On Wed, 14 Sep 2005, Chris White wrote:
> That's correct, gcc 3.4 started the -mtune flag. Chances are if you really
> want the -mtune optimizations you're going to have to upgrade to gcc 3.4 or
> greater.
>
> > This, of course, heavily penalizes P4's (the notorious inc/dec).
>
> Are you referring to cpu cycle counts? Is there certain code that causes the
> kernel to perform that unfavorably by a large scale?
It's documented as being suboptimal to use inc/dec due to it modifying all
of eflags resulting in dependency related stalls. add/sub only modifies
one bit of eflags so is more optimal. However there is a problem of
increased code size with add/sub.
But i've never benchmarked all of this ;)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
| |
 |