← Lab
fusedgemv
confirmedC++ · NEON / Apple M4Systems & data structuresJuly 6, 2026
the question
Does fusing dequant into the matmul beat dequant-then-matmul?
what came out
Yes -- ~2.3x faster (5.1->11.7 GFLOP/s), bit-for-bit identical to the unfused path, consistent across shapes. Fusing avoids streaming the dequantized weights out to memory and back. The capstone of the kernel series; all three pre-registered predictions held.
method & receipts
- Result: confirmed
- Pre-registered — the prediction was written down and committed before the run.
- Reproducible — one script re-runs the whole thing from scratch.
- Independently reviewed — an adversarial review pass, kept in the repo.
- Machine-readable claims — every reported number, in a checkable file.
- Tested — a correctness/benchmark suite ships alongside the code.
→ read the code and re-run it
github.com/v-code01/fusedgemv