HP Fortran Programmer's Reference (September 2007)

BLAS and libU77 libraries

Calling libU77 and BLAS routines

Chapter 12 643

Calling libU77 and BLAS routines

This section discusses considerations pertinent to writing and compiling programs that call

libU77 and BLAS routines, including:

• The compile-line options that make libU77 and BLAS routines available to your

programs

• Declaring the type of return type of library functions

• Declaring library functions with the EXTERNAL attribute

• BLAS and libU77 man pages

Compile-line options

The following sections describe the compile-line options to use to access routines from the

libU77 and BLAS libraries.

+U77 option

To access libU77 routines, compile with the +U77 option. The entry-point name of each

libU77 routine has an appended underscore, which must also be added to the external name

of any libU77 routine that your program calls. The +U77 option does this. For example, if your

program contains the following call:

CALL FLUSH(unit_no)

compiling with +U77 causes the compiler to generate the external name access_. The +ppu

and +uppercase options have no effect on libU77 external names.

-lblas option

To access BLAS routines, compile with the -lblas option. Unlike most compile-line options,

the -l option must appear at the end of the command line, following any source ﬁles that call

BLAS routines. Here is an example command line for compiling do_math.f90 to access BLAS

routines:

$ f90 do_math.f90 -lblas