5a9f05560e
Previously the builtins table had a value for every single OperandScale/Bytecode combination regardless of whether it was valid. This change makes it so that only valid bytecode handlers are stored in the builtins table. This prevents placeholders being serialized into the snapshot (and embedded into the binary) saving 9KB in CODE_SPACE/OLD_SPACE and 2.5KB in the embedded data as well as 66 entries in the builtins table. To do this, it generates a new header file bytecodes-builtins-list.h which is created from the BYTECODE_LIST and OPERAND_SCALE_LIST macros. Since list macros cannot be used to conditionally generate elements in the C-preprocessor, this is done by generator executable, compiled from interpreter/generate-flat-headers.cc. Additionally the generator creates the flat bytecode list so that it is transposed from the previous result, i.e. the results are grouped by bytecode and then operand scale rather than operand scale then bytecode. This should give better locality for commonly used bytecodes and may allow less commonly used ExtraWide bytecodes to never be mapped into memory at all. The cost to storing the handlers densely is that looking up a handler now requires a binary search through the builtins table, but this should only happen during debugging. It is also fixable at least for non-wide handlers and could be improved for wide ones if the need arises. Bug: v8:8068 Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng Change-Id: Iaad22a952e2858f508030c5ddc082f91bf59f667 Reviewed-on: https://chromium-review.googlesource.com/1209304 Commit-Queue: Dan Elphick <delphick@chromium.org> Reviewed-by: Jakob Gruber <jgruber@chromium.org> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org> Cr-Commit-Position: refs/heads/master@{#55757} |
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| benchmarks | ||
| build_overrides | ||
| custom_deps | ||
| docs | ||
| gni | ||
| include | ||
| infra | ||
| samples | ||
| src | ||
| test | ||
| testing | ||
| third_party | ||
| tools | ||
| .clang-format | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .gn | ||
| .vpython | ||
| .ycm_extra_conf.py | ||
| AUTHORS | ||
| BUILD.gn | ||
| ChangeLog | ||
| CODE_OF_CONDUCT.md | ||
| codereview.settings | ||
| DEPS | ||
| LICENSE | ||
| LICENSE.fdlibm | ||
| LICENSE.strongtalk | ||
| LICENSE.v8 | ||
| LICENSE.valgrind | ||
| OWNERS | ||
| PRESUBMIT.py | ||
| README.md | ||
| snapshot_toolchain.gni | ||
| WATCHLISTS | ||
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.