s_fmax.c (1878B)
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 <math.h> 28 29 #include "math_private.h" 30 31 double 32 fmax(double x, double y) 33 { 34 union IEEEd2bits u[2]; 35 36 u[0].d = x; 37 u[1].d = y; 38 39 /* Check for NaNs to avoid raising spurious exceptions. */ 40 if (u[0].bits.exp == 2047 && (u[0].bits.manh | u[0].bits.manl) != 0) 41 return (y); 42 if (u[1].bits.exp == 2047 && (u[1].bits.manh | u[1].bits.manl) != 0) 43 return (x); 44 45 /* Handle comparisons of signed zeroes. */ 46 if (u[0].bits.sign != u[1].bits.sign) 47 return (u[u[0].bits.sign].d); 48 49 return (x > y ? x : y); 50 }