GMP 5.0.5 build fails with tcc due to x86_64 asm (unknown register...)

[Paul Leyland]

On Wed, 2012-06-20 at 11:41 +0200, Vincent Lefevre wrote:
> On 2012-06-20 11:13:19 +0200, Torbjorn Granlund wrote:
> > Vincent Lefevre <vincent at vinc17.net> writes:
> > 
> >   Not to remove it, but to make it *optional*, i.e. to have a fallback
> >   in C.
> >   
> > Excellent proposal.  Implemented in GMP since the beginning...
> > 
> >   Here it doesn't work with tcc. If you had a fallback in C, things
> >   would be fine.
> > 
> > Please see the manual for how to exercise the fallback.
> 
> But why isn't this detected by configure?
> 
> > (Silently disabling assembly for incapable compilers seem like a very
> > poor idea.)
> 
> Well, perhaps. But I think that a configure test + an error message
> (e.g. "Your compiler does not support the assembly code required by
> GMP. You can configure with --host=none to disable assembly code.")
> would be better than an error with "make".

FWIW, this is The Right Thing to do in my view.

It's friendly, helpful, needs implementing only once and gives a strong
hint that the person might do better to use a more powerful compiler if
the explicit advice is not followed for whatever reason.

Paul