Chapter 12 BLAS and libU77 libraries

This chapter describes the Basic Linear Algebra Subroutines (BLAS) and the BSD 3f (libU77) libraries that are shipped with HP Fortran.

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”.

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.