Set the machine switch according to the characteristics of the system on which KAP Fortran output runs.
Use any combination of the following switch settings, except do not
specify switches s and n simultaneously:
n - Prefers non-stride-1 array access over
stride-1 array access. This is suitable for machine architectures
that have special interleaved memory hardware where non-stride-1
array access provides the best performance.
o - Directs KAP Fortran not to parallelize
innermost loops when optimizing, that is, to parallelize
only outermost loops. This capability is available to prevent
concurrentization on applications that have small inner loop
bounds, thereby reducing overhead costs. KAP Fortran makes
decisions concerning the overhead:benefit ratio when making
concurrentization decisions. When the loop bounds are unknown
at compile time, KAP Fortran may generate concurrent code for
innermost loops, a practice that may be inefficient for the
actual loop bounds.
s - Directs KAP Fortran to prefer
optimization of a DO loop that generates stride-1 contiguous
references over one which generates nonstride-1 operands. Some
computers perform better if consecutive references are contiguous
in memory.
To disable all of the switch settings, enter -nomachine
on the command line.