https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83338
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2017-12-08 CC| |jakub at gcc dot gnu.org Ever confirmed|0 |1 --- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- I believe the bug is that get_vectype_for_scalar_type for the operands of POINTER_DIFF_EXPR is vector of unsigned elements, the result of POINTER_DIFF_EXPR is a signed and thus we IMHO need to vectorize POINTER_DIFF_EXPR as effectively MINUS_EXPR on the vector unsigned operands producing vector unsigned result, and then VIEW_CONVERT_EXPR the result into vector signed result. The reason POINTER_PLUS_EXPR works by being mapped as PLUS_EXPR is that both sizetype and pointers are TYPE_UNSIGNED and we get the same vector types for both.