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Michael Hablich (vacation) 27905a33f5 Revert "[turbofan] Speculate on bounds checks for String#charAt and String#charCodeAt."
This reverts commit db129b6525.

Reason for revert: blocks roll: https://chromium-review.googlesource.com/c/chromium/src/+/873150

Original change's description:
> [turbofan] Speculate on bounds checks for String#charAt and String#charCodeAt.
> 
> With the new builtin optimization guard we can just speculatively assume
> that the index passed to String#charAt and String#charCodeAt (in optimized
> code) is going to be within the valid range for the receiver. This is
> what Crankshaft used to do, and it avoids Smi checks on the result for
> String#charCodeAt, since it can no longer return NaN.
> 
> This gives rise to further optimizations of these builtins (i.e. to
> completely avoid the tagging of char codes), and by itself already
> improves the regression test originally reported from 650ms to
> 610ms.
> 
> Bug: v8:7127, v8:7326
> Change-Id: Ia25a555c5c1a48d229c094b1ecd2487eec81e390
> Reviewed-on: https://chromium-review.googlesource.com/872850
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#50667}

TBR=yangguo@chromium.org,bmeurer@chromium.org

Change-Id: I6d393a0797cac2fdfd67487a26ac1b178bd52813
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7127, v8:7326
Reviewed-on: https://chromium-review.googlesource.com/873355
Reviewed-by: Michael Hablich (vacation) <hablich@chromium.org>
Commit-Queue: Michael Hablich (vacation) <hablich@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50672}
2018-01-18 11:34:17 +00:00
benchmarks Fix common misspellings 2017-08-02 09:35:28 +00:00
build_overrides [ndk] Change android ndk root for v8 2018-01-11 08:10:33 +00:00
docs [Docs] Removed unused docs because they are moved to GitHub 2015-11-19 10:23:30 +00:00
gni [gn] do not hide symbols for monolithic build. 2018-01-05 16:11:55 +00:00
gypfiles [test] Add a d8_default test suite collection 2018-01-12 15:18:04 +00:00
include [api] Advance deprecation of v8::Script APIs 2018-01-17 18:48:54 +00:00
infra [test] Group test features behind a single GN switch 2018-01-17 14:06:58 +00:00
samples [cleanup] use unique_ptr for the DefaultPlatform 2017-11-14 09:57:18 +00:00
src Revert "[turbofan] Speculate on bounds checks for String#charAt and String#charCodeAt." 2018-01-18 11:34:17 +00:00
test [typedarray] Port ConstructByTypedArray to CSA. 2018-01-18 11:27:54 +00:00
testing Use GTEST_LANG_CXX11 in V8 2016-07-25 13:06:42 +00:00
third_party Update third_party/binutils version to match Chromium. 2017-12-08 07:28:26 +00:00
tools [node] pass host OS to build_gn.py. 2018-01-18 10:11:22 +00:00
.clang-format [clang-format] Don't derive pointer alignment 2017-01-17 09:28:19 +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
.gitignore [test] Remove promises-aplus test suite 2017-12-19 09:29:26 +00:00
.gn For building v8 using gn on aix_ppc64, linux_s390x and linux_ppc64(both LE and BE). 2017-05-12 01:35:09 +00:00
.vpython Add a comment for the VPython dep 2017-10-25 12:23:35 +00:00
.ycm_extra_conf.py [ycm] Switch from gnu++11 to gnu++14 2017-11-27 07:48:21 +00:00
AUTHORS [snapshot]: Fix missing Cast in {Private, Signature, AccessorSignature} 2018-01-16 12:07:41 +00:00
BUILD.gn [regexp] Initial go at a builtins fuzzer 2018-01-18 11:02:57 +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. 2018-01-17 04:51:38 +00:00
LICENSE Updates to the license information of third party components. 2015-06-16 12:37:50 +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
Makefile [test] Continued test support for make targets 2017-10-20 15:01:51 +00:00
Makefile.android [build] Fix d8-for-Android builds 2016-05-20 12:10:45 +00:00
OWNERS Add myself to OWNERS to be able to approve/make infra-related changes 2017-11-09 22:52:19 +00:00
PRESUBMIT.py Replace all tryserver.v8 entries with corresponding LUCI bucket 2017-12-22 14:39:42 +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 MIPS[64]: Generate snapshots on MIPS big-endian targets 2017-11-24 19:00:32 +00:00
WATCHLISTS Add adamk to a few WATCHLISTS 2017-11-10 21:38:29 +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.