The introduced "constants" transformation can evaluate constant expressions. The
original use-sites of constant expressions are replaced by a new [ConstantExpression]
node, which points to a subclass of a new [Constant] class hierarchy. Constant
[Field]s and [VariableDeclarations]s will be removed, since all use-sites are
re-written.
The [Constant] class hierarchy is, similarly to the [DartType] class hierarchy, not
part of the AST tree (also has no parent pointer). The constants form a
DAG (directed acyclic graph).
There is no canonicalization requirement of the [Constant] objects referenced by the
AST (via [ConstantExpression]). Although it is beneficial to canonicalize them during
construction, since it reduces time spent in operator==/hashCode.
This CL furthermore adds support for a constant table in the binary format. Similarly
to [String]s, we canonicalize the constants before writing the table to the binary.
The constant table entries in the binary are written in a post-order way, to ensure
easy construction on the backend side.
The text format will be augmented with a "constants { ... }" section at the end,
which lists the constants in the same order as in the binary format.
The transformation can be used by those backends who choose to do so. It is not
enabled by default atm. It should therefore not affect analyzer, fasta or other
components.
Change-Id: I57cd9624fedcf537ab6870db76246149647bed21
Reviewed-on: https://dart-review.googlesource.com/14382
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Kevin Millikin <kmillikin@google.com>
This change brings down core snapshot size by ~750KB, and brings
down app-jit snapshot size of simple "Hello, World" dart script by
~650KB. The bot cycle times will also come down by around ~20%.
Change-Id: I2a01c98bedc7ebfa2a653983995486a71504daf3
Reviewed-on: https://dart-review.googlesource.com/16323
Commit-Queue: Siva Chandra <sivachandra@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>
The kernel format has been designed so that one can concatenate several
dill files into one file and then load it. For instance the dart
function BinaryBuilder.readProgram supports this.
Currently a dill file contains one or more programs.
In the VM each of these programs are called either program or subprogram.
Technically a dill "program" isn't necessarily a program at all (e.g. it
could be missing a library).
This naming snafu should probably be cleaned up at some point, but that's
for another CL.
When loading a dill file via BinaryBuilder.readProgram what happens is
this:
- Each program in the dill file ends in 4 bytes that indicates the size
of the program.
- Reading the input from the end one can then read the size, skip back
that amount of bytes, if we have more data (i.e. there's another
program), read another size and so on, and continue until we have
accounted for all bytes in the input.
- We then read each program from the start, and basically overwrite any
library, class, procedure etc. we find.
The first main reference found is the one used though.
(Saying that we overwrite is not completely true, but when the library
is a non-external library that's basically what happens).
This CL introduces (some) support on the C++ side for the same thing.
So far the C++ side could only handle single-program-dills, and trying
to load anything else would probably crash the VM.
The support added is this:
- Assume the SDK (i.e. vm_platform.dill) is not a concatenated file
(error out if it is).
- For user provided input, loop over each contained program one-by-one,
for each individual one behave as normal.
- The way LibraryLoad is implemented (i.e. it skips if the library is
already loaded) this means that it currently would behave differently
than the dart version (i.e. the first one is used, not the last one).
For now it is assumed that that's not a problem.
- There is a possibly snafu if the same script is included several times.
This could probably mostly be remedied by not creating scripts up front,
but only as needed. By the "keep only one" (and fixing the above point,
probably by simply loading in the opposite order, i.e. last program
in the binary first) the (theoretical) problem would probably do away.
Note that we will have separate string tables, canonical name tables etc
per "sub program" and that there might be some duplication.
The implementation was tested as indicated below, but introduces no tests.
$ cat test_lib1.dart
import "test_lib2.dart" as lib2;
String lib1field = "lib #1 field!!";
main() {
foo();
lib2.foo();
print("From lib2: ${lib2.lib2field}");
}
foo() {
print("Hello, Foo, from test_lib1!");
var x = 42;
print(x);
}
$ cat test_lib2.dart
String lib2field = "Lib #2 field!!!!";
foo() {
print("Hello, Foo, from test_lib2!");
var y = 34;
print(y);
}
$ out/ReleaseX64/dart pkg/front_end/tool/_fasta/compile.dart --packages=.packages --platform=out/ReleaseX64/vm_platform.dill test_lib1.dart
$ ls -lha test_lib1.dart.dill
[...] 4.2M Oct 26 14:42 test_lib1.dart.dill
$ dart pkg/kernel/bin/split.dart test_lib1.dart.dill
Wrote test_lib1.dart.dill.part1.dill
Wrote test_lib1.dart.dill.part2.dill
$ ls -lha test_lib1.dart.dill.part{1,2}.dill
[...] 811 Oct 26 14:42 test_lib1.dart.dill.part1.dill
[...] 582 Oct 26 14:42 test_lib1.dart.dill.part2.dill
$ cat test_lib1.dart.dill.part1.dill test_lib1.dart.dill.part2.dill > test_lib1.dart.dill.concat.dill
$ ls -lha test_lib1.dart.dill.concat.dill
[...] 1.4K Oct 26 14:44 test_lib1.dart.dill.concat.dill
$ out/ReleaseX64/dart --kernel-binaries=out/ReleaseX64 --packages=.packages test_lib1.dart.dill.concat.dill
Hello, Foo, from test_lib1!
42
Hello, Foo, from test_lib2!
34
From lib2: Lib #2 field!!!!
Change-Id: I233a033aa3042b202dd4708908a5be3089474588
Reviewed-on: https://dart-review.googlesource.com/16820
Commit-Queue: Jens Johansen <jensj@google.com>
Reviewed-by: Dmitry Stefantsov <dmitryas@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>
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>
Before this CL we skipped procedure bodies in kernel_loader.cc by
parsing the body (but not storing anything).
With this CL we now skip them directly (i.e. don't read them at all)
in kernel_loader.cc by using the newly available extra indexes in kernel.
Change-Id: I48cf0599b2a85102c9008ff7c455785151ef3c9c
Reviewed-on: https://dart-review.googlesource.com/5764
Commit-Queue: Jens Johansen <jensj@google.com>
Reviewed-by: Samir Jindel <sjindel@google.com>
Currently serializing the ast for kernel is done in two passe:
1) Scan the program to find and index all strings. These are then
sorted based on frequency and assigned an id. All string-
references are refering to that id. As small numbers use less
space in the binary than big numbers, sorting the numbers by
frequency saves a certain amount of space.
In addition the string indexing is "hijacked" for the
"LimitedBinaryPrinter" to also perform some CanonicalName
re-indexing.
2) We then serialize the entire thing.
This CL gets rid of a pass by not indexing the strings up-front.
Whenever it is asked to serialize a string it adds it to the index
(if not already there). The serialization is otherwise the same.
This means that:
1) Strings are not sorted by frequency, i.e. the binary output size
can by bigger (numbers below).
2) The stringindex and canonical names are moved to the end of the
binary instead of the front. As we still need it up front for
deserialization some additional data is added to the
ProgramIndex.
3) The "hijacking" done in "LimitedBinaryPrinter" is replaced by
an alternative.
4) We don't spend time on walking the tree twice.
The cost is the binary size. Compiling helloworld with fasta,
as well as looking at outline.dill, platform.dill and
vmservice_io.dill reveals these numbers:
* helloworld.dill is 0.657248732% bigger (26573 bytes)
* outline.dill is 1.686911399% bigger (9395 bytes)
* platform.dill is 0.657062238% bigger (26565 bytes)
* vmservice_io.dill is 0.44991899% bigger (19147 bytes)
The cost does thus not appear to be very big.
The gain is the serialization time.
From 20 runs of an instrumented VM/serialization, running numbers
through calculations stolens from ministat
(https://www.freebsd.org/cgi/man.cgi?query=ministat) reveals the
following:
* Serialization time: -21.69% +/- 1.44%
* Total time spend in relevant parts of bootstrap_nocore.cc,
dart_api_impl.cc (Dart_LoadKernel), bootstrap_nocore.cc,
dart_api_impl.cc (LoadKernelProgram) as well as serialization:
-14.01% +/- 1.58%
From 5 runs of
"time python tools/test.py -m release -cdartk language -j6"
(again run through ministat calculations):
* real: -4.18% +/- 0.5%
* user: -4.2% +/- 0.29%
* sys: No difference at 95%
* user+sys: -3.3% +/- 0.36%
Change-Id: I1c220eac083496994f0a9f1e2a2445b3707c9a93
Reviewed-on: https://dart-review.googlesource.com/2880
Reviewed-by: Samir Jindel <sjindel@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>
There already exists a class named "Reader" in the "kernel" namespace
which reads bytes from a kernel binary. The class KernelLoader
(KernelReader before this change) creates VM heap objects and populates
them.
R=kmillikin@google.com
Review-Url: https://codereview.chromium.org/3010543002 .
Ben Konyi