#define F1(a,b)     (((long)(a) - (long)(b)) - (((long)(b) -(long)(a))* -3UL))
#define F2(a,b)     (((long)(a) - (long)(b)) - (((long)(b) -(long)(a))* -2UL))

long f1(long, long, long);
long f2(long, long, long);

RET(f1(0,    3,  20) == F1(   3,  20) &&
    f1(0, -100,  80) == F1(-100,  80) &&
    f1(0,   50,  -9) == F1(  50,  -9) &&
    f1(0,  -77, -50) == F1( -77, -50) &&

    f2(0,    3,  20) == F2(   3,  20) &&
    f2(0, -100,  80) == F2(-100,  80) &&
    f2(0,   50,  -9) == F2(  50,  -9) &&
    f2(0,  -77, -50) == F2( -77, -50) &&

    f1(0, 0x7FFFFFFFFFFFFFFFUL, 0x7FFFFFFFFFFFFFFFUL) ==
       F1(0x7FFFFFFFFFFFFFFFUL, 0x7FFFFFFFFFFFFFFFUL) &&
    f2(0, 0x7FFFFFFFFFFFFFFFUL, 0x7FFFFFFFFFFFFFFFUL) ==
       F2(0x7FFFFFFFFFFFFFFFUL, 0x7FFFFFFFFFFFFFFFUL) &&

    f1(0, 0x8FFFFFFFFFFFFFFFUL, 0x8FFFFFFFFFFFFFFFUL) ==
       F1(0x8FFFFFFFFFFFFFFFUL, 0x8FFFFFFFFFFFFFFFUL) &&
    f2(0, 0x8FFFFFFFFFFFFFFFUL, 0x8FFFFFFFFFFFFFFFUL) ==
       F2(0x8FFFFFFFFFFFFFFFUL, 0x8FFFFFFFFFFFFFFFUL) 
   );