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Animatstoday at 1:00 AM3 repliesview on HN

At 4 bits, you could just have a hard-wired table lookup. Two 4 bit values in, 256 entry table. You can have saturating arithmetic and a post-processing function for free. Somebody must be building hardware like that.


Replies

londons_exploretoday at 7:30 AM

Low level software engineers use look up tables.

Hardware engineers realise that a compiler will almost always find some combination of gates which is smaller/faster than the contents of any table.

AlotOfReadingtoday at 3:30 AM

A LUT is pretty wasteful. You only have a one bit significand, so the mantissa and sign bits are boolean binops, and the exponent is a 2 bit adder.

Taniwhatoday at 3:24 AM

and so you can at 1-bit too, and the hardware will be even smaller and cheaper