[interpreter] Introduce bytecode generation pipeline.

src/interpreter/bytecode-array-iterator.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/bytecode-array-iterator.h"
 
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 113 matching lines @@
       Bytecodes::GetOperandOffset(current_bytecode(), operand_index,
                                   current_operand_scale());
   return Bytecodes::DecodeRegisterOperand(operand_start, operand_type,
                                           current_operand_scale());
 }
 
 int BytecodeArrayIterator::GetRegisterOperandRange(int operand_index) const {
   interpreter::OperandType operand_type =
       Bytecodes::GetOperandType(current_bytecode(), operand_index);
   DCHECK(Bytecodes::IsRegisterOperandType(operand_type));
-  switch (operand_type) {
-    case OperandType::kRegPair:
-    case OperandType::kRegOutPair:
-      return 2;
-    case OperandType::kRegOutTriple:
-      return 3;
-    default: {
-      if (operand_index + 1 !=
-          Bytecodes::NumberOfOperands(current_bytecode())) {
-        OperandType next_operand_type =
-            Bytecodes::GetOperandType(current_bytecode(), operand_index + 1);
-        if (OperandType::kRegCount == next_operand_type) {
-          return GetRegisterCountOperand(operand_index + 1);
-        }
-      }
-      return 1;
-    }
+  int count = Bytecodes::GetNumberOfRegistersRepresentedBy(operand_type);
+  if (count == 1 &&

[rmcilroy, 2016/05/10 11:14:09]

nit - how about:

if (++operand_index < Bytecodes::NumberOfOperands(current_bytecode()) &&
    Bytecodes::GetOperandType(current_bytecode(), operand_index) ==
        OperandType::kRegCount) {
  DCHECK_EQ(1, Bytecodes::GetNumberOfRegistersRepresentedBy(operand_type));
  return GetRegisterCountOperand(operand_index);
} else {
  return Bytecodes::GetNumberOfRegistersRepresentedBy(operand_type);
}

[oth, 2016/05/11 13:17:30]

Updated to use GetOperandTypes instead.

+      ++operand_index < Bytecodes::NumberOfOperands(current_bytecode()) &&
+      Bytecodes::GetOperandType(current_bytecode(), operand_index) ==
+          OperandType::kRegCount) {
+    return GetRegisterCountOperand(operand_index);
+  } else {
+    return count;
   }
 }
 
 uint32_t BytecodeArrayIterator::GetRuntimeIdOperand(int operand_index) const {
   OperandType operand_type =
       Bytecodes::GetOperandType(current_bytecode(), operand_index);
   DCHECK(operand_type == OperandType::kRuntimeId);
   return GetUnsignedOperand(operand_index, operand_type);
 }
 
@@ skipping 15 matching lines @@
     return current_offset() + smi->value() + current_prefix_offset();
   } else {
     UNREACHABLE();
     return kMinInt;
   }
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8