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use core::u64;
#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
pub fn fmod(x: f64, y: f64) -> f64 {
let mut uxi = x.to_bits();
let mut uyi = y.to_bits();
let mut ex = (uxi >> 52 & 0x7ff) as i64;
let mut ey = (uyi >> 52 & 0x7ff) as i64;
let sx = uxi >> 63;
let mut i;
if uyi << 1 == 0 || y.is_nan() || ex == 0x7ff {
return (x * y) / (x * y);
}
if uxi << 1 <= uyi << 1 {
if uxi << 1 == uyi << 1 {
return 0.0 * x;
}
return x;
}
/* normalize x and y */
if ex == 0 {
i = uxi << 12;
while i >> 63 == 0 {
ex -= 1;
i <<= 1;
}
uxi <<= -ex + 1;
} else {
uxi &= u64::MAX >> 12;
uxi |= 1 << 52;
}
if ey == 0 {
i = uyi << 12;
while i >> 63 == 0 {
ey -= 1;
i <<= 1;
}
uyi <<= -ey + 1;
} else {
uyi &= u64::MAX >> 12;
uyi |= 1 << 52;
}
/* x mod y */
while ex > ey {
i = uxi.wrapping_sub(uyi);
if i >> 63 == 0 {
if i == 0 {
return 0.0 * x;
}
uxi = i;
}
uxi <<= 1;
ex -= 1;
}
i = uxi.wrapping_sub(uyi);
if i >> 63 == 0 {
if i == 0 {
return 0.0 * x;
}
uxi = i;
}
while uxi >> 52 == 0 {
uxi <<= 1;
ex -= 1;
}
/* scale result */
if ex > 0 {
uxi -= 1 << 52;
uxi |= (ex as u64) << 52;
} else {
uxi >>= -ex + 1;
}
uxi |= (sx as u64) << 63;
f64::from_bits(uxi)
}
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