[hashcash] Re: Hashcash performance improvements
- From: Adam Back <adam@xxxxxxxxxxxxxxx>
- To: hashcash@xxxxxxxxxxxxx
- Date: Sun, 30 May 2004 19:19:13 +0100
Jonathan Morton wrote:
> Hmm. I suspect a bug in the cpuid test, which I've corrected just now -
> the cpuid instruction clobbers several registers, which need to be
> accounted for along with the actual result code.
That fixed it.
> I did a minor optimisation that might remove a data-dependency stall
> between each round - it appears to be slightly faster on the Athlon, but
> no change on the Pentium-MMX. I also updated the "MMX Compact" routine
> to use optimised assembly in the right places. The latter is still a
> little slower than the MMX Standard routine on both my PCs, so I've
> moved it out of the "preferred" position in the list.
seems a little faster on P4; I also tried turning on -msse -msse2 for a
noticeable speed improvement even on assember versions:
-O3 -funroll-loops -march=pentium3 -mmmx
1705904 ANSI Compact 1-pipe
1487198 ANSI Standard 1-pipe
2071455 ANSI Compact 2-pipe
1611131 ANSI Standard 2-pipe
2974397 AMD64/x86 MMX Compact 1x2-pipe
3741983 AMD64/x86 MMX Standard 1x2-pipe *
-O3 -funroll-loops -march=pentium4 -mmmx
1841293 ANSI Compact 1-pipe
1468373 ANSI Standard 1-pipe
2071455 ANSI Compact 2-pipe
1589061 ANSI Standard 2-pipe
2974397 AMD64/x86 MMX Compact 1x2-pipe
3625046 AMD64/x86 MMX Standard 1x2-pipe *
-O3 -funroll-loops -march=pentium4 -mno-mmx
1901663 ANSI Compact 1-pipe
1432117 ANSI Standard 1-pipe
2000025 ANSI Compact 2-pipe
1589061 ANSI Standard 2-pipe
2974397 AMD64/x86 MMX Compact 1x2-pipe
3625046 AMD64/x86 MMX Standard 1x2-pipe *
-O3 -funroll-loops -march=pentium4 -mmmx -msse -msse2
1841293 ANSI Compact 1-pipe
1506512 ANSI Standard 1-pipe
2109118 ANSI Compact 2-pipe
1611131 ANSI Standard 2-pipe
3052671 AMD64/x86 MMX Compact 1x2-pipe
3866716 AMD64/x86 MMX Standard 1x2-pipe *
>> btw I was thinking it would be useful to have a selection of hardware
>> with linux shell accounts for people who are working on this.
>
> Don't OSDL, or people like them, have a facility for that?
I was thinking of list members. If I can fix up my DSL link/wifi-router
to be more reliable, eg my laptop. I looked a bit and:
http://www.osdl.org/lab_activities/lab_projects/
sounds more kernel focussed.
Adam
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