[llvm-branch-commits] [mlir] [MLIR] Fix incorrect slice contiguity inference in `vector::isContiguousSlice` (PR #142422)

[James Newling via llvm-branch-commits]

================
@@ -49,35 +49,37 @@ FailureOr<std::pair<int, int>> isTranspose2DSlice(vector::TransposeOp op);
 
 /// Return true if `vectorType` is a contiguous slice of `memrefType`.
 ///
-/// Only the N = vectorType.getRank() trailing dims of `memrefType` are
-/// checked (the other dims are not relevant). Note that for `vectorType` to be
-/// a contiguous slice of `memrefType`, the trailing dims of the latter have
-/// to be contiguous - this is checked by looking at the corresponding strides.
+/// The leading unit dimensions of the vector type are ignored as they
+/// are not relevant to the result. Let N be the number of the vector
+/// dimensions after ignoring a leading sequence of unit ones.
 ///
-/// There might be some restriction on the leading dim of `VectorType`:
+/// For `vectorType` to be a contiguous slice of `memrefType`
+///   a) the N trailing dimensions of the latter must be contiguous, and
+///   b) the trailing N dimensions of `vectorType` and `memrefType`,
----------------
newling wrote:

```suggestion
///   b) the trailing N-1 dimensions of `vectorType` and `memrefType` must match.
```

https://github.com/llvm/llvm-project/pull/142422