ex3-56.txt

====
3.56
====

A. esi: x
   ebx: n
   edi: result
   edx: mask

B. result: 0x55555555
   mask:   0x80000000

C. mask != 0

D. mask = (unsigned)mask >> (n&0xFF)

E. result ^= x & mask

================================================================================
int loop(int x, int n)
{
    int result = 0x55555555;
    int mask;
    for (mask = 0x80000000; mask != 0; mask = (unsigned)mask & (n&0xFF))
        result ^= x & mask;
    return result;
}
================================================================================