HP-UX Floating-Point Guide

180 Chapter 7

Performance Tuning

BLAS Library Versions

As we said in “Math Libraries and System Architecture” on page 25, the

main HP-UX math libraries, libm and libcl, are provided in a version

targeted to the PA-RISC 1.1 and PA-RISC 2.0 architectures.

The two HP Fortran products also provide a version of the BLAS library,

libblas, that is specially tuned to the PA2.0 narrow-mode architecture.

If you are compiling code that will run only on PA2.0 systems, use this

library for optimum performance. If you use the +DA2.0 option and link

in the BLAS library, you will automatically link in the PA2.0 version.

See Chapter 4 for more information about math libraries. See

“Determining Your System’s Architecture Type” on page 26 if you do not

know what kind of system you have.