In LAPACK there is this function for diagonalization
  SUBROUTINE DSPGVX( ITYPE, JOBZ, RANGE, UPLO, N, AP, BP, VL, VU,
 $                   IL, IU, ABSTOL, M, W, Z, LDZ, WORK, IWORK,
 $                   IFAIL, INFO )
*
I am looking for its GPU implementation. I am trying to find whether this function has been already implemented in CUDA (or OpenCL), but have only found CULA, which is not open source.
Therefore and side CUBLAS exists, I wonder how could I know whether a BLAS or CUBLAS equivalent of this subroutine is available.
 
     
    