HP Fortran Programmer's Reference (September 2007)

BLAS and libU77 libraries
Chapter 12642
The libU77 library provides routines that have a Fortran 90 interface for system routines in
the libc library. The libU77 routines make it easier to call HP-UX system-level routines from
Fortran 90 programs because they use Fortran 90 argument-passing conventions. The libU77
routines are also compatible with other Fortran implementations that supply these routines
by default.
NOTE Even though system routines use different argument-passing rules from
HP Fortran programs, you can call these routines from HP Fortran programs
by using the %VAL and %REF built-in functions to change how arguments are
passed. For more information about %VAL and %REF, see “%VAL and %REF
built-in functions” on page 178.
The Basic Linear Algebra Subroutine (BLAS) library consists of a set of routines that perform
low-level vector and matrix operations. These routines have been tuned for maximum
performance and are callable from HP Fortran programs. For information about the
background and significance of the BLAS library, refer to the LAPACK User’s Guide, by E.
Anderson et al (SIAM Press, 1992).
The following sections considerations to keep in mind when writing and compiling a program
that calls routines from the BLAS or libU77 library, and briefly describes the routines in the
libraries. For information about other libraries that are shipped with HP Fortran, including
how to create and link libraries with your programs—refer to the HP Fortran Programmer’s
Guide.