--- /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/stackslotalloc/StackInterval.java	2016-12-09 00:54:34.307757154 -0800
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2014, 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.stackslotalloc;
+
+import org.graalvm.compiler.lir.VirtualStackSlot;
+
+import jdk.vm.ci.code.StackSlot;
+import jdk.vm.ci.meta.ValueKind;
+
+public final class StackInterval {
+
+    private static final int INVALID_START = Integer.MAX_VALUE;
+    private static final int INVALID_END = Integer.MIN_VALUE;
+    private final VirtualStackSlot operand;
+    private StackInterval hint;
+    private final ValueKind<?> kind;
+    private int from = INVALID_START;
+    private int to = INVALID_END;
+    private StackSlot location;
+
+    public StackInterval(VirtualStackSlot operand, ValueKind<?> kind) {
+        this.operand = operand;
+        this.kind = kind;
+    }
+
+    public boolean verify(int maxOpId) {
+        // maxOpId + 1 is the last position in the last block (i.e. the "write position")
+        assert 0 <= from && from <= to && to <= maxOpId + 1 : String.format("from %d, to %d, maxOpId %d", from, to, maxOpId);
+        return true;
+    }
+
+    public VirtualStackSlot getOperand() {
+        return operand;
+    }
+
+    public void addTo(int opId) {
+        if (opId >= to) {
+            to = opId;
+        }
+    }
+
+    protected void addFrom(int opId) {
+        if (from > opId) {
+            from = opId;
+            // set opId also as to if it has not yet been set
+            if (to == INVALID_END) {
+                to = opId;
+            }
+        }
+    }
+
+    public ValueKind<?> kind() {
+        return kind;
+    }
+
+    public StackSlot location() {
+        return location;
+    }
+
+    public void setLocation(StackSlot location) {
+        this.location = location;
+    }
+
+    public int from() {
+        return from;
+    }
+
+    public int to() {
+        return to;
+    }
+
+    public void fixFrom() {
+        if (from == INVALID_START) {
+            from = 0;
+        }
+    }
+
+    public boolean isFixed() {
+        return from == 0;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("SI[%d-%d] k=%s o=%s l=%s h=%s", from, to, kind, operand, location, hint != null ? hint.getOperand() : "null");
+    }
+
+    public void setLocationHint(StackInterval locationHint) {
+        hint = locationHint;
+    }
+
+    public StackInterval locationHint() {
+        return hint;
+    }
+
+}