HP MLIB for PA-RISC and Itanium HP-UX Version 9.5.6 Release Note

Known Problems and Workarounds

User and library subprogram name conflicts

Some applications make use of some MLIB subprograms, but not others. For example, an

application may use the MLIB matrix-multiplication subprogram, DGEMM, but have its own

subprogram DCOPY. A subroutine name conflict occurs because DGEMM calls DCOPY and

expects the functionality of the MLIB DCOPY subprogram. DGEMM fails if the user’s version

of DCOPY performs a different operation.

Use one of the following workarounds:

• Change your source code to rename the application subprograms that are colliding with

the MLIB namespace.

• Use the Fortran 90 compiler command line option +pre_include=file to rename the

colliding subprograms without changing your source code.

For example, to rename DCOPY:

— Create a file containing the f90 compiler directive and include the

+pre_include=file option on your f90 compile command line:

% !$HP$ ALIAS dcopy='_dcopy'

% f90 +pre_include=file main.f dcopy.f

Work length for LAPACK standard eigensolver routine ZHEEVD

In the LAPACK User's Guide, documentation of the routine ZHEEVD (JOBZ, UPLO, N, A,

LDA, W, WORK, LWORK, RWORK, LRWORK, IWORK, LIWORK, INFO) specifies if JOBZ =

'V' and N > 1, LWORK must be at least 2*N + N**2. However, to achieve optimum

performance, LWORK must be at least 2*N + N**2 + NB*N, where NB is the optimal block

size for ZUNMQR that is computed by the function ILAENV. Enough work space allows

LAPACK computational routines to go through block versions of algorithms with optimum

performance.