I'm using LLVM to read IR files using parseInputIR(inputIR) function; compile them and execute them similar to what is done in llvm's Kaleidoscope examples. However when doing so I get error which complains that omp_get_num_procs is not known as following
clang/bin/Kaleidoscope-Orc-fully_lazy_with_recompile_try prime_toy/main.bc prime_toy/prime_number.bc LLVM ERROR: Program used external function 'omp_get_num_procs' which could not be resolved!
One of the IR files contains omp directives and thus has to be linked against omp library. I should add this support inside llvm by using dlsym.
My question is about the libgomp version - I think I need to use the openmp library from llvm (http://openmp.llvm.org/) But I do not see omp_get_num_procs in it (only ones with suffix) and I wonder why.
nm llvm_openmp/openmp/runtime/build/runtime/src/libgomp.so | grep omp_get_num_procs
0000000000067369 t __kmp_api_omp_get_num_procs
0000000000068180 t __kmp_api_omp_get_num_procs_
0000000000067369 t __kmp_api_omp_get_num_procs_10_alias
0000000000068180 t __kmp_api_omp_get_num_procs__10_alias
0000000000067369 T omp_get_num_procs@@VERSION
0000000000067369 T omp_get_num_procs@OMP_1.0
0000000000068180 T omp_get_num_procs_@@VERSION
0000000000068180 T omp_get_num_procs_@OMP_1.0
The suffixes that you're seeing (starting with "@") are for ELF symbol versioning, https://sourceware.org/binutils/docs/ld/VERSION.html, which very likely you don't have to care about particularly, so you can mentally "strip them off".