--- a/src/hotspot/share/opto/loopnode.cpp	Tue Feb 13 16:13:20 2018 +0100
+++ b/src/hotspot/share/opto/loopnode.cpp	Tue Feb 13 16:57:01 2018 +0100
@@ -2347,7 +2347,7 @@
     tty->print("  ");
   tty->print("Loop: N%d/N%d ",_head->_idx,_tail->_idx);
   if (_irreducible) tty->print(" IRREDUCIBLE");
-  Node* entry = _head->as_Loop()->skip_strip_mined(-1)->in(LoopNode::EntryControl);
+  Node* entry = _head->is_Loop() ? _head->as_Loop()->skip_strip_mined(-1)->in(LoopNode::EntryControl) : _head->in(LoopNode::EntryControl);
   Node* predicate = PhaseIdealLoop::find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check);
   if (predicate != NULL ) {
     tty->print(" limit_check");
@@ -2398,7 +2398,7 @@
   if (Verbose) {
     tty->print(" body={"); _body.dump_simple(); tty->print(" }");
   }
-  if (_head->as_Loop()->is_strip_mined()) {
+  if (_head->is_Loop() && _head->as_Loop()->is_strip_mined()) {
     tty->print(" strip_mined");
   }
   tty->cr();

--- a/src/hotspot/share/opto/loopopts.cpp	Tue Feb 13 16:13:20 2018 +0100
+++ b/src/hotspot/share/opto/loopopts.cpp	Tue Feb 13 16:57:01 2018 +0100
@@ -693,7 +693,9 @@
 Node* PhaseIdealLoop::try_move_store_before_loop(Node* n, Node *n_ctrl) {
   // Store has to be first in the loop body
   IdealLoopTree *n_loop = get_loop(n_ctrl);
-  if (n->is_Store() && n_loop != _ltree_root && n_loop->is_loop() && n->in(0) != NULL) {
+  if (n->is_Store() && n_loop != _ltree_root &&
+      n_loop->is_loop() && n_loop->_head->is_Loop() &&
+      n->in(0) != NULL) {
     Node* address = n->in(MemNode::Address);
     Node* value = n->in(MemNode::ValueIn);
     Node* mem = n->in(MemNode::Memory);

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/compiler/loopopts/StoreMovedBeforeInfiniteLoop.java	Tue Feb 13 16:57:01 2018 +0100
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2018, Red Hat, Inc. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8197563
+ * @summary assert(is_Loop()) crash in PhaseIdealLoop::try_move_store_before_loop()
+ *
+ * @run main/othervm -Xcomp -XX:-TieredCompilation -XX:CompileOnly=StoreMovedBeforeInfiniteLoop::test  StoreMovedBeforeInfiniteLoop
+ *
+ */
+
+public class StoreMovedBeforeInfiniteLoop {
+    public static void main(String[] args) {
+        field = -1;
+        test(new Object());
+    }
+
+    static int field;
+
+    static int constant() {
+        return 65;
+    }
+
+    private static int test(Object o) {
+        do {
+            if (field <= 0) {
+                return -109;
+            }
+            do {
+                field = 4;
+            } while (constant() >= 0);
+        } while (o == null);
+        return -109;
+    }
+}