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Benedikt Meurer d3f74c9853 [turbofan] Enable loop peeling for various higher-order Array builtins.
This adds appropriate LoopExit nodes for the JSCallReducer lowerings of
the following higher order Array builtins:

  - Array.prototype.every()
  - Array.prototype.find()
  - Array.prototype.findIndex()
  - Array.prototype.some()

Loop peeling allows TurboFan to make loop invariant operations in the
callback passed to the higher order builtin fully redundant, and thus
completely eliminate the loop invariant code from the subsequent loop
iterations. This can have a huge performance impact, depending on what
kind of code runs inside of the callback. For example, on the micro-
benchmarks outlined in http://crbug.com/v8/8273 we go from

  forLoop: 364 ms.
  every: 443 ms.
  some: 432 ms.
  find: 522 ms.
  findIndex: 437 ms.

to

  forLoop: 369 ms.
  every: 354 ms.
  some: 348 ms.
  find: 419 ms.
  findIndex: 360 ms.

which is 20% improvement, and essentially brings the Array builtins (the
appropriate ones Array#some() and Array#every() in this case) on par
with the hand-written `for`-loop.

Bug: v8:1956, v8:8273
Change-Id: I9d32736e5402807b4ac79cd5ad15ceacd1945681
Reviewed-on: https://chromium-review.googlesource.com/c/1305935
Reviewed-by: Daniel Clifford <danno@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57110}
2018-10-30 09:11:57 +00:00
benchmarks Reland: [builtins] Implement Array.prototype.slice in Torque 2018-10-19 21:27:19 +00:00
build_overrides [ndk] Change android ndk root for v8 2018-01-11 08:10:33 +00:00
custom_deps [build] Add common directory for custom deps 2018-06-08 19:23:02 +00:00
docs [Docs] Removed unused docs because they are moved to GitHub 2015-11-19 10:23:30 +00:00
gni [build] disable asan on Windows for Torque 2018-10-10 11:47:40 +00:00
include [ptr-compr] Move IsolateData from Heap to Isolate 2018-10-26 14:27:57 +00:00
infra [CQ] Remove linux-chromeos-rel from CQ experiment 2018-10-26 17:11:40 +00:00
samples Add a sample that uses the JS API to create wasm 2018-06-07 23:43:38 +00:00
src [turbofan] Enable loop peeling for various higher-order Array builtins. 2018-10-30 09:11:57 +00:00
test [turbofan] Enable loop peeling for various higher-order Array builtins. 2018-10-30 09:11:57 +00:00
testing Remove dummy files created for rolling googletest. 2018-03-27 05:55:56 +00:00
third_party [torque] Implement transient types and checking 2018-10-29 07:48:20 +00:00
tools [js weak refs] Fix contexts + task scheduling 2018-10-29 12:39:37 +00:00
.clang-format [clang-format] Don't derive pointer alignment 2017-01-17 09:28:19 +00:00
.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
.git-blame-ignore-revs [build] Add DEPS formatting to hyper-blame 2017-10-09 14:08:45 +00:00
.gitattributes .gitattributes: Mark minified emscripten js files as -diff 2018-09-19 16:27:10 +00:00
.gitignore Ignore .torquelint-cache 2018-10-24 10:24:11 +00:00
.gn [test] Remove obsolete test262 archive extract 2018-03-28 13:52:15 +00:00
.vpython [tools] Add VPython config for callstats.py 2018-08-14 10:15:46 +00:00
.ycm_extra_conf.py [ycm] Switch from gnu++11 to gnu++14 2017-11-27 07:48:21 +00:00
AUTHORS [typedarray] Use fast path for Float32Array.from(float_64_array) and similar 2018-10-26 09:47:46 +00:00
BUILD.gn [js weak refs] Fix contexts + task scheduling 2018-10-29 12:39:37 +00:00
ChangeLog [tools] Merge ChangeLog from latest release 2017-12-19 12:30:56 +00:00
CODE_OF_CONDUCT.md Explicitly state that the Chromium Code of Conduct also applies to V8 2016-03-02 09:51:24 +00:00
codereview.settings Make Gerrit the default code review for V8 2017-06-30 17:37:37 +00:00
DEPS Update V8 DEPS. 2018-10-29 03:25:53 +00:00
LICENSE Add antlr4 runtime library to support Torque 2018-04-10 10:01:01 +00:00
LICENSE.fdlibm Add LICENSE.fdlibm for all the fdlibm imported sources. 2016-06-09 07:17:03 +00:00
LICENSE.strongtalk Add LICENSE.v8, LICENSE.strongtalk and LICENSE.valgrind to the v8 2011-02-03 07:10:06 +00:00
LICENSE.v8 Add LICENSE.v8, LICENSE.strongtalk and LICENSE.valgrind to the v8 2011-02-03 07:10:06 +00:00
LICENSE.valgrind Add LICENSE.v8, LICENSE.strongtalk and LICENSE.valgrind to the v8 2011-02-03 07:10:06 +00:00
OWNERS Reduce wasm OWNERS to current team members 2018-10-15 14:47:49 +00:00
PRESUBMIT.py [tools] Move path-specific try-builders to the CQ config 2018-10-24 13:52:21 +00:00
README.md [Docs] Removed unused docs because they are moved to GitHub 2015-11-19 10:23:30 +00:00
snapshot_toolchain.gni Reland "Add Windows ARM64 ABI support to V8" 2018-10-24 19:46:36 +00:00
WATCHLISTS Add myself to the watch list. 2018-10-22 16:20:40 +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://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.