auto op = cast<SparseMatMulOp>(src_op);

    // Result type must be f32 for applying the pattern (currently this is
    // required by the op anyway but this might change).
    if (!mlir::cast<TensorType>(op.getProduct().getType())
             .getElementType()
             .isF32()) {
      return failure();
    }
    MLIRContext *context = rewriter.getContext();