On 10/21/2015 05:18 PM, Alexander Monakov wrote:
On Wed, 21 Oct 2015, Bernd Schmidt wrote:
On 10/20/2015 08:34 PM, Alexander Monakov wrote:
This patch series ports enough of libgomp.c to get warp-level parallelism
working for OpenMP offloading. The overall approach is as follows.
Could you elaborate a bit what you mean by this just so we understand each
other in terms of terminology? "Warp-level" sounds to me like you have all
threads in a warp executing in lockstep at all times. If individual threads
can take different paths, I'd expect it to be called thread-level parallelism
or something like that.
Sorry, that was unclear. What I meant is that there is a degree of
parallelism available across different warps, but not across different teams
(because only 1 team is spawned), nor across threads in a warp (because all
threads in a warp except one exit immediately -- later on we'd need to
keep them converged so they can enter a simd region together).
I see. That ensures that you wouldn't see any problems related to
reconvergence yet. I think I would like to see something with actual
thread parallelism to demonstrate at least as a proof of concept that
the synchronization code is roughly sane.
Bernd
