| commit | 1f1b63559e9e71182b201cdcfcddb327807a1abb | [log] [tgz] |
|---|---|---|
| author | Vyacheslav Egorov <vegorov@google.com> | Thu Apr 25 14:26:55 2024 +0000 |
| committer | dart-internal-monorepo <dart-internal-monorepo@dart-ci-internal.iam.gserviceaccount.com> | Thu Apr 25 07:28:40 2024 -0700 |
| tree | f95f52068f3e118b7bbf548f0cafc04a49913248 | |
| parent | 9e8c9c4c5e3d532b711334a048e343acb274e0eb [diff] |
[vm] Add pragma vm:unsafe:no-bounds-checks This pragma instructs compiler to remove all bounds checks from the annotated function. This can be helpful when tuning performance of hot tight loops where compiler is unable to eliminate bounds check itself. For very tight loops I have measured 25-50% overhead from bounds checks which I think comes from some combination of general code quality issues due to fixed input registers and increased branch density. In future it could be possible to teach our range analysis to eliminate bounds checks when loop bound is itself bounded by array length, but for now we can resort to this pragma for extremely hot library code. Issue https://github.com/dart-lang/sdk/issues/55522 TEST=vm/cc/BoundsCheckElimination_Pragma R=alexmarkov@google.com Change-Id: Ia7b1e88a16a2b45fa8593a227a4985568892b29c Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/364500 Reviewed-by: Alexander Markov <alexmarkov@google.com> Commit-Queue: Slava Egorov <vegorov@google.com> https://dart.googlesource.com/sdk/+/b0535bddd688609c014c2d65d56f67eb618e72fe
Monorepo is:
With depot_tools installed and on your path, create a directory for your monorepo checkout and run these commands to create a gclient solution in that directory:
mkdir monorepo cd monorepo gclient config --unmanaged https://dart.googlesource.com/monorepo gclient sync -D
This gives you a checkout in the monorepo directory that contains:
monorepo/ DEPS - the DEPS used for this gclient checkout commits.json - the pinned commits for Dart, flutter/engine, and flutter/flutter tools/ - scripts used to create monorepo DEPS engine/src/ - the flutter/buildroot repo flutter/ - the flutter/engine repo out/ - the build directory, where Flutter engine builds are created third_party/ - Flutter dependencies checked out by DEPS dart/ - the Dart SDK checkout. third_party - Dart dependencies, also used by Flutter flutter/ - the flutter/flutter repo
Flutter's instructions for building the engine are at Compiling the engine
They can be followed closely, with a few changes:
goma_ctl ensure_start is sufficient.Example build commands that work on linux:
MONOREPO_PATH=$PWD if [[ ! $PATH =~ (^|:)$MONOREPO_PATH/flutter/bin(:|$) ]]; then PATH=$MONOREPO_PATH/flutter/bin:$PATH fi export GOMA_DIR=$(dirname $(command -v gclient))/.cipd_bin goma_ctl ensure_start pushd engine/src flutter/tools/gn --goma --no-prebuilt-dart-sdk --unoptimized --full-dart-sdk autoninja -C out/host_debug_unopt popd
The Flutter commands used to build and run apps will use the locally built Flutter engine and Dart SDK, instead of the one downloaded by the Flutter tool, if the --local-engine option is provided.
For example, to build and run the Flutter spinning square sample on the web platform,
MONOREPO_PATH=$PWD cd flutter/examples/layers flutter --local-engine=host_debug_unopt \ -d chrome run widgets/spinning_square.dart cd $MONOREPO_PATH
To build for desktop, specify the desktop platform device in flutter run as -d macos or -d linux or -d windows. You may also need to run the command
flutter create --platforms=windows,macos,linux
on existing apps, such as sample apps. New apps created with flutter create already include these support files. Details of desktop support are at Desktop Support for Flutter
Tests in the Flutter source tree can be run with the flutter test command, run in the directory of a package containing tests. For example:
MONOREPO_PATH=$PWD cd flutter/packages/flutter flutter test --local-engine=host_debug_unopt cd $MONOREPO_PATH
Please file an issue or email the dart-engprod team with any problems with or questions about using monorepo.
We will update this documentation to address them.
flutter commands may download the engine and Dart SDK files for the configured channel, even though they will be using the local engine and its SDK.gclient sync needs to be run in an administrator session, because some installed dependencies create symlinks.