Fix #61429: Fast arithmetic type check for type-parameters upper-bounded by `bigint` fixed #61571

CurtisFenner · 2025-04-13T03:50:13Z

The maybeTypeOfKind function is a simpler version of full type-checking which is used by arithmetic. Previously it was used to determine whether arithmetic operations such as +, <<, and ~ were acting on number types or bigint types.

Note that these type checks are somewhat complicated by a desire to preserve unsoundness: any * any should be number, rather than the (sound but exceedingly impractical) number | bigint.

Previously, the maybeTypeOfKind function did not return true when an operand has a type T, regardless of the bounds of T. This meant that when maybeTypeOfKind is passed T extends bigint and bigint, it returned false.

This caused expressions like a & b to be assigned the "default" type number instead of bigint.

To fix this issue, I updated the checks to instead use maybeTypeOfKindConsideringBaseConstraint. I suspect that some of the other uses of maybeTypeOfKind have similar issues, but if so they seem much more subtle and I wasn't able to construct any suspicious tests for them.

I added the bigintSubtypingTypeParameter test which includes a variety of unary and binary operators acting on such T extends bigint values.

This is my first PR, so apologies if I'm missing something important.

CurtisFenner · 2025-04-13T03:51:33Z

@microsoft-github-policy-service agree

src/compiler/checker.ts

…straint

CurtisFenner · 2025-04-27T03:19:45Z

@jakebailey Hi, I'm not sure if you missed the new approach I took. I found a more appropriate maybeTypeOfKindConsideringBaseConstraint and audited all the existing callers of maybeTypeOfKind to see which obviously should be using it. (I also did an extraction of getBinaryArithmeticResultType into a function since it was a large code block in a large chain of alternatives, to be more similar to the getUnaryResultType)

Apologies if you were already aware, I'm sure you have more important tasks to attend to for TypeScript!

jakebailey · 2025-05-09T19:34:45Z

@typescript-bot test it

typescript-bot · 2025-05-09T19:34:50Z

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 · 2025-05-09T19:56:10Z

@jakebailey Here are the results of running the user tests with tsc comparing main and refs/pull/61571/merge:

Everything looks good!

typescript-bot · 2025-05-09T19:58:10Z

Hey @jakebailey, the results of running the DT tests are ready.

Everything looks the same!

You can check the log here.

typescript-bot · 2025-05-09T20:21:53Z

@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	₃₄	₃₄	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_62,390	_62,390	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,395	_50,395	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{193,034k (± 0.07%)}	_{194,151k (± 0.95%)}	_~	_192,930k	_196,581k	_{p=1.000 n=6}
_{Parse Time}	_{1.31s (± 0.62%)}	_{1.31s (± 0.62%)}	_~	_1.29s	_1.31s	_{p=1.000 n=6}
_{Bind Time}	_0.73s	_0.73s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.76s (± 0.45%)}	_{9.69s (± 0.36%)}	_{-0.08s (- 0.80%)}	_9.64s	_9.73s	_{p=0.020 n=6}
_{Emit Time}	_{2.73s (± 0.68%)}	_{2.75s (± 0.84%)}	_~	_2.73s	_2.78s	_{p=0.292 n=6}
_{Total Time}	_{14.54s (± 0.42%)}	_{14.48s (± 0.30%)}	_~	_14.42s	_14.55s	_{p=0.106 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₅₆	₅₆	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_949,240	_949,240	_~	_~	_~	_{p=1.000 n=6}
_Types	_411,065	_411,065	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,225,135k (± 0.01%)}	_{1,225,081k (± 0.00%)}	_~	_1,225,051k	_1,225,130k	_{p=0.093 n=6}
_{Parse Time}	_{6.66s (± 0.61%)}	_{6.63s (± 1.13%)}	_~	_6.53s	_6.69s	_{p=0.627 n=6}
_{Bind Time}	_{1.88s (± 0.22%)}	_{1.88s (± 0.22%)}	_~	_1.88s	_1.89s	_{p=1.000 n=6}
_{Check Time}	_{31.88s (± 0.19%)}	_{31.95s (± 0.27%)}	_~	_31.89s	_32.12s	_{p=0.196 n=6}
_{Emit Time}	_{15.20s (± 0.63%)}	_{15.15s (± 0.29%)}	_~	_15.09s	_15.21s	_{p=0.686 n=6}
_{Total Time}	_{55.62s (± 0.28%)}	_{55.61s (± 0.29%)}	_~	_55.45s	_55.88s	_{p=0.810 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,439,920	_2,439,920	_~	_~	_~	_{p=1.000 n=6}
_Types	_872,553	_872,553	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,448,513k (± 0.00%)}	_{2,448,450k (± 0.00%)}	_~	_2,448,361k	_2,448,501k	_{p=0.066 n=6}
_{Parse Time}	_{10.51s (± 0.57%)}	_{10.53s (± 0.37%)}	_~	_10.46s	_10.57s	_{p=0.470 n=6}
_{Bind Time}	_{2.67s (± 1.03%)}	_{2.68s (± 0.41%)}	_~	_2.67s	_2.69s	_{p=0.498 n=6}
_{Check Time}	_{87.44s (± 1.55%)}	_{87.35s (± 1.56%)}	_~	_86.20s	_89.50s	_{p=0.689 n=6}
_{Emit Time}	_{0.37s (± 1.71%)}	_{0.37s (± 2.04%)}	_~	_0.36s	_0.38s	_{p=0.718 n=6}
_{Total Time}	_{100.99s (± 1.34%)}	_{100.93s (± 1.36%)}	_~	_99.72s	_103.10s	_{p=0.748 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,228,052	_1,228,055	_{+3 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_267,262	_267,261	_{-1 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,360,628k (± 0.02%)}	_{2,361,074k (± 0.03%)}	_~	_2,360,348k	_2,361,978k	_{p=0.173 n=6}
_{Parse Time}	_{5.24s (± 0.79%)}	_{5.20s (± 0.35%)}	_~	_5.18s	_5.22s	_{p=0.109 n=6}
_{Bind Time}	_{1.80s (± 0.65%)}	_{1.80s (± 0.61%)}	_~	_1.78s	_1.81s	_{p=0.557 n=6}
_{Check Time}	_{35.36s (± 0.43%)}	_{35.24s (± 0.24%)}	_~	_35.10s	_35.33s	_{p=0.173 n=6}
_{Emit Time}	_{3.03s (± 3.16%)}	_{2.95s (± 1.92%)}	_~	_2.87s	_3.03s	_{p=0.128 n=6}
_{Total Time}	_{45.43s (± 0.43%)}	_{45.20s (± 0.27%)}	_~	_45.00s	_45.34s	_{p=0.054 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,228,052	_1,228,055	_{+3 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_267,262	_267,261	_{-1 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,427,516k (± 0.03%)}	_{2,427,798k (± 0.02%)}	_~	_2,427,085k	_2,428,457k	_{p=0.575 n=6}
_{Parse Time}	_{5.46s (± 1.25%)}	_{5.42s (± 0.23%)}	_~	_5.41s	_5.44s	_{p=1.000 n=6}
_{Bind Time}	_{1.82s (± 0.92%)}	_{1.82s (± 0.69%)}	_~	_1.80s	_1.83s	_{p=1.000 n=6}
_{Check Time}	_{35.48s (± 0.78%)}	_{35.25s (± 0.20%)}	_~	_35.17s	_35.37s	_{p=0.261 n=6}
_{Emit Time}	_{3.10s (± 1.89%)}	_{3.02s (± 1.56%)}	_~	_2.94s	_3.06s	_{p=0.076 n=6}
_{Total Time}	_{45.85s (± 0.71%)}	_{45.52s (± 0.16%)}	_~	_45.44s	_45.65s	_{p=0.093 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_263,419	_263,422	_{+3 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_107,098	_107,097	_{-1 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{441,781k (± 0.02%)}	_{441,837k (± 0.02%)}	_~	_441,767k	_441,915k	_{p=0.298 n=6}
_{Parse Time}	_{3.55s (± 0.99%)}	_{3.55s (± 1.09%)}	_~	_3.50s	_3.59s	_{p=0.935 n=6}
_{Bind Time}	_{1.32s (± 0.63%)}	_{1.33s (± 1.11%)}	_~	_1.31s	_1.35s	_{p=0.797 n=6}
_{Check Time}	_{19.06s (± 0.38%)}	_{18.96s (± 0.46%)}	_~	_18.84s	_19.06s	_{p=0.078 n=6}
_{Emit Time}	_{1.53s (± 1.41%)}	_{1.51s (± 0.97%)}	_~	_1.50s	_1.54s	_{p=0.217 n=6}
_{Total Time}	_{25.46s (± 0.25%)}	_{25.35s (± 0.38%)}	_{-0.11s (- 0.45%)}	_25.20s	_25.45s	_{p=0.036 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₇₁	₇₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_225,981	_225,981	_~	_~	_~	_{p=1.000 n=6}
_Types	_94,356	_94,356	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{371,258k (± 0.01%)}	_{371,331k (± 0.04%)}	_~	_371,173k	_371,570k	_{p=0.471 n=6}
_{Parse Time}	_{2.92s (± 0.73%)}	_{2.90s (± 1.23%)}	_~	_2.86s	_2.94s	_{p=0.256 n=6}
_{Bind Time}	_{1.60s (± 1.00%)}	_{1.61s (± 1.14%)}	_~	_1.59s	_1.64s	_{p=0.324 n=6}
_{Check Time}	_{16.50s (± 0.37%)}	_{16.44s (± 0.36%)}	_~	_16.38s	_16.52s	_{p=0.172 n=6}
_{Emit Time}	_{0.00s (±244.70%)}	_0.00s	_~	_~	_~	_{p=0.405 n=6}
_{Total Time}	_{21.02s (± 0.41%)}	_{20.95s (± 0.40%)}	_~	_20.85s	_21.08s	_{p=0.228 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₅₁	₅₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_3,427,986	_3,427,986	_~	_~	_~	_{p=1.000 n=6}
_Types	_1,156,177	_1,156,177	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,477,216k (± 0.01%)}	_{3,477,330k (± 0.00%)}	_~	_3,477,123k	_3,477,494k	_{p=0.298 n=6}
_{Parse Time}	_{14.66s (± 0.32%)}	_{14.74s (± 1.03%)}	_~	_14.62s	_15.04s	_{p=0.293 n=6}
_{Bind Time}	_{4.80s (± 1.06%)}	_{4.76s (± 0.54%)}	_~	_4.74s	_4.80s	_{p=0.122 n=6}
_{Check Time}	_{94.61s (± 2.47%)}	_{94.94s (± 2.81%)}	_~	_93.40s	_100.35s	_{p=0.575 n=6}
_{Emit Time}	_{30.48s (± 2.29%)}	_{30.11s (± 2.20%)}	_~	_29.58s	_31.43s	_{p=0.108 n=6}
_{Total Time}	_{144.56s (± 2.07%)}	_{144.55s (± 2.29%)}	_~	_142.86s	_151.31s	_{p=0.936 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₂	₂	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_317,848	_317,848	_~	_~	_~	_{p=1.000 n=6}
_Types	_140,485	_140,485	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{473,035k (± 0.01%)}	_{473,047k (± 0.04%)}	_~	_472,896k	_473,370k	_{p=0.471 n=6}
_{Parse Time}	_{5.17s (± 0.50%)}	_{5.17s (± 0.87%)}	_~	_5.12s	_5.25s	_{p=1.000 n=6}
_{Bind Time}	_{2.26s (± 2.29%)}	_{2.27s (± 1.16%)}	_~	_2.23s	_2.31s	_{p=1.000 n=6}
_{Check Time}	_{25.99s (± 0.29%)}	_{25.93s (± 0.36%)}	_~	_25.80s	_26.03s	_{p=0.378 n=6}
_{Emit Time}	_{0.00s (±244.70%)}	_0.00s	_~	_~	_~	_{p=0.405 n=6}
_{Total Time}	_{33.42s (± 0.28%)}	_{33.37s (± 0.37%)}	_~	_33.21s	_33.56s	_{p=0.471 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_570,733	_570,733	_~	_~	_~	_{p=1.000 n=6}
_Types	_191,446	_191,446	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{501,157k (± 0.04%)}	_{501,292k (± 0.01%)}	_~	_501,189k	_501,350k	_{p=0.298 n=6}
_{Parse Time}	_{4.31s (± 0.41%)}	_{4.31s (± 0.32%)}	_~	_4.30s	_4.34s	_{p=0.934 n=6}
_{Bind Time}	_{1.53s (± 0.96%)}	_{1.54s (± 0.71%)}	_~	_1.53s	_1.56s	_{p=0.452 n=6}
_{Check Time}	_{25.74s (± 3.60%)}	_{24.85s (± 0.26%)}	_~	_24.78s	_24.95s	_{p=0.065 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{31.58s (± 2.87%)}	_{30.71s (± 0.18%)}	_{-0.88s (- 2.78%)}	_30.66s	_30.81s	_{p=0.037 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

typescript-bot · 2025-05-09T21:19:28Z

@jakebailey Here are the results of running the top 400 repos with tsc comparing main and refs/pull/61571/merge:

Everything looks good!

Add failing test for microsoft#61429

f33a6a6

github-project-automation bot added this to PR Backlog Apr 13, 2025

github-project-automation bot moved this to Not started in PR Backlog Apr 13, 2025

typescript-bot added the For Backlog Bug PRs that fix a backlog bug label Apr 13, 2025

jakebailey reviewed Apr 14, 2025

View reviewed changes

src/compiler/checker.ts Outdated Show resolved Hide resolved

CurtisFenner force-pushed the fix-61429-bigint-type-parameter-maybeTypeOfKind-bug branch from ae470a1 to 1390f5f Compare April 18, 2025 00:44

Fix 61429: Update arithmetic to use maybeTypeOfKindConsideringBaseCon…

71d535a

…straint

CurtisFenner force-pushed the fix-61429-bigint-type-parameter-maybeTypeOfKind-bug branch from 1390f5f to 71d535a Compare April 18, 2025 00:47

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Fix #61429: Fast arithmetic type check for type-parameters upper-bounded by `bigint` fixed #61571

Fix #61429: Fast arithmetic type check for type-parameters upper-bounded by `bigint` fixed #61571

Uh oh!

CurtisFenner commented Apr 13, 2025 •

edited

Loading

Uh oh!

CurtisFenner commented Apr 13, 2025

Uh oh!

Uh oh!

CurtisFenner commented Apr 27, 2025 •

edited

Loading

Uh oh!

jakebailey commented May 9, 2025

Uh oh!

typescript-bot commented May 9, 2025 •

edited

Loading

Uh oh!

typescript-bot commented May 9, 2025

Uh oh!

typescript-bot commented May 9, 2025

Uh oh!

typescript-bot commented May 9, 2025

tsc

Uh oh!

typescript-bot commented May 9, 2025

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Fix #61429: Fast arithmetic type check for type-parameters upper-bounded by bigint fixed #61571

Are you sure you want to change the base?

Fix #61429: Fast arithmetic type check for type-parameters upper-bounded by bigint fixed #61571

Uh oh!

Conversation

CurtisFenner commented Apr 13, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

CurtisFenner commented Apr 13, 2025

Uh oh!

Uh oh!

CurtisFenner commented Apr 27, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

jakebailey commented May 9, 2025

Uh oh!

typescript-bot commented May 9, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

typescript-bot commented May 9, 2025

Uh oh!

typescript-bot commented May 9, 2025

Uh oh!

typescript-bot commented May 9, 2025

tsc

Uh oh!

typescript-bot commented May 9, 2025

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Fix #61429: Fast arithmetic type check for type-parameters upper-bounded by `bigint` fixed #61571

Fix #61429: Fast arithmetic type check for type-parameters upper-bounded by `bigint` fixed #61571

CurtisFenner commented Apr 13, 2025 •

edited

Loading

CurtisFenner commented Apr 27, 2025 •

edited

Loading

typescript-bot commented May 9, 2025 •

edited

Loading