10 engineers on Hacker News describe using LLVM first-hand: 3 endorse it, 3 regret it, 1 are mixed.
“Practically all the bottlenecks we run into with Rust compilation have to do with the LLVM passes.”
regret · production · lsuresh · 2025-06-12 · source ↗ · wrong label?“We use that in Zig but our time spent compiling is still 77% waiting for LLVM to emit an object file.”
regret · production · AndyKelley · 2022-12-09 · source ↗ · wrong label?“WebKit used LLVM as its optimizing JIT compiler for a couple years, and it was fine.”
endorse · production · 2 yr · pizlonator · 2017-06-22 · source ↗ · wrong label?“I can't even get through getting Clang, LLVM, and Emscripten built from source as it is, it's such a house-of-cards”
regret · personal · moron4hire · 2015-06-17 · source ↗ · wrong label?“LLVM was completely indispensable for the language to get off the ground, and I don't regret using it for a minute.”
endorse · production · pcwalton · 2015-06-05 · source ↗ · wrong label?“We use LLVM on Windows in Rust. It works OK in general, but the biggest issue is that C++ zero-cost exceptions don't work.”
mixed · production · pcwalton · 2012-12-21 · source ↗ · wrong label?“I yesterday compiled latest llvm/clang myself (surprisingly easy, by the way) to test how it would help our build times.”
endorse · production · dirtyaura · 2010-10-07 · source ↗ · wrong label?“we build llvm right away as the system compiler used to build the whole tree instead of gcc.”
neutral · production · lrvick · 2026-10-05 · source ↗ · wrong label?“We use LLVM/clang and so does Apple.”
neutral · production · gcasa · 2021-12-14 · source ↗ · wrong label?“we're working on the LLVM bitcode so we do have to compile the code”
neutral · personal · Choc13 · 2021-09-09 · source ↗ · wrong label?