Microblaze decompile

[chants]

Most FPGA are using these cores AFAIK, and there is both a GitHub project (already referenced in your other thread) and even a Codeproject article on a somewhat related task to have C code that can program that FPGA from the bitstream.

Reverse-engineering tools for FPGA bitstreams, Altera and Xilinx:

https://github.com/djn3m0/debit

Convert Xilinx FPGA/CPLD to C Source:

https://www.codeproject.com/Articles/177990/Convert-Xilinx-FPGA-CPLD-to-C-Source