A new algorithm for building the GSA-form

Gated Single Assignment (GSA) form is used to transform an imperative program into a form suitable for dataflow interpretation. We describe a GSA-formed Control Flow Graph (CFG) that contains gating functions and the information of switches. We also present an algorithm to transform an imperative program into a GSA-formed CFG. Transformation of an imperative program into a GSA-formed CFG provides the basis for generating dataflow graphs(DFG). By using GSA-formed CFG, we can transform an imperative program into a DFG more simply comparing with previous methods, and show an expectation of use with demand- and control-driven model. As we create an intermediate form which has essential information for translation, it will be used to do transformations for various kinds of dataflow models.