[Mlir-commits] [mlir] [MLIR][XeGPU] Add support for cross-subgroup reduction from wg to sg (PR #170936)

[Nishant Patel]

nbpatel wrote:

> * if size(red_dims) > 1, rewrite the reduction into multiple reductions where each reduction is over single dims and return.


why do we need to rewrite it as multiple reduction instructions doing one reduce dim at at time? Wg to sg can do multi-dim reduce locally first  and then do cross-subgroup reduction using SLM? 


https://github.com/llvm/llvm-project/pull/170936