Go to file
Leszek Swirski f7cc70de2b [maglev] Fix dead predecessors after EmitUnconditionalDeopt
Fixes the iteration after emitting an unconditional deopt to kill all
Jumps along the way, not just ones preceeding a merge point. This fixes
several issues:

  a) That Jump may be to a not yet created merge point, in which case we
     were getting a nullptr deref.
  b) Not-yet created merge points would not be detected as merge points,
     so we'd skip over them and miss killing the control node before
     them.
  c) We weren't reducing predecessor counts, so even after fixing the
     nullptr deref above, merge states created later would have the wrong
     predecessor count.

Now, we check bytecode targets (including fallthrough for non-returning
bytecodes) on for every bytecode, and skip over both not-yet created
merges, and loop merges that have no predecessors other than the loop
jump itself.

As part of this, the dead predecessor merging is changed; instead of
setting the predecessor to nullptr, we drop the predecessor count by
one, and trim any Phis' input counts.

Bug: v8:7700
Change-Id: I904c82df7c5dd44d7637e07f6750b35e7e219284
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3599470
Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80083}
2022-04-21 13:02:35 +00:00
.github [github] Close PRs created on the V8 GitHub mirror automatically 2021-01-12 08:39:59 +00:00
bazel [bazel] Add v8_enable_short_builtin_calls flag 2022-03-18 13:45:04 +00:00
build_overrides [build] Remove obsolete gn flag 2021-01-11 15:50:59 +00:00
custom_deps Use relative paths to OWNERS files 2019-08-12 13:52:52 +00:00
docs Add OWNERS for docs/ 2019-05-15 12:06:15 +00:00
gni Add new owner to branch cut artifact 2022-04-01 10:50:51 +00:00
include [api] Deprecate unused GlobalHandles APIs that peek into internals 2022-04-21 12:55:15 +00:00
infra [infra] increase shards for v8_linux_rel_ng 2022-04-20 08:28:46 +00:00
samples [test] Add a unittest platform setup mixin 2022-04-06 13:07:43 +00:00
src [maglev] Fix dead predecessors after EmitUnconditionalDeopt 2022-04-21 13:02:35 +00:00
test [api] Deprecate unused GlobalHandles APIs that peek into internals 2022-04-21 12:55:15 +00:00
testing [test][cleanup] Fix -Wshadow warnings in unittests 2021-09-27 08:59:01 +00:00
third_party Convert inspector_protocol/roll.py to python3 2022-03-24 18:07:17 +00:00
tools [tools][gcmole] Add run_gcmole.py --help and drop env vars 2022-04-20 15:26:35 +00:00
.bazelrc [bazel] Use v8_enable_handle_zapping only in debug builds. 2022-01-11 11:32:39 +00:00
.clang-format
.clang-tidy [tool] Remove unfixed clang-tidy warnings to ease use. 2018-10-26 07:40:32 +00:00
.editorconfig Add .editorconfig 2017-07-28 13:39:24 +00:00
.flake8 remove swarming_client 2021-08-24 10:39:33 +00:00
.git-blame-ignore-revs [infra] Update .git-blame-ignore-revs 2020-03-03 12:59:13 +00:00
.gitattributes .gitattributes: Mark minified emscripten js files as -diff 2018-09-19 16:27:10 +00:00
.gitignore [infra] Fork test262-harness 2022-02-23 18:47:35 +00:00
.gn Revert "[build] Separate out inspector as a shared library" 2021-07-02 16:15:20 +00:00
.mailmap Restore consistency between .mailmap and AUTHORS 2021-06-24 08:58:04 +00:00
.style.yapf [tools] Add basic pointer compression to grokdump 2022-02-04 14:35:26 +00:00
.vpython Verify mac-arm64 wheels for v8/.vpython spec. 2021-09-15 21:11:50 +00:00
.vpython3 Use numpy 1.2x.supported.1 in V8 2022-03-03 15:21:21 +00:00
.ycm_extra_conf.py [ycm] Fix python script 2021-07-29 09:48:32 +00:00
AUTHORS [wasm] Place spilled params as WasmCallDescriptor expects. 2022-04-06 08:59:53 +00:00
BUILD.bazel [web snapshots] Add a JS API for deserializing Web snapshots 2022-04-20 16:02:20 +00:00
BUILD.gn [web snapshots] Add a JS API for deserializing Web snapshots 2022-04-20 16:02:20 +00:00
CODE_OF_CONDUCT.md
codereview.settings
COMMON_OWNERS add tebbi@chromium.org to COMMON_OWNERS 2022-03-08 14:08:25 +00:00
DEPS Update V8 DEPS. 2022-04-21 03:55:05 +00:00
DIR_METADATA Add DIR_METADATA files to v8. 2020-10-20 22:12:28 +00:00
ENG_REVIEW_OWNERS Add verwaest@ to ENG_REVIEW_OWNERS. 2021-09-16 15:00:57 +00:00
INFRA_OWNERS Add team members as owners 2020-08-18 08:29:04 +00:00
INTL_OWNERS add ftang as owner 2020-04-24 19:19:36 +00:00
LICENSE [wasm] Draft version of C/C++ Wasm API 2019-04-17 16:00:26 +00:00
LICENSE.fdlibm
LICENSE.strongtalk
LICENSE.v8
LOONG_OWNERS [LOONG64] Add LoongArch64 backend 2021-08-16 13:05:19 +00:00
MIPS_OWNERS [mips] Add LiuYu to MIPS_OWNERS 2021-09-08 01:38:52 +00:00
OWNERS Let infra owners own all dot files 2021-11-05 18:57:18 +00:00
PPC_OWNERS Adding myself to relevant OWNERS files. 2020-11-02 16:37:28 +00:00
PRESUBMIT.py [infra] use format strings instead of .format 2022-03-15 11:31:40 +00:00
README.md [docs] Change links from old wiki to v8.dev 2019-03-07 12:13:30 +00:00
RISCV_OWNERS Add Lu Yahan to RISC-V owners list 2021-09-13 16:35:00 +00:00
S390_OWNERS Adding myself to relevant OWNERS files. 2020-11-02 16:37:28 +00:00
WATCHLISTS Update WATCHLISTS 2022-02-24 11:37:36 +00:00
WORKSPACE [bazel] Cleanup style with Buildifier. 2022-01-11 10:00:36 +00:00

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.