quicktime/ffmpeg/libavcodec/bswap.h

   1 /**
   2  * @file bswap.h
   3  * byte swap.
   4  */
   5
   6 #ifndef __BSWAP_H__
   7 #define __BSWAP_H__
   8
   9 #ifdef HAVE_BYTESWAP_H
  10 #include <byteswap.h>
  11 #else
  12
  13 #ifdef ARCH_X86_64
  14 #  define LEGACY_REGS "=Q"
  15 #else
  16 #  define LEGACY_REGS "=q"
  17 #endif
  18
  19 #if defined(ARCH_X86) || defined(ARCH_X86_64)
  20 static always_inline uint16_t bswap_16(uint16_t x)
  21 {
  22   __asm("rorw $8, %0"   :
  23         LEGACY_REGS (x) :
  24         "0" (x));
  25     return x;
  26 }
  27
  28 static always_inline uint32_t bswap_32(uint32_t x)
  29 {
  30 #if __CPU__ > 386
  31  __asm("bswap   %0":
  32       "=r" (x)     :
  33 #else
  34  __asm("xchgb   %b0,%h0\n"
  35       " rorl    $16,%0\n"
  36       " xchgb   %b0,%h0":
  37       LEGACY_REGS (x)           :
  38 #endif
  39       "0" (x));
  40   return x;
  41 }
  42
  43 static inline uint64_t bswap_64(uint64_t x)
  44 {
  45 #ifdef ARCH_X86_64
  46   __asm("bswap  %0":
  47         "=r" (x)     :
  48         "0" (x));
  49   return x;
  50 #else
  51     union {
  52         uint64_t ll;
  53         struct {
  54            uint32_t l,h;
  55         } l;
  56     } r;
  57     r.l.l = bswap_32 (x);
  58     r.l.h = bswap_32 (x>>32);
  59     return r.ll;
  60 #endif
  61 }
  62
  63 #elif defined(ARCH_SH4)
  64
  65 static always_inline uint16_t bswap_16(uint16_t x) {
  66         __asm__("swap.b %0,%0":"=r"(x):"0"(x));
  67         return x;
  68 }
  69
  70 static always_inline uint32_t bswap_32(uint32_t x) {
  71         __asm__(
  72         "swap.b %0,%0\n"
  73         "swap.w %0,%0\n"
  74         "swap.b %0,%0\n"
  75         :"=r"(x):"0"(x));
  76         return x;
  77 }
  78
  79 static inline uint64_t bswap_64(uint64_t x)
  80 {
  81     union {
  82         uint64_t ll;
  83         struct {
  84            uint32_t l,h;
  85         } l;
  86     } r;
  87     r.l.l = bswap_32 (x);
  88     r.l.h = bswap_32 (x>>32);
  89     return r.ll;
  90 }
  91 #else
  92
  93 static always_inline uint16_t bswap_16(uint16_t x){
  94     return (x>>8) | (x<<8);
  95 }
  96
  97 #ifdef ARCH_ARM
  98 static always_inline uint32_t bswap_32(uint32_t x){
  99     uint32_t t;
 100     __asm__ (
 101       "eor %1, %0, %0, ror #16 \n\t"
 102       "bic %1, %1, #0xFF0000   \n\t"
 103       "mov %0, %0, ror #8      \n\t"
 104       "eor %0, %0, %1, lsr #8  \n\t"
 105       : "+r"(x), "+r"(t));
 106     return x;
 107 }
 108 #else
 109 static always_inline uint32_t bswap_32(uint32_t x){
 110     x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
 111     return (x>>16) | (x<<16);
 112 }
 113 #endif
 114
 115 static inline uint64_t bswap_64(uint64_t x)
 116 {
 117 #if 0
 118     x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
 119     x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
 120     return (x>>32) | (x<<32);
 121 #else
 122     union {
 123         uint64_t ll;
 124         uint32_t l[2];
 125     } w, r;
 126     w.ll = x;
 127     r.l[0] = bswap_32 (w.l[1]);
 128     r.l[1] = bswap_32 (w.l[0]);
 129     return r.ll;
 130 #endif
 131 }
 132 #endif  /* !ARCH_X86 */
 133
 134 #endif  /* !HAVE_BYTESWAP_H */
 135
 136 // be2me ... BigEndian to MachineEndian
 137 // le2me ... LittleEndian to MachineEndian
 138
 139 #ifdef WORDS_BIGENDIAN
 140 #define be2me_16(x) (x)
 141 #define be2me_32(x) (x)
 142 #define be2me_64(x) (x)
 143 #define le2me_16(x) bswap_16(x)
 144 #define le2me_32(x) bswap_32(x)
 145 #define le2me_64(x) bswap_64(x)
 146 #else
 147 #define be2me_16(x) bswap_16(x)
 148 #define be2me_32(x) bswap_32(x)
 149 #define be2me_64(x) bswap_64(x)
 150 #define le2me_16(x) (x)
 151 #define le2me_32(x) (x)
 152 #define le2me_64(x) (x)
 153 #endif
 154
 155 #endif /* __BSWAP_H__ */