I'm Gideon. 18. Three years of writing C++ from the ground up — ray tracers, video codecs, and now a compiler. No frameworks. No LLVM. Just me, the hardware manuals, and a lot of wrong turns.
This post starts a series where I document the build in real time. I'm currently in the parser stage. By the end, I want a compiler that emits x86-64 and SPIR-V from a C++-like language, with SIMD vectorization and security-hardened codegen baked in.
What I'm Actually Building
Not a programming language. A compiler backend toolkit — the part that turns intermediate representation into fast machine code across multiple targets.
The pipeline:
Source → Parser → AST → SSMOL (HIR) → MREL (LIR) → x86-64 / SPIR-V / ARM64 / RISC-V / WASM
MREL is my target-agnostic low-level IR. It knows about virtual registers, stack slots, and machine operations — but not physical register names. The backend handles that per-target.
Why Not Just Use LLVM?
LLVM is 4 million lines of code. It solves everyone's problem and no one's perfectly. I need:
- Fine-grained control over SIMD width selection per target
- Constant-time crypto primitive emission with secret register annotations
- Security obfuscation passes (control flow flattening, opaque predicates)
- A codebase I fully understand and can license
Building from scratch is slower. But I own every decision.
Where I Am Right Now
Parser stage. Hand-written recursive descent. C++-like syntax with:
- Functions, structs, basic types
- Ownership semantics (borrowed from my Rust phase, simplified)
- Explicit SIMD types (
v128,v256,v512)
The parser emits an AST that gets lowered to SSMOL — my high-level IR that knows about types, ownership, and semantics.
What's Next
- SSMOL → MREL lowering (types to sizes, structs to offsets, control flow to basic blocks)
- MREL → x86-64 backend (register allocation, instruction selection, ELF emission)
- One working program: compile, link, run
main()that returns 42
Then SPIR-V compute kernels. Then the rest.
What I'll Write About
Each stage, when I hit it. The problems that took me three days to solve. The specs I wrote to keep myself honest. The wrong assumptions that cost me a week.
Not polished tutorials. Build logs from someone actually building.
Follow This Series If
- You work in systems, compilers, or graphics
- You're curious what "building from scratch" actually looks like
- You want to see if I crash or ship
My Specs (For the Curious)
I write technical specifications to keep the design coherent across months of work. The MREL backend spec covers x86-64, ARM64, RISC-V, SPIR-V, and WebAssembly with calling conventions, opcode tables, and security passes. Link in bio.
GitHub: (https://github.com/ayndlr)
Closing
This is post 1 of however many it takes. Next post: parsing expressions with operator precedence and why I gave up on Pratt parsing.
Follow for the crash or the ship. Either way, it's real.