X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FSupport%2FConstantRange.cpp;h=fdfe28aaa95c88289d6cb830422f66f46f271e8a;hb=e15c2db9935eee66a8008f1bd09882aff2ed3aae;hp=becb8b61f78322b8535bb5b9bdc6357017419c42;hpb=3400e6af6b10acea219c02ac262637220f84218f;p=oota-llvm.git

diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index becb8b61f78..fdfe28aaa95 100644
--- a/lib/Support/ConstantRange.cpp
+++ b/lib/Support/ConstantRange.cpp
@@ -44,22 +44,20 @@ 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,
@@ -108,9 +106,9 @@ APInt ConstantRange::getUnsignedMin() const {
 /// ConstantRange.
 ///
 APInt ConstantRange::getSignedMax() const {
-  APInt SignedMax = APInt::getSignedMaxValue(getBitWidth());
+  APInt SignedMax(APInt::getSignedMaxValue(getBitWidth()));
   if (!isWrappedSet()) {
-    if (getLower().slt(getUpper() - 1))
+    if (getLower().sle(getUpper() - 1))
       return getUpper() - 1;
     else
       return SignedMax;
@@ -130,9 +128,9 @@ APInt ConstantRange::getSignedMax() const {
 /// ConstantRange.
 ///
 APInt ConstantRange::getSignedMin() const {
-  APInt SignedMin = APInt::getSignedMinValue(getBitWidth());
+  APInt SignedMin(APInt::getSignedMinValue(getBitWidth()));
   if (!isWrappedSet()) {
-    if (getLower().slt(getUpper() - 1))
+    if (getLower().sle(getUpper() - 1))
       return getLower();
     else
       return SignedMin;
@@ -248,11 +246,94 @@ ConstantRange ConstantRange::intersectWith(const ConstantRange &CR) const {
   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) const {
   assert(getBitWidth() == CR.getBitWidth() && 
@@ -261,13 +342,71 @@ ConstantRange ConstantRange::unionWith(const ConstantRange &CR) const {
   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 (!contains(CR.Lower))
-    L = APIntOps::umin(L, CR.Lower);
+  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 (!contains(CR.Upper - 1))
-    U = APIntOps::umax(U, CR.Upper);
+    if (L == U) return ConstantRange(getBitWidth());
+  }
 
   return ConstantRange(L, U);
 }
@@ -288,6 +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
@@ -295,7 +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);