https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85992
--- Comment #2 from Matt Peddie <mpeddie at gmail dot com> --- Thank you for your quick response. The explanation makes sense, and I agree this is not a bug. I'd like to understand -- this seems to me to imply that GCC will use MPFR to evaluate calls to libm functions even when optimizations are disabled with -O0, since in the -O0 case I still get the MPFR result if I don't use a separate function and call atanf() on a constant. Is there a way to disable this behavior?
