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Diffstat (limited to 'bitmap.h')
| -rw-r--r-- | bitmap.h | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/bitmap.h b/bitmap.h new file mode 100644 index 0000000000..efd5d3a1ed --- /dev/null +++ b/bitmap.h @@ -0,0 +1,222 @@ +/* + * Bitmap Module + * + * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com> + * + * Mostly inspired by (stolen from) linux/bitmap.h and linux/bitops.h + * + * This work is licensed under the terms of the GNU LGPL, version 2.1 or later. + * See the COPYING.LIB file in the top-level directory. + */ + +#ifndef BITMAP_H +#define BITMAP_H + +#include "qemu-common.h" +#include "bitops.h" + +/* + * The available bitmap operations and their rough meaning in the + * case that the bitmap is a single unsigned long are thus: + * + * Note that nbits should be always a compile time evaluable constant. + * Otherwise many inlines will generate horrible code. + * + * bitmap_zero(dst, nbits) *dst = 0UL + * bitmap_fill(dst, nbits) *dst = ~0UL + * bitmap_copy(dst, src, nbits) *dst = *src + * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2 + * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2 + * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2 + * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2) + * bitmap_complement(dst, src, nbits) *dst = ~(*src) + * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal? + * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap? + * bitmap_empty(src, nbits) Are all bits zero in *src? + * bitmap_full(src, nbits) Are all bits set in *src? + * bitmap_set(dst, pos, nbits) Set specified bit area + * bitmap_clear(dst, pos, nbits) Clear specified bit area + * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area + */ + +/* + * Also the following operations apply to bitmaps. + * + * set_bit(bit, addr) *addr |= bit + * clear_bit(bit, addr) *addr &= ~bit + * change_bit(bit, addr) *addr ^= bit + * test_bit(bit, addr) Is bit set in *addr? + * test_and_set_bit(bit, addr) Set bit and return old value + * test_and_clear_bit(bit, addr) Clear bit and return old value + * test_and_change_bit(bit, addr) Change bit and return old value + * find_first_zero_bit(addr, nbits) Position first zero bit in *addr + * find_first_bit(addr, nbits) Position first set bit in *addr + * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit + * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit + */ + +#define BITMAP_LAST_WORD_MASK(nbits) \ + ( \ + ((nbits) % BITS_PER_LONG) ? \ + (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \ + ) + +#define DECLARE_BITMAP(name,bits) \ + unsigned long name[BITS_TO_LONGS(bits)] + +#define small_nbits(nbits) \ + ((nbits) <= BITS_PER_LONG) + +int slow_bitmap_empty(const unsigned long *bitmap, int bits); +int slow_bitmap_full(const unsigned long *bitmap, int bits); +int slow_bitmap_equal(const unsigned long *bitmap1, + const unsigned long *bitmap2, int bits); +void slow_bitmap_complement(unsigned long *dst, const unsigned long *src, + int bits); +void slow_bitmap_shift_right(unsigned long *dst, + const unsigned long *src, int shift, int bits); +void slow_bitmap_shift_left(unsigned long *dst, + const unsigned long *src, int shift, int bits); +int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, int bits); +void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, int bits); +void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, int bits); +int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, int bits); +int slow_bitmap_intersects(const unsigned long *bitmap1, + const unsigned long *bitmap2, int bits); + +static inline unsigned long *bitmap_new(int nbits) +{ + int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + return qemu_mallocz(len); +} + +static inline void bitmap_zero(unsigned long *dst, int nbits) +{ + if (small_nbits(nbits)) { + *dst = 0UL; + } else { + int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + memset(dst, 0, len); + } +} + +static inline void bitmap_fill(unsigned long *dst, int nbits) +{ + size_t nlongs = BITS_TO_LONGS(nbits); + if (!small_nbits(nbits)) { + int len = (nlongs - 1) * sizeof(unsigned long); + memset(dst, 0xff, len); + } + dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); +} + +static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, + int nbits) +{ + if (small_nbits(nbits)) { + *dst = *src; + } else { + int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + memcpy(dst, src, len); + } +} + +static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, int nbits) +{ + if (small_nbits(nbits)) { + return (*dst = *src1 & *src2) != 0; + } + return slow_bitmap_and(dst, src1, src2, nbits); +} + +static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, int nbits) +{ + if (small_nbits(nbits)) { + *dst = *src1 | *src2; + } else { + slow_bitmap_or(dst, src1, src2, nbits); + } +} + +static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, int nbits) +{ + if (small_nbits(nbits)) { + *dst = *src1 ^ *src2; + } else { + slow_bitmap_xor(dst, src1, src2, nbits); + } +} + +static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, int nbits) +{ + if (small_nbits(nbits)) { + return (*dst = *src1 & ~(*src2)) != 0; + } + return slow_bitmap_andnot(dst, src1, src2, nbits); +} + +static inline void bitmap_complement(unsigned long *dst, const unsigned long *src, + int nbits) +{ + if (small_nbits(nbits)) { + *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits); + } else { + slow_bitmap_complement(dst, src, nbits); + } +} + +static inline int bitmap_equal(const unsigned long *src1, + const unsigned long *src2, int nbits) +{ + if (small_nbits(nbits)) { + return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); + } else { + return slow_bitmap_equal(src1, src2, nbits); + } +} + +static inline int bitmap_empty(const unsigned long *src, int nbits) +{ + if (small_nbits(nbits)) { + return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); + } else { + return slow_bitmap_empty(src, nbits); + } +} + +static inline int bitmap_full(const unsigned long *src, int nbits) +{ + if (small_nbits(nbits)) { + return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); + } else { + return slow_bitmap_full(src, nbits); + } +} + +static inline int bitmap_intersects(const unsigned long *src1, + const unsigned long *src2, int nbits) +{ + if (small_nbits(nbits)) { + return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; + } else { + return slow_bitmap_intersects(src1, src2, nbits); + } +} + +void bitmap_set(unsigned long *map, int i, int len); +void bitmap_clear(unsigned long *map, int start, int nr); +unsigned long bitmap_find_next_zero_area(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr, + unsigned long align_mask); + +#endif /* BITMAP_H */ |