Don wrote: > Walter Bright wrote: >> You know, the unimplemented 128 bit integer types. >> >> Does anyone have a use for these? > > I would have liked them when implementing a fallback (non-asm) bigint > implementation for 64-bit CPUs. Actually the only operations required are: > ulong * ulong -> ulong[2] > ulong[2] / ulong = ulong (only the case where it doesn't overflow, is > required) > ulong + ulong = ulong[2] > ulong - ulong = ulong[2] > > Otherwise, it's hard to imagine many cases where 64 bits are inadequate > but 128 bits are enough. Actually there are very few cases where 32 bits > are inadequate but 64 bits are enough.
32 bit -> 64 bit: 8x8 bit boards in computer chess. zorbist hash codes 64 bit -> 128 bit: bit boards in 9x9 computer go. Depending on the implementation, 11x11 bit boards (121 bits) can be very handy.
