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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