--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.test/src/org/graalvm/compiler/core/test/ConditionalEliminationTestBase.java	2017-02-15 16:57:30.007717593 -0800
@@ -0,0 +1,119 @@
+/*
+ * 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.core.test;
+
+import org.junit.Assert;
+
+import org.graalvm.compiler.debug.Debug;
+import org.graalvm.compiler.nodes.ProxyNode;
+import org.graalvm.compiler.nodes.StructuredGraph;
+import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
+import org.graalvm.compiler.nodes.spi.LoweringTool;
+import org.graalvm.compiler.phases.common.CanonicalizerPhase;
+import org.graalvm.compiler.phases.common.ConvertDeoptimizeToGuardPhase;
+import org.graalvm.compiler.phases.common.DominatorConditionalEliminationPhase;
+import org.graalvm.compiler.phases.common.IterativeConditionalEliminationPhase;
+import org.graalvm.compiler.phases.common.LoweringPhase;
+import org.graalvm.compiler.phases.schedule.SchedulePhase;
+import org.graalvm.compiler.phases.tiers.PhaseContext;
+
+/**
+ * Collection of tests for
+ * {@link org.graalvm.compiler.phases.common.DominatorConditionalEliminationPhase} including those
+ * that triggered bugs in this phase.
+ */
+public class ConditionalEliminationTestBase extends GraalCompilerTest {
+
+    private final boolean disableSimplification;
+
+    protected ConditionalEliminationTestBase() {
+        disableSimplification = true;
+    }
+
+    protected ConditionalEliminationTestBase(boolean disableSimplification) {
+        this.disableSimplification = disableSimplification;
+    }
+
+    protected void testConditionalElimination(String snippet, String referenceSnippet) {
+        testConditionalElimination(snippet, referenceSnippet, false);
+    }
+
+    @SuppressWarnings("try")
+    protected void testConditionalElimination(String snippet, String referenceSnippet, boolean applyConditionalEliminationOnReference) {
+        StructuredGraph graph = parseEager(snippet, AllowAssumptions.YES);
+        Debug.dump(Debug.BASIC_LOG_LEVEL, graph, "Graph");
+        PhaseContext context = new PhaseContext(getProviders());
+        CanonicalizerPhase canonicalizer1 = new CanonicalizerPhase();
+        if (disableSimplification) {
+            /**
+             * Some tests break if simplification is done so only do it when needed.
+             */
+            canonicalizer1.disableSimplification();
+        }
+        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();
+        try (Debug.Scope scope = Debug.scope("ConditionalEliminationTest", graph)) {
+            canonicalizer1.apply(graph, context);
+            new ConvertDeoptimizeToGuardPhase().apply(graph, context);
+            // new DominatorConditionalEliminationPhase(true).apply(graph, context);
+            new IterativeConditionalEliminationPhase(canonicalizer, true).apply(graph, context);
+            canonicalizer.apply(graph, context);
+            canonicalizer.apply(graph, context);
+            new ConvertDeoptimizeToGuardPhase().apply(graph, context);
+        } catch (Throwable t) {
+            Debug.handle(t);
+        }
+        StructuredGraph referenceGraph = parseEager(referenceSnippet, AllowAssumptions.YES);
+        try (Debug.Scope scope = Debug.scope("ConditionalEliminationTest.ReferenceGraph", referenceGraph)) {
+
+            new ConvertDeoptimizeToGuardPhase().apply(referenceGraph, context);
+            if (applyConditionalEliminationOnReference) {
+                new DominatorConditionalEliminationPhase(true).apply(referenceGraph, context);
+                canonicalizer.apply(referenceGraph, context);
+                canonicalizer.apply(referenceGraph, context);
+            } else {
+                canonicalizer.apply(referenceGraph, context);
+            }
+        } catch (Throwable t) {
+            Debug.handle(t);
+        }
+        assertEquals(referenceGraph, graph);
+    }
+
+    public void testProxies(String snippet, int expectedProxiesCreated) {
+        StructuredGraph graph = parseEager(snippet, AllowAssumptions.YES);
+        PhaseContext context = new PhaseContext(getProviders());
+        CanonicalizerPhase canonicalizer1 = new CanonicalizerPhase();
+        canonicalizer1.disableSimplification();
+        canonicalizer1.apply(graph, context);
+        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();
+        new LoweringPhase(canonicalizer, LoweringTool.StandardLoweringStage.HIGH_TIER).apply(graph, context);
+        canonicalizer.apply(graph, context);
+
+        int baseProxyCount = graph.getNodes().filter(ProxyNode.class).count();
+        new DominatorConditionalEliminationPhase(true).apply(graph, context);
+        canonicalizer.apply(graph, context);
+        new SchedulePhase().apply(graph, context);
+        int actualProxiesCreated = graph.getNodes().filter(ProxyNode.class).count() - baseProxyCount;
+        Assert.assertEquals(expectedProxiesCreated, actualProxiesCreated);
+    }
+}