• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.107-117
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• 2006

Java language creates class files through Java compiler. Class files include informations involved with achievement of program. We can do analysis and optimization for efficient codes by analyzing class files. This paper analyzes bytecodes using informations of Java class files. We translate stack-based Java bytecodes into 3-address codes. Then we translate into static single assignment form using the 3-address codes. Static single assignment form provides a compact representation of a variable's definition-use information. Static single assignment form is often used as an intermediate representation during code optimization. Static sing1e assignment form renames each occurrence of a variable such that each variable is defined only once.

• The Journal of the Korea Contents Association
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• v.5 no.3
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• pp.73-81
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• 2005

CTOC(Classes To Optimized Classes) is a Java bytecode framework for optimization and analysis. Although Java bytecode has a significant amount of type information embedded in it, there are no explicit types for local variables. However, knowing types for local variables is very useful for both program optimization and analysis. This paper is a first part of CTOC framework. In this paper, we present methods for inferring static types for local variables in a 3-address, stackless, representation of Java bytecode. We use SSA Form(Single Static Assignment Form) for spliting local variables. Splited local variables will use to prepare for static type inference.

• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.87-96
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• 2006

Although bytecode has many good features, it has slow execution speed and it is not an ideal representation for program analysis or optimization. For analysises and optimizations. bytecode must be translated to a Static Single Assignment Form(SSA Form) But when bytecode is translated a SSA Form it has lost type informations of son variables. For resolving these problem in this paper, we create extended control flow graph on bytecode. Also we convert the control flow graph to SSA Form for static analysis. Calculation about many informations such as dominator, immediate dominator. dominance frontier. ${\phi}$-Function. renaming are required to convert to SSA Form. To obtain appropriate type for generated SSA Form, we proceed the followings. First. we construct call graph and derivation graph of classes. And the we collect information associated with each node. After finding equivalence nodes and constructing Strongly Connected Component based on the collected informations. we assign type to each node.