Channel select definition

[edubois]

Hi, As I cannot write this:

out(x, y, 0) = selection[0];
out(x, y, 1) = selection[1];
out(x, y, 2) = selection[2];
out(x, y, 3) = selection[3];

Is there a better way to write this? out(x, y, c) = select(c == 0, selection[0], select(c == 1, selection[1], select(c == 2, selection[2], selection[3])));

[abadams]

Just a change in syntax and formatting, but I usually write it as:

out(x, y, c) = select(c == 0, selection[0],
                      c == 1, selection[1],
                      c == 2, selection[2],
                      selection[3]);

[edubois]

Ok, but this implies a if that has a cost, isn't it?

[abadams]

I would normally couple this with out.reorder(c, x, y).bound(c, 0, 4).unroll(c) to make the select go away.

[edubois]

Ok, I see. Last question: is the auto scheduler doing that automatically?

[abadams]

No, the autoscheduler doesn't know that trick.

[edubois]

Ok, thanks, good to know.

[edubois]

I just remembered something bad that I saw, and is somehow related to this last fact: the autoscheduler vs bounds of the channels: I saw that it is adding a parallelization on the channel dimension, which is not making sense. What do you think?