[wasm] Implement table.drop

The table.drop bytecode "drops" the backing storage for an element
initializer. In the V8 implementation, this is a nop, other than
updating a per-instance boolean array so that two drops of the same
segment or a drop of an active segment will trap.

This is implemented with inline code in TurboFan in order to be symmetric
to memory.drop, but could as easily be a runtime call to be supported in
Liftoff.

R=mstarzinger@chromium.org
CC=​binji@chromium.org
BUG=v8:7747

Change-Id: Ic017398eaa764dd3a9ff19523453ff7142c9abf6
Reviewed-on: https://chromium-review.googlesource.com/c/1408996
Reviewed-by: Ben Smith <binji@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58817}
10 files changed
tree: ca75f0a82e41d3854a88dde5a75bdd7daa16849e
  1. benchmarks/
  2. build_overrides/
  3. custom_deps/
  4. docs/
  5. gni/
  6. include/
  7. infra/
  8. samples/
  9. src/
  10. test/
  11. testing/
  12. third_party/
  13. tools/
  14. .clang-format
  15. .clang-tidy
  16. .editorconfig
  17. .git-blame-ignore-revs
  18. .gitattributes
  19. .gitignore
  20. .gn
  21. .vpython
  22. .ycm_extra_conf.py
  23. AUTHORS
  24. BUILD.gn
  25. ChangeLog
  26. CODE_OF_CONDUCT.md
  27. codereview.settings
  28. DEPS
  29. LICENSE
  30. LICENSE.fdlibm
  31. LICENSE.strongtalk
  32. LICENSE.v8
  33. LICENSE.valgrind
  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.