https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116017
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Note on riscv float conversion are not sign preserving for nans. That is conversions from 32bit to 64bit floats will lose the sign bit for nans. So having 128bit to/from 64bit conversions also lose the sign bit is consistent with hard floats.
