HP Fortran Programmer's Guide (September 2007)

Compiling and linking
Special-purpose compilations
Chapter 286
Managing .mod files
By default, the compiler writes .mod files to the current working directory and looks there
when it has to read them. The +moddir= directory and -I directory options enable you to
specify different directories. The +moddir option causes the compiler to write .mod files in
directory , and the -I option causes the compiler to search directory for .mod files to read.
(The space character between -I and directory is optional.)
Using the example of the do_stats program, the following command line compiles (without
linking) data.f90 and writes a .mod file to the subdirectory mod_files:
$ f90 -c +moddir=mod_files data.f90
The command line:
$ f90 -c +moddir=mod_files -I mod_files code.f90
uses both the +moddir and -I options, as follows:
• The +moddir option causes f90 to write the .mod file for code.f90 in the subdirectory
mod_files.
• The -I option causes f90 to look in the same subdirectory for the .mod file to read when
compiling code.f90.
The command line:
$ f90 -odo_stats -I mod_files main.f90 code.o data.o
causes f90 to compile main.f90, look for the .mod file in the subdirectory mod_files, and link
all of the object files into an executable program named do_stats.
Compiling for different PA-RISC machines
When you compile an HP Fortran 90 program, the object code that the compiler generates by
default is based on the PA-RISC model of the machine that is running the compiler. If your
program will execute on a different PA-RISC model machine, the code may run less efficiently
or (in the case of PA2.0 code that attempts to run on a PA1.1 machine) may not run at all.
Also, some libraries (for example, the math library) are available in different PA-RISC
versions. By default, the compiler selects the version that is based on the PA-RISC model of
the compiling machine. If your program will execute on a different model machine, it may not
be linked with the appropriate libraries.
Compiling with the +DA model option ensures that the compiler generates code that is based
on the architecture specified by model and that the linker selects libraries that are compatible
with model . model must be one of the following: