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author | Jakub Jelinek <jakub@redhat.com> | 2021-08-23 10:16:24 +0200 |
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committer | Jakub Jelinek <jakub@redhat.com> | 2021-08-23 10:16:24 +0200 |
commit | 3bc75533d1f87f0617be6c1af98804f9127ec637 (patch) | |
tree | fa6ecc3f9840f638a87d8f4f39884c31ec7e7bab /libgomp/taskloop.c | |
parent | 6f1a3668f5ee5152bdcca59843802e587339eda1 (diff) | |
download | gcc-3bc75533d1f87f0617be6c1af98804f9127ec637.zip gcc-3bc75533d1f87f0617be6c1af98804f9127ec637.tar.gz gcc-3bc75533d1f87f0617be6c1af98804f9127ec637.tar.bz2 |
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.
Diffstat (limited to 'libgomp/taskloop.c')
-rw-r--r-- | libgomp/taskloop.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/libgomp/taskloop.c b/libgomp/taskloop.c index 791178a..9d27dd0 100644 --- a/libgomp/taskloop.c +++ b/libgomp/taskloop.c @@ -97,6 +97,7 @@ GOMP_taskloop (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), #endif TYPE task_step = step; + TYPE nfirst_task_step = step; unsigned long nfirst = n; if (flags & GOMP_TASK_FLAG_GRAINSIZE) { @@ -109,7 +110,22 @@ GOMP_taskloop (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), if (num_tasks != ndiv) num_tasks = ~0UL; #endif - if (num_tasks <= 1) + 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; @@ -124,6 +140,7 @@ GOMP_taskloop (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), task_step = (TYPE) grainsize * step; if (mul != n) { + nfirst_task_step = task_step; task_step += step; nfirst = n - mul - 1; } @@ -135,6 +152,7 @@ GOMP_taskloop (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), task_step = (TYPE) div * step; if (mod) { + nfirst_task_step = task_step; task_step += step; nfirst = mod - 1; } @@ -153,6 +171,7 @@ GOMP_taskloop (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), task_step = (TYPE) div * step; if (mod) { + nfirst_task_step = task_step; task_step += step; nfirst = mod - 1; } @@ -225,7 +244,7 @@ GOMP_taskloop (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), start += task_step; ((TYPE *)arg)[1] = start; if (i == nfirst) - task_step -= step; + task_step = nfirst_task_step; fn (arg); arg += arg_size; if (!priority_queue_empty_p (&task[i].children_queue, @@ -258,7 +277,7 @@ GOMP_taskloop (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), start += task_step; ((TYPE *)data)[1] = start; if (i == nfirst) - task_step -= step; + task_step = nfirst_task_step; fn (data); if (!priority_queue_empty_p (&task.children_queue, MEMMODEL_RELAXED)) @@ -303,7 +322,7 @@ GOMP_taskloop (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *), start += task_step; ((TYPE *)arg)[1] = start; if (i == nfirst) - task_step -= step; + task_step = nfirst_task_step; thr->task = parent; task->kind = GOMP_TASK_WAITING; task->fn = fn; |