Various embodiments test an optimized binary module. In one embodiment, a region in a set of original binary code of an original binary module in which branch coverage is expected to be achieved is selected based on a set of profile information. The region is selected as a target region to be optimized. An optimized binary module is created, where the target region has been optimized in the optimized binary module. The optimized binary module is verified by synchronizing execution of the optimized binary module with execution of the original binary module at a checkpoint while executing both the optimized binary module and the original binary module. The optimized binary module is further verified by comparing an output from executing the optimized binary module to an output from executing the original binary module.