From: Stefan Monnier <monnier@iro.umontreal.ca>
To: emacs-devel@gnu.org
Subject: Execution speed
Date: Sun, 19 Mar 2017 11:12:59 -0400 [thread overview]
Message-ID: <jwv1sttcnv2.fsf-monnier+emacs@gnu.org> (raw)
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Someone on SO reported a surprising behavior where a recursive
implementation of `gcd` turned out faster than the iterative version:
http://stackoverflow.com/questions/42792988/
The more surprising thing is that when I try it I get the
opposite result, even though it's basically on the same kind of system
(GNU/Linx x86).
I'm curious where the difference might come from. Could you guys try
out the test?
Just do `emacs -Q --batch -l .../ir-test.el`. Here's what I got:
% emacs24 -Q --batch -l ~/tmp/ir-test.el
Interpreted: Iterative=1.770s; Recursive=1.937s
Bytecompiled: Iterative=1.187s; Recursive=1.496s
% .../src/emacs -Q --batch -l ~/tmp/ir-test.el
Interpreted: Iterative=4.496s; Recursive=4.595s
Bytecompiled: Iterative=2.471s; Recursive=2.983s
where `emacs24` is Debian's whereas the other one is my locally
built&hacked version with debugging assertions and stuff.
Stefan
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next reply other threads:[~2017-03-19 15:12 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-19 15:12 Stefan Monnier [this message]
2017-03-19 15:26 ` Execution speed Mark Oteiza
2017-03-19 15:32 ` Eli Zaretskii
2017-03-19 16:01 ` Tino Calancha
2017-03-19 16:14 ` Andreas Politz
2017-03-19 16:33 ` Teemu Likonen
2017-03-19 19:09 ` npostavs
2017-03-19 22:49 ` Phil Sainty
2017-03-20 10:36 ` Performance of lexical closures in interpreted code? (was Re: Execution speed) Phil Sainty
2017-03-20 12:50 ` Stefan Monnier
2017-03-20 13:12 ` Stefan Monnier
2017-03-19 22:30 ` Execution speed Phil Sainty
2017-03-20 9:46 ` Ivan Kanis
2017-03-20 10:46 ` Philippe Vaucher
2017-03-20 14:26 ` Filipp Gunbin
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