svn commit: r333240 - in head/sys: powerpc/powerpc sys

Mateusz Guzik mjguzik at gmail.com
Fri May 4 22:38:34 UTC 2018


On Fri, May 4, 2018 at 5:53 PM, Brooks Davis <brooks at freebsd.org> wrote:

> On Fri, May 04, 2018 at 04:00:48AM +0000, Mateusz Guzik wrote:
> > Author: mjg
> > Date: Fri May  4 04:00:48 2018
> > New Revision: 333240
> > URL: https://svnweb.freebsd.org/changeset/base/333240
> >
> > Log:
> >   Allow __builtin_memmove instead of bcopy for small buffers of known
> size
>
> What is the justification for forcing a size rather than using the
> compiler's built-in fallback to memmove?  Is the kernel compilation
> environment disabling that?
>
>
It will fallback to memmove which is super pessimized as being wrapped
around bcopy.

These limits will get lifted after the fallback routines get sorted out.

-- 
Mateusz Guzik <mjguzik gmail.com>


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