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| From | 88888 Dihedral <dihedral88888@googlemail.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! |
| Date | 2011-11-26 19:40 -0800 |
| Organization | http://groups.google.com |
| Message-ID | <29635857.168.1322365237185.JavaMail.geo-discussion-forums@prnh1> (permalink) |
| References | (2 earlier) <459390d2-53c4-49cc-9b97-c25337d9007e@o5g2000yqa.googlegroups.com> <14304310.720.1322271627269.JavaMail.geo-discussion-forums@pret21> <77639a05-64f7-41c8-bb3a-c7f3194f16db@v8g2000yqk.googlegroups.com> <19347638.434.1322289811366.JavaMail.geo-discussion-forums@prmr38> <kPydnZ1pJ8wJDE3TnZ2dnUVZ_rSdnZ2d@giganews.com> |
On Saturday, November 26, 2011 3:13:26 PM UTC+8, Joe Wright wrote:
> On 11/26/2011 01:43, 88888 Dihedral wrote:
> > I know that a division in C in some compiler in most CPUs is really slow. I write that in assembly.
>
> Do you? Would you tell me what you know about division that the compiler
> writer doesn't know?
>
> --
> Joe Wright
> "If you rob Peter to pay Paul you can depend on the support of Paul."
I contribute a c function to divide a pointer to an unsigned char array with a known length that produces a remainder of the long real number.
int longreal_divide_mod5( char *longnum, int length)
{
int i;
unsinged long remainder; // 32 or 64 bits, I'll show the 32 bit version
tmp=0;
for( i=0, remainder=0;i<length;i++)
remainder+=longnum[i]; // mod 255 done in the first pass
// assume remainder won't over flow
tmp+= (remainder>>24); //top 8 bits
tmp+= ((remainder)<<8)>>24 ; // another 8 bits
tmp+= ((remainder)<<16)>>24 ; // another 8 bits
tmp+= remainder & 0xff;// final 8 bits
//4 *255<=1020 in 10 bits
while (i=tmp&512) if i { tmp^=512; tmp++};
while (i=tmp&256) if i { tmp^=256; tmp++};
// tmp in a byte now
return tmp%5; //there is another way to avoid the mod
}
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OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-20 11:12 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Ian Collins <ian-news@hotmail.com> - 2011-11-21 08:18 +1300
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Vincenzo Mercuri <vincenzo.mercuri@yahoo.it> - 2011-11-20 20:22 +0100
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-20 11:23 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-20 15:03 -0500
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Kaz Kylheku <kaz@kylheku.com> - 2011-11-20 20:06 +0000
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-20 12:13 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Ian Collins <ian-news@hotmail.com> - 2011-11-21 09:16 +1300
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-20 15:37 -0500
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-11-20 14:15 -0700
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-20 13:45 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-21 00:44 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-21 12:44 +0200
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-21 10:41 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-21 00:53 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! "io_x" <a@b.c.invalid> - 2011-11-24 19:08 +0100
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Martin Ambuhl <mambuhl@earthlink.net> - 2011-11-20 17:32 -0500
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Keith Thompson <kst-u@mib.org> - 2011-11-20 14:55 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-20 16:54 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Keith Thompson <kst-u@mib.org> - 2011-11-20 19:35 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-22 00:39 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Keith Thompson <kst-u@mib.org> - 2011-11-22 13:18 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-24 01:50 -0800
Re: Euler's constant jacob navia <jacob@spamsink.net> - 2011-11-21 12:45 +0100
Re: Euler's constant Vincenzo Mercuri <vincenzo.mercuri@yahoo.it> - 2011-11-21 13:54 +0100
Re: Euler's constant jacob navia <jacob@spamsink.net> - 2011-11-21 14:48 +0100
Re: Euler's constant Vincenzo Mercuri <vincenzo.mercuri@yahoo.it> - 2011-11-21 18:58 +0100
Re: Euler's constant Markus Wichmann <nullplan@gmx.net> - 2011-11-21 14:10 +0100
Re: Euler's constant jacob navia <jacob@spamsink.net> - 2011-11-21 15:36 +0100
Re: Euler's constant 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-21 07:08 -0800
Re: Euler's constant jacob navia <jacob@spamsink.net> - 2011-11-21 16:16 +0100
Re: Euler's constant Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-22 00:44 -0800
Re: Euler's constant Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-21 15:33 +0000
Re: Euler's constant Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-21 08:50 -0800
Re: Euler's constant "BartC" <bc@freeuk.com> - 2011-11-21 17:13 +0000
Re: Euler's constant James Kuyper <jameskuyper@verizon.net> - 2011-11-21 12:29 -0500
Re: Euler's constant Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-21 09:28 -0800
Re: Euler's constant Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-21 23:07 +0000
Re: Euler's constant Kaz Kylheku <kaz@kylheku.com> - 2011-11-21 17:29 +0000
Re: Euler's constant James Kuyper <jameskuyper@verizon.net> - 2011-11-21 12:36 -0500
Re: Euler's constant Keith Thompson <kst-u@mib.org> - 2011-11-21 13:46 -0800
Re: Euler's constant "io_x" <a@b.c.invalid> - 2011-11-24 19:08 +0100
Re: Euler's constant Markus Wichmann <nullplan@gmx.net> - 2011-11-24 20:31 +0100
Re: Euler's constant "io_x" <a@b.c.invalid> - 2011-11-27 11:24 +0100
Re: Euler's constant Markus Wichmann <nullplan@gmx.net> - 2011-11-27 12:09 +0100
Re: Euler's constant "io_x" <a@b.c.invalid> - 2011-11-27 13:33 +0100
Re: Euler's constant Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-21 10:44 -0800
Re: Euler's constant Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-21 22:53 +0000
Re: Euler's constant Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-21 23:51 +0000
Re: Euler's constant 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-22 04:17 -0800
Re: Euler's constant 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-27 17:50 -0800
Re: Euler's constant Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-28 03:09 +0000
Re: Euler's constant 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-28 02:52 -0800
Re: Euler's constant Seebs <usenet-nospam@seebs.net> - 2011-12-28 18:17 +0000
Re: Euler's constant Dr Nick <3-nospam@temporary-address.org.uk> - 2011-12-28 18:49 +0000
Re: Euler's constant 88888 Dihedral <dihedral88888@googlemail.com> - 2012-01-04 04:44 -0800
Re: Euler's constant Robert Wessel <robertwessel2@yahoo.com> - 2012-01-04 12:33 -0600
Re: Euler's constant 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-21 15:07 -0800
Re: Euler's constant "io_x" <a@b.c.invalid> - 2011-11-24 19:08 +0100
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-21 04:00 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-11-21 12:37 +0000
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-21 04:45 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-11-21 13:35 +0000
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-22 00:01 +0200
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-11-22 11:53 +0000
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Keith Thompson <kst-u@mib.org> - 2011-11-22 13:21 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Kleuske <kleuske@nowhere.net> - 2011-11-24 14:50 +0000
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! "io_x" <a@b.c.invalid> - 2011-11-24 14:08 +0100
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! "io_x" <a@b.c.invalid> - 2011-11-24 18:02 +0100
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-25 15:31 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-25 17:40 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-25 22:03 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-25 22:43 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Joe Wright <joewwright@comcast.net> - 2011-11-26 02:13 -0500
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-26 19:40 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-27 15:35 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Ian Collins <ian-news@hotmail.com> - 2011-11-26 20:22 +1300
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-26 10:55 -0500
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Seebs <usenet-nospam@seebs.net> - 2011-11-28 08:32 +0000
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! superpollo <superpollo@tznvy.pbz> - 2011-11-26 12:11 +0100
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-26 10:37 -0500
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! superpollo <superpollo@tznvy.pbz> - 2011-11-26 21:48 +0100
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Keith Thompson <kst-u@mib.org> - 2011-11-28 01:56 -0800
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-28 13:34 -0500
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! James Kuyper <jameskuyper@verizon.net> - 2011-11-28 13:45 -0500
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-28 13:50 -0500
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! James Kuyper <jameskuyper@verizon.net> - 2011-11-28 14:32 -0500
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Kleuske <kleuske@nowhere.net> - 2011-11-28 21:16 +0000
Re: OK. LETS START REAL PROGRAMMING IN C FOR PROBLEMS!!! Keith Thompson <kst-u@mib.org> - 2011-11-28 14:59 -0800
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