HP Fortran Programmer's Guide (September 2007)

Compiling and linking
Compiling with the f90 command
Chapter 2 53
The compiler will use more accurate cosd, sind, and tand intrinsics, than
the standard ones. While the standard ones have some accuracy problems
with the boundary cases (i.e., cosd(90) needs to be 0.0), these new intrinsics
get these cases right.
+[no]ttybuf
+ttybuf controls tty buffering, using buffered output. +nottybuf uses
unbuffered output. The default is buffered output (+ttybuf). The +ttybuf
option forces buffered output even on systems whose default is unbuffered
output.
The +[no]ttybuf option is recognized only when the main program is a
Fortran program. If the main program is written in another language, use
the TTYUNBUF environment variable (see f90 (1)).
The +nottybuf option is incompatible with certain BSD 3F library routines.
When it is used on the same command line with the +U77 option, the
compiler will warn of a potential tty buffering conflict.
-U name
-U undefines or removes any initial definition of name in the C preprocessor
(cpp). See the cpp (1) in the
HP-UX Reference for details.
+[no]U77
+U77 option invokes support for the BSD 3F library, libU77, which provides
an HP Fortran interface to some of the libc system routines. To call
routines in this library, you must compile and link with +U77. For
information about these routines, see the HP Fortran Programmer’s
Reference.
If +noU77 (the default) is specified or if +U77 is not specified, the compiler
treats libU77 routine names as ordinary external names with no name
mapping. If the name is not present in one of the libraries linked to, the
linker emits an error message because of an unsatisfied symbol. If the
libU77 name is the same as a libc name, the name might resolve to a libc
name. This situation does not cause an error at compile time, but can
produce unpredictable results.
+[no]uppercase
+uppercase uses uppercase for external names. The default,
+nouppercase, is to convert external names to lowercase.