[Bug c/87390] [x86 32bit only] GCC does not honor FLT_EVAL_METHOD on implicit conversion of integer to floating point

[joseph at codesourcery dot com]

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.