From 19aa23d84ee1f001e748f8f8a6da9982dcc30a39 Mon Sep 17 00:00:00 2001
From: Yuri Rumyantsev <ysrumyan@gmail.com>
Date: Fri, 6 May 2016 12:07:25 +0000
Subject: [PATCH] re PR debug/70935 (ICE: verify_ssa failed (error: definition
 in block 9 does not dominate use in block 12) w/ -O3 -g)

gcc/

2016-05-06  Yuri Rumyantsev  <ysrumyan@gmail.com>

	PR debug/70935
	* tree-ssa-loop-unswitch.c (find_loop_guard): Reject guard edge with
	loop latch destination.

gcc/testsuite/

2016-05-06  Yuri Rumyantsev  <ysrumyan@gmail.com>

	PR debug/70935
	* gcc.dg/torture/pr70935.c: New test.

From-SVN: r235962
---
 gcc/ChangeLog                          |  6 ++++
 gcc/testsuite/ChangeLog                |  5 ++++
 gcc/testsuite/gcc.dg/torture/pr70935.c | 39 ++++++++++++++++++++++++++
 gcc/tree-ssa-loop-unswitch.c           |  6 ++++
 4 files changed, 56 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr70935.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ed6c31b2824..8f3679a52b3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-05-06  Yuri Rumyantsev  <ysrumyan@gmail.com>
+
+	PR debug/70935
+	* tree-ssa-loop-unswitch.c (find_loop_guard): Reject guard edge with
+	loop latch destination.
+
 2016-05-06  Martin Liska  <mliska@suse.cz>
 
 	* tree-ssa-uninit.c: Apply manual changes
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index fc12a060fee..510e3feeeea 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-05-06  Yuri Rumyantsev  <ysrumyan@gmail.com>
+
+	PR debug/70935
+	* gcc.dg/torture/pr70935.c: New test.
+
 2016-05-06  Oleg Endo  <olegendo@gcc.gnu.org>
 
 	PR target/58219
diff --git a/gcc/testsuite/gcc.dg/torture/pr70935.c b/gcc/testsuite/gcc.dg/torture/pr70935.c
new file mode 100644
index 00000000000..eb7f034ce83
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr70935.c
@@ -0,0 +1,39 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -g" } */
+
+int d0, sj, v0, rp, zi;
+
+void
+zn(void)
+{
+  if (v0 != 0)
+    {
+      int *js, *r3;
+      int pm, gc;
+
+      for (gc = 0; gc < 1; ++gc)
+        {
+          sj = 1;
+          while (sj != 0)
+            ;
+        }
+      r3 = &pm;
+      *js = (long)&gc;
+ka:
+      for (d0 = 0; d0 < 2; ++d0)
+        {
+          d0 = zi;
+          if (zi)
+            for (pm = 2; pm != 0; --pm)
+              ;
+        }
+      while (*r3 != 0)
+        {
+          while (pm)
+            ;
+          ++r3;
+        }
+    }
+  rp = 0;
+  goto ka;
+}
diff --git a/gcc/tree-ssa-loop-unswitch.c b/gcc/tree-ssa-loop-unswitch.c
index 77acd66e997..bf9fafa63b2 100644
--- a/gcc/tree-ssa-loop-unswitch.c
+++ b/gcc/tree-ssa-loop-unswitch.c
@@ -536,6 +536,12 @@ find_loop_guard (struct loop *loop)
 		 guard_edge->src->index, guard_edge->dest->index);
       return NULL;
     }
+  if (guard_edge->dest == loop->latch)
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	fprintf (dump_file, "Guard edge destination is loop latch.\n");
+      return NULL;
+    }
 
   if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file,