http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46862
--- Comment #4 from Janis Johnson <janis at gcc dot gnu.org> 2010-12-09 18:50:13 UTC --- This doesn't have anything to do with libdecnumber, it's about how std::decimal::decimalxx are defined in libstdc++. Instead of an ICE with a nice message it would be more appropriate to issue a warning (error?) that GCC can't pass the class the same as the associated scalar type as required by the ABI, and don't set TYPE_TRANSPARENT_AGGR.