X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FSupport%2FConstantRange.cpp;h=4593eb9dff9e925a85063a174658ac77ed8c419e;hb=34e992da381bf8b1a9cbcc1bde0b117207809649;hp=4f132e5ed5fd2900f949c5031fcb80b6e00afbea;hpb=377b1190cbcf99e9298300d890c4b744dd2ed2c7;p=oota-llvm.git

diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index 4f132e5ed5f..4593eb9dff9 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.
 //
 //===----------------------------------------------------------------------===//
 //
@@ -22,14 +22,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/ConstantRange.h"
-#include "llvm/Support/Streams.h"
-#include <ostream>
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Instructions.h"
 using namespace llvm;
 
 /// 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) {
+ConstantRange::ConstantRange(uint32_t BitWidth, bool Full) {
   if (Full)
     Lower = Upper = APInt::getMaxValue(BitWidth);
   else
@@ -38,16 +37,63 @@ 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) : Lower(V), Upper(V + 1) {}
 
 ConstantRange::ConstantRange(const APInt &L, const APInt &U) :
   Lower(L), Upper(U) {
-  assert(L.getBitWidth() == U.getBitWidth() && 
+  assert(L.getBitWidth() == U.getBitWidth() &&
          "ConstantRange with unequal bit widths");
   assert((L != U || (L.isMaxValue() || L.isMinValue())) &&
          "Lower == Upper, but they aren't min or max value!");
 }
 
+ConstantRange ConstantRange::makeICmpRegion(unsigned Pred,
+                                            const ConstantRange &CR) {
+  uint32_t W = CR.getBitWidth();
+  switch (Pred) {
+    default: assert(!"Invalid ICmp predicate to makeICmpRegion()");
+    case ICmpInst::ICMP_EQ:
+      return CR;
+    case ICmpInst::ICMP_NE:
+      if (CR.isSingleElement())
+        return ConstantRange(CR.getUpper(), CR.getLower());
+      return ConstantRange(W);
+    case ICmpInst::ICMP_ULT:
+      return ConstantRange(APInt::getMinValue(W), CR.getUnsignedMax());
+    case ICmpInst::ICMP_SLT:
+      return ConstantRange(APInt::getSignedMinValue(W), CR.getSignedMax());
+    case ICmpInst::ICMP_ULE: {
+      APInt UMax(CR.getUnsignedMax());
+      if (UMax.isMaxValue())
+        return ConstantRange(W);
+      return ConstantRange(APInt::getMinValue(W), UMax + 1);
+    }
+    case ICmpInst::ICMP_SLE: {
+      APInt SMax(CR.getSignedMax());
+      if (SMax.isMaxSignedValue() || (SMax+1).isMaxSignedValue())
+        return ConstantRange(W);
+      return ConstantRange(APInt::getSignedMinValue(W), SMax + 1);
+    }
+    case ICmpInst::ICMP_UGT:
+      return ConstantRange(CR.getUnsignedMin() + 1, APInt::getNullValue(W));
+    case ICmpInst::ICMP_SGT:
+      return ConstantRange(CR.getSignedMin() + 1,
+                           APInt::getSignedMinValue(W));
+    case ICmpInst::ICMP_UGE: {
+      APInt UMin(CR.getUnsignedMin());
+      if (UMin.isMinValue())
+        return ConstantRange(W);
+      return ConstantRange(UMin, APInt::getNullValue(W));
+    }
+    case ICmpInst::ICMP_SGE: {
+      APInt SMin(CR.getSignedMin());
+      if (SMin.isMinSignedValue())
+        return ConstantRange(W);
+      return ConstantRange(SMin, APInt::getSignedMinValue(W));
+    }
+  }
+}
+
 /// isFullSet - Return true if this set contains all of the elements possible
 /// for this data-type
 bool ConstantRange::isFullSet() const {
@@ -113,14 +159,10 @@ APInt ConstantRange::getSignedMax() const {
     else
       return SignedMax;
   } else {
-    if ((getUpper() - 1).slt(getLower())) {
-      if (getLower() != SignedMax)
-        return SignedMax;
-      else
-        return getUpper() - 1;
-    } else {
+    if (getLower().isNegative() == getUpper().isNegative())
+      return SignedMax;
+    else
       return getUpper() - 1;
-    }
   }
 }
 
@@ -158,6 +200,30 @@ bool ConstantRange::contains(const APInt &V) const {
     return Lower.ule(V) || V.ult(Upper);
 }
 
+/// contains - Return true if the argument is a subset of this range.
+/// Two equal set contain each other. The empty set is considered to be
+/// contained by all other sets.
+///
+bool ConstantRange::contains(const ConstantRange &Other) const {
+  if (isFullSet()) return true;
+  if (Other.isFullSet()) return false;
+  if (Other.isEmptySet()) return true;
+  if (isEmptySet()) return false;
+
+  if (!isWrappedSet()) {
+    if (Other.isWrappedSet())
+      return false;
+
+    return Lower.ule(Other.getLower()) && Other.getUpper().ule(Upper);
+  }
+
+  if (!Other.isWrappedSet())
+    return Other.getUpper().ule(Upper) ||
+           Lower.ule(Other.getLower());
+
+  return Other.getUpper().ule(Upper) && Lower.ule(Other.getLower());
+}
+
 /// subtract - Subtract the specified constant from the endpoints of this
 /// constant range.
 ConstantRange ConstantRange::subtract(const APInt &Val) const {
@@ -209,48 +275,11 @@ ConstantRange::intersect1Wrapped(const ConstantRange &LHS,
 }
 
 /// intersectWith - Return the range that results from the intersection of this
-/// range with another range.
-///
+/// 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 ConstantRange::intersectWith(const ConstantRange &CR) const {
-  assert(getBitWidth() == CR.getBitWidth() && 
-         "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()) {
-      using namespace APIntOps;
-      APInt L = umax(Lower, CR.Lower);
-      APInt U = umin(Upper, CR.Upper);
-
-      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);
-  } else {   // We know "this" is wrapped...
-    if (!CR.isWrappedSet())
-      return intersect1Wrapped(*this, CR);
-    else {
-      // Both ranges are wrapped...
-      using namespace APIntOps;
-      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 is also guaranteed
-/// to be the smallest possible set that does so.
-ConstantRange ConstantRange::maximalIntersectWith(const ConstantRange &CR) const {
   assert(getBitWidth() == CR.getBitWidth() && 
          "ConstantRange types don't agree!");
 
@@ -259,7 +288,7 @@ ConstantRange ConstantRange::maximalIntersectWith(const ConstantRange &CR) const
   if (CR.isEmptySet() ||    isFullSet()) return CR;
 
   if (!isWrappedSet() && CR.isWrappedSet())
-    return CR.maximalIntersectWith(*this);
+    return CR.intersectWith(*this);
 
   if (!isWrappedSet() && !CR.isWrappedSet()) {
     if (Lower.ult(CR.Lower)) {
@@ -342,69 +371,74 @@ ConstantRange ConstantRange::unionWith(const ConstantRange &CR) const {
 
   if (!isWrappedSet() && CR.isWrappedSet()) return CR.unionWith(*this);
 
-  APInt L = Lower, U = Upper;
-
   if (!isWrappedSet() && !CR.isWrappedSet()) {
+    if (CR.Upper.ult(Lower) || Upper.ult(CR.Lower)) {
+      // If the two ranges are disjoint, find the smaller gap and bridge it.
+      APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper;
+      if (d1.ult(d2))
+        return ConstantRange(Lower, CR.Upper);
+      else
+        return ConstantRange(CR.Lower, Upper);
+    }
+
+    APInt L = Lower, U = Upper;
     if (CR.Lower.ult(L))
       L = CR.Lower;
-
-    if (CR.Upper.ugt(U))
+    if ((CR.Upper - 1).ugt(U - 1))
       U = CR.Upper;
+
+    if (L == 0 && U == 0)
+      return ConstantRange(getBitWidth());
+
+    return ConstantRange(L, U);
   }
 
-  if (isWrappedSet() && !CR.isWrappedSet()) {
-    if ((CR.Lower.ult(Upper) && CR.Upper.ult(Upper)) ||
-        (CR.Lower.ugt(Lower) && CR.Upper.ugt(Lower))) {
+  if (!CR.isWrappedSet()) {
+    // ------U   L-----  and  ------U   L----- : this
+    //   L--U                            L--U  : CR
+    if (CR.Upper.ule(Upper) || CR.Lower.uge(Lower))
       return *this;
-    }
 
-    if (CR.Lower.ule(Upper) && Lower.ule(CR.Upper)) {
+    // ------U   L----- : this
+    //    L---------U   : CR
+    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)) {
+    // ----U       L---- : this
+    //       L---U       : CR
+    //    <d1>  <d2>
+    if (Upper.ule(CR.Lower) && CR.Upper.ule(Lower)) {
       APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper;
-      if (d1.ult(d2)) {
-        U = CR.Lower + 1;
-      } else {
-        L = CR.Upper - 1;
-      }
+      if (d1.ult(d2))
+        return ConstantRange(Lower, CR.Upper);
+      else
+        return ConstantRange(CR.Lower, Upper);
     }
 
-    if (Upper.ult(CR.Lower) && Lower.ult(CR.Upper)) {
-      APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Lower;
+    // ----U     L----- : this
+    //        L----U    : CR
+    if (Upper.ult(CR.Lower) && Lower.ult(CR.Upper))
+      return ConstantRange(CR.Lower, Upper);
 
-      if (d1.ult(d2)) {
-        U = CR.Lower + 1;
-      } else {
-        L = CR.Lower;
-      }
-    }
+    // ------U    L---- : this
+    //    L-----U       : CR
+    if (CR.Lower.ult(Upper) && CR.Upper.ult(Lower))
+      return ConstantRange(Lower, CR.Upper);
   }
 
-  if (isWrappedSet() && CR.isWrappedSet()) {
-    if (Lower.ult(CR.Upper) || CR.Lower.ult(Upper))
-      return ConstantRange(getBitWidth());
-
-    if (CR.Upper.ugt(U)) {
-      U = CR.Upper;
-    }
+  assert(isWrappedSet() && CR.isWrappedSet() &&
+         "ConstantRange::unionWith missed wrapped union unwrapped case");
 
-    if (CR.Lower.ult(L)) {
-      L = CR.Lower;
-    }
+  // ------U    L----  and  ------U    L---- : this
+  // -U  L-----------  and  ------------U  L : CR
+  if (CR.Lower.ule(Upper) || Lower.ule(CR.Upper))
+    return ConstantRange(getBitWidth());
 
-    if (L == U) return ConstantRange(getBitWidth());
-  }
+  APInt L = Lower, U = Upper;
+  if (CR.Upper.ugt(U))
+    U = CR.Upper;
+  if (CR.Lower.ult(L))
+    L = CR.Lower;
 
   return ConstantRange(L, U);
 }
@@ -434,7 +468,7 @@ ConstantRange ConstantRange::signExtend(uint32_t DstTySize) const {
   assert(SrcTySize < DstTySize && "Not a value extension");
   if (isFullSet()) {
     return ConstantRange(APInt::getHighBitsSet(DstTySize,DstTySize-SrcTySize+1),
-                         APInt::getLowBitsSet(DstTySize, SrcTySize-1));
+                         APInt::getLowBitsSet(DstTySize, SrcTySize-1) + 1);
   }
 
   APInt L = Lower; L.sext(DstTySize);
@@ -458,15 +492,170 @@ ConstantRange ConstantRange::truncate(uint32_t DstTySize) const {
   return ConstantRange(L, U);
 }
 
+/// zextOrTrunc - make this range have the bit width given by \p DstTySize. The
+/// value is zero extended, truncated, or left alone to make it that width.
+ConstantRange ConstantRange::zextOrTrunc(uint32_t DstTySize) const {
+  unsigned SrcTySize = getBitWidth();
+  if (SrcTySize > DstTySize)
+    return truncate(DstTySize);
+  else if (SrcTySize < DstTySize)
+    return zeroExtend(DstTySize);
+  else
+    return *this;
+}
+
+/// sextOrTrunc - make this range have the bit width given by \p DstTySize. The
+/// value is sign extended, truncated, or left alone to make it that width.
+ConstantRange ConstantRange::sextOrTrunc(uint32_t DstTySize) const {
+  unsigned SrcTySize = getBitWidth();
+  if (SrcTySize > DstTySize)
+    return truncate(DstTySize);
+  else if (SrcTySize < DstTySize)
+    return signExtend(DstTySize);
+  else
+    return *this;
+}
+
+ConstantRange
+ConstantRange::add(const ConstantRange &Other) const {
+  if (isEmptySet() || Other.isEmptySet())
+    return ConstantRange(getBitWidth(), /*isFullSet=*/false);
+  if (isFullSet() || Other.isFullSet())
+    return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+
+  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 {
+  if (isEmptySet() || Other.isEmptySet())
+    return ConstantRange(getBitWidth(), /*isFullSet=*/false);
+  if (isFullSet() || Other.isFullSet())
+    return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+
+  APInt this_min = getUnsignedMin().zext(getBitWidth() * 2);
+  APInt this_max = getUnsignedMax().zext(getBitWidth() * 2);
+  APInt Other_min = Other.getUnsignedMin().zext(getBitWidth() * 2);
+  APInt Other_max = Other.getUnsignedMax().zext(getBitWidth() * 2);
+
+  ConstantRange Result_zext = ConstantRange(this_min * Other_min,
+                                            this_max * Other_max + 1);
+  return Result_zext.truncate(getBitWidth());
+}
+
+ConstantRange
+ConstantRange::smax(const ConstantRange &Other) const {
+  // X smax Y is: range(smax(X_smin, Y_smin),
+  //                    smax(X_smax, Y_smax))
+  if (isEmptySet() || Other.isEmptySet())
+    return ConstantRange(getBitWidth(), /*isFullSet=*/false);
+  APInt NewL = APIntOps::smax(getSignedMin(), Other.getSignedMin());
+  APInt NewU = APIntOps::smax(getSignedMax(), Other.getSignedMax()) + 1;
+  if (NewU == NewL)
+    return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+  return ConstantRange(NewL, NewU);
+}
+
+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);
+  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 &RHS) const {
+  if (isEmptySet() || RHS.isEmptySet() || RHS.getUnsignedMax() == 0)
+    return ConstantRange(getBitWidth(), /*isFullSet=*/false);
+  if (RHS.isFullSet())
+    return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+
+  APInt Lower = getUnsignedMin().udiv(RHS.getUnsignedMax());
+
+  APInt RHS_umin = RHS.getUnsignedMin();
+  if (RHS_umin == 0) {
+    // We want the lowest value in RHS excluding zero. Usually that would be 1
+    // except for a range in the form of [X, 1) in which case it would be X.
+    if (RHS.getUpper() == 1)
+      RHS_umin = RHS.getLower();
+    else
+      RHS_umin = APInt(getBitWidth(), 1);
+  }
+
+  APInt Upper = getUnsignedMax().udiv(RHS_umin) + 1;
+
+  // If the LHS is Full and the RHS is a wrapped interval containing 1 then
+  // this could occur.
+  if (Lower == Upper)
+    return ConstantRange(getBitWidth(), /*isFullSet=*/true);
+
+  return ConstantRange(Lower, Upper);
+}
+
+ConstantRange
+ConstantRange::shl(const ConstantRange &Amount) const {
+  if (isEmptySet())
+    return *this;
+
+  APInt min = getUnsignedMin() << Amount.getUnsignedMin();
+  APInt max = getUnsignedMax() << Amount.getUnsignedMax();
+
+  // there's no overflow!
+  APInt Zeros(sizeof(unsigned)*8, getUnsignedMax().countLeadingZeros());
+  if (Zeros.uge(Amount.getUnsignedMax()))
+    return ConstantRange(min, max);
+
+  // FIXME: implement the other tricky cases
+  return ConstantRange(getBitWidth());
+}
+
+ConstantRange
+ConstantRange::ashr(const ConstantRange &Amount) const {
+  if (isEmptySet())
+    return *this;
+
+  APInt min = getUnsignedMax().ashr(Amount.getUnsignedMin());
+  APInt max = getUnsignedMin().ashr(Amount.getUnsignedMax());
+  return ConstantRange(min, max);
+}
+
+ConstantRange
+ConstantRange::lshr(const ConstantRange &Amount) const {
+  if (isEmptySet())
+    return *this;
+  
+  APInt min = getUnsignedMax().lshr(Amount.getUnsignedMin());
+  APInt max = getUnsignedMin().lshr(Amount.getUnsignedMax());
+  return ConstantRange(min, max);
+}
+
 /// print - Print out the bounds to a stream...
 ///
-void ConstantRange::print(std::ostream &OS) const {
-  OS << "[" << Lower.toStringSigned(10) << "," 
-            << Upper.toStringSigned(10) << " )";
+void ConstantRange::print(raw_ostream &OS) const {
+  OS << "[" << Lower << "," << Upper << ")";
 }
 
 /// dump - Allow printing from a debugger easily...
 ///
 void ConstantRange::dump() const {
-  print(cerr);
+  print(errs());
 }
+
+