Handle DR_NUM_DIMENSIONS == 0 in initialize_data_dependence_relation

2016-01-26  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/69110
	* 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.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@232852 138bc75d-0d04-0410-961f-82ee72b054a4

6 files changed, 70 insertions, 10 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0358f1c04aa..f38b374e58f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-01-26  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/69110
+	* tree-data-ref.c (initialize_data_dependence_relation): Handle
+	DR_NUM_DIMENSIONS == 0.
+
 2016-01-26  Abderrazek Zaafrani  <a.zaafrani@samsung.com>
             Sebastian Pop  <s.pop@samsung.com>
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ee59ff14610..08e24850865 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-01-26  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/69110
+	* gcc.dg/autopar/pr69110.c: New test.
+
 2016-01-26  Abderrazek Zaafrani  <a.zaafrani@samsung.com>
             Sebastian Pop  <s.pop@samsung.com>
 
diff --git a/gcc/testsuite/gcc.dg/autopar/pr69110.c b/gcc/testsuite/gcc.dg/autopar/pr69110.c
new file mode 100644
index 00000000000..27cdae535b8
--- /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 a40f40dc339..d6d9ffcaa34 100644
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -1509,13 +1509,14 @@ initialize_data_dependence_relation (struct data_reference *a,
   /* The case where the references are exactly the same.  */
   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)))
-      {
-        DDR_ARE_DEPENDENT (res) = chrec_dont_know;
-        return res;
-      }
+      if ((loop_nest.exists ()
+	   && !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;
+	}
       DDR_AFFINE_P (res) = true;
       DDR_ARE_DEPENDENT (res) = NULL_TREE;
       DDR_SUBSCRIPTS (res).create (DR_NUM_DIMENSIONS (a));
@@ -1547,9 +1548,9 @@ initialize_data_dependence_relation (struct data_reference *a,
   /* If the base of the object is not invariant in the loop nest, we cannot
      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)))
+  if ((loop_nest.exists ()
+       && !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/ChangeLog b/libgomp/ChangeLog
index 818d9942e4b..9c09ac50cba 100644
--- a/libgomp/ChangeLog
+++ b/libgomp/ChangeLog
@@ -1,3 +1,8 @@
+2016-01-26  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/69110
+	* testsuite/libgomp.c/pr69110.c: New test.
+
 2016-01-25  Richard Biener  <rguenther@suse.de>
 
 	PR lto/69393
diff --git a/libgomp/testsuite/libgomp.c/pr69110.c b/libgomp/testsuite/libgomp.c/pr69110.c
new file mode 100644
index 00000000000..0d9e5ca5c3c
--- /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;
+}