| commit | 462d671075c2f7b76b015cfc42e33de8ba13b8e9 | [log] [tgz] |
|---|---|---|
| author | Søren Gjesse <sgjesse@google.com> | Mon Jun 19 13:50:08 2017 +0200 |
| committer | Søren Gjesse <sgjesse@google.com> | Mon Jun 19 13:50:08 2017 +0200 |
| tree | 0a905b769ce214f4c9a34f83f7bf7d8186359ba5 | |
| parent | 569452b5000955d4887e0f0e6fc768a7ad9f841b [diff] |
Ensure deterministic IR optimization When the IR processing have to break cycles in the call graph to produce a set of leaves to process, the processing order can change the generated code as optimization feedback from processing one method feeds into another method. To get deterministic behaviour the optimization feedback is collected without making it available to other methods immediately. When all methods in the set of leaves have been processed the collected optimization feedback is applied. After the optimization feedback has been applied the methods calling any of the methods with new optimization feedback will be re-processed. When methods are re-processed for other reasons (double-inlining and outlining) no additional optimization feedback is collected to ensure deterministic behaviour. This also brings back concurrent IR processing as the issue with deterministic processing was also hit there. Bug: 37133161 Change-Id: Idf0ba09510038a0634cc1e34e44b50c6918b08cc
The R8 repo contains two tools:
D8 is a replacement for the DX dexer and R8 is a replacement for the Proguard shrinking and minification tool.
The R8 project uses depot_tools from the chromium project to manage dependencies. Install depot_tools and add it to your path before proceeding.
The R8 project uses Java 8 language features and requires a Java 8 compiler and runtime system.
Typical steps to download and build:
$ git clone https://r8.googlesource.com/r8 $ cd r8 $ tools/gradle.py d8 r8
The tools/gradle.py script will bootstrap using depot_tools to download a version of gradle to use for building on the first run. This will produce two jar files: build/libs/d8.jar and build/libs/r8.jar.
The D8 dexer has a simple command-line interface with only a few options.
The most important option is whether to build in debug or release mode. Debug is the default mode and includes debugging information in the resulting dex files. Debugging information contains information about local variables used when debugging dex code. This information is not useful when shipping final Android apps to users and therefore, final builds should use the --release flag to remove this debugging information to produce smaller dex files.
Typical invocations of D8 to produce dex file(s) in the out directoy:
Debug mode build:
$ java -jar build/libs/d8.jar --output out input.jar
Release mode build:
$ java -jar build/libs/d8.jar --release --output out input.jar
The full set of D8 options can be obtained by running the command line tool with the --help option.
R8 is a Proguard replacement for whole-program optimization, shrinking and minification. R8 uses the Proguard keep rule format for specifying the entry points for an application.
Typical invocations of R8 to produce optimized dex file(s) in the out directory:
$ java -jar build/libs/r8.jar --release --output out --pg-conf proguard.cfg input.jar
The full set of R8 options can be obtained by running the command line tool with the --help option.
Typical steps to run tests:
$ tools/test.py --no_internal
The tools/test.py script will use depot_tools to download a lot of tests and test dependencies on the first run. This includes prebuilt version of the art runtime on which to validate the produced dex code.
For questions, bug reports and other issues reach out to us at r8-dev@googlegroups.com.