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

   1
   2 /* @(#)z_isinff.c 1.0 98/08/13 */
   3 /******************************************************************
   4  * isinff
   5  *
   6  * Input:
   7  *   x - pointer to a floating point value
   8  *
   9  * Output:
  10  *   An integer that indicates if the number is infinite.
  11  *
  12  * Description:
  13  *   This routine returns an integer that indicates if the number
  14  *   passed in is infinite (1) or is finite (0).
  15  *
  16  *****************************************************************/
  17
  18 #include "fdlibm.h"
  19 #include "zmath.h"
  20
  21 int
  22 _DEFUN (isinff, (float),
  23         float x)
  24 {
  25   __uint32_t wx;
  26   int exp;
  27
  28   GET_FLOAT_WORD (wx, x);
  29   exp = (wx & 0x7f800000) >> 23;
  30
  31   if ((exp == 0x7f8) && !(wx & 0xf0000))
  32     return (1);
  33   else
  34     return (0);
  35 }
  36
  37 #ifdef _DOUBLE_IS_32BITS
  38
  39 int
  40 _DEFUN (isinf, (double),
  41         double x)
  42 {
  43   return isinff ((float) x);
  44 }
  45
  46 #endif /* defined(_DOUBLE_IS_32BITS) */
  47
  48