Move up View when keyboard appears, but only for device X - ios

Question

I wasn't able to find a solution here for my problem which seems to be just that little step above the regular "move up view when keyboard appears" thing.
Although this is exactly what I need I want this only to happen on an iPhone 5S or iPhone SE.
So I've got the following code so far which is working fine with iOS 11:
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(notification:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
#objc func keyboardWillHide() {
self.view.frame.origin.y = 0
}
#objc func keyboardWillChange(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
if myTextField.isFirstResponder {
self.view.frame.origin.y = -keyboardSize.height
}
}
}
I've tried several things to put this into an if case and I've searched for how to define things only for types of devices but as a beginner (6th week learning...) I've totally failed so far.

Answer 1

After #rmaddy gave me the right hint I'm giving the answer myself. All I did was adding an if case checking the view size with view.bounds.height (which is 568pt for an iPhone 5).
So the above code was changed to:
override func viewDidLoad() {
super.viewDidLoad()
let screenHeight = view!.bounds.height
//Checking the view size in pt here
if screenHeight <= 568 {
//add this to perform only for devices with view size 568 or lower
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(notification:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
}
#objc func keyboardWillHide() {
self.view.frame.origin.y = 0
}
#objc func keyboardWillChange(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
if myTextField.isFirstResponder {
self.view.frame.origin.y = -keyboardSize.height
}
}
}