*** 102,112 ****
          ln2lo = 1.90821492927058770002e-10,   /* 0x3dea39ef, 0x35793c76 */
          one = 1.0,
          zero = 0.0;
  
  static const int hiinf = 0x7ff00000;
! double atan2pi(double, double);
  
  /*
   * Assuming |t[0]| > |t[1]| and |t[2]| > |t[3]|, sum4fp subroutine
   * compute t[0] + t[1] + t[2] + t[3] into two double fp numbers.
   */
--- 102,112 ----
          ln2lo = 1.90821492927058770002e-10,   /* 0x3dea39ef, 0x35793c76 */
          one = 1.0,
          zero = 0.0;
  
  static const int hiinf = 0x7ff00000;
! extern double atan2pi(double, double);
  
  /*
   * Assuming |t[0]| > |t[1]| and |t[2]| > |t[3]|, sum4fp subroutine
   * compute t[0] + t[1] + t[2] + t[3] into two double fp numbers.
   */