Comment by saagarjha
7 hours ago
Signed overflow checks are typically not free unfortunately they have a cost of about 5% or thereabouts
7 hours ago
Signed overflow checks are typically not free unfortunately they have a cost of about 5% or thereabouts
In hot paths it can be even more. This is why even Rust defines it as wrapping but elides the overflow panic in release builds.
It is defined as an error. That error’s default handling is wrapping when debug_assertions is off, and panic when it’s on, but since it’s an incorrect program (though not UB) either behavior is acceptable in any mode.
If it is defined as an error, but the compiled build will continue to run with the value wrapped around, I would say that's indistinguishable from UB.
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