // if (pre_val != NULL)
 322     __ if_then(pre_val, BoolTest::ne, kit->null()); {
 323       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
 324 
 325       // is the queue for this thread full?
 326       __ if_then(index, BoolTest::ne, zeroX, likely); {
 327 


 344   } __ end_if();  // (!marking)
 345 
 346   // Final sync IdealKit and GraphKit.
 347   kit->final_sync(ideal);
 348 
 349   if (ShenandoahSATBBarrier && adr != NULL) {
 350     Node* c = kit->control();
 351     Node* call = c->in(1)->in(1)->in(1)->in(0);
 352     assert(is_shenandoah_wb_pre_call(call), "shenandoah_wb_pre call expected");
 353     call->add_req(adr);
 354   }
 355 }
 356 
 357 bool ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(Node* call) {
 358   return call->is_CallLeaf() &&
 359          call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry);
 360 }
 361 
 362 bool ShenandoahBarrierSetC2::is_shenandoah_wb_call(Node* call) {
 363   return call->is_CallLeaf() &&
 364          call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_JRT);
 365 }
 366 
 367 bool ShenandoahBarrierSetC2::is_shenandoah_marking_if(PhaseTransform *phase, Node* n) {
 368   if (n->Opcode() != Op_If) {
 369     return false;
 370   }
 371 
 372   Node* bol = n->in(1);
 373   assert(bol->is_Bool(), "");
 374   Node* cmpx = bol->in(1);
 375   if (bol->as_Bool()->_test._test == BoolTest::ne &&
 376       cmpx->is_Cmp() && cmpx->in(2) == phase->intcon(0) &&
 377       is_shenandoah_state_load(cmpx->in(1)->in(1)) &&
 378       cmpx->in(1)->in(2)->is_Con() &&
 379       cmpx->in(1)->in(2) == phase->intcon(ShenandoahHeap::MARKING)) {
 380     return true;
 381   }
 382 
 383   return false;
 384 }


 532   // create result type (range)
 533   fields = TypeTuple::fields(0);
 534   const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields);
 535 
 536   return TypeFunc::make(domain, range);
 537 }
 538 
 539 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_write_barrier_Type() {
 540   const Type **fields = TypeTuple::fields(1);
 541   fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
 542   const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields);
 543 
 544   // create result type (range)
 545   fields = TypeTuple::fields(1);
 546   fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL;
 547   const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields);
 548 
 549   return TypeFunc::make(domain, range);
 550 }
 551 
 552 void ShenandoahBarrierSetC2::resolve_address(C2Access& access) const {
 553   const TypePtr* adr_type = access.addr().type();
 554 
 555   if ((access.decorators() & IN_NATIVE) == 0 && (adr_type->isa_instptr() || adr_type->isa_aryptr())) {
 556     int off = adr_type->is_ptr()->offset();
 557     int base_off = adr_type->isa_instptr() ? instanceOopDesc::base_offset_in_bytes() :
 558       arrayOopDesc::base_offset_in_bytes(adr_type->is_aryptr()->elem()->array_element_basic_type());
 559     assert(off != Type::OffsetTop, "unexpected offset");
 560     if (off == Type::OffsetBot || off >= base_off) {
 561       DecoratorSet decorators = access.decorators();
 562       bool is_write = (decorators & C2_WRITE_ACCESS) != 0;
 563       GraphKit* kit = NULL;
 564       if (access.is_parse_access()) {
 565         C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
 566         kit = parse_access.kit();
 567       }
 568       Node* adr = access.addr().node();
 569       assert(adr->is_AddP(), "unexpected address shape");
 570       Node* base = adr->in(AddPNode::Base);
 571 
 572       if (is_write) {
 573         if (kit != NULL) {
 574           base = shenandoah_write_barrier(kit, base);
 575         } else {
 576           assert(access.is_opt_access(), "either parse or opt access");
 577           assert((access.decorators() & C2_ARRAY_COPY) != 0, "can be skipped for clone");
 578         }
 579       } else {
 580         if (adr_type->isa_instptr()) {
 581           Compile* C = access.gvn().C;
 582           ciField* field = C->alias_type(adr_type)->field();
 583 
 584           // Insert read barrier for Shenandoah.
 585           if (field != NULL &&
 586               ((ShenandoahOptimizeStaticFinals   && field->is_static()  && field->is_final()) ||
 587                (ShenandoahOptimizeInstanceFinals && !field->is_static() && field->is_final()) ||
 588                (ShenandoahOptimizeStableFinals   && field->is_stable()))) {
 589             // Skip the barrier for special fields
 590           } else {
 591             if (kit != NULL) {
 592               base = shenandoah_read_barrier(kit, base);
 593             } else {
 594               assert(access.is_opt_access(), "either parse or opt access");
 595               assert((access.decorators() & C2_ARRAY_COPY) != 0, "can be skipped for arraycopy");
 596             }
 597           }
 598         } else {
 599           if (kit != NULL) {
 600             base = shenandoah_read_barrier(kit, base);
 601           } else {
 602             assert(access.is_opt_access(), "either parse or opt access");
 603             assert((access.decorators() & C2_ARRAY_COPY) != 0, "can be skipped for arraycopy");
 604           }
 605         }
 606       }
 607       if (base != adr->in(AddPNode::Base)) {
 608         assert(kit != NULL, "no barrier should have been added");
 609 
 610         Node* address = adr->in(AddPNode::Address);
 611 
 612         if (address->is_AddP()) {
 613           assert(address->in(AddPNode::Base) == adr->in(AddPNode::Base), "unexpected address shape");
 614           assert(!address->in(AddPNode::Address)->is_AddP(), "unexpected address shape");
 615           assert(address->in(AddPNode::Address) == adr->in(AddPNode::Base), "unexpected address shape");
 616           address = address->clone();
 617           address->set_req(AddPNode::Base, base);
 618           address->set_req(AddPNode::Address, base);
 619           address = kit->gvn().transform(address);
 620         } else {
 621           assert(address == adr->in(AddPNode::Base), "unexpected address shape");
 622           address = base;
 623         }
 624         adr = adr->clone();
 625         adr->set_req(AddPNode::Base, base);
 626         adr->set_req(AddPNode::Address, address);
 627         adr = kit->gvn().transform(adr);
 628         access.addr().set_node(adr);
 629       }
 630     }
 631   }
 632 }
 633 
 634 Node* ShenandoahBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const {
 635   DecoratorSet decorators = access.decorators();
 636 
 637   const TypePtr* adr_type = access.addr().type();
 638   Node* adr = access.addr().node();
 639 
 640   bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
 641   bool on_heap = (decorators & IN_HEAP) != 0;
 642 
 643   if (!access.is_oop() || (!on_heap && !anonymous)) {
 644     return BarrierSetC2::store_at_resolved(access, val);
 645   }
 646 
 647   if (access.is_parse_access()) {
 648     C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
 649     GraphKit* kit = parse_access.kit();
 650 
 651     uint adr_idx = kit->C->get_alias_index(adr_type);
 652     assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
 653     Node* value = val.node();
 654     value = shenandoah_storeval_barrier(kit, value);
 655     val.set_node(value);
 656     shenandoah_write_barrier_pre(kit, true /* do_load */, /*kit->control(),*/ access.base(), adr, adr_idx, val.node(),
 657                                  static_cast<const TypeOopPtr*>(val.type()), NULL /* pre_val */, access.type());
 658   } else {
 659     assert(access.is_opt_access(), "only for optimization passes");
 660     assert(((decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0 || !ShenandoahSATBBarrier) && (decorators & C2_ARRAY_COPY) != 0, "unexpected caller of this code");
 661     C2OptAccess& opt_access = static_cast<C2OptAccess&>(access);
 662     PhaseGVN& gvn =  opt_access.gvn();
 663     MergeMemNode* mm = opt_access.mem();
 664 
 665     if (ShenandoahStoreValReadBarrier) {
 666       RegionNode* region = new RegionNode(3);
 667       const Type* v_t = gvn.type(val.node());
 668       Node* phi = new PhiNode(region, v_t->isa_oopptr() ? v_t->is_oopptr()->cast_to_nonconst() : v_t);
 669       Node* cmp = gvn.transform(new CmpPNode(val.node(), gvn.zerocon(T_OBJECT)));
 670       Node* bol = gvn.transform(new BoolNode(cmp, BoolTest::ne));
 671       IfNode* iff = new IfNode(opt_access.ctl(), bol, PROB_LIKELY_MAG(3), COUNT_UNKNOWN);
 672 
 673       gvn.transform(iff);
 674       if (gvn.is_IterGVN()) {
 675         gvn.is_IterGVN()->_worklist.push(iff);
 676       } else {
 677         gvn.record_for_igvn(iff);
 678       }
 679 
 680       Node* null_true = gvn.transform(new IfFalseNode(iff));
 681       Node* null_false = gvn.transform(new IfTrueNode(iff));
 682       region->init_req(1, null_true);
 683       region->init_req(2, null_false);
 684       phi->init_req(1, gvn.zerocon(T_OBJECT));
 685       Node* cast = new CastPPNode(val.node(), gvn.type(val.node())->join_speculative(TypePtr::NOTNULL));
 686       cast->set_req(0, null_false);
 687       cast = gvn.transform(cast);
 688       Node* rb = gvn.transform(new ShenandoahReadBarrierNode(null_false, gvn.C->immutable_memory(), cast, false));
 689       phi->init_req(2, rb);
 690       opt_access.set_ctl(gvn.transform(region));
 691       val.set_node(gvn.transform(phi));
 692     }
 693     if (ShenandoahStoreValEnqueueBarrier) {
 694       const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(gvn.type(val.node()));
 695       int alias = gvn.C->get_alias_index(adr_type);
 696       Node* wb = new ShenandoahWriteBarrierNode(gvn.C, opt_access.ctl(), mm->memory_at(alias), val.node());
 697       Node* wb_transformed = gvn.transform(wb);
 698       Node* enqueue = gvn.transform(new ShenandoahEnqueueBarrierNode(wb_transformed));
 699       if (wb_transformed == wb) {
 700         Node* proj = gvn.transform(new ShenandoahWBMemProjNode(wb));
 701         mm->set_memory_at(alias, proj);
 702       }
 703       val.set_node(enqueue);
 704     }
 705   }
 706   return BarrierSetC2::store_at_resolved(access, val);
 707 }
 708 
 709 Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {
 710   DecoratorSet decorators = access.decorators();
 711 
 712   Node* adr = access.addr().node();
 713   Node* obj = access.base();
 714 
 715   bool mismatched = (decorators & C2_MISMATCHED) != 0;
 716   bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0;
 717   bool on_heap = (decorators & IN_HEAP) != 0;
 718   bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
 719   bool is_unordered = (decorators & MO_UNORDERED) != 0;
 720   bool need_cpu_mem_bar = !is_unordered || mismatched || !on_heap;
 721 
 722   Node* top = Compile::current()->top();
 723 
 724   Node* offset = adr->is_AddP() ? adr->in(AddPNode::Offset) : top;
 725   Node* load = BarrierSetC2::load_at_resolved(access, val_type);
 726 











 727   // If we are reading the value of the referent field of a Reference
 728   // object (either by using Unsafe directly or through reflection)
 729   // then, if SATB is enabled, we need to record the referent in an
 730   // SATB log buffer using the pre-barrier mechanism.
 731   // Also we need to add memory barrier to prevent commoning reads
 732   // from this field across safepoint since GC can change its value.
 733   bool need_read_barrier = ShenandoahKeepAliveBarrier &&
 734     (on_heap && (on_weak || (unknown && offset != top && obj != top)));
 735 
 736   if (!access.is_oop() || !need_read_barrier) {
 737     return load;
 738   }
 739 
 740   assert(access.is_parse_access(), "entry not supported at optimization time");
 741   C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
 742   GraphKit* kit = parse_access.kit();
 743 
 744   if (on_weak) {
 745     // Use the pre-barrier to record the value in the referent field
 746     satb_write_barrier_pre(kit, false /* do_load */,


 780       if (ShenandoahCASBarrier) {
 781         load_store = kit->gvn().transform(new ShenandoahCompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo));
 782       } else {
 783         load_store = kit->gvn().transform(new CompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo));
 784       }
 785     } else
 786 #endif
 787     {
 788       if (ShenandoahCASBarrier) {
 789         load_store = kit->gvn().transform(new ShenandoahCompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo));
 790       } else {
 791         load_store = kit->gvn().transform(new CompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo));
 792       }
 793     }
 794 
 795     access.set_raw_access(load_store);
 796     pin_atomic_op(access);
 797 
 798 #ifdef _LP64
 799     if (adr->bottom_type()->is_ptr_to_narrowoop()) {
 800       return kit->gvn().transform(new DecodeNNode(load_store, load_store->get_ptr_type()));
 801     }
 802 #endif

 803     return load_store;
 804   }
 805   return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);
 806 }
 807 
 808 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
 809                                                               Node* new_val, const Type* value_type) const {
 810   GraphKit* kit = access.kit();
 811   if (access.is_oop()) {
 812     new_val = shenandoah_storeval_barrier(kit, new_val);
 813     shenandoah_write_barrier_pre(kit, false /* do_load */,
 814                                  NULL, NULL, max_juint, NULL, NULL,
 815                                  expected_val /* pre_val */, T_OBJECT);
 816     DecoratorSet decorators = access.decorators();
 817     MemNode::MemOrd mo = access.mem_node_mo();
 818     Node* mem = access.memory();
 819     bool is_weak_cas = (decorators & C2_WEAK_CMPXCHG) != 0;
 820     Node* load_store = NULL;
 821     Node* adr = access.addr().node();
 822 #ifdef _LP64


 850           load_store = kit->gvn().transform(new WeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
 851         } else {
 852           load_store = kit->gvn().transform(new CompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
 853         }
 854       }
 855     }
 856     access.set_raw_access(load_store);
 857     pin_atomic_op(access);
 858     return load_store;
 859   }
 860   return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);
 861 }
 862 
 863 Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* val, const Type* value_type) const {
 864   GraphKit* kit = access.kit();
 865   if (access.is_oop()) {
 866     val = shenandoah_storeval_barrier(kit, val);
 867   }
 868   Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type);
 869   if (access.is_oop()) {

 870     shenandoah_write_barrier_pre(kit, false /* do_load */,
 871                                  NULL, NULL, max_juint, NULL, NULL,
 872                                  result /* pre_val */, T_OBJECT);
 873   }
 874   return result;
 875 }
 876 
 877 void ShenandoahBarrierSetC2::clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const {
 878   assert(!src->is_AddP(), "unexpected input");
 879   src = shenandoah_read_barrier(kit, src);
 880   BarrierSetC2::clone(kit, src, dst, size, is_array);
 881 }
 882 
 883 Node* ShenandoahBarrierSetC2::resolve(GraphKit* kit, Node* n, DecoratorSet decorators) const {
 884   bool is_write = decorators & ACCESS_WRITE;
 885   if (is_write) {
 886     return shenandoah_write_barrier(kit, n);
 887   } else {
 888   return shenandoah_read_barrier(kit, n);
 889   }
 890 }
 891 
 892 Node* ShenandoahBarrierSetC2::obj_allocate(PhaseMacroExpand* macro, Node* ctrl, Node* mem, Node* toobig_false, Node* size_in_bytes,
 893                                            Node*& i_o, Node*& needgc_ctrl,
 894                                            Node*& fast_oop_ctrl, Node*& fast_oop_rawmem,
 895                                            intx prefetch_lines) const {
 896   PhaseIterGVN& igvn = macro->igvn();
 897 
 898   // Allocate several words more for the Shenandoah brooks pointer.
 899   size_in_bytes = new AddXNode(size_in_bytes, igvn.MakeConX(ShenandoahBrooksPointer::byte_size()));
 900   macro->transform_later(size_in_bytes);
 901 
 902   Node* fast_oop = BarrierSetC2::obj_allocate(macro, ctrl, mem, toobig_false, size_in_bytes,
 903                                               i_o, needgc_ctrl, fast_oop_ctrl, fast_oop_rawmem,
 904                                               prefetch_lines);
 905 
 906   // Bump up object for Shenandoah brooks pointer.
 907   fast_oop = new AddPNode(macro->top(), fast_oop, igvn.MakeConX(ShenandoahBrooksPointer::byte_size()));
 908   macro->transform_later(fast_oop);
 909 
 910   // Initialize Shenandoah brooks pointer to point to the object itself.
 911   fast_oop_rawmem = macro->make_store(fast_oop_ctrl, fast_oop_rawmem, fast_oop, ShenandoahBrooksPointer::byte_offset(), fast_oop, T_OBJECT);
 912 
 913   return fast_oop;
 914 }
 915 
 916 // Support for GC barriers emitted during parsing
 917 bool ShenandoahBarrierSetC2::is_gc_barrier_node(Node* node) const {

 918   if (node->Opcode() != Op_CallLeaf && node->Opcode() != Op_CallLeafNoFP) {
 919     return false;
 920   }
 921   CallLeafNode *call = node->as_CallLeaf();
 922   if (call->_name == NULL) {
 923     return false;
 924   }
 925 
 926   return strcmp(call->_name, "shenandoah_clone_barrier") == 0 ||
 927          strcmp(call->_name, "shenandoah_cas_obj") == 0 ||
 928          strcmp(call->_name, "shenandoah_wb_pre") == 0;
 929 }
 930 
 931 Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) const {
 932   return ShenandoahBarrierNode::skip_through_barrier(c);






 933 }
 934 
 935 bool ShenandoahBarrierSetC2::expand_barriers(Compile* C, PhaseIterGVN& igvn) const {
 936   return !ShenandoahWriteBarrierNode::expand(C, igvn);
 937 }
 938 
 939 bool ShenandoahBarrierSetC2::optimize_loops(PhaseIdealLoop* phase, LoopOptsMode mode, VectorSet& visited, Node_Stack& nstack, Node_List& worklist) const {
 940   if (mode == LoopOptsShenandoahExpand) {
 941     assert(UseShenandoahGC, "only for shenandoah");
 942     ShenandoahWriteBarrierNode::pin_and_expand(phase);
 943     return true;
 944   } else if (mode == LoopOptsShenandoahPostExpand) {
 945     assert(UseShenandoahGC, "only for shenandoah");
 946     visited.Clear();
 947     ShenandoahWriteBarrierNode::optimize_after_expansion(visited, nstack, worklist, phase);
 948     return true;
 949   }
 950   GrowableArray<MemoryGraphFixer*> memory_graph_fixers;
 951   ShenandoahWriteBarrierNode::optimize_before_expansion(phase, memory_graph_fixers, false);
 952   return false;
 953 }
 954 
 955 bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const {
 956   bool is_oop = type == T_OBJECT || type == T_ARRAY;
 957   if (!is_oop) {
 958     return false;
 959   }
 960 
 961   if (tightly_coupled_alloc) {
 962     if (phase == Optimization) {
 963       return false;
 964     }
 965     return !is_clone;
 966   }
 967   if (phase == Optimization) {
 968     return !ShenandoahStoreValEnqueueBarrier;
 969   }
 970   return true;
 971 }
 972 
 973 bool ShenandoahBarrierSetC2::clone_needs_postbarrier(ArrayCopyNode *ac, PhaseIterGVN& igvn) {
 974   Node* src = ac->in(ArrayCopyNode::Src);
 975   const TypeOopPtr* src_type = igvn.type(src)->is_oopptr();
 976   if (src_type->isa_instptr() != NULL) {
 977     ciInstanceKlass* ik = src_type->klass()->as_instance_klass();
 978     if ((src_type->klass_is_exact() || (!ik->is_interface() && !ik->has_subklass())) && !ik->has_injected_fields()) {
 979       if (ik->has_object_fields()) {
 980         return true;


1021   barrier_call->init_req(TypeFunc::Memory , m);
1022   barrier_call->init_req(TypeFunc::ReturnAdr, igvn.C->top());
1023   barrier_call->init_req(TypeFunc::FramePtr, igvn.C->top());
1024   barrier_call->init_req(TypeFunc::Parms+0, dest->in(AddPNode::Base));
1025 
1026   barrier_call = igvn.transform(barrier_call);
1027   c = new ProjNode(barrier_call,TypeFunc::Control);
1028   c = igvn.transform(c);
1029   m = new ProjNode(barrier_call, TypeFunc::Memory);
1030   m = igvn.transform(m);
1031 
1032   Node* out_c = ac->proj_out(TypeFunc::Control);
1033   Node* out_m = ac->proj_out(TypeFunc::Memory);
1034   igvn.replace_node(out_c, c);
1035   igvn.replace_node(out_m, m);
1036 }
1037 
1038 
1039 // Support for macro expanded GC barriers
1040 void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const {
1041   if (node->Opcode() == Op_ShenandoahWriteBarrier) {
1042     state()->add_shenandoah_barrier((ShenandoahWriteBarrierNode*) node);



1043   }
1044 }
1045 
1046 void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const {
1047   if (node->Opcode() == Op_ShenandoahWriteBarrier) {
1048     state()->remove_shenandoah_barrier((ShenandoahWriteBarrierNode*) node);



1049   }
1050 }
1051 
1052 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* n) const {
1053   if (is_shenandoah_wb_pre_call(n)) {
1054     shenandoah_eliminate_wb_pre(n, &macro->igvn());
1055   }
1056 }
1057 
1058 void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const {
1059   assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), "");
1060   Node* c = call->as_Call()->proj_out(TypeFunc::Control);
1061   c = c->unique_ctrl_out();
1062   assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1063   c = c->unique_ctrl_out();
1064   assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1065   Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
1066   assert(iff->is_If(), "expect test");
1067   if (!is_shenandoah_marking_if(igvn, iff)) {
1068     c = c->unique_ctrl_out();


1074   igvn->replace_node(cmpx, igvn->makecon(TypeInt::CC_EQ));
1075   igvn->rehash_node_delayed(call);
1076   call->del_req(call->req()-1);
1077 }
1078 
1079 void ShenandoahBarrierSetC2::enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const {
1080   if (node->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(node)) {
1081     igvn->add_users_to_worklist(node);
1082   }
1083 }
1084 
1085 void ShenandoahBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const {
1086   for (uint i = 0; i < useful.size(); i++) {
1087     Node* n = useful.at(i);
1088     if (n->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(n)) {
1089       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1090         C->record_for_igvn(n->fast_out(i));
1091       }
1092     }
1093   }
1094   for (int i = state()->shenandoah_barriers_count()-1; i >= 0; i--) {
1095     ShenandoahWriteBarrierNode* n = state()->shenandoah_barrier(i);
1096     if (!useful.member(n)) {
1097       state()->remove_shenandoah_barrier(n);






1098     }
1099   }
1100 
1101 }
1102 
1103 bool ShenandoahBarrierSetC2::has_special_unique_user(const Node* node) const {
1104   assert(node->outcnt() == 1, "match only for unique out");
1105   Node* n = node->unique_out();
1106   return node->Opcode() == Op_ShenandoahWriteBarrier && n->Opcode() == Op_ShenandoahWBMemProj;
1107 }
1108 
1109 void ShenandoahBarrierSetC2::add_users_to_worklist(Unique_Node_List* worklist) const {}
1110 
1111 void* ShenandoahBarrierSetC2::create_barrier_state(Arena* comp_arena) const {
1112   return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena);
1113 }
1114 
1115 ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const {
1116   return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state());
1117 }
1118 
1119 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be
1120 // expanded later, then now is the time to do so.
1121 bool ShenandoahBarrierSetC2::expand_macro_nodes(PhaseMacroExpand* macro) const { return false; }
1122 
1123 #ifdef ASSERT
1124 void ShenandoahBarrierSetC2::verify_gc_barriers(Compile* compile, CompilePhase phase) const {
1125   if (ShenandoahVerifyOptoBarriers && phase == BarrierSetC2::BeforeExpand) {
1126     ShenandoahBarrierNode::verify(Compile::current()->root());
1127   } else if (phase == BarrierSetC2::BeforeCodeGen) {
1128     // Verify G1 pre-barriers
1129     const int marking_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset());
1130 
1131     ResourceArea *area = Thread::current()->resource_area();
1132     Unique_Node_List visited(area);
1133     Node_List worklist(area);
1134     // We're going to walk control flow backwards starting from the Root
1135     worklist.push(compile->root());
1136     while (worklist.size() > 0) {
1137       Node *x = worklist.pop();
1138       if (x == NULL || x == compile->top()) continue;
1139       if (visited.member(x)) {
1140         continue;
1141       } else {
1142         visited.push(x);
1143       }
1144 
1145       if (x->is_Region()) {
1146         for (uint i = 1; i < x->req(); i++) {


1212     PhaseIterGVN* igvn = phase->is_IterGVN();
1213     if (in1 != n->in(1)) {
1214       if (igvn != NULL) {
1215         n->set_req_X(1, in1, igvn);
1216       } else {
1217         n->set_req(1, in1);
1218       }
1219       assert(in2 == n->in(2), "only one change");
1220       return n;
1221     }
1222     if (in2 != n->in(2)) {
1223       if (igvn != NULL) {
1224         n->set_req_X(2, in2, igvn);
1225       } else {
1226         n->set_req(2, in2);
1227       }
1228       return n;
1229     }
1230   } else if (can_reshape &&
1231              n->Opcode() == Op_If &&
1232              ShenandoahWriteBarrierNode::is_heap_stable_test(n) &&
1233              n->in(0) != NULL) {
1234     Node* dom = n->in(0);
1235     Node* prev_dom = n;
1236     int op = n->Opcode();
1237     int dist = 16;
1238     // Search up the dominator tree for another heap stable test
1239     while (dom->Opcode() != op    ||  // Not same opcode?
1240            !ShenandoahWriteBarrierNode::is_heap_stable_test(dom) ||  // Not same input 1?
1241            prev_dom->in(0) != dom) {  // One path of test does not dominate?
1242       if (dist < 0) return NULL;
1243 
1244       dist--;
1245       prev_dom = dom;
1246       dom = IfNode::up_one_dom(dom);
1247       if (!dom) return NULL;
1248     }
1249 
1250     // Check that we did not follow a loop back to ourselves
1251     if (n == dom) {
1252       return NULL;
1253     }
1254 
1255     return n->as_If()->dominated_by(prev_dom, phase->is_IterGVN());
1256   }
1257 
1258   return NULL;
1259 }
1260 
1261 Node* ShenandoahBarrierSetC2::identity_node(PhaseGVN* phase, Node* n) const {
1262   if (n->is_Load()) {
1263     Node *mem = n->in(MemNode::Memory);
1264     Node *value = n->as_Load()->can_see_stored_value(mem, phase);
1265     if (value) {
1266       PhaseIterGVN *igvn = phase->is_IterGVN();
1267       if (igvn != NULL &&
1268           value->is_Phi() &&
1269           value->req() > 2 &&
1270           value->in(1) != NULL &&
1271           value->in(1)->is_ShenandoahBarrier()) {
1272         if (igvn->_worklist.member(value) ||
1273             igvn->_worklist.member(value->in(0)) ||
1274             (value->in(0)->in(1) != NULL &&
1275              value->in(0)->in(1)->is_IfProj() &&
1276              (igvn->_worklist.member(value->in(0)->in(1)) ||
1277               (value->in(0)->in(1)->in(0) != NULL &&
1278                igvn->_worklist.member(value->in(0)->in(1)->in(0)))))) {
1279           igvn->_worklist.push(n);
1280           return n;
1281         }
1282       }
1283       // (This works even when value is a Con, but LoadNode::Value
1284       // usually runs first, producing the singleton type of the Con.)
1285       Node *value_no_barrier = step_over_gc_barrier(value->Opcode() == Op_EncodeP ? value->in(1) : value);
1286       if (value->Opcode() == Op_EncodeP) {
1287         if (value_no_barrier != value->in(1)) {
1288           Node *encode = value->clone();
1289           encode->set_req(1, value_no_barrier);
1290           encode = phase->transform(encode);
1291           return encode;
1292         }
1293       } else {
1294         return value_no_barrier;
1295       }
1296     }
1297   }
1298   return n;
1299 }
1300 
1301 bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) {
1302   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1303     Node* u = n->fast_out(i);
1304     if (!is_shenandoah_wb_pre_call(u)) {
1305       return false;
1306     }
1307   }
1308   return n->outcnt() > 0;
1309 }
1310 
1311 bool ShenandoahBarrierSetC2::flatten_gc_alias_type(const TypePtr*& adr_type) const {
1312   int offset = adr_type->offset();
1313   if (offset == ShenandoahBrooksPointer::byte_offset()) {
1314     if (adr_type->isa_aryptr()) {
1315       adr_type = TypeAryPtr::make(adr_type->ptr(), adr_type->isa_aryptr()->ary(), adr_type->isa_aryptr()->klass(), false, offset);
1316     } else if (adr_type->isa_instptr()) {
1317       adr_type = TypeInstPtr::make(adr_type->ptr(), ciEnv::current()->Object_klass(), false, NULL, offset);
1318     }
1319     return true;
1320   } else {
1321     return false;
1322   }
1323 }
1324 
1325 bool ShenandoahBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode) const {
1326   switch (opcode) {
1327     case Op_CallLeaf:
1328     case Op_CallLeafNoFP: {
1329       assert (n->is_Call(), "");
1330       CallNode *call = n->as_Call();
1331       if (ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(call)) {
1332         uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt();
1333         if (call->req() > cnt) {
1334           assert(call->req() == cnt + 1, "only one extra input");
1335           Node *addp = call->in(cnt);
1336           assert(!ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(addp), "useless address computation?");
1337           call->del_req(cnt);
1338         }
1339       }
1340       return false;
1341     }
1342     case Op_ShenandoahCompareAndSwapP:
1343     case Op_ShenandoahCompareAndSwapN:
1344     case Op_ShenandoahWeakCompareAndSwapN:
1345     case Op_ShenandoahWeakCompareAndSwapP:
1346     case Op_ShenandoahCompareAndExchangeP:
1347     case Op_ShenandoahCompareAndExchangeN:
1348 #ifdef ASSERT
1349       if( VerifyOptoOopOffsets ) {
1350         MemNode* mem  = n->as_Mem();
1351         // Check to see if address types have grounded out somehow.
1352         const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
1353         ciInstanceKlass *k = tp->klass()->as_instance_klass();
1354         bool oop_offset_is_sane = k->contains_field_offset(tp->offset());
1355         assert( !tp || oop_offset_is_sane, "" );
1356       }
1357 #endif
1358       return true;
1359     case Op_ShenandoahReadBarrier:
1360       return true;
1361     case Op_ShenandoahWriteBarrier:
1362       assert(false, "should have been expanded already");
1363       return true;
1364     default:
1365       return false;
1366   }
1367 }
1368 
1369 #ifdef ASSERT
1370 bool ShenandoahBarrierSetC2::verify_gc_alias_type(const TypePtr* adr_type, int offset) const {
1371   if (offset == ShenandoahBrooksPointer::byte_offset() &&
1372       (adr_type->base() == Type::AryPtr || adr_type->base() == Type::OopPtr)) {
1373     return true;
1374   } else {
1375     return false;
1376   }
1377 }
1378 #endif
1379 
1380 bool ShenandoahBarrierSetC2::escape_add_to_con_graph(ConnectionGraph* conn_graph, PhaseGVN* gvn, Unique_Node_List* delayed_worklist, Node* n, uint opcode) const {
1381   switch (opcode) {
1382     case Op_ShenandoahCompareAndExchangeP:
1383     case Op_ShenandoahCompareAndExchangeN:
1384       conn_graph->add_objload_to_connection_graph(n, delayed_worklist);
1385       // fallthrough
1386     case Op_ShenandoahWeakCompareAndSwapP:
1387     case Op_ShenandoahWeakCompareAndSwapN:
1388     case Op_ShenandoahCompareAndSwapP:
1389     case Op_ShenandoahCompareAndSwapN:
1390       conn_graph->add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
1391       return true;
1392     case Op_StoreP: {
1393       Node* adr = n->in(MemNode::Address);
1394       const Type* adr_type = gvn->type(adr);
1395       // Pointer stores in G1 barriers looks like unsafe access.
1396       // Ignore such stores to be able scalar replace non-escaping
1397       // allocations.
1398       if (adr_type->isa_rawptr() && adr->is_AddP()) {
1399         Node* base = conn_graph->get_addp_base(adr);
1400         if (base->Opcode() == Op_LoadP &&
1401           base->in(MemNode::Address)->is_AddP()) {
1402           adr = base->in(MemNode::Address);
1403           Node* tls = conn_graph->get_addp_base(adr);
1404           if (tls->Opcode() == Op_ThreadLocal) {
1405              int offs = (int) gvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
1406              const int buf_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset());
1407              if (offs == buf_offset) {
1408                return true; // Pre barrier previous oop value store.
1409              }
1410           }
1411         }
1412       }
1413       return false;
1414     }
1415     case Op_ShenandoahReadBarrier:
1416     case Op_ShenandoahWriteBarrier:
1417       // Barriers 'pass through' its arguments. I.e. what goes in, comes out.
1418       // It doesn't escape.
1419       conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahBarrierNode::ValueIn), delayed_worklist);
1420       break;
1421     case Op_ShenandoahEnqueueBarrier:
1422       conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist);
1423       break;



1424     default:
1425       // Nothing
1426       break;
1427   }
1428   return false;
1429 }
1430 
1431 bool ShenandoahBarrierSetC2::escape_add_final_edges(ConnectionGraph* conn_graph, PhaseGVN* gvn, Node* n, uint opcode) const {
1432   switch (opcode) {
1433     case Op_ShenandoahCompareAndExchangeP:
1434     case Op_ShenandoahCompareAndExchangeN: {
1435       Node *adr = n->in(MemNode::Address);
1436       conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
1437       // fallthrough
1438     }
1439     case Op_ShenandoahCompareAndSwapP:
1440     case Op_ShenandoahCompareAndSwapN:
1441     case Op_ShenandoahWeakCompareAndSwapP:
1442     case Op_ShenandoahWeakCompareAndSwapN:
1443       return conn_graph->add_final_edges_unsafe_access(n, opcode);
1444     case Op_ShenandoahReadBarrier:
1445     case Op_ShenandoahWriteBarrier:
1446       // Barriers 'pass through' its arguments. I.e. what goes in, comes out.
1447       // It doesn't escape.
1448       conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahBarrierNode::ValueIn), NULL);
1449       return true;
1450     case Op_ShenandoahEnqueueBarrier:
1451       conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), NULL);
1452       return true;



1453     default:
1454       // Nothing
1455       break;
1456   }
1457   return false;
1458 }
1459 
1460 bool ShenandoahBarrierSetC2::escape_has_out_with_unsafe_object(Node* n) const {
1461   return n->has_out_with(Op_ShenandoahCompareAndExchangeP) || n->has_out_with(Op_ShenandoahCompareAndExchangeN) ||
1462          n->has_out_with(Op_ShenandoahCompareAndSwapP, Op_ShenandoahCompareAndSwapN, Op_ShenandoahWeakCompareAndSwapP, Op_ShenandoahWeakCompareAndSwapN);
1463 
1464 }
1465 
1466 bool ShenandoahBarrierSetC2::escape_is_barrier_node(Node* n) const {
1467   return n->is_ShenandoahBarrier();
1468 }
1469 
1470 bool ShenandoahBarrierSetC2::matcher_find_shared_visit(Matcher* matcher, Matcher::MStack& mstack, Node* n, uint opcode, bool& mem_op, int& mem_addr_idx) const {
1471   switch (opcode) {
1472     case Op_ShenandoahReadBarrier:
1473       if (n->in(ShenandoahBarrierNode::ValueIn)->is_DecodeNarrowPtr()) {
1474         matcher->set_shared(n->in(ShenandoahBarrierNode::ValueIn)->in(1));
1475       }
1476       matcher->set_shared(n);
1477       return true;
1478     default:
1479       break;
1480   }
1481   return false;
1482 }
1483 
1484 bool ShenandoahBarrierSetC2::matcher_find_shared_post_visit(Matcher* matcher, Node* n, uint opcode) const {
1485   switch (opcode) {
1486     case Op_ShenandoahCompareAndExchangeP:
1487     case Op_ShenandoahCompareAndExchangeN:
1488     case Op_ShenandoahWeakCompareAndSwapP:
1489     case Op_ShenandoahWeakCompareAndSwapN:
1490     case Op_ShenandoahCompareAndSwapP:
1491     case Op_ShenandoahCompareAndSwapN: {   // Convert trinary to binary-tree
1492       Node* newval = n->in(MemNode::ValueIn);
1493       Node* oldval = n->in(LoadStoreConditionalNode::ExpectedIn);
1494       Node* pair = new BinaryNode(oldval, newval);
1495       n->set_req(MemNode::ValueIn,pair);
1496       n->del_req(LoadStoreConditionalNode::ExpectedIn);
1497       return true;
1498     }
1499     default:
1500       break;
1501   }
1502   return false;
1503 }
1504 
1505 bool ShenandoahBarrierSetC2::matcher_is_store_load_barrier(Node* x, uint xop) const {
1506   return xop == Op_ShenandoahCompareAndExchangeP ||
1507          xop == Op_ShenandoahCompareAndExchangeN ||
1508          xop == Op_ShenandoahWeakCompareAndSwapP ||
1509          xop == Op_ShenandoahWeakCompareAndSwapN ||
1510          xop == Op_ShenandoahCompareAndSwapN ||
1511          xop == Op_ShenandoahCompareAndSwapP;
1512 }
1513 
1514 void ShenandoahBarrierSetC2::igvn_add_users_to_worklist(PhaseIterGVN* igvn, Node* use) const {
1515   if (use->is_ShenandoahBarrier()) {
1516     for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1517       Node* u = use->fast_out(i2);
1518       Node* cmp = use->find_out_with(Op_CmpP);
1519       if (u->Opcode() == Op_CmpP) {
1520         igvn->_worklist.push(cmp);
1521       }
1522     }
1523   }
1524 }
1525 
1526 void ShenandoahBarrierSetC2::ccp_analyze(PhaseCCP* ccp, Unique_Node_List& worklist, Node* use) const {
1527   if (use->is_ShenandoahBarrier()) {
1528     for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1529       Node* p = use->fast_out(i2);
1530       if (p->Opcode() == Op_AddP) {
1531         for (DUIterator_Fast i3max, i3 = p->fast_outs(i3max); i3 < i3max; i3++) {
1532           Node* q = p->fast_out(i3);
1533           if (q->is_Load()) {
1534             if(q->bottom_type() != ccp->type(q)) {
1535               worklist.push(q);
1536             }
1537           }
1538         }
1539       }
1540     }
1541   }
1542 }
1543 
1544 Node* ShenandoahBarrierSetC2::split_if_pre(PhaseIdealLoop* phase, Node* n) const {
1545   if (n->Opcode() == Op_ShenandoahReadBarrier) {
1546     ((ShenandoahReadBarrierNode*)n)->try_move(phase);
1547   } else if (n->Opcode() == Op_ShenandoahWriteBarrier) {
1548     return ((ShenandoahWriteBarrierNode*)n)->try_split_thru_phi(phase);
1549   }
1550 
1551   return NULL;
1552 }
1553 
1554 bool ShenandoahBarrierSetC2::build_loop_late_post(PhaseIdealLoop* phase, Node* n) const {
1555   return ShenandoahBarrierNode::build_loop_late_post(phase, n);
1556 }
1557 
1558 bool ShenandoahBarrierSetC2::sink_node(PhaseIdealLoop* phase, Node* n, Node* x, Node* x_ctrl, Node* n_ctrl) const {
1559   if (n->is_ShenandoahBarrier()) {
1560     return x->as_ShenandoahBarrier()->sink_node(phase, x_ctrl, n_ctrl);
1561   }
1562   if (n->is_MergeMem()) {
1563     // PhaseIdealLoop::split_if_with_blocks_post() would:
1564     // _igvn._worklist.yank(x);
1565     // which sometimes causes chains of MergeMem which some of
1566     // shenandoah specific code doesn't support
1567     phase->register_new_node(x, x_ctrl);
1568     return true;
1569   }
1570   return false;
1571 }


  26 #include "gc/shenandoah/shenandoahHeap.hpp"
  27 #include "gc/shenandoah/shenandoahHeuristics.hpp"
  28 #include "gc/shenandoah/shenandoahRuntime.hpp"
  29 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
  30 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
  31 #include "gc/shenandoah/c2/shenandoahSupport.hpp"
  32 #include "opto/arraycopynode.hpp"
  33 #include "opto/escape.hpp"
  34 #include "opto/graphKit.hpp"
  35 #include "opto/idealKit.hpp"
  36 #include "opto/macro.hpp"
  37 #include "opto/movenode.hpp"
  38 #include "opto/narrowptrnode.hpp"
  39 #include "opto/rootnode.hpp"
  40 
  41 ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() {
  42   return reinterpret_cast<ShenandoahBarrierSetC2*>(BarrierSet::barrier_set()->barrier_set_c2());
  43 }
  44 
  45 ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena)
  46   : _enqueue_barriers(new (comp_arena) GrowableArray<ShenandoahEnqueueBarrierNode*>(comp_arena, 8,  0, NULL)),
  47     _load_reference_barriers(new (comp_arena) GrowableArray<ShenandoahLoadReferenceBarrierNode*>(comp_arena, 8,  0, NULL)) {
  48 }
  49 
  50 int ShenandoahBarrierSetC2State::enqueue_barriers_count() const {
  51   return _enqueue_barriers->length();
  52 }
  53 
  54 ShenandoahEnqueueBarrierNode* ShenandoahBarrierSetC2State::enqueue_barrier(int idx) const {
  55   return _enqueue_barriers->at(idx);
  56 }
  57 
  58 void ShenandoahBarrierSetC2State::add_enqueue_barrier(ShenandoahEnqueueBarrierNode * n) {
  59   assert(!_enqueue_barriers->contains(n), "duplicate entry in barrier list");
  60   _enqueue_barriers->append(n);
  61 }
  62 
  63 void ShenandoahBarrierSetC2State::remove_enqueue_barrier(ShenandoahEnqueueBarrierNode * n) {
  64   if (_enqueue_barriers->contains(n)) {
  65     _enqueue_barriers->remove(n);
  66   }
  67 }
  68 
  69 int ShenandoahBarrierSetC2State::load_reference_barriers_count() const {
  70   return _load_reference_barriers->length();





  71 }
  72 
  73 ShenandoahLoadReferenceBarrierNode* ShenandoahBarrierSetC2State::load_reference_barrier(int idx) const {
  74   return _load_reference_barriers->at(idx);







  75 }
  76 
  77 void ShenandoahBarrierSetC2State::add_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n) {
  78   assert(!_load_reference_barriers->contains(n), "duplicate entry in barrier list");
  79   _load_reference_barriers->append(n);









































  80 }
  81 
  82 void ShenandoahBarrierSetC2State::remove_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n) {
  83   if (_load_reference_barriers->contains(n)) {
  84     _load_reference_barriers->remove(n);



  85   }

  86 }
  87 
  88 Node* ShenandoahBarrierSetC2::shenandoah_storeval_barrier(GraphKit* kit, Node* obj) const {
  89   if (ShenandoahStoreValEnqueueBarrier) {
  90     obj = shenandoah_enqueue_barrier(kit, obj);
  91   }
  92   return obj;
  93 }
  94 
  95 #define __ kit->









  96 
  97 bool ShenandoahBarrierSetC2::satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr,
  98                                                          BasicType bt, uint adr_idx) const {
  99   intptr_t offset = 0;
 100   Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
 101   AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
 102 
 103   if (offset == Type::OffsetBot) {
 104     return false; // cannot unalias unless there are precise offsets
 105   }
 106 
 107   if (alloc == NULL) {
 108     return false; // No allocation found
 109   }
 110 
 111   intptr_t size_in_bytes = type2aelembytes(bt);
 112 
 113   Node* mem = __ memory(adr_idx); // start searching here...
 114 
 115   for (int cnt = 0; cnt < 50; cnt++) {


 222   Node* no_base = __ top();
 223   Node* zero  = __ ConI(0);
 224   Node* zeroX = __ ConX(0);
 225 
 226   float likely  = PROB_LIKELY(0.999);
 227   float unlikely  = PROB_UNLIKELY(0.999);
 228 
 229   // Offsets into the thread
 230   const int index_offset   = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset());
 231   const int buffer_offset  = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset());
 232 
 233   // Now the actual pointers into the thread
 234   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
 235   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
 236 
 237   // Now some of the values
 238   Node* marking;
 239   Node* gc_state = __ AddP(no_base, tls, __ ConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset())));
 240   Node* ld = __ load(__ ctrl(), gc_state, TypeInt::BYTE, T_BYTE, Compile::AliasIdxRaw);
 241   marking = __ AndI(ld, __ ConI(ShenandoahHeap::MARKING));
 242   assert(ShenandoahBarrierC2Support::is_gc_state_load(ld), "Should match the shape");
 243 
 244   // if (!marking)
 245   __ if_then(marking, BoolTest::ne, zero, unlikely); {
 246     BasicType index_bt = TypeX_X->basic_type();
 247     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
 248     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
 249 
 250     if (do_load) {
 251       // load original value
 252       // alias_idx correct??
 253       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
 254     }
 255 
 256     // if (pre_val != NULL)
 257     __ if_then(pre_val, BoolTest::ne, kit->null()); {
 258       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
 259 
 260       // is the queue for this thread full?
 261       __ if_then(index, BoolTest::ne, zeroX, likely); {
 262 


 279   } __ end_if();  // (!marking)
 280 
 281   // Final sync IdealKit and GraphKit.
 282   kit->final_sync(ideal);
 283 
 284   if (ShenandoahSATBBarrier && adr != NULL) {
 285     Node* c = kit->control();
 286     Node* call = c->in(1)->in(1)->in(1)->in(0);
 287     assert(is_shenandoah_wb_pre_call(call), "shenandoah_wb_pre call expected");
 288     call->add_req(adr);
 289   }
 290 }
 291 
 292 bool ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(Node* call) {
 293   return call->is_CallLeaf() &&
 294          call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry);
 295 }
 296 
 297 bool ShenandoahBarrierSetC2::is_shenandoah_wb_call(Node* call) {
 298   return call->is_CallLeaf() &&
 299          call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_JRT);
 300 }
 301 
 302 bool ShenandoahBarrierSetC2::is_shenandoah_marking_if(PhaseTransform *phase, Node* n) {
 303   if (n->Opcode() != Op_If) {
 304     return false;
 305   }
 306 
 307   Node* bol = n->in(1);
 308   assert(bol->is_Bool(), "");
 309   Node* cmpx = bol->in(1);
 310   if (bol->as_Bool()->_test._test == BoolTest::ne &&
 311       cmpx->is_Cmp() && cmpx->in(2) == phase->intcon(0) &&
 312       is_shenandoah_state_load(cmpx->in(1)->in(1)) &&
 313       cmpx->in(1)->in(2)->is_Con() &&
 314       cmpx->in(1)->in(2) == phase->intcon(ShenandoahHeap::MARKING)) {
 315     return true;
 316   }
 317 
 318   return false;
 319 }


 467   // create result type (range)
 468   fields = TypeTuple::fields(0);
 469   const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields);
 470 
 471   return TypeFunc::make(domain, range);
 472 }
 473 
 474 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_write_barrier_Type() {
 475   const Type **fields = TypeTuple::fields(1);
 476   fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
 477   const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields);
 478 
 479   // create result type (range)
 480   fields = TypeTuple::fields(1);
 481   fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL;
 482   const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields);
 483 
 484   return TypeFunc::make(domain, range);
 485 }
 486 


















































































 487 Node* ShenandoahBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const {
 488   DecoratorSet decorators = access.decorators();
 489 
 490   const TypePtr* adr_type = access.addr().type();
 491   Node* adr = access.addr().node();
 492 
 493   bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
 494   bool on_heap = (decorators & IN_HEAP) != 0;
 495 
 496   if (!access.is_oop() || (!on_heap && !anonymous)) {
 497     return BarrierSetC2::store_at_resolved(access, val);
 498   }
 499 
 500   if (access.is_parse_access()) {
 501     C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
 502     GraphKit* kit = parse_access.kit();
 503 
 504     uint adr_idx = kit->C->get_alias_index(adr_type);
 505     assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
 506     Node* value = val.node();
 507     value = shenandoah_storeval_barrier(kit, value);
 508     val.set_node(value);
 509     shenandoah_write_barrier_pre(kit, true /* do_load */, /*kit->control(),*/ access.base(), adr, adr_idx, val.node(),
 510                                  static_cast<const TypeOopPtr*>(val.type()), NULL /* pre_val */, access.type());
 511   } else {
 512     assert(access.is_opt_access(), "only for optimization passes");
 513     assert(((decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0 || !ShenandoahSATBBarrier) && (decorators & C2_ARRAY_COPY) != 0, "unexpected caller of this code");
 514     C2OptAccess& opt_access = static_cast<C2OptAccess&>(access);
 515     PhaseGVN& gvn =  opt_access.gvn();
 516     MergeMemNode* mm = opt_access.mem();
 517 




























 518     if (ShenandoahStoreValEnqueueBarrier) {
 519       Node* enqueue = gvn.transform(new ShenandoahEnqueueBarrierNode(val.node()));








 520       val.set_node(enqueue);
 521     }
 522   }
 523   return BarrierSetC2::store_at_resolved(access, val);
 524 }
 525 
 526 Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {
 527   DecoratorSet decorators = access.decorators();
 528 
 529   Node* adr = access.addr().node();
 530   Node* obj = access.base();
 531 
 532   bool mismatched = (decorators & C2_MISMATCHED) != 0;
 533   bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0;
 534   bool on_heap = (decorators & IN_HEAP) != 0;
 535   bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
 536   bool is_unordered = (decorators & MO_UNORDERED) != 0;
 537   bool need_cpu_mem_bar = !is_unordered || mismatched || !on_heap;
 538 
 539   Node* top = Compile::current()->top();
 540 
 541   Node* offset = adr->is_AddP() ? adr->in(AddPNode::Offset) : top;
 542   Node* load = BarrierSetC2::load_at_resolved(access, val_type);
 543 
 544   if (access.is_oop()) {
 545     if (ShenandoahLoadRefBarrier) {
 546       load = new ShenandoahLoadReferenceBarrierNode(NULL, load);
 547       if (access.is_parse_access()) {
 548         load = static_cast<C2ParseAccess &>(access).kit()->gvn().transform(load);
 549       } else {
 550         load = static_cast<C2OptAccess &>(access).gvn().transform(load);
 551       }
 552     }
 553   }
 554 
 555   // If we are reading the value of the referent field of a Reference
 556   // object (either by using Unsafe directly or through reflection)
 557   // then, if SATB is enabled, we need to record the referent in an
 558   // SATB log buffer using the pre-barrier mechanism.
 559   // Also we need to add memory barrier to prevent commoning reads
 560   // from this field across safepoint since GC can change its value.
 561   bool need_read_barrier = ShenandoahKeepAliveBarrier &&
 562     (on_heap && (on_weak || (unknown && offset != top && obj != top)));
 563 
 564   if (!access.is_oop() || !need_read_barrier) {
 565     return load;
 566   }
 567 
 568   assert(access.is_parse_access(), "entry not supported at optimization time");
 569   C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
 570   GraphKit* kit = parse_access.kit();
 571 
 572   if (on_weak) {
 573     // Use the pre-barrier to record the value in the referent field
 574     satb_write_barrier_pre(kit, false /* do_load */,


 608       if (ShenandoahCASBarrier) {
 609         load_store = kit->gvn().transform(new ShenandoahCompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo));
 610       } else {
 611         load_store = kit->gvn().transform(new CompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo));
 612       }
 613     } else
 614 #endif
 615     {
 616       if (ShenandoahCASBarrier) {
 617         load_store = kit->gvn().transform(new ShenandoahCompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo));
 618       } else {
 619         load_store = kit->gvn().transform(new CompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo));
 620       }
 621     }
 622 
 623     access.set_raw_access(load_store);
 624     pin_atomic_op(access);
 625 
 626 #ifdef _LP64
 627     if (adr->bottom_type()->is_ptr_to_narrowoop()) {
 628       load_store = kit->gvn().transform(new DecodeNNode(load_store, load_store->get_ptr_type()));
 629     }
 630 #endif
 631     load_store = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(NULL, load_store));
 632     return load_store;
 633   }
 634   return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);
 635 }
 636 
 637 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
 638                                                               Node* new_val, const Type* value_type) const {
 639   GraphKit* kit = access.kit();
 640   if (access.is_oop()) {
 641     new_val = shenandoah_storeval_barrier(kit, new_val);
 642     shenandoah_write_barrier_pre(kit, false /* do_load */,
 643                                  NULL, NULL, max_juint, NULL, NULL,
 644                                  expected_val /* pre_val */, T_OBJECT);
 645     DecoratorSet decorators = access.decorators();
 646     MemNode::MemOrd mo = access.mem_node_mo();
 647     Node* mem = access.memory();
 648     bool is_weak_cas = (decorators & C2_WEAK_CMPXCHG) != 0;
 649     Node* load_store = NULL;
 650     Node* adr = access.addr().node();
 651 #ifdef _LP64


 679           load_store = kit->gvn().transform(new WeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
 680         } else {
 681           load_store = kit->gvn().transform(new CompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
 682         }
 683       }
 684     }
 685     access.set_raw_access(load_store);
 686     pin_atomic_op(access);
 687     return load_store;
 688   }
 689   return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);
 690 }
 691 
 692 Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* val, const Type* value_type) const {
 693   GraphKit* kit = access.kit();
 694   if (access.is_oop()) {
 695     val = shenandoah_storeval_barrier(kit, val);
 696   }
 697   Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type);
 698   if (access.is_oop()) {
 699     result = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(NULL, result));
 700     shenandoah_write_barrier_pre(kit, false /* do_load */,
 701                                  NULL, NULL, max_juint, NULL, NULL,
 702                                  result /* pre_val */, T_OBJECT);
 703   }
 704   return result;
 705 }
 706 
 707 void ShenandoahBarrierSetC2::clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const {
 708   assert(!src->is_AddP(), "unexpected input");

 709   BarrierSetC2::clone(kit, src, dst, size, is_array);
 710 }
 711 









 712 Node* ShenandoahBarrierSetC2::obj_allocate(PhaseMacroExpand* macro, Node* ctrl, Node* mem, Node* toobig_false, Node* size_in_bytes,
 713                                            Node*& i_o, Node*& needgc_ctrl,
 714                                            Node*& fast_oop_ctrl, Node*& fast_oop_rawmem,
 715                                            intx prefetch_lines) const {
 716   PhaseIterGVN& igvn = macro->igvn();
 717 
 718   // Allocate several words more for the Shenandoah brooks pointer.
 719   size_in_bytes = new AddXNode(size_in_bytes, igvn.MakeConX(ShenandoahBrooksPointer::byte_size()));
 720   macro->transform_later(size_in_bytes);
 721 
 722   Node* fast_oop = BarrierSetC2::obj_allocate(macro, ctrl, mem, toobig_false, size_in_bytes,
 723                                               i_o, needgc_ctrl, fast_oop_ctrl, fast_oop_rawmem,
 724                                               prefetch_lines);
 725 
 726   // Bump up object for Shenandoah brooks pointer.
 727   fast_oop = new AddPNode(macro->top(), fast_oop, igvn.MakeConX(ShenandoahBrooksPointer::byte_size()));
 728   macro->transform_later(fast_oop);
 729 
 730   // Initialize Shenandoah brooks pointer to point to the object itself.
 731   fast_oop_rawmem = macro->make_store(fast_oop_ctrl, fast_oop_rawmem, fast_oop, ShenandoahBrooksPointer::byte_offset(), fast_oop, T_OBJECT);
 732 
 733   return fast_oop;
 734 }
 735 
 736 // Support for GC barriers emitted during parsing
 737 bool ShenandoahBarrierSetC2::is_gc_barrier_node(Node* node) const {
 738   if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) return true;
 739   if (node->Opcode() != Op_CallLeaf && node->Opcode() != Op_CallLeafNoFP) {
 740     return false;
 741   }
 742   CallLeafNode *call = node->as_CallLeaf();
 743   if (call->_name == NULL) {
 744     return false;
 745   }
 746 
 747   return strcmp(call->_name, "shenandoah_clone_barrier") == 0 ||
 748          strcmp(call->_name, "shenandoah_cas_obj") == 0 ||
 749          strcmp(call->_name, "shenandoah_wb_pre") == 0;
 750 }
 751 
 752 Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) const {
 753   if (c->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
 754     return c->in(ShenandoahLoadReferenceBarrierNode::ValueIn);
 755   }
 756   if (c->Opcode() == Op_ShenandoahEnqueueBarrier) {
 757     c = c->in(1);
 758   }
 759   return c;
 760 }
 761 
 762 bool ShenandoahBarrierSetC2::expand_barriers(Compile* C, PhaseIterGVN& igvn) const {
 763   return !ShenandoahBarrierC2Support::expand(C, igvn);
 764 }
 765 
 766 bool ShenandoahBarrierSetC2::optimize_loops(PhaseIdealLoop* phase, LoopOptsMode mode, VectorSet& visited, Node_Stack& nstack, Node_List& worklist) const {
 767   if (mode == LoopOptsShenandoahExpand) {
 768     assert(UseShenandoahGC, "only for shenandoah");
 769     ShenandoahBarrierC2Support::pin_and_expand(phase);
 770     return true;
 771   } else if (mode == LoopOptsShenandoahPostExpand) {
 772     assert(UseShenandoahGC, "only for shenandoah");
 773     visited.Clear();
 774     ShenandoahBarrierC2Support::optimize_after_expansion(visited, nstack, worklist, phase);
 775     return true;
 776   }


 777   return false;
 778 }
 779 
 780 bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const {
 781   bool is_oop = type == T_OBJECT || type == T_ARRAY;
 782   if (!is_oop) {
 783     return false;
 784   }

 785   if (tightly_coupled_alloc) {
 786     if (phase == Optimization) {
 787       return false;
 788     }
 789     return !is_clone;
 790   }
 791   if (phase == Optimization) {
 792     return !ShenandoahStoreValEnqueueBarrier;
 793   }
 794   return true;
 795 }
 796 
 797 bool ShenandoahBarrierSetC2::clone_needs_postbarrier(ArrayCopyNode *ac, PhaseIterGVN& igvn) {
 798   Node* src = ac->in(ArrayCopyNode::Src);
 799   const TypeOopPtr* src_type = igvn.type(src)->is_oopptr();
 800   if (src_type->isa_instptr() != NULL) {
 801     ciInstanceKlass* ik = src_type->klass()->as_instance_klass();
 802     if ((src_type->klass_is_exact() || (!ik->is_interface() && !ik->has_subklass())) && !ik->has_injected_fields()) {
 803       if (ik->has_object_fields()) {
 804         return true;


 845   barrier_call->init_req(TypeFunc::Memory , m);
 846   barrier_call->init_req(TypeFunc::ReturnAdr, igvn.C->top());
 847   barrier_call->init_req(TypeFunc::FramePtr, igvn.C->top());
 848   barrier_call->init_req(TypeFunc::Parms+0, dest->in(AddPNode::Base));
 849 
 850   barrier_call = igvn.transform(barrier_call);
 851   c = new ProjNode(barrier_call,TypeFunc::Control);
 852   c = igvn.transform(c);
 853   m = new ProjNode(barrier_call, TypeFunc::Memory);
 854   m = igvn.transform(m);
 855 
 856   Node* out_c = ac->proj_out(TypeFunc::Control);
 857   Node* out_m = ac->proj_out(TypeFunc::Memory);
 858   igvn.replace_node(out_c, c);
 859   igvn.replace_node(out_m, m);
 860 }
 861 
 862 
 863 // Support for macro expanded GC barriers
 864 void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const {
 865   if (node->Opcode() == Op_ShenandoahEnqueueBarrier) {
 866     state()->add_enqueue_barrier((ShenandoahEnqueueBarrierNode*) node);
 867   }
 868   if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
 869     state()->add_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node);
 870   }
 871 }
 872 
 873 void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const {
 874   if (node->Opcode() == Op_ShenandoahEnqueueBarrier) {
 875     state()->remove_enqueue_barrier((ShenandoahEnqueueBarrierNode*) node);
 876   }
 877   if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
 878     state()->remove_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node);
 879   }
 880 }
 881 
 882 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* n) const {
 883   if (is_shenandoah_wb_pre_call(n)) {
 884     shenandoah_eliminate_wb_pre(n, &macro->igvn());
 885   }
 886 }
 887 
 888 void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const {
 889   assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), "");
 890   Node* c = call->as_Call()->proj_out(TypeFunc::Control);
 891   c = c->unique_ctrl_out();
 892   assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
 893   c = c->unique_ctrl_out();
 894   assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
 895   Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
 896   assert(iff->is_If(), "expect test");
 897   if (!is_shenandoah_marking_if(igvn, iff)) {
 898     c = c->unique_ctrl_out();


 904   igvn->replace_node(cmpx, igvn->makecon(TypeInt::CC_EQ));
 905   igvn->rehash_node_delayed(call);
 906   call->del_req(call->req()-1);
 907 }
 908 
 909 void ShenandoahBarrierSetC2::enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const {
 910   if (node->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(node)) {
 911     igvn->add_users_to_worklist(node);
 912   }
 913 }
 914 
 915 void ShenandoahBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const {
 916   for (uint i = 0; i < useful.size(); i++) {
 917     Node* n = useful.at(i);
 918     if (n->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(n)) {
 919       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 920         C->record_for_igvn(n->fast_out(i));
 921       }
 922     }
 923   }
 924   for (int i = state()->enqueue_barriers_count() - 1; i >= 0; i--) {
 925     ShenandoahEnqueueBarrierNode* n = state()->enqueue_barrier(i);
 926     if (!useful.member(n)) {
 927       state()->remove_enqueue_barrier(n);
 928     }
 929   }
 930   for (int i = state()->load_reference_barriers_count() - 1; i >= 0; i--) {
 931     ShenandoahLoadReferenceBarrierNode* n = state()->load_reference_barrier(i);
 932     if (!useful.member(n)) {
 933       state()->remove_load_reference_barrier(n);
 934     }
 935   }







 936 }
 937 
 938 void ShenandoahBarrierSetC2::add_users_to_worklist(Unique_Node_List* worklist) const {}
 939 
 940 void* ShenandoahBarrierSetC2::create_barrier_state(Arena* comp_arena) const {
 941   return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena);
 942 }
 943 
 944 ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const {
 945   return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state());
 946 }
 947 
 948 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be
 949 // expanded later, then now is the time to do so.
 950 bool ShenandoahBarrierSetC2::expand_macro_nodes(PhaseMacroExpand* macro) const { return false; }
 951 
 952 #ifdef ASSERT
 953 void ShenandoahBarrierSetC2::verify_gc_barriers(Compile* compile, CompilePhase phase) const {
 954   if (ShenandoahVerifyOptoBarriers && phase == BarrierSetC2::BeforeExpand) {
 955     ShenandoahBarrierC2Support::verify(Compile::current()->root());
 956   } else if (phase == BarrierSetC2::BeforeCodeGen) {
 957     // Verify G1 pre-barriers
 958     const int marking_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset());
 959 
 960     ResourceArea *area = Thread::current()->resource_area();
 961     Unique_Node_List visited(area);
 962     Node_List worklist(area);
 963     // We're going to walk control flow backwards starting from the Root
 964     worklist.push(compile->root());
 965     while (worklist.size() > 0) {
 966       Node *x = worklist.pop();
 967       if (x == NULL || x == compile->top()) continue;
 968       if (visited.member(x)) {
 969         continue;
 970       } else {
 971         visited.push(x);
 972       }
 973 
 974       if (x->is_Region()) {
 975         for (uint i = 1; i < x->req(); i++) {


1041     PhaseIterGVN* igvn = phase->is_IterGVN();
1042     if (in1 != n->in(1)) {
1043       if (igvn != NULL) {
1044         n->set_req_X(1, in1, igvn);
1045       } else {
1046         n->set_req(1, in1);
1047       }
1048       assert(in2 == n->in(2), "only one change");
1049       return n;
1050     }
1051     if (in2 != n->in(2)) {
1052       if (igvn != NULL) {
1053         n->set_req_X(2, in2, igvn);
1054       } else {
1055         n->set_req(2, in2);
1056       }
1057       return n;
1058     }
1059   } else if (can_reshape &&
1060              n->Opcode() == Op_If &&
1061              ShenandoahBarrierC2Support::is_heap_stable_test(n) &&
1062              n->in(0) != NULL) {
1063     Node* dom = n->in(0);
1064     Node* prev_dom = n;
1065     int op = n->Opcode();
1066     int dist = 16;
1067     // Search up the dominator tree for another heap stable test
1068     while (dom->Opcode() != op    ||  // Not same opcode?
1069            !ShenandoahBarrierC2Support::is_heap_stable_test(dom) ||  // Not same input 1?
1070            prev_dom->in(0) != dom) {  // One path of test does not dominate?
1071       if (dist < 0) return NULL;
1072 
1073       dist--;
1074       prev_dom = dom;
1075       dom = IfNode::up_one_dom(dom);
1076       if (!dom) return NULL;
1077     }
1078 
1079     // Check that we did not follow a loop back to ourselves
1080     if (n == dom) {
1081       return NULL;
1082     }
1083 
1084     return n->as_If()->dominated_by(prev_dom, phase->is_IterGVN());
1085   }
1086 
1087   return NULL;
1088 }
1089 








































1090 bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) {
1091   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1092     Node* u = n->fast_out(i);
1093     if (!is_shenandoah_wb_pre_call(u)) {
1094       return false;
1095     }
1096   }
1097   return n->outcnt() > 0;
1098 }
1099 














1100 bool ShenandoahBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode) const {
1101   switch (opcode) {
1102     case Op_CallLeaf:
1103     case Op_CallLeafNoFP: {
1104       assert (n->is_Call(), "");
1105       CallNode *call = n->as_Call();
1106       if (ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(call)) {
1107         uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt();
1108         if (call->req() > cnt) {
1109           assert(call->req() == cnt + 1, "only one extra input");
1110           Node *addp = call->in(cnt);
1111           assert(!ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(addp), "useless address computation?");
1112           call->del_req(cnt);
1113         }
1114       }
1115       return false;
1116     }
1117     case Op_ShenandoahCompareAndSwapP:
1118     case Op_ShenandoahCompareAndSwapN:
1119     case Op_ShenandoahWeakCompareAndSwapN:
1120     case Op_ShenandoahWeakCompareAndSwapP:
1121     case Op_ShenandoahCompareAndExchangeP:
1122     case Op_ShenandoahCompareAndExchangeN:
1123 #ifdef ASSERT
1124       if( VerifyOptoOopOffsets ) {
1125         MemNode* mem  = n->as_Mem();
1126         // Check to see if address types have grounded out somehow.
1127         const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
1128         ciInstanceKlass *k = tp->klass()->as_instance_klass();
1129         bool oop_offset_is_sane = k->contains_field_offset(tp->offset());
1130         assert( !tp || oop_offset_is_sane, "" );
1131       }
1132 #endif
1133       return true;
1134     case Op_ShenandoahLoadReferenceBarrier:


1135       assert(false, "should have been expanded already");
1136       return true;
1137     default:
1138       return false;
1139   }
1140 }
1141 











1142 bool ShenandoahBarrierSetC2::escape_add_to_con_graph(ConnectionGraph* conn_graph, PhaseGVN* gvn, Unique_Node_List* delayed_worklist, Node* n, uint opcode) const {
1143   switch (opcode) {
1144     case Op_ShenandoahCompareAndExchangeP:
1145     case Op_ShenandoahCompareAndExchangeN:
1146       conn_graph->add_objload_to_connection_graph(n, delayed_worklist);
1147       // fallthrough
1148     case Op_ShenandoahWeakCompareAndSwapP:
1149     case Op_ShenandoahWeakCompareAndSwapN:
1150     case Op_ShenandoahCompareAndSwapP:
1151     case Op_ShenandoahCompareAndSwapN:
1152       conn_graph->add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
1153       return true;
1154     case Op_StoreP: {
1155       Node* adr = n->in(MemNode::Address);
1156       const Type* adr_type = gvn->type(adr);
1157       // Pointer stores in G1 barriers looks like unsafe access.
1158       // Ignore such stores to be able scalar replace non-escaping
1159       // allocations.
1160       if (adr_type->isa_rawptr() && adr->is_AddP()) {
1161         Node* base = conn_graph->get_addp_base(adr);
1162         if (base->Opcode() == Op_LoadP &&
1163           base->in(MemNode::Address)->is_AddP()) {
1164           adr = base->in(MemNode::Address);
1165           Node* tls = conn_graph->get_addp_base(adr);
1166           if (tls->Opcode() == Op_ThreadLocal) {
1167              int offs = (int) gvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
1168              const int buf_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset());
1169              if (offs == buf_offset) {
1170                return true; // Pre barrier previous oop value store.
1171              }
1172           }
1173         }
1174       }
1175       return false;
1176     }






1177     case Op_ShenandoahEnqueueBarrier:
1178       conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist);
1179       break;
1180     case Op_ShenandoahLoadReferenceBarrier:
1181       conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), delayed_worklist);
1182       return true;
1183     default:
1184       // Nothing
1185       break;
1186   }
1187   return false;
1188 }
1189 
1190 bool ShenandoahBarrierSetC2::escape_add_final_edges(ConnectionGraph* conn_graph, PhaseGVN* gvn, Node* n, uint opcode) const {
1191   switch (opcode) {
1192     case Op_ShenandoahCompareAndExchangeP:
1193     case Op_ShenandoahCompareAndExchangeN: {
1194       Node *adr = n->in(MemNode::Address);
1195       conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
1196       // fallthrough
1197     }
1198     case Op_ShenandoahCompareAndSwapP:
1199     case Op_ShenandoahCompareAndSwapN:
1200     case Op_ShenandoahWeakCompareAndSwapP:
1201     case Op_ShenandoahWeakCompareAndSwapN:
1202       return conn_graph->add_final_edges_unsafe_access(n, opcode);






1203     case Op_ShenandoahEnqueueBarrier:
1204       conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), NULL);
1205       return true;
1206     case Op_ShenandoahLoadReferenceBarrier:
1207       conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), NULL);
1208       return true;
1209     default:
1210       // Nothing
1211       break;
1212   }
1213   return false;
1214 }
1215 
1216 bool ShenandoahBarrierSetC2::escape_has_out_with_unsafe_object(Node* n) const {
1217   return n->has_out_with(Op_ShenandoahCompareAndExchangeP) || n->has_out_with(Op_ShenandoahCompareAndExchangeN) ||
1218          n->has_out_with(Op_ShenandoahCompareAndSwapP, Op_ShenandoahCompareAndSwapN, Op_ShenandoahWeakCompareAndSwapP, Op_ShenandoahWeakCompareAndSwapN);
1219 
1220 }
1221 
1222 bool ShenandoahBarrierSetC2::escape_is_barrier_node(Node* n) const {
1223   return n->Opcode() == Op_ShenandoahLoadReferenceBarrier;














1224 }
1225 
1226 bool ShenandoahBarrierSetC2::matcher_find_shared_post_visit(Matcher* matcher, Node* n, uint opcode) const {
1227   switch (opcode) {
1228     case Op_ShenandoahCompareAndExchangeP:
1229     case Op_ShenandoahCompareAndExchangeN:
1230     case Op_ShenandoahWeakCompareAndSwapP:
1231     case Op_ShenandoahWeakCompareAndSwapN:
1232     case Op_ShenandoahCompareAndSwapP:
1233     case Op_ShenandoahCompareAndSwapN: {   // Convert trinary to binary-tree
1234       Node* newval = n->in(MemNode::ValueIn);
1235       Node* oldval = n->in(LoadStoreConditionalNode::ExpectedIn);
1236       Node* pair = new BinaryNode(oldval, newval);
1237       n->set_req(MemNode::ValueIn,pair);
1238       n->del_req(LoadStoreConditionalNode::ExpectedIn);
1239       return true;
1240     }
1241     default:
1242       break;
1243   }
1244   return false;
1245 }
1246 
1247 bool ShenandoahBarrierSetC2::matcher_is_store_load_barrier(Node* x, uint xop) const {
1248   return xop == Op_ShenandoahCompareAndExchangeP ||
1249          xop == Op_ShenandoahCompareAndExchangeN ||
1250          xop == Op_ShenandoahWeakCompareAndSwapP ||
1251          xop == Op_ShenandoahWeakCompareAndSwapN ||
1252          xop == Op_ShenandoahCompareAndSwapN ||
1253          xop == Op_ShenandoahCompareAndSwapP;



























































1254 }
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