Early Java implementations relied on interpretation, leading to poor performance compared to compiled programs. Java just-in-time (JIT) compiler can compile Java programs at runtime, so it not only improves Java's...Early Java implementations relied on interpretation, leading to poor performance compared to compiled programs. Java just-in-time (JIT) compiler can compile Java programs at runtime, so it not only improves Java's performance prominently, but also preserves Java's portability. In this paper the design and implementing techniques of Java JIT compiler based on Chinese open system are discussed in detail. To enhance the portability, a translating method which combines the static simulating method and macro expansion method is adopted. The optimization technique for JIT compiler is also discussed and a way to evaluate the hotspots in Java programs is presented. Experiments have been conducted to verify JIT compilation technique as an efficient way to accelerate Java.展开更多
文摘针对当前大量遗产代码无法重复利用的问题,设计一种新的编译工具将C的串行代码转换为基于MPI＋Open MP的混合并行编程代码,降低了并行编程的开发成本。首先,通过对Java CC的优化,实现一种可以解析C语言的词法和语法分析器,进行源代码分析并生成抽象语法树;其次,根据语法树对源代码进行控制依赖性和数据依赖性分析,产生可并行化的语句块分区;再次,按照提出的并行代码生成方法得到目标代码;最后,基于Visual Studio 2010构建目标代码仿真验证环境。实验结果表明,该工具可以较为理想地实现串行代码自动并行化,与手工编写的代码在加速比上的误差为8.2%~18.4%。
文摘Early Java implementations relied on interpretation, leading to poor performance compared to compiled programs. Java just-in-time (JIT) compiler can compile Java programs at runtime, so it not only improves Java's performance prominently, but also preserves Java's portability. In this paper the design and implementing techniques of Java JIT compiler based on Chinese open system are discussed in detail. To enhance the portability, a translating method which combines the static simulating method and macro expansion method is adopted. The optimization technique for JIT compiler is also discussed and a way to evaluate the hotspots in Java programs is presented. Experiments have been conducted to verify JIT compilation technique as an efficient way to accelerate Java.
