abi-superpower-wdbx-compute

name	abi-superpower-wdbx-compute
description	WDBX compute backend superpower. CPU/GPU/NPU/TPU backend selector with deterministic CPU SIMD fallback. ANE detection, remote TPU dispatch.
superpower	{"command":"execute","parameters":[{"name":"action","type":"string","enum":["info","select","backend","remote"],"description":"Compute action"},{"name":"backend","type":"string","enum":["cpu","gpu","npu","tpu","auto"],"description":"Target backend"},{"name":"endpoint","type":"string","description":"Remote compute endpoint (TPU)"}]}

ABI Superpower: WDBX Compute

Exposes the WDBX compute backend selector as a superpower. Dynamic backend selection across CPU (scalar/AVX2/AVX-512/NEON), GPU (CUDA/Metal/Vulkan), NPU (ANE detection), and TPU (remote dispatch transport). Always degrades to deterministic CPU SIMD path — native accelerator kernels are NOT linked.

Actions

info

Show compute backend matrix (availability + dispatch status):

/abi-superpower-wdbx-compute info

Output includes:

• CPU: scalar, AVX2, AVX-512, NEON (host-detected via std.simd.suggestVectorLength)
• GPU: CUDA, Metal, Vulkan (capability reporting only — no native kernels linked)
• NPU: ANE hardware presence (truthful detection, no execution)
• TPU: Report-only endpoint metadata (ABI_REMOTE_COMPUTE_ENDPOINT) plus a separately tested reference TCP transport

select

Select and initialize a backend:

/abi-superpower-wdbx-compute select --backend auto

Options: cpu, gpu, npu, tpu, auto (prefers Metal on macOS, else CPU SIMD)

backend

Get details for a specific backend:

/abi-superpower-wdbx-compute backend --backend metal

remote

Show or plan remote TPU reference transport configuration:

/abi-superpower-wdbx-compute remote --endpoint http://tpu-server:8080

Backend Matrix (Honest)

Backend	Available	Dispatches	Reality
CPU SIMD	Always	✅ Always	Vectorized @Vector with host-matched width
Metal (macOS)	On macOS	⚠️ Only if g_metal_context.init() succeeds	Pure-Zig ObjC FFI, runtime MSL compile
CUDA	Never	❌ No	Capability reported, not linked
Vulkan	Never	❌ No	Needs loader/ICD + SPIR-V; not linked
ANE (NPU)	On Apple Silicon	❌ No	compute.aneHardwarePresent() truthfully detects; needs CoreML/ObjC
TPU (remote)	Reference only	❌ Not production-wired	remote_compute.zig has a loopback-tested DOT transport; the environment endpoint is report-only

Implementation

Component	Source	Role
Backend Selector	src/features/wdbx/compute.zig	Dynamic CPU/GPU/NPU/TPU selection
CPU SIMD	src/features/wdbx/hnsw_distance.zig	@Vector cosine, std.simd.suggestVectorLength
GPU	src/features/gpu/vector_ops.zig + compute_api.zig	cosineSimilarity() via Metal, CPU fallback
NPU Detection	src/features/wdbx/compute.zig	aneHardwarePresent() — truthful
Remote TPU	src/features/wdbx/remote_compute.zig	Reference DOT transport; no production caller wires ABI_REMOTE_COMPUTE_ENDPOINT
Parity Test	src/features/gpu/compute_api.zig	CPU/GPU dot-product parity

CLI Access

abi wdbx compute info

Feature Gates

Requires feat-wdbx=true and feat-gpu=true (both default). When disabled, returns FeatureDisabled.

Claim Boundary

Per docs/spec/wdbx-north-star.mdx §3.3 and docs/contracts/external-claims-audit.mdx:

• ✅ Dynamic backend selector across CPU/GPU/NPU/TPU
• ✅ CPU SIMD parity test against GPU path
• ✅ ANE hardware detection (truthful)
• ✅ Remote TPU dispatch transport (operator's endpoint)
• ❌ Native CUDA/Metal/Vulkan/ANE kernel execution NOT linked
• ❌ No bundled accelerator — TPU points at operator's own service
• ❌ ANE execution requires CoreML/ObjC (not pure Zig) — disclosed non-goal