Contents

Quantize

General

Quantize operation converts a f32 tensor to a quantized (u8/s8) tensor. It supports both per-tensor and per-channel asymmetric linear quantization. Output data type is specified in output tensor data type. Rounding mode is library-implementation defined.

For per-tensor quantization:

\[\dst_{i} = round(\src_{i} / scale + zp)\]

For per-channel quantization, taking channel axis = 1 as an example:

\[dst_{\cdots,i,\cdots,\cdots} = round(\src_{\cdots,i,\cdots,\cdots} / scale_i + zp_i), i \in {[0, ic-1]}\]

where \(ic\) is the number of channels.

Operation attributes

Attribute Name

De

qtype

Specifies which quantization type is used.

string

per_tensor (default), per_channel

Optional

axis

Specifies dimension on which per-channel quantization is applied.

s64

A s64 value in the range of [-r, r-1] where r = rank(src), 1 by default

Optional

scales

Scalings applied on the src data.

f32

A f32 list (only contain one element if qtype is per_tensor )

Required

zps

Offset values that maps to float zero.

s64

A s64 list (only contain one element if qtype is per_tensor )

Required

Execution arguments

The inputs and outputs must be provided according to below index order when constructing an operation.

Inputs

Index

Argu

0

src

Required

Outputs

Index

Argu

0

dst

Required

Supported data types

Quantize operation supports the following data type combinations.

Src

D

f32

s8, u8

Note

This operation is to support int8 quantization model.

PReLUBackward Reciprocal