diff options
author | Joel Challis <git@zvecr.com> | 2021-02-07 23:16:15 +0000 |
---|---|---|
committer | GitHub <noreply@github.com> | 2021-02-07 23:16:15 +0000 |
commit | 99bffc2a21ebed07fd767ad2a9a7e1aadd491ef3 (patch) | |
tree | 499edfaa4b2a180047f7ca5f6bc882e77f5262fa /quantum/bitwise.c | |
parent | 7e828795534f7351df54d2c0545b2ed159b1bfde (diff) |
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.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/quantum/bitwise.c b/quantum/bitwise.c new file mode 100644 index 0000000000..861cca0054 --- /dev/null +++ b/quantum/bitwise.c @@ -0,0 +1,123 @@ +/* +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 - return number of on-bit +__attribute__((noinline)) uint8_t bitpop(uint8_t bits) { + uint8_t c; + for (c = 0; bits; c++) bits &= bits - 1; + return c; + /* + const uint8_t bit_count[] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4 }; + return bit_count[bits>>4] + bit_count[bits&0x0F] + */ +} + +uint8_t bitpop16(uint16_t bits) { + uint8_t c; + for (c = 0; bits; c++) bits &= bits - 1; + return c; +} + +uint8_t bitpop32(uint32_t bits) { + uint8_t c; + for (c = 0; bits; c++) bits &= bits - 1; + return c; +} + +// most significant on-bit - return highest location of on-bit +// NOTE: return 0 when bit0 is on or all bits are off +__attribute__((noinline)) uint8_t biton(uint8_t bits) { + uint8_t 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; +} + +uint8_t biton16(uint16_t bits) { + uint8_t n = 0; + if (bits >> 8) { + bits >>= 8; + n += 8; + } + if (bits >> 4) { + bits >>= 4; + n += 4; + } + if (bits >> 2) { + bits >>= 2; + n += 2; + } + if (bits >> 1) { + bits >>= 1; + n += 1; + } + return n; +} + +uint8_t biton32(uint32_t bits) { + uint8_t n = 0; + if (bits >> 16) { + bits >>= 16; + n += 16; + } + if (bits >> 8) { + bits >>= 8; + n += 8; + } + if (bits >> 4) { + bits >>= 4; + n += 4; + } + if (bits >> 2) { + bits >>= 2; + n += 2; + } + if (bits >> 1) { + bits >>= 1; + n += 1; + } + return n; +} + +__attribute__((noinline)) uint8_t bitrev(uint8_t bits) { + bits = (bits & 0x0f) << 4 | (bits & 0xf0) >> 4; + bits = (bits & 0b00110011) << 2 | (bits & 0b11001100) >> 2; + bits = (bits & 0b01010101) << 1 | (bits & 0b10101010) >> 1; + return bits; +} + +uint16_t bitrev16(uint16_t bits) { + bits = bitrev(bits & 0x00ff) << 8 | bitrev((bits & 0xff00) >> 8); + return bits; +} + +uint32_t bitrev32(uint32_t bits) { + bits = (uint32_t)bitrev16(bits & 0x0000ffff) << 16 | bitrev16((bits & 0xffff0000) >> 16); + return bits; +} |