Improve codegen for enums with many cases #9122
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This commit improves the compile time of generating bindings for enums with many cases in them (e.g. 1000+). This is done by optimizing for enums specifically rather than handling them generically like other variants which can reduce the amount of code going into rustc to O(1) instead of O(N) with the number of cases. This in turn can greatly reduce compile time. The tradeoff made in this commit is that enums are now required to have `#[repr(...)]` annotations along with no Rust-level discriminants specified. This enables the use of a `transmute` to lift a discriminant into Rust with a simple bounds check. Previously this was one large `match` statement. Closes bytecodealliance#9081
pchickey
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* Improve codegen for enums with many cases This commit improves the compile time of generating bindings for enums with many cases in them (e.g. 1000+). This is done by optimizing for enums specifically rather than handling them generically like other variants which can reduce the amount of code going into rustc to O(1) instead of O(N) with the number of cases. This in turn can greatly reduce compile time. The tradeoff made in this commit is that enums are now required to have `#[repr(...)]` annotations along with no Rust-level discriminants specified. This enables the use of a `transmute` to lift a discriminant into Rust with a simple bounds check. Previously this was one large `match` statement. Closes #9081 * Fix some tests * Add repr tag in fuzzing
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This commit improves the compile time of generating bindings for enums with many cases in them (e.g. 1000+). This is done by optimizing for enums specifically rather than handling them generically like other variants which can reduce the amount of code going into rustc to O(1) instead of O(N) with the number of cases. This in turn can greatly reduce compile time.
The tradeoff made in this commit is that enums are now required to have
#[repr(...)]annotations along with no Rust-level discriminants specified. This enables the use of atransmuteto lift a discriminant into Rust with a simple bounds check. Previously this was one largematchstatement.Closes #9081