Complications to Dataflow Analysis*
Unrestricted goto statements (jumps)
??Introduce overly-pessimistic dependencies during static analysis
??Values of variables references in the statements following a label depend on the assignments to variables in the code sections that can jump to the label.
Global variables
??i.e. variables declared outside of any function and therefore able to be shared by all functions
??Last-use cannot be determined without examining the entire program.
*J. T. Deutsch, “Behavioral-Level Simulation and Synthesis of Digital Systems,” UCB/ERL M83/47, August 1983