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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/bytecode-array-accessor.h"
#include "src/interpreter/bytecode-decoder.h"
#include "src/interpreter/interpreter-intrinsics.h"
#include "src/objects-inl.h"
namespace v8 {
namespace internal {
namespace interpreter {
BytecodeArrayAccessor::BytecodeArrayAccessor(
Handle<BytecodeArray> bytecode_array, int initial_offset)
: bytecode_array_(bytecode_array),
bytecode_offset_(initial_offset),
operand_scale_(OperandScale::kSingle),
prefix_offset_(0) {
UpdateOperandScale();
}
void BytecodeArrayAccessor::SetOffset(int offset) {
bytecode_offset_ = offset;
UpdateOperandScale();
}
void BytecodeArrayAccessor::UpdateOperandScale() {
if (OffsetInBounds()) {
uint8_t current_byte = bytecode_array()->get(bytecode_offset_);
Bytecode current_bytecode = Bytecodes::FromByte(current_byte);
if (Bytecodes::IsPrefixScalingBytecode(current_bytecode)) {
operand_scale_ =
Bytecodes::PrefixBytecodeToOperandScale(current_bytecode);
prefix_offset_ = 1;
} else {
operand_scale_ = OperandScale::kSingle;
prefix_offset_ = 0;
}
}
}
bool BytecodeArrayAccessor::OffsetInBounds() const {
return bytecode_offset_ >= 0 && bytecode_offset_ < bytecode_array()->length();
}
Bytecode BytecodeArrayAccessor::current_bytecode() const {
DCHECK(OffsetInBounds());
uint8_t current_byte =
bytecode_array()->get(bytecode_offset_ + current_prefix_offset());
Bytecode current_bytecode = Bytecodes::FromByte(current_byte);
DCHECK(!Bytecodes::IsPrefixScalingBytecode(current_bytecode));
return current_bytecode;
}
int BytecodeArrayAccessor::current_bytecode_size() const {
return current_prefix_offset() +
Bytecodes::Size(current_bytecode(), current_operand_scale());
}
uint32_t BytecodeArrayAccessor::GetUnsignedOperand(
int operand_index, OperandType operand_type) const {
DCHECK_GE(operand_index, 0);
DCHECK_LT(operand_index, Bytecodes::NumberOfOperands(current_bytecode()));
DCHECK_EQ(operand_type,
Bytecodes::GetOperandType(current_bytecode(), operand_index));
DCHECK(Bytecodes::IsUnsignedOperandType(operand_type));
const uint8_t* operand_start =
bytecode_array()->GetFirstBytecodeAddress() + bytecode_offset_ +
current_prefix_offset() +
Bytecodes::GetOperandOffset(current_bytecode(), operand_index,
current_operand_scale());
return BytecodeDecoder::DecodeUnsignedOperand(operand_start, operand_type,
current_operand_scale());
}
int32_t BytecodeArrayAccessor::GetSignedOperand(
int operand_index, OperandType operand_type) const {
DCHECK_GE(operand_index, 0);
DCHECK_LT(operand_index, Bytecodes::NumberOfOperands(current_bytecode()));
DCHECK_EQ(operand_type,
Bytecodes::GetOperandType(current_bytecode(), operand_index));
DCHECK(!Bytecodes::IsUnsignedOperandType(operand_type));
const uint8_t* operand_start =
bytecode_array()->GetFirstBytecodeAddress() + bytecode_offset_ +
current_prefix_offset() +
Bytecodes::GetOperandOffset(current_bytecode(), operand_index,
current_operand_scale());
return BytecodeDecoder::DecodeSignedOperand(operand_start, operand_type,
current_operand_scale());
}
uint32_t BytecodeArrayAccessor::GetFlagOperand(int operand_index) const {
DCHECK_EQ(Bytecodes::GetOperandType(current_bytecode(), operand_index),
OperandType::kFlag8);
return GetUnsignedOperand(operand_index, OperandType::kFlag8);
}
uint32_t BytecodeArrayAccessor::GetUnsignedImmediateOperand(
int operand_index) const {
DCHECK_EQ(Bytecodes::GetOperandType(current_bytecode(), operand_index),
OperandType::kUImm);
return GetUnsignedOperand(operand_index, OperandType::kUImm);
}
int32_t BytecodeArrayAccessor::GetImmediateOperand(int operand_index) const {
DCHECK_EQ(Bytecodes::GetOperandType(current_bytecode(), operand_index),
OperandType::kImm);
return GetSignedOperand(operand_index, OperandType::kImm);
}
uint32_t BytecodeArrayAccessor::GetRegisterCountOperand(
int operand_index) const {
DCHECK_EQ(Bytecodes::GetOperandType(current_bytecode(), operand_index),
OperandType::kRegCount);
return GetUnsignedOperand(operand_index, OperandType::kRegCount);
}
uint32_t BytecodeArrayAccessor::GetIndexOperand(int operand_index) const {
OperandType operand_type =
Bytecodes::GetOperandType(current_bytecode(), operand_index);
DCHECK_EQ(operand_type, OperandType::kIdx);
return GetUnsignedOperand(operand_index, operand_type);
}
Register BytecodeArrayAccessor::GetRegisterOperand(int operand_index) const {
OperandType operand_type =
Bytecodes::GetOperandType(current_bytecode(), operand_index);
const uint8_t* operand_start =
bytecode_array()->GetFirstBytecodeAddress() + bytecode_offset_ +
current_prefix_offset() +
Bytecodes::GetOperandOffset(current_bytecode(), operand_index,
current_operand_scale());
return BytecodeDecoder::DecodeRegisterOperand(operand_start, operand_type,
current_operand_scale());
}
int BytecodeArrayAccessor::GetRegisterOperandRange(int operand_index) const {
DCHECK_LE(operand_index, Bytecodes::NumberOfOperands(current_bytecode()));
const OperandType* operand_types =
Bytecodes::GetOperandTypes(current_bytecode());
OperandType operand_type = operand_types[operand_index];
DCHECK(Bytecodes::IsRegisterOperandType(operand_type));
if (operand_type == OperandType::kRegList) {
return GetRegisterCountOperand(operand_index + 1);
} else {
return Bytecodes::GetNumberOfRegistersRepresentedBy(operand_type);
}
}
Runtime::FunctionId BytecodeArrayAccessor::GetRuntimeIdOperand(
int operand_index) const {
OperandType operand_type =
Bytecodes::GetOperandType(current_bytecode(), operand_index);
DCHECK(operand_type == OperandType::kRuntimeId);
uint32_t raw_id = GetUnsignedOperand(operand_index, operand_type);
return static_cast<Runtime::FunctionId>(raw_id);
}
Runtime::FunctionId BytecodeArrayAccessor::GetIntrinsicIdOperand(
int operand_index) const {
OperandType operand_type =
Bytecodes::GetOperandType(current_bytecode(), operand_index);
DCHECK(operand_type == OperandType::kIntrinsicId);
uint32_t raw_id = GetUnsignedOperand(operand_index, operand_type);
return IntrinsicsHelper::ToRuntimeId(
static_cast<IntrinsicsHelper::IntrinsicId>(raw_id));
}
Handle<Object> BytecodeArrayAccessor::GetConstantForIndexOperand(
int operand_index) const {
return FixedArray::get(bytecode_array()->constant_pool(),
GetIndexOperand(operand_index),
bytecode_array()->GetIsolate());
}
int BytecodeArrayAccessor::GetJumpTargetOffset() const {
Bytecode bytecode = current_bytecode();
if (interpreter::Bytecodes::IsJumpImmediate(bytecode)) {
int relative_offset = GetUnsignedImmediateOperand(0);
if (bytecode == Bytecode::kJumpLoop) {
relative_offset = -relative_offset;
}
return current_offset() + relative_offset + current_prefix_offset();
} else if (interpreter::Bytecodes::IsJumpConstant(bytecode)) {
Smi* smi = Smi::cast(*GetConstantForIndexOperand(0));
return current_offset() + smi->value() + current_prefix_offset();
} else {
UNREACHABLE();
return kMinInt;
}
}
bool BytecodeArrayAccessor::OffsetWithinBytecode(int offset) const {
return current_offset() <= offset &&
offset < current_offset() + current_bytecode_size();
}
std::ostream& BytecodeArrayAccessor::PrintTo(std::ostream& os) const {
return BytecodeDecoder::Decode(
os, bytecode_array()->GetFirstBytecodeAddress() + bytecode_offset_,
bytecode_array()->parameter_count());
}
} // namespace interpreter
} // namespace internal
} // namespace v8
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