| The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame^] | 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 |
| 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 | } |