Precompute per-parameter interop binding flags#2719
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Interop argument binding re-derived three per-parameter-type facts on every call: typeof(JsValue).IsAssignableFrom(parameterType), the generic-shape test hidden inside IsGenericParameter (which forced a boxing argument.ToObject() detour for every argument, including plain int parameters), and the JsValue[] params-signature check. MethodDescriptor now classifies each parameter once into InteropParameterFlags; MethodInfoFunction.TryCall and MethodDescriptor.Call branch on the cached flags. Resolved generic methods re-classify their own parameters (their ParameterInfos differ from the descriptor's). The general conversion branch computes the boxed argument lazily now that the generic probe no longer produces it as a side effect. Conversion semantics are unchanged - the same conversions run, only constant-per-method reflection checks and the needless pre-boxing are gone. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
lahma
enabled auto-merge (squash)
July 21, 2026 11:20
This was referenced Jul 22, 2026
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Part of the V8-gap performance campaign (#1775 follow-up). Profiling
interop-method-callsshowedMethodInfoFunction.TryCallat 15.9% self — and most of it is constant-per-method work re-derived on every call.Change
Interop argument binding re-derived three per-parameter-type facts per argument per call:
typeof(JsValue).IsAssignableFrom(parameterType), the generic-shape test hidden insideIsGenericParameter(which forced a boxingargument.ToObject()detour for every argument, including plainintparameters), and theJsValue[]params-signature check.MethodDescriptornow classifies each parameter once intoInteropParameterFlags;MethodInfoFunction.TryCallandMethodDescriptor.Callbranch on the cached flags. Resolved generic methods re-classify their own parameters (theirParameterInfos differ from the descriptor's). The general conversion branch computes the boxed argument lazily now that the generic probe no longer produces it as a side effect. Conversion semantics are unchanged — the same conversions run in the same order; only constant-per-method reflection checks and the needless pre-boxing are gone.Numbers (default BDN job, same-base A/B)
Three rows (TwoArgs, Overloaded, Params) initially read +3–4% on single launches; a launchCount-5 verification on both sides shows them statistically tied (+0.2%, +0.3%, −2.1%) — layout bimodality, not regressions.
Gates
Rebased on current main (includes #2716–#2718): Jint.Tests 3658/3595 (net10/net472), PublicInterface 114/114 both TFMs, Test262 99,431 passed / 0 failed.
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