--- /dev/null	2017-11-16 08:17:56.803999947 +0100
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/gc/g1/G1PreWriteBarrier.java	2019-03-09 03:57:55.549438325 +0100
@@ -0,0 +1,82 @@
+/*
+ * 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
+ * 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.
+ */
+
+
+
+package org.graalvm.compiler.hotspot.gc.g1;
+
+import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_64;
+import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_64;
+
+import org.graalvm.compiler.graph.NodeClass;
+import org.graalvm.compiler.hotspot.gc.shared.ObjectWriteBarrier;
+import org.graalvm.compiler.nodeinfo.InputType;
+import org.graalvm.compiler.nodeinfo.NodeInfo;
+import org.graalvm.compiler.nodes.DeoptimizingNode;
+import org.graalvm.compiler.nodes.FrameState;
+import org.graalvm.compiler.nodes.ValueNode;
+import org.graalvm.compiler.nodes.memory.address.AddressNode;
+
+@NodeInfo(cycles = CYCLES_64, size = SIZE_64)
+public final class G1PreWriteBarrier extends ObjectWriteBarrier implements DeoptimizingNode.DeoptBefore {
+
+    public static final NodeClass<G1PreWriteBarrier> TYPE = NodeClass.create(G1PreWriteBarrier.class);
+
+    @OptionalInput(InputType.State) private FrameState stateBefore;
+    private final boolean nullCheck;
+    private final boolean doLoad;
+
+    public G1PreWriteBarrier(AddressNode address, ValueNode expectedObject, boolean doLoad, boolean nullCheck) {
+        super(TYPE, address, expectedObject, true);
+        this.doLoad = doLoad;
+        this.nullCheck = nullCheck;
+    }
+
+    public ValueNode getExpectedObject() {
+        return getValue();
+    }
+
+    public boolean doLoad() {
+        return doLoad;
+    }
+
+    public boolean getNullCheck() {
+        return nullCheck;
+    }
+
+    @Override
+    public boolean canDeoptimize() {
+        return nullCheck;
+    }
+
+    @Override
+    public FrameState stateBefore() {
+        return stateBefore;
+    }
+
+    @Override
+    public void setStateBefore(FrameState state) {
+        updateUsages(stateBefore, state);
+        stateBefore = state;
+    }
+}