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

[Charitha Saumya]

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@@ -1152,64 +1152,232 @@ struct WgToSgVectorShapeCastOp
   }
 };
 
-/// Pattern for lowering vector.multi_reduction op to subgroup level.
-/// Current limitation: the sg_layout in the reduced dimension being 1
-/// so that reduction is local to subgroup & no cross-subgroup communication is
-/// needed.
-/// TODO: Add cases to handle more general situations which require SLM access.
+// This pattern transforms vector.multi_dim_reduction ops to work at subgroup
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charithaintc wrote:

please add the summary of your algo here. 

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