Igor Schein on Wed, 26 Oct 2005 23:36:43 +0200

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Re: GMP performance on Opteron

On Tue, Oct 25, 2005 at 10:56:34PM +0200, Guillaume Hanrot wrote:
> > As far as I understand, GMP 4.x is not optimised on Opteron as much 
> > as on ix86 or sparc, while PARI include assembly code for Opteron, so it
> > might be that PARI is faster for small operands. 
> > 
> > You might want to try the patch I sent for lower GMP overhead to see
> > if it make a difference, see
> > <http://pari/archives/pari-dev-0508/msg00019.html>.
> ... or (and) you can recompile GMP with the assembly routines 
> for Opteron written by Pierrick Gaudry, see 
> http://www.loria.fr/~gaudry/mpn_AMD64/
> which should give a significant speedup. 

Indeed, 3.5x faster for command in question.  Very impressive, thanks
for the link.  I haven't tried Bill's patch for comparison yet, will
post separately once I do.