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dart / sdk / a4294c354ce110691e8602ed4e437f6d7f8229b4
commita4294c354ce110691e8602ed4e437f6d7f8229b4[log] [tgz]
authorStephen Adams <sra@google.com>Fri Oct 21 00:53:59 2022 +0000
committerCommit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com>Fri Oct 21 00:53:59 2022 +0000
tree6850a9f7a7d17329dd2cdbbd5addffbc550c58cf
parent84df527eba5ffea24e9663f1df0371a2736acaa3 [diff]
Benchmark for comparing reading Uint8List vs UnmodifiableUint8ListView

The benchmark reports per-element times for summing the elements of a typed-data List.

----

The VM implementation is quite good but it looks like there is still a little room for improvement since the views are 2x slower than a simple array.

dart compile exe:

TypedDataPoly.mono.array.2(RunTime): 1.9670880036279512 ns.
TypedDataPoly.A_V.array.2(RunTime): 4.392355 ns.
TypedDataPoly.A_V.view.2(RunTime): 5.730097499999999 ns.
TypedDataPoly.A_UV.array.2(RunTime): 4.455393750000001 ns.
TypedDataPoly.A_UV.view.2(RunTime): 5.811122500000001 ns.
TypedDataPoly.A_VUV.array.2(RunTime): 4.386336250000001 ns.
TypedDataPoly.A_VUV.view.2(RunTime): 5.7639675 ns.
TypedDataPoly.A_UVx5.array.2(RunTime): 4.62768 ns.
TypedDataPoly.A_UVx5.view.2(RunTime): 5.7099649999999995 ns.
TypedDataPoly.mega.array.2(RunTime): 5.272632499999999 ns.
TypedDataPoly.mega.mixed.2(RunTime): 5.62861 ns.

TypedDataPoly.mono.array.100(RunTime): 0.6455633088733822 ns.
TypedDataPoly.A_V.array.100(RunTime): 3.1558100965636964 ns.
TypedDataPoly.A_V.view.100(RunTime): 4.476973567105732 ns.
TypedDataPoly.A_UV.array.100(RunTime): 3.149724878714137 ns.
TypedDataPoly.A_UV.view.100(RunTime): 4.500062299750802 ns.
TypedDataPoly.A_VUV.array.100(RunTime): 3.1438380581862146 ns.
TypedDataPoly.A_VUV.view.100(RunTime): 4.499246259421757 ns.
TypedDataPoly.A_UVx5.array.100(RunTime): 3.1570175999999996 ns.
TypedDataPoly.A_UVx5.view.100(RunTime): 4.482889818440727 ns.
TypedDataPoly.mega.array.100(RunTime): 3.649420567570034 ns.
TypedDataPoly.mega.mixed.100(RunTime): 4.068594455581881 ns.


On the other hand, there is a massive performance tax for using UnmodifiableUint8ListView on the web, especially views of views.
https://github.com/dart-lang/sdk/issues/50255 discusses how this might be fixed.

compile js -O3:

TypedDataPoly.mono.array.2(RunTime): 2.209502118308509 ns.
TypedDataPoly.A_V.array.2(RunTime): 2.58625 ns.
TypedDataPoly.A_V.view.2(RunTime): 2.32 ns.
TypedDataPoly.A_UV.array.2(RunTime): 51.633530557495135 ns.
TypedDataPoly.A_UV.view.2(RunTime): 302.4986387561256 ns.
TypedDataPoly.A_VUV.array.2(RunTime): 52.19476512355694 ns.
TypedDataPoly.A_VUV.view.2(RunTime): 302.84394312113756 ns.
TypedDataPoly.A_UVx5.array.2(RunTime): 55.649763488505165 ns.
TypedDataPoly.A_UVx5.view.2(RunTime): 849.458699173131 ns.
TypedDataPoly.mega.array.2(RunTime): 59.75952192382461 ns.
TypedDataPoly.mega.mixed.2(RunTime): 142.7126082991336 ns.

TypedDataPoly.mono.array.100(RunTime): 0.9815000000000002 ns.
TypedDataPoly.A_V.array.100(RunTime): 1.1626947678735444 ns.
TypedDataPoly.A_V.view.100(RunTime): 1.2075 ns.
TypedDataPoly.A_UV.array.100(RunTime): 17.17602868362643 ns.
TypedDataPoly.A_UV.view.100(RunTime): 231.5 ns.
TypedDataPoly.A_VUV.array.100(RunTime): 16.85678073510773 ns.
TypedDataPoly.A_VUV.view.100(RunTime): 229.7 ns.
TypedDataPoly.A_UVx5.array.100(RunTime): 17.01657458563536 ns.
TypedDataPoly.A_UVx5.view.100(RunTime): 697.5524475524476 ns.
TypedDataPoly.mega.array.100(RunTime): 22.770700636942674 ns.
TypedDataPoly.mega.mixed.100(RunTime): 94.4 ns.

Change-Id: If8878efd4c57bbd87effcd1d3f1339bc0cffbd75
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/264897
Commit-Queue: Stephen Adams <sra@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>
1 file changed
tree: 6850a9f7a7d17329dd2cdbbd5addffbc550c58cf
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. docs/
  6. pkg/
  7. runtime/
  8. samples/
  9. sdk/
  10. tests/
  11. third_party/
  12. tools/
  13. utils/
  14. .clang-format
  15. .gitattributes
  16. .gitconfig
  17. .gitignore
  18. .gn
  19. .mailmap
  20. .style.yapf
  21. .vpython
  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. README.dart-sdk
  33. README.md
  34. sdk_args.gni
  35. SECURITY.md
  36. WATCHLISTS
README.md

Dart

A client-optimized language for fast apps on any platform

Dart is:

  • Optimized for UI: Develop with a programming language specialized around the needs of user interface creation.

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

  • Fast on all platforms: Compile to ARM & x64 machine code for mobile, desktop, and backend. Or compile to JavaScript for the web.

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 on our wiki.

Contributing to Dart

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You can also contribute patches, as described in Contributing.