urjlew@uncecs.edu (Rostyk Lewyckyj) (02/09/90)
This is a request for information that is specific to the IBM
3090 system. It is really more an operating system, rather than a
language issue. However in this case the specifics are Fortran
related.
Our center offers users access to VM/CMS, MVS batch, and TSO. We
used to have an IBM 4381 and offered VS Fortran rel 1.41 and
IMSL. We have installed an IBM 3090 with a vector facility and
have obtained VS Fortran rel 2.4 and ESSL. It's time to upgrade
the software.
So here's the problem.
Both IMSL and ESSL have a set of commonly named routines. Most
obviously the set of BLAS routines such as: ISAMAX, SSCAL,
SASUM, SAXPY, SGEMV, SROT ... , and their double precision
versions. In the IMSL package some of these are second level
routines, i.e. not directly user callable, but called by other
IMSL routines.
My problem is how to make access to both of these packages
simultaneously available to our users. My questions and concerns
are about the problems that may be caused by the existence of the
identically named routines. Here are some specific scenarios and
questions:
1. Is there any problem, known or possible, caused by simply
making the ESSL package available first in the list of libraries
used to resolve library calls: different calling sequences,
handling of exception conditions, i/o considerations?
2. Suppose that a user wishes to use an IMSL routine that calls
on some of the BLAS routines and would also like to use some of
the ESSL BLAS, or other, routines directly. This is even more
likely to occur with the vectorized version of ESSL. If the IMSL
library is used first then the BLAS calls will be resolved from
it, and the user will not get the vectorized routines that they
want. If the ESSL library is first then it will be used to
resolve the calls from within the IMSL routine. Will this cause
any problems. OR will it simply improve the performance of the
IMSL routine???
3. With regard to the scalar vs. vector versions of ESSL. What is
a good, the best, way to give users their choice of which library
they access??
I would like any information regarding the above. Please mail me
your replies. Please describe to me how this situation is being
dealt with at your center. Please suggest other lists where
posting this may elicit informative answers.
*---------------------------------------------------------------*
Rostyk Lewyckyj, University of North Carolina, Academic Computing
Services, Phillips Hall, Box #3455 University of North Carolina,
Chapel Hill NC 27599-3455. tel. 919-962-6501
e-mail: urjlew@unc.bitnet urjlew@uncvm1.bitnet
urjlew@uncvm1.acs.unc.edu (internet)
urjlew@ecsvax.uncecs.edu (uucp)