adjust docs to latest offload usage
diff --git a/src/offload/usage.md b/src/offload/usage.md index 77b8935..56a29d7 100644 --- a/src/offload/usage.md +++ b/src/offload/usage.md
@@ -89,38 +89,21 @@ ``` RUSTFLAGS="-Ctarget-cpu=gfx90a --emit=llvm-bc,llvm-ir -Zoffload=Device=/absolute/path/to/offload.manifest -Csave-temps -Zunstable-options" cargo +offload build -Zunstable-options -r -v --target amdgcn-amd-amdhsa -Zbuild-std=core ``` -You might afterwards need to copy your target/release/deps/<lib_name>.bc to lib.bc for now, before the next step. -Now we generate the host (CPU) code. +Next we generate the host (CPU) code. ``` -RUSTFLAGS="--emit=llvm-bc,llvm-ir -Csave-temps -Zoffload=Host=/p/lustre1/drehwald1/prog/offload/r/target/amdgcn-amd-amdhsa/release/deps/device.bin -Zunstable-options" cargo +offload build -r -``` -This call also does a lot of work and generates multiple intermediate files for LLVM offload. -While we integrated most offload steps into rustc by now, one binary invocation still remains for now: - -``` -"clang-linker-wrapper" "--should-extract=gfx90a" "--device-compiler=amdgcn-amd-amdhsa=-g" "--device-compiler=amdgcn-amd-amdhsa=-save-temps=cwd" "--device-linker=amdgcn-amd-amdhsa=-lompdevice" "--host-triple=x86_64-unknown-linux-gnu" "--save-temps" "--linker-path=/ABSOlUTE_PATH_TO/rust/build/x86_64-unknown-linux-gnu/lld/bin/ld.lld" "--hash-style=gnu" "--eh-frame-hdr" "-m" "elf_x86_64" "-pie" "-dynamic-linker" "/lib64/ld-linux-x86-64.so.2" "-o" "main" "/lib/../lib64/Scrt1.o" "/lib/../lib64/crti.o" "/ABSOLUTE_PATH_TO/crtbeginS.o" "-L/ABSOLUTE_PATH_TO/rust/build/x86_64-unknown-linux-gnu/llvm/bin/../lib/x86_64-unknown-linux-gnu" "-L/ABSOLUTE_PATH_TO/rust/build/x86_64-unknown-linux-gnu/llvm/lib/clang/21/lib/x86_64-unknown-linux-gnu" "-L/lib/../lib64" "-L/usr/lib64" "-L/lib" "-L/usr/lib" "target/<GPU_DIR>/release/host.o" "-lstdc++" "-lm" "-lomp" "-lomptarget" "-L/ABSOLUTE_PATH_TO/rust/build/x86_64-unknown-linux-gnu/llvm/lib" "-lgcc_s" "-lgcc" "-lpthread" "-lc" "-lgcc_s" "-lgcc" "/ABSOLUTE_PATH_TO/crtendS.o" "/lib/../lib64/crtn.o" -``` - -You can try to find the paths to those files on your system. -However, I recommend to not fix the paths, but rather just re-generate them by copying a bare-mode OpenMP example and compiling it with your clang. -By adding `-###` to your clang invocation, you can see the invidual steps. -It will show multiple steps, just look for the clang-linker-wrapper example. -Make sure to still include the path to the `host.o` file, and not whatever tmp file you got when compiling your c++ example with the following call. -``` -myclang++ -fuse-ld=lld -O3 -fopenmp -fopenmp-offload-mandatory --offload-arch=gfx90a omp_bare.cpp -o main -### +RUSTFLAGS="--emit=llvm-bc,llvm-ir -Csave-temps -Zoffload=Host=$PWD/target/amdgcn-amd-amdhsa/release/deps/device.bin -Zunstable-options" cargo +offload build -r ``` In the final step, you can now run your binary ``` -./main +LD_LIBRARY_PATH=$(rustc +nightly --print sysroot)/lib ./target/x86_64-unknown-linux-gnu/release/binary-name all checks passed! ``` -To receive more information about the memory transfer, you can enable info printing with -``` -LIBOMPTARGET_INFO=-1 ./main -``` +These three steps will soon be wrapped into a single command, once we had more time to test all steps. + +To receive more information about the memory transfer, you can enable info printing by adding `LIBOMPTARGET_INFO=-1` ahead of your binary call. [^list]: https://rocm.docs.amd.com/en/latest/reference/gpu-arch-specs.html or https://developer.nvidia.com/cuda/gpus. Alternatively, check `rustc --print target-cpus`.