X-POP3-Rcpt: mlehmann AT universe DOT sgh-net DOT de
Message-ID: <19980125020825.22422@cerebro.laendle>
25 Jan 1998 02:08:25 +0100
From: Marc Lehmann <pcg AT goof DOT com>
To: Dustin Marquess <jailbird AT alcatraz DOT fdf DOT net>
Cc: beastium <beastium-list AT Desk DOT nl>
Subject: Re: -malign-double & zgv
References: <199801240204 DOT VAA29208 AT ppp-x9-16.> <Pine DOT LNX DOT 3 DOT 96 DOT 980124104522 DOT 1000C-100000 AT sanitarium DOT fdf DOT net>
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In-Reply-To: <Pine.LNX.3.96.980124104522.1000C-100000@sanitarium.fdf.net>; from Dustin Marquess on Sat, Jan 24, 1998 at 10:46:45AM -0600
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On Sat, Jan 24, 1998 at 10:46:45AM -0600, Dustin Marquess wrote:
> On Fri, 23 Jan 1998, Dinesh Somasekhar wrote:
> 
> > Hi,
> > 
> >   You   were right,   -mamdk6  seems  to   the  best   for  the  cyrix
> >   6x86.     Surprisingly   -mamdk6    and    -mamdk6  -fno-risc  bench
> >   identically. The  -mamdk6 opt fixes core  dumps (SEGV). Almost every
> >   one of the results is better except for  FP emulation, and the float
> >   benchmarks. Maybe you should just set -mcyrix to -mamdk6 :-).
> > 
> > f) pgcc -mamdk6 -O6 -malign-double -malign-loops=4 -malign-jumps=4
> >    -malign-functions=4 -Wall -Wno-unused
> 
> 	Hmmm... When compiling zgv on my 6x86/200, zgv won't run right
> when compiled with -malign-double.  It doesn't seem to mind the other
> switches though.

-malign-double breaks the abi... libjpeg for example is sensitive to this,
so you have to recompile libjpeg with -malign-double, too (and ALL
applications using it as a shared library), or alternatively get rid of the
-malign-double, the speed shouldn't be affected (in zgv).

In my system, I compiled applications myself, so I normally can specify
this flag safely. Recently, though, I recompiled xv, gimp & the hdf
libraries without -malign-double... how do I shoot myself into the foot?


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      ---==---(_)__  __ ____  __       Marc Lehmann       +--
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    The choice of a GNU generation                        |
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