[Mlir-commits] [mlir] [mlir][sparse] Load the vector dialect in pre-sparsification-rewrite (PR #216491)

[Hamza Qureshi]

https://github.com/hamzaqureshi5 created https://github.com/llvm/llvm-project/pull/216491

Fixes #216273

`mlir-opt --pre-sparsification-rewrite` aborts on this input:

```mlir
#sparse = #sparse_tensor.encoding<{ map = (d0, d1) -> (d0 : dense, d1 : compressed) }>
func.func @print(%arg0: !llvm.ptr) {
  %0 = sparse_tensor.new %arg0 : !llvm.ptr to tensor<?x?xf32, #sparse>
  sparse_tensor.print %0 : tensor<?x?xf32, #sparse>
  llvm.return
}
```

```
LLVM ERROR: can't create Attribute 'mlir::vector::PrintPunctuationAttr' because
storage uniquer isn't initialized: the dialect was likely not loaded, ...
```

`PrintRewriter` lowers `sparse_tensor.print` into `vector.print` operations, but `PreSparsificationRewrite` does not list the vector dialect in `dependentDialects`. When the input does not use the dialect either, it is never loaded and building the punctuation attribute aborts.

The pass already declares the other dialects it needs, so this just adds the missing one.

Testing: added a `sparse_tensor.print` case to `mlir/test/Dialect/SparseTensor/pre_rewriting.mlir`, which does not otherwise mention the vector dialect. The test fails on main and passes with the change, and `mlir/test/Dialect/SparseTensor` stays at 113/113.

>From e376daebd6f89780b9d8ffae3b408a20201f6408 Mon Sep 17 00:00:00 2001
From: hamzaqureshi5 <hamza7771.861 at gmail.com>
Date: Sat, 15 Aug 2026 18:49:14 +0500
Subject: [PATCH] [mlir][sparse] Load the vector dialect in
 pre-sparsification-rewrite

The print rewrite lowers sparse_tensor.print into vector.print operations, but
the pass did not list the vector dialect as a dependent dialect. Running the
pass on input that does not otherwise use the dialect left it unloaded, and
creating vector::PrintPunctuationAttr aborted with an uninitialized storage
uniquer.

Fixes #216273
---
 .../mlir/Dialect/SparseTensor/Transforms/Passes.td   |  1 +
 mlir/test/Dialect/SparseTensor/pre_rewriting.mlir    | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/mlir/include/mlir/Dialect/SparseTensor/Transforms/Passes.td b/mlir/include/mlir/Dialect/SparseTensor/Transforms/Passes.td
index 207fab1366294..c4c83819f1e0e 100644
--- a/mlir/include/mlir/Dialect/SparseTensor/Transforms/Passes.td
+++ b/mlir/include/mlir/Dialect/SparseTensor/Transforms/Passes.td
@@ -105,6 +105,7 @@ def PreSparsificationRewrite : Pass<"pre-sparsification-rewrite", "ModuleOp"> {
     "linalg::LinalgDialect",
     "memref::MemRefDialect",
     "scf::SCFDialect",
+    "vector::VectorDialect",
   ];
 }
 
diff --git a/mlir/test/Dialect/SparseTensor/pre_rewriting.mlir b/mlir/test/Dialect/SparseTensor/pre_rewriting.mlir
index 5fdbb46e3d8b0..79c0bb93802e5 100644
--- a/mlir/test/Dialect/SparseTensor/pre_rewriting.mlir
+++ b/mlir/test/Dialect/SparseTensor/pre_rewriting.mlir
@@ -99,3 +99,15 @@ func.func @sparse_select(%cond: tensor<4x4xi1>,
   } -> tensor<4x4xf64, #DCSR>
   return %0 : tensor<4x4xf64, #DCSR>
 }
+
+// The print rewrite generates vector.print, so the pass has to load the vector
+// dialect even when the input does not use it.
+//
+// CHECK-LABEL: func.func @sparse_print(
+//  CHECK-SAME: %[[A:.*]]: tensor<?x?xf32, #sparse{{[0-9]*}}>)
+//       CHECK:   vector.print
+//       CHECK:   return
+func.func @sparse_print(%arg0: tensor<?x?xf32, #DCSR>) {
+  sparse_tensor.print %arg0 : tensor<?x?xf32, #DCSR>
+  return
+}