I am just highlighting that one extra thing offered by DONT_BUFFER_PORTS is that you have control over which output ports to remove buffers from.

@kareefardi I'll leave reviewing this one to you since it's more your domain.

@kareefardi if it is still useful, perhaps we can something to the documentation.

@antonblanchard I would prefer that as it can be useful beyond the scope of tristate nets buffering.

The real issue here is that run_placement calls remove_buffers after repair_design, which removes any buffers inserted by repair_design to fix max slew, cap, fanout or long wire violations. That makes no sense at all. Buffers inserted by synthesis (which has no awareness of placement or parasitics should be removed BEFORE repair_design, not after.

@jjcherry56 makes sense. @kareefardi do you have a way to test this feature? Could you make the suggested change and test if it still works?

Sorry, we can't merge this.

This feature is needed for some internal designs where the resizer would add buffers to output nets. We can't find a method to declare a net as untouchable. If there is one such method in OpenROAD, @maliberty, please point us to it.

I will rename the fn explicitly to remove_port_buffers and clearly label it as a workaround for something.