/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <fenv.h>
#include <math.h>
#include <float.h>

#pragma STDC FENV_ACCESS ON

/*
 * We save and restore the floating-point environment to avoid raising
 * an inexact exception.  We can get away with using fesetenv()
 * instead of feclearexcept()/feupdateenv() to restore the environment
 * because the only exception defined for rint() is overflow, and
 * rounding can't overflow as long as emax >= p.
 *
 * FENV_ACCESS ON is required so the compiler does not move the rounding
 * (which it may inline as a hardware round-to-integer instruction) across
 * the fegetenv()/fesetenv() calls.  Without it, clang hoists the rounding
 * before fegetenv() on the binary128 path, so the saved environment already
 * carries the inexact flag and fesetenv() restores it, leaking the exception.
 * The volatile keyword on ret is kept as a belt-and-suspenders guard.
 */
#define DECL(type, fn, rint)    \
type                            \
fn(type x)                      \
{                               \
        volatile type ret;      \
        fenv_t env;             \
                                \
        fegetenv(&env);         \
        ret = rint(x);          \
        fesetenv(&env);         \
        return (ret);           \
}

DECL(double, nearbyint, rint)
DECL(float, nearbyintf, rintf)
DECL(long double, nearbyintl, rintl)

#if LDBL_MANT_DIG == 113
__weak_reference(nearbyintl, nearbyintf128);
#endif