mpz_tdiv_2exp?

Torbjorn Granlund tg at swox.com
Fri Sep 19 17:07:15 CEST 2008


Paul Zimmermann <Paul.Zimmermann at loria.fr> writes:

  is there any reason why there is no mpz_[cft]div_2exp function in GMP?
  Could it be more efficient than the following?
  
     mpz_tdiv_q_2exp (q, n, b);
     mpz_tdiv_r_2exp (r, n, b);
  
I am not sure which function you think is missing.

I believe we have a fairly complete set of functions for division by a
power fo two, with all possible rounding rules.

Perhaps you mean "qr" variants, i.e., mpz_[cft]div_qr_2exp?
We don't have such combined functions since they wouldn't be any faster
than the correspnding separate calls.

-- 
Torbjörn


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