diff options
Diffstat (limited to 'lib/Support/ConstantRange.cpp')
-rw-r--r-- | lib/Support/ConstantRange.cpp | 48 |
1 files changed, 5 insertions, 43 deletions
diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp index 4cb54bde1b..5f3d6f8db2 100644 --- a/lib/Support/ConstantRange.cpp +++ b/lib/Support/ConstantRange.cpp @@ -275,58 +275,20 @@ 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()) { - 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); + return CR.intersectWith(*this); if (!isWrappedSet() && !CR.isWrappedSet()) { if (Lower.ult(CR.Lower)) { |