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 #ifndef lint
19 static char rcsid[] = "$FreeBSD: src/lib/msun/src/k_sinf.c,v 1.13 2005/11/30 11:51:17 bde Exp $";
20 #endif
21 #endif
22
23 #include "math.h"
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 #ifdef INLINE_KERNEL_SINDF
34 extern inline
35 #endif
36 float
__kernel_sindf(double x)37 __kernel_sindf(double x)
38 {
39 double r, s, w, z;
40
41 /* Try to optimize for parallel evaluation as in k_tanf.c. */
42 z = x*x;
43 w = z*z;
44 r = S3+z*S4;
45 s = z*x;
46 return (x + s*(S1+z*S2)) + s*w*r;
47 }
48