Reply To: Introduction to the Mill CPU Programming Model

Yeah I had that solution too for cases as simple as my example. The problem is when you try to scale that to a larger conditional code block that could push several arguments on the belt. Another example:

add b0, b1
if(cond) {
mult b0, b1
div  b0, b1
add  b0, b1
sub  b0, b1
xor  b0, b1
and  b0, b1
}

That would either be turned into a branch or you could make each statement conditional with pick but that would increase code size, execution time, and could push a lot of useless stuff onto the belt just to keep indices consistent. Only other option I see would be to store anything important / send it to the spiller and restore them after the branch was executed but that’s still slow because latencies. 🙁