http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57994
--- Comment #7 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- An example of MPC not following all the Annex G special cases is that catanh (1 + i0) is specified in Annex G to return Inf + i0 with divide-by-zero exception, but at least with my MPC installation it returns Inf + iNaN. I haven't tried to check how MPFR handles special cases; the issue with MPC is simply something I noticed incidentally while fixing glibc libm handling of various <complex.h> functions. > I was wondering about that last point. Couldn't we replace: > > x=sin(Inf); > > with: > > x=NaN; > errno=EDOM; // only if flag_math_errno errno is typically a macro.... > volatile double f=NaN+NaN; // if flag_trapping_math, something to raise > invalid > (make sure we don't recursively try to propagate the constant there, so maybe > the NaN argument should be volatile) I think you mean 0.0 / 0.0 or Inf - Inf or similar; NaN+NaN doesn't raise an exception if the NaNs are quiet NaNs.
