Use fast hashing helpers for types with trailing padding #118986
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This is same as dotnet#111620 but with an extra thing: enable unconditional method body folding on `__GetFieldHelper` overrides (both the simplified ones that just return a negative number and normal ones).
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Pull Request Overview
This PR improves performance of value type hashing and equality comparisons by enabling fast hashing helpers for types with trailing padding. The changes allow value types to use memory-based comparisons up to a specified offset rather than requiring field-by-field comparisons when there's trailing padding.
Key changes:
- Modified the compiler to enable method body folding for
__GetFieldHelperoverrides unconditionally - Enhanced the fast path logic to handle value types with trailing padding by comparing memory up to the last field's end offset
- Updated the API semantics to use negative return values to indicate the byte offset for memory comparison
Reviewed Changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| ObjectDataInterner.cs | Enables unconditional method body folding for ValueTypeGetFieldHelperMethodOverride methods |
| ValueTypeGetFieldHelperMethodOverride.cs | Adds fast path for value types that can use memory comparison up to a specific offset |
| ComparerIntrinsics.cs | Extends the analysis to support partial memory comparison up to the last field's end offset |
| ValueType.cs | Updates the runtime implementation to handle negative return values as byte offsets for memory comparison |
|
Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas |
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This is same as #111620 but with an extra thing: enable unconditional method body folding on
__GetFieldHelperoverrides (both the simplified ones that just return a negative number and normal ones).Fixes #111542