1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 24 */ 25 /* 26 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 30 #if defined(ELFOBJ) 31 #pragma weak fmax = __fmax 32 #endif 33 34 /* 35 * fmax(x,y) returns the larger of x and y. If just one of the 36 * arguments is NaN, fmax returns the other argument. If both 37 * arguments are NaN, fmax returns NaN. 38 * 39 * See fmaxf.c for a discussion of implementation trade-offs. 40 */ 41 42 #include "libm.h" /* for isgreaterequal macro */ 43 #include <fenv.h> 44 45 double 46 __fmax(double x, double y) { 47 union { 48 unsigned i[2]; 49 double d; 50 } xx, yy; 51 unsigned s; 52 53 /* if y is nan, replace it by x */ 54 if (y != y) 55 y = x; 56 57 /* if x is nan, replace it by y */ 58 if (x != x) 59 x = y; 60 61 /* At this point, x and y are either both numeric, or both NaN */ 62 if (!isnan(x) && !isgreaterequal(x, y)) 63 x = y; 64 65 /* 66 * clear the sign of the result if either x or y has its sign clear 67 */ 68 xx.d = x; 69 yy.d = y; 70 #if defined(__sparc) 71 s = ~(xx.i[0] & yy.i[0]) & 0x80000000; 72 xx.i[0] &= ~s; 73 #elif defined(__x86) 74 s = ~(xx.i[1] & yy.i[1]) & 0x80000000; 75 xx.i[1] &= ~s; 76 #else 77 #error Unknown architecture 78 #endif 79 80 return (xx.d); 81 } 82