Auto-compile elisp

gistfile1.el

(defun ph/is-elisp-file (filename)
    "Returns non-nil if FILENAME ends in either '.el' or '.el.gz'"
    (string-match-p "\\.el\\(\\.gz\\)?\\'" filename)
)

(defun ph/autocompile-elisp ()
    "Compiles and tags my custom elisp code files on save:
<`dot-emacs'>, and files under the <`ph/elisp-root'> directory.

References: `dot-emacs-file'"
    (interactive)
    (when
        (and
            (ph/is-elisp-file (buffer-file-name))
            (or
                (string= (buffer-file-name) dot-emacs-file)
                (string-match-p (concat "^" ph/elisp-root) (buffer-file-name))
            )
        )
        (byte-compile-file (buffer-file-name))
        (call-process "rebuild_tags" nil "*Messages*")
    )
)

(add-hook 'after-save-hook 'ph/autocompile-elisp)

'dot-emacs-file' is the pathname of your init.el or .emacs

'ph/elisp-root' is the directory where you keep your own elisp code.