Re: [Monotone-devel] could we get away with requiring perl during the build, for botan's sake?

[Jack Lloyd]

On Tue, Oct 16, 2007 at 09:49:35AM -0400, Jack Lloyd wrote:
> On Tue, Oct 16, 2007 at 12:30:49PM +0200, Markus Schiltknecht wrote:
> > Hi,
> > 
> > Markus Schiltknecht wrote:
> > >AFAICT botan doesn't provide 
> > >lots of optimized assembler code, yet. So that might not be much of an 
> > >issue, yet.
> > 
> > Sorry, I revoke that statement. There are quite some CPU specific 
> > assembler optimizations in botan. Especially also for SHA-1, which could 
> > serve us very well.
> > 
> > I'm currently trying to measure potential gains on my Core2Duo CPU with 
> > manually configured and added amd64 (ia64) optimizations.
> 
> TBH you won't see much performance increase from the x86-64 SHA-1 asm,
> I saw it at perhaps 5% faster than GCC-compiled C++ on my Core2. RSA
> will be 3-5x faster with the modules alg_amd64 (.S files, AT&T syntax,
> assumes ELF ABI) and mp_amd64 (uses GCC-style inline asm with AT&T
> syntax). I'm not sure about the 32-bit numbers.

Some quick and dirty SHA benchmarks (GCC, Linux, Athlon64 X2 4200, all
in MB/s):

64-bit w/OpenSSL engine (0.9.8a): 229
64-bit w/asm: 195
32-bit w/asm: 190
64-bit C++: 177
32-bit C++: 160

Obviously the x86-64 SHA asm could use some work.

-Jack