[PATCH] Optimize MIPS memcpy

[Steve Ellcey]

On Mon, 2012-10-15 at 13:50 -0700, Andrew Pinski wrote:

Building you could use __OCTEON__ but that does not change the fact
you could build glibc for the standard mips32/mips64 and then not get
a working glibc if it defaults to 32bytes prefetch.

So are you saying that we shouldn't use the 'prepare to store' prefetch
in the glibc memcpy then?  We could use one of the other prefetches
without having to worry about bad code on machines with different size
prefetches, but it would not be as fast as using 'prepare to store'.

> Also it would be nice to use ifunc's like they are used on x86_64 (and
> I think PPC also) so we can compile one generic version of glibc and
> get the optimized version of memcpy.  Though ifunc's have their own
> issue as they don't currently work on MIPS (they cause internal linker
> errors).

I'll have to look at that, I am not familiar with the ifunc's except in
very general terms.

Steve Ellcey
sellcey@mips.com