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bcee140617
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Benedikt Meurer bcee140617 [turbofan] Introduce InstanceOfIC to collect rhs feedback. 
This adds a new InstanceOfIC where the TestInstanceOf bytecode collects
constant feedback about the right-hand side of instanceof operators,
including both JSFunction and JSBoundFunction instances. TurboFan then
uses the feedback to optimize instanceof in places where the right-hand
side is not a known constant (known to TurboFan).

This addresses the odd performance cliff that we see with instanceof in
functions with multiple closures. It was discovered as one of the main
bottlenecks on the uglify-es test in the web-tooling-benchmark. The
uglify-es test (run in separation) is ~18% faster with this change.

On the micro-benchmark in the tracking bug we go from

  instanceofSingleClosure_Const: 69 ms.
  instanceofSingleClosure_Class: 246 ms.
  instanceofMultiClosure: 246 ms.
  instanceofParameter: 246 ms.

to

  instanceofSingleClosure_Const: 70 ms.
  instanceofSingleClosure_Class: 75 ms.
  instanceofMultiClosure: 76 ms.
  instanceofParameter: 73 ms.

boosting performance by roughly 3.6x and thus effectively removing the
performance cliff around instanceof.

Bug: v8:6936, v8:6971
Change-Id: Ib88dbb9eaef9cafa4a0e260fbbde73427a54046e
Reviewed-on: https://chromium-review.googlesource.com/730686
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48820}
2017-10-23 10:15:36 +00:00
benchmarks Fix common misspellings 2017-08-02 09:35:28 +00:00
build_overrides Remove build_override for macOS min SDK and deployment target. 2017-07-14 18:24:44 +00:00
docs [Docs] Removed unused docs because they are moved to GitHub 2015-11-19 10:23:30 +00:00
gni [test] Fix isolate for auto-detect in gyp 2017-10-19 11:52:11 +00:00
gypfiles [test] Continued test support for make targets 2017-10-20 15:01:51 +00:00
include Add JSSpecialApiObjectType to fast path 2017-10-19 17:30:52 +00:00
infra [CQ] Add v8_linux_shared_compile_rel to CQ 2017-10-23 07:58:40 +00:00
samples [presubmit] Enable and fix "build/namespaces" linter check. 2017-09-04 11:24:26 +00:00
src [turbofan] Introduce InstanceOfIC to collect rhs feedback. 2017-10-23 10:15:36 +00:00
test [turbofan] Introduce InstanceOfIC to collect rhs feedback. 2017-10-23 10:15:36 +00:00
testing Use GTEST_LANG_CXX11 in V8 2016-07-25 13:06:42 +00:00
third_party Roll third_party/inspector_protocol to 8cb7a4f50ff7d5b1b7f2e5df0542dc577c88bdc3 2017-10-11 22:52:17 +00:00
tools Remove "Skipping X download..." messages from gclient hooks 2017-10-21 14:22:37 +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 [wasm] Add uma stat for wasm lazy throughput 2017-10-11 21:00:22 +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
.ycm_extra_conf.py Use C++11 / gnu++11, not 0x 2016-03-22 15:24:43 +00:00
AUTHORS [modules] Optimize import.meta in the interpreter 2017-10-20 20:31:49 +00:00
BUILD.gn [builtins] Port String.raw to CPP 2017-10-19 13:47:33 +00:00
ChangeLog [Release] Update ChangeLog file 2016-02-17 21:29:09 +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. 2017-10-22 03:37:37 +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 eholk and gdeepti to toplevel owners 2017-08-12 07:07:29 +00:00
PRESUBMIT.py [iwyu] Turn inclusion presubmit warning into and error. 2017-09-14 10:17:58 +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]: Add support for big endian build using GN 2017-06-02 15:02:18 +00:00
WATCHLISTS [V8Tracing] Add lpy@ and fmeawad@ into watchlist for tracing/. 2017-05-22 19:40:17 +00:00

README.md

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.