[Interpreter] Add support for loading globals in the interpreter.

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 "src/code-factory.h"
 #include "src/compiler.h"
 #include "src/compiler/interpreter-assembler.h"
 #include "src/factory.h"
@@ skipping 173 matching lines @@
 //
 // Store accumulator to register <dst>.
 void Interpreter::DoStar(compiler::InterpreterAssembler* assembler) {
   Node* reg_index = __ BytecodeOperandReg(0);
   Node* accumulator = __ GetAccumulator();
   __ StoreRegister(accumulator, reg_index);
   __ Dispatch();
 }
 
 
+// LdaGlobal <slot_index>
+//
+// Load the global at |slot_index| into the accumulator.
+void Interpreter::DoLdaGlobal(compiler::InterpreterAssembler* assembler) {
+  Node* slot_index = __ BytecodeOperandIdx(0);
+  Node* smi_slot_index = __ SmiTag(slot_index);
+  Node* result = __ CallRuntime(Runtime::kLoadGlobalViaContext, smi_slot_index);
+  __ SetAccumulator(result);
+  __ Dispatch();
+}
+
+
 void Interpreter::DoPropertyLoadIC(Callable ic,
                                    compiler::InterpreterAssembler* assembler) {
   Node* code_target = __ HeapConstant(ic.code());
   Node* reg_index = __ BytecodeOperandReg(0);
   Node* object = __ LoadRegister(reg_index);
   Node* name = __ GetAccumulator();
   Node* raw_slot = __ BytecodeOperandIdx(1);
   Node* smi_slot = __ SmiTag(raw_slot);
   Node* type_feedback_vector = __ LoadTypeFeedbackVector();
   Node* result = __ CallIC(ic.descriptor(), code_target, object, name, smi_slot,
@@ skipping 138 matching lines @@
 //
 // Return the value in register 0.
 void Interpreter::DoReturn(compiler::InterpreterAssembler* assembler) {
   __ Return();
 }
 
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8