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use super::atanf;
use super::fabsf;
const PI: f32 = 3.1415927410e+00;
const PI_LO: f32 = -8.7422776573e-08;
#[inline]
pub fn atan2f(y: f32, x: f32) -> f32 {
if x.is_nan() || y.is_nan() {
return x + y;
}
let mut ix = x.to_bits();
let mut iy = y.to_bits();
if ix == 0x3f800000 {
return atanf(y);
}
let m = ((iy >> 31) & 1) | ((ix >> 30) & 2);
ix &= 0x7fffffff;
iy &= 0x7fffffff;
if iy == 0 {
return match m {
0 | 1 => y,
2 => PI,
3 | _ => -PI,
};
}
if ix == 0 {
return if m & 1 != 0 { -PI / 2. } else { PI / 2. };
}
if ix == 0x7f800000 {
return if iy == 0x7f800000 {
match m {
0 => PI / 4.,
1 => -PI / 4.,
2 => 3. * PI / 4.,
3 | _ => -3. * PI / 4.,
}
} else {
match m {
0 => 0.,
1 => -0.,
2 => PI,
3 | _ => -PI,
}
};
}
if (ix + (26 << 23) < iy) || (iy == 0x7f800000) {
return if m & 1 != 0 { -PI / 2. } else { PI / 2. };
}
let z = if (m & 2 != 0) && (iy + (26 << 23) < ix) {
0.
} else {
atanf(fabsf(y / x))
};
match m {
0 => z,
1 => -z,
2 => PI - (z - PI_LO),
_ => (z - PI_LO) - PI,
}
}