Function cusolverDnSsyevdx 

pub unsafe extern "C" fn cusolverDnSsyevdx(
    handle: cusolverDnHandle_t,
    jobz: cusolverEigMode_t,
    range: cusolverEigRange_t,
    uplo: cublasFillMode_t,
    n: c_int,
    A: *mut f32,
    lda: c_int,
    vl: f32,
    vu: f32,
    il: c_int,
    iu: c_int,
    meig: *mut 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 all or selection of the eigenvalues and optionally 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×h_meig diagonal matrix. V is an n×h_meig unitary matrix. h_meig is the number of eigenvalues/eigenvectors computed by the routine, h_meig is equal to n when the whole spectrum (e.g., range = cusolverEigRange_t::CUSOLVER_EIG_RANGE_ALL) is requested. 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 syevdx_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 - syevdx for a code example.