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 /* 31 * sincosl(x) 32 * Table look-up algorithm by K.C. Ng, November, 1989. 33 * 34 * kernel function: 35 * __k_sincosl ... sin and cos function on [-pi/4,pi/4] 36 * __rem_pio2l ... argument reduction routine 37 * 38 * Method. 39 * Let S and C denote the sin and cos respectively on [-PI/4, +PI/4]. 40 * 1. Assume the argument x is reduced to y1+y2 = x-k*pi/2 in 41 * [-pi/2 , +pi/2], and let n = k mod 4. 42 * 2. Let S=S(y1+y2), C=C(y1+y2). Depending on n, we have 43 * 44 * n sin(x) cos(x) tan(x) 45 * ---------------------------------------------------------- 46 * 0 S C S/C 47 * 1 C -S -C/S 48 * 2 -S -C S/C 49 * 3 -C S -C/S 50 * ---------------------------------------------------------- 51 * 52 * Special cases: 53 * Let trig be any of sin, cos, or tan. 54 * trig(+-INF) is NaN, with signals; 55 * trig(NaN) is that NaN; 56 * 57 * Accuracy: 58 * computer TRIG(x) returns trig(x) nearly rounded. 59 */ 60 61 #pragma weak __sincosl = sincosl 62 63 #include "libm.h" 64 #include "longdouble.h" 65 66 void 67 sincosl(long double x, long double *s, long double *c) { 68 long double y[2], z = 0.0L; 69 int n, ix; 70 71 ix = *(int *) &x; /* High word of x */ 72 73 /* |x| ~< pi/4 */ 74 ix &= 0x7fffffff; 75 if (ix <= 0x3ffe9220) 76 *s = __k_sincosl(x, z, c); 77 else if (ix >= 0x7fff0000) 78 *s = *c = x - x; /* trig(Inf or NaN) is NaN */ 79 else { /* argument reduction needed */ 80 n = __rem_pio2l(x, y); 81 switch (n & 3) { 82 case 0: 83 *s = __k_sincosl(y[0], y[1], c); 84 break; 85 case 1: 86 *c = -__k_sincosl(y[0], y[1], s); 87 break; 88 case 2: 89 *s = -__k_sincosl(y[0], y[1], c); 90 *c = -*c; 91 break; 92 case 3: 93 *c = __k_sincosl(y[0], y[1], s); 94 *s = -*s; 95 break; 96 } 97 } 98 } 99