code: function calcCFFSubroutineBias(subrs) {
              var bias;
              if (subrs.length < 1240) {
                  bias = 107;
              }
              else if (subrs.length < 33900) {
                  bias = 1131;
              }
              else {
                  bias = 32768;
              }
  
              return bias;
          }
docs: Subroutines are encoded using the negative half of the number space. See type 2 chapter 4.7 "Subroutine operators".