display-buffer-pop-up-window is a compiled Lisp function in `window.el'.

(display-buffer-pop-up-window BUFFER ALIST)

Display BUFFER by popping up a new window.
The new window is created on the selected frame, or in
`last-nonminibuffer-frame' if no windows can be created there.
If successful, return the new window; otherwise return nil.

If ALIST has a non-nil `inhibit-switch-frame' entry, then in the
event that the new window is created on another frame, avoid
raising the frame.