| 1 | use super::{exp2, modf, pow}; |
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| 3 | const LN10: f64 = 3.32192809488736234787031942948939; |
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| 4 | const P10: &[f64] = &[ |
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| 5 | 1e-15, 1e-14, 1e-13, 1e-12, 1e-11, 1e-10, 1e-9, 1e-8, 1e-7, 1e-6, 1e-5, 1e-4, 1e-3, 1e-2, 1e-1, |
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| 6 | 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, |
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| 7 | ]; |
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| 8 | |
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| 9 | #[cfg_attr (all(test, assert_no_panic), no_panic::no_panic)] |
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| 10 | pub fn exp10(x: f64) -> f64 { |
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| 11 | let (mut y: f64, n: f64) = modf(x); |
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| 12 | let u: u64 = n.to_bits(); |
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| 13 | /* fabs(n) < 16 without raising invalid on nan */ |
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| 14 | if (u >> 52 & 0x7ff) < 0x3ff + 4 { |
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| 15 | if y == 0.0 { |
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| 16 | return i!(P10, ((n as isize) + 15) as usize); |
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| 17 | } |
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| 18 | y = exp2(LN10 * y); |
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| 19 | return y * i!(P10, ((n as isize) + 15) as usize); |
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| 20 | } |
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| 21 | return pow(x:10.0, y:x); |
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| 22 | } |
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| 23 | |
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