1 /* 2 * Mesa 3-D graphics library 3 * 4 * Copyright (C) 2006 Brian Paul All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included 14 * in all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 22 * OTHER DEALINGS IN THE SOFTWARE. 23 */ 24 25 /** 26 * \file bitset.h 27 * \brief Bitset of arbitrary size definitions. 28 * \author Michal Krol 29 */ 30 31 #ifndef BITSET_H 32 #define BITSET_H 33 34 #include "util/u_math.h" 35 36 /**************************************************************************** 37 * generic bitset implementation 38 */ 39 40 #define BITSET_WORD unsigned int 41 #define BITSET_WORDBITS (sizeof (BITSET_WORD) * 8) 42 43 /* bitset declarations 44 */ 45 #define BITSET_WORDS(bits) (((bits) + BITSET_WORDBITS - 1) / BITSET_WORDBITS) 46 #define BITSET_DECLARE(name, bits) BITSET_WORD name[BITSET_WORDS(bits)] 47 48 /* bitset operations 49 */ 50 #define BITSET_COPY(x, y) memcpy( (x), (y), sizeof (x) ) 51 #define BITSET_EQUAL(x, y) (memcmp( (x), (y), sizeof (x) ) == 0) 52 #define BITSET_ZERO(x) memset( (x), 0, sizeof (x) ) 53 #define BITSET_ONES(x) memset( (x), 0xff, sizeof (x) ) 54 55 #define BITSET_BITWORD(b) ((b) / BITSET_WORDBITS) 56 #define BITSET_BIT(b) (1 << ((b) % BITSET_WORDBITS)) 57 58 /* single bit operations 59 */ 60 #define BITSET_TEST(x, b) ((x)[BITSET_BITWORD(b)] & BITSET_BIT(b)) 61 #define BITSET_SET(x, b) ((x)[BITSET_BITWORD(b)] |= BITSET_BIT(b)) 62 #define BITSET_CLEAR(x, b) ((x)[BITSET_BITWORD(b)] &= ~BITSET_BIT(b)) 63 64 #define BITSET_MASK(b) ((b) == BITSET_WORDBITS ? ~0 : BITSET_BIT(b) - 1) 65 #define BITSET_RANGE(b, e) (BITSET_MASK((e) + 1) & ~BITSET_MASK(b)) 66 67 /* bit range operations 68 */ 69 #define BITSET_TEST_RANGE(x, b, e) \ 70 (BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \ 71 ((x)[BITSET_BITWORD(b)] & BITSET_RANGE(b, e)) : \ 72 (assert (!"BITSET_TEST_RANGE: bit range crosses word boundary"), 0)) 73 #define BITSET_SET_RANGE(x, b, e) \ 74 (BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \ 75 ((x)[BITSET_BITWORD(b)] |= BITSET_RANGE(b, e)) : \ 76 (assert (!"BITSET_SET_RANGE: bit range crosses word boundary"), 0)) 77 #define BITSET_CLEAR_RANGE(x, b, e) \ 78 (BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \ 79 ((x)[BITSET_BITWORD(b)] &= ~BITSET_RANGE(b, e)) : \ 80 (assert (!"BITSET_CLEAR_RANGE: bit range crosses word boundary"), 0)) 81 82 /* Get first bit set in a bitset. 83 */ 84 static inline int 85 __bitset_ffs(const BITSET_WORD *x, int n) 86 { 87 int i; 88 89 for (i = 0; i < n; i++) { 90 if (x[i]) 91 return ffs(x[i]) + BITSET_WORDBITS * i; 92 } 93 94 return 0; 95 } 96 97 #define BITSET_FFS(x) __bitset_ffs(x, ARRAY_SIZE(x)) 98 99 static inline unsigned 100 __bitset_next_set(unsigned i, BITSET_WORD *tmp, 101 const BITSET_WORD *set, unsigned size) 102 { 103 unsigned bit, word; 104 105 /* NOTE: The initial conditions for this function are very specific. At 106 * the start of the loop, the tmp variable must be set to *set and the 107 * initial i value set to 0. This way, if there is a bit set in the first 108 * word, we ignore the i-value and just grab that bit (so 0 is ok, even 109 * though 0 may be returned). If the first word is 0, then the value of 110 * `word` will be 0 and we will go on to look at the second word. 111 */ 112 word = BITSET_BITWORD(i); 113 while (*tmp == 0) { 114 word++; 115 116 if (word >= BITSET_WORDS(size)) 117 return size; 118 119 *tmp = set[word]; 120 } 121 122 /* Find the next set bit in the non-zero word */ 123 bit = ffs(*tmp) - 1; 124 125 /* Unset the bit */ 126 *tmp &= ~(1ull << bit); 127 128 return word * BITSET_WORDBITS + bit; 129 } 130 131 #define BITSET_FOREACH_SET(__i, __tmp, __set, __size) \ 132 for (__tmp = *(__set), __i = 0; \ 133 (__i = __bitset_next_set(__i, &__tmp, __set, __size)) < __size;) 134 135 #endif 136
