https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121831
--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Note, I think the decision to punt should be based on the number of non-zero elements or bytes. Even with gigabytes long CONSTRUCTOR if it contains say just 64 bytes of non-zeros it will be beneficial to expand it the way it is right now. But if it is more than say a kilobyte of non-zeros, I think just copying the whole thing over will be better.
