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authorKevin Ryde <user42@zip.com.au>2003-03-29 00:35:02 +0100
committerKevin Ryde <user42@zip.com.au>2003-03-29 00:35:02 +0100
commitad871fe05af096df436d96b5a2c862b1076ab834 (patch)
tree82b401c66c1692b78053324487275fb9a5cfa5d4 /randbui.c
parent49b292e1138647e5b8a293591b2b339ec6e4d635 (diff)
downloadgmp-ad871fe05af096df436d96b5a2c862b1076ab834.tar.gz
* randbui.c, randmui.c: New files.
Diffstat (limited to 'randbui.c')
-rw-r--r--randbui.c48
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
+}