LLVM for Grad Students

This is (in my humble opinion) a fantastic introduction, and relevant to a much wider audience than the title implies. If you want to keep up to date with LLVM developments, you might also be interested in my LLVM Weekly newsletter (<a href="http:&#x2F;&#x2F;llvmweekly.org&#x2F;" rel="nofollow">http:&#x2F;&#x2F;llvmweekly.org&#x2F;</a>). I try to highlight interesting commits, mailing list discussions, and blog posts (tips and submissions always welcome!).

Adrian might have mentioned an important drawback of using LLVM: active effort is required to keep up with it. Many an LLVM-based research project has gotten stuck on 2.9 or 3.2 at which point it starts becoming less and less relevant.<p>It&#x27;s not that big of a deal, but active effort is required. The amount of effort depends on how many and which APIs your project uses; for a small&#x2F;medium project perhaps a couple of hours every couple of weeks.

For the past year, i had two projects which required me to work with LLVM. Because of the scarcity of articles&#x2F;documentation, i found it really hard to get into it. The API Docs and a few articles by Eli Bendersky(thank you so much!!! ) was all i found useful.<p>But once i got past the basic hurdles, the llvm project code was so well written, i felt a certain pleasure working with it.

A nice introduction, I&#x27;m currently working on a compiler which uses LLVM for code generation... it was very difficult to get into at first. Especially since I was using C (now Go), so I would have to work through 2&#x2F;3 layers of language and documentation. (Was just C to C++, now it&#x27;s Go, to C, to C++).<p>If you&#x27;re interested in learning more about LLVM, there are some good open source projects that use it. If you aren&#x27;t using C++, people have also ported the kaleidoscope tutorial project to Haskell, Rust, C, etc... Additionally, a lot of bigger compilers like Rust, and Clang use it - Swift also uses LLVM, and should be open source soon?

This is a great intro into the subject.<p>We use LLVM to at MapD (<a href="http:&#x2F;&#x2F;mapd.com" rel="nofollow">http:&#x2F;&#x2F;mapd.com</a>) to compile SQL queries to CPU and GPU machine code - it has given us a major boost over an interpreter based approach. For more see here - <a href="http:&#x2F;&#x2F;devblogs.nvidia.com&#x2F;parallelforall&#x2F;mapd-massive-throughput-database-queries-llvm-gpus&#x2F;" rel="nofollow">http:&#x2F;&#x2F;devblogs.nvidia.com&#x2F;parallelforall&#x2F;mapd-massive-throu...</a>. If you have a background in LLVM or compilers in general and are interested in tackling problems like this please reach out at jobs@mapd.com.

If you&#x27;re really interested in this stuff and looking for an opportunity, we&#x27;re looking for talented LLVM developers for our Austin location.<p><a href="http:&#x2F;&#x2F;www.bitfusion.io&#x2F;jobs.php" rel="nofollow">http:&#x2F;&#x2F;www.bitfusion.io&#x2F;jobs.php</a><p>Mazhar Memon, Bitfusion.io

&gt; LLVM is nicely written: its architecture is way more modular than other compilers. Part of the reason for this niceness comes from its original implementor, who is one of us.<p>What on earth is that supposd to mean?

This is indeed a great intro article.<p>For those interested in seeing examples of LLVM hacking in action, I would recommend reading the source for Halide – <a href="https:&#x2F;&#x2F;github.com&#x2F;halide&#x2F;Halide" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;halide&#x2F;Halide</a> – which is an image-processing DSL implemented in C++ and piggybacking on LLVM. I myself learned a lot about LLVM this way.

Not just for grad students! I wish I would have seen this a week ago. LLVM passes are surprisingly readable too.

This isn&#x27;t germane to the main topic but this paper they cite about using a compiler pass to verify OS security (&quot;Protecting Applications from Hostile Operating Systems&quot;) is pretty darn interesting: <a href="http:&#x2F;&#x2F;sva.cs.illinois.edu&#x2F;pubs&#x2F;VirtualGhost-ASPLOS-2014.pdf" rel="nofollow">http:&#x2F;&#x2F;sva.cs.illinois.edu&#x2F;pubs&#x2F;VirtualGhost-ASPLOS-2014.pdf</a>

How difficult would it be to add a garbage collector to a language that you have written a compiler for?

Long time ago I read a post by Mathew Flatt about LLVM and gcc and how mini optimization and selling points were important not able to find the post, but it was a interesting read.

&quot;backed by the largest company on Earth.&quot;<p>Wal-Mart?

This would have been great during my grad school compilers class.