Replace store array length builtin with codestub.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 6bef42f28eb56b74f628e1c1ecf6ca284f667f08..a0424acd03af9f4b54adfe3352f989bd9be56154 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -2442,6 +2442,68 @@ void StringLengthStub::Generate(MacroAssembler* masm) {
 }
 
 
+void StoreArrayLengthStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- rax    : value
+  //  -- rcx    : key
+  //  -- rdx    : receiver
+  //  -- rsp[0] : return address
+  // -----------------------------------
+  //
+  // This accepts as a receiver anything JSArray::SetElementsLength accepts
+  // (currently anything except for external arrays which means anything with
+  // elements of FixedArray type).  Value must be a number, but only smis are
+  // accepted as the most common case.
+
+  Label miss;
+
+  Register receiver = rdx;
+  Register value = rax;
+  Register scratch = rbx;
+  if (kind() == Code::KEYED_STORE_IC) {
+    __ Cmp(rcx, masm->isolate()->factory()->length_symbol());
+  }
+
+  // Check that the receiver isn't a smi.
+  __ JumpIfSmi(receiver, &miss);
+
+  // Check that the object is a JS array.
+  __ CmpObjectType(receiver, JS_ARRAY_TYPE, scratch);
+  __ j(not_equal, &miss);
+
+  // Check that elements are FixedArray.
+  // We rely on StoreIC_ArrayLength below to deal with all types of
+  // fast elements (including COW).
+  __ movq(scratch, FieldOperand(receiver, JSArray::kElementsOffset));
+  __ CmpObjectType(scratch, FIXED_ARRAY_TYPE, scratch);
+  __ j(not_equal, &miss);
+
+  // Check that the array has fast properties, otherwise the length
+  // property might have been redefined.
+  __ movq(scratch, FieldOperand(receiver, JSArray::kPropertiesOffset));
+  __ CompareRoot(FieldOperand(scratch, FixedArray::kMapOffset),
+                 Heap::kHashTableMapRootIndex);
+  __ j(equal, &miss);
+
+  // Check that value is a smi.
+  __ JumpIfNotSmi(value, &miss);
+
+  // Prepare tail call to StoreIC_ArrayLength.
+  __ pop(scratch);
+  __ push(receiver);
+  __ push(value);
+  __ push(scratch);  // return address
+
+  ExternalReference ref =
+      ExternalReference(IC_Utility(IC::kStoreIC_ArrayLength), masm->isolate());
+  __ TailCallExternalReference(ref, 2, 1);
+
+  __ bind(&miss);
+
+  StubCompiler::GenerateStoreMiss(masm, kind());
+}
+
+
 void ArgumentsAccessStub::GenerateReadElement(MacroAssembler* masm) {
   // The key is in rdx and the parameter count is in rax.