[generators] Create the fixed array holding the registers only once.

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 1718 matching lines @@
 }
 
 // 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 = __ ExportRegisterFile();
+  Node* array =
+      __ LoadObjectField(generator, JSGeneratorObject::kOperandStackOffset);
   Node* context = __ GetContext();
   Node* state = __ GetAccumulator();
 
-  __ StoreObjectField(generator, JSGeneratorObject::kOperandStackOffset, array);
+  __ ExportRegisterFile(array);
   __ StoreObjectField(generator, JSGeneratorObject::kContextOffset, context);
   __ StoreObjectField(generator, JSGeneratorObject::kContinuationOffset, state);
 
   __ Dispatch();
 }
 
 // ResumeGenerator <generator>
 //
 // Imports the register file stored in the generator. Also loads the
 // generator's state and stores it in the accumulator, before overwriting it
 // with kGeneratorExecuting.
 void Interpreter::DoResumeGenerator(InterpreterAssembler* assembler) {
   Node* generator_reg = __ BytecodeOperandReg(0);
   Node* generator = __ LoadRegister(generator_reg);
 
   __ ImportRegisterFile(
       __ LoadObjectField(generator, JSGeneratorObject::kOperandStackOffset));
-  __ StoreObjectField(generator, JSGeneratorObject::kOperandStackOffset,
-      __ HeapConstant(isolate_->factory()->empty_fixed_array()));
 
   Node* old_state =
       __ LoadObjectField(generator, JSGeneratorObject::kContinuationOffset);
   Node* new_state = __ Int32Constant(JSGeneratorObject::kGeneratorExecuting);
   __ StoreObjectField(generator, JSGeneratorObject::kContinuationOffset,
       __ SmiTag(new_state));
   __ SetAccumulator(old_state);
 
   __ Dispatch();
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8