On 18/09/18 12:21, Richard Sandiford wrote:
Would the same be useful for GCN, or do you basically always want a VF of 64?
Always 64; the vector size varies between 512-bit and 4096-bit, as needed.
None of this is a fundamental restriction in theory. It's just something that needs to be fixed. One approach would be to get the loop vectoriser to iterate over the number of lanes the target supports insteaad of all possible vector sizes. The problem is that on its own this would mean trying 4 lane counts even on targets with a single supported vector size. So we'd need to do something a bit smarter...
Yeah, that sounds like an interesting project, but way more than I think I need. Basically, we don't need to iterate over anything; there's only one option for each mode.
For the purposes of this patch, might it be enough to track down all the places that use the current_vector_size and fix them up, somehow?
Obviously, I'm not sure what that means just yet ... Andrew
