reading big-endian types on little-endian machine

#define READ_BYTES(var, type)          \
    do {                               \
    var = 0;                           \
    type n;                            \
    int count = sizeof(type);          \
    int last_bit = (count-1)*8;        \
    int i;                             \
                                       \
    fread(&n, sizeof(type), 1, f);     \
                                           \
    for(i=0; i<=last_bit; i+=8) {               \
        int start = i;                              \
        int end = last_bit - i;                         \
                                                           \
        if(start < end)                                     \
            var |= (n & (0xff << start)) << (end - start);  \
        else                                                \
            var |= (n & (0xff << start)) >> (start - end);  \
    }                                                       \
    } while(0);                                             \