https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127107
--- Comment #3 from Drea Pinski <pinskia at gcc dot gnu.org> --- Yes we should not be producing uint256_t at all during forwprop. That is invalid gimple (though we don't check). There needs to be a check for MAX_FIXED_MODE_SIZE in there. This is what was also breaking 32bit with 64x64 multiply. Let me try to clean up this mess.
