long long simple_rand () { static unsigned long long seed = 47114711; unsigned long long this = seed * 1103515245 + 12345; seed = this; return this >> 8; } unsigned long long int random_bitstring () { unsigned long long int x; int n_bits; long long ran; int tot_bits = 0; x = 0; for (;;) { ran = simple_rand (); n_bits = (ran >> 1) % 16; tot_bits += n_bits; if (n_bits == 0) return x; else { x <<= n_bits; if (ran & 1) x |= (1 << n_bits) - 1; if (tot_bits > 8 * sizeof (long long) + 6) return x; } } } #define ABS(x) ((x) >= 0 ? (x) : -(x)) main () { long long int i; for (i = 0; i < 10000; i++) { unsigned long long x, y; x = random_bitstring (); y = random_bitstring (); if (sizeof (int) == sizeof (long long)) goto save_time; { unsigned long long xx = x, yy = y, r1, r2; if (yy == 0) continue; r1 = xx / yy; r2 = xx % yy; if (r2 >= yy || r1 * yy + r2 != xx) abort (); } { signed long long xx = x, yy = y, r1, r2; if ((unsigned long long) xx << 1 == 0 && yy == -1) continue; r1 = xx / yy; r2 = xx % yy; if (ABS (r2) >= (unsigned long long) ABS (yy) || (signed long long) (r1 * yy + r2) != xx) abort (); } save_time: { unsigned int xx = x, yy = y, r1, r2; if (yy == 0) continue; r1 = xx / yy; r2 = xx % yy; if (r2 >= yy || r1 * yy + r2 != xx) abort (); } { signed int xx = x, yy = y, r1, r2; if ((unsigned int) xx << 1 == 0 && yy == -1) continue; r1 = xx / yy; r2 = xx % yy; if (ABS (r2) >= (unsigned int) ABS (yy) || (signed int) (r1 * yy + r2) != xx || ((xx < 0) != (r2 < 0) && r2)) abort (); } { unsigned short xx = x, yy = y, r1, r2; if (yy == 0) continue; r1 = xx / yy; r2 = xx % yy; if (r2 >= yy || r1 * yy + r2 != xx) abort (); } { signed short xx = x, yy = y, r1, r2; r1 = xx / yy; r2 = xx % yy; if (ABS (r2) >= (unsigned short) ABS (yy) || (signed short) (r1 * yy + r2) != xx) abort (); } { unsigned char xx = x, yy = y, r1, r2; if (yy == 0) continue; r1 = xx / yy; r2 = xx % yy; if (r2 >= yy || r1 * yy + r2 != xx) abort (); } { signed char xx = x, yy = y, r1, r2; r1 = xx / yy; r2 = xx % yy; if (ABS (r2) >= (unsigned char) ABS (yy) || (signed char) (r1 * yy + r2) != xx) abort (); } } exit (0); }