--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.replacements/src/org/graalvm/compiler/replacements/nodes/BasicArrayCopyNode.java	Tue Sep 24 08:54:08 2019 -0700
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.replacements/src/org/graalvm/compiler/replacements/nodes/BasicArrayCopyNode.java	Tue Sep 24 12:47:15 2019 -0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2019, Oracle and/or its affiliates. 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
@@ -144,7 +144,8 @@
     }
 
     private static boolean checkBounds(int position, int length, VirtualObjectNode virtualObject) {
-        return position >= 0 && position + length <= virtualObject.entryCount();
+        assert length >= 0;
+        return position >= 0 && position <= virtualObject.entryCount() - length;
     }
 
     private static boolean checkEntryTypes(int srcPos, int length, VirtualObjectNode src, ResolvedJavaType destComponentType, VirtualizerTool tool) {