The matrix gains `cuda_kernel` (rendered into miner.env as
MINER_CUDA_KERNEL) next to `kernel`, the id validate asserts. benjy's
4090 measured +1.7% on the loop kernel (727-736 vs 716-718 MH/s, parity
200/200), so it runs loop / cuda-loop; quadbrat (-1.8%) and beast
(-3.4%) stay on unrolled / cuda. A rollback to a binary that predates
the switch is safe: it ignores the variable.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ue5ZZm1Hiv5zPnucykKKuF
A second entry point in the same fatbin, sharing every arithmetic
primitive with mining_main, with the round loops rolled and the round
constants fetched from constant memory by index (quantus/miner#27). The
per-nonce body is one template used by both entries, so the deployed
kernel is byte-identical (sm_120 21,120 instructions, 110 registers).
Selected at run time: MINER_CUDA_KERNEL=loop loads mining_loop, reports
kernel id cuda-loop on the per-device metrics, and defaults the block
size to 512 (LAIR_LOOP_TPB); unset or unrolled keeps mining_main and the
cuda kernel id the deploy validate asserts.
Measured on beast, three interleaved rounds, parity 500/500 on both:
unrolled 2206, loop 2130 MH/s (-3.4%). The loop kernel is 11,840 static
instructions at 128 registers (88 bytes of spill) on sm_120; 88 registers
with no spill on sm_86/89. Shapes tried for it: 192 registers 1976 (one
block per SM, card underfilled), 80 registers 2005 (424 B spill), 64
registers 373-532 (716-872 B spill), two internal rounds per iteration
1976 against one at 2105, 256/128-thread blocks below 512.
Not the win #27 hoped for yet: the loop structure alone does not lower
this arithmetic's register footprint the way the quanpool kernel's is,
and its internal round is 254 instructions to their 199. Kept as an
opt-in path so the next steps (the round arithmetic as one carry chain)
can be measured against the deployed kernel without touching it.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ue5ZZm1Hiv5zPnucykKKuF
