Endian Swap

#include <stdio.h>
#include <stdint.h>

typedef uint64_t u64;
typedef uint32_t u32;
typedef uint16_t u16;
typedef uint8_t u8;
typedef int64_t s64;
typedef int32_t s32;
typedef int16_t s16;
typedef char s8;

static u16
EndianSwap16(u16 var)
{
    var = (var >> 8) + (var << 8);
    return var;
}

static u32
EndianSwap32(u32 var)
{
    var = (var >> 24) +
        ((var & 0x00ff0000) >> 8) +
        ((var & 0x0000ff00) << 8) +
        (var << 24);
    return var;
}

static u64
EndianSwap64(u64 var)
{
    var = (var >> 56) +
        ((var & 0x00ff000000000000) >> 40) +
        ((var & 0x0000ff0000000000) >> 24) +
        ((var & 0x000000ff00000000) >> 8) +
        ((var & 0x00000000ff000000) << 8) +
        ((var & 0x0000000000ff0000) << 24) +
        ((var & 0x000000000000ff00) << 40) +
        (var << 56);
    return var;
}

int main()
{
    s64 hhhd = EndianSwap64(0x8877665544332211);
    s32 hhhf = EndianSwap32(0x44332211);
    s16 hhhg = EndianSwap16(0x2211);
    s8 hhhh = 0x11;
    printf("%lx, %x, %x, %x\n", hhhd, hhhf, hhhg, hhhh);
    
    return 0;
}