lkml.org 
[lkml]   [2010]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: Big git diff speedup by avoiding x86 "fast string" memcmp
Date

Nick Piggin:
> It's not scaling but just single threaded performance. gcc turns memcmp
> into rep cmp, which has quite a long latency, so it's not appripriate
> for short strings.

Honestly speaking I doubt how this 'long *' approach is effective
(Of course it never means that your result (by 'char *') is doubtful).
But is the "rep cmp has quite a long latency" issue generic for all x86
architecture, or Westmere system specific?


J. R. Okajima


\
 
 \ /
  Last update: 2010-12-13 08:39    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site