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 .
Jens Johansen