WEIGHTS_DIR redefinition

[KOVI89alipes]

WEIGHTS_DIR is hard-coded in https://github.com/fastmachinelearning/hls4ml/blob/f31b52fca2a85deb8d1b91d637636a365151194f/hls4ml/templates/vivado/nnet_utils/nnet_helpers.h#L35 And it requires copying or symlinking weights folder into the build folder whenever the model function is compiled from the outside of HLS4ML project.

Possible fix:

#ifndef WEIGHTS_DIR
#define WEIGHTS_DIR "weights"
#endif

In this case WEIGHTS_DIR can be redefined during compilation

Another option - do not store TXT files, but dump weights into includes

[vloncar]

Can you expand a little bit on your workflow? We can make the change you propose, but note that if you generate weights yourself from outside of hls4ml, you need both the .txt files and .h includes. Text files are used only during C simulation to speed up compilation. During synthesis, we have to use the includes.

[KOVI89alipes]

Hi @vloncar , it's clear about synthesis, but I'm talking about the situation when one needs to call the top C++ function as normal function.

Let's say, I have the following file structure and wish to call my_fancy_core function from my host_app

work/ip_cores/my_fancy_core/
            my_fancy_core_test.cpp
            firmware/
                my_fancy_core.cpp
                my_fancy_core.h
                weights/*.txt << Txt files here

work/host_app/
    main.cpp

And here's my main.cpp

===== main.cpp ====
#include "firmware/my_fancy_core.h"  << Path "work/ip_cores/my_fancy_core/" is added to include path
int main(){
     // Layes assignment goes here
    my_fancy_core(input_1,layer9_out,size_in1,size_out1);   
}

main.cpp can be compiled with no errors, but when I call the binary, it fails with https://github.com/fastmachinelearning/hls4ml/blob/f31b52fca2a85deb8d1b91d637636a365151194f/hls4ml/templates/vivado/nnet_utils/nnet_helpers.h#L43

    if (infile.fail()) {
        std::cerr << "ERROR: file " << std::string(fname) << " does not exist" << std::endl;
        exit(1);
    }

Because directory weights obviously doesn't exist in the work\host_app dir and I can not redefine weights_dir from the compilation flow.

So I believe it makes sense to let the user an option to redefine WEIGHTS_DIR from the compilation flow.

[vloncar]

@KOVI89alipes That's reasonable. I created #274 , sorry for the delay.