--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.lir/src/org/graalvm/compiler/lir/gen/VerifyingMoveFactory.java	2016-12-09 00:54:26.567415967 -0800
@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2015, 2015, 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.gen;
+
+import static org.graalvm.compiler.lir.LIRValueUtil.isJavaConstant;
+import static org.graalvm.compiler.lir.LIRValueUtil.isVariable;
+
+import java.util.EnumSet;
+
+import org.graalvm.compiler.lir.LIRInstruction;
+import org.graalvm.compiler.lir.LIRInstruction.OperandFlag;
+import org.graalvm.compiler.lir.LIRInstruction.OperandMode;
+import org.graalvm.compiler.lir.StandardOp.LoadConstantOp;
+import org.graalvm.compiler.lir.gen.LIRGeneratorTool.MoveFactory;
+
+import jdk.vm.ci.meta.AllocatableValue;
+import jdk.vm.ci.meta.Constant;
+import jdk.vm.ci.meta.JavaConstant;
+import jdk.vm.ci.meta.Value;
+
+/**
+ * Wrapper for {@link MoveFactory} that checks that the instructions created adhere to the contract
+ * of {@link MoveFactory}.
+ */
+public final class VerifyingMoveFactory implements MoveFactory {
+
+    private final MoveFactory inner;
+
+    public VerifyingMoveFactory(MoveFactory inner) {
+        this.inner = inner;
+    }
+
+    @Override
+    public boolean canInlineConstant(JavaConstant c) {
+        return inner.canInlineConstant(c);
+    }
+
+    @Override
+    public boolean allowConstantToStackMove(Constant constant) {
+        return inner.allowConstantToStackMove(constant);
+    }
+
+    @Override
+    public LIRInstruction createMove(AllocatableValue result, Value input) {
+        LIRInstruction inst = inner.createMove(result, input);
+        assert checkResult(inst, result, input);
+        return inst;
+    }
+
+    @Override
+    public LIRInstruction createStackMove(AllocatableValue result, AllocatableValue input) {
+        LIRInstruction inst = inner.createStackMove(result, input);
+        assert checkResult(inst, result, input);
+        return inst;
+    }
+
+    @Override
+    public LIRInstruction createLoad(AllocatableValue result, Constant input) {
+        LIRInstruction inst = inner.createLoad(result, input);
+        assert inst instanceof LoadConstantOp && checkResult(inst, result, null);
+        return inst;
+    }
+
+    /** Closure for {@link VerifyingMoveFactory#checkResult}. */
+    @SuppressWarnings("unused")
+    private static class CheckClosure {
+
+        private final AllocatableValue result;
+        private final Value input;
+
+        private int tempCount = 0;
+        private int aliveCount = 0;
+        private int stateCount = 0;
+        private int inputCount = 0;
+        private int outputCount = 0;
+
+        CheckClosure(AllocatableValue result, Value input) {
+            this.result = result;
+            this.input = input;
+        }
+
+        void tempProc(LIRInstruction op, Value value, OperandMode mode, EnumSet<OperandFlag> flags) {
+            assert false : String.format("SpillMoveFactory: Instruction %s is not allowed to contain operand %s of mode %s", op, value, mode);
+            tempCount++;
+        }
+
+        void stateProc(LIRInstruction op, Value value, OperandMode mode, EnumSet<OperandFlag> flags) {
+            assert false : String.format("SpillMoveFactory: Instruction %s is not allowed to contain operand %s of mode %s", op, value, mode);
+            stateCount++;
+        }
+
+        void aliveProc(LIRInstruction op, Value value, OperandMode mode, EnumSet<OperandFlag> flags) {
+            assert !isVariable(value) && flags.contains(OperandFlag.UNINITIALIZED) : String.format("SpillMoveFactory: Instruction %s is not allowed to contain operand %s of mode %s", op, value, mode);
+            aliveCount++;
+        }
+
+        void inputProc(LIRInstruction op, Value value, OperandMode mode, EnumSet<OperandFlag> flags) {
+            assert value.equals(input) || isJavaConstant(value) : String.format("SpillMoveFactory: Instruction %s can only have %s as input, got %s", op, input, value);
+            inputCount++;
+        }
+
+        void outputProc(LIRInstruction op, Value value, OperandMode mode, EnumSet<OperandFlag> flags) {
+            assert value.equals(result) : String.format("SpillMoveFactory: Instruction %s can only have %s as input, got %s", op, input, value);
+            outputCount++;
+        }
+    }
+
+    /**
+     * Checks that the instructions adheres to the contract of {@link MoveFactory}.
+     */
+    private static boolean checkResult(LIRInstruction inst, AllocatableValue result, Value input) {
+
+        VerifyingMoveFactory.CheckClosure c = new CheckClosure(result, input);
+        inst.visitEachInput(c::inputProc);
+        inst.visitEachOutput(c::outputProc);
+        inst.visitEachAlive(c::aliveProc);
+        inst.visitEachTemp(c::tempProc);
+        inst.visitEachState(c::stateProc);
+
+        assert c.outputCount >= 1 : "no output produced" + inst;
+        assert c.stateCount == 0 : "SpillMoveFactory: instruction must not have a state: " + inst;
+        return true;
+    }
+}