What is d32 format?

[apivovarov]

Sorry for posting my question as an issue

Many quantized hexagon_nn ops has _d32 variant. What is D32 format and how it is different from "flat"?
e.g.

QuantizedAdd_8p8to8 - elementwisely adds Input A and Input B together. (flat format)
0: Input A data (quint8 tensor)
1: Input B data (quint8 tensor)
...
0: Output data (quint8 tensor)

QuantizedAdd_8p8to8_d32 - Elementwise Add; inputs and output are in d32 format
0: Input A data (qint8)
1: Input B data (qint8)
...
0: Output data (quint8)

[lee-bin]

These two files clarify the format, d32_diagram.png, d32.txt.