mini-gmp

[Vincent Lefevre]

On 2018-12-15 09:48:41 +0100, Niels Möller wrote:
> paul zimmermann <Paul.Zimmermann at inria.fr> writes:
> 
> > would it be possible to move the following from mini-gmp.c to mini-gmp.h?
> >
> > #define GMP_LIMB_BITS (sizeof(mp_limb_t) * CHAR_BIT)
> >
> > It would expose GMP_LIMB_BITS to applications using mini-gmp,
> > without requiring them to redefine it.
> 
> The reason it's not already in mini-gmp.h, is that I'd expect
> applications to want to do things like
> 
> #if GMP_LIMB_BITS == 64
> ...
> #endif

Yes, this is expected by MPFR. But since mini-gmp.c includes
mini-gmp.h, this prevents one from redefining GMP_LIMB_BITS
in mini-gmp.h, except by exactly the same content, which is
not interesting.

I suggest either:

#undef GMP_LIMB_BITS
#define GMP_LIMB_BITS (sizeof(mp_limb_t) * CHAR_BIT)

in order to allow the redefinition in case it was already defined,
or

#ifndef GMP_LIMB_BITS
#define GMP_LIMB_BITS (sizeof(mp_limb_t) * CHAR_BIT)
#endif

The latter one is better, IMHO, in the rare case
(sizeof(mp_limb_t) * CHAR_BIT) was a wrong guess.

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Vincent Lefèvre <vincent at vinc17.net> - Web: <https://www.vinc17.net/>
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