This is the next step towards preventing compiler from directly peeking
into runtime and instead interact with runtime through a well defined
surface. The goal of the refactoring to locate all places where compiler
accesses some runtime information and partion those accesses into two
categories:
- creating objects in the host runtime (e.g. allocating strings, numbers, etc)
during compilation;
- accessing properties of the target runtime (e.g. offsets of fields) to
embed those into the generated code;
This change introduces dart::compiler and dart::compiler::target namespaces.
All code in the compiler will gradually be moved into dart::compiler namespace.
One of the motivations for this change is to be able to prevent access to
globally defined host constants like kWordSize by shadowing them in the
dart::compiler namespace.
The nested namespace dart::compiler::target hosts all information about
target runtime that compiler could access, e.g. compiler::target::kWordSize
defines word size of the target which will eventually be made different
from the host kWordSize (defined by dart::kWordSize).
The API for compiler to runtime interaction is placed into compiler_api.h.
Note that we still permit runtime to access compiler internals directly -
this is not going to be decoupled as part of this work.
Issue https://github.com/dart-lang/sdk/issues/31709
Change-Id: If4396d295879391becfa6c38d4802bbff81f5b20
Reviewed-on: https://dart-review.googlesource.com/c/90242
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
This is the final CL which adds a new --use-bare-instructions flag to
the VM.
If this flag is set during AOT compilation, we will:
* Build one global object pool (abbr: GOP) which all code objects
share. This gop will be stored in the object store. The PP register
is populated in the enter dart stub and it is restored when
returning from native calls.
* Gets rid of the CODE_REG/PP slots from the dart frames. Instead the
compiled code uses the global object pool, which is always in PP.
* Starts emitting pc-relative calls for calls between two dart
functions or when invoking a stub.
Limitation: We only emit pc-relative calls between two code objects
in the same isolate (this is because the image writer is writing
instruction objects for vm-isolate/main-isolate seperately)
* We do compile-time relocation of those static calls after the
precompiler has finished its work, but before writing the snapshot.
This patches all the instruction objects with pc-relative calls to
have the right .text distance.
* We emit a sorted list of code objects in ObjectStore::reverse_code_table,
which will be used by the AOT runtime to go back from PC to Code
objects (where all metadata, e.g. stack maps, catch entry moves, pc
descriptors are available).
Issue https://github.com/dart-lang/sdk/issues/33274
Change-Id: I6c5dd2b1571e3a889b27e804a24c2986c71e03b6
Reviewed-on: https://dart-review.googlesource.com/c/85769
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
This CL adds a [ReversePcLookupCache] which, based on a list of code
objects, builds up a binary searchable table for mapping PCs to Code
objects (where all the metadata is available, like stackmaps, ...).
This CL also adds stack walking support for "bare instruction" frames.
In a later part we will start emitting the sorted list of code objects
(via the new field in the object store) under a flag.
Issue https://github.com/dart-lang/sdk/issues/33274
Change-Id: I3c06c12bc0fb266dc1bd843a4a11b5208773151d
Reviewed-on: https://dart-review.googlesource.com/c/85746
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
When GC is visiting pointers, it scans mutator thread even if it is not
active. It could happen if a thread has (temporarily) exitted isolate.
In such case, stack frame iteration would not find interpreter and
would not recognize interpreter frames. An attempt to visit interpreter
frame as non-interpreter causes crashes/assertions.
The fix is to move interpreter from Isolate to Thread. This way
interpreter is available for stack walking even if thread doesn't have
isolate.
This is the re-land of https://dart-review.googlesource.com/c/sdk/+/80760
with the fix for precompiler failures.
Change-Id: I1fa054d43b86aa49c48490d0951b876b7c7218d8
Reviewed-on: https://dart-review.googlesource.com/c/80782
Auto-Submit: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Régis Crelier <regis@google.com>
This reverts commit a0cc3e2684.
Reason for revert: broken precompiler bots
Original change's description:
> [vm/interpreter] Fix interpreter frame recognition in stack walking
>
> When GC is visiting pointers, it scans mutator thread even if it is not
> active. It could happen if a thread has (temporarily) exitted isolate.
> In such case, stack frame iteration would not find interpreter and
> would not recognize interpreter frames. An attempt to visit interpreter
> frame as non-interpreter causes crashes/assertions.
>
> The fix is to move interpreter from Isolate to Thread. This way
> interpreter is available for stack walking even if thread doesn't have
> isolate.
>
> Change-Id: Iff12ce7391b19a6f87bd4fac94137cba5623dfb9
> Reviewed-on: https://dart-review.googlesource.com/c/80760
> Reviewed-by: Régis Crelier <regis@google.com>
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
TBR=rmacnak@google.com,alexmarkov@google.com,zra@google.com,asiva@google.com,regis@google.com
Change-Id: Ic4d73536eadb6601ee323918c65f5f2b2b2b2418
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/80781
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
When GC is visiting pointers, it scans mutator thread even if it is not
active. It could happen if a thread has (temporarily) exitted isolate.
In such case, stack frame iteration would not find interpreter and
would not recognize interpreter frames. An attempt to visit interpreter
frame as non-interpreter causes crashes/assertions.
The fix is to move interpreter from Isolate to Thread. This way
interpreter is available for stack walking even if thread doesn't have
isolate.
Change-Id: Iff12ce7391b19a6f87bd4fac94137cba5623dfb9
Reviewed-on: https://dart-review.googlesource.com/c/80760
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Alexander Markov <alexmarkov@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>
This fixes a crash in StackFrameIterator when using interpreter.
Prevent timeout in thread test when using interpreter.
Adjust kernel status file for known issue.
Change-Id: I9e28675a3532153df24456e65407a8ce73503928
Reviewed-on: https://dart-review.googlesource.com/71222
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Régis Crelier <regis@google.com>
So far the frontend (parser, flow graph builder, ssa construction) were
aware of the actual frame layout.
This CL makes the indices we assign to [LocalVariable]s logical
indices, assigning:
* M parameters the indices 1 ... M
* N local variables the indices 0 -1 ... -(N-1)
The scope building, flow graph builder and ssa construction operate on
those logical indices.
When emitting actual code, the backend will translate those indices into
actual FP relative indices. This allows us to be more flexible in the
backend which frame layout we choose.
Issue https://github.com/dart-lang/sdk/issues/33274
Change-Id: I9a504bf97821c257aafd2b3430df9f4c9da4b442
Reviewed-on: https://dart-review.googlesource.com/57321
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Previously there were places in the code where an API accepted a
`bool validate_frames` and call sites passed an enum value (which
implicitly got converted to a bool).
By changing the APIs to require an enum, the compiler will tell us if a
caller doesn't pass one.
Change-Id: I29fcd0b018e6cdd7e00b5bb03e83b9636d1345d4
Reviewed-on: https://dart-review.googlesource.com/57823
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Improves the space overhead of compaction from O(size of live objects) to O(number of live objects).
Future work includes:
- a smaller, faster representation the forwarding table via a bitmap of used allocation units
- sorting class sizes off-heap to allow sliding classes
- running forwarding in parallel
Removes unnecessary sweep from evacuating compactor.
Change-Id: If0991bfb75573201c6e8feed142ca0cc69fccab4
Bug: https://github.com/dart-lang/sdk/issues/30978
Reviewed-on: https://dart-review.googlesource.com/15988
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Erik Corry <erikcorry@google.com>
The compactor copies all live objects in old space to fresh pages, places forwarding pointers in the old objects, forwards all the pointers, then frees the old pages. This has a high space overhead. It is not meant for use in production, but meant to test that the VM is properly set up to handle old-space objects moving.
Large page objects and instruction objects are not moved.
Bug: https://github.com/dart-lang/sdk/issues/30978
Change-Id: Ia42683fd5e27a33702aa5e83bece803a8b005a4b
Reviewed-on: https://dart-review.googlesource.com/13624
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Zach Anderson <zra@google.com>
Reviewed-by: Erik Corry <erikcorry@google.com>
We've been getting away with skipping this slot because
- ObjectPools are allocated into old space and never move, and
- the ObjectPools are also reachable from the PC marker in the caller's frame.
However, ObjectPools will become movable during compacting GCs.
Bug: https://github.com/dart-lang/sdk/issues/30978
Change-Id: Ied3a1588365fe5362ad7f1d2d446a7a59df6ced6
Reviewed-on: https://dart-review.googlesource.com/10680
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
New folder structure (nested under vm/):
- compiler/
- jit/ - JIT specific code
- aot/ - AOT specific code
- backend/ - all middle-end and back-end code (IL, flow graph)
- assembler/ - assemblers and disassemblers
- frontend/ - front ends (AST -> IL, Kernel -> IL)
compiler/README.md would be the documentation root for the compiler
pipeline
Bug: https://github.com/dart-lang/sdk/issues/30575
Change-Id: I2dfd9688793bff737f7632ddc77fca766875ce36
Reviewed-on: https://dart-review.googlesource.com/2940
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
The assertions which tried to assert that we only use
StackFrameIterator to walk frames of the current thread was incorrect.
We already have cases where other threads will walk the stack of the
mutator thread, see below for an example where this can happen.
Thread::VisitObjectPointers was incorrectly passing Thread::Current() to
the StackFrameIterator instead of 'this'. (Code in thread_registry.cc will
loop over a number of threads and calls VisitObjectPointers on them)
Mutator thread:
0 pthread_cond_wait@@GLIBC_2.3.2
1 dart::Monitor::WaitMicros
2 dart::Monitor::Wait
3 dart::MonitorLocker::Wait
4 dart::ThreadBarrier::Sync
5 dart::GCMarker::MarkObjects
6 dart::PageSpace::MarkSweep
7 dart::Heap::CollectOldSpaceGarbage
8 dart::Heap::CollectNewSpaceGarbage
9 dart::Heap::CollectGarbage
10 dart::DN_HelperObject_<native>
11 dart::BootstrapNatives::<native>
<dart frames>
MarkTask thread:
1 dart::EntryFrame::VisitObjectPointers
2 dart::Thread::VisitObjectPointers <---- Walks mutator thread stack
3 dart::ThreadRegistry::VisitObjectPointers <---- Iterates over a number of threads
4 dart::Isolate::VisitStackPointers
5 dart::Isolate::VisitObjectPointers
6 dart::GCMarker::IterateRoots
7 dart::MarkTask::Run
8 dart::ThreadPool::Worker::Loop
9 dart::ThreadPool::Worker::Main
10 dart::ThreadStart
R=rmacnak@google.com
Review-Url: https://codereview.chromium.org/2845053003 .
One slot in each Dart frame contains a "pc marker". Prior to the calling convention change, the pc marker was a fixed offset from the code's entry point, from which the code object could be derived. After the change, the pc marker is a pointer to the code object itself.
R=asiva@google.com
Review-Url: https://codereview.chromium.org/2804793003 .
Like HOST_ARCH_*, HOST_OS_* describes the OS the VM is running on, which may be different from the OS the VM is generating code for during AOT compilation.
Currently we conflate the two when emitting AOT as assembly, and we get away with it because Flutter only uses assembly for targeting iOS and one can only target iOS from a Mac, but we expect to use assembly for Android as well so native tools can unwind Dart frames.
R=zra@google.com
Review-Url: https://codereview.chromium.org/2750843003 .
Use that to sync variables to predefined stack
slots inside of exception handler, not before
each MayThrow() instruction.
In JIT mode we can avoid storing extra metadata
by using deopt info instead.
Introduce caching of metadata and
exception handler based on PC.
R=fschneider@google.com, vegorov@google.com
Review-Url: https://codereview.chromium.org/2734323003 .
Use that to sync variables to predefined stack
slots inside of exception handler, not before
each MayThrow() instruction.
In JIT mode we can avoid storing extra metadata
by using deopt info instead.
Introduce caching of metadata and
exception handler based on PC.
R=fschneider@google.com
Review-Url: https://codereview.chromium.org/2640853002 .
The call sequence is very similar to a classic IC call, except the guarded class and the target are loaded indirectly from the constant pool instead of as immediates. In the monomorphic case, we call directly to the expected target with a class check in the callee. In the unlinked, polymorphic and megamorphic cases, we call a stub; these case are now call-through instead of call-and-return.
Every code, except stubs involved in switchable calls, includes the class check sequence at the beginning. So we now distinguish between a checked and an unchecked entry point. Generated code except the switchable call continues to use the unchecked entry point.
PC offsets are calculated relative to the beginning of the instruction stream, rather than either entry point.
BUG=
R=fschneider@google.com
Review URL: https://codereview.chromium.org/2226893002 .
Most of the infrastructure is fixed to work with DBC stack layout:
- register allocator allocates DBC registers with the limitation that we allocate only 20 registers and bail out if anything needs spilling (there is no use implementing spilling on DBC because registers are memory locations themselves). We should be able to bump number of CPU registers on DBC up to 256 but this requires major surgery in some parts - so I postponed this;
- lazy deoptimization is implemented, eager deoptimization is not - because we don't emit any code that actually requires it. it's a minor change to support it once we have a target;
- stack scanning respects stack maps built by registers allocator;
We bailout from all unsupported instructions.
R=zra@google.com
Review URL: https://codereview.chromium.org/1992963002 .
This undoes most of b2f3e8efe1.
This optimization prevents precompiled code from being disabled and re-enabled, because disabling causes the code to lose its only reference to its own instructions. This was okay for precompilated code that ran without a JIT because it is never disabled, but precompiled code that runs in a JIT will become disabled when corresponding optimized code is compiled and re-abled after a deopt.
R=fschneider@google.com
Review URL: https://codereview.chromium.org/1925153003 .
Vyacheslav Egorov