metaltest

Documentation

Overview

metaltest — smallest pure-Go Metal compute proof: no cgo, no shell-out, drive a kernel + mutate a buffer through tmc/apple/metal (purego objc_msgSend). Doubles a buffer on the GPU and reads it back. The point isn't the math — it's that Go owns the Metal command path directly.

Three things this proves, in order:

1. correctness — compile MSL, dispatch, mutate a buffer, read it back;
2. throughput — serial commit+wait (GPU held-but-idle) vs batched (GPU fed);
3. encode-bypass — re-encoding a fixed command sequence every step (MLX's ~68 ms/step host cost) vs recording it ONCE into an Indirect Command Buffer and replaying — the decode/diffusion lever, in pure Go;
4. kernel reach — our real 150 MB mlx.metallib loads + enumerates through the same no-cgo path: the foundation for keeping the kernels and dropping mlx-c.