Supersede the old greenlet-primitive/load_async/single-kernel DDD. Align to
ADR-0060's composite-hybrid + hierarchical CUBE-Group SP with two kernels:
decode+SP (head-replicated, contiguous C×P static shard, 2-level
reduce-to-root) and prefill+SP (1 Q head/CUBE, Ring KV, no reduce). Updated
file plan (lazy tl.load, scratch_scope, broadcast-opt; evolve
_attention_mesh_mlo_2d/_kv; DPPolicy.cube_start; llama70b_4sip.yaml),
placement (contiguous shared KV), phase plan (P1..P8), verification, perf
model, risks, glossary. Defers design rationale to ADR-0060 (now
authoritative); open items point to ADR-0060 §B. ADR-0064 cost model noted.
Docs only.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Verified against sim_engine data path (memory_store, data_executor):
- GQA reuse does NOT need a broadcast op. The baseline's h_q==h_kv limit
is its head-packing reshape hack, not a missing primitive. Correct fix:
per-KV-head loop with G folded into matmul M dim (byte-conserving
reshape) — runs today, timing correct (m=G*T_q), data mode runs.
- ADR-0061 broadcast demoted from 'the blocker' to optional convenience.
- Surfaced tl.trans = reshape-not-transpose (memory_store reshapes;
data_executor np.matmul on reshaped operands) -> numeric parity is
bounded; verification is structural/timing/determinism-first (matches
SPEC perf-model purpose). Optional tl.transpose deferred.
- Reordered DDD phase plan (P1 GQA needs no new feature; P3 scratch_scope
is the key scale feature); added open decisions 10.10 (transpose) and
10.11 (GQA-via-M-fold finding).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
ywkang