Re: [PATCH] KVM: 'asm' operand has impossible constraints

Avi Kivity
2007-01-28T09:45:09Z

S.Çağlar Onur wrote:
> 27 Oca 2007 Cts tarihinde, Avi Kivity şunları yazmıştı:
>
>> The patch looks correct, but I don't understand the gcc error message.
>> Are we sure this isn't a gcc 4.2 bug?
>>
>> "g" appears to be equivalent to "rmi", if "i" is impossible, gcc is free
>> to use "r" or "m", no?
>>
>
> Accorgind to GCC devs. its not a bug
> (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29808), on comment #5 the
> problem described like;
>
> "g" means "r"+"i" so the register allocator in the -O0 case is selecting "r"
> while in the optimize case is selecting "i"
>
>

That's a different bug. The gcc PR has an assembler error message, as
expected, whereas the kvm miscompile has a compiler error, which I don't
understand.

Anyhow, your patch is correct (because selecting "i" is indeed
erroneous) so I'll apply it, but I'm worried that there's a gcc bug in
there that we ought to report.

--
error compiling committee.c: too many arguments to function

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