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// Copyright 2015 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/interpreter/constant-array-builder.h"
#include "src/isolate.h"
#include "src/objects-inl.h"
namespace v8 {
namespace internal {
namespace interpreter {
ConstantArrayBuilder::ConstantArraySlice::ConstantArraySlice(
Zone* zone, size_t start_index, size_t capacity, OperandSize operand_size)
: start_index_(start_index),
capacity_(capacity),
reserved_(0),
operand_size_(operand_size),
constants_(zone) {}
void ConstantArrayBuilder::ConstantArraySlice::Reserve() {
DCHECK_GT(available(), 0u);
reserved_++;
DCHECK_LE(reserved_, capacity() - constants_.size());
}
void ConstantArrayBuilder::ConstantArraySlice::Unreserve() {
DCHECK_GT(reserved_, 0u);
reserved_--;
}
size_t ConstantArrayBuilder::ConstantArraySlice::Allocate(
Handle<Object> object) {
DCHECK_GT(available(), 0u);
size_t index = constants_.size();
DCHECK_LT(index, capacity());
constants_.push_back(object);
return index + start_index();
}
Handle<Object> ConstantArrayBuilder::ConstantArraySlice::At(
size_t index) const {
DCHECK_GE(index, start_index());
DCHECK_LT(index, start_index() + size());
return constants_[index - start_index()];
}
STATIC_CONST_MEMBER_DEFINITION const size_t ConstantArrayBuilder::k8BitCapacity;
STATIC_CONST_MEMBER_DEFINITION const size_t
ConstantArrayBuilder::k16BitCapacity;
STATIC_CONST_MEMBER_DEFINITION const size_t
ConstantArrayBuilder::k32BitCapacity;
ConstantArrayBuilder::ConstantArrayBuilder(Isolate* isolate, Zone* zone)
: isolate_(isolate), constants_map_(isolate->heap(), zone) {
idx_slice_[0] =
new (zone) ConstantArraySlice(zone, 0, k8BitCapacity, OperandSize::kByte);
idx_slice_[1] = new (zone) ConstantArraySlice(
zone, k8BitCapacity, k16BitCapacity, OperandSize::kShort);
idx_slice_[2] = new (zone) ConstantArraySlice(
zone, k8BitCapacity + k16BitCapacity, k32BitCapacity, OperandSize::kQuad);
}
size_t ConstantArrayBuilder::size() const {
size_t i = arraysize(idx_slice_);
while (i > 0) {
ConstantArraySlice* slice = idx_slice_[--i];
if (slice->size() > 0) {
return slice->start_index() + slice->size();
}
}
return idx_slice_[0]->size();
}
const ConstantArrayBuilder::ConstantArraySlice*
ConstantArrayBuilder::IndexToSlice(size_t index) const {
for (const ConstantArraySlice* slice : idx_slice_) {
if (index <= slice->max_index()) {
return slice;
}
}
UNREACHABLE();
return nullptr;
}
Handle<Object> ConstantArrayBuilder::At(size_t index) const {
const ConstantArraySlice* slice = IndexToSlice(index);
if (index < slice->start_index() + slice->size()) {
return slice->At(index);
} else {
DCHECK_LT(index, slice->capacity());
return isolate_->factory()->the_hole_value();
}
}
Handle<FixedArray> ConstantArrayBuilder::ToFixedArray() {
Handle<FixedArray> fixed_array = isolate_->factory()->NewFixedArray(
static_cast<int>(size()), PretenureFlag::TENURED);
int array_index = 0;
for (const ConstantArraySlice* slice : idx_slice_) {
if (array_index == fixed_array->length()) {
break;
}
DCHECK(array_index == 0 ||
base::bits::IsPowerOfTwo32(static_cast<uint32_t>(array_index)));
// Copy objects from slice into array.
for (size_t i = 0; i < slice->size(); ++i) {
fixed_array->set(array_index++, *slice->At(slice->start_index() + i));
}
// Insert holes where reservations led to unused slots.
size_t padding =
std::min(static_cast<size_t>(fixed_array->length() - array_index),
slice->capacity() - slice->size());
for (size_t i = 0; i < padding; i++) {
fixed_array->set(array_index++, *isolate_->factory()->the_hole_value());
}
}
DCHECK_EQ(array_index, fixed_array->length());
constants_map()->Clear();
return fixed_array;
}
size_t ConstantArrayBuilder::Insert(Handle<Object> object) {
index_t* entry = constants_map()->Find(object);
return (entry == nullptr) ? AllocateEntry(object) : *entry;
}
ConstantArrayBuilder::index_t ConstantArrayBuilder::AllocateEntry(
Handle<Object> object) {
DCHECK(!object->IsOddball());
index_t* entry = constants_map()->Get(object);
for (size_t i = 0; i < arraysize(idx_slice_); ++i) {
if (idx_slice_[i]->available() > 0) {
size_t index = idx_slice_[i]->Allocate(object);
*entry = static_cast<index_t>(index);
return *entry;
break;
}
}
UNREACHABLE();
return kMaxUInt32;
}
OperandSize ConstantArrayBuilder::CreateReservedEntry() {
for (size_t i = 0; i < arraysize(idx_slice_); ++i) {
if (idx_slice_[i]->available() > 0) {
idx_slice_[i]->Reserve();
return idx_slice_[i]->operand_size();
}
}
UNREACHABLE();
return OperandSize::kNone;
}
ConstantArrayBuilder::ConstantArraySlice*
ConstantArrayBuilder::OperandSizeToSlice(OperandSize operand_size) const {
ConstantArraySlice* slice = nullptr;
switch (operand_size) {
case OperandSize::kNone:
UNREACHABLE();
break;
case OperandSize::kByte:
slice = idx_slice_[0];
break;
case OperandSize::kShort:
slice = idx_slice_[1];
break;
case OperandSize::kQuad:
slice = idx_slice_[2];
break;
}
DCHECK(slice->operand_size() == operand_size);
return slice;
}
size_t ConstantArrayBuilder::CommitReservedEntry(OperandSize operand_size,
Handle<Object> object) {
DiscardReservedEntry(operand_size);
size_t index;
index_t* entry = constants_map()->Find(object);
if (nullptr == entry) {
index = AllocateEntry(object);
} else {
ConstantArraySlice* slice = OperandSizeToSlice(operand_size);
if (*entry > slice->max_index()) {
// The object is already in the constant array, but may have an
// index too big for the reserved operand_size. So, duplicate
// entry with the smaller operand size.
*entry = static_cast<index_t>(slice->Allocate(object));
}
index = *entry;
}
return index;
}
void ConstantArrayBuilder::DiscardReservedEntry(OperandSize operand_size) {
OperandSizeToSlice(operand_size)->Unreserve();
}
} // namespace interpreter
} // namespace internal
} // namespace v8
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