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llvm/lib/Support/ConstantRange.cpp
Dan Gohman a3755d8d36 Add a ConstantSignedRange class, which does for signed integers 
what ConstantRange does for unsigned integers. Factor out a
common base class for common functionality.

Add some new functions for performing arithmetic on constant
ranges. Some of these are currently just stubbed out with
conservative implementations.

Add unittests for ConstantRange and ConstantSignedRange.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75177 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-09 22:07:27 +00:00

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//===-- ConstantRange.cpp - ConstantRange implementation ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file 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/raw_ostream.h"
using namespace llvm;
/// Initialize a range to hold the single specified value.
///
ConstantRangeBase::ConstantRangeBase(const APInt & V)
: Lower(V), Upper(V + 1) {}
ConstantRangeBase::ConstantRangeBase(const APInt &L, const APInt &U)
: Lower(L), Upper(U) {
assert(L.getBitWidth() == U.getBitWidth() &&
"ConstantRange with unequal bit widths");
}
/// print - Print out the bounds to a stream...
///
void ConstantRangeBase::print(raw_ostream &OS) const {
OS << "[" << Lower << "," << Upper << ")";
}
/// dump - Allow printing from a debugger easily...
///
void ConstantRangeBase::dump() const {
print(errs());
}
std::ostream &llvm::operator<<(std::ostream &o,
const ConstantRangeBase &CR) {
raw_os_ostream OS(o);
OS << CR;
return o;
}
/// Initialize a full (the default) or empty set for the specified type.
///
ConstantRange::ConstantRange(uint32_t BitWidth, bool Full) :
ConstantRangeBase(APInt(BitWidth, 0), APInt(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) : ConstantRangeBase(V) {}
ConstantRange::ConstantRange(const APInt &L, const APInt &U)
: ConstantRangeBase(L, U) {
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.isMaxValue();
}
/// isEmptySet - Return true if this set contains no members.
///
bool ConstantRange::isEmptySet() const {
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() const {
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;
}
/// 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.
///
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;
}
}
}
/// 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 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);
}
/// 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) {
assert(LHS.isWrappedSet() && !RHS.isWrappedSet());
// Check to see if we overlap on the Left side of RHS...
//
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 (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...
//
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 (RHS.Upper.ugt(LHS.Lower)) {
// 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) 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()) {
APInt L = APIntOps::umax(Lower, CR.Lower);
APInt U = APIntOps::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...
APInt L = APIntOps::umax(Lower, CR.Lower);
APInt U = APIntOps::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.
///
ConstantRange ConstantRange::unionWith(const ConstantRange &CR) const {
assert(getBitWidth() == CR.getBitWidth() &&
"ConstantRange types don't agree!");
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 (!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
/// 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);
}
/// 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
/// 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::getLowBitsSet(SrcTySize, DstTySize));
if (isFullSet() || getSetSize().ugt(Size))
return ConstantRange(DstTySize);
APInt L = Lower; L.trunc(DstTySize);
APInt U = Upper; U.trunc(DstTySize);
return ConstantRange(L, U);
}
ConstantRange
ConstantRange::add(const ConstantRange &Other) const {
if (isEmptySet() || Other.isEmptySet())
return ConstantRange(getBitWidth(), /*isFullSet=*/false);
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 {
// TODO: Implement multiply.
return ConstantRange(getBitWidth(),
!(isEmptySet() || Other.isEmptySet()));
}
ConstantRange
ConstantRange::smax(const ConstantRange &Other) const {
// TODO: Implement smax.
return ConstantRange(getBitWidth(),
!(isEmptySet() || Other.isEmptySet()));
}
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);
if (isFullSet() || Other.isFullSet())
return ConstantRange(getBitWidth(), /*isFullSet=*/true);
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 &Other) const {
// TODO: Implement udiv.
return ConstantRange(getBitWidth(),
!(isEmptySet() || Other.isEmptySet()));
}
/// Initialize a full (the default) or empty set for the specified type.
///
ConstantSignedRange::ConstantSignedRange(uint32_t BitWidth, bool Full) :
ConstantRangeBase(APInt(BitWidth, 0), APInt(BitWidth, 0)) {
if (Full)
Lower = Upper = APInt::getSignedMaxValue(BitWidth);
else
Lower = Upper = APInt::getSignedMinValue(BitWidth);
}
/// Initialize a range to hold the single specified value.
///
ConstantSignedRange::ConstantSignedRange(const APInt & V)
: ConstantRangeBase(V) {}
ConstantSignedRange::ConstantSignedRange(const APInt &L, const APInt &U)
: ConstantRangeBase(L, U) {
assert((L != U || (L.isMaxSignedValue() || L.isMinSignedValue())) &&
"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 ConstantSignedRange::isFullSet() const {
return Lower == Upper && Lower.isMaxSignedValue();
}
/// isEmptySet - Return true if this set contains no members.
///
bool ConstantSignedRange::isEmptySet() const {
return Lower == Upper && Lower.isMinSignedValue();
}
/// isWrappedSet - Return true if this set wraps around the top of the range,
/// for example: [100, 8)
///
bool ConstantSignedRange::isWrappedSet() const {
return Lower.sgt(Upper);
}
/// getSetSize - Return the number of elements in this set.
///
APInt ConstantSignedRange::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;
}
/// getSignedMax - Return the largest signed value contained in the
/// ConstantSignedRange.
///
APInt ConstantSignedRange::getSignedMax() const {
if (isFullSet() || isWrappedSet())
return APInt::getSignedMaxValue(getBitWidth());
else
return getUpper() - 1;
}
/// getSignedMin - Return the smallest signed value contained in the
/// ConstantSignedRange.
///
APInt ConstantSignedRange::getSignedMin() const {
if (isFullSet() || (isWrappedSet() &&
getUpper() != APInt::getSignedMinValue(getBitWidth())))
return APInt::getSignedMinValue(getBitWidth());
else
return getLower();
}
/// getUnsignedMax - Return the largest unsigned value contained in the
/// ConstantSignedRange.
///
APInt ConstantSignedRange::getUnsignedMax() const {
APInt UnsignedMax(APInt::getMaxValue(getBitWidth()));
if (!isWrappedSet()) {
if (getLower().ule(getUpper() - 1))
return getUpper() - 1;
else
return UnsignedMax;
} else {
if ((getUpper() - 1).ult(getLower())) {
if (getLower() != UnsignedMax)
return UnsignedMax;
else
return getUpper() - 1;
} else {
return getUpper() - 1;
}
}
}
/// getUnsignedMin - Return the smallest unsigned value contained in the
/// ConstantSignedRange.
///
APInt ConstantSignedRange::getUnsignedMin() const {
APInt UnsignedMin(APInt::getMinValue(getBitWidth()));
if (!isWrappedSet()) {
if (getLower().ule(getUpper() - 1))
return getLower();
else
return UnsignedMin;
} else {
if ((getUpper() - 1).ult(getLower())) {
if (getUpper() != UnsignedMin)
return UnsignedMin;
else
return getLower();
} else {
return getLower();
}
}
}
/// contains - Return true if the specified value is in the set.
///
bool ConstantSignedRange::contains(const APInt &V) const {
if (Lower == Upper)
return isFullSet();
if (!isWrappedSet())
return Lower.sle(V) && V.slt(Upper);
else
return Lower.sle(V) || V.slt(Upper);
}
/// subtract - Subtract the specified constant from the endpoints of this
/// constant range.
ConstantSignedRange ConstantSignedRange::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 ConstantSignedRange(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.
//
ConstantSignedRange
ConstantSignedRange::intersect1Wrapped(const ConstantSignedRange &LHS,
const ConstantSignedRange &RHS) {
assert(LHS.isWrappedSet() && !RHS.isWrappedSet());
// Check to see if we overlap on the Left side of RHS...
//
if (RHS.Lower.slt(LHS.Upper)) {
// We do overlap on the left side of RHS, see if we overlap on the right of
// RHS...
if (RHS.Upper.sgt(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...
//
if (LHS.getSetSize().ult(RHS.getSetSize()))
return LHS;
else
return RHS;
} else {
// No overlap on the right, just on the left.
return ConstantSignedRange(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 (RHS.Upper.sgt(LHS.Lower)) {
// Simple overlap...
return ConstantSignedRange(LHS.Lower, RHS.Upper);
} else {
// No overlap...
return ConstantSignedRange(LHS.getBitWidth(), false);
}
}
}
/// intersectWith - Return the range that results from the intersection of this
/// range with another range.
///
ConstantSignedRange
ConstantSignedRange::intersectWith(const ConstantSignedRange &CR) const {
assert(getBitWidth() == CR.getBitWidth() &&
"ConstantSignedRange 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()) {
APInt L = APIntOps::smax(Lower, CR.Lower);
APInt U = APIntOps::smin(Upper, CR.Upper);
if (L.slt(U)) // If range isn't empty...
return ConstantSignedRange(L, U);
else
return ConstantSignedRange(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...
APInt L = APIntOps::smax(Lower, CR.Lower);
APInt U = APIntOps::smin(Upper, CR.Upper);
return ConstantSignedRange(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).
ConstantSignedRange
ConstantSignedRange::maximalIntersectWith(const ConstantSignedRange &CR) const {
assert(getBitWidth() == CR.getBitWidth() &&
"ConstantSignedRange 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.slt(CR.Lower)) {
if (Upper.sle(CR.Lower))
return ConstantSignedRange(getBitWidth(), false);
if (Upper.slt(CR.Upper))
return ConstantSignedRange(CR.Lower, Upper);
return CR;
} else {
if (Upper.slt(CR.Upper))
return *this;
if (Lower.slt(CR.Upper))
return ConstantSignedRange(Lower, CR.Upper);
return ConstantSignedRange(getBitWidth(), false);
}
}
if (isWrappedSet() && !CR.isWrappedSet()) {
if (CR.Lower.slt(Upper)) {
if (CR.Upper.slt(Upper))
return CR;
if (CR.Upper.slt(Lower))
return ConstantSignedRange(CR.Lower, Upper);
if (getSetSize().ult(CR.getSetSize()))
return *this;
else
return CR;
} else if (CR.Lower.slt(Lower)) {
if (CR.Upper.sle(Lower))
return ConstantSignedRange(getBitWidth(), false);
return ConstantSignedRange(Lower, CR.Upper);
}
return CR;
}
if (CR.Upper.slt(Upper)) {
if (CR.Lower.slt(Upper)) {
if (getSetSize().ult(CR.getSetSize()))
return *this;
else
return CR;
}
if (CR.Lower.slt(Lower))
return ConstantSignedRange(Lower, CR.Upper);
return CR;
} else if (CR.Upper.slt(Lower)) {
if (CR.Lower.slt(Lower))
return *this;
return ConstantSignedRange(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.
///
ConstantSignedRange
ConstantSignedRange::unionWith(const ConstantSignedRange &CR) const {
assert(getBitWidth() == CR.getBitWidth() &&
"ConstantSignedRange types don't agree!");
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 (!isWrappedSet() && !CR.isWrappedSet()) {
if (CR.Lower.slt(L))
L = CR.Lower;
if (CR.Upper.sgt(U))
U = CR.Upper;
}
if (isWrappedSet() && !CR.isWrappedSet()) {
if ((CR.Lower.slt(Upper) && CR.Upper.slt(Upper)) ||
(CR.Lower.sgt(Lower) && CR.Upper.sgt(Lower))) {
return *this;
}
if (CR.Lower.sle(Upper) && Lower.sle(CR.Upper)) {
return ConstantSignedRange(getBitWidth());
}
if (CR.Lower.sle(Upper) && CR.Upper.sle(Lower)) {
APInt d1 = CR.Upper - Upper, d2 = Lower - CR.Upper;
if (d1.slt(d2)) {
U = CR.Upper;
} else {
L = CR.Upper;
}
}
if (Upper.slt(CR.Lower) && CR.Upper.slt(Lower)) {
APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper;
if (d1.slt(d2)) {
U = CR.Lower + 1;
} else {
L = CR.Upper - 1;
}
}
if (Upper.slt(CR.Lower) && Lower.slt(CR.Upper)) {
APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Lower;
if (d1.slt(d2)) {
U = CR.Lower + 1;
} else {
L = CR.Lower;
}
}
}
if (isWrappedSet() && CR.isWrappedSet()) {
if (Lower.slt(CR.Upper) || CR.Lower.slt(Upper))
return ConstantSignedRange(getBitWidth());
if (CR.Upper.sgt(U)) {
U = CR.Upper;
}
if (CR.Lower.slt(L)) {
L = CR.Lower;
}
if (L == U) return ConstantSignedRange(getBitWidth());
}
return ConstantSignedRange(L, U);
}
/// 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.
ConstantSignedRange ConstantSignedRange::zeroExtend(uint32_t DstTySize) const {
unsigned SrcTySize = getBitWidth();
assert(SrcTySize < DstTySize && "Not a value extension");
if (isEmptySet())
return ConstantSignedRange(SrcTySize, /*isFullSet=*/false);
if (isFullSet())
// Change a source full set into [0, 1 << 8*numbytes)
return ConstantSignedRange(APInt(DstTySize,0),
APInt(DstTySize,1).shl(SrcTySize));
APInt L, U;
if (Lower.isNegative() && !Upper.isNegative()) {
L = APInt(SrcTySize, 0);
U = APInt::getSignedMinValue(SrcTySize);
} else {
L = Lower;
U = Upper;
}
L.zext(DstTySize);
U.zext(DstTySize);
return ConstantSignedRange(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.
ConstantSignedRange ConstantSignedRange::signExtend(uint32_t DstTySize) const {
unsigned SrcTySize = getBitWidth();
assert(SrcTySize < DstTySize && "Not a value extension");
if (isEmptySet())
return ConstantSignedRange(SrcTySize, /*isFullSet=*/false);
if (isFullSet())
return ConstantSignedRange(APInt(getSignedMin()).sext(DstTySize),
APInt(getSignedMax()).sext(DstTySize)+1);
APInt L = Lower; L.sext(DstTySize);
APInt U = Upper; U.sext(DstTySize);
return ConstantSignedRange(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.
ConstantSignedRange ConstantSignedRange::truncate(uint32_t DstTySize) const {
// TODO: Implement truncate.
return ConstantSignedRange(DstTySize, !isEmptySet());
}
ConstantSignedRange
ConstantSignedRange::add(const ConstantSignedRange &Other) const {
// TODO: Implement add.
return ConstantSignedRange(getBitWidth(),
!(isEmptySet() || Other.isEmptySet()));
}
ConstantSignedRange
ConstantSignedRange::multiply(const ConstantSignedRange &Other) const {
// TODO: Implement multiply.
return ConstantSignedRange(getBitWidth(),
!(isEmptySet() || Other.isEmptySet()));
}
ConstantSignedRange
ConstantSignedRange::smax(const ConstantSignedRange &Other) const {
// X smax Y is: range(smax(X_smin, Y_smin),
// smax(X_smax, Y_smax))
if (isEmptySet() || Other.isEmptySet())
return ConstantSignedRange(getBitWidth(), /*isFullSet=*/false);
if (isFullSet() || Other.isFullSet())
return ConstantSignedRange(getBitWidth(), /*isFullSet=*/true);
APInt NewL = APIntOps::smax(getSignedMin(), Other.getSignedMin());
APInt NewU = APIntOps::smax(getSignedMax(), Other.getSignedMax()) + 1;
if (NewU == NewL)
return ConstantSignedRange(getBitWidth(), /*isFullSet=*/true);
return ConstantSignedRange(NewL, NewU);
}
ConstantSignedRange
ConstantSignedRange::umax(const ConstantSignedRange &Other) const {
// TODO: Implement umax.
return ConstantSignedRange(getBitWidth(),
!(isEmptySet() || Other.isEmptySet()));
}
ConstantSignedRange
ConstantSignedRange::udiv(const ConstantSignedRange &Other) const {
// TODO: Implement udiv.
return ConstantSignedRange(getBitWidth(),
!(isEmptySet() || Other.isEmptySet()));
}
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