The follow construct should implicitly
map(tofrom:sum) according to 5.2 p341, line 10-13, and 5.1 page 254 line 4-7.
#pragma omp target teams loop reduction(+:sum)
loop is in a combined construct with
teams, and the
reduction clause is on a combined target construct, the behaviour should be an implicit to from map. LLVM 14 looks to still use
firstprivate behaviour here.