From: Basil L. Contovounesios <contovob@tcd.ie>
Date: Tue, 9 Apr 2019 15:51:55 +0000 (+0100)
Subject: Optimize byte-compilation of proper-list-p
X-Git-Tag: emacs-27.0.90~3259^2~27
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=9a54e70c184cd9f65f1141a1b1df87e9afb83d2f;p=emacs.git

Optimize byte-compilation of proper-list-p

For discussion, see thread starting at:
https://lists.gnu.org/archive/html/emacs-devel/2019-04/msg00316.html
* lisp/emacs-lisp/byte-opt.el: Optimize proper-list-p as a
predicate.
* lisp/subr.el: Mark proper-list-p as pure, and side-effect and
error free.
---

diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 33d49647638..44cca6136c0 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -879,7 +879,8 @@
 (put 'symbolp 'byte-optimizer 'byte-optimize-predicate)
 (put 'stringp 'byte-optimizer 'byte-optimize-predicate)
 (put 'string< 'byte-optimizer 'byte-optimize-predicate)
-(put 'string-lessp 'byte-optimizer 'byte-optimize-predicate)
+(put 'string-lessp  'byte-optimizer 'byte-optimize-predicate)
+(put 'proper-list-p 'byte-optimizer 'byte-optimize-predicate)
 
 (put 'logand 'byte-optimizer 'byte-optimize-predicate)
 (put 'logior 'byte-optimizer 'byte-optimize-predicate)
diff --git a/lisp/subr.el b/lisp/subr.el
index bdf98979c49..bf3716bbd37 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -604,6 +604,11 @@ If N is omitted or nil, remove the last element."
 	   (if (> n 0) (setcdr (nthcdr (- (1- m) n) list) nil))
 	   list))))
 
+;; The function's definition was moved to fns.c,
+;; but it's easier to set properties here.
+(put 'proper-list-p 'pure t)
+(put 'proper-list-p 'side-effect-free 'error-free)
+
 (defun delete-dups (list)
   "Destructively remove `equal' duplicates from LIST.
 Store the result in LIST and return it.  LIST must be a proper list.