What is the purpose of reduce range

I go want to make a specific change in MOVINGAVERAGEPERCHANNELMINMAXOBSERVER. I saw reduced range exists. I saw the default setting for fbgemm for activation reduce range is set to true.

When should you set the reduced range to true or false?

Reduced range is forcing the quantization to use 7 bits instead of 8 bits. Due to internal implementation, FBGEMM needs this for the weight tensors.