newlib-cygwin/newlib/libm/ld/s_lround.c

73 lines
2.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2005 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 <sys/cdefs.h>
#include <limits.h>
#include <fenv.h>
#include <math.h>
#ifndef type
__FBSDID("$FreeBSD$");
#define type double
#define roundit round
#define dtype long
#define DTYPE_MIN LONG_MIN
#define DTYPE_MAX LONG_MAX
#define fn lround
#endif
/*
* If type has more precision than dtype, the endpoints dtype_(min|max) are
* of the form xxx.5; they are "out of range" because lround() rounds away
* from 0. On the other hand, if type has less precision than dtype, then
* all values that are out of range are integral, so we might as well assume
* that everything is in range. At compile time, INRANGE(x) should reduce to
* two floating-point comparisons in the former case, or TRUE otherwise.
*/
static const type type_min = (type)DTYPE_MIN;
static const type type_max = (type)DTYPE_MAX;
static const type dtype_min = (type)DTYPE_MIN - 0.5;
static const type dtype_max = (type)DTYPE_MAX + 0.5;
#define INRANGE(x) (dtype_max - type_max != 0.5 || \
((x) > dtype_min && (x) < dtype_max))
dtype
fn(type x)
{
if (INRANGE(x)) {
x = roundit(x);
return ((dtype)x);
} else {
#ifdef FE_INVALID
feraiseexcept(FE_INVALID);
#endif
return (DTYPE_MAX);
}
}