- Drop the K % 2 entry rejection and the per-K if/else load-width branch: the weight stream now anchors uint4 loads at each row's first 16-byte-aligned address, with scalar head/tail sweeps covering at most 14 remainder elements, so any positive K and any storage offset is correct
- Keep one pure-uint4 loop (no branching inside the loop) for the production case where every x row base is 16-byte aligned (K % 8 == 0 with allocator-aligned tensors) and a scalar-x pairing loop only for unaligned K, where per-row uint4 loads are not addressable; measured cost of scalar x everywhere was up to 2.5x on multi-row shapes (down M=4 28.4us vs 11.3us)
- Remove the now-obsolete k_aligned axis and K divisibility gate from the linear dispatch spec since the primitive no longer rejects any K
- Add test coverage for unaligned K (7, 12, 100, 1534) at M=1 and M=3
Benchmark: 8x L20 (sm_89, CUDA 12.8), L2-resident microbench, 300 iters; hot path unchanged within noise vs the pure-uint4 kernel (q M=2 5.8us, down M=4 11.3us, lm M=1 391us); full gate green
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