Here are some regressions that did not happen:It turned out that this regression was caused by moving the vector grow implementation for POD types into the header, which (naturally) resulted in excessive inlining. The current transition plan focuses on migrating only the source code. This regression was mitigated by One regression that I failed to prevent is a steady increase in max-rss. Thank you to everyone who has been involved and let’s keep working to make this migration a success.
Features →. We will be posting updates to this page as we get closer to the completion date. Questions? If you are a developer that needs to commit code, please use the git-llvm script for committing changes. One common source of performance issues in LLVM are There’s two ways to optimize this: Make the query cheaper, or make less calls to it. Requirements. In aggregate, this metric is also relatively stable, with the exception of the ThinLTO configuration.The binary size metrics are not really useful to judge compile time, but they do help to identify whether a change has impact on codegen. If you are a developer that needs to commit code, please use the page, if you want to track the current progress of the migration. Each LLVM release is a few percent slower than the last. A change of 1% is large. & workflows (pre-merge testing, pull-request, etc. Make LLVM fast again 10. One of the first questions people ask when they hear about the GitHub plans is: Will the project start using GitHub pull requests and issues? 16.04 LTS) or Debian, we recommend you to use the LLVM packages provided by LLVM itself. See Status. Instructions retired on the other hand is very stable, and allows us to confidently identify compile-time changes as small as 0.1%.Max-rss is the maximum resident set size, which is one possible measure of memory usage (a surprisingly hard concept to pin down). A change of 0.25% is already worth looking at. I have only started tracking this recently (see the I can’t say a 10% improvement is making LLVM fast again, we would need a 10x improvement for it to deserve that label. If you run into issues of any kind with GitHub you can file a bug in This entire process has been a large community effort. While that may be true, I don’t think it is a desirable trend: For the most part, optimization is already “good enough”, and additional optimizations have the unfortunate trend to trade large compile-time increases for very minor (and/or very rare) improvements to run-time performance.The larger problem is that LLVM simply does not track compile-time regressions. We will continue to use for issue tracking after the migration is complete. This means that there will be a single git repository with one top-level directory for each LLVM sub-project. To view additional settings for the extension, you can open VS Code settings and search for "github pull requests". Given how important issues are to our team and other GitHub projects, we wanted to add GitHub issues integration to VS Code. May 2020 The front page of the LLVM website proudly claims that:. And the answer to that for now is: no. In the following I’ll describe some of the improvements that I have implemented over the last few weeks.The largest one, and a complete outlier in terms of impact, was switching Attributes in LLVM come in two forms: Enum attributes, which are predefined (e.g. We have not ruled out using pull requests and issues at some point in the future, but these are discussions we still need to have as a community.The most important takeaway from this post, though, is that if you consume the LLVM source code in any way, you need to take action now to migrate your workflows. Ctrl-R, write “cmd”, click enter, then run "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Auxiliary\Build\vcvarsall.bat" x64 This is contrary to Clang, which only emits alignment for exception cases. If you manage any continuous integration or other systems that need read-only access to the LLVM source code, you should begin pulling from the official GitHub repository instead of SVN or the current sub-project mirrors. It is a good opportunity to brainstorm on … But it’s a start…One key problem here is the choice of benchmarks. We have made great progress over the last nine months and are on track to complete the migration on October 21, 2019.As part of the migration to GitHub we are maintaining the ‘monorepo’ layout which currently exists in SVN. Clang is an “LLVM native” C/C++/Objective-C compiler, which aims to deliver amazingly fast compiles […]I’m not sure whether this has been true in the past, but it certainly isn’t true now. Below are the financial and technical arguments as to why we are proposing such a move and how people (and validation infrastructure) will continue to work with a Git-based LLVM. Clang is an “LLVM native” C/C++/Objective-C …
A compile-time regression that results in a code-size change is at least doing Different benchmarks have different variance. This could be mitigated by running benchmarks many times, but I don’t have the compute capacity to do that. VULFI performs fault injection at LLVM's intermediate representation (IR) level. If you'd like to write a post, please get in touch with After several years of discussion and planning, the LLVM project is getting ready to complete the migration of its source code from SVN to GitHub! ): "We're almost on GitHub!