| 1 | /* origin: FreeBSD /usr/src/lib/msun/src/k_sinf.c */ |
| 2 | /* |
| 3 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| 4 | * Optimized by Bruce D. Evans. |
| 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 "libm.h" |
| 18 | |
| 19 | /* |sin(x)/x - s(x)| < 2**-37.5 (~[-4.89e-12, 4.824e-12]). */ |
| 20 | static const double |
| 21 | S1 = -0x15555554cbac77.0p-55, /* -0.166666666416265235595 */ |
| 22 | S2 = 0x111110896efbb2.0p-59, /* 0.0083333293858894631756 */ |
| 23 | S3 = -0x1a00f9e2cae774.0p-65, /* -0.000198393348360966317347 */ |
| 24 | S4 = 0x16cd878c3b46a7.0p-71; /* 0.0000027183114939898219064 */ |
| 25 | |
| 26 | float __sindf(double x) |
| 27 | { |
| 28 | 	double_t r, s, w, z; |
| 29 | |
| 30 | 	/* Try to optimize for parallel evaluation as in __tandf.c. */ |
| 31 | 	z = x*x; |
| 32 | 	w = z*z; |
| 33 | 	r = S3 + z*S4; |
| 34 | 	s = z*x; |
| 35 | 	return (x + s*(S1 + z*S2)) + s*w*r; |
| 36 | } |