HP Fortran v2.9 for HP-UX 11i v2 Release Note5991-0697

HP Fortran for HP-UX v2.9

Known Problems and Workarounds

Chapter 118

Known Problems and Workarounds

This section details known problems and workarounds for HP Fortran.

• When very large arrays are declared to be local to a subroutine, the arrays are privatized.

This means that the arrays are allocated in stack space.Workaround: The default stack

size for an OPENMP thread is 8 megabytes. This can be changed by setting the

environment variable CPS_STACK_SIZE. For example, setenv CPS_STACK_SIZE

20000000 changes the stack size per thread from 8MB to 20MB.

• HP Fortran only accepts the !$ALIAS directive, not $ALIAS.

• A program compiled with “+DA2.0W +check=all +fp_exception” results in a divide by

zero trap during a subroutine call.

• Compiling an array slice assignment at +O0 results in an internal compiler error.

• Dummy arguments in multiple entry routines are not correctly handled by the WDB

debugger.

• Printing a dummy argument that is a CHARACTER in 64-bit wide mode (+DA2.0W) does

not work in the WDB debugger.

• When compiling, the +ppu switch is enabled by default. To access C routines, use the

ALIAS directive to map the C routine name to itself. For example:

!$HP ALIAS getrusage=`getrusage’

If the ALIAS directive is not used, `getrusage’ is mapped to `getrusage_’ in the object file.

• With +DD64, memory addresses are 64-bit values. This allows common blocks and

dynamically allocated memory to exceed 32-bit address limits. This feature is restricted

by the available virtual memory on the system where the application is run.

Common blocks greater than 2GBytes are automatically placed into a huge data segment

and initialization is performed at program start-up.

Workaround: To force smaller common blocks into the huge data segment, use the

+hugecommon and +hugesize compiler switches.

NOTE When using initialized huge common blocks, large repeat counts are

represented compactly to help reduce object file size.