| commit | 23f0c0b27b3e797f9f7918735ad3461c34847b11 | [log] [tgz] |
|---|---|---|
| author | Jens Johansen <jensj@google.com> | Wed Sep 25 07:08:56 2024 +0000 |
| committer | Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> | Wed Sep 25 07:08:56 2024 +0000 |
| tree | 3f4e23143a8505e95473e8c7dc002fca1f7b9028 | |
| parent | 465bbbd720657a0e2477d6212b2c080be817f375 [diff] |
[scanner/paser] Don't use identical on ints Short explanation: For whatever reason, when using `identical` on `int`s the ints are first boxed (`BoxInt64`) before being compared (`StrictCompare`) whereas just doing `==` just does a compare (`EqualityCompare`). Results: With the CFE compiling (a fixed version of) itself I get these results: ``` instructions:u: -0.5756% +/- 0.0003% (-124825401.80 +/- 64013.17) ``` i.e. almost 125 mio instructions saved. Another run - with 100 iterations each - I get ``` msec task-clock:u: -0.4927% +/- 0.2585% (-20.85 +/- 10.94) page-faults:u: 0.0174% +/- 0.0139% (18.80 +/- 15.00) cycles:u: -0.5233% +/- 0.2683% (-91305451.82 +/- 46815747.30) instructions:u: -0.5754% +/- 0.0002% (-124793061.49 +/- 37426.30) branch-misses:u: -1.6903% +/- 1.1207% (-1091410.69 +/- 723627.04) seconds time elapsed: -0.4863% +/- 0.2581% (-0.02 +/- 0.01) seconds user: -0.4547% +/- 0.3253% (-0.02 +/- 0.01) ``` In the scanner benchmark with `--string` (i.e. using string scanner) I get these results: ``` msec task-clock:u: -3.7992% +/- 0.3316% (-190.54 +/- 16.63) cycles:u: -4.1423% +/- 0.3566% (-836808313.28 +/- 72033424.19) instructions:u: -3.3524% +/- 0.0000% (-1480262370.08 +/- 828.58) branch-misses:u: -1.7591% +/- 0.9582% (-1781144.28 +/- 970258.82) seconds time elapsed: -3.7988% +/- 0.3303% (-0.19 +/- 0.02) seconds user: -4.0211% +/- 0.4161% (-0.19 +/- 0.02) ``` (Just running the benchmark also sees the characters/µs go from ~93 to ~97). In the scanner benchmark with `--bytes` (i.e. using the utf8 scanner) I get these results: ``` msec task-clock:u: -4.2872% +/- 0.4467% (-185.64 +/- 19.34) cycles:u: -4.2972% +/- 0.4382% (-812955454.92 +/- 82892232.23) instructions:u: -3.4867% +/- 0.0000% (-1479744935.28 +/- 297.12) seconds time elapsed: -4.2872% +/- 0.4470% (-0.19 +/- 0.02) seconds user: -4.2204% +/- 0.4730% (-0.18 +/- 0.02) ``` (Just running the benchmark also sees the bytes/µs go from ~108 to ~113). In both cases we notice how the actual time, cycles and instructions agree pretty well. Combining the data for the compile and the benchmark I assume this CL actually reduces the runtime of the CFE compiling itself by a about half a percent. Change-Id: I67d056837240aef61b6707d02507ab4121b31715 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/385940 Commit-Queue: Jens Johansen <jensj@google.com> Reviewed-by: Johnni Winther <johnniwinther@google.com> Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
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 is free and open source.
See LICENSE and PATENT_GRANT.
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).
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.
The easiest way to contribute to Dart is to file issues.
You can also contribute patches, as described in Contributing.
Future plans for Dart are included in the combined Dart and Flutter roadmap on the Flutter wiki.