blob: 36afdd44706670bf0e4ec79b86d7573703f4b692 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
/*
Copyright 2011 Jun Wako <wakojun@gmail.com>
This program is free software: you can redistribute it and/or modify
it under the terms of 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.
This program 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 a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "util.h"
// bit population
int bitpop(uint8_t bits)
{
int c;
for (c = 0; bits; c++)
bits &= bits -1;
return c;
}
// most significant on-bit
int biton(uint8_t bits)
{
int n = 0;
if (bits >> 4) { bits >>= 4; n += 4;}
if (bits >> 2) { bits >>= 2; n += 2;}
if (bits >> 1) { bits >>= 1; n += 1;}
return n;
}
|
