Re: Number of 32-bit words in an integer

[Karim Belabas <Karim.Belabas@math.u-bordeaux.fr>]

* Charles Greathouse [2017-01-30 18:41]:
> Is there a nicer way to compute the number of 32-bit words in a given
> integer than what I'm doing now?
> 
> #ifdef LONG_IS_64BIT
>     long words = (lgefint(n) - 2) << 1;
>     if ((ulong)*int_MSW(n) <= 0xFFFFFFFF)
>         words--;
> #else
>     long words = lgefint(n) - 2;
> #endif

  (expi(n) + 31) >> 5

? (But your version will be faster :-)

Cheers,

    K.B.
--
Karim Belabas, IMB (UMR 5251)  Tel: (+33) (0)5 40 00 26 17
Universite de Bordeaux         Fax: (+33) (0)5 40 00 21 23
351, cours de la Liberation    http://www.math.u-bordeaux.fr/~kbelabas/
F-33405 Talence (France)       http://pari.math.u-bordeaux.fr/  [PARI/GP]
`