From a140513acb4ce27bd2b3472ee7a6ecb92676a8e9 Mon Sep 17 00:00:00 2001 From: Vibhav Pant Date: Sun, 25 Mar 2018 00:38:01 +0530 Subject: [PATCH] Optimize certain memq forms during byte-compilation. * lisp/emacs-lisp/byte-opt.el (byte-optimize-memq): New function. Set the byte optimizer function for memq to byte-optimize-memq. --- lisp/emacs-lisp/byte-opt.el | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el index a5e0e219644..54421e01be6 100644 --- a/lisp/emacs-lisp/byte-opt.el +++ b/lisp/emacs-lisp/byte-opt.el @@ -764,7 +764,23 @@ (if (= 1 (length (cdr form))) "" "s")) form)) +(defun byte-optimize-memq (form) + ;; (memq foo '(bar)) => (and (eq foo 'bar) '(bar)) + (if (/= (length (cdr form)) 2) + (byte-compile-warn "memq called with %d arg%s, but requires 2" + (length (cdr form)) + (if (= 1 (length (cdr form))) "" "s")) + (let ((list (nth 2 form))) + (when (and (eq (car-safe list) 'quote) + (listp (setq list (cadr list))) + (= (length list) 1)) + (setq form `(and ,(byte-optimize-predicate + `(eq ,(nth 1 form) ',(nth 0 list))) + ',list)))) + (byte-optimize-and form))) + (put 'identity 'byte-optimizer 'byte-optimize-identity) +(put 'memq 'byte-optimizer 'byte-optimize-memq) (put '+ 'byte-optimizer 'byte-optimize-plus) (put '* 'byte-optimizer 'byte-optimize-multiply) @@ -787,7 +803,6 @@ (put '1- 'byte-optimizer 'byte-optimize-predicate) (put 'not 'byte-optimizer 'byte-optimize-predicate) (put 'null 'byte-optimizer 'byte-optimize-predicate) -(put 'memq 'byte-optimizer 'byte-optimize-predicate) (put 'consp 'byte-optimizer 'byte-optimize-predicate) (put 'listp 'byte-optimizer 'byte-optimize-predicate) (put 'symbolp 'byte-optimizer 'byte-optimize-predicate) @@ -805,7 +820,6 @@ (put 'car-safe 'byte-optimizer 'byte-optimize-predicate) (put 'cdr-safe 'byte-optimizer 'byte-optimize-predicate) - ;; I'm not convinced that this is necessary. Doesn't the optimizer loop ;; take care of this? - Jamie ;; I think this may some times be necessary to reduce ie (quote 5) to 5, -- 2.39.5