[Max Schwenk (maschwenk)]

isWeakType resolves the members of the type it's given. for an instantiation of a generic class or interface that instantiates every declared member and copies in every inherited one, only to check that there are no signatures or index infos and every property is optional. instantiating doesn't change any of that unless a base type is a type parameter (a class declared in a generic function can extend base<T>()), so when none is, this asks the target instead, whose members are resolved once and never instantiated. weakTypeWithTypeParameterBase.ts covers the type parameter case

isRelatedToEx calls isWeakType on the target before it gets to structuredTypeRelatedTo, where two references to the same generic type are compared by variance without looking at members. so an instantiation that's only ever a relation target, and only ever related through its type arguments, still had its whole member table built here

tuple targets are left out. doing the same for them made vscode slightly worse, and tuples are never weak anyway (length is required)

heap after check (Memory used from --extendedDiagnostics), median of 3, same diagnostics with and without this:

	4 checkers	--singleThreaded
t3code apps/server	4.78 → 3.86 GB (−19%)	2.58 → 2.33 GB (−10%)
webpack	0.93 → 0.87 GB (−6%)	0.71 → 0.67 GB (−5%)
xstate-main	0.58 → 0.56 GB (−3%)	0.46 → 0.45 GB (−1%)
vscode	6.09 → 6.04 GB (−0.8%)	5.18 → 5.15 GB (−0.6%)
mui-docs, Compiler, Compiler-Unions	within ±0.3%	within ±0.3%
a private 38k-file monorepo project	19.83 → 17.55 GB (−11.5%)	13.07 → 11.85 GB (−9.3%)

on t3code peak rss goes from 5.49 to 4.62 GB with 4 checkers and the symbol count from 11.1M to 7.5M. on the monorepo project peak rss goes from 23.1 to 21.0 GB. check time doesn't get worse anywhere (it's within noise except the monorepo project single threaded, 42.9 → 38.7s)

my guess at why t3code gains the most: effect's api is built from generic interfaces with a lot of members, often through long extends chains (Rpc, the schema Bottom* interfaces, Effect), and every rpc or schema definition is its own instantiation. most checks between them are reference to reference with the same target, which variance answers from the type arguments, so before this the member tables were mostly built just for isWeakType. on t3code's server, 1.02M of the 1.03M instantiated members of Rpc came from this check

t3code is pingdotgg/t3code at 9bd1d800 (effect 4), tsc -p apps/server --noEmit. webpack, xstate-main, vscode, mui-docs and the Compiler cases are the typescript-benchmarking projects

related, avoids these resolutions (and more) by building member tables lazily:

• build member tables of instantiated classes/interfaces lazily #64475

🤖 Generated with Claude Code

[typescript-automation]

This PR doesn't have any linked issues. Please open an issue that references this PR. From there we can discuss and prioritise.

[Copilot]

Copilot review overview

🟡 Changes recommended

Captured generic base types can change inherited signatures, causing incorrect weak-type diagnostics.

Review effort: Balanced
Findings: 1

Open (1)

• Preserve instantiation-specific checking for captured generic base shapes · New

What changed in this PR

Optimizes weak-type detection to avoid resolving members for generic class/interface instantiations.

Changes:

• Checks the generic target instead of instantiated members.
• Excludes tuples from the optimization.

File	Description
tsc/​internal/​checker/​relater.go	Optimizes isWeakType for type references.

---

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The results of the perf run you requested are in!

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tsc

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Compiler-Unions - native
Errors	41	41	~	~	~	p=1.000 n=12
Symbols	115,276	114,129	-1,147 (- 1.00%)	~	~	p=0.000 n=12
Types	79,613	79,277	-336 (- 0.42%)	~	~	p=0.000 n=12
Memory Used	141,849k (± 0.33%)	141,284k (± 0.30%)	~	140,204k	142,336k	p=0.052 n=12
Memory Allocs	2,193,620 (± 0.01%)	2,191,308 (± 0.01%)	-2,312 (- 0.11%)	2,190,868	2,191,763	p=0.000 n=12
Config Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Parse Time	0.050s (± 3.12%)	0.052s (± 4.15%)	~	0.046s	0.056s	p=0.134 n=12
Bind Time	0.015s (±13.12%)	0.015s (± 8.11%)	~	0.013s	0.018s	p=0.893 n=12
Check Time	0.592s (± 0.65%)	0.609s (± 0.86%)	+0.017s (+ 2.81%)	0.599s	0.624s	p=0.000 n=12
Emit Time	0.324s (± 2.30%)	0.331s (± 2.30%)	~	0.304s	0.346s	p=0.117 n=12
Total Time	0.990s (± 0.77%)	1.014s (± 1.06%)	+0.025s (+ 2.52%)	0.981s	1.046s	p=0.001 n=12
angular-1 - native
Errors	3	3	~	~	~	p=1.000 n=12
Symbols	846,902 (± 0.08%)	837,259 (± 0.08%)	-9,642 (- 1.14%)	836,007	838,813	p=0.000 n=12
Types	249,941 (± 0.00%)	249,860 (± 0.00%)	-81 (- 0.03%)	249,856	249,868	p=0.000 n=12
Memory Used	789,309k (± 0.04%)	786,897k (± 0.03%)	-2,412k (- 0.31%)	786,290k	787,654k	p=0.000 n=12
Memory Allocs	12,864,708 (± 0.04%)	12,858,412 (± 0.01%)	-6,295 (- 0.05%)	12,854,892	12,865,521	p=0.008 n=12
Config Time	0.020s	0.020s (± 1.21%)	~	0.020s	0.021s	p=0.478 n=12
Parse Time	0.320s (± 2.77%)	0.326s (± 2.80%)	~	0.297s	0.346s	p=0.131 n=12
Bind Time	0.084s (±18.20%)	0.077s (± 7.34%)	~	0.069s	0.100s	p=0.286 n=12
Check Time	0s	0s	~	~	~	p=1.000 n=12
Emit Time	1.917s (± 1.06%)	1.928s (± 1.21%)	~	1.897s	2.030s	p=0.271 n=12
Total Time	2.355s (± 1.26%)	2.368s (± 1.15%)	~	2.324s	2.488s	p=0.139 n=12
mui-docs - native
Errors	11,405	11,405	~	~	~	p=1.000 n=12
Symbols	4,351,480	4,356,767	+5,287 (+ 0.12%)	~	~	p=0.000 n=12
Types	1,380,970	1,379,976	-994 (- 0.07%)	~	~	p=0.000 n=12
Memory Used	2,974,898k (± 0.05%)	2,982,342k (± 0.04%)	+7,444k (+ 0.25%)	2,979,300k	2,987,455k	p=0.000 n=12
Memory Allocs	32,827,685 (± 0.06%)	32,822,610 (± 0.04%)	~	32,781,895	32,862,134	p=0.799 n=12
Config Time	0.020s (± 1.21%)	0.020s	~	~	~	p=0.478 n=12
Parse Time	0.611s (± 2.56%)	0.610s (± 2.69%)	~	0.556s	0.667s	p=0.766 n=12
Bind Time	0.003s (±12.54%)	0.003s (±13.14%)	~	0.002s	0.003s	p=1.000 n=12
Check Time	10.164s (± 0.66%)	10.239s (± 0.87%)	~	9.918s	10.400s	p=0.060 n=12
Emit Time	0.525s (± 6.39%)	0.517s (± 5.00%)	-0.008s (- 1.54%)	0.499s	0.647s	p=0.023 n=12
Total Time	12.269s (± 0.44%)	12.327s (± 0.47%)	~	12.218s	12.475s	p=0.089 n=12
strada-build-src - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	1,390,229	1,388,249	-1,980 (- 0.14%)	~	~	p=0.000 n=12
Types	441,498	440,506	-992 (- 0.22%)	~	~	p=0.000 n=12
Memory Used	1,681,724k (± 1.10%)	1,671,732k (± 0.76%)	~	1,645,572k	1,718,296k	p=0.671 n=12
Memory Allocs	92,114,503 (± 0.19%)	92,011,194 (± 0.12%)	~	91,667,286	92,264,795	p=0.291 n=12
Config Time	0.004s (±11.30%)	0.004s (±12.60%)	~	0.003s	0.005s	p=0.800 n=12
Parse Time	0.244s (± 4.85%)	0.229s (± 3.00%)	🟩-0.015s (- 6.04%)	0.213s	0.249s	p=0.037 n=12
Bind Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Check Time	2.167s (± 0.58%)	2.206s (± 0.76%)	+0.038s (+ 1.78%)	2.155s	2.243s	p=0.001 n=12
Emit Time	0.351s (± 5.10%)	0.352s (± 4.35%)	~	0.324s	0.392s	p=0.943 n=12
Total Time	28.350s (± 0.67%)	28.595s (± 0.61%)	~	28.132s	29.024s	p=0.052 n=12
strada-compiler - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	334,953	332,790	-2,163 (- 0.65%)	~	~	p=0.000 n=12
Types	197,616	197,112	-504 (- 0.26%)	~	~	p=0.000 n=12
Memory Used	313,275k (± 0.04%)	312,414k (± 0.03%)	-861k (- 0.27%)	312,227k	312,710k	p=0.000 n=12
Memory Allocs	4,622,964 (± 0.01%)	4,619,290 (± 0.01%)	-3,675 (- 0.08%)	4,617,640	4,620,791	p=0.000 n=12
Config Time	0.001s	0.001s	~	~	~	p=1.000 n=12
Parse Time	0.111s (± 5.99%)	0.114s (± 4.42%)	~	0.103s	0.127s	p=0.385 n=12
Bind Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Check Time	1.048s (± 0.60%)	1.062s (± 0.52%)	+0.014s (+ 1.32%)	1.050s	1.080s	p=0.004 n=12
Emit Time	0.119s (±13.13%)	0.134s (±12.11%)	~	0.098s	0.160s	p=0.075 n=12
Total Time	1.336s (± 0.95%)	1.362s (± 0.99%)	+0.026s (+ 1.95%)	1.331s	1.398s	p=0.015 n=12
ts-pre-modules - native
Errors	87	87	~	~	~	p=1.000 n=12
Symbols	303,834	301,677	-2,157 (- 0.71%)	~	~	p=0.000 n=12
Types	181,663	181,129	-534 (- 0.29%)	~	~	p=0.000 n=12
Memory Used	273,883k (± 0.02%)	273,172k (± 0.02%)	-712k (- 0.26%)	272,966k	273,327k	p=0.000 n=12
Memory Allocs	1,615,976 (± 0.01%)	1,612,516 (± 0.01%)	-3,460 (- 0.21%)	1,612,077	1,613,329	p=0.000 n=12
Config Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Parse Time	0.096s (± 2.91%)	0.101s (± 5.62%)	~	0.087s	0.111s	p=0.139 n=12
Bind Time	0.038s (±10.20%)	0.041s (±10.75%)	~	0.029s	0.051s	p=0.223 n=12
Check Time	0.823s (± 0.45%)	0.832s (± 0.58%)	+0.010s (+ 1.16%)	0.822s	0.845s	p=0.004 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	0.971s (± 0.41%)	0.990s (± 0.67%)	+0.019s (+ 2.01%)	0.974s	1.009s	p=0.000 n=12
vscode - native
Errors	380	380	~	~	~	p=1.000 n=12
Symbols	10,815,602	10,650,969	-164,633 (- 1.52%)	~	~	p=0.000 n=12
Types	3,599,368	3,587,540	-11,828 (- 0.33%)	~	~	p=0.000 n=12
Memory Used	6,988,889k (± 0.02%)	6,936,545k (± 0.02%)	-52,343k (- 0.75%)	6,934,153k	6,940,196k	p=0.000 n=12
Memory Allocs	53,528,400 (± 0.02%)	53,386,874 (± 0.01%)	-141,527 (- 0.26%)	53,374,098	53,406,640	p=0.000 n=12
Config Time	0.074s (± 0.53%)	0.074s (± 0.49%)	~	0.073s	0.075s	p=0.870 n=12
Parse Time	1.807s (± 3.86%)	1.795s (± 4.41%)	~	1.641s	1.960s	p=0.855 n=12
Bind Time	0.583s (±18.42%)	0.600s (±20.19%)	~	0.434s	0.894s	p=0.932 n=12
Check Time	13.623s (± 1.29%)	13.494s (± 1.35%)	~	13.154s	13.842s	p=0.410 n=12
Emit Time	4.628s (±11.07%)	5.198s (±11.18%)	~	4.130s	6.117s	p=0.089 n=12
Total Time	20.797s (± 1.88%)	21.248s (± 2.05%)	~	20.392s	21.985s	p=0.052 n=12
webpack - native
Errors	589	589	~	~	~	p=1.000 n=12
Symbols	1,298,698	1,218,100	🟩-80,598 (- 6.21%)	~	~	p=0.000 n=12
Types	614,057	604,703	-9,354 (- 1.52%)	~	~	p=0.000 n=12
Memory Used	1,003,869k (± 0.02%)	976,904k (± 0.02%)	-26,965k (- 2.69%)	976,309k	977,470k	p=0.000 n=12
Memory Allocs	6,537,134 (± 0.03%)	6,461,263 (± 0.04%)	-75,871 (- 1.16%)	6,455,801	6,468,841	p=0.000 n=12
Config Time	0.009s	0.009s	~	~	~	p=1.000 n=12
Parse Time	0.283s (± 3.97%)	0.287s (± 3.62%)	~	0.257s	0.313s	p=0.451 n=12
Bind Time	0.083s (±17.84%)	0.082s (±16.81%)	~	0.062s	0.127s	p=0.831 n=12
Check Time	2.061s (± 1.02%)	2.054s (± 1.38%)	~	2.008s	2.162s	p=0.355 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	2.472s (± 0.82%)	2.467s (± 1.43%)	~	2.407s	2.588s	p=0.434 n=12
xstate-main - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	1,055,167	987,563	🟩-67,604 (- 6.41%)	~	~	p=0.000 n=12
Types	387,939	385,710	-2,229 (- 0.57%)	~	~	p=0.000 n=12
Memory Used	610,243k (± 0.03%)	591,449k (± 0.03%)	🟩-18,793k (- 3.08%)	591,150k	592,082k	p=0.000 n=12
Memory Allocs	4,880,457 (± 0.07%)	4,833,642 (± 0.08%)	-46,814 (- 0.96%)	4,824,907	4,845,610	p=0.000 n=12
Config Time	0.002s	0.002s	~	~	~	p=1.000 n=12
Parse Time	0.116s (± 2.59%)	0.115s (± 3.41%)	~	0.105s	0.124s	p=0.560 n=12
Bind Time	0.031s (±12.91%)	0.034s (±19.93%)	~	0.025s	0.055s	p=0.674 n=12
Check Time	1.062s (± 0.54%)	1.050s (± 0.73%)	-0.012s (- 1.16%)	1.038s	1.081s	p=0.005 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	1.220s (± 0.66%)	1.207s (± 0.69%)	~	1.184s	1.233s	p=0.066 n=12

System info unknown

Hosts

• native

Scenarios

• Compiler-Unions - native
• angular-1 - native
• mui-docs - native
• strada-build-src - native
• strada-compiler - native
• ts-pre-modules - native
• vscode - native
• webpack - native
• xstate-main - native

Benchmark	Name	Iterations
Current	pr	12
Baseline	baseline	12

Developer Information:

Download Benchmarks

[typescript-automation]

Jake Bailey (@jakebailey) Here are the results of running the user tests with tsc comparing baseline and pr:

Everything looks good!

[typescript-automation]

Jake Bailey (@jakebailey) Here are the results of running the top 400 repos with tsc comparing baseline and pr:

Everything looks good!

[Anders Hejlsberg (ahejlsberg)]

This likely is no longer relevant now that #64915 is in main. With that PR, isWeakType operates on uninstantiated member layout properties.

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Anders Hejlsberg (@ahejlsberg)
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=12
Symbols	88,466	88,466	~	~	~	p=1.000 n=12
Types	79,607	79,271	-336 (- 0.42%)	~	~	p=0.000 n=12
Memory Used	109,195k (± 0.04%)	109,143k (± 0.06%)	~	109,015k	109,336k	p=0.117 n=12
Memory Allocs	2,196,680 (± 0.01%)	2,195,541 (± 0.01%)	-1,139 (- 0.05%)	2,195,019	2,196,176	p=0.000 n=12
Config Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Parse Time	0.038s (± 3.20%)	0.039s (± 4.74%)	~	0.036s	0.044s	p=0.382 n=12
Bind Time	0.014s (±12.39%)	0.013s (± 8.96%)	~	0.011s	0.017s	p=0.326 n=12
Check Time	0.477s (± 0.65%)	0.480s (± 0.90%)	~	0.474s	0.497s	p=0.520 n=12
Emit Time	0.266s (± 1.86%)	0.264s (± 1.74%)	~	0.252s	0.276s	p=0.540 n=12
Total Time	0.801s (± 0.74%)	0.802s (± 0.58%)	~	0.786s	0.812s	p=0.681 n=12
angular-1 - native
Errors	3	3	~	~	~	p=1.000 n=12
Symbols	586,636 (± 0.02%)	586,670 (± 0.02%)	~	586,392	586,899	p=0.799 n=12
Types	241,724 (± 0.00%)	241,645 (± 0.00%)	-79 (- 0.03%)	241,641	241,654	p=0.000 n=12
Memory Used	551,276k (± 0.03%)	551,304k (± 0.03%)	~	550,787k	551,731k	p=0.755 n=12
Memory Allocs	13,075,511 (± 0.04%)	13,073,619 (± 0.04%)	~	13,067,286	13,098,085	p=0.128 n=12
Config Time	0.017s (± 1.99%)	0.017s (± 1.07%)	~	0.016s	0.017s	p=0.069 n=12
Parse Time	0.227s (± 3.45%)	0.222s (± 2.28%)	~	0.210s	0.239s	p=0.234 n=12
Bind Time	0.073s (±15.09%)	0.082s (±12.82%)	~	0.059s	0.104s	p=0.202 n=12
Check Time	0s	0s	~	~	~	p=1.000 n=12
Emit Time	1.501s (± 1.60%)	1.519s (± 1.60%)	~	1.434s	1.574s	p=0.298 n=12
Total Time	1.835s (± 1.40%)	1.860s (± 1.54%)	~	1.762s	1.924s	p=0.104 n=12
arktype - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	685,943	685,039	-904 (- 0.13%)	~	~	p=0.000 n=12
Types	939,496	938,292	-1,204 (- 0.13%)	~	~	p=0.000 n=12
Memory Used	533,239k (± 0.01%)	532,949k (± 0.02%)	-290k (- 0.05%)	532,730k	533,262k	p=0.000 n=12
Memory Allocs	12,771,728 (± 0.01%)	12,769,953 (± 0.02%)	~	12,765,532	12,783,478	p=0.143 n=12
Config Time	0.002s	0.002s	~	~	~	p=1.000 n=12
Parse Time	0.072s (± 3.67%)	0.070s (± 3.02%)	~	0.066s	0.077s	p=0.245 n=12
Bind Time	0.021s (±11.57%)	0.020s (±11.30%)	~	0.018s	0.031s	p=0.276 n=12
Check Time	1.828s (± 0.66%)	1.825s (± 0.82%)	~	1.786s	1.860s	p=0.900 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	1.973s (± 0.52%)	1.964s (± 0.54%)	~	1.940s	1.998s	p=0.213 n=12
mui-docs - native
Errors	11,405	11,405	~	~	~	p=1.000 n=12
Symbols	3,855,253	3,856,921	+1,668 (+ 0.04%)	~	~	p=0.000 n=12
Types	1,370,331	1,369,085	-1,246 (- 0.09%)	~	~	p=0.000 n=12
Memory Used	2,309,655k (± 0.05%)	2,309,172k (± 0.05%)	~	2,305,475k	2,311,790k	p=0.724 n=12
Memory Allocs	27,160,676 (± 0.08%)	27,152,344 (± 0.06%)	~	27,087,408	27,182,748	p=0.443 n=12
Config Time	0.017s (± 1.86%)	0.017s (± 1.95%)	~	0.016s	0.017s	p=1.000 n=12
Parse Time	0.465s (± 2.56%)	0.476s (± 3.05%)	~	0.413s	0.503s	p=0.075 n=12
Bind Time	0.002s	0.002s	~	~	~	p=1.000 n=12
Check Time	6.572s (± 0.38%)	6.632s (± 0.65%)	+0.060s (+ 0.91%)	6.566s	6.772s	p=0.001 n=12
Emit Time	0.461s (± 1.80%)	0.453s (± 3.05%)	~	0.414s	0.466s	p=0.956 n=12
Total Time	8.273s (± 0.17%)	8.322s (± 0.19%)	+0.049s (+ 0.59%)	8.278s	8.366s	p=0.000 n=12
sentry - native
Errors	2	2	~	~	~	p=1.000 n=12
Symbols	4,793,345	4,799,215	+5,870 (+ 0.12%)	~	~	p=0.000 n=12
Types	2,607,067	2,579,286	-27,781 (- 1.07%)	~	~	p=0.000 n=12
Memory Used	3,207,883k (± 0.04%)	3,199,470k (± 0.03%)	-8,413k (- 0.26%)	3,197,451k	3,202,849k	p=0.000 n=12
Memory Allocs	75,281,387 (± 0.06%)	75,156,017 (± 0.10%)	-125,370 (- 0.17%)	75,001,823	75,411,547	p=0.003 n=12
Config Time	0.060s (± 0.54%)	0.061s (± 0.47%)	~	0.060s	0.061s	p=0.214 n=12
Parse Time	1.012s (± 2.09%)	1.025s (± 2.86%)	~	0.970s	1.131s	p=0.523 n=12
Bind Time	0.323s (±13.94%)	0.307s (±12.16%)	~	0.250s	0.441s	p=0.355 n=12
Check Time	13.757s (± 0.66%)	13.791s (± 0.52%)	~	13.620s	13.975s	p=0.452 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	15.232s (± 0.66%)	15.260s (± 0.54%)	~	15.084s	15.528s	p=0.524 n=12
social-app - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	1,883,343	1,883,857	+514 (+ 0.03%)	~	~	p=0.000 n=12
Types	1,158,474	1,154,151	-4,323 (- 0.37%)	~	~	p=0.000 n=12
Memory Used	1,057,607k (± 0.02%)	1,056,130k (± 0.01%)	-1,477k (- 0.14%)	1,055,873k	1,056,484k	p=0.000 n=12
Memory Allocs	13,590,981 (± 0.45%)	13,555,487 (± 0.16%)	~	13,511,448	13,621,584	p=0.266 n=12
Config Time	0.017s (± 1.65%)	0.017s (± 1.86%)	~	0.017s	0.018s	p=0.667 n=12
Parse Time	0.357s (± 2.33%)	0.353s (± 1.68%)	~	0.344s	0.372s	p=0.339 n=12
Bind Time	0.078s (± 7.27%)	0.084s (±14.79%)	~	0.073s	0.145s	p=0.127 n=12
Check Time	3.297s (± 0.71%)	3.312s (± 0.68%)	~	3.256s	3.361s	p=0.247 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	3.774s (± 0.53%)	3.791s (± 0.51%)	~	3.747s	3.850s	p=0.259 n=12
strada-build-src - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	1,184,988	1,184,999	+11 (+ 0.00%)	~	~	p=0.000 n=12
Types	438,967	437,965	-1,002 (- 0.23%)	~	~	p=0.000 n=12
Memory Used	1,274,371k (± 0.77%)	1,276,922k (± 0.50%)	~	1,268,156k	1,305,928k	p=0.514 n=12
Memory Allocs	77,405,542 (± 0.12%)	77,367,428 (± 0.05%)	~	77,270,878	77,485,828	p=0.089 n=12
Config Time	0.004s (±12.60%)	0.004s (±15.55%)	~	0.002s	0.005s	p=0.719 n=12
Parse Time	0.309s (± 1.49%)	0.311s (± 1.50%)	~	0.295s	0.321s	p=0.311 n=12
Bind Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Check Time	1.937s (± 0.40%)	1.948s (± 0.63%)	~	1.906s	1.970s	p=0.117 n=12
Emit Time	0.373s (± 4.10%)	0.378s (± 3.44%)	~	0.357s	0.423s	p=0.580 n=12
Total Time	23.383s (± 0.50%)	23.503s (± 0.42%)	~	23.261s	23.728s	p=0.143 n=12
strada-compiler - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	263,525	263,525	~	~	~	p=1.000 n=12
Types	196,118	195,614	-504 (- 0.26%)	~	~	p=0.000 n=12
Memory Used	236,009k (± 0.04%)	235,878k (± 0.03%)	-132k (- 0.06%)	235,686k	236,069k	p=0.039 n=12
Memory Allocs	4,287,161 (± 0.01%)	4,285,809 (± 0.01%)	-1,352 (- 0.03%)	4,284,763	4,286,609	p=0.001 n=12
Config Time	0.001s	0.001s	~	~	~	p=1.000 n=12
Parse Time	0.114s (± 3.52%)	0.114s (± 4.81%)	~	0.102s	0.131s	p=0.831 n=12
Bind Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Check Time	0.948s (± 0.52%)	0.949s (± 0.59%)	~	0.937s	0.964s	p=0.744 n=12
Emit Time	0.146s (± 2.60%)	0.137s (± 7.32%)	~	0.103s	0.153s	p=0.223 n=12
Total Time	1.262s (± 0.65%)	1.252s (± 0.75%)	~	1.226s	1.267s	p=0.103 n=12
t3code-server - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	4,350,705	4,153,590	🟩-197,115 (- 4.53%)	~	~	p=0.000 n=12
Types	3,040,691	3,006,818	-33,873 (- 1.11%)	~	~	p=0.000 n=12
Memory Used	2,610,559k (± 0.02%)	2,517,391k (± 0.02%)	🟩-93,169k (- 3.57%)	2,516,265k	2,518,693k	p=0.000 n=12
Memory Allocs	37,321,196 (± 0.04%)	35,858,748 (± 0.08%)	🟩-1,462,449 (- 3.92%)	35,809,751	35,987,247	p=0.000 n=12
Config Time	0.006s	0.006s	~	~	~	p=1.000 n=12
Parse Time	0.559s (± 2.53%)	0.575s (± 2.75%)	~	0.531s	0.617s	p=0.173 n=12
Bind Time	0.194s (±15.12%)	0.183s (±15.70%)	~	0.149s	0.273s	p=0.416 n=12
Check Time	16.450s (± 0.21%)	16.352s (± 0.23%)	-0.098s (- 0.60%)	16.206s	16.424s	p=0.000 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	17.226s (± 0.19%)	17.132s (± 0.25%)	-0.094s (- 0.55%)	16.974s	17.259s	p=0.000 n=12
ts-pre-modules - native
Errors	87	87	~	~	~	p=1.000 n=12
Symbols	231,636	231,636	~	~	~	p=1.000 n=12
Types	181,196	180,662	-534 (- 0.29%)	~	~	p=0.000 n=12
Memory Used	203,555k (± 0.01%)	203,363k (± 0.02%)	-192k (- 0.09%)	203,270k	203,432k	p=0.000 n=12
Memory Allocs	1,358,290 (± 0.01%)	1,356,050 (± 0.01%)	-2,239 (- 0.16%)	1,355,503	1,356,443	p=0.000 n=12
Config Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Parse Time	0.098s (± 5.20%)	0.099s (± 5.25%)	~	0.085s	0.107s	p=0.830 n=12
Bind Time	0.040s (±10.60%)	0.043s (± 9.68%)	~	0.031s	0.052s	p=0.560 n=12
Check Time	0.720s (± 0.94%)	0.722s (± 0.95%)	~	0.711s	0.745s	p=0.831 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	0.873s (± 0.75%)	0.878s (± 0.72%)	~	0.858s	0.892s	p=0.270 n=12
vscode - native
Errors	10	10	~	~	~	p=1.000 n=12
Symbols	7,184,157	7,184,097	-60 (- 0.00%)	~	~	p=0.000 n=12
Types	4,230,408	4,215,625	-14,783 (- 0.35%)	~	~	p=0.000 n=12
Memory Used	5,350,338k (± 0.02%)	5,345,164k (± 0.02%)	-5,174k (- 0.10%)	5,342,143k	5,347,558k	p=0.000 n=12
Memory Allocs	61,784,616 (± 0.01%)	61,720,997 (± 0.03%)	-63,619 (- 0.10%)	61,703,254	61,783,958	p=0.000 n=12
Config Time	0.078s (± 0.31%)	0.078s (± 0.36%)	~	0.078s	0.079s	p=1.000 n=12
Parse Time	1.947s (± 2.51%)	1.934s (± 2.57%)	~	1.831s	2.046s	p=0.887 n=12
Bind Time	0.702s (±15.07%)	0.769s (±15.73%)	~	0.544s	1.022s	p=0.452 n=12
Check Time	15.657s (± 1.38%)	15.540s (± 1.14%)	~	15.237s	15.975s	p=0.378 n=12
Emit Time	5.677s (± 8.92%)	6.000s (± 8.53%)	~	5.045s	6.919s	p=0.143 n=12
Total Time	24.144s (± 1.64%)	24.404s (± 1.77%)	~	23.409s	25.137s	p=0.213 n=12
webpack - native
Errors	602	602	~	~	~	p=1.000 n=12
Symbols	916,593	916,515	-78 (- 0.01%)	~	~	p=0.000 n=12
Types	643,793	633,115	-10,678 (- 1.66%)	~	~	p=0.000 n=12
Memory Used	765,075k (± 0.02%)	761,712k (± 0.01%)	-3,363k (- 0.44%)	761,494k	762,026k	p=0.000 n=12
Memory Allocs	6,540,156 (± 0.02%)	6,500,755 (± 0.02%)	-39,402 (- 0.60%)	6,498,072	6,504,253	p=0.000 n=12
Config Time	0.009s	0.009s	~	~	~	p=1.000 n=12
Parse Time	0.327s (± 2.33%)	0.319s (± 3.02%)	~	0.299s	0.346s	p=0.192 n=12
Bind Time	0.080s (± 7.06%)	0.079s (± 7.34%)	~	0.072s	0.101s	p=0.989 n=12
Check Time	2.976s (± 0.30%)	3.002s (± 0.26%)	+0.026s (+ 0.89%)	2.986s	3.022s	p=0.000 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	3.432s (± 0.47%)	3.448s (± 0.43%)	~	3.417s	3.490s	p=0.127 n=12
xstate-main - native
Errors	0	0	~	~	~	p=1.000 n=12
Symbols	640,566	639,795	-771 (- 0.12%)	~	~	p=0.000 n=12
Types	388,220	386,031	-2,189 (- 0.56%)	~	~	p=0.000 n=12
Memory Used	398,607k (± 0.03%)	397,501k (± 0.03%)	-1,106k (- 0.28%)	397,237k	397,731k	p=0.000 n=12
Memory Allocs	3,993,331 (± 0.12%)	3,969,346 (± 0.08%)	-23,985 (- 0.60%)	3,961,421	3,976,421	p=0.000 n=12
Config Time	0.002s	0.002s	~	~	~	p=1.000 n=12
Parse Time	0.107s (± 3.54%)	0.105s (± 3.46%)	~	0.098s	0.113s	p=0.503 n=12
Bind Time	0.037s (±16.80%)	0.035s (±19.30%)	~	0.026s	0.055s	p=0.408 n=12
Check Time	0.791s (± 0.69%)	0.796s (± 0.57%)	~	0.784s	0.809s	p=0.065 n=12
Emit Time	0.000s	0.000s	~	~	~	p=1.000 n=12
Total Time	0.943s (± 1.07%)	0.943s (± 0.79%)	~	0.930s	0.966s	p=0.744 n=12

System info unknown

Hosts

• native

Scenarios

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

Benchmark	Name	Iterations
Current	pr	12
Baseline	baseline	12

Developer Information:

Download Benchmarks

[typescript-automation]

Anders Hejlsberg (@ahejlsberg) Here are the results of running the user tests with tsc comparing baseline and pr:

Everything looks good!

[typescript-automation]

Anders Hejlsberg (@ahejlsberg) Here are the results of running the top 400 repos with tsc comparing baseline and pr:

Everything looks good!