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Date:      Wed, 14 Mar 2001 15:12:41 -0800
From:      Alex Zepeda <jazepeda@pacbell.net>
To:        hackers@FreeBSD.ORG
Subject:   Re: optimizing apache with php and nfs mounts
Message-ID:  <20010314151241.B62712@zippy.mybox.zip>
In-Reply-To: <20010314025840.A93046@dragon.nuxi.com>; from TrimYourCc@NUXI.com on Wed, Mar 14, 2001 at 02:58:40AM -0800
References:  <Pine.BSO.4.21.0103121542460.23058-100000@gandalf.bravenet.com> <Pine.BSF.4.33.0103122226150.60221-100000@sdmail0.sd.bmarts.com> <20010313074140.B75117@dragon.nuxi.com> <20010313122053.A1339@zippy.mybox.zip> <20010313125119.X29888@fw.wintelcom.net> <20010314011931.D549@zippy.mybox.zip> <20010314025840.A93046@dragon.nuxi.com>

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On Wed, Mar 14, 2001 at 02:58:40AM -0800, David O'Brien wrote:

> I won't even to there...

Well, the only reason I mentioned it.. was that the pgcc folks don't seem
to be too delusioned about the dangers.  -ON (N > 2) is regarded as at
least possibly in danger of generating incorrect code.

> Not untested -- but you should go grab a graduate text on compiler
> optimizations and familiarize yourself with the complexity of the problem.

Care to recommend any starting places.  You've piqued my interest.

> If hello_world.c showed a problem with an optimization, I guarantee it
> would be fixed.

Of course depending on the problem.

> The current test case of holding up the entire FreeBSD
> kernel as showing an optimization problem doesn't cut it.  If you care to
> trim it down to a single module showing the problem....

Well I've just made buildworld with CFLAGS = "-O2 -march=pentiumpro
-malign-double" from a world built with the same flags.  Not so sure of
any performance impact however.

- alex

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