How to debug Internal compiler error of I++ - How to debug Internal compiler error of I++ I am experimenting with Quartus 19.4. I have a component to create IP using the HLS compiler. I followed a Makefile structure very similar to what is found in the counter example. While that example seems to work fine, when doing make test-fpga I get the following output: Target FPGA part name: 10CX220YF780I5G Target FPGA family name: Cyclone10GX Target FPGA speed grade: -5 Analyzing testbench_bilateral_filter_fixed.cpp for testbench generation Creating x86-64 testbench Analyzing testbench_bilateral_filter_fixed.cpp for hardware generation Optimizing component(s) and generating Verilog files Internal Compiler Error: Number of parameters mismatched. This may be due to empty types are being optimized away HLS Main Optimizer FAILED. Makefile:61: recipe for target 'test-fpga' failed make: *** [test-fpga] Error 1 How can I debug or find more information about the actual issue? I have reduced the code to a minimum and hardcoded many parts but cannot find a way around this issue. UPDATE: I have reduced the code to a minimum to reproduce this issue. It seems the problem is when the component is a class member (code adapted from this video ): #include "stdlib.h" #include "HLS/stdio.h" #include "assert.h" #include "HLS/hls.h" class ProofOfComponent { public: component int accelerate(int a, int b); }; component int ProofOfComponent::accelerate(int a, int b) { return a+b; } int main(int argc, char** argv) { ProofOfComponent poc; srand(0); int x = rand()%10; int y = rand()%10; int z = poc.accelerate(x, y); printf("%d + %d = %d\n", x, y, z); assert(z == x + y); return 0; } Could somebody explain why this is not possible? It is standard C++. Thank you in advance! Replies: Re: How to debug Internal compiler error of I++ Hi, Upon checking, the HLS does not allow you to compile class methods as functions into RTL unless they are declared ‘static’. Thanks Replies: Re: How to debug Internal compiler error of I++ Hi, There is an mismatched parameter as stated: "Internal Compiler Error: Number of parameters mismatched. This may be due to empty types are being optimized away" I am checking the information internally with developer. Thanks