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      1 /*-
      2  * Copyright (c) 2005 David Schultz <das (at) 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  */
     56 static const stype dtype_min = DTYPE_MIN - 0.5;
     57 static 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 
     61 dtype
     62 fn(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