bswapcomp.cpp

#ifdef __APPLE__
#include <libkern/OSByteOrder.h>
#define bswap_64(x) OSSwapInt64(x)
#define bswap_32(x) OSSwapInt32(x)
#define bswap_16(x) OSSwapInt16(x)
#else
#include <byteswap.h>
#endif
#include <cstdint>

extern uint64_t out64;
extern uint32_t out32;
extern uint16_t out16;
void myswaps(uint64_t in64, uint32_t in32, uint16_t in16);
void systemswaps(uint64_t in64, uint32_t in32, uint16_t in16);

inline uint16_t mybswap_16(uint16_t x)
{
    return (x >> 8) | ((x & 0x00ff) << 8);
}

inline uint32_t mybswap_32(uint32_t x)
{
    return (((x & 0xff000000U) >> 24) | ((x & 0x00ff0000U) >>  8) |
            ((x & 0x0000ff00U) <<  8) | ((x & 0x000000ffU) << 24));
}

inline uint64_t mybswap_64(uint64_t x)
{
     return (((x & 0xff00000000000000ull) >> 56)
          | ((x & 0x00ff000000000000ull) >> 40)
          | ((x & 0x0000ff0000000000ull) >> 24)
          | ((x & 0x000000ff00000000ull) >> 8)
          | ((x & 0x00000000ff000000ull) << 8)
          | ((x & 0x0000000000ff0000ull) << 24)
          | ((x & 0x000000000000ff00ull) << 40)
          | ((x & 0x00000000000000ffull) << 56));
}

void systemswaps(uint64_t in64, uint32_t in32, uint16_t in16)
{
    out64 = bswap_64(in64);
    out32 = bswap_32(in32);
    out16 = bswap_16(in16);
}

void myswaps(uint64_t in64, uint32_t in32, uint16_t in16)
{
    out64 = mybswap_64(in64);
    out32 = mybswap_32(in32);
    out16 = mybswap_16(in16);
}