When cp_placement=pe packs multiple CP ranks intra-cube, the PE-level
layout now:
1. Colors each PE's background by its CP rank (8-color palette wraps
for cp > 8). Cp_placement=cube keeps the historical light-blue
styling (only one CP rank per cube tile).
2. Adds "TP=N | CP=M" to the per-PE header so users can read the
(cp_rank, tp_rank) pair without inferring from position.
3. Fixes a head-assignment bug: _q_heads_for_pe / _kv_heads_for_pe /
_per_pe_bytes used to be called with the raw PE-in-group index,
which treated every PE as a distinct TP rank. Under cp_placement=pe
this gave wrong Q/KV head lists for PEs beyond the first TP group
(PE 2..7 with tp=2, cp=4 would ask for head slots 32..127 in a
32-head model). Now called with tp_rank = pe_id % tp, so all CP
ranks in the cube share the correct head split.
Verified via a headless matplotlib smoke test with CP=4/TP=2 on Qwen 3
8B: 8 PE patches + 1 cube patch → 5 distinct facecolors (cube + 4 CP
ranks), no errors.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
mukesh
ed28eea156