[AMDGPU][OpenMP] Disable tests when amdgpu-arch fails

[pdhaliwal]

Summary

This patch prevents runtime tests running on systems without amdgpu.

[pdhaliwal]

Remove useless libomptarget_say

[JonChesterfield]

Looks reasonable to me. Let's wait for a second opinion though

[tianshilei1992]

LGTM. Actually I'm wondering if it is possible to do something like: check the eligibility in CMake and set something, then in lit if corresponding platform is not ready (no matter what reason), simply ignore corresponding execution line.

[JonChesterfield]

Similarly we could do the test in lit.

I'd like something similar for cuda, where a system may have cuda installed but no nvidia card present. I wonder if there's an executable in the cuda toolkit that could serve the same purpose.

[protze.joachim]

lgtm as well.

In D102054#2744637, @JonChesterfield wrote:

I'd like something similar for cuda, where a system may have cuda installed but no nvidia card present. I wonder if there's an executable in the cuda toolkit that could serve the same purpose.

$ nvidia-smi -L
GPU 0: Tesla V100-SXM2-16GB (UUID: GPU-xyz...)
GPU 1: Tesla V100-SXM2-16GB (UUID: GPU-xyz...)

SUMMARY OPTIONS
-L, --list-gpus
    List each of the NVIDIA GPUs in the system, along with their UUIDs.

I cannot test, what the tool does, if no NVIDIA GPU is available in a system. We only have the tool installed on nodes with GPUs. It might return an error code or just have an empty output.

openmp/libomptarget/plugins/amdgpu/CMakeLists.txt

target_link_libraries(
   PRIVATE
   elf_common
   hsa-runtime64::hsa-runtime64
   pthread dl elf
   "-Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/../exports"
   "-Wl,-z,defs"
   )
 
+if (LLVM_BINARY_DIR)
+  # for in-tree build using LLVM_ENABLE_RUNTIMES
+  set(AMDGPU_ARCH_TOOL "${LLVM_BINARY_DIR}/bin/amdgpu-arch")
+elseif (OPENMP_LLVM_TOOLS_DIR)
+  set(AMDGPU_ARCH_TOOL "${OPENMP_LLVM_TOOLS_DIR}/amdgpu-arch")
+else()
+  set(AMDGPU_ARCH_TOOL "amdgpu-arch")
+endif()
+
+# in case of amdgcn, skip running tests if amdgpu-arch was not built or fails
+if (NOT EXISTS "${AMDGPU_ARCH_TOOL}")
+  libomptarget_say("Not generating amdgcn test targets as amdgpu-arch is not found")
+  return()
+endif()
+
+execute_process(COMMAND "${AMDGPU_ARCH_TOOL}" RESULT_VARIABLE amdgpu_arch_result
+  OUTPUT_VARIABLE amdgpu_arch_output)
+if (${amdgpu_arch_result})
+  libomptarget_say("Not generating amdgcn test targets as amdgpu-arch exited with ${amdgpu_arch_result}")
+  return()
+endif()
+
 # Report to the parent scope that we are building a plugin for amdgpu
 set(LIBOMPTARGET_SYSTEM_TARGETS "${LIBOMPTARGET_SYSTEM_TARGETS} amdgcn-amd-amdhsa" PARENT_SCOPE)