xref: /netbsd/lib/libm/src/k_sinf.c (revision bf9ec67e)
1 /* k_sinf.c -- float version of k_sin.c
2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3  */
4 
5 /*
6  * ====================================================
7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8  *
9  * Developed at SunPro, a Sun Microsystems, Inc. business.
10  * Permission to use, copy, modify, and distribute this
11  * software is freely granted, provided that this notice
12  * is preserved.
13  * ====================================================
14  */
15 
16 #include <sys/cdefs.h>
17 #if defined(LIBM_SCCS) && !defined(lint)
18 __RCSID("$NetBSD: k_sinf.c,v 1.7 2002/05/26 22:01:53 wiz Exp $");
19 #endif
20 
21 #include "math.h"
22 #include "math_private.h"
23 
24 static const float
25 half =  5.0000000000e-01,/* 0x3f000000 */
26 S1  = -1.6666667163e-01, /* 0xbe2aaaab */
27 S2  =  8.3333337680e-03, /* 0x3c088889 */
28 S3  = -1.9841270114e-04, /* 0xb9500d01 */
29 S4  =  2.7557314297e-06, /* 0x3638ef1b */
30 S5  = -2.5050759689e-08, /* 0xb2d72f34 */
31 S6  =  1.5896910177e-10; /* 0x2f2ec9d3 */
32 
33 float
34 __kernel_sinf(float x, float y, int iy)
35 {
36 	float z,r,v;
37 	int32_t ix;
38 	GET_FLOAT_WORD(ix,x);
39 	ix &= 0x7fffffff;			/* high word of x */
40 	if(ix<0x32000000)			/* |x| < 2**-27 */
41 	   {if((int)x==0) return x;}		/* generate inexact */
42 	z	=  x*x;
43 	v	=  z*x;
44 	r	=  S2+z*(S3+z*(S4+z*(S5+z*S6)));
45 	if(iy==0) return x+v*(S1+z*r);
46 	else      return x-((z*(half*y-v*r)-y)-v*S1);
47 }
48