lkml.org 
[lkml]   [2007]   [Aug]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] i386: optimize memset of 6 and 8 bytes
    On Fri, 17 Aug 2007 18:57:00 -0700
    Arjan van de Ven <arjan@infradead.org> wrote:

    >
    > On Fri, 2007-08-17 at 18:54 -0700, Stephen Hemminger wrote:
    > > On Fri, 17 Aug 2007 18:49:34 -0700
    > > Arjan van de Ven <arjan@infradead.org> wrote:
    > >
    > > >
    > > > On Fri, 2007-08-17 at 16:50 -0700, Stephen Hemminger wrote:
    > > > > Tne network code does memset for 6 and 8 byte values, that can easily
    > > > > be optimized into simple assignments without string instructions.
    > > >
    > > >
    > > > so... question.
    > > > Why are we doing this by hand? Wouldn't gcc just generate this code in
    > > > the first place (when using __builtin_memset)? I very much suspect it
    > > > would (and if some version doesn't.... we really ought to get that
    > > > fixed)
    > >
    > > i386 and x86_64 are not using __builtin_memset, as least from the
    > > code that I see generated.
    >
    > .. maybe we should just fix it that way then?
    >
    There probably is history behind the decision, like gcc problems
    on some old compiler version.

    --
    Stephen Hemminger <shemminger@linux-foundation.org>
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-08-18 05:35    [W:3.187 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site