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authorJoel Challis <git@zvecr.com>2021-02-07 23:16:15 +0000
committerGitHub <noreply@github.com>2021-02-07 23:16:15 +0000
commit99bffc2a21ebed07fd767ad2a9a7e1aadd491ef3 (patch)
tree499edfaa4b2a180047f7ca5f6bc882e77f5262fa /quantum/bitwise.c
parent7e828795534f7351df54d2c0545b2ed159b1bfde (diff)
downloadqmk_firmware-99bffc2a21ebed07fd767ad2a9a7e1aadd491ef3.tar.gz
qmk_firmware-99bffc2a21ebed07fd767ad2a9a7e1aadd491ef3.zip
Migrate some tmk_core files to quantum (#11791)
* Migrate some tmk_core files to quantum * Fix build errors
Diffstat (limited to 'quantum/bitwise.c')
-rw-r--r--quantum/bitwise.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/quantum/bitwise.c b/quantum/bitwise.c
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1/*
2Copyright 2011 Jun Wako <wakojun@gmail.com>
3
4This program is free software: you can redistribute it and/or modify
5it under the terms of the GNU General Public License as published by
6the Free Software Foundation, either version 2 of the License, or
7(at your option) any later version.
8
9This program is distributed in the hope that it will be useful,
10but WITHOUT ANY WARRANTY; without even the implied warranty of
11MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12GNU General Public License for more details.
13
14You should have received a copy of the GNU General Public License
15along with this program. If not, see <http://www.gnu.org/licenses/>.
16*/
17
18#include "util.h"
19
20// bit population - return number of on-bit
21__attribute__((noinline)) uint8_t bitpop(uint8_t bits) {
22 uint8_t c;
23 for (c = 0; bits; c++) bits &= bits - 1;
24 return c;
25 /*
26 const uint8_t bit_count[] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4 };
27 return bit_count[bits>>4] + bit_count[bits&0x0F]
28 */
29}
30
31uint8_t bitpop16(uint16_t bits) {
32 uint8_t c;
33 for (c = 0; bits; c++) bits &= bits - 1;
34 return c;
35}
36
37uint8_t bitpop32(uint32_t bits) {
38 uint8_t c;
39 for (c = 0; bits; c++) bits &= bits - 1;
40 return c;
41}
42
43// most significant on-bit - return highest location of on-bit
44// NOTE: return 0 when bit0 is on or all bits are off
45__attribute__((noinline)) uint8_t biton(uint8_t bits) {
46 uint8_t n = 0;
47 if (bits >> 4) {
48 bits >>= 4;
49 n += 4;
50 }
51 if (bits >> 2) {
52 bits >>= 2;
53 n += 2;
54 }
55 if (bits >> 1) {
56 bits >>= 1;
57 n += 1;
58 }
59 return n;
60}
61
62uint8_t biton16(uint16_t bits) {
63 uint8_t n = 0;
64 if (bits >> 8) {
65 bits >>= 8;
66 n += 8;
67 }
68 if (bits >> 4) {
69 bits >>= 4;
70 n += 4;
71 }
72 if (bits >> 2) {
73 bits >>= 2;
74 n += 2;
75 }
76 if (bits >> 1) {
77 bits >>= 1;
78 n += 1;
79 }
80 return n;
81}
82
83uint8_t biton32(uint32_t bits) {
84 uint8_t n = 0;
85 if (bits >> 16) {
86 bits >>= 16;
87 n += 16;
88 }
89 if (bits >> 8) {
90 bits >>= 8;
91 n += 8;
92 }
93 if (bits >> 4) {
94 bits >>= 4;
95 n += 4;
96 }
97 if (bits >> 2) {
98 bits >>= 2;
99 n += 2;
100 }
101 if (bits >> 1) {
102 bits >>= 1;
103 n += 1;
104 }
105 return n;
106}
107
108__attribute__((noinline)) uint8_t bitrev(uint8_t bits) {
109 bits = (bits & 0x0f) << 4 | (bits & 0xf0) >> 4;
110 bits = (bits & 0b00110011) << 2 | (bits & 0b11001100) >> 2;
111 bits = (bits & 0b01010101) << 1 | (bits & 0b10101010) >> 1;
112 return bits;
113}
114
115uint16_t bitrev16(uint16_t bits) {
116 bits = bitrev(bits & 0x00ff) << 8 | bitrev((bits & 0xff00) >> 8);
117 return bits;
118}
119
120uint32_t bitrev32(uint32_t bits) {
121 bits = (uint32_t)bitrev16(bits & 0x0000ffff) << 16 | bitrev16((bits & 0xffff0000) >> 16);
122 return bits;
123}