https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65242
--- Comment #13 from Michael Meissner <meissner at gcc dot gnu.org> --- My gut feeling is we don't want to change ?m to !m, because it might impact floating point conversions <-> integer, where we need the DI mode in a floating point register. In addition, I might worry that it could impact breaking apart _Decimal128 values, which I believe uses DImode for the two parts. I was also trying to make the minimal change, and I didn't want an iteration where we fix up any collateral damage.
