From 07fe1d2f96c0850d0a5d1ddc5e69d054b5b7d999 Mon Sep 17 00:00:00 2001 From: hanrot Date: Sun, 21 May 2000 16:35:52 +0000 Subject: Compatibility with mpf. WARNING: THESE FUNCTIONS ARE UNTESTED IN THEIR PRESENT FORM. THEY *DO* COMPILE HOWEVER. git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@524 280ebfd0-de03-0410-8827-d642c229c3f4 --- urandomb.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 urandomb.c (limited to 'urandomb.c') diff --git a/urandomb.c b/urandomb.c new file mode 100644 index 000000000..fd7be497d --- /dev/null +++ b/urandomb.c @@ -0,0 +1,75 @@ +/* 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 (C) 1999, 2000 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 Library General Public License as published by +the Free Software Foundation; either version 2 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 Library General Public +License for more details. + +You should have received a copy of the GNU Library General Public License +along with the GNU MP Library; see the file COPYING.LIB. If not, write to +the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, +MA 02111-1307, USA. */ + +#include +#include "gmp.h" +#include "gmp-impl.h" +#include "mpfr.h" + +void +#if __STDC__ +mpfr_urandomb (mpfr_t rop, gmp_randstate_t rstate, unsigned long int nbits) +#else +mpfr_urandomb (rop, rstate, nbits) + mpfr_t rop; + gmp_randstate_t rstate; + unsigned long int nbits; +#endif +{ + mp_ptr rp; + mp_size_t nlimbs; + mp_exp_t exp; + unsigned long cnt; + + rp = PTR (rop); + nlimbs = (nbits + BITS_PER_MP_LIMB - 1) / BITS_PER_MP_LIMB; + + _gmp_rand (rp, rstate, nbits); + + /* If nbits isn't a multiple of BITS_PER_MP_LIMB, shift up. */ + if (nlimbs != 0) + { + if (nbits % BITS_PER_MP_LIMB != 0) + mpn_lshift (rp, rp, nlimbs, + BITS_PER_MP_LIMB - nbits % BITS_PER_MP_LIMB); + } + + exp = 0; + while (nlimbs != 0 && rp[nlimbs - 1] == 0) + { + nlimbs--; + exp--; + } + + count_leading_zeros(cnt, rp[nlimbs - 1]); + if (cnt) mpn_lshift(rp, rp, nlimbs, cnt); + exp -= cnt; + + cnt = nlimbs*BITS_PER_MP_LIMB - nbits; + /* cnt is the number of non significant bits in the low limb */ + rp[0] &= ~((((mp_limb_t)1)<