toolchain/gcc/newlib/libm/mathfp/sf_atan.c

   1
   2 /* @(#)z_atanf.c 1.0 98/08/13 */
   3 /******************************************************************
   4  * Arctangent
   5  *
   6  * Input:
   7  *   x - floating point value
   8  *
   9  * Output:
  10  *   arctan of x
  11  *
  12  * Description:
  13  *   This routine returns the arctan of x.
  14  *
  15  *****************************************************************/
  16
  17 #include "fdlibm.h"
  18 #include "zmath.h"
  19
  20 float
  21 _DEFUN (atanf, (float),
  22         float x)
  23 {
  24   switch (numtestf (x))
  25     {
  26       case NAN:
  27         errno = EDOM;
  28         return (x);
  29       case INF:
  30         /* this should check to see if neg NaN or pos NaN... */
  31         return (__PI_OVER_TWO);
  32       case 0:
  33         return (0.0);
  34       default:
  35         return (atangentf (x, 0, 0, 0));
  36     }
  37 }
  38
  39 #ifdef _DOUBLE_IS_32BITS
  40 double atan (double x)
  41 {
  42   return (double) atangentf ((float) x, 0, 0, 0);
  43 }
  44
  45 #endif /* defined(_DOUBLE_IS_32BITS) */