test-fusion runs every dummy model generated by test-llama-archs on a
single backend (single-threaded encoding, n_cb == 0) with fusion enabled
and disabled, and for each mode (prefill / decode) reports the per-fusion
counters and the NMSE between the fused and unfused logits, plus the NMSE
against a CPU reference.
A fusion pattern that silently stops matching (or fires when it should
not) is caught as a regression by comparing the counters against a
committed per-backend TSV baseline:
- --record writes the golden baseline, --check (default) validates it
- the unfused run doubles as a control: its counters must be all-zero
- NMSE is skipped when it is NaN or the arch is already broken on the
device (e.g. plamo2 on Metal), so the count check is the hard gate
- baseline counts depend only on graph structure, not weights (verified
stable across weight seeds)
- the fusion stats API is resolved through the ad-hoc get_proc_address
mechanism with generic names; a backend that does not export it makes
the test fail with an error
The committed MTL0.tsv baseline covers 110 dummy archs (298 rows).
Assisted-by: pi:llama.cpp/DeepSeek-V4-Flash-0731
Georgi Gerganov
c9c0ceca0a