diff options
Diffstat (limited to 'gcc/tree-parloops.cc')
| -rw-r--r-- | gcc/tree-parloops.cc | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/gcc/tree-parloops.cc b/gcc/tree-parloops.cc index 666c6a1..7361828 100644 --- a/gcc/tree-parloops.cc +++ b/gcc/tree-parloops.cc @@ -2601,10 +2601,19 @@ create_parallel_loop (class loop *loop, tree loop_fn, tree data, gsi = gsi_last_bb (paral_bb); gcc_checking_assert (n_threads != 0); - t = build_omp_clause (loc, OMP_CLAUSE_NUM_THREADS); - OMP_CLAUSE_NUM_THREADS_EXPR (t) - = build_int_cst (integer_type_node, n_threads); - omp_par_stmt = gimple_build_omp_parallel (NULL, t, loop_fn, data); + if (n_threads == INT_MAX) + /* No hardcoded thread count, let OpenMP runtime decide. */ + omp_par_stmt = gimple_build_omp_parallel (NULL, NULL_TREE, loop_fn, + data); + else + { + /* Build the OMP_CLAUSE_NUM_THREADS clause only if we have a fixed + thread count. */ + t = build_omp_clause (loc, OMP_CLAUSE_NUM_THREADS); + OMP_CLAUSE_NUM_THREADS_EXPR (t) + = build_int_cst (integer_type_node, n_threads); + omp_par_stmt = gimple_build_omp_parallel (NULL, t, loop_fn, data); + } gimple_set_location (omp_par_stmt, loc); gsi_insert_after (&gsi, omp_par_stmt, GSI_NEW_STMT); @@ -2812,7 +2821,6 @@ gen_parallel_loop (class loop *loop, struct clsn_data clsn_data; location_t loc; gimple *cond_stmt; - unsigned int m_p_thread=2; /* From @@ -2885,15 +2893,14 @@ gen_parallel_loop (class loop *loop, if (!oacc_kernels_p) { - if (loop->inner) - m_p_thread=2; - else - m_p_thread=MIN_PER_THREAD; - gcc_checking_assert (n_threads != 0); + /* For runtime thread detection, use a conservative estimate of 2 threads + for the many iterations condition check. */ + unsigned threads = (n_threads == INT_MAX) ? 2 : n_threads; + unsigned m_p_thread = loop->inner ? 2 : MIN_PER_THREAD; many_iterations_cond = fold_build2 (GE_EXPR, boolean_type_node, - nit, build_int_cst (type, m_p_thread * n_threads - 1)); + nit, build_int_cst (type, m_p_thread * threads - 1)); many_iterations_cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, @@ -3905,14 +3912,15 @@ parallelize_loops (bool oacc_kernels_p) estimated = estimated_loop_iterations_int (loop); if (estimated == -1) estimated = get_likely_max_loop_iterations_int (loop); + /* For runtime thread detection, use an estimate of 2 threads. */ + unsigned threads = (n_threads == INT_MAX) ? 2 : n_threads; + unsigned m_p_thread = loop->inner ? 2 : MIN_PER_THREAD; /* FIXME: Bypass this check as graphite doesn't update the count and frequency correctly now. */ if (!flag_loop_parallelize_all && !oacc_kernels_p && ((estimated != -1 - && (estimated - < ((HOST_WIDE_INT) n_threads - * (loop->inner ? 2 : MIN_PER_THREAD) - 1))) + && (estimated < ((HOST_WIDE_INT) threads * m_p_thread - 1))) /* Do not bother with loops in cold areas. */ || optimize_loop_nest_for_size_p (loop))) continue; |