auto spmd_info = phi::distributed::StackGradInferSpmd(dist_meta_out_grad, axis);
DebugInfoForInferSpmd("StackGradOp", spmd_info);
// Raise error here, because its infer spmd function has only one input, so 
// spmd_info.first.size() is 1u. 
PADDLE_ENFORCE_EQ(spmd_info.first.size(), 2u, common::errors::Unavailable(
    "Size of spmd_info.first for op[SumGradOp]is unexpected."));
// The input x's dist_attr is not in spmd_info, so also incorrect here.
for(auto& arg_dist : spmd_info.first) {{
    dist_operand_attrs.push_back(CvtToPirAttr(arg_dist));
}}

auto dist_meta_out_grad = CvtToDistMetaTensor(out_grad_.type().dyn_cast<DistDenseTensorType>());
auto spmd_info = phi::distributed::StackGradInferSpmd(dist_meta_out_grad, axis);
DebugInfoForInferSpmd("StackGradOp", spmd_info);
// spmd_info.first.size() is equal to infer_spmd function's input size
PADDLE_ENFORCE_EQ(spmd_info.first.size(), 1u, common::errors::Unavailable(
    "Size of spmd_info.first for op[StackGradOp]is unexpected."));
// Get the dist_attr from operation input
dist_operand_attrs.push_back(GetTensorDistAttrArray(x));
dist_operand_attrs.push_back(CvtToPirAttr(spmd_info.first[0]));