[Interpreter]: Add kRegList operand type for register list operands.

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
index b47c0e281a4989ba04a8cfd9f01df307f88a2235..49751897ee8a46608829be148fdb2ae153b4835a 100644
--- a/src/interpreter/bytecode-decoder.cc
+++ b/src/interpreter/bytecode-decoder.cc
@@ -23,6 +23,15 @@ Register BytecodeDecoder::DecodeRegisterOperand(const uint8_t* operand_start,
 }
 
 // static
+RegisterList BytecodeDecoder::DecodeRegisterListOperand(
+    const uint8_t* operand_start, uint32_t count, OperandType operand_type,
+    OperandScale operand_scale) {
+  Register first_reg =
+      DecodeRegisterOperand(operand_start, operand_type, operand_scale);
+  return RegisterList(first_reg.index(), static_cast<int>(count));
+}
+
+// static
 int32_t BytecodeDecoder::DecodeSignedOperand(const uint8_t* operand_start,
                                              OperandType operand_type,
                                              OperandScale operand_scale) {
@@ -94,7 +103,6 @@ std::ostream& BytecodeDecoder::Decode(std::ostream& os,
   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 =
@@ -102,10 +110,6 @@ std::ostream& BytecodeDecoder::Decode(std::ostream& os,
     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::kUImm:
       case interpreter::OperandType::kRuntimeId:
@@ -122,7 +126,6 @@ std::ostream& BytecodeDecoder::Decode(std::ostream& os,
         os << "#"
            << DecodeUnsignedOperand(operand_start, op_type, operand_scale);
         break;
-      case interpreter::OperandType::kMaybeReg:
       case interpreter::OperandType::kReg:
       case interpreter::OperandType::kRegOut: {
         Register reg =
@@ -130,19 +133,40 @@ std::ostream& BytecodeDecoder::Decode(std::ostream& os,
         os << reg.ToString(parameter_count);
         break;
       }
-      case interpreter::OperandType::kRegOutTriple:
-        range += 1;
+      case interpreter::OperandType::kRegOutTriple: {
+        RegisterList reg_list =
+            DecodeRegisterListOperand(operand_start, 3, op_type, operand_scale);
+        os << reg_list.first_register().ToString(parameter_count) << "-"
+           << reg_list.last_register().ToString(parameter_count);
+        break;
+      }
       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);
+        RegisterList reg_list =
+            DecodeRegisterListOperand(operand_start, 2, op_type, operand_scale);
+        os << reg_list.first_register().ToString(parameter_count) << "-"
+           << reg_list.last_register().ToString(parameter_count);
+        break;
+      }
+      case interpreter::OperandType::kRegList: {
+        DCHECK_LT(i, number_of_operands - 1);
+        DCHECK_EQ(Bytecodes::GetOperandType(bytecode, i + 1),
+                  OperandType::kRegCount);
+        int reg_count_offset =
+            Bytecodes::GetOperandOffset(bytecode, i + 1, operand_scale);
+        const uint8_t* reg_count_operand =
+            &bytecode_start[prefix_offset + reg_count_offset];
+        uint32_t count = DecodeUnsignedOperand(
+            reg_count_operand, OperandType::kRegCount, operand_scale);
+        RegisterList reg_list = DecodeRegisterListOperand(
+            operand_start, count, op_type, operand_scale);
+        os << reg_list.first_register().ToString(parameter_count) << "-"
+           << reg_list.last_register().ToString(parameter_count);
+        i++;  // Skip kRegCount.
         break;
       }
       case interpreter::OperandType::kNone:
+      case interpreter::OperandType::kRegCount:  // Dealt with in kRegList.
         UNREACHABLE();
         break;
     }