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/scan1.c | 59 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 gmp-6.3.0/mpn/generic/scan1.c (limited to 'gmp-6.3.0/mpn/generic/scan1.c') diff --git a/gmp-6.3.0/mpn/generic/scan1.c b/gmp-6.3.0/mpn/generic/scan1.c new file mode 100644 index 0000000..09e8060 --- /dev/null +++ b/gmp-6.3.0/mpn/generic/scan1.c @@ -0,0 +1,59 @@ +/* mpn_scan1 -- Scan from a given bit position for the next set bit. + +Copyright 1994, 1996, 2001, 2002, 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 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" +#include "longlong.h" + +/* Argument constraints: + 1. U must sooner or later have a limb != 0. + */ + +mp_bitcnt_t +mpn_scan1 (mp_srcptr up, mp_bitcnt_t starting_bit) +{ + mp_size_t starting_word; + mp_limb_t alimb; + int cnt; + mp_srcptr p; + + /* Start at the word implied by STARTING_BIT. */ + starting_word = starting_bit / GMP_NUMB_BITS; + p = up + starting_word; + alimb = *p++; + + /* Mask off any bits before STARTING_BIT in the first limb. */ + alimb &= - (mp_limb_t) 1 << (starting_bit % GMP_NUMB_BITS); + + while (alimb == 0) + alimb = *p++; + + count_trailing_zeros (cnt, alimb); + return (p - up - 1) * GMP_NUMB_BITS + cnt; +} -- cgit v1.2.3