| 1 | /* origin: FreeBSD /usr/src/lib/msun/src/k_sinf.c */ |
| 2 | /* |
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| 3 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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| 4 | * Optimized by Bruce D. Evans. |
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| 5 | */ |
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| 6 | /* |
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| 7 | * ==================================================== |
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| 8 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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| 9 | * |
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| 10 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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| 11 | * Permission to use, copy, modify, and distribute this |
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| 12 | * software is freely granted, provided that this notice |
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| 13 | * is preserved. |
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| 14 | * ==================================================== |
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| 15 | */ |
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| 16 | |
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| 17 | /* |sin(x)/x - s(x)| < 2**-37.5 (~[-4.89e-12, 4.824e-12]). */ |
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| 18 | const S1: f64 = -0.166666666416265235595; /* -0x15555554cbac77.0p-55 */ |
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| 19 | const S2: f64 = 0.0083333293858894631756; /* 0x111110896efbb2.0p-59 */ |
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| 20 | const S3: f64 = -0.000198393348360966317347; /* -0x1a00f9e2cae774.0p-65 */ |
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| 21 | const S4: f64 = 0.0000027183114939898219064; /* 0x16cd878c3b46a7.0p-71 */ |
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| 22 | |
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| 23 | #[cfg_attr (all(test, assert_no_panic), no_panic::no_panic)] |
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| 24 | pub(crate) fn k_sinf(x: f64) -> f32 { |
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| 25 | let z: f64 = x * x; |
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| 26 | let w: f64 = z * z; |
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| 27 | let r: f64 = S3 + z * S4; |
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| 28 | let s: f64 = z * x; |
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| 29 | ((x + s * (S1 + z * S2)) + s * w * r) as f32 |
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| 30 | } |
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| 31 | |
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