| /* |
| * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "gc/shared/barrierSet.hpp" |
| #include "gc/shenandoah/shenandoahBarrierSet.hpp" |
| #include "gc/shenandoah/shenandoahForwarding.hpp" |
| #include "gc/shenandoah/shenandoahHeap.hpp" |
| #include "gc/shenandoah/shenandoahRuntime.hpp" |
| #include "gc/shenandoah/shenandoahThreadLocalData.hpp" |
| #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp" |
| #include "gc/shenandoah/c2/shenandoahSupport.hpp" |
| #include "gc/shenandoah/heuristics/shenandoahHeuristics.hpp" |
| #include "opto/arraycopynode.hpp" |
| #include "opto/escape.hpp" |
| #include "opto/graphKit.hpp" |
| #include "opto/idealKit.hpp" |
| #include "opto/macro.hpp" |
| #include "opto/movenode.hpp" |
| #include "opto/narrowptrnode.hpp" |
| #include "opto/rootnode.hpp" |
| #include "opto/runtime.hpp" |
| |
| ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() { |
| return reinterpret_cast<ShenandoahBarrierSetC2*>(BarrierSet::barrier_set()->barrier_set_c2()); |
| } |
| |
| ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena) |
| : _iu_barriers(new (comp_arena) GrowableArray<ShenandoahIUBarrierNode*>(comp_arena, 8, 0, NULL)), |
| _load_reference_barriers(new (comp_arena) GrowableArray<ShenandoahLoadReferenceBarrierNode*>(comp_arena, 8, 0, NULL)) { |
| } |
| |
| int ShenandoahBarrierSetC2State::iu_barriers_count() const { |
| return _iu_barriers->length(); |
| } |
| |
| ShenandoahIUBarrierNode* ShenandoahBarrierSetC2State::iu_barrier(int idx) const { |
| return _iu_barriers->at(idx); |
| } |
| |
| void ShenandoahBarrierSetC2State::add_iu_barrier(ShenandoahIUBarrierNode * n) { |
| assert(!_iu_barriers->contains(n), "duplicate entry in barrier list"); |
| _iu_barriers->append(n); |
| } |
| |
| void ShenandoahBarrierSetC2State::remove_iu_barrier(ShenandoahIUBarrierNode * n) { |
| if (_iu_barriers->contains(n)) { |
| _iu_barriers->remove(n); |
| } |
| } |
| |
| int ShenandoahBarrierSetC2State::load_reference_barriers_count() const { |
| return _load_reference_barriers->length(); |
| } |
| |
| ShenandoahLoadReferenceBarrierNode* ShenandoahBarrierSetC2State::load_reference_barrier(int idx) const { |
| return _load_reference_barriers->at(idx); |
| } |
| |
| void ShenandoahBarrierSetC2State::add_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n) { |
| assert(!_load_reference_barriers->contains(n), "duplicate entry in barrier list"); |
| _load_reference_barriers->append(n); |
| } |
| |
| void ShenandoahBarrierSetC2State::remove_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n) { |
| if (_load_reference_barriers->contains(n)) { |
| _load_reference_barriers->remove(n); |
| } |
| } |
| |
| Node* ShenandoahBarrierSetC2::shenandoah_iu_barrier(GraphKit* kit, Node* obj) const { |
| if (ShenandoahIUBarrier) { |
| return kit->gvn().transform(new ShenandoahIUBarrierNode(obj)); |
| } |
| return obj; |
| } |
| |
| #define __ kit-> |
| |
| bool ShenandoahBarrierSetC2::satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr, |
| BasicType bt, uint adr_idx) const { |
| intptr_t offset = 0; |
| Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset); |
| AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase); |
| |
| if (offset == Type::OffsetBot) { |
| return false; // cannot unalias unless there are precise offsets |
| } |
| |
| if (alloc == NULL) { |
| return false; // No allocation found |
| } |
| |
| intptr_t size_in_bytes = type2aelembytes(bt); |
| |
| Node* mem = __ memory(adr_idx); // start searching here... |
| |
| for (int cnt = 0; cnt < 50; cnt++) { |
| |
| if (mem->is_Store()) { |
| |
| Node* st_adr = mem->in(MemNode::Address); |
| intptr_t st_offset = 0; |
| Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset); |
| |
| if (st_base == NULL) { |
| break; // inscrutable pointer |
| } |
| |
| // Break we have found a store with same base and offset as ours so break |
| if (st_base == base && st_offset == offset) { |
| break; |
| } |
| |
| if (st_offset != offset && st_offset != Type::OffsetBot) { |
| const int MAX_STORE = BytesPerLong; |
| if (st_offset >= offset + size_in_bytes || |
| st_offset <= offset - MAX_STORE || |
| st_offset <= offset - mem->as_Store()->memory_size()) { |
| // Success: The offsets are provably independent. |
| // (You may ask, why not just test st_offset != offset and be done? |
| // The answer is that stores of different sizes can co-exist |
| // in the same sequence of RawMem effects. We sometimes initialize |
| // a whole 'tile' of array elements with a single jint or jlong.) |
| mem = mem->in(MemNode::Memory); |
| continue; // advance through independent store memory |
| } |
| } |
| |
| if (st_base != base |
| && MemNode::detect_ptr_independence(base, alloc, st_base, |
| AllocateNode::Ideal_allocation(st_base, phase), |
| phase)) { |
| // Success: The bases are provably independent. |
| mem = mem->in(MemNode::Memory); |
| continue; // advance through independent store memory |
| } |
| } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) { |
| |
| InitializeNode* st_init = mem->in(0)->as_Initialize(); |
| AllocateNode* st_alloc = st_init->allocation(); |
| |
| // Make sure that we are looking at the same allocation site. |
| // The alloc variable is guaranteed to not be null here from earlier check. |
| if (alloc == st_alloc) { |
| // Check that the initialization is storing NULL so that no previous store |
| // has been moved up and directly write a reference |
| Node* captured_store = st_init->find_captured_store(offset, |
| type2aelembytes(T_OBJECT), |
| phase); |
| if (captured_store == NULL || captured_store == st_init->zero_memory()) { |
| return true; |
| } |
| } |
| } |
| |
| // Unless there is an explicit 'continue', we must bail out here, |
| // because 'mem' is an inscrutable memory state (e.g., a call). |
| break; |
| } |
| |
| return false; |
| } |
| |
| #undef __ |
| #define __ ideal. |
| |
| void ShenandoahBarrierSetC2::satb_write_barrier_pre(GraphKit* kit, |
| bool do_load, |
| Node* obj, |
| Node* adr, |
| uint alias_idx, |
| Node* val, |
| const TypeOopPtr* val_type, |
| Node* pre_val, |
| BasicType bt) const { |
| // Some sanity checks |
| // Note: val is unused in this routine. |
| |
| if (do_load) { |
| // We need to generate the load of the previous value |
| assert(obj != NULL, "must have a base"); |
| assert(adr != NULL, "where are loading from?"); |
| assert(pre_val == NULL, "loaded already?"); |
| assert(val_type != NULL, "need a type"); |
| |
| if (ReduceInitialCardMarks |
| && satb_can_remove_pre_barrier(kit, &kit->gvn(), adr, bt, alias_idx)) { |
| return; |
| } |
| |
| } else { |
| // In this case both val_type and alias_idx are unused. |
| assert(pre_val != NULL, "must be loaded already"); |
| // Nothing to be done if pre_val is null. |
| if (pre_val->bottom_type() == TypePtr::NULL_PTR) return; |
| assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here"); |
| } |
| assert(bt == T_OBJECT, "or we shouldn't be here"); |
| |
| IdealKit ideal(kit, true); |
| |
| Node* tls = __ thread(); // ThreadLocalStorage |
| |
| Node* no_base = __ top(); |
| Node* zero = __ ConI(0); |
| Node* zeroX = __ ConX(0); |
| |
| float likely = PROB_LIKELY(0.999); |
| float unlikely = PROB_UNLIKELY(0.999); |
| |
| // Offsets into the thread |
| const int index_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()); |
| const int buffer_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()); |
| |
| // Now the actual pointers into the thread |
| Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset)); |
| Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset)); |
| |
| // Now some of the values |
| Node* marking; |
| Node* gc_state = __ AddP(no_base, tls, __ ConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset()))); |
| Node* ld = __ load(__ ctrl(), gc_state, TypeInt::BYTE, T_BYTE, Compile::AliasIdxRaw); |
| marking = __ AndI(ld, __ ConI(ShenandoahHeap::MARKING)); |
| assert(ShenandoahBarrierC2Support::is_gc_state_load(ld), "Should match the shape"); |
| |
| // if (!marking) |
| __ if_then(marking, BoolTest::ne, zero, unlikely); { |
| BasicType index_bt = TypeX_X->basic_type(); |
| assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading Shenandoah SATBMarkQueue::_index with wrong size."); |
| Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw); |
| |
| if (do_load) { |
| // load original value |
| // alias_idx correct?? |
| pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx); |
| } |
| |
| // if (pre_val != NULL) |
| __ if_then(pre_val, BoolTest::ne, kit->null()); { |
| Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw); |
| |
| // is the queue for this thread full? |
| __ if_then(index, BoolTest::ne, zeroX, likely); { |
| |
| // decrement the index |
| Node* next_index = kit->gvn().transform(new SubXNode(index, __ ConX(sizeof(intptr_t)))); |
| |
| // Now get the buffer location we will log the previous value into and store it |
| Node *log_addr = __ AddP(no_base, buffer, next_index); |
| __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered); |
| // update the index |
| __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered); |
| |
| } __ else_(); { |
| |
| // logging buffer is full, call the runtime |
| const TypeFunc *tf = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type(); |
| __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), "shenandoah_wb_pre", pre_val, tls); |
| } __ end_if(); // (!index) |
| } __ end_if(); // (pre_val != NULL) |
| } __ end_if(); // (!marking) |
| |
| // Final sync IdealKit and GraphKit. |
| kit->final_sync(ideal); |
| |
| if (ShenandoahSATBBarrier && adr != NULL) { |
| Node* c = kit->control(); |
| Node* call = c->in(1)->in(1)->in(1)->in(0); |
| assert(is_shenandoah_wb_pre_call(call), "shenandoah_wb_pre call expected"); |
| call->add_req(adr); |
| } |
| } |
| |
| bool ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(Node* call) { |
| return call->is_CallLeaf() && |
| call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry); |
| } |
| |
| bool ShenandoahBarrierSetC2::is_shenandoah_lrb_call(Node* call) { |
| if (!call->is_CallLeaf()) { |
| return false; |
| } |
| |
| address entry_point = call->as_CallLeaf()->entry_point(); |
| return (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier)) || |
| (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_narrow)); |
| } |
| |
| bool ShenandoahBarrierSetC2::is_shenandoah_marking_if(PhaseTransform *phase, Node* n) { |
| if (n->Opcode() != Op_If) { |
| return false; |
| } |
| |
| Node* bol = n->in(1); |
| assert(bol->is_Bool(), ""); |
| Node* cmpx = bol->in(1); |
| if (bol->as_Bool()->_test._test == BoolTest::ne && |
| cmpx->is_Cmp() && cmpx->in(2) == phase->intcon(0) && |
| is_shenandoah_state_load(cmpx->in(1)->in(1)) && |
| cmpx->in(1)->in(2)->is_Con() && |
| cmpx->in(1)->in(2) == phase->intcon(ShenandoahHeap::MARKING)) { |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool ShenandoahBarrierSetC2::is_shenandoah_state_load(Node* n) { |
| if (!n->is_Load()) return false; |
| const int state_offset = in_bytes(ShenandoahThreadLocalData::gc_state_offset()); |
| return n->in(2)->is_AddP() && n->in(2)->in(2)->Opcode() == Op_ThreadLocal |
| && n->in(2)->in(3)->is_Con() |
| && n->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == state_offset; |
| } |
| |
| void ShenandoahBarrierSetC2::shenandoah_write_barrier_pre(GraphKit* kit, |
| bool do_load, |
| Node* obj, |
| Node* adr, |
| uint alias_idx, |
| Node* val, |
| const TypeOopPtr* val_type, |
| Node* pre_val, |
| BasicType bt) const { |
| if (ShenandoahSATBBarrier) { |
| IdealKit ideal(kit); |
| kit->sync_kit(ideal); |
| |
| satb_write_barrier_pre(kit, do_load, obj, adr, alias_idx, val, val_type, pre_val, bt); |
| |
| ideal.sync_kit(kit); |
| kit->final_sync(ideal); |
| } |
| } |
| |
| // Helper that guards and inserts a pre-barrier. |
| void ShenandoahBarrierSetC2::insert_pre_barrier(GraphKit* kit, Node* base_oop, Node* offset, |
| Node* pre_val, bool need_mem_bar) const { |
| // We could be accessing the referent field of a reference object. If so, when G1 |
| // is enabled, we need to log the value in the referent field in an SATB buffer. |
| // This routine performs some compile time filters and generates suitable |
| // runtime filters that guard the pre-barrier code. |
| // Also add memory barrier for non volatile load from the referent field |
| // to prevent commoning of loads across safepoint. |
| |
| // Some compile time checks. |
| |
| // If offset is a constant, is it java_lang_ref_Reference::_reference_offset? |
| const TypeX* otype = offset->find_intptr_t_type(); |
| if (otype != NULL && otype->is_con() && |
| otype->get_con() != java_lang_ref_Reference::referent_offset) { |
| // Constant offset but not the reference_offset so just return |
| return; |
| } |
| |
| // We only need to generate the runtime guards for instances. |
| const TypeOopPtr* btype = base_oop->bottom_type()->isa_oopptr(); |
| if (btype != NULL) { |
| if (btype->isa_aryptr()) { |
| // Array type so nothing to do |
| return; |
| } |
| |
| const TypeInstPtr* itype = btype->isa_instptr(); |
| if (itype != NULL) { |
| // Can the klass of base_oop be statically determined to be |
| // _not_ a sub-class of Reference and _not_ Object? |
| ciKlass* klass = itype->klass(); |
| if ( klass->is_loaded() && |
| !klass->is_subtype_of(kit->env()->Reference_klass()) && |
| !kit->env()->Object_klass()->is_subtype_of(klass)) { |
| return; |
| } |
| } |
| } |
| |
| // The compile time filters did not reject base_oop/offset so |
| // we need to generate the following runtime filters |
| // |
| // if (offset == java_lang_ref_Reference::_reference_offset) { |
| // if (instance_of(base, java.lang.ref.Reference)) { |
| // pre_barrier(_, pre_val, ...); |
| // } |
| // } |
| |
| float likely = PROB_LIKELY( 0.999); |
| float unlikely = PROB_UNLIKELY(0.999); |
| |
| IdealKit ideal(kit); |
| |
| Node* referent_off = __ ConX(java_lang_ref_Reference::referent_offset); |
| |
| __ if_then(offset, BoolTest::eq, referent_off, unlikely); { |
| // Update graphKit memory and control from IdealKit. |
| kit->sync_kit(ideal); |
| |
| Node* ref_klass_con = kit->makecon(TypeKlassPtr::make(kit->env()->Reference_klass())); |
| Node* is_instof = kit->gen_instanceof(base_oop, ref_klass_con); |
| |
| // Update IdealKit memory and control from graphKit. |
| __ sync_kit(kit); |
| |
| Node* one = __ ConI(1); |
| // is_instof == 0 if base_oop == NULL |
| __ if_then(is_instof, BoolTest::eq, one, unlikely); { |
| |
| // Update graphKit from IdeakKit. |
| kit->sync_kit(ideal); |
| |
| // Use the pre-barrier to record the value in the referent field |
| satb_write_barrier_pre(kit, false /* do_load */, |
| NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */, |
| pre_val /* pre_val */, |
| T_OBJECT); |
| if (need_mem_bar) { |
| // Add memory barrier to prevent commoning reads from this field |
| // across safepoint since GC can change its value. |
| kit->insert_mem_bar(Op_MemBarCPUOrder); |
| } |
| // Update IdealKit from graphKit. |
| __ sync_kit(kit); |
| |
| } __ end_if(); // _ref_type != ref_none |
| } __ end_if(); // offset == referent_offset |
| |
| // Final sync IdealKit and GraphKit. |
| kit->final_sync(ideal); |
| } |
| |
| #undef __ |
| |
| const TypeFunc* ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type() { |
| const Type **fields = TypeTuple::fields(2); |
| fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value |
| fields[TypeFunc::Parms+1] = TypeRawPtr::NOTNULL; // thread |
| const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields); |
| |
| // create result type (range) |
| fields = TypeTuple::fields(0); |
| const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields); |
| |
| return TypeFunc::make(domain, range); |
| } |
| |
| const TypeFunc* ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type() { |
| const Type **fields = TypeTuple::fields(1); |
| fields[TypeFunc::Parms+0] = TypeOopPtr::NOTNULL; // src oop |
| const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields); |
| |
| // create result type (range) |
| fields = TypeTuple::fields(0); |
| const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields); |
| |
| return TypeFunc::make(domain, range); |
| } |
| |
| const TypeFunc* ShenandoahBarrierSetC2::shenandoah_load_reference_barrier_Type() { |
| const Type **fields = TypeTuple::fields(2); |
| fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value |
| fields[TypeFunc::Parms+1] = TypeRawPtr::BOTTOM; // original load address |
| |
| const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields); |
| |
| // create result type (range) |
| fields = TypeTuple::fields(1); |
| fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; |
| const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields); |
| |
| return TypeFunc::make(domain, range); |
| } |
| |
| Node* ShenandoahBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const { |
| DecoratorSet decorators = access.decorators(); |
| |
| const TypePtr* adr_type = access.addr().type(); |
| Node* adr = access.addr().node(); |
| |
| bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0; |
| bool on_heap = (decorators & IN_HEAP) != 0; |
| |
| if (!access.is_oop() || (!on_heap && !anonymous)) { |
| return BarrierSetC2::store_at_resolved(access, val); |
| } |
| |
| GraphKit* kit = access.kit(); |
| |
| uint adr_idx = kit->C->get_alias_index(adr_type); |
| assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" ); |
| Node* value = val.node(); |
| value = shenandoah_iu_barrier(kit, value); |
| val.set_node(value); |
| shenandoah_write_barrier_pre(kit, true /* do_load */, /*kit->control(),*/ access.base(), adr, adr_idx, val.node(), |
| static_cast<const TypeOopPtr*>(val.type()), NULL /* pre_val */, access.type()); |
| return BarrierSetC2::store_at_resolved(access, val); |
| } |
| |
| Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const { |
| // 1: non-reference load, no additional barrier is needed |
| if (!access.is_oop()) { |
| return BarrierSetC2::load_at_resolved(access, val_type);; |
| } |
| |
| Node* load = BarrierSetC2::load_at_resolved(access, val_type); |
| DecoratorSet decorators = access.decorators(); |
| BasicType type = access.type(); |
| |
| // 2: apply LRB if needed |
| if (ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) { |
| load = new ShenandoahLoadReferenceBarrierNode(NULL, load); |
| load = access.kit()->gvn().transform(load); |
| } |
| |
| // 3: apply keep-alive barrier if needed |
| if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) { |
| Node* top = Compile::current()->top(); |
| Node* adr = access.addr().node(); |
| Node* offset = adr->is_AddP() ? adr->in(AddPNode::Offset) : top; |
| Node* obj = access.base(); |
| |
| bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0; |
| bool on_weak_ref = (decorators & (ON_WEAK_OOP_REF | ON_PHANTOM_OOP_REF)) != 0; |
| bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0; |
| |
| // If we are reading the value of the referent field of a Reference |
| // object (either by using Unsafe directly or through reflection) |
| // then, if SATB is enabled, we need to record the referent in an |
| // SATB log buffer using the pre-barrier mechanism. |
| // Also we need to add memory barrier to prevent commoning reads |
| // from this field across safepoint since GC can change its value. |
| if (!on_weak_ref || (unknown && (offset == top || obj == top)) || !keep_alive) { |
| return load; |
| } |
| GraphKit* kit = access.kit(); |
| bool mismatched = (decorators & C2_MISMATCHED) != 0; |
| bool is_unordered = (decorators & MO_UNORDERED) != 0; |
| bool need_cpu_mem_bar = !is_unordered || mismatched; |
| |
| if (on_weak_ref) { |
| // Use the pre-barrier to record the value in the referent field |
| satb_write_barrier_pre(kit, false /* do_load */, |
| NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */, |
| load /* pre_val */, T_OBJECT); |
| // Add memory barrier to prevent commoning reads from this field |
| // across safepoint since GC can change its value. |
| kit->insert_mem_bar(Op_MemBarCPUOrder); |
| } else if (unknown) { |
| // We do not require a mem bar inside pre_barrier if need_mem_bar |
| // is set: the barriers would be emitted by us. |
| insert_pre_barrier(kit, obj, offset, load, !need_cpu_mem_bar); |
| } |
| } |
| |
| return load; |
| } |
| |
| static void pin_atomic_op(C2AtomicAccess& access) { |
| if (!access.needs_pinning()) { |
| return; |
| } |
| // SCMemProjNodes represent the memory state of a LoadStore. Their |
| // main role is to prevent LoadStore nodes from being optimized away |
| // when their results aren't used. |
| GraphKit* kit = access.kit(); |
| Node* load_store = access.raw_access(); |
| assert(load_store != NULL, "must pin atomic op"); |
| Node* proj = kit->gvn().transform(new SCMemProjNode(load_store)); |
| kit->set_memory(proj, access.alias_idx()); |
| } |
| |
| Node* ShenandoahBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicAccess& access, Node* expected_val, |
| Node* new_val, const Type* value_type) const { |
| GraphKit* kit = access.kit(); |
| if (access.is_oop()) { |
| new_val = shenandoah_iu_barrier(kit, new_val); |
| shenandoah_write_barrier_pre(kit, false /* do_load */, |
| NULL, NULL, max_juint, NULL, NULL, |
| expected_val /* pre_val */, T_OBJECT); |
| |
| MemNode::MemOrd mo = access.mem_node_mo(); |
| Node* mem = access.memory(); |
| Node* adr = access.addr().node(); |
| const TypePtr* adr_type = access.addr().type(); |
| Node* load_store = NULL; |
| |
| #ifdef _LP64 |
| if (adr->bottom_type()->is_ptr_to_narrowoop()) { |
| Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop())); |
| Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop())); |
| if (ShenandoahCASBarrier) { |
| load_store = kit->gvn().transform(new ShenandoahCompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo)); |
| } else { |
| load_store = kit->gvn().transform(new CompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo)); |
| } |
| } else |
| #endif |
| { |
| if (ShenandoahCASBarrier) { |
| load_store = kit->gvn().transform(new ShenandoahCompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo)); |
| } else { |
| load_store = kit->gvn().transform(new CompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo)); |
| } |
| } |
| |
| access.set_raw_access(load_store); |
| pin_atomic_op(access); |
| |
| #ifdef _LP64 |
| if (adr->bottom_type()->is_ptr_to_narrowoop()) { |
| load_store = kit->gvn().transform(new DecodeNNode(load_store, load_store->get_ptr_type())); |
| } |
| #endif |
| load_store = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(NULL, load_store)); |
| return load_store; |
| } |
| return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type); |
| } |
| |
| Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicAccess& access, Node* expected_val, |
| Node* new_val, const Type* value_type) const { |
| GraphKit* kit = access.kit(); |
| if (access.is_oop()) { |
| new_val = shenandoah_iu_barrier(kit, new_val); |
| shenandoah_write_barrier_pre(kit, false /* do_load */, |
| NULL, NULL, max_juint, NULL, NULL, |
| expected_val /* pre_val */, T_OBJECT); |
| DecoratorSet decorators = access.decorators(); |
| MemNode::MemOrd mo = access.mem_node_mo(); |
| Node* mem = access.memory(); |
| bool is_weak_cas = (decorators & C2_WEAK_CMPXCHG) != 0; |
| Node* load_store = NULL; |
| Node* adr = access.addr().node(); |
| #ifdef _LP64 |
| if (adr->bottom_type()->is_ptr_to_narrowoop()) { |
| Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop())); |
| Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop())); |
| if (ShenandoahCASBarrier) { |
| if (is_weak_cas) { |
| load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); |
| } else { |
| load_store = kit->gvn().transform(new ShenandoahCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); |
| } |
| } else { |
| if (is_weak_cas) { |
| load_store = kit->gvn().transform(new WeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); |
| } else { |
| load_store = kit->gvn().transform(new CompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); |
| } |
| } |
| } else |
| #endif |
| { |
| if (ShenandoahCASBarrier) { |
| if (is_weak_cas) { |
| load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); |
| } else { |
| load_store = kit->gvn().transform(new ShenandoahCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); |
| } |
| } else { |
| if (is_weak_cas) { |
| load_store = kit->gvn().transform(new WeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); |
| } else { |
| load_store = kit->gvn().transform(new CompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); |
| } |
| } |
| } |
| access.set_raw_access(load_store); |
| pin_atomic_op(access); |
| return load_store; |
| } |
| return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type); |
| } |
| |
| Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicAccess& access, Node* val, const Type* value_type) const { |
| GraphKit* kit = access.kit(); |
| if (access.is_oop()) { |
| val = shenandoah_iu_barrier(kit, val); |
| } |
| Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type); |
| if (access.is_oop()) { |
| result = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(NULL, result)); |
| shenandoah_write_barrier_pre(kit, false /* do_load */, |
| NULL, NULL, max_juint, NULL, NULL, |
| result /* pre_val */, T_OBJECT); |
| } |
| return result; |
| } |
| |
| // Support for GC barriers emitted during parsing |
| bool ShenandoahBarrierSetC2::is_gc_barrier_node(Node* node) const { |
| if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) return true; |
| if (node->Opcode() != Op_CallLeaf && node->Opcode() != Op_CallLeafNoFP) { |
| return false; |
| } |
| CallLeafNode *call = node->as_CallLeaf(); |
| if (call->_name == NULL) { |
| return false; |
| } |
| |
| return strcmp(call->_name, "shenandoah_clone_barrier") == 0 || |
| strcmp(call->_name, "shenandoah_cas_obj") == 0 || |
| strcmp(call->_name, "shenandoah_wb_pre") == 0; |
| } |
| |
| Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) const { |
| if (c == NULL) { |
| return c; |
| } |
| if (c->Opcode() == Op_ShenandoahLoadReferenceBarrier) { |
| return c->in(ShenandoahLoadReferenceBarrierNode::ValueIn); |
| } |
| if (c->Opcode() == Op_ShenandoahIUBarrier) { |
| c = c->in(1); |
| } |
| return c; |
| } |
| |
| bool ShenandoahBarrierSetC2::expand_barriers(Compile* C, PhaseIterGVN& igvn) const { |
| return !ShenandoahBarrierC2Support::expand(C, igvn); |
| } |
| |
| bool ShenandoahBarrierSetC2::optimize_loops(PhaseIdealLoop* phase, LoopOptsMode mode, VectorSet& visited, Node_Stack& nstack, Node_List& worklist) const { |
| if (mode == LoopOptsShenandoahExpand) { |
| assert(UseShenandoahGC, "only for shenandoah"); |
| ShenandoahBarrierC2Support::pin_and_expand(phase); |
| return true; |
| } else if (mode == LoopOptsShenandoahPostExpand) { |
| assert(UseShenandoahGC, "only for shenandoah"); |
| visited.Clear(); |
| ShenandoahBarrierC2Support::optimize_after_expansion(visited, nstack, worklist, phase); |
| return true; |
| } |
| return false; |
| } |
| |
| bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(BasicType type) const { |
| return false; |
| } |
| |
| bool ShenandoahBarrierSetC2::clone_needs_barrier(Node* src, PhaseGVN& gvn) { |
| const TypeOopPtr* src_type = gvn.type(src)->is_oopptr(); |
| if (src_type->isa_instptr() != NULL) { |
| ciInstanceKlass* ik = src_type->klass()->as_instance_klass(); |
| if ((src_type->klass_is_exact() || (!ik->is_interface() && !ik->has_subklass())) && !ik->has_injected_fields()) { |
| if (ik->has_object_fields()) { |
| return true; |
| } else { |
| if (!src_type->klass_is_exact()) { |
| Compile::current()->dependencies()->assert_leaf_type(ik); |
| } |
| } |
| } else { |
| return true; |
| } |
| } else if (src_type->isa_aryptr()) { |
| BasicType src_elem = src_type->klass()->as_array_klass()->element_type()->basic_type(); |
| if (src_elem == T_OBJECT || src_elem == T_ARRAY) { |
| return true; |
| } |
| } else { |
| return true; |
| } |
| return false; |
| } |
| |
| void ShenandoahBarrierSetC2::clone_at_expansion(PhaseMacroExpand* phase, ArrayCopyNode* ac) const { |
| Node* ctrl = ac->in(TypeFunc::Control); |
| Node* mem = ac->in(TypeFunc::Memory); |
| Node* src = ac->in(ArrayCopyNode::Src); |
| Node* src_offset = ac->in(ArrayCopyNode::SrcPos); |
| Node* dest = ac->in(ArrayCopyNode::Dest); |
| Node* dest_offset = ac->in(ArrayCopyNode::DestPos); |
| Node* length = ac->in(ArrayCopyNode::Length); |
| assert (src_offset == NULL && dest_offset == NULL, "for clone offsets should be null"); |
| assert (src->is_AddP(), "for clone the src should be the interior ptr"); |
| assert (dest->is_AddP(), "for clone the dst should be the interior ptr"); |
| |
| if (ShenandoahCloneBarrier && clone_needs_barrier(src, phase->igvn())) { |
| // Check if heap is has forwarded objects. If it does, we need to call into the special |
| // routine that would fix up source references before we can continue. |
| |
| enum { _heap_stable = 1, _heap_unstable, PATH_LIMIT }; |
| Node* region = new RegionNode(PATH_LIMIT); |
| Node* mem_phi = new PhiNode(region, Type::MEMORY, TypeRawPtr::BOTTOM); |
| |
| Node* thread = phase->transform_later(new ThreadLocalNode()); |
| Node* offset = phase->igvn().MakeConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset())); |
| Node* gc_state_addr = phase->transform_later(new AddPNode(phase->C->top(), thread, offset)); |
| |
| uint gc_state_idx = Compile::AliasIdxRaw; |
| const TypePtr* gc_state_adr_type = NULL; // debug-mode-only argument |
| debug_only(gc_state_adr_type = phase->C->get_adr_type(gc_state_idx)); |
| |
| Node* gc_state = phase->transform_later(new LoadBNode(ctrl, mem, gc_state_addr, gc_state_adr_type, TypeInt::BYTE, MemNode::unordered)); |
| int flags = ShenandoahHeap::HAS_FORWARDED; |
| if (ShenandoahIUBarrier) { |
| flags |= ShenandoahHeap::MARKING; |
| } |
| Node* stable_and = phase->transform_later(new AndINode(gc_state, phase->igvn().intcon(flags))); |
| Node* stable_cmp = phase->transform_later(new CmpINode(stable_and, phase->igvn().zerocon(T_INT))); |
| Node* stable_test = phase->transform_later(new BoolNode(stable_cmp, BoolTest::ne)); |
| |
| IfNode* stable_iff = phase->transform_later(new IfNode(ctrl, stable_test, PROB_UNLIKELY(0.999), COUNT_UNKNOWN))->as_If(); |
| Node* stable_ctrl = phase->transform_later(new IfFalseNode(stable_iff)); |
| Node* unstable_ctrl = phase->transform_later(new IfTrueNode(stable_iff)); |
| |
| // Heap is stable, no need to do anything additional |
| region->init_req(_heap_stable, stable_ctrl); |
| mem_phi->init_req(_heap_stable, mem); |
| |
| // Heap is unstable, call into clone barrier stub |
| Node* call = phase->make_leaf_call(unstable_ctrl, mem, |
| ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type(), |
| CAST_FROM_FN_PTR(address, ShenandoahRuntime::shenandoah_clone_barrier), |
| "shenandoah_clone", |
| TypeRawPtr::BOTTOM, |
| src->in(AddPNode::Base)); |
| call = phase->transform_later(call); |
| |
| ctrl = phase->transform_later(new ProjNode(call, TypeFunc::Control)); |
| mem = phase->transform_later(new ProjNode(call, TypeFunc::Memory)); |
| region->init_req(_heap_unstable, ctrl); |
| mem_phi->init_req(_heap_unstable, mem); |
| |
| // Wire up the actual arraycopy stub now |
| ctrl = phase->transform_later(region); |
| mem = phase->transform_later(mem_phi); |
| |
| const char* name = "arraycopy"; |
| call = phase->make_leaf_call(ctrl, mem, |
| OptoRuntime::fast_arraycopy_Type(), |
| phase->basictype2arraycopy(T_LONG, NULL, NULL, true, name, true), |
| name, TypeRawPtr::BOTTOM, |
| src, dest, length |
| LP64_ONLY(COMMA phase->top())); |
| call = phase->transform_later(call); |
| |
| // Hook up the whole thing into the graph |
| phase->igvn().replace_node(ac, call); |
| } else { |
| BarrierSetC2::clone_at_expansion(phase, ac); |
| } |
| } |
| |
| // Support for macro expanded GC barriers |
| void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const { |
| if (node->Opcode() == Op_ShenandoahIUBarrier) { |
| state()->add_iu_barrier((ShenandoahIUBarrierNode*) node); |
| } |
| if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) { |
| state()->add_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node); |
| } |
| } |
| |
| void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const { |
| if (node->Opcode() == Op_ShenandoahIUBarrier) { |
| state()->remove_iu_barrier((ShenandoahIUBarrierNode*) node); |
| } |
| if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) { |
| state()->remove_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node); |
| } |
| } |
| |
| void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* n) const { |
| if (is_shenandoah_wb_pre_call(n)) { |
| shenandoah_eliminate_wb_pre(n, ¯o->igvn()); |
| } |
| } |
| |
| void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const { |
| assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), ""); |
| Node* c = call->as_Call()->proj_out(TypeFunc::Control); |
| c = c->unique_ctrl_out(); |
| assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); |
| c = c->unique_ctrl_out(); |
| assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); |
| Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0); |
| assert(iff->is_If(), "expect test"); |
| if (!is_shenandoah_marking_if(igvn, iff)) { |
| c = c->unique_ctrl_out(); |
| assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); |
| iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0); |
| assert(is_shenandoah_marking_if(igvn, iff), "expect marking test"); |
| } |
| Node* cmpx = iff->in(1)->in(1); |
| igvn->replace_node(cmpx, igvn->makecon(TypeInt::CC_EQ)); |
| igvn->rehash_node_delayed(call); |
| call->del_req(call->req()-1); |
| } |
| |
| void ShenandoahBarrierSetC2::enqueue_useful_gc_barrier(Unique_Node_List &worklist, Node* node) const { |
| if (node->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(node)) { |
| for (DUIterator_Fast imax, i = node->fast_outs(imax); i < imax; i++) { |
| Node* use = node->fast_out(i); |
| worklist.push(use); |
| } |
| } |
| } |
| |
| void ShenandoahBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful) const { |
| for (uint i = 0; i < useful.size(); i++) { |
| Node* n = useful.at(i); |
| if (n->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(n)) { |
| for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { |
| Compile::current()->record_for_igvn(n->fast_out(i)); |
| } |
| } |
| } |
| for (int i = state()->iu_barriers_count() - 1; i >= 0; i--) { |
| ShenandoahIUBarrierNode* n = state()->iu_barrier(i); |
| if (!useful.member(n)) { |
| state()->remove_iu_barrier(n); |
| } |
| } |
| for (int i = state()->load_reference_barriers_count() - 1; i >= 0; i--) { |
| ShenandoahLoadReferenceBarrierNode* n = state()->load_reference_barrier(i); |
| if (!useful.member(n)) { |
| state()->remove_load_reference_barrier(n); |
| } |
| } |
| } |
| |
| void ShenandoahBarrierSetC2::add_users_to_worklist(Unique_Node_List* worklist) const {} |
| |
| void* ShenandoahBarrierSetC2::create_barrier_state(Arena* comp_arena) const { |
| return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena); |
| } |
| |
| ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const { |
| return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state()); |
| } |
| |
| // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be |
| // expanded later, then now is the time to do so. |
| bool ShenandoahBarrierSetC2::expand_macro_nodes(PhaseMacroExpand* macro) const { return false; } |
| |
| #ifdef ASSERT |
| void ShenandoahBarrierSetC2::verify_gc_barriers(bool post_parse) const { |
| if (ShenandoahVerifyOptoBarriers && !post_parse) { |
| ShenandoahBarrierC2Support::verify(Compile::current()->root()); |
| } |
| } |
| #endif |
| |
| Node* ShenandoahBarrierSetC2::ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const { |
| if (is_shenandoah_wb_pre_call(n)) { |
| uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt(); |
| if (n->req() > cnt) { |
| Node* addp = n->in(cnt); |
| if (has_only_shenandoah_wb_pre_uses(addp)) { |
| n->del_req(cnt); |
| if (can_reshape) { |
| phase->is_IterGVN()->_worklist.push(addp); |
| } |
| return n; |
| } |
| } |
| } |
| if (n->Opcode() == Op_CmpP) { |
| Node* in1 = n->in(1); |
| Node* in2 = n->in(2); |
| if (in1->bottom_type() == TypePtr::NULL_PTR) { |
| in2 = step_over_gc_barrier(in2); |
| } |
| if (in2->bottom_type() == TypePtr::NULL_PTR) { |
| in1 = step_over_gc_barrier(in1); |
| } |
| PhaseIterGVN* igvn = phase->is_IterGVN(); |
| if (in1 != n->in(1)) { |
| if (igvn != NULL) { |
| n->set_req_X(1, in1, igvn); |
| } else { |
| n->set_req(1, in1); |
| } |
| assert(in2 == n->in(2), "only one change"); |
| return n; |
| } |
| if (in2 != n->in(2)) { |
| if (igvn != NULL) { |
| n->set_req_X(2, in2, igvn); |
| } else { |
| n->set_req(2, in2); |
| } |
| return n; |
| } |
| } else if (can_reshape && |
| n->Opcode() == Op_If && |
| ShenandoahBarrierC2Support::is_heap_stable_test(n) && |
| n->in(0) != NULL) { |
| Node* dom = n->in(0); |
| Node* prev_dom = n; |
| int op = n->Opcode(); |
| int dist = 16; |
| // Search up the dominator tree for another heap stable test |
| while (dom->Opcode() != op || // Not same opcode? |
| !ShenandoahBarrierC2Support::is_heap_stable_test(dom) || // Not same input 1? |
| prev_dom->in(0) != dom) { // One path of test does not dominate? |
| if (dist < 0) return NULL; |
| |
| dist--; |
| prev_dom = dom; |
| dom = IfNode::up_one_dom(dom); |
| if (!dom) return NULL; |
| } |
| |
| // Check that we did not follow a loop back to ourselves |
| if (n == dom) { |
| return NULL; |
| } |
| |
| return n->as_If()->dominated_by(prev_dom, phase->is_IterGVN()); |
| } |
| return NULL; |
| } |
| |
| bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) { |
| for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { |
| Node* u = n->fast_out(i); |
| if (!is_shenandoah_wb_pre_call(u)) { |
| return false; |
| } |
| } |
| return n->outcnt() > 0; |
| } |
| |
| Node* ShenandoahBarrierSetC2::arraycopy_load_reference_barrier(PhaseGVN *phase, Node* v) { |
| if (ShenandoahLoadRefBarrier) { |
| return phase->transform(new ShenandoahLoadReferenceBarrierNode(NULL, v)); |
| } |
| if (ShenandoahIUBarrier) { |
| return phase->transform(new ShenandoahIUBarrierNode(v)); |
| } |
| return v; |
| } |
| |
