jhuber6 added a comment. In D140158#3999783 <https://reviews.llvm.org/D140158#3999783>, @tra wrote:
> In D140158#3999716 <https://reviews.llvm.org/D140158#3999716>, @jhuber6 wrote: > >> I just realized the method of copying the `.o` to a `.cubin` doesn't work if >> the link step is done in the same compilation because it doesn't exist yet. >> To fix this I could either make the tool chain emit `.cubin` if we're going >> straight to `nvlink`, or use a symbolic link. The former is uglier, the >> latter will probably only work on Linux. > > Does it have to be `.cubin` ? Does nvlink require it? Yes, it's one of the dumbest things in the CUDA toolchain. If the filename is a `.o` they assume it's a host file containing embedded RDC-code that needs to be combined. If it's a `.cubin` they assume it's device code. I have no clue why they couldn't just check the ELF flags, it's trivial. >> Also do you think I should include the CUDA headers in with this? We can >> always get rid of them with `nogpuinc` or similar if they're not needed. The >> AMDGPU compilation still links in the device libraries so I'm wondering if >> we should at least be consistent. > > Only some CUDA headers can be used from C++ and they tend to contain > host-only declarations, and stubs or CPU implementations of GPU-side > functions in that case. > The rest rely on CUDA extensions, attributes, So, in this case doing a C++ > compilation will give you a host-side view of the headers in the best case, > which is not going to be particularly useful. > > If we want to make GPU-side functions available, we'll need to have a > pre-included wrapper with more preprocessor magic to make CUDA headers > usable. Doing that in a C++ compilation would be questionable as for a C++ > compilation a user would normally assume that no headers are pre-included by > the compiler. We might want to at least include the `libdevice` files, most of our wrappers definitely won't work without CUDA or OpenMP language modes. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D140158/new/ https://reviews.llvm.org/D140158 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
