https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87256
--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #6) > For the above case, there are during the recursion 77608 synth_mult calls, > which might be ok, so indeed better hashing would help, but 10311 is too > large and is not a prime number. Plus this hash table is resolving all > collisions by evicting older cash entries. > That is perhaps fine for the toplevel synth_mult calls, but for the > recursive ones I guess we want to make sure we cache all the values needed > to compute the same toplevel call and perhaps only record the toplevel > call's entry if it would need to evict older entries. > So maybe use the current hash table + another temporary hash_map live just > during the outermost synth_mult call (and activate this behavior only if say > seeing a recursion count of 16)? Sounds reasonable - I'd try activating the behavior on the first collision?
