Class AssignInstruction


public class AssignInstruction extends SSAUnaryOpInstruction
A simple assignment statement. Only appears in the IR before SSA conversion, and temporarily when needed to undo copy propagation during processing of new lexical definitions and uses.
Author:
Julian Dolby (dolby@us.ibm.com)
  • Constructor Details

    • AssignInstruction

      public AssignInstruction(int iindex, int result, int val)
      create the assignment v_result := v_val
  • Method Details

    • copyForSSA

      public SSAInstruction copyForSSA(SSAInstructionFactory insts, int[] defs, int[] uses)
      Description copied from class: SSAInstruction
      This method is meant to be used during SSA conversion for an IR that is not in SSA form. It creates a new SSAInstruction of the same type as the receiver, with a combination of the receiver's uses and defs and those from the method parameters.

      In particular, if the 'defs' parameter is null, then the new instruction has the same defs as the receiver. If 'defs' is not null, it must be an array with a size equal to the number of defs that the receiver instruction has. In this case, the new instruction has defs taken from the array. The uses of the new instruction work in the same way with the 'uses' parameter.

      Note that this only applies to CAst-based IR translation, since Java bytecode-based IR generation uses a different SSA construction mechanism.

      TODO: move this into the SSAInstructionFactory

      Overrides:
      copyForSSA in class SSAUnaryOpInstruction
      See Also:
    • toString

      public String toString(SymbolTable symbolTable)
      Overrides:
      toString in class SSAUnaryOpInstruction
      See Also:
    • visit

      public void visit(SSAInstruction.IVisitor v)
      Description copied from class: SSAInstruction
      Apply an IVisitor to this instruction. We invoke the appropriate IVisitor method according to the type of this instruction.
      Overrides:
      visit in class SSAUnaryOpInstruction
      See Also:
    • getVal

      public int getVal()