diff --git a/src/IceRangeSpec.h b/src/IceRangeSpec.h
new file mode 100644
index 0000000..cdd9c35
--- /dev/null
+++ b/src/IceRangeSpec.h
@@ -0,0 +1,73 @@
+//===- subzero/src/IceRangeSpec.h - Include/exclude specs -------*- C++ -*-===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief Declares a class for specifying inclusion/exclusion of values, such
+/// as functions to match.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef SUBZERO_SRC_ICERANGESPEC_H
+#define SUBZERO_SRC_ICERANGESPEC_H
+
+#include "IceStringPool.h"
+
+#include <string>
+#include <unordered_set>
+#include <vector>
+
+#include "llvm/ADT/BitVector.h"
+
+namespace Ice {
+
+class RangeSpec {
+  RangeSpec(const RangeSpec &) = delete;
+  RangeSpec &operator=(const RangeSpec &) = delete;
+
+public:
+  static constexpr char DELIM_LIST = ',';
+  static constexpr char DELIM_RANGE = ':';
+  static constexpr uint32_t RangeMax = std::numeric_limits<uint32_t>::max();
+  RangeSpec() = default;
+  struct Desc {
+    // Set of names explicitly provided.
+    std::unordered_set<std::string> Names;
+    // Set of numbers explicitly provided.
+    llvm::BitVector Numbers;
+    // The smallest X for which the open-ended interval "X:" was provided.  This
+    // is needed because the intervals are parsed before we know the largest
+    // number that might be matched against, and we can't make the Numbers
+    // bitvector infinitely long.
+    uint32_t AllFrom = RangeMax;
+    // Whether a clause was explicitly provided.
+    bool IsExplicit = false;
+  };
+  void init(const std::string &Spec);
+  bool match(const std::string &Name, uint32_t Number) const;
+  bool match(GlobalString Name, uint32_t Number) const {
+    return match(Name.toStringOrEmpty(), Number);
+  }
+  // Returns true if any RangeSpec object has had init() called with an explicit
+  // name rather than (or in addition to) a numeric range.  If so, we want to
+  // construct explicit names for functions even in a non-DUMP build so that
+  // matching on function name works correctly.  Note that this is not
+  // thread-safe, so we count on all this being handled by the startup thread.
+  static bool hasNames() { return HasNames; }
+
+private:
+  void include(const std::string &Token);
+  void exclude(const std::string &Token);
+  Desc Includes;
+  Desc Excludes;
+  static bool HasNames;
+};
+
+} // end of namespace Ice
+
+#endif // SUBZERO_SRC_ICERANGESPEC_H