I'm mixed on Gustafson's posit stuff. For me, the only thing I'd change for fp would be:
1. -0 now encodes NAN.
2. +inf/-inf are all Fs with sign: 0x7FFFFFFF, 0xFFFFFFFF.
3. 0 is the only denorm.
Which does four good things:
1. Gets rid of the utter insanity which is -0.
2. Gets rid of all the redundant NANs.
3. Makes INF "look like" INF.
4. Gets rid of "hard" mixed denorm/norm math.
And one seriously bad thing:
1. Lose a bunch of underflow values in the denorm range.
However, as to the latter: who the fuck cares! Getting down to that range using anything other than divide-by-two completely trashes the error rate anyways, so why bother?
The rest of Gustafson's stuff always sounds like crazy-people talk, to me.
1. -0 now encodes NAN.
2. +inf/-inf are all Fs with sign: 0x7FFFFFFF, 0xFFFFFFFF.
3. 0 is the only denorm.
Which does four good things:
1. Gets rid of the utter insanity which is -0.
2. Gets rid of all the redundant NANs.
3. Makes INF "look like" INF.
4. Gets rid of "hard" mixed denorm/norm math.
And one seriously bad thing:
1. Lose a bunch of underflow values in the denorm range.
However, as to the latter: who the fuck cares! Getting down to that range using anything other than divide-by-two completely trashes the error rate anyways, so why bother?
The rest of Gustafson's stuff always sounds like crazy-people talk, to me.