[modules] Speed up access to module exports

By adding LoadIC support for JSModuleNamespace objects. The index
of the corresponding slot in the Module's "exports" dictionary is
cached in the feedback vector, so the value can be loaded directly,
without having to call the C++ accessor.
This speeds up the "foo" property access in code like the following
snippet by about 10x:
  import * as m from "module.js"
  m.foo;

Bug: v8:1569
Change-Id: I152abedcbdc6f90b5bedd203cfdf97ed88d1137c
Reviewed-on: https://chromium-review.googlesource.com/631136
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47625}
7 files changed
tree: fdc6b42b425858d9a03dea324d1088cf9b77f3b8
  1. benchmarks/
  2. build_overrides/
  3. docs/
  4. gni/
  5. gypfiles/
  6. include/
  7. infra/
  8. samples/
  9. src/
  10. test/
  11. testing/
  12. third_party/
  13. tools/
  14. .clang-format
  15. .editorconfig
  16. .gitignore
  17. .gn
  18. .ycm_extra_conf.py
  19. AUTHORS
  20. BUILD.gn
  21. ChangeLog
  22. CODE_OF_CONDUCT.md
  23. codereview.settings
  24. DEPS
  25. LICENSE
  26. LICENSE.fdlibm
  27. LICENSE.strongtalk
  28. LICENSE.v8
  29. LICENSE.valgrind
  30. Makefile
  31. Makefile.android
  32. OWNERS
  33. PRESUBMIT.py
  34. README.md
  35. snapshot_toolchain.gni
  36. WATCHLISTS
README.md

V8 JavaScript Engine

V8 is Google's open source JavaScript engine.

V8 implements ECMAScript as specified in ECMA-262.

V8 is written in C++ and is used in Google Chrome, the open source browser from Google.

V8 can run standalone, or can be embedded into any C++ application.

V8 Project page: https://github.com/v8/v8/wiki

Getting the Code

Checkout depot tools, and run

    fetch v8

This will checkout V8 into the directory v8 and fetch all of its dependencies. To stay up to date, run

    git pull origin
    gclient sync

For fetching all branches, add the following into your remote configuration in .git/config:

    fetch = +refs/branch-heads/*:refs/remotes/branch-heads/*
    fetch = +refs/tags/*:refs/tags/*

Contributing

Please follow the instructions mentioned on the V8 wiki.