Possible bug in mini-gmp (gmp-6.0.0)

[Torbjörn Granlund]

Zach Metzinger <zmetzing at pobox.com> writes:

  
  While trying to generate the value (2^N)-1 for N := {8,512} and using 
  the mini-gmp library, I did the following:
  
      mpz_init(m);
      mpz_set_ui(m, 0);
      mpz_setbit(m, n-1);
      mpz_sub_ui(m, m, 1);
  
  This produced, in the case of N == 0:
  
  0x81
  
  While the following code:
  
      mpz_set_ui(t0, 1);
      mpz_mul_2exp(m, t0, n);
      mpz_sub_ui(m, m, 1);
  
  produces the correct result:
  
  0xff

This makes no sense.

You need to send a complete stripped down executable test case.


-- 
Torbjörn
Please encrypt, key id 0xC8601622