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      1 /*-
      2  * Copyright (c) 2004 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 __RCSID("$NetBSD: s_fmaxl.c,v 1.4 2013/11/29 22:16:10 joerg Exp $");
     29 #ifdef notdef
     30 __FBSDID("$FreeBSD: src/lib/msun/src/s_fmaxl.c,v 1.1 2004/06/30 07:04:01 das Exp $");
     31 #endif
     32 
     33 #include <string.h>
     34 #include <math.h>
     35 
     36 #include <machine/ieee.h>
     37 #ifdef __HAVE_LONG_DOUBLE
     38 long double
     39 fmaxl(long double x, long double y)
     40 {
     41 	union ieee_ext_u u[2];
     42 
     43 	memset(&u, 0, sizeof u);
     44 	u[0].extu_ld = x;
     45 	u[0].extu_ext.ext_frach &= ~0x80000000;
     46 	u[1].extu_ld = y;
     47 	u[1].extu_ext.ext_frach &= ~0x80000000;
     48 
     49 	/* Check for NaNs to avoid raising spurious exceptions. */
     50 	if (u[0].extu_ext.ext_exp == EXT_EXP_INFNAN &&
     51 	    (u[0].extu_ext.ext_frach | u[0].extu_ext.ext_fracl) != 0)
     52 		return (y);
     53 	if (u[1].extu_ext.ext_exp == EXT_EXP_INFNAN &&
     54 	    (u[1].extu_ext.ext_frach | u[1].extu_ext.ext_fracl) != 0)
     55 		return (x);
     56 
     57 	/* Handle comparisons of ext_signed zeroes. */
     58 	if (u[0].extu_ext.ext_sign != u[1].extu_ext.ext_sign)
     59 		return (u[0].extu_ext.ext_sign ? y : x);
     60 
     61 	return (x > y ? x : y);
     62 }
     63 #endif
     64