The set of available operators and the quantization numerics also depend on the backend being used to run quantized models. Currently quantized operators are supported only for CPU inference in the following backends: x86 and ARM. Both the quantization configuration (how tensors should be quantized and the quantized kernels (arithmetic with quantized tensors) are backend dependent. One can specify the backend by doing:
import torchbackend='fbgemm'
# 'fbgemm' for server, 'qnnpack' for mobile
my_model.qconfig = torch.quantization.get_default_qconfig(backend)
# prepare and convert model
# Set the backend on which the quantized kernels need to be run
torch.backends.quantized.engine=backend
