MLIR Dialects & Code Generation

How Nyx utilizes Multi-Level Intermediate Representation (MLIR) for high-level domain optimizations, async concurrency lowering, and LLVM machine code generation.

1. Why MLIR?

Traditional compilers lower directly from AST to low-level LLVM IR or C, losing high-level language semantics like regions, async tasks, pattern matching, and tensor operations. Nyx leverages MLIR to perform optimizations at multiple levels of abstraction before emitting final machine instructions.

Nyx Source (.nyx)
       ↓
    AST & Semantic Analysis
       ↓
   Nyx High-Level Dialect (`nyx.*`)
       ↓ [Region Lifetime Optimization & Async Lowering]
   MLIR Standard Dialects (`async`, `memref`, `scf`, `arith`)
       ↓ [LLVM Lowering Pass]
   LLVM IR Dialect (`llvm.*`)
       ↓
   Target Machine Code (.exe, .so, .dylib, .wasm)

2. The Nyx Custom Dialect (`nyx.*`)

The nyx MLIR dialect models Nyx's core language constructs:

Core Operations Table:

Operation	Syntax	Description
`nyx.func`	`nyx.func @name(%arg: !nyx.type) -> !nyx.ret`	Function declaration with region ownership parameters
`nyx.region.alloc`	`%ptr = nyx.region.alloc(%reg, !nyx.struct)`	Bump-pointer allocation within a designated memory region
`nyx.async.spawn`	`%task = nyx.async.spawn { ... }`	Schedules work onto the work-stealing cooperative thread pool
`nyx.async.await`	`%val = nyx.async.await %task : !nyx.future`	Asynchronously suspends current task until future completion
`nyx.match`	`nyx.match %enum [case0: ..., case1: ...]`	Exhaustive pattern matching jump table
`nyx.tensor.gemm`	`%res = nyx.tensor.gemm %A, %B : tensor<f32>`	SIMD/AVX-512 hardware-accelerated matrix multiplication

3. Sample MLIR Output for a Region-Allocated Function

module {
  nyx.func @compute_geospatial_hash(%lat: f64, %lon: f64) -> !nyx.string {
    %reg = nyx.region.create() : !nyx.region
    
    // Allocate temporary vector in local region
    %pt = nyx.struct.create(%lat, %lon) : !nyx.point
    %hash = nyx.call @rt_geohash_encode(%pt, %reg) : (!nyx.point, !nyx.region) -> !nyx.string
    
    // Transfer hash result ownership to caller, release local region
    nyx.region.destroy %reg : !nyx.region
    nyx.return %hash : !nyx.string
  }
}

4. Lowering Pipeline & Passes

nyx-region-inference-pass: Analyzes variable lifetimes and inserts deterministic nyx.region.destroy instructions.
nyx-async-lowering-pass: Lowers nyx.async.spawn into state-machine coroutines conforming to MLIR Async runtime.
nyx-to-llvm-pass: Maps high-level types to native LLVM structures with zero abstraction penalties.

← Region Inference Runtime Engine →