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authorTorbjorn Granlund <tege@gmplib.org>2010-11-11 09:56:42 +0100
committerTorbjorn Granlund <tege@gmplib.org>2010-11-11 09:56:42 +0100
commitfb80223734ba92b2a182f29b00751e509dbece06 (patch)
tree014931d1dc5a4f1024644986a489c3859f1df727 /rand/randbui.c
parent5b824f09ff34399acf7458217a903c928f7eb83b (diff)
downloadgmp-fb80223734ba92b2a182f29b00751e509dbece06.tar.gz
Move global random file to new 'rand' subdirectory.
Diffstat (limited to 'rand/randbui.c')
-rw-r--r--rand/randbui.c46
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
+}