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tract_linalg/generic/
erf.rs

1#[allow(non_upper_case_globals)]
2#[allow(clippy::excessive_precision)]
3fn serf(x: &mut f32) {
4    const a1: f32 = 0.0705230784;
5    const a2: f32 = 0.0422820123;
6    const a3: f32 = 0.0092705272;
7    const a4: f32 = 0.0001520143;
8    const a5: f32 = 0.0002765672;
9    const a6: f32 = 0.0000430638;
10
11    let signum = x.signum();
12    let abs = x.abs();
13    let y = a6 * abs;
14    let y = (a5 + y) * abs;
15    let y = (a4 + y) * abs;
16    let y = (a3 + y) * abs;
17    let y = (a2 + y) * abs;
18    let y = (a1 + y) * abs;
19    let y = 1.0 - (y + 1.0).powi(16).recip();
20
21    *x = y.copysign(signum)
22}
23
24routine_ew_rust!(generic;
25    f32,
26    generic_erf_f32_4n,
27    4,
28    4,
29    fn run(x: &mut [f32], _: ()) {
30        debug_assert!(x.len() % Self::nr() == 0);
31        debug_assert!(x.as_ptr() as usize % Self::alignment_bytes() == 0);
32        x.iter_mut().for_each(serf)
33    },
34    func(Erf)
35);