]>
git.gir.st - tmk_keyboard.git/blob - common/util.c
2 Copyright 2011 Jun Wako <wakojun@gmail.com>
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 // bit population - return number of on-bit
21 uint8_t bitpop(uint8_t bits
)
24 for (c
= 0; bits
; c
++)
28 const uint8_t bit_count[] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4 };
29 return bit_count[bits>>4] + bit_count[bits&0x0F]
33 uint8_t bitpop16(uint16_t bits
)
36 for (c
= 0; bits
; c
++)
41 uint8_t bitpop32(uint32_t bits
)
44 for (c
= 0; bits
; c
++)
49 // most significant on-bit - return highest location of on-bit
50 // NOTE: return 0 when bit0 is on or all bits are off
51 uint8_t biton(uint8_t bits
)
54 if (bits
>> 4) { bits
>>= 4; n
+= 4;}
55 if (bits
>> 2) { bits
>>= 2; n
+= 2;}
56 if (bits
>> 1) { bits
>>= 1; n
+= 1;}
60 uint8_t biton16(uint16_t bits
)
63 if (bits
>> 8) { bits
>>= 8; n
+= 8;}
64 if (bits
>> 4) { bits
>>= 4; n
+= 4;}
65 if (bits
>> 2) { bits
>>= 2; n
+= 2;}
66 if (bits
>> 1) { bits
>>= 1; n
+= 1;}
70 uint8_t biton32(uint32_t bits
)
73 if (bits
>>16) { bits
>>=16; n
+=16;}
74 if (bits
>> 8) { bits
>>= 8; n
+= 8;}
75 if (bits
>> 4) { bits
>>= 4; n
+= 4;}
76 if (bits
>> 2) { bits
>>= 2; n
+= 2;}
77 if (bits
>> 1) { bits
>>= 1; n
+= 1;}
83 uint8_t bitrev(uint8_t bits
)
85 bits
= (bits
& 0x0f)<<4 | (bits
& 0xf0)>>4;
86 bits
= (bits
& 0b00110011)<<2 | (bits
& 0b11001100)>>2;
87 bits
= (bits
& 0b01010101)<<1 | (bits
& 0b10101010)>>1;
91 uint16_t bitrev16(uint16_t bits
)
93 bits
= bitrev(bits
& 0x00ff)<<8 | bitrev((bits
& 0xff00)>>8);
97 uint32_t bitrev32(uint32_t bits
)
99 bits
= (uint32_t)bitrev16(bits
& 0x0000ffff)<<16 | bitrev16((bits
& 0xffff0000)>>16);