[interpreter] Reduce dependencies in bytecodes.{h,cc}

src/interpreter/bytecode-decoder.cc

Index: src/interpreter/bytecode-decoder.cc
diff --git a/src/interpreter/bytecode-decoder.cc b/src/interpreter/bytecode-decoder.cc
new file mode 100644
index 0000000000000000000000000000000000000000..74c5806ef5e9257a3eeb68eac8e0e128ee20bc0d
--- /dev/null
+++ b/src/interpreter/bytecode-decoder.cc
@@ -0,0 +1,157 @@
+// 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-decoder.h"
+
+#include <iomanip>
+
+#include "src/utils.h"
+
+namespace v8 {
+namespace internal {
+namespace interpreter {
+
+// static
+Register BytecodeDecoder::DecodeRegisterOperand(const uint8_t* operand_start,
+                                                OperandType operand_type,
+                                                OperandScale operand_scale) {
+  DCHECK(Bytecodes::IsRegisterOperandType(operand_type));
+  int32_t operand =
+      DecodeSignedOperand(operand_start, operand_type, operand_scale);
+  return Register::FromOperand(operand);
+}
+
+// static
+int32_t BytecodeDecoder::DecodeSignedOperand(const uint8_t* operand_start,
+                                             OperandType operand_type,
+                                             OperandScale operand_scale) {
+  DCHECK(!Bytecodes::IsUnsignedOperandType(operand_type));
+  switch (Bytecodes::SizeOfOperand(operand_type, operand_scale)) {
+    case OperandSize::kByte:
+      return static_cast<int8_t>(*operand_start);
+    case OperandSize::kShort:
+      return static_cast<int16_t>(ReadUnalignedUInt16(operand_start));
+    case OperandSize::kQuad:
+      return static_cast<int32_t>(ReadUnalignedUInt32(operand_start));
+    case OperandSize::kNone:
+      UNREACHABLE();
+  }
+  return 0;
+}
+
+// static
+uint32_t BytecodeDecoder::DecodeUnsignedOperand(const uint8_t* operand_start,
+                                                OperandType operand_type,
+                                                OperandScale operand_scale) {
+  DCHECK(Bytecodes::IsUnsignedOperandType(operand_type));
+  switch (Bytecodes::SizeOfOperand(operand_type, operand_scale)) {
+    case OperandSize::kByte:
+      return *operand_start;
+    case OperandSize::kShort:
+      return ReadUnalignedUInt16(operand_start);
+    case OperandSize::kQuad:
+      return ReadUnalignedUInt32(operand_start);
+    case OperandSize::kNone:
+      UNREACHABLE();
+  }
+  return 0;
+}
+
+// static
+std::ostream& BytecodeDecoder::Decode(std::ostream& os,
+                                      const uint8_t* bytecode_start,
+                                      int parameter_count) {
+  Bytecode bytecode = Bytecodes::FromByte(bytecode_start[0]);
+  int prefix_offset = 0;
+  OperandScale operand_scale = OperandScale::kSingle;
+  if (Bytecodes::IsPrefixScalingBytecode(bytecode)) {
+    prefix_offset = 1;
+    operand_scale = Bytecodes::PrefixBytecodeToOperandScale(bytecode);
+    bytecode = Bytecodes::FromByte(bytecode_start[1]);
+  }
+
+  // Prepare to print bytecode and operands as hex digits.
+  std::ios saved_format(nullptr);
+  saved_format.copyfmt(saved_format);
+  os.fill('0');
+  os.flags(std::ios::hex);
+
+  int bytecode_size = Bytecodes::Size(bytecode, operand_scale);
+  for (int i = 0; i < prefix_offset + bytecode_size; i++) {
+    os << std::setw(2) << static_cast<uint32_t>(bytecode_start[i]) << ' ';
+  }
+  os.copyfmt(saved_format);
+
+  const int kBytecodeColumnSize = 6;
+  for (int i = prefix_offset + bytecode_size; i < kBytecodeColumnSize; i++) {
+    os << "   ";
+  }
+
+  os << Bytecodes::ToString(bytecode, operand_scale) << " ";
+
+  // Operands for the debug break are from the original instruction.
+  if (Bytecodes::IsDebugBreak(bytecode)) return os;
+
+  int number_of_operands = Bytecodes::NumberOfOperands(bytecode);
+  int range = 0;
+  for (int i = 0; i < number_of_operands; i++) {
+    OperandType op_type = Bytecodes::GetOperandType(bytecode, i);
+    int operand_offset =
+        Bytecodes::GetOperandOffset(bytecode, i, operand_scale);
+    const uint8_t* operand_start =
+        &bytecode_start[prefix_offset + operand_offset];
+    switch (op_type) {
+      case interpreter::OperandType::kRegCount:
+        os << "#"
+           << DecodeUnsignedOperand(operand_start, op_type, operand_scale);
+        break;
+      case interpreter::OperandType::kIdx:
+      case interpreter::OperandType::kRuntimeId:
+      case interpreter::OperandType::kIntrinsicId:
+        os << "["
+           << DecodeUnsignedOperand(operand_start, op_type, operand_scale)
+           << "]";
+        break;
+      case interpreter::OperandType::kImm:
+        os << "[" << DecodeSignedOperand(operand_start, op_type, operand_scale)
+           << "]";
+        break;
+      case interpreter::OperandType::kFlag8:
+        os << "#"
+           << DecodeUnsignedOperand(operand_start, op_type, operand_scale);
+        break;
+      case interpreter::OperandType::kMaybeReg:
+      case interpreter::OperandType::kReg:
+      case interpreter::OperandType::kRegOut: {
+        Register reg =
+            DecodeRegisterOperand(operand_start, op_type, operand_scale);
+        os << reg.ToString(parameter_count);
+        break;
+      }
+      case interpreter::OperandType::kRegOutTriple:
+        range += 1;
+      case interpreter::OperandType::kRegOutPair:
+      case interpreter::OperandType::kRegPair: {
+        range += 1;
+        Register first_reg =
+            DecodeRegisterOperand(operand_start, op_type, operand_scale);
+        Register last_reg = Register(first_reg.index() + range);
+        os << first_reg.ToString(parameter_count) << "-"
+           << last_reg.ToString(parameter_count);
+        break;
+      }
+      case interpreter::OperandType::kNone:
+        UNREACHABLE();
+        break;
+    }
+    if (i != number_of_operands - 1) {
+      os << ", ";
+    }
+  }
+  return os;
+}
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8