Revert broken ArrayPop changes

src/x64/stub-cache-x64.cc

Index: src/x64/stub-cache-x64.cc
diff --git a/src/x64/stub-cache-x64.cc b/src/x64/stub-cache-x64.cc
index dbfd419290c692b61758bacb58d9e76dcea55668..53e9f886f4a946954f52619c70f38b447eb3a983 100644
--- a/src/x64/stub-cache-x64.cc
+++ b/src/x64/stub-cache-x64.cc
@@ -1534,6 +1534,77 @@ Handle<Code> CallStubCompiler::CompileCallField(Handle<JSObject> object,
 }
 
 
+Handle<Code> CallStubCompiler::CompileArrayPopCall(
+    Handle<Object> object,
+    Handle<JSObject> holder,
+    Handle<Cell> cell,
+    Handle<JSFunction> function,
+    Handle<String> name,
+    Code::StubType type) {
+  // If object is not an array or is observed or sealed, bail out to regular
+  // call.
+  if (!object->IsJSArray() ||
+      !cell.is_null() ||
+      Handle<JSArray>::cast(object)->map()->is_observed() ||
+      !Handle<JSArray>::cast(object)->map()->is_extensible()) {
+    return Handle<Code>::null();
+  }
+
+  Label miss, return_undefined, call_builtin;
+
+  HandlerFrontendHeader(object, holder, name, RECEIVER_MAP_CHECK, &miss);
+
+  // Get the elements array of the object.
+  __ movp(rbx, FieldOperand(rdx, JSArray::kElementsOffset));
+
+  // Check that the elements are in fast mode and writable.
+  __ CompareRoot(FieldOperand(rbx, HeapObject::kMapOffset),
+                 Heap::kFixedArrayMapRootIndex);
+  __ j(not_equal, &call_builtin);
+
+  // Get the array's length into rcx and calculate new length.
+  __ SmiToInteger32(rcx, FieldOperand(rdx, JSArray::kLengthOffset));
+  __ subl(rcx, Immediate(1));
+  __ j(negative, &return_undefined);
+
+  // Get the last element.
+  __ LoadRoot(r9, Heap::kTheHoleValueRootIndex);
+  __ movp(rax, FieldOperand(rbx,
+                            rcx, times_pointer_size,
+                            FixedArray::kHeaderSize));
+  // Check if element is already the hole.
+  __ cmpq(rax, r9);
+  // If so, call slow-case to also check prototypes for value.
+  __ j(equal, &call_builtin);
+
+  // Set the array's length.
+  __ Integer32ToSmiField(FieldOperand(rdx, JSArray::kLengthOffset), rcx);
+
+  // Fill with the hole and return original value.
+  __ movp(FieldOperand(rbx,
+                       rcx, times_pointer_size,
+                       FixedArray::kHeaderSize),
+          r9);
+  const int argc = arguments().immediate();
+  __ ret((argc + 1) * kPointerSize);
+
+  __ bind(&return_undefined);
+  __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
+  __ ret((argc + 1) * kPointerSize);
+
+  __ bind(&call_builtin);
+  __ TailCallExternalReference(
+      ExternalReference(Builtins::c_ArrayPop, isolate()),
+      argc + 1,
+      1);
+
+  HandlerFrontendFooter(&miss);
+
+  // Return the generated code.
+  return GetCode(type, name);
+}
+
+
 Handle<Code> CallStubCompiler::CompileFastApiCall(
     const CallOptimization& optimization,
     Handle<Object> object,