Function cusparseSpMM_preprocess 

pub unsafe extern "C" fn cusparseSpMM_preprocess(
    handle: cusparseHandle_t,
    opA: cusparseOperation_t,
    opB: cusparseOperation_t,
    alpha: *const c_void,
    matA: cusparseConstSpMatDescr_t,
    matB: cusparseConstDnMatDescr_t,
    beta: *const c_void,
    matC: cusparseDnMatDescr_t,
    computeType: cudaDataType,
    alg: cusparseSpMMAlg_t,
    externalBuffer: *mut c_void,
) -> cusparseStatus_t