Cache discriminated contextual types by ahejlsberg · Pull Request #58372 · microsoft/TypeScript

Anders Hejlsberg (ahejlsberg) · 2024-04-30T14:53:17Z

While researching another issue, Jake Bailey (@jakebailey) noticed this statement takes an exceedingly long time to type check. With the caching added in this PR, the check time for the statement drops from 250ms to about zero on my machine.

Anders Hejlsberg (ahejlsberg) · 2024-04-30T14:53:30Z

TypeScript Bot (@typescript-bot) test it

Jake Bailey (jakebailey) · 2024-04-30T15:17:01Z

TypeScript Bot (@typescript-bot) test it

Sorry, the new function app we had to deploy has some scaling issues being worked out.

TypeScript Bot (typescript-bot) · 2024-04-30T15:17:04Z

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

Command	Status	Results
`test top400`	✅ Started	✅ Results
`user test this`	✅ Started	✅ Results
`run dt`	✅ Started	✅ Results
`perf test this faster`	✅ Started	👀 Results

TypeScript Bot (typescript-bot) · 2024-04-30T15:38:23Z

Hey Jake Bailey (@jakebailey), the results of running the DT tests are ready.

Everything looks the same!

You can check the log here.

TypeScript Bot (typescript-bot) · 2024-04-30T15:45:49Z

Jake Bailey (@jakebailey) Here are the results of running the user tests comparing main and refs/pull/58372/merge:

Everything looks good!

TypeScript Bot (typescript-bot) · 2024-04-30T15:52:45Z

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 - node (v18.15.0, x64)}
_Errors	₃₀	₃₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_62,154	_62,154	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,273	_50,273	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{192,256k (± 0.07%)}	_{193,409k (± 0.96%)}	_~	_192,208k	_195,802k	_{p=0.378 n=6}
_{Parse Time}	_{1.29s (± 1.82%)}	_{1.29s (± 1.80%)}	_~	_1.25s	_1.31s	_{p=0.935 n=6}
_{Bind Time}	_0.72s	_0.72s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.57s (± 0.40%)}	_{9.53s (± 0.32%)}	_~	_9.49s	_9.58s	_{p=0.126 n=6}
_{Emit Time}	_{2.62s (± 0.68%)}	_{2.63s (± 0.31%)}	_~	_2.62s	_2.64s	_{p=0.677 n=6}
_{Total Time}	_{14.20s (± 0.28%)}	_{14.16s (± 0.25%)}	_~	_14.13s	_14.22s	_{p=0.171 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_945,322	_945,322	_~	_~	_~	_{p=1.000 n=6}
_Types	_408,088	_408,088	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,222,131k (± 0.00%)}	_{1,222,776k (± 0.00%)}	_{+645k (+ 0.05%)}	_1,222,725k	_1,222,846k	_{p=0.005 n=6}
_{Parse Time}	_{6.78s (± 0.30%)}	_{6.77s (± 0.22%)}	_~	_6.75s	_6.79s	_{p=0.289 n=6}
_{Bind Time}	_{1.88s (± 0.62%)}	_{1.88s (± 0.29%)}	_~	_1.87s	_1.88s	_{p=0.498 n=6}
_{Check Time}	_{31.34s (± 0.47%)}	_{31.34s (± 0.62%)}	_~	_31.11s	_31.65s	_{p=0.873 n=6}
_{Emit Time}	_{14.74s (± 0.34%)}	_{14.73s (± 1.11%)}	_~	_14.56s	_15.01s	_{p=0.521 n=6}
_{Total Time}	_{54.75s (± 0.30%)}	_{54.72s (± 0.39%)}	_~	_54.45s	_54.96s	_{p=0.936 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,955,956	_1,955,956	_~	_~	_~	_{p=1.000 n=6}
_Types	_676,324	_676,324	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,754,529k (± 0.00%)}	_{1,757,311k (± 0.00%)}	_{+2,782k (+ 0.16%)}	_1,757,287k	_1,757,337k	_{p=0.005 n=6}
_{Parse Time}	_{6.72s (± 0.33%)}	_{6.73s (± 0.11%)}	_~	_6.72s	_6.74s	_{p=1.000 n=6}
_{Bind Time}	_{2.30s (± 0.51%)}	_{2.29s (± 0.24%)}	_~	_2.29s	_2.30s	_{p=0.859 n=6}
_{Check Time}	_{56.80s (± 0.34%)}	_{55.92s (± 0.21%)}	_{-0.87s (- 1.54%)}	_55.71s	_56.02s	_{p=0.005 n=6}
_{Emit Time}	_{0.14s (± 5.44%)}	_{0.13s (± 3.87%)}	_~	_0.13s	_0.14s	_{p=0.247 n=6}
_{Total Time}	_{65.96s (± 0.32%)}	_{65.08s (± 0.18%)}	_{-0.87s (- 1.32%)}	_64.87s	_65.18s	_{p=0.005 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,215,731	_1,215,734	_{+3 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_257,647	_257,647	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,324,027k (± 0.03%)}	_{2,323,756k (± 0.02%)}	_~	_2,323,216k	_2,324,229k	_{p=0.298 n=6}
_{Parse Time}	_{4.96s (± 1.09%)}	_{4.96s (± 1.00%)}	_~	_4.91s	_5.05s	_{p=0.936 n=6}
_{Bind Time}	_{1.88s (± 1.10%)}	_{1.88s (± 0.22%)}	_~	_1.88s	_1.89s	_{p=0.246 n=6}
_{Check Time}	_{34.01s (± 0.36%)}	_{33.33s (± 0.29%)}	_{-0.68s (- 2.00%)}	_33.19s	_33.43s	_{p=0.005 n=6}
_{Emit Time}	_{2.59s (± 0.63%)}	_{2.61s (± 1.33%)}	_~	_2.58s	_2.67s	_{p=0.627 n=6}
_{Total Time}	_{43.44s (± 0.25%)}	_{42.79s (± 0.26%)}	_{-0.64s (- 1.48%)}	_42.58s	_42.87s	_{p=0.005 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,215,731	_1,215,734	_{+3 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_257,647	_257,647	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,399,215k (± 0.03%)}	_{2,398,341k (± 0.00%)}	_{-874k (- 0.04%)}	_2,398,239k	_2,398,435k	_{p=0.005 n=6}
_{Parse Time}	_{6.21s (± 0.57%)}	_{6.17s (± 0.69%)}	_~	_6.11s	_6.23s	_{p=0.169 n=6}
_{Bind Time}	_{2.01s (± 0.91%)}	_{2.01s (± 1.62%)}	_~	_1.97s	_2.06s	_{p=0.935 n=6}
_{Check Time}	_{40.51s (± 0.27%)}	_{39.87s (± 0.26%)}	_{-0.64s (- 1.57%)}	_39.70s	_39.99s	_{p=0.005 n=6}
_{Emit Time}	_{3.12s (± 2.47%)}	_{3.14s (± 1.65%)}	_~	_3.05s	_3.19s	_{p=0.689 n=6}
_{Total Time}	_{51.87s (± 0.26%)}	_{51.23s (± 0.16%)}	_{-0.63s (- 1.22%)}	_51.11s	_51.33s	_{p=0.005 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_256,206	_256,209	_{+3 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_103,653	_103,653	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{424,265k (± 0.01%)}	_{424,235k (± 0.01%)}	_~	_424,201k	_424,297k	_{p=0.230 n=6}
_{Parse Time}	_{3.34s (± 1.17%)}	_{3.40s (± 3.34%)}	_~	_3.33s	_3.63s	_{p=0.418 n=6}
_{Bind Time}	_{1.31s (± 0.75%)}	_{1.30s (± 0.90%)}	_~	_1.28s	_1.31s	_{p=0.177 n=6}
_{Check Time}	_{18.32s (± 0.44%)}	_{17.74s (± 0.29%)}	_{🟩-0.58s (- 3.18%)}	_17.68s	_17.81s	_{p=0.005 n=6}
_{Emit Time}	_{1.36s (± 1.77%)}	_{1.36s (± 2.37%)}	_~	_1.33s	_1.41s	_{p=0.936 n=6}
_{Total Time}	_{24.34s (± 0.38%)}	_{23.80s (± 0.64%)}	_{-0.54s (- 2.20%)}	_23.70s	_24.11s	_{p=0.005 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₃₅	₃₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_224,824	_224,824	_~	_~	_~	_{p=1.000 n=6}
_Types	_93,390	_93,390	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{369,318k (± 0.01%)}	_{369,313k (± 0.02%)}	_~	_369,248k	_369,422k	_{p=0.521 n=6}
_{Parse Time}	_{2.83s (± 1.53%)}	_{2.85s (± 0.69%)}	_~	_2.81s	_2.86s	_{p=0.195 n=6}
_{Bind Time}	_{1.59s (± 0.69%)}	_{1.59s (± 1.17%)}	_~	_1.57s	_1.62s	_{p=0.510 n=6}
_{Check Time}	_{15.72s (± 0.40%)}	_{15.61s (± 0.40%)}	_{-0.11s (- 0.71%)}	_15.51s	_15.68s	_{p=0.010 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{20.14s (± 0.41%)}	_{20.04s (± 0.40%)}	_{-0.10s (- 0.51%)}	_19.92s	_20.16s	_{p=0.044 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₄	₄	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,799,544	_2,799,544	_~	_~	_~	_{p=1.000 n=6}
_Types	_950,964	_950,964	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,927,257k (± 0.01%)}	_{2,928,489k (± 0.00%)}	_{+1,232k (+ 0.04%)}	_2,928,315k	_2,928,557k	_{p=0.005 n=6}
_{Parse Time}	_{13.35s (± 0.42%)}	_{13.30s (± 0.23%)}	_~	_13.27s	_13.35s	_{p=0.126 n=6}
_{Bind Time}	_{4.26s (± 1.92%)}	_{4.13s (± 1.96%)}	_~	_4.08s	_4.29s	_{p=0.050 n=6}
_{Check Time}	_{73.00s (± 0.39%)}	_{73.22s (± 0.64%)}	_~	_72.52s	_73.75s	_{p=0.298 n=6}
_{Emit Time}	_{20.08s (± 4.72%)}	_{20.93s (± 9.49%)}	_~	_19.59s	_23.58s	_{p=0.810 n=6}
_{Total Time}	_{110.69s (± 1.03%)}	_{111.58s (± 1.77%)}	_~	_110.01s	_114.72s	_{p=0.471 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_265,858	_265,858	_~	_~	_~	_{p=1.000 n=6}
_Types	_108,442	_108,442	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{410,472k (± 0.01%)}	_{410,410k (± 0.02%)}	_~	_410,323k	_410,490k	_{p=0.230 n=6}
_{Parse Time}	_{4.76s (± 0.25%)}	_{4.76s (± 0.68%)}	_~	_4.72s	_4.80s	_{p=0.936 n=6}
_{Bind Time}	_{2.06s (± 1.24%)}	_{2.06s (± 0.73%)}	_~	_2.05s	_2.08s	_{p=0.935 n=6}
_{Check Time}	_{21.10s (± 0.53%)}	_{20.92s (± 0.26%)}	_{-0.17s (- 0.83%)}	_20.85s	_21.01s	_{p=0.013 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{27.92s (± 0.38%)}	_{27.74s (± 0.27%)}	_{-0.18s (- 0.64%)}	_27.65s	_27.87s	_{p=0.016 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_524,146	_524,146	_~	_~	_~	_{p=1.000 n=6}
_Types	_178,732	_178,732	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{461,405k (± 0.02%)}	_{462,183k (± 0.01%)}	_{+779k (+ 0.17%)}	_462,144k	_462,293k	_{p=0.005 n=6}
_{Parse Time}	_{3.90s (± 0.75%)}	_{3.90s (± 0.68%)}	_~	_3.86s	_3.93s	_{p=1.000 n=6}
_{Bind Time}	_{1.47s (± 0.55%)}	_{1.47s (± 0.82%)}	_~	_1.45s	_1.48s	_{p=0.354 n=6}
_{Check Time}	_{22.55s (± 0.97%)}	_{22.44s (± 0.65%)}	_~	_22.21s	_22.59s	_{p=0.229 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{27.92s (± 0.71%)}	_{27.81s (± 0.45%)}	_~	_27.61s	_27.91s	_{p=0.199 n=6}

System info unknown

Hosts

node (v18.15.0, x64)

Scenarios

Compiler-Unions - node (v18.15.0, x64)
angular-1 - node (v18.15.0, x64)
mui-docs - node (v18.15.0, x64)
self-build-src - node (v18.15.0, x64)
self-build-src-public-api - node (v18.15.0, x64)
self-compiler - node (v18.15.0, x64)
ts-pre-modules - node (v18.15.0, x64)
vscode - node (v18.15.0, x64)
webpack - node (v18.15.0, x64)
xstate-main - node (v18.15.0, x64)

_Benchmark	_Name	_Iterations
_Current	_pr	₆
_Baseline	_baseline	₆

Developer Information:

Download Benchmarks

Jake Bailey (jakebailey) · 2024-04-30T15:54:33Z

Wow, that's actually significant., 3% on our self test (expected), but also 1.5% in mui-docs.

Wesley Wigham (weswigham)

Honestly surprised we call this with the same arguments so many times - but I guess at least twice with the same args is basically guaranteed, since signature inference is 2-pass.

Anders Hejlsberg (ahejlsberg) · 2024-04-30T17:56:02Z

TypeScript Bot (@typescript-bot) test it

TypeScript Bot (typescript-bot) · 2024-04-30T17:56:04Z

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

Command	Status	Results
`test top400`	✅ Started
`user test this`	✅ Started
`run dt`	✅ Started
`perf test this faster`	✅ Started	👀 Results

TypeScript Bot (typescript-bot) · 2024-04-30T18:32:39Z

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 - node (v18.15.0, x64)}
_Errors	₃₀	₃₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_62,154	_62,154	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,273	_50,273	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{193,518k (± 0.92%)}	_{194,037k (± 1.02%)}	_~	_192,208k	_196,008k	_{p=1.000 n=6}
_{Parse Time}	_{1.31s (± 0.96%)}	_{1.31s (± 0.64%)}	_~	_1.29s	_1.31s	_{p=0.735 n=6}
_{Bind Time}	_0.72s	_0.72s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.55s (± 0.39%)}	_{9.55s (± 0.28%)}	_~	_9.51s	_9.59s	_{p=1.000 n=6}
_{Emit Time}	_{2.62s (± 0.62%)}	_{2.63s (± 0.54%)}	_~	_2.61s	_2.65s	_{p=0.194 n=6}
_{Total Time}	_{14.19s (± 0.39%)}	_{14.20s (± 0.18%)}	_~	_14.16s	_14.23s	_{p=1.000 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_945,322	_945,923	_{+601 (+ 0.06%)}	_~	_~	_{p=0.001 n=6}
_Types	_408,088	_408,398	_{+310 (+ 0.08%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{1,222,099k (± 0.00%)}	_{1,222,740k (± 0.00%)}	_{+641k (+ 0.05%)}	_1,222,660k	_1,222,828k	_{p=0.005 n=6}
_{Parse Time}	_{6.77s (± 0.76%)}	_{6.77s (± 0.46%)}	_~	_6.75s	_6.83s	_{p=0.807 n=6}
_{Bind Time}	_{1.87s (± 0.44%)}	_{1.87s (± 0.52%)}	_~	_1.86s	_1.88s	_{p=0.862 n=6}
_{Check Time}	_{31.45s (± 0.56%)}	_{31.26s (± 0.30%)}	_~	_31.13s	_31.38s	_{p=0.109 n=6}
_{Emit Time}	_{14.63s (± 1.19%)}	_{14.74s (± 0.52%)}	_~	_14.64s	_14.82s	_{p=0.199 n=6}
_{Total Time}	_{54.72s (± 0.49%)}	_{54.65s (± 0.30%)}	_~	_54.46s	_54.86s	_{p=0.809 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,955,956	_1,999,695	_{+43,739 (+ 2.24%)}	_~	_~	_{p=0.001 n=6}
_Types	_676,324	_681,527	_{+5,203 (+ 0.77%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{1,754,535k (± 0.00%)}	_{1,781,555k (± 0.00%)}	_{+27,020k (+ 1.54%)}	_1,781,507k	_1,781,587k	_{p=0.005 n=6}
_{Parse Time}	_{6.71s (± 0.36%)}	_{6.71s (± 0.37%)}	_~	_6.68s	_6.74s	_{p=0.936 n=6}
_{Bind Time}	_{2.31s (± 0.52%)}	_{2.30s (± 0.27%)}	_~	_2.29s	_2.31s	_{p=0.340 n=6}
_{Check Time}	_{56.86s (± 0.38%)}	_{56.58s (± 0.31%)}	_{-0.28s (- 0.50%)}	_56.27s	_56.77s	_{p=0.037 n=6}
_{Emit Time}	_{0.14s (± 2.95%)}	_{0.14s (± 2.88%)}	_~	_0.14s	_0.15s	_{p=0.218 n=6}
_{Total Time}	_{66.01s (± 0.34%)}	_{65.72s (± 0.27%)}	_~	_65.44s	_65.92s	_{p=0.054 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,215,731	_1,216,274	_{+543 (+ 0.04%)}	_~	_~	_{p=0.001 n=6}
_Types	_257,647	_257,948	_{+301 (+ 0.12%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,324,685k (± 0.03%)}	_{2,322,980k (± 0.02%)}	_{-1,705k (- 0.07%)}	_2,322,555k	_2,323,639k	_{p=0.005 n=6}
_{Parse Time}	_{4.96s (± 0.16%)}	_{4.97s (± 0.77%)}	_~	_4.92s	_5.03s	_{p=0.258 n=6}
_{Bind Time}	_{1.88s (± 0.62%)}	_{1.87s (± 1.37%)}	_~	_1.85s	_1.91s	_{p=0.328 n=6}
_{Check Time}	_{34.04s (± 0.35%)}	_{33.49s (± 0.46%)}	_{-0.54s (- 1.59%)}	_33.24s	_33.64s	_{p=0.005 n=6}
_{Emit Time}	_{2.59s (± 2.50%)}	_{2.62s (± 2.53%)}	_~	_2.51s	_2.69s	_{p=0.378 n=6}
_{Total Time}	_{43.47s (± 0.39%)}	_{42.97s (± 0.42%)}	_{-0.50s (- 1.15%)}	_42.71s	_43.18s	_{p=0.005 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,215,731	_1,216,274	_{+543 (+ 0.04%)}	_~	_~	_{p=0.001 n=6}
_Types	_257,647	_257,948	_{+301 (+ 0.12%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,398,813k (± 0.02%)}	_{2,398,153k (± 0.02%)}	_~	_2,397,364k	_2,398,623k	_{p=0.066 n=6}
_{Parse Time}	_{6.21s (± 1.04%)}	_{6.24s (± 1.17%)}	_~	_6.14s	_6.33s	_{p=0.688 n=6}
_{Bind Time}	_{2.03s (± 1.60%)}	_{2.02s (± 0.68%)}	_~	_2.01s	_2.05s	_{p=0.332 n=6}
_{Check Time}	_{40.63s (± 0.32%)}	_{39.85s (± 0.28%)}	_{-0.78s (- 1.93%)}	_39.75s	_40.05s	_{p=0.005 n=6}
_{Emit Time}	_{3.13s (± 2.12%)}	_{3.11s (± 1.68%)}	_~	_3.02s	_3.17s	_{p=0.575 n=6}
_{Total Time}	_{52.02s (± 0.14%)}	_{51.24s (± 0.24%)}	_{-0.78s (- 1.51%)}	_51.08s	_51.43s	_{p=0.005 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_256,206	_256,432	_{+226 (+ 0.09%)}	_~	_~	_{p=0.001 n=6}
_Types	_103,653	_103,607	_{-46 (- 0.04%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{424,264k (± 0.00%)}	_{424,324k (± 0.01%)}	_{+61k (+ 0.01%)}	_424,278k	_424,372k	_{p=0.008 n=6}
_{Parse Time}	_{3.32s (± 1.62%)}	_{3.34s (± 0.99%)}	_~	_3.29s	_3.38s	_{p=0.629 n=6}
_{Bind Time}	_{1.30s (± 0.58%)}	_{1.30s (± 0.80%)}	_~	_1.28s	_1.31s	_{p=0.437 n=6}
_{Check Time}	_{18.27s (± 0.35%)}	_{17.73s (± 0.20%)}	_{-0.53s (- 2.92%)}	_17.70s	_17.80s	_{p=0.005 n=6}
_{Emit Time}	_{1.35s (± 1.09%)}	_{1.37s (± 1.22%)}	_~	_1.35s	_1.39s	_{p=0.087 n=6}
_{Total Time}	_{24.24s (± 0.38%)}	_{23.74s (± 0.26%)}	_{-0.50s (- 2.06%)}	_23.67s	_23.84s	_{p=0.005 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₃₅	₃₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_224,824	_225,034	_{+210 (+ 0.09%)}	_~	_~	_{p=0.001 n=6}
_Types	_93,390	_93,347	_{-43 (- 0.05%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{369,288k (± 0.01%)}	_{369,416k (± 0.02%)}	_{+128k (+ 0.03%)}	_369,344k	_369,598k	_{p=0.005 n=6}
_{Parse Time}	_{3.49s (± 0.97%)}	_{3.51s (± 0.42%)}	_~	_3.49s	_3.53s	_{p=0.167 n=6}
_{Bind Time}	_{1.92s (± 0.64%)}	_{1.94s (± 1.64%)}	_~	_1.91s	_1.98s	_{p=0.675 n=6}
_{Check Time}	_{19.43s (± 0.33%)}	_{19.33s (± 0.29%)}	_{-0.10s (- 0.51%)}	_19.23s	_19.38s	_{p=0.013 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{24.84s (± 0.27%)}	_{24.78s (± 0.33%)}	_~	_24.64s	_24.85s	_{p=0.230 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₄	₄	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,799,544	_2,801,275	_{+1,731 (+ 0.06%)}	_~	_~	_{p=0.001 n=6}
_Types	_950,964	_950,758	_{-206 (- 0.02%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,927,051k (± 0.01%)}	_{2,927,911k (± 0.01%)}	_{+860k (+ 0.03%)}	_2,927,421k	_2,928,160k	_{p=0.005 n=6}
_{Parse Time}	_{13.38s (± 0.53%)}	_{13.31s (± 0.26%)}	_~	_13.28s	_13.37s	_{p=0.076 n=6}
_{Bind Time}	_{4.29s (± 0.27%)}	_{4.16s (± 2.77%)}	_~	_4.08s	_4.32s	_{p=0.167 n=6}
_{Check Time}	_{73.00s (± 0.31%)}	_{72.58s (± 0.37%)}	_{-0.42s (- 0.57%)}	_72.30s	_73.03s	_{p=0.031 n=6}
_{Emit Time}	_{21.05s (± 7.68%)}	_{21.11s (± 8.23%)}	_~	_19.55s	_23.35s	_{p=0.575 n=6}
_{Total Time}	_{111.72s (± 1.46%)}	_{111.16s (± 1.40%)}	_~	_109.47s	_113.18s	_{p=0.471 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_265,858	_265,858	_~	_~	_~	_{p=1.000 n=6}
_Types	_108,442	_108,442	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{410,483k (± 0.02%)}	_{410,427k (± 0.01%)}	_~	_410,349k	_410,496k	_{p=0.128 n=6}
_{Parse Time}	_{4.77s (± 1.18%)}	_{4.74s (± 0.71%)}	_~	_4.71s	_4.80s	_{p=0.333 n=6}
_{Bind Time}	_{2.08s (± 0.95%)}	_{2.06s (± 0.90%)}	_~	_2.04s	_2.09s	_{p=0.280 n=6}
_{Check Time}	_{21.18s (± 0.22%)}	_{20.98s (± 0.17%)}	_{-0.20s (- 0.95%)}	_20.92s	_21.02s	_{p=0.005 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{28.03s (± 0.32%)}	_{27.79s (± 0.24%)}	_{-0.24s (- 0.87%)}	_27.69s	_27.89s	_{p=0.005 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_524,146	_553,173	_{🔻+29,027 (+ 5.54%)}	_~	_~	_{p=0.001 n=6}
_Types	_178,732	_188,311	_{🔻+9,579 (+ 5.36%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{461,380k (± 0.02%)}	_{476,795k (± 0.03%)}	_{+15,416k (+ 3.34%)}	_476,628k	_476,998k	_{p=0.005 n=6}
_{Parse Time}	_{3.89s (± 0.32%)}	_{3.89s (± 0.70%)}	_~	_3.85s	_3.93s	_{p=1.000 n=6}
_{Bind Time}	_{1.46s (± 1.28%)}	_{1.47s (± 1.34%)}	_~	_1.43s	_1.48s	_{p=0.870 n=6}
_{Check Time}	_{22.56s (± 0.79%)}	_{22.78s (± 0.40%)}	_{+0.23s (+ 1.00%)}	_22.68s	_22.92s	_{p=0.031 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{27.91s (± 0.62%)}	_{28.14s (± 0.42%)}	_{+0.23s (+ 0.82%)}	_27.99s	_28.28s	_{p=0.045 n=6}

System info unknown

Hosts

node (v18.15.0, x64)

Scenarios

Compiler-Unions - node (v18.15.0, x64)
angular-1 - node (v18.15.0, x64)
mui-docs - node (v18.15.0, x64)
self-build-src - node (v18.15.0, x64)
self-build-src-public-api - node (v18.15.0, x64)
self-compiler - node (v18.15.0, x64)
ts-pre-modules - node (v18.15.0, x64)
vscode - node (v18.15.0, x64)
webpack - node (v18.15.0, x64)
xstate-main - node (v18.15.0, x64)

_Benchmark	_Name	_Iterations
_Current	_pr	₆
_Baseline	_baseline	₆

Developer Information:

Download Benchmarks

Anders Hejlsberg (ahejlsberg) · 2024-04-30T18:35:15Z

Hmm, removing null and undefined from apparent contextual types seems to be a net negative. I'll get rid of that again.

This reverts commit 3f2c24f.

This reverts commit 8d4f369.

TypeScript Bot (typescript-bot) · 2024-04-30T19:35:59Z

Jake Bailey (@jakebailey) Here are the results of running the top 400 repos comparing main and refs/pull/58372/merge:

Everything looks good!

David Blass (ssalbdivad) · 2024-06-07T11:49:04Z

I bisected a perf regression typechecking https://github.com/arktypeio/arktype and found the following:

{"checkTime": 9.68,"types": 483415,"instantiations": 2629152}
devDependencies:
-typescript5.5.0-dev.20240429+typescript5.5.0-dev.20240430{"checkTime": 12.2,"types": 514846,"instantiations": 2819487}

It seems likely this change was somehow involved?

Mateusz Burzyński (Andarist) · 2024-06-07T12:58:55Z

Guided by package.json#gitHead in both of those we can see the diff between those versions here:
3358157...dc316af

This PR isn't part of that.

David Blass (ssalbdivad) · 2024-06-07T13:12:29Z

My mistake, I likely jumped to conclusions when I saw this in the release notes as a likely candidate since I use quite a lot of unions internally.

Mateusz Burzyński (@Andarist) and I have been looking at which of the changes from that day could have caused such a large increase in type instantiations and check time and haven't been able to identify it yet.

Cache discriminated contextual types
b23cd28

TypeScript Bot (typescript-bot) assigned Anders Hejlsberg (ahejlsberg)Apr 30, 2024

TypeScript Bot (typescript-bot) added Author: Team For Uncommitted Bug PR for untriaged, rejected, closed or missing bug labels Apr 30, 2024

Formatting
5c682f6

Anders Hejlsberg (ahejlsberg) requested review from Ryan Cavanaugh (RyanCavanaugh) and Jake Bailey (jakebailey)April 30, 2024 14:56

typeholes mentioned this pull request Apr 30, 2024
fixed types for Object.values and Object.entries #58358
Closed

Jake Bailey (jakebailey) approved these changes Apr 30, 2024
View reviewed changes

Wesley Wigham (weswigham) approved these changes Apr 30, 2024
View reviewed changes

Anders Hejlsberg (ahejlsberg) added 2 commits April 30, 2024 10:55

Remove null and undefined from apparent contextual types
8d4f369

Accept new baselines
3f2c24f

Anders Hejlsberg (ahejlsberg) added 2 commits April 30, 2024 11:37

Revert "Accept new baselines"
b5aa46e
This reverts commit 3f2c24f.

Revert "Remove null and undefined from apparent contextual types"
22c12c6
This reverts commit 8d4f369.

Anders Hejlsberg (ahejlsberg) merged commit 749bd83 into mainApr 30, 2024

Anders Hejlsberg (ahejlsberg) deleted the cacheDiscriminatedContextualTypes branch April 30, 2024 19:40

David Blass (ssalbdivad) mentioned this pull request Jun 7, 2024
Fix ghost errors resulting from out-of-order type checking #58337
Merged

typeholes mentioned this pull request Jun 7, 2024
Trace analysis and suggestions tsperf/tracer#42
Open

Daniel Rosenwasser (DanielRosenwasser) mentioned this pull request Jun 7, 2024
Typescript 5.5 performance regression on arktype #58805
Open

Microsoft (microsoft) locked as resolved and limited conversation to collaborators Oct 16, 2025

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tsc

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