From 2a85d7a07c16dd854490b5eff72930d4a80b1415 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Mattias=20Engdeg=C3=A5rd?= Date: Thu, 12 Jan 2023 14:07:45 +0100 Subject: [PATCH] Optimise `apply` with `cons` in tail argument * lisp/emacs-lisp/byte-opt.el (byte-optimize-apply): Transform (apply F ... (cons X Y)) -> (apply F ... X Y) This pattern is seen both in hand-written code and in backquote expansions. --- lisp/emacs-lisp/byte-opt.el | 3 +++ 1 file changed, 3 insertions(+) diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el index d7a0d851e01..039cebedb44 100644 --- a/lisp/emacs-lisp/byte-opt.el +++ b/lisp/emacs-lisp/byte-opt.el @@ -1380,6 +1380,9 @@ See Info node `(elisp) Integer Basics'." ;; (apply F ... (list X Y ...)) -> (funcall F ... X Y ...) ((eq (car-safe last) 'list) `(funcall ,fn ,@(butlast (cddr form)) ,@(cdr last))) + ;; (apply F ... (cons X Y)) -> (apply F ... X Y) + ((eq (car-safe last) 'cons) + (append (butlast form) (cdr last))) (t form))) form))) -- 2.39.5