Routing Iteration Update Order

[amin1377]

The information for the current routing iteration is added after estimated_success_iteration is calculated. I was wondering if it should be added beforehand instead. If so, let me know and I’ll update the code accordingly.

The estimated successs iteration is calculated here: Link (Line 311)
The information about the current iteration is added to the model here: Link (Line 321)

[AlexandreSinger]

This makes sense to me.

I walked through this method. This is the current flow of each pathfinder iteration for this:

1. Route each net.
2. Use the predictor to estimate the success iteration from the last iteration (not this one).
3. Update the predictor with the information from route net (as you have noted, this is happening after it is predicted).
4. Log this predicted value.
5. Break out of the routing loop if the predicted value.

So it looks like you are right that the predicted value is always based on the prior iteration, not the current one.

If you do change this though, we will always stop an iteration earlier than we did in the past. I am personally fine with this; the only things that should be affected by this are things that were literally on the edge of routability.

@vaughnbetz What do you think?

[vaughnbetz]

Good catch. Your proposed change makes sense to me @amin1377 .

[amin1377]

Addressed in PR #3795