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| From | Kaz Kylheku <kaz@kylheku.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Function pointer vs conditional branch |
| Date | 2012-01-05 01:25 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <20120104172059.667@kylheku.com> (permalink) |
| References | <je2jb2$886$1@speranza.aioe.org> <je2tiv$2j2$1@dont-email.me> |
On 2012-01-05, Eric Sosman <esosman@ieee-dot-org.invalid> wrote:
> Here's a counter-question: Does it matter? Estimate, pray,
> the amount of time spent dispatching to one rendering function or
> another versus the amount of time spent in that function actually
> doing the rendering. Let's see: A smallish 640x480 image has 50K
> pixels, depending on image characteristics that's anywhere from
> 50K to 200K values to compute, 50K pixel-to-pixel navigations to
> figure out ("Have I hit the end of a row?"), ... And you're
> worried about the once-per-rendering cost of deciding which
> function to call?
My reaction (hitherto unwritten) was that he must be just handing the images
off to some very fast hardware to care about the dispatch speed.
> I've mentioned an old friend's metaphor more than once, but
> I think it applies rather strongly here: You're cleaning the bottle
> caps and cigarette butts off the beach, to make the sand nice and
> neat around the whale carcases.
That little beauty doesn't apply that well; if you keep using it, you will soon
wear a hole right through!
Here, we may have a case of borrowing a motorcycle for the last 50 meters
of a marathon.
(Well, that might be attractive, depending on what shape you're in, but
it won't make a big difference to your time.)
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Function pointer vs conditional branch Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2012-01-04 22:20 +0000
Re: Function pointer vs conditional branch Kaz Kylheku <kaz@kylheku.com> - 2012-01-04 22:46 +0000
Re: Function pointer vs conditional branch Ian Collins <ian-news@hotmail.com> - 2012-01-05 11:47 +1300
Re: Function pointer vs conditional branch Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-01-04 20:15 -0500
Re: Function pointer vs conditional branch Kaz Kylheku <kaz@kylheku.com> - 2012-01-05 01:25 +0000
Re: Function pointer vs conditional branch Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-01-04 20:36 -0500
Re: Function pointer vs conditional branch Kaz Kylheku <kaz@kylheku.com> - 2012-01-05 06:02 +0000
Re: Function pointer vs conditional branch "BartC" <bc@freeuk.com> - 2012-01-05 01:25 +0000
Re: Function pointer vs conditional branch Gene <gene.ressler@gmail.com> - 2012-01-04 17:57 -0800
Re: Function pointer vs conditional branch gordonb.vj0cm@burditt.org (Gordon Burditt) - 2012-01-04 23:54 -0600
Re: Function pointer vs conditional branch 88888 Dihedral <dihedral88888@googlemail.com> - 2012-01-04 23:25 -0800
Re: Function pointer vs conditional branch 88888 Dihedral <dihedral88888@googlemail.com> - 2012-01-04 23:38 -0800
Re: Function pointer vs conditional branch Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2012-01-05 13:47 -0700
Re: Function pointer vs conditional branch Nobody <nobody@nowhere.com> - 2012-01-05 21:29 +0000
Re: Function pointer vs conditional branch Dr Nick <3-nospam@temporary-address.org.uk> - 2012-01-06 06:44 +0000
Re: Function pointer vs conditional branch BGB <cr88192@hotmail.com> - 2012-01-06 11:41 -0600
Re: Function pointer vs conditional branch Kaz Kylheku <kaz@kylheku.com> - 2012-01-06 18:33 +0000
Re: Function pointer vs conditional branch Willem <willem@toad.stack.nl> - 2012-01-06 21:41 +0000
Re: Function pointer vs conditional branch Stephen Sprunk <stephen@sprunk.org> - 2012-01-06 16:08 -0600
Re: Function pointer vs conditional branch Kaz Kylheku <kaz@kylheku.com> - 2012-01-06 22:35 +0000
Re: Function pointer vs conditional branch BGB <cr88192@hotmail.com> - 2012-01-06 17:00 -0600
Re: Function pointer vs conditional branch Kaz Kylheku <kaz@kylheku.com> - 2012-01-06 23:44 +0000
Re: Function pointer vs conditional branch Stephen Sprunk <stephen@sprunk.org> - 2012-01-06 17:08 -0600
Re: Function pointer vs conditional branch Kaz Kylheku <kaz@kylheku.com> - 2012-01-06 23:49 +0000
Re: Function pointer vs conditional branch jacob navia <jacob@spamsink.net> - 2012-01-07 00:55 +0100
Re: Function pointer vs conditional branch Kaz Kylheku <kaz@kylheku.com> - 2012-01-07 00:07 +0000
Re: Function pointer vs conditional branch "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2012-01-07 06:14 -0800
Re: Function pointer vs conditional branch "BartC" <bc@freeuk.com> - 2012-01-07 14:44 +0000
Re: Function pointer vs conditional branch Robert Wessel <robertwessel2@yahoo.com> - 2012-01-07 14:37 -0600
Re: Function pointer vs conditional branch Kaz Kylheku <kaz@kylheku.com> - 2012-01-07 20:42 +0000
Re: Function pointer vs conditional branch Stephen Sprunk <stephen@sprunk.org> - 2012-01-07 16:47 -0600
Re: Function pointer vs conditional branch Robert Wessel <robertwessel2@yahoo.com> - 2012-01-08 01:49 -0600
Re: Function pointer vs conditional branch Kaz Kylheku <kaz@kylheku.com> - 2012-01-08 08:35 +0000
Re: Function pointer vs conditional branch Stephen Sprunk <stephen@sprunk.org> - 2012-01-07 17:02 -0600
Re: Function pointer vs conditional branch "BartC" <bc@freeuk.com> - 2012-01-06 21:29 +0000
Re: Function pointer vs conditional branch BGB <cr88192@hotmail.com> - 2012-01-06 17:15 -0600
Re: Function pointer vs conditional branch Michael Angelo Ravera <maravera@prodigy.net> - 2012-01-06 23:00 -0800
Re: Function pointer vs conditional branch jgk@panix.com (Joe keane) - 2012-01-07 21:04 +0000
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