Reply To: Metadata

I’ve been following the talks (from a long way away, unfortunately) quite carefully, waiting for the really interesting stuff. Finally things are starting to come together, although there are still quite a few holes. In particular the spiller and how it captures and replays in-flight operations at the time of a call.

> only one opcode per signature

That’s what I thought, I was just making sure.

> “broadcast” operation: there isn’t one. There is a “splat” operation that replicates a scalar into a vector, but that’s not the same. Just do “add” and it’s happy with either vector or scalar data, whichever it gets. There’s only one adder; the width just sets breaks in the carry tree.

No, “splat” sounds exactly what I meant “broadacst” to be. A functional unit could also do this implicitly if one operand was a scalar of the appropriate side, but it’s a lot of wiring and presumably not worth it.

> However, the loop control bool is at the wrong end of the bool vector from where smeari puts it,

Um, huh? So you’re big-endian? I was assuming little-endian, in which case the unused “first” byte result would also be the overall lsbit (you did say that boolean was the lsbit of the field, right?), which would be in the same place as a scalar, and thus presumably in the right place to branch on directly, with no extract.