[Bug c/96793] __builtin_floor produces wrong result when rounding direction is FE_DOWNWARD

[chfast at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96793

--- Comment #4 from Paweł Bylica <chfast at gmail dot com> ---
I missed some information:

This affects both double and float variants: __builtin_floor() and
__builtin_floorf().

This affects also usage of floor() C standard library function as the function
call usually replaced with __builtin_floor() in optimized builds.

This affects also libstdc++ where std::floor() is implemented with
__builtin_floor().