/* 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 <errno.h>

#include <math.h>

#include <math_private.h>

#include <libm-alias-ldouble.h>

long double __sinl(long double x)

{

	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 (i1 == 0 && i0 == 0x80000000)

	    __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]);

	    }

	}

}

libm_alias_ldouble (__sin, sin)