[Bug middle-end/105781] GCC does not unroll auto-vectorized loops.
rguenth at gcc dot gnu.org
Wed Jun 1 11:49:38 GMT 2022
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
The issue is cost modeling which is what the existing -funroll-[all-]loops RTL
unrolling lacks. The vectorizer meanwhile can unroll vectorized loops by means
of increasing the vectorization factor which the target can suggest by
adjusting m_suggested_unroll_factor in the finish_cost hook. See the aarch64
port for an example.
More information about the Gcc-bugs