zpteqr(3) on Linux
The text 60c66290d665, as Debian 4.0 (Etch), Debian 3.1 (Sarge) shipped it.
compute all eigenvalues and, optionally, eigenvectors of a symmetric positive definite tridiagonal matrix by first factoring the matrix using DPTTRF and then calling ZBDSQR to compute the singular values of the bidiagonal factor