lib/libc/gnu/ieee_float/isnan.c

   1 /*
   2 libc/ieee_float/isnan.c
   3
   4 Created:        Oct 14, 1993 by Philip Homburg <philip@cs.vu.nl>
   5
   6 Implementation of isnan that directly tests the bits in an ieee float
   7 */
   8
   9 #define _MINIX_SOURCE
  10
  11 #include <sys/types.h>
  12
  13 #include "ieee_float.h"
  14
  15 int isnan(value)
  16 double value;
  17 {
  18         struct f64 *f64p;
  19         int exp;
  20
  21         f64p= (struct f64 *)&value;
  22         exp= F64_GET_EXP(f64p);
  23         if (exp != F64_EXP_MAX)
  24                 return 0;
  25         return F64_GET_MANT_LOW(f64p) != 0 || F64_GET_MANT_HIGH(f64p) != 0;
  26 }
  27
  28 /*
  29  * $PchId: isnan.c,v 1.3 1996/02/22 21:01:39 philip Exp $
  30  */