HP MLIB for Itanium Linux Version 9.6.1 Release Note

Known Problems and Workarounds

HP MLIB for Itanium Linux Version 9.6.1 Release Note18

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 the following workaround:

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

the MLIB namespace. This can be done with ALIAS directives in order to minimize the

actual code changes required. The ALIAS directives can be enclosed in C preprocessor

conditional blocks so that the code will run unmodified in the current environment.

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.