[interpreter] Introduce bytecode generation pipeline.

src/interpreter/interpreter.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/interpreter.h"
 
 #include <fstream>
 
 #include "src/ast/prettyprinter.h"
 #include "src/code-factory.h"
@@ skipping 27 matching lines @@
 
   if (FLAG_trace_ignition_dispatches) {
     static const int kBytecodeCount = static_cast<int>(Bytecode::kLast) + 1;
     bytecode_dispatch_counters_table_.Reset(
         new uintptr_t[kBytecodeCount * kBytecodeCount]);
     memset(bytecode_dispatch_counters_table_.get(), 0,
            sizeof(uintptr_t) * kBytecodeCount * kBytecodeCount);
   }
 
   // Generate bytecode handlers for all bytecodes and scales.
-  for (OperandScale operand_scale = OperandScale::kSingle;
-       operand_scale <= OperandScale::kMaxValid;
-       operand_scale = Bytecodes::NextOperandScale(operand_scale)) {
+  const OperandScale kOperandScales[] = {
+#define VALUE(Name, _) OperandScale::k##Name,
+      OPERAND_SCALE_LIST(VALUE)
+#undef VALUE
+  };
+
+  for (OperandScale operand_scale : kOperandScales) {
 #define GENERATE_CODE(Name, ...)                                               \
   {                                                                            \
     if (Bytecodes::BytecodeHasHandler(Bytecode::k##Name, operand_scale)) {     \
       InterpreterAssembler assembler(isolate_, &zone, Bytecode::k##Name,       \
                                      operand_scale);                           \
       Do##Name(&assembler);                                                    \
       Handle<Code> code = assembler.GenerateCode();                            \
       size_t index = GetDispatchTableIndex(Bytecode::k##Name, operand_scale);  \
       dispatch_table_[index] = code->entry();                                  \
       TraceCodegen(code);                                                      \
@@ skipping 25 matching lines @@
   size_t index = GetDispatchTableIndex(bytecode, operand_scale);
   Address code_entry = dispatch_table_[index];
   return Code::GetCodeFromTargetAddress(code_entry);
 }
 
 // static
 size_t Interpreter::GetDispatchTableIndex(Bytecode bytecode,
                                           OperandScale operand_scale) {
   static const size_t kEntriesPerOperandScale = 1u << kBitsPerByte;
   size_t index = static_cast<size_t>(bytecode);
-  OperandScale current_scale = OperandScale::kSingle;
-  while (current_scale != operand_scale) {
-    index += kEntriesPerOperandScale;
-    current_scale = Bytecodes::NextOperandScale(current_scale);
+  switch (operand_scale) {
+    case OperandScale::kSingle:
+      return index;
+    case OperandScale::kDouble:
+      return index + kEntriesPerOperandScale;
+    case OperandScale::kQuadruple:
+      return index + 2 * kEntriesPerOperandScale;
   }
-  return index;
+  UNREACHABLE();
+  return 0;
 }
 
 void Interpreter::IterateDispatchTable(ObjectVisitor* v) {
   for (int i = 0; i < kDispatchTableSize; i++) {
     Address code_entry = dispatch_table_[i];
     Object* code = code_entry == nullptr
                        ? nullptr
                        : Code::GetCodeFromTargetAddress(code_entry);
     Object* old_code = code;
     v->VisitPointer(&code);
@@ skipping 1648 matching lines @@
   __ DispatchWide(OperandScale::kQuadruple);
 }
 
 // Illegal
 //
 // An invalid bytecode aborting execution if dispatched.
 void Interpreter::DoIllegal(InterpreterAssembler* assembler) {
   __ Abort(kInvalidBytecode);
 }
 
+// Nop
+//
+// No operation.
+void Interpreter::DoNop(InterpreterAssembler* assembler) { __ Dispatch(); }
+
 // SuspendGenerator <generator>
 //
 // Exports the register file and stores it into the generator.  Also stores the
 // current context and the state given in the accumulator into the generator.
 void Interpreter::DoSuspendGenerator(InterpreterAssembler* assembler) {
   Node* generator_reg = __ BytecodeOperandReg(0);
   Node* generator = __ LoadRegister(generator_reg);
 
   Node* array =
       __ LoadObjectField(generator, JSGeneratorObject::kOperandStackOffset);
@@ skipping 25 matching lines @@
   __ StoreObjectField(generator, JSGeneratorObject::kContinuationOffset,
       __ SmiTag(new_state));
   __ SetAccumulator(old_state);
 
   __ Dispatch();
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8