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diff --git a/include/llvm/Support/ConstantRange.h b/include/llvm/Support/ConstantRange.h
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+//===-- llvm/Support/ConstantRange.h - Represent a range --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Represent a range of possible values that may occur when the program is run
+// for an integral value.  This keeps track of a lower and upper bound for the
+// constant, which MAY wrap around the end of the numeric range.  To do this, it
+// keeps track of a [lower, upper) bound, which specifies an interval just like
+// STL iterators.  When used with boolean values, the following are important
+// ranges: :
+//
+//  [F, F) = {}     = Empty set
+//  [T, F) = {T}
+//  [F, T) = {F}
+//  [T, T) = {F, T} = Full set
+//
+// The other integral ranges use min/max values for special range values. For
+// example, for 8-bit types, it uses:
+// [0, 0)     = {}       = Empty set
+// [255, 255) = {0..255} = Full Set
+//
+// Note that ConstantRange always keeps unsigned values.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_CONSTANT_RANGE_H
+#define LLVM_SUPPORT_CONSTANT_RANGE_H
+
+#include "llvm/ADT/APInt.h"
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+
+class ConstantRange {
+  APInt Lower, Upper;
+  static ConstantRange intersect1Wrapped(const ConstantRange &LHS,
+                                         const ConstantRange &RHS);
+ public:
+  /// Initialize a full (the default) or empty set for the specified bit width.
+  ///
+  explicit ConstantRange(uint32_t BitWidth, bool isFullSet = true);
+
+  /// Initialize a range to hold the single specified value.
+  ///
+  ConstantRange(const APInt &Value);
+
+  /// @brief Initialize a range of values explicitly. This will assert out if
+  /// Lower==Upper and Lower != Min or Max value for its type. It will also
+  /// assert out if the two APInt's are not the same bit width.
+  ConstantRange(const APInt& Lower, const APInt& Upper);
+
+  /// getLower - Return the lower value for this range...
+  ///
+  const APInt &getLower() const { return Lower; }
+
+  /// getUpper - Return the upper value for this range...
+  ///
+  const APInt &getUpper() const { return Upper; }
+
+  /// getBitWidth - get the bit width of this ConstantRange
+  ///
+  uint32_t getBitWidth() const { return Lower.getBitWidth(); }
+
+  /// isFullSet - Return true if this set contains all of the elements possible
+  /// for this data-type
+  ///
+  bool isFullSet() const;
+
+  /// isEmptySet - Return true if this set contains no members.
+  ///
+  bool isEmptySet() const;
+
+  /// isWrappedSet - Return true if this set wraps around the top of the range,
+  /// for example: [100, 8)
+  ///
+  bool isWrappedSet() const;
+
+  /// contains - Return true if the specified value is in the set.
+  ///
+  bool contains(const APInt &Val) const;
+
+  /// getSingleElement - If this set contains a single element, return it,
+  /// otherwise return null.
+  ///
+  const APInt *getSingleElement() const {
+    if (Upper == Lower + 1)
+      return &Lower;
+    return 0;
+  }
+
+  /// isSingleElement - Return true if this set contains exactly one member.
+  ///
+  bool isSingleElement() const { return getSingleElement() != 0; }
+
+  /// getSetSize - Return the number of elements in this set.
+  ///
+  APInt getSetSize() const;
+
+  /// getUnsignedMax - Return the largest unsigned value contained in the
+  /// ConstantRange.
+  ///
+  APInt getUnsignedMax() const;
+
+  /// getUnsignedMin - Return the smallest unsigned value contained in the
+  /// ConstantRange.
+  ///
+  APInt getUnsignedMin() const;
+
+  /// getSignedMax - Return the largest signed value contained in the
+  /// ConstantRange.
+  ///
+  APInt getSignedMax() const;
+
+  /// getSignedMin - Return the smallest signed value contained in the
+  /// ConstantRange.
+  ///
+  APInt getSignedMin() const;
+
+  /// operator== - Return true if this range is equal to another range.
+  ///
+  bool operator==(const ConstantRange &CR) const {
+    return Lower == CR.Lower && Upper == CR.Upper;
+  }
+  bool operator!=(const ConstantRange &CR) const {
+    return !operator==(CR);
+  }
+
+  /// subtract - Subtract the specified constant from the endpoints of this
+  /// constant range.
+  ConstantRange subtract(const APInt &CI) const;
+
+  /// intersectWith - Return the range that results from the intersection of
+  /// this range with another range.  The resultant range is pruned as much as
+  /// possible, but there may be cases where elements are included that are in
+  /// one of the sets but not the other.  For example: [100, 8) intersect [3,
+  /// 120) yields [3, 120)
+  ///
+  ConstantRange intersectWith(const ConstantRange &CR) const;
+
+  /// maximalIntersectWith - Return the range that results from the intersection
+  /// of this range with another range.  The resultant range is guaranteed to
+  /// include all elements contained in both input ranges, and to have the
+  /// smallest possible set size that does so.  Because there may be two
+  /// intersections with the same set size, A.maximalIntersectWith(B) might not
+  /// be equal to B.maximalIntersectWith(A).
+  ///
+  ConstantRange maximalIntersectWith(const ConstantRange &CR) const;
+
+  /// unionWith - Return the range that results from the union of this range
+  /// with another range.  The resultant range is guaranteed to include the
+  /// elements of both sets, but may contain more.  For example, [3, 9) union
+  /// [12,15) is [3, 15), which includes 9, 10, and 11, which were not included
+  /// in either set before.
+  ///
+  ConstantRange unionWith(const ConstantRange &CR) const;
+
+  /// zeroExtend - Return a new range in the specified integer type, which must
+  /// be strictly larger than the current type.  The returned range will
+  /// correspond to the possible range of values if the source range had been
+  /// zero extended to BitWidth.
+  ConstantRange zeroExtend(uint32_t BitWidth) const;
+
+  /// signExtend - Return a new range in the specified integer type, which must
+  /// be strictly larger than the current type.  The returned range will
+  /// correspond to the possible range of values if the source range had been
+  /// sign extended to BitWidth.
+  ConstantRange signExtend(uint32_t BitWidth) const;
+
+  /// truncate - Return a new range in the specified integer type, which must be
+  /// strictly smaller than the current type.  The returned range will
+  /// correspond to the possible range of values if the source range had been
+  /// truncated to the specified type.
+  ConstantRange truncate(uint32_t BitWidth) const;
+
+  /// print - Print out the bounds to a stream...
+  ///
+  void print(raw_ostream &OS) const;
+
+  /// dump - Allow printing from a debugger easily...
+  ///
+  void dump() const;
+};
+
+inline raw_ostream &operator<<(raw_ostream &OS, const ConstantRange &CR) {
+  CR.print(OS);
+  return OS;
+}
+
+} // End llvm namespace
+
+#endif