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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 <sys/cdefs.h>
     28 #include <limits.h>
     29 #include <fenv.h>
     30 #include <math.h>
     31 
     32 #ifndef type
     33 /* __FBSDID("$FreeBSD: src/lib/msun/src/s_lround.c,v 1.2 2005/04/08 00:52:16 das Exp $"); */
     34 #define type		double
     35 #define	roundit		round
     36 #define dtype		long
     37 #define	DTYPE_MIN	LONG_MIN
     38 #define	DTYPE_MAX	LONG_MAX
     39 #define	fn		lround
     40 #endif
     41 
     42 /*
     43  * If type has more precision than dtype, the endpoints dtype_(min|max) are
     44  * of the form xxx.5; they are "out of range" because lround() rounds away
     45  * from 0.  On the other hand, if type has less precision than dtype, then
     46  * all values that are out of range are integral, so we might as well assume
     47  * that everything is in range.  At compile time, INRANGE(x) should reduce to
     48  * two floating-point comparisons in the former case, or TRUE otherwise.
     49  */
     50 static const type dtype_min = DTYPE_MIN - 0.5;
     51 static const type dtype_max = DTYPE_MAX + 0.5;
     52 #define	INRANGE(x)	(dtype_max - DTYPE_MAX != 0.5 || \
     53 			 ((x) > dtype_min && (x) < dtype_max))
     54 
     55 dtype
     56 fn(type x)
     57 {
     58 
     59 	if (INRANGE(x)) {
     60 		x = roundit(x);
     61 		return ((dtype)x);
     62 	} else {
     63 		feraiseexcept(FE_INVALID);
     64 		return (DTYPE_MAX);
     65 	}
     66 }
     67