/* * Copyright (c) 2018, 2026, Red Hat, Inc. All rights reserved. * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * 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 "classfile/javaClasses.hpp" #include "gc/shared/barrierSet.hpp" #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp" #include "gc/shenandoah/c2/shenandoahSupport.hpp" #include "gc/shenandoah/heuristics/shenandoahHeuristics.hpp" #include "gc/shenandoah/shenandoahBarrierSet.hpp" #include "gc/shenandoah/shenandoahCardTable.hpp" #include "gc/shenandoah/shenandoahForwarding.hpp" #include "gc/shenandoah/shenandoahHeap.hpp" #include "gc/shenandoah/shenandoahRuntime.hpp" #include "gc/shenandoah/shenandoahThreadLocalData.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(BarrierSet::barrier_set()->barrier_set_c2()); } ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena) : _load_reference_barriers(new (comp_arena) GrowableArray(comp_arena, 8, 0, nullptr)) { } 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); } } #define __ kit-> bool ShenandoahBarrierSetC2::satb_can_remove_pre_barrier(GraphKit* kit, PhaseValues* 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); if (offset == Type::OffsetBot) { return false; // cannot unalias unless there are precise offsets } if (alloc == nullptr) { 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 == nullptr) { 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)) { // 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 == nullptr || 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(adr != nullptr, "where are loading from?"); assert(pre_val == nullptr, "loaded already?"); assert(val_type != nullptr, "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 != nullptr, "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 != nullptr) __ 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_barrier_pre_Type(); __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_pre), "shenandoah_wb_pre", pre_val); } __ end_if(); // (!index) } __ end_if(); // (pre_val != nullptr) } __ end_if(); // (!marking) // Final sync IdealKit and GraphKit. kit->final_sync(ideal); if (ShenandoahSATBBarrier && adr != nullptr) { 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_barrier_pre); } bool ShenandoahBarrierSetC2::is_shenandoah_clone_call(Node* call) { return call->is_CallLeaf() && call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::clone_barrier); } 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_strong)) || (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_strong_narrow)) || (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_weak)) || (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_weak_narrow)) || (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_phantom)) || (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_phantom_narrow)); } bool ShenandoahBarrierSetC2::is_shenandoah_marking_if(PhaseValues* 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 Shenandoah // 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 != nullptr && 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 != nullptr) { if (btype->isa_aryptr()) { // Array type so nothing to do return; } const TypeInstPtr* itype = btype->isa_instptr(); if (itype != nullptr) { // Can the klass of base_oop be statically determined to be // _not_ a sub-class of Reference and _not_ Object? ciKlass* klass = itype->instance_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 == nullptr __ 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 */, nullptr /* obj */, nullptr /* adr */, max_juint /* alias_idx */, nullptr /* val */, nullptr /* 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); } void ShenandoahBarrierSetC2::post_barrier(GraphKit* kit, Node* ctl, Node* oop_store, Node* obj, Node* adr, uint adr_idx, Node* val, BasicType bt, bool use_precise) const { assert(ShenandoahCardBarrier, "Should have been checked by caller"); // No store check needed if we're storing a null. if (val != nullptr && val->is_Con()) { // must be either an oop or null const Type* t = val->bottom_type(); if (t == TypePtr::NULL_PTR || t == Type::TOP) return; } if (ReduceInitialCardMarks && obj == kit->just_allocated_object(kit->control())) { // We use card marks to track old to young references in Generational Shenandoah; // see flag ShenandoahCardBarrier above. // Objects are always allocated in the young generation and initialized // before they are promoted. There's always a safepoint (e.g. at final mark) // before an object is promoted from young to old. Promotion entails dirtying of // the cards backing promoted objects, so they will be guaranteed to be scanned // at the next remembered set scan of the old generation. // Thus, we can safely skip card-marking of initializing stores on a // freshly-allocated object. If any of the assumptions above change in // the future, this code will need to be re-examined; see check in // ShenandoahCardBarrier::on_slowpath_allocation_exit(). return; } if (!use_precise) { // All card marks for a (non-array) instance are in one place: adr = obj; } // (Else it's an array (or unknown), and we want more precise card marks.) assert(adr != nullptr, ""); IdealKit ideal(kit, true); Node* tls = __ thread(); // ThreadLocalStorage // Convert the pointer to an int prior to doing math on it Node* cast = __ CastPX(__ ctrl(), adr); Node* curr_ct_holder_offset = __ ConX(in_bytes(ShenandoahThreadLocalData::card_table_offset())); Node* curr_ct_holder_addr = __ AddP(__ top(), tls, curr_ct_holder_offset); Node* curr_ct_base_addr = __ load( __ ctrl(), curr_ct_holder_addr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw); // Divide by card size Node* card_offset = __ URShiftX( cast, __ ConI(CardTable::card_shift()) ); // Combine card table base and card offset Node* card_adr = __ AddP(__ top(), curr_ct_base_addr, card_offset); // Get the alias_index for raw card-mark memory int adr_type = Compile::AliasIdxRaw; Node* zero = __ ConI(0); // Dirty card value if (UseCondCardMark) { // The classic GC reference write barrier is typically implemented // as a store into the global card mark table. Unfortunately // unconditional stores can result in false sharing and excessive // coherence traffic as well as false transactional aborts. // UseCondCardMark enables MP "polite" conditional card mark // stores. In theory we could relax the load from ctrl() to // no_ctrl, but that doesn't buy much latitude. Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, T_BYTE, adr_type); __ if_then(card_val, BoolTest::ne, zero); } // Smash zero into card __ store(__ ctrl(), card_adr, zero, T_BYTE, adr_type, MemNode::unordered); if (UseCondCardMark) { __ end_if(); } // Final sync IdealKit and GraphKit. kit->final_sync(ideal); } #undef __ const TypeFunc* ShenandoahBarrierSetC2::_write_barrier_pre_Type = nullptr; const TypeFunc* ShenandoahBarrierSetC2::_clone_barrier_Type = nullptr; const TypeFunc* ShenandoahBarrierSetC2::_load_reference_barrier_Type = nullptr; inline const TypeFunc* ShenandoahBarrierSetC2::write_barrier_pre_Type() { assert(ShenandoahBarrierSetC2::_write_barrier_pre_Type != nullptr, "should be initialized"); return ShenandoahBarrierSetC2::_write_barrier_pre_Type; } inline const TypeFunc* ShenandoahBarrierSetC2::clone_barrier_Type() { assert(ShenandoahBarrierSetC2::_clone_barrier_Type != nullptr, "should be initialized"); return ShenandoahBarrierSetC2::_clone_barrier_Type; } const TypeFunc* ShenandoahBarrierSetC2::load_reference_barrier_Type() { assert(ShenandoahBarrierSetC2::_load_reference_barrier_Type != nullptr, "should be initialized"); return ShenandoahBarrierSetC2::_load_reference_barrier_Type; } void ShenandoahBarrierSetC2::init() { ShenandoahBarrierSetC2::make_write_barrier_pre_Type(); ShenandoahBarrierSetC2::make_clone_barrier_Type(); ShenandoahBarrierSetC2::make_load_reference_barrier_Type(); } void ShenandoahBarrierSetC2::make_write_barrier_pre_Type() { assert(ShenandoahBarrierSetC2::_write_barrier_pre_Type == nullptr, "should be"); const Type **fields = TypeTuple::fields(1); fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value 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); ShenandoahBarrierSetC2::_write_barrier_pre_Type = TypeFunc::make(domain, range); } void ShenandoahBarrierSetC2::make_clone_barrier_Type() { assert(ShenandoahBarrierSetC2::_clone_barrier_Type == nullptr, "should be"); 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); ShenandoahBarrierSetC2::_clone_barrier_Type = TypeFunc::make(domain, range); } void ShenandoahBarrierSetC2::make_load_reference_barrier_Type() { assert(ShenandoahBarrierSetC2::_load_reference_barrier_Type == nullptr, "should be"); const Type **fields = TypeTuple::fields(2); fields[TypeFunc::Parms+0] = TypeOopPtr::BOTTOM; // 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] = TypeOopPtr::BOTTOM; const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields); ShenandoahBarrierSetC2::_load_reference_barrier_Type = 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 no_keepalive = (decorators & AS_NO_KEEPALIVE) != 0; if (!access.is_oop()) { return BarrierSetC2::store_at_resolved(access, val); } if (no_keepalive) { // No keep-alive means no need for the pre-barrier. return BarrierSetC2::store_at_resolved(access, val); } if (access.is_parse_access()) { C2ParseAccess& parse_access = static_cast(access); GraphKit* kit = parse_access.kit(); uint adr_idx = kit->C->get_alias_index(adr_type); assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" ); shenandoah_write_barrier_pre(kit, true /* do_load */, /*kit->control(),*/ access.base(), adr, adr_idx, val.node(), static_cast(val.type()), nullptr /* pre_val */, access.type()); Node* result = BarrierSetC2::store_at_resolved(access, val); if (ShenandoahCardBarrier) { const bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0; const bool is_array = (decorators & IS_ARRAY) != 0; const bool use_precise = is_array || anonymous; post_barrier(kit, kit->control(), access.raw_access(), access.base(), adr, adr_idx, val.node(), access.type(), use_precise); } return result; } else { assert(access.is_opt_access(), "only for optimization passes"); assert(((decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0 || !ShenandoahSATBBarrier) && (decorators & C2_ARRAY_COPY) != 0, "unexpected caller of this code"); 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(nullptr, load, decorators); if (access.is_parse_access()) { load = static_cast(access).kit()->gvn().transform(load); } else { load = static_cast(access).gvn().transform(load); } } // 3: apply keep-alive barrier for java.lang.ref.Reference 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; } assert(access.is_parse_access(), "entry not supported at optimization time"); C2ParseAccess& parse_access = static_cast(access); GraphKit* kit = parse_access.kit(); bool mismatched = (decorators & C2_MISMATCHED) != 0; bool is_unordered = (decorators & MO_UNORDERED) != 0; bool in_native = (decorators & IN_NATIVE) != 0; bool need_cpu_mem_bar = !is_unordered || mismatched || in_native; if (on_weak_ref) { // Use the pre-barrier to record the value in the referent field satb_write_barrier_pre(kit, false /* do_load */, nullptr /* obj */, nullptr /* adr */, max_juint /* alias_idx */, nullptr /* val */, nullptr /* 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; } Node* ShenandoahBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val, Node* new_val, const Type* value_type) const { GraphKit* kit = access.kit(); if (access.is_oop()) { shenandoah_write_barrier_pre(kit, false /* do_load */, nullptr, nullptr, max_juint, nullptr, nullptr, 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 = nullptr; #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(nullptr, load_store, access.decorators())); if (ShenandoahCardBarrier) { post_barrier(kit, kit->control(), access.raw_access(), access.base(), access.addr().node(), access.alias_idx(), new_val, T_OBJECT, true); } return load_store; } return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type); } Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val, Node* new_val, const Type* value_type) const { GraphKit* kit = access.kit(); if (access.is_oop()) { shenandoah_write_barrier_pre(kit, false /* do_load */, nullptr, nullptr, max_juint, nullptr, nullptr, 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 = nullptr; 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); if (ShenandoahCardBarrier) { post_barrier(kit, kit->control(), access.raw_access(), access.base(), access.addr().node(), access.alias_idx(), new_val, T_OBJECT, true); } return load_store; } return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type); } Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* val, const Type* value_type) const { GraphKit* kit = access.kit(); Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type); if (access.is_oop()) { result = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(nullptr, result, access.decorators())); shenandoah_write_barrier_pre(kit, false /* do_load */, nullptr, nullptr, max_juint, nullptr, nullptr, result /* pre_val */, T_OBJECT); if (ShenandoahCardBarrier) { post_barrier(kit, kit->control(), access.raw_access(), access.base(), access.addr().node(), access.alias_idx(), val, T_OBJECT, true); } } return result; } bool ShenandoahBarrierSetC2::is_gc_pre_barrier_node(Node* node) const { return is_shenandoah_wb_pre_call(node); } bool ShenandoahBarrierSetC2::is_gc_barrier_node(Node* node) const { return (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) || is_shenandoah_lrb_call(node) || is_shenandoah_wb_pre_call(node) || is_shenandoah_clone_call(node); } Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) const { if (c == nullptr) { return c; } if (c->Opcode() == Op_ShenandoahLoadReferenceBarrier) { return c->in(ShenandoahLoadReferenceBarrierNode::ValueIn); } 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; } return false; } bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, bool is_clone_instance, ArrayCopyPhase phase) const { bool is_oop = is_reference_type(type); if (!is_oop) { return false; } if (ShenandoahSATBBarrier && tightly_coupled_alloc) { if (phase == Optimization) { return false; } return !is_clone; } return true; } bool ShenandoahBarrierSetC2::clone_needs_barrier(Node* src, PhaseGVN& gvn) { const TypeOopPtr* src_type = gvn.type(src)->is_oopptr(); if (src_type->isa_instptr() != nullptr) { ciInstanceKlass* ik = src_type->is_instptr()->instance_klass(); if ((src_type->klass_is_exact() || !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->isa_aryptr()->elem()->array_element_basic_type(); if (is_reference_type(src_elem, true)) { 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_base = ac->in(ArrayCopyNode::Src); Node* src_offset = ac->in(ArrayCopyNode::SrcPos); Node* dest_base = ac->in(ArrayCopyNode::Dest); Node* dest_offset = ac->in(ArrayCopyNode::DestPos); Node* length = ac->in(ArrayCopyNode::Length); Node* src = phase->basic_plus_adr(src_base, src_offset); Node* dest = phase->basic_plus_adr(dest_base, dest_offset); 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 = nullptr; // 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)); Node* stable_and = phase->transform_later(new AndINode(gc_state, phase->igvn().intcon(ShenandoahHeap::HAS_FORWARDED))); 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::clone_barrier_Type(), CAST_FROM_FN_PTR(address, ShenandoahRuntime::clone_barrier), "shenandoah_clone", TypeRawPtr::BOTTOM, src_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); if (should_copy_int_prefix(phase, ac)) { mem = arraycopy_copy_int_prefix(phase, ctrl, mem, src, dest); // We've copied the prefix, bump the pointers. src = phase->basic_plus_adr(src_base, src, BytesPerInt); dest = phase->basic_plus_adr(dest_base, dest, BytesPerInt); } // Bulk copy. const char* name = "arraycopy"; call = phase->make_leaf_call(ctrl, mem, OptoRuntime::fast_arraycopy_Type(), phase->basictype2arraycopy(T_LONG, nullptr, nullptr, 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_ShenandoahLoadReferenceBarrier) { state()->add_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node); } } void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const { if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) { state()->remove_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node); } } void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const { if (is_shenandoah_wb_pre_call(node)) { shenandoah_eliminate_wb_pre(node, ¯o->igvn()); } if (ShenandoahCardBarrier && node->Opcode() == Op_CastP2X) { Node* shift = node->unique_out(); Node* addp = shift->unique_out(); for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) { Node* mem = addp->last_out(j); if (UseCondCardMark && mem->is_Load()) { assert(mem->Opcode() == Op_LoadB, "unexpected code shape"); // The load is checking if the card has been written so // replace it with zero to fold the test. macro->replace_node(mem, macro->intcon(0)); continue; } assert(mem->is_Store(), "store required"); macro->replace_node(mem, mem->in(MemNode::Memory)); } } } 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(PhaseIterGVN* igvn, Node* node) const { if (node->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(node)) { igvn->add_users_to_worklist(node); } } void ShenandoahBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) 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++) { C->record_for_igvn(n->fast_out(i)); } } } 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::create_barrier_state(Arena* comp_arena) const { return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena); } ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const { return reinterpret_cast(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(Compile* compile, CompilePhase phase) const { if (ShenandoahVerifyOptoBarriers && phase == BarrierSetC2::BeforeMacroExpand) { ShenandoahBarrierC2Support::verify(Compile::current()->root()); } else if (phase == BarrierSetC2::BeforeCodeGen) { // Verify Shenandoah pre-barriers const int gc_state_offset = in_bytes(ShenandoahThreadLocalData::gc_state_offset()); Unique_Node_List visited; Node_List worklist; // We're going to walk control flow backwards starting from the Root worklist.push(compile->root()); while (worklist.size() > 0) { Node *x = worklist.pop(); if (x == nullptr || x == compile->top()) { continue; } if (visited.member(x)) { continue; } else { visited.push(x); } if (x->is_Region()) { for (uint i = 1; i < x->req(); i++) { worklist.push(x->in(i)); } } else { worklist.push(x->in(0)); // We are looking for the pattern: // /->ThreadLocal // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset) // \->ConI(0) // We want to verify that the If and the LoadB have the same control // See GraphKit::g1_write_barrier_pre() if (x->is_If()) { IfNode *iff = x->as_If(); if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) { CmpNode *cmp = iff->in(1)->in(1)->as_Cmp(); if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0 && cmp->in(1)->is_Load()) { LoadNode *load = cmp->in(1)->as_Load(); if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal && load->in(2)->in(3)->is_Con() && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == gc_state_offset) { Node *if_ctrl = iff->in(0); Node *load_ctrl = load->in(0); if (if_ctrl != load_ctrl) { // Skip possible CProj->NeverBranch in infinite loops if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj) && if_ctrl->in(0)->is_NeverBranch()) { if_ctrl = if_ctrl->in(0)->in(0); } } assert(load_ctrl != nullptr && if_ctrl == load_ctrl, "controls must match"); } } } } } } } } #endif Node* ShenandoahBarrierSetC2::ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const { if (is_shenandoah_wb_pre_call(n)) { uint cnt = ShenandoahBarrierSetC2::write_barrier_pre_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 one input is null, then step over the strong LRB barriers on the other input if (in1->bottom_type() == TypePtr::NULL_PTR && !((in2->Opcode() == Op_ShenandoahLoadReferenceBarrier) && !ShenandoahBarrierSet::is_strong_access(((ShenandoahLoadReferenceBarrierNode*)in2)->decorators()))) { in2 = step_over_gc_barrier(in2); } if (in2->bottom_type() == TypePtr::NULL_PTR && !((in1->Opcode() == Op_ShenandoahLoadReferenceBarrier) && !ShenandoahBarrierSet::is_strong_access(((ShenandoahLoadReferenceBarrierNode*)in1)->decorators()))) { in1 = step_over_gc_barrier(in1); } if (in1 != n->in(1)) { n->set_req_X(1, in1, phase); assert(in2 == n->in(2), "only one change"); return n; } if (in2 != n->in(2)) { n->set_req_X(2, in2, phase); return n; } } else if (can_reshape && n->Opcode() == Op_If && ShenandoahBarrierC2Support::is_heap_stable_test(n) && n->in(0) != nullptr && n->outcnt() == 2) { 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 nullptr; dist--; prev_dom = dom; dom = IfNode::up_one_dom(dom); if (!dom) return nullptr; } // Check that we did not follow a loop back to ourselves if (n == dom) { return nullptr; } return n->as_If()->dominated_by(prev_dom, phase->is_IterGVN(), false); } return nullptr; } 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; } bool ShenandoahBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode, Unique_Node_List& dead_nodes) const { switch (opcode) { case Op_CallLeaf: case Op_CallLeafNoFP: { assert (n->is_Call(), ""); CallNode *call = n->as_Call(); if (ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(call)) { uint cnt = ShenandoahBarrierSetC2::write_barrier_pre_Type()->domain()->cnt(); if (call->req() > cnt) { assert(call->req() == cnt + 1, "only one extra input"); Node *addp = call->in(cnt); assert(!ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(addp), "useless address computation?"); call->del_req(cnt); } } return false; } case Op_ShenandoahCompareAndSwapP: case Op_ShenandoahCompareAndSwapN: case Op_ShenandoahWeakCompareAndSwapN: case Op_ShenandoahWeakCompareAndSwapP: case Op_ShenandoahCompareAndExchangeP: case Op_ShenandoahCompareAndExchangeN: return true; case Op_ShenandoahLoadReferenceBarrier: assert(false, "should have been expanded already"); return true; default: return false; } } bool ShenandoahBarrierSetC2::escape_add_to_con_graph(ConnectionGraph* conn_graph, PhaseGVN* gvn, Unique_Node_List* delayed_worklist, Node* n, uint opcode) const { switch (opcode) { case Op_ShenandoahCompareAndExchangeP: case Op_ShenandoahCompareAndExchangeN: conn_graph->add_objload_to_connection_graph(n, delayed_worklist); // fallthrough case Op_ShenandoahWeakCompareAndSwapP: case Op_ShenandoahWeakCompareAndSwapN: case Op_ShenandoahCompareAndSwapP: case Op_ShenandoahCompareAndSwapN: conn_graph->add_to_congraph_unsafe_access(n, opcode, delayed_worklist); return true; case Op_StoreP: { Node* adr = n->in(MemNode::Address); const Type* adr_type = gvn->type(adr); // Pointer stores in Shenandoah barriers looks like unsafe access. // Ignore such stores to be able scalar replace non-escaping // allocations. if (adr_type->isa_rawptr() && adr->is_AddP()) { Node* base = conn_graph->get_addp_base(adr); if (base->Opcode() == Op_LoadP && base->in(MemNode::Address)->is_AddP()) { adr = base->in(MemNode::Address); Node* tls = conn_graph->get_addp_base(adr); if (tls->Opcode() == Op_ThreadLocal) { int offs = (int) gvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot); const int buf_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()); if (offs == buf_offset) { return true; // Pre barrier previous oop value store. } } } } return false; } case Op_ShenandoahLoadReferenceBarrier: conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), delayed_worklist); return true; default: // Nothing break; } return false; } bool ShenandoahBarrierSetC2::escape_add_final_edges(ConnectionGraph* conn_graph, PhaseGVN* gvn, Node* n, uint opcode) const { switch (opcode) { case Op_ShenandoahCompareAndExchangeP: case Op_ShenandoahCompareAndExchangeN: { Node *adr = n->in(MemNode::Address); conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, adr, nullptr); // fallthrough } case Op_ShenandoahCompareAndSwapP: case Op_ShenandoahCompareAndSwapN: case Op_ShenandoahWeakCompareAndSwapP: case Op_ShenandoahWeakCompareAndSwapN: return conn_graph->add_final_edges_unsafe_access(n, opcode); case Op_ShenandoahLoadReferenceBarrier: conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), nullptr); return true; default: // Nothing break; } return false; } bool ShenandoahBarrierSetC2::escape_has_out_with_unsafe_object(Node* n) const { return n->has_out_with(Op_ShenandoahCompareAndExchangeP) || n->has_out_with(Op_ShenandoahCompareAndExchangeN) || n->has_out_with(Op_ShenandoahCompareAndSwapP, Op_ShenandoahCompareAndSwapN, Op_ShenandoahWeakCompareAndSwapP, Op_ShenandoahWeakCompareAndSwapN); } bool ShenandoahBarrierSetC2::matcher_find_shared_post_visit(Matcher* matcher, Node* n, uint opcode) const { switch (opcode) { case Op_ShenandoahCompareAndExchangeP: case Op_ShenandoahCompareAndExchangeN: case Op_ShenandoahWeakCompareAndSwapP: case Op_ShenandoahWeakCompareAndSwapN: case Op_ShenandoahCompareAndSwapP: case Op_ShenandoahCompareAndSwapN: { // Convert trinary to binary-tree Node* newval = n->in(MemNode::ValueIn); Node* oldval = n->in(LoadStoreConditionalNode::ExpectedIn); Node* pair = new BinaryNode(oldval, newval); n->set_req(MemNode::ValueIn,pair); n->del_req(LoadStoreConditionalNode::ExpectedIn); return true; } default: break; } return false; } bool ShenandoahBarrierSetC2::matcher_is_store_load_barrier(Node* x, uint xop) const { return xop == Op_ShenandoahCompareAndExchangeP || xop == Op_ShenandoahCompareAndExchangeN || xop == Op_ShenandoahWeakCompareAndSwapP || xop == Op_ShenandoahWeakCompareAndSwapN || xop == Op_ShenandoahCompareAndSwapN || xop == Op_ShenandoahCompareAndSwapP; }