--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.loop.phases/src/org/graalvm/compiler/loop/phases/LoopPartialUnrollPhase.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2012, 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.loop.phases;
+
+import org.graalvm.compiler.graph.Graph;
+import org.graalvm.compiler.loop.LoopEx;
+import org.graalvm.compiler.loop.LoopPolicies;
+import org.graalvm.compiler.loop.LoopsData;
+import org.graalvm.compiler.nodes.StructuredGraph;
+import org.graalvm.compiler.phases.common.CanonicalizerPhase;
+import org.graalvm.compiler.phases.common.util.HashSetNodeEventListener;
+import org.graalvm.compiler.phases.tiers.PhaseContext;
+
+public class LoopPartialUnrollPhase extends LoopPhase<LoopPolicies> {
+
+    private final CanonicalizerPhase canonicalizer;
+
+    public LoopPartialUnrollPhase(LoopPolicies policies, CanonicalizerPhase canonicalizer) {
+        super(policies);
+        this.canonicalizer = canonicalizer;
+    }
+
+    @Override
+    @SuppressWarnings("try")
+    protected void run(StructuredGraph graph, PhaseContext context) {
+        if (graph.hasLoops()) {
+            HashSetNodeEventListener listener = new HashSetNodeEventListener();
+            boolean changed = true;
+            while (changed) {
+                changed = false;
+                try (Graph.NodeEventScope nes = graph.trackNodeEvents(listener)) {
+                    LoopsData dataCounted = new LoopsData(graph);
+                    dataCounted.detectedCountedLoops();
+                    Graph.Mark mark = graph.getMark();
+                    boolean prePostInserted = false;
+                    for (LoopEx loop : dataCounted.countedLoops()) {
+                        if (!LoopTransformations.isUnrollableLoop(loop)) {
+                            continue;
+                        }
+                        if (getPolicies().shouldPartiallyUnroll(loop)) {
+                            if (loop.loopBegin().isSimpleLoop()) {
+                                // First perform the pre/post transformation and do the partial
+                                // unroll when we come around again.
+                                LoopTransformations.insertPrePostLoops(loop);
+                                prePostInserted = true;
+                            } else {
+                                LoopTransformations.partialUnroll(loop);
+                            }
+                            changed = true;
+                        }
+                    }
+                    dataCounted.deleteUnusedNodes();
+
+                    if (!listener.getNodes().isEmpty()) {
+                        canonicalizer.applyIncremental(graph, context, listener.getNodes());
+                        listener.getNodes().clear();
+                    }
+
+                    assert !prePostInserted || checkCounted(graph, mark);
+                }
+            }
+        }
+    }
+
+    private static boolean checkCounted(StructuredGraph graph, Graph.Mark mark) {
+        LoopsData dataCounted;
+        dataCounted = new LoopsData(graph);
+        dataCounted.detectedCountedLoops();
+        for (LoopEx anyLoop : dataCounted.loops()) {
+            if (graph.isNew(mark, anyLoop.loopBegin())) {
+                assert anyLoop.isCounted() : "pre/post transformation loses counted loop " + anyLoop.loopBegin();
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public boolean checkContract() {
+        return false;
+    }
+}