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 #include "libm.h" 30 31 static const double invpi = 0.3183098861837906715377675; 32 33 float 34 atan2pif(float y, float x) { 35 int ix, iy, hx, hy; 36 37 ix = *(int *)&x; 38 iy = *(int *)&y; 39 hx = ix & ~0x80000000; 40 hy = iy & ~0x80000000; 41 if (hx > 0x7f800000 || hy > 0x7f800000) /* x or y is nan */ 42 return (x * y); 43 if ((hx | hy) == 0) { 44 /* x and y are both zero */ 45 if (ix == 0) 46 return (y); 47 return ((iy == 0)? 1.0f : -1.0f); 48 } 49 return ((float)(invpi * atan2((double)y, (double)x))); 50 } 51