[Mlir-commits] [mlir] [mlir][linalg] Update createWriteOrMaskedWrite (PR #174810)

Andrzej WarzyƄski llvmlistbot at llvm.org
Wed Jan 7 10:54:31 PST 2026


https://github.com/banach-space updated https://github.com/llvm/llvm-project/pull/174810

>From f5570b1f6d87c2843b45207c50e85253c61d84bd Mon Sep 17 00:00:00 2001
From: Andrzej Warzynski <andrzej.warzynski at arm.com>
Date: Wed, 7 Jan 2026 17:04:34 +0000
Subject: [PATCH] [mlir][linalg] Update createWriteOrMaskedWrite

`createWriteOrMaskedWrite` is used extensively in the Linalg vectorizer.
When a write uses non-zero indices, the helper currently computes mask
sizes as if the write started at 0 (`size = dim(d)`), which can produce
incorrect `vector.create_mask` operands for the generated
`vector.transfer_write`. Instead, the mask size should be computed as
`size = dim(d) - write_index(d)`.

EXAMPLE
-------
Let`s use this example to illustrate:
```mlir
%res = tensor.insert_slice
    %src into %dest[0, %c2] [5, 1] [1, 1] : tensor<5x1xi32> into tensor<?x3xi32>
```

This op is vectorized as a pair of `vector.transfer_read` +
`vector.transfer_write` ops. When calculating the mask for the
vector.transfer_write operation, the write indices should be taken into
account (*):
```mlir
  %dim = tensor.dim %dest, %c_0 : tensor<?x3xi32>
  // Subtract dim-0 and idx-0
  %mask_size_0 = arith.subi %dim, %c0 : index
  %x3 = arith.constant 3 : index
  // Subtract dim-1 and idx-1
  %mask_size_1 = arith.subi %c3, %c2 : index
  %mask = vector.create_mask %mask_size_0, %mask_size_1 : vector<8x1xi1>
```

Currently, the mask is incorrectly computed as:
```mlir
  %dim = tensor.dim %dest, %c_0 : tensor<?x3xi32>
  %mask = vector.create_mask %dim, %c3 : vector<8x1xi1>
```

This PR fixes that.

(*) Vectorized with `transform.structured.vectorize %0 vector_sizes [8, 1]`
---
 .../Linalg/Transforms/Vectorization.cpp       | 20 ++++++--
 .../Linalg/vectorization/insert-slice.mlir    | 49 ++++++++++++-------
 2 files changed, 49 insertions(+), 20 deletions(-)

diff --git a/mlir/lib/Dialect/Linalg/Transforms/Vectorization.cpp b/mlir/lib/Dialect/Linalg/Transforms/Vectorization.cpp
index 2b76c24334c0a..a0ac74db4ab1a 100644
--- a/mlir/lib/Dialect/Linalg/Transforms/Vectorization.cpp
+++ b/mlir/lib/Dialect/Linalg/Transforms/Vectorization.cpp
@@ -1711,7 +1711,8 @@ createWriteOrMaskedWrite(OpBuilder &builder, Location loc, Value vecToStore,
   }
 
   // If missing, initialize the write indices to 0.
-  assert((writeIndices.empty() ||
+  bool useDefaultWriteIdxs = writeIndices.empty();
+  assert((useDefaultWriteIdxs ||
           writeIndices.size() == static_cast<size_t>(destRank)) &&
          "Invalid number of write indices!");
   if (writeIndices.empty()) {
@@ -1742,8 +1743,21 @@ createWriteOrMaskedWrite(OpBuilder &builder, Location loc, Value vecToStore,
       isa<MemRefType>(dest.getType())
           ? memref::getMixedSizes(builder, loc, dest)
           : tensor::getMixedSizes(builder, loc, dest);
-  SmallVector<OpFoldResult> maskSizes(destSizes.end() - vecToStoreRank,
-                                      destSizes.end());
+
+  // Compute sizes for write-mask
+  SmallVector<OpFoldResult> maskSizes;
+  if (useDefaultWriteIdxs) {
+    maskSizes = SmallVector<OpFoldResult>(destSizes.end() - vecToStoreRank,
+                                          destSizes.end());
+  } else {
+    size_t diff = destShape.size() - vecToStoreRank;
+    for (int64_t idx = 0; idx < vecToStoreRank; idx++) {
+      auto value =
+          getValueOrCreateConstantIndexOp(builder, loc, destSizes[diff + idx]);
+      auto neg = arith::SubIOp::create(builder, loc, value, writeIndices[idx]);
+      maskSizes.push_back(OpFoldResult(neg));
+    }
+  }
 
   if (isMaskTriviallyFoldable(maskSizes, writeIndices, destShape,
                               vecToStoreShape))
diff --git a/mlir/test/Dialect/Linalg/vectorization/insert-slice.mlir b/mlir/test/Dialect/Linalg/vectorization/insert-slice.mlir
index 0563c21f220eb..8f96b240468ef 100644
--- a/mlir/test/Dialect/Linalg/vectorization/insert-slice.mlir
+++ b/mlir/test/Dialect/Linalg/vectorization/insert-slice.mlir
@@ -26,13 +26,17 @@ func.func private @insert_slice_static_sizes(%source: tensor<?x3x?x1xi32>) -> te
 // CHECK-DAG:       %[[C_1:.*]] = arith.constant 1 : index
 // CHECK:           %[[MASK_READ:.*]] = vector.create_mask %[[C_5]], %[[C_1]] : vector<8x1xi1>
 // CHECK:           %[[READ:.*]] = vector.mask %[[MASK_READ]] { vector.transfer_read %[[SRC_SLICE]][%[[C_0]], %[[C_0]]], %[[PAD]] {{.*}} : tensor<5x1xi32>, vector<8x1xi32> } : vector<8x1xi1> -> vector<8x1xi32>
-// CHECK:           %[[C_0_1:.*]] = arith.constant 0 : index
+// CHECK:           %[[C_0_2:.*]] = arith.constant 0 : index
 // CHECK:           %[[C_5_1:.*]] = arith.constant 5 : index
+// CHECK:           %[[SUBI_0:.*]] = arith.subi %[[C_5_1]], %[[C_0_2]] : index
 // CHECK:           %[[C_3:.*]] = arith.constant 3 : index
-// CHECK:           %[[MASK_WRITE:.*]] = vector.create_mask %[[C_5_1]], %[[C_3]] : vector<8x1xi1>
-// CHECK:           %[[RES:.*]] = vector.mask %[[MASK_WRITE]] { vector.transfer_write %[[READ]], %[[INIT]][%[[C_0_1]], %[[C_2]]]  {in_bounds = [true, true]} : vector<8x1xi32>, tensor<5x3xi32> } : vector<8x1xi1> -> tensor<5x3xi32>
+// CHECK:           %[[SUBI_1:.*]] = arith.subi %[[C_3]], %[[C_2]] : index
+// CHECK:           %[[MASK_WRITE:.*]] = vector.create_mask %[[SUBI_0]], %[[SUBI_1]] : vector<8x1xi1>
+// CHECK:           %[[RES:.*]] = vector.mask %[[MASK_WRITE]] { vector.transfer_write %[[READ]], %[[INIT]][%[[C_0_2]], %[[C_2]]]  {in_bounds = [true, true]} : vector<8x1xi32>, tensor<5x3xi32> } : vector<8x1xi1> -> tensor<5x3xi32>
 // CHECK:           return %[[RES]] : tensor<5x3xi32>
 
+
+
 module attributes {transform.with_named_sequence} {
  transform.named_sequence @__transform_main(%arg0: !transform.any_op {transform.readonly}) {
    %0 = transform.structured.match ops{["tensor.insert_slice"]} in %arg0 : (!transform.any_op) -> !transform.any_op
@@ -69,11 +73,13 @@ func.func private @insert_slice_dynamic_src_dim(%source: tensor<?x3x?x1xi32>, %s
 // CHECK-DAG:       %[[D0:.*]] = tensor.dim %[[SRC_SLICE]], %[[C_0_2]] : tensor<?x1xi32>
 // CHECK:           %[[MASK:.*]] = vector.create_mask %[[D0]], %[[C_1]] : vector<8x1xi1>
 // CHECK:           %[[READ:.*]] = vector.mask %[[MASK]] { vector.transfer_read %[[SRC_SLICE]][%[[C_0_1]], %[[C_0_1]]], %[[PAD]] {{.*}} : tensor<?x1xi32>, vector<8x1xi32> } : vector<8x1xi1> -> vector<8x1xi32>
-// CHECK:           %[[C_0_1:.*]] = arith.constant 0 : index
-// CHECK:           %[[C_5_1:.*]] = arith.constant 5 : index
-// CHECK:           %[[C_3:.*]] = arith.constant 3 : index
-// CHECK:           %[[MASK_WRITE:.*]] = vector.create_mask %[[C_5_1]], %[[C_3]] : vector<8x1xi1>
-// CHECK:           %[[RES:.*]] = vector.mask %[[MASK_WRITE]] { vector.transfer_write %[[READ]], %[[INIT]][%[[C_0_1]], %[[C_2]]]  {in_bounds = [true, true]} : vector<8x1xi32>, tensor<5x3xi32> } : vector<8x1xi1> -> tensor<5x3xi32>
+// CHECK:           %[[C_0_2:.*]] = arith.constant 0 : index
+// CHECK:           %[[C_5_2:.*]] = arith.constant 5 : index
+// CHECK:           %[[SUBI_0:.*]] = arith.subi %[[C_5_2]], %[[C_0_2]] : index
+// CHECK:           %[[C_3_1:.*]] = arith.constant 3 : index
+// CHECK:           %[[SUBI_1:.*]] = arith.subi %[[C_3_1]], %[[C_2]] : index
+// CHECK:           %[[MASK_WRITE:.*]] = vector.create_mask %[[SUBI_0]], %[[SUBI_1]] : vector<8x1xi1>
+// CHECK:           %[[RES:.*]] = vector.mask %[[MASK_WRITE]] { vector.transfer_write %[[READ]], %[[INIT]][%[[C_0_2]], %[[C_2]]]  {in_bounds = [true, true]} : vector<8x1xi32>, tensor<5x3xi32> } : vector<8x1xi1> -> tensor<5x3xi32>
 // CHECK:           return %[[RES]] : tensor<5x3xi32>
 
  module attributes {transform.with_named_sequence} {
@@ -111,12 +117,16 @@ func.func private @insert_slice_dynamic_dest_dim(%source: tensor<?x3x?x1xi32>, %
 // CHECK-DAG:       %[[C_0:.*]] = arith.constant 0 : index
 // CHECK-DAG:       %[[C_0_1:.*]] = arith.constant 0 : index
 // CHECK:           %[[READ:.*]] = vector.mask %[[MASK]] { vector.transfer_read %[[SRC_SLICE]][%[[C_0_1]], %[[C_0_1]]], %[[PAD]] {{.*}} : tensor<5x1xi32>, vector<8x1xi32> } : vector<8x1xi1> -> vector<8x1xi32>
-// CHECK:           %[[C_0_1:.*]] = arith.constant 0 : index
+
 // CHECK:           %[[C_0_2:.*]] = arith.constant 0 : index
-// CHECK:           %[[DIM:.*]] = tensor.dim %[[INIT]], %[[C_0_2]] : tensor<?x3xi32>
+// CHECK:           %[[C_0_3:.*]] = arith.constant 0 : index
+// CHECK:           %[[DIM_0:.*]] = tensor.dim %[[INIT]], %[[C_0_3]] : tensor<?x3xi32>
+// CHECK:           %[[SUBI_0:.*]] = arith.subi %[[DIM_0]], %[[C_0_2]] : index
 // CHECK:           %[[C_3:.*]] = arith.constant 3 : index
-// CHECK:           %[[MASK_WRITE:.*]] = vector.create_mask %[[DIM]], %[[C_3]] : vector<8x1xi1>
-// CHECK:           %[[RES:.*]] = vector.mask %[[MASK_WRITE]] { vector.transfer_write %[[READ]], %[[INIT]][%[[C_0_1]], %[[C_2]]]  {in_bounds = [true, true]} : vector<8x1xi32>, tensor<?x3xi32> } : vector<8x1xi1> -> tensor<?x3xi32>
+// CHECK:           %[[SUBI_1:.*]] = arith.subi %[[C_3]], %[[C_2]] : index
+// CHECK:           %[[MASK_WRITE:.*]] = vector.create_mask %[[SUBI_0]], %[[SUBI_1]] : vector<8x1xi1>
+
+// CHECK:           %[[RES:.*]] = vector.mask %[[MASK_WRITE]] { vector.transfer_write %[[READ]], %[[INIT]][%[[C_0_2]], %[[C_2]]]  {in_bounds = [true, true]} : vector<8x1xi32>, tensor<?x3xi32> } : vector<8x1xi1> -> tensor<?x3xi32>
 // CHECK:           return %[[RES]] : tensor<?x3xi32>
 
  module attributes {transform.with_named_sequence} {
@@ -155,12 +165,17 @@ func.func private @insert_slice_dynamic_source_and_dest_dim(%source: tensor<?x3x
 // CHECK:           %[[C1:.*]] = arith.constant 1 : index
 // CHECK:           %[[MASK:.*]] = vector.create_mask %[[D0]], %[[C1]] : vector<8x1xi1>
 // CHECK:           %[[READ:.*]] = vector.mask %[[MASK]] { vector.transfer_read %[[SRC_SLICE]][%[[C0_1]], %[[C0_1]]], %[[PAD]] {{.*}} : tensor<?x1xi32>, vector<8x1xi32> } : vector<8x1xi1> -> vector<8x1xi32>
-// CHECK:           %[[C_0_1:.*]] = arith.constant 0 : index
-// CHECK:           %[[C_0_2:.*]] = arith.constant 0 : index
-// CHECK:           %[[DIM:.*]] = tensor.dim %[[INIT]], %[[C_0_2]] : tensor<?x3xi32>
+
+// CHECK:           %[[C_0_3:.*]] = arith.constant 0 : index
+// CHECK:           %[[C_0_4:.*]] = arith.constant 0 : index
+// CHECK:           %[[DIM_1:.*]] = tensor.dim %[[INIT]], %[[C_0_4]] : tensor<?x3xi32>
+// CHECK:           %[[SUBI_0:.*]] = arith.subi %[[DIM_1]], %[[C_0_3]] : index
 // CHECK:           %[[C_3:.*]] = arith.constant 3 : index
-// CHECK:           %[[MASK_WRITE:.*]] = vector.create_mask %[[DIM]], %[[C_3]] : vector<8x1xi1>
-// CHECK:           %[[RES:.*]] = vector.mask %[[MASK_WRITE]] { vector.transfer_write %[[READ]], %[[INIT]][%[[C_0_1]], %[[C_2]]]  {in_bounds = [true, true]} : vector<8x1xi32>, tensor<?x3xi32> } : vector<8x1xi1> -> tensor<?x3xi32>
+// CHECK:           %[[SUBI_1:.*]] = arith.subi %[[C_3]], %[[C_2]] : index
+// CHECK:           %[[MASK_WRITE:.*]] = vector.create_mask %[[SUBI_0]], %[[SUBI_1]] : vector<8x1xi1>
+
+// CHECK:           %[[RES:.*]] = vector.mask %[[MASK_WRITE]] { vector.transfer_write %[[READ]], %[[INIT]][%[[C_0_3]], %[[C_2]]]  {in_bounds = [true, true]} : vector<8x1xi32>, tensor<?x3xi32> } : vector<8x1xi1> -> tensor<?x3xi32>
+
 
  module attributes {transform.with_named_sequence} {
   transform.named_sequence @__transform_main(%arg0: !transform.any_op {transform.readonly}) {



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