1  /* s_isnanl.c -- long double version for i387 of s_isnan.c.
       2   */
       3  
       4  /*
       5   * ====================================================
       6   * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
       7   *
       8   * Developed at SunPro, a Sun Microsystems, Inc. business.
       9   * Permission to use, copy, modify, and distribute this
      10   * software is freely granted, provided that this notice
      11   * is preserved.
      12   * ====================================================
      13   */
      14  
      15  #if defined(LIBM_SCCS) && !defined(lint)
      16  static char rcsid[] = "$NetBSD: $";
      17  #endif
      18  
      19  /*
      20   * isnanl(x) returns 1 is x is nan, else 0;
      21   * no branching!
      22   */
      23  
      24  #include <math.h>
      25  #include <math_private.h>
      26  
      27  int __isnanl(long double x)
      28  {
      29  	int32_t se,hx,lx,pn;
      30  	GET_LDOUBLE_WORDS(se,hx,lx,x);
      31  	se = (se & 0x7fff) << 1;
      32  	/* Detect pseudo-normal numbers, i.e. exponent is non-zero and the top
      33  	   bit of the significand is not set.   */
      34  	pn = (uint32_t)((~hx & 0x80000000) & (se|(-se)))>>31;
      35  	/* Clear the significand bit when computing mantissa.  */
      36  	lx |= hx & 0x7fffffff;
      37  	se |= (uint32_t)(lx|(-lx))>>31;
      38  	se = 0xfffe - se;
      39  
      40  	return (int)(((uint32_t)(se)) >> 16) | pn;
      41  }
      42  hidden_def (__isnanl)
      43  weak_alias (__isnanl, isnanl)