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oneDNN/examples/cnn_inference_int8.cpp
2022-10-19 17:40:40 -07:00

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* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
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/// @example cnn_inference_int8.cpp
/// @copybrief cnn_inference_int8_cpp
/// > Annotated version: @ref cnn_inference_int8_cpp
/// @page cnn_inference_int8_cpp CNN int8 inference example
/// This C++ API example demonstrates how to run AlexNet's conv3 and relu3
/// with int8 data type.
///
/// > Example code: @ref cnn_inference_int8.cpp
#include <stdexcept>
#include "oneapi/dnnl/dnnl.hpp"
#include "example_utils.hpp"
using namespace dnnl;
void simple_net_int8(engine::kind engine_kind) {
using tag = memory::format_tag;
using dt = memory::data_type;
auto eng = engine(engine_kind, 0);
stream s(eng);
const int batch = 8;
/// Configure tensor shapes
/// @snippet cnn_inference_int8.cpp Configure tensor shapes
//[Configure tensor shapes]
// AlexNet: conv3
// {batch, 256, 13, 13} (x) {384, 256, 3, 3}; -> {batch, 384, 13, 13}
// strides: {1, 1}
memory::dims conv_src_tz = {batch, 256, 13, 13};
memory::dims conv_weights_tz = {384, 256, 3, 3};
memory::dims conv_bias_tz = {384};
memory::dims conv_dst_tz = {batch, 384, 13, 13};
memory::dims conv_strides = {1, 1};
memory::dims conv_padding = {1, 1};
//[Configure tensor shapes]
/// Next, the example configures the scales used to quantize f32 data
/// into int8. For this example, the scaling value is chosen as an
/// arbitrary number, although in a realistic scenario, it should be
/// calculated from a set of precomputed values as previously mentioned.
/// @snippet cnn_inference_int8.cpp Choose scaling factors
//[Choose scaling factors]
// Choose scaling factors for input, weight, output and bias quantization
std::vector<float> src_scales = {1.8f};
std::vector<float> weight_scales = {2.0f};
std::vector<float> bias_scales = {1.0f};
std::vector<float> dst_scales = {0.55f};
// Choose channel-wise scaling factors for convolution
std::vector<float> conv_scales(384);
const int scales_half = 384 / 2;
std::fill(conv_scales.begin(), conv_scales.begin() + scales_half, 0.3f);
std::fill(conv_scales.begin() + scales_half + 1, conv_scales.end(), 0.8f);
//[Choose scaling factors]
/// The *source, weights, bias* and *destination* datasets use the single-scale
/// format with mask set to '0', while the *output* from the convolution
/// (conv_scales) will use the array format where mask = 2 corresponding
/// to the output dimension.
/// @snippet cnn_inference_int8.cpp Set scaling mask
//[Set scaling mask]
const int src_mask = 0;
const int weight_mask = 0;
const int bias_mask = 0;
const int dst_mask = 0;
const int conv_mask = 2; // 1 << output_channel_dim
//[Set scaling mask]
// Allocate input and output buffers for user data
std::vector<float> user_src(batch * 256 * 13 * 13);
std::vector<float> user_dst(batch * 384 * 13 * 13);
// Allocate and fill buffers for weights and bias
std::vector<float> conv_weights(product(conv_weights_tz));
std::vector<float> conv_bias(product(conv_bias_tz));
/// Create the memory primitives for user data (source, weights, and bias).
/// The user data will be in its original 32-bit floating point format.
/// @snippet cnn_inference_int8.cpp Allocate buffers
//[Allocate buffers]
auto user_src_memory = memory({{conv_src_tz}, dt::f32, tag::nchw}, eng);
write_to_dnnl_memory(user_src.data(), user_src_memory);
auto user_weights_memory
= memory({{conv_weights_tz}, dt::f32, tag::oihw}, eng);
write_to_dnnl_memory(conv_weights.data(), user_weights_memory);
auto user_bias_memory = memory({{conv_bias_tz}, dt::f32, tag::x}, eng);
write_to_dnnl_memory(conv_bias.data(), user_bias_memory);
//[Allocate buffers]
/// Create a memory descriptor for each convolution parameter.
/// The convolution data uses 8-bit integer values, so the memory
/// descriptors are configured as:
///
/// * 8-bit unsigned (u8) for source and destination.
/// * 8-bit signed (s8) for bias and weights.
///
/// > **Note**
/// > The destination type is chosen as *unsigned* because the
/// > convolution applies a ReLU operation where data results \f$\geq 0\f$.
/// @snippet cnn_inference_int8.cpp Create convolution memory descriptors
//[Create convolution memory descriptors]
auto conv_src_md = memory::desc({conv_src_tz}, dt::u8, tag::any);
auto conv_bias_md = memory::desc({conv_bias_tz}, dt::s8, tag::any);
auto conv_weights_md = memory::desc({conv_weights_tz}, dt::s8, tag::any);
auto conv_dst_md = memory::desc({conv_dst_tz}, dt::u8, tag::any);
//[Create convolution memory descriptors]
/// Configuring int8-specific parameters in an int8 primitive is done
/// via the Attributes Primitive. Create an attributes object for the
/// convolution and configure it accordingly.
/// @snippet cnn_inference_int8.cpp Configure scaling
//[Configure scaling]
primitive_attr conv_attr;
conv_attr.set_output_scales_mask(conv_mask);
auto oscale_md = memory::desc({384}, dt::f32, tag::x);
auto oscale_memory = memory(oscale_md, eng);
write_to_dnnl_memory(conv_scales.data(), oscale_memory);
//[Configure scaling]
/// The ReLU layer from Alexnet is executed through the PostOps feature. Create
/// a PostOps object and configure it to execute an _eltwise relu_ operation.
/// @snippet cnn_inference_int8.cpp Configure post-ops
//[Configure post-ops]
const float ops_scale = 1.f;
const float ops_alpha = 0.f; // relu negative slope
const float ops_beta = 0.f;
post_ops ops;
ops.append_eltwise(ops_scale, algorithm::eltwise_relu, ops_alpha, ops_beta);
conv_attr.set_post_ops(ops);
//[Configure post-ops]
// check if int8 convolution is supported
try {
convolution_forward::primitive_desc(eng, prop_kind::forward,
algorithm::convolution_direct, conv_src_md, conv_weights_md,
conv_bias_md, conv_dst_md, conv_strides, conv_padding,
conv_padding, conv_attr);
} catch (error &e) {
if (e.status == dnnl_unimplemented)
throw example_allows_unimplemented {
"No int8 convolution implementation is available for this "
"platform.\n"
"Please refer to the developer guide for details."};
// on any other error just re-throw
throw;
}
/// Create a primitive descriptor passing the int8 memory descriptors
/// and int8 attributes to the constructor. The primitive
/// descriptor for the convolution will contain the specific memory
/// formats for the computation.
/// @snippet cnn_inference_int8.cpp Create convolution primitive descriptor
//[Create convolution primitive descriptor]
auto conv_prim_desc = convolution_forward::primitive_desc(eng,
prop_kind::forward, algorithm::convolution_direct, conv_src_md,
conv_weights_md, conv_bias_md, conv_dst_md, conv_strides,
conv_padding, conv_padding, conv_attr);
//[Create convolution primitive descriptor]
/// Create a memory for each of the convolution's data input
/// parameters (source, bias, weights, and destination). Using the convolution
/// primitive descriptor as the creation parameter enables oneDNN
/// to configure the memory formats for the convolution.
///
/// Scaling parameters are passed to the reorder primitive via the attributes
/// primitive.
///
/// User memory must be transformed into convolution-friendly memory
/// (for int8 and memory format). A reorder layer performs the data
/// transformation from f32 (the original user data) into int8 format
/// (the data used for the convolution). In addition, the reorder
/// transforms the user data into the required memory format (as explained
/// in the simple_net example).
///
/// @snippet cnn_inference_int8.cpp Quantize data and weights
//[Quantize data and weights]
auto conv_src_memory = memory(conv_prim_desc.src_desc(), eng);
primitive_attr src_attr;
src_attr.set_output_scales_mask(src_mask);
auto src_oscale_md = memory::desc({1}, dt::f32, tag::x);
auto src_oscale_memory = memory(src_oscale_md, eng);
write_to_dnnl_memory(src_scales.data(), src_oscale_memory);
auto src_reorder_pd
= reorder::primitive_desc(eng, user_src_memory.get_desc(), eng,
conv_src_memory.get_desc(), src_attr);
auto src_reorder = reorder(src_reorder_pd);
src_reorder.execute(s,
{{DNNL_ARG_FROM, user_src_memory}, {DNNL_ARG_TO, conv_src_memory},
{DNNL_ARG_ATTR_OUTPUT_SCALES, src_oscale_memory}});
auto conv_weights_memory = memory(conv_prim_desc.weights_desc(), eng);
primitive_attr weight_attr;
weight_attr.set_output_scales_mask(weight_mask);
auto wei_oscale_md = memory::desc({1}, dt::f32, tag::x);
auto wei_oscale_memory = memory(wei_oscale_md, eng);
write_to_dnnl_memory(weight_scales.data(), wei_oscale_memory);
auto weight_reorder_pd
= reorder::primitive_desc(eng, user_weights_memory.get_desc(), eng,
conv_weights_memory.get_desc(), weight_attr);
auto weight_reorder = reorder(weight_reorder_pd);
weight_reorder.execute(s,
{{DNNL_ARG_FROM, user_weights_memory},
{DNNL_ARG_TO, conv_weights_memory},
{DNNL_ARG_ATTR_OUTPUT_SCALES, wei_oscale_memory}});
auto conv_bias_memory = memory(conv_prim_desc.bias_desc(), eng);
primitive_attr bias_attr;
bias_attr.set_output_scales_mask(bias_mask);
auto bias_oscale_md = memory::desc({1}, dt::f32, tag::x);
auto bias_oscale_memory = memory(bias_oscale_md, eng);
write_to_dnnl_memory(bias_scales.data(), bias_oscale_memory);
auto bias_reorder_pd
= reorder::primitive_desc(eng, user_bias_memory.get_desc(), eng,
conv_bias_memory.get_desc(), bias_attr);
auto bias_reorder = reorder(bias_reorder_pd);
bias_reorder.execute(s,
{{DNNL_ARG_FROM, user_bias_memory}, {DNNL_ARG_TO, conv_bias_memory},
{DNNL_ARG_ATTR_OUTPUT_SCALES, bias_oscale_memory}});
//[Quantize data and weights]
auto conv_dst_memory = memory(conv_prim_desc.dst_desc(), eng);
/// Create the convolution primitive and add it to the net. The int8 example
/// computes the same Convolution +ReLU layers from AlexNet simple-net.cpp
/// using the int8 and PostOps approach. Although performance is not
/// measured here, in practice it would require less computation time to achieve
/// similar results.
/// @snippet cnn_inference_int8.cpp Create convolution primitive
//[Create convolution primitive]
auto conv = convolution_forward(conv_prim_desc);
conv.execute(s,
{{DNNL_ARG_SRC, conv_src_memory},
{DNNL_ARG_WEIGHTS, conv_weights_memory},
{DNNL_ARG_BIAS, conv_bias_memory},
{DNNL_ARG_DST, conv_dst_memory},
{DNNL_ARG_ATTR_OUTPUT_SCALES, oscale_memory}});
//[Create convolution primitive]
/// @page cnn_inference_int8_cpp
/// Finally, *dst memory* may be dequantized from int8 into the original
/// f32 format. Create a memory primitive for the user data in the original
/// 32-bit floating point format and then apply a reorder to transform the
/// computation output data.
/// @snippet cnn_inference_int8.cpp Dequantize the result
///[Dequantize the result]
auto user_dst_memory = memory({{conv_dst_tz}, dt::f32, tag::nchw}, eng);
write_to_dnnl_memory(user_dst.data(), user_dst_memory);
primitive_attr dst_attr;
dst_attr.set_output_scales_mask(dst_mask);
auto dst_oscale_md = memory::desc({1}, dt::f32, tag::x);
auto dst_oscale_memory = memory(dst_oscale_md, eng);
write_to_dnnl_memory(dst_scales.data(), dst_oscale_memory);
auto dst_reorder_pd
= reorder::primitive_desc(eng, conv_dst_memory.get_desc(), eng,
user_dst_memory.get_desc(), dst_attr);
auto dst_reorder = reorder(dst_reorder_pd);
dst_reorder.execute(s,
{{DNNL_ARG_FROM, conv_dst_memory}, {DNNL_ARG_TO, user_dst_memory},
{DNNL_ARG_ATTR_OUTPUT_SCALES, dst_oscale_memory}});
//[Dequantize the result]
s.wait();
}
int main(int argc, char **argv) {
return handle_example_errors(
simple_net_int8, parse_engine_kind(argc, argv));
}