Re: [nvptx] propagating conditionals in worker-vector partitioned loops

[Cesar Philippidis <cesar_philippidis@mentor.com>]

Ping.

On 10/26/2016 03:29 PM, Cesar Philippidis wrote:
> Currently, the nvptx backend is only neutering the worker axis when
> propagating variables used in conditional expressions across the worker
> and vector axes. That's a problem with the worker-state spill and fill
> propagation implementation because all of the vector threads in worker 0
> all write the the same address location being spilled. As the attached
> test case demonstrates, this might cause an infinite loop depending on
> the values in the vector threads being propagated.
> 
> This patch fixes this issue by introducing a new worker-vector
> predicate, so that both the worker and vector threads can be predicated
> together, not separately. I.e., instead of first neutering worker axis,
> then neutering the vector axis, this patch uses a single predicate for
> tid.x == 0 && tid.y == 0.
> 
> Is this patch ok for trunk?
> 
> Cesar
>