__builtin_cpow((0,0),(0,0))

[Marcin Dalecki]

On 2005-03-08, at 01:21, Robert Dewar wrote:

> Paolo Carlini wrote:
>
>> Interesting, thanks. The problem is, since the C standard is 
>> admittedly
>> rather vague in this area, some implementation of the C library simply
>> implement the basic formula (i.e., cexp(c*clog(z))) and don't deal 
>> *at all*
>> with special cases. This leads *naturally* to (nan, nan).
>> In other cases we are more "lucky", though.
>
> Well this is a grotesquely inaccurate way of computing exponentiation
> anyway unless you have a lot of extra guard bits for the intermediate
> value, so any library that does this is brain dead anyway.

Amen.