if (VM.VerifyAssertions)
if (VM.VerifyAssertions) {
  public void perform (OPT_IR ir) {    if (ir.hasReachableExceptionHandlers() || OPT_GCP.tooBig(ir)) return;    verbose = OPT_LICM.verbose;    this.ir = ir;    dominator = ir.HIRInfo.dominatorTree;    (new OPT_GlobalValueNumber()).perform(ir);    valueNumbers = ir.HIRInfo.valueNumbers;    if (true || ir.IRStage == ir.LIR) {      if (verbose) VM.sysWrite ("in GCSE for "+ir.method+"\n");      OPT_DefUse.computeDU(ir);      OPT_Simple.copyPropagation(ir);      OPT_DefUse.computeDU(ir);      GlobalCSE(ir.firstBasicBlockInCodeOrder());      if (VM.VerifyAssertions)        VM._assert(avail.size() == 0, avail.toString());    }  }