/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2011 Nexenta Systems, Inc. All rights reserved. */ /* * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* * sinl(x) * Table look-up algorithm by K.C. Ng, November, 1989. * * kernel function: * __k_sinl ... sin function on [-pi/4,pi/4] * __k_cosl ... cos function on [-pi/4,pi/4] * __rem_pio2l ... argument reduction routine * * Method. * Let S and C denote the sin and cos respectively on [-PI/4, +PI/4]. * 1. Assume the argument x is reduced to y1+y2 = x-k*pi/2 in * [-pi/2 , +pi/2], and let n = k mod 4. * 2. Let S=S(y1+y2), C=C(y1+y2). Depending on n, we have * * n sin(x) cos(x) tan(x) * ---------------------------------------------------------- * 0 S C S/C * 1 C -S -C/S * 2 -S -C S/C * 3 -C S -C/S * ---------------------------------------------------------- * * Special cases: * Let trig be any of sin, cos, or tan. * trig(+-INF) is NaN, with signals; * trig(NaN) is that NaN; * * Accuracy: * computer TRIG(x) returns trig(x) nearly rounded. */ #pragma weak sinl = __sinl #include "libm.h" #include "longdouble.h" long double sinl(long double x) { long double y[2], z = 0.0L; int n, ix; ix = *(int *) &x; /* High word of x */ ix &= 0x7fffffff; if (ix <= 0x3ffe9220) /* |x| ~< pi/4 */ return (__k_sinl(x, z)); else if (ix >= 0x7fff0000) /* sin(Inf or NaN) is NaN */ return (x - x); else { /* argument reduction needed */ n = __rem_pio2l(x, y); switch (n & 3) { case 0: return (__k_sinl(y[0], y[1])); case 1: return (__k_cosl(y[0], y[1])); case 2: return (-__k_sinl(y[0], y[1])); case 3: return (-__k_cosl(y[0], y[1])); } } /* NOTREACHED */ return 0.0L; }