[mlir][vector] Add a check to ensure input vector rank equals target shape rank

[CoTinker]

The crash is caused because, during IR transformation, the vector-unrolling pass (using ExtractStridedSliceOp) attempts to slice an
input vector of higher rank using a target vector of lower rank, which is not supported. Fixes #148368.

[llvmbot]

@llvm/pr-subscribers-mlir-vector

@llvm/pr-subscribers-mlir

Author: Longsheng Mou (CoTinker)

Changes

The crash is caused because, during IR transformation, the vector-unrolling pass (using ExtractStridedSliceOp) attempts to slice an
input vector of higher rank using a target vector of lower rank, which is not supported. Fixed #148368.

---

Full diff: https://github.com/llvm/llvm-project/pull/149239.diff

2 Files Affected:

• (modified) mlir/lib/Dialect/Vector/Transforms/VectorUnroll.cpp (+15-1)
• (modified) mlir/test/Dialect/Vector/vector-unroll-options.mlir (+22)

diff --git a/mlir/lib/Dialect/Vector/Transforms/VectorUnroll.cpp b/mlir/lib/Dialect/Vector/Transforms/VectorUnroll.cpp
index 693f4f955994d..be911901c2afc 100644
--- a/mlir/lib/Dialect/Vector/Transforms/VectorUnroll.cpp
+++ b/mlir/lib/Dialect/Vector/Transforms/VectorUnroll.cpp
@@ -169,7 +169,13 @@ struct UnrollTransferReadPattern
     auto sourceVectorType = readOp.getVectorType();
     SmallVector<int64_t> strides(targetShape->size(), 1);
     Location loc = readOp.getLoc();
-    ArrayRef<int64_t> originalSize = readOp.getVectorType().getShape();
+    ArrayRef<int64_t> originalSize = sourceVectorType.getShape();
+    // Bail-out if rank(source) != rank(target). The main limitation here is the
+    // fact that `InsertStridedSliceOp` requires the rank for the input and
+    // output to match. If needed, we can relax this later.
+    if (originalSize.size() != targetShape->size())
+      return rewriter.notifyMatchFailure(
+          readOp, "expected source vector rank to match target shape rank");
 
     // Prepare the result vector;
     Value result = rewriter.create<arith::ConstantOp>(
@@ -224,6 +230,14 @@ struct UnrollTransferWritePattern
     SmallVector<int64_t> strides(targetShape->size(), 1);
     Location loc = writeOp.getLoc();
     ArrayRef<int64_t> originalSize = sourceVectorType.getShape();
+    // Bail-out if rank(source) != rank(target). The main limitation here is the
+    // fact that `ExtractStridedSlice` requires the rank for the input and
+    // output to match. If needed, we can relax this later.
+    if (originalSize.size() != targetShape->size())
+      return rewriter.notifyMatchFailure(
+          writeOp,
+          "expected source input vector rank to match target shape rank");
+
     SmallVector<Value> originalIndices(writeOp.getIndices().begin(),
                                        writeOp.getIndices().end());
     SmallVector<int64_t> loopOrder =
diff --git a/mlir/test/Dialect/Vector/vector-unroll-options.mlir b/mlir/test/Dialect/Vector/vector-unroll-options.mlir
index e129cd5c40b9c..8f6945468feb3 100644
--- a/mlir/test/Dialect/Vector/vector-unroll-options.mlir
+++ b/mlir/test/Dialect/Vector/vector-unroll-options.mlir
@@ -420,3 +420,25 @@ func.func @vector_store_2D(%mem: memref<4x4xf16>, %v: vector<4x4xf16>) {
   // CHECK: vector.store %[[V2]], %[[ARG0]][%[[C2]], %[[C0]]] : memref<4x4xf16>, vector<2x2xf16>
   // CHECK: %[[V3:.*]] = vector.extract_strided_slice %[[ARG1]] {offsets = [2, 2], sizes = [2, 2], strides = [1, 1]} : vector<4x4xf16> to vector<2x2xf16>
   // CHECK: vector.store %[[V3]], %[[ARG0]][%[[C2]], %[[C2]]] : memref<4x4xf16>, vector<2x2xf16>
+
+func.func @vector_transfer_read(%arg0: memref<6x34x62xi8>) -> vector<6x34x62xi8> {
+  %c0_i8 = arith.constant 0 : i8
+  %c0 = arith.constant 0 : index
+  %0 = vector.transfer_read %arg0[%c0, %c0, %c0], %c0_i8 : memref<6x34x62xi8>, vector<6x34x62xi8>
+  return %0 : vector<6x34x62xi8>
+}
+// CHECK-LABEL: func @vector_transfer_read
+//   CHECK-NOT: vector.intert_strided_slice
+//       CHECK: vector.transfer_read
+//       CHECK: return
+
+func.func @vector_transfer_write(%arg0: vector<6x34x62xi8>) {
+  %c0 = arith.constant 0 : index
+  %alloc = memref.alloc() : memref<6x34x62xi8>
+  vector.transfer_write %arg0, %alloc[%c0, %c0, %c0]: vector<6x34x62xi8>, memref<6x34x62xi8>
+  return
+}
+// CHECK-LABEL: func @vector_transfer_write
+//   CHECK-NOT: vector.extract_strided_slice
+//       CHECK: vector.transfer_write
+//       CHECK: return

[newling]

Thank you for providing a fix!

[newling]

There's a file vector-transfer-unroll.mlir which might be a better place for these tests.

Please add comments above the tests describing what is being tested.

Such tests generally are prefixed with negative_

[newling]

insert_strided_slice can have a smaller source vector: https://mlir.llvm.org/docs/Dialects/Vector/#vectorinsert_strided_slice-vectorinsertstridedsliceop