79ac69b83c
Tagged templates were previously desugared during parsing using some combination of runtime support written in JavaScript and C++, which prevented some optimizations from happening, namely the constant folding of the template object in TurboFan optimized code. This CL adds a new bytecode GetTemplateObject (with a corresponding GetTemplateObject AST node), which represents the abstract operation in the ES6 specification and allows TurboFan to simply constant-fold template objects at compile time (which is explicitly supported by the specification). This also pays down some technical debt by removing the template.js runtime support and therefore should reduce the size of the native context (snapshot) a bit. With this change in-place the ES6 version microbenchmark in the referenced tracking bug is now faster than the transpiled Babel code, it goes from templateStringTagES5: 4552 ms. templateStringTagES6: 14185 ms. templateStringTagBabel: 7626 ms. to templateStringTagES5: 4515 ms. templateStringTagES6: 7491 ms. templateStringTagBabel: 7639 ms. which corresponds to a solid 45% reduction in execution time. With some further optimizations the ES6 version should be able to outperform the ES5 version. This micro-benchmark should be fairly representative of the six-speed-templatestringtag-es6 benchmark, and as such that benchmark should also improve by around 50%. Bug: v8:6819,v8:6820 Tbr: mlippautz@chromium.org Change-Id: I821085e3794717fc7f52b5c306fcb93ba03345dc Reviewed-on: https://chromium-review.googlesource.com/677462 Reviewed-by: Mythri Alle <mythria@chromium.org> Reviewed-by: Caitlin Potter <caitp@igalia.com> Reviewed-by: Adam Klein <adamk@chromium.org> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org> Cr-Commit-Position: refs/heads/master@{#48126} |
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| docs | ||
| gni | ||
| gypfiles | ||
| include | ||
| infra | ||
| samples | ||
| src | ||
| test | ||
| testing | ||
| third_party | ||
| tools | ||
| .clang-format | ||
| .editorconfig | ||
| .gitignore | ||
| .gn | ||
| .ycm_extra_conf.py | ||
| AUTHORS | ||
| BUILD.gn | ||
| ChangeLog | ||
| CODE_OF_CONDUCT.md | ||
| codereview.settings | ||
| DEPS | ||
| LICENSE | ||
| LICENSE.fdlibm | ||
| LICENSE.strongtalk | ||
| LICENSE.v8 | ||
| LICENSE.valgrind | ||
| Makefile | ||
| Makefile.android | ||
| 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.