Update Adler32 to correctly filter intrinsics. #1229
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## master #1229 +/- ##
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Coverage 82.54% 82.54%
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Files 697 697
Lines 30512 30512
Branches 3469 3469
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Misses 4605 4605
Partials 720 720
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We can disable runtime features with environment variables , and run some Adler32 tests in external process. ( I would also add @tannergooding if you are around: do you think this is a reliable approach? |
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That is a reliable way to test the software fallback path and is what we do in the runtime (it's also why we exposed these knobs). |
| @@ -63,7 +63,7 @@ public static uint Calculate(uint adler, ReadOnlySpan<byte> buffer) | |||
| } | |||
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| #if SUPPORTS_RUNTIME_INTRINSICS | |||
| if (Sse3.IsSupported && buffer.Length >= MinBufferSize) | |||
| if (Ssse3.IsSupported && buffer.Length >= MinBufferSize) | |||
| { | |||
| return CalculateSse(adler, buffer); | |||
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Should we also rename CalculateSse to CalculateSsse?
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I would say no. It’s still an iteration of SSE technology.
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@antonfirsov @tannergooding Test added now. Think I've got it right. |
| public const string EnableBMI2 = "COMPlus_EnableBMI2"; | ||
| public const string EnableFMA = "COMPlus_EnableFMA"; | ||
| public const string EnableHWIntrinsic = "COMPlus_EnableHWIntrinsic"; | ||
| public const string EnableIncompleteISAClass = "COMPlus_EnableIncompleteISAClass"; |
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This one isn't a production switch.
For the others, there is a rough hierarchy they follow:
- EnableHWIntrinsic
- EnableSSE
- EnableSSE2
- EnableAES
- EnablePCLMULQDQ
- EnableSSE3
- EnableSSSE3
- EnableSSE41
- EnableSSE42
- EnablePOPCNT
- EnableAVX
- EnableFMA
- EnableAVX2
- EnableSSE42
- EnableSSE41
- EnableSSSE3
- EnableSSE2
- EnableBMI1
- EnableBMI2
- EnableLZCNT
- EnableSSE
FeatureSIMD ends up impacting all SIMD support (including System.Numerics) but not things like LZCNT, BMI1, or BMI2
EnableSSE3_4 is a legacy switch that exists for compat and is basically the same as EnableSSE3
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The hierarchy basically means disabling SSE (EnableSSE=0) will also disable everything below it
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Ah lovely. I'll reference that. I intend on doing more intrinsics work in the near future.
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Description
Introduces the correct intrinsics support check in the enhanced Adler32 implementation. Fix #1228
@antonfirsov if you have any idea how to test this please let me know if you have any thoughts.