The /roundoff
qualifier allows you to specify
the change from serial roundoff error that is tolerable. If
an arithmetic reduction is accumulated in a different order
than in the scalar program, the roundoff error is accumulated
differently and the final result may differ from that of the
original program. Although the difference is usually insignificant,
certain restructuring transformations performed by KAP must be
disabled to obtain exactly the same results as the scalar program.
KAP classifies its transformations by the amount of difference in
roundoff error that can accumulate so you can decide what level of
roundoff error differences is allowable. The /roundoff
command qualifier has the values 0 to 3.
Roundoff levels are cumulative, performing what is listed for each level, as well as what is listed for the lower levels. The meaning of each roundoff level is as follows:
/optimize
>4. Allow loop
rerolling, when /scalaropt
>1.
/scalaropt
>2
or /optimize
>1. Enable memory management, if
/scalaropt=3
. INTEGER multiple division can be
rotated into multiplication.
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