Re: Fwd: motion 7 NaIŁ
Vincent LefÛvre a ©crit:
> So, what would be the payload status in P1788?
The payload being discussed here is that of a NaI and NOT that of
an IEEE 754 NaN, so you cannot and should not infer NaI propagation
rules from the (incompletely specified) 754 NaN propagation rules.
Indeed, one proposal uses a non-NaN to carry the NaI payload precisely
to avoid depending on the undefined part of 754 NaN propagation rules.
(The defined part makes sure that the NaN component of a NaI, and hence
the NaI itself, is propagated as expected.)
Unfortunately the non-NaN component of a NaI may be lost a bit too easily
when interacting with other NaIs -- and we would like to avoid too much
special-case code in common arithmetic operations. So the mechanics of
NaI propagation may be very dependent on implementation details, and
finding a good compromise in terms of over- and under-specification may
be difficult...
Michel.
---Sent: 2009-08-24 15:15:11 UTC