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

[Cullen Rhodes]

================
@@ -66,6 +68,77 @@ using ScalableMaskedDivFOpLowering =
     OneToOneConvertToLLVMPattern<ScalableMaskedDivFOp,
                                  ScalableMaskedDivFIntrOp>;
 
+namespace {
+
+/// Unrolls a conversion to/from equivalent vector types, to allow using a
+/// conversion intrinsic that only supports 1-D vector types.
+///
+/// Example:
+/// ```
+/// %result = arm_sve.convert_to_svbool %source : vector<2x[4]xi1>
+/// ```
+/// is rewritten into:
+/// ```
+/// %cst = arith.constant dense<false> : vector<2x[16]xi1>
+/// %1 = vector.extract %source[0] : vector<[4]xi1> from vector<2x[4]xi1>
+/// %2 = "arm_sve.intr.convert.to.svbool"(%1)
+///                : (vector<[4]xi1>) -> vector<[16]xi1>
+/// %3 = vector.insert %2, %cst [0] : vector<[16]xi1> into vector<2x[16]xi1>
+/// %4 = vector.extract %source[1] : vector<[4]xi1> from vector<2x[4]xi1>
+/// %5 = "arm_sve.intr.convert.to.svbool"(%4)
+///                : (vector<[4]xi1>) -> vector<[16]xi1>
+/// %result = vector.insert %5, %3 [1] : vector<[16]xi1> into vector<2x[16]xi1>
----------------
c-rhodes wrote:

```suggestion
/// %result = vector.insert %5, %3[1] : vector<[16]xi1> into vector<2x[16]xi1>
```

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