int jsroffset = local0Offset - ((bitnum -1) <<LOG_BYTES_IN_ADDRESS);
int jsroffset = startLocal0Offset - (bitnum <<LOG_BYTES_IN_ADDRESS);
  private int convertJsrBitNumToOffset(int bitnum)   {    // convert from top of local words    int jsroffset = local0Offset - ((bitnum -1) <<LOG_BYTES_IN_ADDRESS); // minus 1 for being 1 based, no jsrbit here    if (VM.TraceStkMaps) {      VM.sysWriteln("convertJsrBitnumToOffset- input bitnum = ", bitnum, "  offset = ", jsroffset);    }    return jsroffset;  }