# `Nx.Vulkan.Compiler`
[🔗](https://github.com/borodark/nx_vulkan/blob/main/lib/nx_vulkan/compiler.ex#L1)

Path A.2 v2 (partial) — `Nx.Defn.Compiler` that auto-detects fusable
elementwise chains and dispatches `Nx.Vulkan.fused_chain/3` instead
of N separate shader calls.

## What it does today

At `__jit__` time, calls `fun.(vars)` once to materialize the IR.
Walks the result looking for a chain of supported elementwise ops
whose only inputs are the two function arguments. If matched: skip
Evaluator entirely and dispatch a single `fused_chain` call.

## What it doesn't do yet

  * **Multi-output**: only single-output chains. A defn that returns
    a tuple falls through to `Nx.Defn.Evaluator`.
  * **Branched chains**: only linear chains. A node that's used
    twice falls through.
  * **More than 2 vars**: 2-arg functions only (matches the shader's
    two-input layout). Wider arities fall through.
  * **Chains > 8 ops**: shader limit; longer chains fall through.
  * **Non-elementwise ops**: any reduce/reshape/dot in the chain
    falls through.

All fall-through cases delegate to `Nx.Defn.Evaluator` so behavior
stays correct — the worst case is "no fusion, same speed as before."

## Configuration

    config :exmc, :compiler, :vulkan

`Exmc.JIT` then routes to `Nx.Vulkan.jit/2`, which uses this compiler
when available (defaults to `Nx.Defn.Evaluator` if unsupported).

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*Consult [api-reference.md](api-reference.md) for complete listing*