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>
This new object points to program wide data like string offsets,
string data etc. It also holds an array of pointers to all Script
objects corresponding scripts in the program's source table.
This new object type is required for two reasons:
1. The Script objects now have a number of fields which point to
program wide data. All Script objects point to the same data in the
VM heap. By introducing an indirection via this new object, we reduce
the number of pointers in Script objects.
2. Lazy loading of VM objects - Kernel nodes of
entities like fields and functions have a field which point to the
source file in which they are defined. This entry is an index into
the program wide source table and helps in associating
functions/fields with their actual source location. When lazy loading
functions and fields, the pre-loaded script objects in the
program's KernelProgramInfo help in associating the functions and
fields with the correct source script at load time.
Change-Id: Id863284ae7dd98b0832e5dfc115dabad1ed762d8
Reviewed-on: https://dart-review.googlesource.com/13920
Commit-Queue: Siva Chandra <sivachandra@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
This flag indicates when a procedure's return type makes contravariant
use of a class type parameter. The front end will have to insert "as"
checks at any call sites that refer to such a procedure as their
interface target. Placing the flag on the procedure will allow the
front end to determine whether the check is needed once, at the same
time as it's determining the need for covariant parameter checks,
rather than when compiling individual call sites.
Once this lands I will follow up with CLs that cause the front end to
set the flag appropriately, and to generate the necessary "as" checks.
Change-Id: I989fc702bc233384eb5ea8cd630c8efd384ab248
Reviewed-on: https://dart-review.googlesource.com/14365
Reviewed-by: Samir Jindel <sjindel@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
This CL adds internal binary format version to kernel binaries.
Kernel readers in the front-end and VM verify that the reader's format
version matches the format version in the binary file.
This improves detection and diagnostics of stale kernel binary files.
Change-Id: Ic69b16057397a84627040bdd6420ffa1852a4b3f
Reviewed-on: https://dart-review.googlesource.com/13280
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>
Reviewed-by: Kevin Millikin <kmillikin@google.com>
Commit-Queue: Alexander Markov <alexmarkov@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>
Such a call site starts with a reference to a stub in the VM isolate, so the pointer was not recordered, but after it first runs it will be patched to a code object in the current isolate, which may move during compaction.
Bug: https://github.com/dart-lang/sdk/issues/30978
Change-Id: I3bf8fd1cf8884cbba9956254cad70f46e8b8cc00
Reviewed-on: https://dart-review.googlesource.com/12701
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Previously, a lot of recognized instance methods were inlined
only if they are called using InstanceCall instruction.
This CL enables inlining of such methods even if they are called
using StaticCall instruction. Such static calls may appear as the
result of devirtualization of instance calls.
Fixes slow-down of Flutter gestures/velocity_tracker benchmark when
devirtualization is enabled without --experimental-strong-mode.
(The slow-down was caused by inline heuristics rejecting to inline
several methods as their speculative bodies contain non-inlined
calls to recognized methods.)
Issue: https://github.com/dart-lang/sdk/issues/30480
Change-Id: Id0ec0669d0e3fe05aa708baec4a468892dbe7f8e
Reviewed-on: https://dart-review.googlesource.com/13200
Reviewed-by: Ryan Macnak <rmacnak@google.com>
This reverts commit af251ddfec.
Reason for revert: Crashes on Windows.
Original change's description:
> [vm] Prefer stack bounds from the system thread library for overflow checks.
>
> Before this change, we would assume all stacks have the size the VM specifies for threads it creates, but this won't be accurate for the initial thread or threads created by the embedder.
>
> Change-Id: I6605a88d6666a6f9d47fbe047d3fdd02aa22c80a
> Reviewed-on: https://dart-review.googlesource.com/10209
> Reviewed-by: Zach Anderson <zra@google.com>
TBR=rmacnak@google.com,zra@google.com
Change-Id: I96eaccdc8edf6e3d319827a63d168534bad0518e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/13106
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Before this change, we would assume all stacks have the size the VM specifies for threads it creates, but this won't be accurate for the initial thread or threads created by the embedder.
Change-Id: I6605a88d6666a6f9d47fbe047d3fdd02aa22c80a
Reviewed-on: https://dart-review.googlesource.com/10209
Reviewed-by: Zach Anderson <zra@google.com>
This CL optimizes Type.hashCode similarly to String.hashCode, by
introducing intrinsic version of hashCode calculation which uses
hashcode stored in Type instance.
This is important for Flutter's .of pattern, which heavily uses
Maps with Type keys.
Results on Flutter stocks/build_bench.dart microbenchmark:
Before: 4906 µs
After: 4751 µs
(minimum of 5 runs, using tip of Flutter and Flutter engine)
Issue: https://github.com/dart-lang/sdk/issues/31011
Issue: https://github.com/flutter/flutter/issues/11572
Change-Id: Ifbaf721050007db49bbd969dc669d070f4ce839e
Reviewed-on: https://dart-review.googlesource.com/12622
Reviewed-by: Zach Anderson <zra@google.com>
Devirtualization optimization now adds metadata to kernel AST instead
of transforming nodes to Direct* ones. The direct call metadata
provides information about checking receiver for null, while
Direct* kernel nodes do not support null checking.
VM's kernel binary loader is extended to extract arbitrary metadata
from kernel binaries and keep it for flow graph builder.
Kernel flow graph builder is extended to take direct call metadata
into account and generate CheckNull/StaticCall instructions
for devirtualized PropertyGet, PropertySet and MethodInvocation nodes.
Issue: https://github.com/dart-lang/sdk/issues/30480
Change-Id: I57f56fbf4a8981d33b1571c0d93105cf8ca71d76
Reviewed-on: https://dart-review.googlesource.com/12260
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
This change does a couple things:
- When there is a non-default namespace, on Linux, Android, and Fuchsia
the current working directory is per-Isolate.
- On Fuchsia, it caches the fd from fdio_ns_t instead of recomputing it
on every fs access.
Change-Id: I3735330884de51ca853a17d66dcfcfa984b9a041
Reviewed-on: https://dart-review.googlesource.com/9367
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Zach Anderson <zra@google.com>
Before this change, each function and field had its own kernel data blob
in the VM heap. With this change, the entire kernel data of a library is
stored as one single blob in the VM heap. Functions and fields store an
offset which points to the kernel data, specific to them, in that single
blob.
The pointer to the kernel data for a library is saved in two places:
1. With the library objects themselves.
2. With all the patch classes of the library.
3. With the patch classes created during hot reload.
Change-Id: Ie03e738c4d20f16056a5ef04341b75506fda9c60
Bug:
Reviewed-on: https://dart-review.googlesource.com/6601
Commit-Queue: Siva Chandra <sivachandra@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>
When precompiling we might trigger optimizing compilation eagerly
so constant evaluation did not have a chance to run.
It is totally fine though because precompiler does not use
background thread.
Bug:
Change-Id: I6e889284d9ef9be8b09c6f4fe7695c82a78bcee4
Reviewed-on: https://dart-review.googlesource.com/12280
Reviewed-by: Alexander Markov <alexmarkov@google.com>
This CL unifies 31 diverse Simd instructions into a single flexible SimdOp instruction.
These instructions were not different enough to warrant being implemented
as separate IL instructions. The separation did not bring any benefit but
instead we payed the price with considerable amounts of duplicated code
across the pipeline.
Main motivation for this refactoring is to reduce the surface of our IL.
Bug:
Change-Id: Ie8e39fecd2a51cb8edffdfe9c22e76835f912a9b
Reviewed-on: https://dart-review.googlesource.com/10120
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Zach Anderson <zra@google.com>
Ryan Macnak