Revert "[mlir][memref] Verify out-of-bounds access for memref.subview (#131…"

This reverts commit d4304d8.

Author: basioli-k

mlir/include/mlir/Dialect/MemRef/IR/MemRefOps.td

@@ -1859,11 +1859,11 @@ def SubViewOp : MemRef_OpWithOffsetSizesAndStrides<"subview", [
   ]> {
   let summary = "memref subview operation";
   let description = [{
-    The `subview` operation converts a memref type to a memref type which
-    represents a reduced-size view of the original memref as specified by the
-    operation's offsets, sizes and strides arguments.
+    The "subview" operation converts a memref type to another memref type
+    which represents a reduced-size view of the original memref as specified by
+    the operation's offsets, sizes and strides arguments.
 
-    The `subview` operation supports the following arguments:
+    The SubView operation supports the following arguments:
 
     * source: the "base" memref on which to create a "view" memref.
     * offsets: memref-rank number of offsets into the "base" memref at which to
@@ -1876,73 +1876,118 @@ def SubViewOp : MemRef_OpWithOffsetSizesAndStrides<"subview", [
     The representation based on offsets, sizes and strides support a
     partially-static specification via attributes specified through the
     `static_offsets`, `static_sizes` and `static_strides` arguments. A special
-    sentinel value `ShapedType::kDynamic` encodes that the corresponding entry
-    has a dynamic value.
+    sentinel value ShapedType::kDynamic encodes that the corresponding entry has
+    a dynamic value.
 
-    A `subview` operation may additionally reduce the rank of the resulting
-    view by removing dimensions that are statically known to be of size 1.
-
-    In the absence of rank reductions, the resulting memref type is computed
-    as follows:
-    ```
-    result_sizes[i] = size_operands[i]
-    result_strides[i] = src_strides[i] * stride_operands[i]
-    result_offset = src_offset + dot_product(offset_operands, src_strides)
-    ```
-
-    The offset, size and stride operands must be in-bounds with respect to the
-    source memref. When possible, the static operation verifier will detect
-    out-of-bounds subviews. Subviews that cannot be confirmed to be in-bounds
-    or out-of-bounds based on compile-time information are valid. However,
-    performing an out-of-bounds subview at runtime is undefined behavior.
+    A subview operation may additionally reduce the rank of the resulting view
+    by removing dimensions that are statically known to be of size 1.
 
     Example 1:
 
     ```mlir
-    // Subview of static memref with strided layout at static offsets, sizes
-    // and strides.
-    %1 = memref.subview %0[4, 2][8, 2][3, 2]
-        : memref<64x4xf32, strided<[7, 9], offset: 91>> to
-          memref<8x2xf32, strided<[21, 18], offset: 137>>
+    %0 = memref.alloc() : memref<64x4xf32, affine_map<(d0, d1) -> (d0 * 4 + d1)>>
+
+    // Create a sub-view of "base" memref '%0' with offset arguments '%c0',
+    // dynamic sizes for each dimension, and stride arguments '%c1'.
+    %1 = memref.subview %0[%c0, %c0][%size0, %size1][%c1, %c1]
+      : memref<64x4xf32, affine_map<(d0, d1) -> (d0 * 4 + d1)>> to
+        memref<?x?xf32, affine_map<(d0, d1)[s0, s1] -> (d0 * s1 + d1 + s0)>>
     ```
 
     Example 2:
 
     ```mlir
-    // Subview of static memref with identity layout at dynamic offsets, sizes
+    %0 = memref.alloc() : memref<8x16x4xf32, affine_map<(d0, d1, d2) -> (d0 * 64 + d1 * 4 + d2)>>
+
+    // Create a sub-view of "base" memref '%0' with dynamic offsets, sizes,
     // and strides.
-    %1 = memref.subview %0[%off0, %off1][%sz0, %sz1][%str0, %str1]
-        : memref<64x4xf32> to memref<?x?xf32, strided<[?, ?], offset: ?>>
+    // Note that dynamic offsets are represented by the linearized dynamic
+    // offset symbol 's0' in the subview memref layout map, and that the
+    // dynamic strides operands, after being applied to the base memref
+    // strides in each dimension, are represented in the view memref layout
+    // map as symbols 's1', 's2' and 's3'.
+    %1 = memref.subview %0[%i, %j, %k][%size0, %size1, %size2][%x, %y, %z]
+      : memref<8x16x4xf32, affine_map<(d0, d1, d2) -> (d0 * 64 + d1 * 4 + d2)>> to
+        memref<?x?x?xf32,
+          affine_map<(d0, d1, d2)[s0, s1, s2, s3] -> (d0 * s1 + d1 * s2 + d2 * s3 + s0)>>
     ```
 
     Example 3:
 
     ```mlir
-    // Subview of dynamic memref with strided layout at dynamic offsets and
-    // strides, but static sizes.
-    %1 = memref.subview %0[%off0, %off1][4, 4][%str0, %str1]
-        : memref<?x?xf32, strided<[?, ?], offset: ?>> to
-          memref<4x4xf32, strided<[?, ?], offset: ?>>
+    %0 = memref.alloc() : memref<8x16x4xf32, affine_map<(d0, d1, d2) -> (d0 * 64 + d1 * 4 + d2)>>
+
+    // Subview with constant offsets, sizes and strides.
+    %1 = memref.subview %0[0, 2, 0][4, 4, 4][1, 1, 1]
+      : memref<8x16x4xf32, affine_map<(d0, d1, d2) -> (d0 * 64 + d1 * 4 + d2)>> to
+        memref<4x4x4xf32, affine_map<(d0, d1, d2) -> (d0 * 64 + d1 * 4 + d2 + 8)>>
     ```
 
     Example 4:
 
     ```mlir
-    // Rank-reducing subviews.
-    %1 = memref.subview %0[0, 0, 0][1, 16, 4][1, 1, 1]
-        : memref<8x16x4xf32> to memref<16x4xf32>
-    %3 = memref.subview %2[3, 4, 2][1, 6, 3][1, 1, 1]
-        : memref<8x16x4xf32> to memref<6x3xf32, strided<[4, 1], offset: 210>>
+    %0 = memref.alloc(%arg0, %arg1) : memref<?x?xf32>
+
+    // Subview with constant size, but dynamic offsets and
+    // strides. The resulting memref has a static shape, but if the
+    // base memref has an affine map to describe the layout, the result
+    // memref also uses an affine map to describe the layout. The
+    // strides of the result memref is computed as follows:
+    //
+    // Let #map1 represents the layout of the base memref, and #map2
+    // represents the layout of the result memref. A #mapsubview can be
+    // constructed to map an index from the result memref to the base
+    // memref (note that the description below uses more convenient
+    // naming for symbols, while in affine maps, symbols are
+    // represented as unsigned numbers that identify that symbol in the
+    // given affine map.
+    //
+    // #mapsubview = (d0, d1)[o0, o1, t0, t1] -> (d0 * t0 + o0, d1 * t1 + o1)
+    //
+    // where, o0, o1, ... are offsets, and t0, t1, ... are strides. Then,
+    //
+    // #map2 = #map1.compose(#mapsubview)
+    //
+    // If the layout map is represented as
+    //
+    // #map1 = (d0, d1)[s0, s1, s2] -> (d0 * s1 + d1 * s2 + s0)
+    //
+    // then,
+    //
+    // #map2 = (d0, d1)[s0, s1, s2, o0, o1, t0, t1] ->
+    //              (d0 * s1 * t0 + d1 * s2 * t1 + o0 * s1 + o1 * s2 + s0)
+    //
+    // Representing this canonically
+    //
+    // #map2 = (d0, d1)[r0, r1, r2] -> (d0 * r1 + d1 * r2 + r0)
+    //
+    // where, r0 = o0 * s1 + o1 * s2 + s0, r1 = s1 * t0, r2 = s2 * t1.
+    %1 = memref.subview %0[%i, %j][4, 4][%x, %y] :
+      : memref<?x?xf32, affine_map<(d0, d1)[s0, s1, s2] -> (d0 * s1 + d1 * s2 + s0)>> to
+        memref<4x4xf32, affine_map<(d0, d1)[r0, r1, r2] -> (d0 * r1 + d1 * r2 + r0)>>
+
+    // Note that the subview op does not guarantee that the result
+    // memref is "inbounds" w.r.t to base memref. It is upto the client
+    // to ensure that the subview is accessed in a manner that is
+    // in-bounds.
     ```
 
     Example 5:
 
     ```mlir
-    // Identity subview. The subview is the full source memref.
-    %1 = memref.subview %0[0, 0, 0] [8, 16, 4] [1, 1, 1]
-        : memref<8x16x4xf32> to memref<8x16x4xf32>
+    // Rank-reducing subview.
+    %1 = memref.subview %0[0, 0, 0][1, 16, 4][1, 1, 1] :
+      memref<8x16x4xf32> to memref<16x4xf32>
+
+    // Original layout:
+    // (d0, d1, d2) -> (64 * d0 + 16 * d1 + d2)
+    // Subviewed layout:
+    // (d0, d1, d2) -> (64 * (d0 + 3) + 4 * (d1 + 4) + d2 + 2) = (64 * d0 + 4 * d1 + d2 + 210)
+    // After rank reducing:
+    // (d0, d1) -> (4 * d0 + d1 + 210)
+    %3 = memref.subview %2[3, 4, 2][1, 6, 3][1, 1, 1] :
+      memref<8x16x4xf32> to memref<6x3xf32, strided<[4, 1], offset: 210>>
     ```
-
   }];
 
   let arguments = (ins AnyMemRef:$source,

mlir/include/mlir/Interfaces/ViewLikeInterface.h

@@ -76,7 +76,8 @@ SliceBoundsVerificationResult verifyInBoundsSlice(
 /// returns the new result type of the op, based on the new offsets, sizes and
 /// strides. `CastOpFunc` is used to generate a cast op if the result type of
 /// the op has changed.
-template <typename OpType, typename ResultTypeFn, typename CastOpFunc>
+template <typename OpType, typename ResultTypeFn, typename CastOpFunc,
+          bool CheckInBounds = false>
 class OpWithOffsetSizesAndStridesConstantArgumentFolder final
     : public OpRewritePattern<OpType> {
 public:
@@ -94,12 +95,14 @@ class OpWithOffsetSizesAndStridesConstantArgumentFolder final
         failed(foldDynamicIndexList(mixedStrides)))
       return failure();
 
-    // Pattern does not apply if the produced op would not verify.
-    SliceBoundsVerificationResult sliceResult = verifyInBoundsSlice(
-        cast<ShapedType>(op.getSource().getType()).getShape(), mixedOffsets,
-        mixedSizes, mixedStrides);
-    if (!sliceResult.isValid)
-      return failure();
+    if (CheckInBounds) {
+      // Pattern does not apply if the produced op would not verify.
+      SliceBoundsVerificationResult sliceResult = verifyInBoundsSlice(
+          cast<ShapedType>(op.getSource().getType()).getShape(), mixedOffsets,
+          mixedSizes, mixedStrides);
+      if (!sliceResult.isValid)
+        return failure();
+    }
 
     // Compute the new result type.
     auto resultType =

mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp

@@ -2977,9 +2977,6 @@ static LogicalResult produceSubViewErrorMsg(SliceVerificationResult result,
 LogicalResult SubViewOp::verify() {
   MemRefType baseType = getSourceType();
   MemRefType subViewType = getType();
-  ArrayRef<int64_t> staticOffsets = getStaticOffsets();
-  ArrayRef<int64_t> staticSizes = getStaticSizes();
-  ArrayRef<int64_t> staticStrides = getStaticStrides();
 
   // The base memref and the view memref should be in the same memory space.
   if (baseType.getMemorySpace() != subViewType.getMemorySpace())
@@ -2994,7 +2991,7 @@ LogicalResult SubViewOp::verify() {
   // Compute the expected result type, assuming that there are no rank
   // reductions.
   MemRefType expectedType = SubViewOp::inferResultType(
-      baseType, staticOffsets, staticSizes, staticStrides);
+      baseType, getStaticOffsets(), getStaticSizes(), getStaticStrides());
 
   // Verify all properties of a shaped type: rank, element type and dimension
   // sizes. This takes into account potential rank reductions.
@@ -3028,14 +3025,6 @@ LogicalResult SubViewOp::verify() {
     return produceSubViewErrorMsg(SliceVerificationResult::LayoutMismatch,
                                   *this, expectedType);
 
-  // Verify that offsets, sizes, strides do not run out-of-bounds with respect
-  // to the base memref.
-  SliceBoundsVerificationResult boundsResult =
-      verifyInBoundsSlice(baseType.getShape(), staticOffsets, staticSizes,
-                          staticStrides, /*generateErrorMessage=*/true);
-  if (!boundsResult.isValid)
-    return getOperation()->emitError(boundsResult.errorMessage);
-
   return success();
 }
 

mlir/lib/Dialect/Tensor/IR/TensorOps.cpp

@@ -2617,10 +2617,10 @@ struct SliceCanonicalizer {
 
 void ExtractSliceOp::getCanonicalizationPatterns(RewritePatternSet &results,
                                                  MLIRContext *context) {
-  results.add<
-      OpWithOffsetSizesAndStridesConstantArgumentFolder<
-          ExtractSliceOp, SliceReturnTypeCanonicalizer, SliceCanonicalizer>,
-      ExtractSliceOpCastFolder>(context);
+  results.add<OpWithOffsetSizesAndStridesConstantArgumentFolder<
+                  ExtractSliceOp, SliceReturnTypeCanonicalizer,
+                  SliceCanonicalizer, /*CheckInBounds=*/true>,
+              ExtractSliceOpCastFolder>(context);
 }
 
 //

mlir/test/Conversion/MemRefToLLVM/expand-then-convert-to-llvm.mlir

@@ -192,7 +192,7 @@ func.func @subview_const_stride(%0 : memref<64x4xf32, strided<[4, 1], offset: 0>
 
 // CHECK-LABEL: func @subview_const_stride_and_offset(
 // CHECK-SAME:         %[[MEM:.*]]: memref<{{.*}}>
-func.func @subview_const_stride_and_offset(%0 : memref<64x8xf32, strided<[8, 1], offset: 0>>) -> memref<62x3xf32, strided<[8, 1], offset: 2>> {
+func.func @subview_const_stride_and_offset(%0 : memref<64x4xf32, strided<[4, 1], offset: 0>>) -> memref<62x3xf32, strided<[4, 1], offset: 8>> {
   // The last "insertvalue" that populates the memref descriptor from the function arguments.
   // CHECK: %[[MEMREF:.*]] = builtin.unrealized_conversion_cast %[[MEM]]
 
@@ -201,21 +201,21 @@ func.func @subview_const_stride_and_offset(%0 : memref<64x8xf32, strided<[8, 1],
   // CHECK: %[[DESC:.*]] = llvm.mlir.poison : !llvm.struct<(ptr, ptr, i64, array<2 x i64>, array<2 x i64>)>
   // CHECK: %[[DESC0:.*]] = llvm.insertvalue %[[BASE]], %[[DESC]][0] : !llvm.struct<(ptr, ptr, i64, array<2 x i64>, array<2 x i64>)>
   // CHECK: %[[DESC1:.*]] = llvm.insertvalue %[[BASE_ALIGNED]], %[[DESC0]][1] : !llvm.struct<(ptr, ptr, i64, array<2 x i64>, array<2 x i64>)>
-  // CHECK: %[[CST_OFF:.*]] = llvm.mlir.constant(2 : index) : i64
+  // CHECK: %[[CST_OFF:.*]] = llvm.mlir.constant(8 : index) : i64
   // CHECK: %[[DESC2:.*]] = llvm.insertvalue %[[CST_OFF]], %[[DESC1]][2] : !llvm.struct<(ptr, ptr, i64, array<2 x i64>, array<2 x i64>)>
   // CHECK: %[[CST_SIZE0:.*]] = llvm.mlir.constant(62 : index) : i64
   // CHECK: %[[DESC3:.*]] = llvm.insertvalue %[[CST_SIZE0]], %[[DESC2]][3, 0] : !llvm.struct<(ptr, ptr, i64, array<2 x i64>, array<2 x i64>)>
-  // CHECK: %[[CST_STRIDE0:.*]] = llvm.mlir.constant(8 : index) : i64
+  // CHECK: %[[CST_STRIDE0:.*]] = llvm.mlir.constant(4 : index) : i64
   // CHECK: %[[DESC4:.*]] = llvm.insertvalue %[[CST_STRIDE0]], %[[DESC3]][4, 0] : !llvm.struct<(ptr, ptr, i64, array<2 x i64>, array<2 x i64>)>
   // CHECK: %[[CST_SIZE1:.*]] = llvm.mlir.constant(3 : index) : i64
   // CHECK: %[[DESC5:.*]] = llvm.insertvalue %[[CST_SIZE1]], %[[DESC4]][3, 1] : !llvm.struct<(ptr, ptr, i64, array<2 x i64>, array<2 x i64>)>
   // CHECK: %[[CST_STRIDE1:.*]] = llvm.mlir.constant(1 : index) : i64
   // CHECK: %[[DESC6:.*]] = llvm.insertvalue %[[CST_STRIDE1]], %[[DESC5]][4, 1] : !llvm.struct<(ptr, ptr, i64, array<2 x i64>, array<2 x i64>)>
 
-  %1 = memref.subview %0[0, 2][62, 3][1, 1] :
-    memref<64x8xf32, strided<[8, 1], offset: 0>>
-    to memref<62x3xf32, strided<[8, 1], offset: 2>>
-  return %1 : memref<62x3xf32, strided<[8, 1], offset: 2>>
+  %1 = memref.subview %0[0, 8][62, 3][1, 1] :
+    memref<64x4xf32, strided<[4, 1], offset: 0>>
+    to memref<62x3xf32, strided<[4, 1], offset: 8>>
+  return %1 : memref<62x3xf32, strided<[4, 1], offset: 8>>
 }
 
 // -----
@@ -238,7 +238,7 @@ func.func @subview_mixed_static_dynamic(%0 : memref<64x4xf32, strided<[4, 1], of
   // CHECK: %[[TMP:.*]] = builtin.unrealized_conversion_cast %[[DESCSTRIDE0]] : i64 to index
   // CHECK: %[[DESCSTRIDE0_V2:.*]] = builtin.unrealized_conversion_cast %[[TMP]] : index to i64
   // CHECK: %[[OFF0:.*]] = llvm.mul %[[ARG1]], %[[STRIDE0]] overflow<nsw> : i64
-  // CHECK: %[[BASE_OFF:.*]] = llvm.mlir.constant(2 : index)  : i64
+  // CHECK: %[[BASE_OFF:.*]] = llvm.mlir.constant(8 : index)  : i64
   // CHECK: %[[OFF2:.*]] = llvm.add %[[OFF0]], %[[BASE_OFF]] : i64
   // CHECK: %[[TMP:.*]] = builtin.unrealized_conversion_cast %[[OFF2]] : i64 to index
   // CHECK: %[[OFF2:.*]] = builtin.unrealized_conversion_cast %[[TMP]] : index to i64
@@ -253,7 +253,7 @@ func.func @subview_mixed_static_dynamic(%0 : memref<64x4xf32, strided<[4, 1], of
   // CHECK: %[[CST_STRIDE1:.*]] = llvm.mlir.constant(1 : index) : i64
   // CHECK: %[[DESC6:.*]] = llvm.insertvalue %[[CST_STRIDE1]], %[[DESC5]][4, 1] : !llvm.struct<(ptr, ptr, i64, array<2 x i64>, array<2 x i64>)>
 
-  %1 = memref.subview %0[%arg1, 2][62, %arg2][%arg0, 1] :
+  %1 = memref.subview %0[%arg1, 8][62, %arg2][%arg0, 1] :
     memref<64x4xf32, strided<[4, 1], offset: 0>>
     to memref<62x?xf32, strided<[?, 1], offset: ?>>
   return %1 : memref<62x?xf32, strided<[?, 1], offset: ?>>

mlir/test/Dialect/Linalg/promote.mlir

@@ -287,18 +287,18 @@ module attributes {transform.with_named_sequence} {
 #map = affine_map<(d0, d1) -> (d0, d1)>
 
   // CHECK-LABEL:   func.func @linalg_generic_update_all_function_inputs_outputs(
-  // CHECK-SAME:                                                                 %[[VAL_0:.*]]: memref<8x4xf32, 1>,
-  // CHECK-SAME:                                                                 %[[VAL_1:.*]]: memref<8x4xf32, 1>) -> memref<8x4xf32, 1> {
-func.func @linalg_generic_update_all_function_inputs_outputs(%arg0: memref<8x4xf32, 1>, %arg1: memref<8x4xf32, 1>) -> memref<8x4xf32, 1> {
-  // CHECK:           %[[VAL_2:.*]] = memref.alloc() {alignment = 64 : i64} : memref<8x4xf32, 1>
-  // CHECK:           %[[VAL_3:.*]] = memref.subview %[[VAL_0]][0, 0] [4, 3] [1, 1] : memref<8x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
-  // CHECK:           %[[VAL_4:.*]] = memref.subview %[[VAL_1]][0, 0] [4, 3] [1, 1] : memref<8x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
-  // CHECK:           %[[VAL_5:.*]] = memref.subview %[[VAL_2]][0, 0] [4, 3] [1, 1] : memref<8x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
-
-  %alloc = memref.alloc() {alignment = 64 : i64} : memref<8x4xf32, 1>
-  %subview = memref.subview %arg0[0, 0] [4, 3] [1, 1] : memref<8x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
-  %subview_0 = memref.subview %arg1[0, 0] [4, 3] [1, 1] : memref<8x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
-  %subview_1 = memref.subview %alloc[0, 0] [4, 3] [1, 1] : memref<8x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
+  // CHECK-SAME:                                                                 %[[VAL_0:.*]]: memref<3x4xf32, 1>,
+  // CHECK-SAME:                                                                 %[[VAL_1:.*]]: memref<3x4xf32, 1>) -> memref<3x4xf32, 1> {
+func.func @linalg_generic_update_all_function_inputs_outputs(%arg0: memref<3x4xf32, 1>, %arg1: memref<3x4xf32, 1>) -> memref<3x4xf32, 1> {
+  // CHECK:           %[[VAL_2:.*]] = memref.alloc() {alignment = 64 : i64} : memref<3x4xf32, 1>
+  // CHECK:           %[[VAL_3:.*]] = memref.subview %[[VAL_0]][0, 0] [4, 3] [1, 1] : memref<3x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
+  // CHECK:           %[[VAL_4:.*]] = memref.subview %[[VAL_1]][0, 0] [4, 3] [1, 1] : memref<3x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
+  // CHECK:           %[[VAL_5:.*]] = memref.subview %[[VAL_2]][0, 0] [4, 3] [1, 1] : memref<3x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
+
+  %alloc = memref.alloc() {alignment = 64 : i64} : memref<3x4xf32, 1>
+  %subview = memref.subview %arg0[0, 0] [4, 3] [1, 1] : memref<3x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
+  %subview_0 = memref.subview %arg1[0, 0] [4, 3] [1, 1] : memref<3x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
+  %subview_1 = memref.subview %alloc[0, 0] [4, 3] [1, 1] : memref<3x4xf32, 1> to memref<4x3xf32, strided<[4, 1]>, 1>
 
   // CHECK:           %[[VAL_6:.*]] = arith.constant 0 : index
   // CHECK:           %[[VAL_7:.*]] = arith.constant 4 : index
@@ -376,10 +376,10 @@ func.func @linalg_generic_update_all_function_inputs_outputs(%arg0: memref<8x4xf
   // CHECK:           memref.dealloc %[[VAL_22]] : memref<48xi8, #gpu.address_space<workgroup>>
   // CHECK:           memref.dealloc %[[VAL_41]] : memref<48xi8, #gpu.address_space<workgroup>>
   // CHECK:           memref.dealloc %[[VAL_60]] : memref<48xi8, #gpu.address_space<workgroup>>
-  // CHECK:           return %[[VAL_2]] : memref<8x4xf32, 1>
+  // CHECK:           return %[[VAL_2]] : memref<3x4xf32, 1>
   // CHECK:         }
 
-  return %alloc : memref<8x4xf32, 1>
+  return %alloc : memref<3x4xf32, 1>
 }