On-device objective-C application optimization framework for high-performance mobile processors

摘要

Smartphones provide applications that are increasingly similar to those of interactive desktop programs, providing rich graphics and animations. To simplify the creation of these interactive applications, mobile operating systems employ highlevel object-oriented programming languages and shared libraries to manipulate the device's peripherals and provide common userinterface frameworks. The presence of dynamic dispatch and polymorphism allows for robust and extensible application coding. Unfortunately, the presence of dynamic dispatch also introduces significant overheads during method calls, which directly impact execution time. Furthermore, since these applications rely heavily on shared libraries and helper routines, the quantity of these method calls is higher than those found in typical desktop-based programs. Optimizing these method calls centrally before consumers download the application onto a given phone is exacerbated due to the large diversity of hardware and operating system versions that the application could run on. This paper proposes a methodology to tailor a given Objective-C application and its associated device-specific shared library codebase using on-device post-compilation code optimization and transformation. In doing so, many polymorphic sites can be resolved statically, improving the overall application performance.