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[turbofan] staging new implementation of escape analysis

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Bug: 
Change-Id: Idebe4fa6d651a404a0dc1947ed4a34a8dc9707a9
Reviewed-on: https://chromium-review.googlesource.com/565720
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46966}
This commit is contained in:
Tobias Tebbi 2017-07-28 13:13:44 +02:00 committed by Commit Bot
parent 7c8a75e508
commit d230b44f0c
30 changed files with 2340 additions and 93 deletions
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5
BUILD.gn
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@ -1381,6 +1381,10 @@ v8_source_set("v8_base") {
"src/compiler/memory-optimizer.h",
"src/compiler/move-optimizer.cc",
"src/compiler/move-optimizer.h",
"src/compiler/new-escape-analysis-reducer.cc",
"src/compiler/new-escape-analysis-reducer.h",
"src/compiler/new-escape-analysis.cc",
"src/compiler/new-escape-analysis.h",
"src/compiler/node-aux-data.h",
"src/compiler/node-cache.cc",
"src/compiler/node-cache.h",
@ -1402,6 +1406,7 @@ v8_source_set("v8_base") {
"src/compiler/operator.h",
"src/compiler/osr.cc",
"src/compiler/osr.h",
"src/compiler/persistent-map.h",
"src/compiler/pipeline-statistics.cc",
"src/compiler/pipeline-statistics.h",
"src/compiler/pipeline.cc",

1
src/base/functional.h
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@ -172,7 +172,6 @@ struct hash<T*> : public std::unary_function<T*, size_t> {
}
};
// base::bit_equal_to is a function object class for bitwise equality
// comparison, similar to std::equal_to, except that the comparison is performed
// on the bit representation of the operands.

52
src/compiler/common-operator.cc
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@ -142,6 +142,22 @@ std::ostream& operator<<(std::ostream& os, ParameterInfo const& i) {
return os;
}
std::ostream& operator<<(std::ostream& os, ObjectStateInfo const& i) {
return os << "id:" << i.object_id() << "|size:" << i.size();
}
size_t hash_value(ObjectStateInfo const& p) {
return base::hash_combine(p.object_id(), p.size());
}
std::ostream& operator<<(std::ostream& os, TypedObjectStateInfo const& i) {
return os << "id:" << i.object_id() << "|" << i.machine_types();
}
size_t hash_value(TypedObjectStateInfo const& p) {
return base::hash_combine(p.object_id(), p.machine_types());
}
bool operator==(RelocatablePtrConstantInfo const& lhs,
RelocatablePtrConstantInfo const& rhs) {
return lhs.rmode() == rhs.rmode() && lhs.value() == rhs.value() &&
@ -322,7 +338,7 @@ ZoneVector<MachineType> const* MachineTypesOf(Operator const* op) {
if (op->opcode() == IrOpcode::kTypedStateValues) {
return OpParameter<TypedStateValueInfo>(op).machine_types();
}
return OpParameter<const ZoneVector<MachineType>*>(op);
return OpParameter<TypedObjectStateInfo>(op).machine_types();
}
#define CACHED_OP_LIST(V) \
@ -1076,6 +1092,14 @@ const Operator* CommonOperatorBuilder::RelocatableInt64Constant(
RelocatablePtrConstantInfo(value, rmode)); // parameter
}
const Operator* CommonOperatorBuilder::ObjectId(uint32_t object_id) {
return new (zone()) Operator1<uint32_t>( // --
IrOpcode::kObjectId, Operator::kPure, // opcode
"ObjectId", // name
0, 0, 0, 1, 0, 0, // counts
object_id); // parameter
}
const Operator* CommonOperatorBuilder::Select(MachineRepresentation rep,
BranchHint hint) {
return new (zone()) Operator1<SelectParameters>( // --
@ -1220,21 +1244,35 @@ bool IsRestOf(Operator const* op) {
return OpParameter<bool>(op);
}
const Operator* CommonOperatorBuilder::ObjectState(int pointer_slots) {
return new (zone()) Operator1<int>( // --
const Operator* CommonOperatorBuilder::ObjectState(int object_id,
int pointer_slots) {
return new (zone()) Operator1<ObjectStateInfo>( // --
IrOpcode::kObjectState, Operator::kPure, // opcode
"ObjectState", // name
pointer_slots, 0, 0, 1, 0, 0, // counts
pointer_slots); // parameter
ObjectStateInfo{object_id, pointer_slots}); // parameter
}
const Operator* CommonOperatorBuilder::TypedObjectState(
const ZoneVector<MachineType>* types) {
return new (zone()) Operator1<const ZoneVector<MachineType>*>( // --
int object_id, const ZoneVector<MachineType>* types) {
return new (zone()) Operator1<TypedObjectStateInfo>( // --
IrOpcode::kTypedObjectState, Operator::kPure, // opcode
"TypedObjectState", // name
static_cast<int>(types->size()), 0, 0, 1, 0, 0, // counts
types); // parameter
TypedObjectStateInfo(object_id, types)); // parameter
}
uint32_t ObjectIdOf(Operator const* op) {
switch (op->opcode()) {
case IrOpcode::kObjectState:
return OpParameter<ObjectStateInfo>(op).object_id();
case IrOpcode::kTypedObjectState:
return OpParameter<TypedObjectStateInfo>(op).object_id();
case IrOpcode::kObjectId:
return OpParameter<uint32_t>(op);
default:
UNREACHABLE();
}
}
const Operator* CommonOperatorBuilder::FrameState(

25
src/compiler/common-operator.h
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@ -123,6 +123,23 @@ std::ostream& operator<<(std::ostream&, ParameterInfo const&);
V8_EXPORT_PRIVATE int ParameterIndexOf(const Operator* const);
const ParameterInfo& ParameterInfoOf(const Operator* const);
struct ObjectStateInfo final : std::pair<uint32_t, int> {
using std::pair<uint32_t, int>::pair;
uint32_t object_id() const { return first; }
int size() const { return second; }
};
std::ostream& operator<<(std::ostream&, ObjectStateInfo const&);
size_t hash_value(ObjectStateInfo const& p);
struct TypedObjectStateInfo final
: std::pair<uint32_t, const ZoneVector<MachineType>*> {
using std::pair<uint32_t, const ZoneVector<MachineType>*>::pair;
uint32_t object_id() const { return first; }
const ZoneVector<MachineType>* machine_types() const { return second; }
};
std::ostream& operator<<(std::ostream&, TypedObjectStateInfo const&);
size_t hash_value(TypedObjectStateInfo const& p);
class RelocatablePtrConstantInfo final {
public:
enum Type { kInt32, kInt64 };
@ -296,6 +313,8 @@ ZoneVector<MachineType> const* MachineTypesOf(Operator const*)
// IsRestOf(op) is true in the second case.
bool IsRestOf(Operator const*);
uint32_t ObjectIdOf(Operator const*);
// Interface for building common operators that can be used at any level of IR,
// including JavaScript, mid-level, and low-level.
class V8_EXPORT_PRIVATE CommonOperatorBuilder final
@ -340,6 +359,7 @@ class V8_EXPORT_PRIVATE CommonOperatorBuilder final
const Operator* NumberConstant(volatile double);
const Operator* PointerConstant(intptr_t);
const Operator* HeapConstant(const Handle<HeapObject>&);
const Operator* ObjectId(uint32_t);
const Operator* RelocatableInt32Constant(int32_t value,
RelocInfo::Mode rmode);
@ -362,8 +382,9 @@ class V8_EXPORT_PRIVATE CommonOperatorBuilder final
SparseInputMask bitmask);
const Operator* ArgumentsElementsState(bool is_rest);
const Operator* ArgumentsLengthState(bool is_rest);
const Operator* ObjectState(int pointer_slots);
const Operator* TypedObjectState(const ZoneVector<MachineType>* types);
const Operator* ObjectState(int object_id, int pointer_slots);
const Operator* TypedObjectState(int object_id,
const ZoneVector<MachineType>* types);
const Operator* FrameState(BailoutId bailout_id,
OutputFrameStateCombine state_combine,
const FrameStateFunctionInfo* function_info);

9
src/compiler/escape-analysis.cc
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@ -125,6 +125,8 @@ const Alias EscapeStatusAnalysis::kNotReachable =
const Alias EscapeStatusAnalysis::kUntrackable =
std::numeric_limits<Alias>::max() - 1;
namespace impl {
class VirtualObject : public ZoneObject {
public:
enum Status {
@ -566,6 +568,9 @@ bool VirtualState::MergeFrom(MergeCache* cache, Zone* zone, Graph* graph,
return changed;
}
} // namespace impl
using namespace impl;
EscapeStatusAnalysis::EscapeStatusAnalysis(EscapeAnalysis* object_analysis,
Graph* graph, Zone* zone)
: stack_(zone),
@ -1684,8 +1689,8 @@ Node* EscapeAnalysis::GetOrCreateObjectState(Node* effect, Node* node) {
}
int input_count = static_cast<int>(cache_->fields().size());
Node* new_object_state =
graph()->NewNode(common()->ObjectState(input_count), input_count,
&cache_->fields().front());
graph()->NewNode(common()->ObjectState(vobj->id(), input_count),
input_count, &cache_->fields().front());
NodeProperties::SetType(new_object_state, Type::OtherInternal());
vobj->SetObjectState(new_object_state);
TRACE(

20
src/compiler/escape-analysis.h
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@ -15,9 +15,11 @@ namespace compiler {
// Forward declarations.
class CommonOperatorBuilder;
class EscapeStatusAnalysis;
namespace impl {
class MergeCache;
class VirtualState;
class VirtualObject;
}; // namespace impl
// EscapeObjectAnalysis simulates stores to determine values of loads if
// an object is virtual and eliminated.
@ -55,17 +57,19 @@ class V8_EXPORT_PRIVATE EscapeAnalysis {
bool ProcessEffectPhi(Node* node);
void ForwardVirtualState(Node* node);
VirtualState* CopyForModificationAt(VirtualState* state, Node* node);
VirtualObject* CopyForModificationAt(VirtualObject* obj, VirtualState* state,
impl::VirtualState* CopyForModificationAt(impl::VirtualState* state,
Node* node);
impl::VirtualObject* CopyForModificationAt(impl::VirtualObject* obj,
impl::VirtualState* state,
Node* node);
Node* replacement(Node* node);
bool UpdateReplacement(VirtualState* state, Node* node, Node* rep);
bool UpdateReplacement(impl::VirtualState* state, Node* node, Node* rep);
VirtualObject* GetVirtualObject(VirtualState* state, Node* node);
impl::VirtualObject* GetVirtualObject(impl::VirtualState* state, Node* node);
void DebugPrint();
void DebugPrintState(VirtualState* state);
void DebugPrintState(impl::VirtualState* state);
Graph* graph() const;
Zone* zone() const { return zone_; }
@ -75,10 +79,10 @@ class V8_EXPORT_PRIVATE EscapeAnalysis {
Node* const slot_not_analyzed_;
CommonOperatorBuilder* const common_;
EscapeStatusAnalysis* status_analysis_;
ZoneVector<VirtualState*> virtual_states_;
ZoneVector<impl::VirtualState*> virtual_states_;
ZoneVector<Node*> replacements_;
ZoneSet<VirtualObject*> cycle_detection_;
MergeCache* cache_;
ZoneSet<impl::VirtualObject*> cycle_detection_;
impl::MergeCache* cache_;
DISALLOW_COPY_AND_ASSIGN(EscapeAnalysis);
};

24
src/compiler/instruction-selector.cc
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@ -482,21 +482,39 @@ class StateObjectDeduplicator {
static const size_t kNotDuplicated = SIZE_MAX;
size_t GetObjectId(Node* node) {
DCHECK(node->opcode() == IrOpcode::kTypedObjectState ||
node->opcode() == IrOpcode::kObjectId ||
node->opcode() == IrOpcode::kArgumentsElementsState);
for (size_t i = 0; i < objects_.size(); ++i) {
if (objects_[i] == node) {
if (objects_[i] == node) return i;
// ObjectId nodes are the Turbofan way to express objects with the same
// identity in the deopt info. So they should always be mapped to
// previously appearing TypedObjectState nodes.
if (HasObjectId(objects_[i]) && HasObjectId(node) &&
ObjectIdOf(objects_[i]->op()) == ObjectIdOf(node->op())) {
return i;
}
}
DCHECK(node->opcode() == IrOpcode::kTypedObjectState ||
node->opcode() == IrOpcode::kArgumentsElementsState);
return kNotDuplicated;
}
size_t InsertObject(Node* node) {
DCHECK(node->opcode() == IrOpcode::kTypedObjectState ||
node->opcode() == IrOpcode::kObjectId ||
node->opcode() == IrOpcode::kArgumentsElementsState);
size_t id = objects_.size();
objects_.push_back(node);
return id;
}
private:
static bool HasObjectId(Node* node) {
return node->opcode() == IrOpcode::kTypedObjectState ||
node->opcode() == IrOpcode::kObjectId;
}
ZoneVector<Node*> objects_;
};
@ -527,9 +545,11 @@ size_t InstructionSelector::AddOperandToStateValueDescriptor(
case IrOpcode::kObjectState: {
UNREACHABLE();
}
case IrOpcode::kTypedObjectState: {
case IrOpcode::kTypedObjectState:
case IrOpcode::kObjectId: {
size_t id = deduplicator->GetObjectId(input);
if (id == StateObjectDeduplicator::kNotDuplicated) {
DCHECK(input->opcode() == IrOpcode::kTypedObjectState);
size_t entries = 0;
id = deduplicator->InsertObject(input);
StateValueList* nested = values->PushRecursiveField(zone, id);

397
src/compiler/new-escape-analysis-reducer.cc Normal file
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@ -0,0 +1,397 @@
// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/compiler/new-escape-analysis-reducer.h"
#include "src/compiler/all-nodes.h"
#include "src/compiler/simplified-operator.h"
#include "src/compiler/type-cache.h"
namespace v8 {
namespace internal {
namespace compiler {
#ifdef DEBUG
#define TRACE(...) \
do { \
if (FLAG_trace_turbo_escape) PrintF(__VA_ARGS__); \
} while (false)
#else
#define TRACE(...)
#endif // DEBUG
NewEscapeAnalysisReducer::NewEscapeAnalysisReducer(
Editor* editor, JSGraph* jsgraph, EscapeAnalysisResult analysis_result,
Zone* zone)
: AdvancedReducer(editor),
jsgraph_(jsgraph),
analysis_result_(analysis_result),
object_id_cache_(zone),
node_cache_(jsgraph->graph(), zone),
arguments_elements_(zone),
zone_(zone) {}
Node* NewEscapeAnalysisReducer::MaybeGuard(Node* original, Node* replacement) {
// We might need to guard the replacement if the type of the {replacement}
// node is not in a sub-type relation to the type of the the {original} node.
Type* const replacement_type = NodeProperties::GetType(replacement);
Type* const original_type = NodeProperties::GetType(original);
if (!replacement_type->Is(original_type)) {
Node* const control = NodeProperties::GetControlInput(original);
replacement = jsgraph()->graph()->NewNode(
jsgraph()->common()->TypeGuard(original_type), replacement, control);
NodeProperties::SetType(replacement, original_type);
}
return replacement;
}
Node* NewEscapeAnalysisReducer::ObjectIdNode(const VirtualObject* vobject) {
VirtualObject::Id id = vobject->id();
if (id >= object_id_cache_.size()) object_id_cache_.resize(id + 1);
if (!object_id_cache_[id]) {
Node* node = jsgraph()->graph()->NewNode(jsgraph()->common()->ObjectId(id));
NodeProperties::SetType(node, Type::Object());
object_id_cache_[id] = node;
}
return object_id_cache_[id];
}
Reduction NewEscapeAnalysisReducer::Reduce(Node* node) {
if (Node* replacement = analysis_result().GetReplacementOf(node)) {
DCHECK(node->opcode() != IrOpcode::kAllocate &&
node->opcode() != IrOpcode::kFinishRegion);
RelaxEffectsAndControls(node);
if (replacement != jsgraph()->Dead()) {
replacement = MaybeGuard(node, replacement);
}
RelaxEffectsAndControls(node);
return Replace(replacement);
}
switch (node->opcode()) {
case IrOpcode::kAllocate: {
const VirtualObject* vobject = analysis_result().GetVirtualObject(node);
if (vobject && !vobject->HasEscaped()) {
RelaxEffectsAndControls(node);
}
return NoChange();
}
case IrOpcode::kFinishRegion: {
Node* effect = NodeProperties::GetEffectInput(node, 0);
if (effect->opcode() == IrOpcode::kBeginRegion) {
RelaxEffectsAndControls(effect);
RelaxEffectsAndControls(node);
}
return NoChange();
}
case IrOpcode::kNewUnmappedArgumentsElements:
arguments_elements_.insert(node);
return NoChange();
default: {
// TODO(sigurds): Change this to GetFrameStateInputCount once
// it is working. For now we use EffectInputCount > 0 to determine
// whether a node might have a frame state input.
if (node->op()->EffectInputCount() > 0) {
ReduceFrameStateInputs(node);
}
return NoChange();
}
}
}
// While doing DFS on the FrameState tree, we have to recognize duplicate
// occurrences of virtual objects.
class Deduplicator {
public:
explicit Deduplicator(Zone* zone) : is_duplicate_(zone) {}
bool SeenBefore(const VirtualObject* vobject) {
VirtualObject::Id id = vobject->id();
if (id >= is_duplicate_.size()) {
is_duplicate_.resize(id + 1);
}
bool is_duplicate = is_duplicate_[id];
is_duplicate_[id] = true;
return is_duplicate;
}
private:
ZoneVector<bool> is_duplicate_;
};
void NewEscapeAnalysisReducer::ReduceFrameStateInputs(Node* node) {
DCHECK_GE(node->op()->EffectInputCount(), 1);
for (int i = 0; i < node->InputCount(); ++i) {
Node* input = node->InputAt(i);
if (input->opcode() == IrOpcode::kFrameState) {
Deduplicator deduplicator(zone());
if (Node* ret = ReduceDeoptState(input, node, &deduplicator)) {
node->ReplaceInput(i, ret);
}
}
}
}
Node* NewEscapeAnalysisReducer::ReduceDeoptState(Node* node, Node* effect,
Deduplicator* deduplicator) {
TRACE_FN("ReduceDeoptState", node);
if (node->opcode() == IrOpcode::kFrameState) {
NodeHashCache::Constructor new_node(&node_cache_, node);
// This input order is important to match the DFS traversal used in the
// instruction selector. Otherwise, the instruction selector might find a
// duplicate node before the original one.
for (int input_id : {kFrameStateOuterStateInput, kFrameStateFunctionInput,
kFrameStateParametersInput, kFrameStateContextInput,
kFrameStateLocalsInput, kFrameStateStackInput}) {
Node* input = node->InputAt(input_id);
new_node.ReplaceInput(ReduceDeoptState(input, effect, deduplicator),
input_id);
}
return new_node.Get();
} else if (node->opcode() == IrOpcode::kStateValues) {
NodeHashCache::Constructor new_node(&node_cache_, node);
for (int i = 0; i < node->op()->ValueInputCount(); ++i) {
Node* input = NodeProperties::GetValueInput(node, i);
new_node.ReplaceValueInput(ReduceDeoptState(input, effect, deduplicator),
i);
}
return new_node.Get();
} else if (const VirtualObject* vobject =
analysis_result().GetVirtualObject(node)) {
if (vobject->HasEscaped()) return node;
if (deduplicator->SeenBefore(vobject)) {
return ObjectIdNode(vobject);
} else {
std::vector<Node*> inputs;
for (int offset = 0; offset < vobject->size(); offset += kPointerSize) {
Node* field =
analysis_result().GetVirtualObjectField(vobject, offset, effect);
CHECK_NOT_NULL(field);
if (field != jsgraph()->Dead()) {
inputs.push_back(ReduceDeoptState(field, effect, deduplicator));
}
}
int num_inputs = static_cast<int>(inputs.size());
NodeHashCache::Constructor new_node(
&node_cache_,
jsgraph()->common()->ObjectState(vobject->id(), num_inputs),
num_inputs, &inputs.front(), NodeProperties::GetType(node));
return new_node.Get();
}
} else {
return node;
}
}
void NewEscapeAnalysisReducer::VerifyReplacement() const {
AllNodes all(zone(), jsgraph()->graph());
for (Node* node : all.reachable) {
if (node->opcode() == IrOpcode::kAllocate) {
if (const VirtualObject* vobject =
analysis_result().GetVirtualObject(node)) {
if (!vobject->HasEscaped()) {
V8_Fatal(__FILE__, __LINE__,
"Escape analysis failed to remove node %s#%d\n",
node->op()->mnemonic(), node->id());
}
}
}
}
}
void NewEscapeAnalysisReducer::Finalize() {
for (Node* node : arguments_elements_) {
DCHECK(node->opcode() == IrOpcode::kNewUnmappedArgumentsElements);
Node* arguments_frame = NodeProperties::GetValueInput(node, 0);
if (arguments_frame->opcode() != IrOpcode::kArgumentsFrame) continue;
Node* arguments_length = NodeProperties::GetValueInput(node, 1);
if (arguments_length->opcode() != IrOpcode::kArgumentsLength) continue;
Node* arguments_length_state = nullptr;
for (Edge edge : arguments_length->use_edges()) {
Node* use = edge.from();
switch (use->opcode()) {
case IrOpcode::kObjectState:
case IrOpcode::kTypedObjectState:
case IrOpcode::kStateValues:
case IrOpcode::kTypedStateValues:
if (!arguments_length_state) {
arguments_length_state = jsgraph()->graph()->NewNode(
jsgraph()->common()->ArgumentsLengthState(
IsRestLengthOf(arguments_length->op())));
NodeProperties::SetType(arguments_length_state,
Type::OtherInternal());
}
edge.UpdateTo(arguments_length_state);
break;
default:
break;
}
}
bool escaping_use = false;
ZoneVector<Node*> loads(zone());
for (Edge edge : node->use_edges()) {
Node* use = edge.from();
if (!NodeProperties::IsValueEdge(edge)) continue;
if (use->use_edges().empty()) {
// A node without uses is dead, so we don't have to care about it.
continue;
}
switch (use->opcode()) {
case IrOpcode::kStateValues:
case IrOpcode::kTypedStateValues:
case IrOpcode::kObjectState:
case IrOpcode::kTypedObjectState:
break;
case IrOpcode::kLoadElement:
loads.push_back(use);
break;
case IrOpcode::kLoadField:
if (FieldAccessOf(use->op()).offset == FixedArray::kLengthOffset) {
loads.push_back(use);
} else {
escaping_use = true;
}
break;
default:
// If the arguments elements node node is used by an unhandled node,
// then we cannot remove this allocation.
escaping_use = true;
break;
}
if (escaping_use) break;
}
if (!escaping_use) {
Node* arguments_elements_state = jsgraph()->graph()->NewNode(
jsgraph()->common()->ArgumentsElementsState(
IsRestLengthOf(arguments_length->op())));
NodeProperties::SetType(arguments_elements_state, Type::OtherInternal());
ReplaceWithValue(node, arguments_elements_state);
ElementAccess stack_access;
stack_access.base_is_tagged = BaseTaggedness::kUntaggedBase;
// Reduce base address by {kPointerSize} such that (length - index)
// resolves to the right position.
stack_access.header_size =
CommonFrameConstants::kFixedFrameSizeAboveFp - kPointerSize;
stack_access.type = Type::NonInternal();
stack_access.machine_type = MachineType::AnyTagged();
stack_access.write_barrier_kind = WriteBarrierKind::kNoWriteBarrier;
const Operator* load_stack_op =
jsgraph()->simplified()->LoadElement(stack_access);
for (Node* load : loads) {
switch (load->opcode()) {
case IrOpcode::kLoadElement: {
Node* index = NodeProperties::GetValueInput(load, 1);
// {offset} is a reverted index starting from 1. The base address is
// adapted to allow offsets starting from 1.
Node* offset = jsgraph()->graph()->NewNode(
jsgraph()->simplified()->NumberSubtract(), arguments_length,
index);
NodeProperties::SetType(offset,
TypeCache::Get().kArgumentsLengthType);
NodeProperties::ReplaceValueInput(load, arguments_frame, 0);
NodeProperties::ReplaceValueInput(load, offset, 1);
NodeProperties::ChangeOp(load, load_stack_op);
break;
}
case IrOpcode::kLoadField: {
DCHECK_EQ(FieldAccessOf(load->op()).offset,
FixedArray::kLengthOffset);
Node* length = NodeProperties::GetValueInput(node, 1);
ReplaceWithValue(load, length);
break;
}
default:
UNREACHABLE();
}
}
}
}
}
Node* NodeHashCache::Query(Node* node) {
auto it = cache_.find(node);
if (it != cache_.end()) {
return *it;
} else {
return nullptr;
}
}
NodeHashCache::Constructor::Constructor(NodeHashCache* cache,
const Operator* op, int input_count,
Node** inputs, Type* type)
: node_cache_(cache), from_(nullptr) {
if (node_cache_->temp_nodes_.size() > 0) {
tmp_ = node_cache_->temp_nodes_.back();
node_cache_->temp_nodes_.pop_back();
int tmp_input_count = tmp_->InputCount();
if (input_count <= tmp_input_count) {
tmp_->TrimInputCount(input_count);
}
for (int i = 0; i < input_count; ++i) {
if (i < tmp_input_count) {
tmp_->ReplaceInput(i, inputs[i]);
} else {
tmp_->AppendInput(node_cache_->graph_->zone(), inputs[i]);
}
}
NodeProperties::ChangeOp(tmp_, op);
} else {
tmp_ = node_cache_->graph_->NewNode(op, input_count, inputs);
}
NodeProperties::SetType(tmp_, type);
}
Node* NodeHashCache::Constructor::Get() {
DCHECK(tmp_ || from_);
Node* node;
if (!tmp_) {
node = node_cache_->Query(from_);
if (!node) node = from_;
} else {
node = node_cache_->Query(tmp_);
if (node) {
node_cache_->temp_nodes_.push_back(tmp_);
} else {
node = tmp_;
node_cache_->Insert(node);
}
}
tmp_ = from_ = nullptr;
return node;
}
Node* NodeHashCache::Constructor::MutableNode() {
DCHECK(tmp_ || from_);
if (!tmp_) {
if (node_cache_->temp_nodes_.empty()) {
tmp_ = node_cache_->graph_->CloneNode(from_);
} else {
tmp_ = node_cache_->temp_nodes_.back();
node_cache_->temp_nodes_.pop_back();
int from_input_count = from_->InputCount();
int tmp_input_count = tmp_->InputCount();
if (from_input_count <= tmp_input_count) {
tmp_->TrimInputCount(from_input_count);
}
for (int i = 0; i < from_input_count; ++i) {
if (i < tmp_input_count) {
tmp_->ReplaceInput(i, from_->InputAt(i));
} else {
tmp_->AppendInput(node_cache_->graph_->zone(), from_->InputAt(i));
}
}
NodeProperties::SetType(tmp_, NodeProperties::GetType(from_));
NodeProperties::ChangeOp(tmp_, from_->op());
}
}
return tmp_;
}
} // namespace compiler
} // namespace internal
} // namespace v8

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// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_COMPILER_NEW_ESCAPE_ANALYSIS_REDUCER_H_
#define V8_COMPILER_NEW_ESCAPE_ANALYSIS_REDUCER_H_
#include "src/base/compiler-specific.h"
#include "src/compiler/graph-reducer.h"
#include "src/compiler/new-escape-analysis.h"
#include "src/globals.h"
namespace v8 {
namespace internal {
namespace compiler {
class Deduplicator;
class JSGraph;
// Perform hash-consing when creating or mutating nodes. Used to avoid duplicate
// nodes when creating ObjectState, StateValues and FrameState nodes
class NodeHashCache {
public:
NodeHashCache(Graph* graph, Zone* zone)
: graph_(graph), cache_(zone), temp_nodes_(zone) {}
// Handle to a conceptually new mutable node. Tries to re-use existing nodes
// and to recycle memory if possible.
class Constructor {
public:
// Construct a new node as a clone of [from].
Constructor(NodeHashCache* cache, Node* from)
: node_cache_(cache), from_(from), tmp_(nullptr) {}
// Construct a new node from scratch.
Constructor(NodeHashCache* cache, const Operator* op, int input_count,
Node** inputs, Type* type);
// Modify the new node.
void ReplaceValueInput(Node* input, int i) {
if (!tmp_ && input == NodeProperties::GetValueInput(from_, i)) return;
Node* node = MutableNode();
NodeProperties::ReplaceValueInput(node, input, i);
}
void ReplaceInput(Node* input, int i) {
if (!tmp_ && input == from_->InputAt(i)) return;
Node* node = MutableNode();
node->ReplaceInput(i, input);
}
// Obtain the mutated node or a cached copy. Invalidates the [Constructor].
Node* Get();
private:
Node* MutableNode();
NodeHashCache* node_cache_;
// Original node, copied on write.
Node* from_;
// Temporary node used for mutations, can be recycled if cache is hit.
Node* tmp_;
};
private:
Node* Query(Node* node);
void Insert(Node* node) { cache_.insert(node); }
Graph* graph_;
struct NodeEquals {
bool operator()(Node* a, Node* b) const {
return NodeProperties::Equals(a, b);
}
};
struct NodeHashCode {
size_t operator()(Node* n) const { return NodeProperties::HashCode(n); }
};
ZoneUnorderedSet<Node*, NodeHashCode, NodeEquals> cache_;
// Unused nodes whose memory can be recycled.
ZoneVector<Node*> temp_nodes_;
};
// Modify the graph according to the information computed in the previous phase.
class V8_EXPORT_PRIVATE NewEscapeAnalysisReducer final
: public NON_EXPORTED_BASE(AdvancedReducer) {
public:
NewEscapeAnalysisReducer(Editor* editor, JSGraph* jsgraph,
EscapeAnalysisResult analysis_result, Zone* zone);
Reduction Reduce(Node* node) override;
const char* reducer_name() const override {
return "NewEscapeAnalysisReducer";
}
void Finalize() override;
// Verifies that all virtual allocation nodes have been dealt with. Run it
// after this reducer has been applied.
void VerifyReplacement() const;
private:
void ReduceFrameStateInputs(Node* node);
Node* ReduceDeoptState(Node* node, Node* effect, Deduplicator* deduplicator);
Node* ObjectIdNode(const VirtualObject* vobject);
Node* MaybeGuard(Node* original, Node* replacement);
JSGraph* jsgraph() const { return jsgraph_; }
EscapeAnalysisResult analysis_result() const { return analysis_result_; }
Zone* zone() const { return zone_; }
JSGraph* const jsgraph_;
EscapeAnalysisResult analysis_result_;
ZoneVector<Node*> object_id_cache_;
NodeHashCache node_cache_;
ZoneSet<Node*> arguments_elements_;
Zone* const zone_;
DISALLOW_COPY_AND_ASSIGN(NewEscapeAnalysisReducer);
};
} // namespace compiler
} // namespace internal
} // namespace v8
#endif // V8_COMPILER_NEW_ESCAPE_ANALYSIS_REDUCER_H_

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// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/compiler/new-escape-analysis.h"
#include "src/bootstrapper.h"
#include "src/compiler/linkage.h"
#include "src/compiler/node-matchers.h"
#include "src/compiler/operator-properties.h"
#include "src/compiler/simplified-operator.h"
#include "src/objects-inl.h"
namespace v8 {
namespace internal {
namespace compiler {
#ifdef DEBUG
thread_local int TraceScope::depth = 0;
#endif
template <class T>
class Sidetable {
public:
explicit Sidetable(Zone* zone) : map_(zone) {}
T& operator[](const Node* node) {
NodeId id = node->id();
if (id >= map_.size()) {
map_.resize(id + 1);
}
return map_[id];
}
private:
ZoneVector<T> map_;
};
template <class T>
class SparseSidetable {
public:
explicit SparseSidetable(Zone* zone, T def_value = T())
: def_value_(std::move(def_value)), map_(zone) {}
T& operator[](const Node* node) {
return map_.insert(std::make_pair(node->id(), def_value_)).first->second;
}
private:
T def_value_;
ZoneUnorderedMap<NodeId, T> map_;
};
// Keeps track of the changes to the current node during reduction.
// Encapsulates the current state of the IR graph and the reducer state like
// side-tables. All access to the IR and the reducer state should happen through
// a ReduceScope to ensure that changes and dependencies are tracked and all
// necessary node revisitations happen.
class ReduceScope {
public:
typedef EffectGraphReducer::Reduction Reduction;
explicit ReduceScope(Node* node, Reduction* reduction)
: current_node_(node), reduction_(reduction) {}
protected:
Node* current_node() const { return current_node_; }
Reduction* reduction() { return reduction_; }
private:
Node* current_node_;
Reduction* reduction_;
};
// A VariableTracker object keeps track of the values of variables at all points
// of the effect chain and introduces new phi nodes when necessary.
// Initially and by default, variables are mapped to nullptr, which means that
// the variable allocation point does not dominate the current point on the
// effect chain. We map variables that represent uninitialized memory to the
// Dead node to ensure it is not read.
// Unmapped values are impossible by construction, it is indistinguishable if a
// PersistentMap does not contain an element or maps it to the default element.
class VariableTracker {
private:
// The state of all variables at one point in the effect chain.
class State {
typedef PersistentMap<Variable, Node*> Map;
public:
explicit State(Zone* zone) : map_(zone) {}
Node* Get(Variable var) const {
CHECK(var != Variable::Invalid());
return map_.Get(var);
}
void Set(Variable var, Node* node) {
CHECK(var != Variable::Invalid());
return map_.Set(var, node);
}
Map::iterator begin() const { return map_.begin(); }
Map::iterator end() const { return map_.end(); }
bool operator!=(const State& other) const { return map_ != other.map_; }
private:
Map map_;
};
public:
VariableTracker(JSGraph* graph, EffectGraphReducer* reducer, Zone* zone);
Variable NewVariable() { return Variable(next_variable_++); }
Node* Get(Variable var, Node* effect) { return table_[effect].Get(var); }
Zone* zone() { return zone_; }
class Scope : public ReduceScope {
public:
Scope(VariableTracker* tracker, Node* node, Reduction* reduction);
~Scope();
Node* Get(Variable var) { return current_state_.Get(var); }
void Set(Variable var, Node* node) { current_state_.Set(var, node); }
private:
VariableTracker* states_;
State current_state_;
};
private:
State MergeInputs(Node* effect_phi);
Zone* zone_;
JSGraph* graph_;
SparseSidetable<State> table_;
ZoneVector<Node*> buffer_;
EffectGraphReducer* reducer_;
int next_variable_ = 0;
DISALLOW_COPY_AND_ASSIGN(VariableTracker);
};
// Encapsulates the current state of the escape analysis reducer to preserve
// invariants regarding changes and re-visitation.
class EscapeAnalysisTracker : public ZoneObject {
public:
EscapeAnalysisTracker(JSGraph* jsgraph, EffectGraphReducer* reducer,
Zone* zone)
: virtual_objects_(zone),
replacements_(zone),
variable_states_(jsgraph, reducer, zone),
jsgraph_(jsgraph),
zone_(zone) {}
class Scope : public VariableTracker::Scope {
public:
Scope(EffectGraphReducer* reducer, EscapeAnalysisTracker* tracker,
Node* node, Reduction* reduction)
: VariableTracker::Scope(&tracker->variable_states_, node, reduction),
tracker_(tracker),
reducer_(reducer) {}
const VirtualObject* GetVirtualObject(Node* node) {
VirtualObject* vobject = tracker_->virtual_objects_[node];
if (vobject) vobject->AddDependency(current_node());
return vobject;
}
// Create or retrieve a virtual object for the current node.
const VirtualObject* InitVirtualObject(int size) {
DCHECK(current_node()->opcode() == IrOpcode::kAllocate);
VirtualObject* vobject = tracker_->virtual_objects_[current_node()];
if (vobject) {
CHECK(vobject->size() == size);
} else {
vobject = tracker_->NewVirtualObject(size);
}
if (vobject) vobject->AddDependency(current_node());
vobject_ = vobject;
return vobject;
}
void SetVirtualObject(Node* object) {
vobject_ = tracker_->virtual_objects_[object];
}
void SetEscaped(Node* node) {
if (VirtualObject* object = tracker_->virtual_objects_[node]) {
if (object->HasEscaped()) return;
TRACE("Setting %s#%d to escaped because of use by %s#%d\n",
node->op()->mnemonic(), node->id(),
current_node()->op()->mnemonic(), current_node()->id());
object->SetEscaped();
object->RevisitDependants(reducer_);
}
}
// The inputs of the current node have to be accessed through the scope to
// ensure that they respect the node replacements.
Node* ValueInput(int i) {
return tracker_->ResolveReplacement(
NodeProperties::GetValueInput(current_node(), i));
}
Node* ContextInput() {
return tracker_->ResolveReplacement(
NodeProperties::GetContextInput(current_node()));
}
void SetReplacement(Node* replacement) {
replacement_ = replacement;
vobject_ =
replacement ? tracker_->virtual_objects_[replacement] : nullptr;
TRACE("Set %s#%d as replacement.\n", replacement->op()->mnemonic(),
replacement->id());
}
void MarkForDeletion() { SetReplacement(tracker_->jsgraph_->Dead()); }
~Scope() {
if (replacement_ != tracker_->replacements_[current_node()] ||
vobject_ != tracker_->virtual_objects_[current_node()]) {
reduction()->set_value_changed();
}
tracker_->replacements_[current_node()] = replacement_;
tracker_->virtual_objects_[current_node()] = vobject_;
}
private:
EscapeAnalysisTracker* tracker_;
EffectGraphReducer* reducer_;
VirtualObject* vobject_ = nullptr;
Node* replacement_ = nullptr;
};
Node* GetReplacementOf(Node* node) { return replacements_[node]; }
Node* ResolveReplacement(Node* node) {
if (Node* replacement = GetReplacementOf(node)) {
// Replacements cannot have replacements. This is important to ensure
// re-visitation: If a replacement is replaced, then all nodes accessing
// the replacement have to be updated.
DCHECK_NULL(GetReplacementOf(replacement));
return replacement;
}
return node;
}
private:
friend class EscapeAnalysisResult;
static const size_t kMaxTrackedObjects = 100;
VirtualObject* NewVirtualObject(int size) {
if (next_object_id_ >= kMaxTrackedObjects) return nullptr;
return new (zone_)
VirtualObject(&variable_states_, next_object_id_++, size);
}
SparseSidetable<VirtualObject*> virtual_objects_;
Sidetable<Node*> replacements_;
VariableTracker variable_states_;
VirtualObject::Id next_object_id_ = 0;
JSGraph* const jsgraph_;
Zone* const zone_;
DISALLOW_COPY_AND_ASSIGN(EscapeAnalysisTracker);
};
EffectGraphReducer::EffectGraphReducer(
Graph* graph, std::function<void(Node*, Reduction*)> reduce, Zone* zone)
: graph_(graph),
state_(graph, kNumStates),
revisit_(zone),
stack_(zone),
reduce_(reduce) {}
void EffectGraphReducer::ReduceFrom(Node* node) {
// Perform DFS and eagerly trigger revisitation as soon as possible.
// A stack element {node, i} indicates that input i of node should be visited
// next.
DCHECK(stack_.empty());
stack_.push({node, 0});
while (!stack_.empty()) {
Node* current = stack_.top().node;
int& input_index = stack_.top().input_index;
if (input_index < current->InputCount()) {
Node* input = current->InputAt(input_index);
input_index++;
switch (state_.Get(input)) {
case State::kVisited:
// The input is already reduced.
break;
case State::kOnStack:
// The input is on the DFS stack right now, so it will be revisited
// later anyway.
break;
case State::kUnvisited:
case State::kRevisit: {
state_.Set(input, State::kOnStack);
stack_.push({input, 0});
break;
}
}
} else {
stack_.pop();
Reduction reduction;
reduce_(current, &reduction);
for (Edge edge : current->use_edges()) {
// Mark uses for revisitation.
Node* use = edge.from();
if (NodeProperties::IsEffectEdge(edge)) {
if (reduction.effect_changed()) Revisit(use);
} else {
if (reduction.value_changed()) Revisit(use);
}
}
state_.Set(current, State::kVisited);
// Process the revisitation buffer immediately. This improves performance
// of escape analysis. Using a stack for {revisit_} reverses the order in
// which the revisitation happens. This also seems to improve performance.
while (!revisit_.empty()) {
Node* revisit = revisit_.top();
if (state_.Get(revisit) == State::kRevisit) {
state_.Set(revisit, State::kOnStack);
stack_.push({revisit, 0});
}
revisit_.pop();
}
}
}
}
void EffectGraphReducer::Revisit(Node* node) {
if (state_.Get(node) == State::kVisited) {
TRACE(" Queueing for revisit: %s#%d\n", node->op()->mnemonic(),
node->id());
state_.Set(node, State::kRevisit);
revisit_.push(node);
}
}
VariableTracker::VariableTracker(JSGraph* graph, EffectGraphReducer* reducer,
Zone* zone)
: zone_(zone),
graph_(graph),
table_(zone, State(zone)),
buffer_(zone),
reducer_(reducer) {}
VariableTracker::Scope::Scope(VariableTracker* states, Node* node,
Reduction* reduction)
: ReduceScope(node, reduction),
states_(states),
current_state_(states->zone_) {
switch (node->opcode()) {
case IrOpcode::kEffectPhi:
current_state_ = states_->MergeInputs(node);
break;
default:
int effect_inputs = node->op()->EffectInputCount();
if (effect_inputs == 1) {
current_state_ =
states_->table_[NodeProperties::GetEffectInput(node, 0)];
} else {
DCHECK_EQ(0, effect_inputs);
}
}
}
VariableTracker::Scope::~Scope() {
if (!reduction()->effect_changed() &&
states_->table_[current_node()] != current_state_) {
reduction()->set_effect_changed();
}
states_->table_[current_node()] = current_state_;
}
VariableTracker::State VariableTracker::MergeInputs(Node* effect_phi) {
// A variable that is mapped to [nullptr] was not assigned a value on every
// execution path to the current effect phi. Relying on the invariant that
// every variable is initialized (at least with a sentinel like the Dead
// node), this means that the variable initialization does not dominate the
// current point. So for loop effect phis, we can keep nullptr for a variable
// as long as the first input of the loop has nullptr for this variable. For
// non-loop effect phis, we can even keep it nullptr as long as any input has
// nullptr.
DCHECK(effect_phi->opcode() == IrOpcode::kEffectPhi);
int arity = effect_phi->op()->EffectInputCount();
Node* control = NodeProperties::GetControlInput(effect_phi, 0);
TRACE("control: %s#%d\n", control->op()->mnemonic(), control->id());
bool is_loop = control->opcode() == IrOpcode::kLoop;
buffer_.reserve(arity + 1);
State first_input = table_[NodeProperties::GetEffectInput(effect_phi, 0)];
State result = first_input;
for (std::pair<Variable, Node*> var_value : first_input) {
if (Node* value = var_value.second) {
Variable var = var_value.first;
TRACE("var %i:\n", var.id_);
buffer_.clear();
buffer_.push_back(value);
bool identical_inputs = true;
int num_defined_inputs = 1;
TRACE(" input 0: %s#%d\n", value->op()->mnemonic(), value->id());
for (int i = 1; i < arity; ++i) {
Node* next_value =
table_[NodeProperties::GetEffectInput(effect_phi, i)].Get(var);
if (next_value != value) identical_inputs = false;
if (next_value != nullptr) {
num_defined_inputs++;
TRACE(" input %i: %s#%d\n", i, next_value->op()->mnemonic(),
next_value->id());
} else {
TRACE(" input %i: nullptr\n", i);
}
buffer_.push_back(next_value);
}
Node* old_value = table_[effect_phi].Get(var);
if (old_value) {
TRACE(" old: %s#%d\n", old_value->op()->mnemonic(), old_value->id());
} else {
TRACE(" old: nullptr\n");
}
// Reuse a previously created phi node if possible.
if (old_value && old_value->opcode() == IrOpcode::kPhi &&
NodeProperties::GetControlInput(old_value, 0) == control) {
// Since a phi node can never dominate its control node,
// [old_value] cannot originate from the inputs. Thus [old_value]
// must have been created by a previous reduction of this [effect_phi].
for (int i = 0; i < arity; ++i) {
NodeProperties::ReplaceValueInput(
old_value, buffer_[i] ? buffer_[i] : graph_->Dead(), i);
// This change cannot affect the rest of the reducer, so there is no
// need to trigger additional revisitations.
}
result.Set(var, old_value);
} else {
if (num_defined_inputs == 1 && is_loop) {
// For loop effect phis, the variable initialization dominates iff it
// dominates the first input.
DCHECK_EQ(2, arity);
DCHECK_EQ(value, buffer_[0]);
result.Set(var, value);
} else if (num_defined_inputs < arity) {
// If the variable is undefined on some input of this non-loop effect
// phi, then its initialization does not dominate this point.
result.Set(var, nullptr);
} else {
DCHECK_EQ(num_defined_inputs, arity);
// We only create a phi if the values are different.
if (identical_inputs) {
result.Set(var, value);
} else {
TRACE("Creating new phi\n");
buffer_.push_back(control);
Node* phi = graph_->graph()->NewNode(
graph_->common()->Phi(MachineRepresentation::kTagged, arity),
arity + 1, &buffer_.front());
// TODO(tebbi): Computing precise types here is tricky, because of
// the necessary revisitations. If we really need this, we should
// probably do it afterwards.
NodeProperties::SetType(phi, Type::Any());
reducer_->AddRoot(phi);
result.Set(var, phi);
}
}
}
#ifdef DEBUG
if (Node* result_node = result.Get(var)) {
TRACE(" result: %s#%d\n", result_node->op()->mnemonic(),
result_node->id());
} else {
TRACE(" result: nullptr\n");
}
#endif
}
}
return result;
}
namespace {
int OffsetOfFieldAccess(const Operator* op) {
DCHECK(op->opcode() == IrOpcode::kLoadField ||
op->opcode() == IrOpcode::kStoreField);
FieldAccess access = FieldAccessOf(op);
return access.offset;
}
Maybe<int> OffsetOfElementsAccess(const Operator* op, Node* index_node) {
DCHECK(op->opcode() == IrOpcode::kLoadElement ||
op->opcode() == IrOpcode::kStoreElement);
Type* index_type = NodeProperties::GetType(index_node);
if (!index_type->Is(Type::Number())) return Nothing<int>();
double max = index_type->Max();
double min = index_type->Min();
int index = static_cast<int>(min);
if (!(index == min && index == max)) return Nothing<int>();
ElementAccess access = ElementAccessOf(op);
DCHECK_GE(ElementSizeLog2Of(access.machine_type.representation()),
kPointerSizeLog2);
return Just(access.header_size + (index << ElementSizeLog2Of(
access.machine_type.representation())));
}
void ReduceNode(const Operator* op, EscapeAnalysisTracker::Scope* current,
JSGraph* jsgraph) {
switch (op->opcode()) {
case IrOpcode::kAllocate: {
NumberMatcher size(current->ValueInput(0));
if (!size.HasValue()) break;
int size_int = static_cast<int>(size.Value());
if (size_int != size.Value()) break;
if (const VirtualObject* vobject = current->InitVirtualObject(size_int)) {
// Initialize with dead nodes as a sentinel for uninitialized memory.
for (Variable field : *vobject) {
current->Set(field, jsgraph->Dead());
}
}
break;
}
case IrOpcode::kFinishRegion:
current->SetVirtualObject(current->ValueInput(0));
break;
case IrOpcode::kStoreField: {
Node* object = current->ValueInput(0);
Node* value = current->ValueInput(1);
const VirtualObject* vobject = current->GetVirtualObject(object);
Variable var;
if (vobject && !vobject->HasEscaped() &&
vobject->FieldAt(OffsetOfFieldAccess(op)).To(&var)) {
current->Set(var, value);
current->MarkForDeletion();
} else {
current->SetEscaped(object);
current->SetEscaped(value);
}
break;
}
case IrOpcode::kStoreElement: {
Node* object = current->ValueInput(0);
Node* index = current->ValueInput(1);
Node* value = current->ValueInput(2);
const VirtualObject* vobject = current->GetVirtualObject(object);
int offset;
Variable var;
if (vobject && !vobject->HasEscaped() &&
OffsetOfElementsAccess(op, index).To(&offset) &&
vobject->FieldAt(offset).To(&var)) {
current->Set(var, value);
current->MarkForDeletion();
} else {
current->SetEscaped(value);
current->SetEscaped(object);
}
break;
}
case IrOpcode::kLoadField: {
Node* object = current->ValueInput(0);
const VirtualObject* vobject = current->GetVirtualObject(object);
Variable var;
if (vobject && !vobject->HasEscaped() &&
vobject->FieldAt(OffsetOfFieldAccess(op)).To(&var)) {
current->SetReplacement(current->Get(var));
} else {
// TODO(tebbi): At the moment, we mark objects as escaping if there
// is a load from an invalid location to avoid dead nodes. This is a
// workaround that should be removed once we can handle dead nodes
// everywhere.
current->SetEscaped(object);
}
break;
}
case IrOpcode::kLoadElement: {
Node* object = current->ValueInput(0);
Node* index = current->ValueInput(1);
const VirtualObject* vobject = current->GetVirtualObject(object);
int offset;
Variable var;
if (vobject && !vobject->HasEscaped() &&
OffsetOfElementsAccess(op, index).To(&offset) &&
vobject->FieldAt(offset).To(&var)) {
current->SetReplacement(current->Get(var));
} else {
current->SetEscaped(object);
}
break;
}
case IrOpcode::kTypeGuard: {
// The type-guard is re-introduced in the final reducer if the types
// don't match.
current->SetReplacement(current->ValueInput(0));
break;
}
case IrOpcode::kReferenceEqual: {
Node* left = current->ValueInput(0);
Node* right = current->ValueInput(1);
const VirtualObject* left_object = current->GetVirtualObject(left);
const VirtualObject* right_object = current->GetVirtualObject(right);
if (left_object && !left_object->HasEscaped()) {
if (right_object && !right_object->HasEscaped() &&
left_object->id() == right_object->id()) {
current->SetReplacement(jsgraph->TrueConstant());
} else {
current->SetReplacement(jsgraph->FalseConstant());
}
} else if (right_object && !right_object->HasEscaped()) {
current->SetReplacement(jsgraph->FalseConstant());
}
break;
}
case IrOpcode::kCheckMaps: {
CheckMapsParameters params = CheckMapsParametersOf(op);
Node* checked = current->ValueInput(0);
const VirtualObject* vobject = current->GetVirtualObject(checked);
Variable map_field;
if (vobject && !vobject->HasEscaped() &&
vobject->FieldAt(HeapObject::kMapOffset).To(&map_field)) {
Node* map = current->Get(map_field);
if (map) {
Type* const map_type = NodeProperties::GetType(map);
if (map_type->IsHeapConstant() &&
params.maps().contains(ZoneHandleSet<Map>(bit_cast<Handle<Map>>(
map_type->AsHeapConstant()->Value())))) {
current->MarkForDeletion();
break;
}
}
}
current->SetEscaped(checked);
break;
}
case IrOpcode::kCheckHeapObject: {
Node* checked = current->ValueInput(0);
switch (checked->opcode()) {
case IrOpcode::kAllocate:
case IrOpcode::kFinishRegion:
case IrOpcode::kHeapConstant:
current->SetReplacement(checked);
break;
default:
current->SetEscaped(checked);
break;
}
break;
}
case IrOpcode::kStateValues:
case IrOpcode::kFrameState:
// These uses are always safe.
break;
default: {
// For unknown nodes, treat all value inputs as escaping.
int value_input_count = op->ValueInputCount();
for (int i = 0; i < value_input_count; ++i) {
Node* input = current->ValueInput(i);
current->SetEscaped(input);
}
if (OperatorProperties::HasContextInput(op)) {
current->SetEscaped(current->ContextInput());
}
break;
}
} // namespace
} // namespace
} // namespace
void NewEscapeAnalysis::Reduce(Node* node, Reduction* reduction) {
const Operator* op = node->op();
TRACE("Reducing %s#%d\n", op->mnemonic(), node->id());
EscapeAnalysisTracker::Scope current(this, tracker_, node, reduction);
ReduceNode(op, &current, jsgraph());
}
NewEscapeAnalysis::NewEscapeAnalysis(JSGraph* jsgraph, Zone* zone)
: EffectGraphReducer(
jsgraph->graph(),
[this](Node* node, Reduction* reduction) { Reduce(node, reduction); },
zone),
tracker_(new (zone) EscapeAnalysisTracker(jsgraph, this, zone)),
jsgraph_(jsgraph) {}
Node* EscapeAnalysisResult::GetReplacementOf(Node* node) {
return tracker_->GetReplacementOf(node);
}
Node* EscapeAnalysisResult::GetVirtualObjectField(const VirtualObject* vobject,
int field, Node* effect) {
return tracker_->variable_states_.Get(vobject->FieldAt(field).FromJust(),
effect);
}
const VirtualObject* EscapeAnalysisResult::GetVirtualObject(Node* node) {
return tracker_->virtual_objects_[node];
}
VirtualObject::VirtualObject(VariableTracker* var_states, VirtualObject::Id id,
int size)
: Dependable(var_states->zone()), id_(id), fields_(var_states->zone()) {
DCHECK(size % kPointerSize == 0);
TRACE("Creating VirtualObject id:%d size:%d\n", id, size);
int num_fields = size / kPointerSize;
fields_.reserve(num_fields);
for (int i = 0; i < num_fields; ++i) {
fields_.push_back(var_states->NewVariable());
}
}
} // namespace compiler
} // namespace internal
} // namespace v8

214
src/compiler/new-escape-analysis.h Normal file
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@ -0,0 +1,214 @@
// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_COMPILER_NEW_ESCAPE_ANALYSIS_H_
#define V8_COMPILER_NEW_ESCAPE_ANALYSIS_H_
#include "src/base/functional.h"
#include "src/compiler/graph-reducer.h"
#include "src/compiler/js-graph.h"
#include "src/compiler/persistent-map.h"
#include "src/globals.h"
#ifdef DEBUG
#define TRACE(...) \
do { \
if (FLAG_trace_turbo_escape) PrintF(__VA_ARGS__); \
} while (false)
#else
#define TRACE(...)
#endif
namespace v8 {
namespace internal {
namespace compiler {
class CommonOperatorBuilder;
class VariableTracker;
class EscapeAnalysisTracker;
#ifdef DEBUG
class TraceScope {
public:
TraceScope(const char* name, Node* node) : name_(name), node_(node) {
for (int i = 0; i < depth; ++i) TRACE(" ");
TRACE("[ %s %s#%d\n", name, node->op()->mnemonic(), node->id());
++depth;
}
~TraceScope() {
--depth;
for (int i = 0; i < depth; ++i) TRACE(" ");
TRACE("] %s %s#%d\n", name_, node_->op()->mnemonic(), node_->id());
}
private:
const char* name_;
Node* node_;
static thread_local int depth;
};
#define TRACE_FN(name, node) TraceScope __trace_scope_(name, node)
#else
#define TRACE_FN(name, node)
#endif
// {EffectGraphReducer} reduces up to a fixed point. It distinguishes changes to
// the effect output of a node from changes to the value output to reduce the
// number of revisitations.
class EffectGraphReducer {
public:
class Reduction {
public:
bool value_changed() const { return value_changed_; }
void set_value_changed() { value_changed_ = true; }
bool effect_changed() const { return effect_changed_; }
void set_effect_changed() { effect_changed_ = true; }
private:
bool value_changed_ = false;
bool effect_changed_ = false;
};
EffectGraphReducer(Graph* graph,
std::function<void(Node*, Reduction*)> reduce, Zone* zone);
void ReduceGraph() { ReduceFrom(graph_->end()); }
// Mark node for revisitation.
void Revisit(Node* node);
// Add a new root node to start reduction from. This is useful if the reducer
// adds nodes that are not yet reachable, but should already be considered
// part of the graph.
void AddRoot(Node* node) {
DCHECK(state_.Get(node) == State::kUnvisited);
state_.Set(node, State::kRevisit);
revisit_.push(node);
}
bool Complete() { return stack_.empty() && revisit_.empty(); }
private:
struct NodeState {
Node* node;
int input_index;
};
void ReduceFrom(Node* node);
enum class State : uint8_t { kUnvisited = 0, kRevisit, kOnStack, kVisited };
const uint8_t kNumStates = static_cast<uint8_t>(State::kVisited) + 1;
Graph* graph_;
NodeMarker<State> state_;
ZoneStack<Node*> revisit_;
ZoneStack<NodeState> stack_;
std::function<void(Node*, Reduction*)> reduce_;
};
// A variable is an abstract storage location, which is lowered to SSA values
// and phi nodes by {VariableTracker}.
class Variable {
public:
Variable() : id_(kInvalid) {}
bool operator==(Variable other) const { return id_ == other.id_; }
bool operator!=(Variable other) const { return id_ != other.id_; }
bool operator<(Variable other) const { return id_ < other.id_; }
static Variable Invalid() { return Variable(kInvalid); }
friend V8_INLINE size_t hash_value(Variable v) {
return base::hash_value(v.id_);
}
friend std::ostream& operator<<(std::ostream& os, Variable var) {
return os << var.id_;
}
private:
typedef int Id;
explicit Variable(Id id) : id_(id) {}
Id id_;
static const Id kInvalid = -1;
friend class VariableTracker;
};
// An object that can track the nodes in the graph whose current reduction
// depends on the value of the object.
class Dependable : public ZoneObject {
public:
explicit Dependable(Zone* zone) : dependants_(zone) {}
void AddDependency(Node* node) { dependants_.push_back(node); }
void RevisitDependants(EffectGraphReducer* reducer) {
for (Node* node : dependants_) {
reducer->Revisit(node);
}
dependants_.clear();
}
private:
ZoneVector<Node*> dependants_;
};
// A virtual object represents an allocation site and tracks the Variables
// associated with its fields as well as its global escape status.
class VirtualObject : public Dependable {
public:
typedef uint32_t Id;
typedef ZoneVector<Variable>::const_iterator const_iterator;
VirtualObject(VariableTracker* var_states, Id id, int size);
Maybe<Variable> FieldAt(int offset) const {
DCHECK(offset % kPointerSize == 0);
CHECK(!HasEscaped());
if (offset >= size()) {
// This can only happen in unreachable code.
return Nothing<Variable>();
}
return Just(fields_.at(offset / kPointerSize));
}
Id id() const { return id_; }
int size() const { return static_cast<int>(kPointerSize * fields_.size()); }
// Escaped might mean that the object escaped to untracked memory or that it
// is used in an operation that requires materialization.
void SetEscaped() { escaped_ = true; }
bool HasEscaped() const { return escaped_; }
const_iterator begin() const { return fields_.begin(); }
const_iterator end() const { return fields_.end(); }
private:
bool escaped_ = false;
Id id_;
ZoneVector<Variable> fields_;
};
class EscapeAnalysisResult {
public:
explicit EscapeAnalysisResult(EscapeAnalysisTracker* tracker)
: tracker_(tracker) {}
const VirtualObject* GetVirtualObject(Node* node);
Node* GetVirtualObjectField(const VirtualObject* vobject, int field,
Node* effect);
Node* GetReplacementOf(Node* node);
private:
EscapeAnalysisTracker* tracker_;
};
class V8_EXPORT_PRIVATE NewEscapeAnalysis final
: public NON_EXPORTED_BASE(EffectGraphReducer) {
public:
NewEscapeAnalysis(JSGraph* jsgraph, Zone* zone);
EscapeAnalysisResult analysis_result() {
DCHECK(Complete());
return EscapeAnalysisResult(tracker_);
}
private:
void Reduce(Node* node, Reduction* reduction);
JSGraph* jsgraph() { return jsgraph_; }
EscapeAnalysisTracker* tracker_;
JSGraph* jsgraph_;
};
} // namespace compiler
} // namespace internal
} // namespace v8
#endif // V8_COMPILER_NEW_ESCAPE_ANALYSIS_H_

32
src/compiler/node-properties.cc
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@ -482,6 +482,38 @@ bool NodeProperties::IsInputRange(Edge edge, int first, int num) {
return first <= index && index < first + num;
}
// static
size_t NodeProperties::HashCode(Node* node) {
size_t h = base::hash_combine(node->op()->HashCode(), node->InputCount());
for (Node* input : node->inputs()) {
h = base::hash_combine(h, input->id());
}
return h;
}
// static
bool NodeProperties::Equals(Node* a, Node* b) {
DCHECK_NOT_NULL(a);
DCHECK_NOT_NULL(b);
DCHECK_NOT_NULL(a->op());
DCHECK_NOT_NULL(b->op());
if (!a->op()->Equals(b->op())) return false;
if (a->InputCount() != b->InputCount()) return false;
Node::Inputs aInputs = a->inputs();
Node::Inputs bInputs = b->inputs();
auto aIt = aInputs.begin();
auto bIt = bInputs.begin();
auto aEnd = aInputs.end();
for (; aIt != aEnd; ++aIt, ++bIt) {
DCHECK_NOT_NULL(*aIt);
DCHECK_NOT_NULL(*bIt);
if ((*aIt)->id() != (*bIt)->id()) return false;
}
return true;
}
} // namespace compiler
} // namespace internal
} // namespace v8

6
src/compiler/node-properties.h
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@ -132,6 +132,12 @@ class V8_EXPORT_PRIVATE NodeProperties final {
// Checks if two nodes are the same, looking past {CheckHeapObject}.
static bool IsSame(Node* a, Node* b);
// Check if two nodes have equal operators and reference-equal inputs. Used
// for value numbering/hash-consing.
static bool Equals(Node* a, Node* b);
// A corresponding hash function.
static size_t HashCode(Node* node);
// Walks up the {effect} chain to find a witness that provides map
// information about the {receiver}. Can look through potentially
// side effecting nodes.

1
src/compiler/opcodes.h
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@ -62,6 +62,7 @@
V(ArgumentsElementsState) \
V(ArgumentsLengthState) \
V(ObjectState) \
V(ObjectId) \
V(TypedObjectState) \
V(Call) \
V(Parameter) \

514
src/compiler/persistent-map.h Normal file
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@ -0,0 +1,514 @@
// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_COMPILER_PERSISTENT_H_
#define V8_COMPILER_PERSISTENT_H_
#include <array>
#include <bitset>
#include <tuple>
#include "src/base/functional.h"
#include "src/zone/zone-containers.h"
namespace v8 {
namespace internal {
namespace compiler {
// PersistentMap is a persistent map datastructure based on hash trees (a binary
// tree using the bits of a hash value as addresses). The map is a conceptually
// infinite: All keys are initially mapped to a default value, values are
// deleted by overwriting them with the default value. The iterators produce
// exactly the keys that are not the default value. The hash values should have
// high variance in their high bits, so dense integers are a bad choice.
// Complexity:
// - Copy and assignment: O(1)
// - access: O(log n)
// - update: O(log n) time and space
// - iteration: amortized O(1) per step
// - Zip: O(n)
// - equality check: O(n)
// TODO(tebbi): Cache map transitions to avoid re-allocation of the same map.
// TODO(tebbi): Implement an O(1) equality check based on hash consing or
// something similar.
template <class Key, class Value, class Hasher = base::hash<Key>>
class PersistentMap {
public:
using key_type = Key;
using mapped_type = Value;
using value_type = std::pair<Key, Value>;
private:
static constexpr size_t kHashBits = 32;
enum Bit : int { kLeft = 0, kRight = 1 };
// Access hash bits starting from the high bits and compare them according to
// their unsigned value. This way, the order in the hash tree is compatible
// with numeric hash comparisons.
class HashValue;
struct KeyValue : std::pair<Key, Value> {
const Key& key() const { return this->first; }
const Value& value() const { return this->second; }
using std::pair<Key, Value>::pair;
};
struct FocusedTree;
public:
// Depth of the last added element. This is a cheap estimate for the size of
// the hash tree.
size_t last_depth() const {
if (tree_) {
return tree_->length;
} else {
return 0;
}
}
const Value& Get(const Key& key) const {
HashValue key_hash = HashValue(Hasher()(key));
const FocusedTree* tree = FindHash(key_hash);
return GetFocusedValue(tree, key);
}
// Add or overwrite an existing key-value pair.
PersistentMap Add(Key key, Value value) const;
void Set(Key key, Value value) { *this = Add(key, value); }
bool operator==(const PersistentMap& other) const {
if (tree_ == other.tree_) return true;
if (def_value_ != other.def_value_) return false;
for (const std::tuple<Key, Value, Value>& triple : Zip(other)) {
if (std::get<1>(triple) != std::get<2>(triple)) return false;
}
return true;
}
bool operator!=(const PersistentMap& other) const {
return !(*this == other);
}
// The iterator produces key-value pairs in the lexicographical order of
// hash value and key. It produces exactly the key-value pairs where the value
// is not the default value.
class iterator;
iterator begin() const {
if (!tree_) return end();
return iterator::begin(tree_, def_value_);
}
iterator end() const { return iterator::end(def_value_); }
// Iterator to traverse two maps in lockstep, producing matching value pairs
// for each key where at least one value is different from the respective
// default.
class double_iterator;
// An iterable to iterate over the two maps in lockstep.
struct ZipIterable {
PersistentMap a;
PersistentMap b;
double_iterator begin() { return double_iterator(a.begin(), b.begin()); }
double_iterator end() { return double_iterator(a.end(), b.end()); }
};
ZipIterable Zip(const PersistentMap& other) const { return {*this, other}; }
explicit PersistentMap(Zone* zone, Value def_value = Value())
: PersistentMap(nullptr, zone, def_value) {}
private:
// Find the {FocusedTree} that contains a key-value pair with key hash {hash}.
const FocusedTree* FindHash(HashValue hash) const;
// Find the {FocusedTree} that contains a key-value pair with key hash {hash}.
// Output the path to this {FocusedTree} and its length. If no such
// {FocusedTree} exists, return {nullptr} and output the path to the last node
// with a matching hash prefix. Note that {length} is the length of the found
// path and may be less than the length of the found {FocusedTree}.
const FocusedTree* FindHash(HashValue hash,
std::array<const FocusedTree*, kHashBits>* path,
int* length) const;
// Load value from the leaf node on the focused path of {tree}.
const Value& GetFocusedValue(const FocusedTree* tree, const Key& key) const;
// Return the {FocusedTree} representing the left (bit==kLeft) or right
// (bit==kRight) child of the node on the path of {tree} at tree level
// {level}.
static const FocusedTree* GetChild(const FocusedTree* tree, int level,
Bit bit);
// Find the leftmost path in the tree, starting at the node at tree level
// {level} on the path of {start}. Output the level of the leaf to {level} and
// the path to {path}.
static const FocusedTree* FindLeftmost(
const FocusedTree* start, int* level,
std::array<const FocusedTree*, kHashBits>* path);
PersistentMap(const FocusedTree* tree, Zone* zone, Value def_value)
: tree_(tree), def_value_(def_value), zone_(zone) {}
const FocusedTree* tree_;
Value def_value_;
Zone* zone_;
};
// This structure represents a hash tree with one focused path to a specific
// leaf. For the focused leaf, it stores key, value and key hash. The path is
// defined by the hash bits of the focused leaf. In a traditional tree
// datastructure, the nodes of a path form a linked list with the values being
// the pointers outside of this path. Instead of storing all of these nodes,
// we store an array of the pointers pointing outside of the path. This is
// similar to the stack used when doing DFS traversal of a tree. The hash of
// the leaf is used to know if the pointers point to the left or the
// right of the path. As there is no explicit representation of a tree node,
// this structure also represents all the nodes on its path. The intended node
// depends on the tree depth, which is always clear from the referencing
// context. So the pointer to a {FocusedTree} stored in the
// {PersistentMap.tree_} always references the root, while a pointer from a
// focused node of another {FocusedTree} always references to one tree level
// lower than before.
template <class Key, class Value, class Hasher>
struct PersistentMap<Key, Value, Hasher>::FocusedTree {
KeyValue key_value;
// The depth of the focused path, that is, the number of pointers stored in
// this structure.
int8_t length;
HashValue key_hash;
// Out-of-line storage for hash collisions.
const ZoneMap<Key, Value>* more;
using more_iterator = typename ZoneMap<Key, Value>::const_iterator;
// {path_array} has to be the last member: To store an array inline, we
// over-allocate memory for this structure and access memory beyond
// {path_array}. This corresponds to a flexible array member as defined in
// C99.
const FocusedTree* path_array[1];
const FocusedTree*& path(int i) {
DCHECK(i < length);
return reinterpret_cast<const FocusedTree**>(
reinterpret_cast<byte*>(this) + offsetof(FocusedTree, path_array))[i];
}
const FocusedTree* path(int i) const {
DCHECK(i < length);
return reinterpret_cast<const FocusedTree* const*>(
reinterpret_cast<const byte*>(this) +
offsetof(FocusedTree, path_array))[i];
}
};
template <class Key, class Value, class Hasher>
class PersistentMap<Key, Value, Hasher>::HashValue {
public:
explicit HashValue(size_t hash) : bits_(hash) {}
explicit HashValue(std::bitset<kHashBits> hash) : bits_(hash) {}
Bit operator[](int pos) const {
return bits_[kHashBits - pos - 1] ? kRight : kLeft;
}
bool operator<(HashValue other) const {
static_assert(sizeof(*this) <= sizeof(unsigned long), ""); // NOLINT
return bits_.to_ulong() < other.bits_.to_ulong();
}
bool operator==(HashValue other) const { return bits_ == other.bits_; }
bool operator!=(HashValue other) const { return bits_ != other.bits_; }
HashValue operator^(HashValue other) const {
return HashValue(bits_ ^ other.bits_);
}
private:
std::bitset<kHashBits> bits_;
};
template <class Key, class Value, class Hasher>
class PersistentMap<Key, Value, Hasher>::iterator {
public:
const value_type operator*() const {
if (current_->more) {
return *more_iter_;
} else {
return current_->key_value;
}
}
iterator& operator++() {
do {
if (!current_) {
// Iterator is past the end.
return *this;
}
if (current_->more) {
DCHECK(more_iter_ != current_->more->end());
++more_iter_;
if (more_iter_ != current_->more->end()) return *this;
}
if (level_ == 0) {
*this = end(def_value_);
return *this;
}
--level_;
while (current_->key_hash[level_] == kRight || path_[level_] == nullptr) {
if (level_ == 0) {
*this = end(def_value_);
return *this;
}
--level_;
}
const FocusedTree* first_right_alternative = path_[level_];
level_++;
current_ = FindLeftmost(first_right_alternative, &level_, &path_);
if (current_->more) {
more_iter_ = current_->more->begin();
}
} while ((**this).second == def_value());
return *this;
}
bool operator==(const iterator& other) const {
if (is_end()) return other.is_end();
if (other.is_end()) return false;
if (current_->key_hash != other.current_->key_hash) {
return false;
} else {
return (**this).first == (*other).first;
}
}
bool operator!=(const iterator& other) const { return !(*this == other); }
bool operator<(const iterator& other) const {
if (is_end()) return false;
if (other.is_end()) return true;
if (current_->key_hash < other.current_->key_hash) {
return true;
} else if (current_->key_hash == other.current_->key_hash) {
return (**this).first < (*other).first;
} else {
return false;
}
}
bool is_end() const { return current_ == nullptr; }
const Value& def_value() { return def_value_; }
static iterator begin(const FocusedTree* tree, Value def_value) {
iterator i(def_value);
i.current_ = FindLeftmost(tree, &i.level_, &i.path_);
if (i.current_->more) {
i.more_iter_ = i.current_->more->begin();
}
return i;
}
static iterator end(Value def_value) { return iterator(def_value); }
private:
int level_;
typename FocusedTree::more_iterator more_iter_;
const FocusedTree* current_;
std::array<const FocusedTree*, kHashBits> path_;
Value def_value_;
explicit iterator(Value def_value)
: level_(0), current_(nullptr), def_value_(def_value) {}
};
template <class Key, class Value, class Hasher>
class PersistentMap<Key, Value, Hasher>::double_iterator {
public:
std::tuple<Key, Value, Value> operator*() {
if (first_current_) {
auto pair = *first_;
return std::make_tuple(
pair.first, pair.second,
second_current_ ? (*second_).second : second_.def_value());
} else {
DCHECK(second_current_);
auto pair = *second_;
return std::make_tuple(pair.first, first_.def_value(), pair.second);
}
}
double_iterator& operator++() {
if (first_current_) ++first_;
if (second_current_) ++second_;
return *this = double_iterator(first_, second_);
}
double_iterator(iterator first, iterator second)
: first_(first), second_(second) {
if (first_ == second_) {
first_current_ = second_current_ = true;
} else if (first_ < second_) {
first_current_ = true;
second_current_ = false;
} else {
first_current_ = false;
second_current_ = true;
}
}
bool operator!=(const double_iterator& other) {
return first_ != other.first_ || second_ != other.second_;
}
bool is_end() const { return first_.is_end() && second_.is_end(); }
private:
iterator first_;
iterator second_;
bool first_current_;
bool second_current_;
};
template <class Key, class Value, class Hasher>
PersistentMap<Key, Value, Hasher> PersistentMap<Key, Value, Hasher>::Add(
Key key, Value value) const {
HashValue key_hash = HashValue(Hasher()(key));
std::array<const FocusedTree*, kHashBits> path;
int length = 0;
const FocusedTree* old = FindHash(key_hash, &path, &length);
ZoneMap<Key, Value>* more = nullptr;
if (GetFocusedValue(old, key) == value) return *this;
if (old && !(old->more == nullptr && old->key_value.key() == key)) {
more = new (zone_->New(sizeof(*more))) ZoneMap<Key, Value>(zone_);
if (old->more) {
*more = *old->more;
} else {
(*more)[old->key_value.key()] = old->key_value.value();
}
(*more)[key] = value;
}
FocusedTree* tree =
new (zone_->New(sizeof(FocusedTree) +
std::max(0, length - 1) * sizeof(const FocusedTree*)))
FocusedTree{KeyValue(std::move(key), std::move(value)),
static_cast<int8_t>(length),
key_hash,
more,
{}};
for (int i = 0; i < length; ++i) {
tree->path(i) = path[i];
}
return PersistentMap(tree, zone_, def_value_);
}
template <class Key, class Value, class Hasher>
const typename PersistentMap<Key, Value, Hasher>::FocusedTree*
PersistentMap<Key, Value, Hasher>::FindHash(HashValue hash) const {
const FocusedTree* tree = tree_;
int level = 0;
while (tree && hash != tree->key_hash) {
while ((hash ^ tree->key_hash)[level] == 0) {
++level;
}
tree = level < tree->length ? tree->path(level) : nullptr;
++level;
}
return tree;
}
template <class Key, class Value, class Hasher>
const typename PersistentMap<Key, Value, Hasher>::FocusedTree*
PersistentMap<Key, Value, Hasher>::FindHash(
HashValue hash, std::array<const FocusedTree*, kHashBits>* path,
int* length) const {
const FocusedTree* tree = tree_;
int level = 0;
while (tree && hash != tree->key_hash) {
int map_length = tree->length;
while ((hash ^ tree->key_hash)[level] == 0) {
(*path)[level] = level < map_length ? tree->path(level) : nullptr;
++level;
}
(*path)[level] = tree;
tree = level < tree->length ? tree->path(level) : nullptr;
++level;
}
if (tree) {
while (level < tree->length) {
(*path)[level] = tree->path(level);
++level;
}
}
*length = level;
return tree;
}
template <class Key, class Value, class Hasher>
const Value& PersistentMap<Key, Value, Hasher>::GetFocusedValue(
const FocusedTree* tree, const Key& key) const {
if (!tree) {
return def_value_;
}
if (tree->more) {
auto it = tree->more->find(key);
if (it == tree->more->end())
return def_value_;
else
return it->second;
} else {
if (key == tree->key_value.key()) {
return tree->key_value.value();
} else {
return def_value_;
}
}
}
template <class Key, class Value, class Hasher>
const typename PersistentMap<Key, Value, Hasher>::FocusedTree*
PersistentMap<Key, Value, Hasher>::GetChild(const FocusedTree* tree, int level,
Bit bit) {
if (tree->key_hash[level] == bit) {
return tree;
} else if (level < tree->length) {
return tree->path(level);
} else {
return nullptr;
}
}
template <class Key, class Value, class Hasher>
const typename PersistentMap<Key, Value, Hasher>::FocusedTree*
PersistentMap<Key, Value, Hasher>::FindLeftmost(
const FocusedTree* start, int* level,
std::array<const FocusedTree*, kHashBits>* path) {
const FocusedTree* current = start;
while (*level < current->length) {
if (const FocusedTree* child = GetChild(current, *level, kLeft)) {
(*path)[*level] = GetChild(current, *level, kRight);
current = child;
++*level;
} else if (const FocusedTree* child = GetChild(current, *level, kRight)) {
(*path)[*level] = GetChild(current, *level, kLeft);
current = child;
++*level;
} else {
UNREACHABLE();
}
}
return current;
}
template <class Key, class Value, class Hasher>
std::ostream& operator<<(std::ostream& os,
const PersistentMap<Key, Value, Hasher>& map) {
os << "{";
bool first = true;
for (auto pair : map) {
if (!first) os << ", ";
first = false;
os << pair.first << ": " << pair.second;
}
return os << "}";
}
} // namespace compiler
} // namespace internal
} // namespace v8
#endif // V8_COMPILER_PERSISTENT_MAP_H_

15
src/compiler/pipeline.cc
View File

@ -51,6 +51,8 @@
#include "src/compiler/machine-operator-reducer.h"
#include "src/compiler/memory-optimizer.h"
#include "src/compiler/move-optimizer.h"
#include "src/compiler/new-escape-analysis-reducer.h"
#include "src/compiler/new-escape-analysis.h"
#include "src/compiler/osr.h"
#include "src/compiler/pipeline-statistics.h"
#include "src/compiler/redundancy-elimination.h"
@ -1157,6 +1159,18 @@ struct EscapeAnalysisPhase {
static const char* phase_name() { return "escape analysis"; }
void Run(PipelineData* data, Zone* temp_zone) {
if (FLAG_turbo_new_escape) {
NewEscapeAnalysis escape_analysis(data->jsgraph(), temp_zone);
escape_analysis.ReduceGraph();
JSGraphReducer reducer(data->jsgraph(), temp_zone);
NewEscapeAnalysisReducer escape_reducer(&reducer, data->jsgraph(),
escape_analysis.analysis_result(),
temp_zone);
AddReducer(data, &reducer, &escape_reducer);
reducer.ReduceGraph();
// TODO(tebbi): Turn this into a debug mode check once we have confidence.
escape_reducer.VerifyReplacement();
} else {
EscapeAnalysis escape_analysis(data->graph(), data->jsgraph()->common(),
temp_zone);
if (!escape_analysis.Run()) return;
@ -1171,6 +1185,7 @@ struct EscapeAnalysisPhase {
}
escape_reducer.VerifyReplacement();
}
}
};
struct SimplifiedLoweringPhase {

14
src/compiler/simplified-lowering.cc
View File

@ -142,12 +142,10 @@ UseInfo TruncatingUseInfoFromRepresentation(MachineRepresentation rep) {
UNREACHABLE();
}
UseInfo UseInfoForBasePointer(const FieldAccess& access) {
return access.tag() != 0 ? UseInfo::AnyTagged() : UseInfo::PointerInt();
}
UseInfo UseInfoForBasePointer(const ElementAccess& access) {
return access.tag() != 0 ? UseInfo::AnyTagged() : UseInfo::PointerInt();
}
@ -1014,7 +1012,8 @@ class RepresentationSelector {
// The target of the call.
ProcessInput(node, i, UseInfo::Any());
} else if ((i - 1) < params) {
ProcessInput(node, i, TruncatingUseInfoFromRepresentation(
ProcessInput(node, i,
TruncatingUseInfoFromRepresentation(
desc->GetInputType(i).representation()));
} else {
ProcessInput(node, i, UseInfo::AnyTagged());
@ -1158,8 +1157,8 @@ class RepresentationSelector {
(*types)[i] =
DeoptMachineTypeOf(GetInfo(input)->representation(), TypeOf(input));
}
NodeProperties::ChangeOp(node,
jsgraph_->common()->TypedObjectState(types));
NodeProperties::ChangeOp(node, jsgraph_->common()->TypedObjectState(
ObjectIdOf(node->op()), types));
}
SetOutput(node, MachineRepresentation::kTagged);
}
@ -2852,6 +2851,8 @@ class RepresentationSelector {
return VisitStateValues(node);
case IrOpcode::kObjectState:
return VisitObjectState(node);
case IrOpcode::kObjectId:
return SetOutput(node, MachineRepresentation::kTaggedPointer);
case IrOpcode::kTypeGuard: {
// We just get rid of the sigma here, choosing the best representation
// for the sigma's type.
@ -3295,7 +3296,6 @@ void SimplifiedLowering::DoLoadBuffer(Node* node,
}
}
void SimplifiedLowering::DoStoreBuffer(Node* node) {
DCHECK_EQ(IrOpcode::kStoreBuffer, node->opcode());
MachineRepresentation const rep =
@ -3423,7 +3423,6 @@ Node* SimplifiedLowering::Int32Div(Node* const node) {
return graph()->NewNode(phi_op, true0, false0, merge0);
}
Node* SimplifiedLowering::Int32Mod(Node* const node) {
Int32BinopMatcher m(node);
Node* const zero = jsgraph()->Int32Constant(0);
@ -3556,7 +3555,6 @@ Node* SimplifiedLowering::Uint32Div(Node* const node) {
return d.Phi(MachineRepresentation::kWord32, zero, div);
}
Node* SimplifiedLowering::Uint32Mod(Node* const node) {
Uint32BinopMatcher m(node);
Node* const minus_one = jsgraph()->Int32Constant(-1);

2
src/compiler/typer.cc
View File

@ -832,6 +832,8 @@ Type* Typer::Visitor::TypeTypedStateValues(Node* node) {
return Type::Internal();
}
Type* Typer::Visitor::TypeObjectId(Node* node) { UNREACHABLE(); }
Type* Typer::Visitor::TypeArgumentsElementsState(Node* node) {
return Type::Internal();
}

44
src/compiler/value-numbering-reducer.cc
View File

@ -14,41 +14,6 @@ namespace v8 {
namespace internal {
namespace compiler {
namespace {
size_t HashCode(Node* node) {
size_t h = base::hash_combine(node->op()->HashCode(), node->InputCount());
for (Node* input : node->inputs()) {
h = base::hash_combine(h, input->id());
}
return h;
}
bool Equals(Node* a, Node* b) {
DCHECK_NOT_NULL(a);
DCHECK_NOT_NULL(b);
DCHECK_NOT_NULL(a->op());
DCHECK_NOT_NULL(b->op());
if (!a->op()->Equals(b->op())) return false;
if (a->InputCount() != b->InputCount()) return false;
Node::Inputs aInputs = a->inputs();
Node::Inputs bInputs = b->inputs();
auto aIt = aInputs.begin();
auto bIt = bInputs.begin();
auto aEnd = aInputs.end();
for (; aIt != aEnd; ++aIt, ++bIt) {
DCHECK_NOT_NULL(*aIt);
DCHECK_NOT_NULL(*bIt);
if ((*aIt)->id() != (*bIt)->id()) return false;
}
return true;
}
} // namespace
ValueNumberingReducer::ValueNumberingReducer(Zone* temp_zone, Zone* graph_zone)
: entries_(nullptr),
capacity_(0),
@ -62,7 +27,7 @@ ValueNumberingReducer::~ValueNumberingReducer() {}
Reduction ValueNumberingReducer::Reduce(Node* node) {
if (!node->op()->HasProperty(Operator::kIdempotent)) return NoChange();
const size_t hash = HashCode(node);
const size_t hash = NodeProperties::HashCode(node);
if (!entries_) {
DCHECK(size_ == 0);
DCHECK(capacity_ == 0);
@ -131,7 +96,7 @@ Reduction ValueNumberingReducer::Reduce(Node* node) {
// Otherwise, keep searching for another collision.
continue;
}
if (Equals(entry, node)) {
if (NodeProperties::Equals(entry, node)) {
Reduction reduction = ReplaceIfTypesMatch(node, entry);
if (reduction.Changed()) {
// Overwrite the colliding entry with the actual entry.
@ -153,7 +118,7 @@ Reduction ValueNumberingReducer::Reduce(Node* node) {
dead = i;
continue;
}
if (Equals(entry, node)) {
if (NodeProperties::Equals(entry, node)) {
return ReplaceIfTypesMatch(node, entry);
}
}
@ -197,7 +162,8 @@ void ValueNumberingReducer::Grow() {
for (size_t i = 0; i < old_capacity; ++i) {
Node* const old_entry = old_entries[i];
if (!old_entry || old_entry->IsDead()) continue;
for (size_t j = HashCode(old_entry) & mask;; j = (j + 1) & mask) {
for (size_t j = NodeProperties::HashCode(old_entry) & mask;;
j = (j + 1) & mask) {
Node* const entry = entries_[j];
if (entry == old_entry) {
// Skip duplicate of the old entry.

2
src/compiler/verifier.cc
View File

@ -507,6 +507,8 @@ void Verifier::Visitor::Check(Node* node) {
// still be kStateValues.
break;
}
case IrOpcode::kObjectId:
CheckTypeIs(node, Type::Object());
case IrOpcode::kStateValues:
case IrOpcode::kTypedStateValues:
case IrOpcode::kArgumentsElementsState:

2
src/flag-definitions.h
View File

@ -465,6 +465,8 @@ DEFINE_BOOL(turbo_loop_variable, true, "Turbofan loop variable optimization")
DEFINE_BOOL(turbo_cf_optimization, true, "optimize control flow in TurboFan")
DEFINE_BOOL(turbo_frame_elision, true, "elide frames in TurboFan")
DEFINE_BOOL(turbo_escape, true, "enable escape analysis")
DEFINE_BOOL(turbo_new_escape, false,
"enable new implementation of escape analysis")
DEFINE_BOOL(turbo_instruction_scheduling, false,
"enable instruction scheduling in TurboFan")
DEFINE_BOOL(turbo_stress_instruction_scheduling, false,

2
src/frames.cc
View File

@ -1430,7 +1430,7 @@ void OptimizedFrame::Summarize(List<FrameSummary>* frames,
} else {
// The receiver is not in a stack slot nor in a literal. We give up.
it.Skip(Translation::NumberOfOperandsFor(opcode));
// TODO(3029): Materializing a captured object (or duplicated
// TODO(6586): Materializing a captured object (or duplicated
// object) is hard, we return undefined for now. This breaks the
// produced stack trace, as constructor frames aren't marked as
// such anymore.

5
src/v8.gyp
View File

@ -811,6 +811,10 @@
'compiler/memory-optimizer.h',
'compiler/move-optimizer.cc',
'compiler/move-optimizer.h',
'compiler/new-escape-analysis.cc',
'compiler/new-escape-analysis.h',
'compiler/new-escape-analysis-reducer.cc',
'compiler/new-escape-analysis-reducer.h',
'compiler/node-aux-data.h',
'compiler/node-cache.cc',
'compiler/node-cache.h',
@ -832,6 +836,7 @@
'compiler/operator.h',
'compiler/osr.cc',
'compiler/osr.h',
'compiler/persistent-map.h',
'compiler/pipeline.cc',
'compiler/pipeline.h',
'compiler/pipeline-statistics.cc',

32
src/zone/zone-containers.h
View File

@ -12,8 +12,11 @@
#include <queue>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "src/base/functional.h"
#include "src/zone/zone-allocator.h"
namespace v8 {
@ -133,6 +136,35 @@ class ZoneMap
Compare(), ZoneAllocator<std::pair<const K, V>>(zone)) {}
};
// A wrapper subclass for std::unordered_map to make it easy to construct one
// that uses a zone allocator.
template <typename K, typename V, typename Hash = base::hash<K>,
typename KeyEqual = std::equal_to<K>>
class ZoneUnorderedMap
: public std::unordered_map<K, V, Hash, KeyEqual,
ZoneAllocator<std::pair<const K, V>>> {
public:
// Constructs an empty map.
explicit ZoneUnorderedMap(Zone* zone)
: std::unordered_map<K, V, Hash, KeyEqual,
ZoneAllocator<std::pair<const K, V>>>(
100, Hash(), KeyEqual(),
ZoneAllocator<std::pair<const K, V>>(zone)) {}
};
// A wrapper subclass for std::unordered_set to make it easy to construct one
// that uses a zone allocator.
template <typename K, typename Hash = base::hash<K>,
typename KeyEqual = std::equal_to<K>>
class ZoneUnorderedSet
: public std::unordered_set<K, Hash, KeyEqual, ZoneAllocator<K>> {
public:
// Constructs an empty map.
explicit ZoneUnorderedSet(Zone* zone)
: std::unordered_set<K, Hash, KeyEqual, ZoneAllocator<K>>(
100, Hash(), KeyEqual(), ZoneAllocator<K>(zone)) {}
};
// A wrapper subclass for std::multimap to make it easy to construct one that
// uses a zone allocator.
template <typename K, typename V, typename Compare = std::less<K>>

22
test/mjsunit/compiler/escape-analysis-cycle.js Normal file
View File

@ -0,0 +1,22 @@
// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --allow-natives-syntax --turbo-escape
function g(o) {
return {a : o, b: 42, c: o};
}
function f() {
var o = {a: {}, b: 43};
o.a = g(g(o));
o.c = o.a.c;
%DeoptimizeNow();
return o.c.a.c.a.c.a.c.b;
}
assertEquals(42, f());
assertEquals(42, f());
%OptimizeFunctionOnNextCall(f);
assertEquals(42, f());

7
test/mjsunit/optimized-foreach.js
View File

@ -249,14 +249,17 @@ var c = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25];
})();
(function() {
var re = /Array\.forEach/;
var lazyDeopt = function(deopt) {
// TODO(6586): Once we fixed the materailization of receivers for stack trace
// computation, this should be /Array\.forEach/ again.
var re = /forEach/;
var lazyDeopt = function foobar(deopt) {
var b = [1,2,3];
var result = 0;
var sum = function(v,i,o) {
result += v;
if (i == 1) {
var e = new Error();
print(e.stack);
assertTrue(re.exec(e.stack) !== null);
}
};

2
test/mjsunit/optimized-map.js
View File

@ -259,7 +259,7 @@ var c = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25];
})();
(function() {
var re = /Array\.map/;
var re = /map/;
var lazyDeopt = function(deopt) {
var b = [1,2,3];
var result = 0;

1
test/unittests/BUILD.gn
View File

@ -85,6 +85,7 @@ v8_executable("unittests") {
"compiler/node-test-utils.h",
"compiler/node-unittest.cc",
"compiler/opcodes-unittest.cc",
"compiler/persistent-unittest.cc",
"compiler/regalloc/live-range-unittest.cc",
"compiler/regalloc/move-optimizer-unittest.cc",
"compiler/regalloc/register-allocator-unittest.cc",

121
test/unittests/compiler/persistent-unittest.cc Normal file
View File

@ -0,0 +1,121 @@
// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <tuple>
#include "src/base/utils/random-number-generator.h"
#include "src/compiler/persistent-map.h"
#include "test/unittests/test-utils.h"
#include "testing/gmock/include/gmock/gmock.h"
namespace v8 {
namespace internal {
namespace compiler {
// A random distribution that produces both small values and arbitrary numbers.
static int small_big_distr(base::RandomNumberGenerator* rand) {
return rand->NextInt() / std::max(1, rand->NextInt() / 100);
}
TEST(PersistentMap, RefTest) {
base::RandomNumberGenerator rand(92834738);
AccountingAllocator allocator;
Zone zone(&allocator, ZONE_NAME);
std::vector<PersistentMap<int, int>> pers_maps;
pers_maps.emplace_back(&zone);
std::vector<std::map<int, int>> ref_maps = {{}};
for (int i = 0; i < 100000; ++i) {
if (rand.NextInt(2) == 0) {
// Read value;
int key = small_big_distr(&rand);
if (ref_maps[0].count(key) > 0) {
ASSERT_EQ(pers_maps[0].Get(key), ref_maps[0][key]);
} else {
ASSERT_EQ(pers_maps[0].Get(key), 0);
}
}
if (rand.NextInt(2) == 0) {
// Add value;
int key = small_big_distr(&rand);
int value = small_big_distr(&rand);
pers_maps[0].Set(key, value);
ref_maps[0][key] = value;
}
if (rand.NextInt(1000) == 0) {
// Create empty map.
pers_maps.emplace_back(&zone);
ref_maps.emplace_back();
}
if (rand.NextInt(100) == 0) {
// Copy and move around maps.
int num_maps = static_cast<int>(pers_maps.size());
int source = rand.NextInt(num_maps - 1) + 1;
int target = rand.NextInt(num_maps - 1) + 1;
pers_maps[target] = std::move(pers_maps[0]);
ref_maps[target] = std::move(ref_maps[0]);
pers_maps[0] = pers_maps[source];
ref_maps[0] = ref_maps[source];
}
}
for (size_t i = 0; i < pers_maps.size(); ++i) {
std::set<int> keys;
for (auto pair : pers_maps[i]) {
ASSERT_EQ(keys.count(pair.first), 0u);
keys.insert(pair.first);
ASSERT_EQ(ref_maps[i][pair.first], pair.second);
}
for (auto pair : ref_maps[i]) {
ASSERT_EQ(pers_maps[i].Get(pair.first), pair.second);
}
}
}
TEST(PersistentMap, Zip) {
base::RandomNumberGenerator rand(92834738);
AccountingAllocator allocator;
Zone zone(&allocator, ZONE_NAME);
// Provoke hash collisions to stress the iterator.
struct bad_hash {
size_t operator()(int key) { return static_cast<size_t>(key) % 1000; }
};
PersistentMap<int, int, bad_hash> a(&zone);
PersistentMap<int, int, bad_hash> b(&zone);
int sum_a = 0;
int sum_b = 0;
for (int i = 0; i < 30000; ++i) {
int key = small_big_distr(&rand);
int value = small_big_distr(&rand);
if (rand.NextBool()) {
sum_a += value;
a.Set(key, a.Get(key) + value);
} else {
sum_b += value;
b.Set(key, b.Get(key) + value);
}
}
int sum = sum_a + sum_b;
for (auto pair : a) {
sum_a -= pair.second;
}
ASSERT_EQ(0, sum_a);
for (auto pair : b) {
sum_b -= pair.second;
}
ASSERT_EQ(0, sum_b);
for (auto triple : a.Zip(b)) {
sum -= std::get<1>(triple) + std::get<2>(triple);
}
ASSERT_EQ(0, sum);
}
} // namespace compiler
} // namespace internal
} // namespace v8

1
test/unittests/unittests.gyp
View File

@ -80,6 +80,7 @@
'compiler/node-test-utils.h',
'compiler/node-unittest.cc',
'compiler/opcodes-unittest.cc',
'compiler/persistent-unittest.cc',
'compiler/regalloc/register-allocator-unittest.cc',
'compiler/schedule-unittest.cc',
'compiler/scheduler-unittest.cc',