Document the -fintelfpga flag ?

[fwyzard]

Is there any documentation about the -fintelfpga flag ?

I've tried to build the simply SYCL application from the getting started page with

/data/user/fwyzard/sycl/build/bin/clang++ -O2 -g -Wno-unknown-cuda-version -fsycl -fintelfpga -DFPGA_EMULATOR simple-sycl-app.cpp -o simple-sycl-app-fpga_emu

but that failed with

clang-11: error: unable to execute command: Executable "aoc" doesn't exist!
clang-11: error: fpga compiler command failed with exit code 1 (use -v to see invocation)

Where do I get aoc (apart from the oneAPI beta) ?
One installed, Is there any way to point the location of aoc to clang++, other than having it in the PATH ?

I've also tried to build multiple backends at the same time, bit I got the error

clang-11: error: The option -fsycl-targets= conflicts with -fintelfpga

Is that a design choice, or just a short term issue to be improved later ?

[fwyzard]

It looks like -fintelfpga is roughly equivalent to -fsycl-targets=spir64_fpga-unknown-unknown-sycldevice -MMD -lOpenCL ?

[bader]

SYCL specific compiler options are documented here:
https://github.com/intel/llvm/blob/sycl/sycl/doc/SYCLCompilerUserManual.md#intel-fpga-specific-options

Please, let us know if it's not clear.

[fwyzard]

Thanks @bader.
I think I understand what it means, and I would find it useful to add a bit more information, e.g.

• that it relies on the aoc external tool
• that it is a shortcut for -fsycl-targets=spir64_fpga-unknown-unknown-sycldevice or similar
• that (unlike this) it is not compatible with other -fsycl-targets options

[bader]

@fwyzard, if you could propose a new wording via PR, it would be great.
If not, @AGindinson and/or @mdtoguchi should be able to help.

[fwyzard]

Done in #1218.

[bader]

@fwyzard, can we close this issue or there is anything else you wanted to add regarding -fintelfpga flag?

[fwyzard]

Is there a way to install aoc without installing the full oneAPI beta ?

[AGindinson]

Is there a way to install aoc without installing the full oneAPI beta ?

None that I'm aware of. @GarveyJoe, could you please chime in?

[GarveyJoe]

There is not.

[fwyzard]

Thanks.
Do you know if the installation from beta 4 is compatible with this branch ?

[AlexeySachkov]

Tagging @vladimirlaz to answer the question

[vladimirlaz]

Tagging @vladimirlaz to answer the question

Late anawer is better than nothing. There is no hard correlation between aoc and siycl compiler. So the latest one should be ok.