On Tue, Nov 17, 2020 at 12:29 PM Richard Sandiford via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On arm* and aarch64* targets, we can vectorise the second of the main
> loops using SLP, not just the third. As the comments say, whether this
> is supported depends on a very specific permutation, so it seemed better
> to use direct target selectors.
>
> Tested on aarch64-linux-gnu (with and without SVE), arm-linux-gnueabihf
> and x86_64-linux-gnu. OK to install?
OK
> Richard
>
>
> gcc/testsuite/
> * gcc.dg/vect/slp-21.c: Expect 4 SLP instances to be vectorized
> on arm* and aarch64* targets.
> ---
> gcc/testsuite/gcc.dg/vect/slp-21.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/testsuite/gcc.dg/vect/slp-21.c
> b/gcc/testsuite/gcc.dg/vect/slp-21.c
> index 1f8c82e8ba8..117d65c5ddb 100644
> --- a/gcc/testsuite/gcc.dg/vect/slp-21.c
> +++ b/gcc/testsuite/gcc.dg/vect/slp-21.c
> @@ -201,6 +201,16 @@ int main (void)
>
> /* { dg-final { scan-tree-dump-times "vectorized 4 loops" 1 "vect" { target
> { vect_strided4 || vect_extract_even_odd } } } } */
> /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { target
> { ! { vect_strided4 || vect_extract_even_odd } } } } } */
> -/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 2 "vect"
> { target vect_strided4 } } } */
> +/* Some targets can vectorize the second of the three main loops using
> + hybrid SLP. For 128-bit vectors, the required 4->3 permutations are:
> +
> + { 0, 1, 2, 4, 5, 6, 8, 9 }
> + { 2, 4, 5, 6, 8, 9, 10, 12 }
> + { 5, 6, 8, 9, 10, 12, 13, 14 }
> +
> + Not all vect_perm targets support that, and it's a bit too specific to
> have
> + its own effective-target selector, so we just test targets directly. */
> +/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 4 "vect"
> { target { aarch64*-*-* arm*-*-* } } } } */
> +/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 2 "vect"
> { target { vect_strided4 && { ! { aarch64*-*-* arm*-*-* } } } } } } */
> /* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 0 "vect"
> { target { ! { vect_strided4 } } } } } */
>
