The below compilation warning issue has been fixed.

src/top/tensor/matrix_op.cc:37:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < lshape.ndim() - 1; i++) oshape[i] = lshape[i];
                     ^
src/top/tensor/matrix_op.cc:38:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 1; i < rshape.ndim(); i++) oshape[i + lshape.ndim() - 1] = rshap