/* Copyright (C) 2005, 2008, 2009 Free Software Foundation, Inc.
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/* Copyright (C) 2005, 2008, 2009 Free Software Foundation, Inc.
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Contributed by Richard Henderson <rth@redhat.com>.
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Contributed by Richard Henderson <rth@redhat.com>.
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This file is part of the GNU OpenMP Library (libgomp).
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This file is part of the GNU OpenMP Library (libgomp).
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Libgomp is free software; you can redistribute it and/or modify it
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Libgomp is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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any later version.
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Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
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Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details.
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more details.
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Under Section 7 of GPL version 3, you are granted additional
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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<http://www.gnu.org/licenses/>. */
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/* This file contains routines for managing work-share iteration, both
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/* This file contains routines for managing work-share iteration, both
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for loops and sections. */
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for loops and sections. */
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#include "libgomp.h"
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#include "libgomp.h"
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#include <stdlib.h>
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#include <stdlib.h>
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typedef unsigned long long gomp_ull;
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typedef unsigned long long gomp_ull;
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/* This function implements the STATIC scheduling method. The caller should
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/* This function implements the STATIC scheduling method. The caller should
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iterate *pstart <= x < *pend. Return zero if there are more iterations
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iterate *pstart <= x < *pend. Return zero if there are more iterations
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to perform; nonzero if not. Return less than 0 if this thread had
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to perform; nonzero if not. Return less than 0 if this thread had
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received the absolutely last iteration. */
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received the absolutely last iteration. */
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int
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int
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gomp_iter_ull_static_next (gomp_ull *pstart, gomp_ull *pend)
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gomp_iter_ull_static_next (gomp_ull *pstart, gomp_ull *pend)
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{
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{
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struct gomp_thread *thr = gomp_thread ();
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struct gomp_thread *thr = gomp_thread ();
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struct gomp_team *team = thr->ts.team;
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struct gomp_team *team = thr->ts.team;
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struct gomp_work_share *ws = thr->ts.work_share;
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struct gomp_work_share *ws = thr->ts.work_share;
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unsigned long nthreads = team ? team->nthreads : 1;
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unsigned long nthreads = team ? team->nthreads : 1;
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if (thr->ts.static_trip == -1)
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if (thr->ts.static_trip == -1)
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return -1;
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return -1;
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/* Quick test for degenerate teams and orphaned constructs. */
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/* Quick test for degenerate teams and orphaned constructs. */
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if (nthreads == 1)
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if (nthreads == 1)
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{
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{
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*pstart = ws->next_ull;
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*pstart = ws->next_ull;
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*pend = ws->end_ull;
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*pend = ws->end_ull;
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thr->ts.static_trip = -1;
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thr->ts.static_trip = -1;
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return ws->next_ull == ws->end_ull;
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return ws->next_ull == ws->end_ull;
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}
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}
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/* We interpret chunk_size zero as "unspecified", which means that we
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/* We interpret chunk_size zero as "unspecified", which means that we
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should break up the iterations such that each thread makes only one
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should break up the iterations such that each thread makes only one
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trip through the outer loop. */
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trip through the outer loop. */
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if (ws->chunk_size_ull == 0)
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if (ws->chunk_size_ull == 0)
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{
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{
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gomp_ull n, q, i, s0, e0, s, e;
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gomp_ull n, q, i, s0, e0, s, e;
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if (thr->ts.static_trip > 0)
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if (thr->ts.static_trip > 0)
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return 1;
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return 1;
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/* Compute the total number of iterations. */
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/* Compute the total number of iterations. */
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if (__builtin_expect (ws->mode, 0) == 0)
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if (__builtin_expect (ws->mode, 0) == 0)
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n = (ws->end_ull - ws->next_ull + ws->incr_ull - 1) / ws->incr_ull;
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n = (ws->end_ull - ws->next_ull + ws->incr_ull - 1) / ws->incr_ull;
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else
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else
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n = (ws->next_ull - ws->end_ull - ws->incr_ull - 1) / -ws->incr_ull;
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n = (ws->next_ull - ws->end_ull - ws->incr_ull - 1) / -ws->incr_ull;
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i = thr->ts.team_id;
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i = thr->ts.team_id;
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/* Compute the "zero-based" start and end points. That is, as
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/* Compute the "zero-based" start and end points. That is, as
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if the loop began at zero and incremented by one. */
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if the loop began at zero and incremented by one. */
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q = n / nthreads;
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q = n / nthreads;
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q += (q * nthreads != n);
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q += (q * nthreads != n);
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s0 = q * i;
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s0 = q * i;
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e0 = s0 + q;
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e0 = s0 + q;
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if (e0 > n)
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if (e0 > n)
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e0 = n;
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e0 = n;
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/* Notice when no iterations allocated for this thread. */
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/* Notice when no iterations allocated for this thread. */
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if (s0 >= e0)
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if (s0 >= e0)
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{
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{
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thr->ts.static_trip = 1;
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thr->ts.static_trip = 1;
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return 1;
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return 1;
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}
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}
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/* Transform these to the actual start and end numbers. */
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/* Transform these to the actual start and end numbers. */
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s = s0 * ws->incr_ull + ws->next_ull;
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s = s0 * ws->incr_ull + ws->next_ull;
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e = e0 * ws->incr_ull + ws->next_ull;
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e = e0 * ws->incr_ull + ws->next_ull;
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*pstart = s;
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*pstart = s;
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*pend = e;
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*pend = e;
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thr->ts.static_trip = (e0 == n ? -1 : 1);
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thr->ts.static_trip = (e0 == n ? -1 : 1);
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return 0;
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return 0;
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}
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}
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else
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else
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{
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{
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gomp_ull n, s0, e0, i, c, s, e;
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gomp_ull n, s0, e0, i, c, s, e;
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/* Otherwise, each thread gets exactly chunk_size iterations
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/* Otherwise, each thread gets exactly chunk_size iterations
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(if available) each time through the loop. */
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(if available) each time through the loop. */
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if (__builtin_expect (ws->mode, 0) == 0)
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if (__builtin_expect (ws->mode, 0) == 0)
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n = (ws->end_ull - ws->next_ull + ws->incr_ull - 1) / ws->incr_ull;
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n = (ws->end_ull - ws->next_ull + ws->incr_ull - 1) / ws->incr_ull;
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else
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else
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n = (ws->next_ull - ws->end_ull - ws->incr_ull - 1) / -ws->incr_ull;
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n = (ws->next_ull - ws->end_ull - ws->incr_ull - 1) / -ws->incr_ull;
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i = thr->ts.team_id;
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i = thr->ts.team_id;
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c = ws->chunk_size_ull;
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c = ws->chunk_size_ull;
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/* Initial guess is a C sized chunk positioned nthreads iterations
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/* Initial guess is a C sized chunk positioned nthreads iterations
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in, offset by our thread number. */
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in, offset by our thread number. */
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s0 = (thr->ts.static_trip * (gomp_ull) nthreads + i) * c;
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s0 = (thr->ts.static_trip * (gomp_ull) nthreads + i) * c;
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e0 = s0 + c;
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e0 = s0 + c;
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/* Detect overflow. */
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/* Detect overflow. */
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if (s0 >= n)
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if (s0 >= n)
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return 1;
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return 1;
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if (e0 > n)
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if (e0 > n)
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e0 = n;
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e0 = n;
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/* Transform these to the actual start and end numbers. */
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/* Transform these to the actual start and end numbers. */
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s = s0 * ws->incr_ull + ws->next_ull;
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s = s0 * ws->incr_ull + ws->next_ull;
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e = e0 * ws->incr_ull + ws->next_ull;
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e = e0 * ws->incr_ull + ws->next_ull;
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*pstart = s;
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*pstart = s;
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*pend = e;
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*pend = e;
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if (e0 == n)
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if (e0 == n)
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thr->ts.static_trip = -1;
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thr->ts.static_trip = -1;
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else
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else
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thr->ts.static_trip++;
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thr->ts.static_trip++;
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return 0;
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return 0;
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}
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}
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}
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}
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/* This function implements the DYNAMIC scheduling method. Arguments are
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/* This function implements the DYNAMIC scheduling method. Arguments are
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as for gomp_iter_ull_static_next. This function must be called with
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as for gomp_iter_ull_static_next. This function must be called with
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ws->lock held. */
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ws->lock held. */
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bool
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bool
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gomp_iter_ull_dynamic_next_locked (gomp_ull *pstart, gomp_ull *pend)
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gomp_iter_ull_dynamic_next_locked (gomp_ull *pstart, gomp_ull *pend)
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{
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{
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struct gomp_thread *thr = gomp_thread ();
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struct gomp_thread *thr = gomp_thread ();
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struct gomp_work_share *ws = thr->ts.work_share;
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struct gomp_work_share *ws = thr->ts.work_share;
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gomp_ull start, end, chunk, left;
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gomp_ull start, end, chunk, left;
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start = ws->next_ull;
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start = ws->next_ull;
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if (start == ws->end_ull)
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if (start == ws->end_ull)
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return false;
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return false;
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chunk = ws->chunk_size_ull;
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chunk = ws->chunk_size_ull;
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left = ws->end_ull - start;
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left = ws->end_ull - start;
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if (__builtin_expect (ws->mode & 2, 0))
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if (__builtin_expect (ws->mode & 2, 0))
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{
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{
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if (chunk < left)
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if (chunk < left)
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chunk = left;
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chunk = left;
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}
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}
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else
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else
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{
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{
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if (chunk > left)
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if (chunk > left)
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chunk = left;
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chunk = left;
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}
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}
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end = start + chunk;
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end = start + chunk;
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ws->next_ull = end;
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ws->next_ull = end;
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*pstart = start;
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*pstart = start;
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*pend = end;
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*pend = end;
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return true;
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return true;
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}
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}
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#if defined HAVE_SYNC_BUILTINS && defined __LP64__
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#if defined HAVE_SYNC_BUILTINS && defined __LP64__
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/* Similar, but doesn't require the lock held, and uses compare-and-swap
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/* Similar, but doesn't require the lock held, and uses compare-and-swap
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instead. Note that the only memory value that changes is ws->next_ull. */
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instead. Note that the only memory value that changes is ws->next_ull. */
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bool
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bool
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gomp_iter_ull_dynamic_next (gomp_ull *pstart, gomp_ull *pend)
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gomp_iter_ull_dynamic_next (gomp_ull *pstart, gomp_ull *pend)
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{
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{
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struct gomp_thread *thr = gomp_thread ();
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struct gomp_thread *thr = gomp_thread ();
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struct gomp_work_share *ws = thr->ts.work_share;
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struct gomp_work_share *ws = thr->ts.work_share;
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gomp_ull start, end, nend, chunk;
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gomp_ull start, end, nend, chunk;
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end = ws->end_ull;
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end = ws->end_ull;
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chunk = ws->chunk_size_ull;
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chunk = ws->chunk_size_ull;
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if (__builtin_expect (ws->mode & 1, 1))
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if (__builtin_expect (ws->mode & 1, 1))
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{
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{
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gomp_ull tmp = __sync_fetch_and_add (&ws->next_ull, chunk);
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gomp_ull tmp = __sync_fetch_and_add (&ws->next_ull, chunk);
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if (__builtin_expect (ws->mode & 2, 0) == 0)
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if (__builtin_expect (ws->mode & 2, 0) == 0)
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{
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{
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if (tmp >= end)
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if (tmp >= end)
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return false;
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return false;
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nend = tmp + chunk;
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nend = tmp + chunk;
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if (nend > end)
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if (nend > end)
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nend = end;
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nend = end;
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*pstart = tmp;
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*pstart = tmp;
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*pend = nend;
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*pend = nend;
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return true;
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return true;
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}
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}
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else
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else
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{
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{
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if (tmp <= end)
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if (tmp <= end)
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return false;
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return false;
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nend = tmp + chunk;
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nend = tmp + chunk;
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if (nend < end)
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if (nend < end)
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nend = end;
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nend = end;
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*pstart = tmp;
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*pstart = tmp;
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*pend = nend;
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*pend = nend;
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return true;
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return true;
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}
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}
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}
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}
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start = ws->next_ull;
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start = ws->next_ull;
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while (1)
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while (1)
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{
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{
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gomp_ull left = end - start;
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gomp_ull left = end - start;
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gomp_ull tmp;
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gomp_ull tmp;
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if (start == end)
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if (start == end)
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return false;
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return false;
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if (__builtin_expect (ws->mode & 2, 0))
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if (__builtin_expect (ws->mode & 2, 0))
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{
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{
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if (chunk < left)
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if (chunk < left)
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chunk = left;
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chunk = left;
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}
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}
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else
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else
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{
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{
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if (chunk > left)
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if (chunk > left)
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chunk = left;
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chunk = left;
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}
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}
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nend = start + chunk;
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nend = start + chunk;
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tmp = __sync_val_compare_and_swap (&ws->next_ull, start, nend);
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tmp = __sync_val_compare_and_swap (&ws->next_ull, start, nend);
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if (__builtin_expect (tmp == start, 1))
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if (__builtin_expect (tmp == start, 1))
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break;
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break;
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start = tmp;
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start = tmp;
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}
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}
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*pstart = start;
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*pstart = start;
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*pend = nend;
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*pend = nend;
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return true;
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return true;
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}
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}
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#endif /* HAVE_SYNC_BUILTINS */
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#endif /* HAVE_SYNC_BUILTINS */
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/* This function implements the GUIDED scheduling method. Arguments are
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/* This function implements the GUIDED scheduling method. Arguments are
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as for gomp_iter_ull_static_next. This function must be called with the
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as for gomp_iter_ull_static_next. This function must be called with the
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work share lock held. */
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work share lock held. */
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bool
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bool
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gomp_iter_ull_guided_next_locked (gomp_ull *pstart, gomp_ull *pend)
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gomp_iter_ull_guided_next_locked (gomp_ull *pstart, gomp_ull *pend)
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{
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{
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struct gomp_thread *thr = gomp_thread ();
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struct gomp_thread *thr = gomp_thread ();
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struct gomp_work_share *ws = thr->ts.work_share;
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struct gomp_work_share *ws = thr->ts.work_share;
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struct gomp_team *team = thr->ts.team;
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struct gomp_team *team = thr->ts.team;
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gomp_ull nthreads = team ? team->nthreads : 1;
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gomp_ull nthreads = team ? team->nthreads : 1;
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gomp_ull n, q;
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gomp_ull n, q;
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gomp_ull start, end;
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gomp_ull start, end;
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|
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if (ws->next_ull == ws->end_ull)
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if (ws->next_ull == ws->end_ull)
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return false;
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return false;
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|
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start = ws->next_ull;
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start = ws->next_ull;
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if (__builtin_expect (ws->mode, 0) == 0)
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if (__builtin_expect (ws->mode, 0) == 0)
|
n = (ws->end_ull - start) / ws->incr_ull;
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n = (ws->end_ull - start) / ws->incr_ull;
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else
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else
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n = (start - ws->end_ull) / -ws->incr_ull;
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n = (start - ws->end_ull) / -ws->incr_ull;
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q = (n + nthreads - 1) / nthreads;
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q = (n + nthreads - 1) / nthreads;
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|
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if (q < ws->chunk_size_ull)
|
if (q < ws->chunk_size_ull)
|
q = ws->chunk_size_ull;
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q = ws->chunk_size_ull;
|
if (q <= n)
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if (q <= n)
|
end = start + q * ws->incr_ull;
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end = start + q * ws->incr_ull;
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else
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else
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end = ws->end_ull;
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end = ws->end_ull;
|
|
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ws->next_ull = end;
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ws->next_ull = end;
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*pstart = start;
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*pstart = start;
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*pend = end;
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*pend = end;
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return true;
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return true;
|
}
|
}
|
|
|
#if defined HAVE_SYNC_BUILTINS && defined __LP64__
|
#if defined HAVE_SYNC_BUILTINS && defined __LP64__
|
/* Similar, but doesn't require the lock held, and uses compare-and-swap
|
/* Similar, but doesn't require the lock held, and uses compare-and-swap
|
instead. Note that the only memory value that changes is ws->next_ull. */
|
instead. Note that the only memory value that changes is ws->next_ull. */
|
|
|
bool
|
bool
|
gomp_iter_ull_guided_next (gomp_ull *pstart, gomp_ull *pend)
|
gomp_iter_ull_guided_next (gomp_ull *pstart, gomp_ull *pend)
|
{
|
{
|
struct gomp_thread *thr = gomp_thread ();
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struct gomp_thread *thr = gomp_thread ();
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struct gomp_work_share *ws = thr->ts.work_share;
|
struct gomp_work_share *ws = thr->ts.work_share;
|
struct gomp_team *team = thr->ts.team;
|
struct gomp_team *team = thr->ts.team;
|
gomp_ull nthreads = team ? team->nthreads : 1;
|
gomp_ull nthreads = team ? team->nthreads : 1;
|
gomp_ull start, end, nend, incr;
|
gomp_ull start, end, nend, incr;
|
gomp_ull chunk_size;
|
gomp_ull chunk_size;
|
|
|
start = ws->next_ull;
|
start = ws->next_ull;
|
end = ws->end_ull;
|
end = ws->end_ull;
|
incr = ws->incr_ull;
|
incr = ws->incr_ull;
|
chunk_size = ws->chunk_size_ull;
|
chunk_size = ws->chunk_size_ull;
|
|
|
while (1)
|
while (1)
|
{
|
{
|
gomp_ull n, q;
|
gomp_ull n, q;
|
gomp_ull tmp;
|
gomp_ull tmp;
|
|
|
if (start == end)
|
if (start == end)
|
return false;
|
return false;
|
|
|
if (__builtin_expect (ws->mode, 0) == 0)
|
if (__builtin_expect (ws->mode, 0) == 0)
|
n = (end - start) / incr;
|
n = (end - start) / incr;
|
else
|
else
|
n = (start - end) / -incr;
|
n = (start - end) / -incr;
|
q = (n + nthreads - 1) / nthreads;
|
q = (n + nthreads - 1) / nthreads;
|
|
|
if (q < chunk_size)
|
if (q < chunk_size)
|
q = chunk_size;
|
q = chunk_size;
|
if (__builtin_expect (q <= n, 1))
|
if (__builtin_expect (q <= n, 1))
|
nend = start + q * incr;
|
nend = start + q * incr;
|
else
|
else
|
nend = end;
|
nend = end;
|
|
|
tmp = __sync_val_compare_and_swap (&ws->next_ull, start, nend);
|
tmp = __sync_val_compare_and_swap (&ws->next_ull, start, nend);
|
if (__builtin_expect (tmp == start, 1))
|
if (__builtin_expect (tmp == start, 1))
|
break;
|
break;
|
|
|
start = tmp;
|
start = tmp;
|
}
|
}
|
|
|
*pstart = start;
|
*pstart = start;
|
*pend = nend;
|
*pend = nend;
|
return true;
|
return true;
|
}
|
}
|
#endif /* HAVE_SYNC_BUILTINS */
|
#endif /* HAVE_SYNC_BUILTINS */
|
|
|
