Revert "Simplify FunctionKind, saving 4 bits in SharedFunctionInfo"

This reverts commit 42667bab5b310b26bfc0ceb300550696cfbbb3ae.

Reason for revert: Breaks msvc compile:
https://build.chromium.org/p/client.v8/builders/V8%20Win64%20-%20msvc/builds/908

Original change's description:
> Simplify FunctionKind, saving 4 bits in SharedFunctionInfo
> 
> Since we only need to store 18 different function kinds,
> the bitfield approach was wasting space (requiring 11 bits).
> 
> This patch replaces the bitfield with a regular enum, and
> updates all the FunctionKind predicates to use comparisons
> instead of bitwise ops.
> 
> For the small amount of builtin code that depended upon being
> able to do masking to determine whether something is a class
> constructor, we still store two extra bits on FunctionKind,
> which are computed when the SFI is initialized.
> 
> If this approach causes performance regressions (i.e., if it
> turns out that other code was implicitly depending on masking
> for fast checks), we can revert this or address it in
> other ways (e.g., by doing similar caching of repeated checks
> in the caller).
> 
> Change-Id: Iebb3214f564ea8bd7b21e78fda33517d63247124
> Reviewed-on: https://chromium-review.googlesource.com/860896
> Commit-Queue: Adam Klein <adamk@chromium.org>
> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#50559}

TBR=adamk@chromium.org,gsathya@chromium.org

Change-Id: I8e1faa0ca6213d1e70a00fcb417b1bfa35ebd643
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/866310
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50561}
13 files changed
tree: b8ec92a14a307758ac67dc67d6979aa1444360b3
  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. .git-blame-ignore-revs
  17. .gitignore
  18. .gn
  19. .vpython
  20. .ycm_extra_conf.py
  21. AUTHORS
  22. BUILD.gn
  23. ChangeLog
  24. CODE_OF_CONDUCT.md
  25. codereview.settings
  26. DEPS
  27. LICENSE
  28. LICENSE.fdlibm
  29. LICENSE.strongtalk
  30. LICENSE.v8
  31. LICENSE.valgrind
  32. Makefile
  33. Makefile.android
  34. OWNERS
  35. PRESUBMIT.py
  36. README.md
  37. snapshot_toolchain.gni
  38. 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.