xref: /openbsd-src/lib/libm/src/ld80/k_sinl.c (revision beb15867ad58c144f0b15621aba82cb13678cd97)
1*beb15867Skrw /*	$OpenBSD: k_sinl.c,v 1.2 2017/01/21 08:29:13 krw Exp $	*/
2390c8400Smartynas /* From: @(#)k_sin.c 1.3 95/01/18 */
3390c8400Smartynas /*
4390c8400Smartynas  * ====================================================
5390c8400Smartynas  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6390c8400Smartynas  * Copyright (c) 2008 Steven G. Kargl, David Schultz, Bruce D. Evans.
7390c8400Smartynas  *
8390c8400Smartynas  * Developed at SunSoft, a Sun Microsystems, Inc. business.
9390c8400Smartynas  * Permission to use, copy, modify, and distribute this
10390c8400Smartynas  * software is freely granted, provided that this notice
11390c8400Smartynas  * is preserved.
12390c8400Smartynas  * ====================================================
13390c8400Smartynas  */
14390c8400Smartynas 
15390c8400Smartynas /*
16390c8400Smartynas  * ld80 version of k_sin.c.  See ../k_sin.c for most comments.
17390c8400Smartynas  */
18390c8400Smartynas 
19390c8400Smartynas #include "math_private.h"
20390c8400Smartynas 
21390c8400Smartynas static const double
22390c8400Smartynas half =  0.5;
23390c8400Smartynas 
24390c8400Smartynas /*
25390c8400Smartynas  * Domain [-0.7854, 0.7854], range ~[-1.89e-22, 1.915e-22]
26390c8400Smartynas  * |sin(x)/x - s(x)| < 2**-72.1
27390c8400Smartynas  *
28390c8400Smartynas  * See ../ld80/k_cosl.c for more details about the polynomial.
29390c8400Smartynas  */
30390c8400Smartynas #if defined(__amd64__) || defined(__i386__)
31390c8400Smartynas /* Long double constants are slow on these arches, and broken on i386. */
32390c8400Smartynas static const volatile double
33390c8400Smartynas S1hi = -0.16666666666666666,		/* -0x15555555555555.0p-55 */
34390c8400Smartynas S1lo = -9.2563760475949941e-18;		/* -0x15580000000000.0p-109 */
35390c8400Smartynas #define	S1	((long double)S1hi + S1lo)
36390c8400Smartynas #else
37390c8400Smartynas static const long double
38390c8400Smartynas S1 = -0.166666666666666666671L;		/* -0xaaaaaaaaaaaaaaab.0p-66 */
39390c8400Smartynas #endif
40390c8400Smartynas 
41390c8400Smartynas static const double
42390c8400Smartynas S2 =  0.0083333333333333332,		/*  0x11111111111111.0p-59 */
43390c8400Smartynas S3 = -0.00019841269841269427,		/* -0x1a01a01a019f81.0p-65 */
44390c8400Smartynas S4 =  0.0000027557319223597490,		/*  0x171de3a55560f7.0p-71 */
45390c8400Smartynas S5 = -0.000000025052108218074604,	/* -0x1ae64564f16cad.0p-78 */
46390c8400Smartynas S6 =  1.6059006598854211e-10,		/*  0x161242b90243b5.0p-85 */
47390c8400Smartynas S7 = -7.6429779983024564e-13,		/* -0x1ae42ebd1b2e00.0p-93 */
48390c8400Smartynas S8 =  2.6174587166648325e-15;		/*  0x179372ea0b3f64.0p-101 */
49390c8400Smartynas 
50390c8400Smartynas long double
__kernel_sinl(long double x,long double y,int iy)51390c8400Smartynas __kernel_sinl(long double x, long double y, int iy)
52390c8400Smartynas {
53390c8400Smartynas 	long double z,r,v;
54390c8400Smartynas 
55390c8400Smartynas 	z	=  x*x;
56390c8400Smartynas 	v	=  z*x;
57390c8400Smartynas 	r	=  S2+z*(S3+z*(S4+z*(S5+z*(S6+z*(S7+z*S8)))));
58390c8400Smartynas 	if(iy==0) return x+v*(S1+z*r);
59390c8400Smartynas 	else      return x-((z*(half*y-v*r)-y)-v*S1);
60390c8400Smartynas }
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