harmony-scoping: Implement LoadIC handler for loads from global contexts.

src/hydrogen-instructions.cc

 // Copyright 2012 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/v8.h"
 
 #include "src/base/bits.h"
 #include "src/double.h"
 #include "src/factory.h"
 #include "src/hydrogen-infer-representation.h"
@@ skipping 4623 matching lines @@
 
 HObjectAccess HObjectAccess::ForContextSlot(int index) {
   DCHECK(index >= 0);
   Portion portion = kInobject;
   int offset = Context::kHeaderSize + index * kPointerSize;
   DCHECK_EQ(offset, Context::SlotOffset(index) + kHeapObjectTag);
   return HObjectAccess(portion, offset, Representation::Tagged());
 }
 
 
+HObjectAccess HObjectAccess::ForGlobalContext(int index) {
+  DCHECK(index >= 0);
+  Portion portion = kInobject;
+  int offset = GlobalContextTable::kHeaderSize + (index + 1) * kPointerSize;

[adamk, 2014/11/07 16:57:03]

Here's that "+ 1" again. Now that it's leaking out of the GlobalContextTable
implementation, perhaps it's worth adding a constant?

+  return HObjectAccess(portion, offset, Representation::Tagged());
+}
+
+
 HObjectAccess HObjectAccess::ForJSArrayOffset(int offset) {
   DCHECK(offset >= 0);
   Portion portion = kInobject;
 
   if (offset == JSObject::kElementsOffset) {
     portion = kElementsPointer;
   } else if (offset == JSArray::kLengthOffset) {
     portion = kArrayLengths;
   } else if (offset == JSObject::kMapOffset) {
     portion = kMaps;
@@ skipping 135 matching lines @@
       break;
     case HObjectAccess::kExternalMemory:
       os << "[external-memory]";
       break;
   }
 
   return os << "@" << access.offset();
 }
 
 } }  // namespace v8::internal