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Rollup merge of #89351 - tspiteri:wrapping_rem, r=dtolnay

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for signed wrapping remainder, do not compare lhs with MIN

Since the wrapped remainder is going to be 0 for all cases when the rhs is -1, there is no need to compare the lhs with MIN.
This commit is contained in:
Manish Goregaokar 2021-10-05 12:52:45 -07:00 • committed by GitHub
commit e745e098c4
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1 changed files with 4 additions and 6 deletions
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10
library/core/src/num/int_macros.rs
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@ -1533,9 +1533,8 @@ macro_rules! int_impl {
#[must_use = "this returns the result of the operation, \ #[must_use = "this returns the result of the operation, \
without modifying the original"] without modifying the original"]
pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) { pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) {
// Using `&` helps LLVM see that it is the same check made in division. if unlikely!(rhs == -1) {
if unlikely!((self == Self::MIN) & (rhs == -1)) { (0, self == Self::MIN)
(0, true)
} else { } else {
(self % rhs, false) (self % rhs, false)
} }
@ -1565,9 +1564,8 @@ macro_rules! int_impl {
without modifying the original"] without modifying the original"]
#[inline] #[inline]
pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) { pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) {
// Using `&` helps LLVM see that it is the same check made in division. if unlikely!(rhs == -1) {
if unlikely!((self == Self::MIN) & (rhs == -1)) { (0, self == Self::MIN)
(0, true)
} else { } else {
(self.rem_euclid(rhs), false) (self.rem_euclid(rhs), false)
} }