LAPACK 3.12.0
LAPACK: Linear Algebra PACKage

Functions  
subroutine  chetd2 (uplo, n, a, lda, d, e, tau, info) 
CHETD2 reduces a Hermitian matrix to real symmetric tridiagonal form by an unitary similarity transformation (unblocked algorithm).  
subroutine  dsytd2 (uplo, n, a, lda, d, e, tau, info) 
DSYTD2 reduces a symmetric matrix to real symmetric tridiagonal form by an orthogonal similarity transformation (unblocked algorithm).  
subroutine  ssytd2 (uplo, n, a, lda, d, e, tau, info) 
SSYTD2 reduces a symmetric matrix to real symmetric tridiagonal form by an orthogonal similarity transformation (unblocked algorithm).  
subroutine  zhetd2 (uplo, n, a, lda, d, e, tau, info) 
ZHETD2 reduces a Hermitian matrix to real symmetric tridiagonal form by an unitary similarity transformation (unblocked algorithm).  