[interpreter] Reduce move operations for wide register support.

Introduces the concept of transfer direction to register operands. This
enables the register translator to emit exactly the moves that a
bytecode having it's register operands translated needs.

BUG=v8:4280,v8:4675
LOG=N

Review URL: https://codereview.chromium.org/1633153002

Cr-Commit-Position: refs/heads/master@{#33544}

src/compiler/interpreter-assembler.cc

@@ -305,31 +305,18 @@ Node* InterpreterAssembler::BytecodeOperandIdx(int operand_index) {
 
 
 Node* InterpreterAssembler::BytecodeOperandReg(int operand_index) {
-  switch (interpreter::Bytecodes::GetOperandType(bytecode_, operand_index)) {
-    case interpreter::OperandType::kMaybeReg8:
-    case interpreter::OperandType::kReg8:
-    case interpreter::OperandType::kRegPair8:
-    case interpreter::OperandType::kRegTriple8:
-      DCHECK_EQ(
-          interpreter::OperandSize::kByte,
-          interpreter::Bytecodes::GetOperandSize(bytecode_, operand_index));
+  interpreter::OperandType operand_type =
+      interpreter::Bytecodes::GetOperandType(bytecode_, operand_index);
+  if (interpreter::Bytecodes::IsRegisterOperandType(operand_type)) {
+    interpreter::OperandSize operand_size =
+        interpreter::Bytecodes::SizeOfOperand(operand_type);
+    if (operand_size == interpreter::OperandSize::kByte) {
       return BytecodeOperandSignExtended(operand_index);
-    case interpreter::OperandType::kMaybeReg16:
-    case interpreter::OperandType::kReg16:
-    case interpreter::OperandType::kRegPair16:
-    case interpreter::OperandType::kRegTriple16:
-      DCHECK_EQ(
-          interpreter::OperandSize::kShort,
-          interpreter::Bytecodes::GetOperandSize(bytecode_, operand_index));
+    } else if (operand_size == interpreter::OperandSize::kShort) {
       return BytecodeOperandShortSignExtended(operand_index);
-    case interpreter::OperandType::kNone:
-    case interpreter::OperandType::kIdx8:
-    case interpreter::OperandType::kIdx16:
-    case interpreter::OperandType::kImm8:
-    case interpreter::OperandType::kRegCount8:
-    case interpreter::OperandType::kRegCount16:
-      UNREACHABLE();
+    }
   }
+  UNREACHABLE();
   return nullptr;
 }
 

src/interpreter/bytecode-array-builder.cc

@@ -401,25 +401,6 @@ void BytecodeArrayBuilder::MoveRegisterUntranslated(Register from,
   Output(Bytecode::kMovWide, from.ToRawOperand(), to.ToRawOperand());
 }
 
-bool BytecodeArrayBuilder::RegisterOperandIsMovable(Bytecode bytecode,
-                                                    int operand_index) {
-  // By design, we only support moving individual registers. There
-  // should be wide variants of such bytecodes instead to avoid the
-  // need for a large translation window.
-  OperandType operand_type = Bytecodes::GetOperandType(bytecode, operand_index);
-  if (operand_type != OperandType::kReg8 &&
-      operand_type != OperandType::kReg16) {
-    return false;
-  } else if (operand_index + 1 == Bytecodes::NumberOfOperands(bytecode)) {
-    return true;
-  } else {
-    OperandType next_operand_type =
-        Bytecodes::GetOperandType(bytecode, operand_index + 1);
-    return (next_operand_type != OperandType::kRegCount8 &&
-            next_operand_type != OperandType::kRegCount16);
-  }
-}
-
 BytecodeArrayBuilder& BytecodeArrayBuilder::LoadGlobal(
     const Handle<String> name, int feedback_slot, LanguageMode language_mode,
     TypeofMode typeof_mode) {
@@ -1413,8 +1394,11 @@ bool BytecodeArrayBuilder::OperandIsValid(Bytecode bytecode, int operand_index,
       }
     // Fall-through to kReg8 case.
     case OperandType::kReg8:
+    case OperandType::kRegOut8:
       return RegisterIsValid(Register::FromRawOperand(operand_value),
                              operand_type);
+    case OperandType::kRegOutPair8:
+    case OperandType::kRegOutPair16:
     case OperandType::kRegPair8:
     case OperandType::kRegPair16: {
       Register reg0 = Register::FromRawOperand(operand_value);
@@ -1422,8 +1406,8 @@ bool BytecodeArrayBuilder::OperandIsValid(Bytecode bytecode, int operand_index,
       return RegisterIsValid(reg0, operand_type) &&
              RegisterIsValid(reg1, operand_type);
     }
-    case OperandType::kRegTriple8:
-    case OperandType::kRegTriple16: {
+    case OperandType::kRegOutTriple8:
+    case OperandType::kRegOutTriple16: {
       Register reg0 = Register::FromRawOperand(operand_value);
       Register reg1 = Register(reg0.index() + 1);
       Register reg2 = Register(reg0.index() + 2);
@@ -1436,7 +1420,8 @@ bool BytecodeArrayBuilder::OperandIsValid(Bytecode bytecode, int operand_index,
         return true;
       }
     // Fall-through to kReg16 case.
-    case OperandType::kReg16: {
+    case OperandType::kReg16:
+    case OperandType::kRegOut16: {
       Register reg = Register::FromRawOperand(operand_value);
       return RegisterIsValid(reg, operand_type);
     }

src/interpreter/bytecode-array-builder.h

@@ -281,9 +281,8 @@ class BytecodeArrayBuilder final : private RegisterMover {
   static bool FitsInReg16Operand(Register value);
   static bool FitsInReg16OperandUntranslated(Register value);
 
-  // RegisterMover interface methods.
+  // RegisterMover interface.
   void MoveRegisterUntranslated(Register from, Register to) override;
-  bool RegisterOperandIsMovable(Bytecode bytecode, int operand_index) override;
 
   static Bytecode GetJumpWithConstantOperand(Bytecode jump_smi8_operand);
   static Bytecode GetJumpWithConstantWideOperand(Bytecode jump_smi8_operand);

src/interpreter/bytecode-array-iterator.cc

@@ -87,11 +87,7 @@ int BytecodeArrayIterator::GetIndexOperand(int operand_index) const {
 Register BytecodeArrayIterator::GetRegisterOperand(int operand_index) const {
   OperandType operand_type =
       Bytecodes::GetOperandType(current_bytecode(), operand_index);
-  DCHECK(operand_type == OperandType::kReg8 ||
-         operand_type == OperandType::kRegPair8 ||
-         operand_type == OperandType::kRegTriple8 ||
-         operand_type == OperandType::kMaybeReg8 ||
-         operand_type == OperandType::kReg16);
+  DCHECK(Bytecodes::IsRegisterOperandType(operand_type));
   uint32_t operand = GetRawOperand(operand_index, operand_type);
   switch (Bytecodes::GetOperandSize(current_bytecode(), operand_index)) {
     case OperandSize::kByte:

src/interpreter/bytecodes.cc

@@ -262,6 +262,58 @@ bool Bytecodes::IsJumpOrReturn(Bytecode bytecode) {
   return bytecode == Bytecode::kReturn || IsJump(bytecode);
 }
 
+// static
+bool Bytecodes::IsRegisterOperandType(OperandType operand_type) {
+  switch (operand_type) {
+#define CASE(Name, _)        \
+  case OperandType::k##Name: \
+    return true;
+    REGISTER_OPERAND_TYPE_LIST(CASE)
+#undef CASE
+#define CASE(Name, _)        \
+  case OperandType::k##Name: \
+    break;
+    NON_REGISTER_OPERAND_TYPE_LIST(CASE)
+#undef CASE
+  }
+  return false;
+}
+
+// static
+bool Bytecodes::IsRegisterInputOperandType(OperandType operand_type) {
+  switch (operand_type) {
+#define CASE(Name, _)        \
+  case OperandType::k##Name: \
+    return true;
+    REGISTER_INPUT_OPERAND_TYPE_LIST(CASE)
+#undef CASE
+#define CASE(Name, _)        \
+  case OperandType::k##Name: \
+    break;
+    NON_REGISTER_OPERAND_TYPE_LIST(CASE)
+    REGISTER_OUTPUT_OPERAND_TYPE_LIST(CASE)
+#undef CASE
+  }
+  return false;
+}
+
+// static
+bool Bytecodes::IsRegisterOutputOperandType(OperandType operand_type) {
+  switch (operand_type) {
+#define CASE(Name, _)        \
+  case OperandType::k##Name: \
+    return true;
+    REGISTER_OUTPUT_OPERAND_TYPE_LIST(CASE)
+#undef CASE
+#define CASE(Name, _)        \
+  case OperandType::k##Name: \
+    break;
+    NON_REGISTER_OPERAND_TYPE_LIST(CASE)
+    REGISTER_INPUT_OPERAND_TYPE_LIST(CASE)
+#undef CASE
+  }
+  return false;
+}
 
 namespace {
 static Register DecodeRegister(const uint8_t* operand_start,
@@ -300,6 +352,7 @@ std::ostream& Bytecodes::Decode(std::ostream& os, const uint8_t* bytecode_start,
   os << bytecode << " ";
 
   int number_of_operands = NumberOfOperands(bytecode);
+  int range = 0;
   for (int i = 0; i < number_of_operands; i++) {
     OperandType op_type = GetOperandType(bytecode, i);
     const uint8_t* operand_start =
@@ -323,7 +376,9 @@ std::ostream& Bytecodes::Decode(std::ostream& os, const uint8_t* bytecode_start,
       case interpreter::OperandType::kMaybeReg8:
       case interpreter::OperandType::kMaybeReg16:
       case interpreter::OperandType::kReg8:
-      case interpreter::OperandType::kReg16: {
+      case interpreter::OperandType::kReg16:
+      case interpreter::OperandType::kRegOut8:
+      case interpreter::OperandType::kRegOut16: {
         Register reg = DecodeRegister(operand_start, op_type);
         if (reg.is_current_context()) {
           os << "<context>";
@@ -343,12 +398,15 @@ std::ostream& Bytecodes::Decode(std::ostream& os, const uint8_t* bytecode_start,
         }
         break;
       }
+      case interpreter::OperandType::kRegOutTriple8:
+      case interpreter::OperandType::kRegOutTriple16:
+        range += 1;
+      case interpreter::OperandType::kRegOutPair8:
+      case interpreter::OperandType::kRegOutPair16:
       case interpreter::OperandType::kRegPair8:
-      case interpreter::OperandType::kRegTriple8:
-      case interpreter::OperandType::kRegPair16:
-      case interpreter::OperandType::kRegTriple16: {
+      case interpreter::OperandType::kRegPair16: {
+        range += 1;
         Register reg = DecodeRegister(operand_start, op_type);
-        int range = op_type == interpreter::OperandType::kRegPair8 ? 1 : 2;
         if (reg.is_parameter()) {
           int parameter_index = reg.ToParameterIndex(parameter_count);
           DCHECK_GT(parameter_index, 0);
@@ -456,7 +514,6 @@ bool Register::is_new_target() const {
   return index() == kNewTargetRegisterIndex;
 }
 
-
 int Register::MaxParameterIndex() { return kMaxParameterIndex; }
 
 int Register::MaxRegisterIndex() { return kMaxRegisterIndex; }

src/interpreter/bytecodes.h

@@ -18,17 +18,25 @@ namespace interpreter {
 #define INVALID_OPERAND_TYPE_LIST(V) \
   V(None, OperandSize::kNone)
 
-#define REGISTER_OPERAND_TYPE_LIST(V) \
-  /* Byte operands. */                \
-  V(MaybeReg8, OperandSize::kByte)    \
-  V(Reg8, OperandSize::kByte)         \
-  V(RegPair8, OperandSize::kByte)     \
-  V(RegTriple8, OperandSize::kByte)   \
-  /* Short operands. */               \
-  V(MaybeReg16, OperandSize::kShort)  \
-  V(Reg16, OperandSize::kShort)       \
-  V(RegPair16, OperandSize::kShort)   \
-  V(RegTriple16, OperandSize::kShort)
+#define REGISTER_INPUT_OPERAND_TYPE_LIST(V) \
+  /* Byte operands. */                      \
+  V(MaybeReg8, OperandSize::kByte)          \
+  V(Reg8, OperandSize::kByte)               \
+  V(RegPair8, OperandSize::kByte)           \
+  /* Short operands. */                     \
+  V(MaybeReg16, OperandSize::kShort)        \
+  V(Reg16, OperandSize::kShort)             \
+  V(RegPair16, OperandSize::kShort)
+
+#define REGISTER_OUTPUT_OPERAND_TYPE_LIST(V) \
+  /* Byte operands. */                       \
+  V(RegOut8, OperandSize::kByte)             \
+  V(RegOutPair8, OperandSize::kByte)         \
+  V(RegOutTriple8, OperandSize::kByte)       \
+  /* Short operands. */                      \
+  V(RegOut16, OperandSize::kShort)           \
+  V(RegOutPair16, OperandSize::kShort)       \
+  V(RegOutTriple16, OperandSize::kShort)
 
 #define SCALAR_OPERAND_TYPE_LIST(V) \
   /* Byte operands. */              \
@@ -39,12 +47,19 @@ namespace interpreter {
   V(Idx16, OperandSize::kShort)     \
   V(RegCount16, OperandSize::kShort)
 
-// The list of operand types used by bytecodes.
-#define OPERAND_TYPE_LIST(V)    \
-  INVALID_OPERAND_TYPE_LIST(V)  \
-  REGISTER_OPERAND_TYPE_LIST(V) \
+#define REGISTER_OPERAND_TYPE_LIST(V) \
+  REGISTER_INPUT_OPERAND_TYPE_LIST(V) \
+  REGISTER_OUTPUT_OPERAND_TYPE_LIST(V)
+
+#define NON_REGISTER_OPERAND_TYPE_LIST(V) \
+  INVALID_OPERAND_TYPE_LIST(V)            \
   SCALAR_OPERAND_TYPE_LIST(V)
 
+// The list of operand types used by bytecodes.
+#define OPERAND_TYPE_LIST(V)        \
+  NON_REGISTER_OPERAND_TYPE_LIST(V) \
+  REGISTER_OPERAND_TYPE_LIST(V)
+
 // The list of bytecodes which are interpreted by the interpreter.
 #define BYTECODE_LIST(V)                                                       \
                                                                                \
@@ -93,11 +108,11 @@ namespace interpreter {
                                                                                \
   /* Register-accumulator transfers */                                         \
   V(Ldar, OperandType::kReg8)                                                  \
-  V(Star, OperandType::kReg8)                                                  \
+  V(Star, OperandType::kRegOut8)                                               \
                                                                                \
   /* Register-register transfers */                                            \
-  V(Mov, OperandType::kReg8, OperandType::kReg8)                               \
-  V(MovWide, OperandType::kReg16, OperandType::kReg16)                         \
+  V(Mov, OperandType::kReg8, OperandType::kRegOut8)                            \
+  V(MovWide, OperandType::kReg16, OperandType::kRegOut16)                      \
                                                                                \
   /* LoadIC operations */                                                      \
   V(LoadICSloppy, OperandType::kReg8, OperandType::kIdx8, OperandType::kIdx8)  \
@@ -159,9 +174,9 @@ namespace interpreter {
   V(CallRuntimeWide, OperandType::kIdx16, OperandType::kMaybeReg16,            \
     OperandType::kRegCount8)                                                   \
   V(CallRuntimeForPair, OperandType::kIdx16, OperandType::kMaybeReg8,          \
-    OperandType::kRegCount8, OperandType::kRegPair8)                           \
+    OperandType::kRegCount8, OperandType::kRegOutPair8)                        \
   V(CallRuntimeForPairWide, OperandType::kIdx16, OperandType::kMaybeReg16,     \
-    OperandType::kRegCount8, OperandType::kRegPair16)                          \
+    OperandType::kRegCount8, OperandType::kRegOutPair16)                       \
   V(CallJSRuntime, OperandType::kIdx16, OperandType::kReg8,                    \
     OperandType::kRegCount8)                                                   \
   V(CallJSRuntimeWide, OperandType::kIdx16, OperandType::kReg16,               \
@@ -235,8 +250,8 @@ namespace interpreter {
   V(JumpIfUndefinedConstantWide, OperandType::kIdx16)                          \
                                                                                \
   /* Complex flow control For..in */                                           \
-  V(ForInPrepare, OperandType::kRegTriple8)                                    \
-  V(ForInPrepareWide, OperandType::kRegTriple16)                               \
+  V(ForInPrepare, OperandType::kRegOutTriple8)                                 \
+  V(ForInPrepareWide, OperandType::kRegOutTriple16)                            \
   V(ForInDone, OperandType::kReg8, OperandType::kReg8)                         \
   V(ForInNext, OperandType::kReg8, OperandType::kReg8, OperandType::kRegPair8) \
   V(ForInNextWide, OperandType::kReg16, OperandType::kReg16,                   \
@@ -248,7 +263,6 @@ namespace interpreter {
   V(ReThrow, OperandType::kNone)                                               \
   V(Return, OperandType::kNone)
 
-
 // Enumeration of the size classes of operand types used by bytecodes.
 enum class OperandSize : uint8_t {
   kNone = 0,
@@ -382,10 +396,10 @@ class Bytecodes {
   // Returns the number of register operands expected by |bytecode|.
   static int NumberOfRegisterOperands(Bytecode bytecode);
 
-  // Return the i-th operand of |bytecode|.
+  // Returns the i-th operand of |bytecode|.
   static OperandType GetOperandType(Bytecode bytecode, int i);
 
-  // Return the size of the i-th operand of |bytecode|.
+  // Returns the size of the i-th operand of |bytecode|.
   static OperandSize GetOperandSize(Bytecode bytecode, int i);
 
   // Returns the offset of the i-th operand of |bytecode| relative to the start
@@ -430,13 +444,22 @@ class Bytecodes {
   // constant pool entry (OperandType::kIdx16).
   static bool IsJumpConstantWide(Bytecode bytecode);
 
-  // Return true if the bytecode is a jump or conditional jump taking
+  // Returns true if the bytecode is a jump or conditional jump taking
   // any kind of operand.
   static bool IsJump(Bytecode bytecode);
 
-  // Return true if the bytecode is a conditional jump, a jump, or a return.
+  // Returns true if the bytecode is a conditional jump, a jump, or a return.
   static bool IsJumpOrReturn(Bytecode bytecode);
 
+  // Returns true if |operand_type| is any type of register operand.
+  static bool IsRegisterOperandType(OperandType operand_type);
+
+  // Returns true if |operand_type| represents a register used as an input.
+  static bool IsRegisterInputOperandType(OperandType operand_type);
+
+  // Returns true if |operand_type| represents a register used as an output.
+  static bool IsRegisterOutputOperandType(OperandType operand_type);
+
   // Decode a single bytecode and operands to |os|.
   static std::ostream& Decode(std::ostream& os, const uint8_t* bytecode_start,
                               int number_of_parameters);

src/interpreter/register-translator.cc

@@ -11,7 +11,10 @@ namespace internal {
 namespace interpreter {
 
 RegisterTranslator::RegisterTranslator(RegisterMover* mover)
-    : mover_(mover), emitting_moves_(false), window_registers_count_(0) {}
+    : mover_(mover),
+      emitting_moves_(false),
+      window_registers_count_(0),
+      output_moves_count_(0) {}
 
 void RegisterTranslator::TranslateInputRegisters(Bytecode bytecode,
                                                  uint32_t* raw_operands,
@@ -29,6 +32,7 @@ void RegisterTranslator::TranslateInputRegisters(Bytecode bytecode,
       Register out_reg = TranslateAndMove(bytecode, i, in_reg);
       raw_operands[i] = out_reg.ToRawOperand();
     }
+    window_registers_count_ = 0;
     emitting_moves_ = false;
   } else {
     // When the register translator is translating registers, it will
@@ -42,49 +46,70 @@ void RegisterTranslator::TranslateInputRegisters(Bytecode bytecode,
 
 Register RegisterTranslator::TranslateAndMove(Bytecode bytecode,
                                               int operand_index, Register reg) {
+  if (FitsInReg8Operand(reg)) {
+    return reg;
+  }
+
   OperandType operand_type = Bytecodes::GetOperandType(bytecode, operand_index);
+  OperandSize operand_size = Bytecodes::SizeOfOperand(operand_type);
+  if (operand_size == OperandSize::kShort) {
+    CHECK(FitsInReg16Operand(reg));
+    return Translate(reg);
+  }
+
+  CHECK((operand_type == OperandType::kReg8 ||
+         operand_type == OperandType::kRegOut8) &&
+        RegisterIsMovableToWindow(bytecode, operand_index));
   Register translated_reg = Translate(reg);
-  Register addressable_reg = MakeAddressable(translated_reg, operand_type);
-  if (addressable_reg != translated_reg) {
-    CHECK(operand_type == OperandType::kReg8 &&
-          mover()->RegisterOperandIsMovable(bytecode, operand_index));
-    mover()->MoveRegisterUntranslated(translated_reg, addressable_reg);
+  Register window_reg(kTranslationWindowStart + window_registers_count_);
+  window_registers_count_ += 1;
+  if (Bytecodes::IsRegisterInputOperandType(operand_type)) {
+    DCHECK(!Bytecodes::IsRegisterOutputOperandType(operand_type));
+    mover()->MoveRegisterUntranslated(translated_reg, window_reg);
+  } else if (Bytecodes::IsRegisterOutputOperandType(operand_type)) {
+    DCHECK_LT(output_moves_count_, kTranslationWindowLength);
+    output_moves_[output_moves_count_] =
+        std::make_pair(window_reg, translated_reg);
+    output_moves_count_ += 1;
+  } else {
+    UNREACHABLE();
+  }
+  return window_reg;
+}
+
+// static
+bool RegisterTranslator::RegisterIsMovableToWindow(Bytecode bytecode,
+                                                   int operand_index) {
+  // By design, we only support moving individual registers. There
+  // should be wide variants of such bytecodes instead to avoid the
+  // need for a large translation window.
+  OperandType operand_type = Bytecodes::GetOperandType(bytecode, operand_index);
+  if (operand_type != OperandType::kReg8 &&
+      operand_type != OperandType::kRegOut8) {
+    return false;
+  } else if (operand_index + 1 == Bytecodes::NumberOfOperands(bytecode)) {
+    return true;
+  } else {
+    OperandType next_operand_type =
+        Bytecodes::GetOperandType(bytecode, operand_index + 1);
+    return (next_operand_type != OperandType::kRegCount8 &&
+            next_operand_type != OperandType::kRegCount16);
   }
-  return addressable_reg;
 }
 
 void RegisterTranslator::TranslateOutputRegisters() {
   if (!emitting_moves_) {
     emitting_moves_ = true;
-    while (window_registers_count_ > 0) {
-      window_registers_count_ -= 1;
-      Register source(kTranslationWindowStart + window_registers_count_);
-      Register destination = window_registers_[window_registers_count_];
-      mover()->MoveRegisterUntranslated(source, destination);
+    while (output_moves_count_ > 0) {
+      output_moves_count_ -= 1;
+      mover()->MoveRegisterUntranslated(
+          output_moves_[output_moves_count_].first,
+          output_moves_[output_moves_count_].second);
     }
     emitting_moves_ = false;
   }
 }
 
-Register RegisterTranslator::MakeAddressable(Register reg,
-                                             OperandType reg_type) {
-  DCHECK(!InTranslationWindow(reg));
-  OperandSize reg_size = Bytecodes::SizeOfOperand(reg_type);
-  if (reg_size == OperandSize::kByte && !FitsInReg8Operand(reg)) {
-    // TODO(oth): Moves into and out from translation window could be
-    // decoupled if there were metadata to say whether the register
-    // operand was an input, output, or input-and-output for a given
-    // bytecode.
-    Register destination(kTranslationWindowStart + window_registers_count_);
-    window_registers_[window_registers_count_] = reg;
-    window_registers_count_ += 1;
-    DCHECK_LE(window_registers_count_, kTranslationWindowLength);
-    return destination;
-  } else {
-    return reg;
-  }
-}
-
 // static
 Register RegisterTranslator::Translate(Register reg) {
   if (reg.index() >= kTranslationWindowStart) {

src/interpreter/register-translator.h

@@ -77,7 +77,8 @@ class RegisterTranslator final {
       kTranslationWindowLimit - kTranslationWindowLength + 1;
 
   Register TranslateAndMove(Bytecode bytecode, int operand_index, Register reg);
-  Register MakeAddressable(Register reg, OperandType reg_type);
+  static bool RegisterIsMovableToWindow(Bytecode bytecode, int operand_index);
+
   static Register Translate(Register reg);
 
   RegisterMover* mover() const { return mover_; }
@@ -90,9 +91,12 @@ class RegisterTranslator final {
   // translation.
   bool emitting_moves_;
 
-  // State for restoring registers after bytecode.
-  Register window_registers_[kTranslationWindowLength];
+  // Number of window registers in use.
   int window_registers_count_;
+
+  // State for restoring register moves emitted by TranslateOutputRegisters.
+  std::pair<Register, Register> output_moves_[kTranslationWindowLength];
+  int output_moves_count_;
 };
 
 // Interface for RegisterTranslator helper class that will emit
@@ -106,11 +110,6 @@ class RegisterMover {
   // of this method must be aware that register moves with bad
   // register values are a security hole.
   virtual void MoveRegisterUntranslated(Register from, Register to) = 0;
-
-  // Returns true if the register operand can be moved into the
-  // translation window.
-  virtual bool RegisterOperandIsMovable(Bytecode bytecode,
-                                        int operand_index) = 0;
 };
 
 }  // namespace interpreter

test/unittests/compiler/interpreter-assembler-unittest.cc

@@ -350,8 +350,10 @@ TARGET_TEST_F(InterpreterAssemblerTest, BytecodeOperand) {
           break;
         case interpreter::OperandType::kMaybeReg8:
         case interpreter::OperandType::kReg8:
+        case interpreter::OperandType::kRegOut8:
+        case interpreter::OperandType::kRegOutPair8:
+        case interpreter::OperandType::kRegOutTriple8:
         case interpreter::OperandType::kRegPair8:
-        case interpreter::OperandType::kRegTriple8:
           EXPECT_THAT(m.BytecodeOperandReg(i),
                       m.IsBytecodeOperandSignExtended(offset));
           break;
@@ -365,8 +367,10 @@ TARGET_TEST_F(InterpreterAssemblerTest, BytecodeOperand) {
           break;
         case interpreter::OperandType::kMaybeReg16:
         case interpreter::OperandType::kReg16:
+        case interpreter::OperandType::kRegOut16:
+        case interpreter::OperandType::kRegOutPair16:
+        case interpreter::OperandType::kRegOutTriple16:
         case interpreter::OperandType::kRegPair16:
-        case interpreter::OperandType::kRegTriple16:
           EXPECT_THAT(m.BytecodeOperandReg(i),
                       m.IsBytecodeOperandShortSignExtended(offset));
           break;

test/unittests/interpreter/bytecodes-unittest.cc

@@ -43,7 +43,6 @@ TEST(OperandConversion, Registers) {
   }
 }
 
-
 TEST(OperandConversion, Parameters) {
   int parameter_counts[] = {7, 13, 99};
 
@@ -59,7 +58,6 @@ TEST(OperandConversion, Parameters) {
   }
 }
 
-
 TEST(OperandConversion, RegistersParametersNoOverlap) {
   int register_count = Register::MaxRegisterIndex() + 1;
   int parameter_count = Register::MaxParameterIndex() + 1;
@@ -118,6 +116,46 @@ TEST(Bytecodes, RegisterOperandBitmaps) {
   CHECK_EQ(Bytecodes::GetRegisterOperandBitmap(Bytecode::kForInNext), 7);
 }
 
+TEST(Bytecodes, RegisterOperands) {
+  CHECK(Bytecodes::IsRegisterOperandType(OperandType::kReg8));
+  CHECK(Bytecodes::IsRegisterInputOperandType(OperandType::kReg8));
+  CHECK(!Bytecodes::IsRegisterOutputOperandType(OperandType::kReg8));
+  CHECK(!Bytecodes::IsRegisterInputOperandType(OperandType::kRegOut8));
+  CHECK(Bytecodes::IsRegisterOutputOperandType(OperandType::kRegOut8));
+
+#define IS_REGISTER_OPERAND_TYPE(Name, _) \
+  CHECK(Bytecodes::IsRegisterOperandType(OperandType::k##Name));
+  REGISTER_OPERAND_TYPE_LIST(IS_REGISTER_OPERAND_TYPE)
+#undef IS_REGISTER_OPERAND_TYPE
+
+#define IS_NOT_REGISTER_OPERAND_TYPE(Name, _) \
+  CHECK(!Bytecodes::IsRegisterOperandType(OperandType::k##Name));
+  NON_REGISTER_OPERAND_TYPE_LIST(IS_NOT_REGISTER_OPERAND_TYPE)
+#undef IS_NOT_REGISTER_OPERAND_TYPE
+
+#define IS_REGISTER_INPUT_OPERAND_TYPE(Name, _) \
+  CHECK(Bytecodes::IsRegisterInputOperandType(OperandType::k##Name));
+  REGISTER_INPUT_OPERAND_TYPE_LIST(IS_REGISTER_INPUT_OPERAND_TYPE)
+#undef IS_REGISTER_INPUT_OPERAND_TYPE
+
+#define IS_NOT_REGISTER_INPUT_OPERAND_TYPE(Name, _) \
+  CHECK(!Bytecodes::IsRegisterInputOperandType(OperandType::k##Name));
+  NON_REGISTER_OPERAND_TYPE_LIST(IS_NOT_REGISTER_INPUT_OPERAND_TYPE);
+  REGISTER_OUTPUT_OPERAND_TYPE_LIST(IS_NOT_REGISTER_INPUT_OPERAND_TYPE)
+#undef IS_NOT_REGISTER_INPUT_OPERAND_TYPE
+
+#define IS_REGISTER_OUTPUT_OPERAND_TYPE(Name, _) \
+  CHECK(Bytecodes::IsRegisterOutputOperandType(OperandType::k##Name));
+  REGISTER_OUTPUT_OPERAND_TYPE_LIST(IS_REGISTER_OUTPUT_OPERAND_TYPE)
+#undef IS_REGISTER_OUTPUT_OPERAND_TYPE
+
+#define IS_NOT_REGISTER_OUTPUT_OPERAND_TYPE(Name, _) \
+  CHECK(!Bytecodes::IsRegisterOutputOperandType(OperandType::k##Name));
+  NON_REGISTER_OPERAND_TYPE_LIST(IS_NOT_REGISTER_OUTPUT_OPERAND_TYPE)
+  REGISTER_INPUT_OPERAND_TYPE_LIST(IS_NOT_REGISTER_OUTPUT_OPERAND_TYPE)
+#undef IS_NOT_REGISTER_INPUT_OPERAND_TYPE
+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8

test/unittests/interpreter/register-translator-unittest.cc

@@ -27,10 +27,14 @@ class RegisterTranslatorTest : public TestWithIsolateAndZone,
   ~RegisterTranslatorTest() override {}
 
   bool PopMoveAndMatch(Register from, Register to) {
-    CHECK(from.is_valid() && to.is_valid());
-    const std::pair<Register, Register> top = moves_.top();
-    moves_.pop();
-    return top.first == from && top.second == to;
+    if (!moves_.empty()) {
+      CHECK(from.is_valid() && to.is_valid());
+      const std::pair<Register, Register> top = moves_.top();
+      moves_.pop();
+      return top.first == from && top.second == to;
+    } else {
+      return false;
+    }
   }
 
   int move_count() const { return move_count_; }
@@ -49,23 +53,6 @@ class RegisterTranslatorTest : public TestWithIsolateAndZone,
     move_count_++;
   }
 
-  bool RegisterOperandIsMovable(Bytecode bytecode, int operand_index) override {
-    OperandType operand_type =
-        Bytecodes::GetOperandType(bytecode, operand_index);
-    if (operand_type == OperandType::kReg8 ||
-        operand_type == OperandType::kReg16) {
-      if (operand_index == Bytecodes::NumberOfOperands(bytecode) - 1) {
-        return true;
-      }
-      OperandType next_operand_type =
-          Bytecodes::GetOperandType(bytecode, operand_index + 1);
-      return (next_operand_type != OperandType::kRegCount8 &&
-              next_operand_type != OperandType::kRegCount16);
-    } else {
-      return false;
-    }
-  }
-
   RegisterTranslator translator_;
   std::stack<std::pair<Register, Register>> moves_;
   int move_count_;
@@ -74,7 +61,8 @@ class RegisterTranslatorTest : public TestWithIsolateAndZone,
 };
 
 const char* const RegisterTranslatorTest::kBadOperandRegex =
-    ".*OperandType::kReg8 && mover\\(\\)->RegisterOperandIsMovable.*";
+    ".*OperandType::kReg8 \\|\\| .*OperandType::kRegOut8\\) && "
+    "RegisterIsMovableToWindow.*";
 
 TEST_F(RegisterTranslatorTest, TestFrameSizeAdjustmentsForTranslationWindow) {
   EXPECT_EQ(0, RegisterTranslator::RegisterCountAdjustment(0, 0));
@@ -157,7 +145,7 @@ TEST_F(RegisterTranslatorTest, NoTranslationRequired) {
 
   Register param_reg = Register::FromParameterIndex(129, 130);
   operands[0] = param_reg.ToRawOperand();
-  translator()->TranslateInputRegisters(Bytecode::kLdar, operands, 1);
+  translator()->TranslateInputRegisters(Bytecode::kAdd, operands, 1);
   translator()->TranslateOutputRegisters();
   EXPECT_EQ(0, move_count());
 }
@@ -172,6 +160,14 @@ TEST_F(RegisterTranslatorTest, TranslationRequired) {
   EXPECT_EQ(1, move_count());
   EXPECT_TRUE(PopMoveAndMatch(local_reg_translated, window_reg));
   translator()->TranslateOutputRegisters();
+  EXPECT_EQ(1, move_count());
+  EXPECT_FALSE(PopMoveAndMatch(window_reg, local_reg_translated));
+
+  operands[0] = local_reg.ToRawOperand();
+  translator()->TranslateInputRegisters(Bytecode::kStar, operands, 1);
+  EXPECT_EQ(1, move_count());
+  EXPECT_FALSE(PopMoveAndMatch(local_reg_translated, window_reg));
+  translator()->TranslateOutputRegisters();
   EXPECT_EQ(2, move_count());
   EXPECT_TRUE(PopMoveAndMatch(window_reg, local_reg_translated));
 
@@ -181,6 +177,14 @@ TEST_F(RegisterTranslatorTest, TranslationRequired) {
   EXPECT_EQ(3, move_count());
   EXPECT_TRUE(PopMoveAndMatch(param_reg, window_reg));
   translator()->TranslateOutputRegisters();
+  EXPECT_EQ(3, move_count());
+  EXPECT_FALSE(PopMoveAndMatch(window_reg, param_reg));
+
+  operands[0] = {param_reg.ToRawOperand()};
+  translator()->TranslateInputRegisters(Bytecode::kStar, operands, 1);
+  EXPECT_EQ(3, move_count());
+  EXPECT_FALSE(PopMoveAndMatch(local_reg_translated, window_reg));
+  translator()->TranslateOutputRegisters();
   EXPECT_EQ(4, move_count());
   EXPECT_TRUE(PopMoveAndMatch(window_reg, param_reg));
 }