mirror of
https://review.haiku-os.org/buildtools
synced 2025-01-19 21:01:18 +01:00
99d8158635
git-svn-id: file:///srv/svn/repos/haiku/buildtools/trunk@29042 a95241bf-73f2-0310-859d-f6bbb57e9c96
82 lines
2.3 KiB
C
82 lines
2.3 KiB
C
/* mpfr_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 2000, 2001, 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
|
|
Contributed by the Arenaire and Cacao projects, INRIA.
|
|
|
|
This file is part of the MPFR Library.
|
|
|
|
The MPFR 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 2.1 of the License, or (at your
|
|
option) any later version.
|
|
|
|
The MPFR 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 MPFR Library; see the file COPYING.LIB. If not, write to
|
|
the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
|
|
MA 02110-1301, USA. */
|
|
|
|
|
|
#define MPFR_NEED_LONGLONG_H
|
|
#include "mpfr-impl.h"
|
|
|
|
int
|
|
mpfr_urandomb (mpfr_ptr rop, gmp_randstate_t rstate)
|
|
{
|
|
mp_ptr rp;
|
|
mp_prec_t nbits;
|
|
mp_size_t nlimbs;
|
|
mp_size_t k; /* number of high zero limbs */
|
|
mp_exp_t exp;
|
|
int cnt;
|
|
|
|
MPFR_CLEAR_FLAGS(rop);
|
|
|
|
rp = MPFR_MANT(rop);
|
|
nbits = MPFR_PREC(rop);
|
|
nlimbs = MPFR_LIMB_SIZE(rop);
|
|
MPFR_SET_POS (rop);
|
|
|
|
_gmp_rand (rp, rstate, nlimbs * BITS_PER_MP_LIMB);
|
|
|
|
/* If nbits isn't a multiple of BITS_PER_MP_LIMB, mask the low bits */
|
|
cnt = nlimbs * BITS_PER_MP_LIMB - nbits;
|
|
if (MPFR_LIKELY(cnt != 0))
|
|
rp[0] &= ~MPFR_LIMB_MASK (cnt);
|
|
|
|
exp = 0;
|
|
k = 0;
|
|
while (nlimbs != 0 && rp[nlimbs - 1] == 0)
|
|
{
|
|
k ++;
|
|
nlimbs --;
|
|
exp -= BITS_PER_MP_LIMB;
|
|
}
|
|
|
|
if (MPFR_LIKELY(nlimbs != 0)) /* otherwise value is zero */
|
|
{
|
|
count_leading_zeros (cnt, rp[nlimbs - 1]);
|
|
if (mpfr_set_exp (rop, exp - cnt))
|
|
{
|
|
MPFR_SET_NAN (rop);
|
|
__gmpfr_flags |= MPFR_FLAGS_NAN; /* Can't use MPFR_RET_NAN */
|
|
return 1;
|
|
}
|
|
if (cnt != 0)
|
|
mpn_lshift (rp + k, rp, nlimbs, cnt);
|
|
if (k)
|
|
MPN_ZERO (rp, k);
|
|
}
|
|
else
|
|
MPFR_SET_ZERO(rop);
|
|
|
|
return 0;
|
|
}
|