  Exact polyhedral model (PM) can be built in the general case if the only
control structures are {\tt do}-loops and structured {\tt if}s, and if loop
counter bounds, array subscripts and {\tt if}-conditions are affine expressions
of enclosing loop counters and possibly some integer constants. In more general
dynamic control programs, where arbitrary {\tt if}s and {\tt while}s are
allowed, in the general case the usual dataflow analysis can be only fuzzy.
This is not a problem when PM is used just for guiding the parallelizing
transformations, but is insufficient for transforming source programs to other
computation models (CM) relying on the PM, such as our version of dataflow CM
or the well-known KPN.
  The paper presents a novel way of building the exact polyhedral model and an
extension of the concept of the exact PM, which allowed us to add in a natural
way all the processing related to the data dependent conditions. Currently, in
our system, only arbirary {\tt if}s (not {\tt while}s) are allowed in input
programs. The resulting polyhedral model can be easily put out as an equivalent
program with the dataflow computation semantics.

Programming Languages