Cross-module program restructuring

A computer-implemented method for code optimization includes collecting a profile of execution of an application program, which includes a target module, which calls one or more functions in a source module. The source and target modules may be independently-linked object files. Responsively to the profile, at least one function from the source module is identified and cloned to the target module, thereby generating an expanded target module. The expended target module is restructured so as to optimize the execution of the application program.