Summary: Different ordering modes aren't supported for an atomic load, so we just do an add of zero as the same thing. It's less efficient, but it works. Fixes https://github.com/llvm/llvm-project/issues/138560
Summary: This removes the use of OpenMP offloading to build the device runtime. The main benefit here is that we no longer need to rely on offloading semantics to build a device only runtime. Things like variants are now no longer needed and can just be simple if-defs. In the future, I will remove most of the special handling here and fold it into calls to the `<gpuintrin.h>` functions instead. Additionally I will rework the compilation to make this a separate runtime. The current plan is to have this, but make including OpenMP and offloading either automatically add it, or print a warning if it's missing. This will allow us to use a normal CMake workflow and delete all the weird 'lets pull the clang binary out of the build' business. ``` -DRUNTIMES_amdgcn-amd-amdhsa_LLVM_ENABLE_RUNTIMES=offload -DLLVM_RUNTIME_TARGETS=amdgcn-amd-amdhsa ``` After that, linking the OpenMP device runtime will be `-Xoffload-linker -lomp`. I.e. no more fat binary business. Only look at the most recent commit since this includes the two dependencies (fix to AMDGPUEmitPrintfBinding and the PointerToMember bug).
https://github.com/codespell-project/codespell % `codespell --ignore-words-list=archtype,hsa,identty,inout,iself,nd,te,ths,vertexes --write-changes`
Summary: Right now we just default to device for each type, and mix an ad-hoc scope with the one used by the compiler's builtins. Unify this can make each version take the scope optionally. For @ronlieb, this will remove the need for `add_system` in the fork as well as the extra `cas` with system scope, just pass `system`.
Summary: This is spelled `ompx_aligned_barrier` when used directly, but wasn't included in the list of known assumptions. Fix that so now th test works.
Summary: We used this globally scoped `ext_no_call_asm` as a sort of hack around the compiler that allowed the attributor to optimize out inline assembly calls to PTX instructions. Quite some time ago I got rid of every inline assembly call and replaced it with a builitin, so this can just be deleted. Furthermore, I use the `[[omp::assume]]` attribute directly for the aligned barrier usage. This prints an unknown assumption warning (even though it isn't) so I'm just silencing that for now until I fix it later. --------- Co-authored-by: Michael Kruse <github@meinersbur.de>
Summary: We used to do a fetch add of zero to approximate a load. This is because the NVPTX backend didn't handle this properly. It's not an issue anymore so simply use the proper atomic builtin.
Summary: Use a normal bitcast, remove from the shared utils since it's not available in GCC 7.4
Summary: Previously we had some indirection here, this patch updates these utilities to just be normal template functions. We use SFINAE to manage the special case handling for floats. Also this strips address spaces so it can be used more generally.
Summary: This is simpler and more common. I would've replaced the CUDA uses and made this the same but currently it doesn't codegen these fences fully and just emits a full system wide barrier as a fallback.