Changing CFLAGS for i386 packages on x86_64 (benchmarks included)
dragoran
dragoran at feuerpokemon.de
Sun Jul 16 12:31:48 UTC 2006
Dave Jones wrote:
> On Sun, Jul 16, 2006 at 08:15:46AM -0400, Dave Jones wrote:
> > On Sun, Jul 16, 2006 at 02:10:22PM +0200, dragoran wrote:
> > > I did same benchmarks using flops.c (attached) the results are attached
> > > to it seems that
> > > -march=k8 -mtune=k8 -m32 is the fastes but not by much ...
>
> Additionally, whilst you found these flags speed things up
> slightly on AMD systems, it may have a noticable detrimental
> impact on Intel systems, and shipping multiple sets of binaries
> for a negligable speedup doesn't make a lot of sense.
>
>
this might be true but unfortunatelly I don't have a system to test
(only dc opteron running FC5 and amd64 3000+ running rawhide)
> > > the last one (-m64) is weird (much slower!!) no -OX was used.
>
> When run in 32bit, this is doubling the amount of loads/stores used,
> so little wonder it's slower.
>
what do you mean by "when run in 32bit" ? the resulting binary was a
x86_64 one ??
> Dave
>
>
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