Per spec §8.2 (3.1) post-amendment-2 fix: ALPHA_SPLIT slot initialized
DIRECTLY to 0.5 in trainer constructor. Formula α = grad_norm_q /
(grad_norm_q + grad_norm_d + ε) takes over only after BOTH grad-norm
EMAs accumulate ≥ N_WARM=100 non-zero observations.
Two kernels in r_quality_discipline_split_kernel.cu (single cubin per
established 1:1-source-to-cubin pattern with multiple kernels):
- r_quality_discipline_split_kernel: per-step composition + warm count
- alpha_split_producer_kernel: per-step ALPHA_SPLIT update from grad ratio
(gated on warm count to prevent premature formula activation)
3 ISV slots (417 ALPHA_SPLIT, 418 GRAD_NORM_QUALITY, 419 GRAD_NORM_DISCIPLINE)
+ sp15_alpha_warm_count [1] mapped-pinned scratch buffer on the trainer
struct. 4 fold-reset registry entries + dispatch arms (one for the
non-ISV warm-count buffer mirrors the sp11_novelty_hash host_slice_mut
pattern).
Per established Phase precedent: kernels + launchers land first; consumer
migration (per-step launches in training_loop.rs reward composition site)
deferred to a follow-up commit per feedback_no_partial_refactor.
Anchor tests: 2.4 cost_sensitivity + 2.6 regime_silences (Phase 2B
contracts) — green via Phase 3.4 regret + 3.2 cost; this commit lands
the split structure they depend on.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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