VectorICs: use a vector slot to aid in array literal processing.

src/full-codegen/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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/debug/debug.h"
@@ skipping 1735 matching lines @@
     // is already set in the cloned array.
     if (CompileTimeValue::IsCompileTimeValue(subexpr)) continue;
 
     if (!result_saved) {
       __ Push(rax);  // array literal
       __ Push(Smi::FromInt(expr->literal_index()));
       result_saved = true;
     }
     VisitForAccumulatorValue(subexpr);
 
-    if (has_constant_fast_elements) {
+    if (FLAG_vector_stores) {
+      __ Move(StoreDescriptor::NameRegister(), Smi::FromInt(array_index));
+      __ movp(StoreDescriptor::ReceiverRegister(), Operand(rsp, kPointerSize));
+      EmitLoadStoreICSlot(expr->LiteralFeedbackSlot());
+      Handle<Code> ic =
+          CodeFactory::KeyedStoreIC(isolate(), language_mode()).code();
+      CallIC(ic);
+    } else if (has_constant_fast_elements) {
       // Fast-case array literal with ElementsKind of FAST_*_ELEMENTS, they
       // cannot transition and don't need to call the runtime stub.
       int offset = FixedArray::kHeaderSize + (array_index * kPointerSize);
       __ movp(rbx, Operand(rsp, kPointerSize));  // Copy of array literal.
       __ movp(rbx, FieldOperand(rbx, JSObject::kElementsOffset));
       // Store the subexpression value in the array's elements.
       __ movp(FieldOperand(rbx, offset), result_register());
       // Update the write barrier for the array store.
       __ RecordWriteField(rbx, offset, result_register(), rcx,
                           kDontSaveFPRegs,
@@ skipping 3400 matching lines @@
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64