Class SSA

java.lang.Object
EDU.purdue.cs.bloat.ssa.SSA
public class SSA extends Object
Compute the SSA form of the control flow graph and build FUD chains.

The SSA algorithm is from: 

    R. Cytron, J. Ferrante J, B. K. Rosen, M. N. Wegman, and F. K. Zadeck,
    "Efficiently Computing Static Single Assignment Form and the Control
    Dependence Graph", TOPLAS, 13(4): 451-490, October 1991.

I made modifications to the algorithm to compute FUD chains and to run the algorithm separately for each variable similar to the SSAPRE algorithm. Making a separate pass for each variable allows variables to be added incrementally.

  • Field Details

    • DEBUG

      public static boolean DEBUG

  • Constructor Details

    • SSA

      public SSA()

  • Method Details

    • transform

      public static void transform(FlowGraph cfg)
      Transforms a control flow graph into Single Static Assignment (SSA) form. First, the CFG is traversed and a list of all variables (both local and stack) eligible for SSA renaming is compiled. Variables are represented by instances of SSAConstructionInfo. Each of these variables is then transformed.
      See Also:

    • transform

      public static void transform(FlowGraph cfg, SSAConstructionInfo info)
      Performs the actions necessary to convert a CFG into SSA form with respect to one variable. The variable's information is stored in the SSAConstructionInfo.