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/*
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 * Bitmap Module
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 *
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 * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
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 *
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 * Mostly inspired by (stolen from) linux/bitmap.h and linux/bitops.h
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 *
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 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
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 * See the COPYING.LIB file in the top-level directory.
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 */
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#ifndef BITMAP_H
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#define BITMAP_H
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#include "qemu-common.h"
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#include "qemu/bitops.h"
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/*
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 * The available bitmap operations and their rough meaning in the
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 * case that the bitmap is a single unsigned long are thus:
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 *
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 * Note that nbits should be always a compile time evaluable constant.
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 * Otherwise many inlines will generate horrible code.
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 *
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 * bitmap_zero(dst, nbits)                        *dst = 0UL
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 * bitmap_fill(dst, nbits)                        *dst = ~0UL
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 * bitmap_copy(dst, src, nbits)                        *dst = *src
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 * bitmap_and(dst, src1, src2, nbits)                *dst = *src1 & *src2
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 * bitmap_or(dst, src1, src2, nbits)                *dst = *src1 | *src2
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 * bitmap_xor(dst, src1, src2, nbits)                *dst = *src1 ^ *src2
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 * bitmap_andnot(dst, src1, src2, nbits)        *dst = *src1 & ~(*src2)
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 * bitmap_complement(dst, src, nbits)                *dst = ~(*src)
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 * bitmap_equal(src1, src2, nbits)                Are *src1 and *src2 equal?
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 * bitmap_intersects(src1, src2, nbits)         Do *src1 and *src2 overlap?
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 * bitmap_empty(src, nbits)                        Are all bits zero in *src?
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 * bitmap_full(src, nbits)                        Are all bits set in *src?
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 * bitmap_set(dst, pos, nbits)                        Set specified bit area
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 * bitmap_clear(dst, pos, nbits)                Clear specified bit area
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 * bitmap_find_next_zero_area(buf, len, pos, n, mask)        Find bit free area
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 */
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/*
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 * Also the following operations apply to bitmaps.
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 *
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 * set_bit(bit, addr)                        *addr |= bit
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 * clear_bit(bit, addr)                        *addr &= ~bit
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 * change_bit(bit, addr)                *addr ^= bit
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 * test_bit(bit, addr)                        Is bit set in *addr?
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 * test_and_set_bit(bit, addr)                Set bit and return old value
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 * test_and_clear_bit(bit, addr)        Clear bit and return old value
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 * test_and_change_bit(bit, addr)        Change bit and return old value
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 * find_first_zero_bit(addr, nbits)        Position first zero bit in *addr
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 * find_first_bit(addr, nbits)                Position first set bit in *addr
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 * find_next_zero_bit(addr, nbits, bit)        Position next zero bit in *addr >= bit
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 * find_next_bit(addr, nbits, bit)        Position next set bit in *addr >= bit
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 */
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#define BITMAP_LAST_WORD_MASK(nbits)                                    \
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    (                                                                   \
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        ((nbits) % BITS_PER_LONG) ?                                     \
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        (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL                       \
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        )
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#define DECLARE_BITMAP(name,bits)                  \
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        unsigned long name[BITS_TO_LONGS(bits)]
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#define small_nbits(nbits)                      \
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        ((nbits) <= BITS_PER_LONG)
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int slow_bitmap_empty(const unsigned long *bitmap, int bits);
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int slow_bitmap_full(const unsigned long *bitmap, int bits);
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int slow_bitmap_equal(const unsigned long *bitmap1,
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                   const unsigned long *bitmap2, int bits);
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void slow_bitmap_complement(unsigned long *dst, const unsigned long *src,
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                         int bits);
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void slow_bitmap_shift_right(unsigned long *dst,
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                          const unsigned long *src, int shift, int bits);
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void slow_bitmap_shift_left(unsigned long *dst,
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                         const unsigned long *src, int shift, int bits);
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int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
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                 const unsigned long *bitmap2, int bits);
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void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
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                 const unsigned long *bitmap2, int bits);
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void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
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                  const unsigned long *bitmap2, int bits);
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int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
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                    const unsigned long *bitmap2, int bits);
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int slow_bitmap_intersects(const unsigned long *bitmap1,
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                        const unsigned long *bitmap2, int bits);
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static inline unsigned long *bitmap_new(int nbits)
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{
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    int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
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    return g_malloc0(len);
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}
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static inline void bitmap_zero(unsigned long *dst, int nbits)
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{
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    if (small_nbits(nbits)) {
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        *dst = 0UL;
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    } else {
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        int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
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        memset(dst, 0, len);
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    }
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}
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static inline void bitmap_fill(unsigned long *dst, int nbits)
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{
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    size_t nlongs = BITS_TO_LONGS(nbits);
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    if (!small_nbits(nbits)) {
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        int len = (nlongs - 1) * sizeof(unsigned long);
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        memset(dst, 0xff,  len);
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    }
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    dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
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}
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static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
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                               int nbits)
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{
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    if (small_nbits(nbits)) {
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        *dst = *src;
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    } else {
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        int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
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        memcpy(dst, src, len);
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    }
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}
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static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
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                             const unsigned long *src2, int nbits)
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{
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    if (small_nbits(nbits)) {
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        return (*dst = *src1 & *src2) != 0;
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    }
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    return slow_bitmap_and(dst, src1, src2, nbits);
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}
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static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
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                        const unsigned long *src2, int nbits)
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{
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    if (small_nbits(nbits)) {
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        *dst = *src1 | *src2;
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    } else {
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        slow_bitmap_or(dst, src1, src2, nbits);
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    }
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}
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static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
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                        const unsigned long *src2, int nbits)
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{
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    if (small_nbits(nbits)) {
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        *dst = *src1 ^ *src2;
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    } else {
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        slow_bitmap_xor(dst, src1, src2, nbits);
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    }
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}
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static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
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                        const unsigned long *src2, int nbits)
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{
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    if (small_nbits(nbits)) {
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        return (*dst = *src1 & ~(*src2)) != 0;
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    }
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    return slow_bitmap_andnot(dst, src1, src2, nbits);
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}
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static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
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                        int nbits)
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{
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    if (small_nbits(nbits)) {
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        *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
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    } else {
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        slow_bitmap_complement(dst, src, nbits);
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    }
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}
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static inline int bitmap_equal(const unsigned long *src1,
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                        const unsigned long *src2, int nbits)
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{
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    if (small_nbits(nbits)) {
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        return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
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    } else {
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        return slow_bitmap_equal(src1, src2, nbits);
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    }
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}
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static inline int bitmap_empty(const unsigned long *src, int nbits)
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{
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    if (small_nbits(nbits)) {
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        return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
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    } else {
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        return slow_bitmap_empty(src, nbits);
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    }
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}
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static inline int bitmap_full(const unsigned long *src, int nbits)
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{
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    if (small_nbits(nbits)) {
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        return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
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    } else {
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        return slow_bitmap_full(src, nbits);
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    }
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}
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static inline int bitmap_intersects(const unsigned long *src1,
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                        const unsigned long *src2, int nbits)
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{
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    if (small_nbits(nbits)) {
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        return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
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    } else {
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        return slow_bitmap_intersects(src1, src2, nbits);
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    }
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}
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void bitmap_set(unsigned long *map, int i, int len);
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void bitmap_clear(unsigned long *map, int start, int nr);
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unsigned long bitmap_find_next_zero_area(unsigned long *map,
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                                         unsigned long size,
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                                         unsigned long start,
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                                         unsigned int nr,
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                                         unsigned long align_mask);
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#endif /* BITMAP_H */