Re: Types in C

From	"BartC" <bc@freeuk.com>
Newsgroups	comp.lang.c
Subject	Re: Types in C
Date	2011-05-25 01:29 +0100
Organization	A noiseless patient Spider
Message-ID	<irhijf$ibt$1@dont-email.me> (permalink)
References	(7 earlier) <slrnitlt2f.19ga.usenet-nospam@guild.seebs.net> <5e3bc1901a4e1d6-bdea9@gmail.com> <slrnitm1l4.1hcs.usenet-nospam@guild.seebs.net> <3f20bcd1c8b23d8-db1ae@gmail.com> <slrnitmcfj.1niq.usenet-nospam@guild.seebs.net>

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"Seebs" <usenet-nospam@seebs.net> wrote in message 
news:slrnitmcfj.1niq.usenet-nospam@guild.seebs.net...
> On 2011-05-24, Uncle Steve <stevet810@gmail.com> wrote:
>> I suppose it's possible, but that seems a bit like putting the cart
>> before the horse.  If I say "do not blaspheme" because it might
>> piss-off God, I am presupposing the existence of God, which could very
>> well be false.  You are presupposing that a hardware manufacturer is
>> going to build a CPU with those characteristics.  How likely is that?
>
> I've used several.  There have been MANY systems where larger types were
> faster than smaller types.  It's common.
>
> Idle question:  Have you ever used an Intel processor?  Like, an x86?
>
> I wrote a little routine which does a trivial tight loop on objects.
>
> chars: 4.084635 secs.
> shorts: 4.161859 secs.
> ints: 2.729034 secs.
> longs: 3.284039 secs.
> quads: 3.134092 secs.
>
> So, if you "knew" that you needed a 16-bit type, and used short, you'd
> be taking a 50% performance hit for picking an inefficient type.  If all
> you need is "can store values up to 30000", that would be silly.  Heck,

I've just written a routine where using short is 10% faster than int, 
because it allocates a large number of them and therefore uses half the 
memory (and half the bandwidth).

Not much difference, but in other cases using a wider type than is necessary 
can cause more severe problems ...

> you'd get better performance on *64-bit* objects than you would on
> 16-bit shorts.

... such as running out of memory completely.

-- 
Bartc

Thread

Types in C jacob navia <jacob@spamsink.net> - 2011-05-22 21:29 +0200
  Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-22 12:48 -0700
  Re: Types in C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-22 23:03 +0100
    Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-23 10:35 +0200
      Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-23 08:40 -0700
        Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 17:19 +0000
          Re: Types in C John Gordon <gordon@panix.com> - 2011-05-23 17:54 +0000
            Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-23 11:33 -0700
              Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-23 11:44 -0700
            Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 19:08 +0000
          Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-23 20:50 +0200
            Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-23 12:11 -0700
              Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 19:45 +0000
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-23 13:03 -0700
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-23 22:25 +0200
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-23 14:38 -0700
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-23 23:45 +0200
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 22:02 +0000
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-24 00:10 +0200
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-23 22:12 +0200
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-23 13:27 -0700
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-23 22:33 +0200
                Re: Types in C Martin Ambuhl <mambuhl@earthlink.net> - 2011-05-24 03:17 -0400
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-24 10:55 +0200
                Re: Types in C Ian Collins <ian-news@hotmail.com> - 2011-05-24 09:29 +1200
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-23 23:42 +0200
                Re: Types in C Ian Collins <ian-news@hotmail.com> - 2011-05-24 09:51 +1200
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-24 00:04 +0200
                Re: Types in C Ian Collins <ian-news@hotmail.com> - 2011-05-24 10:57 +1200
                Re: Types in C David Thompson <dave.thompson2@verizon.net> - 2011-06-01 16:33 -0400
                Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-23 19:33 -0500
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-24 08:27 -0700
                Re: Types in C Tim Rentsch <txr@alumni.caltech.edu> - 2011-05-31 00:40 -0700
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-31 11:32 +0200
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-31 11:30 -0700
                Re: Types in C Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-01 01:23 -0700
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 16:51 -0400
                Re: Types in C Ian Collins <ian-news@hotmail.com> - 2011-05-24 09:25 +1200
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-23 23:40 +0200
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-24 08:36 -0700
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 17:53 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 22:24 +0000
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 19:23 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 23:57 +0000
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 21:22 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-24 03:46 +0000
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-24 00:24 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-24 04:44 +0000
                Re: Types in C pete <pfiland@mindspring.com> - 2011-05-24 07:46 -0400
                Re: Types in C James Kuyper <jameskuyper@verizon.net> - 2011-05-24 07:48 -0400
                Re: Types in C Ian Collins <ian-news@hotmail.com> - 2011-05-24 10:35 +1200
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 22:38 +0000
                Re: Types in C Ian Collins <ian-news@hotmail.com> - 2011-05-24 10:53 +1200
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 23:17 +0000
                Re: Types in C Ian Collins <ian-news@hotmail.com> - 2011-05-24 11:24 +1200
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 23:39 +0000
                Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-24 11:23 +0200
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-24 08:46 -0700
                Re: Types in C Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-05-24 09:14 -0700
                Re: Types in C Michael Press <rubrum@pacbell.net> - 2011-05-28 21:50 -0700
                Re: Types in C "io_x" <a@b.c.invalid> - 2011-06-07 19:50 +0200
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 19:33 -0400
                Re: Types in C Ian Collins <ian-news@hotmail.com> - 2011-05-24 12:03 +1200
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 21:27 -0400
                Re: Types in C Ian Collins <ian-news@hotmail.com> - 2011-05-24 13:47 +1200
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 23:45 -0400
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-24 00:07 -0700
                Re: Types in C James Kuyper <jameskuyper@verizon.net> - 2011-05-24 08:05 -0400
                Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-23 19:54 -0500
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 21:03 -0400
                Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-23 22:12 -0500
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-24 00:03 -0400
                Re: Types in C pete <pfiland@mindspring.com> - 2011-05-24 00:19 -0400
                Re: Types in C pete <pfiland@mindspring.com> - 2011-05-24 00:20 -0400
                Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-24 00:46 -0500
                Re: Types in C pete <pfiland@mindspring.com> - 2011-05-24 07:36 -0400
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-24 10:58 -0400
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-24 09:40 -0700
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-24 21:36 -0400
                Re: Types in C David Thompson <dave.thompson2@verizon.net> - 2011-06-01 16:33 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-24 16:50 +0000
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-24 21:10 -0400
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-24 18:19 -0700
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-24 21:42 -0400
                Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-24 23:47 -0500
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-25 10:13 -0400
                Re: Types in C Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-05-24 22:19 -0600
                Re: Types in C Dr Nick <3-nospam@temporary-address.org.uk> - 2011-05-25 07:04 +0100
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-25 08:53 -0700
                Re: Types in C Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-05-25 10:11 -0600
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-24 09:02 -0700
                Re: Types in C James Kuyper <jameskuyper@verizon.net> - 2011-05-24 07:37 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 22:02 +0000
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 18:15 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 22:25 +0000
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 19:39 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-23 23:57 +0000
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 21:10 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-24 01:58 +0000
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-23 23:56 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-24 04:32 +0000
                Re: Types in C "BartC" <bc@freeuk.com> - 2011-05-25 01:29 +0100
                Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-23 22:20 -0500
                Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-23 22:42 -0500
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-24 00:07 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-24 04:44 +0000
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-24 10:24 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-24 16:50 +0000
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-24 21:16 -0400
                Re: Types in C Seebs <usenet-nospam@seebs.net> - 2011-05-25 03:36 +0000
                Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-24 01:26 -0500
                Re: Types in C Uncle Steve <stevet810@gmail.com> - 2011-05-24 11:04 -0400
                Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-24 09:06 -0700
            Re: Types in C David Thompson <dave.thompson2@verizon.net> - 2011-06-01 16:33 -0400
  Re: Types in C Marcin Grzegorczyk <mgrzegor@poczta.onet.pl> - 2011-05-30 22:42 +0200
    Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-30 17:45 -0500
      Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-05-31 08:47 -0700
        Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-31 13:54 -0400
    Re: Types in C jacob navia <jacob@spamsink.net> - 2011-05-31 00:16 +0200
      Re: Types in C Shao Miller <sha0.miller@gmail.com> - 2011-05-30 18:30 -0500
      Re: Types in C Marcin Grzegorczyk <mgrzegor@poczta.onet.pl> - 2011-06-02 22:44 +0200
        Re: Types in C jacob navia <jacob@spamsink.net> - 2011-06-02 22:49 +0200
          Re: Types in C Keith Thompson <kst-u@mib.org> - 2011-06-02 15:26 -0700

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