Method intersectWithComplement

svf/include/Util/SparseBitVector.h:943–999

Intersect our bitmap with the complement of the RHS and return true if ours changed.

    // Intersect our bitmap with the complement of the RHS and return true
    // if ours changed.
    bool intersectWithComplement(const SparseBitVector &RHS)
    {
        if (this == &RHS)
        {
            if (!empty())
            {
                clear();
                return true;
            }
            return false;
        }

        bool changed = false;
        ElementListIter Iter1 = Elements.begin();
        ElementListConstIter Iter2 = RHS.Elements.begin();

        // If either our bitmap or RHS is empty, we are done
        if (Elements.empty() || RHS.Elements.empty())
            return false;

        // Loop through, intersecting as we go, erasing elements when necessary.
        while (Iter2 != RHS.Elements.end())
        {
            if (Iter1 == Elements.end())
            {
                CurrElementIter = Elements.begin();
                return changed;
            }

            if (Iter1->index() > Iter2->index())
            {
                ++Iter2;
            }
            else if (Iter1->index() == Iter2->index())
            {
                bool BecameZero;
                changed |= Iter1->intersectWithComplement(*Iter2, BecameZero);
                if (BecameZero)
                {
                    ElementListIter IterTmp = Iter1;
                    ++Iter1;
                    Elements.erase(IterTmp);
                }
                else
                {
                    ++Iter1;
                }
                ++Iter2;
            }
            else
            {
                ++Iter1;
            }
        }
        CurrElementIter = Elements.begin();
        return changed;
    }