From: Stefan Monnier <monnier@iro.umontreal.ca>
To: Daniel Colascione <dancol@dancol.org>
Cc: Philipp Stephani <p.stephani2@gmail.com>,
Paul Eggert <eggert@cs.ucla.edu>,
emacs-devel@gnu.org
Subject: Re: [Emacs-diffs] emacs-25 3eb93c0: Rely on conservative stack scanning to find "emacs_value"s
Date: Thu, 31 Mar 2016 17:29:07 -0400 [thread overview]
Message-ID: <jwvpoua4a10.fsf-monnier+emacsdiffs@gnu.org> (raw)
In-Reply-To: <56FD796B.4000703@dancol.org> (Daniel Colascione's message of "Thu, 31 Mar 2016 12:24:27 -0700")
> That's cheap: you can do it with linear allocation out of an array.
> Why would that be expensive?
That's very expensive compared to doing nothing.
It means that you have to allocate a new array, loop through the old one
calling your "cheap allocation" function on each element, instead of
just passing the array pointer untouched.
Of course, the advantage of your scheme is that you get to do manual
memory management, with the endless hours of fun that entails.
"There's worse, but it's more expensive!"
Stefan
next prev parent reply other threads:[~2016-03-31 21:29 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20151130193446.22218.14685@vcs.savannah.gnu.org>
[not found] ` <E1a3UDm-0005my-HI@vcs.savannah.gnu.org>
2016-01-03 13:59 ` [Emacs-diffs] emacs-25 3eb93c0: Rely on conservative stack scanning to find "emacs_value"s Daniel Colascione
2016-01-03 15:45 ` Paul Eggert
2016-03-29 10:07 ` Philipp Stephani
2016-03-29 12:59 ` Stefan Monnier
2016-03-30 1:35 ` Paul Eggert
2016-03-30 18:26 ` Philipp Stephani
2016-03-30 18:28 ` Daniel Colascione
2016-03-30 18:42 ` Paul Eggert
2016-03-30 18:48 ` Daniel Colascione
2016-03-30 21:13 ` Stefan Monnier
2016-03-30 21:18 ` Daniel Colascione
2016-03-30 21:30 ` Stefan Monnier
2016-03-31 18:46 ` Philipp Stephani
2016-03-31 19:24 ` Daniel Colascione
2016-03-31 21:29 ` Stefan Monnier [this message]
2016-04-01 18:34 ` Daniel Colascione
2016-04-01 19:05 ` Stefan Monnier
2016-04-01 19:15 ` Daniel Colascione
2016-04-01 22:46 ` Stefan Monnier
2016-04-03 1:11 ` Daniel Colascione
2016-04-03 5:49 ` Stefan Monnier
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