quantization.cpp

#include <migraphx/quantization.hpp>
#include <migraphx/program.hpp>
#include <migraphx/instruction.hpp>
#include <migraphx/iterator_for.hpp>
#include <migraphx/op/convert.hpp>
#include <migraphx/op/capture.hpp>
#include <migraphx/stringutils.hpp>
#include <migraphx/ranges.hpp>
#include <utility>

namespace migraphx {
inline namespace MIGRAPHX_INLINE_NS {

instruction_ref insert_fp16(program& prog,
                            instruction_ref& ins,
                            shape::type_t type,
                            std::unordered_map<instruction_ref, instruction_ref>& map_fp16)
{
    if(map_fp16.count(ins) > 0)
    {
        return map_fp16[ins];
    }

    assert(ins->get_shape().type() == shape::float_type ||
           ins->get_shape().type() == shape::double_type);
    instruction_ref ins_fp16{};
    ins_fp16      = prog.insert_instruction(std::next(ins), op::convert{type}, ins);
    map_fp16[ins] = ins_fp16;

    return ins_fp16;
}

void quantize(program& prog, const std::vector<std::string>& ins_names)
{
    std::unordered_map<instruction_ref, instruction_ref> map_fp16;
    for(auto ins : iterator_for(prog))
    {
        // all indicates every instruction is converted
        if((not contains(ins_names, "all")) and (not contains(ins_names, ins->name())))
        {
            continue;
        }

        shape::type_t orig_type = ins->get_shape().type();
        // process all inputs, if input is a fp32 or fp64, convert it
        // to a fp16 by adding a convert operator.
        auto inputs = ins->inputs();
        std::vector<instruction_ref> converted_inputs;
        for(auto input : inputs)
        {
            auto s = input->get_shape();
            if(s.type() == shape::float_type || s.type() == shape::double_type)
            {
                // if the input is a convert operator, uses its input
                // as its current input
                instruction_ref input_fp16{};
                if(input->name() == "convert")
                {
                    input_fp16 = input->inputs().front();
                }
                else
                {
                    input_fp16 = insert_fp16(prog, input, shape::half_type, map_fp16);
                }
                converted_inputs.push_back(input_fp16);
            }
            else
            {
                converted_inputs.push_back(input);
            }
        }

        // no change for the input, go to the next instruction
        if(inputs == converted_inputs)
        {
            continue;
        }

        auto op        = ins->get_operator();
        auto ins_shape = compute_shape(op, converted_inputs);
        if(ins_shape.type() != orig_type)
        {
            // insert another convert instruction to convert it back
            if(ins == std::prev(prog.end()))
            {
                prog.add_instruction(op::convert{orig_type}, ins);
            }
            else
            {
                // check the dead code case to avoid assert
                bool output_empty = ins->outputs().empty();
                auto ins_orig_type =
                    prog.insert_instruction(std::next(ins), op::convert{orig_type}, ins);
                if(!output_empty)
                {
                    prog.replace_instruction(ins, ins_orig_type);
                }
            }
        }

        prog.replace_instruction(ins, op, converted_inputs);
    }
}

void quantize(program& prog) { quantize(prog, {"all"}); }

std::vector<std::vector<argument> > ins_args;
void capture_args(std::size_t ins_index, std::vector<argument> args) {
    if (ins_index = ins_args.size())
    {
        ins_args.push_back(std::vector<argument>{});
    }
    ins_args[ins_index].push_back(args.front());

    return;
}

void calc_quant_params(std::vector<std::vector<argument>>&ins_arg, std::vector<std::pair<float, float>>& ins_params)
{
    return;
}

// For the input of each input argument, we need to insert a
// capture operator to compute the scale and shift
void capture_arguments(program& prog, const std::vector<std::string>& ins_names)
{
    // the int8 quantization only support dot and convolution
    std::vector<std::string> op_names = {"dot", "convolution"};
    if (!std::all_of(ins_names.begin(), ins_names.end(), [&](auto name) {
        return std::find(op_names.begin(), op_names.end(), name) != op_names.end();
    }))
    {
        MIGRAPHX_THROW("CAPTURE_ARGUMENTS: input operator is not supported");
    }

    std::unordered_map<instruction_ref, instruction_ref> ins_map;
    std::size_t index = 0;
    for(auto ins : iterator_for(prog))
    {
        if (not contains(ins_names, ins->name()))
        {
            continue;
        }

        auto inputs = ins->inputs();
        std::vector<instruction_ref> new_args;
        for (auto input : inputs)
        {
            instruction_ref new_ins{};
            if (ins_map.count(input) > 0)
            {
                new_ins = ins_map[input];
            }
            else
            {
                new_ins = prog.insert_instruction(std::next(input), op::capture{index++, capture_args}, input);                
                ins_map[input] = new_ins;
            }
            new_args.push_back(new_ins);
        }
        instruction::replace(ins, ins->get_operator(), ins->get_shape(), new_args);
    }
}

} // namespace MIGRAPHX_INLINE_NS
} // namespace migraphx