The -scalaropt command-line switch sets the level to
which dusty-deck and other scalar transformations are performed.
Unlike the -scalaropt command-line switch, the
C*$* scalar optimize directive sets the level of
loop-based optimizations (for example, loop fusion) only, and not
straight-code optimizations (for example, dead-code elimination).
The allowed values and their meanings are as follows:
0 - No scalar optimizations are performed.
1 - IF loops are changed into DO loops.
Simple code floating out of loops is performed. Inaccessible
or unused code is removed. Forward substitution of variables is
performed. Dusty-deck IF transformations are enabled.
2 - The full range of scalar optimization
is performed. Included are floating invariant IFs out of
loops, induction variable recognition, loop rerolling (if
-roundoff > 0,) loop peeling, loop fusion, induction
variable recognition, and loop unrolling.
3 - Memory management is performed (if
-roundoff=3 ); additional dead-code elimination
is performed during output conversion.