Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?

From: Andi Kleen
Date: Mon Nov 08 2010 - 06:20:13 EST


Richard Guenther <richard.guenther@xxxxxxxxx> writes:

> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:
>> Andreas Schwab <schwab@xxxxxxxxxxxxxx> writes:
>>>
>>> The asm fails to mention that it modifies *regs.
>>
>> It has a memory clobber, that should be enough, no?
>
> No. A memory clobber does not cover automatic storage.

That's a separate problem.

> Btw, I can't see a testcase anywhere so I just assume Andreas got
> it right as usual.

An asm with live inputs and outputs should never be optimized
way. If 4.5.1 started doing that it's seriously broken.

-Andi

--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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