xref: /relibc/openlibm/src/k_sinf.c (revision 06dbb6e72b1d3e43ca813caa0b139094068e6a88)
1 /* k_sinf.c -- float version of k_sin.c
2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3  * Optimized by Bruce D. Evans.
4  */
5 
6 /*
7  * ====================================================
8  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9  *
10  * Developed at SunPro, a Sun Microsystems, Inc. business.
11  * Permission to use, copy, modify, and distribute this
12  * software is freely granted, provided that this notice
13  * is preserved.
14  * ====================================================
15  */
16 
17 #ifndef INLINE_KERNEL_SINDF
18 #include "cdefs-compat.h"
19 //__FBSDID("$FreeBSD: src/lib/msun/src/k_sinf.c,v 1.16 2009/06/03 08:16:34 ed Exp $");
20 #endif
21 
22 #include <openlibm.h>
23 
24 #include "math_private.h"
25 
26 /* |sin(x)/x - s(x)| < 2**-37.5 (~[-4.89e-12, 4.824e-12]). */
27 static const double
28 S1 = -0x15555554cbac77.0p-55,	/* -0.166666666416265235595 */
29 S2 =  0x111110896efbb2.0p-59,	/*  0.0083333293858894631756 */
30 S3 = -0x1a00f9e2cae774.0p-65,	/* -0.000198393348360966317347 */
31 S4 =  0x16cd878c3b46a7.0p-71;	/*  0.0000027183114939898219064 */
32 
33 #ifndef INLINE_KERNEL_SINDF
34 extern
35 #endif
36 //__inline float
37 DLLEXPORT float
38 __kernel_sindf(double x)
39 {
40 	double r, s, w, z;
41 
42 	/* Try to optimize for parallel evaluation as in k_tanf.c. */
43 	z = x*x;
44 	w = z*z;
45 	r = S3+z*S4;
46 	s = z*x;
47 	return (x + s*(S1+z*S2)) + s*w*r;
48 }
49