1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 #include <float.h> 31 #include <math.h> 32 33 #include "fpmath.h" 34 35 #ifdef USE_BUILTIN_FMAX 36 double 37 fmax(double x, double y) 38 { 39 return (__builtin_fmax(x, y)); 40 } 41 #else 42 double 43 fmax(double x, double y) 44 { 45 union IEEEd2bits u[2]; 46 47 u[0].d = x; 48 u[1].d = y; 49 50 /* Check for NaNs to avoid raising spurious exceptions. */ 51 if (u[0].bits.exp == 2047 && (u[0].bits.manh | u[0].bits.manl) != 0) 52 return (y); 53 if (u[1].bits.exp == 2047 && (u[1].bits.manh | u[1].bits.manl) != 0) 54 return (x); 55 56 /* Handle comparisons of signed zeroes. */ 57 if (u[0].bits.sign != u[1].bits.sign) 58 return (u[u[0].bits.sign].d); 59 60 return (x > y ? x : y); 61 } 62 #endif 63 64 #if (LDBL_MANT_DIG == 53) 65 __weak_reference(fmax, fmaxl); 66 #endif 67