/* * Mesa 3-D graphics library * * Copyright (C) 2006 Brian Paul All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ /** * \file bitset.h * \brief Bitset of arbitrary size definitions. * \author Michal Krol */ #ifndef BITSET_H #define BITSET_H #include "util/bitscan.h" #include "util/macros.h" /**************************************************************************** * generic bitset implementation */ #define BITSET_WORD unsigned int #define BITSET_WORDBITS (sizeof (BITSET_WORD) * 8) /* bitset declarations */ #define BITSET_WORDS(bits) (((bits) + BITSET_WORDBITS - 1) / BITSET_WORDBITS) #define BITSET_DECLARE(name, bits) BITSET_WORD name[BITSET_WORDS(bits)] /* bitset operations */ #define BITSET_COPY(x, y) memcpy( (x), (y), sizeof (x) ) #define BITSET_EQUAL(x, y) (memcmp( (x), (y), sizeof (x) ) == 0) #define BITSET_ZERO(x) memset( (x), 0, sizeof (x) ) #define BITSET_ONES(x) memset( (x), 0xff, sizeof (x) ) #define BITSET_SIZE(x) (8 * sizeof(x)) // bitset size in bits #define BITSET_BITWORD(b) ((b) / BITSET_WORDBITS) #define BITSET_BIT(b) (1u << ((b) % BITSET_WORDBITS)) /* single bit operations */ #define BITSET_TEST(x, b) (((x)[BITSET_BITWORD(b)] & BITSET_BIT(b)) != 0) #define BITSET_SET(x, b) ((x)[BITSET_BITWORD(b)] |= BITSET_BIT(b)) #define BITSET_CLEAR(x, b) ((x)[BITSET_BITWORD(b)] &= ~BITSET_BIT(b)) #define BITSET_MASK(b) (((b) % BITSET_WORDBITS == 0) ? ~0 : BITSET_BIT(b) - 1) #define BITSET_RANGE(b, e) ((BITSET_MASK((e) + 1)) & ~(BITSET_BIT(b) - 1)) /* logic bit operations */ static inline void __bitset_and(BITSET_WORD *r, const BITSET_WORD *x, const BITSET_WORD *y, unsigned n) { for (unsigned i = 0; i < n; i++) r[i] = x[i] & y[i]; } static inline void __bitset_or(BITSET_WORD *r, const BITSET_WORD *x, const BITSET_WORD *y, unsigned n) { for (unsigned i = 0; i < n; i++) r[i] = x[i] | y[i]; } static inline void __bitset_not(BITSET_WORD *x, unsigned n) { for (unsigned i = 0; i < n; i++) x[i] = ~x[i]; } #define BITSET_AND(r, x, y) \ do { \ assert(ARRAY_SIZE(r) == ARRAY_SIZE(x)); \ assert(ARRAY_SIZE(r) == ARRAY_SIZE(y)); \ __bitset_and(r, x, y, ARRAY_SIZE(r)); \ } while (0) #define BITSET_OR(r, x, y) \ do { \ assert(ARRAY_SIZE(r) == ARRAY_SIZE(x)); \ assert(ARRAY_SIZE(r) == ARRAY_SIZE(y)); \ __bitset_or(r, x, y, ARRAY_SIZE(r)); \ } while (0) #define BITSET_NOT(x) \ __bitset_not(x, ARRAY_SIZE(x)) static inline void __bitset_rotate_right(BITSET_WORD *x, unsigned amount, unsigned n) { assert(amount < BITSET_WORDBITS); if (amount == 0) return; for (unsigned i = 0; i < n - 1; i++) { x[i] = (x[i] >> amount) | (x[i + 1] << (BITSET_WORDBITS - amount)); } x[n - 1] = x[n - 1] >> amount; } static inline void __bitset_rotate_left(BITSET_WORD *x, unsigned amount, unsigned n) { assert(amount < BITSET_WORDBITS); if (amount == 0) return; for (int i = n - 1; i > 0; i--) { x[i] = (x[i] << amount) | (x[i - 1] >> (BITSET_WORDBITS - amount)); } x[0] = x[0] << amount; } static inline void __bitset_shr(BITSET_WORD *x, unsigned amount, unsigned n) { const unsigned int words = amount / BITSET_WORDBITS; if (amount == 0) return; if (words) { unsigned i; for (i = 0; i < n - words; i++) x[i] = x[i + words]; while (i < n) x[i++] = 0; amount %= BITSET_WORDBITS; } __bitset_rotate_right(x, amount, n); } static inline void __bitset_shl(BITSET_WORD *x, unsigned amount, unsigned n) { const int words = amount / BITSET_WORDBITS; if (amount == 0) return; if (words) { int i; for (i = n - 1; i >= words; i--) { x[i] = x[i - words]; } while (i >= 0) { x[i--] = 0; } amount %= BITSET_WORDBITS; } __bitset_rotate_left(x, amount, n); } #define BITSET_SHR(x, n) \ __bitset_shr(x, n, ARRAY_SIZE(x)); #define BITSET_SHL(x, n) \ __bitset_shl(x, n, ARRAY_SIZE(x)); /* bit range operations */ #define BITSET_TEST_RANGE_INSIDE_WORD(x, b, e) \ (BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \ (((x)[BITSET_BITWORD(b)] & BITSET_RANGE(b, e)) != 0) : \ (assert (!"BITSET_TEST_RANGE: bit range crosses word boundary"), 0)) #define BITSET_SET_RANGE_INSIDE_WORD(x, b, e) \ (BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \ ((x)[BITSET_BITWORD(b)] |= BITSET_RANGE(b, e)) : \ (assert (!"BITSET_SET_RANGE_INSIDE_WORD: bit range crosses word boundary"), 0)) #define BITSET_CLEAR_RANGE_INSIDE_WORD(x, b, e) \ (BITSET_BITWORD(b) == BITSET_BITWORD(e) ? \ ((x)[BITSET_BITWORD(b)] &= ~BITSET_RANGE(b, e)) : \ (assert (!"BITSET_CLEAR_RANGE: bit range crosses word boundary"), 0)) static inline bool __bitset_test_range(const BITSET_WORD *r, unsigned start, unsigned end) { const unsigned size = end - start + 1; const unsigned start_mod = start % BITSET_WORDBITS; if (start_mod + size <= BITSET_WORDBITS) { return BITSET_TEST_RANGE_INSIDE_WORD(r, start, end); } else { const unsigned first_size = BITSET_WORDBITS - start_mod; return __bitset_test_range(r, start, start + first_size - 1) || __bitset_test_range(r, start + first_size, end); } } #define BITSET_TEST_RANGE(x, b, e) \ __bitset_test_range(x, b, e) static inline void __bitset_set_range(BITSET_WORD *r, unsigned start, unsigned end) { const unsigned size = end - start + 1; const unsigned start_mod = start % BITSET_WORDBITS; if (start_mod + size <= BITSET_WORDBITS) { BITSET_SET_RANGE_INSIDE_WORD(r, start, end); } else { const unsigned first_size = BITSET_WORDBITS - start_mod; __bitset_set_range(r, start, start + first_size - 1); __bitset_set_range(r, start + first_size, end); } } #define BITSET_SET_RANGE(x, b, e) \ __bitset_set_range(x, b, e) static inline void __bitclear_clear_range(BITSET_WORD *r, unsigned start, unsigned end) { const unsigned size = end - start + 1; const unsigned start_mod = start % BITSET_WORDBITS; if (start_mod + size <= BITSET_WORDBITS) { BITSET_CLEAR_RANGE_INSIDE_WORD(r, start, end); } else { const unsigned first_size = BITSET_WORDBITS - start_mod; __bitclear_clear_range(r, start, start + first_size - 1); __bitclear_clear_range(r, start + first_size, end); } } #define BITSET_CLEAR_RANGE(x, b, e) \ __bitclear_clear_range(x, b, e) static inline unsigned __bitset_prefix_sum(const BITSET_WORD *x, unsigned b, unsigned n) { unsigned prefix = 0; for (unsigned i = 0; i < n; i++) { if ((i + 1) * BITSET_WORDBITS <= b) { prefix += util_bitcount(x[i]); } else { prefix += util_bitcount(x[i] & BITFIELD_MASK(b - i * BITSET_WORDBITS)); break; } } return prefix; } /* Count set bits in the bitset (compute the size/cardinality of the bitset). * This is a special case of prefix sum, but this convenience method is more * natural when applicable. */ static inline unsigned __bitset_count(const BITSET_WORD *x, unsigned n) { return __bitset_prefix_sum(x, ~0, n); } #define BITSET_PREFIX_SUM(x, b) \ __bitset_prefix_sum(x, b, ARRAY_SIZE(x)) #define BITSET_COUNT(x) \ __bitset_count(x, ARRAY_SIZE(x)) /* Get first bit set in a bitset. */ static inline int __bitset_ffs(const BITSET_WORD *x, int n) { for (int i = 0; i < n; i++) { if (x[i]) return ffs(x[i]) + BITSET_WORDBITS * i; } return 0; } /* Get the last bit set in a bitset. */ static inline int __bitset_last_bit(const BITSET_WORD *x, int n) { for (int i = n - 1; i >= 0; i--) { if (x[i]) return util_last_bit(x[i]) + BITSET_WORDBITS * i; } return 0; } #define BITSET_FFS(x) __bitset_ffs(x, ARRAY_SIZE(x)) #define BITSET_LAST_BIT(x) __bitset_last_bit(x, ARRAY_SIZE(x)) #define BITSET_LAST_BIT_SIZED(x, size) __bitset_last_bit(x, size) static inline unsigned __bitset_next_set(unsigned i, BITSET_WORD *tmp, const BITSET_WORD *set, unsigned size) { unsigned bit, word; /* NOTE: The initial conditions for this function are very specific. At * the start of the loop, the tmp variable must be set to *set and the * initial i value set to 0. This way, if there is a bit set in the first * word, we ignore the i-value and just grab that bit (so 0 is ok, even * though 0 may be returned). If the first word is 0, then the value of * `word` will be 0 and we will go on to look at the second word. */ word = BITSET_BITWORD(i); while (*tmp == 0) { word++; if (word >= BITSET_WORDS(size)) return size; *tmp = set[word]; } /* Find the next set bit in the non-zero word */ bit = ffs(*tmp) - 1; /* Unset the bit */ *tmp &= ~(1ull << bit); return word * BITSET_WORDBITS + bit; } /** * Iterates over each set bit in a set * * @param __i iteration variable, bit number * @param __set the bitset to iterate (will not be modified) * @param __size number of bits in the set to consider */ #define BITSET_FOREACH_SET(__i, __set, __size) \ for (BITSET_WORD __tmp = (__size) == 0 ? 0 : *(__set), *__foo = &__tmp; __foo != NULL; __foo = NULL) \ for (__i = 0; \ (__i = __bitset_next_set(__i, &__tmp, __set, __size)) < __size;) static inline void __bitset_next_range(unsigned *start, unsigned *end, const BITSET_WORD *set, unsigned size) { /* To find the next start, start searching from end. In the first iteration * it will be at 0, in every subsequent iteration it will be at the first * 0-bit after the range. */ unsigned word = BITSET_BITWORD(*end); if (word >= BITSET_WORDS(size)) { *start = *end = size; return; } BITSET_WORD tmp = set[word] & ~(BITSET_BIT(*end) - 1); while (!tmp) { word++; if (word >= BITSET_WORDS(size)) { *start = *end = size; return; } tmp = set[word]; } *start = word * BITSET_WORDBITS + ffs(tmp) - 1; /* Now do the opposite to find end. Here we can start at start + 1, because * we know that the bit at start is 1 and we're searching for the first * 0-bit. */ word = BITSET_BITWORD(*start + 1); if (word >= BITSET_WORDS(size)) { *end = size; return; } tmp = set[word] | (BITSET_BIT(*start + 1) - 1); while (~tmp == 0) { word++; if (word >= BITSET_WORDS(size)) { *end = size; return; } tmp = set[word]; } /* Cap "end" at "size" in case there are extra bits past "size" set in the * word. This is only necessary for "end" because we terminate the loop if * "start" goes past "size". */ *end = MIN2(word * BITSET_WORDBITS + ffs(~tmp) - 1, size); } /** * Iterates over each contiguous range of set bits in a set * * @param __start the first 1 bit of the current range * @param __end the bit after the last 1 bit of the current range * @param __set the bitset to iterate (will not be modified) * @param __size number of bits in the set to consider */ #define BITSET_FOREACH_RANGE(__start, __end, __set, __size) \ for (__start = 0, __end = 0, \ __bitset_next_range(&__start, &__end, __set, __size); \ __start < __size; \ __bitset_next_range(&__start, &__end, __set, __size)) #ifdef __cplusplus /** * Simple C++ wrapper of a bitset type of static size, with value semantics * and basic bitwise arithmetic operators. The operators defined below are * expected to have the same semantics as the same operator applied to other * fundamental integer types. T is the name of the struct to instantiate * it as, and N is the number of bits in the bitset. */ #define DECLARE_BITSET_T(T, N) struct T { \ EXPLICIT_CONVERSION \ operator bool() const \ { \ for (unsigned i = 0; i < BITSET_WORDS(N); i++) \ if (words[i]) \ return true; \ return false; \ } \ \ T & \ operator=(int x) \ { \ const T c = {{ (BITSET_WORD)x }}; \ return *this = c; \ } \ \ friend bool \ operator==(const T &b, const T &c) \ { \ return BITSET_EQUAL(b.words, c.words); \ } \ \ friend bool \ operator!=(const T &b, const T &c) \ { \ return !(b == c); \ } \ \ friend bool \ operator==(const T &b, int x) \ { \ const T c = {{ (BITSET_WORD)x }}; \ return b == c; \ } \ \ friend bool \ operator!=(const T &b, int x) \ { \ return !(b == x); \ } \ \ friend T \ operator~(const T &b) \ { \ T c; \ for (unsigned i = 0; i < BITSET_WORDS(N); i++) \ c.words[i] = ~b.words[i]; \ return c; \ } \ \ T & \ operator|=(const T &b) \ { \ for (unsigned i = 0; i < BITSET_WORDS(N); i++) \ words[i] |= b.words[i]; \ return *this; \ } \ \ friend T \ operator|(const T &b, const T &c) \ { \ T d = b; \ d |= c; \ return d; \ } \ \ T & \ operator&=(const T &b) \ { \ for (unsigned i = 0; i < BITSET_WORDS(N); i++) \ words[i] &= b.words[i]; \ return *this; \ } \ \ friend T \ operator&(const T &b, const T &c) \ { \ T d = b; \ d &= c; \ return d; \ } \ \ bool \ test(unsigned i) const \ { \ return BITSET_TEST(words, i); \ } \ \ T & \ set(unsigned i) \ { \ BITSET_SET(words, i); \ return *this; \ } \ \ T & \ clear(unsigned i) \ { \ BITSET_CLEAR(words, i); \ return *this; \ } \ \ BITSET_WORD words[BITSET_WORDS(N)]; \ } #endif #endif