[Interpreter] Add support for short (16 bit) operands.

src/interpreter/bytecodes.cc

 // 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/bytecodes.h"
 
 #include "src/frames.h"
+#include "src/interpreter/bytecode-traits.h"
 
 namespace v8 {
 namespace internal {
 namespace interpreter {
 
-// Maximum number of operands a bytecode may have.
-static const int kMaxOperands = 3;
-
-// kBytecodeTable relies on kNone being the same as zero to detect length.
-STATIC_ASSERT(static_cast<int>(OperandType::kNone) == 0);
-
-static const OperandType kBytecodeTable[][kMaxOperands] = {
-#define DECLARE_OPERAND(_, ...) \
-  { __VA_ARGS__ }               \
-  ,
-    BYTECODE_LIST(DECLARE_OPERAND)
-#undef DECLARE_OPERAND
-};
-
 
 // static
 const char* Bytecodes::ToString(Bytecode bytecode) {
   switch (bytecode) {
 #define CASE(Name, ...)   \
   case Bytecode::k##Name: \
     return #Name;
     BYTECODE_LIST(CASE)
 #undef CASE
   }
   UNREACHABLE();
   return "";
 }
 
 
 // static
 const char* Bytecodes::OperandTypeToString(OperandType operand_type) {
   switch (operand_type) {
-#define CASE(Name)           \
+#define CASE(Name, _)        \
   case OperandType::k##Name: \
     return #Name;
     OPERAND_TYPE_LIST(CASE)
 #undef CASE
   }
   UNREACHABLE();
   return "";
 }
 
 
 // static
 uint8_t Bytecodes::ToByte(Bytecode bytecode) {
   return static_cast<uint8_t>(bytecode);
 }
 
 
 // static
 Bytecode Bytecodes::FromByte(uint8_t value) {
   Bytecode bytecode = static_cast<Bytecode>(value);
   DCHECK(bytecode <= Bytecode::kLast);
   return bytecode;
 }
 
 
 // static
+int Bytecodes::Size(Bytecode bytecode) {
+  DCHECK(bytecode <= Bytecode::kLast);
+  switch (bytecode) {
+#define CASE(Name, ...)   \
+  case Bytecode::k##Name: \
+    return internal::BytecodeTraits<__VA_ARGS__, OPERAND_TERM>::kSize;
+    BYTECODE_LIST(CASE)
+#undef CASE
+  }
+  UNREACHABLE();
+  return 0;
+}
+
+
+// static
 int Bytecodes::NumberOfOperands(Bytecode bytecode) {
   DCHECK(bytecode <= Bytecode::kLast);
-  int count;
-  uint8_t row = ToByte(bytecode);
-  for (count = 0; count < kMaxOperands; count++) {
-    if (kBytecodeTable[row][count] == OperandType::kNone) {
-      break;
-    }
+  switch (bytecode) {
+#define CASE(Name, ...)   \
+  case Bytecode::k##Name: \
+    return internal::BytecodeTraits<__VA_ARGS__, OPERAND_TERM>::kOperandCount;
+    BYTECODE_LIST(CASE)
+#undef CASE
   }
-  return count;
+  UNREACHABLE();
+  return 0;
 }
 
 
 // static
 OperandType Bytecodes::GetOperandType(Bytecode bytecode, int i) {
-  DCHECK(bytecode <= Bytecode::kLast && i < NumberOfOperands(bytecode));
-  return kBytecodeTable[ToByte(bytecode)][i];
+  DCHECK(bytecode <= Bytecode::kLast);
+  switch (bytecode) {
+#define CASE(Name, ...)                          \
+  case Bytecode::k##Name:                        \
+    return internal::BytecodeTraits<__VA_ARGS__, \
+                                    OPERAND_TERM>::GetOperandType(i);
+    BYTECODE_LIST(CASE)
+#undef CASE
+  }
+  UNREACHABLE();
+  return OperandType::kNone;
 }
 
 
 // static
-int Bytecodes::Size(Bytecode bytecode) {
-  return 1 + NumberOfOperands(bytecode);
+int Bytecodes::GetOperandOffset(Bytecode bytecode, int i) {
+  DCHECK(bytecode <= Bytecode::kLast);
+  switch (bytecode) {
+#define CASE(Name, ...)                          \
+  case Bytecode::k##Name:                        \
+    return internal::BytecodeTraits<__VA_ARGS__, \
+                                    OPERAND_TERM>::GetOperandOffset(i);
+    BYTECODE_LIST(CASE)
+#undef CASE
+  }
+  UNREACHABLE();
+  return 0;
 }
 
 
 // static
-int Bytecodes::MaximumNumberOfOperands() { return kMaxOperands; }
+OperandSize Bytecodes::SizeOfOperand(OperandType operand_type) {
+  switch (operand_type) {
+#define CASE(Name, Size)     \
+  case OperandType::k##Name: \
+    return Size;
+    OPERAND_TYPE_LIST(CASE)
+#undef CASE
+  }
+  UNREACHABLE();
+  return OperandSize::kNone;
+}
 
 
 // static
-int Bytecodes::MaximumSize() { return 1 + kMaxOperands; }
+uint16_t Bytecodes::WideOperandFromBytes(const uint8_t* bytes) {
+  return *reinterpret_cast<const uint16_t*>(bytes);
+}
 
 
 // static
+void Bytecodes::WideOperandToBytes(uint16_t operand, uint8_t* bytes_out) {
+  *reinterpret_cast<uint16_t*>(bytes_out) = operand;
+}
+
+
+// static
 std::ostream& Bytecodes::Decode(std::ostream& os, const uint8_t* bytecode_start,
                                 int parameter_count) {
   Vector<char> buf = Vector<char>::New(50);
 
   Bytecode bytecode = Bytecodes::FromByte(bytecode_start[0]);
   int bytecode_size = Bytecodes::Size(bytecode);
 
   for (int i = 0; i < bytecode_size; i++) {
     SNPrintF(buf, "%02x ", bytecode_start[i]);
     os << buf.start();
   }
-  for (int i = bytecode_size; i < Bytecodes::MaximumSize(); i++) {
+  const int kBytecodeColumnSize = 6;
+  for (int i = bytecode_size; i < kBytecodeColumnSize; i++) {
     os << "   ";
   }
 
   os << bytecode << " ";
 
-  const uint8_t* operands_start = bytecode_start + 1;
-  int operands_size = bytecode_size - 1;
-  for (int i = 0; i < operands_size; i++) {
+  int number_of_operands = NumberOfOperands(bytecode);
+  for (int i = 0; i < number_of_operands; i++) {
     OperandType op_type = GetOperandType(bytecode, i);
-    uint8_t operand = operands_start[i];
+    const uint8_t* operand_start =
+        &bytecode_start[GetOperandOffset(bytecode, i)];
     switch (op_type) {
       case interpreter::OperandType::kCount:
-        os << "#" << static_cast<unsigned int>(operand);
+        os << "#" << static_cast<unsigned int>(*operand_start);
         break;
       case interpreter::OperandType::kIdx:
-        os << "[" << static_cast<unsigned int>(operand) << "]";
+        os << "[" << static_cast<unsigned int>(*operand_start) << "]";
         break;
+      case interpreter::OperandType::kWideIdx: {
+        os << "[" << Bytecodes::WideOperandFromBytes(operand_start) << "]";
+        break;
+      }
       case interpreter::OperandType::kImm8:
-        os << "#" << static_cast<int>(static_cast<int8_t>(operand));
+        os << "#" << static_cast<int>(static_cast<int8_t>(*operand_start));
         break;
       case interpreter::OperandType::kReg: {
-        Register reg = Register::FromOperand(operand);
+        Register reg = Register::FromOperand(*operand_start);
         if (reg.is_parameter()) {
           int parameter_index = reg.ToParameterIndex(parameter_count);
           if (parameter_index == 0) {
             os << "<this>";
           } else {
             os << "a" << parameter_index - 1;
           }
         } else {
           os << "r" << reg.index();
         }
         break;
       }
       case interpreter::OperandType::kNone:
         UNREACHABLE();
         break;
     }
-    if (i != operands_size - 1) {
+    if (i != number_of_operands - 1) {
       os << ", ";
     }
   }
   return os;
 }
 
 
 std::ostream& operator<<(std::ostream& os, const Bytecode& bytecode) {
   return os << Bytecodes::ToString(bytecode);
 }
@@ skipping 37 matching lines @@
 uint8_t Register::ToOperand() const { return static_cast<uint8_t>(-index_); }
 
 
 Register Register::FromOperand(uint8_t operand) {
   return Register(-static_cast<int8_t>(operand));
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8