Well, I try to use symmetric quantization scheme, which will force the zero point to 128, because asymmetric quantization mode will cause some other effects to our project. In this case, as I suppose, the range is [-128, 127], and after ReLU, the range become [0, 127]. This seems to be wrong. In fact, I prefer to using qint8 as feature map’s data type, but qint8 is not supported.
So can I say that in fbgemm, the qconv calculate the unsigned integer summation first and then minus summation with zero points? And the summation may cause saturation.
Also, the different behaviors confuse me…