[PATCH 4/5] New target check: vect_nopeel

[Andreas Krebbel]

Without peeling loops for vector alignment the vectorization costs are
lower and in some cases make the loop vectorizer cover optimizations
which otherwise would be handelt in slp instead.

This adds a new target check for that purpose.

gcc/testsuite/ChangeLog:

2017-09-26  Andreas Krebbel  <kreb...@linux.vnet.ibm.com>

        * g++.dg/vect/slp-pr56812.cc: Check vect_nopeel.
        * lib/target-supports.exp (check_effective_target_vect_nopeel):
        New proc.
---
 gcc/testsuite/g++.dg/vect/slp-pr56812.cc |  4 +++-
 gcc/testsuite/lib/target-supports.exp    | 22 ++++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/gcc/testsuite/g++.dg/vect/slp-pr56812.cc 
b/gcc/testsuite/g++.dg/vect/slp-pr56812.cc
index 80bdcdd..955b2ef 100644
--- a/gcc/testsuite/g++.dg/vect/slp-pr56812.cc
+++ b/gcc/testsuite/g++.dg/vect/slp-pr56812.cc
@@ -17,4 +17,6 @@ void mydata::Set (float x)
     data[i] = x;
 }
 
-/* { dg-final { scan-tree-dump-times "basic block vectorized" 1 "slp1" } } */
+/* For targets without vector loop peeling the loop becomes cheap
+   enough to be vectorized.  */
+/* { dg-final { scan-tree-dump-times "basic block vectorized" 1 "slp1" { 
target { ! vect_nopeel } } } } */
diff --git a/gcc/testsuite/lib/target-supports.exp 
b/gcc/testsuite/lib/target-supports.exp
index 7fdfbbb..686465a 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -3199,6 +3199,28 @@ proc check_effective_target_vect_floatuint_cvt { } {
     return $et_vect_floatuint_cvt_saved($et_index)
 }
 
+# Return 1 if peeling for alignment is never profitable on the target
+#
+
+proc check_effective_target_vect_nopeel { } {
+    global et_vect_nopeel_saved
+    global et_index
+
+    if [info exists et_vect_nopeel_saved($et_index)] {
+       verbose "check_effective_target_vect_nopeel: using cached result" 2
+    } else {
+       set et_vect_nopeel_saved($et_index) 0
+        if { ([istarget s390*-*-*]
+             && [check_effective_target_s390_vx]) } {
+           set et_vect_nopeel_saved($et_index) 1
+        }
+    }
+
+    verbose "check_effective_target_vect_nopeel:\
+            returning $et_vect_nopeel_saved($et_index)" 2
+    return $et_vect_nopeel_saved($et_index)
+}
+
 # Return 1 if the target supports #pragma omp declare simd, 0 otherwise.
 #
 # This won't change for different subtargets so cache the result.
-- 
2.9.1