From 23fab8aee7a9d510c9f451d5f31ed0b9b7b30981 Mon Sep 17 00:00:00 2001
From: Tom de Vries <tom@codesourcery.com>
Date: Sun, 10 Jan 2016 09:12:03 +0000
Subject: [PATCH] Only allow single exit phi for reduction in
 try_create_reduction_list

2016-01-10  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/69039
	* tree-parloops.c (try_create_reduction_list): Only allow single exit
	phi for reduction.

	* gcc.dg/autopar/pr69039.c: New test.

From-SVN: r232196
---
 gcc/ChangeLog                          |  6 ++++++
 gcc/testsuite/ChangeLog                |  5 +++++
 gcc/testsuite/gcc.dg/autopar/pr69039.c | 15 +++++++++++++++
 gcc/tree-parloops.c                    |  8 ++++++++
 4 files changed, 34 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/autopar/pr69039.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 609a6a3eab8..21b47fea579 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-01-10  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/69039
+	* tree-parloops.c (try_create_reduction_list): Only allow single exit
+	phi for reduction.
+
 2016-01-09  John David Anglin  <danglin@gcc.gnu.org>
 
 	PR middle-end/68743
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4af4374cea6..198f26c3cab 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-01-10  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/69039
+	* gcc.dg/autopar/pr69039.c: New test.
+
 2016-01-09  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/69113
diff --git a/gcc/testsuite/gcc.dg/autopar/pr69039.c b/gcc/testsuite/gcc.dg/autopar/pr69039.c
new file mode 100644
index 00000000000..556f70004e8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/autopar/pr69039.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2" } */
+
+unsigned int b;
+
+unsigned int
+fn1 (unsigned int d)
+{
+  int i;
+
+  for (i = 0; i < 1000; i++)
+    b |= d;
+
+  return b;
+}
diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c
index 84f18bd8f03..394aba8d121 100644
--- a/gcc/tree-parloops.c
+++ b/gcc/tree-parloops.c
@@ -2595,6 +2595,14 @@ try_create_reduction_list (loop_p loop,
 			 "  FAILED: it is not a part of reduction.\n");
 	      return false;
 	    }
+	  if (red->keep_res != NULL)
+	    {
+	      if (dump_file && (dump_flags & TDF_DETAILS))
+		fprintf (dump_file,
+			 "  FAILED: reduction has multiple exit phis.\n");
+	      return false;
+	    }
+	  red->keep_res = phi;
 	  if (dump_file && (dump_flags & TDF_DETAILS))
 	    {
 	      fprintf (dump_file, "reduction phi is  ");