gmp-impl.h assumes 32-bit unsigned int in fft_table_nk

Robert Baruch robert.c.baruch at
Sat Dec 19 04:05:58 UTC 2015

Thanks for the discussion! The fun thing is that I'll try to deal with
integers on the order of 200 decimals (figure on the order of 700 bits). I
think that mini-gmp is billed as "several orders of magnitude slower" than
gmp on numbers over a few hundred bits, so I'd still like to see what gmp
does (with --disable-fft).

On Fri, Dec 18, 2015 at 7:50 AM Torbjörn Granlund <tg at> wrote:

> Marc Glisse <marc.glisse at> writes:
>   We have --disable-fft, maybe the code in gmp-impl.h could be protected
>   by WANT_FFT. gmp_uint_least32_t also looks like it is unlikely to
>   hurt, and we are already using it for other bitfields in the same
>   file.
>   Those changes could make sense whether we support 16 bit systems or not.
> Agreed with both suggestions.  (Our usage of unsigned long as basetype
> is not standards conformant, and it might not work on an environment
> where int is just 2 bytes.)
> --
> Torbjörn
> Please encrypt, key id 0xC8601622

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