Control optimizations using behavioral don't cares

Optimization of control flow is an important problem in the synthesis of embedded systems. While considerable progress has been made in data-oriented optimizations, control optimization has been fairly limited to those carried out by compilers at the register transfer level. Control optimizations are needed to make the final system design insensitive to individual programming styles, and more importantly to provide implementation flexibility using the Don't Care (DC) information. Broadly speaking, a DC refers to a condition under which the outcome of an specified set of actions is not important. This paper describes the sources of the Don't Care information at the behavioral and structural levels, and its use in optimization of the control flow in system descriptions.