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 #include "math.h"
18 #include "math_private.h"
19
20 /* |sin(x)/x - s(x)| < 2**-37.5 (~[-4.89e-12, 4.824e-12]). */
21 static const double
22 S1 = -0x15555554cbac77.0p-55, /* -0.166666666416265235595 */
23 S2 = 0x111110896efbb2.0p-59, /* 0.0083333293858894631756 */
24 S3 = -0x1a00f9e2cae774.0p-65, /* -0.000198393348360966317347 */
25 S4 = 0x16cd878c3b46a7.0p-71; /* 0.0000027183114939898219064 */
26
27 #ifdef INLINE_KERNEL_SINDF
28 static __inline
29 #endif
30 float
__kernel_sindf(double x)31 __kernel_sindf(double x)
32 {
33 double r, s, w, z;
34
35 /* Try to optimize for parallel evaluation as in k_tanf.c. */
36 z = x*x;
37 w = z*z;
38 r = S3+z*S4;
39 s = z*x;
40 return (x + s*(S1+z*S2)) + s*w*r;
41 }
42