Static methods and constructors may receive unboxed parameters.
This change adds a bitmap to the RawFunction object indicating
which parameters are unboxed and their types. Also, the stack frame
bitmap was updated to include new bits for those parameters.
The ArgumentsDescriptor object was updated to store not only the number
of arguments, but also their size, since 32-bit platforms would use two
words for each int64 and double value.
In addition, static methods that return non-nullable integers
and doubles may return these values unboxed.
Dart AOT x64:
TypedData.Uint8ClampedListViewVarBench +11.73%
DeltaBlue +9.32%
Meteor (Intel Xeon) +4.64%
Flutter release android-armv8:
velocity_tracker_bench -2.32% (less is better)
flutter_gallery_readonlydata_size +0.18%
flutter_gallery_total_size +0.13%
flutter_gallery_instructions_size +0.12%
Issue https://github.com/dart-lang/sdk/issues/33549
Change-Id: I97e310f8f30213920af2333fbdedf193d03db5c3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/135313
Commit-Queue: Victor Agnez Lima <victoragnez@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
This reverts commit 5f81efb4a3.
Reason for revert: 3xH bot is green again.
Original change's description:
> Revert "[vm/aot] Only patch call-sites to monomorphic entry-points when the receiver is proven to be a heap object."
>
> This reverts commit ab2026af45.
>
> Reason for revert: Flutter 3xH is broken on Golem.
>
> Original change's description:
> > [vm/aot] Only patch call-sites to monomorphic entry-points when the receiver is proven to be a heap object.
> >
> > Flutter Gallery ARMv8: -0.8% total, -1.3% instructions
> > Flutter Gallery ARMv7: -0.7% total, -1.2% instructions
> >
> > There are some performance regressions, in four categories:
> >
> > 1. Arithmetic on num types (e.g. MinLib, MaxLib):
> > We believe arithmetic on num types is rare in practice, and can be optimized later
> > by specializing the call-sites.
> >
> > 2. Lack of types (e.g. MeshDecompression, ImagingGaussianBlur, Crypto*):
> > These (and similar benchmarks) are written in a very untyped style, which is not
> > representative of Dart 2 style. We've confirmed that the regressions disappear if
> > the benchmarks are annotated with appropriate types.
> >
> > 3. Megamorphic calls which are specialized in the benchmark (e.g. DeltaBlue):
> > DeltaBlue uses string interpolation in one place, so the toString() method in the
> > string interpolation helper is monomorphic for _Smis. However, in a realistic programs,
> > string interpolation is used much more frequently and with different types, so it's very
> > unlikely that this call would be monomorphic. When string interpolation is removed, there's
> > a remaining 1.3% regression on DeltaBlue which is not yet accounted for.
> >
> > 4. Noisy benchmarks
> > The remaining regressions are on benchmarks which show frequent jitter historically.
> >
> > There are also 1-4% improvements on many benchmarks (Golem's "noise" analysis is hiding
> > many of them, look at the graphs).
> >
> > For the reasons above, we believe the regressions justified by the code size improvement.
> >
> > Change-Id: Ic9b281d4383a6111de9d6f44347976ffa61a6ca6
> > Cq-Include-Trybots:luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-bare-linux-release-simarm64-try
> > Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/128667
> > Commit-Queue: Samir Jindel <sjindel@google.com>
> > Reviewed-by: Ryan Macnak <rmacnak@google.com>
> > Reviewed-by: Martin Kustermann <kustermann@google.com>
>
> TBR=kustermann@google.com,rmacnak@google.com,alexmarkov@google.com,sjindel@google.com
>
> Change-Id: I411aae4b230f2a08146ad3bf3e7a10aa6592db0e
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try, vm-kernel-precomp-linux-release-simarm-try, vm-kernel-precomp-linux-release-simarm64-try, vm-kernel-precomp-bare-linux-release-simarm64-try
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/131660
> Reviewed-by: Samir Jindel <sjindel@google.com>
> Commit-Queue: Samir Jindel <sjindel@google.com>
TBR=kustermann@google.com,rmacnak@google.com,alexmarkov@google.com,sjindel@google.com
# Not skipping CQ checks because original CL landed > 1 day ago.
Change-Id: I36e4e9d598033fcc934c2cdf5b061aa11255d3b2
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try, vm-kernel-precomp-linux-release-simarm-try, vm-kernel-precomp-linux-release-simarm64-try, vm-kernel-precomp-bare-linux-release-simarm64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/131837
Reviewed-by: Samir Jindel <sjindel@google.com>
Commit-Queue: Samir Jindel <sjindel@google.com>
This reverts commit ab2026af45.
Reason for revert: Flutter 3xH is broken on Golem.
Original change's description:
> [vm/aot] Only patch call-sites to monomorphic entry-points when the receiver is proven to be a heap object.
>
> Flutter Gallery ARMv8: -0.8% total, -1.3% instructions
> Flutter Gallery ARMv7: -0.7% total, -1.2% instructions
>
> There are some performance regressions, in four categories:
>
> 1. Arithmetic on num types (e.g. MinLib, MaxLib):
> We believe arithmetic on num types is rare in practice, and can be optimized later
> by specializing the call-sites.
>
> 2. Lack of types (e.g. MeshDecompression, ImagingGaussianBlur, Crypto*):
> These (and similar benchmarks) are written in a very untyped style, which is not
> representative of Dart 2 style. We've confirmed that the regressions disappear if
> the benchmarks are annotated with appropriate types.
>
> 3. Megamorphic calls which are specialized in the benchmark (e.g. DeltaBlue):
> DeltaBlue uses string interpolation in one place, so the toString() method in the
> string interpolation helper is monomorphic for _Smis. However, in a realistic programs,
> string interpolation is used much more frequently and with different types, so it's very
> unlikely that this call would be monomorphic. When string interpolation is removed, there's
> a remaining 1.3% regression on DeltaBlue which is not yet accounted for.
>
> 4. Noisy benchmarks
> The remaining regressions are on benchmarks which show frequent jitter historically.
>
> There are also 1-4% improvements on many benchmarks (Golem's "noise" analysis is hiding
> many of them, look at the graphs).
>
> For the reasons above, we believe the regressions justified by the code size improvement.
>
> Change-Id: Ic9b281d4383a6111de9d6f44347976ffa61a6ca6
> Cq-Include-Trybots:luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-bare-linux-release-simarm64-try
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/128667
> Commit-Queue: Samir Jindel <sjindel@google.com>
> Reviewed-by: Ryan Macnak <rmacnak@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
TBR=kustermann@google.com,rmacnak@google.com,alexmarkov@google.com,sjindel@google.com
Change-Id: I411aae4b230f2a08146ad3bf3e7a10aa6592db0e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try, vm-kernel-precomp-linux-release-simarm-try, vm-kernel-precomp-linux-release-simarm64-try, vm-kernel-precomp-bare-linux-release-simarm64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/131660
Reviewed-by: Samir Jindel <sjindel@google.com>
Commit-Queue: Samir Jindel <sjindel@google.com>
Flutter Gallery ARMv8: -0.8% total, -1.3% instructions
Flutter Gallery ARMv7: -0.7% total, -1.2% instructions
There are some performance regressions, in four categories:
1. Arithmetic on num types (e.g. MinLib, MaxLib):
We believe arithmetic on num types is rare in practice, and can be optimized later
by specializing the call-sites.
2. Lack of types (e.g. MeshDecompression, ImagingGaussianBlur, Crypto*):
These (and similar benchmarks) are written in a very untyped style, which is not
representative of Dart 2 style. We've confirmed that the regressions disappear if
the benchmarks are annotated with appropriate types.
3. Megamorphic calls which are specialized in the benchmark (e.g. DeltaBlue):
DeltaBlue uses string interpolation in one place, so the toString() method in the
string interpolation helper is monomorphic for _Smis. However, in a realistic programs,
string interpolation is used much more frequently and with different types, so it's very
unlikely that this call would be monomorphic. When string interpolation is removed, there's
a remaining 1.3% regression on DeltaBlue which is not yet accounted for.
4. Noisy benchmarks
The remaining regressions are on benchmarks which show frequent jitter historically.
There are also 1-4% improvements on many benchmarks (Golem's "noise" analysis is hiding
many of them, look at the graphs).
For the reasons above, we believe the regressions justified by the code size improvement.
Change-Id: Ic9b281d4383a6111de9d6f44347976ffa61a6ca6
Cq-Include-Trybots:luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-bare-linux-release-simarm64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/128667
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Right now `Script::yield_positions()` is an array mapping function start
token positions to arrays. Those arrays contain token positions and are
indexed by yield index.
=> This `Script::yield_positions()` is not available in AOT mode.
The fast async stack implementation will need to be able to find out
where an async closure was suspended. It does so by looking at the
":await_jump_var", which contains the yield index. It then needs to
associate the yield index to token position of the yield.
This CL adds an entry into the PcDescriptors for every yield in a
async/async* function and removes `Script::yield_positions()`.
The entry will associate the yield index with the token position.
Flutter gallery total size impact for flutter-release:
- armv7: +0.016%
- armv8: +0.045%
Issue https://github.com/dart-lang/sdk/issues/37668
Change-Id: I0b2ce41e85d8f5d590201bf2fb091578d7379890
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/125408
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Clement Skau <cskau@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Fixes the changes to assembly snapshot writer in SIMARM_X64 mode. This unfortunately can't be tested until the ELF loader is available.
Take 2 is in patchset 1.
Change-Id: Ib8b067dd4f09dcba3b142705e9cb4dfbf4e3eb53
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/117726
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
The original change is in Patchset 1.
The dependency contains the fix for the non-bare-instructions bot.
Change-Id: Iab02ab0736a2ee9144b667d2777ca526341b2a36
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-android-release-arm-try,vm-dartkb-linux-release-x64-abi-try,vm-kernel-precomp-bare-linux-release-x64-try,vm-kernel-precomp-mac-debug-simarm_x64-try,vm-kernel-precomp-win-release-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/115241
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
This reverts commit ecbea5a58e.
Reason for revert: broken with bare instructions and ABI bot
Original change's description:
> [vm/ffi] Implement FFI callbacks on AOT for ELF and Asm snapshots (excl. blobs).
>
> To do this, we add writable data sections (currently uninitialzed) to ELF and Asm snapshots
> and allow Instructions to have patchable relocations against (the start of) these sections.
>
> Issue https://github.com/dart-lang/sdk/issues/37295 (see also for design & discussion).
>
> Change-Id: If20bfa55776f4044aaa6bb8ea2101d2ada41842c
> Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-android-release-arm-try
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/110221
> Commit-Queue: Samir Jindel <sjindel@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
TBR=kustermann@google.com,rmacnak@google.com,alexmarkov@google.com,sjindel@google.com
Change-Id: I9787da6d42575ca4f5ae0a698052a19ac4275afd
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try, vm-kernel-precomp-linux-product-x64-try, vm-kernel-precomp-linux-release-x64-try, vm-kernel-precomp-android-release-arm-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/115240
Reviewed-by: Samir Jindel <sjindel@google.com>
Commit-Queue: Samir Jindel <sjindel@google.com>
To do this, we add writable data sections (currently uninitialzed) to ELF and Asm snapshots
and allow Instructions to have patchable relocations against (the start of) these sections.
Issue https://github.com/dart-lang/sdk/issues/37295 (see also for design & discussion).
Change-Id: If20bfa55776f4044aaa6bb8ea2101d2ada41842c
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-android-release-arm-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/110221
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Move generation of Function objects for native trampolines to the Precompiler, so they can be generated during AOT and tree-shaken if possible.
Issue dartbug.com/35765
Change-Id: I0e69b7e0b22db73e3a40f2fe445660e57ddb6fa9
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-bare-linux-release-simarm64-try, vm-kernel-precomp-bare-linux-release-x64-try, vm-kernel-precomp-linux-debug-x64-try, vm-dartkb-linux-debug-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/107407
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
This reverts commit ab6aeaa106.
Revert "[vm/compiler] Speed up the compiler part which deals with kernel reading up in DEBUG mode"
This reverts commit b316210d94.
Reason for revert: regression of snapshot sizes (DNO-599).
Original change's description:
> [vm/kernel] Use GC-tracked ExternalTypedData/TypedDataView for kernel buffers
>
> Until now we often leaked kernel buffers (e.g. hot reload buffers) because various
> objects were referencing ExternalTypedData objects pointing into the middle of
> c-allocated memory. This made it impossible for the GC to determine when the last
> reference is gone.
>
> This CL ensures that the actual buffers are *always* made available via
> ExternalTypedData and any inner pointers into it are created via TypedDataViews.
>
> The embedder guarantees to the free kernel buffers it has provided to:
> - Dart_CreateIsolateFromKernel
> - Dart_LoadScriptFromKernel
> - Dart_LoadLibraryFromKernel
> - Dart_SetDartLibrarySourcesKernel
> on isolate shutdown.
>
> All other kernel buffers will get a finalizer attached, which ensures the
> kernel buffers get freed by the GC once they are no longer referenced:
> - Kernel blobs for expression evaluation
> - Kernel blobs for Hot-Reload
> - Kernel blobs for cc tests
>
> Fixes https://github.com/dart-lang/sdk/issues/33973
> Fixes https://github.com/dart-lang/sdk/issues/36857
> Issue https://github.com/dart-lang/sdk/issues/37030
>
> Change-Id: I1cc410c94c0f4b229413e793728a261afcb10aaf
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103130
> Reviewed-by: Ryan Macnak <rmacnak@google.com>
> Commit-Queue: Martin Kustermann <kustermann@google.com>
TBR=kustermann@google.com,rmacnak@google.com
# Not skipping CQ checks because original CL landed > 1 day ago.
Change-Id: I49715d2400f4a5c8806b7d6a2912b7258f671a0a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/104343
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Auto-Submit: Alexander Markov <alexmarkov@google.com>
Until now we often leaked kernel buffers (e.g. hot reload buffers) because various
objects were referencing ExternalTypedData objects pointing into the middle of
c-allocated memory. This made it impossible for the GC to determine when the last
reference is gone.
This CL ensures that the actual buffers are *always* made available via
ExternalTypedData and any inner pointers into it are created via TypedDataViews.
The embedder guarantees to the free kernel buffers it has provided to:
- Dart_CreateIsolateFromKernel
- Dart_LoadScriptFromKernel
- Dart_LoadLibraryFromKernel
- Dart_SetDartLibrarySourcesKernel
on isolate shutdown.
All other kernel buffers will get a finalizer attached, which ensures the
kernel buffers get freed by the GC once they are no longer referenced:
- Kernel blobs for expression evaluation
- Kernel blobs for Hot-Reload
- Kernel blobs for cc tests
Fixes https://github.com/dart-lang/sdk/issues/33973
Fixes https://github.com/dart-lang/sdk/issues/36857
Issue https://github.com/dart-lang/sdk/issues/37030
Change-Id: I1cc410c94c0f4b229413e793728a261afcb10aaf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103130
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
When a mixin class is created, there might be anonymous closures copied over to the other script.
Previously the script of closure function is the script of its parent function, which is not true in that case.
The solution is to create a patch class as the owner if parent function has a different script object. Return script of owner when query for script of closure function.
Bug: https://github.com/dart-lang/sdk/issues/34841
Change-Id: I53065cbf13f2d0dc8da320993fd3cd425e5c9714
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/102226
Commit-Queue: Zichang Guo <zichangguo@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
E.g. trying to set a breakpoint on the if in this code
```
if (args == null) {
print("was null");
}
// more code below
```
would actually set a breakpoint on the print, and the breakpoint - unless
the argument is null - would never be hit.
Change-Id: I072abb3bf2783e9f36c8d3ac6be4885ca454db94
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/98663
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>
This change replaces kernel AST declarations of fields and functions
with bytecode declarations.
Size of dilp files is reduced by 11-12%.
Startup latency:
Time to the first full frame: 1.945s -> 1.687s
FinalizeClass: 554ms -> 277ms
FinishClassLoading: 296ms -> 156ms
There are following regressions in bytecode mode, which will be fixed
in future:
* dart:mirrors are not supported yet (implementation of mirrors relies
on reading kernel AST in certain cases).
As the result, lib_2/mirrors/* tests fail.
* native extensions are not supported yet (annotations on libraries
and classes in AST are cleaned up as they could reference members
which are now removed from AST).
As the result, standalone_2/entrypoints_verification_test test fails.
* language_2/spread_collections/const_error_test/* tests fail
due to https://github.com/dart-lang/sdk/issues/36286.
Change-Id: I5130f401fd7b84038b136136e7ccc1a6e51b6cea
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/97561
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
This is a reland of 1a4cff1bd4
Original change's description:
> [VM] Remove unused flags
>
> Remove the following flags which are always ON
> --strong
> --reify_generic_functions
>
> and these flags which are not applicable anymore
> --error-on-bad-override
> --error-on-bad-type
> --enable-type-checks
>
> Change-Id: I6e1aeb68e663953f4ae49ca94ea0daa87b661900
> Reviewed-on: https://dart-review.googlesource.com/c/79431
> Commit-Queue: Siva Annamalai <asiva@google.com>
> Reviewed-by: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Régis Crelier <regis@google.com>
Change-Id: Ib4452c22fb05eed38820708abb648939e03b1df0
Reviewed-on: https://dart-review.googlesource.com/c/84923
Reviewed-by: Siva Annamalai <asiva@google.com>
Remove the following flags which are always ON
--strong
--reify_generic_functions
and these flags which are not applicable anymore
--error-on-bad-override
--error-on-bad-type
--enable-type-checks
Change-Id: I6e1aeb68e663953f4ae49ca94ea0daa87b661900
Reviewed-on: https://dart-review.googlesource.com/c/79431
Commit-Queue: Siva Annamalai <asiva@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Make StoreIntanceField and LoadField instructions use a single uniform
abstraction: Slot (used to be called NativeFieldDesc), which represents
either a real Dart field (i.e. a field that has a corresponding Field object)
or a native VM field that does not have a corresponding Field object.
This refactoring eliminates raw stores/loads that were just using offsets
before - now we always know what kind of slots we are accessing and
this yields better aliasing information.
Change-Id: I2f48332d58258219565bd961764e8cc9dd4d75ce
Reviewed-on: https://dart-review.googlesource.com/c/74582
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Similar to how we treat catch entry instructions, this cl adds new
function and osr entry instructions. The [FunctionEntry] and
[OsrEntry] - just like [CatchBlockEntry] - have now their own initial
definitions. The [GraphEntry] has only initial definitions for
constants.
Explicit phis are inserted for all parameter / special parameter
instructions if necessary.
Future work is:
a) Minimize parallel moves due to the phis on parameters
b) Cleanup frame setup: Move it entirely into FunctionEntry/CatchEntry
(instead of the split version we have now)
Fixes https://github.com/dart-lang/sdk/issues/34435
Fixes https://github.com/dart-lang/sdk/issues/34287
Change-Id: Iefa0280a709716f748d6fb0523b8d0f4d8de1fec
Reviewed-on: https://dart-review.googlesource.com/c/74782
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
After this CL, the interpreter is included by default in the
JIT VM under the flag --enable-interpreter.
Reland with fix to NativeArgument setup in simulator_arm.cc
Change-Id: Ib9b4df6eb4d997dfbe361188b8a127828c1d9c6f
Reviewed-on: https://dart-review.googlesource.com/74003
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Zach Anderson <zra@google.com>