function bnpClamp() {
  var this_array = this.array;
  var c = this.s&BI_DM;
  while(this.t > 0 && this_array[this.t-1] == c) --this.t;
}
function bnpClamp() {
  var this_array = this.array;
  var c = this.s&BI_DM;
  while(this.t > 0 && this_array[this.t-1] == c) --this.t;
}
function bnpClamp ( ) { var this_array = this . array ; var c = this . s & BI_DM ; while ( this . t > 0 && this_array [ this . t - 1 ] == c ) -- this . t ; }
(protected) clamp off excess high words
( protected ) clamp off excess high words