I would like to contribute routines for solving symmetric EIG(A,B) by MRRR.
Now LAPACK has MRRR and D&C routines to solve standard eigenproblem, but only D&C for generalized.
MRRR for generalized eigenproblem would be a natural addition to LAPACK as it computes eigenvectors faster compared to D&C.
Additionally, I saw that such routines might be of interest in some fields [1].
Guided by this idea, I wrote MRRR-functions: DSYGVR, ZHEGVR (attached).
Both are analogous to existing Divide & Conquer routines: DSYGVD, ZHEGVD.
Would it be interesting to include the routines to LAPACK?
Forking, adding new routines, updating CMake files are easy.
But I have little experience with unit tests in LAPACK.
Of course, I have tested the routines in my environment.
[1] Metallic Systems: A Quantum Chemist's Perspective

