Fixing small bug in CUSPARSE spmm w/ CUDA 12.2 (#2117)

Authors:
  - Corey J. Nolet (https://github.com/cjnolet)

Approvers:
  - Divye Gala (https://github.com/divyegala)

URL: #2117

cpp/include/raft/sparse/linalg/spmm.hpp

@@ -60,12 +60,19 @@ void spmm(raft::resources const& handle,
 {
   bool is_row_major = detail::is_row_major(y, z);
 
+  auto z_tmp = raft::make_device_matrix<ValueType, IndexType>(handle, z.extent(0), z.extent(1));
+  auto z_tmp_view = raft::make_device_strided_matrix_view<ValueType, IndexType, LayoutPolicyZ>(
+    z_tmp.data_handle(), z.extent(0), z.extent(1), is_row_major ? z.stride(0) : z.stride(1));
+
   auto descr_x = detail::create_descriptor(x);
   auto descr_y = detail::create_descriptor(y);
-  auto descr_z = detail::create_descriptor(z);
+  auto descr_z = detail::create_descriptor(z_tmp_view);
 
   detail::spmm(handle, trans_x, trans_y, is_row_major, alpha, descr_x, descr_y, beta, descr_z);
 
+  raft::copy(
+    z.data_handle(), z_tmp.data_handle(), z_tmp.size(), raft::resource::get_cuda_stream(handle));
+
   RAFT_CUSPARSE_TRY_NO_THROW(cusparseDestroySpMat(descr_x));
   RAFT_CUSPARSE_TRY_NO_THROW(cusparseDestroyDnMat(descr_y));
   RAFT_CUSPARSE_TRY_NO_THROW(cusparseDestroyDnMat(descr_z));
@@ -76,4 +83,4 @@ void spmm(raft::resources const& handle,
 }  // end namespace sparse
 }  // end namespace raft
 
-#endif
+#endif