[Mlir-commits] [mlir] [mlir][ArmSVE] Add convert_to/from_svbool ops (PR #68586)

[Andrzej Warzyński]

================
@@ -236,6 +243,66 @@ def UmmlaOp : ArmSVE_Op<"ummla",
     "$acc `,` $src1 `,` $src2 attr-dict `:` type($src1) `to` type($dst)";
 }
 
+
+class SvboolTypeContraint<string lhsArg, string rhsArg> : TypesMatchWith<
+      "expected corresponding svbool type widened to [16]xi1",
+      lhsArg, rhsArg,
+      "VectorType(VectorType::Builder(::llvm::cast<VectorType>($_self)).setDim(::llvm::cast<VectorType>($_self).getRank() - 1, 16))">;
+
+def ConvertFromSvboolOp : ArmSVE_Op<"convert_from_svbool",
+                            [Pure, SvboolTypeContraint<"result", "source">]>
+{
+  let summary = "Convert a svbool type to a SVE predicate type";
+  let description = [{
+    Converts svbool types (`vector<[16]xi1>` or vectors of that type, e.g.
+    `vector<2x3x[16]xi1>`) to SVE predicate types. Note: Only the trailing
+    dimension can be scalable.
+
+    Example 1: Convert a 1-D svbool mask to a SVE predicate.
+    ```mlir
+    %svbool = vector.load %memref[%c0] : memref<?xi1>, vector<[16]xi1>
+    %mask = arm_sve.convert_from_svbool %svbool : vector<[4]xi1>
+    ```
+
+    Example 2: Convert a 2-D svbool mask to a mask of SVE predicates.
+    ```mlir
+    %svbool = vector.load %memref[%c0, %c0] : memref<2x?xi1>, vector<2x[16]xi1>
+    %mask = arm_sve.convert_from_svbool %svbool : vector<2x[8]xi1>
+    ```
+  }];
----------------
banach-space wrote:

How would somebody reading this file know what `svbool` and "SVE predicate" types are? It would be good to define both. Note that also input/output names are a bit inconsistent: 
```
  let arguments = (ins SVBoolMask:$source);
  let results = (outs SVEMask:$result);
```
Given how subtle this is, I'd suggest either expanding this definition, adding links or adding some definition at the top of this file. Or perhaps these types are defined somewhere? (as in, other than as "TableGen" definitions).

Also, "a SVE" -> "an SVE"?

https://github.com/llvm/llvm-project/pull/68586