Fix clobber removal in parloops

2016-01-23  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/69426
	* tree-parloops.c (eliminate_local_variables_stmt): Handle vdef of
	removed clobber.

	* gcc.dg/autopar/pr69426.c: New test.

---
 gcc/testsuite/gcc.dg/autopar/pr69426.c | 19 +++++++++++++++++++
 gcc/tree-parloops.c                    |  1 +
 2 files changed, 20 insertions(+)

diff --git a/gcc/testsuite/gcc.dg/autopar/pr69426.c b/gcc/testsuite/gcc.dg/autopar/pr69426.c
new file mode 100644
index 0000000..e91421c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/autopar/pr69426.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2" } */
+
+int iq;
+
+void
+mr(void)
+{
+  unsigned int i8;
+
+  for (i8 = 0; i8 != 1; i8 += 3) {
+    void *f0[] = { f0 };
+    int hv;
+
+    for (; hv < 1; ++hv)
+      iq = 0;
+  }
+  ++iq;
+}
diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c
index 7749d34..f9db43b 100644
--- a/gcc/tree-parloops.c
+++ b/gcc/tree-parloops.c
@@ -725,6 +725,7 @@ eliminate_local_variables_stmt (edge entry, gimple_stmt_iterator *gsi,
     }
   else if (gimple_clobber_p (stmt))
     {
+      replace_uses_by (gimple_vdef (stmt), gimple_vuse (stmt));
       stmt = gimple_build_nop ();
       gsi_replace (gsi, stmt, false);
       dta.changed = true;