Bitarrays in the age of 64bit

[Faux Amis]

On 2020-04-03 09:31, Dominikus Dittes Scherkl wrote:
> It was said that implementing bitarrays is complicated, because of the 
> indexing.
> 
> Has anybody ever considered to use bit-pointers?
> Nobody really uses the full address range that 64bit pointers have - in 
> fact some hardware internally still uses 48bit or 56bit 
> address-registers, so instead adding three lower address bits would not 
> cost a lot (just forward bit 3..58 to the register instead of bit 0..55).
> This would also allow for implementing 2bit-types (one that I really 
> would appreciate, because it can represent sign values, providing -1, 0, 
> 1 and NaN - which is necessary as a comparison result for non-ordered 
> values), and 4bit-types (so called nibbles).
> And with bit-pointers of course implementing arrays of boolean, sign, 
> nibbles or even odd-length types would be straight forward. All the 
> strange side-effects of byte clustering would vanish.
> 
> Just an idea.

I see what you mean. The addressable space would be 8 times less (not a 
problem for the foreseeable future of course).

No clue what implementations this would have though :)