| # AOT code size analysis |
| |
| The Dart VM's AOT compiler has support for emitting binary size information |
| for all the code that gets generated. This information can then be visualized. |
| |
| ## Telling the AOT compiler to generate binary size information |
| |
| Our AOT compiler accepts an extra `--print-instructions-sizes-to=sizes.json` |
| flag. If supplied the AOT compiler will emit binary size information for all |
| generated functions to `sizes.json`. |
| |
| This flag can be passed to `gen_snapshot` directly, or to the various wrapper |
| scripts (e.g. `pkg/vm/tool/precompiler2`): |
| |
| ``` |
| % tools/build.py -mrelease -ax64 runtime_kernel dart_precompiled_runtime |
| % pkg/vm/tool/precompiler2 --print-instructions-sizes-to=hello_sizes.json hello.dart hello.dart.aot |
| ``` |
| |
| ## Visualizing the information from the binary size json file |
| |
| To visualize the information emitted by the AOT compiler one can use our binary |
| size analysis tool: |
| |
| ``` |
| % dart pkg/vm/bin/run_binary_size_analysis.dart hello_sizes.json hello_sizes |
| Generated file:///.../sdk/hello_sizes/index.html |
| % chrome hello_sizes/index.html |
| ``` |
| |
