libquadmath/math/isnanq.c

   1 /* s_isnanl.c -- long double version of s_isnan.c.
   2  * Conversion to long double by Jakub Jelinek, jj@ultra.linux.cz.
   3  */
   4
   5 /*
   6  * ====================================================
   7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   8  *
   9  * Developed at SunPro, a Sun Microsystems, Inc. business.
  10  * Permission to use, copy, modify, and distribute this
  11  * software is freely granted, provided that this notice
  12  * is preserved.
  13  * ====================================================
  14  */
  15
  16 #if defined(LIBM_SCCS) && !defined(lint)
  17 static char rcsid[] = "$NetBSD: $";
  18 #endif
  19
  20 /*
  21  * isnanq(x) returns 1 is x is nan, else 0;
  22  * no branching!
  23  */
  24
  25 #include "quadmath-imp.h"
  26
  27 int isnanq(__float128 x)
  28 {
  29         int64_t hx,lx;
  30         GET_FLT128_WORDS64(hx,lx,x);
  31         hx &= 0x7fffffffffffffffLL;
  32         hx |= (uint64_t)(lx|(-lx))>>63;
  33         hx = 0x7fff000000000000LL - hx;
  34         return (int)((uint64_t)hx>>63);
  35 }