From: Dmitry Gutov <dgutov@yandex.ru>
To: Stefan Monnier <monnier@iro.umontreal.ca>
Cc: 15294@debbugs.gnu.org
Subject: bug#15294: 24.3.50; js2-mode parser is several times slower in lexical-binding mode
Date: Sat, 14 Sep 2013 07:20:29 +0300 [thread overview]
Message-ID: <5233E40D.4000102@yandex.ru> (raw)
In-Reply-To: <jwvhadps8a1.fsf-monnier+emacs@gnu.org>
On 13.09.2013 06:40, Stefan Monnier wrote:
> It seems the slowdown is indeed linked to the way `catch' is handled
> (indeed, this non-idiomatic ELisp code ends up byte-compiled in a really
> poor way).
What's non-idiomatic about this use of `catch'?
> The trivial patch below brings the time down from 5s to 2.6s (as
> compared to 2.1s for the dynamic-binding version).
Indeed, it does, in the compiled mode (but please don't install it yet,
because it'll complicate merging the `arrow-functions' branch(*)). It
does not make much of a difference in the interpreted mode.
Now that we have eager macro-expansion, I was rather happy that
interpreted js2-mode performance is only like 2x worse than when compiled.
But 2.6 vs 2.1, it still a noticeable regression. Do you suppose the
usage of `setq' is the main contributor?
Speaking of byte-code changes, that seems like a fine idea, but ideally
the code should work similarly well on Emacs 24.1-24.3. Or we can just
hold off on making js2-mode switch to lexical-binding until [long] after
24.4 is out.
(*) Would you take a look at it, too? It has quite a few changes in
`js2-get-token' and related functions. They also make performing the
same change as in your patch more difficult, since I'm actually using
the value returned by `catch' before returning from the function.
On 13.09.2013 07:37, Stefan Monnier wrote:
> the mere existence of a single `setq'
> on a variable can sometimes slow other chunks of code: in many cases
> `let' is cheaper than `setq').
I see. Does this also extend to `setf' and its defstruct-related
functionality? It's all over the js2-mode codebase.
next prev parent reply other threads:[~2013-09-14 4:20 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-06 20:59 bug#15294: 24.3.50; js2-mode parser is several times slower in lexical-binding mode Dmitry Gutov
2013-09-06 23:44 ` Xue Fuqiao
2013-09-07 3:15 ` Stefan Monnier
2013-09-08 22:32 ` Stefan Monnier
2013-09-10 2:04 ` Stefan Monnier
2013-09-13 3:40 ` Stefan Monnier
2013-09-13 3:59 ` Drew Adams
2013-09-13 4:37 ` Stefan Monnier
2013-09-13 5:45 ` Drew Adams
2013-09-13 13:01 ` Stefan Monnier
2013-09-14 0:09 ` Lexical let and setq Michael Welsh Duggan
2013-09-14 3:46 ` Stefan Monnier
2013-09-14 11:13 ` Lars Magne Ingebrigtsen
2013-09-14 14:04 ` Pascal J. Bourguignon
2013-09-15 5:11 ` Stefan Monnier
2013-09-14 21:47 ` Richard Stallman
2013-09-15 5:09 ` Stefan Monnier
2013-09-15 16:54 ` Richard Stallman
2013-09-15 17:06 ` Stefan Monnier
2013-09-16 10:47 ` Richard Stallman
2013-09-14 4:20 ` Dmitry Gutov [this message]
2013-09-14 14:27 ` bug#15294: 24.3.50; js2-mode parser is several times slower in lexical-binding mode Stefan Monnier
2013-09-15 0:11 ` Dmitry Gutov
2013-09-15 5:04 ` Stefan Monnier
2013-09-15 16:54 ` Richard Stallman
2013-09-15 0:24 ` Dmitry Gutov
2013-09-15 5:06 ` Stefan Monnier
2013-09-18 23:48 ` Stefan Monnier
2013-09-22 4:56 ` Dmitry Gutov
2013-10-03 5:00 ` Stefan Monnier
2013-10-04 2:38 ` Dmitry Gutov
2013-10-04 13:52 ` Stefan Monnier
2013-10-05 3:27 ` Dmitry Gutov
2014-12-14 12:31 ` Dmitry Gutov
2014-12-14 14:08 ` Stefan Monnier
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