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use core::f64;
const TOINT: f64 = 1.0 / f64::EPSILON;
#[inline]
#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
pub fn round(mut x: f64) -> f64 {
let (f, i) = (x, x.to_bits());
let e: u64 = i >> 52 & 0x7ff;
let mut y: f64;
if e >= 0x3ff + 52 {
return x;
}
if i >> 63 != 0 {
x = -x;
}
if e < 0x3ff - 1 {
// raise inexact if x!=0
force_eval!(x + TOINT);
return 0.0 * f;
}
y = x + TOINT - TOINT - x;
if y > 0.5 {
y = y + x - 1.0;
} else if y <= -0.5 {
y = y + x + 1.0;
} else {
y = y + x;
}
if i >> 63 != 0 {
-y
} else {
y
}
}
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