[Bug libstdc++/50880] __complex_acosh() picks wrong complex branch

[gdr at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50880

--- Comment #14 from Gabriel Dos Reis <gdr at gcc dot gnu.org> 2011-11-02 12:27:20 UTC ---
(In reply to comment #9)
> Created attachment 25654 [details]
> BC2

Since we are talking about branch cut and prespectiving
since zeros, I think we should avoid the 
the arithmetic z -/+ one, whee one is of a complex<T>.
Rather the computation should be be directly on
the components.  This is to prevent signed zeros
to have their mutated.