[Interpreter] Add support for context slot loads / stores to BytecodeGraphBuilder.

src/interpreter/bytecode-generator.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-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler.h"
 #include "src/interpreter/control-flow-builders.h"
 #include "src/objects.h"
@@ skipping 1310 matching lines @@
       int depth = execution_context()->ContextChainDepth(variable->scope());
       ContextScope* context = execution_context()->Previous(depth);
       Register context_reg;
       if (context) {
         context_reg = context->reg();
       } else {
         context_reg = execution_result()->NewRegister();
         // Walk the context chain to find the context at the given depth.
         // TODO(rmcilroy): Perform this work in a bytecode handler once we have
         // a generic mechanism for performing jumps in interpreter.cc.
+        // TODO(mythria): Also update bytecode graph builder with correct depth
+        // when this changes.
         builder()
             ->LoadAccumulatorWithRegister(execution_context()->reg())
             .StoreAccumulatorInRegister(context_reg);
         for (int i = 0; i < depth; ++i) {
           builder()
               ->LoadContextSlot(context_reg, Context::PREVIOUS_INDEX)
               .StoreAccumulatorInRegister(context_reg);
         }
       }
       builder()->LoadContextSlot(context_reg, variable->index());
@@ skipping 56 matching lines @@
       ContextScope* context = execution_context()->Previous(depth);
       Register context_reg;
       if (context) {
         context_reg = context->reg();
       } else {
         Register value_temp = execution_result()->NewRegister();
         context_reg = execution_result()->NewRegister();
         // Walk the context chain to find the context at the given depth.
         // TODO(rmcilroy): Perform this work in a bytecode handler once we have
         // a generic mechanism for performing jumps in interpreter.cc.
+        // TODO(mythria): Also update bytecode graph builder with correct depth
+        // when this changes.
         builder()
             ->StoreAccumulatorInRegister(value_temp)
             .LoadAccumulatorWithRegister(execution_context()->reg())
             .StoreAccumulatorInRegister(context_reg);
         for (int i = 0; i < depth; ++i) {
           builder()
               ->LoadContextSlot(context_reg, Context::PREVIOUS_INDEX)
               .StoreAccumulatorInRegister(context_reg);
         }
         builder()->LoadAccumulatorWithRegister(value_temp);
@@ skipping 811 matching lines @@
 }
 
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return info()->feedback_vector()->GetIndex(slot);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8