libm/s_finite.c

   1 /*
   2  * ====================================================
   3  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   4  *
   5  * Developed at SunPro, a Sun Microsystems, Inc. business.
   6  * Permission to use, copy, modify, and distribute this
   7  * software is freely granted, provided that this notice
   8  * is preserved.
   9  * ====================================================
  10  */
  11
  12 /*
  13  * finite(x) returns 1 is x is finite, else 0;
  14  * no branching!
  15  */
  16
  17 #include <features.h>
  18 /* Prevent math.h from defining a colliding inline */
  19 #undef __USE_EXTERN_INLINES
  20 #include "math.h"
  21 #include "math_private.h"
  22
  23 int __finite(double x)
  24 {
  25         u_int32_t hx;
  26
  27         GET_HIGH_WORD(hx, x);
  28         /* Finite numbers have at least one zero bit in exponent. */
  29         /* All other numbers will result in 0xffffffff after OR: */
  30         return (hx | 0x800fffff) != 0xffffffff;
  31 }
  32 libm_hidden_def(__finite)