diff --git a/mlir/include/mlir/Dialect/GPU/IR/GPUOps.td b/mlir/include/mlir/Dialect/GPU/IR/GPUOps.td
--- a/mlir/include/mlir/Dialect/GPU/IR/GPUOps.td
+++ b/mlir/include/mlir/Dialect/GPU/IR/GPUOps.td
@@ -1902,6 +1902,8 @@
   }];
 }
 
+// TODO: add GPU_SDDMMOp
+
 def GPU_SpMMOp : GPU_Op<"spmm", [GPU_AsyncOpInterface]> {
   let summary = "SpMM operation";
   let description = [{
diff --git a/mlir/lib/Conversion/GPUCommon/GPUToLLVMConversion.cpp b/mlir/lib/Conversion/GPUCommon/GPUToLLVMConversion.cpp
--- a/mlir/lib/Conversion/GPUCommon/GPUToLLVMConversion.cpp
+++ b/mlir/lib/Conversion/GPUCommon/GPUToLLVMConversion.cpp
@@ -596,6 +596,8 @@
                   ConversionPatternRewriter &rewriter) const override;
 };
 
+// TODO: impl SDDMM Op lowering pass here
+
 class ConvertSpMMOpToGpuRuntimeCallPattern
     : public ConvertOpToGpuRuntimeCallPattern<gpu::SpMMOp> {
 public:
diff --git a/mlir/lib/Dialect/SparseTensor/Transforms/SparseGPUCodegen.cpp b/mlir/lib/Dialect/SparseTensor/Transforms/SparseGPUCodegen.cpp
--- a/mlir/lib/Dialect/SparseTensor/Transforms/SparseGPUCodegen.cpp
+++ b/mlir/lib/Dialect/SparseTensor/Transforms/SparseGPUCodegen.cpp
@@ -500,6 +500,8 @@
   return success();
 }
 
+// TODO: implement SDDMM rewriter here
+
 /// Match and rewrite SpMM kernel.
 static LogicalResult rewriteSpMM(PatternRewriter &rewriter,
                                  linalg::GenericOp op, bool enableRT) {