* bug#23772: 24.5; (format "%s" INTEGER) is slow
@ 2016-06-15 11:40 ynyaaa
2016-06-15 14:59 ` Eli Zaretskii
0 siblings, 1 reply; 2+ messages in thread
From: ynyaaa @ 2016-06-15 11:40 UTC (permalink / raw)
To: 23772
(format "%s" INTEGER) is slower than (format "%s" (format "%d" INTEGER)).
(benchmark-run-compiled 100000 (format "%s" 0))
=>(1.134 12 0.09000000000000119)
(benchmark-run-compiled 100000 (format "%d" 0))
=>(0.571 6 0.05500000000000016)
(benchmark-run-compiled 100000 (format "%s" (format "%d" 0)))
=>(0.652 13 0.12200000000000033)
In GNU Emacs 24.5.1 (i686-pc-mingw32)
of 2015-04-11 on LEG570
Windowing system distributor `Microsoft Corp.', version 6.0.6002
Configured using:
`configure --prefix=/c/usr --host=i686-pc-mingw32'
Important settings:
value of $LANG: JPN
locale-coding-system: cp932
Major mode: Lisp Interaction
Minor modes in effect:
tooltip-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
Recent messages:
Load-path shadows:
None found.
Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils advice help-at-pt misearch multi-isearch info
cus-start cus-load byte-opt bytecomp byte-compile cl-extra cl-loaddefs
cl-lib cconv benchmark help-mode easymenu help-fns time-date japan-util
tooltip electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
dos-w32 ls-lisp w32-common-fns disp-table w32-win w32-vars tool-bar dnd
fontset image regexp-opt fringe tabulated-list newcomment lisp-mode
prog-mode register page menu-bar rfn-eshadow timer select scroll-bar
mouse jit-lock font-lock syntax facemenu font-core frame cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev
minibuffer nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process
w32notify w32 multi-tty emacs)
Memory information:
((conses 8 100246 4506)
(symbols 32 19808 0)
(miscs 32 91 254)
(strings 16 17110 3554)
(string-bytes 1 453874)
(vectors 8 12074)
(vector-slots 4 483850 2486)
(floats 8 64 468)
(intervals 28 1181 16)
(buffers 508 14))
^ permalink raw reply [flat|nested] 2+ messages in thread
* bug#23772: 24.5; (format "%s" INTEGER) is slow
2016-06-15 11:40 bug#23772: 24.5; (format "%s" INTEGER) is slow ynyaaa
@ 2016-06-15 14:59 ` Eli Zaretskii
0 siblings, 0 replies; 2+ messages in thread
From: Eli Zaretskii @ 2016-06-15 14:59 UTC (permalink / raw)
To: ynyaaa; +Cc: 23772
> From: ynyaaa@gmail.com
> Date: Wed, 15 Jun 2016 20:40:04 +0900
>
> (benchmark-run-compiled 100000 (format "%s" 0))
> =>(1.134 12 0.09000000000000119)
> (benchmark-run-compiled 100000 (format "%d" 0))
> =>(0.571 6 0.05500000000000016)
> (benchmark-run-compiled 100000 (format "%s" (format "%d" 0)))
> =>(0.652 13 0.12200000000000033)
Why is that a problem? %d is passed to sprintf, so it's very fast; %s
whose argument is a string or a symbol is also fast, because it just
copies characters. But %s with an argument that is neither a string
nor a symbol is implemented via a call to prin1-to-string, which is
more expensive because it produces a string representation of an
arbitrary Lisp object. This is consistent with your results.
IOW, if you know the argument is an integer, and you care about
performance, don't use %s.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2016-06-15 11:40 bug#23772: 24.5; (format "%s" INTEGER) is slow ynyaaa
2016-06-15 14:59 ` Eli Zaretskii
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