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Groups > comp.lang.c > #385811
| From | Tim Rentsch <tr.17687@z991.linuxsc.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Good hash for pointers |
| Date | 2024-06-09 18:31 -0700 |
| Organization | A noiseless patient Spider |
| Message-ID | <86le3dlh24.fsf@linuxsc.com> (permalink) |
| References | (10 earlier) <86ed9ofq14.fsf@linuxsc.com> <20240605005916.00001b33@yahoo.com> <v3vkvp$268b2$1@raubtier-asyl.eternal-september.org> <v4441o$3f3lt$1@raubtier-asyl.eternal-september.org> <v45hmd$3t9dq$1@dont-email.me> |
Malcolm McLean <malcolm.arthur.mclean@gmail.com> writes:
> On 09/06/2024 12:35, Bonita Montero wrote:
>
>> uint64_t MichaelsHash( uint64_t key )
>> {
>> __m128i xkey = _mm_set_epi64x( key, 42 );
>> using bar_t = pair<uint64_t, uint64_t>;
>> static bar_t const bars[8] =
>> {
>> { 0xBB09BBCC90B24BF2, 0x825C622FF2792A01 },
>> { 0x94F0535CB06D4060, 0x939C756246DBFD1D },
>> { 0x5B835E01A7E14CA1, 0xAC2BDAFC023CDD06 },
>> { 0xE0B6A4735B774AEC, 0x9CAFB43E7DDE494C },
>> };
>> for( bar_t const &bar : bars )
>> xkey = _mm_aesenc_si128( xkey, _mm_set_epi64x( bar.second,
>> bar.first ) );
>> return xkey.m128i_u64[0];
>> }
>>
>> Now the code is about six times faster and I get a eight times
>> speedup over single-threaded processing with the same code. Of
>> course the results are still the same.
>
> I have your permission to drop that in?
Note that this code was cribbed from Michael S. If you
think it's important to ask permission, I think he is
the one you should be asking.
By the way, I thought you were looking for code that works
in standard C, and acceptable under C90 rules. Have you
changed your mind about that? The code above is a far
cry from C, let alone C90.
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-05 00:59 +0300
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-05 11:10 +0200
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-05 12:34 +0300
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-05 12:05 +0200
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-05 13:11 +0300
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-05 08:58 -0700
AES problem (was: Good hash for pointers) Michael S <already5chosen@yahoo.com> - 2024-06-05 19:51 +0300
Re: AES problem (was: Good hash for pointers) Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-05 21:24 -0700
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-05 19:59 +0300
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-05 21:40 -0700
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-06 11:00 +0300
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-17 00:56 -0700
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-17 12:39 +0300
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 10:47 -0700
Re: Good hash for pointers Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 15:17 -0700
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 16:17 -0700
Re: Good hash for pointers James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-18 19:23 -0400
Re: Good hash for pointers Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 17:17 -0700
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-06 13:35 +0300
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-16 04:38 -0700
Re: Good hash for pointers "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-06-16 12:34 -0700
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-07 20:53 +0200
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-09 13:35 +0200
Re: Good hash for pointers Richard Harnden <richard.nospam@gmail.invalid> - 2024-06-09 12:40 +0100
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-09 15:09 +0200
Re: Good hash for pointers Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-06-10 01:34 +0100
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-09 18:31 -0700
Re: Good hash for pointers Michael S <already5chosen@yahoo.com> - 2024-06-10 15:14 +0300
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-10 14:40 +0200
Re: Good hash for pointers Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-15 20:32 -0700
Re: Good hash for pointers Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-10 09:35 +0200
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