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/* mpf_urandomb (rop, state, nbits) -- Generate a uniform pseudorandom
real number between 0 (inclusive) and 1 (exclusive) of size NBITS,
using STATE as the random state previously initialized by a call to
gmp_randinit().
Copyright 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or (at your
option) any later version.
The GNU MP Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
#include "gmp.h"
#include "gmp-impl.h"
void
mpf_urandomb (mpf_t rop, gmp_randstate_t rstate, unsigned long int nbits)
{
mp_ptr rp;
mp_size_t nlimbs;
mp_exp_t exp;
mp_size_t prec;
rp = PTR (rop);
nlimbs = BITS_TO_LIMBS (nbits);
prec = PREC (rop);
if (nlimbs > prec + 1 || nlimbs == 0)
{
nlimbs = prec + 1;
nbits = nlimbs * GMP_NUMB_BITS;
}
_gmp_rand (rp, rstate, nbits);
/* If nbits isn't a multiple of GMP_NUMB_BITS, shift up. */
if (nbits % GMP_NUMB_BITS != 0)
mpn_lshift (rp, rp, nlimbs, GMP_NUMB_BITS - nbits % GMP_NUMB_BITS);
exp = 0;
while (nlimbs != 0 && rp[nlimbs - 1] == 0)
{
nlimbs--;
exp--;
}
EXP (rop) = exp;
SIZ (rop) = nlimbs;
}
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