gcc/gimple-iterator.c

   1 /* Iterator routines for GIMPLE statements.
   2    Copyright (C) 2007, 2008 Free Software Foundation, Inc.
   3    Contributed by Aldy Hernandez  <aldy@quesejoda.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tm.h"
  25 #include "tree.h"
  26 #include "gimple.h"
  27 #include "tree-flow.h"
  28 #include "value-prof.h"
  29
  30
  31 /* Mark the statement STMT as modified, and update it.  */
  32
  33 static inline void
  34 update_modified_stmt (gimple stmt)
  35 {
  36   if (!ssa_operands_active ())
  37     return;
  38   update_stmt_if_modified (stmt);
  39 }
  40
  41
  42 /* Mark the statements in SEQ as modified, and update them.  */
  43
  44 static void
  45 update_modified_stmts (gimple_seq seq)
  46 {
  47   gimple_stmt_iterator gsi;
  48
  49   if (!ssa_operands_active ())
  50     return;
  51   for (gsi = gsi_start (seq); !gsi_end_p (gsi); gsi_next (&gsi))
  52     update_stmt_if_modified (gsi_stmt (gsi));
  53 }
  54
  55
  56 /* Set BB to be the basic block for all the statements in the list
  57    starting at FIRST and LAST.  */
  58
  59 static void
  60 update_bb_for_stmts (gimple_seq_node first, basic_block bb)
  61 {
  62   gimple_seq_node n;
  63
  64   for (n = first; n; n = n->next)
  65     gimple_set_bb (n->stmt, bb);
  66 }
  67
  68
  69 /* Insert the sequence delimited by nodes FIRST and LAST before
  70    iterator I.  M specifies how to update iterator I after insertion
  71    (see enum gsi_iterator_update).
  72
  73    This routine assumes that there is a forward and backward path
  74    between FIRST and LAST (i.e., they are linked in a doubly-linked
  75    list).  Additionally, if FIRST == LAST, this routine will properly
  76    insert a single node.  */
  77
  78 static void
  79 gsi_insert_seq_nodes_before (gimple_stmt_iterator *i,
  80                              gimple_seq_node first,
  81                              gimple_seq_node last,
  82                              enum gsi_iterator_update mode)
  83 {
  84   basic_block bb;
  85   gimple_seq_node cur = i->ptr;
  86
  87   if ((bb = gsi_bb (*i)) != NULL)
  88     update_bb_for_stmts (first, bb);
  89
  90   /* Link SEQ before CUR in the sequence.  */
  91   if (cur)
  92     {
  93       first->prev = cur->prev;
  94       if (first->prev)
  95         first->prev->next = first;
  96       else
  97         gimple_seq_set_first (i->seq, first);
  98       last->next = cur;
  99       cur->prev = last;
 100     }
 101   else
 102     {
 103       gimple_seq_node itlast = gimple_seq_last (i->seq);
 104
 105       /* If CUR is NULL, we link at the end of the sequence (this case happens
 106          when gsi_after_labels is called for a basic block that contains only
 107          labels, so it returns an iterator after the end of the block, and
 108          we need to insert before it; it might be cleaner to add a flag to the
 109          iterator saying whether we are at the start or end of the list).  */
 110       first->prev = itlast;
 111       if (itlast)
 112         itlast->next = first;
 113       else
 114         gimple_seq_set_first (i->seq, first);
 115       gimple_seq_set_last (i->seq, last);
 116     }
 117
 118   /* Update the iterator, if requested.  */
 119   switch (mode)
 120     {
 121     case GSI_NEW_STMT:
 122     case GSI_CONTINUE_LINKING:
 123       i->ptr = first;
 124       break;
 125     case GSI_SAME_STMT:
 126       break;
 127     default:
 128       gcc_unreachable ();
 129     }
 130 }
 131
 132
 133 /* Inserts the sequence of statements SEQ before the statement pointed
 134    by iterator I.  MODE indicates what to do with the iterator after
 135    insertion (see enum gsi_iterator_update).
 136
 137    This function does not scan for new operands.  It is provided for
 138    the use of the gimplifier, which manipulates statements for which
 139    def/use information has not yet been constructed.  Most callers
 140    should use gsi_insert_seq_before.  */
 141
 142 void
 143 gsi_insert_seq_before_without_update (gimple_stmt_iterator *i, gimple_seq seq,
 144                                       enum gsi_iterator_update mode)
 145 {
 146   gimple_seq_node first, last;
 147
 148   if (seq == NULL)
 149     return;
 150
 151   /* Don't allow inserting a sequence into itself.  */
 152   gcc_assert (seq != i->seq);
 153
 154   first = gimple_seq_first (seq);
 155   last = gimple_seq_last (seq);
 156
 157   gimple_seq_set_first (seq, NULL);
 158   gimple_seq_set_last (seq, NULL);
 159   gimple_seq_free (seq);
 160
 161   /* Empty sequences need no work.  */
 162   if (!first || !last)
 163     {
 164       gcc_assert (first == last);
 165       return;
 166     }
 167
 168   gsi_insert_seq_nodes_before (i, first, last, mode);
 169 }
 170
 171
 172 /* Inserts the sequence of statements SEQ before the statement pointed
 173    by iterator I.  MODE indicates what to do with the iterator after
 174    insertion (see enum gsi_iterator_update). Scan the statements in SEQ
 175    for new operands.  */
 176
 177 void
 178 gsi_insert_seq_before (gimple_stmt_iterator *i, gimple_seq seq,
 179                        enum gsi_iterator_update mode)
 180 {
 181   update_modified_stmts (seq);
 182   gsi_insert_seq_before_without_update (i, seq, mode);
 183 }
 184
 185
 186 /* Insert the sequence delimited by nodes FIRST and LAST after
 187    iterator I.  M specifies how to update iterator I after insertion
 188    (see enum gsi_iterator_update).
 189
 190    This routine assumes that there is a forward and backward path
 191    between FIRST and LAST (i.e., they are linked in a doubly-linked
 192    list).  Additionally, if FIRST == LAST, this routine will properly
 193    insert a single node.  */
 194
 195 static void
 196 gsi_insert_seq_nodes_after (gimple_stmt_iterator *i,
 197                             gimple_seq_node first,
 198                             gimple_seq_node last,
 199                             enum gsi_iterator_update m)
 200 {
 201   basic_block bb;
 202   gimple_seq_node cur = i->ptr;
 203
 204   /* If the iterator is inside a basic block, we need to update the
 205      basic block information for all the nodes between FIRST and LAST.  */
 206   if ((bb = gsi_bb (*i)) != NULL)
 207     update_bb_for_stmts (first, bb);
 208
 209   /* Link SEQ after CUR.  */
 210   if (cur)
 211     {
 212       last->next = cur->next;
 213       if (last->next)
 214         last->next->prev = last;
 215       else
 216         gimple_seq_set_last (i->seq, last);
 217       first->prev = cur;
 218       cur->next = first;
 219     }
 220   else
 221     {
 222       gcc_assert (!gimple_seq_last (i->seq));
 223       gimple_seq_set_first (i->seq, first);
 224       gimple_seq_set_last (i->seq, last);
 225     }
 226
 227   /* Update the iterator, if requested.  */
 228   switch (m)
 229     {
 230     case GSI_NEW_STMT:
 231       i->ptr = first;
 232       break;
 233     case GSI_CONTINUE_LINKING:
 234       i->ptr = last;
 235       break;
 236     case GSI_SAME_STMT:
 237       gcc_assert (cur);
 238       break;
 239     default:
 240       gcc_unreachable ();
 241     }
 242 }
 243
 244
 245 /* Links sequence SEQ after the statement pointed-to by iterator I.
 246    MODE is as in gsi_insert_after.
 247
 248    This function does not scan for new operands.  It is provided for
 249    the use of the gimplifier, which manipulates statements for which
 250    def/use information has not yet been constructed.  Most callers
 251    should use gsi_insert_seq_after.  */
 252
 253 void
 254 gsi_insert_seq_after_without_update (gimple_stmt_iterator *i, gimple_seq seq,
 255                                      enum gsi_iterator_update mode)
 256 {
 257   gimple_seq_node first, last;
 258
 259   if (seq == NULL)
 260     return;
 261
 262   /* Don't allow inserting a sequence into itself.  */
 263   gcc_assert (seq != i->seq);
 264
 265   first = gimple_seq_first (seq);
 266   last = gimple_seq_last (seq);
 267
 268   gimple_seq_set_first (seq, NULL);
 269   gimple_seq_set_last (seq, NULL);
 270   gimple_seq_free (seq);
 271
 272   /* Empty sequences need no work.  */
 273   if (!first || !last)
 274     {
 275       gcc_assert (first == last);
 276       return;
 277     }
 278
 279   gsi_insert_seq_nodes_after (i, first, last, mode);
 280 }
 281
 282
 283 /* Links sequence SEQ after the statement pointed-to by iterator I.
 284    MODE is as in gsi_insert_after.  Scan the statements in SEQ
 285    for new operands.  */
 286
 287 void
 288 gsi_insert_seq_after (gimple_stmt_iterator *i, gimple_seq seq,
 289                       enum gsi_iterator_update mode)
 290 {
 291   update_modified_stmts (seq);
 292   gsi_insert_seq_after_without_update (i, seq, mode);
 293 }
 294
 295
 296 /* Move all statements in the sequence after I to a new sequence.
 297    Return this new sequence.  */
 298
 299 gimple_seq
 300 gsi_split_seq_after (gimple_stmt_iterator i)
 301 {
 302   gimple_seq_node cur, next;
 303   gimple_seq old_seq, new_seq;
 304
 305   cur = i.ptr;
 306
 307   /* How can we possibly split after the end, or before the beginning?  */
 308   gcc_assert (cur && cur->next);
 309   next = cur->next;
 310
 311   old_seq = i.seq;
 312   new_seq = gimple_seq_alloc ();
 313
 314   gimple_seq_set_first (new_seq, next);
 315   gimple_seq_set_last (new_seq, gimple_seq_last (old_seq));
 316   gimple_seq_set_last (old_seq, cur);
 317   cur->next = NULL;
 318   next->prev = NULL;
 319
 320   return new_seq;
 321 }
 322
 323
 324 /* Move all statements in the sequence before I to a new sequence.
 325    Return this new sequence.  I is set to the head of the new list.  */
 326
 327 gimple_seq
 328 gsi_split_seq_before (gimple_stmt_iterator *i)
 329 {
 330   gimple_seq_node cur, prev;
 331   gimple_seq old_seq, new_seq;
 332
 333   cur = i->ptr;
 334
 335   /* How can we possibly split after the end?  */
 336   gcc_assert (cur);
 337   prev = cur->prev;
 338
 339   old_seq = i->seq;
 340   new_seq = gimple_seq_alloc ();
 341   i->seq = new_seq;
 342
 343   /* Set the limits on NEW_SEQ.  */
 344   gimple_seq_set_first (new_seq, cur);
 345   gimple_seq_set_last (new_seq, gimple_seq_last (old_seq));
 346
 347   /* Cut OLD_SEQ before I.  */
 348   gimple_seq_set_last (old_seq, prev);
 349   cur->prev = NULL;
 350   if (prev)
 351     prev->next = NULL;
 352   else
 353     gimple_seq_set_first (old_seq, NULL);
 354
 355   return new_seq;
 356 }
 357
 358
 359 /* Replace the statement pointed-to by GSI to STMT.  If UPDATE_EH_INFO
 360    is true, the exception handling information of the original
 361    statement is moved to the new statement.  Assignments must only be
 362    replaced with assignments to the same LHS.  */
 363
 364 void
 365 gsi_replace (gimple_stmt_iterator *gsi, gimple stmt, bool update_eh_info)
 366 {
 367   gimple orig_stmt = gsi_stmt (*gsi);
 368
 369   if (stmt == orig_stmt)
 370     return;
 371
 372   gcc_assert (!gimple_has_lhs (orig_stmt)
 373               || gimple_get_lhs (orig_stmt) == gimple_get_lhs (stmt));
 374
 375   gimple_set_location (stmt, gimple_location (orig_stmt));
 376   gimple_set_bb (stmt, gsi_bb (*gsi));
 377
 378   /* Preserve EH region information from the original statement, if
 379      requested by the caller.  */
 380   if (update_eh_info)
 381     maybe_clean_or_replace_eh_stmt (orig_stmt, stmt);
 382
 383   gimple_duplicate_stmt_histograms (cfun, stmt, cfun, orig_stmt);
 384   gimple_remove_stmt_histograms (cfun, orig_stmt);
 385   delink_stmt_imm_use (orig_stmt);
 386   *gsi_stmt_ptr (gsi) = stmt;
 387   gimple_set_modified (stmt, true);
 388   update_modified_stmt (stmt);
 389 }
 390
 391
 392 /* Insert statement STMT before the statement pointed-to by iterator I.
 393    M specifies how to update iterator I after insertion (see enum
 394    gsi_iterator_update).
 395
 396    This function does not scan for new operands.  It is provided for
 397    the use of the gimplifier, which manipulates statements for which
 398    def/use information has not yet been constructed.  Most callers
 399    should use gsi_insert_before.  */
 400
 401 void
 402 gsi_insert_before_without_update (gimple_stmt_iterator *i, gimple stmt,
 403                                   enum gsi_iterator_update m)
 404 {
 405   gimple_seq_node n;
 406
 407   n = GGC_NEW (struct gimple_seq_node_d);
 408   n->prev = n->next = NULL;
 409   n->stmt = stmt;
 410   gsi_insert_seq_nodes_before (i, n, n, m);
 411 }
 412
 413 /* Insert statement STMT before the statement pointed-to by iterator I.
 414    Update STMT's basic block and scan it for new operands.  M
 415    specifies how to update iterator I after insertion (see enum
 416    gsi_iterator_update).  */
 417
 418 void
 419 gsi_insert_before (gimple_stmt_iterator *i, gimple stmt,
 420                    enum gsi_iterator_update m)
 421 {
 422   update_modified_stmt (stmt);
 423   gsi_insert_before_without_update (i, stmt, m);
 424 }
 425
 426
 427 /* Insert statement STMT after the statement pointed-to by iterator I.
 428    M specifies how to update iterator I after insertion (see enum
 429    gsi_iterator_update).
 430
 431    This function does not scan for new operands.  It is provided for
 432    the use of the gimplifier, which manipulates statements for which
 433    def/use information has not yet been constructed.  Most callers
 434    should use gsi_insert_after.  */
 435
 436 void
 437 gsi_insert_after_without_update (gimple_stmt_iterator *i, gimple stmt,
 438                                  enum gsi_iterator_update m)
 439 {
 440   gimple_seq_node n;
 441
 442   n = GGC_NEW (struct gimple_seq_node_d);
 443   n->prev = n->next = NULL;
 444   n->stmt = stmt;
 445   gsi_insert_seq_nodes_after (i, n, n, m);
 446 }
 447
 448
 449 /* Insert statement STMT after the statement pointed-to by iterator I.
 450    Update STMT's basic block and scan it for new operands.  M
 451    specifies how to update iterator I after insertion (see enum
 452    gsi_iterator_update).  */
 453
 454 void
 455 gsi_insert_after (gimple_stmt_iterator *i, gimple stmt,
 456                   enum gsi_iterator_update m)
 457 {
 458   update_modified_stmt (stmt);
 459   gsi_insert_after_without_update (i, stmt, m);
 460 }
 461
 462
 463 /* Remove the current stmt from the sequence.  The iterator is updated
 464    to point to the next statement.
 465
 466    REMOVE_PERMANENTLY is true when the statement is going to be removed
 467    from the IL and not reinserted elsewhere.  In that case we remove the
 468    statement pointed to by iterator I from the EH tables, and free its
 469    operand caches.  Otherwise we do not modify this information.  */
 470
 471 void
 472 gsi_remove (gimple_stmt_iterator *i, bool remove_permanently)
 473 {
 474   gimple_seq_node cur, next, prev;
 475   gimple stmt = gsi_stmt (*i);
 476
 477   insert_debug_temps_for_defs (i);
 478
 479   /* Free all the data flow information for STMT.  */
 480   gimple_set_bb (stmt, NULL);
 481   delink_stmt_imm_use (stmt);
 482   gimple_set_modified (stmt, true);
 483
 484   if (remove_permanently)
 485     {
 486       remove_stmt_from_eh_lp (stmt);
 487       gimple_remove_stmt_histograms (cfun, stmt);
 488     }
 489
 490   /* Update the iterator and re-wire the links in I->SEQ.  */
 491   cur = i->ptr;
 492   next = cur->next;
 493   prev = cur->prev;
 494
 495   if (prev)
 496     prev->next = next;
 497   else
 498     gimple_seq_set_first (i->seq, next);
 499
 500   if (next)
 501     next->prev = prev;
 502   else
 503     gimple_seq_set_last (i->seq, prev);
 504
 505   i->ptr = next;
 506 }
 507
 508
 509 /* Finds iterator for STMT.  */
 510
 511 gimple_stmt_iterator
 512 gsi_for_stmt (gimple stmt)
 513 {
 514   gimple_stmt_iterator i;
 515   basic_block bb = gimple_bb (stmt);
 516
 517   if (gimple_code (stmt) == GIMPLE_PHI)
 518     i = gsi_start_phis (bb);
 519   else
 520     i = gsi_start_bb (bb);
 521
 522   for (; !gsi_end_p (i); gsi_next (&i))
 523     if (gsi_stmt (i) == stmt)
 524       return i;
 525
 526   gcc_unreachable ();
 527 }
 528
 529
 530 /* Move the statement at FROM so it comes right after the statement at TO.  */
 531
 532 void
 533 gsi_move_after (gimple_stmt_iterator *from, gimple_stmt_iterator *to)
 534 {
 535   gimple stmt = gsi_stmt (*from);
 536   gsi_remove (from, false);
 537
 538   /* We must have GSI_NEW_STMT here, as gsi_move_after is sometimes used to
 539      move statements to an empty block.  */
 540   gsi_insert_after (to, stmt, GSI_NEW_STMT);
 541 }
 542
 543
 544 /* Move the statement at FROM so it comes right before the statement
 545    at TO.  */
 546
 547 void
 548 gsi_move_before (gimple_stmt_iterator *from, gimple_stmt_iterator *to)
 549 {
 550   gimple stmt = gsi_stmt (*from);
 551   gsi_remove (from, false);
 552
 553   /* For consistency with gsi_move_after, it might be better to have
 554      GSI_NEW_STMT here; however, that breaks several places that expect
 555      that TO does not change.  */
 556   gsi_insert_before (to, stmt, GSI_SAME_STMT);
 557 }
 558
 559
 560 /* Move the statement at FROM to the end of basic block BB.  */
 561
 562 void
 563 gsi_move_to_bb_end (gimple_stmt_iterator *from, basic_block bb)
 564 {
 565   gimple_stmt_iterator last = gsi_last_bb (bb);
 566 #ifdef ENABLE_CHECKING
 567   gcc_assert (gsi_bb (last) == bb);
 568 #endif
 569
 570   /* Have to check gsi_end_p because it could be an empty block.  */
 571   if (!gsi_end_p (last) && is_ctrl_stmt (gsi_stmt (last)))
 572     gsi_move_before (from, &last);
 573   else
 574     gsi_move_after (from, &last);
 575 }
 576
 577
 578 /* Add STMT to the pending list of edge E.  No actual insertion is
 579    made until a call to gsi_commit_edge_inserts () is made.  */
 580
 581 void
 582 gsi_insert_on_edge (edge e, gimple stmt)
 583 {
 584   gimple_seq_add_stmt (&PENDING_STMT (e), stmt);
 585 }
 586
 587 /* Add the sequence of statements SEQ to the pending list of edge E.
 588    No actual insertion is made until a call to gsi_commit_edge_inserts
 589    is made.  */
 590
 591 void
 592 gsi_insert_seq_on_edge (edge e, gimple_seq seq)
 593 {
 594   gimple_seq_add_seq (&PENDING_STMT (e), seq);
 595 }
 596
 597
 598 /* Insert the statement pointed-to by GSI into edge E.  Every attempt
 599    is made to place the statement in an existing basic block, but
 600    sometimes that isn't possible.  When it isn't possible, the edge is
 601    split and the statement is added to the new block.
 602
 603    In all cases, the returned *GSI points to the correct location.  The
 604    return value is true if insertion should be done after the location,
 605    or false if it should be done before the location.  If a new basic block
 606    has to be created, it is stored in *NEW_BB.  */
 607
 608 static bool
 609 gimple_find_edge_insert_loc (edge e, gimple_stmt_iterator *gsi,
 610                              basic_block *new_bb)
 611 {
 612   basic_block dest, src;
 613   gimple tmp;
 614
 615   dest = e->dest;
 616
 617   /* If the destination has one predecessor which has no PHI nodes,
 618      insert there.  Except for the exit block.
 619
 620      The requirement for no PHI nodes could be relaxed.  Basically we
 621      would have to examine the PHIs to prove that none of them used
 622      the value set by the statement we want to insert on E.  That
 623      hardly seems worth the effort.  */
 624  restart:
 625   if (single_pred_p (dest)
 626       && gimple_seq_empty_p (phi_nodes (dest))
 627       && dest != EXIT_BLOCK_PTR)
 628     {
 629       *gsi = gsi_start_bb (dest);
 630       if (gsi_end_p (*gsi))
 631         return true;
 632
 633       /* Make sure we insert after any leading labels.  */
 634       tmp = gsi_stmt (*gsi);
 635       while (gimple_code (tmp) == GIMPLE_LABEL)
 636         {
 637           gsi_next (gsi);
 638           if (gsi_end_p (*gsi))
 639             break;
 640           tmp = gsi_stmt (*gsi);
 641         }
 642
 643       if (gsi_end_p (*gsi))
 644         {
 645           *gsi = gsi_last_bb (dest);
 646           return true;
 647         }
 648       else
 649         return false;
 650     }
 651
 652   /* If the source has one successor, the edge is not abnormal and
 653      the last statement does not end a basic block, insert there.
 654      Except for the entry block.  */
 655   src = e->src;
 656   if ((e->flags & EDGE_ABNORMAL) == 0
 657       && single_succ_p (src)
 658       && src != ENTRY_BLOCK_PTR)
 659     {
 660       *gsi = gsi_last_bb (src);
 661       if (gsi_end_p (*gsi))
 662         return true;
 663
 664       tmp = gsi_stmt (*gsi);
 665       if (!stmt_ends_bb_p (tmp))
 666         return true;
 667
 668       switch (gimple_code (tmp))
 669         {
 670         case GIMPLE_RETURN:
 671         case GIMPLE_RESX:
 672           return false;
 673         default:
 674           break;
 675         }
 676     }
 677
 678   /* Otherwise, create a new basic block, and split this edge.  */
 679   dest = split_edge (e);
 680   if (new_bb)
 681     *new_bb = dest;
 682   e = single_pred_edge (dest);
 683   goto restart;
 684 }
 685
 686
 687 /* Similar to gsi_insert_on_edge+gsi_commit_edge_inserts.  If a new
 688    block has to be created, it is returned.  */
 689
 690 basic_block
 691 gsi_insert_on_edge_immediate (edge e, gimple stmt)
 692 {
 693   gimple_stmt_iterator gsi;
 694   basic_block new_bb = NULL;
 695
 696   gcc_assert (!PENDING_STMT (e));
 697
 698   if (gimple_find_edge_insert_loc (e, &gsi, &new_bb))
 699     gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
 700   else
 701     gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
 702
 703   return new_bb;
 704 }
 705
 706 /* Insert STMTS on edge E.  If a new block has to be created, it
 707    is returned.  */
 708
 709 basic_block
 710 gsi_insert_seq_on_edge_immediate (edge e, gimple_seq stmts)
 711 {
 712   gimple_stmt_iterator gsi;
 713   basic_block new_bb = NULL;
 714
 715   gcc_assert (!PENDING_STMT (e));
 716
 717   if (gimple_find_edge_insert_loc (e, &gsi, &new_bb))
 718     gsi_insert_seq_after (&gsi, stmts, GSI_NEW_STMT);
 719   else
 720     gsi_insert_seq_before (&gsi, stmts, GSI_NEW_STMT);
 721
 722   return new_bb;
 723 }
 724
 725 /* This routine will commit all pending edge insertions, creating any new
 726    basic blocks which are necessary.  */
 727
 728 void
 729 gsi_commit_edge_inserts (void)
 730 {
 731   basic_block bb;
 732   edge e;
 733   edge_iterator ei;
 734
 735   gsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL);
 736
 737   FOR_EACH_BB (bb)
 738     FOR_EACH_EDGE (e, ei, bb->succs)
 739       gsi_commit_one_edge_insert (e, NULL);
 740 }
 741
 742
 743 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
 744    to this block, otherwise set it to NULL.  */
 745
 746 void
 747 gsi_commit_one_edge_insert (edge e, basic_block *new_bb)
 748 {
 749   if (new_bb)
 750     *new_bb = NULL;
 751
 752   if (PENDING_STMT (e))
 753     {
 754       gimple_stmt_iterator gsi;
 755       gimple_seq seq = PENDING_STMT (e);
 756
 757       PENDING_STMT (e) = NULL;
 758
 759       if (gimple_find_edge_insert_loc (e, &gsi, new_bb))
 760         gsi_insert_seq_after (&gsi, seq, GSI_NEW_STMT);
 761       else
 762         gsi_insert_seq_before (&gsi, seq, GSI_NEW_STMT);
 763     }
 764 }
 765
 766 /* Returns iterator at the start of the list of phi nodes of BB.  */
 767
 768 gimple_stmt_iterator
 769 gsi_start_phis (basic_block bb)
 770 {
 771   return gsi_start (phi_nodes (bb));
 772 }