dsfb-gpu-debug-cuda

dsfb-gpu-debug-cuda is the CUDA evidence factory for DSFB-GPU. It exists to accelerate deterministic witness production while preserving the CPU-side court boundary: kernels may compute stage bytes and digests, but they do not admit episodes, assign final meaning, or bypass the bank authority in dsfb-gpu-debug-core.

The default build is deliberately ordinary-host friendly. Without the cuda feature, this crate compiles as a Rust shim and reports GpuError::CudaUnavailable from GPU entry points. With cuda, build.rs invokes nvcc and links the kernels under the workspace cuda/ directory.

What

This crate provides:

a small Rust FFI boundary around CUDA kernels;
GPU dispatch for deterministic evidence-production stages;
pinned-host and workspace abstractions used by throughput paths;
explicit GpuError reporting for unavailable CUDA, kernel failure, and invalid inputs;
non-CUDA stubs so CPU and Atlas crates can build without an NVIDIA toolkit.

Where

This crate lives at crates/dsfb-gpu/crates/dsfb-gpu-debug-cuda in the DSFB repository. It depends on dsfb-gpu-debug-core for semantic types, numeric contracts, and case-file construction. The CLI surface is dsfb-gpu-debug-demo. The Atlas court and registry crates are separate host-only surfaces: dsfb-gpu-atlas-corpus and dsfb-gpu-atlas-registry.

Why

DSFB-GPU uses CUDA as an acceleration mechanism, not as an oracle. The GPU is allowed to produce evidence bytes that can be checked against the CPU reference path. It is not allowed to decide what the evidence means. That split is the point: high-throughput evidence production remains subordinate to a replayable, inspectable, CPU-side admission court.

Mathematical Contract

The CUDA path mirrors the core arithmetic contract:

Q16.16 value = raw_i32 / 65536

Stage computations are integer and contract-driven. The load-bearing equivalence target is not floating-point closeness; it is byte identity for the stage material and digest chain under the declared mode. The device side may compute:

residual fields;
drift/slew signs;
detector motif bitsets;
consensus axes 1, 2, 3, 4, and 7;
candidate summaries and stage digests on throughput paths.

The bank-reserved axes stay host-side:

axis 5: entity locality
axis 6: topological adjacency
axis 8: semantic admissibility
axis 9: confuser suppression

This is the semantic non-bypass boundary. A GPU result can be evidence for a later court decision; it is not itself an admitted episode.

Code

Default build, no CUDA toolkit required:

cargo test -p dsfb-gpu-debug-cuda

CUDA build, requiring nvcc and a compatible NVIDIA environment:

cargo test -p dsfb-gpu-debug-cuda --features cuda

Minimal Rust surface:

use dsfb_gpu_debug_cuda::{pipeline_available, GpuError};

match pipeline_available() {
    Ok(()) => println!("CUDA feature enabled"),
    Err(GpuError::CudaUnavailable) => println!("built without CUDA"),
    Err(e) => println!("GPU error: {e:?}"),
}

Claim Boundary

This crate claims a bounded CUDA dispatch and FFI surface for deterministic evidence production. It does not claim peak bandwidth, optimal occupancy, optimal multi-GPU scaling, production CUDA performance, probabilistic inference, learned detector usefulness, or semantic authority.

Publish Order

Publish after dsfb-gpu-debug-core = 0.1.1 is visible on crates.io.

Citation

de Beer, R. (2026). DSFB-GPU: Clear-Box Pure Deterministic Inference CUDA Acceleration for Replayable Trace-Event Verdicts A Prior-Art Architecture for non-probabilistic, non-stochastic, non-weighted, GPU-Accelerated Residual Signs, Detector Motifs, Bank-Governed Fusion, and Byte-Exact Case Files Without Probabilistic Models (1.1). Zenodo. https://doi.org/10.5281/zenodo.20346478

IP Notice

DSFB-GPU Copyright 2026 Invariant Forge LLC This product includes software developed by Invariant Forge LLC. Apache 2.0 (reference implementation). Background IP: Invariant Forge LLC. Commercial deployment requires separate written license. Contact: licensing@invariantforge.net.

dsfb-gpu-debug-cuda 0.1.1