sysdeps/i386/fpu/s_isnanl.c

   1 /* s_isnanl.c -- long double version for i387 of s_isnan.c.
   2  * Conversion to long double by Ulrich Drepper,
   3  * Cygnus Support, drepper@cygnus.com.
   4  */
   5
   6 /*
   7  * ====================================================
   8  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   9  *
  10  * Developed at SunPro, a Sun Microsystems, Inc. business.
  11  * Permission to use, copy, modify, and distribute this
  12  * software is freely granted, provided that this notice
  13  * is preserved.
  14  * ====================================================
  15  */
  16
  17 #if defined(LIBM_SCCS) && !defined(lint)
  18 static char rcsid[] = "$NetBSD: $";
  19 #endif
  20
  21 /*
  22  * isnanl(x) returns 1 is x is nan, else 0;
  23  * no branching!
  24  */
  25
  26 #include <math.h>
  27 #include <math_private.h>
  28
  29 int __isnanl(long double x)
  30 {
  31         int32_t se,hx,lx;
  32         GET_LDOUBLE_WORDS(se,hx,lx,x);
  33         se = (se & 0x7fff) << 1;
  34         /* The additional & 0x7fffffff is required because Intel's
  35            extended format has the normally implicit 1 explicit
  36            present.  Sigh!  */
  37         lx |= hx & 0x7fffffff;
  38         se |= (u_int32_t)(lx|(-lx))>>31;
  39         se = 0xfffe - se;
  40         return (int)((u_int32_t)(se))>>16;
  41 }
  42 hidden_def (__isnanl)
  43 weak_alias (__isnanl, isnanl)