Cache type classification answers on types by jakebailey · Pull Request #65042 · microsoft/TypeScript

Jake Bailey (jakebailey) · 2026-10-29T22:37:00Z

Thanks Steven (@teamchong) for finding these!

resolveStructuredTypeMembers is called on nearly every property, signature and index lookup, and almost always finds the members already resolved. Because the resolution switch lived in the same function, the whole thing was too large to inline, so every lookup paid for a call just to test one flag. Move the resolution switch into a separate worker so the remaining resolved-bit check and cast fit in the inlining budget. To get under the budget, AsStructuredType now only checks the lower bound of the kind range, which is sufficient because intersection is the last type kind. Co-authored-by: Steven Chong <[email protected]>

Type has a byte of padding after its kind. Use it for a small set of internal flags that record answers which never change for a type. shouldNormalizeIntersection is asked repeatedly for the same intersections during relation checking and rescans every constituent each time. Its answer depends only on constituent flags and on whether anonymous constituents are empty, so remember it once those answers are final. Some member resolvers publish empty members before resolution finishes, so a bit now marks types whose members are still being resolved, and the result is not cached while any anonymous constituent is unresolved or mid-resolution. Unions whose constituents are all definitely non-nullable and not instantiable can never produce undefined/null type facts. Record this when the union is created, so that getTypeFacts can skip walking the constituents when the caller only asks about nullability, as it already does for object types. Co-authored-by: Steven Chong <[email protected]>

isWeakType runs for the target of nearly every assignability check against an object type, and each time it re-examines the signatures, index infos and every property of the target, which for large interfaces is a full walk of the member list. The classification is a fixed property of the type once its members are resolved, so remember it in the type's cache flags. The answer is cached only when the members are fully resolved (not published early by an in-progress resolver) and the properties came from the type itself rather than a different apparent type. When getBaseTypes resets partially resolved members of a class or interface, the cached answer is reset along with them. Co-authored-by: Steven Chong <[email protected]>

Every relation cache key computation calls isTypeReferenceWithGenericArguments on both the source and the target, and the check recursively walks all type arguments of nested type references. For deeply nested generic references this repeats the same walk on every relation check involving them. The type arguments of a non-deferred type reference are fixed when it is created, so the answer never changes. Remember it in the type's cache flags so later calls are a flag test. Co-authored-by: Steven Chong <[email protected]>

getSingleBaseForNonAugmentingSubtype is called for every pair of type references during relation checks. Once computed, the common answer is that there is no single equivalent base type, yet each call still did a map lookup to find that out. Set IdenticalBaseTypeExists when a base is actually cached, as Strada does, so a computed reference without one returns immediately and only the positive case consults the map. Co-authored-by: Steven Chong <[email protected]>

Jake Bailey (jakebailey) · 2026-10-29T22:37:11Z

TypeScript Bot (@typescript-bot) perf test this faster

typescript-automation · 2026-10-29T22:37:17Z

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
`perf test this faster`	✅ Started	👀 Results

Copilot

🔵 Needs a closer look

The cache changes affect reentrant member resolution, and their lifetime assumptions require compiler regression-suite validation that cannot be run in this review environment.

No open issues 🎉

What changed in this PR

This PR reduces repeated type-classification work in the native TypeScript checker by caching answers directly on types, with safeguards for members that are still being resolved.

Changes:

Adds compact cache flags within existing Type padding.
Caches generic-argument, weak-type, and intersection-normalization checks.
Adds shortcuts for non-nullable union facts and absent equivalent base types.

File	Description
`tsc/internal/checker/types.go`	Defines cache flags and simplifies the structured-type kind check.
`tsc/internal/checker/relater.go`	Caches weak-type results when member resolution is final.
`tsc/internal/checker/checker.go`	Implements classification caches, resolution tracking, invalidation, and lookup shortcuts.

_{Review effort: Balanced}

typescript-automation · 2026-10-29T23:35:11Z

Jake Bailey (@jakebailey)
The results of the perf run you requested are in!

Here they are:

tsc

Comparison Report - baseline..pr

_Metric	_baseline	_pr	_Delta	_Best	_Worst	_p-value
_{Compiler-Unions - native}
_Errors	₄₁	₄₁	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_88,466	_88,466	_~	_~	_~	_{p=1.000 n=20}
_Types	_79,607	_79,607	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{104,151k (± 0.02%)}	_{104,153k (± 0.03%)}	_~	_104,034k	_104,231k	_{p=0.799 n=20}
_{Memory Allocs}	_{1,263,826 (± 0.01%)}	_{1,263,835 (± 0.01%)}	_~	_1,263,330	_1,264,472	_{p=0.883 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.024s (± 2.48%)}	_{0.023s (± 2.90%)}	_~	_0.021s	_0.026s	_{p=0.333 n=20}
_{Bind Time}	_{0.009s (± 6.20%)}	_{0.009s (± 6.32%)}	_~	_0.008s	_0.013s	_{p=0.579 n=20}
_{Check Time}	_{0.222s (± 2.30%)}	_{0.218s (± 3.40%)}	_{-0.003s (- 1.49%)}	_0.208s	_0.271s	_{p=0.000 n=20}
_{Emit Time}	_{0.143s (± 0.77%)}	_{0.144s (± 2.50%)}	_~	_0.137s	_0.173s	_{p=0.984 n=20}
_{Total Time}	_{0.401s (± 1.57%)}	_{0.398s (± 2.66%)}	_{-0.002s (- 0.55%)}	_0.385s	_0.484s	_{p=0.002 n=20}
_{angular-1 - native}
_Errors	₃	₃	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_{586,519 (± 0.01%)}	_{586,456 (± 0.01%)}	_~	_586,140	_586,712	_{p=0.199 n=20}
_Types	_{241,687 (± 0.00%)}	_{241,687 (± 0.00%)}	_~	_241,683	_241,698	_{p=0.355 n=20}
_{Memory Used}	_{517,991k (± 0.02%)}	_{517,878k (± 0.01%)}	_~	_517,565k	_518,129k	_{p=0.096 n=20}
_{Memory Allocs}	_{7,800,361 (± 0.17%)}	_{7,793,356 (± 0.06%)}	_~	_7,785,754	_7,829,081	_{p=0.620 n=20}
_{Config Time}	_0.009s	_0.009s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.131s (± 4.56%)}	_{0.125s (± 2.50%)}	_~	_0.113s	_0.135s	_{p=0.323 n=20}
_{Bind Time}	_{0.043s (±10.51%)}	_{0.047s (±11.26%)}	_~	_0.038s	_0.069s	_{p=0.118 n=20}
_{Check Time}	_0s	_0s	_~	_~	_~	_{p=1.000 n=20}
_{Emit Time}	_{0.852s (± 1.75%)}	_{0.852s (± 0.99%)}	_~	_0.824s	_0.884s	_{p=0.507 n=20}
_{Total Time}	_{1.045s (± 1.78%)}	_{1.044s (± 1.17%)}	_~	_1.015s	_1.085s	_{p=0.644 n=20}
_{arktype - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_685,920	_685,920	_~	_~	_~	_{p=1.000 n=20}
_Types	_939,467	_939,467	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{497,278k (± 0.01%)}	_{497,258k (± 0.01%)}	_~	_497,066k	_497,459k	_{p=0.417 n=20}
_{Memory Allocs}	_{12,109,194 (± 0.02%)}	_{12,108,885 (± 0.02%)}	_~	_12,104,066	_12,118,804	_{p=0.968 n=20}
_{Config Time}	_0.001s	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.042s (± 4.32%)}	_{0.043s (± 3.20%)}	_~	_0.038s	_0.048s	_{p=0.539 n=20}
_{Bind Time}	_{0.013s (± 8.32%)}	_{0.014s (±10.07%)}	_~	_0.012s	_0.020s	_{p=0.681 n=20}
_{Check Time}	_{1.016s (± 0.66%)}	_{1.001s (± 0.63%)}	_{-0.015s (- 1.46%)}	_0.972s	_1.029s	_{p=0.002 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{1.104s (± 0.58%)}	_{1.088s (± 0.58%)}	_{-0.016s (- 1.44%)}	_1.061s	_1.109s	_{p=0.001 n=20}
_{class-transformer - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_45,376	_45,376	_~	_~	_~	_{p=1.000 n=20}
_Types	_7,573	_7,573	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{27,835k (± 0.02%)}	_{27,835k (± 0.02%)}	_~	_27,815k	_27,863k	_{p=0.878 n=20}
_{Memory Allocs}	_{248,602 (± 0.04%)}	_{248,506 (± 0.06%)}	_~	_247,894	_249,319	_{p=0.204 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.011s (± 5.56%)}	_{0.011s (± 4.46%)}	_~	_0.009s	_0.013s	_{p=0.689 n=20}
_{Bind Time}	_{0.003s (±10.28%)}	_{0.003s (± 8.07%)}	_~	_0.003s	_0.005s	_{p=0.919 n=20}
_{Check Time}	_{0.008s (± 3.58%)}	_{0.008s (± 5.25%)}	_~	_0.007s	_0.010s	_{p=0.119 n=20}
_{Emit Time}	_{0.008s (± 5.80%)}	_{0.008s (± 6.60%)}	_~	_0.007s	_0.010s	_{p=0.722 n=20}
_{Total Time}	_{0.031s (± 2.70%)}	_{0.032s (± 2.12%)}	_~	_0.029s	_0.033s	_{p=0.320 n=20}
_{effect - native}
_Errors	₁₂	₁₂	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_1,235,115	_1,235,115	_~	_~	_~	_{p=1.000 n=20}
_Types	_894,113	_894,113	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{940,553k (± 0.02%)}	_{940,646k (± 0.03%)}	_~	_939,720k	_941,755k	_{p=0.583 n=20}
_{Memory Allocs}	_{12,669,768 (± 0.02%)}	_{12,671,308 (± 0.03%)}	_~	_12,663,512	_12,690,831	_{p=0.799 n=20}
_{Config Time}	_0.002s	_0.002s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.148s (± 1.59%)}	_{0.147s (± 1.48%)}	_~	_0.140s	_0.157s	_{p=0.372 n=20}
_{Bind Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{0.933s (± 0.72%)}	_{0.923s (± 0.66%)}	_{-0.010s (- 1.06%)}	_0.900s	_0.947s	_{p=0.026 n=20}
_{Emit Time}	_{0.507s (± 2.15%)}	_{0.522s (± 4.84%)}	_~	_0.461s	_0.737s	_{p=0.763 n=20}
_{Total Time}	_{1.684s (± 0.58%)}	_{1.691s (± 1.57%)}	_~	_1.648s	_1.923s	_{p=0.394 n=20}
_{mui-docs - native}
_Errors	_11,405	_11,405	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_3,784,019	_3,784,019	_~	_~	_~	_{p=1.000 n=20}
_Types	_1,355,974	_1,355,974	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{1,836,608k (± 0.07%)}	_{1,836,424k (± 0.07%)}	_~	_1,829,441k	_1,840,177k	_{p=0.718 n=20}
_{Memory Allocs}	_{25,980,436 (± 0.12%)}	_{25,981,113 (± 0.11%)}	_~	_25,899,275	_26,124,498	_{p=0.925 n=20}
_{Config Time}	_0.008s	_0.008s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.293s (± 2.11%)}	_{0.290s (± 1.78%)}	_~	_0.276s	_0.322s	_{p=0.304 n=20}
_{Bind Time}	_{0.001s (±18.96%)}	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{3.138s (± 0.58%)}	_{3.134s (± 0.85%)}	_~	_3.075s	_3.342s	_{p=0.425 n=20}
_{Emit Time}	_{0.247s (± 1.70%)}	_{0.245s (± 1.33%)}	_~	_0.236s	_0.258s	_{p=0.569 n=20}
_{Total Time}	_{4.189s (± 0.63%)}	_{4.174s (± 0.72%)}	_~	_4.089s	_4.396s	_{p=0.274 n=20}
_{sentry - native}
_Errors	₂	₂	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_4,793,245	_4,793,245	_~	_~	_~	_{p=1.000 n=20}
_Types	_2,607,045	_2,607,045	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{2,880,943k (± 0.02%)}	_{2,880,931k (± 0.02%)}	_~	_2,879,571k	_2,885,706k	_{p=0.904 n=20}
_{Memory Allocs}	_{75,271,962 (± 0.19%)}	_{75,327,708 (± 0.24%)}	_~	_74,809,688	_76,097,403	_{p=0.678 n=20}
_{Config Time}	_{0.026s (± 1.19%)}	_{0.026s (± 1.00%)}	_~	_0.025s	_0.027s	_{p=0.762 n=20}
_{Parse Time}	_{0.484s (± 3.16%)}	_{0.500s (± 4.65%)}	_~	_0.438s	_0.630s	_{p=0.208 n=20}
_{Bind Time}	_{0.161s (±10.34%)}	_{0.173s (±10.57%)}	_~	_0.140s	_0.238s	_{p=0.279 n=20}
_{Check Time}	_{6.831s (± 0.50%)}	_{6.778s (± 0.55%)}	_{-0.053s (- 0.78%)}	_6.657s	_6.930s	_{p=0.039 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{7.553s (± 0.49%)}	_{7.529s (± 0.52%)}	_~	_7.396s	_7.677s	_{p=0.449 n=20}
_{social-app - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_1,883,074	_1,883,074	_~	_~	_~	_{p=1.000 n=20}
_Types	_1,158,168	_1,158,168	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{972,408k (± 0.02%)}	_{972,399k (± 0.01%)}	_~	_971,239k	_972,874k	_{p=0.888 n=20}
_{Memory Allocs}	_{13,579,674 (± 0.14%)}	_{13,606,268 (± 0.31%)}	_~	_13,523,688	_13,853,997	_{p=0.698 n=20}
_{Config Time}	_0.008s	_{0.008s (± 1.30%)}	_~	_0.008s	_0.009s	_{p=1.000 n=20}
_{Parse Time}	_{0.159s (± 2.32%)}	_{0.164s (± 2.51%)}	_~	_0.148s	_0.182s	_{p=0.092 n=20}
_{Bind Time}	_{0.046s (±11.23%)}	_{0.045s (± 8.45%)}	_~	_0.039s	_0.066s	_{p=0.242 n=20}
_{Check Time}	_{1.492s (± 0.69%)}	_{1.478s (± 0.84%)}	_~	_1.430s	_1.533s	_{p=0.092 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{1.721s (± 0.82%)}	_{1.713s (± 0.82%)}	_~	_1.664s	_1.783s	_{p=0.465 n=20}
_{strada-build-src - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_1,184,972	_1,184,972	_~	_~	_~	_{p=1.000 n=20}
_Types	_438,963	_438,963	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{1,170,883k (± 0.60%)}	_{1,167,987k (± 0.26%)}	_~	_1,155,560k	_1,188,764k	_{p=0.862 n=20}
_{Memory Allocs}	_{47,721,096 (± 0.11%)}	_{47,739,426 (± 0.10%)}	_~	_47,597,872	_48,026,484	_{p=0.640 n=20}
_{Config Time}	_{0.002s (±16.91%)}	_{0.002s (±18.20%)}	_~	_0.000s	_0.002s	_{p=0.229 n=20}
_{Parse Time}	_{0.140s (± 1.94%)}	_{0.140s (± 1.23%)}	_~	_0.133s	_0.146s	_{p=0.514 n=20}
_{Bind Time}	_{0.000s (±143.57%)}	_0.000s	_~	_~	_~	_{p=0.487 n=20}
_{Check Time}	_{0.837s (± 1.19%)}	_{0.832s (± 0.87%)}	_~	_0.816s	_0.872s	_{p=0.267 n=20}
_{Emit Time}	_{0.145s (± 2.08%)}	_{0.145s (± 1.41%)}	_~	_0.140s	_0.157s	_{p=0.835 n=20}
_{Total Time}	_{9.696s (± 1.24%)}	_{9.633s (± 1.02%)}	_~	_9.425s	_10.275s	_{p=0.331 n=20}
_{strada-compiler - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_263,511	_263,511	_~	_~	_~	_{p=1.000 n=20}
_Types	_196,116	_196,116	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{224,624k (± 0.02%)}	_{224,587k (± 0.02%)}	_~	_224,448k	_224,697k	_{p=0.242 n=20}
_{Memory Allocs}	_{2,401,710 (± 0.01%)}	_{2,401,414 (± 0.01%)}	_~	_2,399,640	_2,402,598	_{p=0.327 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.050s (± 2.70%)}	_{0.052s (± 3.46%)}	_~	_0.045s	_0.058s	_{p=0.138 n=20}
_{Bind Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{0.397s (± 0.90%)}	_{0.393s (± 1.29%)}	_~	_0.378s	_0.428s	_{p=0.053 n=20}
_{Emit Time}	_{0.048s (± 5.63%)}	_{0.051s (± 4.61%)}	_~	_0.043s	_0.058s	_{p=0.078 n=20}
_{Total Time}	_{0.523s (± 0.88%)}	_{0.525s (± 1.20%)}	_~	_0.507s	_0.569s	_{p=0.888 n=20}
_{t3code-server - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_4,350,661	_4,350,661	_~	_~	_~	_{p=1.000 n=20}
_Types	_3,040,644	_3,040,644	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{2,433,944k (± 0.04%)}	_{2,433,389k (± 0.02%)}	_~	_2,432,109k	_2,436,461k	_{p=0.380 n=20}
_{Memory Allocs}	_{37,415,107 (± 0.13%)}	_{37,373,584 (± 0.06%)}	_~	_37,308,580	_37,464,783	_{p=0.265 n=20}
_{Config Time}	_{0.003s (± 6.00%)}	_{0.003s (± 6.84%)}	_~	_0.002s	_0.003s	_{p=1.000 n=20}
_{Parse Time}	_{0.252s (± 2.15%)}	_{0.249s (± 1.75%)}	_~	_0.233s	_0.272s	_{p=0.364 n=20}
_{Bind Time}	_{0.088s (±11.03%)}	_{0.079s (± 4.76%)}	_~	_0.073s	_0.112s	_{p=0.055 n=20}
_{Check Time}	_{7.140s (± 0.37%)}	_{7.026s (± 0.36%)}	_{-0.115s (- 1.61%)}	_6.962s	_7.154s	_{p=0.000 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{7.492s (± 0.36%)}	_{7.367s (± 0.38%)}	_{-0.125s (- 1.67%)}	_7.297s	_7.508s	_{p=0.000 n=20}
_{tanstack-router - native}
_Errors	₁	₁	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_571,756	_571,756	_~	_~	_~	_{p=1.000 n=20}
_Types	_397,689	_397,689	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{331,435k (± 0.01%)}	_{331,451k (± 0.01%)}	_~	_331,193k	_331,642k	_{p=0.344 n=20}
_{Memory Allocs}	_{4,389,047 (± 0.12%)}	_{4,395,061 (± 0.19%)}	_~	_4,376,848	_4,439,355	_{p=0.461 n=20}
_{Config Time}	_0.001s	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.042s (± 3.80%)}	_{0.040s (± 4.26%)}	_~	_0.034s	_0.049s	_{p=0.138 n=20}
_{Bind Time}	_{0.013s (± 9.09%)}	_{0.014s (±12.31%)}	_~	_0.011s	_0.022s	_{p=0.683 n=20}
_{Check Time}	_{0.574s (± 1.05%)}	_{0.572s (± 0.57%)}	_~	_0.564s	_0.590s	_{p=0.135 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.650s (± 1.00%)}	_{0.648s (± 0.67%)}	_~	_0.636s	_0.673s	_{p=0.323 n=20}
_{ts-pre-modules - native}
_Errors	₈₇	₈₇	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_231,616	_231,616	_~	_~	_~	_{p=1.000 n=20}
_Types	_181,195	_181,195	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{193,533k (± 0.01%)}	_{193,523k (± 0.01%)}	_~	_193,429k	_193,612k	_{p=0.387 n=20}
_{Memory Allocs}	_{1,318,367 (± 0.02%)}	_{1,318,211 (± 0.01%)}	_~	_1,317,599	_1,319,239	_{p=0.602 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.044s (± 3.15%)}	_{0.043s (± 2.37%)}	_~	_0.039s	_0.049s	_{p=0.413 n=20}
_{Bind Time}	_{0.020s (± 6.22%)}	_{0.022s (± 4.63%)}	_{🔻+0.002s (+11.00%)}	_0.019s	_0.027s	_{p=0.008 n=20}
_{Check Time}	_{0.294s (± 0.90%)}	_{0.290s (± 0.99%)}	_~	_0.280s	_0.298s	_{p=0.072 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.364s (± 0.64%)}	_{0.362s (± 0.73%)}	_~	_0.352s	_0.371s	_{p=0.309 n=20}
_{vscode - native}
_Errors	₁₁	₁₁	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_7,480,295	_7,480,295	_~	_~	_~	_{p=1.000 n=20}
_Types	_4,389,939	_4,389,939	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{5,201,136k (± 0.01%)}	_{5,200,833k (± 0.02%)}	_~	_5,197,695k	_5,204,394k	_{p=0.565 n=20}
_{Memory Allocs}	_{56,960,948 (± 0.02%)}	_{56,965,822 (± 0.02%)}	_~	_56,939,077	_57,036,993	_{p=0.620 n=20}
_{Config Time}	_{0.034s (± 3.15%)}	_{0.033s (± 0.90%)}	_~	_0.032s	_0.035s	_{p=0.983 n=20}
_{Parse Time}	_{0.906s (± 3.02%)}	_{0.895s (± 1.81%)}	_~	_0.825s	_1.002s	_{p=0.784 n=20}
_{Bind Time}	_{0.307s (± 5.32%)}	_{0.316s (± 7.80%)}	_~	_0.291s	_0.495s	_{p=0.364 n=20}
_{Check Time}	_{7.391s (± 0.52%)}	_{7.359s (± 0.68%)}	_~	_7.142s	_7.594s	_{p=0.245 n=20}
_{Emit Time}	_{2.830s (± 4.80%)}	_{2.890s (± 5.31%)}	_~	_2.583s	_3.536s	_{p=0.273 n=20}
_{Total Time}	_{11.526s (± 1.02%)}	_{11.553s (± 1.18%)}	_~	_11.254s	_12.265s	_{p=0.968 n=20}
_{webpack - native}
_Errors	₆₁₆	₆₁₆	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_917,188	_917,188	_~	_~	_~	_{p=1.000 n=20}
_Types	_636,859	_636,859	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{693,424k (± 0.02%)}	_{693,559k (± 0.01%)}	_~	_693,221k	_693,937k	_{p=0.086 n=20}
_{Memory Allocs}	_{6,499,934 (± 0.04%)}	_{6,500,744 (± 0.05%)}	_~	_6,493,903	_6,518,222	_{p=0.862 n=20}
_{Config Time}	_0.004s	_0.004s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.141s (± 2.05%)}	_{0.139s (± 3.26%)}	_~	_0.124s	_0.165s	_{p=0.615 n=20}
_{Bind Time}	_{0.045s (±10.61%)}	_{0.045s (± 9.21%)}	_~	_0.038s	_0.074s	_{p=0.576 n=20}
_{Check Time}	_{1.131s (± 0.34%)}	_{1.097s (± 0.52%)}	_{🟩-0.034s (- 3.01%)}	_1.078s	_1.120s	_{p=0.000 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{1.345s (± 0.56%)}	_{1.310s (± 0.54%)}	_{-0.035s (- 2.60%)}	_1.288s	_1.340s	_{p=0.000 n=20}
_{xstate-main - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_640,490	_640,490	_~	_~	_~	_{p=1.000 n=20}
_Types	_387,984	_387,984	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{350,906k (± 0.02%)}	_{350,955k (± 0.03%)}	_~	_350,663k	_351,537k	_{p=0.478 n=20}
_{Memory Allocs}	_{3,991,054 (± 0.07%)}	_{3,993,299 (± 0.12%)}	_~	_3,982,116	_4,031,084	_{p=0.738 n=20}
_{Config Time}	_0.001s	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.061s (± 2.83%)}	_{0.061s (± 2.60%)}	_~	_0.055s	_0.067s	_{p=0.549 n=20}
_{Bind Time}	_{0.022s (±10.14%)}	_{0.021s (± 8.80%)}	_~	_0.018s	_0.028s	_{p=0.511 n=20}
_{Check Time}	_{0.425s (± 2.05%)}	_{0.426s (± 1.40%)}	_~	_0.410s	_0.464s	_{p=0.440 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.514s (± 1.74%)}	_{0.514s (± 1.26%)}	_~	_0.493s	_0.553s	_{p=0.634 n=20}

System info unknown

Hosts

native

Scenarios

Compiler-Unions - native
angular-1 - native
arktype - native
class-transformer - native
effect - native
mui-docs - native
sentry - native
social-app - native
strada-build-src - native
strada-compiler - native
t3code-server - native
tanstack-router - native
ts-pre-modules - native
vscode - native
webpack - native
xstate-main - native

_Benchmark	_Name	_Iterations
_Current	_pr	₂₀
_Baseline	_baseline	₂₀

Developer Information:

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Jake Bailey (jakebailey) and others added 5 commits October 29, 2026 15:08

Copilot AI balanced review requested due to automatic review settings October 29, 2026 22:37

github-project-automation Bot added this to PR Backlog Oct 29, 2026

github-project-automation Bot moved this to Not started in PR Backlog Oct 29, 2026

typescript-automation Bot assigned Jake Bailey (jakebailey) Oct 29, 2026

typescript-automation Bot added Author: Team For Uncommitted Bug PR for untriaged, rejected, closed or missing bug labels Oct 29, 2026

Copilot started reviewing on behalf of Jake Bailey (jakebailey) October 29, 2026 22:37

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Jake Bailey (jakebailey) added the Domain: Performance Reports of unusually slow behavior label Oct 29, 2026

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Cache type classification answers on types - #65042

Cache type classification answers on types#65042
Jake Bailey (jakebailey) wants to merge 5 commits into
microsoft:mainfrom
jakebailey:perf/type-fact-bits

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