Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame^] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include "src/interpreter/bytecode-array-iterator.h" |
| 6 | |
| 7 | #include "src/objects-inl.h" |
| 8 | |
| 9 | namespace v8 { |
| 10 | namespace internal { |
| 11 | namespace interpreter { |
| 12 | |
| 13 | BytecodeArrayIterator::BytecodeArrayIterator( |
| 14 | Handle<BytecodeArray> bytecode_array) |
| 15 | : bytecode_array_(bytecode_array), bytecode_offset_(0) {} |
| 16 | |
| 17 | |
| 18 | void BytecodeArrayIterator::Advance() { |
| 19 | bytecode_offset_ += Bytecodes::Size(current_bytecode()); |
| 20 | } |
| 21 | |
| 22 | |
| 23 | bool BytecodeArrayIterator::done() const { |
| 24 | return bytecode_offset_ >= bytecode_array()->length(); |
| 25 | } |
| 26 | |
| 27 | |
| 28 | Bytecode BytecodeArrayIterator::current_bytecode() const { |
| 29 | DCHECK(!done()); |
| 30 | uint8_t current_byte = bytecode_array()->get(bytecode_offset_); |
| 31 | return interpreter::Bytecodes::FromByte(current_byte); |
| 32 | } |
| 33 | |
| 34 | |
| 35 | int BytecodeArrayIterator::current_bytecode_size() const { |
| 36 | return Bytecodes::Size(current_bytecode()); |
| 37 | } |
| 38 | |
| 39 | |
| 40 | uint32_t BytecodeArrayIterator::GetRawOperand(int operand_index, |
| 41 | OperandType operand_type) const { |
| 42 | DCHECK_GE(operand_index, 0); |
| 43 | DCHECK_LT(operand_index, Bytecodes::NumberOfOperands(current_bytecode())); |
| 44 | DCHECK_EQ(operand_type, |
| 45 | Bytecodes::GetOperandType(current_bytecode(), operand_index)); |
| 46 | uint8_t* operand_start = |
| 47 | bytecode_array()->GetFirstBytecodeAddress() + bytecode_offset_ + |
| 48 | Bytecodes::GetOperandOffset(current_bytecode(), operand_index); |
| 49 | switch (Bytecodes::SizeOfOperand(operand_type)) { |
| 50 | default: |
| 51 | case OperandSize::kNone: |
| 52 | UNREACHABLE(); |
| 53 | case OperandSize::kByte: |
| 54 | return static_cast<uint32_t>(*operand_start); |
| 55 | case OperandSize::kShort: |
| 56 | return ReadUnalignedUInt16(operand_start); |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | |
| 61 | int8_t BytecodeArrayIterator::GetImmediateOperand(int operand_index) const { |
| 62 | uint32_t operand = GetRawOperand(operand_index, OperandType::kImm8); |
| 63 | return static_cast<int8_t>(operand); |
| 64 | } |
| 65 | |
| 66 | |
| 67 | int BytecodeArrayIterator::GetCountOperand(int operand_index) const { |
| 68 | OperandSize size = |
| 69 | Bytecodes::GetOperandSize(current_bytecode(), operand_index); |
| 70 | OperandType type = (size == OperandSize::kByte) ? OperandType::kCount8 |
| 71 | : OperandType::kCount16; |
| 72 | uint32_t operand = GetRawOperand(operand_index, type); |
| 73 | return static_cast<int>(operand); |
| 74 | } |
| 75 | |
| 76 | |
| 77 | int BytecodeArrayIterator::GetIndexOperand(int operand_index) const { |
| 78 | OperandType operand_type = |
| 79 | Bytecodes::GetOperandType(current_bytecode(), operand_index); |
| 80 | DCHECK(operand_type == OperandType::kIdx8 || |
| 81 | operand_type == OperandType::kIdx16); |
| 82 | uint32_t operand = GetRawOperand(operand_index, operand_type); |
| 83 | return static_cast<int>(operand); |
| 84 | } |
| 85 | |
| 86 | |
| 87 | Register BytecodeArrayIterator::GetRegisterOperand(int operand_index) const { |
| 88 | OperandType operand_type = |
| 89 | Bytecodes::GetOperandType(current_bytecode(), operand_index); |
| 90 | DCHECK(operand_type == OperandType::kReg8 || |
| 91 | operand_type == OperandType::kRegPair8 || |
| 92 | operand_type == OperandType::kMaybeReg8 || |
| 93 | operand_type == OperandType::kReg16); |
| 94 | uint32_t operand = GetRawOperand(operand_index, operand_type); |
| 95 | return Register::FromOperand(operand); |
| 96 | } |
| 97 | |
| 98 | |
| 99 | Handle<Object> BytecodeArrayIterator::GetConstantForIndexOperand( |
| 100 | int operand_index) const { |
| 101 | Handle<FixedArray> constants = handle(bytecode_array()->constant_pool()); |
| 102 | return FixedArray::get(constants, GetIndexOperand(operand_index)); |
| 103 | } |
| 104 | |
| 105 | |
| 106 | int BytecodeArrayIterator::GetJumpTargetOffset() const { |
| 107 | Bytecode bytecode = current_bytecode(); |
| 108 | if (interpreter::Bytecodes::IsJumpImmediate(bytecode)) { |
| 109 | int relative_offset = GetImmediateOperand(0); |
| 110 | return current_offset() + relative_offset; |
| 111 | } else if (interpreter::Bytecodes::IsJumpConstant(bytecode) || |
| 112 | interpreter::Bytecodes::IsJumpConstantWide(bytecode)) { |
| 113 | Smi* smi = Smi::cast(*GetConstantForIndexOperand(0)); |
| 114 | return current_offset() + smi->value(); |
| 115 | } else { |
| 116 | UNREACHABLE(); |
| 117 | return kMinInt; |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | } // namespace interpreter |
| 122 | } // namespace internal |
| 123 | } // namespace v8 |