Add a ConstantSignedRange class, which does for signed integers

what ConstantRange does for unsigned integers. Factor out a
common base class for common functionality.

Add some new functions for performing arithmetic on constant
ranges. Some of these are currently just stubbed out with
conservative implementations.

Add unittests for ConstantRange and ConstantSignedRange.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75177 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 572 insertions, 19 deletions

diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index cb8c4b013c..bb458d4c6b 100644
--- a/lib/Support/ConstantRange.cpp
+++ b/lib/Support/ConstantRange.cpp
@@ -25,10 +25,40 @@
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
+/// Initialize a range to hold the single specified value.
+///
+ConstantRangeBase::ConstantRangeBase(const APInt & V)
+  : Lower(V), Upper(V + 1) {}
+
+ConstantRangeBase::ConstantRangeBase(const APInt &L, const APInt &U)
+  : Lower(L), Upper(U) {
+  assert(L.getBitWidth() == U.getBitWidth() &&
+         "ConstantRange with unequal bit widths");
+}
+
+/// print - Print out the bounds to a stream...
+///
+void ConstantRangeBase::print(raw_ostream &OS) const {
+  OS << "[" << Lower << "," << Upper << ")";
+}
+
+/// dump - Allow printing from a debugger easily...
+///
+void ConstantRangeBase::dump() const {
+  print(errs());
+}
+
+std::ostream &llvm::operator<<(std::ostream &o,
+                               const ConstantRangeBase &CR) {
+  raw_os_ostream OS(o);
+  OS << CR;
+  return o;
+}
+
 /// Initialize a full (the default) or empty set for the specified type.
 ///
 ConstantRange::ConstantRange(uint32_t BitWidth, bool Full) :
-  Lower(BitWidth, 0), Upper(BitWidth, 0) {
+  ConstantRangeBase(APInt(BitWidth, 0), APInt(BitWidth, 0)) {
   if (Full)
     Lower = Upper = APInt::getMaxValue(BitWidth);
   else
@@ -37,12 +67,10 @@ ConstantRange::ConstantRange(uint32_t BitWidth, bool Full) :
 
 /// Initialize a range to hold the single specified value.
 ///
-ConstantRange::ConstantRange(const APInt & V) : Lower(V), Upper(V + 1) { }
+ConstantRange::ConstantRange(const APInt & V) : ConstantRangeBase(V) {}
 
-ConstantRange::ConstantRange(const APInt &L, const APInt &U) :
-  Lower(L), Upper(U) {
-  assert(L.getBitWidth() == U.getBitWidth() && 
-         "ConstantRange with unequal bit widths");
+ConstantRange::ConstantRange(const APInt &L, const APInt &U)
+  : ConstantRangeBase(L, U) {
   assert((L != U || (L.isMaxValue() || L.isMinValue())) &&
          "Lower == Upper, but they aren't min or max value!");
 }
@@ -221,9 +249,8 @@ ConstantRange ConstantRange::intersectWith(const ConstantRange &CR) const {
 
   if (!isWrappedSet()) {
     if (!CR.isWrappedSet()) {
-      using namespace APIntOps;
-      APInt L = umax(Lower, CR.Lower);
-      APInt U = umin(Upper, CR.Upper);
+      APInt L = APIntOps::umax(Lower, CR.Lower);
+      APInt U = APIntOps::umin(Upper, CR.Upper);
 
       if (L.ult(U)) // If range isn't empty...
         return ConstantRange(L, U);
@@ -236,9 +263,8 @@ ConstantRange ConstantRange::intersectWith(const ConstantRange &CR) const {
       return intersect1Wrapped(*this, CR);
     else {
       // Both ranges are wrapped...
-      using namespace APIntOps;
-      APInt L = umax(Lower, CR.Lower);
-      APInt U = umin(Upper, CR.Upper);
+      APInt L = APIntOps::umax(Lower, CR.Lower);
+      APInt U = APIntOps::umin(Upper, CR.Upper);
       return ConstantRange(L, U);
     }
   }
@@ -251,7 +277,8 @@ ConstantRange ConstantRange::intersectWith(const ConstantRange &CR) const {
 /// 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.maximalIntersect(A).
-ConstantRange ConstantRange::maximalIntersectWith(const ConstantRange &CR) const {
+ConstantRange
+ConstantRange::maximalIntersectWith(const ConstantRange &CR) const {
   assert(getBitWidth() == CR.getBitWidth() && 
          "ConstantRange types don't agree!");
 
@@ -459,14 +486,540 @@ ConstantRange ConstantRange::truncate(uint32_t DstTySize) const {
   return ConstantRange(L, U);
 }
 
-/// print - Print out the bounds to a stream...
+ConstantRange
+ConstantRange::add(const ConstantRange &Other) const {
+  if (isEmptySet() || Other.isEmptySet())
+    return ConstantRange(getBitWidth(), /*isFullSet=*/false);
+
+  APInt Spread_X = getSetSize(), Spread_Y = Other.getSetSize();
+  APInt NewLower = getLower() + Other.getLower();
+  APInt NewUpper = getUpper() + Other.getUpper() - 1;
+  if (NewLower == NewUpper)
+    return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+
+  ConstantRange X = ConstantRange(NewLower, NewUpper);
+  if (X.getSetSize().ult(Spread_X) || X.getSetSize().ult(Spread_Y))
+    // We've wrapped, therefore, full set.
+    return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+
+  return X;
+}
+
+ConstantRange
+ConstantRange::multiply(const ConstantRange &Other) const {
+  // TODO: Implement multiply.
+  return ConstantRange(getBitWidth(),
+                       !(isEmptySet() || Other.isEmptySet()));
+}
+
+ConstantRange
+ConstantRange::smax(const ConstantRange &Other) const {
+  // TODO: Implement smax.
+  return ConstantRange(getBitWidth(),
+                       !(isEmptySet() || Other.isEmptySet()));
+}
+
+ConstantRange
+ConstantRange::umax(const ConstantRange &Other) const {
+  // X umax Y is: range(umax(X_umin, Y_umin),
+  //                    umax(X_umax, Y_umax))
+  if (isEmptySet() || Other.isEmptySet())
+    return ConstantRange(getBitWidth(), /*isFullSet=*/false);
+  if (isFullSet() || Other.isFullSet())
+    return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+  APInt NewL = APIntOps::umax(getUnsignedMin(), Other.getUnsignedMin());
+  APInt NewU = APIntOps::umax(getUnsignedMax(), Other.getUnsignedMax()) + 1;
+  if (NewU == NewL)
+    return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+  return ConstantRange(NewL, NewU);
+}
+
+ConstantRange
+ConstantRange::udiv(const ConstantRange &Other) const {
+  // TODO: Implement udiv.
+  return ConstantRange(getBitWidth(),
+                       !(isEmptySet() || Other.isEmptySet()));
+}
+
+/// Initialize a full (the default) or empty set for the specified type.
 ///
-void ConstantRange::print(raw_ostream &OS) const {
-  OS << "[" << Lower << "," << Upper << ")";
+ConstantSignedRange::ConstantSignedRange(uint32_t BitWidth, bool Full) :
+  ConstantRangeBase(APInt(BitWidth, 0), APInt(BitWidth, 0)) {
+  if (Full)
+    Lower = Upper = APInt::getSignedMaxValue(BitWidth);
+  else
+    Lower = Upper = APInt::getSignedMinValue(BitWidth);
 }
 
-/// dump - Allow printing from a debugger easily...
+/// Initialize a range to hold the single specified value.
 ///
-void ConstantRange::dump() const {
-  print(errs());
+ConstantSignedRange::ConstantSignedRange(const APInt & V)
+  : ConstantRangeBase(V) {}
+
+ConstantSignedRange::ConstantSignedRange(const APInt &L, const APInt &U)
+  : ConstantRangeBase(L, U) {
+  assert((L != U || (L.isMaxSignedValue() || L.isMinSignedValue())) &&
+         "Lower == Upper, but they aren't min or max value!");
+}
+
+/// isFullSet - Return true if this set contains all of the elements possible
+/// for this data-type
+bool ConstantSignedRange::isFullSet() const {
+  return Lower == Upper && Lower.isMaxSignedValue();
+}
+
+/// isEmptySet - Return true if this set contains no members.
+///
+bool ConstantSignedRange::isEmptySet() const {
+  return Lower == Upper && Lower.isMinSignedValue();
+}
+
+/// isWrappedSet - Return true if this set wraps around the top of the range,
+/// for example: [100, 8)
+///
+bool ConstantSignedRange::isWrappedSet() const {
+  return Lower.sgt(Upper);
+}
+
+/// getSetSize - Return the number of elements in this set.
+///
+APInt ConstantSignedRange::getSetSize() const {
+  if (isEmptySet())
+    return APInt(getBitWidth(), 0);
+  if (getBitWidth() == 1) {
+    if (Lower != Upper)  // One of T or F in the set...
+      return APInt(2, 1);
+    return APInt(2, 2);      // Must be full set...
+  }
+
+  // Simply subtract the bounds...
+  return Upper - Lower;
+}
+
+/// getSignedMax - Return the largest signed value contained in the
+/// ConstantSignedRange.
+///
+APInt ConstantSignedRange::getSignedMax() const {
+  if (isFullSet() || isWrappedSet())
+    return APInt::getSignedMaxValue(getBitWidth());
+  else
+    return getUpper() - 1;
+}
+
+/// getSignedMin - Return the smallest signed value contained in the
+/// ConstantSignedRange.
+///
+APInt ConstantSignedRange::getSignedMin() const {
+  if (isFullSet() || (isWrappedSet() &&
+                      getUpper() != APInt::getSignedMinValue(getBitWidth())))
+    return APInt::getSignedMinValue(getBitWidth());
+  else
+    return getLower();
+}
+
+/// getUnsignedMax - Return the largest unsigned value contained in the
+/// ConstantSignedRange.
+///
+APInt ConstantSignedRange::getUnsignedMax() const {
+  APInt UnsignedMax(APInt::getMaxValue(getBitWidth()));
+  if (!isWrappedSet()) {
+    if (getLower().ule(getUpper() - 1))
+      return getUpper() - 1;
+    else
+      return UnsignedMax;
+  } else {
+    if ((getUpper() - 1).ult(getLower())) {
+      if (getLower() != UnsignedMax)
+        return UnsignedMax;
+      else
+        return getUpper() - 1;
+    } else {
+      return getUpper() - 1;
+    }
+  }
+}
+
+/// getUnsignedMin - Return the smallest unsigned value contained in the
+/// ConstantSignedRange.
+///
+APInt ConstantSignedRange::getUnsignedMin() const {
+  APInt UnsignedMin(APInt::getMinValue(getBitWidth()));
+  if (!isWrappedSet()) {
+    if (getLower().ule(getUpper() - 1))
+      return getLower();
+    else
+      return UnsignedMin;
+  } else {
+    if ((getUpper() - 1).ult(getLower())) {
+      if (getUpper() != UnsignedMin)
+        return UnsignedMin;
+      else
+        return getLower();
+    } else {
+      return getLower();
+    }
+  }
+}
+
+/// contains - Return true if the specified value is in the set.
+///
+bool ConstantSignedRange::contains(const APInt &V) const {
+  if (Lower == Upper)
+    return isFullSet();
+
+  if (!isWrappedSet())
+    return Lower.sle(V) && V.slt(Upper);
+  else
+    return Lower.sle(V) || V.slt(Upper);
+}
+
+/// subtract - Subtract the specified constant from the endpoints of this
+/// constant range.
+ConstantSignedRange ConstantSignedRange::subtract(const APInt &Val) const {
+  assert(Val.getBitWidth() == getBitWidth() && "Wrong bit width");
+  // If the set is empty or full, don't modify the endpoints.
+  if (Lower == Upper)
+    return *this;
+  return ConstantSignedRange(Lower - Val, Upper - Val);
+}
+
+
+// intersect1Wrapped - This helper function is used to intersect two ranges when
+// it is known that LHS is wrapped and RHS isn't.
+//
+ConstantSignedRange
+ConstantSignedRange::intersect1Wrapped(const ConstantSignedRange &LHS,
+                                 const ConstantSignedRange &RHS) {
+  assert(LHS.isWrappedSet() && !RHS.isWrappedSet());
+
+  // Check to see if we overlap on the Left side of RHS...
+  //
+  if (RHS.Lower.slt(LHS.Upper)) {
+    // We do overlap on the left side of RHS, see if we overlap on the right of
+    // RHS...
+    if (RHS.Upper.sgt(LHS.Lower)) {
+      // Ok, the result overlaps on both the left and right sides.  See if the
+      // resultant interval will be smaller if we wrap or not...
+      //
+      if (LHS.getSetSize().ult(RHS.getSetSize()))
+        return LHS;
+      else
+        return RHS;
+
+    } else {
+      // No overlap on the right, just on the left.
+      return ConstantSignedRange(RHS.Lower, LHS.Upper);
+    }
+  } else {
+    // We don't overlap on the left side of RHS, see if we overlap on the right
+    // of RHS...
+    if (RHS.Upper.sgt(LHS.Lower)) {
+      // Simple overlap...
+      return ConstantSignedRange(LHS.Lower, RHS.Upper);
+    } else {
+      // No overlap...
+      return ConstantSignedRange(LHS.getBitWidth(), false);
+    }
+  }
+}
+
+/// intersectWith - Return the range that results from the intersection of this
+/// range with another range.
+///
+ConstantSignedRange
+ConstantSignedRange::intersectWith(const ConstantSignedRange &CR) const {
+  assert(getBitWidth() == CR.getBitWidth() &&
+         "ConstantSignedRange types don't agree!");
+  // Handle common special cases
+  if (isEmptySet() || CR.isFullSet())
+    return *this;
+  if (isFullSet()  || CR.isEmptySet())
+    return CR;
+
+  if (!isWrappedSet()) {
+    if (!CR.isWrappedSet()) {
+      APInt L = APIntOps::smax(Lower, CR.Lower);
+      APInt U = APIntOps::smin(Upper, CR.Upper);
+
+      if (L.slt(U)) // If range isn't empty...
+        return ConstantSignedRange(L, U);
+      else
+        return ConstantSignedRange(getBitWidth(), false);// Otherwise, empty set
+    } else
+      return intersect1Wrapped(CR, *this);
+  } else {   // We know "this" is wrapped...
+    if (!CR.isWrappedSet())
+      return intersect1Wrapped(*this, CR);
+    else {
+      // Both ranges are wrapped...
+      APInt L = APIntOps::smax(Lower, CR.Lower);
+      APInt U = APIntOps::smin(Upper, CR.Upper);
+      return ConstantSignedRange(L, U);
+    }
+  }
+  return *this;
+}
+
+/// 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.maximalIntersect(A).
+ConstantSignedRange
+ConstantSignedRange::maximalIntersectWith(const ConstantSignedRange &CR) const {
+  assert(getBitWidth() == CR.getBitWidth() &&
+         "ConstantSignedRange types don't agree!");
+
+  // Handle common cases.
+  if (   isEmptySet() || CR.isFullSet()) return *this;
+  if (CR.isEmptySet() ||    isFullSet()) return CR;
+
+  if (!isWrappedSet() && CR.isWrappedSet())
+    return CR.maximalIntersectWith(*this);
+
+  if (!isWrappedSet() && !CR.isWrappedSet()) {
+    if (Lower.slt(CR.Lower)) {
+      if (Upper.sle(CR.Lower))
+        return ConstantSignedRange(getBitWidth(), false);
+
+      if (Upper.slt(CR.Upper))
+        return ConstantSignedRange(CR.Lower, Upper);
+
+      return CR;
+    } else {
+      if (Upper.slt(CR.Upper))
+        return *this;
+
+      if (Lower.slt(CR.Upper))
+        return ConstantSignedRange(Lower, CR.Upper);
+
+      return ConstantSignedRange(getBitWidth(), false);
+    }
+  }
+
+  if (isWrappedSet() && !CR.isWrappedSet()) {
+    if (CR.Lower.slt(Upper)) {
+      if (CR.Upper.slt(Upper))
+        return CR;
+
+      if (CR.Upper.slt(Lower))
+        return ConstantSignedRange(CR.Lower, Upper);
+
+      if (getSetSize().ult(CR.getSetSize()))
+        return *this;
+      else
+        return CR;
+    } else if (CR.Lower.slt(Lower)) {
+      if (CR.Upper.sle(Lower))
+        return ConstantSignedRange(getBitWidth(), false);
+
+      return ConstantSignedRange(Lower, CR.Upper);
+    }
+    return CR;
+  }
+
+  if (CR.Upper.slt(Upper)) {
+    if (CR.Lower.slt(Upper)) {
+      if (getSetSize().ult(CR.getSetSize()))
+        return *this;
+      else
+        return CR;
+    }
+
+    if (CR.Lower.slt(Lower))
+      return ConstantSignedRange(Lower, CR.Upper);
+
+    return CR;
+  } else if (CR.Upper.slt(Lower)) {
+    if (CR.Lower.slt(Lower))
+      return *this;
+
+    return ConstantSignedRange(CR.Lower, Upper);
+  }
+  if (getSetSize().ult(CR.getSetSize()))
+    return *this;
+  else
+    return CR;
+}
+
+
+/// 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.
+///
+ConstantSignedRange
+ConstantSignedRange::unionWith(const ConstantSignedRange &CR) const {
+  assert(getBitWidth() == CR.getBitWidth() &&
+         "ConstantSignedRange types don't agree!");
+
+  if (   isFullSet() || CR.isEmptySet()) return *this;
+  if (CR.isFullSet() ||    isEmptySet()) return CR;
+
+  if (!isWrappedSet() && CR.isWrappedSet()) return CR.unionWith(*this);
+
+  APInt L = Lower, U = Upper;
+
+  if (!isWrappedSet() && !CR.isWrappedSet()) {
+    if (CR.Lower.slt(L))
+      L = CR.Lower;
+
+    if (CR.Upper.sgt(U))
+      U = CR.Upper;
+  }
+
+  if (isWrappedSet() && !CR.isWrappedSet()) {
+    if ((CR.Lower.slt(Upper) && CR.Upper.slt(Upper)) ||
+        (CR.Lower.sgt(Lower) && CR.Upper.sgt(Lower))) {
+      return *this;
+    }
+
+    if (CR.Lower.sle(Upper) && Lower.sle(CR.Upper)) {
+      return ConstantSignedRange(getBitWidth());
+    }
+
+    if (CR.Lower.sle(Upper) && CR.Upper.sle(Lower)) {
+      APInt d1 = CR.Upper - Upper, d2 = Lower - CR.Upper;
+      if (d1.slt(d2)) {
+        U = CR.Upper;
+      } else {
+        L = CR.Upper;
+      }
+    }
+
+    if (Upper.slt(CR.Lower) && CR.Upper.slt(Lower)) {
+      APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper;
+      if (d1.slt(d2)) {
+        U = CR.Lower + 1;
+      } else {
+        L = CR.Upper - 1;
+      }
+    }
+
+    if (Upper.slt(CR.Lower) && Lower.slt(CR.Upper)) {
+      APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Lower;
+
+      if (d1.slt(d2)) {
+        U = CR.Lower + 1;
+      } else {
+        L = CR.Lower;
+      }
+    }
+  }
+
+  if (isWrappedSet() && CR.isWrappedSet()) {
+    if (Lower.slt(CR.Upper) || CR.Lower.slt(Upper))
+      return ConstantSignedRange(getBitWidth());
+
+    if (CR.Upper.sgt(U)) {
+      U = CR.Upper;
+    }
+
+    if (CR.Lower.slt(L)) {
+      L = CR.Lower;
+    }
+
+    if (L == U) return ConstantSignedRange(getBitWidth());
+  }
+
+  return ConstantSignedRange(L, U);
+}
+
+/// 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 as if the source range had been
+/// zero extended.
+ConstantSignedRange ConstantSignedRange::zeroExtend(uint32_t DstTySize) const {
+  unsigned SrcTySize = getBitWidth();
+  assert(SrcTySize < DstTySize && "Not a value extension");
+  if (isEmptySet())
+    return ConstantSignedRange(SrcTySize, /*isFullSet=*/false);
+  if (isFullSet())
+    // Change a source full set into [0, 1 << 8*numbytes)
+    return ConstantSignedRange(APInt(DstTySize,0),
+                               APInt(DstTySize,1).shl(SrcTySize));
+
+  APInt L, U;
+  if (Lower.isNegative() && !Upper.isNegative()) {
+    L = APInt(SrcTySize, 0);
+    U = APInt::getSignedMinValue(SrcTySize);
+  } else {
+    L = Lower;
+    U = Upper;
+  }
+  L.zext(DstTySize);
+  U.zext(DstTySize);
+  return ConstantSignedRange(L, U);
+}
+
+/// 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 as if the source range had been
+/// sign extended.
+ConstantSignedRange ConstantSignedRange::signExtend(uint32_t DstTySize) const {
+  unsigned SrcTySize = getBitWidth();
+  assert(SrcTySize < DstTySize && "Not a value extension");
+  if (isEmptySet())
+    return ConstantSignedRange(SrcTySize, /*isFullSet=*/false);
+  if (isFullSet())
+    return ConstantSignedRange(APInt(getSignedMin()).sext(DstTySize),
+                               APInt(getSignedMax()).sext(DstTySize)+1);
+
+  APInt L = Lower; L.sext(DstTySize);
+  APInt U = Upper; U.sext(DstTySize);
+  return ConstantSignedRange(L, U);
+}
+
+/// 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 as if the source range had been
+/// truncated to the specified type.
+ConstantSignedRange ConstantSignedRange::truncate(uint32_t DstTySize) const {
+  // TODO: Implement truncate.
+  return ConstantSignedRange(DstTySize, !isEmptySet());
+}
+
+ConstantSignedRange
+ConstantSignedRange::add(const ConstantSignedRange &Other) const {
+  // TODO: Implement add.
+  return ConstantSignedRange(getBitWidth(),
+                             !(isEmptySet() || Other.isEmptySet()));
+}
+
+ConstantSignedRange
+ConstantSignedRange::multiply(const ConstantSignedRange &Other) const {
+  // TODO: Implement multiply.
+  return ConstantSignedRange(getBitWidth(),
+                             !(isEmptySet() || Other.isEmptySet()));
+}
+
+ConstantSignedRange
+ConstantSignedRange::smax(const ConstantSignedRange &Other) const {
+  // X smax Y is: range(smax(X_smin, Y_smin),
+  //                    smax(X_smax, Y_smax))
+  if (isEmptySet() || Other.isEmptySet())
+    return ConstantSignedRange(getBitWidth(), /*isFullSet=*/false);
+  if (isFullSet() || Other.isFullSet())
+    return ConstantSignedRange(getBitWidth(), /*isFullSet=*/true);
+  APInt NewL = APIntOps::smax(getSignedMin(), Other.getSignedMin());
+  APInt NewU = APIntOps::smax(getSignedMax(), Other.getSignedMax()) + 1;
+  if (NewU == NewL)
+    return ConstantSignedRange(getBitWidth(), /*isFullSet=*/true);
+  return ConstantSignedRange(NewL, NewU);
+}
+
+ConstantSignedRange
+ConstantSignedRange::umax(const ConstantSignedRange &Other) const {
+  // TODO: Implement umax.
+  return ConstantSignedRange(getBitWidth(),
+                             !(isEmptySet() || Other.isEmptySet()));
+}
+
+ConstantSignedRange
+ConstantSignedRange::udiv(const ConstantSignedRange &Other) const {
+  // TODO: Implement udiv.
+  return ConstantSignedRange(getBitWidth(),
+                             !(isEmptySet() || Other.isEmptySet()));
 }