https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87390
--- Comment #26 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- On Thu, 27 Sep 2018, vincent-gcc at vinc17 dot net wrote: > > The interpretation of C99 rules for excess precision used in GCC has been > > explained at length from 2008 onwards. > > Could you cite where this bug is documented in GCC? The general explanation of the choices made in the cases where C99 was less than optimally clear is in <https://gcc.gnu.org/ml/gcc-patches/2008-11/msg00105.html>, the original addition of support for -fexcess-precision=standard. The part of this issue that I consider a bug (i.e. the case of C11 and later modes, the default being -std=gnu17, so if someone just uses -fexcess-precision=standard in the default mode they'll get the C11 semantics) is fixed for GCC 9.
