From: Andrew Haley <aph@redhat.com>
To: gcc-help@gcc.gnu.org
Subject: Re: [BUG?] GCC inline assembler optimization issue
Date: Mon, 28 Dec 2009 03:22:00 -0000 [thread overview]
Message-ID: <4B36AB0E.5000605@redhat.com> (raw)
In-Reply-To: <20091227025622.7c5c0c35@godel>
On 12/26/2009 11:56 PM, Dan Kruchinin wrote:
> As I wrote earlier, memory clobber didn't help, but there is an interesting thing:
> I replaced description of the third argument of spin_lock function from "rI" to "r" and it fixed my problem.
> AFAIK the only one thing "I" does and that is describing my argument as a constant in range 0 - 31.
> I don't understand why it so radically changes generated code.
It doesn't. Your problem is the missing clobber on Operand 1
in the asm in spin_unlock.
Andrew.
next prev parent reply other threads:[~2009-12-27 0:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-27 0:28 Dan Kruchinin
2009-12-28 3:22 ` Andrew Haley [this message]
-- strict thread matches above, loose matches on Subject: below --
2009-12-27 0:28 Dan Kruchinin
2009-12-27 0:32 ` Andrew Haley
2009-12-26 23:06 Dan Kruchinin
2009-12-26 23:43 ` Andrew Haley
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