X-Spam-Check-By:	sourceware.org
MIME-Version:	1.0
Subject:	RE: possible compiler optimization error
Date:	Thu, 28 Jun 2007 16:11:18 -0400
Message-ID:	<C6EEDB0EB45A56439F73B1D23E39694A35C856@USORL02P702.ww007.siemens.net>
In-Reply-To:	<46840F0E.9EA8612B@dessent.net>
References:	<BAY108-F1181298FD58A847ABB9088BE090 AT phx DOT gbl> <46840F0E DOT 9EA8612B AT dessent DOT net>
From:	"Frederich, Eric P21322" <eric DOT frederich AT siemens DOT com>
To:	<cygwin AT cygwin DOT com>
X-IsSubscribed:	yes
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Unsubscribe:	<mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com
X-MIME-Autoconverted:	from quoted-printable to 8bit by delorie.com id l5SKBVH1007256

> -----Original Message-----
> From: cygwin-owner AT cygwin DOT com On Behalf Of Brian Dessent
> Sent: Thursday, June 28, 2007 3:42 PM
> To: cygwin AT cygwin DOT com
> Subject: Re: possible compiler optimization error
> 
>
> But both of these are too new to be in Cygwin's gcc 3.4.x so this is
> kind of off-topic.
> 
> Brian
> 

To bring things back on topic.  The programs I am porting from Solaris
to Linux and Windows need to run on a variety of hardware.  Without
using -march and creating different libraries and binaries for each
piece of hardware, what would a good set of compiler options be?

You said that combining -march=i686 and -msse2 didn't make too much
sense.
So without setting -march, what all should I be setting?
On my laptop with CPU-Z I see MMX, SSE, and SSE2.
On my Opteron Linux box I obviously see a lot more when I cat
/proc/cpuinfo.

If I just use what is common between them, -mmmx, -msse, and -msse2 I
should be free of floating point errors and hopefully get some
performance increase.  Should I be using -mmmx if I'm also using -msse
and -msse2?

I am comfortable locking out users without sse and sse2 since most of
our users are using computers that are no more than 2 or 3 years old.

Again, thanks a lot for your help.

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

- Raw text -