GNU bug report logs - #11617
Don't use 'register'; these days it's not needed.

Previous Next

Full log

View this message in rfc822 format

From: Eli Zaretskii <eliz <at> gnu.org>
To: Chong Yidong <cyd <at> gnu.org>
Cc: eggert <at> cs.ucla.edu, 11617 <at> debbugs.gnu.org
Subject: bug#11617: Don't use 'register'; these days it's not needed.
Date: Sun, 03 Jun 2012 18:09:07 +0300

> From: Chong Yidong <cyd <at> gnu.org>
> Cc: Paul Eggert <eggert <at> cs.ucla.edu>,  11617 <at> debbugs.gnu.org
> Date: Sun, 03 Jun 2012 22:50:02 +0800
> 
> Eli Zaretskii <eliz <at> gnu.org> writes:
> 
> >> Attached is a patch to remove 'register' from the mainline
> >> Emacs source code.
> >
> > FWIW, I see no compelling reason for this change, even after I've read
> > the explanations.  This keyword is a cue to the compiler, so it in
> > general conveys non-trivial information.  If today's compilers mostly
> > ignore that, it doesn't mean this will always be the state of affairs.
> > However, by removing this, we lose those cues forever.
> 
> I wonder how many of those register variables were actually added after
> profiling to see if they make any difference.  My guess is none,
> i.e. those keywords are bogus.

??? I don't necessarily see the connection between profiling and the
keyword uses.  The way I see it, these are cues to the compiler, they
tell which of the variables are accessed in the inner loops and more
intensively, under the expected data flow.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.