"hls_half.h": Error: no member named '...' in namespace 'std'

[seek64]

Hello everyone,

I recently switched to SDx 2017.2. After trying to import and build a project, SDx prints out the following error messages regarding "hls_half.h":

C:/Xilinx/SDx/2017.2/Vivado_HLS/include/hls_half.h:2187:17: error: no member named 'fmax' in namespace 'std'; did you mean simply 'fmax'?
                                return expr(std::fmax(x, y));
                                            ^~~~~~~~~
                                            fmax

This happens for every c++11 function included from cmath. I tried specifying "-std=c++11" in the compiler options, but without success.

I currently using a workaround by hardcoding the functions into "half_hls.h"....

Thanks a lot,

Seek

[zhch7777]

hi  seek64：

     i havethe same problem, and in SDCOC 2017.02?

     how can you solve the problem.my project have the error yet

thanks

[seek64]

Hello zhch7777,

try adding

#define HALF_ENABLE_CPP11_CMATH 0

at the top of the "hls_half.h" file. Not a 100% clean solution, but worked for me. :)

Regards,

Seek

[zhch777777]

hi  seek64：

   thank for reply,

   yes i  add 

#define HALF_ENABLE_CPP11_CMATH 0

  and could compile with warning.but can not build elf file 

  do you have the same problem.

[seek64]

Hello,

no unfortunately I do not get this error, so I don't know how to fix it. :/

I also do not get the warnings before.

I had another workaround before I found this by replacing the hls_half.h from 2017.2 with the one from 2017.1.

There is the one from 2017.1 attached, maybe this will help you.

Regards,

Seek

[zhch777777]

hello

      thanks

       i have the same problem by the 2017.01 hls_half.h

       i cant do any thing,but waiting for the new SDX 

[kami]

Hi,
I have the same problem in SDSoC 2018.2
Still nothing to fix it?

[xilinxacct]

@kami

@seek64

@zhch777777

@zhch7777

Here are two things to try...

1) remove the std:: (and any using namespace std)... e.g. just call fmax with no namespace (you should include the the math include file)

OR

2) define your own FMAX macro, and call that instead e.g. #define FMAX(_a, _b) ((_a) >= (_b)) ? (_a) : (_b)

Hope that helps

[kami]

Thanks for your reply @xilinxacct, but same project works good on another PC without any code change. Both are SDSoC 2018.2 and the only difference between them is Ubuntu versions (16.04 and 18.04). I checked includes and libraries. I tried -std=c++11 flag but still it can't build.

[xilinxacct]

@kami

With both of those suggestions, you should not need the std=c++11 flag any more, since it is as basic as it gets at that point. Using 2018.2 The compiler worked fine for both of those methods. Suggestion #2 is just code, so doesn't even count on a library. Maybe you have some other issue (especially, as you say, it works elsewhere)

[kami]

Hi,

I fixed the problem with updating the petalinux platform file which I was downloaded from Avnet Ultra96 support page. I think sw part of the platform folder is updated in the new version and it works ok in SDSoC 2018.2.

[yugi_nhc]

Hi, I also have this problem when working with SDSoC 2018.2 on Windows 10.

#define HALF_ENABLE_CPP11_CMATH 0 can compile but can not create elf file.

Do you know how to fix it on SDSoC 2018.2 Windows