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ac6310d5f3
64 bit objects have 32 bits of free space in the header word.
This is used for the hash code in string objects. We take it
for the default hash code on all objects that don't override
the hashCode getter.
This is both faster and a memory reduction. Eg it shaves about
70% off the running time of this microbenchmark:
List list = [];
class Thing {
get hashCode => 42;
}
class Thing2 {
get hashCode => 42;
}
class Thing3 { }
class Thing4 { }
main() {
int sum = 103;
for (int i = 0; i < 10000000; i++) {
list = [];
list.add("foo");
list.add(123);
list.add(1.23);
list.add(new Object());
list.add(new Thing());
list.add(new Thing2());
list.add(new Thing3());
list.add(new Thing4());
for (int j = 0; j < 2; j++) {
sum ^= biz(list);
}
}
print(sum);
}
int biz(List list) {
int sum = 103;
for (var x in list) {
sum ^= x.hashCode;
}
return sum;
}
R=rmacnak@google.com, vegorov@google.com
BUG=
Review-Url: https://codereview.chromium.org/2912863006 .
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|---|---|---|
| build | ||
| client | ||
| docs/language | ||
| pkg | ||
| runtime | ||
| samples | ||
| samples-dev | ||
| sdk | ||
| tests | ||
| third_party | ||
| tools | ||
| utils | ||
| .clang-format | ||
| .gitattributes | ||
| .gitignore | ||
| .gn | ||
| .mailmap | ||
| .packages | ||
| .travis.yml | ||
| AUTHORS | ||
| BUILD.gn | ||
| CHANGELOG.md | ||
| codereview.settings | ||
| create_sdk.gyp | ||
| dart.gyp | ||
| DEPS | ||
| LICENSE | ||
| PATENTS | ||
| PRESUBMIT.py | ||
| README.dart-sdk | ||
| README.md | ||
| WATCHLISTS | ||
Dart
Dart is an open-source, scalable programming language, with robust libraries and runtimes, for building web, server, and mobile apps.
Using Dart
Visit the dartlang.org to learn more about the language, tools, getting started, and more.
Browse pub.dartlang.org for more packages and libraries contributed by the community and the Dart team.
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.