blog: add LLVM IR export post

docs/blog/posts/blog/2026-10-21-llvm-export.md

@@ -0,0 +1,49 @@
+---
+date: 2026-10-21
+title: Exporting LLVM IR from xDSL
+tags:
+  - technical
+---
+
+xDSL is a compiler toolkit optimised for accessibility and low iteration time
+during experimentation and development. Since the beginning, users have been
+able to design their own abstractions and rewrites on them, but getting an
+executable required going via `mlir-translate`, still requiring users to
+download and install MLIR. We recently bridged this gap, allowing users to emit
+LLVM directly in xDSL. We leverage
+[llvmlite](https://github.com/numba/llvmlite), a package developed by the
+[Numba](https://numba.pydata.org/) team, to convert xDSL modules in the llvm
+dialect to llvmlite modules. Users of the Python API can do this with the
+`convert_module` function, and the llvm IR can be printed via the command line
+with `--target llvm`. This functionality allows users to more easily produce
+LLVM IR files when prototyping, and unlocks JIT functionality which will
+describe in a future post.
+
+Please find a detailed user guide on the [documentation
+page](https://docs.xdsl.dev/reference/backend/llvm/convert/).
+
+We did a quick comparison of disk usage of xDSL + llvmlite and a full MLIR
+installation using Homebrew on MacOS ARM64.
+
+```bash
+# xdsl + llvmlite
+uv venv /tmp/lite
+uv pip install --python /tmp/lite/bin/python "xdsl[llvm]"
+du -sh /tmp/lite                                     # 127M - total venv
+du -sh /tmp/lite/lib/python*/site-packages/xdsl      # 5.5M - xdsl
+du -sh /tmp/lite/lib/python*/site-packages/llvmlite  # 112M - llvmlite
+
+# mlir-translate
+brew install llvm
+ls -lh /opt/homebrew/opt/llvm/bin/mlir-translate  # 34K  - binary
+du -sh /opt/homebrew/opt/llvm/lib/libMLIR.dylib   # 149M - dependency
+du -sh /opt/homebrew/opt/llvm/lib/libLLVM.dylib   # 156M - dependency
+du -sh /opt/homebrew/Cellar/llvm                  # 1.7G - full keg
+```
+
+The actual `mlir-translate` binary is just 34 KB but it’s linked against two
+very large dylibs at around 305 MB that aren’t split by Homebrew, forcing you to
+download the entire ~2 GB keg. The optional llvmlite dependency with xDSL on the
+other hand is around 13x smaller and can be omitted from your build image.
+
+We hope you find this functionality useful. Happy hacking!