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.  */
 362
 363 void
 364 gsi_replace (gimple_stmt_iterator *gsi, gimple stmt, bool update_eh_info)
 365 {
 366   int eh_region;
 367   gimple orig_stmt = gsi_stmt (*gsi);
 368
 369   if (stmt == orig_stmt)
 370     return;
 371
 372   gimple_set_location (stmt, gimple_location (orig_stmt));
 373   gimple_set_bb (stmt, gsi_bb (*gsi));
 374
 375   /* Preserve EH region information from the original statement, if
 376      requested by the caller.  */
 377   if (update_eh_info)
 378     {
 379       eh_region = lookup_stmt_eh_region (orig_stmt);
 380       if (eh_region >= 0)
 381         {
 382           remove_stmt_from_eh_region (orig_stmt);
 383           add_stmt_to_eh_region (stmt, eh_region);
 384         }
 385     }
 386
 387   gimple_duplicate_stmt_histograms (cfun, stmt, cfun, orig_stmt);
 388   gimple_remove_stmt_histograms (cfun, orig_stmt);
 389   delink_stmt_imm_use (orig_stmt);
 390   *gsi_stmt_ptr (gsi) = stmt;
 391   gimple_set_modified (stmt, true);
 392   update_modified_stmt (stmt);
 393 }
 394
 395
 396 /* Insert statement STMT before the statement pointed-to by iterator I.
 397    M specifies how to update iterator I after insertion (see enum
 398    gsi_iterator_update).
 399
 400    This function does not scan for new operands.  It is provided for
 401    the use of the gimplifier, which manipulates statements for which
 402    def/use information has not yet been constructed.  Most callers
 403    should use gsi_insert_before.  */
 404
 405 void
 406 gsi_insert_before_without_update (gimple_stmt_iterator *i, gimple stmt,
 407                                   enum gsi_iterator_update m)
 408 {
 409   gimple_seq_node n;
 410
 411   n = GGC_NEW (struct gimple_seq_node_d);
 412   n->prev = n->next = NULL;
 413   n->stmt = stmt;
 414   gsi_insert_seq_nodes_before (i, n, n, m);
 415 }
 416
 417 /* Insert statement STMT before the statement pointed-to by iterator I.
 418    Update STMT's basic block and scan it for new operands.  M
 419    specifies how to update iterator I after insertion (see enum
 420    gsi_iterator_update).  */
 421
 422 void
 423 gsi_insert_before (gimple_stmt_iterator *i, gimple stmt,
 424                    enum gsi_iterator_update m)
 425 {
 426   update_modified_stmt (stmt);
 427   gsi_insert_before_without_update (i, stmt, m);
 428 }
 429
 430
 431 /* Insert statement STMT after the statement pointed-to by iterator I.
 432    M specifies how to update iterator I after insertion (see enum
 433    gsi_iterator_update).
 434
 435    This function does not scan for new operands.  It is provided for
 436    the use of the gimplifier, which manipulates statements for which
 437    def/use information has not yet been constructed.  Most callers
 438    should use gsi_insert_after.  */
 439
 440 void
 441 gsi_insert_after_without_update (gimple_stmt_iterator *i, gimple stmt,
 442                                  enum gsi_iterator_update m)
 443 {
 444   gimple_seq_node n;
 445
 446   n = GGC_NEW (struct gimple_seq_node_d);
 447   n->prev = n->next = NULL;
 448   n->stmt = stmt;
 449   gsi_insert_seq_nodes_after (i, n, n, m);
 450 }
 451
 452
 453 /* Insert statement STMT after the statement pointed-to by iterator I.
 454    Update STMT's basic block and scan it for new operands.  M
 455    specifies how to update iterator I after insertion (see enum
 456    gsi_iterator_update).  */
 457
 458 void
 459 gsi_insert_after (gimple_stmt_iterator *i, gimple stmt,
 460                   enum gsi_iterator_update m)
 461 {
 462   update_modified_stmt (stmt);
 463   gsi_insert_after_without_update (i, stmt, m);
 464 }
 465
 466
 467 /* Remove the current stmt from the sequence.  The iterator is updated
 468    to point to the next statement.
 469
 470    REMOVE_PERMANENTLY is true when the statement is going to be removed
 471    from the IL and not reinserted elsewhere.  In that case we remove the
 472    statement pointed to by iterator I from the EH tables, and free its
 473    operand caches.  Otherwise we do not modify this information.  */
 474
 475 void
 476 gsi_remove (gimple_stmt_iterator *i, bool remove_permanently)
 477 {
 478   gimple_seq_node cur, next, prev;
 479   gimple stmt = gsi_stmt (*i);
 480
 481   /* Free all the data flow information for STMT.  */
 482   gimple_set_bb (stmt, NULL);
 483   delink_stmt_imm_use (stmt);
 484   gimple_set_modified (stmt, true);
 485
 486   if (remove_permanently)
 487     {
 488       remove_stmt_from_eh_region (stmt);
 489       gimple_remove_stmt_histograms (cfun, stmt);
 490     }
 491
 492   /* Update the iterator and re-wire the links in I->SEQ.  */
 493   cur = i->ptr;
 494   next = cur->next;
 495   prev = cur->prev;
 496
 497   if (prev)
 498     prev->next = next;
 499   else
 500     gimple_seq_set_first (i->seq, next);
 501
 502   if (next)
 503     next->prev = prev;
 504   else
 505     gimple_seq_set_last (i->seq, prev);
 506
 507   i->ptr = next;
 508 }
 509
 510
 511 /* Finds iterator for STMT.  */
 512
 513 gimple_stmt_iterator
 514 gsi_for_stmt (gimple stmt)
 515 {
 516   gimple_stmt_iterator i;
 517   basic_block bb = gimple_bb (stmt);
 518
 519   if (gimple_code (stmt) == GIMPLE_PHI)
 520     i = gsi_start_phis (bb);
 521   else
 522     i = gsi_start_bb (bb);
 523
 524   for (; !gsi_end_p (i); gsi_next (&i))
 525     if (gsi_stmt (i) == stmt)
 526       return i;
 527
 528   gcc_unreachable ();
 529 }
 530
 531
 532 /* Move the statement at FROM so it comes right after the statement at TO.  */
 533
 534 void
 535 gsi_move_after (gimple_stmt_iterator *from, gimple_stmt_iterator *to)
 536 {
 537   gimple stmt = gsi_stmt (*from);
 538   gsi_remove (from, false);
 539
 540   /* We must have GSI_NEW_STMT here, as gsi_move_after is sometimes used to
 541      move statements to an empty block.  */
 542   gsi_insert_after (to, stmt, GSI_NEW_STMT);
 543 }
 544
 545
 546 /* Move the statement at FROM so it comes right before the statement
 547    at TO.  */
 548
 549 void
 550 gsi_move_before (gimple_stmt_iterator *from, gimple_stmt_iterator *to)
 551 {
 552   gimple stmt = gsi_stmt (*from);
 553   gsi_remove (from, false);
 554
 555   /* For consistency with gsi_move_after, it might be better to have
 556      GSI_NEW_STMT here; however, that breaks several places that expect
 557      that TO does not change.  */
 558   gsi_insert_before (to, stmt, GSI_SAME_STMT);
 559 }
 560
 561
 562 /* Move the statement at FROM to the end of basic block BB.  */
 563
 564 void
 565 gsi_move_to_bb_end (gimple_stmt_iterator *from, basic_block bb)
 566 {
 567   gimple_stmt_iterator last = gsi_last_bb (bb);
 568 #ifdef ENABLE_CHECKING
 569   gcc_assert (gsi_bb (last) == bb);
 570 #endif
 571
 572   /* Have to check gsi_end_p because it could be an empty block.  */
 573   if (!gsi_end_p (last) && is_ctrl_stmt (gsi_stmt (last)))
 574     gsi_move_before (from, &last);
 575   else
 576     gsi_move_after (from, &last);
 577 }
 578
 579
 580 /* Add STMT to the pending list of edge E.  No actual insertion is
 581    made until a call to gsi_commit_edge_inserts () is made.  */
 582
 583 void
 584 gsi_insert_on_edge (edge e, gimple stmt)
 585 {
 586   gimple_seq_add_stmt (&PENDING_STMT (e), stmt);
 587 }
 588
 589 /* Add the sequence of statements SEQ to the pending list of edge E.
 590    No actual insertion is made until a call to gsi_commit_edge_inserts
 591    is made.  */
 592
 593 void
 594 gsi_insert_seq_on_edge (edge e, gimple_seq seq)
 595 {
 596   gimple_seq_add_seq (&PENDING_STMT (e), seq);
 597 }
 598
 599
 600 /* Insert the statement pointed-to by GSI into edge E.  Every attempt
 601    is made to place the statement in an existing basic block, but
 602    sometimes that isn't possible.  When it isn't possible, the edge is
 603    split and the statement is added to the new block.
 604
 605    In all cases, the returned *GSI points to the correct location.  The
 606    return value is true if insertion should be done after the location,
 607    or false if it should be done before the location.  If a new basic block
 608    has to be created, it is stored in *NEW_BB.  */
 609
 610 static bool
 611 gimple_find_edge_insert_loc (edge e, gimple_stmt_iterator *gsi,
 612                              basic_block *new_bb)
 613 {
 614   basic_block dest, src;
 615   gimple tmp;
 616
 617   dest = e->dest;
 618
 619   /* If the destination has one predecessor which has no PHI nodes,
 620      insert there.  Except for the exit block.
 621
 622      The requirement for no PHI nodes could be relaxed.  Basically we
 623      would have to examine the PHIs to prove that none of them used
 624      the value set by the statement we want to insert on E.  That
 625      hardly seems worth the effort.  */
 626 restart:
 627   if (single_pred_p (dest)
 628       && ! phi_nodes (dest)
 629       && dest != EXIT_BLOCK_PTR)
 630     {
 631       *gsi = gsi_start_bb (dest);
 632       if (gsi_end_p (*gsi))
 633         return true;
 634
 635       /* Make sure we insert after any leading labels.  */
 636       tmp = gsi_stmt (*gsi);
 637       while (gimple_code (tmp) == GIMPLE_LABEL)
 638         {
 639           gsi_next (gsi);
 640           if (gsi_end_p (*gsi))
 641             break;
 642           tmp = gsi_stmt (*gsi);
 643         }
 644
 645       if (gsi_end_p (*gsi))
 646         {
 647           *gsi = gsi_last_bb (dest);
 648           return true;
 649         }
 650       else
 651         return false;
 652     }
 653
 654   /* If the source has one successor, the edge is not abnormal and
 655      the last statement does not end a basic block, insert there.
 656      Except for the entry block.  */
 657   src = e->src;
 658   if ((e->flags & EDGE_ABNORMAL) == 0
 659       && single_succ_p (src)
 660       && src != ENTRY_BLOCK_PTR)
 661     {
 662       *gsi = gsi_last_bb (src);
 663       if (gsi_end_p (*gsi))
 664         return true;
 665
 666       tmp = gsi_stmt (*gsi);
 667       if (!stmt_ends_bb_p (tmp))
 668         return true;
 669
 670       if (gimple_code (tmp) == GIMPLE_RETURN)
 671         {
 672           gsi_prev (gsi);
 673           return true;
 674         }
 675     }
 676
 677   /* Otherwise, create a new basic block, and split this edge.  */
 678   dest = split_edge (e);
 679   if (new_bb)
 680     *new_bb = dest;
 681   e = single_pred_edge (dest);
 682   goto restart;
 683 }
 684
 685
 686 /* Similar to gsi_insert_on_edge+gsi_commit_edge_inserts.  If a new
 687    block has to be created, it is returned.  */
 688
 689 basic_block
 690 gsi_insert_on_edge_immediate (edge e, gimple stmt)
 691 {
 692   gimple_stmt_iterator gsi;
 693   basic_block new_bb = NULL;
 694
 695   gcc_assert (!PENDING_STMT (e));
 696
 697   if (gimple_find_edge_insert_loc (e, &gsi, &new_bb))
 698     gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
 699   else
 700     gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
 701
 702   return new_bb;
 703 }
 704
 705 /* Insert STMTS on edge E.  If a new block has to be created, it
 706    is returned.  */
 707
 708 basic_block
 709 gsi_insert_seq_on_edge_immediate (edge e, gimple_seq stmts)
 710 {
 711   gimple_stmt_iterator gsi;
 712   basic_block new_bb = NULL;
 713
 714   gcc_assert (!PENDING_STMT (e));
 715
 716   if (gimple_find_edge_insert_loc (e, &gsi, &new_bb))
 717     gsi_insert_seq_after (&gsi, stmts, GSI_NEW_STMT);
 718   else
 719     gsi_insert_seq_before (&gsi, stmts, GSI_NEW_STMT);
 720
 721   return new_bb;
 722 }
 723
 724 /* This routine will commit all pending edge insertions, creating any new
 725    basic blocks which are necessary.  */
 726
 727 void
 728 gsi_commit_edge_inserts (void)
 729 {
 730   basic_block bb;
 731   edge e;
 732   edge_iterator ei;
 733
 734   gsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL);
 735
 736   FOR_EACH_BB (bb)
 737     FOR_EACH_EDGE (e, ei, bb->succs)
 738       gsi_commit_one_edge_insert (e, NULL);
 739 }
 740
 741
 742 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
 743    to this block, otherwise set it to NULL.  */
 744
 745 void
 746 gsi_commit_one_edge_insert (edge e, basic_block *new_bb)
 747 {
 748   if (new_bb)
 749     *new_bb = NULL;
 750
 751   if (PENDING_STMT (e))
 752     {
 753       gimple_stmt_iterator gsi;
 754       gimple_seq seq = PENDING_STMT (e);
 755
 756       PENDING_STMT (e) = NULL;
 757
 758       if (gimple_find_edge_insert_loc (e, &gsi, new_bb))
 759         gsi_insert_seq_after (&gsi, seq, GSI_NEW_STMT);
 760       else
 761         gsi_insert_seq_before (&gsi, seq, GSI_NEW_STMT);
 762     }
 763 }
 764
 765 /* Returns iterator at the start of the list of phi nodes of BB.  */
 766
 767 gimple_stmt_iterator
 768 gsi_start_phis (basic_block bb)
 769 {
 770   return gsi_start (phi_nodes (bb));
 771 }