HP Fortran Programmer Guide HP-UX 11i v1, HP-UX 11i v2, and HP-UX 11i v3 (B3908-90032,December 2012)

perform. The defined values for optlevel
are:
strict—disallow any floating point
optimization that can result in numerical
differences. This is the same as
+Ofltacc.
default—allow contractions, such as
fused multiply-add (FMA), but disallows
any other floating point optimization that
can result in numerical differences.
limited—like default, but also allows
floating point optimizations which may
affect the generation and propogation of
infinities, NaNs, and the sign of zero.
Also implies +Ocxlimitedrange.
relaxed—in addition to the
optimizations allowed by limited, permits
optimizations, such as reordering of
expressions, even if parenthesized, that
may affect a rounding error. This is the
same as +Onofltacc. Also implies
+Ocxlimitedrange.
The named functions are assumed to be
frequently called. This option overrides
any information in a profile database.
+Ofrequently_called=function1[,function2...]
The file indicated by filename contains a
list of function names, separated by
+Ofrequently_called:filename
spaces or newlines. These functions are
assumed to be frequently called. This
option overrides any information in a
profile database.
+Oinfo causes the compiler to display
informational messages about the
+O[no]info
optimization process. The +Oinfo option
provides feedback that can help you to
determine whether the compiler optimized
time-critical sections of your program. It
can be used at any level of optimization
but is most useful at level 3.
Currently, this option provides feedback
for the following optimizations:
• Cloning, the replacement of a call to
a routine by a call to a clone, which
is a copy of the routine with changes
specific to that call site.
• Inlining.
• Loop transformations to improve cache
performance.
• Vectorization
The default, +Onoinfo, disables the
display of informational messages about
optimization.
The initialization checking feature of the
optimizer has three possible states: on,
+O[no]initcheck
off, or unspecified. When this option is
specified in the on state (+Oinitcheck),
the optimizer initializes to zero any local,
nonarray, nonstatic variables that are
42 Compiling and linking