Java bytecode optimizations

We present our results obtained from applying well known optimizations to Java bytecodes. We survey the optimizations implemented thus far, which include peephole optimizations, jump redundancy eliminations, and common subexpression elimination. The transformations are each analyzed according to several criteria. We measure the impact each has on reducing a program's execution time and size, the frequency by which the optimizations can be applied, and the extra compile time incurred. Together, these results quantify the overall effectiveness of employing classical optimizations on bytecodes. Our experiments were conducted on a representative set of public domain Java programs which were compiled using Sun's JDK 1.0.2. All transformations were applied to bytecodes with no access to their original source.