[Mlir-commits] [mlir] [mlir][ArmSME] Add initial SME vector legalization pass (PR #79152)

[Benjamin Maxwell]

================
@@ -122,4 +122,23 @@ def TileAllocation
   let dependentDialects = ["func::FuncDialect"];
 }
 
+def VectorLegalization
+  : Pass<"arm-sme-vector-legalization", "mlir::ModuleOp"> {
+  let summary = "Legalize vectors for ArmSME";
+  let description = [{
+    This pass legalizes vector operations so that they can be lowered to ArmSME.
+    This includes decomposing operations that operate on vector types larger
+    than a single SME tile (e.g. `vector<[8]x[8]xf32>`) into multiple SME
----------------
MacDue wrote:

`legal` - means something that can be lowered to ArmSME, as mentioned this pass will be broader than just type decomposition, and will include rewrites to eliminate illegal types like `vector<[8]x4xf32>` (which also falls under legalizing vector operations). 

(I think the description already mentions that the decomposition breaks down larger vector types into multiple SME-sized operations?)

I'll add the input size limitation :+1: 



https://github.com/llvm/llvm-project/pull/79152