82 lines
1.8 KiB
C
82 lines
1.8 KiB
C
/* bits.c - bits.h tests
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*
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* Copyright (C) 2021 Bruno Raoult ("br")
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* Licensed under the GNU General Public License v3.0 or later.
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* Some rights reserved. See COPYING.
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*
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* You should have received a copy of the GNU General Public License along with this
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* program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.htmlL>.
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*
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* SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
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*
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*/
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#include "bits.h"
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#ifdef BIN_bits
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#include <stdio.h>
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#include <stdlib.h>
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static inline int _popcount64(u64 n)
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{
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int count = 0;
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while (n) {
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count++;
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n &= (n - 1);
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}
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return count;
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}
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static inline int _ctz64(u64 n)
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{
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return _popcount64((n & -n) - 1);
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}
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static inline int _clz64(u64 n)
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{
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u64 r, q;
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r = (n > 0xFFFFFFFF) << 5; n >>= r;
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q = (n > 0xFFFF) << 4; n >>= q; r |= q;
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q = (n > 0xFF ) << 3; n >>= q; r |= q;
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q = (n > 0xF ) << 2; n >>= q; r |= q;
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q = (n > 0x3 ) << 1; n >>= q; r |= q;
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r |= (n >> 1);
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return __WORDSIZE - r - 1;
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}
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static inline int _ffs64(u64 n)
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{
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if (n == 0)
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return (0);
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return _popcount64(n ^ ~-n);
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}
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int main(int ac, char **av)
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{
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u64 u = 123, _tmp;
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int curbit;
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int base = 10;
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debug_init(0);
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if (ac > 2)
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base = atoi(*(av+2));
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if (ac > 1) {
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u = strtoul(*(av+1), NULL, base);
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printf("base=%d input=%#lx\n", base, u);
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printf("popcount64(%lu) = %d/%d\n", u, popcount64(u), _popcount64(u));
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printf("ctz64(%lu) = %d/%d\n", u, ctz64(u), _ctz64(u));
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printf("clz64(%lu) = %d/%d\n", u, clz64(u), _clz64(u));
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printf("ffs64(%lu) = %d/%d\n", u, ffs64(u), _ffs64(u));
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printf("\n");
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bit_for_each64(curbit, _tmp, u) {
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printf("loop: curbit=%d\n", curbit);
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}
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}
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return 0;
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}
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#endif /* BIN_bits */
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