From 11da511c784eca003deb90c23570f0873954e0de Mon Sep 17 00:00:00 2001 From: Duncan Wilkie Date: Sat, 18 Nov 2023 06:11:09 -0600 Subject: Initial commit. --- gmp-6.3.0/mpn/generic/lshiftc.c | 73 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 gmp-6.3.0/mpn/generic/lshiftc.c (limited to 'gmp-6.3.0/mpn/generic/lshiftc.c') diff --git a/gmp-6.3.0/mpn/generic/lshiftc.c b/gmp-6.3.0/mpn/generic/lshiftc.c new file mode 100644 index 0000000..a583602 --- /dev/null +++ b/gmp-6.3.0/mpn/generic/lshiftc.c @@ -0,0 +1,73 @@ +/* mpn_lshiftc -- Shift left low level with complement. + +Copyright 1991, 1993, 1994, 1996, 2000-2002, 2009 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-impl.h" + +/* Shift U (pointed to by up and n limbs long) cnt bits to the left + and store the n least significant limbs of the result at rp. + Return the bits shifted out from the most significant limb. + + 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_lshiftc (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_DECR_P (rp, up, n)); + + up += n; + rp += n; + + tnc = GMP_NUMB_BITS - cnt; + low_limb = *--up; + retval = low_limb >> tnc; + high_limb = (low_limb << cnt); + + for (i = n - 1; i != 0; i--) + { + low_limb = *--up; + *--rp = (~(high_limb | (low_limb >> tnc))) & GMP_NUMB_MASK; + high_limb = low_limb << cnt; + } + *--rp = (~high_limb) & GMP_NUMB_MASK; + + return retval; +} -- cgit v1.2.3