include/side/endian.h

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  *
   4  * Copyright (C) 2012,2022 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  */
   6
   7 /*
   8  * This header defines the following endian macros based on the current
   9  * platform endian headers:
  10  *
  11  *   BYTE_ORDER         this macro shall have a value equal to one
  12  *                      of the *_ENDIAN macros in this header.
  13  *   FLOAT_WORD_ORDER   this macro shall have a value equal to one
  14  *                      of the *_ENDIAN macros in this header.
  15  *   LITTLE_ENDIAN      if BYTE_ORDER == LITTLE_ENDIAN, the host
  16  *                      byte order is from least significant to
  17  *                      most significant.
  18  *   BIG_ENDIAN         if BYTE_ORDER == BIG_ENDIAN, the host byte
  19  *                      order is from most significant to least
  20  *                      significant.
  21  *
  22  * Direct byte swapping interfaces:
  23  *
  24  *   uint16_t bswap_16(uint16_t x); (* swap bytes 16-bit word *)
  25  *   uint32_t bswap_32(uint32_t x); (* swap bytes 32-bit word *)
  26  *   uint64_t bswap_64(uint32_t x); (* swap bytes 64-bit word *)
  27  */
  28
  29 #ifndef _SIDE_ENDIAN_H
  30 #define _SIDE_ENDIAN_H
  31
  32 #include <math.h>
  33
  34 #if defined(__SIZEOF_LONG__)
  35 # define SIDE_BITS_PER_LONG     (__SIZEOF_LONG__ * 8)
  36 #elif defined(_LP64)
  37 # define SIDE_BITS_PER_LONG     64
  38 #else
  39 # define SIDE_BITS_PER_LONG     32
  40 #endif
  41
  42 #if (defined(__linux__) || defined(__CYGWIN__))
  43 #include <endian.h>
  44 #include <byteswap.h>
  45
  46 #define side_bswap_16(x)                bswap_16(x)
  47 #define side_bswap_32(x)                bswap_32(x)
  48 #define side_bswap_64(x)                bswap_64(x)
  49
  50 #define SIDE_BYTE_ORDER                 __BYTE_ORDER
  51 #define SIDE_LITTLE_ENDIAN              __LITTLE_ENDIAN
  52 #define SIDE_BIG_ENDIAN                 __BIG_ENDIAN
  53
  54 #ifdef __FLOAT_WORD_ORDER
  55 #define SIDE_FLOAT_WORD_ORDER           __FLOAT_WORD_ORDER
  56 #else /* __FLOAT_WORD_ORDER */
  57 #define SIDE_FLOAT_WORD_ORDER           __BYTE_ORDER
  58 #endif /* __FLOAT_WORD_ORDER */
  59
  60 #elif defined(__FreeBSD__)
  61
  62 #include <sys/endian.h>
  63
  64 #define side_bswap_16(x)                bswap16(x)
  65 #define side_bswap_32(x)                bswap32(x)
  66 #define side_bswap_64(x)                bswap64(x)
  67
  68 #define SIDE_BYTE_ORDER                 BYTE_ORDER
  69 #define SIDE_LITTLE_ENDIAN              LITTLE_ENDIAN
  70 #define SIDE_BIG_ENDIAN                 BIG_ENDIAN
  71 #define SIDE_FLOAT_WORD_ORDER           BYTE_ORDER
  72
  73 #else
  74 #error "Please add support for your OS."
  75 #endif
  76
  77 #ifdef __cplusplus
  78 extern "C" {
  79 #endif
  80
  81 #ifdef __HAVE_FLOAT128
  82 static inline
  83 void side_bswap_128p(char *p)
  84 {
  85         int i;
  86
  87         for (i = 0; i < 8; i++)
  88                 p[i] = p[15 - i];
  89 }
  90 #endif
  91
  92 #ifdef __cplusplus
  93 }
  94 #endif
  95
  96 #if SIDE_BITS_PER_LONG == 64
  97 # define side_bswap_pointer(x)  side_bswap_64(x)
  98 #else
  99 # define side_bswap_pointer(x)  side_bswap_32(x)
 100 #endif
 101
 102 #endif /* _SIDE_ENDIAN_H */