For C++ implementation, there are no plans to migrate quantization kernels.  For sparsity, we plan to follow the structure below:

./torch/aten/src/ATen
├── (...)
├── native
│   ├── ao_sparse  # New folder containing ops with sparse packed weights
│   │   ├── cpu
│   │   ├── cuda
│   │   └── quantized  # New folder with fused sparse and quantized packed weights
│   │       ├── cpu
│   │       └── cuda
│   ├── quantized  # Existing quantized kernels
│   │   ├── cpu
│   │   │   ├── kernels
│   │   │   └── qnnpack  # Existing mobile quantized and sparse kernels
│   │   ├── cuda
│   │   ├── QTensor.cpp
│   │   ├── library.cpp
│   │   └── (*.cpp, *.h)
│   └── sparse  # Existing folder containing torch.sparse methods
└── quantized  # Quantized Tensor definition and methods
    ├── QTensorImpl.{cpp,h}
    └── Quantizer.{cpp,h}