xref: /dragonfly/contrib/openbsd_libm/src/k_sinf.c (revision 0db87cb7)
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 "math.h"
17 #include "math_private.h"
18 
19 static const float
20 half =  5.0000000000e-01,/* 0x3f000000 */
21 S1  = -1.6666667163e-01, /* 0xbe2aaaab */
22 S2  =  8.3333337680e-03, /* 0x3c088889 */
23 S3  = -1.9841270114e-04, /* 0xb9500d01 */
24 S4  =  2.7557314297e-06, /* 0x3638ef1b */
25 S5  = -2.5050759689e-08, /* 0xb2d72f34 */
26 S6  =  1.5896910177e-10; /* 0x2f2ec9d3 */
27 
28 float
29 __kernel_sinf(float x, float y, int iy)
30 {
31 	float z,r,v;
32 	int32_t ix;
33 	GET_FLOAT_WORD(ix,x);
34 	ix &= 0x7fffffff;			/* high word of x */
35 	if(ix<0x32000000)			/* |x| < 2**-27 */
36 	   {if((int)x==0) return x;}		/* generate inexact */
37 	z	=  x*x;
38 	v	=  z*x;
39 	r	=  S2+z*(S3+z*(S4+z*(S5+z*S6)));
40 	if(iy==0) return x+v*(S1+z*r);
41 	else      return x-((z*(half*y-v*r)-y)-v*S1);
42 }
43