summaryrefslogtreecommitdiff
path: root/Build/source/libs/gmp/gmp-6.0.0/mpn/generic/rshift.c
diff options
context:
space:
mode:
Diffstat (limited to 'Build/source/libs/gmp/gmp-6.0.0/mpn/generic/rshift.c')
-rw-r--r--Build/source/libs/gmp/gmp-6.0.0/mpn/generic/rshift.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/Build/source/libs/gmp/gmp-6.0.0/mpn/generic/rshift.c b/Build/source/libs/gmp/gmp-6.0.0/mpn/generic/rshift.c
new file mode 100644
index 00000000000..ec61f2f7e24
--- /dev/null
+++ b/Build/source/libs/gmp/gmp-6.0.0/mpn/generic/rshift.c
@@ -0,0 +1,70 @@
+/* mpn_rshift -- Shift right low level.
+
+Copyright 1991, 1993, 1994, 1996, 2000-2002 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 either:
+
+ * 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.
+
+or
+
+ * the GNU General Public License as published by the Free Software
+ Foundation; either version 2 of the License, or (at your option) any
+ later version.
+
+or both in parallel, as here.
+
+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 General Public License
+for more details.
+
+You should have received copies of the GNU General Public License and the
+GNU Lesser General Public License along with the GNU MP Library. If not,
+see https://www.gnu.org/licenses/. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+/* Shift U (pointed to by up and N limbs long) cnt bits to the right
+ and store the n least significant limbs of the result at rp.
+ The bits shifted out to the right are returned.
+
+ Argument constraints:
+ 1. 0 < cnt < GMP_NUMB_BITS.
+ 2. If the result is to be written over the input, rp must be <= up.
+*/
+
+mp_limb_t
+mpn_rshift (mp_ptr rp, mp_srcptr up, mp_size_t n, unsigned int cnt)
+{
+ mp_limb_t high_limb, low_limb;
+ unsigned int tnc;
+ mp_size_t i;
+ mp_limb_t retval;
+
+ ASSERT (n >= 1);
+ ASSERT (cnt >= 1);
+ ASSERT (cnt < GMP_NUMB_BITS);
+ ASSERT (MPN_SAME_OR_INCR_P (rp, up, n));
+
+ tnc = GMP_NUMB_BITS - cnt;
+ high_limb = *up++;
+ retval = (high_limb << tnc) & GMP_NUMB_MASK;
+ low_limb = high_limb >> cnt;
+
+ for (i = n - 1; i != 0; i--)
+ {
+ high_limb = *up++;
+ *rp++ = low_limb | ((high_limb << tnc) & GMP_NUMB_MASK);
+ low_limb = high_limb >> cnt;
+ }
+ *rp = low_limb;
+
+ return retval;
+}