Add AggressiveInlining to Char.IsLatin1
#84414
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* Force the JIT to inline this 17 byte method to elide bounds checks. * Remove useless `uint` casts as `char` is unsigned and `ReadOnlySpan<T>.Length` is never negative.
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| @@ -81,7 +81,8 @@ namespace System | |||
| }; | |||
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| // Return true for all characters below or equal U+00ff, which is ASCII + Latin-1 Supplement. | |||
| private static bool IsLatin1(char c) => (uint)c < (uint)Latin1CharInfo.Length; | |||
| [MethodImpl(MethodImplOptions.AggressiveInlining)] | |||
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Do you have an example where it's not inlined currently?
casts are indeed not needed (since net8)
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https://csharp.godbolt.org/z/fexKr3f4x
However, it looks like IsLatin1 is actually inlined in Char as it is a struct not a class.
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@EgorBo Is it worth keeping the AggressiveInlining to express intent, or not?
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Thanks, I see it's not inlined, but as far as I remember I already complained about it somewhere, the problem was that RVA spans emit an IL that JIT's inliner is not able analyze properly (it doesn't know that it's foldable)
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@EgorBo Sorry for not being clear, since Char is a struct the method is in fact inlined (sharplab.io).
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However, not with crossgen2 (godbolt).
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@xtqqczze change host type from struct to class
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Ah you meant that in this case it's fine - yes. But overall it showcases a real problem inliner is not able to figure out
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Is it worth keeping the AggressiveInlining to express intent, or not?
No, but thanks
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uintcasts ascharis unsigned andReadOnlySpan<T>.Lengthis never negative.