diff --git a/mlir/test/Integration/Dialect/SparseTensor/GPU/CUDA/sparse-sampled-matmul-lib.mlir b/mlir/test/Integration/Dialect/SparseTensor/GPU/CUDA/sparse-sampled-matmul-lib.mlir
--- a/mlir/test/Integration/Dialect/SparseTensor/GPU/CUDA/sparse-sampled-matmul-lib.mlir
+++ b/mlir/test/Integration/Dialect/SparseTensor/GPU/CUDA/sparse-sampled-matmul-lib.mlir
@@ -1,8 +1,21 @@
 //
 // NOTE: this test requires gpu-sm80
 //
+// with RT lib:
+//
+// RUN: mlir-opt %s \
+// RUN:   --sparse-compiler="enable-runtime-library=true enable-gpu-libgen gpu-triple=nvptx64-nvidia-cuda gpu-chip=sm_80 gpu-features=+ptx71" \
+// RUN: | TENSOR0="%mlir_src_dir/test/Integration/data/test.mtx" \
+// RUN:   mlir-cpu-runner \
+// RUN:   --shared-libs=%mlir_cuda_runtime \
+// RUN:   --shared-libs=%mlir_c_runner_utils \
+// RUN:   --e entry --entry-point-result=void \
+// RUN: | FileCheck %s
+//
+// without RT lib:
+//
 // RUN: mlir-opt %s \
-// RUN:   --sparse-compiler="enable-runtime-library=true enable-gpu-libgen gpu-triple=nvptx64-nvidia-cuda gpu-chip=sm_80 gpu-features=+ptx71"  \
+// RUN:   --sparse-compiler="enable-runtime-library=false enable-gpu-libgen gpu-triple=nvptx64-nvidia-cuda gpu-chip=sm_80 gpu-features=+ptx71" \
 // RUN: | TENSOR0="%mlir_src_dir/test/Integration/data/test.mtx" \
 // RUN:   mlir-cpu-runner \
 // RUN:   --shared-libs=%mlir_cuda_runtime \
@@ -21,20 +34,21 @@
   indexing_maps = [
     affine_map<(i,j,k) -> (i,k)>,  // A
     affine_map<(i,j,k) -> (k,j)>,  // B
-    affine_map<(i,j,k) -> (i,j)>   // S (out)
+    affine_map<(i,j,k) -> (i,j)>   // S (in/out)
   ],
   iterator_types = ["parallel", "parallel", "reduction"],
-  doc = "X(i,j) += S(i,j) SUM_k A(i,k) B(k,j)"
+  doc = "S(i,j) += spy[S(i,j)] x SUM_k A(i,k) B(k,j)"
 }
 
 //
 // Integration test that lowers a kernel annotated as sparse to
-// actual sparse code, initializes a matching sparse storage scheme
-// from file, and runs the resulting code with the JIT compiler.
+// actual sparse code, initializes sparse storage schemes, and
+// runs the resulting code with the JIT compiler.
 //
 module {
   //
-  // A kernel that computes a sampled matrix matrix multiplication.
+  // A kernel that computes a sampled dense matrix matrix multiplication
+  // using a "spy" function and in-place update of the sampling sparse matrix.
   //
   func.func @sampled_dense_dense(%args: tensor<?x?xf32, #CSR>,
                                  %arga: tensor<?x?xf32>,
@@ -64,7 +78,7 @@
   func.func private @getTensorFilename(index) -> (!Filename)
 
   //
-  // Main driver that reads matrix from file and calls the sparse kernel.
+  // Main driver.
   //
   func.func @entry() {
     %d0 = arith.constant 0.0 : f32
@@ -74,11 +88,6 @@
     %c10 = arith.constant 10 : index
 
     // Initialize dense matrices.
-    %x = tensor.generate %c5, %c5 {
-    ^bb0(%i : index, %j : index):
-      tensor.yield %d0 : f32
-    } : tensor<?x?xf32>
-
     %a = tensor.generate %c5, %c10 {
     ^bb0(%i: index, %j: index):
       %p = arith.addi %i, %c1 : index
@@ -86,7 +95,6 @@
       %d = arith.sitofp %q : i32 to f32
       tensor.yield %d : f32
     } : tensor<?x?xf32>
-
     %b = tensor.generate %c10, %c5 {
     ^bb0(%i: index, %j: index):
       %p = arith.addi %j, %c1 : index
@@ -104,15 +112,42 @@
        : (tensor<?x?xf32, #CSR>,
           tensor<?x?xf32>, tensor<?x?xf32>) -> tensor<?x?xf32, #CSR>
 
+    //
     // Print the result for verification.
     //
     // CHECK: ( 11, 41.4, 42, 102.5, 93, 44.1, 164, 105.2, 255 )
+    //
     %vm = sparse_tensor.values %0 : tensor<?x?xf32, #CSR> to memref<?xf32>
     %vv = vector.transfer_read %vm[%c0], %d0 : memref<?xf32>, vector<9xf32>
     vector.print %vv : vector<9xf32>
 
+    // Create a much sparser sampling matrix.
+    %t = arith.constant sparse<[[0,0], [0,1], [1,0], [3,4], [7,7]],
+                               [1.0, 2.0, 3.0, 4.0, 5.0]
+			      > : tensor<8x8xf32>
+    %q = sparse_tensor.convert %t : tensor<8x8xf32> to tensor<?x?xf32, #CSR>
+    %a2 = arith.constant dense<2.0> : tensor<8x8xf32>
+    %b1 = arith.constant dense<1.0> : tensor<8x8xf32>
+    %a2c = tensor.cast %a2 : tensor<8x8xf32> to tensor<?x?xf32>
+    %b1c = tensor.cast %b1 : tensor<8x8xf32> to tensor<?x?xf32>
+
+    // Call the kernel again.
+    %1 = call @sampled_dense_dense(%q, %a2c, %b1c)
+       : (tensor<?x?xf32, #CSR>,
+          tensor<?x?xf32>, tensor<?x?xf32>) -> tensor<?x?xf32, #CSR>
+
+    //
+    // Print the result for verification.
+    //
+    // CHECK: ( ( 17, 18, 0, 0, 0, 0, 0, 0 ), ( 19, 0, 0, 0, 0, 0, 0, 0 ), ( 0, 0, 0, 0, 0, 0, 0, 0 ), ( 0, 0, 0, 0, 20, 0, 0, 0 ), ( 0, 0, 0, 0, 0, 0, 0, 0 ), ( 0, 0, 0, 0, 0, 0, 0, 0 ), ( 0, 0, 0, 0, 0, 0, 0, 0 ), ( 0, 0, 0, 0, 0, 0, 0, 21 ) )
+    //
+    %d = sparse_tensor.convert %1 : tensor<?x?xf32, #CSR> to tensor<?x?xf32>
+    %mm = vector.transfer_read %d[%c0, %c0], %d0 : tensor<?x?xf32>, vector<8x8xf32>
+    vector.print %mm : vector<8x8xf32>
+
     // Release the resources.
     bufferization.dealloc_tensor %0 : tensor<?x?xf32, #CSR>
+    bufferization.dealloc_tensor %1 : tensor<?x?xf32, #CSR>
 
     return
   }