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dart/sdk/ee6a560cb5055e10918018af55a4fbb4174c97cc
commit
ee6a560cb5055e10918018af55a4fbb4174c97cc
[log]
author
Jens Johansen <jensj@google.com>
Wed Mar 18 07:28:49 2026 -0700
committer
Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com>
Wed Mar 18 07:28:49 2026 -0700
tree
5b1f4e04022033b309d9ffca9c152042615872ab
parent
16507101bf903f0fd4f5e05c16c2281ccd7476ad [diff]
[analyzer] Remove regex in DartdocDirectiveInfo.extractTemplate

Data from `valgrind --tool=callgrind`:

Before: `DartdocDirectiveInfo.extractFromUnit` is at ~186 mio with `DartdocDirectiveInfo.extractTemplate` costing ~125 mio

Now: `DartdocDirectiveInfo.extractFromUnit` is at ~106 mio with `DartdocDirectiveInfo.extractTemplate` costing ~45 mio

Saving: ~80 mio

Total ICs goes from 40,213,854,370 to 40,120,379,441 --- a ~93 mio saving.

Probably because of 14,148,946 less instructions in `dart::Scavenger::TryAllocateNewTLAB`...

Running the benchmarker (which runs `perf stat`) says:

Normal GC:

```
task-clock:u: 1.5667% +/- 0.8994% (176854617.80 +/- 101524587.84) (11288053844.40 -> 11464908462.20)
page-faults:u: -0.6488% +/- 0.0448% (-1258.60 +/- 86.92) (194000.80 -> 192742.20)
cycles:u: 1.5262% +/- 0.7400% (726682511.40 +/- 352348644.40) (47612955361.40 -> 48339637872.80)
instructions:u: 0.9768% +/- 0.0015% (559490177.40 +/- 879495.32) (57280641756.00 -> 57840131933.40)
branch-misses:u: 4.2985% +/- 3.5545% (7755058.00 +/- 6412676.26) (180411259.20 -> 188166317.20)
seconds time elapsed: 1.5629% +/- 0.8966% (0.18 +/- 0.10) (11.29 -> 11.47)
seconds user: 1.6461% +/- 0.9382% (0.18 +/- 0.10) (10.93 -> 11.11)
maxRssKbytes: 0.7869% +/- 0.0178% (4852.80 +/- 109.61) (616688.80 -> 621541.60)
maxRssBytes: 0.7869% +/- 0.0178% (4969267.20 +/- 112237.34) (631489331.20 -> 636458598.40)

Comparing GC data:
Scavenge(   new space) goes from 173 to 172
MarkSweep(   old space) goes from 1 to 0
Notice combined GC time goes from 3577 ms to 3647 ms (notice only 1 run each).
```

GC disabled:

```
task-clock:u: -0.6269% +/- 0.4868% (-119642101.80 +/- 92900467.80) (19083506432.00 -> 18963864330.20)
page-faults:u: -0.0239% +/- 0.0001% (-297.20 +/- 1.08) (1245278.60 -> 1244981.40)
cycles:u: -0.6443% +/- 0.5443% (-474993485.80 +/- 401307649.98) (73726665028.40 -> 73251671542.60)
instructions:u: -0.1969% +/- 0.0018% (-78882198.40 +/- 720592.45) (40060467059.80 -> 39981584861.40)
seconds time elapsed: -0.6242% +/- 0.4824% (-0.12 +/- 0.09) (19.09 -> 18.98)
maxRssKbytes: -0.0232% +/- 0.0025% (-1157.60 +/- 122.95) (4995760.80 -> 4994603.20)
maxRssBytes: -0.0232% +/- 0.0025% (-1185382.40 +/- 125903.93) (5115659059.20 -> 5114473676.80)
```

So probably some shift in when GC happens causes it to look worse with normal GC, but with GC disabled to decreases the cost by ~79 mio instructions.

Change-Id: Idcafb28bc09dd4b1d5249478d0a1d32a7a2d68b1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/487900
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>
2 files changed
tree: 5b1f4e04022033b309d9ffca9c152042615872ab
  1. .agents/
  2. .dart_tool/
  3. .github/
  4. benchmarks/
  5. build/
  6. docs/
  7. pkg/
  8. runtime/
  9. samples/
  10. sdk/
  11. tests/
  12. third_party/
  13. tools/
  14. utils/
  15. .clang-format
  16. .gitattributes
  17. .gitconfig
  18. .gitignore
  19. .gn
  20. .mailmap
  21. .style.yapf
  22. AUTHORS
  23. BUILD.gn
  24. CHANGELOG.md
  25. codereview.settings
  26. CONTRIBUTING.md
  27. DEPS
  28. LICENSE
  29. OWNERS
  30. PATENT_GRANT
  31. PRESUBMIT.py
  32. pubspec.yaml
  33. README.dart-sdk
  34. README.md
  35. sdk.code-workspace
  36. sdk_args.gni
  37. sdk_packages.yaml
  38. SECURITY.md
  39. WATCHLISTS
README.md

Dart

An approachable, portable, and productive language for high-quality apps on any platform

Dart is:

  • Approachable: Develop with a strongly typed programming language that is consistent, concise, and offers modern language features like null safety and patterns.

  • Portable: Compile to ARM, x64, or RISC-V machine code for mobile, desktop, and backend. Compile to JavaScript or WebAssembly for the web.

  • Productive: Make changes iteratively: use hot reload to see the result instantly in your running app. Diagnose app issues using DevTools.

Dart's flexible compiler technology lets you run Dart code in different ways, depending on your target platform and goals:

  • Dart Native: For programs targeting devices (mobile, desktop, server, and more), Dart Native includes both a Dart VM with JIT (just-in-time) compilation and an AOT (ahead-of-time) compiler for producing machine code.

  • Dart Web: For programs targeting the web, Dart Web includes both a development time compiler (dartdevc) and a production time compiler (dart2js).

Dart platforms illustration

License & patents

Dart is free and open source.

See LICENSE and PATENT_GRANT.

Using Dart

Visit dart.dev to learn more about the language, tools, and to find codelabs.

Browse pub.dev for more packages and libraries contributed by the community and the Dart team.

Our API reference documentation is published at api.dart.dev, based on the stable release. (We also publish docs from our beta and dev channels, as well as from the primary development branch).

Building Dart

If you want to build Dart yourself, here is a guide to getting the source, preparing your machine to build the SDK, and building.

There are more documents in our repo at docs.

Contributing to Dart

The easiest way to contribute to Dart is to file issues.

You can also contribute patches, as described in Contributing.

Roadmap

Future plans for Dart are included in the combined Dart and Flutter roadmap on the Flutter wiki.