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

[Avi Kivity <avi@qumranet.com>]

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

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/