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BROADCAST LOAD SCHEDULE

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Round | Unique | Load Strategy

------|--------|------------------------------------------

   0  |    1   | 1 broadcast → all 256 items

   1  |    2   | 2 broadcasts → groups

   2  |    4   | 4 broadcasts → groups

   3  |    8   | 8 broadcasts → groups

   4  |   16   | 16 broadcasts → groups

   5  |   32   | 32 broadcasts → groups

   6  |   63   | 63 loads (sparse, use indirection)

   7  |  108   | 108 loads (sparse, use indirection)

   8  |  159   | 159 loads (sparse, use indirection)

   9  |  191   | 191 loads (sparse, use indirection)

  10  |  224   | 224 loads (sparse, use indirection)

  11  |    1   | 1 broadcast → all 256 items

  12  |    2   | 2 broadcasts → groups

  13  |    4   | 4 broadcasts → groups

  14  |    8   | 8 broadcasts → groups

  15  |   16   | 16 broadcasts → groups

Total loads with grouping: 839

Total loads naive: 4096

Load reduction: 4.9x

take advantage of index collisions, optimizing round 0 and 11, speculative pre-loading, and the early branch predictor (which now I am doing looking at bits output at stage 3)

it's actually pretty funny since opus will suggest both of these with enough prying (though with a single-prompt it might not try it).