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/* Copyright (C) 2015-2022 Free Software Foundation, Inc.
Contributed by Jakub Jelinek <jakub@redhat.com>.
This file is part of the GNU Offloading and Multi Processing Library
(libgomp).
Libgomp is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* This file handles the taskloop construct. It is included twice, once
for the long and once for unsigned long long variant. */
/* Called when encountering an explicit task directive. If IF_CLAUSE is
false, then we must not delay in executing the task. If UNTIED is true,
then the task may be executed by any member of the team. */
void
GOMP_taskloop (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *),
long arg_size, long arg_align, unsigned flags,
unsigned long num_tasks, int priority,
TYPE start, TYPE end, TYPE step)
{
struct gomp_thread *thr = gomp_thread ();
struct gomp_team *team = thr->ts.team;
#ifdef HAVE_BROKEN_POSIX_SEMAPHORES
/* If pthread_mutex_* is used for omp_*lock*, then each task must be
tied to one thread all the time. This means UNTIED tasks must be
tied and if CPYFN is non-NULL IF(0) must be forced, as CPYFN
might be running on different thread than FN. */
if (cpyfn)
flags &= ~GOMP_TASK_FLAG_IF;
flags &= ~GOMP_TASK_FLAG_UNTIED;
#endif
/* If parallel or taskgroup has been cancelled, don't start new tasks. */
if (team && gomp_team_barrier_cancelled (&team->barrier))
{
early_return:
if ((flags & (GOMP_TASK_FLAG_NOGROUP | GOMP_TASK_FLAG_REDUCTION))
== GOMP_TASK_FLAG_REDUCTION)
{
struct gomp_data_head { TYPE t1, t2; uintptr_t *ptr; };
uintptr_t *ptr = ((struct gomp_data_head *) data)->ptr;
/* Tell callers GOMP_taskgroup_reduction_register has not been
called. */
ptr[2] = 0;
}
return;
}
#ifdef TYPE_is_long
TYPE s = step;
if (step > 0)
{
if (start >= end)
goto early_return;
s--;
}
else
{
if (start <= end)
goto early_return;
s++;
}
UTYPE n = (end - start + s) / step;
#else
UTYPE n;
if (flags & GOMP_TASK_FLAG_UP)
{
if (start >= end)
goto early_return;
n = (end - start + step - 1) / step;
}
else
{
if (start <= end)
goto early_return;
n = (start - end - step - 1) / -step;
}
#endif
TYPE task_step = step;
TYPE nfirst_task_step = step;
unsigned long nfirst = n;
if (flags & GOMP_TASK_FLAG_GRAINSIZE)
{
unsigned long grainsize = num_tasks;
#ifdef TYPE_is_long
num_tasks = n / grainsize;
#else
UTYPE ndiv = n / grainsize;
num_tasks = ndiv;
if (num_tasks != ndiv)
num_tasks = ~0UL;
#endif
if ((flags & GOMP_TASK_FLAG_STRICT)
&& num_tasks != ~0ULL)
{
UTYPE mod = n % grainsize;
task_step = (TYPE) grainsize * step;
if (mod)
{
num_tasks++;
nfirst_task_step = (TYPE) mod * step;
if (num_tasks == 1)
task_step = nfirst_task_step;
else
nfirst = num_tasks - 2;
}
}
else if (num_tasks <= 1)
{
num_tasks = 1;
task_step = end - start;
}
else if (num_tasks >= grainsize
#ifndef TYPE_is_long
&& num_tasks != ~0UL
#endif
)
{
UTYPE mul = num_tasks * grainsize;
task_step = (TYPE) grainsize * step;
if (mul != n)
{
nfirst_task_step = task_step;
task_step += step;
nfirst = n - mul - 1;
}
}
else
{
UTYPE div = n / num_tasks;
UTYPE mod = n % num_tasks;
task_step = (TYPE) div * step;
if (mod)
{
nfirst_task_step = task_step;
task_step += step;
nfirst = mod - 1;
}
}
}
else
{
if (num_tasks == 0)
num_tasks = team ? team->nthreads : 1;
if (num_tasks >= n)
num_tasks = n;
else
{
UTYPE div = n / num_tasks;
UTYPE mod = n % num_tasks;
task_step = (TYPE) div * step;
if (mod)
{
nfirst_task_step = task_step;
task_step += step;
nfirst = mod - 1;
}
}
}
if (flags & GOMP_TASK_FLAG_NOGROUP)
{
if (__builtin_expect (gomp_cancel_var, 0)
&& thr->task
&& thr->task->taskgroup)
{
if (thr->task->taskgroup->cancelled)
return;
if (thr->task->taskgroup->workshare
&& thr->task->taskgroup->prev
&& thr->task->taskgroup->prev->cancelled)
return;
}
}
else
{
ialias_call (GOMP_taskgroup_start) ();
if (flags & GOMP_TASK_FLAG_REDUCTION)
{
struct gomp_data_head { TYPE t1, t2; uintptr_t *ptr; };
uintptr_t *ptr = ((struct gomp_data_head *) data)->ptr;
ialias_call (GOMP_taskgroup_reduction_register) (ptr);
}
}
if (priority > gomp_max_task_priority_var)
priority = gomp_max_task_priority_var;
if ((flags & GOMP_TASK_FLAG_IF) == 0 || team == NULL
|| (thr->task && thr->task->final_task)
|| team->task_count + num_tasks > 64 * team->nthreads)
{
unsigned long i;
if (__builtin_expect (cpyfn != NULL, 0))
{
struct gomp_task task[num_tasks];
struct gomp_task *parent = thr->task;
arg_size = (arg_size + arg_align - 1) & ~(arg_align - 1);
char buf[num_tasks * arg_size + arg_align - 1];
char *arg = (char *) (((uintptr_t) buf + arg_align - 1)
& ~(uintptr_t) (arg_align - 1));
char *orig_arg = arg;
for (i = 0; i < num_tasks; i++)
{
gomp_init_task (&task[i], parent, gomp_icv (false));
task[i].priority = priority;
task[i].kind = GOMP_TASK_UNDEFERRED;
task[i].final_task = (thr->task && thr->task->final_task)
|| (flags & GOMP_TASK_FLAG_FINAL);
if (thr->task)
{
task[i].in_tied_task = thr->task->in_tied_task;
task[i].taskgroup = thr->task->taskgroup;
}
thr->task = &task[i];
cpyfn (arg, data);
arg += arg_size;
}
arg = orig_arg;
for (i = 0; i < num_tasks; i++)
{
thr->task = &task[i];
((TYPE *)arg)[0] = start;
start += task_step;
((TYPE *)arg)[1] = start;
if (i == nfirst)
task_step = nfirst_task_step;
fn (arg);
arg += arg_size;
if (!priority_queue_empty_p (&task[i].children_queue,
MEMMODEL_RELAXED))
{
gomp_mutex_lock (&team->task_lock);
gomp_clear_parent (&task[i].children_queue);
gomp_mutex_unlock (&team->task_lock);
}
gomp_end_task ();
}
}
else
for (i = 0; i < num_tasks; i++)
{
struct gomp_task task;
gomp_init_task (&task, thr->task, gomp_icv (false));
task.priority = priority;
task.kind = GOMP_TASK_UNDEFERRED;
task.final_task = (thr->task && thr->task->final_task)
|| (flags & GOMP_TASK_FLAG_FINAL);
if (thr->task)
{
task.in_tied_task = thr->task->in_tied_task;
task.taskgroup = thr->task->taskgroup;
}
thr->task = &task;
((TYPE *)data)[0] = start;
start += task_step;
((TYPE *)data)[1] = start;
if (i == nfirst)
task_step = nfirst_task_step;
fn (data);
if (!priority_queue_empty_p (&task.children_queue,
MEMMODEL_RELAXED))
{
gomp_mutex_lock (&team->task_lock);
gomp_clear_parent (&task.children_queue);
gomp_mutex_unlock (&team->task_lock);
}
gomp_end_task ();
}
}
else
{
struct gomp_task *tasks[num_tasks];
struct gomp_task *parent = thr->task;
struct gomp_taskgroup *taskgroup = parent->taskgroup;
char *arg;
int do_wake;
unsigned long i;
for (i = 0; i < num_tasks; i++)
{
struct gomp_task *task
= gomp_malloc (sizeof (*task) + arg_size + arg_align - 1);
tasks[i] = task;
arg = (char *) (((uintptr_t) (task + 1) + arg_align - 1)
& ~(uintptr_t) (arg_align - 1));
gomp_init_task (task, parent, gomp_icv (false));
task->priority = priority;
task->kind = GOMP_TASK_UNDEFERRED;
task->in_tied_task = parent->in_tied_task;
task->taskgroup = taskgroup;
thr->task = task;
if (cpyfn)
{
cpyfn (arg, data);
task->copy_ctors_done = true;
}
else
memcpy (arg, data, arg_size);
((TYPE *)arg)[0] = start;
start += task_step;
((TYPE *)arg)[1] = start;
if (i == nfirst)
task_step = nfirst_task_step;
thr->task = parent;
task->kind = GOMP_TASK_WAITING;
task->fn = fn;
task->fn_data = arg;
task->final_task = (flags & GOMP_TASK_FLAG_FINAL) >> 1;
}
gomp_mutex_lock (&team->task_lock);
/* If parallel or taskgroup has been cancelled, don't start new
tasks. */
if (__builtin_expect (gomp_cancel_var, 0)
&& cpyfn == NULL)
{
if (gomp_team_barrier_cancelled (&team->barrier))
{
do_cancel:
gomp_mutex_unlock (&team->task_lock);
for (i = 0; i < num_tasks; i++)
{
gomp_finish_task (tasks[i]);
free (tasks[i]);
}
if ((flags & GOMP_TASK_FLAG_NOGROUP) == 0)
ialias_call (GOMP_taskgroup_end) ();
return;
}
if (taskgroup)
{
if (taskgroup->cancelled)
goto do_cancel;
if (taskgroup->workshare
&& taskgroup->prev
&& taskgroup->prev->cancelled)
goto do_cancel;
}
}
if (taskgroup)
taskgroup->num_children += num_tasks;
for (i = 0; i < num_tasks; i++)
{
struct gomp_task *task = tasks[i];
priority_queue_insert (PQ_CHILDREN, &parent->children_queue,
task, priority,
PRIORITY_INSERT_BEGIN,
/*last_parent_depends_on=*/false,
task->parent_depends_on);
if (taskgroup)
priority_queue_insert (PQ_TASKGROUP, &taskgroup->taskgroup_queue,
task, priority, PRIORITY_INSERT_BEGIN,
/*last_parent_depends_on=*/false,
task->parent_depends_on);
priority_queue_insert (PQ_TEAM, &team->task_queue, task, priority,
PRIORITY_INSERT_END,
/*last_parent_depends_on=*/false,
task->parent_depends_on);
++team->task_count;
++team->task_queued_count;
}
gomp_team_barrier_set_task_pending (&team->barrier);
if (team->task_running_count + !parent->in_tied_task
< team->nthreads)
{
do_wake = team->nthreads - team->task_running_count
- !parent->in_tied_task;
if ((unsigned long) do_wake > num_tasks)
do_wake = num_tasks;
}
else
do_wake = 0;
gomp_mutex_unlock (&team->task_lock);
if (do_wake)
gomp_team_barrier_wake (&team->barrier, do_wake);
}
if ((flags & GOMP_TASK_FLAG_NOGROUP) == 0)
ialias_call (GOMP_taskgroup_end) ();
}
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