gcc/ira-emit.c

   1 /* Integrated Register Allocator.  Changing code and generating moves.
   2    Copyright (C) 2006, 2007, 2008
   3    Free Software Foundation, Inc.
   4    Contributed by Vladimir Makarov <vmakarov@redhat.com>.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "tm.h"
  27 #include "regs.h"
  28 #include "rtl.h"
  29 #include "tm_p.h"
  30 #include "target.h"
  31 #include "flags.h"
  32 #include "obstack.h"
  33 #include "bitmap.h"
  34 #include "hard-reg-set.h"
  35 #include "basic-block.h"
  36 #include "expr.h"
  37 #include "recog.h"
  38 #include "params.h"
  39 #include "timevar.h"
  40 #include "tree-pass.h"
  41 #include "output.h"
  42 #include "reload.h"
  43 #include "errors.h"
  44 #include "df.h"
  45 #include "ira-int.h"
  46
  47
  48 typedef struct move *move_t;
  49
  50 /* The structure represents an allocno move.  Both allocnos have the
  51    same origional regno but different allocation.  */
  52 struct move
  53 {
  54   /* The allocnos involved in the move.  */
  55   ira_allocno_t from, to;
  56   /* The next move in the move sequence.  */
  57   move_t next;
  58   /* Used for finding dependencies.  */
  59   bool visited_p;
  60   /* The size of the following array. */
  61   int deps_num;
  62   /* Moves on which given move depends on.  Dependency can be cyclic.
  63      It means we need a temporary to generates the moves.  Sequence
  64      A1->A2, B1->B2 where A1 and B2 are assigned to reg R1 and A2 and
  65      B1 are assigned to reg R2 is an example of the cyclic
  66      dependencies.  */
  67   move_t *deps;
  68   /* First insn generated for the move.  */
  69   rtx insn;
  70 };
  71
  72 /* Array of moves (indexed by BB index) which should be put at the
  73    start/end of the corresponding basic blocks.  */
  74 static move_t *at_bb_start, *at_bb_end;
  75
  76 /* Max regno before renaming some pseudo-registers.  For example, the
  77    same pseudo-register can be renamed in a loop if its allocation is
  78    different outside the loop.  */
  79 static int max_regno_before_changing;
  80
  81 /* Return new move of allocnos TO and FROM.  */
  82 static move_t
  83 create_move (ira_allocno_t to, ira_allocno_t from)
  84 {
  85   move_t move;
  86
  87   move = (move_t) ira_allocate (sizeof (struct move));
  88   move->deps = NULL;
  89   move->deps_num = 0;
  90   move->to = to;
  91   move->from = from;
  92   move->next = NULL;
  93   move->insn = NULL_RTX;
  94   move->visited_p = false;
  95   return move;
  96 }
  97
  98 /* Free memory for MOVE and its dependencies.  */
  99 static void
 100 free_move (move_t move)
 101 {
 102   if (move->deps != NULL)
 103     ira_free (move->deps);
 104   ira_free (move);
 105 }
 106
 107 /* Free memory for list of the moves given by its HEAD.  */
 108 static void
 109 free_move_list (move_t head)
 110 {
 111   move_t next;
 112
 113   for (; head != NULL; head = next)
 114     {
 115       next = head->next;
 116       free_move (head);
 117     }
 118 }
 119
 120 /* Return TRUE if the the move list LIST1 and LIST2 are equal (two
 121    moves are equal if they involve the same allocnos).  */
 122 static bool
 123 eq_move_lists_p (move_t list1, move_t list2)
 124 {
 125   for (; list1 != NULL && list2 != NULL;
 126        list1 = list1->next, list2 = list2->next)
 127     if (list1->from != list2->from || list1->to != list2->to)
 128       return false;
 129   return list1 == list2;
 130 }
 131
 132 /* This recursive function changes pseudo-registers in *LOC if it is
 133    necessary.  The function returns TRUE if a change was done.  */
 134 static bool
 135 change_regs (rtx *loc)
 136 {
 137   int i, regno, result = false;
 138   const char *fmt;
 139   enum rtx_code code;
 140   rtx reg;
 141
 142   if (*loc == NULL_RTX)
 143     return false;
 144   code = GET_CODE (*loc);
 145   if (code == REG)
 146     {
 147       regno = REGNO (*loc);
 148       if (regno < FIRST_PSEUDO_REGISTER)
 149         return false;
 150       if (regno >= max_regno_before_changing)
 151         /* It is a shared register which was changed already.  */
 152         return false;
 153       if (ira_curr_regno_allocno_map[regno] == NULL)
 154         return false;
 155       reg = ALLOCNO_REG (ira_curr_regno_allocno_map[regno]);
 156       if (reg == *loc)
 157         return false;
 158       *loc = reg;
 159       return true;
 160     }
 161
 162   fmt = GET_RTX_FORMAT (code);
 163   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
 164     {
 165       if (fmt[i] == 'e')
 166         result = change_regs (&XEXP (*loc, i)) || result;
 167       else if (fmt[i] == 'E')
 168         {
 169           int j;
 170
 171           for (j = XVECLEN (*loc, i) - 1; j >= 0; j--)
 172             result = change_regs (&XVECEXP (*loc, i, j)) || result;
 173         }
 174     }
 175   return result;
 176 }
 177
 178 /* Attach MOVE to the edge E.  The move is attached to the head of the
 179    list if HEAD_P is TRUE.  */
 180 static void
 181 add_to_edge_list (edge e, move_t move, bool head_p)
 182 {
 183   move_t last;
 184
 185   if (head_p || e->aux == NULL)
 186     {
 187       move->next = (move_t) e->aux;
 188       e->aux = move;
 189     }
 190   else
 191     {
 192       for (last = (move_t) e->aux; last->next != NULL; last = last->next)
 193         ;
 194       last->next = move;
 195       move->next = NULL;
 196     }
 197 }
 198
 199 /* Create and return new pseudo-register with the same attributes as
 200    ORIGINAL_REG.  */
 201 static rtx
 202 create_new_reg (rtx original_reg)
 203 {
 204   rtx new_reg;
 205
 206   new_reg = gen_reg_rtx (GET_MODE (original_reg));
 207   ORIGINAL_REGNO (new_reg) = ORIGINAL_REGNO (original_reg);
 208   REG_USERVAR_P (new_reg) = REG_USERVAR_P (original_reg);
 209   REG_POINTER (new_reg) = REG_POINTER (original_reg);
 210   REG_ATTRS (new_reg) = REG_ATTRS (original_reg);
 211   if (internal_flag_ira_verbose > 3 && ira_dump_file != NULL)
 212     fprintf (ira_dump_file, "      Creating newreg=%i from oldreg=%i\n",
 213              REGNO (new_reg), REGNO (original_reg));
 214   return new_reg;
 215 }
 216
 217 /* Return TRUE if loop given by SUBNODE inside the loop given by
 218    NODE.  */
 219 static bool
 220 subloop_tree_node_p (ira_loop_tree_node_t subnode, ira_loop_tree_node_t node)
 221 {
 222   for (; subnode != NULL; subnode = subnode->parent)
 223     if (subnode == node)
 224       return true;
 225   return false;
 226 }
 227
 228 /* Set up member `reg' to REG for allocnos which has the same regno as
 229    ALLOCNO and which are inside the loop corresponding to ALLOCNO. */
 230 static void
 231 set_allocno_reg (ira_allocno_t allocno, rtx reg)
 232 {
 233   int regno;
 234   ira_allocno_t a;
 235   ira_loop_tree_node_t node;
 236
 237   node = ALLOCNO_LOOP_TREE_NODE (allocno);
 238   for (a = ira_regno_allocno_map[ALLOCNO_REGNO (allocno)];
 239        a != NULL;
 240        a = ALLOCNO_NEXT_REGNO_ALLOCNO (a))
 241     if (subloop_tree_node_p (ALLOCNO_LOOP_TREE_NODE (a), node))
 242       ALLOCNO_REG (a) = reg;
 243   for (a = ALLOCNO_CAP (allocno); a != NULL; a = ALLOCNO_CAP (a))
 244     ALLOCNO_REG (a) = reg;
 245   regno = ALLOCNO_REGNO (allocno);
 246   for (a = allocno;;)
 247     {
 248       if (a == NULL || (a = ALLOCNO_CAP (a)) == NULL)
 249         {
 250           node = node->parent;
 251           if (node == NULL)
 252             break;
 253           a = node->regno_allocno_map[regno];
 254         }
 255       if (a == NULL)
 256         continue;
 257       if (ALLOCNO_CHILD_RENAMED_P (a))
 258         break;
 259       ALLOCNO_CHILD_RENAMED_P (a) = true;
 260     }
 261 }
 262
 263 /* Return TRUE if move of SRC_ALLOCNO to DEST_ALLOCNO does not change
 264    value of the destination.  One possible reason for this is the
 265    situation when SRC_ALLOCNO is not modified in the corresponding
 266    loop.  */
 267 static bool
 268 not_modified_p (ira_allocno_t src_allocno, ira_allocno_t dest_allocno)
 269 {
 270   int regno, orig_regno;
 271   ira_allocno_t a;
 272   ira_loop_tree_node_t node;
 273
 274   ira_assert (ALLOCNO_CAP_MEMBER (src_allocno) == NULL
 275               && ALLOCNO_CAP_MEMBER (dest_allocno) == NULL);
 276   orig_regno = ALLOCNO_REGNO (src_allocno);
 277   regno = REGNO (ALLOCNO_REG (dest_allocno));
 278   for (node = ALLOCNO_LOOP_TREE_NODE (src_allocno);
 279        node != NULL;
 280        node = node->parent)
 281     if ((a = node->regno_allocno_map[orig_regno]) == NULL)
 282       break;
 283     else if (REGNO (ALLOCNO_REG (a)) == (unsigned) regno)
 284       return true;
 285     else if (bitmap_bit_p (node->modified_regnos, orig_regno))
 286       return false;
 287   return node != NULL;
 288 }
 289
 290 /* Generate and attach moves to the edge E.  This looks at the final
 291    regnos of allocnos living on the edge with the same original regno
 292    to figure out when moves should be generated.  */
 293 static void
 294 generate_edge_moves (edge e)
 295 {
 296   ira_loop_tree_node_t src_loop_node, dest_loop_node;
 297   unsigned int regno;
 298   bitmap_iterator bi;
 299   ira_allocno_t src_allocno, dest_allocno, *src_map, *dest_map;
 300   move_t move;
 301
 302   src_loop_node = IRA_BB_NODE (e->src)->parent;
 303   dest_loop_node = IRA_BB_NODE (e->dest)->parent;
 304   e->aux = NULL;
 305   if (src_loop_node == dest_loop_node)
 306     return;
 307   src_map = src_loop_node->regno_allocno_map;
 308   dest_map = dest_loop_node->regno_allocno_map;
 309   EXECUTE_IF_SET_IN_REG_SET (DF_LR_IN (e->dest),
 310                              FIRST_PSEUDO_REGISTER, regno, bi)
 311     if (bitmap_bit_p (DF_LR_OUT (e->src), regno))
 312       {
 313         src_allocno = src_map[regno];
 314         dest_allocno = dest_map[regno];
 315         if (REGNO (ALLOCNO_REG (src_allocno))
 316             == REGNO (ALLOCNO_REG (dest_allocno)))
 317           continue;
 318         /* Remove unnecessary stores at the region exit.  We should do
 319            this for readonly memory for sure and this is guaranteed by
 320            that we never generate moves on region borders (see
 321            checking ira_reg_equiv_invariant_p in function
 322            change_loop).  */
 323         if (ALLOCNO_HARD_REGNO (dest_allocno) < 0
 324             && ALLOCNO_HARD_REGNO (src_allocno) >= 0
 325             && not_modified_p (src_allocno, dest_allocno))
 326           {
 327             ALLOCNO_MEM_OPTIMIZED_DEST (src_allocno) = dest_allocno;
 328             ALLOCNO_MEM_OPTIMIZED_DEST_P (dest_allocno) = true;
 329             if (internal_flag_ira_verbose > 3 && ira_dump_file != NULL)
 330               fprintf (ira_dump_file, "      Remove r%d:a%d->a%d(mem)\n",
 331                        regno, ALLOCNO_NUM (src_allocno),
 332                        ALLOCNO_NUM (dest_allocno));
 333             continue;
 334           }
 335         move = create_move (dest_allocno, src_allocno);
 336         add_to_edge_list (e, move, true);
 337     }
 338 }
 339
 340 /* Bitmap of allocnos local for the current loop.  */
 341 static bitmap local_allocno_bitmap;
 342
 343 /* This bitmap is used to find that we need to generate and to use a
 344    new pseudo-register when processing allocnos with the same original
 345    regno.  */
 346 static bitmap used_regno_bitmap;
 347
 348 /* This bitmap contains regnos of allocnos which were renamed locally
 349    because the allocnos correspond to disjoint live ranges in loops
 350    with a common parent.  */
 351 static bitmap renamed_regno_bitmap;
 352
 353 /* Change (if necessary) pseudo-registers inside loop given by loop
 354    tree node NODE.  */
 355 static void
 356 change_loop (ira_loop_tree_node_t node)
 357 {
 358   bitmap_iterator bi;
 359   unsigned int i;
 360   int regno;
 361   bool used_p;
 362   ira_allocno_t allocno, parent_allocno, *map;
 363   rtx insn, original_reg;
 364   enum reg_class cover_class;
 365   ira_loop_tree_node_t parent;
 366
 367   if (node != ira_loop_tree_root)
 368     {
 369
 370       if (node->bb != NULL)
 371         {
 372           FOR_BB_INSNS (node->bb, insn)
 373             if (INSN_P (insn) && change_regs (&insn))
 374               {
 375                 df_insn_rescan (insn);
 376                 df_notes_rescan (insn);
 377               }
 378           return;
 379         }
 380
 381       if (internal_flag_ira_verbose > 3 && ira_dump_file != NULL)
 382         fprintf (ira_dump_file,
 383                  "      Changing RTL for loop %d (header bb%d)\n",
 384                  node->loop->num, node->loop->header->index);
 385
 386       parent = ira_curr_loop_tree_node->parent;
 387       map = parent->regno_allocno_map;
 388       EXECUTE_IF_SET_IN_REG_SET (ira_curr_loop_tree_node->border_allocnos,
 389                                  0, i, bi)
 390         {
 391           allocno = ira_allocnos[i];
 392           regno = ALLOCNO_REGNO (allocno);
 393           cover_class = ALLOCNO_COVER_CLASS (allocno);
 394           parent_allocno = map[regno];
 395           ira_assert (regno < ira_reg_equiv_len);
 396           /* We generate the same hard register move because the
 397              reload pass can put an allocno into memory in this case
 398              we will have live range splitting.  If it does not happen
 399              such the same hard register moves will be removed.  The
 400              worst case when the both allocnos are put into memory by
 401              the reload is very rare.  */
 402           if (parent_allocno != NULL
 403               && (ALLOCNO_HARD_REGNO (allocno)
 404                   == ALLOCNO_HARD_REGNO (parent_allocno))
 405               && (ALLOCNO_HARD_REGNO (allocno) < 0
 406                   || (parent->reg_pressure[cover_class] + 1
 407                       <= ira_available_class_regs[cover_class])
 408                   || TEST_HARD_REG_BIT (ira_prohibited_mode_move_regs
 409                                         [ALLOCNO_MODE (allocno)],
 410                                         ALLOCNO_HARD_REGNO (allocno))
 411                   /* don't create copies because reload can spill an
 412                      allocno set by copy although the allocno will not
 413                      get memory slot.  */
 414                   || ira_reg_equiv_invariant_p[regno]
 415                   || ira_reg_equiv_const[regno] != NULL_RTX))
 416             continue;
 417           original_reg = ALLOCNO_REG (allocno);
 418           if (parent_allocno == NULL
 419               || REGNO (ALLOCNO_REG (parent_allocno)) == REGNO (original_reg))
 420             {
 421               if (internal_flag_ira_verbose > 3 && ira_dump_file)
 422                 fprintf (ira_dump_file, "  %i vs parent %i:",
 423                          ALLOCNO_HARD_REGNO (allocno),
 424                          ALLOCNO_HARD_REGNO (parent_allocno));
 425               set_allocno_reg (allocno, create_new_reg (original_reg));
 426             }
 427         }
 428     }
 429   /* Rename locals: Local allocnos with same regno in different loops
 430      might get the different hard register.  So we need to change
 431      ALLOCNO_REG.  */
 432   bitmap_and_compl (local_allocno_bitmap,
 433                     ira_curr_loop_tree_node->all_allocnos,
 434                     ira_curr_loop_tree_node->border_allocnos);
 435   EXECUTE_IF_SET_IN_REG_SET (local_allocno_bitmap, 0, i, bi)
 436     {
 437       allocno = ira_allocnos[i];
 438       regno = ALLOCNO_REGNO (allocno);
 439       if (ALLOCNO_CAP_MEMBER (allocno) != NULL)
 440         continue;
 441       used_p = bitmap_bit_p (used_regno_bitmap, regno);
 442       bitmap_set_bit (used_regno_bitmap, regno);
 443       ALLOCNO_SOMEWHERE_RENAMED_P (allocno) = true;
 444       if (! used_p)
 445         continue;
 446       bitmap_set_bit (renamed_regno_bitmap, regno);
 447       set_allocno_reg (allocno, create_new_reg (ALLOCNO_REG (allocno)));
 448     }
 449 }
 450
 451 /* Process to set up flag somewhere_renamed_p.  */
 452 static void
 453 set_allocno_somewhere_renamed_p (void)
 454 {
 455   unsigned int regno;
 456   ira_allocno_t allocno;
 457   ira_allocno_iterator ai;
 458
 459   FOR_EACH_ALLOCNO (allocno, ai)
 460     {
 461       regno = ALLOCNO_REGNO (allocno);
 462       if (bitmap_bit_p (renamed_regno_bitmap, regno)
 463           && REGNO (ALLOCNO_REG (allocno)) == regno)
 464         ALLOCNO_SOMEWHERE_RENAMED_P (allocno) = true;
 465     }
 466 }
 467
 468 /* Return TRUE if move lists on all edges given in vector VEC are
 469    equal.  */
 470 static bool
 471 eq_edge_move_lists_p (VEC(edge,gc) *vec)
 472 {
 473   move_t list;
 474   int i;
 475
 476   list = (move_t) EDGE_I (vec, 0)->aux;
 477   for (i = EDGE_COUNT (vec) - 1; i > 0; i--)
 478     if (! eq_move_lists_p (list, (move_t) EDGE_I (vec, i)->aux))
 479       return false;
 480   return true;
 481 }
 482
 483 /* Look at all entry edges (if START_P) or exit edges of basic block
 484    BB and put move lists at the BB start or end if it is possible.  In
 485    other words, this decreases code duplication of allocno moves.  */
 486 static void
 487 unify_moves (basic_block bb, bool start_p)
 488 {
 489   int i;
 490   edge e;
 491   move_t list;
 492   VEC(edge,gc) *vec;
 493
 494   vec = (start_p ? bb->preds : bb->succs);
 495   if (EDGE_COUNT (vec) == 0 || ! eq_edge_move_lists_p (vec))
 496     return;
 497   e = EDGE_I (vec, 0);
 498   list = (move_t) e->aux;
 499   if (! start_p && control_flow_insn_p (BB_END (bb)))
 500     return;
 501   e->aux = NULL;
 502   for (i = EDGE_COUNT (vec) - 1; i > 0; i--)
 503     {
 504       e = EDGE_I (vec, i);
 505       free_move_list ((move_t) e->aux);
 506       e->aux = NULL;
 507     }
 508   if (start_p)
 509     at_bb_start[bb->index] = list;
 510   else
 511     at_bb_end[bb->index] = list;
 512 }
 513
 514 /* Last move (in move sequence being processed) setting up the
 515    corresponding hard register.  */
 516 static move_t hard_regno_last_set[FIRST_PSEUDO_REGISTER];
 517
 518 /* If the element value is equal to CURR_TICK then the corresponding
 519    element in `hard_regno_last_set' is defined and correct.  */
 520 static int hard_regno_last_set_check[FIRST_PSEUDO_REGISTER];
 521
 522 /* Last move (in move sequence being processed) setting up the
 523    corresponding allocno.  */
 524 static move_t *allocno_last_set;
 525
 526 /* If the element value is equal to CURR_TICK then the corresponding
 527    element in . `allocno_last_set' is defined and correct.  */
 528 static int *allocno_last_set_check;
 529
 530 /* Definition of vector of moves.  */
 531 DEF_VEC_P(move_t);
 532 DEF_VEC_ALLOC_P(move_t, heap);
 533
 534 /* This vec contains moves sorted topologically (depth-first) on their
 535    dependency graph.  */
 536 static VEC(move_t,heap) *move_vec;
 537
 538 /* The variable value is used to check correctness of values of
 539    elements of arrays `hard_regno_last_set' and
 540    `allocno_last_set_check'.  */
 541 static int curr_tick;
 542
 543 /* This recursive function traverses dependencies of MOVE and produces
 544    topological sorting (in depth-first order).  */
 545 static void
 546 traverse_moves (move_t move)
 547 {
 548   int i;
 549
 550   if (move->visited_p)
 551     return;
 552   move->visited_p = true;
 553   for (i = move->deps_num - 1; i >= 0; i--)
 554     traverse_moves (move->deps[i]);
 555   VEC_safe_push (move_t, heap, move_vec, move);
 556 }
 557
 558 /* Remove unnecessary moves in the LIST, makes topological sorting,
 559    and removes cycles on hard reg dependencies by introducing new
 560    allocnos assigned to memory and additional moves.  It returns the
 561    result move list.  */
 562 static move_t
 563 modify_move_list (move_t list)
 564 {
 565   int i, n, nregs, hard_regno;
 566   ira_allocno_t to, from, new_allocno;
 567   move_t move, new_move, set_move, first, last;
 568
 569   if (list == NULL)
 570     return NULL;
 571   /* Creat move deps.  */
 572   curr_tick++;
 573   for (move = list; move != NULL; move = move->next)
 574     {
 575       to = move->to;
 576       if ((hard_regno = ALLOCNO_HARD_REGNO (to)) < 0)
 577         continue;
 578       nregs = hard_regno_nregs[hard_regno][ALLOCNO_MODE (to)];
 579       for (i = 0; i < nregs; i++)
 580         {
 581           hard_regno_last_set[hard_regno + i] = move;
 582           hard_regno_last_set_check[hard_regno + i] = curr_tick;
 583         }
 584     }
 585   for (move = list; move != NULL; move = move->next)
 586     {
 587       from = move->from;
 588       to = move->to;
 589       if ((hard_regno = ALLOCNO_HARD_REGNO (from)) >= 0)
 590         {
 591           nregs = hard_regno_nregs[hard_regno][ALLOCNO_MODE (from)];
 592           for (n = i = 0; i < nregs; i++)
 593             if (hard_regno_last_set_check[hard_regno + i] == curr_tick
 594                 && (ALLOCNO_REGNO (hard_regno_last_set[hard_regno + i]->to)
 595                     != ALLOCNO_REGNO (from)))
 596               n++;
 597           move->deps = (move_t *) ira_allocate (n * sizeof (move_t));
 598           for (n = i = 0; i < nregs; i++)
 599             if (hard_regno_last_set_check[hard_regno + i] == curr_tick
 600                 && (ALLOCNO_REGNO (hard_regno_last_set[hard_regno + i]->to)
 601                     != ALLOCNO_REGNO (from)))
 602               move->deps[n++] = hard_regno_last_set[hard_regno + i];
 603           move->deps_num = n;
 604         }
 605     }
 606   /* Toplogical sorting:  */
 607   VEC_truncate (move_t, move_vec, 0);
 608   for (move = list; move != NULL; move = move->next)
 609     traverse_moves (move);
 610   last = NULL;
 611   for (i = (int) VEC_length (move_t, move_vec) - 1; i >= 0; i--)
 612     {
 613       move = VEC_index (move_t, move_vec, i);
 614       move->next = NULL;
 615       if (last != NULL)
 616         last->next = move;
 617       last = move;
 618     }
 619   first = VEC_last (move_t, move_vec);
 620   /* Removing cycles:  */
 621   curr_tick++;
 622   VEC_truncate (move_t, move_vec, 0);
 623   for (move = first; move != NULL; move = move->next)
 624     {
 625       from = move->from;
 626       to = move->to;
 627       if ((hard_regno = ALLOCNO_HARD_REGNO (from)) >= 0)
 628         {
 629           nregs = hard_regno_nregs[hard_regno][ALLOCNO_MODE (from)];
 630           for (i = 0; i < nregs; i++)
 631             if (hard_regno_last_set_check[hard_regno + i] == curr_tick
 632                 && ALLOCNO_HARD_REGNO
 633                    (hard_regno_last_set[hard_regno + i]->to) >= 0)
 634               {
 635                 set_move = hard_regno_last_set[hard_regno + i];
 636                 /* It does not matter what loop_tree_node (of TO or
 637                    FROM) to use for the new allocno because of
 638                    subsequent IRA internal representation
 639                    flattening.  */
 640                 new_allocno
 641                   = ira_create_allocno (ALLOCNO_REGNO (set_move->to), false,
 642                                         ALLOCNO_LOOP_TREE_NODE (set_move->to));
 643                 ALLOCNO_MODE (new_allocno) = ALLOCNO_MODE (set_move->to);
 644                 ira_set_allocno_cover_class
 645                   (new_allocno, ALLOCNO_COVER_CLASS (set_move->to));
 646                 ALLOCNO_ASSIGNED_P (new_allocno) = true;
 647                 ALLOCNO_HARD_REGNO (new_allocno) = -1;
 648                 ALLOCNO_REG (new_allocno)
 649                   = create_new_reg (ALLOCNO_REG (set_move->to));
 650                 ALLOCNO_CONFLICT_ID (new_allocno) = ALLOCNO_NUM (new_allocno);
 651                 /* Make it possibly conflicting with all earlier
 652                    created allocnos.  Cases where temporary allocnos
 653                    created to remove the cycles are quite rare.  */
 654                 ALLOCNO_MIN (new_allocno) = 0;
 655                 ALLOCNO_MAX (new_allocno) = ira_allocnos_num - 1;
 656                 new_move = create_move (set_move->to, new_allocno);
 657                 set_move->to = new_allocno;
 658                 VEC_safe_push (move_t, heap, move_vec, new_move);
 659                 ira_move_loops_num++;
 660                 if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
 661                   fprintf (ira_dump_file,
 662                            "    Creating temporary allocno a%dr%d\n",
 663                            ALLOCNO_NUM (new_allocno),
 664                            REGNO (ALLOCNO_REG (new_allocno)));
 665               }
 666         }
 667       if ((hard_regno = ALLOCNO_HARD_REGNO (to)) < 0)
 668         continue;
 669       nregs = hard_regno_nregs[hard_regno][ALLOCNO_MODE (to)];
 670       for (i = 0; i < nregs; i++)
 671         {
 672           hard_regno_last_set[hard_regno + i] = move;
 673           hard_regno_last_set_check[hard_regno + i] = curr_tick;
 674         }
 675     }
 676   for (i = (int) VEC_length (move_t, move_vec) - 1; i >= 0; i--)
 677     {
 678       move = VEC_index (move_t, move_vec, i);
 679       move->next = NULL;
 680       last->next = move;
 681       last = move;
 682     }
 683   return first;
 684 }
 685
 686 /* Generate RTX move insns from the move list LIST.  This updates
 687    allocation cost using move execution frequency FREQ.  */
 688 static rtx
 689 emit_move_list (move_t list, int freq)
 690 {
 691   int cost;
 692   rtx result, insn;
 693   enum machine_mode mode;
 694   enum reg_class cover_class;
 695
 696   start_sequence ();
 697   for (; list != NULL; list = list->next)
 698     {
 699       start_sequence ();
 700       emit_move_insn (ALLOCNO_REG (list->to), ALLOCNO_REG (list->from));
 701       list->insn = get_insns ();
 702       end_sequence ();
 703       /* The reload needs to have set up insn codes.  If the reload
 704          sets up insn codes by itself, it may fail because insns will
 705          have hard registers instead of pseudos and there may be no
 706          machine insn with given hard registers.  */
 707       for (insn = list->insn; insn != NULL_RTX; insn = NEXT_INSN (insn))
 708         recog_memoized (insn);
 709       emit_insn (list->insn);
 710       mode = ALLOCNO_MODE (list->to);
 711       cover_class = ALLOCNO_COVER_CLASS (list->to);
 712       cost = 0;
 713       if (ALLOCNO_HARD_REGNO (list->to) < 0)
 714         {
 715           if (ALLOCNO_HARD_REGNO (list->from) >= 0)
 716             {
 717               cost = ira_memory_move_cost[mode][cover_class][0] * freq;
 718               ira_store_cost += cost;
 719             }
 720         }
 721       else if (ALLOCNO_HARD_REGNO (list->from) < 0)
 722         {
 723           if (ALLOCNO_HARD_REGNO (list->to) >= 0)
 724             {
 725               cost = ira_memory_move_cost[mode][cover_class][0] * freq;
 726               ira_load_cost += cost;
 727             }
 728         }
 729       else
 730         {
 731           cost = ira_register_move_cost[mode][cover_class][cover_class] * freq;
 732           ira_shuffle_cost += cost;
 733         }
 734       ira_overall_cost += cost;
 735     }
 736   result = get_insns ();
 737   end_sequence ();
 738   return result;
 739 }
 740
 741 /* Generate RTX move insns from move lists attached to basic blocks
 742    and edges.  */
 743 static void
 744 emit_moves (void)
 745 {
 746   basic_block bb;
 747   edge_iterator ei;
 748   edge e;
 749   rtx insns, tmp;
 750
 751   FOR_EACH_BB (bb)
 752     {
 753       if (at_bb_start[bb->index] != NULL)
 754         {
 755           at_bb_start[bb->index] = modify_move_list (at_bb_start[bb->index]);
 756           insns = emit_move_list (at_bb_start[bb->index],
 757                                   REG_FREQ_FROM_BB (bb));
 758           tmp = BB_HEAD (bb);
 759           if (LABEL_P (tmp))
 760             tmp = NEXT_INSN (tmp);
 761           if (NOTE_INSN_BASIC_BLOCK_P (tmp))
 762             tmp = NEXT_INSN (tmp);
 763           if (tmp == BB_HEAD (bb))
 764             emit_insn_before (insns, tmp);
 765           else if (tmp != NULL_RTX)
 766             emit_insn_after (insns, PREV_INSN (tmp));
 767           else
 768             emit_insn_after (insns, get_last_insn ());
 769         }
 770
 771       if (at_bb_end[bb->index] != NULL)
 772         {
 773           at_bb_end[bb->index] = modify_move_list (at_bb_end[bb->index]);
 774           insns = emit_move_list (at_bb_end[bb->index], REG_FREQ_FROM_BB (bb));
 775           ira_assert (! control_flow_insn_p (BB_END (bb)));
 776           emit_insn_after (insns, BB_END (bb));
 777         }
 778
 779       FOR_EACH_EDGE (e, ei, bb->succs)
 780         {
 781           if (e->aux == NULL)
 782             continue;
 783           ira_assert ((e->flags & EDGE_ABNORMAL) == 0
 784                       || ! EDGE_CRITICAL_P (e));
 785           e->aux = modify_move_list ((move_t) e->aux);
 786           insert_insn_on_edge
 787             (emit_move_list ((move_t) e->aux,
 788                              REG_FREQ_FROM_EDGE_FREQ (EDGE_FREQUENCY (e))),
 789              e);
 790           if (e->src->next_bb != e->dest)
 791             ira_additional_jumps_num++;
 792         }
 793     }
 794 }
 795
 796 /* Update costs of A and corresponding allocnos on upper levels on the
 797    loop tree from reading (if READ_P) or writing A on an execution
 798    path with FREQ.  */
 799 static void
 800 update_costs (ira_allocno_t a, bool read_p, int freq)
 801 {
 802   ira_loop_tree_node_t parent;
 803
 804   for (;;)
 805     {
 806       ALLOCNO_NREFS (a)++;
 807       ALLOCNO_FREQ (a) += freq;
 808       ALLOCNO_MEMORY_COST (a)
 809         += (ira_memory_move_cost[ALLOCNO_MODE (a)][ALLOCNO_COVER_CLASS (a)]
 810             [read_p ? 1 : 0] * freq);
 811       if (ALLOCNO_CAP (a) != NULL)
 812         a = ALLOCNO_CAP (a);
 813       else if ((parent = ALLOCNO_LOOP_TREE_NODE (a)->parent) == NULL
 814                || (a = parent->regno_allocno_map[ALLOCNO_REGNO (a)]) == NULL)
 815         break;
 816     }
 817 }
 818
 819 /* Process moves from LIST with execution FREQ to add ranges, copies,
 820    and modify costs for allocnos involved in the moves.  All regnos
 821    living through the list is in LIVE_THROUGH, and the loop tree node
 822    used to find corresponding allocnos is NODE.  */
 823 static void
 824 add_range_and_copies_from_move_list (move_t list, ira_loop_tree_node_t node,
 825                                      bitmap live_through, int freq)
 826 {
 827   int start, n;
 828   unsigned int regno;
 829   move_t move;
 830   ira_allocno_t to, from, a;
 831   ira_copy_t cp;
 832   allocno_live_range_t r;
 833   bitmap_iterator bi;
 834   HARD_REG_SET hard_regs_live;
 835
 836   if (list == NULL)
 837     return;
 838   n = 0;
 839   EXECUTE_IF_SET_IN_BITMAP (live_through, FIRST_PSEUDO_REGISTER, regno, bi)
 840     n++;
 841   REG_SET_TO_HARD_REG_SET (hard_regs_live, live_through);
 842   /* This is a trick to guarantee that new ranges is not merged with
 843      the old ones.  */
 844   ira_max_point++;
 845   start = ira_max_point;
 846   for (move = list; move != NULL; move = move->next)
 847     {
 848       from = move->from;
 849       to = move->to;
 850       if (ALLOCNO_CONFLICT_ALLOCNO_ARRAY (to) == NULL)
 851         {
 852           if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
 853             fprintf (ira_dump_file, "    Allocate conflicts for a%dr%d\n",
 854                      ALLOCNO_NUM (to), REGNO (ALLOCNO_REG (to)));
 855           ira_allocate_allocno_conflicts (to, n);
 856         }
 857       bitmap_clear_bit (live_through, ALLOCNO_REGNO (from));
 858       bitmap_clear_bit (live_through, ALLOCNO_REGNO (to));
 859       IOR_HARD_REG_SET (ALLOCNO_CONFLICT_HARD_REGS (from), hard_regs_live);
 860       IOR_HARD_REG_SET (ALLOCNO_CONFLICT_HARD_REGS (to), hard_regs_live);
 861       IOR_HARD_REG_SET (ALLOCNO_TOTAL_CONFLICT_HARD_REGS (from),
 862                         hard_regs_live);
 863       IOR_HARD_REG_SET (ALLOCNO_TOTAL_CONFLICT_HARD_REGS (to), hard_regs_live);
 864       update_costs (from, true, freq);
 865       update_costs (to, false, freq);
 866       cp = ira_add_allocno_copy (from, to, freq, move->insn, NULL);
 867       if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
 868         fprintf (ira_dump_file, "    Adding cp%d:a%dr%d-a%dr%d\n",
 869                  cp->num, ALLOCNO_NUM (cp->first),
 870                  REGNO (ALLOCNO_REG (cp->first)), ALLOCNO_NUM (cp->second),
 871                  REGNO (ALLOCNO_REG (cp->second)));
 872       r = ALLOCNO_LIVE_RANGES (from);
 873       if (r == NULL || r->finish >= 0)
 874         {
 875           ALLOCNO_LIVE_RANGES (from)
 876             = ira_create_allocno_live_range (from, start, ira_max_point, r);
 877           if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
 878             fprintf (ira_dump_file,
 879                      "    Adding range [%d..%d] to allocno a%dr%d\n",
 880                      start, ira_max_point, ALLOCNO_NUM (from),
 881                      REGNO (ALLOCNO_REG (from)));
 882         }
 883       else
 884         r->finish = ira_max_point;
 885       ira_max_point++;
 886       ALLOCNO_LIVE_RANGES (to)
 887         = ira_create_allocno_live_range (to, ira_max_point, -1,
 888                                          ALLOCNO_LIVE_RANGES (to));
 889       ira_max_point++;
 890     }
 891   for (move = list; move != NULL; move = move->next)
 892     {
 893       r = ALLOCNO_LIVE_RANGES (move->to);
 894       if (r->finish < 0)
 895         {
 896           r->finish = ira_max_point - 1;
 897           if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
 898             fprintf (ira_dump_file,
 899                      "    Adding range [%d..%d] to allocno a%dr%d\n",
 900                      r->start, r->finish, ALLOCNO_NUM (move->to),
 901                      REGNO (ALLOCNO_REG (move->to)));
 902         }
 903     }
 904   EXECUTE_IF_SET_IN_BITMAP (live_through, FIRST_PSEUDO_REGISTER, regno, bi)
 905     {
 906       a = node->regno_allocno_map[regno];
 907       if (ALLOCNO_MEM_OPTIMIZED_DEST (a) == NULL)
 908         {
 909           ALLOCNO_LIVE_RANGES (a)
 910             = ira_create_allocno_live_range (a, start, ira_max_point - 1,
 911                                              ALLOCNO_LIVE_RANGES (a));
 912           if (internal_flag_ira_verbose > 2 && ira_dump_file != NULL)
 913             fprintf
 914               (ira_dump_file,
 915                "    Adding range [%d..%d] to live through allocno a%dr%d\n",
 916                start, ira_max_point - 1, ALLOCNO_NUM (a),
 917                REGNO (ALLOCNO_REG (a)));
 918         }
 919     }
 920 }
 921
 922 /* Process all move list to add ranges, conflicts, copies, and modify
 923    costs for allocnos involved in the moves.  */
 924 static void
 925 add_ranges_and_copies (void)
 926 {
 927   basic_block bb;
 928   edge_iterator ei;
 929   edge e;
 930   ira_loop_tree_node_t node;
 931   bitmap live_through;
 932
 933   live_through = ira_allocate_bitmap ();
 934   FOR_EACH_BB (bb)
 935     {
 936       /* It does not matter what loop_tree_node (of source or
 937          destination block) to use for searching allocnos by their
 938          regnos because of subsequent IR flattening.  */
 939       node = IRA_BB_NODE (bb)->parent;
 940       bitmap_copy (live_through, DF_LR_IN (bb));
 941       add_range_and_copies_from_move_list
 942         (at_bb_start[bb->index], node, live_through, REG_FREQ_FROM_BB (bb));
 943       bitmap_copy (live_through, DF_LR_OUT (bb));
 944       add_range_and_copies_from_move_list
 945         (at_bb_end[bb->index], node, live_through, REG_FREQ_FROM_BB (bb));
 946       FOR_EACH_EDGE (e, ei, bb->succs)
 947         {
 948           bitmap_and (live_through, DF_LR_IN (e->dest), DF_LR_OUT (bb));
 949           add_range_and_copies_from_move_list
 950             ((move_t) e->aux, node, live_through,
 951              REG_FREQ_FROM_EDGE_FREQ (EDGE_FREQUENCY (e)));
 952         }
 953     }
 954   ira_free_bitmap (live_through);
 955 }
 956
 957 /* The entry function changes code and generates shuffling allocnos on
 958    region borders for the regional (LOOPS_P is TRUE in this case)
 959    register allocation.  */
 960 void
 961 ira_emit (bool loops_p)
 962 {
 963   basic_block bb;
 964   edge_iterator ei;
 965   edge e;
 966   ira_allocno_t a;
 967   ira_allocno_iterator ai;
 968
 969   FOR_EACH_ALLOCNO (a, ai)
 970     ALLOCNO_REG (a) = regno_reg_rtx[ALLOCNO_REGNO (a)];
 971   if (! loops_p)
 972     return;
 973   at_bb_start = (move_t *) ira_allocate (sizeof (move_t) * last_basic_block);
 974   memset (at_bb_start, 0, sizeof (move_t) * last_basic_block);
 975   at_bb_end = (move_t *) ira_allocate (sizeof (move_t) * last_basic_block);
 976   memset (at_bb_end, 0, sizeof (move_t) * last_basic_block);
 977   local_allocno_bitmap = ira_allocate_bitmap ();
 978   used_regno_bitmap = ira_allocate_bitmap ();
 979   renamed_regno_bitmap = ira_allocate_bitmap ();
 980   max_regno_before_changing = max_reg_num ();
 981   ira_traverse_loop_tree (true, ira_loop_tree_root, change_loop, NULL);
 982   set_allocno_somewhere_renamed_p ();
 983   ira_free_bitmap (used_regno_bitmap);
 984   ira_free_bitmap (renamed_regno_bitmap);
 985   ira_free_bitmap (local_allocno_bitmap);
 986   FOR_EACH_BB (bb)
 987     {
 988       at_bb_start[bb->index] = NULL;
 989       at_bb_end[bb->index] = NULL;
 990       FOR_EACH_EDGE (e, ei, bb->succs)
 991         if (e->dest != EXIT_BLOCK_PTR)
 992           generate_edge_moves (e);
 993     }
 994   allocno_last_set
 995     = (move_t *) ira_allocate (sizeof (move_t) * max_reg_num ());
 996   allocno_last_set_check
 997     = (int *) ira_allocate (sizeof (int) * max_reg_num ());
 998   memset (allocno_last_set_check, 0, sizeof (int) * max_reg_num ());
 999   memset (hard_regno_last_set_check, 0, sizeof (hard_regno_last_set_check));
1000   curr_tick = 0;
1001   FOR_EACH_BB (bb)
1002     unify_moves (bb, true);
1003   FOR_EACH_BB (bb)
1004     unify_moves (bb, false);
1005   move_vec = VEC_alloc (move_t, heap, ira_allocnos_num);
1006   emit_moves ();
1007   add_ranges_and_copies ();
1008   /* Clean up: */
1009   FOR_EACH_BB (bb)
1010     {
1011       free_move_list (at_bb_start[bb->index]);
1012       free_move_list (at_bb_end[bb->index]);
1013       FOR_EACH_EDGE (e, ei, bb->succs)
1014         {
1015           free_move_list ((move_t) e->aux);
1016           e->aux = NULL;
1017         }
1018     }
1019   VEC_free (move_t, heap, move_vec);
1020   ira_free (allocno_last_set_check);
1021   ira_free (allocno_last_set);
1022   commit_edge_insertions ();
1023   ira_free (at_bb_end);
1024   ira_free (at_bb_start);
1025 }