Subject: [PATCH] pr94125

---
 gcc/testsuite/gcc.dg/tree-ssa/pr94125.c | 41 +++++++++++++++++++++++++++++++++
 gcc/tree-loop-distribution.c            | 13 ++++-------
 2 files changed, 46 insertions(+), 8 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr94125.c

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr94125.c b/gcc/testsuite/gcc.dg/tree-ssa/pr94125.c
new file mode 100644
index 0000000..c339e51
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr94125.c
@@ -0,0 +1,41 @@
+/* { dg-do run } */
+/* { dg-options "-O3" } */
+
+unsigned char b, f;
+short d[1][8][1], *g = &d[0][3][0];
+
+void __attribute__((noinline)) foo ()
+{
+  int k[256] = { 0, 0, 0, 4, 0, 0 };
+  for (int c = 252; c >= 0; c--)
+    {
+      b = f;
+      *g = k[c + 3];
+      k[c + 1] = 0;
+    }
+  for (int i = 0; i < 8; i++)
+    if (d[0][i][0] != 0)
+      __builtin_abort ();
+}
+
+void __attribute__((noinline)) bar ()
+{
+  int k[256] = { 0, 0, 0, 4, 0, 0 };
+  k[255] = 4;
+  for (int c = 0; c <=252; c++)
+    {
+      b = f;
+      *g = k[c + 3];
+      k[c + 1] = 0;
+    }
+  for (int i = 0; i < 8; i++)
+    if ((i == 3 && d[0][i][0] != 4) || (i != 3 && d[0][i][0] != 0))
+      __builtin_abort ();
+}
+
+int main ()
+{
+  foo ();
+  bar ();
+  return 0;
+}
diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c
index 35d3821..f85f6df 100644
--- a/gcc/tree-loop-distribution.c
+++ b/gcc/tree-loop-distribution.c
@@ -2489,14 +2489,11 @@ loop_distribution::break_alias_scc_partitions (struct graph *rdg,
 	      if (cbdata.vertices_component[k] != i)
 		continue;
 
-	      /* Update postorder number so that merged reduction partition is
-		 sorted after other partitions.  */
-	      if (!partition_reduction_p (first)
-		  && partition_reduction_p (partition))
-		{
-		  gcc_assert (pg->vertices[k].post < pg->vertices[j].post);
-		  pg->vertices[j].post = pg->vertices[k].post;
-		}
+	      /* Update to the minimal postordeer number of vertices in scc so
+		 that merged partition is sorted correctly against others.  */
+              if (pg->vertices[j].post > pg->vertices[k].post)
+		pg->vertices[j].post = pg->vertices[k].post;
+
 	      partition_merge_into (NULL, first, partition, FUSE_SAME_SCC);
 	      (*partitions)[k] = NULL;
 	      partition_free (partition);
-- 
1.8.3.1