Emit a code for reduction clause. Next code should be emitted for reductions:
static kmp_critical_name lock = { 0 };
void reduce_func(void *lhs[<n>], void *rhs[<n>]) {
*(Type0*)lhs[0] = ReductionOperation0(*(Type0*)lhs[0], *(Type0*)rhs[0]);
...
*(Type<n>-1*)lhs[<n>-1] =
ReductionOperation<n>-1(*(Type<n>-1*)lhs[<n>-1],
*(Type<n>-1*)rhs[<n>-1]);
}
...
void *RedList[<n>] = {&<RHSExprs>[0], ..., &<RHSExprs>[<n>-1]};
switch (__kmpc_reduce{_nowait}(<loc>, <gtid>, <n>, sizeof(RedList), RedList, reduce_func, &<lock>)) {
case 1:
<LHSExprs>[0] = ReductionOperation0(*<LHSExprs>[0], *<RHSExprs>[0]);
...
<LHSExprs>[<n>-1] = ReductionOperation<n>-1(*<LHSExprs>[<n>-1], *<RHSExprs>[<n>-1]);
__kmpc_end_reduce{_nowait}(<loc>, <gtid>, &<lock>);
break;
case 2:
Atomic(<LHSExprs>[0] = ReductionOperation0(*<LHSExprs>[0], *<RHSExprs>[0]));
...
Atomic(<LHSExprs>[<n>-1] = ReductionOperation<n>-1(*<LHSExprs>[<n>-1], *<RHSExprs>[<n>-1]));
break;
default:;
}Reduction variables are a kind of a private variables, they have private copies, but initial values are chosen in accordance with the reduction operation.