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/* $OpenBSD: k_sinl.c,v 1.2 2017/01/21 08:29:13 krw Exp $ */ |
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/* From: @(#)k_sin.c 1.3 95/01/18 */ |
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/* |
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* ==================================================== |
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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* Copyright (c) 2008 Steven G. Kargl, David Schultz, Bruce D. Evans. |
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* |
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* Developed at SunSoft, a Sun Microsystems, Inc. business. |
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* Permission to use, copy, modify, and distribute this |
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* software is freely granted, provided that this notice |
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* is preserved. |
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* ==================================================== |
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*/ |
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/* |
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* ld80 version of k_sin.c. See ../k_sin.c for most comments. |
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*/ |
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#include "math_private.h" |
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static const double |
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half = 0.5; |
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/* |
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* Domain [-0.7854, 0.7854], range ~[-1.89e-22, 1.915e-22] |
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* |sin(x)/x - s(x)| < 2**-72.1 |
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* |
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* See ../ld80/k_cosl.c for more details about the polynomial. |
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*/ |
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#if defined(__amd64__) || defined(__i386__) |
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/* Long double constants are slow on these arches, and broken on i386. */ |
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static const volatile double |
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S1hi = -0.16666666666666666, /* -0x15555555555555.0p-55 */ |
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S1lo = -9.2563760475949941e-18; /* -0x15580000000000.0p-109 */ |
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#define S1 ((long double)S1hi + S1lo) |
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#else |
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static const long double |
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S1 = -0.166666666666666666671L; /* -0xaaaaaaaaaaaaaaab.0p-66 */ |
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#endif |
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static const double |
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S2 = 0.0083333333333333332, /* 0x11111111111111.0p-59 */ |
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S3 = -0.00019841269841269427, /* -0x1a01a01a019f81.0p-65 */ |
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S4 = 0.0000027557319223597490, /* 0x171de3a55560f7.0p-71 */ |
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S5 = -0.000000025052108218074604, /* -0x1ae64564f16cad.0p-78 */ |
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S6 = 1.6059006598854211e-10, /* 0x161242b90243b5.0p-85 */ |
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S7 = -7.6429779983024564e-13, /* -0x1ae42ebd1b2e00.0p-93 */ |
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S8 = 2.6174587166648325e-15; /* 0x179372ea0b3f64.0p-101 */ |
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long double |
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__kernel_sinl(long double x, long double y, int iy) |
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{ |
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long double z,r,v; |
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z = x*x; |
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v = z*x; |
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r = S2+z*(S3+z*(S4+z*(S5+z*(S6+z*(S7+z*S8))))); |
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✓✓ |
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if(iy==0) return x+v*(S1+z*r); |
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else return x-((z*(half*y-v*r)-y)-v*S1); |
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} |