[RC5] To slice or not to slice for SuperSPARC
rguyom at mail.dotcom.fr
Sat Jan 31 23:21:26 EST 1998
TwinTowers || wrote:
> In build 390, there are four different binaries for Solaris platform,
> I understand the "mt" differences. But what about the "slice" part,
> especially for SuperSPARC? Can a "slice" run on a SuperSPARC, which is
> 32-bit? I thought "slice" version is only for UltraSPAR. But when I
> benchmarked both "slice" and "noslice" on a SuperSPARC, they ran fine but
> gave very different rates. "Slice" version achieved 247Kkeys/s whereas
> "noslice" only 89Kkeys/s. The strange thing is, the "slice" version
> displayed the progress meter up to "50%." and immediately terminated with
> the key rate.
"Slice" refer to the bitslice algorithm. This algorithm works on 32 and
64 bits platforms. In theory it will work on any platform, whatever the
About performance : the bitslice algorithm needs large caches to work
efficiently. The current bitslice version use various data strutures for
a total of ~73 KB on a 32 bits platform, and 145 KB on a 64 bits one.
This means that on old Sun box you (perhaps) won't find the bitslice
version faster than the non-bitslice one. That's probably why there is
About the progress meter : it's only a cosmetic bug.
RÈmi Don't waste your computer's time. Distribute it!
RC5 cores source code : http://wwwperso.hol.fr/~guyom001/
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