Move ConstantRange class to lib/Support from lib/Analysis and make its
interface not depend on Type or ICmpInst.
llvm-svn: 34761
diff --git a/llvm/lib/Support/ConstantRange.cpp b/llvm/lib/Support/ConstantRange.cpp
new file mode 100644
index 0000000..ba3c472
--- /dev/null
+++ b/llvm/lib/Support/ConstantRange.cpp
@@ -0,0 +1,259 @@
+//===-- 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/Support/Streams.h"
+#include <ostream>
+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) {
+ if (Full)
+ Lower = Upper = APInt::getMaxValue(BitWidth);
+ else
+ Lower = Upper = APInt::getMinValue(BitWidth);
+}
+
+/// Initialize a range to hold the single specified value.
+///
+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() &&
+ "ConstantRange with unequal bit widths");
+ uint32_t BitWidth = L.getBitWidth();
+ assert((L != U || (L == APInt::getMaxValue(BitWidth) ||
+ L == APInt::getMinValue(BitWidth))) &&
+ "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());
+}
+
+/// isEmptySet - Return true if this set contains no members.
+///
+bool ConstantRange::isEmptySet() const {
+ return Lower == Upper && Lower == APInt::getMinValue(getBitWidth());
+}
+
+/// 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);
+ return Lower.ugt(Upper);
+}
+
+/// getSetSize - Return the number of elements in this set.
+///
+APInt ConstantRange::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;
+}
+
+/// contains - Return true if the specified value is in the set.
+///
+bool ConstantRange::contains(const APInt &V, bool isSigned) const {
+ if (Lower == Upper) {
+ if (isFullSet())
+ return true;
+ return false;
+ }
+
+ if (!isWrappedSet(isSigned))
+ if (isSigned)
+ return Lower.sle(V) && V.slt(Upper);
+ else
+ return Lower.ule(V) && V.ult(Upper);
+ if (isSigned)
+ return Lower.sle(V) || V.slt(Upper);
+ else
+ return Lower.ule(V) || V.ult(Upper);
+}
+
+/// subtract - Subtract the specified constant from the endpoints of this
+/// constant range.
+ConstantRange ConstantRange::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 ConstantRange(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.
+//
+ConstantRange
+ConstantRange::intersect1Wrapped(const ConstantRange &LHS,
+ const ConstantRange &RHS, bool isSigned) {
+ assert(LHS.isWrappedSet(isSigned) && !RHS.isWrappedSet(isSigned));
+
+ // 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) {
+ // We do overlap on the left side of RHS, see if we overlap on the right of
+ // RHS...
+ if (GT) {
+ // 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 ConstantRange(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 (GT) {
+ // Simple overlap...
+ return ConstantRange(LHS.Lower, RHS.Upper);
+ } else {
+ // No overlap...
+ return ConstantRange(LHS.getBitWidth(), false);
+ }
+ }
+}
+
+/// intersectWith - Return the range that results from the intersection of this
+/// range with another range.
+///
+ConstantRange ConstantRange::intersectWith(const ConstantRange &CR,
+ bool isSigned) 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(isSigned)) {
+ if (!CR.isWrappedSet(isSigned)) {
+ 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);
+
+ if (isSigned ? L.slt(U) : 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);
+ } else { // We know "this" is wrapped...
+ if (!CR.isWrappedSet(isSigned))
+ return intersect1Wrapped(*this, CR, isSigned);
+ 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);
+ return ConstantRange(L, U);
+ }
+ }
+ return *this;
+}
+
+/// 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.
+///
+ConstantRange ConstantRange::unionWith(const ConstantRange &CR,
+ bool isSigned) const {
+ assert(getBitWidth() == CR.getBitWidth() &&
+ "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 as if the source range had been
+/// zero extended.
+ConstantRange ConstantRange::zeroExtend(uint32_t DstTySize) const {
+ unsigned SrcTySize = getBitWidth();
+ assert(SrcTySize < DstTySize && "Not a value extension");
+ if (isFullSet())
+ // Change a source full set into [0, 1 << 8*numbytes)
+ return ConstantRange(APInt(DstTySize,0), APInt(DstTySize,1).shl(SrcTySize));
+
+ APInt L = Lower; L.zext(DstTySize);
+ APInt U = Upper; U.zext(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
+/// truncated to the specified type.
+ConstantRange ConstantRange::truncate(uint32_t DstTySize) const {
+ unsigned SrcTySize = getBitWidth();
+ assert(SrcTySize > DstTySize && "Not a value truncation");
+ APInt Size = APInt::getMaxValue(DstTySize).zext(SrcTySize);
+ if (isFullSet() || getSetSize().ugt(Size))
+ return ConstantRange(DstTySize);
+
+ APInt L = Lower; L.trunc(DstTySize);
+ APInt U = Upper; U.trunc(DstTySize);
+ return ConstantRange(L, U);
+}
+
+/// print - Print out the bounds to a stream...
+///
+void ConstantRange::print(std::ostream &OS) const {
+ OS << "[" << Lower.toStringSigned(10) << ","
+ << Upper.toStringSigned(10) << " )";
+}
+
+/// dump - Allow printing from a debugger easily...
+///
+void ConstantRange::dump() const {
+ print(cerr);
+}