Mill Computing, Inc. Forums The Mill Architecture Fractional byte packing? Reply To: Fractional byte packing?

Findecanor
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Post count: 34

You could do that with one bitfield extract instructions per bitfield you’d want to extract: in this case six.

Those would all be independent, so max parallelism would be the number of execution units that implement that instruction.
If a bitfield is at the top or the bottom of the word, then a shiftr{s|u} or andl respectively could be done instead, possibly in another execution unit freeing up a bitfield extract unit.

If you have such a layout with one at bits 31:26 and one at 0:0, and there is a CPU with two execution units that do bitfield extract and one unit that does shiftru/andl, then full extraction should be possible with only two cycles of latency.

(Speaking very generically of course. Someone from Mill Computing could fill in the details)

  • This reply was modified 3 months, 2 weeks ago by  Findecanor.