libgomp/loop.c

   1 /* Copyright (C) 2005-2017 Free Software Foundation, Inc.
   2    Contributed by Richard Henderson <rth@redhat.com>.
   3
   4    This file is part of the GNU Offloading and Multi Processing Library
   5    (libgomp).
   6
   7    Libgomp is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3, or (at your option)
  10    any later version.
  11
  12    Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
  13    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  14    FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15    more details.
  16
  17    Under Section 7 of GPL version 3, you are granted additional
  18    permissions described in the GCC Runtime Library Exception, version
  19    3.1, as published by the Free Software Foundation.
  20
  21    You should have received a copy of the GNU General Public License and
  22    a copy of the GCC Runtime Library Exception along with this program;
  23    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24    <http://www.gnu.org/licenses/>.  */
  25
  26 /* This file handles the LOOP (FOR/DO) construct.  */
  27
  28 #include <limits.h>
  29 #include <stdlib.h>
  30 #include "libgomp.h"
  31
  32
  33 /* Initialize the given work share construct from the given arguments.  */
  34
  35 static inline void
  36 gomp_loop_init (struct gomp_work_share *ws, long start, long end, long incr,
  37                 enum gomp_schedule_type sched, long chunk_size)
  38 {
  39   ws->sched = sched;
  40   ws->chunk_size = chunk_size;
  41   /* Canonicalize loops that have zero iterations to ->next == ->end.  */
  42   ws->end = ((incr > 0 && start > end) || (incr < 0 && start < end))
  43             ? start : end;
  44   ws->incr = incr;
  45   ws->next = start;
  46   if (sched == GFS_DYNAMIC)
  47     {
  48       ws->chunk_size *= incr;
  49
  50 #ifdef HAVE_SYNC_BUILTINS
  51       {
  52         /* For dynamic scheduling prepare things to make each iteration
  53            faster.  */
  54         struct gomp_thread *thr = gomp_thread ();
  55         struct gomp_team *team = thr->ts.team;
  56         long nthreads = team ? team->nthreads : 1;
  57
  58         if (__builtin_expect (incr > 0, 1))
  59           {
  60             /* Cheap overflow protection.  */
  61             if (__builtin_expect ((nthreads | ws->chunk_size)
  62                                   >= 1UL << (sizeof (long)
  63                                              * __CHAR_BIT__ / 2 - 1), 0))
  64               ws->mode = 0;
  65             else
  66               ws->mode = ws->end < (LONG_MAX
  67                                     - (nthreads + 1) * ws->chunk_size);
  68           }
  69         /* Cheap overflow protection.  */
  70         else if (__builtin_expect ((nthreads | -ws->chunk_size)
  71                                    >= 1UL << (sizeof (long)
  72                                               * __CHAR_BIT__ / 2 - 1), 0))
  73           ws->mode = 0;
  74         else
  75           ws->mode = ws->end > (nthreads + 1) * -ws->chunk_size - LONG_MAX;
  76       }
  77 #endif
  78     }
  79 }
  80
  81 /* The *_start routines are called when first encountering a loop construct
  82    that is not bound directly to a parallel construct.  The first thread
  83    that arrives will create the work-share construct; subsequent threads
  84    will see the construct exists and allocate work from it.
  85
  86    START, END, INCR are the bounds of the loop; due to the restrictions of
  87    OpenMP, these values must be the same in every thread.  This is not
  88    verified (nor is it entirely verifiable, since START is not necessarily
  89    retained intact in the work-share data structure).  CHUNK_SIZE is the
  90    scheduling parameter; again this must be identical in all threads.
  91
  92    Returns true if there's any work for this thread to perform.  If so,
  93    *ISTART and *IEND are filled with the bounds of the iteration block
  94    allocated to this thread.  Returns false if all work was assigned to
  95    other threads prior to this thread's arrival.  */
  96
  97 static bool
  98 gomp_loop_static_start (long start, long end, long incr, long chunk_size,
  99                         long *istart, long *iend)
 100 {
 101   struct gomp_thread *thr = gomp_thread ();
 102
 103   thr->ts.static_trip = 0;
 104   if (gomp_work_share_start (false))
 105     {
 106       gomp_loop_init (thr->ts.work_share, start, end, incr,
 107                       GFS_STATIC, chunk_size);
 108       gomp_work_share_init_done ();
 109     }
 110
 111   return !gomp_iter_static_next (istart, iend);
 112 }
 113
 114 /* The current dynamic implementation is always monotonic.  The
 115    entrypoints without nonmonotonic in them have to be always monotonic,
 116    but the nonmonotonic ones could be changed to use work-stealing for
 117    improved scalability.  */
 118
 119 static bool
 120 gomp_loop_dynamic_start (long start, long end, long incr, long chunk_size,
 121                          long *istart, long *iend)
 122 {
 123   struct gomp_thread *thr = gomp_thread ();
 124   bool ret;
 125
 126   if (gomp_work_share_start (false))
 127     {
 128       gomp_loop_init (thr->ts.work_share, start, end, incr,
 129                       GFS_DYNAMIC, chunk_size);
 130       gomp_work_share_init_done ();
 131     }
 132
 133 #ifdef HAVE_SYNC_BUILTINS
 134   ret = gomp_iter_dynamic_next (istart, iend);
 135 #else
 136   gomp_mutex_lock (&thr->ts.work_share->lock);
 137   ret = gomp_iter_dynamic_next_locked (istart, iend);
 138   gomp_mutex_unlock (&thr->ts.work_share->lock);
 139 #endif
 140
 141   return ret;
 142 }
 143
 144 /* Similarly as for dynamic, though the question is how can the chunk sizes
 145    be decreased without a central locking or atomics.  */
 146
 147 static bool
 148 gomp_loop_guided_start (long start, long end, long incr, long chunk_size,
 149                         long *istart, long *iend)
 150 {
 151   struct gomp_thread *thr = gomp_thread ();
 152   bool ret;
 153
 154   if (gomp_work_share_start (false))
 155     {
 156       gomp_loop_init (thr->ts.work_share, start, end, incr,
 157                       GFS_GUIDED, chunk_size);
 158       gomp_work_share_init_done ();
 159     }
 160
 161 #ifdef HAVE_SYNC_BUILTINS
 162   ret = gomp_iter_guided_next (istart, iend);
 163 #else
 164   gomp_mutex_lock (&thr->ts.work_share->lock);
 165   ret = gomp_iter_guided_next_locked (istart, iend);
 166   gomp_mutex_unlock (&thr->ts.work_share->lock);
 167 #endif
 168
 169   return ret;
 170 }
 171
 172 bool
 173 GOMP_loop_runtime_start (long start, long end, long incr,
 174                          long *istart, long *iend)
 175 {
 176   struct gomp_task_icv *icv = gomp_icv (false);
 177   switch (icv->run_sched_var)
 178     {
 179     case GFS_STATIC:
 180       return gomp_loop_static_start (start, end, incr,
 181                                      icv->run_sched_chunk_size,
 182                                      istart, iend);
 183     case GFS_DYNAMIC:
 184       return gomp_loop_dynamic_start (start, end, incr,
 185                                       icv->run_sched_chunk_size,
 186                                       istart, iend);
 187     case GFS_GUIDED:
 188       return gomp_loop_guided_start (start, end, incr,
 189                                      icv->run_sched_chunk_size,
 190                                      istart, iend);
 191     case GFS_AUTO:
 192       /* For now map to schedule(static), later on we could play with feedback
 193          driven choice.  */
 194       return gomp_loop_static_start (start, end, incr, 0, istart, iend);
 195     default:
 196       abort ();
 197     }
 198 }
 199
 200 /* The *_ordered_*_start routines are similar.  The only difference is that
 201    this work-share construct is initialized to expect an ORDERED section.  */
 202
 203 static bool
 204 gomp_loop_ordered_static_start (long start, long end, long incr,
 205                                 long chunk_size, long *istart, long *iend)
 206 {
 207   struct gomp_thread *thr = gomp_thread ();
 208
 209   thr->ts.static_trip = 0;
 210   if (gomp_work_share_start (true))
 211     {
 212       gomp_loop_init (thr->ts.work_share, start, end, incr,
 213                       GFS_STATIC, chunk_size);
 214       gomp_ordered_static_init ();
 215       gomp_work_share_init_done ();
 216     }
 217
 218   return !gomp_iter_static_next (istart, iend);
 219 }
 220
 221 static bool
 222 gomp_loop_ordered_dynamic_start (long start, long end, long incr,
 223                                  long chunk_size, long *istart, long *iend)
 224 {
 225   struct gomp_thread *thr = gomp_thread ();
 226   bool ret;
 227
 228   if (gomp_work_share_start (true))
 229     {
 230       gomp_loop_init (thr->ts.work_share, start, end, incr,
 231                       GFS_DYNAMIC, chunk_size);
 232       gomp_mutex_lock (&thr->ts.work_share->lock);
 233       gomp_work_share_init_done ();
 234     }
 235   else
 236     gomp_mutex_lock (&thr->ts.work_share->lock);
 237
 238   ret = gomp_iter_dynamic_next_locked (istart, iend);
 239   if (ret)
 240     gomp_ordered_first ();
 241   gomp_mutex_unlock (&thr->ts.work_share->lock);
 242
 243   return ret;
 244 }
 245
 246 static bool
 247 gomp_loop_ordered_guided_start (long start, long end, long incr,
 248                                 long chunk_size, long *istart, long *iend)
 249 {
 250   struct gomp_thread *thr = gomp_thread ();
 251   bool ret;
 252
 253   if (gomp_work_share_start (true))
 254     {
 255       gomp_loop_init (thr->ts.work_share, start, end, incr,
 256                       GFS_GUIDED, chunk_size);
 257       gomp_mutex_lock (&thr->ts.work_share->lock);
 258       gomp_work_share_init_done ();
 259     }
 260   else
 261     gomp_mutex_lock (&thr->ts.work_share->lock);
 262
 263   ret = gomp_iter_guided_next_locked (istart, iend);
 264   if (ret)
 265     gomp_ordered_first ();
 266   gomp_mutex_unlock (&thr->ts.work_share->lock);
 267
 268   return ret;
 269 }
 270
 271 bool
 272 GOMP_loop_ordered_runtime_start (long start, long end, long incr,
 273                                  long *istart, long *iend)
 274 {
 275   struct gomp_task_icv *icv = gomp_icv (false);
 276   switch (icv->run_sched_var)
 277     {
 278     case GFS_STATIC:
 279       return gomp_loop_ordered_static_start (start, end, incr,
 280                                              icv->run_sched_chunk_size,
 281                                              istart, iend);
 282     case GFS_DYNAMIC:
 283       return gomp_loop_ordered_dynamic_start (start, end, incr,
 284                                               icv->run_sched_chunk_size,
 285                                               istart, iend);
 286     case GFS_GUIDED:
 287       return gomp_loop_ordered_guided_start (start, end, incr,
 288                                              icv->run_sched_chunk_size,
 289                                              istart, iend);
 290     case GFS_AUTO:
 291       /* For now map to schedule(static), later on we could play with feedback
 292          driven choice.  */
 293       return gomp_loop_ordered_static_start (start, end, incr,
 294                                              0, istart, iend);
 295     default:
 296       abort ();
 297     }
 298 }
 299
 300 /* The *_doacross_*_start routines are similar.  The only difference is that
 301    this work-share construct is initialized to expect an ORDERED(N) - DOACROSS
 302    section, and the worksharing loop iterates always from 0 to COUNTS[0] - 1
 303    and other COUNTS array elements tell the library number of iterations
 304    in the ordered inner loops.  */
 305
 306 static bool
 307 gomp_loop_doacross_static_start (unsigned ncounts, long *counts,
 308                                  long chunk_size, long *istart, long *iend)
 309 {
 310   struct gomp_thread *thr = gomp_thread ();
 311
 312   thr->ts.static_trip = 0;
 313   if (gomp_work_share_start (false))
 314     {
 315       gomp_loop_init (thr->ts.work_share, 0, counts[0], 1,
 316                       GFS_STATIC, chunk_size);
 317       gomp_doacross_init (ncounts, counts, chunk_size);
 318       gomp_work_share_init_done ();
 319     }
 320
 321   return !gomp_iter_static_next (istart, iend);
 322 }
 323
 324 static bool
 325 gomp_loop_doacross_dynamic_start (unsigned ncounts, long *counts,
 326                                   long chunk_size, long *istart, long *iend)
 327 {
 328   struct gomp_thread *thr = gomp_thread ();
 329   bool ret;
 330
 331   if (gomp_work_share_start (false))
 332     {
 333       gomp_loop_init (thr->ts.work_share, 0, counts[0], 1,
 334                       GFS_DYNAMIC, chunk_size);
 335       gomp_doacross_init (ncounts, counts, chunk_size);
 336       gomp_work_share_init_done ();
 337     }
 338
 339 #ifdef HAVE_SYNC_BUILTINS
 340   ret = gomp_iter_dynamic_next (istart, iend);
 341 #else
 342   gomp_mutex_lock (&thr->ts.work_share->lock);
 343   ret = gomp_iter_dynamic_next_locked (istart, iend);
 344   gomp_mutex_unlock (&thr->ts.work_share->lock);
 345 #endif
 346
 347   return ret;
 348 }
 349
 350 static bool
 351 gomp_loop_doacross_guided_start (unsigned ncounts, long *counts,
 352                                  long chunk_size, long *istart, long *iend)
 353 {
 354   struct gomp_thread *thr = gomp_thread ();
 355   bool ret;
 356
 357   if (gomp_work_share_start (false))
 358     {
 359       gomp_loop_init (thr->ts.work_share, 0, counts[0], 1,
 360                       GFS_GUIDED, chunk_size);
 361       gomp_doacross_init (ncounts, counts, chunk_size);
 362       gomp_work_share_init_done ();
 363     }
 364
 365 #ifdef HAVE_SYNC_BUILTINS
 366   ret = gomp_iter_guided_next (istart, iend);
 367 #else
 368   gomp_mutex_lock (&thr->ts.work_share->lock);
 369   ret = gomp_iter_guided_next_locked (istart, iend);
 370   gomp_mutex_unlock (&thr->ts.work_share->lock);
 371 #endif
 372
 373   return ret;
 374 }
 375
 376 bool
 377 GOMP_loop_doacross_runtime_start (unsigned ncounts, long *counts,
 378                                   long *istart, long *iend)
 379 {
 380   struct gomp_task_icv *icv = gomp_icv (false);
 381   switch (icv->run_sched_var)
 382     {
 383     case GFS_STATIC:
 384       return gomp_loop_doacross_static_start (ncounts, counts,
 385                                               icv->run_sched_chunk_size,
 386                                               istart, iend);
 387     case GFS_DYNAMIC:
 388       return gomp_loop_doacross_dynamic_start (ncounts, counts,
 389                                                icv->run_sched_chunk_size,
 390                                                istart, iend);
 391     case GFS_GUIDED:
 392       return gomp_loop_doacross_guided_start (ncounts, counts,
 393                                               icv->run_sched_chunk_size,
 394                                               istart, iend);
 395     case GFS_AUTO:
 396       /* For now map to schedule(static), later on we could play with feedback
 397          driven choice.  */
 398       return gomp_loop_doacross_static_start (ncounts, counts,
 399                                               0, istart, iend);
 400     default:
 401       abort ();
 402     }
 403 }
 404
 405 /* The *_next routines are called when the thread completes processing of
 406    the iteration block currently assigned to it.  If the work-share
 407    construct is bound directly to a parallel construct, then the iteration
 408    bounds may have been set up before the parallel.  In which case, this
 409    may be the first iteration for the thread.
 410
 411    Returns true if there is work remaining to be performed; *ISTART and
 412    *IEND are filled with a new iteration block.  Returns false if all work
 413    has been assigned.  */
 414
 415 static bool
 416 gomp_loop_static_next (long *istart, long *iend)
 417 {
 418   return !gomp_iter_static_next (istart, iend);
 419 }
 420
 421 static bool
 422 gomp_loop_dynamic_next (long *istart, long *iend)
 423 {
 424   bool ret;
 425
 426 #ifdef HAVE_SYNC_BUILTINS
 427   ret = gomp_iter_dynamic_next (istart, iend);
 428 #else
 429   struct gomp_thread *thr = gomp_thread ();
 430   gomp_mutex_lock (&thr->ts.work_share->lock);
 431   ret = gomp_iter_dynamic_next_locked (istart, iend);
 432   gomp_mutex_unlock (&thr->ts.work_share->lock);
 433 #endif
 434
 435   return ret;
 436 }
 437
 438 static bool
 439 gomp_loop_guided_next (long *istart, long *iend)
 440 {
 441   bool ret;
 442
 443 #ifdef HAVE_SYNC_BUILTINS
 444   ret = gomp_iter_guided_next (istart, iend);
 445 #else
 446   struct gomp_thread *thr = gomp_thread ();
 447   gomp_mutex_lock (&thr->ts.work_share->lock);
 448   ret = gomp_iter_guided_next_locked (istart, iend);
 449   gomp_mutex_unlock (&thr->ts.work_share->lock);
 450 #endif
 451
 452   return ret;
 453 }
 454
 455 bool
 456 GOMP_loop_runtime_next (long *istart, long *iend)
 457 {
 458   struct gomp_thread *thr = gomp_thread ();
 459
 460   switch (thr->ts.work_share->sched)
 461     {
 462     case GFS_STATIC:
 463     case GFS_AUTO:
 464       return gomp_loop_static_next (istart, iend);
 465     case GFS_DYNAMIC:
 466       return gomp_loop_dynamic_next (istart, iend);
 467     case GFS_GUIDED:
 468       return gomp_loop_guided_next (istart, iend);
 469     default:
 470       abort ();
 471     }
 472 }
 473
 474 /* The *_ordered_*_next routines are called when the thread completes
 475    processing of the iteration block currently assigned to it.
 476
 477    Returns true if there is work remaining to be performed; *ISTART and
 478    *IEND are filled with a new iteration block.  Returns false if all work
 479    has been assigned.  */
 480
 481 static bool
 482 gomp_loop_ordered_static_next (long *istart, long *iend)
 483 {
 484   struct gomp_thread *thr = gomp_thread ();
 485   int test;
 486
 487   gomp_ordered_sync ();
 488   gomp_mutex_lock (&thr->ts.work_share->lock);
 489   test = gomp_iter_static_next (istart, iend);
 490   if (test >= 0)
 491     gomp_ordered_static_next ();
 492   gomp_mutex_unlock (&thr->ts.work_share->lock);
 493
 494   return test == 0;
 495 }
 496
 497 static bool
 498 gomp_loop_ordered_dynamic_next (long *istart, long *iend)
 499 {
 500   struct gomp_thread *thr = gomp_thread ();
 501   bool ret;
 502
 503   gomp_ordered_sync ();
 504   gomp_mutex_lock (&thr->ts.work_share->lock);
 505   ret = gomp_iter_dynamic_next_locked (istart, iend);
 506   if (ret)
 507     gomp_ordered_next ();
 508   else
 509     gomp_ordered_last ();
 510   gomp_mutex_unlock (&thr->ts.work_share->lock);
 511
 512   return ret;
 513 }
 514
 515 static bool
 516 gomp_loop_ordered_guided_next (long *istart, long *iend)
 517 {
 518   struct gomp_thread *thr = gomp_thread ();
 519   bool ret;
 520
 521   gomp_ordered_sync ();
 522   gomp_mutex_lock (&thr->ts.work_share->lock);
 523   ret = gomp_iter_guided_next_locked (istart, iend);
 524   if (ret)
 525     gomp_ordered_next ();
 526   else
 527     gomp_ordered_last ();
 528   gomp_mutex_unlock (&thr->ts.work_share->lock);
 529
 530   return ret;
 531 }
 532
 533 bool
 534 GOMP_loop_ordered_runtime_next (long *istart, long *iend)
 535 {
 536   struct gomp_thread *thr = gomp_thread ();
 537
 538   switch (thr->ts.work_share->sched)
 539     {
 540     case GFS_STATIC:
 541     case GFS_AUTO:
 542       return gomp_loop_ordered_static_next (istart, iend);
 543     case GFS_DYNAMIC:
 544       return gomp_loop_ordered_dynamic_next (istart, iend);
 545     case GFS_GUIDED:
 546       return gomp_loop_ordered_guided_next (istart, iend);
 547     default:
 548       abort ();
 549     }
 550 }
 551
 552 /* The GOMP_parallel_loop_* routines pre-initialize a work-share construct
 553    to avoid one synchronization once we get into the loop.  */
 554
 555 static void
 556 gomp_parallel_loop_start (void (*fn) (void *), void *data,
 557                           unsigned num_threads, long start, long end,
 558                           long incr, enum gomp_schedule_type sched,
 559                           long chunk_size, unsigned int flags)
 560 {
 561   struct gomp_team *team;
 562
 563   num_threads = gomp_resolve_num_threads (num_threads, 0);
 564   team = gomp_new_team (num_threads);
 565   gomp_loop_init (&team->work_shares[0], start, end, incr, sched, chunk_size);
 566   gomp_team_start (fn, data, num_threads, flags, team);
 567 }
 568
 569 void
 570 GOMP_parallel_loop_static_start (void (*fn) (void *), void *data,
 571                                  unsigned num_threads, long start, long end,
 572                                  long incr, long chunk_size)
 573 {
 574   gomp_parallel_loop_start (fn, data, num_threads, start, end, incr,
 575                             GFS_STATIC, chunk_size, 0);
 576 }
 577
 578 void
 579 GOMP_parallel_loop_dynamic_start (void (*fn) (void *), void *data,
 580                                   unsigned num_threads, long start, long end,
 581                                   long incr, long chunk_size)
 582 {
 583   gomp_parallel_loop_start (fn, data, num_threads, start, end, incr,
 584                             GFS_DYNAMIC, chunk_size, 0);
 585 }
 586
 587 void
 588 GOMP_parallel_loop_guided_start (void (*fn) (void *), void *data,
 589                                  unsigned num_threads, long start, long end,
 590                                  long incr, long chunk_size)
 591 {
 592   gomp_parallel_loop_start (fn, data, num_threads, start, end, incr,
 593                             GFS_GUIDED, chunk_size, 0);
 594 }
 595
 596 void
 597 GOMP_parallel_loop_runtime_start (void (*fn) (void *), void *data,
 598                                   unsigned num_threads, long start, long end,
 599                                   long incr)
 600 {
 601   struct gomp_task_icv *icv = gomp_icv (false);
 602   gomp_parallel_loop_start (fn, data, num_threads, start, end, incr,
 603                             icv->run_sched_var, icv->run_sched_chunk_size, 0);
 604 }
 605
 606 ialias_redirect (GOMP_parallel_end)
 607
 608 void
 609 GOMP_parallel_loop_static (void (*fn) (void *), void *data,
 610                            unsigned num_threads, long start, long end,
 611                            long incr, long chunk_size, unsigned flags)
 612 {
 613   gomp_parallel_loop_start (fn, data, num_threads, start, end, incr,
 614                             GFS_STATIC, chunk_size, flags);
 615   fn (data);
 616   GOMP_parallel_end ();
 617 }
 618
 619 void
 620 GOMP_parallel_loop_dynamic (void (*fn) (void *), void *data,
 621                             unsigned num_threads, long start, long end,
 622                             long incr, long chunk_size, unsigned flags)
 623 {
 624   gomp_parallel_loop_start (fn, data, num_threads, start, end, incr,
 625                             GFS_DYNAMIC, chunk_size, flags);
 626   fn (data);
 627   GOMP_parallel_end ();
 628 }
 629
 630 void
 631 GOMP_parallel_loop_guided (void (*fn) (void *), void *data,
 632                           unsigned num_threads, long start, long end,
 633                           long incr, long chunk_size, unsigned flags)
 634 {
 635   gomp_parallel_loop_start (fn, data, num_threads, start, end, incr,
 636                             GFS_GUIDED, chunk_size, flags);
 637   fn (data);
 638   GOMP_parallel_end ();
 639 }
 640
 641 #ifdef HAVE_ATTRIBUTE_ALIAS
 642 extern __typeof(GOMP_parallel_loop_dynamic) GOMP_parallel_loop_nonmonotonic_dynamic
 643         __attribute__((alias ("GOMP_parallel_loop_dynamic")));
 644 extern __typeof(GOMP_parallel_loop_guided) GOMP_parallel_loop_nonmonotonic_guided
 645         __attribute__((alias ("GOMP_parallel_loop_guided")));
 646 #else
 647 void
 648 GOMP_parallel_loop_nonmonotonic_dynamic (void (*fn) (void *), void *data,
 649                                          unsigned num_threads, long start,
 650                                          long end, long incr, long chunk_size,
 651                                          unsigned flags)
 652 {
 653   gomp_parallel_loop_start (fn, data, num_threads, start, end, incr,
 654                             GFS_DYNAMIC, chunk_size, flags);
 655   fn (data);
 656   GOMP_parallel_end ();
 657 }
 658
 659 void
 660 GOMP_parallel_loop_nonmonotonic_guided (void (*fn) (void *), void *data,
 661                                         unsigned num_threads, long start,
 662                                         long end, long incr, long chunk_size,
 663                                         unsigned flags)
 664 {
 665   gomp_parallel_loop_start (fn, data, num_threads, start, end, incr,
 666                             GFS_GUIDED, chunk_size, flags);
 667   fn (data);
 668   GOMP_parallel_end ();
 669 }
 670 #endif
 671
 672 void
 673 GOMP_parallel_loop_runtime (void (*fn) (void *), void *data,
 674                             unsigned num_threads, long start, long end,
 675                             long incr, unsigned flags)
 676 {
 677   struct gomp_task_icv *icv = gomp_icv (false);
 678   gomp_parallel_loop_start (fn, data, num_threads, start, end, incr,
 679                             icv->run_sched_var, icv->run_sched_chunk_size,
 680                             flags);
 681   fn (data);
 682   GOMP_parallel_end ();
 683 }
 684
 685 /* The GOMP_loop_end* routines are called after the thread is told that
 686    all loop iterations are complete.  The first two versions synchronize
 687    all threads; the nowait version does not.  */
 688
 689 void
 690 GOMP_loop_end (void)
 691 {
 692   gomp_work_share_end ();
 693 }
 694
 695 bool
 696 GOMP_loop_end_cancel (void)
 697 {
 698   return gomp_work_share_end_cancel ();
 699 }
 700
 701 void
 702 GOMP_loop_end_nowait (void)
 703 {
 704   gomp_work_share_end_nowait ();
 705 }
 706
 707
 708 /* We use static functions above so that we're sure that the "runtime"
 709    function can defer to the proper routine without interposition.  We
 710    export the static function with a strong alias when possible, or with
 711    a wrapper function otherwise.  */
 712
 713 #ifdef HAVE_ATTRIBUTE_ALIAS
 714 extern __typeof(gomp_loop_static_start) GOMP_loop_static_start
 715         __attribute__((alias ("gomp_loop_static_start")));
 716 extern __typeof(gomp_loop_dynamic_start) GOMP_loop_dynamic_start
 717         __attribute__((alias ("gomp_loop_dynamic_start")));
 718 extern __typeof(gomp_loop_guided_start) GOMP_loop_guided_start
 719         __attribute__((alias ("gomp_loop_guided_start")));
 720 extern __typeof(gomp_loop_dynamic_start) GOMP_loop_nonmonotonic_dynamic_start
 721         __attribute__((alias ("gomp_loop_dynamic_start")));
 722 extern __typeof(gomp_loop_guided_start) GOMP_loop_nonmonotonic_guided_start
 723         __attribute__((alias ("gomp_loop_guided_start")));
 724
 725 extern __typeof(gomp_loop_ordered_static_start) GOMP_loop_ordered_static_start
 726         __attribute__((alias ("gomp_loop_ordered_static_start")));
 727 extern __typeof(gomp_loop_ordered_dynamic_start) GOMP_loop_ordered_dynamic_start
 728         __attribute__((alias ("gomp_loop_ordered_dynamic_start")));
 729 extern __typeof(gomp_loop_ordered_guided_start) GOMP_loop_ordered_guided_start
 730         __attribute__((alias ("gomp_loop_ordered_guided_start")));
 731
 732 extern __typeof(gomp_loop_doacross_static_start) GOMP_loop_doacross_static_start
 733         __attribute__((alias ("gomp_loop_doacross_static_start")));
 734 extern __typeof(gomp_loop_doacross_dynamic_start) GOMP_loop_doacross_dynamic_start
 735         __attribute__((alias ("gomp_loop_doacross_dynamic_start")));
 736 extern __typeof(gomp_loop_doacross_guided_start) GOMP_loop_doacross_guided_start
 737         __attribute__((alias ("gomp_loop_doacross_guided_start")));
 738
 739 extern __typeof(gomp_loop_static_next) GOMP_loop_static_next
 740         __attribute__((alias ("gomp_loop_static_next")));
 741 extern __typeof(gomp_loop_dynamic_next) GOMP_loop_dynamic_next
 742         __attribute__((alias ("gomp_loop_dynamic_next")));
 743 extern __typeof(gomp_loop_guided_next) GOMP_loop_guided_next
 744         __attribute__((alias ("gomp_loop_guided_next")));
 745 extern __typeof(gomp_loop_dynamic_next) GOMP_loop_nonmonotonic_dynamic_next
 746         __attribute__((alias ("gomp_loop_dynamic_next")));
 747 extern __typeof(gomp_loop_guided_next) GOMP_loop_nonmonotonic_guided_next
 748         __attribute__((alias ("gomp_loop_guided_next")));
 749
 750 extern __typeof(gomp_loop_ordered_static_next) GOMP_loop_ordered_static_next
 751         __attribute__((alias ("gomp_loop_ordered_static_next")));
 752 extern __typeof(gomp_loop_ordered_dynamic_next) GOMP_loop_ordered_dynamic_next
 753         __attribute__((alias ("gomp_loop_ordered_dynamic_next")));
 754 extern __typeof(gomp_loop_ordered_guided_next) GOMP_loop_ordered_guided_next
 755         __attribute__((alias ("gomp_loop_ordered_guided_next")));
 756 #else
 757 bool
 758 GOMP_loop_static_start (long start, long end, long incr, long chunk_size,
 759                         long *istart, long *iend)
 760 {
 761   return gomp_loop_static_start (start, end, incr, chunk_size, istart, iend);
 762 }
 763
 764 bool
 765 GOMP_loop_dynamic_start (long start, long end, long incr, long chunk_size,
 766                          long *istart, long *iend)
 767 {
 768   return gomp_loop_dynamic_start (start, end, incr, chunk_size, istart, iend);
 769 }
 770
 771 bool
 772 GOMP_loop_guided_start (long start, long end, long incr, long chunk_size,
 773                         long *istart, long *iend)
 774 {
 775   return gomp_loop_guided_start (start, end, incr, chunk_size, istart, iend);
 776 }
 777
 778 bool
 779 GOMP_loop_nonmonotonic_dynamic_start (long start, long end, long incr,
 780                                       long chunk_size, long *istart,
 781                                       long *iend)
 782 {
 783   return gomp_loop_dynamic_start (start, end, incr, chunk_size, istart, iend);
 784 }
 785
 786 bool
 787 GOMP_loop_nonmonotonic_guided_start (long start, long end, long incr,
 788                                      long chunk_size, long *istart, long *iend)
 789 {
 790   return gomp_loop_guided_start (start, end, incr, chunk_size, istart, iend);
 791 }
 792
 793 bool
 794 GOMP_loop_ordered_static_start (long start, long end, long incr,
 795                                 long chunk_size, long *istart, long *iend)
 796 {
 797   return gomp_loop_ordered_static_start (start, end, incr, chunk_size,
 798                                          istart, iend);
 799 }
 800
 801 bool
 802 GOMP_loop_ordered_dynamic_start (long start, long end, long incr,
 803                                  long chunk_size, long *istart, long *iend)
 804 {
 805   return gomp_loop_ordered_dynamic_start (start, end, incr, chunk_size,
 806                                           istart, iend);
 807 }
 808
 809 bool
 810 GOMP_loop_ordered_guided_start (long start, long end, long incr,
 811                                 long chunk_size, long *istart, long *iend)
 812 {
 813   return gomp_loop_ordered_guided_start (start, end, incr, chunk_size,
 814                                          istart, iend);
 815 }
 816
 817 bool
 818 GOMP_loop_doacross_static_start (unsigned ncounts, long *counts,
 819                                  long chunk_size, long *istart, long *iend)
 820 {
 821   return gomp_loop_doacross_static_start (ncounts, counts, chunk_size,
 822                                           istart, iend);
 823 }
 824
 825 bool
 826 GOMP_loop_doacross_dynamic_start (unsigned ncounts, long *counts,
 827                                   long chunk_size, long *istart, long *iend)
 828 {
 829   return gomp_loop_doacross_dynamic_start (ncounts, counts, chunk_size,
 830                                            istart, iend);
 831 }
 832
 833 bool
 834 GOMP_loop_doacross_guided_start (unsigned ncounts, long *counts,
 835                                  long chunk_size, long *istart, long *iend)
 836 {
 837   return gomp_loop_doacross_guided_start (ncounts, counts, chunk_size,
 838                                           istart, iend);
 839 }
 840
 841 bool
 842 GOMP_loop_static_next (long *istart, long *iend)
 843 {
 844   return gomp_loop_static_next (istart, iend);
 845 }
 846
 847 bool
 848 GOMP_loop_dynamic_next (long *istart, long *iend)
 849 {
 850   return gomp_loop_dynamic_next (istart, iend);
 851 }
 852
 853 bool
 854 GOMP_loop_guided_next (long *istart, long *iend)
 855 {
 856   return gomp_loop_guided_next (istart, iend);
 857 }
 858
 859 bool
 860 GOMP_loop_nonmonotonic_dynamic_next (long *istart, long *iend)
 861 {
 862   return gomp_loop_dynamic_next (istart, iend);
 863 }
 864
 865 bool
 866 GOMP_loop_nonmonotonic_guided_next (long *istart, long *iend)
 867 {
 868   return gomp_loop_guided_next (istart, iend);
 869 }
 870
 871 bool
 872 GOMP_loop_ordered_static_next (long *istart, long *iend)
 873 {
 874   return gomp_loop_ordered_static_next (istart, iend);
 875 }
 876
 877 bool
 878 GOMP_loop_ordered_dynamic_next (long *istart, long *iend)
 879 {
 880   return gomp_loop_ordered_dynamic_next (istart, iend);
 881 }
 882
 883 bool
 884 GOMP_loop_ordered_guided_next (long *istart, long *iend)
 885 {
 886   return gomp_loop_ordered_guided_next (istart, iend);
 887 }
 888 #endif