include/bitops.h

   1 /*
   2  * No copyright is claimed.  This code is in the public domain; do with
   3  * it what you wish.
   4  *
   5  * Written by Karel Zak <kzak@redhat.com>
   6  */
   7 #ifndef BITOPS_H
   8 #define BITOPS_H
   9
  10 #include <stdint.h>
  11 #include <sys/param.h>
  12
  13 #if defined(HAVE_BYTESWAP_H)
  14 # include <byteswap.h>
  15 #endif
  16
  17 #if defined(HAVE_ENDIAN_H)
  18 #  include <endian.h>
  19 #elif defined(HAVE_SYS_ENDIAN_H)        /* BSDs have them here */
  20 #  include <sys/endian.h>
  21 #endif
  22
  23 #if !(defined(HAVE_BYTESWAP_H) && defined(HAVE_ENDIAN_H))
  24 /*
  25  * When both byteswap.h and endian.h are preseent, the proper macros are defined
  26  * as those files are glibc compatible.  Otherwise, compensate for the slightly
  27  * different interfaces between the different BSDs.
  28  */
  29 #if defined(__OpenBSD__)
  30 # include <sys/types.h>
  31 # define be16toh(x) betoh16(x)
  32 # define be32toh(x) betoh32(x)
  33 # define be64toh(x) betoh64(x)
  34 #elif defined(__NetBSD__) || defined(__DragonFly__)
  35 # define bswap_16(x) bswap16(x)
  36 # define bswap_32(x) bswap32(x)
  37 # define bswap_64(x) bswap64(x)
  38 #elif defined(__APPLE__)
  39 # include <libkern/OSByteOrder.h>
  40 # define htobe16(x) OSSwapHostToBigInt16(x)
  41 # define htole16(x) OSSwapHostToLittleInt16(x)
  42 # define be16toh(x) OSSwapBigToHostInt16(x)
  43 # define le16toh(x) OSSwapLittleToHostInt16(x)
  44 # define htobe32(x) OSSwapHostToBigInt32(x)
  45 # define htole32(x) OSSwapHostToLittleInt32(x)
  46 # define be32toh(x) OSSwapBigToHostInt32(x)
  47 # define le32toh(x) OSSwapLittleToHostInt32(x)
  48 # define htobe64(x) OSSwapHostToBigInt64(x)
  49 # define htole64(x) OSSwapHostToLittleInt64(x)
  50 # define be64toh(x) OSSwapBigToHostInt64(x)
  51 # define le64toh(x) OSSwapLittleToHostInt64(x)
  52 # define bswap_16(x) OSSwapInt16(x)
  53 # define bswap_32(x) OSSwapInt32(x)
  54 # define bswap_64(x) OSSwapInt64(x)
  55 #endif
  56 #endif
  57
  58 /*
  59  * Fallbacks
  60  * casts are necessary for constants, because we never know how for sure
  61  * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
  62  */
  63 #ifndef bswap_16
  64 # define bswap_16(x) ((uint16_t)( \
  65         (((uint16_t)(x) & 0x00FF) << 8) | \
  66         (((uint16_t)(x) & 0xFF00) >> 8)))
  67 #endif
  68
  69 #ifndef bswap_32
  70 # define bswap_32(x) ((uint32_t)( \
  71         (((uint32_t)(x) & 0x000000FF) << 24) | \
  72         (((uint32_t)(x) & 0x0000FF00) << 8)  | \
  73         (((uint32_t)(x) & 0x00FF0000) >> 8)  | \
  74         (((uint32_t)(x) & 0xFF000000) >> 24)))
  75 #endif
  76
  77 #ifndef bswap_64
  78 # define bswap_64(x) ((uint64_t)( \
  79         (((uint64_t)(x) & 0x00000000000000FFULL) << 56) | \
  80         (((uint64_t)(x) & 0x000000000000FF00ULL) << 40) | \
  81         (((uint64_t)(x) & 0x0000000000FF0000ULL) << 24) | \
  82         (((uint64_t)(x) & 0x00000000FF000000ULL) << 8)  | \
  83         (((uint64_t)(x) & 0x000000FF00000000ULL) >> 8)  | \
  84         (((uint64_t)(x) & 0x0000FF0000000000ULL) >> 24) | \
  85         (((uint64_t)(x) & 0x00FF000000000000ULL) >> 40) | \
  86         (((uint64_t)(x) & 0xFF00000000000000ULL) >> 56)))
  87 #endif
  88
  89 #ifndef htobe16
  90 # if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
  91 #  define htobe16(x) bswap_16 (x)
  92 #  define htole16(x) (x)
  93 #  define be16toh(x) bswap_16 (x)
  94 #  define le16toh(x) (x)
  95 #  define htobe32(x) bswap_32 (x)
  96 #  define htole32(x) (x)
  97 #  define be32toh(x) bswap_32 (x)
  98 #  define le32toh(x) (x)
  99 #  define htobe64(x) bswap_64 (x)
 100 #  define htole64(x) (x)
 101 #  define be64toh(x) bswap_64 (x)
 102 #  define le64toh(x) (x)
 103 # else
 104 #  define htobe16(x) (x)
 105 #  define htole16(x) bswap_16 (x)
 106 #  define be16toh(x) (x)
 107 #  define le16toh(x) bswap_16 (x)
 108 #  define htobe32(x) (x)
 109 #  define htole32(x) bswap_32 (x)
 110 #  define be32toh(x) (x)
 111 #  define le32toh(x) bswap_32 (x)
 112 #  define htobe64(x) (x)
 113 #  define htole64(x) bswap_64 (x)
 114 #  define be64toh(x) (x)
 115 #  define le64toh(x) bswap_64 (x)
 116 # endif
 117 #endif
 118
 119 /*
 120  * Byte swab macros (based on linux/byteorder/swab.h)
 121  */
 122 #define swab16(x) bswap_16(x)
 123 #define swab32(x) bswap_32(x)
 124 #define swab64(x) bswap_64(x)
 125
 126 #define cpu_to_le16(x) ((uint16_t) htole16(x))
 127 #define cpu_to_le32(x) ((uint32_t) htole32(x))
 128 #define cpu_to_le64(x) ((uint64_t) htole64(x))
 129
 130 #define cpu_to_be16(x) ((uint16_t) htobe16(x))
 131 #define cpu_to_be32(x) ((uint32_t) htobe32(x))
 132 #define cpu_to_be64(x) ((uint64_t) htobe64(x))
 133
 134 #define le16_to_cpu(x) ((uint16_t) le16toh(x))
 135 #define le32_to_cpu(x) ((uint32_t) le32toh(x))
 136 #define le64_to_cpu(x) ((uint64_t) le64toh(x))
 137
 138 #define be16_to_cpu(x) ((uint16_t) be16toh(x))
 139 #define be32_to_cpu(x) ((uint32_t) be32toh(x))
 140 #define be64_to_cpu(x) ((uint64_t) be64toh(x))
 141
 142 /*
 143  * Bit map related macros. Usually provided by libc.
 144  */
 145 #ifndef NBBY
 146 # define NBBY            CHAR_BIT
 147 #endif
 148
 149 #ifndef setbit
 150 # define setbit(a,i)    ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
 151 # define clrbit(a,i)    ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
 152 # define isset(a,i)     ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
 153 # define isclr(a,i)     (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
 154 #endif
 155
 156 #endif /* BITOPS_H */
 157