[gcc r11-5140] testsuite: Adjust gcc.dg/vect/slp-21.c for Arm targets

[Richard Sandiford]

https://gcc.gnu.org/g:ee9dd1c3022aa01ed3733cf58ed1f490872fa214

commit r11-5140-gee9dd1c3022aa01ed3733cf58ed1f490872fa214
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Wed Nov 18 18:40:32 2020 +0000

    testsuite: Adjust gcc.dg/vect/slp-21.c for Arm targets
    
    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.
    
    gcc/testsuite/
            * gcc.dg/vect/slp-21.c: Expect 4 SLP instances to be vectorized
            on arm* and aarch64* targets.

Diff:
---
 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 } } } } } */