1 /*- 2 * Copyright (c) 2004 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 <sys/cdefs.h> 28 __RCSID("$NetBSD: s_fmax.c,v 1.2 2010/03/08 01:05:20 snj Exp $"); 29 #ifdef notdef 30 __FBSDID("$FreeBSD: src/lib/msun/src/s_fmax.c,v 1.1 2004/06/30 07:04:01 das Exp $"); 31 #endif 32 33 #include <math.h> 34 35 #include <machine/ieee.h> 36 37 double 38 fmax(double x, double y) 39 { 40 union ieee_double_u u[2]; 41 42 u[0].dblu_d = x; 43 u[1].dblu_d = y; 44 45 /* Check for NaNs to avoid raising spurious exceptions. */ 46 if (u[0].dblu_dbl.dbl_exp == DBL_EXP_INFNAN && 47 (u[0].dblu_dbl.dbl_frach | u[0].dblu_dbl.dbl_fracl) != 0) 48 return (y); 49 if (u[1].dblu_dbl.dbl_exp == DBL_EXP_INFNAN && 50 (u[1].dblu_dbl.dbl_frach | u[1].dblu_dbl.dbl_fracl) != 0) 51 return (x); 52 53 /* Handle comparisons of signed zeroes. */ 54 if (u[0].dblu_dbl.dbl_sign != u[1].dblu_dbl.dbl_sign) 55 return (u[u[0].dblu_dbl.dbl_sign].dblu_d); 56 57 return (x > y ? x : y); 58 } 59