lib/libc/gen/isnan.c

   1 /*-
   2  * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: head/lib/libc/gen/isnan.c 242894 2012-11-11 13:28:04Z dim $
  27  */
  28
  29 #include <math.h>
  30
  31 #include "fpmath.h"
  32
  33 /*
  34  * XXX These routines belong in libm, but they must remain in libc for
  35  *     binary compat until we can bump libm's major version number.
  36  */
  37
  38 int
  39 __isnan(double d)
  40 {
  41         union IEEEd2bits u;
  42
  43         u.d = d;
  44         return (u.bits.exp == 2047 && (u.bits.manl != 0 || u.bits.manh != 0));
  45 }
  46
  47 int
  48 __isnanf(float f)
  49 {
  50         union IEEEf2bits u;
  51
  52         u.f = f;
  53         return (u.bits.exp == 255 && u.bits.man != 0);
  54 }
  55
  56 __weak_reference(__isnan, isnan);
  57 __weak_reference(__isnanf, isnanf);