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 #pragma weak fmax = __fmax 31 32 /* 33 * fmax(x,y) returns the larger of x and y. If just one of the 34 * arguments is NaN, fmax returns the other argument. If both 35 * arguments are NaN, fmax returns NaN. 36 * 37 * See fmaxf.c for a discussion of implementation trade-offs. 38 */ 39 40 #include "libm.h" /* for isgreaterequal macro */ 41 #include <fenv.h> 42 43 double 44 __fmax(double x, double y) { 45 union { 46 unsigned i[2]; 47 double d; 48 } xx, yy; 49 unsigned s; 50 51 /* if y is nan, replace it by x */ 52 if (y != y) 53 y = x; 54 55 /* if x is nan, replace it by y */ 56 if (x != x) 57 x = y; 58 59 /* At this point, x and y are either both numeric, or both NaN */ 60 if (!isnan(x) && !isgreaterequal(x, y)) 61 x = y; 62 63 /* 64 * clear the sign of the result if either x or y has its sign clear 65 */ 66 xx.d = x; 67 yy.d = y; 68 #if defined(__sparc) 69 s = ~(xx.i[0] & yy.i[0]) & 0x80000000; 70 xx.i[0] &= ~s; 71 #elif defined(__x86) 72 s = ~(xx.i[1] & yy.i[1]) & 0x80000000; 73 xx.i[1] &= ~s; 74 #else 75 #error Unknown architecture 76 #endif 77 78 return (xx.d); 79 } 80