lkml.org 
[lkml]   [2007]   [Jan]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: kernel + gcc 4.1 = several problems


On Wed, 3 Jan 2007, Alan wrote:
>
> > cmov is effectively the same cost as a compare and jump, in both cases
> > the cpu needs to do a prediction, and on a mispredict, restart.
>
> On a P4 it appears to be slower than compare/jump in most cases

On just about EVERYTHING it's slower than compare/jump. See my other post
on why, together with a (largely untested) test app.

Linus
-
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: 2009-11-18 23:46    [W:0.685 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site