Handle DR_NUM_DIMENSIONS == 0 in initialize_data_dependence_relation

2016-01-12  Tom de Vries  <tom@codesourcery.com>

	* tree-data-ref.c (initialize_data_dependence_relation): Handle
	DR_NUM_DIMENSIONS == 0.

	* gcc.dg/autopar/pr69110.c: New test.

	* testsuite/libgomp.c/pr69110.c: New test.

---
 gcc/testsuite/gcc.dg/autopar/pr69110.c | 17 +++++++++++++++++
 gcc/tree-data-ref.c                    | 10 ++++++----
 libgomp/testsuite/libgomp.c/pr69110.c  | 26 ++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/gcc/testsuite/gcc.dg/autopar/pr69110.c b/gcc/testsuite/gcc.dg/autopar/pr69110.c
new file mode 100644
index 0000000..27cdae5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/autopar/pr69110.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -ftree-parallelize-loops=2 -fno-tree-loop-im -fdump-tree-parloops2-details" } */
+
+#define N 1000
+
+unsigned int i = 0;
+
+void
+foo (void)
+{
+  unsigned int z;
+  for (z = 0; z < N; ++z)
+    ++i;
+}
+
+/* { dg-final { scan-tree-dump-times "SUCCESS: may be parallelized" 0 "parloops2" } } */
+/* { dg-final { scan-tree-dump-times "FAILED: data dependencies exist across iterations" 1 "parloops2" } } */
diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
index a40f40d..4c29fc2 100644
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -1510,8 +1510,9 @@ initialize_data_dependence_relation (struct data_reference *a,
   if (operand_equal_p (DR_REF (a), DR_REF (b), 0))
     {
      if (loop_nest.exists ()
-        && !object_address_invariant_in_loop_p (loop_nest[0],
-       					        DR_BASE_OBJECT (a)))
+	 && (!object_address_invariant_in_loop_p (loop_nest[0],
+						  DR_BASE_OBJECT (a))
+	     || DR_NUM_DIMENSIONS (a) == 0))
       {
         DDR_ARE_DEPENDENT (res) = chrec_dont_know;
         return res;
@@ -1548,8 +1549,9 @@ initialize_data_dependence_relation (struct data_reference *a,
      analyze it.  TODO -- in fact, it would suffice to record that there may
      be arbitrary dependences in the loops where the base object varies.  */
   if (loop_nest.exists ()
-      && !object_address_invariant_in_loop_p (loop_nest[0],
-     					      DR_BASE_OBJECT (a)))
+      && (!object_address_invariant_in_loop_p (loop_nest[0],
+					       DR_BASE_OBJECT (a))
+	  || DR_NUM_DIMENSIONS (a) == 0))
     {
       DDR_ARE_DEPENDENT (res) = chrec_dont_know;
       return res;
diff --git a/libgomp/testsuite/libgomp.c/pr69110.c b/libgomp/testsuite/libgomp.c/pr69110.c
new file mode 100644
index 0000000..0d9e5ca
--- /dev/null
+++ b/libgomp/testsuite/libgomp.c/pr69110.c
@@ -0,0 +1,26 @@
+/* { dg-do run } */
+/* { dg-options "-ftree-parallelize-loops=2 -O1 -fno-tree-loop-im" } */
+
+#define N 1000
+
+unsigned int i = 0;
+
+static void __attribute__((noinline, noclone))
+foo (void)
+{
+  unsigned int z;
+  for (z = 0; z < N; ++z)
+    ++i;
+}
+
+extern void abort (void);
+
+int
+main (void)
+{
+  foo ();
+  if (i != N)
+    abort ();
+
+  return 0;
+}