TextEncoder.FindFirstCharacterToEncodeUtf8 not being used anywhere.

[eiriktsarpalis]

Discovered this issue while working on ARM64 intrinsics optimizations for System.Text.Encodings.Web. While the method is public, it is also marked EditorBrowsable.Never. There are however unit tests consuming it.

A lot of the intrinsics optimizations for this project live in FindFirstCharacterToEncodeUtf8 implementations, and as a result we're not seeing performance improvements when benchmarking TextEncoder.EncodeUtf8.

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[tarekgh]

@GrabYourPitchforks just checking if you are triaging this area?

[GrabYourPitchforks]

This method was at one point used by System.Text.Json (see source). They've stopped using the API since then, but since it's a public API we need to keep it around in perpetuity.

What is this bug tracking? That we should stop making perf changes to this API? I'd be fine with that if that's the direction we want to go.

[eiriktsarpalis]

What is this bug tracking?

Unlike TextEncoder.Encode(string) which depends on FindFirstCharacterToEncode(char*), TextEncoder.EncodeUtf8 does not make use of FindFirstCharacterToEncodeUtf8. The issue then is that TextEncoder.EncodeUtf8 does not take advantage of any of the hardware intrinsics optimizations. If that's intentional or not necessary to improve on, I can close the issue.