1 /*
2 * Copyright (c) 2007 - 2015 Joseph Gaeddert
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 * THE SOFTWARE.
21 */
22
23 //
24 // script to generate c_ones_mod2 table
25 //
26
27 #include <stdio.h>
28
29 // count the number of ones in a byte
30 unsigned int count_ones(unsigned char);
31
main()32 int main() {
33
34 unsigned char c_ones_mod2[256];
35
36 unsigned int b;
37 for (b=0; b<256; b++)
38 c_ones_mod2[b] = count_ones((unsigned char)b) % 2;
39
40 // print results
41 printf("unsigned char c_ones_mod2[] = {\n ");
42 for (b=0; b<256; b++) {
43 printf("%1u", c_ones_mod2[b]);
44 if (b==255)
45 printf("\n");
46 else if (((b+1)%16)==0)
47 printf(",\n ");
48 else
49 printf(", ");
50 }
51 printf("};\n");
52 return 0;
53 }
54
55 // count the number of ones in a byte
count_ones(unsigned char _b)56 unsigned int count_ones(unsigned char _b)
57 {
58 unsigned int i, n=0;
59 for (i=0; i<8; i++) {
60 n += _b & 0x01;
61 _b >>= 1;
62 }
63 return n;
64 }
65