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dart / sdk / 8c0df46887744e229b74bfb8c6bfc05df67f67eb
commit8c0df46887744e229b74bfb8c6bfc05df67f67eb[log] [tgz]
authorAlexander Aprelev <aam@google.com>Thu Oct 20 20:31:20 2022 +0000
committerCommit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com>Thu Oct 20 20:31:20 2022 +0000
tree42a7007d27d57dd76e3f40f29db6ce77689a6402
parent9f32d19a420c8f74d5ec2c1e468b81472fc3955d [diff]
[vm] Better implementation of hashCode function.

With this cl hashCode function for integers which used to be identity function becomes `uint128_t hash = value * constant; hash ^= hash >> 64; hash ^= hash >> 32; hash &= 0x3fffffff`. Note that the hashCode has to stay the same across platforms(64-bit/32-bit).

This dramatically improves performance of integer HashSet/HashMap lookups when integers differ in higher bits only(see the issue referenced below).

AOT ARM64 benchmarks:
===
WordSolverIdentity -3.630% (-0.9 noise)
BigInt.parse.0064.bits 15.43% (0.9 noise)
BigInt.parse.4096.bits 40.80% (1.6 noise)
BigInt.parse.0256.bits 42.01% (2.3 noise)
BigInt.parse.1024.bits 50.91% (2.6 noise)
IntegerSetLookup.DefaultHashSet 549916% (14727.6 noise)
IntegerSetLookup.DefaultHashSet 597150% (55520.2 noise)
IntegerSetLookup.HashSet 846924% (78126.7 noise)
IntegerSetLookup.HashSet 791864% (107221.1 noise)
===

AOT x64:
===
Havlak -14.25% (-1.7 noise)
DartMicroBench.Int64Div -7.091% (-1.2 noise)
ObjectHash.manual.5 -9.541% (-0.8 noise)
AsyncLiveVars.LiveInt1 4.726% (0.8 noise)
IsolateJson.SendAndExit_Decode1MBx1 9.067% (0.8 noise)
SplayHarderLatency 4.629% (0.9 noise)
TypedDataDuplicate.Float64List.32.loop 35.01% (1.8 noise)
IntegerSetLookup.DefaultHashSet 627996% (124823.6 noise)
IntegerSetLookup.HashSet 1245362% (244705.3 noise)
===

JIT ARM64:
===
IntegerSetLookup.DefaultHashSet_Random 73.80% (1.2 noise)
IntegerSetLookup.DefaultHashSet 344999% (6202.9 noise)
IntegerSetLookup.HashSet 483731% (7845.7 noise)
===

JIT x64:
===
CollectionSieves-Set-removeLoop -6.294% (-0.9 noise)
Utf8Encode.ru.10M 59.11% (0.8 noise)
Utf8Encode.ru.10k 71.62% (0.9 noise)
Utf8Encode.zh.10M 53.93% (0.9 noise)
Utf8Encode.ne.10k 71.34% (0.9 noise)
Utf8Encode.zh.10k 72.52% (0.9 noise)
Utf8Encode.ne.10M 53.17% (0.9 noise)
IntegerSetLookup.HashSet_Random 27.80% (1.1 noise)
String.replaceAll.String.Zero 8.659% (1.2 noise)
IntegerSetLookup.DefaultHashSet_Random 96.20% (1.3 noise)
IntegerSetLookup.HashSet 481037% (18028.8 noise)
IntegerSetLookup.DefaultHashSet 454450% (31501.3 noise)
==

Fixes https://github.com/dart-lang/sdk/issues/48641
TEST=ci

Change-Id: Id982e4aa30cd1d6a63f93c73917a8b921ad464a3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/258600
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Aprelev <aam@google.com>
29 files changed
tree: 42a7007d27d57dd76e3f40f29db6ce77689a6402
  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

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

You can also contribute patches, as described in Contributing.