Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

Altera preprocessor definitions

Hi all OpenCL / FPGA hackers

I'm working on some OpenCL that I would like to run on our Bittware FPGA card and compare against GPU version (an obvious exercise, which I am sure many have already done). Now while OpenCL is portable, this does not translate to performance portability, so to make a fare comparison I should optimise the OpenCL for an ALtera FPGA and then for th NVidia Card... there should be plenty of code resuse but there will be certain vendor specific things ( num_simd_work_items on the Device side, or changing the kernel coding style significantly in places) so I'd like to do something like

# ifdef __ALTERA__

// special optimised FPGA kernel code# else

// GPU optimised kernel code# endif

But I can find anything about such definitions being asserted by aoc

Does anyone have insider information about the defintions made by aoc?

If not then I can just manually assert -D__ALTERA__ and thats fine... but I'd like to know any proper defintions.

Thank you in advanced,

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    Hi,

    I believe that ALTERA_CL is a preprocessor definition that aoc will automatically set for you upon compilation. Also, __attribute__(...) should be ignored by a vendor's OpenCL compiler if it is not understood, maybe generate a compile warning, but not a compile error.

    Are there any other preprocessor definitions that you have in mind?

    Cheers!
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    --- Quote Start ---

    Hi,

    I believe that ALTERA_CL is a preprocessor definition that aoc will automatically set for you upon compilation. Also, __attribute__(...) should be ignored by a vendor's OpenCL compiler if it is not understood, maybe generate a compile warning, but not a compile error.

    Are there any other preprocessor definitions that you have in mind?

    Cheers!

    --- Quote End ---

    No I think ALTERA_CL will be sufficient for my needs thankyou, I mainly what to have the FPGA and GPU optimised code in the same source file.

    Thank you