Copyright © Digital Equipment Corporation. 1997.
All Rights Reserved.
Set the machine switch according to the characteristics of the system on which DIGITAL KAP for DEC 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 DIGITAL KAP for DEC 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. Digitl KAP
for DEC Fortran makes decisions concerning the overhead:benefit
ratio when making concurrentization decisions. When the loop
bounds are unknown at compile time, DIGITAL KAP for DEC Fortran
may generate concurrent code for innermost loops, a practice that
may be inefficient for the actual loop bounds.
s - Directs DIGITAL KAP for DEC 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.
Copyright © Digital Equipment Corporation. 1997.
All Rights Reserved.