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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-iterator.h"
#include "src/objects-inl.h"
namespace v8 {
namespace internal {
namespace interpreter {
BytecodeArrayIterator::BytecodeArrayIterator(
Handle<BytecodeArray> bytecode_array)
: bytecode_array_(bytecode_array), bytecode_offset_(0) {}
void BytecodeArrayIterator::Advance() {
bytecode_offset_ += Bytecodes::Size(current_bytecode());
}
bool BytecodeArrayIterator::done() const {
return bytecode_offset_ >= bytecode_array()->length();
}
Bytecode BytecodeArrayIterator::current_bytecode() const {
DCHECK(!done());
uint8_t current_byte = bytecode_array()->get(bytecode_offset_);
return interpreter::Bytecodes::FromByte(current_byte);
}
int BytecodeArrayIterator::current_bytecode_size() const {
return Bytecodes::Size(current_bytecode());
}
uint32_t BytecodeArrayIterator::GetRawOperand(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));
uint8_t* operand_start =
bytecode_array()->GetFirstBytecodeAddress() + bytecode_offset_ +
Bytecodes::GetOperandOffset(current_bytecode(), operand_index);
switch (Bytecodes::SizeOfOperand(operand_type)) {
case OperandSize::kByte:
return static_cast<uint32_t>(*operand_start);
case OperandSize::kShort:
return ReadUnalignedUInt16(operand_start);
case OperandSize::kNone:
UNREACHABLE();
}
return 0;
}
int8_t BytecodeArrayIterator::GetImmediateOperand(int operand_index) const {
uint32_t operand = GetRawOperand(operand_index, OperandType::kImm8);
return static_cast<int8_t>(operand);
}
int BytecodeArrayIterator::GetRegisterCountOperand(int operand_index) const {
OperandSize size =
Bytecodes::GetOperandSize(current_bytecode(), operand_index);
OperandType type = (size == OperandSize::kByte) ? OperandType::kRegCount8
: OperandType::kRegCount16;
uint32_t operand = GetRawOperand(operand_index, type);
return static_cast<int>(operand);
}
int BytecodeArrayIterator::GetIndexOperand(int operand_index) const {
OperandType operand_type =
Bytecodes::GetOperandType(current_bytecode(), operand_index);
DCHECK(operand_type == OperandType::kIdx8 ||
operand_type == OperandType::kIdx16);
uint32_t operand = GetRawOperand(operand_index, operand_type);
return static_cast<int>(operand);
}
Register BytecodeArrayIterator::GetRegisterOperand(int operand_index) const {
OperandType operand_type =
Bytecodes::GetOperandType(current_bytecode(), operand_index);
DCHECK(Bytecodes::IsRegisterOperandType(operand_type));
uint32_t operand = GetRawOperand(operand_index, operand_type);
Register reg;
switch (Bytecodes::GetOperandSize(current_bytecode(), operand_index)) {
case OperandSize::kByte:
reg = Register::FromOperand(static_cast<uint8_t>(operand));
break;
case OperandSize::kShort:
reg = Register::FromWideOperand(static_cast<uint16_t>(operand));
break;
case OperandSize::kNone:
UNREACHABLE();
reg = Register::invalid_value();
break;
}
DCHECK_GE(reg.index(),
Register::FromParameterIndex(0, bytecode_array()->parameter_count())
.index());
DCHECK(reg.index() < bytecode_array()->register_count() ||
(reg.index() == 0 &&
Bytecodes::IsMaybeRegisterOperandType(
Bytecodes::GetOperandType(current_bytecode(), operand_index))));
return reg;
}
int BytecodeArrayIterator::GetRegisterOperandRange(int operand_index) const {
interpreter::OperandType operand_type =
Bytecodes::GetOperandType(current_bytecode(), operand_index);
DCHECK(Bytecodes::IsRegisterOperandType(operand_type));
switch (operand_type) {
case OperandType::kRegPair8:
case OperandType::kRegPair16:
case OperandType::kRegOutPair8:
case OperandType::kRegOutPair16:
return 2;
case OperandType::kRegOutTriple8:
case OperandType::kRegOutTriple16:
return 3;
default: {
if (operand_index + 1 !=
Bytecodes::NumberOfOperands(current_bytecode())) {
OperandType next_operand_type =
Bytecodes::GetOperandType(current_bytecode(), operand_index + 1);
if (Bytecodes::IsRegisterCountOperandType(next_operand_type)) {
return GetRegisterCountOperand(operand_index + 1);
}
}
return 1;
}
}
}
Handle<Object> BytecodeArrayIterator::GetConstantForIndexOperand(
int operand_index) const {
return FixedArray::get(bytecode_array()->constant_pool(),
GetIndexOperand(operand_index),
bytecode_array()->GetIsolate());
}
int BytecodeArrayIterator::GetJumpTargetOffset() const {
Bytecode bytecode = current_bytecode();
if (interpreter::Bytecodes::IsJumpImmediate(bytecode)) {
int relative_offset = GetImmediateOperand(0);
return current_offset() + relative_offset;
} else if (interpreter::Bytecodes::IsJumpConstant(bytecode) ||
interpreter::Bytecodes::IsJumpConstantWide(bytecode)) {
Smi* smi = Smi::cast(*GetConstantForIndexOperand(0));
return current_offset() + smi->value();
} else {
UNREACHABLE();
return kMinInt;
}
}
} // namespace interpreter
} // namespace internal
} // namespace v8
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