OPT_Simplifier.simplify(s);
OPT_Simplifier.simplify(ir.regpool, s);
  void foldConstants (OPT_IR ir) {    boolean recomputeRegList = false;    for (OPT_Instruction s = ir.firstInstructionInCodeOrder(); s != null;         s = s.nextInstructionInCodeOrder()) {      byte code = 0;      OPT_Simplifier.simplify(s);      // If something was reduced (as opposed to folded) then its uses may       // be different. This happens so infrequently that it's cheaper to       // handle it by  recomputing the DU from      // scratch rather than trying to do the incremental bookkeeping.       recomputeRegList |= (code == OPT_Simplifier.MOVE_REDUCED ||                            code == OPT_Simplifier.TRAP_REDUCED ||                            code == OPT_Simplifier.REDUCED);    }    if (recomputeRegList) {      OPT_DefUse.computeDU(ir);      OPT_DefUse.recomputeSSA(ir);    }  }