diff options
author | Kevin Ryde <user42@zip.com.au> | 2003-03-29 00:35:02 +0100 |
---|---|---|
committer | Kevin Ryde <user42@zip.com.au> | 2003-03-29 00:35:02 +0100 |
commit | ad871fe05af096df436d96b5a2c862b1076ab834 (patch) | |
tree | 82b401c66c1692b78053324487275fb9a5cfa5d4 /randbui.c | |
parent | 49b292e1138647e5b8a293591b2b339ec6e4d635 (diff) | |
download | gmp-ad871fe05af096df436d96b5a2c862b1076ab834.tar.gz |
* randbui.c, randmui.c: New files.
Diffstat (limited to 'randbui.c')
-rw-r--r-- | randbui.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/randbui.c b/randbui.c new file mode 100644 index 000000000..c43ea07cd --- /dev/null +++ b/randbui.c @@ -0,0 +1,48 @@ +/* gmp_urandomb_ui -- random bits returned in a ulong. + +Copyright 2003 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., 59 Temple Place - Suite 330, Boston, +MA 02111-1307, USA. */ + +#include "gmp.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. */ + +unsigned long +gmp_urandomb_ui (gmp_randstate_ptr rstate, unsigned long bits) +{ + mp_limb_t a[LIMBS_PER_ULONG]; + + /* 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 GMP_NAIL_BITS != 0 + a[1] = 0; +#endif + + _gmp_rand (a, rstate, MIN (bits, BITS_PER_ULONG)); + +#if GMP_NAIL_BITS == 0 + return a[0]; +#else + return a[0] | (a[1] << GMP_NUMB_BITS); +#endif +} |