[MicroPerf] Remove per-node closure allocations in post-inference type checking - #20374
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[MicroPerf] Remove per-node closure allocations in post-inference type checking#20374T-Gro wants to merge 1 commit into
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The recursive type walk allocated a closure for every relevant type node in three places where List.iter2 / List.exists cannot inline the lambda: the IL-generic instantiation walk, the static-abstract-interface type-argument check (#19184), and its interface-constraint predicate. Add ListInline.iter2 / ListInline.exists (inline + InlineIfLambda cursor loops) so the lambda is inlined into a direct loop and no closure is allocated even when it captures per-call state, and use them at the three sites. Same diagnostics in the same order; --deterministic+ self-compile is byte-identical to the base build. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: c1cfa10a-2667-4f34-b9ad-b9fa29e52156
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The recursive type walk in
CheckTypeAux/CheckTypeDeepallocated a closure for every relevant type node in three places whereList.iter2/List.existscannot inline the lambda: the IL-generic instantiation walk, the static-abstract-interface type-argument check (#19184), and its interface-constraint predicate.ListInline.iter2/ListInline.exists(inline +[<InlineIfLambda>]cursor loops, next to the otherilliblist helpers) inline the lambda into a direct loop, so no closure is allocated even when it captures per-call state.Measured
Closure allocation removed at the three sites, per compilation of a 120-file corpus (dotnet-trace
gc-verbose, sampled; measured as the total over a 7-self-compile trace ÷ 7):CheckTypeDeep@401(IL-genericList.iter2lambda)visitAppTy@713(List.iter2#19184 partial-app)CheckInterfaceType…@648(List.existspredicate)Behaviour unchanged
Same diagnostics in the same order. Under
--deterministic+(sequential) the self-compiled output is SHA-256 byte-identical to the base build, including a byref/inref/byref<Span>/SRTP-inline/IWSAM-static-abstract/System.Voidsource. IWSAM/SRTP (incl. #19184) and byref-interop component tests pass.