15a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin/* 25a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * Copyright (C) 2011 The Android Open Source Project 35a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * 45a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * Licensed under the Apache License, Version 2.0 (the "License"); 55a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * you may not use this file except in compliance with the License. 65a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * You may obtain a copy of the License at 75a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * 85a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * http://www.apache.org/licenses/LICENSE-2.0 95a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * 105a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * Unless required by applicable law or agreed to in writing, software 115a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * distributed under the License is distributed on an "AS IS" BASIS, 125a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 135a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * See the License for the specific language governing permissions and 145a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin * limitations under the License. 155a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin */ 165a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin 175a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin#ifndef __CUTILS_BITOPS_H 185a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin#define __CUTILS_BITOPS_H 195a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin 2081ec96df4f83df9781368c6f2b8160ee1b177f75Alex Ray#include <stdbool.h> 212111bc7b28af06757fa8108bab045188d4b337fdAlex Ray#include <string.h> 222111bc7b28af06757fa8108bab045188d4b337fdAlex Ray#include <strings.h> 235a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin#include <sys/cdefs.h> 245a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin 255a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin__BEGIN_DECLS 265a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin 272111bc7b28af06757fa8108bab045188d4b337fdAlex Ray/* 282111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * Bitmask Operations 292111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * 302111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * Note this doesn't provide any locking/exclusion, and isn't atomic. 312111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * Additionally no bounds checking is done on the bitmask array. 322111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * 332111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * Example: 342111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * 352111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * int num_resources; 362111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * unsigned int resource_bits[BITS_TO_WORDS(num_resources)]; 372111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * bitmask_init(resource_bits, num_resources); 382111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * ... 392111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * int bit = bitmask_ffz(resource_bits, num_resources); 402111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * bitmask_set(resource_bits, bit); 412111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * ... 422111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * if (bitmask_test(resource_bits, bit)) { ... } 432111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * ... 442111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * bitmask_clear(resource_bits, bit); 452111bc7b28af06757fa8108bab045188d4b337fdAlex Ray * 462111bc7b28af06757fa8108bab045188d4b337fdAlex Ray */ 472111bc7b28af06757fa8108bab045188d4b337fdAlex Ray 482111bc7b28af06757fa8108bab045188d4b337fdAlex Ray#define BITS_PER_WORD (sizeof(unsigned int) * 8) 492111bc7b28af06757fa8108bab045188d4b337fdAlex Ray#define BITS_TO_WORDS(x) (((x) + BITS_PER_WORD - 1) / BITS_PER_WORD) 502111bc7b28af06757fa8108bab045188d4b337fdAlex Ray#define BIT_IN_WORD(x) ((x) % BITS_PER_WORD) 512111bc7b28af06757fa8108bab045188d4b337fdAlex Ray#define BIT_WORD(x) ((x) / BITS_PER_WORD) 522111bc7b28af06757fa8108bab045188d4b337fdAlex Ray#define BIT_MASK(x) (1 << BIT_IN_WORD(x)) 532111bc7b28af06757fa8108bab045188d4b337fdAlex Ray 542111bc7b28af06757fa8108bab045188d4b337fdAlex Raystatic inline void bitmask_init(unsigned int *bitmask, int num_bits) 552111bc7b28af06757fa8108bab045188d4b337fdAlex Ray{ 562111bc7b28af06757fa8108bab045188d4b337fdAlex Ray memset(bitmask, 0, BITS_TO_WORDS(num_bits)*sizeof(unsigned int)); 572111bc7b28af06757fa8108bab045188d4b337fdAlex Ray} 582111bc7b28af06757fa8108bab045188d4b337fdAlex Ray 592111bc7b28af06757fa8108bab045188d4b337fdAlex Raystatic inline int bitmask_ffz(unsigned int *bitmask, int num_bits) 602111bc7b28af06757fa8108bab045188d4b337fdAlex Ray{ 612111bc7b28af06757fa8108bab045188d4b337fdAlex Ray int bit, result; 622111bc7b28af06757fa8108bab045188d4b337fdAlex Ray unsigned int i; 632111bc7b28af06757fa8108bab045188d4b337fdAlex Ray 642111bc7b28af06757fa8108bab045188d4b337fdAlex Ray for (i = 0; i < BITS_TO_WORDS(num_bits); i++) { 652111bc7b28af06757fa8108bab045188d4b337fdAlex Ray bit = ffs(~bitmask[i]); 662111bc7b28af06757fa8108bab045188d4b337fdAlex Ray if (bit) { 672111bc7b28af06757fa8108bab045188d4b337fdAlex Ray // ffs is 1-indexed, return 0-indexed result 682111bc7b28af06757fa8108bab045188d4b337fdAlex Ray bit--; 692111bc7b28af06757fa8108bab045188d4b337fdAlex Ray result = BITS_PER_WORD * i + bit; 702111bc7b28af06757fa8108bab045188d4b337fdAlex Ray if (result >= num_bits) 712111bc7b28af06757fa8108bab045188d4b337fdAlex Ray return -1; 722111bc7b28af06757fa8108bab045188d4b337fdAlex Ray return result; 732111bc7b28af06757fa8108bab045188d4b337fdAlex Ray } 742111bc7b28af06757fa8108bab045188d4b337fdAlex Ray } 752111bc7b28af06757fa8108bab045188d4b337fdAlex Ray return -1; 762111bc7b28af06757fa8108bab045188d4b337fdAlex Ray} 772111bc7b28af06757fa8108bab045188d4b337fdAlex Ray 78f90fd9eeb32469e41c8f4207afa44929f9ec070eAlex Raystatic inline int bitmask_weight(unsigned int *bitmask, int num_bits) 79f90fd9eeb32469e41c8f4207afa44929f9ec070eAlex Ray{ 80f90fd9eeb32469e41c8f4207afa44929f9ec070eAlex Ray int i; 81f90fd9eeb32469e41c8f4207afa44929f9ec070eAlex Ray int weight = 0; 82f90fd9eeb32469e41c8f4207afa44929f9ec070eAlex Ray 83f90fd9eeb32469e41c8f4207afa44929f9ec070eAlex Ray for (i = 0; i < BITS_TO_WORDS(num_bits); i++) 84f90fd9eeb32469e41c8f4207afa44929f9ec070eAlex Ray weight += __builtin_popcount(bitmask[i]); 85f90fd9eeb32469e41c8f4207afa44929f9ec070eAlex Ray return weight; 86f90fd9eeb32469e41c8f4207afa44929f9ec070eAlex Ray} 87f90fd9eeb32469e41c8f4207afa44929f9ec070eAlex Ray 882111bc7b28af06757fa8108bab045188d4b337fdAlex Raystatic inline void bitmask_set(unsigned int *bitmask, int bit) 892111bc7b28af06757fa8108bab045188d4b337fdAlex Ray{ 902111bc7b28af06757fa8108bab045188d4b337fdAlex Ray bitmask[BIT_WORD(bit)] |= BIT_MASK(bit); 912111bc7b28af06757fa8108bab045188d4b337fdAlex Ray} 922111bc7b28af06757fa8108bab045188d4b337fdAlex Ray 932111bc7b28af06757fa8108bab045188d4b337fdAlex Raystatic inline void bitmask_clear(unsigned int *bitmask, int bit) 942111bc7b28af06757fa8108bab045188d4b337fdAlex Ray{ 952111bc7b28af06757fa8108bab045188d4b337fdAlex Ray bitmask[BIT_WORD(bit)] &= ~BIT_MASK(bit); 962111bc7b28af06757fa8108bab045188d4b337fdAlex Ray} 972111bc7b28af06757fa8108bab045188d4b337fdAlex Ray 982111bc7b28af06757fa8108bab045188d4b337fdAlex Raystatic inline bool bitmask_test(unsigned int *bitmask, int bit) 992111bc7b28af06757fa8108bab045188d4b337fdAlex Ray{ 1002111bc7b28af06757fa8108bab045188d4b337fdAlex Ray return bitmask[BIT_WORD(bit)] & BIT_MASK(bit); 1012111bc7b28af06757fa8108bab045188d4b337fdAlex Ray} 1022111bc7b28af06757fa8108bab045188d4b337fdAlex Ray 1035a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavinstatic inline int popcount(unsigned int x) 1045a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin{ 1055a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin return __builtin_popcount(x); 1065a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin} 1075a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin 1085a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavinstatic inline int popcountl(unsigned long x) 1095a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin{ 1105a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin return __builtin_popcountl(x); 1115a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin} 1125a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin 1135a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavinstatic inline int popcountll(unsigned long long x) 1145a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin{ 1155a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin return __builtin_popcountll(x); 1165a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin} 1175a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin 1185a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin__END_DECLS 1195a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin 1205a809b90e91d2ccf4c84181d10d175eb2c1c6bc7Dima Zavin#endif /* __CUTILS_BITOPS_H */ 121