Optimize the typeof operator.

src/x64/full-codegen-x64.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"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 4728 matching lines @@
         } else {
           __ PushRoot(Heap::kFalseValueRootIndex);
         }
         __ bind(&done);
       }
       break;
     }
 
     case Token::TYPEOF: {
       Comment cmnt(masm_, "[ UnaryOperation (TYPEOF)");
-      { StackValueContext context(this);
+      {
+        AccumulatorValueContext context(this);
         VisitForTypeofValue(expr->expression());
       }
-      __ CallRuntime(Runtime::kTypeof, 1);
+      __ movp(rbx, rax);
+      TypeofStub typeof_stub(isolate());
+      __ CallStub(&typeof_stub);
       context()->Plug(rax);
       break;
     }
 
     default:
       UNREACHABLE();
   }
 }
 
 
@@ skipping 626 matching lines @@
   DCHECK_EQ(isolate->builtins()->OsrAfterStackCheck()->entry(),
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64