Global scheduling and register allocation based on predicated execution

This paper presents an approach for register allocation and scheduling which relies on three main ideas: global optimization, solution space exploration and on-the-fly generation of a symbolic state machine. To allow global optimizations while preserving semantics, the traditional notion of control dependence is replaced by the notion of predicate. In our approach, predicates are used not only as attributes of operations during scheduling (predicated execution), but also as attributes of values during register allocation. Experimental results show that this global approach improves the chances of reaching high-quality solutions in high-level synthesis.