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From: "H. Peter Anvin" <hpa@zytor.com>
To: Jike Song <albcamus@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>,
	tglx@linutronix.de, mingo@redhat.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86: fix inline assembly constraints
Date: Wed, 29 Oct 2008 20:54:58 -0700	[thread overview]
Message-ID: <49093012.7010301@zytor.com> (raw)
In-Reply-To: <df9815e70810291931i4c00966u8f4493386e376b28@mail.gmail.com>

Jike Song wrote:
> 
> Besides, by looking at the inline assembly in kernel,  I found lots of
> codes like this:
> 
>         static inline void atomic_add(int i, atomic_t *v)
>         {
> 	        asm volatile(LOCK_PREFIX "addl %1,%0"
> 		             : "=m" (v->counter)
> 		             : "ir" (i), "m" (v->counter));
>         }
> 
> 
> Yes, it works. But a little ugly..  Should this be cleaned-up with the
> following?
> 
>         : "+m" (v->counter)
>         : "ir" (i)
> 
> If you agrees, I'll send out the patch; otherwise I won't wasting your time ;-)
> 

Please don't change them just to change them, if there is no actual
error.  You never know when you're going to trigger a new bug in some
weird version of gcc.

	-hpa

  reply	other threads:[~2008-10-30  3:55 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-29 16:32 Jike Song
2008-10-29 16:32 ` Jike Song
2008-10-29 16:34 ` Ingo Molnar
2008-10-30  2:31   ` Jike Song
2008-10-30  3:54     ` H. Peter Anvin [this message]
2008-10-30  6:40       ` Jike Song
2008-10-30 14:51         ` H. Peter Anvin
2008-10-30 19:29     ` Ingo Molnar
2008-10-31  2:12       ` Jike Song
     [not found] <fa.IZJ3RdF6xWbbMqWVWyYRstzZBsk@ifi.uio.no>
     [not found] ` <fa.L4yER0Vo1brqQzpHIySgWqUN5UM@ifi.uio.no>
     [not found]   ` <fa.rs0w7okAn1If1ilwD81OTzT4rKg@ifi.uio.no>
2008-10-30  3:52     ` Robert Hancock

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