For tasks codegen for private/firstprivate variables are different rather than for other directives.
- Build an internal structure of privates for each private variable:
struct .kmp_privates_t. {
Ty1 var1;
...
Tyn varn;
};- Add a new field to kmp_task_t type with list of privates.
struct kmp_task_t {
void * shareds;
kmp_routine_entry_t routine;
kmp_int32 part_id;
kmp_routine_entry_t destructors;
.kmp_privates_t. privates;
};- Create a function with destructors calls for all privates after end of task region.
kmp_int32 .omp_task_destructor.(kmp_int32 gtid, kmp_task_t *tt) {
~Destructor(&tt->privates.var1);
...
~Destructor(&tt->privates.varn);
return 0;
}- Perform initialization of all firstprivate fields (by simple copying for POD data, copy constructor calls for classes) + provide address of a destructor function after kmpc_omp_task_alloc() and before kmpc_omp_task() calls.
kmp_task_t *new_task = __kmpc_omp_task_alloc(ident_t *, kmp_int32 gtid, kmp_int32 flags, size_t sizeof_kmp_task_t, size_t sizeof_shareds, kmp_routine_entry_t *task_entry); CopyConstructor(new_task->privates.var1, *new_task->shareds.var1_ref); new_task->shareds.var1_ref = &new_task->privates.var1; ... CopyConstructor(new_task->privates.varn, *new_task->shareds.varn_ref); new_task->shareds.varn_ref = &new_task->privates.varn; new_task->destructors = .omp_task_destructor.; kmp_int32 __kmpc_omp_task(ident_t *, kmp_int32 gtid, kmp_task_t *new_task)