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[Lapack] Divide and conquer diagonalization routines fail when high prec


    Dear Lapack customer support:

    I think I have found a bug in the divide and conquer routines
 supplied in the LAPACK.


    Given platform (AMD Opteron 64 bit, Intel Xeon 32 and 64-bit,
 Mac, Pentium-IV,...), compiler (g95, pathscale, pgf90, ifort,...) 
 and optimization flag (-O0, -O2), the diagonalization using
 divide and conquer seems to work depending on the precision of the
 eigenvalue problem to be solved.

    The problem appears both using the LAPACK routines directly supplied
 by Lapack (in the example provided below, they are included
 in the Libs directory). 
 
    For a medium precision it works nicely. Increasing the precision to high, 
 it crashes independently of the compiler, architecture, compiler flags...

    Please, find enclosed a simplified program showing this bug.
 After unzip and untar the package,
 read the INSTALL file to know how to change the precision, compile and 
 run the code.
 You will also find a file (lapack.pdf) with a
 summary of our results.

     Thank you very much for your help.

     Best regards,

                Javier

-------------------------------------------------------------------------
Javier Junquera

Ciencias de la Tierra y Fisica de la Materia Condensada (CITIMAC)
Avenida de Los Castros s/n
Facultad de Ciencias
Universidad de Cantabria
E-39005 Santander, Cantabria
Spain

e-mail:   javier.junquera@Domain.Removed
Tel:      (+34) 942 20 15 16
Fax:      (+34) 942 20 14 02


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