https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66311
--- Comment #8 from Mikael Morin <mikael at gcc dot gnu.org> --- Created attachment 36121 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36121&action=edit Beginning of a patch The existing code mixes gmp allocation with wide_int allocation. With the patch, an extra sign bit needs to be written in the most significant word. I don't know how to avoid the memory management nightmare.