compiler/stdc/math/s_isinf.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  */
  27
  28 /*
  29  * isinf(x) returns 1 if x is inf, else 0;
  30  * no branching!
  31  */
  32
  33 #include "math.h"
  34 #include "fpmath.h"
  35 #include "math_private.h"
  36
  37 int
  38 __isinf(double d)
  39 {
  40         union IEEEd2bits u;
  41
  42         u.d = d;
  43         return (u.bits.exp == 2047 && u.bits.manl == 0 && u.bits.manh == 0);
  44 }
  45
  46 int
  47 __isinff(float f)
  48 {
  49         union IEEEf2bits u;
  50
  51         u.f = f;
  52         return (u.bits.exp == 255 && u.bits.man == 0);
  53 }
  54
  55 int
  56 __isinfl(long double e)
  57 {
  58         union IEEEl2bits u;
  59
  60         u.e = e;
  61         mask_nbit_l(u);
  62         return (u.bits.exp == 32767 && u.bits.manl == 0 && u.bits.manh == 0);
  63 }