X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FSupport%2FConstantRange.cpp;h=0d22b323502174376c92db9023299ea1be7f338f;hb=73b43b9b549a75fb0015c825df68abd95705a67c;hp=ba3c4723b46d3d2d89bef6d40881073cca706525;hpb=bb626a6751db9a63d159d32522bdf88cedf46eeb;p=oota-llvm.git

diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index ba3c4723b46..0d22b323502 100644
--- a/lib/Support/ConstantRange.cpp
+++ b/lib/Support/ConstantRange.cpp
@@ -2,8 +2,8 @@
 //
 //                     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.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
@@ -44,30 +44,26 @@ ConstantRange::ConstantRange(const APInt &L, const APInt &U) :
   Lower(L), Upper(U) {
   assert(L.getBitWidth() == U.getBitWidth() && 
          "ConstantRange with unequal bit widths");
-  uint32_t BitWidth = L.getBitWidth();
-  assert((L != U || (L == APInt::getMaxValue(BitWidth) ||
-                     L == APInt::getMinValue(BitWidth))) &&
+  assert((L != U || (L.isMaxValue() || L.isMinValue())) &&
          "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 ConstantRange::isFullSet() const {
-  return Lower == Upper && Lower == APInt::getMaxValue(getBitWidth());
+  return Lower == Upper && Lower.isMaxValue();
 }
 
 /// isEmptySet - Return true if this set contains no members.
 ///
 bool ConstantRange::isEmptySet() const {
-  return Lower == Upper && Lower == APInt::getMinValue(getBitWidth());
+  return Lower == Upper && Lower.isMinValue();
 }
 
 /// isWrappedSet - Return true if this set wraps around the top of the range,
 /// for example: [100, 8)
 ///
-bool ConstantRange::isWrappedSet(bool isSigned) const {
-  if (isSigned)
-    return Lower.sgt(Upper);
+bool ConstantRange::isWrappedSet() const {
   return Lower.ugt(Upper);
 }
 
@@ -86,22 +82,78 @@ APInt ConstantRange::getSetSize() const {
   return Upper - Lower;
 }
 
-/// contains - Return true if the specified value is in the set.
+/// getUnsignedMax - Return the largest unsigned value contained in the
+/// ConstantRange.
+///
+APInt ConstantRange::getUnsignedMax() const {
+  if (isFullSet() || isWrappedSet())
+    return APInt::getMaxValue(getBitWidth());
+  else
+    return getUpper() - 1;
+}
+
+/// getUnsignedMin - Return the smallest unsigned value contained in the
+/// ConstantRange.
+///
+APInt ConstantRange::getUnsignedMin() const {
+  if (isFullSet() || (isWrappedSet() && getUpper() != 0))
+    return APInt::getMinValue(getBitWidth());
+  else
+    return getLower();
+}
+
+/// getSignedMax - Return the largest signed value contained in the
+/// ConstantRange.
 ///
-bool ConstantRange::contains(const APInt &V, bool isSigned) const {
-  if (Lower == Upper) {
-    if (isFullSet()) 
-      return true;
-    return false;
+APInt ConstantRange::getSignedMax() const {
+  APInt SignedMax(APInt::getSignedMaxValue(getBitWidth()));
+  if (!isWrappedSet()) {
+    if (getLower().sle(getUpper() - 1))
+      return getUpper() - 1;
+    else
+      return SignedMax;
+  } else {
+    if ((getUpper() - 1).slt(getLower())) {
+      if (getLower() != SignedMax)
+        return SignedMax;
+      else
+        return getUpper() - 1;
+    } else {
+      return getUpper() - 1;
+    }
   }
+}
 
-  if (!isWrappedSet(isSigned))
-    if (isSigned)
-      return Lower.sle(V) && V.slt(Upper);
+/// getSignedMin - Return the smallest signed value contained in the
+/// ConstantRange.
+///
+APInt ConstantRange::getSignedMin() const {
+  APInt SignedMin(APInt::getSignedMinValue(getBitWidth()));
+  if (!isWrappedSet()) {
+    if (getLower().sle(getUpper() - 1))
+      return getLower();
     else
-      return Lower.ule(V) && V.ult(Upper);
-  if (isSigned)
-    return Lower.sle(V) || V.slt(Upper);
+      return SignedMin;
+  } else {
+    if ((getUpper() - 1).slt(getLower())) {
+      if (getUpper() != SignedMin)
+        return SignedMin;
+      else
+        return getLower();
+    } else {
+      return getLower();
+    }
+  }
+}
+
+/// contains - Return true if the specified value is in the set.
+///
+bool ConstantRange::contains(const APInt &V) const {
+  if (Lower == Upper)
+    return isFullSet();
+
+  if (!isWrappedSet())
+    return Lower.ule(V) && V.ult(Upper);
   else
     return Lower.ule(V) || V.ult(Upper);
 }
@@ -122,17 +174,15 @@ ConstantRange ConstantRange::subtract(const APInt &Val) const {
 //
 ConstantRange 
 ConstantRange::intersect1Wrapped(const ConstantRange &LHS,
-                                 const ConstantRange &RHS, bool isSigned) {
-  assert(LHS.isWrappedSet(isSigned) && !RHS.isWrappedSet(isSigned));
+                                 const ConstantRange &RHS) {
+  assert(LHS.isWrappedSet() && !RHS.isWrappedSet());
 
   // Check to see if we overlap on the Left side of RHS...
   //
-  bool LT = (isSigned ? RHS.Lower.slt(LHS.Upper) : RHS.Lower.ult(LHS.Upper));
-  bool GT = (isSigned ? RHS.Upper.sgt(LHS.Lower) : RHS.Upper.ugt(LHS.Lower));
-  if (LT) {
+  if (RHS.Lower.ult(LHS.Upper)) {
     // We do overlap on the left side of RHS, see if we overlap on the right of
     // RHS...
-    if (GT) {
+    if (RHS.Upper.ugt(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...
       //
@@ -148,7 +198,7 @@ ConstantRange::intersect1Wrapped(const ConstantRange &LHS,
   } else {
     // We don't overlap on the left side of RHS, see if we overlap on the right
     // of RHS...
-    if (GT) {
+    if (RHS.Upper.ugt(LHS.Lower)) {
       // Simple overlap...
       return ConstantRange(LHS.Lower, RHS.Upper);
     } else {
@@ -161,8 +211,7 @@ ConstantRange::intersect1Wrapped(const ConstantRange &LHS,
 /// intersectWith - Return the range that results from the intersection of this
 /// range with another range.
 ///
-ConstantRange ConstantRange::intersectWith(const ConstantRange &CR,
-                                           bool isSigned) const {
+ConstantRange ConstantRange::intersectWith(const ConstantRange &CR) const {
   assert(getBitWidth() == CR.getBitWidth() && 
          "ConstantRange types don't agree!");
   // Handle common special cases
@@ -171,46 +220,195 @@ ConstantRange ConstantRange::intersectWith(const ConstantRange &CR,
   if (isFullSet()  || CR.isEmptySet()) 
     return CR;
 
-  if (!isWrappedSet(isSigned)) {
-    if (!CR.isWrappedSet(isSigned)) {
+  if (!isWrappedSet()) {
+    if (!CR.isWrappedSet()) {
       using namespace APIntOps;
-      APInt L = isSigned ? smax(Lower, CR.Lower) : umax(Lower, CR.Lower);
-      APInt U = isSigned ? smin(Upper, CR.Upper) : umin(Upper, CR.Upper);
+      APInt L = umax(Lower, CR.Lower);
+      APInt U = umin(Upper, CR.Upper);
 
-      if (isSigned ? L.slt(U) : L.ult(U)) // If range isn't empty...
+      if (L.ult(U)) // If range isn't empty...
         return ConstantRange(L, U);
       else
         return ConstantRange(getBitWidth(), false);// Otherwise, empty set
     } else
-      return intersect1Wrapped(CR, *this, isSigned);
+      return intersect1Wrapped(CR, *this);
   } else {   // We know "this" is wrapped...
-    if (!CR.isWrappedSet(isSigned))
-      return intersect1Wrapped(*this, CR, isSigned);
+    if (!CR.isWrappedSet())
+      return intersect1Wrapped(*this, CR);
     else {
       // Both ranges are wrapped...
       using namespace APIntOps;
-      APInt L = isSigned ? smax(Lower, CR.Lower) : umax(Lower, CR.Lower);
-      APInt U = isSigned ? smin(Upper, CR.Upper) : umin(Upper, CR.Upper);
+      APInt L = umax(Lower, CR.Lower);
+      APInt U = umin(Upper, CR.Upper);
       return ConstantRange(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).
+ConstantRange ConstantRange::maximalIntersectWith(const ConstantRange &CR) const {
+  assert(getBitWidth() == CR.getBitWidth() && 
+         "ConstantRange 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.ult(CR.Lower)) {
+      if (Upper.ule(CR.Lower))
+        return ConstantRange(getBitWidth(), false);
+
+      if (Upper.ult(CR.Upper))
+        return ConstantRange(CR.Lower, Upper);
+
+      return CR;
+    } else {
+      if (Upper.ult(CR.Upper))
+        return *this;
+
+      if (Lower.ult(CR.Upper))
+        return ConstantRange(Lower, CR.Upper);
+
+      return ConstantRange(getBitWidth(), false);
+    }
+  }
+
+  if (isWrappedSet() && !CR.isWrappedSet()) {
+    if (CR.Lower.ult(Upper)) {
+      if (CR.Upper.ult(Upper))
+        return CR;
+
+      if (CR.Upper.ult(Lower))
+        return ConstantRange(CR.Lower, Upper);
+
+      if (getSetSize().ult(CR.getSetSize()))
+        return *this;
+      else
+        return CR;
+    } else if (CR.Lower.ult(Lower)) {
+      if (CR.Upper.ule(Lower))
+        return ConstantRange(getBitWidth(), false);
+
+      return ConstantRange(Lower, CR.Upper);
+    }
+    return CR;
+  }
+
+  if (CR.Upper.ult(Upper)) {
+    if (CR.Lower.ult(Upper)) {
+      if (getSetSize().ult(CR.getSetSize()))
+        return *this;
+      else
+        return CR;
+    }
+
+    if (CR.Lower.ult(Lower))
+      return ConstantRange(Lower, CR.Upper);
+
+    return CR;
+  } else if (CR.Upper.ult(Lower)) {
+    if (CR.Lower.ult(Lower))
+      return *this;
+
+    return ConstantRange(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.
+/// 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,
-                                       bool isSigned) const {
+ConstantRange ConstantRange::unionWith(const ConstantRange &CR) const {
   assert(getBitWidth() == CR.getBitWidth() && 
          "ConstantRange types don't agree!");
 
-  assert(0 && "Range union not implemented yet!");
+  if (   isFullSet() || CR.isEmptySet()) return *this;
+  if (CR.isFullSet() ||    isEmptySet()) return CR;
 
-  return *this;
+  if (!isWrappedSet() && CR.isWrappedSet()) return CR.unionWith(*this);
+
+  APInt L = Lower, U = Upper;
+
+  if (!isWrappedSet() && !CR.isWrappedSet()) {
+    if (CR.Lower.ult(L))
+      L = CR.Lower;
+
+    if (CR.Upper.ugt(U))
+      U = CR.Upper;
+  }
+
+  if (isWrappedSet() && !CR.isWrappedSet()) {
+    if ((CR.Lower.ult(Upper) && CR.Upper.ult(Upper)) ||
+        (CR.Lower.ugt(Lower) && CR.Upper.ugt(Lower))) {
+      return *this;
+    }
+
+    if (CR.Lower.ule(Upper) && Lower.ule(CR.Upper)) {
+      return ConstantRange(getBitWidth());
+    }
+
+    if (CR.Lower.ule(Upper) && CR.Upper.ule(Lower)) {
+      APInt d1 = CR.Upper - Upper, d2 = Lower - CR.Upper;
+      if (d1.ult(d2)) {
+        U = CR.Upper;
+      } else {
+        L = CR.Upper;
+      }
+    }
+
+    if (Upper.ult(CR.Lower) && CR.Upper.ult(Lower)) {
+      APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper;
+      if (d1.ult(d2)) {
+        U = CR.Lower + 1;
+      } else {
+        L = CR.Upper - 1;
+      }
+    }
+
+    if (Upper.ult(CR.Lower) && Lower.ult(CR.Upper)) {
+      APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Lower;
+
+      if (d1.ult(d2)) {
+        U = CR.Lower + 1;
+      } else {
+        L = CR.Lower;
+      }
+    }
+  }
+
+  if (isWrappedSet() && CR.isWrappedSet()) {
+    if (Lower.ult(CR.Upper) || CR.Lower.ult(Upper))
+      return ConstantRange(getBitWidth());
+
+    if (CR.Upper.ugt(U)) {
+      U = CR.Upper;
+    }
+
+    if (CR.Lower.ult(L)) {
+      L = CR.Lower;
+    }
+
+    if (L == U) return ConstantRange(getBitWidth());
+  }
+
+  return ConstantRange(L, U);
 }
 
 /// zeroExtend - Return a new range in the specified integer type, which must
@@ -229,6 +427,23 @@ ConstantRange ConstantRange::zeroExtend(uint32_t DstTySize) const {
   return ConstantRange(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.
+ConstantRange ConstantRange::signExtend(uint32_t DstTySize) const {
+  unsigned SrcTySize = getBitWidth();
+  assert(SrcTySize < DstTySize && "Not a value extension");
+  if (isFullSet()) {
+    return ConstantRange(APInt::getHighBitsSet(DstTySize,DstTySize-SrcTySize+1),
+                         APInt::getLowBitsSet(DstTySize, SrcTySize-1));
+  }
+
+  APInt L = Lower; L.sext(DstTySize);
+  APInt U = Upper; U.sext(DstTySize);
+  return ConstantRange(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
@@ -236,7 +451,7 @@ ConstantRange ConstantRange::zeroExtend(uint32_t DstTySize) const {
 ConstantRange ConstantRange::truncate(uint32_t DstTySize) const {
   unsigned SrcTySize = getBitWidth();
   assert(SrcTySize > DstTySize && "Not a value truncation");
-  APInt Size = APInt::getMaxValue(DstTySize).zext(SrcTySize);
+  APInt Size(APInt::getLowBitsSet(SrcTySize, DstTySize));
   if (isFullSet() || getSetSize().ugt(Size))
     return ConstantRange(DstTySize);
 
@@ -249,7 +464,7 @@ ConstantRange ConstantRange::truncate(uint32_t DstTySize) const {
 ///
 void ConstantRange::print(std::ostream &OS) const {
   OS << "[" << Lower.toStringSigned(10) << "," 
-            << Upper.toStringSigned(10) << " )";
+            << Upper.toStringSigned(10) << ")";
 }
 
 /// dump - Allow printing from a debugger easily...