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

   1
   2 /* @(#)z_isinf.c 1.0 98/08/13 */
   3 /******************************************************************
   4  * isinf
   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 #ifndef _DOUBLE_IS_32BITS
  22
  23 int isinf (double x)
  24 {
  25   __uint32_t lx, hx;
  26   int exp;
  27
  28   EXTRACT_WORDS (hx, lx, x);
  29   exp = (hx & 0x7ff00000) >> 20;
  30
  31   if ((exp == 0x7ff) && ((hx & 0xf0000 || lx) == 0))
  32     return (1);
  33   else
  34     return (0);
  35 }
  36
  37 #endif /* _DOUBLE_IS_32BITS */