Function PyArray_MatrixProduct2

numpy/core/src/multiarray/multiarraymodule.c:997–1152

NUMPY_API * Numeric.matrixproduct2(a,v,out) * just like inner product but does the swapaxes stuff on the fly */

 * just like inner product but does the swapaxes stuff on the fly
 */
NPY_NO_EXPORT PyObject *
PyArray_MatrixProduct2(PyObject *op1, PyObject *op2, PyArrayObject* out)
{
    PyArrayObject *ap1, *ap2, *out_buf = NULL, *result = NULL;
    PyArrayIterObject *it1, *it2;
    npy_intp i, j, l;
    int typenum, nd, axis, matchDim;
    npy_intp is1, is2, os;
    char *op;
    npy_intp dimensions[NPY_MAXDIMS];
    PyArray_DotFunc *dot;
    PyArray_Descr *typec = NULL;
    NPY_BEGIN_THREADS_DEF;

    typenum = PyArray_ObjectType(op1, NPY_NOTYPE);
    if (typenum == NPY_NOTYPE) {
        return NULL;
    }
    typenum = PyArray_ObjectType(op2, typenum);
    if (typenum == NPY_NOTYPE) {
        return NULL;
    }

    typec = PyArray_DescrFromType(typenum);
    if (typec == NULL) {
        if (!PyErr_Occurred()) {
            PyErr_SetString(PyExc_TypeError,
                            "Cannot find a common data type.");
        }
        return NULL;
    }

    Py_INCREF(typec);
    ap1 = (PyArrayObject *)PyArray_FromAny(op1, typec, 0, 0,
                                        NPY_ARRAY_ALIGNED, NULL);
    if (ap1 == NULL) {
        Py_DECREF(typec);
        return NULL;
    }
    ap2 = (PyArrayObject *)PyArray_FromAny(op2, typec, 0, 0,
                                        NPY_ARRAY_ALIGNED, NULL);
    if (ap2 == NULL) {
        Py_DECREF(ap1);
        return NULL;
    }

#if defined(HAVE_CBLAS)
    if (PyArray_NDIM(ap1) <= 2 && PyArray_NDIM(ap2) <= 2 &&
            (NPY_DOUBLE == typenum || NPY_CDOUBLE == typenum ||
             NPY_FLOAT == typenum || NPY_CFLOAT == typenum)) {
        return cblas_matrixproduct(typenum, ap1, ap2, out);
    }
#endif

    if (PyArray_NDIM(ap1) == 0 || PyArray_NDIM(ap2) == 0) {
        PyObject *mul_res = PyObject_CallFunctionObjArgs(
                n_ops.multiply, ap1, ap2, out, NULL);
        Py_DECREF(ap1);