lkml.org 
[lkml]   [2007]   [Aug]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] memchr (trivial) optimization
On Thu, Aug 23, 2007 at 06:03:29PM -0700, Jeremy Fitzhardinge wrote:
> Matt Mackall wrote:
> > 6e: 38 08 cmp %cl,(%eax)
> > 70: 74 07 je 79 <memchr3+0x1b>
> > 72: 40 inc %eax
> >
> It's a bit gross that the compiler is using inc here rather than lea or
> add, but still...
>
> Er, something's spending 30% of its time in memchr? This is not the
> code to fix.

Indeed. I'm just pointing out the general optimization of walking
one counter instead of two.

Hmm, perhaps the culprit is validate_nla?

--
Mathematics is the supreme nostalgia of our time.
-
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: 2007-08-24 04:21    [from the cache]
©2003-2011 Jasper Spaans