[Interpreter] Add support for loading from / storing to outer context variables.

src/compiler/raw-machine-assembler.h

 // Copyright 2014 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.
 
 #ifndef V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_
 #define V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_
 
 #include "src/assembler.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
@@ skipping 108 matching lines @@
   }
 
   // Memory Operations.
   Node* Load(MachineType rep, Node* base) {
     return Load(rep, base, IntPtrConstant(0));
   }
   Node* Load(MachineType rep, Node* base, Node* index) {
     return AddNode(machine()->Load(rep), base, index, graph()->start(),
                    graph()->start());
   }
-  Node* Store(MachineType rep, Node* base, Node* value) {
-    return Store(rep, base, IntPtrConstant(0), value);
+  Node* Store(MachineType rep, Node* base, Node* value,
+              WriteBarrierKind write_barrier_kind = kNoWriteBarrier) {

[Michael Starzinger, 2015/10/26 13:28:13]

Joking aside: How much overhead would it be to not have a default argument here?
If it turns out to be, lets say, less than ten changes in the test suite, I
would vote for going for it. WDYT?

[rmcilroy, 2015/10/26 15:37:51]

Good point - done by changing Store to take a StoreRepresentation instead of
separate MachineType/WriteBarrierKind arguments (although it was more like 130
change... ;)).

+    return Store(rep, base, IntPtrConstant(0), value, write_barrier_kind);
   }
-  Node* Store(MachineType rep, Node* base, Node* index, Node* value) {
-    return AddNode(machine()->Store(StoreRepresentation(rep, kNoWriteBarrier)),
-                   base, index, value, graph()->start(), graph()->start());
+  Node* Store(MachineType rep, Node* base, Node* index, Node* value,
+              WriteBarrierKind write_barrier_kind = kNoWriteBarrier) {

[Michael Starzinger, 2015/10/26 13:28:13]

Likewise.

[rmcilroy, 2015/10/26 15:37:51]

Done.

+    return AddNode(
+        machine()->Store(StoreRepresentation(rep, write_barrier_kind)), base,
+        index, value, graph()->start(), graph()->start());
   }
 
   // Arithmetic Operations.
   Node* WordAnd(Node* a, Node* b) {
     return AddNode(machine()->WordAnd(), a, b);
   }
   Node* WordOr(Node* a, Node* b) { return AddNode(machine()->WordOr(), a, b); }
   Node* WordXor(Node* a, Node* b) {
     return AddNode(machine()->WordXor(), a, b);
   }
@@ skipping 443 matching lines @@
   BasicBlock* current_block_;
 
   DISALLOW_COPY_AND_ASSIGN(RawMachineAssembler);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_