byte-recompilation of files under a directory

Question

As I move all my emacs.d between my machines using Git, and, obviously, I don’t version control byte-compiled files (*.elc), I sometimes get into a situation when my .el files are newer then the corresponding .elc files.

Right now I construct a find(1) command using find-cmd, to find all .elc files, check if they are older then their .el counterpart, and byte-compile them if so.

(defun recompile-stale-elcs ()
  (interactive)

  (with-temp-buffer
    (setq-local default-directory user-emacs-directory)

    (let ((find-command (find-cmd '(prune (name ".git"))
                                  '(name "*.elc"))))

      (shell-command find-command t t))

    (goto-char (point-min))
    (setq more-lines t)

    (while more-lines
      (let ((start (progn (beginning-of-line)
                          (point)))
            (end (progn (end-of-line)
                        (point))))
        (let ((el (buffer-substring start (- end 1)))
              (elc (buffer-substring start end)))

          (if (file-newer-than-file-p el elc)
              (byte-compile-file (buffer-substring start (- end 1))))))
      (setq more-lines (= 0 (forward-line 1))))))

Is there a way to change that find-cmd call to pure Elisp?

Of course, if there is any other solution for the base problem, I’m open to hear that (probably in comment/chat.)

(Also, I was in doubt when selecting tags for this question. Please add some more relevant ones if such exist.)