The info_array is needed to visit an ObjectPool's pointers, requiring the compactor to move the info_array's body before forwarding the ObjectPool's pointers. Moving the info_array inline remove this constraint on the compactor.
Also saves 3 words per ObjectPool modulo allocation size rounding.
Bug: https://github.com/dart-lang/sdk/issues/30978
Change-Id: I94de0e4b7356d46fb145efee7ab14abd7473eb4c
Reviewed-on: https://dart-review.googlesource.com/27480
Reviewed-by: Erik Corry <erikcorry@google.com>
Coverage uses the value of an execution counter to detect executed functions. However non-positive execution counter does not necessary mean that a function was never executed because we sometimes reset the counter.
Introduce additional bit on a function that is set whenever we reset positive execution counter and use this bit when generating coverage data.
Bug: https://github.com/dart-lang/sdk/issues/31326
Change-Id: I5357109603defad7e7c9415c433203f16bcf88f4
Reviewed-on: https://dart-review.googlesource.com/19760
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@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>
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>
Inline instance object hash code into object header on 64 bit.
64 bit objects have 32 bits of free space in the header word.
This is used for the hash code in string objects. We take it
for the default hash code on all objects that don't override
the hashCode getter.
This is both faster and a memory reduction. Eg it makes the
MegaHashCode part of the Megamorphic benchmark 6 times faster.
This is a reland of https://codereview.chromium.org/2954453002/
which fixes an issue that made script snapshots generated on
64 bit platforms incompatible with 32 bit VMs.
BUG=
R=vegorov@google.com
Review-Url: https://codereview.chromium.org/2965723002 .
Inline instance object hash code into object header on 64 bit.
64 bit objects have 32 bits of free space in the header word.
This is used for the hash code in string objects. We take it
for the default hash code on all objects that don't override
the hashCode getter.
This is both faster and a memory reduction. Eg it makes the
MegaHashCode part of the Megamorphic benchmark 6 times faster.
This is a reland of https://codereview.chromium.org/2912863006/
It fixes issues with the 32 bit compare-swap instruction on
ARM64 and fixes a fragile tree shaking test that is sensitive
to which private methods are in the core libraries.
R=kustermann@google.com, vegorov@google.com
BUG=
Review-Url: https://codereview.chromium.org/2954453002 .
I collected statistics for the sizes and capacities of growable arrays which are promoted to old-space or survive an old-space gc when running dart2js and Fasta. For these applications, the vast majority of arrays stay empty. More than half of the total object size of promoted backing arrays is backing for empty growable arrays.
Furthermore, since the overhead for an array is 3 words (header, type parameters and length), and object sizes are rounded up to an even number of words, we waste one word for all even-sized arrays.
This CL changes the growth strategy so that empty growable arrays are created with a shared, zero-sized array as backing, avoiding the allocation of a backing array if no elements are added. When the array needs to grow, it starts out at 3 and grows to double size plus one each time: 7, 15, 31, ...
A few places in the VM code need to handle these shared, zero-sized arrays specially. In particular, the Array::MakeArray function needs to allocate a new, empty array if its result is to be returned to Dart code.
Benchmarks suggest that the change improves memory usage by a few percent overall and does not significantly affect run time.
BUG=
R=erikcorry@google.com
Review-Url: https://codereview.chromium.org/2949803002 .
64 bit objects have 32 bits of free space in the header word.
This is used for the hash code in string objects. We take it
for the default hash code on all objects that don't override
the hashCode getter.
This is both faster and a memory reduction. Eg it shaves about
70% off the running time of this microbenchmark:
List list = [];
class Thing {
get hashCode => 42;
}
class Thing2 {
get hashCode => 42;
}
class Thing3 { }
class Thing4 { }
main() {
int sum = 103;
for (int i = 0; i < 10000000; i++) {
list = [];
list.add("foo");
list.add(123);
list.add(1.23);
list.add(new Object());
list.add(new Thing());
list.add(new Thing2());
list.add(new Thing3());
list.add(new Thing4());
for (int j = 0; j < 2; j++) {
sum ^= biz(list);
}
}
print(sum);
}
int biz(List list) {
int sum = 103;
for (var x in list) {
sum ^= x.hashCode;
}
return sum;
}
R=rmacnak@google.com, vegorov@google.com
BUG=
Review-Url: https://codereview.chromium.org/2912863006 .
Used for the visitors in the scavenger and marker. Each of these seems to give a few percent speed improvement for new and old space collections, respectively.
Around 0.1% total VM size increase (on ARM64).
R=erikcorry@google.com
BUG=
Review-Url: https://codereview.chromium.org/2908353002 .
This moves the hash code into the header word for strings on 64 bit
platforms. With the old layout, 9 character strings became 48-byte
objects. With the new layout you have to go to 17 characters before
you are bumped from 4 to 6 words (32 to 48 bytes).
As a side effect, the class ID field is now 16 bits on all platforms
instead of having two different sizes, and the size field is 8 bits
on all platforms.
This also paves the way for moving the hash code for instance objects
into the header, so we won't need the side-lookup in the
hash-table-of-hash-codes on 64 bit platforms.
This is a reapplication of https://codereview.chromium.org/2893553002/
after issues were fixed in https://codereview.chromium.org/2888413002/
and https://codereview.chromium.org/2896583002/R=vegorov@google.com
BUG=
Review-Url: https://codereview.chromium.org/2895183002 .
This moves the hash code into the header word for strings on 64 bit
platforms. With the old layout, 9 character strings became 48-byte
objects. With the new layout you have to go to 17 characters before
you are bumped from 4 to 6 words (32 to 48 bytes).
As a side effect, the class ID field is now 16 bits on all platforms
instead of having two different sizes, and the size field is 8 bits
on all platforms.
This also paves the way for moving the hash code for instance objects
into the header, so we won't need the side-lookup in the
hash-table-of-hash-codes on 64 bit platforms.
R=vegorov@google.com
BUG=
Review-Url: https://codereview.chromium.org/2893553002 .
- Conditionally remove fields of Code, Function and ICData that are not used in the AOT runtime.
- Don't include RawClosureData.context_scope_ in AOT snapshots.
- Remove parameter names not needed for method resolution.
- Remove parameter types not needed for function type tests.
- Deduplicate parameter name and parameter type lists.
- Shrink and share the initial MegamorphicCache table.
Flutter gallery (IsolateSnapshotReader event)
snapshot size 2731129 -> 2199999 (-19.4%)
initial heap 7899568 -> 5433176 (-31.2%)
R=fschneider@google.com
Review URL: https://codereview.chromium.org/2326483005 .
Expand the range on a miss if all classes in the range have the same lookup result, otherwise transition to the stub that does a linear scan of ICData.
Because we do a depth-first sort of classes during AOT, if a call site sees only objects all inheriting the same function as the call target, the call site will be handled by this new stub.
Adjust LoadClassIdMayBeSmi on x64 to preserve the object.
R=fschneider@google.com
Review URL: https://codereview.chromium.org/2279563002 .
This is a cut of the work that Todd and I collaborated on in the reload branch.
In this CL, we've dropped the loader port hacks, in other words, on stack reloading in the standalone embedder does not work yet.
- [x] Support for hot reloading of isolate source code
- [x] Unit test harness and many tests
- [x] Service protocol and Observatory support
- [x] Product build does not include support for hot reloading.
R=rmacnak@google.com
Review URL: https://codereview.chromium.org/1965823002 .
Reference Instructions only through Code::entry_point_ (or Function::entry_point_). Store the instructions size in its corresponding Code object.
precompiled dart2js x64 22163470 -> 21621102 (-2.45%)
R=fschneider@google.com
Review URL: https://codereview.chromium.org/1808553002 .
It is only used to test if the Code has been disabled, and we can instead test if the active entry point matches the Instruction's entry point. A Code's entry point is either for its own Instructions or Instructions of stub code in the VM isolate, so we don't need this field to keep the Instructions alive.
precompiled dart2js x64 22254552 -> 22165795 (-0.39%)
BUG=http://dartbug.com/25992R=fschneider@google.com
Review URL: https://codereview.chromium.org/1814623003 .
They were used as the class of closure instances and as the type class of
function types.
All closure instances now have class _Closure and function types are represented
by a new class FunctionType extending AbstractType.
Fix issue 24567 and add regression test.
R=asiva@google.com, rmacnak@google.com
Review URL: https://codereview.chromium.org/1584223006 .
Three types of fixes:
1. Remove redundant const_cast
2. Remove const_cast by adding const when appropiate.
3. Remove const_cast by removing const (e.g. places where we call free with it)
For now I only fixed places where the fix is local enough - i.e. does not require
changed a large amount of code.
BUG=
R=rmacnak@google.com
Review URL: https://codereview.chromium.org/1526123002 .
- Do one eager pass over both the vm and current isolate's heaps to populate the live code table instead of lazily sampling the heap for code objects.
- Remove Instructions -> Code pointer
R=rmacnak@google.com
Review URL: https://codereview.chromium.org/1435533003 .
Instead of calling code object directly, call indirectly and
pass the code object in a register. The object pool is then loaded from
the code object. This is another preparation step for making generated code
relocatable.
All non-ia32 platforms:
No entry patching.
ARM:
PC marker (now code object) moves to the same place as on x64 (below saved PP, above saved FP).
R9 is now used as PP, R10 as CODE_REG.
BUG=
R=rmacnak@google.com
Review URL: https://codereview.chromium.org//1192103004 .
Alexander Markov