sysdeps/ieee754/dbl-64/wordsize-64/s_isnan.c

   1 /* @(#)s_isnan.c 5.1 93/09/24 */
   2 /*
   3  * ====================================================
   4  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   5  *
   6  * Developed at SunPro, a Sun Microsystems, Inc. business.
   7  * Permission to use, copy, modify, and distribute this
   8  * software is freely granted, provided that this notice
   9  * is preserved.
  10  * ====================================================
  11  */
  12
  13 /*
  14  * isnan(x) returns 1 is x is nan, else 0;
  15  * no branching!
  16  */
  17
  18 #include <math.h>
  19 #include <math_private.h>
  20
  21 #undef __isnan
  22 int __isnan(double x)
  23 {
  24         int64_t hx;
  25         EXTRACT_WORDS64(hx,x);
  26         hx &= UINT64_C(0x7fffffffffffffff);
  27         hx = UINT64_C(0x7ff0000000000000) - hx;
  28         return (int)(((uint64_t)hx)>>63);
  29 }
  30 hidden_def (__isnan)
  31 weak_alias (__isnan, isnan)
  32 #ifdef NO_LONG_DOUBLE
  33 strong_alias (__isnan, __isnanl)
  34 weak_alias (__isnan, isnanl)
  35 #endif