[interpreter] Introduce bytecode generation pipeline.

src/interpreter/bytecode-array-iterator.cc

Index: src/interpreter/bytecode-array-iterator.cc
diff --git a/src/interpreter/bytecode-array-iterator.cc b/src/interpreter/bytecode-array-iterator.cc
index a17efcb6ca4b5a36c240e32474fe0ef92834e96a..ec5e26b871c765f72afaf54d449103312711b946 100644
--- a/src/interpreter/bytecode-array-iterator.cc
+++ b/src/interpreter/bytecode-array-iterator.cc
@@ -131,23 +131,14 @@ 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;
   }
 }