11-19-2018 08:54 AM
I am new to Vivado HLS and trying to work the simple example of an fir filter as given in the Xilinx tutorial (pg 13): https://www.xilinx.com/support/documentation/sw_manuals/xilinx2014_2/ug871-vivado-high-level-synthesis-tutorial.pdf. I am working on Ubuntu 18.10
The C Synthesis and C simulation work fine but cosimluation using Vivado HLS simulator( pg 23 of above pdf) gives the attached error.
Following is what I have tried so far:
- I cannot modify floatn.h as that is read only
- I played around with the CFLAGS options (In projects> project settings> simulation> fir_test.c I tried using -std=c++11/14 in accordance to the following StackOverflow post:https://stackoverflow.com/questions/13525774/clang-and-float128-bug-error)
It does not seem to identify the C FILE * pointer and shows that as a bug in the code. Interestingly, when I tried RTL cosimulation with a cpp file, that worked just fine. My hunch is that it complains because I'm working with c files? I have no idea why that would be the case. Any guidance would be helpful.
11-19-2018 10:28 AM
Your hunch about the issue being the difference between c and cpp files could certainly be correct. Many libraries are meant only for one language or the other, e.g., "ap_cint.h" for C and "ap_int.h" for CPP. And one of your warnings complains about float vs. cfloat.
Additionally, I did notice that you're working with Vivado HLS 2018.2 but have linked to the user guide for 2014.2, so you're getting some deprecation warnings. I recommend you refer to the latest version of UG871: https://www.xilinx.com/support/documentation/sw_manuals/xilinx2018_2/ug871-vivado-high-level-synthesis-tutorial.pdf. If you come across any warnings when following the instructions in the latest version of the user guide on the matching release, we would gladly work with the documentation team to get those resolved. The updated example might also offer more information as to what is giving you your errors.
11-22-2018 04:35 AM
Thank you for pointing out the difference in the user manual. I was simultaneously also working with 2018.2. Unfortunately, the error persists. Please advice.
11-22-2018 09:26 PM
I think the issue is mostly related to the compatible OS. Assuming that you are using the latest vivado HLS 2018.2 version, the supported Ubuntu OS is 16.04.3. As you are using Ubuntu 18 version this might be the reason due to which you are getting these errors. So, please use the compatible OS as mentioned at page 11 of UG 973.