uint128.cc

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#if defined __x86_64 && !defined _MSC_VER

// nothing

#else // __x86_64 && !_MSC_VER

#include "uint128.hh"

uint128& uint128::operator*=(const uint128& b)
{
        uint128 a = *this;
        uint128 t = b;

        lo = 0;
        hi = 0;
        while (t != 0) {
                if (t.lo & 1) {
                        *this += a;
                }
                a <<= 1;
                t >>= 1;
        }
        return *this;
}

uint128 uint128::div(const uint128& ds, uint128& remainder) const
{
        uint128 dd = *this;

        uint128 r = 0;
        uint128 q = 0;

        unsigned b = 127;
        while (r < ds) {
                r <<= 1;
                if (dd.bit(b--)) {
                        r.lo |= 1;
                }
        }
        ++b;

        while (true) {
                if (r < ds) {
                        if (!(b--)) break;
                        r <<= 1;
                        if (dd.bit(b)) {
                                r.lo |= 1;
                        }
                } else {
                        r -= ds;
                        q.setBit(b);
                }
        }
        remainder = r;
        return q;
}

bool uint128::bit(unsigned n) const
{
        if (n < 64) {
                return (lo & (1ull << n)) != 0;
        } else {
                return (hi & (1ull << (n - 64))) != 0;
        }
}

void uint128::setBit(unsigned n)
{
        if (n < 64) {
                lo |= (1ull << n);
        } else {
                hi |= (1ull << (n - 64));
        }
}

#endif // __x86_64 && !_MSC_VER