Constant K6_STREAMED_EVERY 

pub const K6_STREAMED_EVERY: usize = 1;

The streamed K6 engine’s register placement: a register after every K6_STREAMED_EVERY-th level of its multiply tree (LaneArith::Streamed). MEASURED (2026-10-17, Artix-7 fabric map, yosys 0.33 synth_xilinx + nextpnr-xilinx, median of the seeds that routed): every level = 3421 LUTs at 128.2 MHz and 24 clocks an operation, 1.56 million results a second per thousand LUTs; every second = 3403 at 106.6 MHz and 21 clocks, 1.49; every third = 3394 at 90.7 and 20, 1.34; the whole tree in one stage = 3387 at 63.7 and 19, 0.99. Fewer registers hold half (every second) to a quarter (one stage) of the flip-flops.