Speed up `removeSubtypes` by looking up each target's key property type once per key property name by Andarist · Pull Request #65061 · microsoft/TypeScript

Mateusz Burzyński (Andarist) · 2026-10-30T17:50:08Z

No description provided.

… removeSubtypes

Jake Bailey (jakebailey) · 2026-10-30T17:53:25Z

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

typescript-automation · 2026-10-30T17:53:31Z

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

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

typescript-automation · 2026-10-30T18:47:44Z

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}	_{104,095k (± 0.03%)}	_{104,096k (± 0.03%)}	_~	_103,990k	_104,244k	_{p=0.846 n=20}
_{Memory Allocs}	_{1,262,381 (± 0.01%)}	_{1,262,555 (± 0.01%)}	_{+174 (+ 0.01%)}	_1,262,324	_1,262,841	_{p=0.001 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.023s (± 2.87%)}	_{0.023s (± 2.45%)}	_~	_0.021s	_0.025s	_{p=0.493 n=20}
_{Bind Time}	_{0.008s (± 6.45%)}	_{0.009s (± 6.91%)}	_~	_0.007s	_0.011s	_{p=0.219 n=20}
_{Check Time}	_{0.216s (± 0.92%)}	_{0.200s (± 0.64%)}	_{🟩-0.016s (- 7.38%)}	_0.195s	_0.207s	_{p=0.000 n=20}
_{Emit Time}	_{0.141s (± 1.29%)}	_{0.142s (± 1.17%)}	_~	_0.135s	_0.150s	_{p=0.447 n=20}
_{Total Time}	_{0.392s (± 0.59%)}	_{0.377s (± 0.62%)}	_{🟩-0.014s (- 3.65%)}	_0.366s	_0.386s	_{p=0.000 n=20}
_{angular-1 - native}
_Errors	₃	₃	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_{586,583 (± 0.01%)}	_{586,616 (± 0.01%)}	_~	_586,190	_586,883	_{p=0.565 n=20}
_Types	_{241,686 (± 0.00%)}	_{241,688 (± 0.00%)}	_~	_241,685	_241,696	_{p=0.199 n=20}
_{Memory Used}	_{517,827k (± 0.02%)}	_{517,799k (± 0.02%)}	_~	_517,307k	_518,287k	_{p=0.779 n=20}
_{Memory Allocs}	_{7,789,854 (± 0.06%)}	_{7,794,292 (± 0.13%)}	_~	_7,780,515	_7,847,757	_{p=0.429 n=20}
_{Config Time}	_{0.008s (± 1.77%)}	_{0.008s (± 1.30%)}	_~	_0.008s	_0.009s	_{p=1.000 n=20}
_{Parse Time}	_{0.121s (± 3.59%)}	_{0.126s (± 3.16%)}	_{🔻+0.005s (+ 4.12%)}	_0.112s	_0.149s	_{p=0.034 n=20}
_{Bind Time}	_{0.045s (±10.97%)}	_{0.040s (± 7.69%)}	_~	_0.036s	_0.063s	_{p=0.280 n=20}
_{Check Time}	_0s	_0s	_~	_~	_~	_{p=1.000 n=20}
_{Emit Time}	_{0.835s (± 1.03%)}	_{0.830s (± 0.74%)}	_~	_0.807s	_0.862s	_{p=0.533 n=20}
_{Total Time}	_{1.020s (± 1.17%)}	_{1.013s (± 0.92%)}	_~	_0.983s	_1.067s	_{p=0.673 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}	_{495,108k (± 0.01%)}	_{495,078k (± 0.01%)}	_~	_494,827k	_495,281k	_{p=0.473 n=20}
_{Memory Allocs}	_{12,062,307 (± 0.01%)}	_{12,062,981 (± 0.01%)}	_~	_12,058,453	_12,069,148	_{p=0.495 n=20}
_{Config Time}	_0.001s	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.041s (± 3.17%)}	_{0.041s (± 3.50%)}	_~	_0.038s	_0.047s	_{p=0.814 n=20}
_{Bind Time}	_{0.013s (±10.01%)}	_{0.013s (±10.46%)}	_~	_0.010s	_0.019s	_{p=0.712 n=20}
_{Check Time}	_{0.864s (± 0.47%)}	_{0.864s (± 0.79%)}	_~	_0.837s	_0.893s	_{p=1.000 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.947s (± 0.38%)}	_{0.949s (± 0.64%)}	_~	_0.922s	_0.975s	_{p=0.507 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}	_{27,840k (± 0.02%)}	_{27,835k (± 0.01%)}	_~	_27,819k	_27,845k	_{p=0.098 n=20}
_{Memory Allocs}	_{248,301 (± 0.04%)}	_{248,213 (± 0.06%)}	_~	_247,814	_249,033	_{p=0.180 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.012s (± 3.07%)}	_{0.012s (± 4.00%)}	_~	_0.009s	_0.013s	_{p=0.597 n=20}
_{Bind Time}	_{0.003s (±10.36%)}	_{0.003s (± 8.07%)}	_~	_0.003s	_0.005s	_{p=0.969 n=20}
_{Check Time}	_{0.008s (± 4.40%)}	_{0.008s (± 5.20%)}	_~	_0.006s	_0.010s	_{p=0.432 n=20}
_{Emit Time}	_{0.008s (± 4.90%)}	_{0.008s (± 5.51%)}	_~	_0.007s	_0.010s	_{p=0.943 n=20}
_{Total Time}	_{0.032s (± 1.58%)}	_{0.032s (± 1.45%)}	_~	_0.029s	_0.033s	_{p=0.302 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}	_{939,153k (± 0.02%)}	_{939,101k (± 0.02%)}	_~	_938,561k	_940,446k	_{p=0.380 n=20}
_{Memory Allocs}	_{12,632,671 (± 0.02%)}	_{12,638,289 (± 0.03%)}	_{+5,619 (+ 0.04%)}	_12,631,264	_12,669,559	_{p=0.002 n=20}
_{Config Time}	_{0.002s (± 5.09%)}	_0.002s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.152s (± 1.36%)}	_{0.150s (± 1.31%)}	_~	_0.143s	_0.158s	_{p=0.081 n=20}
_{Bind Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{0.921s (± 0.86%)}	_{0.906s (± 0.79%)}	_{-0.015s (- 1.62%)}	_0.885s	_0.934s	_{p=0.010 n=20}
_{Emit Time}	_{0.509s (± 2.48%)}	_{0.513s (± 2.24%)}	_~	_0.465s	_0.549s	_{p=0.482 n=20}
_{Total Time}	_{1.677s (± 0.88%)}	_{1.666s (± 0.82%)}	_~	_1.616s	_1.726s	_{p=0.229 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}	_{1,768,864k (± 0.08%)}	_{1,768,274k (± 0.10%)}	_~	_1,761,582k	_1,777,830k	_{p=0.512 n=20}
_{Memory Allocs}	_{25,749,107 (± 0.16%)}	_{25,731,610 (± 0.11%)}	_~	_25,653,388	_25,870,919	_{p=0.820 n=20}
_{Config Time}	_{0.008s (± 2.82%)}	_{0.009s (± 2.73%)}	_~	_0.008s	_0.009s	_{p=0.527 n=20}
_{Parse Time}	_{0.293s (± 2.16%)}	_{0.300s (± 1.56%)}	_{+0.007s (+ 2.30%)}	_0.285s	_0.329s	_{p=0.039 n=20}
_{Bind Time}	_0.001s	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{2.985s (± 0.73%)}	_{2.985s (± 0.64%)}	_~	_2.885s	_3.069s	_{p=0.941 n=20}
_{Emit Time}	_{0.244s (± 1.00%)}	_{0.244s (± 1.39%)}	_~	_0.233s	_0.257s	_{p=0.867 n=20}
_{Total Time}	_{4.033s (± 0.63%)}	_{4.032s (± 0.51%)}	_~	_3.921s	_4.120s	_{p=0.909 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}	_{2,846,342k (± 0.03%)}	_{2,846,884k (± 0.03%)}	_~	_2,844,045k	_2,849,161k	_{p=0.398 n=20}
_{Memory Allocs}	_{75,264,234 (± 0.36%)}	_{75,103,566 (± 0.42%)}	_~	_74,678,616	_77,685,127	_{p=0.149 n=20}
_{Config Time}	_{0.025s (± 1.35%)}	_{0.025s (± 1.41%)}	_~	_0.024s	_0.026s	_{p=0.815 n=20}
_{Parse Time}	_{0.478s (± 3.30%)}	_{0.467s (± 2.97%)}	_~	_0.425s	_0.518s	_{p=0.279 n=20}
_{Bind Time}	_{0.152s (±11.03%)}	_{0.155s (±10.10%)}	_~	_0.130s	_0.237s	_{p=0.753 n=20}
_{Check Time}	_{6.665s (± 0.97%)}	_{6.664s (± 1.26%)}	_~	_6.445s	_7.110s	_{p=0.805 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{7.373s (± 0.90%)}	_{7.363s (± 1.17%)}	_~	_7.083s	_7.810s	_{p=0.634 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}	_{966,857k (± 0.01%)}	_{966,769k (± 0.01%)}	_~	_966,316k	_967,273k	_{p=0.331 n=20}
_{Memory Allocs}	_{13,507,983 (± 0.20%)}	_{13,487,410 (± 0.08%)}	_~	_13,446,287	_13,536,342	_{p=0.659 n=20}
_{Config Time}	_0.008s	_0.008s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.159s (± 3.33%)}	_{0.157s (± 2.30%)}	_~	_0.145s	_0.172s	_{p=0.683 n=20}
_{Bind Time}	_{0.043s (± 9.72%)}	_{0.043s (± 9.35%)}	_~	_0.036s	_0.061s	_{p=0.585 n=20}
_{Check Time}	_{1.422s (± 0.90%)}	_{1.418s (± 0.65%)}	_~	_1.381s	_1.472s	_{p=0.560 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{1.649s (± 0.72%)}	_{1.642s (± 0.50%)}	_~	_1.612s	_1.689s	_{p=0.417 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}	_{1,163,912k (± 0.24%)}	_{1,166,681k (± 0.31%)}	_~	_1,157,008k	_1,192,420k	_{p=0.429 n=20}
_{Memory Allocs}	_{47,467,092 (± 0.10%)}	_{47,532,301 (± 0.10%)}	_{+65,209 (+ 0.14%)}	_47,360,629	_47,742,445	_{p=0.028 n=20}
_{Config Time}	_{0.002s (±22.85%)}	_{0.002s (±14.66%)}	_~	_0.001s	_0.003s	_{p=0.463 n=20}
_{Parse Time}	_{0.139s (± 1.40%)}	_{0.140s (± 1.41%)}	_~	_0.133s	_0.147s	_{p=0.783 n=20}
_{Bind Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{0.810s (± 0.49%)}	_{0.808s (± 0.95%)}	_~	_0.792s	_0.865s	_{p=0.122 n=20}
_{Emit Time}	_{0.140s (± 1.07%)}	_{0.140s (± 1.34%)}	_~	_0.133s	_0.147s	_{p=0.514 n=20}
_{Total Time}	_{9.378s (± 0.39%)}	_{9.393s (± 0.69%)}	_~	_9.245s	_9.884s	_{p=1.000 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}	_{224,122k (± 0.02%)}	_{224,133k (± 0.02%)}	_~	_223,915k	_224,266k	_{p=0.542 n=20}
_{Memory Allocs}	_{2,389,253 (± 0.02%)}	_{2,390,309 (± 0.02%)}	_{+1,056 (+ 0.04%)}	_2,388,507	_2,391,318	_{p=0.000 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.055s (± 7.83%)}	_{0.053s (± 4.00%)}	_~	_0.046s	_0.061s	_{p=0.515 n=20}
_{Bind Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{0.403s (± 1.21%)}	_{0.398s (± 0.81%)}	_{-0.006s (- 1.40%)}	_0.390s	_0.415s	_{p=0.028 n=20}
_{Emit Time}	_{0.050s (± 4.76%)}	_{0.049s (± 5.60%)}	_~	_0.043s	_0.058s	_{p=0.633 n=20}
_{Total Time}	_{0.538s (± 1.99%)}	_{0.528s (± 0.70%)}	_~	_0.515s	_0.545s	_{p=0.054 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}	_{2,425,771k (± 0.03%)}	_{2,425,906k (± 0.03%)}	_~	_2,423,708k	_2,428,372k	_{p=0.583 n=20}
_{Memory Allocs}	_{37,192,412 (± 0.10%)}	_{37,176,888 (± 0.05%)}	_~	_37,121,313	_37,291,411	_{p=0.947 n=20}
_{Config Time}	_{0.003s (± 4.95%)}	_{0.003s (± 8.12%)}	_~	_0.002s	_0.003s	_{p=0.235 n=20}
_{Parse Time}	_{0.249s (± 1.71%)}	_{0.250s (± 2.40%)}	_~	_0.228s	_0.277s	_{p=0.963 n=20}
_{Bind Time}	_{0.082s (± 8.70%)}	_{0.084s (± 8.89%)}	_~	_0.072s	_0.125s	_{p=0.623 n=20}
_{Check Time}	_{6.654s (± 0.61%)}	_{6.622s (± 0.46%)}	_~	_6.536s	_6.821s	_{p=0.194 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{6.999s (± 0.59%)}	_{6.970s (± 0.41%)}	_~	_6.887s	_7.156s	_{p=0.245 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}	_{326,097k (± 0.02%)}	_{326,096k (± 0.02%)}	_~	_325,874k	_326,259k	_{p=0.815 n=20}
_{Memory Allocs}	_{4,335,133 (± 0.19%)}	_{4,342,642 (± 0.31%)}	_~	_4,320,168	_4,443,252	_{p=0.414 n=20}
_{Config Time}	_0.001s	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.039s (± 3.70%)}	_{0.040s (± 3.69%)}	_~	_0.034s	_0.045s	_{p=0.682 n=20}
_{Bind Time}	_{0.012s (±11.28%)}	_{0.013s (±10.33%)}	_~	_0.011s	_0.021s	_{p=0.252 n=20}
_{Check Time}	_{0.507s (± 0.61%)}	_{0.510s (± 0.80%)}	_~	_0.493s	_0.525s	_{p=0.109 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.576s (± 0.62%)}	_{0.581s (± 0.78%)}	_~	_0.558s	_0.596s	_{p=0.079 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}	_{193,200k (± 0.01%)}	_{193,198k (± 0.01%)}	_~	_193,130k	_193,249k	_{p=0.825 n=20}
_{Memory Allocs}	_{1,310,800 (± 0.01%)}	_{1,311,825 (± 0.02%)}	_{+1,026 (+ 0.08%)}	_1,311,053	_1,312,898	_{p=0.000 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.043s (± 3.48%)}	_{0.043s (± 2.84%)}	_~	_0.038s	_0.047s	_{p=0.984 n=20}
_{Bind Time}	_{0.020s (± 6.38%)}	_{0.019s (± 4.63%)}	_~	_0.017s	_0.023s	_{p=0.382 n=20}
_{Check Time}	_{0.293s (± 0.96%)}	_{0.294s (± 0.95%)}	_~	_0.282s	_0.303s	_{p=0.783 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.363s (± 0.87%)}	_{0.363s (± 0.77%)}	_~	_0.348s	_0.373s	_{p=0.723 n=20}
_{vscode - native}
_Errors	₁₁	₁₁	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_7,558,293	_7,558,293	_~	_~	_~	_{p=1.000 n=20}
_Types	_4,444,220	_4,444,220	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{5,234,182k (± 0.01%)}	_{5,234,951k (± 0.02%)}	_~	_5,231,293k	_5,244,103k	_{p=0.369 n=20}
_{Memory Allocs}	_{57,320,158 (± 0.02%)}	_{57,346,346 (± 0.07%)}	_{+26,188 (+ 0.05%)}	_57,314,570	_57,688,102	_{p=0.001 n=20}
_{Config Time}	_{0.033s (± 0.90%)}	_{0.033s (± 0.83%)}	_~	_0.032s	_0.035s	_{p=0.603 n=20}
_{Parse Time}	_{0.904s (± 2.15%)}	_{0.894s (± 1.27%)}	_~	_0.849s	_0.968s	_{p=0.358 n=20}
_{Bind Time}	_{0.291s (± 0.86%)}	_{0.293s (± 0.62%)}	_~	_0.285s	_0.301s	_{p=0.215 n=20}
_{Check Time}	_{7.215s (± 0.58%)}	_{7.190s (± 0.53%)}	_~	_7.052s	_7.428s	_{p=0.176 n=20}
_{Emit Time}	_{2.734s (± 3.27%)}	_{2.719s (± 2.46%)}	_~	_2.622s	_3.169s	_{p=0.644 n=20}
_{Total Time}	_{11.234s (± 0.77%)}	_{11.185s (± 0.54%)}	_~	_11.042s	_11.450s	_{p=0.365 n=20}
_{webpack - native}
_Errors	₆₁₂	₆₁₂	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_925,722	_925,722	_~	_~	_~	_{p=1.000 n=20}
_Types	_650,041	_650,041	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{697,593k (± 0.01%)}	_{697,641k (± 0.02%)}	_~	_697,230k	_698,121k	_{p=0.482 n=20}
_{Memory Allocs}	_{6,506,825 (± 0.08%)}	_{6,506,630 (± 0.05%)}	_~	_6,498,022	_6,522,997	_{p=0.659 n=20}
_{Config Time}	_0.004s	_0.004s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.147s (± 2.64%)}	_{0.145s (± 2.70%)}	_~	_0.124s	_0.158s	_{p=0.507 n=20}
_{Bind Time}	_{0.043s (± 6.83%)}	_{0.042s (±10.40%)}	_{-0.001s (- 2.08%)}	_0.035s	_0.071s	_{p=0.029 n=20}
_{Check Time}	_{1.002s (± 0.32%)}	_{1.003s (± 0.50%)}	_~	_0.984s	_1.025s	_{p=0.920 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{1.220s (± 0.42%)}	_{1.217s (± 0.70%)}	_~	_1.175s	_1.247s	_{p=0.625 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}	_{349,602k (± 0.03%)}	_{349,558k (± 0.02%)}	_~	_349,362k	_349,927k	_{p=0.529 n=20}
_{Memory Allocs}	_{3,968,463 (± 0.06%)}	_{3,968,548 (± 0.08%)}	_~	_3,957,126	_3,983,993	_{p=0.989 n=20}
_{Config Time}	_0.001s	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.059s (± 1.75%)}	_{0.061s (± 3.87%)}	_~	_0.055s	_0.073s	_{p=0.314 n=20}
_{Bind Time}	_{0.021s (± 9.42%)}	_{0.019s (± 8.50%)}	_{🟩-0.002s (-10.71%)}	_0.016s	_0.027s	_{p=0.041 n=20}
_{Check Time}	_{0.390s (± 0.78%)}	_{0.392s (± 1.59%)}	_~	_0.376s	_0.432s	_{p=0.995 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.477s (± 0.85%)}	_{0.478s (± 1.47%)}	_~	_0.457s	_0.521s	_{p=0.899 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:

Download Benchmarks

typescript-automation · 2026-10-31T08:30:52Z

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

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🟢 Approval recommended

No active review issues are recorded for the target key-property lookup caching change in removeSubtypes.

No open issues 🎉

What changed in this PR

This PR optimizes removeSubtypes in the native TypeScript checker by reusing target key-property type lookups across sources with the same key-property name.

Changes:

Caches each target’s regularized unit type or a sentinel for missing/non-unit properties.
Clears the cache when the key-property name changes and keeps it aligned when types are removed.

File	Description
`tsc/internal/checker/checker.go`	Adds and maintains the target key-property type cache in `removeSubtypes`.

_{Review effort: Balanced}

Look up each target's key property type once per key property name in…

3096e89

… removeSubtypes

typescript-automation Bot added the For Uncommitted Bug PR for untriaged, rejected, closed or missing bug label Oct 30, 2026

Jake Bailey (jakebailey) added the Domain: Performance Reports of unusually slow behavior label Oct 30, 2026

Mateusz Burzyński (Andarist) marked this pull request as ready for review October 31, 2026 08:30

Copilot AI balanced review requested due to automatic review settings October 31, 2026 08:30

Copilot started reviewing on behalf of Mateusz Burzyński (Andarist) October 31, 2026 08:31

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Speed up `removeSubtypes` by looking up each target's key property type once per key property name - #65061

Speed up `removeSubtypes` by looking up each target's key property type once per key property name#65061
Mateusz Burzyński (Andarist) wants to merge 1 commit into
microsoft:mainfrom
Andarist:experiment/remove-subtypes-key-types

Mateusz Burzyński (Andarist) commented Oct 30, 2026

Jake Bailey (jakebailey) commented Oct 30, 2026

typescript-automation Bot commented Oct 30, 2026 •

edited

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typescript-automation Bot commented Oct 30, 2026

tsc

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Mateusz Burzyński (Andarist) commented Oct 30, 2026

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typescript-automation Bot commented Oct 30, 2026 •

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