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author | Torbjorn Granlund <tege@gmplib.org> | 2010-11-11 09:56:42 +0100 |
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committer | Torbjorn Granlund <tege@gmplib.org> | 2010-11-11 09:56:42 +0100 |
commit | fb80223734ba92b2a182f29b00751e509dbece06 (patch) | |
tree | 014931d1dc5a4f1024644986a489c3859f1df727 /rand/randbui.c | |
parent | 5b824f09ff34399acf7458217a903c928f7eb83b (diff) | |
download | gmp-fb80223734ba92b2a182f29b00751e509dbece06.tar.gz |
Move global random file to new 'rand' subdirectory.
Diffstat (limited to 'rand/randbui.c')
-rw-r--r-- | rand/randbui.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/rand/randbui.c b/rand/randbui.c new file mode 100644 index 000000000..5fc49b27d --- /dev/null +++ b/rand/randbui.c @@ -0,0 +1,46 @@ +/* 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 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" + + +/* 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 LIMBS_PER_ULONG > 1 + a[1] = 0; +#endif + + _gmp_rand (a, rstate, MIN (bits, BITS_PER_ULONG)); + +#if LIMBS_PER_ULONG == 1 + return a[0]; +#else + return a[0] | (a[1] << GMP_NUMB_BITS); +#endif +} |