BLOAT, the Bytecode-Level Optimizer and Analysis Tools, is a Java classfile optimizer that is written entirely in Java. BLOAT was designed and developed by Nate Nystrom in 1998 and performs a number of intraprocedural optimizations on Java bytecode:

• Control flow graph construction
• Conversion to static single assignment (SSA) form
• Constant and copy propagation
• Dead code elimination
• Partial redundency elimination of expressions and access paths (e.g. array and fieldreferences)
• Efficient "register" (JVM local variables) allocation
• Java bytecode peephole optimizations

More information about BLOAT can be found at:

http://www.cs.purdue.edu/homes/whitlock/bloat