KellenSunderland commented on a change in pull request #13697: [MKLDNN] Enable
signed int8 support for convolution.
URL: https://github.com/apache/incubator-mxnet/pull/13697#discussion_r244628057
##########
File path: example/quantization/imagenet_gen_qsym_mkldnn.py
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@@ -140,8 +140,8 @@ def save_params(fname, arg_params, aux_params,
logger=None):
' thresholds. This mode is expected to produce
the best inference accuracy of all three'
' kinds of quantized models if the calibration
dataset is representative enough of the'
' inference dataset.')
- parser.add_argument('--quantized-dtype', type=str, default='uint8',
- choices=['int8', 'uint8'],
+ parser.add_argument('--quantized-dtype', type=str, default='auto',
Review comment:
So reading a bit more about this from
https://intel.github.io/mkl-dnn/ex_int8_simplenet.html
```C++
const std::vector<float> src_scales = { 1.8 };
const int src_mask = 0;
auto user_src_memory = memory({ { { conv_src_tz }, memory::data_type::f32,
memory::format::nchw }, cpu_engine }, user_src.data());
auto conv_src_md = memory::desc( { conv_src_tz }, memory::data_type::u8,
memory::format::any);
auto conv_desc = convolution_forward::desc(prop_kind::forward,
convolution_direct, conv_src_md, conv_weights_md, conv_bias_md,
conv_dst_md, conv_strides, conv_padding, conv_padding,
padding_kind::zero);
auto conv_prim_desc = convolution_forward::primitive_desc(conv_desc,
conv_attr, cpu_engine);
auto conv_src_memory = memory(conv_prim_desc.src_primitive_desc());
primitive_attr src_attr;
src_attr.set_int_output_round_mode(round_mode::round_nearest);
src_attr.set_output_scales(src_mask, src_scales);
auto src_reorder_pd =
reorder::primitive_desc(user_src_memory.get_primitive_desc(),
conv_src_memory.get_primitive_desc(), src_attr);
```
am I understanding correctly that we can convert from an fp32 input (with
negative values) to uint8 via a reorder primitive. Do we do this for the first
negative input into subgraphs handled by mkldnn? If so is there an advantage
to doing the reorder into a signed type as opposed to unsigned?
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