Debugging optimized code is a desirable capability not provided by most current debuggers. Users are forced to debug the unoptimized code when a bug occurs in the optimized version. Current research offers partial solutions for a small class of optimizations, but not a unified approach that handles a wide range of optimizations, such as the sophisticated optimizations performed by supercomputer compilers.

The authors describe the CONVEX performance analyzer, CX/sub pa/, which has the capability to monitor parallel regions of code, in particular loops, executed in a time-sharing environment. The means by which profiling information is measured for a parallel region is described along with the operating system facilities required to support it. The effectiveness of the approach is evaluated and suggestions for improvement are made. The profiling of parallel regions is implemented on the CONVEX C200 series computers, tightly coupled, shared-memory, parallel/multiprocessor systems running Convex OS V8.0, a UNIX based operating system.>