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mul.rs: use wrapping_mul to avoid infinite recursion #132

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Merged
merged 1 commit into from
Jan 2, 2017
Merged

mul.rs: use wrapping_mul to avoid infinite recursion #132

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8 changes: 4 additions & 4 deletions src/int/mul.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -9,18 +9,18 @@ macro_rules! mul {
pub extern "C" fn $intrinsic(a: $ty, b: $ty) -> $ty {
let half_bits = <$ty>::bits() / 4;
let lower_mask = !0 >> half_bits;
let mut low = (a.low() & lower_mask) * (b.low() & lower_mask);
let mut low = (a.low() & lower_mask).wrapping_mul(b.low() & lower_mask);
let mut t = low >> half_bits;
low &= lower_mask;
t += (a.low() >> half_bits) * (b.low() & lower_mask);
t += (a.low() >> half_bits).wrapping_mul(b.low() & lower_mask);
low += (t & lower_mask) << half_bits;
let mut high = t >> half_bits;
t = low >> half_bits;
low &= lower_mask;
t += (b.low() >> half_bits) * (a.low() & lower_mask);
t += (b.low() >> half_bits).wrapping_mul(a.low() & lower_mask);
low += (t & lower_mask) << half_bits;
high += t >> half_bits;
high += (a.low() >> half_bits) * (b.low() >> half_bits);
high += (a.low() >> half_bits).wrapping_mul(b.low() >> half_bits);
high = high.wrapping_add(a.high().wrapping_mul(b.low()).wrapping_add(a.low().wrapping_mul(b.high())));
<$ty>::from_parts(low, high)
}
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