Symbolic debugging scheme for optimized hardware and software

Symbolic debuggers are system development tools that can accelerate the validation speed of behavioral specifications by allowing a user to interact with an executing code at the source level. In response to a user query, the debugger retrieves the value of a source variable in a manner consistent with respect to the source statement where execution has halted. However, when a behavioral specification has been optimized using transformations, values of variables may be inaccessible in the run-time state. We have developed a set of techniques that, given a behavioral specification CDFG, enforce computation of a selected subset V/sub cut/ of user variables such that (i) all other variables /spl upsi//spl isin/CDFG can be computed from V/sub cut/ and (ii) this enforcement has minimal impact on the optimization potential of the computation. The implementation of the new debugging approach poses several optimization tasks. We have formulated the optimization tasks and developed heuristics to solve them. The effectiveness of the approach has been demonstrated on a set of benchmark designs.