- if(Num >> 32 == 0 && Den >> 32 == 0)
- return (Uint32)Num / (Uint32)Den;
-
- //Log("__udivdi3: (Num={0x%x:%x}, Den={0x%x:%x})",
- // Num>>32, Num&0xFFFFFFFF,
- // Den>>32, Den&0xFFFFFFFF);
-
- while(Num > Den) {
- ret ++;
- Num -= Den;
+ // Restoring division, from wikipedia
+ // http://en.wikipedia.org/wiki/Division_(digital)
+ P[0] = Num; P[1] = 0;
+ for( i = 64; i--; )
+ {
+ // P <<= 1;
+ P[1] = (P[1] << 1) | (P[0] >> 63);
+ P[0] = P[0] << 1;
+
+ // P -= Den << 64
+ P[1] -= Den;
+
+ // P >= 0
+ if( !(P[1] & (1ULL<<63)) ) {
+ q |= (Uint64)1 << (63-i);
+ }
+ else {
+ //q |= 0 << (63-i);
+ P[1] += Den;
+ }