URL
https://opencores.org/ocsvn/openrisc_2011-10-31/openrisc_2011-10-31/trunk
Subversion Repositories openrisc_2011-10-31
[/] [openrisc/] [trunk/] [gnu-src/] [gcc-4.5.1/] [libgomp/] [iter_ull.c] - Rev 424
Go to most recent revision | Compare with Previous | Blame | View Log
/* Copyright (C) 2005, 2008, 2009 Free Software Foundation, Inc. Contributed by Richard Henderson <rth@redhat.com>. This file is part of the GNU OpenMP 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 contains routines for managing work-share iteration, both for loops and sections. */ #include "libgomp.h" #include <stdlib.h> typedef unsigned long long gomp_ull; /* This function implements the STATIC scheduling method. The caller should iterate *pstart <= x < *pend. Return zero if there are more iterations to perform; nonzero if not. Return less than 0 if this thread had received the absolutely last iteration. */ int gomp_iter_ull_static_next (gomp_ull *pstart, gomp_ull *pend) { struct gomp_thread *thr = gomp_thread (); struct gomp_team *team = thr->ts.team; struct gomp_work_share *ws = thr->ts.work_share; unsigned long nthreads = team ? team->nthreads : 1; if (thr->ts.static_trip == -1) return -1; /* Quick test for degenerate teams and orphaned constructs. */ if (nthreads == 1) { *pstart = ws->next_ull; *pend = ws->end_ull; thr->ts.static_trip = -1; return ws->next_ull == ws->end_ull; } /* We interpret chunk_size zero as "unspecified", which means that we should break up the iterations such that each thread makes only one trip through the outer loop. */ if (ws->chunk_size_ull == 0) { gomp_ull n, q, i, s0, e0, s, e; if (thr->ts.static_trip > 0) return 1; /* Compute the total number of iterations. */ if (__builtin_expect (ws->mode, 0) == 0) n = (ws->end_ull - ws->next_ull + ws->incr_ull - 1) / ws->incr_ull; else n = (ws->next_ull - ws->end_ull - ws->incr_ull - 1) / -ws->incr_ull; i = thr->ts.team_id; /* Compute the "zero-based" start and end points. That is, as if the loop began at zero and incremented by one. */ q = n / nthreads; q += (q * nthreads != n); s0 = q * i; e0 = s0 + q; if (e0 > n) e0 = n; /* Notice when no iterations allocated for this thread. */ if (s0 >= e0) { thr->ts.static_trip = 1; return 1; } /* Transform these to the actual start and end numbers. */ s = s0 * ws->incr_ull + ws->next_ull; e = e0 * ws->incr_ull + ws->next_ull; *pstart = s; *pend = e; thr->ts.static_trip = (e0 == n ? -1 : 1); return 0; } else { gomp_ull n, s0, e0, i, c, s, e; /* Otherwise, each thread gets exactly chunk_size iterations (if available) each time through the loop. */ if (__builtin_expect (ws->mode, 0) == 0) n = (ws->end_ull - ws->next_ull + ws->incr_ull - 1) / ws->incr_ull; else n = (ws->next_ull - ws->end_ull - ws->incr_ull - 1) / -ws->incr_ull; i = thr->ts.team_id; c = ws->chunk_size_ull; /* Initial guess is a C sized chunk positioned nthreads iterations in, offset by our thread number. */ s0 = (thr->ts.static_trip * (gomp_ull) nthreads + i) * c; e0 = s0 + c; /* Detect overflow. */ if (s0 >= n) return 1; if (e0 > n) e0 = n; /* Transform these to the actual start and end numbers. */ s = s0 * ws->incr_ull + ws->next_ull; e = e0 * ws->incr_ull + ws->next_ull; *pstart = s; *pend = e; if (e0 == n) thr->ts.static_trip = -1; else thr->ts.static_trip++; return 0; } } /* This function implements the DYNAMIC scheduling method. Arguments are as for gomp_iter_ull_static_next. This function must be called with ws->lock held. */ bool gomp_iter_ull_dynamic_next_locked (gomp_ull *pstart, gomp_ull *pend) { struct gomp_thread *thr = gomp_thread (); struct gomp_work_share *ws = thr->ts.work_share; gomp_ull start, end, chunk, left; start = ws->next_ull; if (start == ws->end_ull) return false; chunk = ws->chunk_size_ull; left = ws->end_ull - start; if (__builtin_expect (ws->mode & 2, 0)) { if (chunk < left) chunk = left; } else { if (chunk > left) chunk = left; } end = start + chunk; ws->next_ull = end; *pstart = start; *pend = end; return true; } #if defined HAVE_SYNC_BUILTINS && defined __LP64__ /* 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. */ bool gomp_iter_ull_dynamic_next (gomp_ull *pstart, gomp_ull *pend) { struct gomp_thread *thr = gomp_thread (); struct gomp_work_share *ws = thr->ts.work_share; gomp_ull start, end, nend, chunk; end = ws->end_ull; chunk = ws->chunk_size_ull; if (__builtin_expect (ws->mode & 1, 1)) { gomp_ull tmp = __sync_fetch_and_add (&ws->next_ull, chunk); if (__builtin_expect (ws->mode & 2, 0) == 0) { if (tmp >= end) return false; nend = tmp + chunk; if (nend > end) nend = end; *pstart = tmp; *pend = nend; return true; } else { if (tmp <= end) return false; nend = tmp + chunk; if (nend < end) nend = end; *pstart = tmp; *pend = nend; return true; } } start = ws->next_ull; while (1) { gomp_ull left = end - start; gomp_ull tmp; if (start == end) return false; if (__builtin_expect (ws->mode & 2, 0)) { if (chunk < left) chunk = left; } else { if (chunk > left) chunk = left; } nend = start + chunk; tmp = __sync_val_compare_and_swap (&ws->next_ull, start, nend); if (__builtin_expect (tmp == start, 1)) break; start = tmp; } *pstart = start; *pend = nend; return true; } #endif /* HAVE_SYNC_BUILTINS */ /* This function implements the GUIDED scheduling method. Arguments are as for gomp_iter_ull_static_next. This function must be called with the work share lock held. */ bool gomp_iter_ull_guided_next_locked (gomp_ull *pstart, gomp_ull *pend) { struct gomp_thread *thr = gomp_thread (); struct gomp_work_share *ws = thr->ts.work_share; struct gomp_team *team = thr->ts.team; gomp_ull nthreads = team ? team->nthreads : 1; gomp_ull n, q; gomp_ull start, end; if (ws->next_ull == ws->end_ull) return false; start = ws->next_ull; if (__builtin_expect (ws->mode, 0) == 0) n = (ws->end_ull - start) / ws->incr_ull; else n = (start - ws->end_ull) / -ws->incr_ull; q = (n + nthreads - 1) / nthreads; if (q < ws->chunk_size_ull) q = ws->chunk_size_ull; if (q <= n) end = start + q * ws->incr_ull; else end = ws->end_ull; ws->next_ull = end; *pstart = start; *pend = end; return true; } #if defined HAVE_SYNC_BUILTINS && defined __LP64__ /* 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. */ bool gomp_iter_ull_guided_next (gomp_ull *pstart, gomp_ull *pend) { struct gomp_thread *thr = gomp_thread (); struct gomp_work_share *ws = thr->ts.work_share; struct gomp_team *team = thr->ts.team; gomp_ull nthreads = team ? team->nthreads : 1; gomp_ull start, end, nend, incr; gomp_ull chunk_size; start = ws->next_ull; end = ws->end_ull; incr = ws->incr_ull; chunk_size = ws->chunk_size_ull; while (1) { gomp_ull n, q; gomp_ull tmp; if (start == end) return false; if (__builtin_expect (ws->mode, 0) == 0) n = (end - start) / incr; else n = (start - end) / -incr; q = (n + nthreads - 1) / nthreads; if (q < chunk_size) q = chunk_size; if (__builtin_expect (q <= n, 1)) nend = start + q * incr; else nend = end; tmp = __sync_val_compare_and_swap (&ws->next_ull, start, nend); if (__builtin_expect (tmp == start, 1)) break; start = tmp; } *pstart = start; *pend = nend; return true; } #endif /* HAVE_SYNC_BUILTINS */
Go to most recent revision | Compare with Previous | Blame | View Log