[OpenMP][OMPT][clang] task frame support fixed in __kmpc_fork_call

__kmp_fork_call sets the enter_frame of the active task (th_curren_task)
before new parallel region begins. After the region is finished, the
enter_frame is cleared.

The old implementation of __kmpc_fork_call didn’t clear the enter_frame of
active task.

Also, the way of initializing the enter_frame of the active task was wrong.
Consider the following two OpenMP programs.

The first program: Let R1 be the serialized parallel region that encloses
another serialized parallel region R2. Assume that thread that executes R2 is
going to create a new serialized parallel region R3 by executing
__kmpc_fork_call. This thread is responsible to set enter_frame of R2's
implicit task. Note that the information about R2's implicit task is present
inside master_th->th.th_current_task at this moment, while lwt represents the
information about R1's implicit task. The old implementation uses lwt and
resets enter_frame of R1's implicit task instead of R2's implicit task. The
new implementation uses master_th->th.th_current_task instead.

The second program: Consider the OpenMP program that contains parallel region
R1 which encloses an explicit task T. Assume that thread should create another
parallel region R2 during the execution of the T. The __kmpc_fork_call is
responsible to create R2 and set enter frame of T whose information is present
inside the master_th->th.th_current_task.
Old implementation tries to set the frame of
parent_team->t.t_implicit_task_taskdata[tid] which corresponds to the implicit
task of the R1, instead of T.

Differential Revision: https://reviews.llvm.org/D112419

GitOrigin-RevId: f2410bfb1c49b6610a8a96dfb22b20d5b478ea17
3 files changed