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COMPILER CUTS INTRINSIC OVERHEAD, RUST-ANALYZER TIGHTENS TYPE SAFETY
By RepoJournal · Filed · About Rust · Composed from the cited sources · methodology
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The Rust compiler eliminated unnecessary memory allocations in intrinsics, while rust-analyzer fixed a critical type safety regression that was breaking generic parameter handling across the ecosystem.
The biggest win landed in the compiler: a PR that stops materializing places for most intrinsics [1] eliminates wasteful allocations like the `alloca` needed just to return a constant from `size_of_val`. By allowing intrinsics to return `OperandValue` directly instead, the codegen layer now handles all but 5 intrinsics more efficiently. This is the kind of invisible performance work that compounds across millions of builds [2]. Meanwhile, rust-analyzer shipped a structural fix to how it handles generic parameters in `hir::Type` [3], enforcing that types remember their owner and panic if you try to work across ownership boundaries. This closes at least two open issues where generic types were leaking context and breaking IDE analysis. On the derive front, the compiler also landed a fast path for `derive(Ord)` when `PartialOrd` is already derived [4], though there's a known limitation when `PartialOrd` comes first [5]. rust-analyzer also merged fixes for tuple struct pattern normalization [6] and array pattern diagnostics [7], improving IDE accuracy for match expressions.
Action items
- → Watch rust-analyzer's type safety changes for any backslash errors in your IDE - this is a defensive refactor rust-lang/rust-analyzer [monitor]
- → If you maintain derive macros, test `derive(Ord)` with preceding `PartialOrd` for the known limitation rust-lang/rust [plan]
References
- [1] Stop needing materialized places for most intrinsics ↗ rust-lang/rust
- [2] Auto merge of #156116 - scottmcm:tweak-layout-of-alternative, r=dianqk rust-lang/rust ↗
- [3] fix: Refactor handling of generic params in `hir::Type` ↗ rust-lang/rust-analyzer
- [4] Implement fast path for `derive(PartialOrd)` when deriving `Ord` ↗ rust-lang/rust
- [5] Auto merge of #155598 - makai410:partial-ord, r=nnethercote rust-lang/rust ↗
- [6] fix: normalize expected tuple struct pat field ↗ rust-lang/rust-analyzer
- [7] Merge pull request #22424 from Abusalah0/diag-array-pattern-without-fixed-length ↗ rust-lang/rust-analyzer
