paul zimmermann <paul.zimmerm...@inria.fr> writes: > would it be possible to add mpn_invert_limb in the public interface? > It would be very useful for GNU MPFR.
Makes sense to me, it's a useful and well-defined operations, and discussed at length in various papers. So should be quite easy to document. As far as I understand, it's not always compiled into the library, though. Internally the code uses the macro invert_limb, which expands to a call to mpn_invert_limb only if there exists a native implementation, otherwise, the macro expands to a call to udiv_qrnnd. Not sure if there's any problem with always making mpn_invert_limb a real function and call it explicitly. In the cases where it expands to udiv_qrnnd, it's probably so slow that an extra level of function call shouldn't matter much. Looking at longlong.h, there appears to be some cases where udiv_qrnnd is in turn defined as mpn_invert_limb + udiv_qrnnd_preinv (not entirely clear when that might happen, seems possible only for alpha, arm, cray, and ia64). And there's some room for cleanup in longlong.h, for example a few #if 0, and some constants (UMUL_TIME and UDIV_TIME) which are no longer used, as far as I can see, and most recently mentioned in ChangeLog back in 2002. Regards, /Niels -- Niels Möller. PGP-encrypted email is preferred. Keyid C0B98E26. Internet email is subject to wholesale government surveillance. _______________________________________________ gmp-devel mailing list gmp-devel@gmplib.org https://gmplib.org/mailman/listinfo/gmp-devel
