s_lround.c revision 1.1
1/*- 2 * Copyright (c) 2005 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#include "namespace.h" 28 29#include <sys/cdefs.h> 30#include <limits.h> 31#include <fenv.h> 32#include <math.h> 33 34#ifndef stype 35#ifdef __FreeBSD__ 36__FBSDID("$FreeBSD: head/lib/msun/src/s_lround.c 144770 2005-04-08 00:52:16Z das $"); 37#else 38__RCSID("$NetBSD: s_lround.c,v 1.1 2017/05/06 18:03:24 christos Exp $"); 39#endif 40#define stype double 41#define roundit round 42#define dtype long 43#define DTYPE_MIN LONG_MIN 44#define DTYPE_MAX LONG_MAX 45#define fn lround 46#endif 47 48/* 49 * If stype has more precision than dtype, the endpoints dtype_(min|max) are 50 * of the form xxx.5; they are "out of range" because lround() rounds away 51 * from 0. On the other hand, if stype has less precision than dtype, then 52 * all values that are out of range are integral, so we might as well assume 53 * that everything is in range. At compile time, INRANGE(x) should reduce to 54 * two floating-point comparisons in the former case, or TRUE otherwise. 55 */ 56static const stype dtype_min = DTYPE_MIN - 0.5; 57static const stype dtype_max = DTYPE_MAX + 0.5; 58#define INRANGE(x) (dtype_max - DTYPE_MAX != 0.5 || \ 59 ((x) > dtype_min && (x) < dtype_max)) 60 61dtype 62fn(stype x) 63{ 64 65 if (INRANGE(x)) { 66 x = roundit(x); 67 return ((dtype)x); 68 } else { 69 feraiseexcept(FE_INVALID); 70 return (DTYPE_MAX); 71 } 72} 73