1 /* $OpenBSD: k_sinl.c,v 1.1 2008/12/09 20:00:35 martynas Exp $ */
2 /* From: @(#)k_sin.c 1.3 95/01/18 */
3 /*
4 * ====================================================
5 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 * Copyright (c) 2008 Steven G. Kargl, David Schultz, Bruce D. Evans.
7 *
8 * Developed at SunSoft, a Sun Microsystems, Inc. business.
9 * Permission to use, copy, modify, and distribute this
10 * software is freely granted, provided that this notice
11 * is preserved.
12 * ====================================================
13 */
14
15 /*
16 * ld80 version of k_sin.c. See ../k_sin.c for most comments.
17 */
18
19 #include "math_private.h"
20
21 static const double
22 half = 0.5;
23
24 /*
25 * Domain [-0.7854, 0.7854], range ~[-1.89e-22, 1.915e-22]
26 * |sin(x)/x - s(x)| < 2**-72.1
27 *
28 * See ../ld80/k_cosl.c for more details about the polynomial.
29 */
30 #if defined(__amd64__) || defined(__i386__)
31 /* Long double constants are slow on these arches, and broken on i386. */
32 static const volatile double
33 S1hi = -0.16666666666666666, /* -0x15555555555555.0p-55 */
34 S1lo = -9.2563760475949941e-18; /* -0x15580000000000.0p-109 */
35 #define S1 ((long double)S1hi + S1lo)
36 #else
37 static const long double
38 S1 = -0.166666666666666666671L; /* -0xaaaaaaaaaaaaaaab.0p-66 */
39 #endif
40
41 static const double
42 S2 = 0.0083333333333333332, /* 0x11111111111111.0p-59 */
43 S3 = -0.00019841269841269427, /* -0x1a01a01a019f81.0p-65 */
44 S4 = 0.0000027557319223597490, /* 0x171de3a55560f7.0p-71 */
45 S5 = -0.000000025052108218074604, /* -0x1ae64564f16cad.0p-78 */
46 S6 = 1.6059006598854211e-10, /* 0x161242b90243b5.0p-85 */
47 S7 = -7.6429779983024564e-13, /* -0x1ae42ebd1b2e00.0p-93 */
48 S8 = 2.6174587166648325e-15; /* 0x179372ea0b3f64.0p-101 */
49
50 long double
__kernel_sinl(long double x,long double y,int iy)51 __kernel_sinl(long double x, long double y, int iy)
52 {
53 long double z,r,v;
54
55 z = x*x;
56 v = z*x;
57 r = S2+z*(S3+z*(S4+z*(S5+z*(S6+z*(S7+z*S8)))));
58 if(iy==0) return x+v*(S1+z*r);
59 else return x-((z*(half*y-v*r)-y)-v*S1);
60 }
61