Auto merge of #126852 - scottmcm:more-checked-math-tweaks, r=Amanieu · model-checking/verify-rust-std@a451b2a (original) (raw)

`@@ -454,8 +454,19 @@ macro_rules! uint_impl {

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` without modifying the original"]

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` #[inline]

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`pub const fn checked_add(self, rhs: Self) -> Option {

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let (a, b) = self.overflowing_add(rhs);

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if unlikely!(b) { None } else { Some(a) }

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// This used to use overflowing_add, but that means it ends up being

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// a wrapping_add, losing some optimization opportunities. Notably,

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// phrasing it this way helps .checked_add(1) optimize to a check

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// against MAX and a add nuw.

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// Per https://github.com/rust-lang/rust/pull/124114#issuecomment-2066173305,

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// LLVM is happy to re-form the intrinsic later if useful.

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if unlikely!(intrinsics::add_with_overflow(self, rhs).1) {

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None

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} else {

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// SAFETY: Just checked it doesn't overflow

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Some(unsafe { intrinsics::unchecked_add(self, rhs) })

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}

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`}

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`` /// Strict integer addition. Computes self + rhs, panicking

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