commit | a0484bc6116ebc2b855de87d862945e2ae07169b | [log] [tgz] |
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author | bmeurer <bmeurer@chromium.org> | Mon Sep 26 12:32:23 2016 |
committer | Commit bot <commit-bot@chromium.org> | Mon Sep 26 12:32:33 2016 |
tree | 23d27939fffed1f416912e20d211b58139a2d042 | |
parent | cc37dff7ba21345b3a867a86127a208e34a3f707 [diff] |
[compiler] Properly guard the speculative optimizations for instanceof. Add a general feedback slot for instanceof similar to what we already have for for-in, which basically has a fast (indicated by the uninitialized sentinel) and a slow (indicated by the megamorphic sentinel) mode. Now we can only take the fast path when the feedback slot says it hasn't seen any funky inputs and nothing funky appeared in the prototype chain. In the TurboFan code we also deoptimize whenever we see a funky object (i.e. a proxy or an object that requires access checks) in the prototype chain (similar to what Crankshaft already did). Drive-by-fix: Also make Crankshaft respect the mode and therefore address the deopt loop in Crankshaft around instanceof. We might want to introduce an InstanceOfIC mechanism at some point and track the map of the right-hand side. BUG=v8:5267 R=mvstanton@chromium.org Review-Url: https://codereview.chromium.org/2370693002 Cr-Commit-Position: refs/heads/master@{#39718}
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
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/*
Please follow the instructions mentioned on the V8 wiki.