Thanks for the catch about the signbit... already changed. On Fri, Jul 31, 2015 at 2:30 PM, John Gustafson <[email protected] > wrote:
> It would be wonderful if someone else would create a super-concise > explanation of unums! Thank you, thank you! I can't seem to do it. I must > be getting long-winded in my old age. > > I looked a > > https://github.com/tbreloff/Unums.jl > > and saw that it erroneously says the sign bit field can have flexible > size. Nope, that's always a single bit. Otherwise, it looks like the web > site is on the right track. Expand the variable size fields up to some > maximum (like the example in the book for a 64-bit fixed size unum) but > still follow the rules of correct unum math within that bound. This is > likely how the first hardware versions will do things, also, and they will > save power by knowing which bits are not in use. > > One thing any language implementation will want is to expand a packed set > of unums (using the utag as a linked list pointer) into unpacked ones of > fixed size, and the reverse operation. That way, block stores and loads can > be optimized. I did not put that in the Mathematica reference > implementation, but it needs to be there. > > On Wednesday, July 29, 2015 at 3:33:52 PM UTC-7, Job van der Zwan wrote: >> >> BTW, Tom, I was already working on a summary of the book (on an IJulia >> notebook). I'm on mobile right now so don't have access to it, but I can >> share it later. I think something like that might be useful to attract more >> collaborators - we can't expect everyone to read it. > >
