Package: emacs;
Reported by: Philipp Stephani <p.stephani2 <at> gmail.com>
Date: Thu, 6 May 2021 17:21:02 UTC
Severity: normal
Tags: patch
Found in version 28.0.50
Done: Philipp Stephani <p.stephani2 <at> gmail.com>
Bug is archived. No further changes may be made.
Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):
From: Philipp Stephani <p.stephani2 <at> gmail.com> To: bug-gnu-emacs <at> gnu.org Subject: 28.0.50; Optimize `eql' to `eq' for fixnums Date: Thu, 06 May 2021 19:20:10 +0200
[Message part 1 (text/plain, inline)]
It would be nice if the byte optimizer could optimize `eql' to `eq' if one of the arguments is guaranteed to be a fixnum. Patch is attached.
[0001-Optimize-calls-to-eql-memql-and-similar-for-fixnums.patch (text/x-diff, inline)]
From 8b6f76df20454bb0caaba71cac9c5c3a7cb2aa62 Mon Sep 17 00:00:00 2001
From: Philipp Stephani <phst <at> google.com>
Date: Thu, 6 May 2021 19:13:00 +0200
Subject: [PATCH] Optimize calls to 'eql', 'memql' and similar for fixnums.
It's good practice to compare integers using 'eql' because two bignum
objects representing the same integer might not be 'eq'. However,
'eql' is slower and doesn't have its own byte code. Therefore,
replace it with 'eq' if one argument is guaranteed to be a fixnum on
all platforms.
* lisp/emacs-lisp/byte-opt.el (byte-optimize--fixnump): New helper
function.
(byte-optimize-equal, byte-optimize-member, byte-optimize-assoc): Use
it to optimize 'eql' etc. to 'eq' if it will always compare fixnums.
---
lisp/emacs-lisp/byte-opt.el | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 33b4d4b3c8..4dd8b90b3a 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -951,12 +951,20 @@ byte-optimize--constant-symbol-p
"Whether EXPR is a constant symbol."
(and (macroexp-const-p expr) (symbolp (eval expr))))
+(defun byte-optimize--fixnump (o)
+ "Return whether O is guaranteed to be a fixnum in all Emacsen.
+See Info node `(elisp) Integer Basics'."
+ (and (fixnump o) (<= -536870912 o 536870911)))
+
(defun byte-optimize-equal (form)
- ;; Replace `equal' or `eql' with `eq' if at least one arg is a symbol.
+ ;; Replace `equal' or `eql' with `eq' if at least one arg is a
+ ;; symbol or fixnum.
(byte-optimize-binary-predicate
(if (= (length (cdr form)) 2)
(if (or (byte-optimize--constant-symbol-p (nth 1 form))
- (byte-optimize--constant-symbol-p (nth 2 form)))
+ (byte-optimize--constant-symbol-p (nth 2 form))
+ (byte-optimize--fixnump (nth 1 form))
+ (byte-optimize--fixnump (nth 2 form)))
(cons 'eq (cdr form))
form)
;; Arity errors reported elsewhere.
@@ -964,14 +972,18 @@ byte-optimize-equal
(defun byte-optimize-member (form)
;; Replace `member' or `memql' with `memq' if the first arg is a symbol,
- ;; or the second arg is a list of symbols.
+ ;; or the second arg is a list of symbols. Same with fixnums.
(if (= (length (cdr form)) 2)
(if (or (byte-optimize--constant-symbol-p (nth 1 form))
+ (byte-optimize--fixnump (nth 1 form))
(let ((arg2 (nth 2 form)))
(and (macroexp-const-p arg2)
(let ((listval (eval arg2)))
(and (listp listval)
- (not (memq nil (mapcar #'symbolp listval))))))))
+ (cl-every
+ (lambda (o)
+ (or (symbolp o) (byte-optimize--fixnump o)))
+ listval))))))
(cons 'memq (cdr form))
form)
;; Arity errors reported elsewhere.
@@ -979,11 +991,12 @@ byte-optimize-member
(defun byte-optimize-assoc (form)
;; Replace 2-argument `assoc' with `assq', `rassoc' with `rassq',
- ;; if the first arg is a symbol.
+ ;; if the first arg is a symbol or fixnum.
(cond
((/= (length form) 3)
form)
- ((byte-optimize--constant-symbol-p (nth 1 form))
+ ((or (byte-optimize--constant-symbol-p (nth 1 form))
+ (byte-optimize--fixnump (nth 1 form)))
(cons (if (eq (car form) 'assoc) 'assq 'rassq)
(cdr form)))
(t (byte-optimize-constant-args form))))
--
2.31.1.607.g51e8a6a459-goog
[Message part 3 (text/plain, inline)]
In GNU Emacs 28.0.50 (build 95, x86_64-pc-linux-gnu, GTK+ Version 3.24.24, cairo version 1.16.0) of 2021-05-06 Repository revision: 8b7495a722a57071cb2a978665f95f8227db2863 Repository branch: master Windowing system distributor 'The X.Org Foundation', version 11.0.12010000 System Description: Debian GNU/Linux rodete Configured using: 'configure --enable-gcc-warnings=warn-only --enable-gtk-deprecation-warnings --without-pop --with-mailutils --enable-checking=all --enable-check-lisp-object-type --with-modules 'CFLAGS=-O0 -ggdb3'' Configured features: CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON LIBSELINUX LIBSYSTEMD MODULES NOTIFY INOTIFY PDUMPER PNG SECCOMP SOUND THREADS TIFF TOOLKIT_SCROLL_BARS X11 XDBE XIM XPM GTK3 ZLIB Important settings: value of $LC_TIME: en_DK.utf8 value of $LANG: en_US.utf8 value of $XMODIFIERS: @im=ibus locale-coding-system: utf-8-unix Major mode: Lisp Interaction Minor modes in effect: tooltip-mode: t global-eldoc-mode: t eldoc-mode: t electric-indent-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t Load-path shadows: None found. Features: (shadow sort mail-extr emacsbug message rmc dired dired-loaddefs rfc822 mml mml-sec epa epg epg-config gnus-util rmail rmail-loaddefs time-date mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils phst skeleton derived edmacro kmacro pcase ffap thingatpt url url-proxy url-privacy url-expand url-methods url-history url-cookie url-domsuf url-util url-parse auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs password-cache json map url-vars mailcap rx gnutls puny dbus xml subr-x seq byte-opt gv bytecomp byte-compile cconv compile text-property-search comint ansi-color ring cl-loaddefs cl-lib iso-transl tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch easymenu timer select scroll-bar mouse jit-lock font-lock syntax font-core term/tty-colors frame minibuffer cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese composite charscript charprop case-table epa-hook jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice button loaddefs faces cus-face macroexp files window text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote threads dbusbind inotify dynamic-setting system-font-setting font-render-setting cairo move-toolbar gtk x-toolkit x multi-tty make-network-process emacs) Memory information: ((conses 16 69305 6969) (symbols 48 8421 3) (strings 32 24389 2023) (string-bytes 1 789279) (vectors 16 15076) (vector-slots 8 195751 5867) (floats 8 26 32) (intervals 56 223 0) (buffers 992 11)) -- Google Germany GmbH Erika-Mann-Straße 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg Diese E-Mail ist vertraulich. Falls Sie diese fälschlicherweise erhalten haben sollten, leiten Sie diese bitte nicht an jemand anderes weiter, löschen Sie alle Kopien und Anhänge davon und lassen Sie mich bitte wissen, dass die E-Mail an die falsche Person gesendet wurde. This e-mail is confidential. If you received this communication by mistake, please don’t forward it to anyone else, please erase all copies and attachments, and please let me know that it has gone to the wrong person.
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