ef661b0804
We have to reland these two commits at once, because the first breaks some asm.js benchmarks without the second. The change was reverted because of bogus checks in the verifier, which will not work in the presence of OSR (and where hidden because of the type back propagation hack in OSR so far). Original messages are below: [turbofan] Add new JSFrameSpecialization reducer. The JSFrameSpecialization specializes an OSR graph to the current unoptimized frame on which we will perform the on-stack replacement. This is used for asm.js functions, where we cannot reuse the OSR code object anyway because of context specialization, and so we could as well specialize to the max instead. It works by replacing all OsrValues in the graph with their values in the JavaScriptFrame. The idea is that using this trick we get better performance without doing the unsound backpropagation of types to OsrValues later. This is the first step towards fixing OSR for TurboFan. [turbofan] Perform OSR deconstruction early and remove type propagation. This way we don't have to deal with dead pre-OSR code in the graph and risk optimizing the wrong code, especially we don't make optimistic assumptions in the dead code that leaks into the OSR code (i.e. deopt guards are in dead code, but the types propagate to OSR code via the OsrValue type back propagation). BUG=v8:4273 LOG=n R=jarin@chromium.org Review URL: https://codereview.chromium.org/1226673005 Cr-Commit-Position: refs/heads/master@{#29486} |
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| benchmarks | ||
| build | ||
| include | ||
| infra | ||
| samples | ||
| src | ||
| test | ||
| testing | ||
| third_party/binutils | ||
| tools | ||
| .clang-format | ||
| .gitignore | ||
| .ycm_extra_conf.py | ||
| AUTHORS | ||
| BUILD.gn | ||
| ChangeLog | ||
| codereview.settings | ||
| DEPS | ||
| LICENSE | ||
| LICENSE.strongtalk | ||
| LICENSE.v8 | ||
| LICENSE.valgrind | ||
| Makefile | ||
| Makefile.android | ||
| Makefile.nacl | ||
| OWNERS | ||
| PRESUBMIT.py | ||
| README.md | ||
| 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://code.google.com/p/v8/
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/*