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Date: Fri, 27 Sep 1996 21:01:10 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199609271101.VAA20607@godzilla.zeta.org.au>
To: ache@nagual.ru, andreas@klemm.gtn.com
Subject: Re: Please remove this lines from XFree configuration comes by default
Cc: current@freebsd.org, jkh@freebsd.org
Sender: owner-current@freebsd.org
X-Loop: FreeBSD.org
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>> Just found in August Snapshot:
>> 
>> /usr/X11R6/lib/X11/config/FreeBSD.cf:
>...
>I'd also suggest to change the CFLAGS from:
>
>	-m486 -O2
>to:
>	-pipe -O2
>
>since many many people are driving Pentiums where m486 isn't that
>good, and -pipe, because it speeds up compilation. People who
>want to run X usually have enough memory for this.
>
>But if not '-pipe -O2', then at least '-O2' without the -m486 !

There's also a -O2 -m486 recommendation in /etc/make.conf.  -O2
might help for a critical loop in the X server, but I think its
advantages are small or negative for general use.

gcc-2.7.2 allows fixing the -m486 problems for Pentiums:

	-m486 -malign-loops=0 -malign-jumps=2 -malign-functions=2

I think even 4-byte alignment for loops is wasteful since misalignment
doesn't cost (much?) and alignment costs for execing no-ops to fall
through to the loop and for cache to hole these no-ops.

Bruce