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? 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 } } } } } */