[Mlir-commits] [mlir] [mlir][vector] Fix off-by-one error in `getTransferChunkAccessed` (PR #70292)

[Matthias Springer]

https://github.com/matthias-springer created https://github.com/llvm/llvm-project/pull/70292

If a dimension does not appear in the permutation map of a vector transfer op, the size of the accessed slice in that dimension is `1`. Before this fix, `getTransferChunkAccessed` used to return `0` for such dimensions, which would means that `0` elements in the underlying tensor/memref are accessed.

>From fe02bc33a31231aefc839746dd6c0a18bd2ce883 Mon Sep 17 00:00:00 2001
From: Matthias Springer <springerm at google.com>
Date: Thu, 26 Oct 2023 14:29:51 +0900
Subject: [PATCH] [mlir][vector] Fix off-by-one error in
 `getTransferChunkAccessed`

If a dimension does not appear in the permutation map of a vector transfer op, the size of the accessed slice in that dimension is `1`. Before this fix, `getTransferChunkAccessed` used to return `0` for such dimensions, which would means that `0` elements in the underlying tensor/memref are accessed.
---
 mlir/include/mlir/Interfaces/VectorInterfaces.td | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/mlir/include/mlir/Interfaces/VectorInterfaces.td b/mlir/include/mlir/Interfaces/VectorInterfaces.td
index 346a409a3f3e0ef..026faf269f368de 100644
--- a/mlir/include/mlir/Interfaces/VectorInterfaces.td
+++ b/mlir/include/mlir/Interfaces/VectorInterfaces.td
@@ -257,22 +257,22 @@ def VectorTransferOpInterface : OpInterface<"VectorTransferOpInterface"> {
     >,
     InterfaceMethod<
       /*desc=*/[{
-      Return an upper-bound shape accessed by the transfer op within the
-      tensor/memref operand.
+      Return the shape of the hyperrectangular slice within the tensor/memref
+      operand that is accessed by the transfer op.
       For example:
       ```
-        vector.transfer %w0[%i, %j] {
-          permutation_map = affine_map<(d0, d1) -> (d1, d0, 0)>} :
-          tensor<?x?xf32>, vector<4x2x6xf32>
+        vector.transfer %w0[%i, %j, %k] {
+          permutation_map = affine_map<(d0, d1, d2) -> (d1, d0, 0)>} :
+          tensor<?x?x?xf32>, vector<4x2x6xf32>
       ```
-      returns a shape [2, 4].
+      returns a shape [2, 4, 1].
       }],
       /*retTy=*/"SmallVector<int64_t>",
       /*methodName=*/"getTransferChunkAccessed",
       /*args=*/(ins),
       /*methodBody=*/"",
       /*defaultImplementation=*/[{
-        SmallVector<int64_t> dimSizes($_op.getPermutationMap().getNumDims(), 0);
+        SmallVector<int64_t> dimSizes($_op.getPermutationMap().getNumDims(), 1);
         for (auto vecDims : llvm::zip($_op.getPermutationMap().getResults(),
                                       $_op.getVectorType().getShape())) {
           AffineExpr dim = std::get<0>(vecDims);