/* s_sinl.c -- long double version of s_sin.c. * Conversion to long double by Ulrich Drepper, * Cygnus Support, drepper@cygnus.com. */ /* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice * is preserved. * ==================================================== */ #if defined(LIBM_SCCS) && !defined(lint) static char rcsid[] = "$NetBSD: $"; #endif /* sinl(x) * Return sine function of x. * * kernel function: * __kernel_sinl ... sine function on [-pi/4,pi/4] * __kernel_cosl ... cose function on [-pi/4,pi/4] * __ieee754_rem_pio2l ... argument reduction routine * * Method. * Let S,C and T denote the sin, cos and tan respectively on * [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2 * in [-pi/4 , +pi/4], and let n = k mod 4. * We have * * n sin(x) cos(x) tan(x) * ---------------------------------------------------------- * 0 S C T * 1 C -S -1/T * 2 -S -C T * 3 -C S -1/T * ---------------------------------------------------------- * * Special cases: * Let trig be any of sin, cos, or tan. * trig(+-INF) is NaN, with signals; * trig(NaN) is that NaN; * * Accuracy: * TRIG(x) returns trig(x) nearly rounded */ #include #include "math.h" #include "math_private.h" #ifdef __STDC__ long double __sinl(long double x) #else long double __sinl(x) long double x; #endif { long double y[2],z=0.0; int32_t n, se, i0, i1; /* High word of x. */ GET_LDOUBLE_WORDS(se,i0,i1,x); /* |x| ~< pi/4 */ se &= 0x7fff; if(se < 0x3ffe || (se == 0x3ffe && i0 <= 0xc90fdaa2)) return __kernel_sinl(x,z,0); /* sin(Inf or NaN) is NaN */ else if (se==0x7fff) { if ((i0 | i1) == 0) __set_errno (EDOM); return x-x; } /* argument reduction needed */ else { n = __ieee754_rem_pio2l(x,y); switch(n&3) { case 0: return __kernel_sinl(y[0],y[1],1); case 1: return __kernel_cosl(y[0],y[1]); case 2: return -__kernel_sinl(y[0],y[1],1); default: return -__kernel_cosl(y[0],y[1]); } } } weak_alias (__sinl, sinl)