From: Tobias Burnus <burnus@net-b.de>
To: Richard Guenther <rguenther@suse.de>
Cc: gcc@gcc.gnu.org
Subject: Re: [RFC] Introduce -Ofast
Date: Thu, 06 May 2010 15:22:00 -0000 [thread overview]
Message-ID: <4BE2DE92.2090608@net-b.de> (raw)
In-Reply-To: <alpine.LNX.2.00.1005061613520.1429@zhemvz.fhfr.qr>
On 05/06/2010 04:24 PM, Richard Guenther wrote:
> I would initially propose to make -Ofast be -O3 -ffast-math
> and would strongly encourage target maintainers that consider
> adding to -Ofast make sure that popular benchmarks for
> their target still behave correctly when using -Ofast.
I am in favour of the suggestion.
How about also adding "-march=native" (for targets where it is
available)? Otherwise, one may end up, e.g. on x86, to compile for i386
- and then -O3 -ffast-math won't help. But also on other systems
configuring for the compile system is useful - but it should be
overridable. Another option one could consider is -funroll-loops.
(Intel's "-fast" also implies "-xHost". Pathscale (always) defaults to
"-march=auto", Portland also [unless "-tp..." is used].)
Tobias
next prev parent reply other threads:[~2010-05-06 15:22 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-06 14:24 Richard Guenther
2010-05-06 15:22 ` Tobias Burnus [this message]
2010-05-06 20:26 ` Ian Lance Taylor
2010-05-07 3:46 ` Dave Korn
2010-05-07 13:59 ` Mark Mitchell
2010-05-13 21:29 ` Diego Novillo
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