/* gmp_urandomb_ui -- random bits returned in a ulong. Copyright 2003, 2004 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 2.1 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; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include "mpir.h" #include "gmp-impl.h" /* Currently bits>=BITS_PER_ULONG is quietly truncated to BITS_PER_ULONG, maybe this should raise an exception or something. */ mpir_ui gmp_urandomb_ui (gmp_randstate_ptr rstate, mpir_ui bits) { mp_limb_t a[LIMBS_PER_UI]; /* start with zeros, since if bits==0 then _gmp_rand will store nothing at all, or if bits <= GMP_NUMB_BITS then it will store only a[0] */ a[0] = 0; #if LIMBS_PER_UI > 1 a[1] = 0; #endif _gmp_rand (a, rstate, MIN (bits, BITS_PER_UI)); #if LIMBS_PER_UI == 1 return a[0]; #else return a[0] | (a[1] << GMP_NUMB_BITS); #endif }