[committed] testsuite: XFAIL some SLP reduction tests for VLA SVE

[committed] testsuite: XFAIL some SLP reduction tests for VLA SVE

[Richard Sandiford]

For variable-length SVE, we can only use SLP for N scalars of type
T if the number of Ts in a vector is a multiple of N.  For ints
this means that N must be 4 or 2, so this patch XFAILs two tests
for N==8.

The exact limit seems inherently target-specific -- variable-length
vectors with a 256-bit granule would work fine -- so I used aarch64_sve
selectors on the XFAILs.

Tested on aarch64-linux-gnu (with and without SVE), arm-linux-gnueabihf
and x86_64-linux-gnu.  Pushed as obvious.

Richard


gcc/testsuite/
	* gcc.dg/vect/slp-reduc-4.c: XFAIL test for SLP vectorization
	for variable-length SVE.
	* gcc.dg/vect/slp-reduc-7.c: Likewise.
---
 gcc/testsuite/gcc.dg/vect/slp-reduc-4.c | 6 ++++--
 gcc/testsuite/gcc.dg/vect/slp-reduc-7.c | 6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/vect/slp-reduc-4.c b/gcc/testsuite/gcc.dg/vect/slp-reduc-4.c
index 266b439f0a6..cffb0114bcb 100644
--- a/gcc/testsuite/gcc.dg/vect/slp-reduc-4.c
+++ b/gcc/testsuite/gcc.dg/vect/slp-reduc-4.c
@@ -57,6 +57,8 @@ int main (void)
 }
 
 /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { xfail vect_no_int_min_max } } } */
-/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect" { xfail { vect_no_int_min_max || vect_variable_length } } } } */
-/* { dg-final { scan-tree-dump-times "VEC_PERM_EXPR" 0 "vect" } } */
+/* For variable-length SVE, the number of scalar statements in the
+   reduction exceeds the number of elements in a 128-bit granule.  */
+/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect" { xfail { vect_no_int_min_max || { aarch64_sve && vect_variable_length } } } } } */
+/* { dg-final { scan-tree-dump-times "VEC_PERM_EXPR" 0 "vect" { xfail { aarch64_sve && vect_variable_length } } } } */
 
diff --git a/gcc/testsuite/gcc.dg/vect/slp-reduc-7.c b/gcc/testsuite/gcc.dg/vect/slp-reduc-7.c
index 05cc9eddacb..7a958f24733 100644
--- a/gcc/testsuite/gcc.dg/vect/slp-reduc-7.c
+++ b/gcc/testsuite/gcc.dg/vect/slp-reduc-7.c
@@ -55,5 +55,7 @@ int main (void)
 }
 
 /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { xfail vect_no_int_add } } } */
-/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect" { xfail { vect_no_int_add || vect_variable_length } } } } */
-/* { dg-final { scan-tree-dump-times "VEC_PERM_EXPR" 0 "vect" } } */
+/* For variable-length SVE, the number of scalar statements in the
+   reduction exceeds the number of elements in a 128-bit granule.  */
+/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect" { xfail { vect_no_int_add || { aarch64_sve && vect_variable_length } } } } } */
+/* { dg-final { scan-tree-dump-times "VEC_PERM_EXPR" 0 "vect" { xfail { aarch64_sve && vect_variable_length } } } } */