Function cusolverDnSsyevd 

pub unsafe extern "C" fn cusolverDnSsyevd(
    handle: cusolverDnHandle_t,
    jobz: cusolverEigMode_t,
    uplo: cublasFillMode_t,
    n: c_int,
    A: *mut f32,
    lda: c_int,
    W: *mut f32,
    work: *mut f32,
    lwork: c_int,
    info: *mut c_int,
) -> cusolverStatus_t

The helper functions below can calculate the sizes needed for pre-allocated buffer.

The S and D data types are real valued single and double precision, respectively.

The C and Z data types are complex valued single and double precision, respectively.

This function computes eigenvalues and eigenvectors of a symmetric (Hermitian) $n \times n$ matrix A. The standard symmetric eigenvalue problem is: $$ A\V = V\\Lambda $$

where Λ is a real $n \times n$ diagonal matrix. V is an $n \times n$ unitary matrix. The diagonal elements of Λ are the eigenvalues of A in ascending order.

The user has to provide working space which is pointed by input parameter work. The input parameter lwork is size of the working space, and it is returned by syevd_bufferSize(). Please note that the size in bytes of the working space is equal to sizeof(<type>) * lwork.

If output parameter devInfo = -i (less than zero), the i-th parameter is wrong (not counting handle). If devInfo = i (greater than zero), i off-diagonal elements of an intermediate tridiagonal form did not converge to zero.

If jobz = cusolverEigMode_t::CUSOLVER_EIG_MODE_VECTOR, A contains the orthonormal eigenvectors of the matrix A. The eigenvectors are computed by a divide and conquer algorithm.

Please visit cuSOLVER Library Samples - syevd for a code example.