Fix gcc_assert in expand_omp_for_static_chunk

2015-08-31  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/65637
	* omp-low.c (expand_omp_for_static_chunk): Fix gcc_assert for the case
	that head is NULL.

	* gcc.dg/autopar/pr46099-chunk-size.c: New test.
---
 gcc/ChangeLog                                     |  6 +++
 gcc/omp-low.c                                     |  2 +-
 gcc/testsuite/gcc.dg/autopar/pr46099-chunk-size.c | 47 +++++++++++++++++++++++
 3 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/autopar/pr46099-chunk-size.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a0123b1..5a273ba 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-05-18  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/65637
+	* omp-low.c (expand_omp_for_static_chunk): Fix gcc_assert for the case
+	that head is NULL.
+
 2015-08-31  Tom de Vries  <tom@codesourcery.com>
 
 	* tree-ssa-loop-manip.c (find_uses_to_rename_use)
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index c3dfc51..4e732ae 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -7326,7 +7326,7 @@ expand_omp_for_static_chunk (struct omp_region *region,
 	  locus = redirect_edge_var_map_location (vm);
 	  add_phi_arg (nphi, redirect_edge_var_map_def (vm), re, locus);
 	}
-      gcc_assert (gsi_end_p (psi) && i == head->length ());
+      gcc_assert (gsi_end_p (psi) && (head == NULL || i == head->length ()));
       redirect_edge_var_map_clear (re);
       while (1)
 	{
diff --git a/gcc/testsuite/gcc.dg/autopar/pr46099-chunk-size.c b/gcc/testsuite/gcc.dg/autopar/pr46099-chunk-size.c
new file mode 100644
index 0000000..709841a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/autopar/pr46099-chunk-size.c
@@ -0,0 +1,47 @@
+/* PR tree-optimization/46099.  */
+/* { dg-do compile } */
+/* { dg-options "-ftree-parallelize-loops=2 -fcompare-debug -O --param parloops-chunk-size=100" } */
+
+static inline void
+bar (int *i)
+{
+  int j = *i;
+}
+
+void baz (int *, int *, int *);
+
+void
+f1 (int n)
+{
+  int i;
+  for (i = 0; i < n; i++)
+    bar (&i);
+}
+
+void
+f2 (int n)
+{
+  int i;
+  int a[10000], b[10000], c[10000];
+  baz (a, b, c);
+  for (i = 0; i < n; i++)
+    {
+      void *p = c;
+      a[i] = b[i] + c[i];
+    }
+  baz (a, b, c);
+}
+
+void
+f3 (int n)
+{
+  int i;
+  int a[10000], b[10000], c[10000];
+  baz (a, b, c);
+  for (i = 0; i < n; i++)
+    {
+      a[i] = b[i] + c[i];
+      void *p = c;
+    }
+  baz (a, b, c);
+}
-- 
1.9.1