8233401: Shenandoah: Refactor/cleanup Shenandoah load barrier code
Reviewed-by: aph, shade, rkennke
/*
* 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/shenandoahConcurrentRoots.hpp"
#include "gc/shenandoah/shenandoahForwarding.hpp"
#include "gc/shenandoah/shenandoahHeap.hpp"
#include "gc/shenandoah/shenandoahHeuristics.hpp"
#include "gc/shenandoah/shenandoahRuntime.hpp"
#include "gc/shenandoah/shenandoahThreadLocalData.hpp"
#include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
#include "gc/shenandoah/c2/shenandoahSupport.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)
: _enqueue_barriers(new (comp_arena) GrowableArray<ShenandoahEnqueueBarrierNode*>(comp_arena, 8, 0, NULL)),
_load_reference_barriers(new (comp_arena) GrowableArray<ShenandoahLoadReferenceBarrierNode*>(comp_arena, 8, 0, NULL)) {
}
int ShenandoahBarrierSetC2State::enqueue_barriers_count() const {
return _enqueue_barriers->length();
}
ShenandoahEnqueueBarrierNode* ShenandoahBarrierSetC2State::enqueue_barrier(int idx) const {
return _enqueue_barriers->at(idx);
}
void ShenandoahBarrierSetC2State::add_enqueue_barrier(ShenandoahEnqueueBarrierNode * n) {
assert(!_enqueue_barriers->contains(n), "duplicate entry in barrier list");
_enqueue_barriers->append(n);
}
void ShenandoahBarrierSetC2State::remove_enqueue_barrier(ShenandoahEnqueueBarrierNode * n) {
if (_enqueue_barriers->contains(n)) {
_enqueue_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_storeval_barrier(GraphKit* kit, Node* obj) const {
if (ShenandoahStoreValEnqueueBarrier) {
obj = shenandoah_enqueue_barrier(kit, 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 G1 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)) ||
(entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_native));
}
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);
}
}
Node* ShenandoahBarrierSetC2::shenandoah_enqueue_barrier(GraphKit* kit, Node* pre_val) const {
return kit->gvn().transform(new ShenandoahEnqueueBarrierNode(pre_val));
}
// 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);
}
if (access.is_parse_access()) {
C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(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" );
Node* value = val.node();
value = shenandoah_storeval_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());
} 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");
C2OptAccess& opt_access = static_cast<C2OptAccess&>(access);
PhaseGVN& gvn = opt_access.gvn();
MergeMemNode* mm = opt_access.mem();
if (ShenandoahStoreValEnqueueBarrier) {
Node* enqueue = gvn.transform(new ShenandoahEnqueueBarrierNode(val.node()));
val.set_node(enqueue);
}
}
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();
bool in_native = (decorators & IN_NATIVE) != 0;
// 2: apply LRB if ShenandoahLoadRefBarrier is set
if (ShenandoahLoadRefBarrier) {
// Native barrier is for concurrent root processing
bool use_native_barrier = in_native && ShenandoahConcurrentRoots::can_do_concurrent_roots();
load = new ShenandoahLoadReferenceBarrierNode(NULL, load, use_native_barrier);
if (access.is_parse_access()) {
load = static_cast<C2ParseAccess &>(access).kit()->gvn().transform(load);
} else {
load = static_cast<C2OptAccess &>(access).gvn().transform(load);
}
}
// 3: apply keep-alive barrier if ShenandoahKeepAliveBarrier is set
if (ShenandoahKeepAliveBarrier) {
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 is_traversal_mode = ShenandoahHeap::heap()->is_traversal_mode();
bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0 || is_traversal_mode;
// 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<C2ParseAccess&>(access);
GraphKit* kit = parse_access.kit();
bool mismatched = (decorators & C2_MISMATCHED) != 0;
bool is_unordered = (decorators & MO_UNORDERED) != 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 */,
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;
}
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()) {
new_val = shenandoah_storeval_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, false));
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()) {
new_val = shenandoah_storeval_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(C2AtomicParseAccess& access, Node* val, const Type* value_type) const {
GraphKit* kit = access.kit();
if (access.is_oop()) {
val = shenandoah_storeval_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, false));
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->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
return c->in(ShenandoahLoadReferenceBarrierNode::ValueIn);
}
if (c->Opcode() == Op_ShenandoahEnqueueBarrier) {
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(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const {
bool is_oop = is_reference_type(type);
if (!is_oop) {
return false;
}
if (tightly_coupled_alloc) {
if (phase == Optimization) {
return false;
}
return !is_clone;
}
if (phase == Optimization) {
return !ShenandoahStoreValEnqueueBarrier;
}
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() != 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 (is_reference_type(src_elem)) {
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));
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::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_ShenandoahEnqueueBarrier) {
state()->add_enqueue_barrier((ShenandoahEnqueueBarrierNode*) 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_ShenandoahEnqueueBarrier) {
state()->remove_enqueue_barrier((ShenandoahEnqueueBarrierNode*) 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(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()->enqueue_barriers_count() - 1; i >= 0; i--) {
ShenandoahEnqueueBarrierNode* n = state()->enqueue_barrier(i);
if (!useful.member(n)) {
state()->remove_enqueue_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::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(Compile* compile, CompilePhase phase) const {
if (ShenandoahVerifyOptoBarriers && phase == BarrierSetC2::BeforeMacroExpand) {
ShenandoahBarrierC2Support::verify(Compile::current()->root());
} else if (phase == BarrierSetC2::BeforeCodeGen) {
// Verify G1 pre-barriers
const int marking_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset());
ResourceArea *area = Thread::current()->resource_area();
Unique_Node_List visited(area);
Node_List worklist(area);
// 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 == NULL || 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() == marking_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_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
if_ctrl = if_ctrl->in(0)->in(0);
}
}
assert(load_ctrl != NULL && 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_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;
}
bool ShenandoahBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode) 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_ref_field_pre_entry_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:
#ifdef ASSERT
if( VerifyOptoOopOffsets ) {
MemNode* mem = n->as_Mem();
// Check to see if address types have grounded out somehow.
const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
ciInstanceKlass *k = tp->klass()->as_instance_klass();
bool oop_offset_is_sane = k->contains_field_offset(tp->offset());
assert( !tp || oop_offset_is_sane, "" );
}
#endif
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 G1 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_ShenandoahEnqueueBarrier:
conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist);
break;
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, NULL);
// 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_ShenandoahEnqueueBarrier:
conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), NULL);
return true;
case Op_ShenandoahLoadReferenceBarrier:
conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), NULL);
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;
}