[mythtv-users] Compiler optimizations
mmcconnell at uniserve.com
Sun Feb 22 12:12:59 EST 2004
The reason I'm surprised, and suspect that it can't be true, is
"generally" compiler optimizations of this nature only yield very minimal
improvement; improvements in the range of 1% - 3% would generally be gained
on some trivial operation calls via compiler optimization. It's very, very
rare to see an improvement of 15% - 20% just through compiler optimization,
however I clearly, and continually see the optimizations made a significant
different. I'm trying to track down where, and what operation call could be
used so heavily in MythTV that a PentiumPro to Pentium3 + FastMath compile
could yield such an improvement.
Ultimately until I can track the point, which result in such different, I'm
still a bit of a sceptic and I see it with my own eyes! (-; Clearly it will
require a "some what trivial" rewrite of whatever is causing this. It must
be bad code.
----- Original Message -----
From: "Joseph A. Caputo" <jcaputo1 at comcast.net>
To: "Discussion about mythtv" <mythtv-users at mythtv.org>
Sent: Sunday, February 22, 2004 6:32 AM
Subject: Re: [mythtv-users] Compiler optimizations
> On Saturday 21 February 2004 21:50, Michael McConnell wrote:
> > The system I'm building on is a Dual P3 800 (mandrake cooker), the
> > I'm executing on is
> > a Dual P3 733 (knoppmyth build).
> > I've conducted the test again, and the results are still similar, which
> > makes little sense...
> > mike
> Am I missing something? I don't understand why you should be surprised.
> expect -march=pentium3 to generate code that took better advantage of P3
> features vs. -march=pentiumpro. Unless it's the --fast-math part that you
> find counter-intuitive?
> mythtv-users mailing list
> mythtv-users at mythtv.org
More information about the mythtv-users