paul zimmermann <paul.zimmerm...@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 Which works with the real GMP. But it does *not* work with the above definition, since the preprocessor doesn't know how to evaluate sizeof. And I'm not aware of any standard preprocessor constants that could be used instead. I guess one *could* try to evaluate log_2(ULONG_MAX) in the preprocessor using a long sequence of conditionals, but that's not so nice... In Nettle, where I need GMP_NUMB_BITS both for a few #ifdefs in the C code, and to run programs to generate ECC tables, I use a configure check do get the correct value (correct also when cross compiling, thanks to autoconf's clever implementation of AC_COMPUTE_INT). See https://git.lysator.liu.se/nettle/nettle/blob/master/configure.ac#L274 If anyone knows a good way to define it as a preprocessor constant without a configure check, that would be great. Regards, /Niels -- Niels Möller. PGP-encrypted email is preferred. Keyid 368C6677. Internet email is subject to wholesale government surveillance. _______________________________________________ gmp-devel mailing list gmp-devel@gmplib.org https://gmplib.org/mailman/listinfo/gmp-devel
