Optimizing Rust code is really fun. When something is run millions or billions of times, nanoseconds and individual CPU instructions matter. The best way to do this isn't to write assembly -- it's to put yourself in LLVM's place, understand the kinds of optimizations it wants to perform, and understand what is blocking them. A common case I run into is "LLVM wants to represent (a, b) as (a + b, b), but it's part of a struct so the change has to be performed every time the struct is loaded." LLVM can't change the struct, obviously...

Has anybody tried teaching LLVM data structure optimization? Along the lines of: "Here's a struct with a completely undefined layout and representation, and every single function that can access the struct. Based on the uses, try to memoize common computations by adding new fields, and try removing unused fields." Getting there requires locating all uses of the fields of a struct, but this is possible (at least, quite often) in Rust.

#programming #optimization #llvm

Optimizing Rust code is really fun. When something is run millions or billions of times, nanoseconds and individual CPU instructions matter. The best way to do this isn't to write assembly -- it's to put yourself in LLVM's place, understand the kinds of optimizations it wants to perform, and understand what is blocking them. A common case I run into is "LLVM wants to represent (a, b) as (a + b, b), but it's part of a struct so the change has to be performed every time the struct is loaded." LLVM can't change the struct, obviously...

Has anybody tried teaching LLVM data structure optimization? Along the lines of: "Here's a struct with a completely undefined layout and representation, and every single function that can access the struct. Based on the uses, try to memoize common computations by adding new fields, and try removing unused fields." Getting there requires locating all uses of the fields of a struct, but this is possible (at least, quite often) in Rust.

#programming #optimization #llvm

like come on

# Indicates whether the LLVM testsuite is enabled in the build or not. Does
# not execute the tests as part of the build as part of x.py build et al,
# just makes it possible to do `ninja check-llvm` in the staged LLVM build
# directory when doing LLVM development as part of Rust development.
#llvm.tests = false

did no one question "hey why do we need to set these things here in the first place if it doesn't matter and we can just delegate to llvm's existing build system?"? idk

👀 Wow, hold your horses! Zig builds are apparently breaking the sound barrier now. 🚀 After years of intense labor and a bit of #LLVM yeeting, they've achieved the unimaginable: a #compiler that might finally compile something before your coffee goes cold. ☕️🔥
https://mitchellh.com/writing/zig-builds-getting-faster #ZigLang #SoundBarrier #FastCompilation #HackerNews #ngated

This is not helping me in the market but what I love doing the most is computer language engineering. I'm learning how to write an #LSP right now to support my born language in neovim. I also discovered #LLVM recently. It lets you compile to any target from a generic ASM. It made me realize something. The first languages where all compiled. Then, we got the interpreted languages. But recently, the new languages are all compiled again! Think of #rust, #go, #zig, #elixir. I wonder if it's because we perfected the tooling in a way that maintaining a compiled language is not that hard anymore. Go is a weird one. It has a garbage collector. Yeah! A compiled language with a garbage collector. It means that there is a process that is embedded in the executable to just do garbage collection. We might now have a real reason anymore to interpret.

My team at Apple is currently hiring for a role that focuses on compiler tools and infrastructure. If you’re interested in this opportunity, please take a look at the job posting here: https://jobs.apple.com/en-us/details/200613714/compiler-tools-engineer?team=SFTWR #llvm #swiftlang

My team at Apple is currently hiring for a role that focuses on compiler tools and infrastructure. If you’re interested in this opportunity, please take a look at the job posting here: https://jobs.apple.com/en-us/details/200613714/compiler-tools-engineer?team=SFTWR #llvm #swiftlang

TPDE Compiler Back-End Framework

https://arxiv.org/abs/2505.22610

"TPDE-LLVM: a standalone back-end for LLVM-IR, which compiles 10--20x faster than LLVM -O0 with similar code quality, usable as library (e.g., for JIT), as tool (tpde-llc), and integrated in Clang/Flang (with a patch)."

Holy cow! 🤯

Open Source on GitHub:
https://github.com/tpde2/tpde

#Performance#Compiler#LLVM