newlib/libm/ld/s_lrint.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   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 <sys/cdefs.h>
  30 #include <fenv.h>
  31 #include <math.h>
  32
  33 #ifndef type
  34 __FBSDID("$FreeBSD$");
  35 #define type            double
  36 #define roundit         rint
  37 #define dtype           long
  38 #define fn              lrint
  39 #endif
  40
  41 /*
  42  * C99 says we should not raise a spurious inexact exception when an
  43  * invalid exception is raised.  Unfortunately, the set of inputs
  44  * that overflows depends on the rounding mode when 'dtype' has more
  45  * significant bits than 'type'.  Hence, we bend over backwards for the
  46  * sake of correctness; an MD implementation could be more efficient.
  47  */
  48 dtype
  49 fn(type x)
  50 {
  51         fenv_t env;
  52         dtype d;
  53
  54         feholdexcept(&env);
  55         d = (dtype)roundit(x);
  56 #if defined(FE_INVALID) && defined(FE_INEXACT)
  57         if (fetestexcept(FE_INVALID))
  58                 feclearexcept(FE_INEXACT);
  59 #endif
  60         feupdateenv(&env);
  61         return (d);
  62 }