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 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 23 */ 24 /* 25 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 26 * Use is subject to license terms. 27 */ 28 29 /* 30 * atan2pi(x) = atan2(x)/pi 31 */ 32 33 #include "libm.h" 34 35 static const double invpi = 0.3183098861837906715377675; 36 37 double 38 atan2pi(double y, double x) { 39 int ix, iy; 40 41 if (x == 0.0 && y == 0.0) { 42 ix = ((int *)&x)[HIWORD]; 43 iy = ((int *)&y)[HIWORD]; 44 if (ix >= 0) 45 return (y); 46 return ((iy >= 0)? 1.0 : -1.0); 47 } 48 return (atan2(y, x) * invpi); 49 } 50