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Be less opinionated (and more accurate) when evaluating saturated arithmetic #59607

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Be less opinionated (and more accurate) when evaluating saturated arithmetic #59607

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Be less opinionated (and more accurate) when evaluating saturated ari…
LilithHafner Sep 19, 2025
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Restore "fast" and fix typos
LilithHafner Sep 19, 2025
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LilithHafner Sep 20, 2025
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Merge branch 'master' into lh/sat
LilithHafner Sep 20, 2025
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6 changes: 3 additions & 3 deletions doc/src/manual/faq.md
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Expand Up @@ -546,9 +546,9 @@ way that is compatible with C and Fortran. Saturated integer arithmetic, however
The first and most obvious issue is that this is not the way machine integer arithmetic works,
so implementing saturated operations requires emitting instructions after each machine integer
operation to check for underflow or overflow and replace the result with [`typemin(Int)`](@ref)
or [`typemax(Int)`](@ref) as appropriate. This alone expands each integer operation from a single,
fast instruction into half a dozen instructions, probably including branches. Ouch. But it gets
worse – saturating integer arithmetic isn't associative. Consider this Matlab computation:
or [`typemax(Int)`](@ref) as appropriate. This expands each integer operation from a single, fast
instruction into a few instructions. But it gets worse – saturating integer arithmetic isn't
associative. Consider this Matlab computation:

```
>> n = int64(2)^62
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