Re: Question on performance
Vincent Lefevre wrote (I dropped the accent, which seems to get mutilated):
> sNaN is undefined behavior in ISO C99:
Perhaps so, but 754-2008 is clear, and suggests that "!=" be QuietNotEqual,
which is Quiet only for QNaNs. SNaNs must set Invalid in ANY comparison;
only certain operations, such as Copy, and explicit category predicates
such as isNan(), can be totally silent.
Even if "!=" were SignallingNotEqual (which is indeed up to Language
standards -- 754-2008 only recommends a choice) there would be a
difference, because isNaN() MUST be quiet.
Michel.
---Sent: 2010-10-15 14:10:48 UTC