Date: Sat, 5 May 2018 00:38:33 +0200 From: Mateusz Guzik <mjguzik@gmail.com> To: Brooks Davis <brooks@freebsd.org> Cc: Mateusz Guzik <mjg@freebsd.org>, src-committers <src-committers@freebsd.org>, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r333240 - in head/sys: powerpc/powerpc sys Message-ID: <CAGudoHGQo1-wGfMssQTCkGYxsVTeBb6zKXbJJJvA%2Bw6q-Fzamw@mail.gmail.com> In-Reply-To: <20180504155301.GA56280@spindle.one-eyed-alien.net> References: <201805040400.w4440moH025057@repo.freebsd.org> <20180504155301.GA56280@spindle.one-eyed-alien.net>
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On Fri, May 4, 2018 at 5:53 PM, Brooks Davis <brooks@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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