xref: /minix3/lib/libm/src/s_sinf.c (revision 2fe8fb192fe7e8720e3e7a77f928da545e872a6a)

/* s_sinf.c -- float version of s_sin.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@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.
 * ====================================================
 */

#include <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
__RCSID("$NetBSD: s_sinf.c,v 1.8 2007/08/20 16:01:39 drochner Exp $");
#endif

#include "namespace.h"
#include "math.h"
#include "math_private.h"

#if 0 /* notyet */
#ifdef __weak_alias
__weak_alias(sinf, _sinf)
#endif
#endif

float
sinf(float x)
{
	float y[2],z=0.0;
	int32_t n, ix;

	GET_FLOAT_WORD(ix,x);

    /* |x| ~< pi/4 */
	ix &= 0x7fffffff;
	if(ix <= 0x3f490fd8) return __kernel_sinf(x,z,0);

    /* sin(Inf or NaN) is NaN */
	else if (ix>=0x7f800000) return x-x;

    /* argument reduction needed */
	else {
	    n = __ieee754_rem_pio2f(x,y);
	    switch(n&3) {
		case 0: return  __kernel_sinf(y[0],y[1],1);
		case 1: return  __kernel_cosf(y[0],y[1]);
		case 2: return -__kernel_sinf(y[0],y[1],1);
		default:
			return -__kernel_cosf(y[0],y[1]);
	    }
	}
}