--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.lir.amd64/src/org/graalvm/compiler/lir/amd64/AMD64ZapStackOp.java	2017-02-15 17:05:04.114555618 -0800
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2016, 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.lir.amd64;
+
+import org.graalvm.compiler.asm.amd64.AMD64MacroAssembler;
+import org.graalvm.compiler.lir.LIRInstructionClass;
+import org.graalvm.compiler.lir.Opcode;
+import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
+
+import jdk.vm.ci.code.StackSlot;
+import jdk.vm.ci.meta.JavaConstant;
+
+/**
+ * Writes well known garbage values to stack slots.
+ */
+@Opcode("ZAP_STACK")
+public final class AMD64ZapStackOp extends AMD64LIRInstruction {
+    public static final LIRInstructionClass<AMD64ZapStackOp> TYPE = LIRInstructionClass.create(AMD64ZapStackOp.class);
+
+    /**
+     * The stack slots that are zapped.
+     */
+    @Def(OperandFlag.STACK) protected final StackSlot[] zappedStack;
+
+    /**
+     * The garbage values that are written to the stack.
+     */
+    protected final JavaConstant[] zapValues;
+
+    public AMD64ZapStackOp(StackSlot[] zappedStack, JavaConstant[] zapValues) {
+        super(TYPE);
+        this.zappedStack = zappedStack;
+        this.zapValues = zapValues;
+    }
+
+    @Override
+    public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler masm) {
+        for (int i = 0; i < zappedStack.length; i++) {
+            StackSlot slot = zappedStack[i];
+            if (slot != null) {
+                AMD64Move.const2stack(crb, masm, slot, zapValues[i]);
+            }
+        }
+    }
+}