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From: "H. Peter Anvin" <hpa@zytor.com>
To: Borislav Petkov <bp@suse.de>, Ingo Molnar <mingo@kernel.org>,
	ling.ma.program@gmail.com, mingo@redhat.com, tglx@linutronix.de,
	linux-kernel@vger.kernel.org, Ma Ling <ling.ml@alipay.com>
Subject: Re: [Suggestion] [x86]: Compiler Option Os is better on latest x86
Date: Thu, 24 Jan 2013 09:35:29 -0600	[thread overview]
Message-ID: <510154C1.4060601@zytor.com> (raw)
In-Reply-To: <20130124152544.GA13504@pd.tnic>

On 01/24/2013 09:25 AM, Borislav Petkov wrote:
> On Thu, Jan 24, 2013 at 08:56:26AM -0600, H. Peter Anvin wrote:
>> There has been occasional talk about a -Ok(ernel) option to gcc, but
>> that would require someone to go through gcc and figure out what bits
>> makes sense and which don't...
> 
> Yep, such an option has a great potential for us and, if done right,
> would be very cool. It could probably be taught to insert HWEIGHT,
> RDRAND, CLFLUSH and whatever other insns we have the inline asm versions
> for... and query CPUID before that... uuh, nice stuff.
> 
> The alternative would be to fork gcc and call it kcc...
> 
> /me runs away pretty quickly without even turning back :-)
> 

I don't expect we'll be teaching gcc about the alternatives mechanism.
-Ok was about optimization, basically a "sane -Os".

	-hpa


  reply	other threads:[~2013-01-24 15:36 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-26  6:32 [Suggestion] [x86]: Compiler Option Os is better on latest x86 ling.ma.program
2013-01-24 14:17 ` Ingo Molnar
2013-01-24 14:46   ` Borislav Petkov
2013-01-24 14:56     ` H. Peter Anvin
2013-01-24 15:25       ` Borislav Petkov
2013-01-24 15:35         ` H. Peter Anvin [this message]
     [not found] <1356939140-4113-1-git-send-email-ling.ma@alipay.com>
2012-12-31  7:52 ` Ling Ma

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