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[zone-compr] Add CompressedZonePtr class and compress TurboFan graphs

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This CL doesn't try to compress containers of Node* yet.

Bug: v8:9923
Change-Id: Ica16b09b6f26321952b440d49a70f9a991d4275f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2324258
Commit-Queue: Igor Sheludko (OOO Aug 3-17) <ishell@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69168}
This commit is contained in:
Igor Sheludko 2020-07-31 13:05:09 +02:00 committed by Commit Bot
parent 9f94090a91
commit ee23306c7c
7 changed files with 203 additions and 53 deletions
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2
BUILD.gn
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@ -2005,6 +2005,7 @@ v8_compiler_sources = [
"src/compiler/graph-trimmer.h",
"src/compiler/graph-visualizer.cc",
"src/compiler/graph-visualizer.h",
"src/compiler/graph-zone-traits.h",
"src/compiler/graph.cc",
"src/compiler/graph.h",
"src/compiler/int64-lowering.cc",
@ -3303,6 +3304,7 @@ v8_source_set("v8_base_without_compiler") {
"src/wasm/wasm-value.h",
"src/zone/accounting-allocator.cc",
"src/zone/accounting-allocator.h",
"src/zone/compressed-zone-ptr.h",
"src/zone/type-stats.cc",
"src/zone/type-stats.h",
"src/zone/zone-allocator.h",

29
src/compiler/graph-zone-traits.h Normal file
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@ -0,0 +1,29 @@
// Copyright 2020 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_GRAPH_ZONE_TRAITS_H_
#define V8_COMPILER_GRAPH_ZONE_TRAITS_H_
#include "src/zone/zone-type-traits.h"
namespace v8 {
namespace internal {
namespace compiler {
// Forward declarations.
class Node;
// GraphZoneTraits provides typedefs for zone pointer types that are either
// compressed or not depending on the kCompressGraphZone flag.
using GraphZoneTraits = ZoneTypeTraits<kCompressGraphZone>;
// ZoneNodePtr is a possibly compressed pointer to a Node allocated in a zone
// memory.
using ZoneNodePtr = GraphZoneTraits::Ptr<Node>;
} // namespace compiler
} // namespace internal
} // namespace v8
#endif // V8_COMPILER_GRAPH_ZONE_TRAITS_H_

8
src/compiler/graph.cc
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@ -22,8 +22,12 @@ Graph::Graph(Zone* zone)
end_(nullptr),
mark_max_(0),
next_node_id_(0),
decorators_(zone) {}
decorators_(zone) {
// Nodes use compressed pointers, so zone must support pointer compression.
// If the check fails, ensure the zone is created with kCompressGraphZone
// flag.
CHECK_IMPLIES(kCompressGraphZone, zone->supports_compression());
}
void Graph::Decorate(Node* node) {
for (GraphDecorator* const decorator : decorators_) {

30
src/compiler/node.cc
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@ -20,14 +20,13 @@ Node::OutOfLineInputs* Node::OutOfLineInputs::New(Zone* zone, int capacity) {
return outline;
}
void Node::OutOfLineInputs::ExtractFrom(Use* old_use_ptr, Node** old_input_ptr,
int count) {
void Node::OutOfLineInputs::ExtractFrom(Use* old_use_ptr,
ZoneNodePtr* old_input_ptr, int count) {
DCHECK_GE(count, 0);
// Extract the inputs from the old use and input pointers and copy them
// to this out-of-line-storage.
Use* new_use_ptr = reinterpret_cast<Use*>(this) - 1;
Node** new_input_ptr = inputs();
ZoneNodePtr* new_input_ptr = inputs();
CHECK_IMPLIES(count > 0, Use::InputIndexField::is_valid(count - 1));
for (int current = 0; current < count; current++) {
new_use_ptr->bit_field_ =
@ -55,11 +54,14 @@ void Node::OutOfLineInputs::ExtractFrom(Use* old_use_ptr, Node** old_input_ptr,
struct NodeWithOutOfLineInputs {};
struct NodeWithInLineInputs {};
Node* Node::New(Zone* zone, NodeId id, const Operator* op, int input_count,
Node* const* inputs, bool has_extensible_inputs) {
template <typename NodePtrT>
Node* Node::NewImpl(Zone* zone, NodeId id, const Operator* op, int input_count,
NodePtrT const* inputs, bool has_extensible_inputs) {
// Node uses compressed pointers, so zone must support pointer compression.
DCHECK_IMPLIES(kCompressGraphZone, zone->supports_compression());
DCHECK_GE(input_count, 0);
Node** input_ptr;
ZoneNodePtr* input_ptr;
Use* use_ptr;
Node* node;
bool is_inline;
@ -80,7 +82,7 @@ Node* Node::New(Zone* zone, NodeId id, const Operator* op, int input_count,
// Allocate node, with space for OutOfLineInputs pointer.
void* node_buffer = zone->Allocate<NodeWithOutOfLineInputs>(
sizeof(Node) + sizeof(OutOfLineInputs*));
sizeof(Node) + sizeof(ZoneOutOfLineInputsPtr));
node = new (node_buffer) Node(id, op, kOutlineMarker, 0);
node->set_outline_inputs(outline);
@ -99,7 +101,7 @@ Node* Node::New(Zone* zone, NodeId id, const Operator* op, int input_count,
capacity = std::min(input_count + 3, max);
}
size_t size = sizeof(Node) + capacity * (sizeof(Node*) + sizeof(Use));
size_t size = sizeof(Node) + capacity * (sizeof(ZoneNodePtr) + sizeof(Use));
intptr_t raw_buffer =
reinterpret_cast<intptr_t>(zone->Allocate<NodeWithInLineInputs>(size));
void* node_buffer =
@ -126,13 +128,17 @@ Node* Node::New(Zone* zone, NodeId id, const Operator* op, int input_count,
return node;
}
Node* Node::New(Zone* zone, NodeId id, const Operator* op, int input_count,
Node* const* inputs, bool has_extensible_inputs) {
return NewImpl(zone, id, op, input_count, inputs, has_extensible_inputs);
}
Node* Node::Clone(Zone* zone, NodeId id, const Node* node) {
int const input_count = node->InputCount();
Node* const* const inputs = node->has_inline_inputs()
ZoneNodePtr const* const inputs = node->has_inline_inputs()
? node->inline_inputs()
: node->outline_inputs()->inputs();
Node* const clone = New(zone, id, node->op(), input_count, inputs, false);
Node* const clone = NewImpl(zone, id, node->op(), input_count, inputs, false);
clone->set_type(node->type());
return clone;
}
@ -236,7 +242,7 @@ Node* Node::RemoveInput(int index) {
}
void Node::ClearInputs(int start, int count) {
Node** input_ptr = GetInputPtr(start);
ZoneNodePtr* input_ptr = GetInputPtr(start);
Use* use_ptr = GetUsePtr(start);
while (count-- > 0) {
DCHECK_EQ(input_ptr, use_ptr->input_ptr());

71
src/compiler/node.h
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@ -6,6 +6,7 @@
#define V8_COMPILER_NODE_H_
#include "src/common/globals.h"
#include "src/compiler/graph-zone-traits.h"
#include "src/compiler/opcodes.h"
#include "src/compiler/operator.h"
#include "src/compiler/types.h"
@ -76,7 +77,7 @@ class V8_EXPORT_PRIVATE Node final {
void ReplaceInput(int index, Node* new_to) {
CHECK_LE(0, index);
CHECK_LT(index, InputCount());
Node** input_ptr = GetInputPtr(index);
ZoneNodePtr* input_ptr = GetInputPtr(index);
Node* old_to = *input_ptr;
if (old_to != new_to) {
Use* use = GetUsePtr(index);
@ -152,35 +153,43 @@ class V8_EXPORT_PRIVATE Node final {
void Print(std::ostream&, int depth = 1) const;
private:
template <typename NodePtrT>
inline static Node* NewImpl(Zone* zone, NodeId id, const Operator* op,
int input_count, NodePtrT const* inputs,
bool has_extensible_inputs);
struct Use;
using ZoneUsePtr = GraphZoneTraits::Ptr<Use>;
// Out of line storage for inputs when the number of inputs overflowed the
// capacity of the inline-allocated space.
struct OutOfLineInputs {
Node* node_;
ZoneNodePtr node_;
int count_;
int capacity_;
// Inputs are allocated right behind the OutOfLineInputs instance.
inline Node** inputs();
inline ZoneNodePtr* inputs();
static OutOfLineInputs* New(Zone* zone, int capacity);
void ExtractFrom(Use* use_ptr, Node** input_ptr, int count);
void ExtractFrom(Use* use_ptr, ZoneNodePtr* input_ptr, int count);
};
using ZoneOutOfLineInputsPtr = GraphZoneTraits::Ptr<OutOfLineInputs>;
// A link in the use chain for a node. Every input {i} to a node {n} has an
// associated {Use} which is linked into the use chain of the {i} node.
struct Use {
Use* next;
Use* prev;
ZoneUsePtr next;
ZoneUsePtr prev;
uint32_t bit_field_;
int input_index() const { return InputIndexField::decode(bit_field_); }
bool is_inline_use() const { return InlineField::decode(bit_field_); }
Node** input_ptr() {
ZoneNodePtr* input_ptr() {
int index = input_index();
Use* start = this + 1 + index;
Node** inputs = is_inline_use()
? reinterpret_cast<Node*>(start)->inline_inputs()
ZoneNodePtr* inputs =
is_inline_use() ? reinterpret_cast<Node*>(start)->inline_inputs()
: reinterpret_cast<OutOfLineInputs*>(start)->inputs();
return &inputs[index];
}
@ -230,21 +239,21 @@ class V8_EXPORT_PRIVATE Node final {
inline Address inputs_location() const;
Node** inline_inputs() const {
return reinterpret_cast<Node**>(inputs_location());
ZoneNodePtr* inline_inputs() const {
return reinterpret_cast<ZoneNodePtr*>(inputs_location());
}
OutOfLineInputs* outline_inputs() const {
return *reinterpret_cast<OutOfLineInputs**>(inputs_location());
return *reinterpret_cast<ZoneOutOfLineInputsPtr*>(inputs_location());
}
void set_outline_inputs(OutOfLineInputs* outline) {
*reinterpret_cast<OutOfLineInputs**>(inputs_location()) = outline;
*reinterpret_cast<ZoneOutOfLineInputsPtr*>(inputs_location()) = outline;
}
Node* const* GetInputPtrConst(int input_index) const {
ZoneNodePtr const* GetInputPtrConst(int input_index) const {
return has_inline_inputs() ? &(inline_inputs()[input_index])
: &(outline_inputs()->inputs()[input_index]);
}
Node** GetInputPtr(int input_index) {
ZoneNodePtr* GetInputPtr(int input_index) {
return has_inline_inputs() ? &(inline_inputs()[input_index])
: &(outline_inputs()->inputs()[input_index]);
}
@ -286,7 +295,7 @@ class V8_EXPORT_PRIVATE Node final {
Type type_;
Mark mark_;
uint32_t bit_field_;
Use* first_use_;
ZoneUsePtr first_use_;
friend class Edge;
friend class NodeMarkerBase;
@ -299,8 +308,8 @@ Address Node::inputs_location() const {
return reinterpret_cast<Address>(this) + sizeof(Node);
}
Node** Node::OutOfLineInputs::inputs() {
return reinterpret_cast<Node**>(reinterpret_cast<Address>(this) +
ZoneNodePtr* Node::OutOfLineInputs::inputs() {
return reinterpret_cast<ZoneNodePtr*>(reinterpret_cast<Address>(this) +
sizeof(Node::OutOfLineInputs));
}
@ -396,11 +405,11 @@ class Node::InputEdges final {
inline value_type operator[](int index) const;
InputEdges(Node** input_root, Use* use_root, int count)
InputEdges(ZoneNodePtr* input_root, Use* use_root, int count)
: input_root_(input_root), use_root_(use_root), count_(count) {}
private:
Node** input_root_;
ZoneNodePtr* input_root_;
Use* use_root_;
int count_;
};
@ -418,11 +427,11 @@ class V8_EXPORT_PRIVATE Node::Inputs final {
inline value_type operator[](int index) const;
explicit Inputs(Node* const* input_root, int count)
explicit Inputs(ZoneNodePtr const* input_root, int count)
: input_root_(input_root), count_(count) {}
private:
Node* const* input_root_;
ZoneNodePtr const* input_root_;
int count_;
};
@ -456,14 +465,15 @@ class Edge final {
friend class Node::InputEdges;
friend class Node::InputEdges::iterator;
Edge(Node::Use* use, Node** input_ptr) : use_(use), input_ptr_(input_ptr) {
Edge(Node::Use* use, ZoneNodePtr* input_ptr)
: use_(use), input_ptr_(input_ptr) {
DCHECK_NOT_NULL(use);
DCHECK_NOT_NULL(input_ptr);
DCHECK_EQ(input_ptr, use->input_ptr());
}
Node::Use* use_;
Node** input_ptr_;
ZoneNodePtr* input_ptr_;
};
bool Node::IsDead() const {
@ -530,11 +540,11 @@ class Node::InputEdges::iterator final {
private:
friend class Node;
explicit iterator(Use* use, Node** input_ptr)
explicit iterator(Use* use, ZoneNodePtr* input_ptr)
: use_(use), input_ptr_(input_ptr) {}
Use* use_;
Node** input_ptr_;
ZoneNodePtr* input_ptr_;
};
@ -588,9 +598,10 @@ class Node::Inputs::const_iterator final {
private:
friend class Node::Inputs;
explicit const_iterator(Node* const* input_ptr) : input_ptr_(input_ptr) {}
explicit const_iterator(ZoneNodePtr const* input_ptr)
: input_ptr_(input_ptr) {}
Node* const* input_ptr_;
ZoneNodePtr const* input_ptr_;
};
@ -618,7 +629,7 @@ class Node::UseEdges::iterator final {
iterator& operator++() {
DCHECK_NOT_NULL(current_);
current_ = next_;
next_ = current_ ? current_->next : nullptr;
next_ = current_ ? static_cast<Node::Use*>(current_->next) : nullptr;
return *this;
}
iterator operator++(int);
@ -629,7 +640,7 @@ class Node::UseEdges::iterator final {
iterator() : current_(nullptr), next_(nullptr) {}
explicit iterator(Node* node)
: current_(node->first_use_),
next_(current_ ? current_->next : nullptr) {}
next_(current_ ? static_cast<Node::Use*>(current_->next) : nullptr) {}
Node::Use* current_;
Node::Use* next_;

93
src/zone/compressed-zone-ptr.h Normal file
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@ -0,0 +1,93 @@
// Copyright 2020 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_ZONE_COMPRESSED_ZONE_PTR_H_
#define V8_ZONE_COMPRESSED_ZONE_PTR_H_
#include <type_traits>
#include "src/base/logging.h"
#include "src/common/globals.h"
#include "src/zone/zone-compression.h"
namespace v8 {
namespace internal {
//
// Compressed pointer to T using aligned-base-relative addressing compression.
//
// Note that the CompressedZonePtr<T> is implicitly convertible to T*.
// Such an approach provides the benefit of almost seamless migration of a code
// using full pointers to compressed pointers.
// However, using CompressedZonePtr<T> in containers is not allowed yet.
//
// It's not recommended to use this class directly, use ZoneTypeTraits::Ptr<T>
// instead.
template <typename T>
class CompressedZonePtr {
public:
CompressedZonePtr() = default;
explicit CompressedZonePtr(std::nullptr_t) : CompressedZonePtr() {}
explicit CompressedZonePtr(T* value) { *this = value; }
// Move- and copy-constructors are explicitly deleted in order to avoid
// creation of temporary objects which we can't uncompress because they will
// live outside of the zone memory.
CompressedZonePtr(const CompressedZonePtr& other) V8_NOEXCEPT = delete;
CompressedZonePtr(CompressedZonePtr&&) V8_NOEXCEPT = delete;
CompressedZonePtr& operator=(const CompressedZonePtr& other) V8_NOEXCEPT {
DCHECK(ZoneCompression::CheckSameBase(this, &other));
compressed_value_ = other.compressed_value_;
return *this;
}
CompressedZonePtr& operator=(CompressedZonePtr&& other) V8_NOEXCEPT = delete;
CompressedZonePtr& operator=(T* value) {
compressed_value_ = ZoneCompression::Compress(value);
DCHECK_EQ(value, Decompress());
return *this;
}
bool operator==(std::nullptr_t) const { return compressed_value_ == 0; }
bool operator!=(std::nullptr_t) const { return compressed_value_ != 0; }
// The equality comparisons assume that both operands point to objects
// allocated by the same allocator supporting pointer compression, therefore
// it's enough to compare compressed values.
bool operator==(const CompressedZonePtr& other) const {
return compressed_value_ == other.compressed_value_;
}
bool operator!=(const CompressedZonePtr& other) const {
return !(*this == other);
}
bool operator==(T* other) const {
return compressed_value_ == ZoneCompression::Compress(other);
}
bool operator!=(T* other) const { return !(*this == other); }
T& operator*() const { return *Decompress(); }
T* operator->() const { return Decompress(); }
operator T*() const { return Decompress(); }
operator bool() const { return compressed_value_ != 0; }
private:
T* Decompress() const {
return reinterpret_cast<T*>(
ZoneCompression::Decompress(this, compressed_value_));
}
uint32_t compressed_value_ = 0;
};
// This requirement is necessary for being able to use memcopy in containers
// of zone pointers.
// TODO(ishell): Re-enable once compressed pointers are supported in containers.
// static_assert(std::is_trivially_copyable<CompressedZonePtr<int>>::value,
// "CompressedZonePtr must be trivially copyable");
} // namespace internal
} // namespace v8
#endif // V8_ZONE_COMPRESSED_ZONE_PTR_H_

17
src/zone/zone-type-traits.h
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@ -7,6 +7,10 @@
#include "src/common/globals.h"
#ifdef V8_COMPRESS_ZONES
#include "src/zone/compressed-zone-ptr.h"
#endif
namespace v8 {
namespace internal {
@ -47,17 +51,18 @@ struct ZoneTypeTraits<false> {
template <>
struct ZoneTypeTraits<true> {
// TODO(ishell): use CompressedZonePtr<T> here
template <typename T>
using Ptr = FullZonePtr<T>;
using Ptr = CompressedZonePtr<T>;
};
// This requirement is necessary for being able to use memcopy in containers
// of zone pointers.
static_assert(
std::is_trivially_copyable<
ZoneTypeTraits<COMPRESS_ZONES_BOOL>::Ptr<int>>::value,
"ZoneTypeTraits<COMPRESS_ZONES_BOOL>::Ptr<T> must be trivially copyable");
// TODO(ishell): Re-enable once compressed pointers are supported in containers.
// static_assert(
// std::is_trivially_copyable<
// ZoneTypeTraits<COMPRESS_ZONES_BOOL>::Ptr<int>>::value,
// "ZoneTypeTraits<COMPRESS_ZONES_BOOL>::Ptr<T> must be trivially
// copyable");
//
// is_compressed_pointer<T> predicate can be used for checking if T is a