tree e5832e955bb3244bf26a93d14e65efc54512a377
parent aae0f7997de4d06df22766a089bc2eb18cb24e2d
author Alexander Markov <alexmarkov@google.com> 1543864122 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> 1543864122 +0000

[vm/bytecode] Revise representation of objects and strings in bytecode

This is a major revamp of bytecode metadata format. Now bytecode has
its own serialization mechanisms.

This CL adds 'bytecode component' metadata, which contains bytecode
object table and string table. All references from bytecode (constant
pools) to libraries, classes, members, types and strings now have a new
format. References to frequently used objects are represented as indices
in object table, while rarely used objects are written inline.
This allows VM to cache frequently used objects while reading bytecode.

Representation of strings is aligned with VM - string characters are
stored in separate pools of one-byte and two-byte strings. This allows
VM to avoid UTF-8 decoding and extra copying.

Closure declarations are now explicit. Type parameters no longer require
enslosing scopes when reading/writing them.

Benchmarks:
GenKernelKernelReadAllBytecode (Intel Core i5) +29.84%
GenKernelKernelReadAllBytecode (Intel Xeon) +28.74%
Change-Id: I4b80009733a8f8c038264af74f97c4e094b9e311
Reviewed-on: https://dart-review.googlesource.com/c/85469
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Reviewed-by: Zach Anderson <zra@google.com>