Merged: [map] Try to in-place transition during map update

When searching for a target map during map update, attempt to
update field representations in-place to the more general
representation, where possible.

Bug: chromium:1143772
No-Try: true
No-Presubmit: true
No-Tree-Checks: true

TBR=leszeks@chromium.org, fgm@chromium.org
(cherry picked from commit 8e3ae62d294818733a0322d8e8abd53d4e410f19)

Change-Id: I659890c2f08c14d1cf94242fb875c19837df2dbb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2509599
Reviewed-by: Francis McCabe <fgm@chromium.org>
Reviewed-by: Michael Hablich <hablich@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/branch-heads/8.6@{#44}
Cr-Branched-From: a64aed2333abf49e494d2a5ce24bbd14fff19f60-refs/heads/8.6.395@{#1}
Cr-Branched-From: a626bc036236c9bf92ac7b87dc40c9e538b087e3-refs/heads/master@{#69472}
4 files changed
tree: 89b592cb4624c79792e7ff1bc8ee9a82abfd2b7f
  1. .clang-format
  2. .clang-tidy
  3. .editorconfig
  4. .flake8
  5. .git-blame-ignore-revs
  6. .gitattributes
  7. .gitignore
  8. .gn
  9. .vpython
  10. .ycm_extra_conf.py
  11. AUTHORS
  12. BUILD.gn
  13. CODE_OF_CONDUCT.md
  14. COMMON_OWNERS
  15. DEPS
  16. ENG_REVIEW_OWNERS
  17. INFRA_OWNERS
  18. INTL_OWNERS
  19. LICENSE
  20. LICENSE.fdlibm
  21. LICENSE.strongtalk
  22. LICENSE.v8
  23. LICENSE.valgrind
  24. MIPS_OWNERS
  25. OWNERS
  26. PPC_OWNERS
  27. PRESUBMIT.py
  28. README.md
  29. S390_OWNERS
  30. WATCHLISTS
  31. build_overrides/
  32. codereview.settings
  33. custom_deps/
  34. docs/
  35. gni/
  36. include/
  37. infra/
  38. samples/
  39. src/
  40. test/
  41. testing/
  42. third_party/
  43. tools/
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://v8.dev/docs

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 at v8.dev/docs/contribute.