Dynamic Code Optimization for Java VM Hardware/Software

• Main Authors: Chun-Lng Lin, 林君玲
• Other Authors: Chun-Jen Tsai
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/12895552090905685456

碩士 === 國立交通大學 === 資訊工程系所 === 93 === Multimedia Home Platform (MHP) is the open middleware system for interactive television and related interactive home entertainment designed by the Digital Video Broadcasting (DVB) project. They use Java as the common programming language and embed the Java Virtual Machine (VM) that provides a stable and cross-platform java runtime environment in the system software layer. A hardware/software co-design approach makes Java VM more flexible and powerful, but it still suffers from the inefficiency of java system. Typical dynamic code optimization can save method lookup and constant pool searching time using the runtime information known in the first time we execute it. However, in such kind of embedded system, it is very expensive due to the overhead of external memory modification. In this thesis, we propose a new hardware/software co-design dynamic code optimization schema for this kind of approach that can significantly improve the efficiency of Java program execution. By analyzing the execution frequency of Java code segment, we can dynamically decide if the dynamic code optimization is needed. This approach can also cut down the power consumption with less microcode execution cycles and less external memory access. We implement this architecture on Java Optimized Processor (JOP) and simulate on Xilinx Spartan-3 developing board. Experiment Result shows that this proposed dynamic code optimization schema for Java VM hardware/software co-design of DVB-MHP terminal has 13.8% average speedup, 10.4% less microcode execution cycles and 11.1% less external memory access than the original system.