anchor.diff:      // For negative numbers we just clamp the shift-by amount. 'a' could be
       // negative but not have its 31st bit set. The ">>" would then shift in
       // 0s instead of 1s. Therefore we cannot simply return 0xFFFFFFFF.
  -    if (b > 31) b = 31;
  +    if (JS('num', '#', b) > 31) b = 31;
       return JS('num', @'(# >> #) >>> 0', a, b);
     }
     return UNINTERCEPTED(a >> b);
  
positive.code: shr(var a, var b) {
    // TODO(floitsch): inputs must be integers.
    if (checkNumbers(a, b)) {
      // TODO(floitsch): Find cleaner way of forcing the type.
      a = JS('num', '#', a);
      b = JS('num', '#', b);
      if (b < 0) throw new IllegalArgumentException(b);
      if (a > 0) {
        // JavaScript only looks at the last 5 bits of the shift-amount. In JS
        // shifting by 33 is hence equivalent to a shift by 1. Shortcut the
        // computation when that happens.
        if (b > 31) return 0;
        // Given that 'a' is positive we must not use '>>'. Otherwise a number
        // that has the 31st bit set would be treated as negative and shift in
        // ones.
  
negative.code: 
  tdiv(var a, var b) {
    if (checkNumbers(a, b)) {
      return (JS('num', @'# / #', a, b)).truncate();
    }
    return UNINTERCEPTED(a ~/ b);
  }
  