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diff --git a/llvm/lib/VMCore/ConstantRange.cpp b/llvm/lib/VMCore/ConstantRange.cpp
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+//===-- ConstantRange.cpp - ConstantRange implementation ------------------===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and 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 (other integral ranges use min/max values for special range values):
+//
+//  [F, F) = {}     = Empty set
+//  [T, F) = {T}
+//  [F, T) = {F}
+//  [T, T) = {F, T} = Full set
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/ConstantRange.h"
+#include "llvm/Constants.h"
+#include "llvm/Instruction.h"
+#include "llvm/Type.h"
+#include <iostream>
+
+using namespace llvm;
+
+static ConstantIntegral *Next(ConstantIntegral *CI) {
+  if (CI->getType() == Type::BoolTy)
+    return CI == ConstantBool::True ? ConstantBool::False : ConstantBool::True;
+      
+  Constant *Result = ConstantExpr::getAdd(CI,
+                                          ConstantInt::get(CI->getType(), 1));
+  return cast<ConstantIntegral>(Result);
+}
+
+static bool LT(ConstantIntegral *A, ConstantIntegral *B) {
+  Constant *C = ConstantExpr::getSetLT(A, B);
+  assert(isa<ConstantBool>(C) && "Constant folding of integrals not impl??");
+  return cast<ConstantBool>(C)->getValue();
+}
+
+static bool LTE(ConstantIntegral *A, ConstantIntegral *B) {
+  Constant *C = ConstantExpr::getSetLE(A, B);
+  assert(isa<ConstantBool>(C) && "Constant folding of integrals not impl??");
+  return cast<ConstantBool>(C)->getValue();
+}
+
+static bool GT(ConstantIntegral *A, ConstantIntegral *B) { return LT(B, A); }
+
+static ConstantIntegral *Min(ConstantIntegral *A, ConstantIntegral *B) {
+  return LT(A, B) ? A : B;
+}
+static ConstantIntegral *Max(ConstantIntegral *A, ConstantIntegral *B) {
+  return GT(A, B) ? A : B;
+}
+
+/// Initialize a full (the default) or empty set for the specified type.
+///
+ConstantRange::ConstantRange(const Type *Ty, bool Full) {
+  assert(Ty->isIntegral() &&
+         "Cannot make constant range of non-integral type!");
+  if (Full)
+    Lower = Upper = ConstantIntegral::getMaxValue(Ty);
+  else
+    Lower = Upper = ConstantIntegral::getMinValue(Ty);
+}
+
+/// Initialize a range to hold the single specified value.
+///
+ConstantRange::ConstantRange(Constant *V)
+  : Lower(cast<ConstantIntegral>(V)), Upper(Next(cast<ConstantIntegral>(V))) {
+}
+
+/// Initialize a range of values explicitly... this will assert out if
+/// Lower==Upper and Lower != Min or Max for its type (or if the two constants
+/// have different types)
+///
+ConstantRange::ConstantRange(Constant *L, Constant *U)
+  : Lower(cast<ConstantIntegral>(L)), Upper(cast<ConstantIntegral>(U)) {
+  assert(Lower->getType() == Upper->getType() &&
+         "Incompatible types for ConstantRange!");
+  
+  // Make sure that if L & U are equal that they are either Min or Max...
+  assert((L != U || (L == ConstantIntegral::getMaxValue(L->getType()) ||
+                     L == ConstantIntegral::getMinValue(L->getType()))) &&
+         "Lower == Upper, but they aren't min or max for type!");
+}
+
+/// Initialize a set of values that all satisfy the condition with C.
+///
+ConstantRange::ConstantRange(unsigned SetCCOpcode, ConstantIntegral *C) {
+  switch (SetCCOpcode) {
+  default: assert(0 && "Invalid SetCC opcode to ConstantRange ctor!");
+  case Instruction::SetEQ: Lower = C; Upper = Next(C); return;
+  case Instruction::SetNE: Upper = C; Lower = Next(C); return;
+  case Instruction::SetLT:
+    Lower = ConstantIntegral::getMinValue(C->getType());
+    Upper = C;
+    return;
+  case Instruction::SetGT:
+    Lower = Next(C);
+    Upper = ConstantIntegral::getMinValue(C->getType());  // Min = Next(Max)
+    return;
+  case Instruction::SetLE:
+    Lower = ConstantIntegral::getMinValue(C->getType());
+    Upper = Next(C);
+    return;
+  case Instruction::SetGE:
+    Lower = C;
+    Upper = ConstantIntegral::getMinValue(C->getType());  // Min = Next(Max)
+    return;
+  }
+}
+
+/// getType - Return the LLVM data type of this range.
+///
+const Type *ConstantRange::getType() const { return Lower->getType(); }
+
+/// isFullSet - Return true if this set contains all of the elements possible
+/// for this data-type
+bool ConstantRange::isFullSet() const {
+  return Lower == Upper && Lower == ConstantIntegral::getMaxValue(getType());
+}
+  
+/// isEmptySet - Return true if this set contains no members.
+///
+bool ConstantRange::isEmptySet() const {
+  return Lower == Upper && Lower == ConstantIntegral::getMinValue(getType());
+}
+
+/// isWrappedSet - Return true if this set wraps around the top of the range,
+/// for example: [100, 8)
+///
+bool ConstantRange::isWrappedSet() const {
+  return GT(Lower, Upper);
+}
+
+  
+/// getSingleElement - If this set contains a single element, return it,
+/// otherwise return null.
+ConstantIntegral *ConstantRange::getSingleElement() const {
+  if (Upper == Next(Lower))  // Is it a single element range?
+    return Lower;
+  return 0;
+}
+
+/// getSetSize - Return the number of elements in this set.
+///
+uint64_t ConstantRange::getSetSize() const {
+  if (isEmptySet()) return 0;
+  if (getType() == Type::BoolTy) {
+    if (Lower != Upper)  // One of T or F in the set...
+      return 1;
+    return 2;            // Must be full set...
+  }
+  
+  // Simply subtract the bounds...
+  Constant *Result = ConstantExpr::getSub(Upper, Lower);
+  return cast<ConstantInt>(Result)->getRawValue();
+}
+
+/// contains - Return true if the specified value is in the set.
+///
+bool ConstantRange::contains(ConstantInt *Val) const {
+  if (Lower == Upper) {
+    if (isFullSet()) return true;
+    return false;
+  }
+
+  if (!isWrappedSet())
+    return LTE(Lower, Val) && LT(Val, Upper);
+  return LTE(Lower, Val) || LT(Val, Upper);
+}
+
+
+
+/// subtract - Subtract the specified constant from the endpoints of this
+/// constant range.
+ConstantRange ConstantRange::subtract(ConstantInt *CI) const {
+  assert(CI->getType() == getType() && getType()->isInteger() &&
+         "Cannot subtract from different type range or non-integer!");
+  // If the set is empty or full, don't modify the endpoints.
+  if (Lower == Upper) return *this;
+  return ConstantRange(ConstantExpr::getSub(Lower, CI),
+                       ConstantExpr::getSub(Upper, CI));
+}
+
+
+// intersect1Wrapped - This helper function is used to intersect two ranges when
+// it is known that LHS is wrapped and RHS isn't.
+//
+static ConstantRange intersect1Wrapped(const ConstantRange &LHS,
+                                       const ConstantRange &RHS) {
+  assert(LHS.isWrappedSet() && !RHS.isWrappedSet());
+
+  // Check to see if we overlap on the Left side of RHS...
+  //
+  if (LT(RHS.getLower(), LHS.getUpper())) {
+    // We do overlap on the left side of RHS, see if we overlap on the right of
+    // RHS...
+    if (GT(RHS.getUpper(), LHS.getLower())) {
+      // 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() < RHS.getSetSize())
+        return LHS;
+      else
+        return RHS;
+
+    } else {
+      // No overlap on the right, just on the left.
+      return ConstantRange(RHS.getLower(), LHS.getUpper());
+    }
+
+  } else {
+    // We don't overlap on the left side of RHS, see if we overlap on the right
+    // of RHS...
+    if (GT(RHS.getUpper(), LHS.getLower())) {
+      // Simple overlap...
+      return ConstantRange(LHS.getLower(), RHS.getUpper());
+    } else {
+      // No overlap...
+      return ConstantRange(LHS.getType(), false);
+    }
+  }
+}
+
+/// intersect - Return the range that results from the intersection of this
+/// range with another range.
+///
+ConstantRange ConstantRange::intersectWith(const ConstantRange &CR) const {
+  assert(getType() == CR.getType() && "ConstantRange 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()) {
+      ConstantIntegral *L = Max(Lower, CR.Lower);
+      ConstantIntegral *U = Min(Upper, CR.Upper);
+
+      if (LT(L, U))  // If range isn't empty...
+        return ConstantRange(L, U);
+      else
+        return ConstantRange(getType(), false);  // Otherwise, return 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...
+      ConstantIntegral *L = Max(Lower, CR.Lower);
+      ConstantIntegral *U = Min(Upper, CR.Upper);
+      return ConstantRange(L, U);
+    }
+  }
+  return *this;
+}
+
+/// union - 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 ConstantRange::unionWith(const ConstantRange &CR) const {
+  assert(getType() == CR.getType() && "ConstantRange types don't agree!");
+
+  assert(0 && "Range union not implemented yet!");
+
+  return *this;
+}
+
+/// 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.
+ConstantRange ConstantRange::zeroExtend(const Type *Ty) const {
+  assert(getLower()->getType()->getPrimitiveSize() < Ty->getPrimitiveSize() &&
+         "Not a value extension");
+  if (isFullSet()) {
+    // Change a source full set into [0, 1 << 8*numbytes)
+    unsigned SrcTySize = getLower()->getType()->getPrimitiveSize();
+    return ConstantRange(Constant::getNullValue(Ty),
+                         ConstantUInt::get(Ty, 1ULL << SrcTySize*8));
+  }
+
+  Constant *Lower = getLower();
+  Constant *Upper = getUpper();
+  if (Lower->getType()->isInteger() && !Lower->getType()->isUnsigned()) {
+    // Ensure we are doing a ZERO extension even if the input range is signed.
+    Lower = ConstantExpr::getCast(Lower, Ty->getUnsignedVersion());
+    Upper = ConstantExpr::getCast(Upper, Ty->getUnsignedVersion());
+  }
+
+  return ConstantRange(ConstantExpr::getCast(Lower, Ty),
+                       ConstantExpr::getCast(Upper, Ty));
+}
+
+/// 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 ConstantRange::truncate(const Type *Ty) const {
+  assert(getLower()->getType()->getPrimitiveSize() > Ty->getPrimitiveSize() &&
+         "Not a value truncation");
+  uint64_t Size = 1ULL << Ty->getPrimitiveSize()*8;
+  if (isFullSet() || getSetSize() >= Size)
+    return ConstantRange(getType());
+
+  return ConstantRange(ConstantExpr::getCast(getLower(), Ty),
+                       ConstantExpr::getCast(getUpper(), Ty));
+}
+
+
+/// print - Print out the bounds to a stream...
+///
+void ConstantRange::print(std::ostream &OS) const {
+  OS << "[" << *Lower << "," << *Upper << " )";
+}
+
+/// dump - Allow printing from a debugger easily...
+///
+void ConstantRange::dump() const {
+  print(std::cerr);
+}