bswap.h

   1 #ifndef __BSWAP_H__
   2 #define __BSWAP_H__
   3
   4 #ifdef HAVE_BYTESWAP_H
   5 #include <byteswap.h>
   6 #else
   7
   8 #include <inttypes.h>
   9
  10 #ifdef ARCH_X86
  11 static inline unsigned short ByteSwap16(unsigned short x)
  12 {
  13   __asm("xchgb %b0,%h0" :
  14         "=q" (x)        :
  15         "0" (x));
  16     return x;
  17 }
  18 #define bswap_16(x) ByteSwap16(x)
  19
  20 static inline unsigned int ByteSwap32(unsigned int x)
  21 {
  22 #if __CPU__ > 386
  23  __asm("bswap   %0":
  24       "=r" (x)     :
  25 #else
  26  __asm("xchgb   %b0,%h0\n"
  27       " rorl    $16,%0\n"
  28       " xchgb   %b0,%h0":
  29       "=q" (x)          :
  30 #endif
  31       "0" (x));
  32   return x;
  33 }
  34 #define bswap_32(x) ByteSwap32(x)
  35
  36 static inline unsigned long long int ByteSwap64(unsigned long long int x)
  37 {
  38   register union { __extension__ uint64_t __ll;
  39           uint32_t __l[2]; } __x;
  40   asm("xchgl    %0,%1":
  41       "=r"(__x.__l[0]),"=r"(__x.__l[1]):
  42       "0"(bswap_32((unsigned long)x)),"1"(bswap_32((unsigned long)(x>>32))));
  43   return __x.__ll;
  44 }
  45 #define bswap_64(x) ByteSwap64(x)
  46
  47 #elif defined(ARCH_SH4)
  48
  49 static inline uint16_t ByteSwap16(uint16_t x) {
  50         __asm__("swap.b %0,%0":"=r"(x):"0"(x));
  51         return x;
  52 }
  53
  54 static inline uint32_t ByteSwap32(uint32_t x) {
  55         __asm__(
  56         "swap.b %0,%0\n"
  57         "swap.w %0,%0\n"
  58         "swap.b %0,%0\n"
  59         :"=r"(x):"0"(x));
  60         return x;
  61 }
  62
  63 #define bswap_16(x) ByteSwap16(x)
  64 #define bswap_32(x) ByteSwap32(x)
  65
  66 static inline uint64_t ByteSwap64(uint64_t x)
  67 {
  68     union {
  69         uint64_t ll;
  70         struct {
  71            uint32_t l,h;
  72         } l;
  73     } r;
  74     r.l.l = bswap_32 (x);
  75     r.l.h = bswap_32 (x>>32);
  76     return r.ll;
  77 }
  78 #define bswap_64(x) ByteSwap64(x)
  79
  80 #else
  81
  82 #define bswap_16(x) (((x) & 0x00ff) << 8 | ((x) & 0xff00) >> 8)
  83
  84
  85 // code from bits/byteswap.h (C) 1997, 1998 Free Software Foundation, Inc.
  86 #define bswap_32(x) \
  87      ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) | \
  88       (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
  89
  90 static inline uint64_t ByteSwap64(uint64_t x)
  91 {
  92     union {
  93         uint64_t ll;
  94         uint32_t l[2];
  95     } w, r;
  96     w.ll = x;
  97     r.l[0] = bswap_32 (w.l[1]);
  98     r.l[1] = bswap_32 (w.l[0]);
  99     return r.ll;
 100 }
 101 #define bswap_64(x) ByteSwap64(x)
 102
 103 #endif  /* !ARCH_X86 */
 104
 105 #endif  /* !HAVE_BYTESWAP_H */
 106
 107 // be2me ... BigEndian to MachineEndian
 108 // le2me ... LittleEndian to MachineEndian
 109
 110 #ifdef WORDS_BIGENDIAN
 111 #define be2me_16(x) (x)
 112 #define be2me_32(x) (x)
 113 #define be2me_64(x) (x)
 114 #define le2me_16(x) bswap_16(x)
 115 #define le2me_32(x) bswap_32(x)
 116 #define le2me_64(x) bswap_64(x)
 117 #else
 118 #define be2me_16(x) bswap_16(x)
 119 #define be2me_32(x) bswap_32(x)
 120 #define be2me_64(x) bswap_64(x)
 121 #define le2me_16(x) (x)
 122 #define le2me_32(x) (x)
 123 #define le2me_64(x) (x)
 124 #endif
 125
 126 #endif /* __BSWAP_H__ */