Sun WorkShop Compiler C 5.0 User's Guide

-xdepend

(SPARC) Analyzes loops for inter-iteration data dependencies and does loop restructuring. Loop restructuring includes loop interchange, loop fusion, scalar replacement, and elimination of "dead" array assignments. If optimization is not at -xO3 or higher, optimization is raised to -xO3 and a warning is issued.

Dependency analysis is also included with -xautopar or -xparallel. The dependency analysis is done at compile time.

Dependency analysis may help on single-processor systems. However, if you try -xdepend on single-processor systems, you should not use either -xautopar or -xexplicitpar. If either of them is on, then the -xdepend optimization is done for multiple-processor systems.