We’re launching Lyria 3.5 in Google Flow Music, with advances across musicality, lyrics, vocals, and creative control
deepmind.google·6d ago
AI Engineering
Lobsters·28d ago·5 min read
Building a Clang Backend and Porting Doom to my Custom Bytecode VM
TL;DR
A custom bytecode virtual machine (UVM) was enhanced by exploring the possibility of integrating a Clang backend. The goal was to compile real software, specifically aiming to run Doom.
✦ Why It Matters
Consider developing a custom backend for LLVM IR to support unique virtual machine architectures.
Key Takeaways
- Explore LLVM IR generation for custom VM architectures.
- Investigate lightweight Rust crates for parsing LLVM IR.
- Consider the implications of compiler design on VM compatibility.
- Utilize open-source projects like PureDOOM for practical testing.
Full Summary
In early 2023, a minimalistic stack-based bytecode virtual machine called UVM was developed, featuring floating-point support and multi-threading capabilities. After a hiatus, the creator sought to enhance UVM by integrating a Clang backend to enable the compilation of real software, particularly the game Doom.
Research indicated that while Clang is optimized for physical CPUs with fixed registers, it can generate textual LLVM Intermediate Representation (IR). The creator compiled PureDOOM using Clang and attempted to parse the resulting LLVM IR, but faced challenges with available Rust crates, which either had large dependencies or were outdated.
The textual LLVM IR format is not stable over time, complicating future compatibility. This exploration highlights the complexities of adapting existing compilers for custom virtual machines and the potential for innovative software development.