[Modules] Move the ConstantRange class into the IR library. This is

a bit surprising, as the class is almost entirely abstracted away from
any particular IR, however it encodes the comparsion predicates which
mutate ranges as ICmp predicate codes. This is reasonable as they're
used for both instructions and constants. Thus, it belongs in the IR
library with instructions and constants.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202838 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 272 insertions, 0 deletions

diff --git a/include/llvm/IR/ConstantRange.h b/include/llvm/IR/ConstantRange.h
new file mode 100644
index 0000000000..86988debff
--- /dev/null
+++ b/include/llvm/IR/ConstantRange.h
@@ -0,0 +1,272 @@
+//===- 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 can be used to represent either signed or
+// unsigned ranges.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_CONSTANTRANGE_H
+#define LLVM_SUPPORT_CONSTANTRANGE_H
+
+#include "llvm/ADT/APInt.h"
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+
+/// ConstantRange - This class represents an range of values.
+///
+class ConstantRange {
+  APInt Lower, Upper;
+
+  // If we have move semantics, pass APInts by value and move them into place.
+  typedef APInt APIntMoveTy;
+
+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(APIntMoveTy 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(APIntMoveTy Lower, APIntMoveTy Upper);
+
+  /// makeICmpRegion - Produce the smallest range that contains all values that
+  /// might satisfy the comparison specified by Pred when compared to any value
+  /// contained within Other.
+  ///
+  /// Solves for range X in 'for all x in X, there exists a y in Y such that
+  /// icmp op x, y is true'. Every value that might make the comparison true
+  /// is included in the resulting range.
+  static ConstantRange makeICmpRegion(unsigned Pred,
+                                      const ConstantRange &Other);
+
+  /// 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;
+
+  /// isSignWrappedSet - Return true if this set wraps around the INT_MIN of
+  /// its bitwidth, for example: i8 [120, 140).
+  ///
+  bool isSignWrappedSet() const;
+
+  /// contains - Return true if the specified value is in the set.
+  ///
+  bool contains(const APInt &Val) const;
+
+  /// contains - Return true if the other range is a subset of this one.
+  ///
+  bool contains(const ConstantRange &CR) 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;
+
+  /// \brief Subtract the specified range from this range (aka relative
+  /// complement of the sets).
+  ConstantRange difference(const ConstantRange &CR) const;
+
+  /// intersectWith - 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.intersectWith(B) might not
+  /// be equal to B.intersectWith(A).
+  ///
+  ConstantRange intersectWith(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;
+
+  /// zextOrTrunc - make this range have the bit width given by \p BitWidth. The
+  /// value is zero extended, truncated, or left alone to make it that width.
+  ConstantRange zextOrTrunc(uint32_t BitWidth) const;
+  
+  /// sextOrTrunc - make this range have the bit width given by \p BitWidth. The
+  /// value is sign extended, truncated, or left alone to make it that width.
+  ConstantRange sextOrTrunc(uint32_t BitWidth) const;
+
+  /// add - Return a new range representing the possible values resulting
+  /// from an addition of a value in this range and a value in \p Other.
+  ConstantRange add(const ConstantRange &Other) const;
+
+  /// sub - Return a new range representing the possible values resulting
+  /// from a subtraction of a value in this range and a value in \p Other.
+  ConstantRange sub(const ConstantRange &Other) const;
+
+  /// multiply - Return a new range representing the possible values resulting
+  /// from a multiplication of a value in this range and a value in \p Other.
+  /// TODO: This isn't fully implemented yet.
+  ConstantRange multiply(const ConstantRange &Other) const;
+
+  /// smax - Return a new range representing the possible values resulting
+  /// from a signed maximum of a value in this range and a value in \p Other.
+  ConstantRange smax(const ConstantRange &Other) const;
+
+  /// umax - Return a new range representing the possible values resulting
+  /// from an unsigned maximum of a value in this range and a value in \p Other.
+  ConstantRange umax(const ConstantRange &Other) const;
+
+  /// udiv - Return a new range representing the possible values resulting
+  /// from an unsigned division of a value in this range and a value in
+  /// \p Other.
+  ConstantRange udiv(const ConstantRange &Other) const;
+
+  /// binaryAnd - return a new range representing the possible values resulting
+  /// from a binary-and of a value in this range by a value in \p Other.
+  ConstantRange binaryAnd(const ConstantRange &Other) const;
+
+  /// binaryOr - return a new range representing the possible values resulting
+  /// from a binary-or of a value in this range by a value in \p Other.
+  ConstantRange binaryOr(const ConstantRange &Other) const;
+
+  /// shl - Return a new range representing the possible values resulting
+  /// from a left shift of a value in this range by a value in \p Other.
+  /// TODO: This isn't fully implemented yet.
+  ConstantRange shl(const ConstantRange &Other) const;
+
+  /// lshr - Return a new range representing the possible values resulting
+  /// from a logical right shift of a value in this range and a value in
+  /// \p Other.
+  ConstantRange lshr(const ConstantRange &Other) const;
+
+  /// inverse - Return a new range that is the logical not of the current set.
+  ///
+  ConstantRange inverse() 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