gcc/libgomp/testsuite/libgomp.c-c++-common/taskloop-5.c
Jakub Jelinek 3bc75533d1 openmp: Add support for strict modifier on grainsize/num_tasks clauses
With strict: modifier on these clauses, the standard is explicit about
how many iterations (and which) each generated task of taskloop directive
should contain.  For num_tasks it actually matches what we were already
implementing, but for grainsize it does not (and even violates the old
rule - without strict it requires that the number of iterations (unspecified
which exactly) handled by each generated task is >= grainsize argument and
< 2 * grainsize argument, with strict: it requires that each generated
task handles exactly == grainsize argument iterations, except for the
generated task handling the last iteration which can handles <= grainsize
iterations).

The following patch implements it for C and C++.

2021-08-23  Jakub Jelinek  <jakub@redhat.com>

gcc/
	* tree.h (OMP_CLAUSE_GRAINSIZE_STRICT): Define.
	(OMP_CLAUSE_NUM_TASKS_STRICT): Define.
	* tree-pretty-print.c (dump_omp_clause) <case OMP_CLAUSE_GRAINSIZE,
	case OMP_CLAUSE_NUM_TASKS>: Print strict: modifier.
	* omp-expand.c (expand_task_call): Use GOMP_TASK_FLAG_STRICT in iflags
	if either grainsize or num_tasks clause has the strict modifier.
gcc/c/
	* c-parser.c (c_parser_omp_clause_num_tasks,
	c_parser_omp_clause_grainsize): Parse the optional strict: modifier.
gcc/cp/
	* parser.c (cp_parser_omp_clause_num_tasks,
	cp_parser_omp_clause_grainsize): Parse the optional strict: modifier.
include/
	* gomp-constants.h (GOMP_TASK_FLAG_STRICT): Define.
libgomp/
	* taskloop.c (GOMP_taskloop): Handle GOMP_TASK_FLAG_STRICT.
	* testsuite/libgomp.c-c++-common/taskloop-4.c (main): Fix up comment.
	* testsuite/libgomp.c-c++-common/taskloop-5.c: New test.
2021-08-23 10:16:24 +02:00

136 lines
3.4 KiB
C

/* { dg-do run } */
/* { dg-options "-O2" } */
int u[64], v, w[64];
__attribute__((noinline, noclone)) int
test (int a, int b, int c, int d, void (*fn) (int, int, int, int),
int *num_tasks, int *min_iters, int *max_iters, int *sep)
{
int i, j, t = 0;
__builtin_memset (u, 0, sizeof u);
v = 0;
fn (a, b, c, d);
*min_iters = 0;
*max_iters = 0;
*num_tasks = v;
*sep = v;
if (v)
{
*min_iters = u[0];
*max_iters = u[0];
t = u[0];
for (i = 1; i < v; i++)
{
if (*min_iters > u[i])
*min_iters = u[i];
if (*max_iters < u[i])
*max_iters = u[i];
t += u[i];
}
if (*min_iters != *max_iters)
{
for (i = 0; i < v - 1; i++)
{
int min_idx = i;
for (j = i + 1; j < v; j++)
if (w[min_idx] > w[j])
min_idx = j;
if (min_idx != i)
{
int tem = u[i];
u[i] = u[min_idx];
u[min_idx] = tem;
tem = w[i];
w[i] = w[min_idx];
w[min_idx] = tem;
}
}
if (u[0] != *max_iters)
__builtin_abort ();
for (i = 1; i < v; i++)
if (u[i] != u[i - 1])
{
if (*sep != v || u[i] != *min_iters)
__builtin_abort ();
*sep = i;
}
}
}
return t;
}
void
grainsize (int a, int b, int c, int d)
{
int i, j = 0, k = 0;
#pragma omp taskloop firstprivate (j, k) grainsize(strict:d)
for (i = a; i < b; i += c)
{
if (j == 0)
{
#pragma omp atomic capture
k = v++;
if (k >= 64)
__builtin_abort ();
w[k] = i;
}
u[k] = ++j;
}
}
void
num_tasks (int a, int b, int c, int d)
{
int i, j = 0, k = 0;
#pragma omp taskloop firstprivate (j, k) num_tasks(strict:d)
for (i = a; i < b; i += c)
{
if (j == 0)
{
#pragma omp atomic capture
k = v++;
if (k >= 64)
__builtin_abort ();
w[k] = i;
}
u[k] = ++j;
}
}
int
main ()
{
#pragma omp parallel
#pragma omp single
{
int min_iters, max_iters, ntasks, sep;
/* If grainsize is present and has strict modifier, # of task loop iters is == grainsize,
except that it can be smaller on the last task. */
if (test (0, 79, 1, 17, grainsize, &ntasks, &min_iters, &max_iters, &sep) != 79
|| ntasks != 5 || min_iters != 11 || max_iters != 17 || sep != 4)
__builtin_abort ();
if (test (-49, 2541, 7, 28, grainsize, &ntasks, &min_iters, &max_iters, &sep) != 370
|| ntasks != 14 || min_iters != 6 || max_iters != 28 || sep != 13)
__builtin_abort ();
if (test (7, 21, 2, 15, grainsize, &ntasks, &min_iters, &max_iters, &sep) != 7
|| ntasks != 1 || min_iters != 7 || max_iters != 7 || sep != 1)
__builtin_abort ();
/* If num_tasks is present, # of tasks is min (# of loop iters, num_tasks)
and each task has at least one iteration. If strict modifier is present,
first set of tasks has ceil (# of loop iters / num_tasks) iterations,
followed by possibly empty set of tasks with floor (# of loop iters / num_tasks)
iterations. */
if (test (-51, 2500, 48, 9, num_tasks, &ntasks, &min_iters, &max_iters, &sep) != 54
|| ntasks != 9 || min_iters != 6 || max_iters != 6 || sep != 9)
__builtin_abort ();
if (test (0, 57, 1, 9, num_tasks, &ntasks, &min_iters, &max_iters, &sep) != 57
|| ntasks != 9 || min_iters != 6 || max_iters != 7 || sep != 3)
__builtin_abort ();
if (test (0, 25, 2, 17, num_tasks, &ntasks, &min_iters, &max_iters, &sep) != 13
|| ntasks != 13 || min_iters != 1 || max_iters != 1 || sep != 13)
__builtin_abort ();
}
return 0;
}