Commit Graph

195 Commits

Author SHA1 Message Date
Ryan Macnak b0c6f00f39 [vm] Use the right stack maps between executing catch entry moves and jumping to the exception handler.
Adds a stack map to the catch block entry pc.

The alternative would be to prevent yielding to a safepoint between these two point. For throws coming from Dart or the embedding API, this is possible by unwinding the transitions before the first point and doing only a non-yielding VM->Generated between the two points. For FFI, this does not work because the final state is Native instead of Generated, and VM->Native is a blocking transition.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/48668
Change-Id: I8164fddae018ed95d9147fafa65785b7638e5301
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/269746
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2022-11-17 17:20:18 +00:00
Alexander Markov bf4bb95308 [vm] New async/await implementation in the VM, part 2 - vm
The new implementation moves away from desugaring of async
functions on kernel AST, state machine generated in the flow graph and
capturing all local variables in the context.

Instead, async/await is implemented using a few stubs
(InitSuspendableFunction, Suspend, Resume, Return and
AsyncExceptionHandler). The stubs are implemented in a
platform-independent way using (macro-)assembler helpers.
When suspending a function, its frame is copied into a SuspendState
object, and when resuming a function it is copied back onto the stack.
No extra code is generated for accessing local variables.
Callback closures are created lazily on the first await.

Design doc: go/compact-async-await.

Part 1 (kernel): https://dart-review.googlesource.com/c/sdk/+/241842

TEST=ci

Issue: https://github.com/dart-lang/sdk/issues/48378
Change-Id: Ibad757035b7cc438ebdff80b460728b1d3eff1f5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/242000
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
2022-04-29 01:03:50 +00:00
Ryan Macnak ad4126bba4 [vm, compiler] Use more compressed instructions on RISC-V.
dart2js.aot.rv64 25290024 -> 25042040 (-0.98%)
dart2js.aot.rv32 24466620 -> 24000012 (-1.91%)

TEST=ci
Change-Id: I0b60d0c3bd8df036426898e00cf650b398abb397
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/242065
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
2022-04-27 17:11:35 +00:00
Ryan Macnak d4bc590c27 [vm, compiler] Match the C frame pointer convention on RISC-V.
The RISC-V frame pointer convention is different from that of x86 and ARM. FP is the caller's SP, and the saved FP is at FP[-2] instead of FP[0].

Making Dart frames match the convention of C frames allows stack walkers to continue their traversals through transitions between Dart and C (e.g., for stack dumps or profiling).

TEST=ci
Change-Id: I463348beba70c1a75bfb0d902b3391be524de0fe
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/235960
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2022-03-10 22:38:26 +00:00
Vyacheslav Egorov 13d27d669d [vm] Improve Code cluster layout for startup
This change bakes binary search table which maps PC ranges
to corresponding stack maps and Code objects (if still present
in the snapshot) into RO data section of the snapshot - instead
of constructing it at load time.

This allows to considerably reduce amount of work done when
loading Code cluster for programs which have majority of their
Code objects discarded (i.e. in DWARF stack traces mode): as
we no longer write / read any information for discarded Code
objects.

This CL also changes program visitor to deduplicate Code objects
if their instructions are deduplicated in AOT mode. Only a single
Code object can be choose as a representative for the given
PC range so it does not make sense to write multiple Code objects
into the snapshot which refer to the same Instructions.

The overall improvement is hard to quantify but ReadProgramSnapshot
shows the following improvement when starting a large
Flutter application on a slow Android device:

  before  223.55±59.94 (192.02 .. 391.74) ms
  after   178.06±47.03 (151.31 .. 291.34) ms

This CL packs CompressedStackMaps next to the binary search table
itself allowing us to address them via offsets instead of
pointers.

Snapshot sizes are actually affected positively by this change. On
the same large Flutter application I see

  DWARF stack traces on:  -1.34% total SO size
  DWARF stack traces off: -1.63% total SO size

Issue https://github.com/dart-lang/sdk/issues/46116

TEST=ci

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Change-Id: Ic997045a33daa81ec68df462a0792915885df66b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/220766
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
2021-12-16 10:39:49 +00:00
Vyacheslav Egorov 71c9c2cd83 [vm] Remove support for non-bare AOT snapshots
Every AOT user out there has been using bare instructions mode
and continuing to maintaining non-bare instructions mode simply
adds costs (both in terms of time spent making changes to work
in a mode that is not used and CI resources spent on testing it).

This change removes FLAG_use_bare_instructions and changes the code
to assume that FLAG_precompiled_mode implies bare instructions.

TEST=ci

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Change-Id: I5032b13bfcb613f79865f2cfa139cca8d1b42556
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/220964
Commit-Queue: Slava Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2021-11-24 13:03:52 +00:00
Ryan Macnak baa1ebb377 [vm, compiler] Fix incorrect register save in breakpoint stub.
Bug introduced in 1e24fe7d69.

Symbolize stub frames.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/47039
Change-Id: Ida3535a01923085cd48a2801ed9b868bfef7418b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212026
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
2021-08-31 23:56:36 +00:00
Zach Anderson f407419d0a [vm] Reland: Prefix HOST_OS_* and TARGET_OS_* with DART_
This relands https://dart-review.googlesource.com/c/sdk/+/205633
but without renaming TARGET_OS_IPHONE to DART_TARGET_OS_IPHONE.
It also changes uses of TARGET_OS_IOS to
DART_TARGET_OS_MACOS_IOS to be consistent with the rest of the
VM.

TargetConditionals.h for XCode 13 defines several
TARGET_OS_* preprocessor symbols that confuse the
Dart build. There is probably a more targeted fix
for this, but renaming the symbols that Dart uses
will also prevent this problem if more symbols
are added to the platform headers in the future.

See: https://github.com/dart-lang/sdk/issues/46499

TEST=It builds.

Change-Id: Ie775c19dd23cfdf5f65e5ebc6ee4ec3a561676fa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/205860
Commit-Queue: Zach Anderson <zra@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
2021-07-02 19:06:45 +00:00
Slava Egorov 42164cc140 Revert "[vm] Prefix HOST_OS_* and TARGET_OS_* with DART_"
This reverts commit aa9201b76b.

Reason for revert: blocks G3 roll (b/192627187)

Original change's description:
> [vm] Prefix HOST_OS_* and TARGET_OS_* with DART_
>
> TargetConditionals.h for XCode 13 defines several
> TARGET_OS_* preprocessor symbols that confuse the
> Dart build. There is probably a more targeted fix
> for this, but renaming the symbols that Dart uses
> will also prevent this problem if more symbols
> are added to the platform headers in the future.
>
> See: https://github.com/dart-lang/sdk/issues/46499
>
> TEST=It builds.
> Change-Id: I3b33a03b4a9a14b76d55fe12f8cdefec4b3c3664
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/205633
> Commit-Queue: Zach Anderson <zra@google.com>
> Reviewed-by: Siva Annamalai <asiva@google.com>

TBR=rmacnak@google.com,zra@google.com,asiva@google.com

Change-Id: Ib06ca418c7e9d3b4df62c72c033cd39f462f7667
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/205790
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
2021-07-02 14:02:02 +00:00
Zach Anderson aa9201b76b [vm] Prefix HOST_OS_* and TARGET_OS_* with DART_
TargetConditionals.h for XCode 13 defines several
TARGET_OS_* preprocessor symbols that confuse the
Dart build. There is probably a more targeted fix
for this, but renaming the symbols that Dart uses
will also prevent this problem if more symbols
are added to the platform headers in the future.

See: https://github.com/dart-lang/sdk/issues/46499

TEST=It builds.
Change-Id: I3b33a03b4a9a14b76d55fe12f8cdefec4b3c3664
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/205633
Commit-Queue: Zach Anderson <zra@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
2021-07-02 06:02:48 +00:00
Alexander Markov 5129cff930 [vm/aot] Discard Code objects from the heap
While deserializing AOT snapshot, Code objects which do not contain
valuable information besides entry point and stack maps are discarded
and not allocated on the heap (they are replaced with
StubCode::UnknownDartCode()).

PC -> Code/CompressedStackMaps lookup is implemented using a separate
table (InstructionsTable).

Flutter gallery in release-sizeopt mode:
Heap size of snapshot objects: arm -26.89%, arm64 -27.68%

Large Flutter application in release mode with --dwarf-stack-traces:
Heap size of snapshot objects: -24.3%.
Discarded Code objects: 72.5% of all Code objects.

Issue: https://github.com/dart-lang/sdk/issues/44852.

TEST=existing tests; "--dwarf_stack_traces --no-retain_function_objects
--no-retain_code_objects" mode is enabled for a few tests.

Change-Id: I5fe3e283630c8e8f4442319d5dcae38d174dd0d8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/189560
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2021-04-13 02:36:16 +00:00
Alexander Markov 26e7106937 [vm/aot] Partially remove Code objects from AOT snapshots
Code objects which do not carry useful information are
marked as 'discarded' during precompilation. Snapshot
serializer only writes instructions, compressed stack
maps and state bits for discarded Code objects.

This is a preliminary step before deserializer would be able
to omit creating instances for discarded Code objects at
runtime.

On a large app, AOT-compiled in PRODUCT mode with
--dwarf-stack-traces on arm64:
Discarded: 77% of all Code objects in snapshot.
Uncompressed AOT snapshot size -1.9%.

AOT snapshot size of Flutter gallery in release-sizeopt mode:
arm64 uncompressed -2.1% (gzip -0.6%, brotli -0.7%)
arm32 uncompressed -1.9% (gzip -0.6%, brotli -0.7%)

TEST=ci
Issue: https://github.com/dart-lang/sdk/issues/44852

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Change-Id: I159cfebbdac76cc60060fedb1d22ed86672a68a1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/187600
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2021-02-27 00:41:37 +00:00
Alexander Markov ddfc98337b Reland "[vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces"
This is a reland of b6dc4dad4d

TEST=ci

Original change's description:
> [vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces
>
> The following changes are done in preparation for the removal of Code
> objects in AOT with --dwarf-stack-traces:
>
> * Stack trace objects are extended to hold uword PCs (which may not
>   fit into Smi range).
>
> * Scanning stack frames in GC (StackFrame::VisitObjectPointers)
>   now avoids using Code objects.
>   In order to find CompressedStackMaps it now calls
>   ReversePc::FindCompressedStackMaps.
>
> * Singleton Code object (StubCode::UnknownDartCode()) is prepared as
>   a replacement for Code objects in stack traces. It has
>   PayloadStart() == 0 and Size() == kUwordMax so it includes
>   arbitrary PCs.
>
> * In --dwarf-stack-traces mode, most Code objects obtained from stack
>   frames are replaced with StubCode::UnknownDartCode().
>   This simulates future behavior of ReversePc::Lookup when Code objects
>   will be removed.
>
> Issue: https://github.com/dart-lang/sdk/issues/44852
> Change-Id: I7cec7b8b9396c9cfeca3c256a412ba4e82a7e0c4
> TEST=ci
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182720
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Tess Strickland <sstrickl@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>

Change-Id: Ia2fc4672a085cd963b7fc103369851df3603590c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/186202
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2021-02-22 10:46:28 +00:00
Alexander Markov fde0ed2e93 Revert "[vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces"
This reverts commit b6dc4dad4d.

Reason for revert: broke package:vm_snapshot_analysis in Flutter
(https://github.com/flutter/flutter/issues/76313).

Original change's description:
> [vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces
>
> The following changes are done in preparation for the removal of Code
> objects in AOT with --dwarf-stack-traces:
>
> * Stack trace objects are extended to hold uword PCs (which may not
>   fit into Smi range).
>
> * Scanning stack frames in GC (StackFrame::VisitObjectPointers)
>   now avoids using Code objects.
>   In order to find CompressedStackMaps it now calls
>   ReversePc::FindCompressedStackMaps.
>
> * Singleton Code object (StubCode::UnknownDartCode()) is prepared as
>   a replacement for Code objects in stack traces. It has
>   PayloadStart() == 0 and Size() == kUwordMax so it includes
>   arbitrary PCs.
>
> * In --dwarf-stack-traces mode, most Code objects obtained from stack
>   frames are replaced with StubCode::UnknownDartCode().
>   This simulates future behavior of ReversePc::Lookup when Code objects
>   will be removed.
>
> Issue: https://github.com/dart-lang/sdk/issues/44852
> Change-Id: I7cec7b8b9396c9cfeca3c256a412ba4e82a7e0c4
> TEST=ci
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182720
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Tess Strickland <sstrickl@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>

Issue: https://github.com/dart-lang/sdk/issues/44852
Change-Id: I6f66171eecf1133363a7ce56193e782e43a20baf
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/185488
Reviewed-by: Zach Anderson <zra@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2021-02-18 18:04:29 +00:00
Alexander Markov b6dc4dad4d [vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces
The following changes are done in preparation for the removal of Code
objects in AOT with --dwarf-stack-traces:

* Stack trace objects are extended to hold uword PCs (which may not
  fit into Smi range).

* Scanning stack frames in GC (StackFrame::VisitObjectPointers)
  now avoids using Code objects.
  In order to find CompressedStackMaps it now calls
  ReversePc::FindCompressedStackMaps.

* Singleton Code object (StubCode::UnknownDartCode()) is prepared as
  a replacement for Code objects in stack traces. It has
  PayloadStart() == 0 and Size() == kUwordMax so it includes
  arbitrary PCs.

* In --dwarf-stack-traces mode, most Code objects obtained from stack
  frames are replaced with StubCode::UnknownDartCode().
  This simulates future behavior of ReversePc::Lookup when Code objects
  will be removed.

Issue: https://github.com/dart-lang/sdk/issues/44852
Change-Id: I7cec7b8b9396c9cfeca3c256a412ba4e82a7e0c4
TEST=ci
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182720
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2021-02-17 20:12:32 +00:00
Ryan Macnak 25fd0200ef [vm] Replace recanonicalization in primary snapshots with weak constant tables.
TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/41974
Change-Id: Icc4a3ebf861dca5172a0cfa2cd2eea266e814d0c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/181480
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
2021-02-10 01:21:07 +00:00
Clement Skau c3ec3e53a1 [VM] Adds Future.then stack unwind. (3)
TEST=ASAN; Various 'causal' tests updated below.

Issues addressed in this revision:
- https://github.com/dart-lang/sdk/issues/44708 ASAN
- https://github.com/dart-lang/sdk/issues/44700 SegFault

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Bug: https://github.com/dart-lang/sdk/issues/40815, https://github.com/dart-lang/sdk/issues/37953
Change-Id: I8b8f6ee2e5d4ca2e6bea988ec1cd9f912ddf8240
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/180186
Commit-Queue: Clement Skau <cskau@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2021-01-26 14:02:39 +00:00
David Morgan 88c1be7e3b Revert "Reland "[VM] Adds Future.then and Future.catchError stack unwinding.""
This reverts commit 9978a246c1.

Reason for revert: VM crashes in google3, b/177506826

Original change's description:
> Reland "[VM] Adds Future.then and Future.catchError stack unwinding."
>
> This reverts commit 978b838461.
>
> Reason for revert: Fix: https://dart-review.googlesource.com/c/sdk/+/179762
>
> TEST=Various 'causal' tests updated below.
>
> Original change's description:
> > Revert "[VM] Adds Future.then and Future.catchError stack unwinding."
> >
> > This reverts commit 8f2c47f24b.
> >
> > Reason for revert: We suspect this is causing VM crashes: http://b/177506826
> >
> > Original change's description:
> > > [VM] Adds Future.then and Future.catchError stack unwinding.
> > >
> > > TEST=Various 'causal' tests updated below.
> > >
> > > Bug: https://github.com/dart-lang/sdk/issues/40815, https://github.com/dart-lang/sdk/issues/37953
> > > Change-Id: I1420d6163ac2e3b22e0971f7b0ad516895dded70
> > > Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/176662
> > > Commit-Queue: Clement Skau <cskau@google.com>
> > > Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
> >
> > TBR=vegorov@google.com,cskau@google.com
> >
> > # Not skipping CQ checks because original CL landed > 1 day ago.
> >
> > Bug: https://github.com/dart-lang/sdk/issues/40815
> > Bug: https://github.com/dart-lang/sdk/issues/37953
> > Change-Id: I870f0202f43588f71a5d2b0f82338978b5a5dda9
> > Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/178998
> > Reviewed-by: Michal Terepeta <michalt@google.com>
> > Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
> > Commit-Queue: Michal Terepeta <michalt@google.com>
>
> TBR=vegorov@google.com,cskau@google.com,michalt@google.com
>
> # Not skipping CQ checks because original CL landed > 1 day ago.
>
> Bug: https://github.com/dart-lang/sdk/issues/40815
> Bug: https://github.com/dart-lang/sdk/issues/37953
> Change-Id: I8a1eb6679b01571b850499cac2dadc5bf9ef2dcd
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/179763
> Reviewed-by: Clement Skau <cskau@google.com>
> Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
> Commit-Queue: Clement Skau <cskau@google.com>

TBR=vegorov@google.com,cskau@google.com,michalt@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: https://github.com/dart-lang/sdk/issues/40815
Bug: https://github.com/dart-lang/sdk/issues/37953
Change-Id: I1274bcb375bf6f9cb0609d372b0b451d51eb99c4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/180147
Reviewed-by: David Morgan <davidmorgan@google.com>
Commit-Queue: David Morgan <davidmorgan@google.com>
2021-01-20 12:44:55 +00:00
Clement Skau 9978a246c1 Reland "[VM] Adds Future.then and Future.catchError stack unwinding."
This reverts commit 978b838461.

Reason for revert: Fix: https://dart-review.googlesource.com/c/sdk/+/179762

TEST=Various 'causal' tests updated below.

Original change's description:
> Revert "[VM] Adds Future.then and Future.catchError stack unwinding."
>
> This reverts commit 8f2c47f24b.
>
> Reason for revert: We suspect this is causing VM crashes: http://b/177506826
>
> Original change's description:
> > [VM] Adds Future.then and Future.catchError stack unwinding.
> >
> > TEST=Various 'causal' tests updated below.
> >
> > Bug: https://github.com/dart-lang/sdk/issues/40815, https://github.com/dart-lang/sdk/issues/37953
> > Change-Id: I1420d6163ac2e3b22e0971f7b0ad516895dded70
> > Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/176662
> > Commit-Queue: Clement Skau <cskau@google.com>
> > Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
>
> TBR=vegorov@google.com,cskau@google.com
>
> # Not skipping CQ checks because original CL landed > 1 day ago.
>
> Bug: https://github.com/dart-lang/sdk/issues/40815
> Bug: https://github.com/dart-lang/sdk/issues/37953
> Change-Id: I870f0202f43588f71a5d2b0f82338978b5a5dda9
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/178998
> Reviewed-by: Michal Terepeta <michalt@google.com>
> Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
> Commit-Queue: Michal Terepeta <michalt@google.com>

TBR=vegorov@google.com,cskau@google.com,michalt@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: https://github.com/dart-lang/sdk/issues/40815
Bug: https://github.com/dart-lang/sdk/issues/37953
Change-Id: I8a1eb6679b01571b850499cac2dadc5bf9ef2dcd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/179763
Reviewed-by: Clement Skau <cskau@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Clement Skau <cskau@google.com>
2021-01-18 12:15:49 +00:00
Ryan Macnak b1c09ecd8f [vm] Make naming more consistent when converting between handles, tagged and untagged pointers.
Currently we have things called XPtr which are not what you get from ptr().

Old world:
handle->raw() returns RawObject* (tagged)
raw_obj->ptr() returns RawObject* (untagged)

After 6fe15f6df9:
handle->raw() returns ObjectPtr
obj_ptr->ptr() returns ObjectLayout*

New world:
handle->ptr() returns ObjectPtr
obj_ptr->untag() returns UntaggedObject*

TEST=ci
Change-Id: I6c7f34014cf20737607caaf84979838300d12df2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/149367
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2021-01-15 23:32:02 +00:00
Michal Terepeta 978b838461 Revert "[VM] Adds Future.then and Future.catchError stack unwinding."
This reverts commit 8f2c47f24b.

Reason for revert: We suspect this is causing VM crashes: http://b/177506826

Original change's description:
> [VM] Adds Future.then and Future.catchError stack unwinding.
>
> TEST=Various 'causal' tests updated below.
>
> Bug: https://github.com/dart-lang/sdk/issues/40815, https://github.com/dart-lang/sdk/issues/37953
> Change-Id: I1420d6163ac2e3b22e0971f7b0ad516895dded70
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/176662
> Commit-Queue: Clement Skau <cskau@google.com>
> Reviewed-by: Vyacheslav Egorov <vegorov@google.com>

TBR=vegorov@google.com,cskau@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: https://github.com/dart-lang/sdk/issues/40815
Bug: https://github.com/dart-lang/sdk/issues/37953
Change-Id: I870f0202f43588f71a5d2b0f82338978b5a5dda9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/178998
Reviewed-by: Michal Terepeta <michalt@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Michal Terepeta <michalt@google.com>
2021-01-14 13:56:53 +00:00
Clement Skau 8f2c47f24b [VM] Adds Future.then and Future.catchError stack unwinding.
TEST=Various 'causal' tests updated below.

Bug: https://github.com/dart-lang/sdk/issues/40815, https://github.com/dart-lang/sdk/issues/37953
Change-Id: I1420d6163ac2e3b22e0971f7b0ad516895dded70
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/176662
Commit-Queue: Clement Skau <cskau@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2021-01-13 08:00:14 +00:00
Martin Kustermann 0f76981bb1 [vm/concurrency] Change references to class_table/object_store/heap from Isolate to IsolateGroup
As part of making the compiler and other subsystems independent
of `Isolate` we have to move various state from `Isolate` to
`IsolateGroup`.

The class_table and object_store were already moved to `IsolateGroup`.

This CL only replaces usages of `Isolate::{object_store,class_table}`
with the equivalent in `IsolateGroup`.

Issue https://github.com/dart-lang/sdk/issues/36097

TEST=Pure refactoring - relying on existing test coverage.

Change-Id: I34a0682d715b054d6c5faff077a513980f59a348
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/177126
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2021-01-06 15:22:11 +00:00
Alexander Markov 7588ed86de Remove bytecode mode from the VM
Change-Id: Ief167b7ffc128105a03cc225ab750234c9a6a7a0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/169147
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2020-10-28 17:42:35 +00:00
Tess Strickland 45a46ca2b8 [vm] Add (S)LEB128 encoding/decoding to BaseWriteStream.
Unlike cfc8e6de, this does _not_ replace the default variable length
encoding for {Read,Write}Streams, but insteads adds separate
{Read,Write}{S,}LEB128 methods to the appropriate classes. If we later
find the cause of the issues that led to the revert of cfc8e6de, it'll
be easy to switch over then.

Note that WriteLEB128 asserts that the value is non-negative if used
with a signed type (since negative values suggests that SLEB128 should
be used instead for minimal encoding).

Also removes the various other encoding and decoding methods for
(S)LEB128 across the codebase and changes those clients to use
{Read,Write}Streams instead.

Other cleanups:

* Various constant-related cleanups in datastream.h.

* Adds DART_FORCE_INLINE to ReadStream::ReadByte and uses it in the
  default variable length decoding methods for retrieving bytes
  from the stream instead of managing current_ by hand.

* Creates a canonical empty CompressedStackMaps instance and uses
  that instead of the null CompressedStackMaps instance in most cases.
  The only remaining (expected) use of the null CompressedStackMaps
  instance is for the global table in the object store when no global
  table exists (e.g., in JIT mode before any snapshotting).

* Moves CompressedStackMapsIterator from code_descriptors.h to an
  Iterator class within CompressedStackMaps in object.h (similar to
  PcDescriptors::Iterator), to limit friend declarations and because it
  conceptually makes more sense as part of CompressedStackMaps.

* Removed CompressedStackMaps::PayloadByte, since existing clients
  (CompressedStackMaps::Iterator, StackMapEntry in program_visitor.cc)
  are better served by just operating on the payload buffer directly
  (with appropriate NoSafepointScopes).

* WriteStreams no longer allocate their initial space on construction,
  but rather on the first write, so no allocation is performed by
  constructing a never-used WriteStream.

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-mac-debug-x64-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-kernel-precomp-win-release-x64-try,vm-kernel-ubsan-linux-release-x64-try,vm-kernel-tsan-linux-release-x64-try,vm-kernel-precomp-ubsan-linux-release-x64-try,vm-kernel-precomp-tsan-linux-release-x64-try,vm-kernel-precomp-msan-linux-release-x64-try,vm-kernel-precomp-asan-linux-release-x64-try,vm-kernel-msan-linux-release-x64-try,vm-kernel-asan-linux-release-x64-try
Change-Id: Ice63321abaa79157fbe9f230a864c8bba0e6dea9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/166421
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
2020-10-09 10:08:16 +00:00
Ryan Macnak 91ed534139 [vm] Support --use_bare_instructions when splitting snapshots.
- Don't use PC-relative calls when calling between loading units.
 - Sort the contents of the code cluster by loading unit, then by text offset.
 - Handle binding PC-relatives calls and inserting trampolines per loading unit.
 - Create one code order table per loading unit to implement PC -> Code lookup.
 - Read code order tables directly, instead of copying into malloc'd memory.

--use_table_dispatch still not yet supported.

This slightly shrinks non-split binaries (~2% clustered part, 0.4% total snapshot) due to the new delta encoding when Code references Instructions.

Bug: https://github.com/dart-lang/sdk/issues/41974
Change-Id: I51052ebc7b4968b554897d1710135a6c41821302
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/157820
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
2020-08-12 17:23:14 +00:00
Ryan Macnak 2707880f1b [vm] Fix various UBSan failures.
Bug: https://github.com/dart-lang/sdk/issues/39427
Change-Id: I74e0eee623d88005fb2893d03e284a87daa09260
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/146696
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2020-05-07 19:40:18 +00:00
Ryan Macnak 6fe15f6df9 [vm] Represent tagged pointers as C++ value types instead of C++ pointer types.
This works around bugs in UndefinedBehaviorSanitizer and Clang.

Bug: b/28638298
Change-Id: I6be595f9664516019d28017d24559583a1ae3a21
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/144354
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2020-04-25 05:21:27 +00:00
Martin Kustermann 25011b80b9 [vm/compiler] Keep one ReversePcLookupCache on the isolate group (instead of making one per-isolate)
There is no need to make each isolate have it's own PC -> RawCode lookup
table, now that we share the program structure.

Issue https://github.com/dart-lang/sdk/issues/36097

Change-Id: Iba2bbf7e735655b52c07a61c399c6d2409598145
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/144297
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
2020-04-22 09:21:48 +00:00
Vyacheslav Egorov a41a1dc917 [vm/compiler] Split compiler sources out of normal VM sources.
Make them form its own source set (libdart_compiler) and completely exclude
them from AOT runtime targets.

Previously we had some inconsistencies, with some files were using
DART_PRECOMPILED_RUNTIME to fully or partially exclude either contents
from their headers or from implementation, while other files did nothing
and relied on linker to throw their contents away.

This change tries to address this inconsistency.

A follow up change would include a check in most compiler headers which
would prohibit to use them while building AOT runtime.

Change-Id: Ief11b11cbc518b301d3e93fce80580a31bbad151
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/142993
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2020-04-16 22:59:03 +00:00
Teagan Strickland b55342cb3e [vm/aot] Drop some Function objects not needed at runtime.
In particular, don't serialize a function if its code is used by the
dispatch table, but there's no need for the function object itself
at runtime like dynamic lookup or dynamic invocation forwarders.

However, just because the owning function is not needed at runtime,
it may be used during serialization for things like assembly label
creation. Thus, instead of just clearing out the Code's owner field,
we add a new WeakSerializationReference (WSR) object whose target is
the original contents of the owner field. The WSR allows the
serializer to access the original owner, but also signals to the
serializer that the target should not be serialized in AOT snapshots
unless there are additional strong (non-WSR) references.

If no strong references are found, then the references to the WSR
in the snapshot are replaced with a reference to a WSR that only
contains the class ID of the original target. The serializer creates
only one WSR per class ID.

If strong references are found, then the target is still serialized.
In this case, the WSR is dropped entirely and any reference to it is
replaced with a direct reference to the serialized target. Thus, WSRs
only exist in the precompiled runtime for targets with no strong
references.

Changes on the Flutter gallery in release mode:
arm7: total size -1.10%, isolate size -6.08%
arm8: total size -1.16%, isolate size -6.09%

Bug: https://github.com/dart-lang/sdk/issues/41052

Change-Id: I5b435ca71ef85f50fe3484789087471a91aa4fe2
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-linux-release-simarm_x64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-precomp-win-release-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/137104
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
2020-03-30 18:33:48 +00:00
Ryan Macnak 714b1d197f [vm] Fix flaky debug-mode crashes when GC happens while a mutator thread is descheduled.
A thread can exit an isolate while it still has Dart frames. The Dart frames must still be visited by the GC, but the dart::Thread is no longer associated with an dart::OSThread.

Add the PID to stack dumps to make it easier to match core dumps to stacks dumps.

Change-Id: Icb427ad99f4c0072d54b7c9516e922904403d1c1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/139747
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2020-03-16 23:46:01 +00:00
Ryan Macnak bc23401ff2 [vm, test] Fix vm/cc/DartAPI_StackOverflowStackTrace* under MSAN.
The old code would unpoison the stack in one operation, based on the requested size of the stack for threads created by the VM. This may be smaller than the actual size of the stack, leaving some of the stack still poisoned.

The new code unpoisons the stack frame by frame, and only frames created by generated code. For exit frames, it guesses the frame size, but for all other frames it is precise.

Change-Id: Ice16480feca19727fcfadf19c9ec6cf205607946
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/137725
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2020-03-13 16:58:41 +00:00
Samir Jindel 4c6a2ab47c Re-land "[vm] Aggressive write-barrier elimination."
Three bugs were fixed:

1. BitVector::Equals was not fully fixed by the original CL.
2. We need to add old objects to the deferred marking queue during
   RememberLiveTemporaries().
3. The thread being scanned in RestoreWriteBarrierInvariant may not
   be scheduled, so we cannot use its store buffer block.

In addition, this changed uncovered another bug fixed in:
https://dart-review.googlesource.com/c/sdk/+/138960.

Original CL is in patchset 3.

This reverts commit 30a12a349e.

Change-Id: I36169b09563998ed5b3c3eac70ee0ebe78853e62
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/138920
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Samir Jindel <sjindel@google.com>
2020-03-11 13:05:59 +00:00
Martin Kustermann 30a12a349e Revert "Re-land "[vm] Aggressive write-barrier elimination.""
This reverts commit eff1a9ff97.

Reason for revert:
  Causes flaky hits of RELEASE_ASSERT in marker.cc, see b/151131634.

Original change's description:
> Re-land "[vm] Aggressive write-barrier elimination."
> 
> The original revision is in Patchset 3.
> 
> Four bugs were fixed:
> 
> 1. JoinEntryInstr::SuccessorCount() is not the correct way to get the
>    number of successor blocks from the Join block;
>    JoinEntryInstr::last_instruction()->SuccessorCount() must be used
>    instead.
> 
> 2. BitVector::Equals() was non-deterministically returning 'false'
>    for equal vectors.
> 
> 3. All blocks need to be processed at least once during the Analysis
>    phase (not only in the SaveResults phase).
> 
> 4. We were not removing write barriers from StoreIndexed instructions,
>    even though we had support for it.
> 
> This reverts commit 7fd8ad5a2d.
> 
> Fixes https://github.com/dart-lang/sdk/issues/40780
> 
> Change-Id: I9650ec2c547ec49cf88ca0524e14f6c245621f6a
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/138086
> Commit-Queue: Samir Jindel <sjindel@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
> Reviewed-by: Ryan Macnak <rmacnak@google.com>

TBR=kustermann@google.com,rmacnak@google.com,sjindel@google.com

Change-Id: If9afd84465175fad2431405a97e9293c8bd5e476
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/138808
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
2020-03-10 10:15:30 +00:00
Samir Jindel eff1a9ff97 Re-land "[vm] Aggressive write-barrier elimination."
The original revision is in Patchset 3.

Four bugs were fixed:

1. JoinEntryInstr::SuccessorCount() is not the correct way to get the
   number of successor blocks from the Join block;
   JoinEntryInstr::last_instruction()->SuccessorCount() must be used
   instead.

2. BitVector::Equals() was non-deterministically returning 'false'
   for equal vectors.

3. All blocks need to be processed at least once during the Analysis
   phase (not only in the SaveResults phase).

4. We were not removing write barriers from StoreIndexed instructions,
   even though we had support for it.

This reverts commit 7fd8ad5a2d.

Fixes https://github.com/dart-lang/sdk/issues/40780

Change-Id: I9650ec2c547ec49cf88ca0524e14f6c245621f6a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/138086
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2020-03-09 14:37:27 +00:00
Ryan Macnak 7fd8ad5a2d Revert "[vm] Re-land aggressive write-barrier elimination."
This reverts commit c7d7552697.

Reason for revert: https://github.com/dart-lang/sdk/issues/40780

Original change's description:
> [vm] Re-land aggressive write-barrier elimination.
> 
> It incorrectly assumed that all stores in Dart code write to Instances.
> There is actually one exception, Contexts, which do not inherit from Instance.
> 
> I've added asserts to ensure this kind of bug cannot resurface.
> 
> The original change is in patchset 4.
> 
> Change-Id: Ic2d8d05e70a4de738eb9fb5980487b4f27111b8c
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/136221
> Commit-Queue: Samir Jindel <sjindel@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
> Reviewed-by: Ryan Macnak <rmacnak@google.com>

TBR=kustermann@google.com,rmacnak@google.com,sjindel@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I1891677b21560c7fc5a54a8eb800ef5850654402
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/137290
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2020-02-26 02:18:25 +00:00
Samir Jindel c7d7552697 [vm] Re-land aggressive write-barrier elimination.
It incorrectly assumed that all stores in Dart code write to Instances.
There is actually one exception, Contexts, which do not inherit from Instance.

I've added asserts to ensure this kind of bug cannot resurface.

The original change is in patchset 4.

Change-Id: Ic2d8d05e70a4de738eb9fb5980487b4f27111b8c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/136221
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2020-02-24 18:26:46 +00:00
Martin Kustermann dae308461c [vm/concurrency] Share [Heap] and [SharedClassTable] between all isolates within one isolate group
This CL:

  * Moves [Heap]/[SharedClassTable] from [Isolate] to [IsolateGroup], which
    will make all isolates in the group use the same heap. The GC will use
    the shared class table for object size information.

  * Adds support for entering/leaving an isolate group as a helper thread
    (e.g. via [Thread::EnterIsolateGroupAsHelper]). The current active
    isolate group can be accessed via TLS `IsolateGroup::Current()` or
    `Thread::isolate_group_`. When entering as a helper thread there will be
    no current isolate.

  * Changes the GC to use the above mechanism and ensures GC works without
    a currently active isolate. The GC will use information purely available via
    [IsolateGroup]. The GC will iterate all isolates within an isolate
    group e.g. for scanning roots.

  * Makes spawning of new isolates start in their own isolate group.
    Once the isolate is fully functional it's heap will be merged into
    the original isolate group

  * Moves ApiState, containing persistent and weak persistent handles,
    from [Isolate] to [IsolateGroup], plus adds appropriate locking.

Issue https://github.com/dart-lang/sdk/issues/36097

Change-Id: Ia8e1d8aa78750e8400864200f4825395a182c004
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/126646
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2020-02-20 21:08:35 +00:00
Teagan Strickland e01457d138 Reland "[vm/aot] Remove object wrapping of bare instructions for AOT snapshots."
Now, when writing an AOT snapshot in bare instructions mode, only
the actual instructions in the RawInstructions payload are serialized
instead of the entire RawInstructions object.

Since there are no longer RawInstructions objects in these AOT
snapshots, we also change how Code objects are serialized. Instead
of just containing a reference to the RawInstructions object, we
serialize two pieces of information: where the instructions
payload for this Code object begins and whether there was a single
entry for the instructions payload. (To save space, the single
entry bit is serialized as the low order bit of the unchecked
offset, which was already being serialized).

While we also need the length of the instructions payload, we
approximate it for all but the last Code object by subtracting
the next Code object's payload start from this Code object's
payload start. For the last Code object, we assume it extends
to the end of the instructions image.

Changes on flutter gallery in release mode:
armv7: instructions size -2.70%, total size -1.73%
armv8: instructions size -6.04%, total size -3.63%

Fixes https://github.com/dart-lang/sdk/issues/38451.

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-linux-release-simarm_x64-try,vm-kernel-precomp-android-release-arm64-try,vm-kernel-precomp-android-release-arm_x64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-precomp-win-release-x64-try
Change-Id: Ia0a5c4e5e47c956776dc62503da38ec55a143c04
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/134325
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2020-02-10 15:08:04 +00:00
Teagan Strickland bb24f98616 Revert "[vm/aot] Remove object wrapping of bare instructions for AOT snapshots."
This reverts commit 7475c637c3.

Reason for revert: Breakage on simarm_x64 (and thus arm_x64)

Original change's description:
> [vm/aot] Remove object wrapping of bare instructions for AOT snapshots.
> 
> Now, when writing an AOT snapshot in bare instructions mode, only
> the actual instructions in the RawInstructions payload are serialized
> instead of the entire RawInstructions object.
> 
> Since there are no longer RawInstructions objects in these AOT
> snapshots, we also change how Code objects are serialized. Instead
> of just containing a reference to the RawInstructions object, we
> serialize two pieces of information: where the instructions
> payload for this Code object begins and whether there was a single
> entry for the instructions payload. (To save space, the single
> entry bit is serialized as the low order bit of the unchecked
> offset, which was already being serialized).
> 
> While we also need the length of the instructions payload, we
> approximate it for all but the last Code object by subtracting
> the next Code object's payload start from this Code object's
> payload start. For the last Code object, we assume it extends
> to the end of the instructions image.
> 
> Changes on flutter gallery in release mode:
> armv7: instructions size -2.66%, total size -1.68%
> armv8: instructions size -5.81%, total size -3.49%
> 
> Fixes https://github.com/dart-lang/sdk/issues/38451.
> 
> Change-Id: Ia458e8d99bae18f5c3b6e849df2519027f06f574
> Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-linux-release-simarm_x64-try,vm-kernel-precomp-android-release-arm64-try,vm-kernel-precomp-android-release-arm_x64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-precomp-win-release-x64-try
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/131067
> Commit-Queue: Teagan Strickland <sstrickl@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>

TBR=kustermann@google.com,rmacnak@google.com,sstrickl@google.com

Change-Id: If2c8ca6b0993211b2509b275af7ff11a8fa2baa3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try, vm-kernel-precomp-linux-release-simarm-try, vm-kernel-precomp-linux-release-simarm64-try, vm-kernel-precomp-linux-release-simarm_x64-try, vm-kernel-precomp-android-release-arm64-try, vm-kernel-precomp-android-release-arm_x64-try, vm-kernel-precomp-mac-release-simarm64-try, vm-kernel-precomp-win-release-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/134322
Reviewed-by: Teagan Strickland <sstrickl@google.com>
Commit-Queue: Teagan Strickland <sstrickl@google.com>
2020-02-04 17:32:28 +00:00
Teagan Strickland 7475c637c3 [vm/aot] Remove object wrapping of bare instructions for AOT snapshots.
Now, when writing an AOT snapshot in bare instructions mode, only
the actual instructions in the RawInstructions payload are serialized
instead of the entire RawInstructions object.

Since there are no longer RawInstructions objects in these AOT
snapshots, we also change how Code objects are serialized. Instead
of just containing a reference to the RawInstructions object, we
serialize two pieces of information: where the instructions
payload for this Code object begins and whether there was a single
entry for the instructions payload. (To save space, the single
entry bit is serialized as the low order bit of the unchecked
offset, which was already being serialized).

While we also need the length of the instructions payload, we
approximate it for all but the last Code object by subtracting
the next Code object's payload start from this Code object's
payload start. For the last Code object, we assume it extends
to the end of the instructions image.

Changes on flutter gallery in release mode:
armv7: instructions size -2.66%, total size -1.68%
armv8: instructions size -5.81%, total size -3.49%

Fixes https://github.com/dart-lang/sdk/issues/38451.

Change-Id: Ia458e8d99bae18f5c3b6e849df2519027f06f574
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-linux-release-simarm_x64-try,vm-kernel-precomp-android-release-arm64-try,vm-kernel-precomp-android-release-arm_x64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-precomp-win-release-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/131067
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2020-02-04 10:28:43 +00:00
Teagan Strickland f6d433dc5e [vm] Remove the unchecked entry point offset field from RawInstructions.
There's just one case where we can't get the offset for Instructions
from somewhere else, and that's when we reset active_instructions_ to
instructions_ in Code::Enable(). Thus, we add a caching field for the
uncached offset to RawCode, but only when the active_instructions_
field is added (when not running in the precompiled runtime).

We also output the unchecked offset in snapshots for Code objects so
we can recalculate the entry point cache on loading. (For full JIT
snapshots, we output both the cached offset and the offset for
active_instructions_.)

Bug: https://github.com/dart-lang/sdk/issues/38451
Change-Id: I78572ec83d1574b00820df148bccb57e5c79eaaa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/125400
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Teagan Strickland <sstrickl@google.com>
2019-12-11 10:00:29 +00:00
Teagan Strickland dc808f3fcb [vm/compiler] Canonicalize CompressedStackMaps payloads when possible.
When we are writing a snapshot, canonicalize all entries within
CompressedStackMaps payloads. We do this by creating a global table
of stack map information (bit counts + bit payload) that we store
in the isolate object store, and then for each existing CSM, we
replace it with an alternate version that refers to the global table.
This gets back some of the canonicalization we lost when we moved from
individual StackMap objects to per-Code CompressedStackMaps objects.

Here, we also represent the global table as a CompressedStackMaps
object. This means that there are three types of CompressedStackMaps:
 * The original version that directly contains all entry information.
 * The version where each entry is just the PC offset delta and an
   offset into the global table payload.
 * A version representing the global table where the entries are like
   the original version except they don't contain a PC offset delta.

-----

The impact on AOT snapshot size when compiling the Flutter Gallery
in release mode:

   armv7: Total size -0.88% (Isolate RO: -5.05%, Isolate snapshot: +0.00%)
   armv8: Total size -1.04% (Isolate RO: -5.28%, Isolate snapshot: +0.00%)

-----

Bug: https://github.com/dart-lang/sdk/issues/35274
Change-Id: I1ce0f8b3cc58e2f11584f3c218e0fdf8984b799b
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120667
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2019-11-14 12:49:06 +00:00
Ryan Macnak be6e5d8717 [vm] Try to symbolize Dart frames on crash or assertion failure when there is an exit frame.
Remove disabled/broken symbolization based on heap iteration.

Bug: https://bugs.fuchsia.dev/p/fuchsia/issues/detail?id=41154
Change-Id: I5e6644e6ef72177cefec920fbe653000a4868f5d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/124826
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2019-11-11 23:56:00 +00:00
Samir Jindel c885bdde1d [vm] DBC is obsolete. Remove dead code.
Change-Id: Ica33af158cca53c8e951e4b2582de83660e8a60d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121851
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2019-10-27 18:18:29 +00:00
Teagan Strickland c9f6e669f9 [vm/compiler] Reland "Further compress the information... in StackMaps."
Fixes an assumption that CompressedStackMapsIterator::Find() is never
passed a PC offset of 0. Adds back an ASSERT that was dropped which checks
for specific cases where a given PC offset does not have a stack map entry.

Original commit message:

Lifting the PC offset in a2bb730 was a small, lightweight change that
gave us big gains, at least on 32-bit architectures. Here, we make
much more invasive changes that will improve the amount of memory used
by the information previously stored in StackMap objects.

Instead of allocating separate objects for StackMaps, we instead compress
all StackMap information for a given Code object into a single object
(CompressedStackMaps, or CSM for short). This replaces the Array used to
store PC offsets (as Smis) and the individual StackMap objects.

While we lose all canonicalization for individual StackMap entries, the
drop in space required to store stack map information more than offsets that.

-----

The impact on AOT snapshot size when compiling the Flutter Gallery
in release mode:

   armv7: Total size -2.58% (Isolate RO: +14.46%, Isolate snapshot: -22.93%)
   armv8: Total size -1.85% (Isolate RO: +15.69%, Isolate snapshot: -22.97%)

The impact on in-memory, not on-disk, size for the Flutter Gallery as seen
in the Observatory while running a profile (not release) build:

   armv7: Drops from 7.1 MB to 6.2MB (-0.9 MB)
   armv8: Drops from 13.5MB to 11.7MB (-1.8 MB)

-----

Bug: https://github.com/dart-lang/sdk/issues/35274, https://github.com/dart-lang/sdk/issues/38873
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-mac-debug-simdbc64-try
Change-Id: I111b129b0ed64f03184370bceb7cda69d5d4b3c9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121700
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2019-10-16 08:25:53 +00:00
Alexander Markov 017a7a6221 Revert "[vm/compiler] Further compress the information previously in StackMaps."
This reverts commit d77f4913a1.

Reason for revert: large number of flaky crashes on flakiness dashboard (https://github.com/dart-lang/sdk/issues/38873); crashes on vm-kernel-mac-debug-simdbc64 bot.

Original change's description:
> [vm/compiler] Further compress the information previously in StackMaps.
> 
> Lifting the PC offset in a2bb730 was a small, lightweight change that
> gave us big gains, at least on 32-bit architectures. Here, we make
> much more invasive changes that will improve the amount of memory used
> by the information previously stored in StackMap objects.
> 
> Instead of allocating separate objects for StackMaps, we instead compress
> all StackMap information for a given Code object into a single object
> (CompressedStackMaps, or CSM for short). This replaces the Array used to
> store PC offsets (as Smis) and the individual StackMap objects.
> 
> While we lose all canonicalization for individual StackMap entries, the
> drop in space required to store stack map information more than offsets that.
> 
> -----
> 
> The impact on AOT snapshot size when compiling the Flutter Gallery
> in release mode:
> 
>    armv7: Total size -2.58% (Isolate RO: +14.46%, Isolate snapshot: -22.93%)
>    armv8: Total size -1.85% (Isolate RO: +15.69%, Isolate snapshot: -22.97%)
> 
> The impact on in-memory, not on-disk, size for the Flutter Gallery as seen
> in the Observatory while running a profile (not release) build:
> 
>    armv7: Drops from 7.1 MB to 6.2MB (-0.9 MB)
>    armv8: Drops from 13.5MB to 11.7MB (-1.8 MB)
> 
> -----
> 
> Bug: https://github.com/dart-lang/sdk/issues/35274
> Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try
> Change-Id: Ie3bb898d557215146260a560423f5fa27bdff512
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/119640
> Commit-Queue: Teagan Strickland <sstrickl@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
> Reviewed-by: Ryan Macnak <rmacnak@google.com>

TBR=kustermann@google.com,rmacnak@google.com,sstrickl@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: https://github.com/dart-lang/sdk/issues/35274
Change-Id: Ib844b4d52e3aa4aca62a896cfe349c680bda7461
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try, vm-kernel-precomp-linux-debug-simarm_x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121642
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2019-10-14 20:20:58 +00:00
Teagan Strickland d77f4913a1 [vm/compiler] Further compress the information previously in StackMaps.
Lifting the PC offset in a2bb730 was a small, lightweight change that
gave us big gains, at least on 32-bit architectures. Here, we make
much more invasive changes that will improve the amount of memory used
by the information previously stored in StackMap objects.

Instead of allocating separate objects for StackMaps, we instead compress
all StackMap information for a given Code object into a single object
(CompressedStackMaps, or CSM for short). This replaces the Array used to
store PC offsets (as Smis) and the individual StackMap objects.

While we lose all canonicalization for individual StackMap entries, the
drop in space required to store stack map information more than offsets that.

-----

The impact on AOT snapshot size when compiling the Flutter Gallery
in release mode:

   armv7: Total size -2.58% (Isolate RO: +14.46%, Isolate snapshot: -22.93%)
   armv8: Total size -1.85% (Isolate RO: +15.69%, Isolate snapshot: -22.97%)

The impact on in-memory, not on-disk, size for the Flutter Gallery as seen
in the Observatory while running a profile (not release) build:

   armv7: Drops from 7.1 MB to 6.2MB (-0.9 MB)
   armv8: Drops from 13.5MB to 11.7MB (-1.8 MB)

-----

Bug: https://github.com/dart-lang/sdk/issues/35274
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try
Change-Id: Ie3bb898d557215146260a560423f5fa27bdff512
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/119640
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2019-10-11 11:28:57 +00:00
Martin Kustermann a64b06ec83 [gardening] Migrate most files to be implicit-bool-conversion free
Issue https://dart-review.googlesource.com/c/sdk/+/115701

Change-Id: Ib579f0bbc8d694aec74afd837217316a10baf910
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/115707
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
2019-09-05 21:41:42 +00:00