On 8/23/19 10:50 AM, Andre Vieira (lists) wrote:
> Hi,
>
> This patch is an improvement on my last RFC. As you pointed out, we can
> do the vectorization analysis of the epilogues before doing the
> transformation, using the same approach as used by openmp simd. I have
> not yet incorporated the cost tweaks for vectorizing the epilogue, I
> would like to do this in a subsequent patch, to make it easier to test
> the differences.
>
> I currently disable the vectorization of epilogues when versioning for
> iterations. This is simply because I do not completely understand how
> the assumptions are created and couldn't determine whether using
> skip_vectors with this would work. If you don't think it is a problem
> or have a testcase to show it work I would gladly look at it.
>
> Bootstrapped this and the next patch on x86_64 and
> aarch64-unknown-linux-gnu, with no regressions (after test changes in
> next patch).
>
> gcc/ChangeLog:
> 2019-08-23 Andre Vieira <andre.simoesdiasvie...@arm.com>
>
> PR 88915
> * gentype.c (main): Add poly_uint64 type to generator.
> * tree-vect-loop.c (vect_analyze_loop_2): Make it determine
> whether we vectorize epilogue loops.
> (vect_analyze_loop): Idem.
> (vect_transform_loop): Pass decision to vectorize epilogues
> to vect_do_peeling.
> * tree-vect-loop-manip.c (vect_do_peeling): Enable skip-vectors
> when doing loop versioning if we decided to vectorize epilogues.
> (vect-loop_versioning): Moved decision to check_profitability
> based on cost model.
> * tree-vectorizer.h (vect_loop_versioning, vect_do_peeling,
> vect_analyze_loop, vect_transform_loop): Update declarations.
> * tree-vectorizer.c: Include params.h
> (try_vectorize_loop_1): Initialize vect_epilogues_nomask
> to PARAM_VECT_EPILOGUES_NOMASK and pass it to vect_analyze_loop
> and vect_transform_loop. Also make sure vectorizing epilogues
> does not count towards number of vectorized loops.
Nit. In several places you use "epilog", proper spelling is "epilogue".
> diff --git a/gcc/tree-vectorizer.c b/gcc/tree-vectorizer.c
> index
> 173e6b51652fd023893b38da786ff28f827553b5..25c3fc8ff55e017ae0b971fa93ce8ce2a07cb94c
> 100644
> --- a/gcc/tree-vectorizer.c
> +++ b/gcc/tree-vectorizer.c
> @@ -1013,8 +1015,13 @@ try_vectorize_loop_1 (hash_table<simduid_to_vf>
> *&simduid_to_vf_htab,
>
> /* Epilogue of vectorized loop must be vectorized too. */
> if (new_loop)
> - ret |= try_vectorize_loop_1 (simduid_to_vf_htab, num_vectorized_loops,
> - new_loop, loop_vinfo, NULL, NULL);
> + {
> + /* Don't include vectorized epilogues in the "vectorized loops" count.
> + */
> + unsigned dont_count = *num_vectorized_loops;
> + ret |= try_vectorize_loop_1 (simduid_to_vf_htab, &dont_count,
> + new_loop, loop_vinfo, NULL, NULL);
> + }
Nit. Don't wrap a comment with just the closing */ on its own line.
Instead wrap before "count" so that.
This is fine for the trunk after fixing those nits.
jeff
