From: Jim Wilson <jim.wilson@linaro.org>
Date: Thu, 10 Nov 2016 15:20:59 +0000 (+0000)
Subject: Fix loop distribution bug with merging edges that creates too many edges.
X-Git-Tag: basepoints/gcc-8~3252
X-Git-Url: https://gcc.gnu.org/git/?a=commitdiff_plain;h=dd18c8c32a865a5432338d1959afefa42bebb718;p=gcc.git

Fix loop distribution bug with merging edges that creates too many edges.

gcc/
	* tree-loop-distribution.c (pg_add_dependence_edges): Return 2 if
	this_dir is 2.  Check for this_dir non-zero before dir != this_dir
	check.

From-SVN: r242038
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9e93f793453d..1e13f598d6fc 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-11-10  Jim Wilson  <jim.wilson@linaro.org>
+
+	* tree-loop-distribution.c (pg_add_dependence_edges): Return 2 if
+	this_dir is 2.  Check for this_dir non-zero before dir != this_dir
+	check.
+
 2016-11-10  Jakub Jelinek  <jakub@redhat.com>
 
 	* omp-low.c (lower_omp_target): Fix up argument to is_reference.
diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c
index 5580f286ccfc..902cf30b78a2 100644
--- a/gcc/tree-loop-distribution.c
+++ b/gcc/tree-loop-distribution.c
@@ -1408,9 +1408,11 @@ pg_add_dependence_edges (struct graph *rdg, vec<loop_p> loops, int dir,
 	else
 	  this_dir = 0;
 	free_dependence_relation (ddr);
-	if (dir == 0)
+	if (this_dir == 2)
+	  return 2;
+	else if (dir == 0)
 	  dir = this_dir;
-	else if (dir != this_dir)
+	else if (this_dir != 0 && dir != this_dir)
 	  return 2;
 	/* Shuffle "back" dr1.  */
 	dr1 = saved_dr1;