blas_sys::cblas_dgbmv

pub unsafe extern fn cblas_dgbmv(layout: CblasLayout, transa: CblasTranspose, m: c_int, n: c_int, kl: c_int, ku: c_int, alpha: c_double, a: *const c_double, lda: c_int, x: *const c_double, incx: c_int, beta: c_double, y: *mut c_double, incy: c_int)