lib/libm/src/s_lrintl.c

   1 /*      $OpenBSD: s_lrintl.c,v 1.2 2012/12/05 23:20:04 deraadt Exp $    */
   2
   3 /*-
   4  * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <fenv.h>
  30 #include <math.h>
  31
  32 #ifndef type
  33 #if 0
  34 __FBSDID("$FreeBSD: src/lib/msun/src/s_lrint.c,v 1.1 2005/01/11 23:12:55 das Exp $");
  35 #endif
  36 #define type            long double
  37 #define roundit         rintl
  38 #define dtype           long
  39 #define fn              lrintl
  40 #endif
  41
  42 /*
  43  * C99 says we should not raise a spurious inexact exception when an
  44  * invalid exception is raised.  Unfortunately, the set of inputs
  45  * that overflows depends on the rounding mode when 'dtype' has more
  46  * significant bits than 'type'.  Hence, we bend over backwards for the
  47  * sake of correctness; an MD implementation could be more efficient.
  48  */
  49 dtype
  50 fn(type x)
  51 {
  52         fenv_t env;
  53         dtype d;
  54
  55         feholdexcept(&env);
  56         d = (dtype)roundit(x);
  57         if (fetestexcept(FE_INVALID))
  58                 feclearexcept(FE_INEXACT);
  59         feupdateenv(&env);
  60         return (d);
  61 }