WARNING: big brain subtractor

[EEVV]

Code:

/warp bigbrain

64 bit 6 tick hex subtractor

b i g
by EEVV and HyperXti

[Matthew]

this makes me H A R D

[baslak19]

Subtractor? You know you could just use two’s complement addition.

[konsumlamm]

Subtractor? You know you could just use two’s complement addition.

this is hex, so you can't use two's complement, you could use 16's complement
apart from that hex subtraction is faster than addition (at least when they used magicals algorithm which i think they did)

[baslak19]

eBut you still have to ripple borrow, right?

Ty! 16’s complement, yes.  I’m researching edge cases with hex 16’s cmp. right now.

[EEVV]

No ripple. This uses BCS logic which is derived from CCA. It uses instant diodes and comparators to generate borrows. The whole thing is literally 6 ticks to compute a subtraction.

[Trecar]

Cool, when do we get a 64 Bit CPU?