xref: /netbsd-src/lib/libm/src/k_sinf.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
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 1.5 1997/10/09 11:30:30 lukem Exp $");
19 #endif
20 
21 #include "math.h"
22 #include "math_private.h"
23 
24 #ifdef __STDC__
25 static const float
26 #else
27 static float
28 #endif
29 half =  5.0000000000e-01,/* 0x3f000000 */
30 S1  = -1.6666667163e-01, /* 0xbe2aaaab */
31 S2  =  8.3333337680e-03, /* 0x3c088889 */
32 S3  = -1.9841270114e-04, /* 0xb9500d01 */
33 S4  =  2.7557314297e-06, /* 0x3638ef1b */
34 S5  = -2.5050759689e-08, /* 0xb2d72f34 */
35 S6  =  1.5896910177e-10; /* 0x2f2ec9d3 */
36 
37 #ifdef __STDC__
38 	float __kernel_sinf(float x, float y, int iy)
39 #else
40 	float __kernel_sinf(x, y, iy)
41 	float x,y; int iy;		/* iy=0 if y is zero */
42 #endif
43 {
44 	float z,r,v;
45 	int32_t ix;
46 	GET_FLOAT_WORD(ix,x);
47 	ix &= 0x7fffffff;			/* high word of x */
48 	if(ix<0x32000000)			/* |x| < 2**-27 */
49 	   {if((int)x==0) return x;}		/* generate inexact */
50 	z	=  x*x;
51 	v	=  z*x;
52 	r	=  S2+z*(S3+z*(S4+z*(S5+z*S6)));
53 	if(iy==0) return x+v*(S1+z*r);
54 	else      return x-((z*(half*y-v*r)-y)-v*S1);
55 }
56