WS1 C3 (#269) closeout evidence¶

Parent: #266 · Depends on: #267 / #268 · Scope: shared forward harness only

Acceptance map¶

#269 criterion	Evidence
Accuracy and invariance separate	`ForwardInvarianceReport.accuracy_reports` and `invariance_reports`
Batch/chunk bitwise after logical unpadding	C1 `forward_invariance` resolver plus exact C2 logical-key validation
C2 transforms	`build_config_matrix`: fixed 2×2 matrix, permutation, packing, left/right padding
Diagnostics	tensor name, config pair, max/mean absolute error, max relative error
Backend provenance	profile, requested/actual backend, candidate/kernel id, device, CC, dtype, seed, fallback reason
Silent/cross-profile fallback	missing or mismatched provenance fails; CLI rejects candidate/profile mismatch
Selected-logprob smoke	C1 `max_abs_dlogp`, `approx_kl0`, and `clipfrac0` verdict
CUDA and Triton same schema	one API/CLI/report schema; both profile contracts are parametrically tested
No private thresholds	all tensor and aggregate thresholds resolve through the C1 contract

CPU-safe contract regression:

python -m pytest -q \
  tests/test_tolerance_contract.py \
  tests/test_ws1_workload.py \
  tests/test_forward_invariance.py \
  tests/test_op_checks.py

Required-profile runtime examples (must run on CUDA hardware and must not be skipped):

python scripts/check_forward_invariance.py \
  --op logp --candidate cuda \
  --backend-profile cuda_bf16 --json

python scripts/check_forward_invariance.py \
  --op batch_invariant_logp --candidate triton \
  --backend-profile triton_cuda_bf16 --json

The CLI exits red when CUDA is unavailable, a candidate is absent, the C2 node is missing_required, the compute capability cannot run a declared SM90 candidate, provenance does not match the profile, or any accuracy/invariance/logprob verdict fails.

Runtime verification¶

Verified on NVIDIA GeForce RTX 3060 Laptop GPU (sm86) with PyTorch 2.8.0+cu128:

Gate	Result
Full pytest suite	`1524 passed, 121 skipped`
Full pre-commit	trailing whitespace, EOF, YAML, large-file, black, isort, flake8 passed
`cuda_bf16` / generic CUDA logp C3 matrix	passed; all invariance max-abs errors `0.0`
`triton_cuda_bf16` / Triton batch-invariant-logp C3 matrix	passed; all invariance max-abs errors `0.0`
CUDA operator accuracy check	passed, max absolute error `0.0287590`
Triton operator accuracy check	passed, max absolute error `9.536743e-07`

The CUDA profile uses the manifest-declared generic CUDA logp candidate on SM86. No SM90 candidate or fallback path is claimed on this device.

Parent boundary¶

This closes only C3. It supplies the report and canonicalization contract that C10 must reuse. It does not claim the full-model, backward, KV-cache, or CI EXIT requirements of #266.