Function qr

src/backend/cpu/qr.cpp:67–93

template<typename T>
void qr(Array<T> &q, Array<T> &r, Array<T> &t, const Array<T> &in) {
    dim4 iDims = in.dims();
    int M      = iDims[0];
    int N      = iDims[1];

    const dim4 NullShape(0, 0, 0, 0);

    dim4 endPadding(M - iDims[0], max(M, N) - iDims[1], 0, 0);
    q = (endPadding == NullShape
             ? copyArray(in)
             : padArrayBorders(in, NullShape, endPadding, AF_PAD_ZERO));
    q.resetDims(iDims);
    t = qr_inplace(q);

    // SPLIT into q and r
    dim4 rdims(M, N);
    r = createEmptyArray<T>(rdims);

    triangle<T>(r, q, true, false);

    auto func = [=](Param<T> q, Param<T> t, int M, int N) {
        gqr_func<T>()(AF_LAPACK_COL_MAJOR, M, M, min(M, N), q.get(),
                      q.strides(1), t.get());
    };
    q.resetDims(dim4(M, M));
    getQueue().enqueue(func, q, t, M, N);
}

template<typename T>
Array<T> qr_inplace(Array<T> &in) {