[PATCH] Enabling Software Prefetching by Default at -O3

[Andi Kleen]

Mark Mitchell <mark@codesourcery.com> writes:
>
> Yes, that might be a good idea for i7.
>
> But, in the meantime, I think we should get a version of the patch that
> turns on prefetching on AMD CPUs with -O3.  There's no reason to demand
> consistency for all CPUs and it clearly benefits the AMD CPUs.
> Changpeng, would you please submit a patch that activates this
> optimization only with tuning for AMD CPUs?

On i7 it will be likely still a win if hardware prefetch is disabled
in the BIOS. Most BIOS have a setting like this.

Unfortunately this cannot be easily detected by a program.

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.