[PATCH] D22198: AMDGPU: Do not clobber SCC in SIWholeQuadMode

[Nicolai Hähnle via llvm-commits]

nhaehnle added a comment.

In https://reviews.llvm.org/D22198#482885, @arsenm wrote:

> Can you post an MI dump example of when this happens? It seems like this isn't something you should need to handle


The added test case in an example (I actually encountered this out in the real world in a piglit test.)

As you can see from the excerpt at http://paste.ubuntu.com/19764805/, the most natural place to insert the s_wqm_b64 would be between the s_cmp_lt and the s_cbranch. What the new code does instead is to maintain a range of places where the s_wqm_b64 could be inserted (based on the correctness constraints for WQM), and then finds a place in that range where SCC isnt' live.


https://reviews.llvm.org/D22198