“068bfbb817611c856acd8c535de2b33a6126786c”上不存在“paddle/legacy/math/CpuSparseMatrix.cpp”
* add sparse support for sum op * typo fix * fix gpu build error * fix unittest error * typo fix * infer var type and shape in op_test * follow comments * fix build error * bypass some unittests depend on NetOp