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 .
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 .
deprecated isolate based API.)
- Update all code impacted by this change. E.g. DARTSCOPE
- TEST_CASE now passes the current thread as a parameter to the unit test.
BUG=
R=asiva@google.com
Review URL: https://codereview.chromium.org//1310463005 .
The AST for static getters differs between parsing the first time, and
subsequent parsings. This leads to a mismatch in deoptimization-ids
between the optimized and the unoptimized code.
This CL avoids creating different ASTs for the same static getters. To allow
better inlining of these getters, the initialization expression is wrapped in a
hidden static initializer-function. As a result the size of such getters is
constant and does not depend on the initializer expression.
R=srdjan@google.com
Review URL: https://codereview.chromium.org//51123003
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@29680 260f80e4-7a28-3924-810f-c04153c831b5
Update VM to latest spec. Referencing a name that is imported
from more than one library is no longer a compile-time error.
If one of the sources of an ambiguous reference is a dart library,
the dart library declaration is automatically hidden.
Also fixes a bug where looking up a getter name in a library
found the getter even though the name is filtered out in the
'hide' combinator.
Long-term we should fix the need for repeatedly convert between
the mangled getter and setter names and the untangled name.
Fixes 12915, 12913, 12724.
R=regis@google.com
Review URL: https://codereview.chromium.org//23484020
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@27312 260f80e4-7a28-3924-810f-c04153c831b5
On each call that triggers a noSuchMethod invocation we
attach a custom dispatch function that allocates the
invocation object and invokes noSuchMethod. This dispatcher
is compiled and optimized like a normal Dart function.
Similar to method-extractors, these implicit dispatchers
do not show up as normal functions.
As a first step this CL only handles invocations of getters
and methods with no like o.foo or o.foo(). This CL gives
a >25x speedup of such noSuchMethod invocations. Calls with
multiple arguments still go through the slow path.
R=srdjan@google.com
Review URL: https://codereview.chromium.org//17315008
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@24266 260f80e4-7a28-3924-810f-c04153c831b5
Zachary Anderson