4465c321a4
Straight-line bytecode with exactly one "next" bytecode (i.e. everything that can't affect control flow) will always have the same "out" liveness as the next bytecode's "in" liveness. For those cases, we can save a bit of time and memory by aliasing the pointers between the bytecode's out liveness and the next bytecode's in liveness, and skipping copying between them. This is done by specializing the current liveness update on whether this is the first pass (which will allocate and initialize the liveness bitvectors) or an update pass (which will revisit loops to collect liveness crossing over the back-edge, and propagate this liveness through the loop bodies). On the first pass, we can delay allocation of the out liveness until we know it needs to be union of multiple in livenesses, and on the update pass we can skip it if it is an alias. As a drive-by, tweak BitVector::CopyFrom to require copying from a vector with the same size (same as Union or Intersect), and move the only different sized vector use (in Resize) to be inline. Change-Id: Iad1b2e1b927a37ad925ef68e2a224152aaa2ba18 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3350452 Auto-Submit: Leszek Swirski <leszeks@chromium.org> Reviewed-by: Maya Lekova <mslekova@chromium.org> Commit-Queue: Maya Lekova <mslekova@chromium.org> Cr-Commit-Position: refs/heads/main@{#78425} |
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| CODE_OF_CONDUCT.md | ||
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| LICENSE.v8 | ||
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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://v8.dev/docs
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 at v8.dev/docs/contribute.