Introduce FLAG_vector_ics.

src/x64/builtins-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/codegen.h"
 #include "src/deoptimizer.h"
@@ skipping 1056 matching lines @@
     // Copy all arguments from the array to the stack.
     Label entry, loop;
     Register receiver = LoadIC::ReceiverRegister();
     Register key = LoadIC::NameRegister();
     __ movp(key, Operand(rbp, kIndexOffset));
     __ jmp(&entry);
     __ bind(&loop);
     __ movp(receiver, Operand(rbp, kArgumentsOffset));  // load arguments
 
     // Use inline caching to speed up access to arguments.
+    if (FLAG_vector_ics) {
+      __ Move(LoadIC::SlotRegister(), Smi::FromInt(0));
+    }
     Handle<Code> ic =
         masm->isolate()->builtins()->KeyedLoadIC_Initialize();
     __ Call(ic, RelocInfo::CODE_TARGET);
     // It is important that we do not have a test instruction after the
     // call.  A test instruction after the call is used to indicate that
     // we have generated an inline version of the keyed load.  In this
     // case, we know that we are not generating a test instruction next.
 
     // Push the nth argument.
     __ Push(rax);
@@ skipping 428 matching lines @@
   __ bind(&ok);
   __ ret(0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64