nsz Git - libfirm/blob - ir/opt/loop.c

   1 /*
   2  * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  11  * Licensees holding valid libFirm Professional Edition licenses may use
  12  * this file in accordance with the libFirm Commercial License.
  13  * Agreement provided with the Software.
  14  *
  15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @brief    Loop peeling and unrolling
  23  * @author   Christian Helmer
  24  * @version  $Id$
  25  */
  26
  27 //#include "config.h"
  28
  29 //#include <limits.h>
  30 #include <assert.h>
  31
  32 #include "irnode.h"
  33 #include "irnode_t.h"
  34 #include "irgraph_t.h"
  35 //#include "irprog_t.h"
  36
  37 //#include "iroptimize.h"
  38 #include "ircons_t.h"
  39 #include "iropt_t.h"
  40 #include "irgopt.h"
  41 //#include "irgmod.h"
  42 #include "irgwalk.h"
  43
  44 //#include "array_t.h"
  45 #include "list.h"
  46 //#include "pset.h"
  47 //#include "pmap.h"
  48 //#include "pdeq.h"
  49 //#include "xmalloc.h"
  50 //#include "pqueue.h"
  51
  52 #include "irouts.h"
  53 #include "irloop_t.h"
  54 #include "irbackedge_t.h"
  55 //#include "opt_inline_t.h"
  56 //#include "cgana.h"
  57 //#include "trouts.h"
  58 //#include "error.h"
  59
  60 //#include "analyze_irg_args.h"
  61 #include "iredges_t.h"
  62 //#include "irflag_t.h"
  63 //#include "irhooks.h"
  64 #include "irtools.h"
  65 //#include "iropt_dbg.h"
  66 #include "irpass_t.h"
  67 #include "irloop.h"
  68
  69 #include "array_t.h"
  70 #include "irdump.h"
  71
  72 /* convenience macro for iterating over every phi node of the given block */
  73 #define for_each_phi(block, phi) \
  74         for ( (phi) = get_Block_phis( (block) ); (phi) ; (phi) = get_Phi_next( (phi) ) )
  75
  76 /* current loop */
  77 ir_loop *cur_loop;
  78
  79 /* The loop walker should be possible to abort if nothing can be done anymore */
  80 typedef unsigned irg_walk_func_abortable(ir_node *, void *);
  81
  82 /* stores pair of node and number for the nodes predecessor */
  83 typedef struct loop_entry_t {
  84         ir_node *node;                  /* node outside of the loop */
  85         int pred_irn_n;                 /* with pred_irn_n pointing inside loop */
  86         //loop_entry_t *next;
  87 } loop_entry_t;
  88
  89 //loop_entry_t loop_entry_list;
  90
  91 /* Store complex values in the nodes link */
  92 typedef struct link_node_state_t {
  93         unsigned cloned:1;
  94         unsigned temp:1;                /* < Node is temporarily copied, to resolve cycles */
  95         unsigned invariant:1;
  96         ir_node *copy;
  97         ir_node *link;                  /*< temporary links for ssa creation */
  98         ir_node **ins;                  /* ins for phi nodes, during rewiring of blocks */
  99 } link_node_state_t;
 100
 101
 102 loop_entry_t *loop_entries;             /* loop entries (from below) in the node graph */
 103 //int loop_entries_n;
 104 loop_entry_t *head_entries;             /* loop entries (from below) in the node graph */
 105 int backedges_n;
 106 //loop_entry_t *backedges;              /* backedges exclusively from the current loop */
 107 //loop_entry_t *alien_backedges;        /* The head can be head of several loops. */
 108 //loop_entry_t *head_edges;     /* The head can be head of several loops. */
 109
 110 ir_node *loop_cf_head = NULL;           /* loop exit in the node graph */
 111 unsigned loop_cf_head_valid = 1;        /* a loop may/must have one head, otherwise invalid */
 112
 113 unsigned has_sto;                               /* If we store inside the loop we might
 114                                                                          * have disambiguation problems */
 115 //DBG
 116 //void arrdump(ir_node **arr)
 117 //{
 118 //      int i;
 119 //      for (i=0; i<ARR_LEN(arr); i++)
 120 //      {
 121 //              printf("inarr: %ld          is block %d \n", (arr[i]->node_nr), is_Block(arr[i]));
 122 //      }
 123 //}
 124
 125 /**
 126  * Returns the state of the given node.
 127  */
 128 link_node_state_t *get_lstate(ir_node *n)
 129 {
 130         return ((link_node_state_t *)n->link);
 131 }
 132
 133 /**
 134  * Returns the link inside of the nodes state which is pointing to its copy
 135  * most of the time during loop peeling.
 136  */
 137 ir_node *get_copy(ir_node *n)
 138 {
 139         return ((link_node_state_t *)n->link)->copy;
 140 }
 141
 142 /**
 143  * Sets the nodes copy information
 144  */
 145 void set_copy(ir_node *n, ir_node *copy)
 146 {
 147         ((link_node_state_t *)n->link)->copy = copy;
 148 }
 149
 150 /**
 151  * Returns true if the node or block is in cur_loop.
 152  */
 153 unsigned is_in_loop(ir_node *node)
 154 {
 155 //      if (is_Block(node)) {
 156 //              if (node->loop == cur_loop) {
 157 //                      printf("                                   INLOOP %ld \n", node->node_nr);
 158 //              }
 159 //              return (node->loop == cur_loop);
 160 //      } else {
 161 //              if ( get_nodes_block(node)->loop == cur_loop ) {
 162 //                      printf("                                   INLOOP %ld \n", node->node_nr);
 163 //              }
 164 //              return ( get_nodes_block(node)->loop == cur_loop );
 165 //      }
 166         if (is_Block(node)) {
 167                 return (node->loop == cur_loop);
 168         } else {
 169                 return ( get_nodes_block(node)->loop == cur_loop );
 170         }
 171 }
 172
 173 unsigned is_in_head(ir_node *node)
 174 {
 175         if (is_Block(node)) {
 176                 return (node == loop_cf_head);
 177         } else {
 178                 return ( get_nodes_block(node) == loop_cf_head );
 179         }
 180 }
 181
 182 /**
 183  * Returns if the given be is an alien edge
 184  */
 185 unsigned is_alien_edge(ir_node *n, int i)
 186 {
 187         return( !is_in_loop( get_irn_n( n, i ) ) );
 188 }
 189
 190 static void add_pred(ir_node* node, ir_node* x)
 191 {
 192         ir_node** ins;
 193         int n;
 194         int i;
 195
 196 //      if(!node)
 197 //              printf("NONODE\n");
 198
 199         //printf("addpred %ld   pred %ld \n", node->node_nr, x->node_nr);
 200
 201         // WHY limit it to blocks and phi?
 202         assert(is_Block(node) || is_Phi(node));
 203
 204         n = get_irn_arity(node);
 205         NEW_ARR_A(ir_node*, ins, n + 1);
 206         for (i = 0; i < n; i++)
 207                 ins[i] = get_irn_n(node, i);
 208         ins[n] = x;
 209         set_irn_in(node, n + 1, ins);
 210 }
 211
 212 void block_phi_walker(ir_node *n, void *env)
 213 {
 214         const ir_edge_t *edge;
 215         (void) env;
 216
 217         /* RETURN */
 218         if (!is_Block(n))
 219                 return;
 220
 221         /* generate phi list for every block */
 222         n->attr.block.phis = NULL;
 223
 224         foreach_out_edge(n, edge) {
 225                 ir_node *src = get_edge_src_irn(edge);
 226                 if (is_Phi(src))
 227                 {
 228                         //printf("%ld has phi %ld \n", block->node_nr, src->node_nr);
 229                         add_Block_phi(n, src);
 230                 }
 231         }
 232 }
 233
 234 /**
 235  * Calls func() for every block in the given loop.
 236  */
 237 void for_each_loop_block(ir_loop *loop, irg_walk_func *func, void *env)
 238 {
 239         int elements, e;
 240         elements = get_loop_n_elements(loop);
 241
 242         for(e=0; e<elements; e++)
 243         {
 244                 loop_element elem = get_loop_element(loop, e);
 245                 if  (is_ir_node(elem.kind) && is_Block(elem.node) )
 246                 {
 247                         //printf(" foreach LOOPBLOCK %ld \n", elem.node->node_nr);
 248                         func(elem.node, env);
 249                 }
 250         }
 251 }
 252
 253 /**
 254  * collects the blocks backedges and creates the phi list for every block
 255  */
 256 void collect_backedges(ir_node *block, void *env)
 257 {
 258         (void) env;
 259
 260         //printf("LOOP BLOCK %ld\n", block->node_nr);
 261
 262         /* collect backedges */
 263         if (has_backedges(block))
 264         {
 265                 int i;
 266                 int arity = get_irn_arity(block);
 267
 268                 for(i = 0; i < arity; ++i) {
 269                         ir_node *pred = get_irn_n(block, i);
 270
 271                         loop_entry_t be;
 272                         be.node = block;
 273                         be.pred_irn_n = i;
 274
 275                         //ARR_APP1(loop_entry_t, head_edges, be);
 276
 277                         if (is_backedge(block, i) )
 278                         {
 279                                 if ( is_in_loop(pred) ) {
 280                                         //printf("be: %ld --> %ld \n", block->node_nr, pred->node_nr);
 281                                         //ARR_APP1(loop_entry_t, backedges, be);
 282                                         ++backedges_n;
 283                                 }
 284 //                              else {
 285 //                                      //printf("alien be: %ld --> %ld \n", block->node_nr, pred->node_nr);
 286 //                                      ARR_APP1(loop_entry_t, alien_backedges, be);
 287 //                              }
 288                         }
 289 //                      else {
 290 //                              if ( !is_in_loop(pred) ) {
 291 //                                      ARR_APP1(loop_entry_t, head_edges, be);
 292 //                      }
 293
 294                 }
 295         }
 296 }
 297
 298 /**
 299  *      Walks through all loop nodes.
 300  */
 301 unsigned loop_walker_rec(ir_node *node,
 302                 irg_walk_func_abortable *pre,
 303                 irg_walk_func_abortable *post, void * env)
 304 {
 305         int i;
 306         unsigned stop = 0;
 307
 308         ir_graph *irg = current_ir_graph;
 309
 310         /* RETURN if we walked out of the loop*/
 311         if (!is_in_loop(node))
 312                 return 0;
 313
 314         if (pre)
 315         {
 316                 unsigned stop = pre(node, env);
 317                 if (stop)
 318                         return stop;
 319         }
 320
 321         set_irn_visited(node, irg->visited);
 322
 323         if (node->op != op_Block) {
 324                 ir_node *pred = get_irn_n(node, -1);
 325                 if (pred->visited < irg->visited)
 326                 {
 327                         stop = loop_walker_rec(pred, pre, post, env);
 328                         if (stop)
 329                                 return stop;
 330                 }
 331         }
 332
 333         for (i = get_irn_arity(node) - 1; i >= 0; --i) {
 334                 ir_node *pred = get_irn_n(node, i);
 335                 if (pred->visited < irg->visited)
 336                 {
 337                         stop = loop_walker_rec(pred, pre, post, env);
 338                         if (stop)
 339                                 return stop;
 340                 }
 341         }
 342
 343         if (post)
 344                 return post(node, env);
 345         return 0;
 346 }
 347
 348 /**
 349  * Walks through loop nodes.
 350  * The entries of the loop (all edges pointing into the loop) have to be given.
 351  */
 352 unsigned loop_walker(loop_entry_t *entries,
 353                 irg_walk_func_abortable *pre, irg_walk_func_abortable *post, void * env)
 354 {
 355         int i;
 356         int stop = 0;
 357
 358         for (i=0; !stop && i<ARR_LEN(entries); i++)
 359         {
 360                 ir_node *pred;
 361                 loop_entry_t entry;
 362                 entry = entries[i];
 363
 364                 pred = get_irn_n( entry.node , entry.pred_irn_n);
 365
 366                 stop = loop_walker_rec( pred, pre, post, env);
 367         }
 368         return stop;
 369 }
 370
 371 /**
 372  *
 373  */
 374 void find_loop_entries_walk(ir_node *node, void *env)
 375 {
 376         unsigned node_in_loop, pred_in_loop;
 377         int i, arity;
 378         (void) env;
 379
 380         arity = get_irn_arity(node);
 381         for (i = 0; i < arity; i++) {
 382                 ir_node *pred = get_irn_n(node, i);
 383
 384                 pred_in_loop = is_in_loop(pred);
 385                 node_in_loop = is_in_loop(node);
 386
 387                 //Find the loops head/the blocks with cfpred outside of the loop
 388                 if (is_Block(node) && node_in_loop
 389                                 && !pred_in_loop && loop_cf_head_valid)
 390                 {
 391                         ir_node *cfgpred = get_Block_cfgpred(node, i);
 392
 393                         if ( !is_in_loop(cfgpred) )
 394                         {
 395                                 // another head? We do not touch this.
 396                                 // is this possible?
 397                                 if (loop_cf_head && loop_cf_head != node)
 398                                 {
 399                                         loop_cf_head_valid = 0;
 400                                 }
 401                                 else
 402                                 {
 403                                         loop_cf_head = node;
 404                                 }
 405                         }
 406                 }
 407
 408                 if ( pred_in_loop && !node_in_loop )
 409                 {
 410                         /* we walked right into the loop. */
 411                         loop_entry_t entry;
 412                         entry.node = node;
 413                         entry.pred_irn_n = i;
 414
 415                         //DBG
 416 //                      printf("inloop: %ld --> inloop %ld (@ %d)  \n",
 417 //                                      node->node_nr, pred->node_nr, i);
 418
 419                         ARR_APP1(loop_entry_t, loop_entries, entry);
 420                 }
 421         }
 422 }
 423
 424 ///**
 425 // * Finds invariant nodes and marks them as invariant.
 426 // * (Post walk)
 427 // */
 428 //unsigned get_invariants(ir_node *node, void *env)
 429 //{
 430 //      unsigned invar = 1;
 431 //      (void) env;
 432 //
 433 //      if (is_Store(node))
 434 //      {
 435 //              has_sto = 1;
 436 //              /* RETURN and abort walker */
 437 //              return 1;
 438 //      }
 439 //
 440 //      int arity = get_irn_arity(node);
 441 //
 442 //      /* RETURN, no preds to visit */
 443 //      if (arity == 0) return 0;
 444 //
 445 //      if (is_Load(node))
 446 //      {
 447 //              assert(arity>=2 && "expected load to have edge nr 1 (address)");
 448 //
 449 //              ir_node *pred = get_irn_n(node, 1);
 450 //              if (!is_in_loop(pred)                   /* Everything outside the loop is considered invariant */
 451 //                              || is_Const(pred)               /* This is not true, but we also want the quasi-invariants. */
 452 //                              || is_SymConst(pred)
 453 //                              || get_lstate(node)->invariant)
 454 //              {
 455 //                      //printf("## CONSTLOAD: %ld \n", node->node_nr);
 456 //                      get_lstate(node)->invariant = 1;
 457 //              } else
 458 //              {
 459 //                      get_lstate(node)->invariant = 0;
 460 //              }
 461 //      }
 462 //      else
 463 //      {
 464 //              int i;
 465 //              invar = 1;
 466 //              /* find loop variant preds */
 467 //              for(i = 0; i < arity; ++i)
 468 //              {
 469 //                      ir_node *pred = get_irn_n(node, i);
 470 //
 471 //                      if ( !(!is_in_loop(pred)        /* outside loop is loop invariant */
 472 //                                      || is_Const(pred)                       /* constants */
 473 //                                      || is_SymConst(pred)            /* SymConst, if no Store */
 474 //                                      || get_lstate(node)->invariant /* pred is marked as invariant */
 475 //                                      ) )
 476 //                      {
 477 //                              invar = 0;
 478 //                      }
 479 //              }
 480 //
 481 //              if (invar) {
 482 //                      printf("const: %ld \n", node->node_nr);
 483 //                      get_lstate(node)->invariant = 1;
 484 //              } else {
 485 //                      get_lstate(node)->invariant = 0;
 486 //              }
 487 //// DBG
 488 ////                            if (!is_nodes_block_marked(pred)) {
 489 ////                                    //printf("pred outloop: %ld, pred %ld (const)\n", node->node_nr, pred->node_nr);
 490 ////                            } else if (is_Const(pred) || is_SymConst(pred)) // || is_Phi(pred)) {
 491 ////                                    //printf("predconst: %ld, pred %ld CONST\n", node->node_nr, pred->node_nr);
 492 ////                            } else if (pred->link == MARKED_CONST) {
 493 ////                                    //printf("predmarked: %ld, pred %ld const\n", node->node_nr, pred->node_nr);
 494 ////                            } else {
 495 ////                                    mark=0;
 496 ////                            }
 497 //      }
 498 //      return 0;
 499 //}
 500
 501 ////TODO DBG Remove
 502 //void phifix(ir_node *node, ir_node *newpred)
 503 //{
 504 //      ir_node *phi=get_Block_phis(node);
 505 //      while(phi)
 506 //      {
 507 //              int pa = get_irn_arity(phi);
 508 //              int ba = get_irn_arity(node);
 509 //
 510 //
 511 //
 512 //              while(ba>pa)
 513 //              {
 514 //                      printf("!!!!!!!!!! block has %d, phi had %d\n", ba, pa );
 515 //                      add_pred(phi, newpred);
 516 //                      pa++;
 517 //                      printf("!!!!!!!!!! block has %d, phi has now %d\n", ba, pa );
 518 //              }
 519 //              phi=get_Phi_next(phi);
 520 //      }
 521 //}
 522
 523 static ir_node *ssa_second_def;
 524 static ir_node *ssa_second_def_block;
 525
 526 /**
 527  *
 528  */
 529 static ir_node *search_def_and_create_phis(ir_node *block, ir_mode *mode,
 530                                            int first)
 531 {
 532         int i;
 533         int n_cfgpreds;
 534         ir_graph *irg;
 535         ir_node *phi;
 536         ir_node **in;
 537
 538         /* This is needed because we create bads sometimes */
 539         if (is_Bad(block))
 540                 return new_Bad();
 541
 542         /* the other defs can't be marked for cases where a user of the original
 543          * value is in the same block as the alternative definition.
 544          * In this case we mustn't use the alternative definition.
 545          * So we keep a flag that indicated wether we walked at least 1 block
 546          * away and may use the alternative definition */
 547         if (block == ssa_second_def_block && !first) {
 548                 return ssa_second_def;
 549         }
 550
 551         /* already processed this block? */
 552         if (irn_visited(block)) {
 553                 ir_node *value = get_lstate(block)->link;
 554                 return value;
 555         }
 556
 557         irg = get_irn_irg(block);
 558         assert(block != get_irg_start_block(irg));
 559
 560         /* a Block with only 1 predecessor needs no Phi */
 561         n_cfgpreds = get_Block_n_cfgpreds(block);
 562         if (n_cfgpreds == 1) {
 563                 ir_node *pred_block = get_Block_cfgpred_block(block, 0);
 564                 ir_node *value      = search_def_and_create_phis(pred_block, mode, 0);
 565
 566                 get_lstate(block)->link = value;
 567                 //set_irn_link(block, value);
 568                 mark_irn_visited(block);
 569                 return value;
 570         }
 571
 572         /* create a new Phi */
 573         NEW_ARR_A(ir_node*, in, n_cfgpreds);
 574         for(i = 0; i < n_cfgpreds; ++i)
 575                 in[i] = new_Unknown(mode);
 576
 577         phi = new_r_Phi(block, n_cfgpreds, in, mode);
 578         //set_irn_link(block, phi);
 579         get_lstate(block)->link = phi;
 580         mark_irn_visited(block);
 581
 582         /* set Phi predecessors */
 583         for(i = 0; i < n_cfgpreds; ++i) {
 584                 ir_node *pred_block = get_Block_cfgpred_block(block, i);
 585                 ir_node *pred_val   = search_def_and_create_phis(pred_block, mode, 0);
 586
 587                 set_irn_n(phi, i, pred_val);
 588         }
 589         return phi;
 590 }
 591
 592 /**
 593  * Given a set of values this function constructs SSA-form for the users of the
 594  * first value (the users are determined through the out-edges of the value).
 595  * Uses the irn_visited flags. Works without using the dominance tree.
 596  */
 597 static void construct_ssa(ir_node *orig_block, ir_node *orig_val,
 598                           ir_node *second_block, ir_node *second_val)
 599 {
 600         ir_graph *irg;
 601         ir_mode *mode;
 602         const ir_edge_t *edge;
 603         const ir_edge_t *next;
 604
 605         /* no need to do anything */
 606         if (orig_val == second_val)
 607                 return;
 608
 609         irg = get_irn_irg(orig_val);
 610         inc_irg_visited(irg);
 611
 612         mode = get_irn_mode(orig_val);
 613         get_lstate(orig_block)->link = orig_val;
 614         //set_irn_link(orig_block, orig_val);
 615         mark_irn_visited(orig_block);
 616
 617         ssa_second_def_block = second_block;
 618         ssa_second_def       = second_val;
 619
 620         /* Only fix the users of the first, i.e. the original node */
 621         foreach_out_edge_safe(orig_val, edge, next) {
 622                 ir_node *user = get_edge_src_irn(edge);
 623                 int j = get_edge_src_pos(edge);
 624                 ir_node *user_block = get_nodes_block(user);
 625                 ir_node *newval;
 626
 627                 /* ignore keeps */
 628                 if (is_End(user))
 629                         continue;
 630
 631                 //DB((dbg, LEVEL_3, ">>> Fixing user %+F (pred %d == %+F)\n", user, j, get_irn_n(user, j)));
 632
 633                 if (is_Phi(user)) {
 634                         ir_node *pred_block = get_Block_cfgpred_block(user_block, j);
 635                         newval = search_def_and_create_phis(pred_block, mode, 1);
 636                 } else {
 637                         newval = search_def_and_create_phis(user_block, mode, 1);
 638                 }
 639
 640                 /* don't fix newly created Phis from the SSA construction */
 641                 if (newval != user) {
 642                         //DB((dbg, LEVEL_4, ">>>> Setting input %d of %+F to %+F\n", j, user, newval));
 643                         set_irn_n(user, j, newval);
 644                 }
 645         }
 646 }
 647
 648
 649
 650 /**
 651  * Rewires the heads after peeling. This results in a tail-controlled loop.
 652  */
 653 void fix_head(ir_node *loophead)
 654 {
 655         int headarity = get_irn_arity(loophead);
 656         int i;
 657         ir_node **loopheadnins;
 658         ir_node **peelheadnins;
 659         ir_node *phi;
 660         ir_node *peelhead = get_copy(loophead);
 661         int lheadin_c = 0;
 662         int pheadin_c = 0;
 663
 664         /**
 665          * the loopheads new preds are:
 666          * its own backedge(s) and the former backedge(s) of the peeled code
 667          */
 668         int lhead_arity = 2 * backedges_n; //ARR_LEN(backedges);
 669         int phead_arity = headarity - backedges_n;  //ARR_LEN(backedges);
 670
 671         /** We assume the worst case, in which every head entry
 672          * origins from the same node. +1 for a null terminated list.
 673          */
 674         //int tchead_arity = ARR_LEN(head_entries) + ( headarity - backedges_n) + 1  ;
 675
 676         NEW_ARR_A(ir_node *, loopheadnins, lhead_arity );
 677         NEW_ARR_A(ir_node *, peelheadnins, phead_arity );
 678
 679         phi = get_Block_phis(loophead);
 680         while(phi) {
 681                 NEW_ARR_A(ir_node *, get_lstate(phi)->ins, lhead_arity);
 682                 phi=get_Phi_next(phi);
 683         }
 684
 685         phi = get_Block_phis(peelhead);
 686         while(phi)
 687         {
 688                 NEW_ARR_A(ir_node *, get_lstate(phi)->ins, phead_arity);
 689                 phi=get_Phi_next(phi);
 690         }
 691
 692         for (i = 0; i < headarity; i++)
 693         {
 694                 ir_node *phi;
 695                 ir_node *orgjmp = get_irn_n(loophead, i);
 696                 ir_node *copyjmp = get_copy(orgjmp);
 697
 698                 /**
 699                  * Rewire the head blocks ins and their phi ins.
 700                  * Requires blocks phi list.
 701                  *
 702                  * 1. Alien bes origin from the peeled head (new head of the whole loop)
 703                  * 2. Loops own bes must be kept/copied to the loophead.
 704                  * 3. All other edges origin from the peeled head (new head of the loop)
 705                  */
 706
 707
 708                 //printf("head i %d\n", i);
 709
 710                 if (is_backedge(loophead, i))
 711                 {
 712                         if (is_alien_edge(loophead, i)) {
 713                                 peelheadnins[pheadin_c] = orgjmp;       /* alien bes go to the peeled head */
 714                                 //set_backedge(peelhead, pheadin_c);
 715
 716                                 // alien bes origin at the peeled head
 717                                 for_each_phi(peelhead, phi)
 718                                 {
 719                                         //printf("alienbe phi %ld @ %d -> %ld\n", phi->node_nr, i, get_irn_n(phi, i)->node_nr);
 720                                         get_lstate( phi )->ins[pheadin_c] = get_irn_n(phi, i);
 721                                 }
 722                                 //printf("alienbe %ld @ %d -> add to peelhead orgjump %ld\n", peelhead->node_nr, i, orgjmp->node_nr);
 723                                 ++pheadin_c;
 724                         } else {
 725                                 loopheadnins[lheadin_c] = orgjmp;       /* keep/copy the loops own bes */
 726                                 //set_backedge(loophead, lheadin_c);
 727
 728                                 for_each_phi(loophead, phi) {
 729                                         //printf("normalbe phi %ld @ %d -> %ld\n", phi->node_nr, i, get_irn_n(phi, i)->node_nr);
 730                                         get_lstate( phi )->ins[lheadin_c] = get_irn_n(phi, i);
 731                                 }
 732                                 //printf("normalbe %ld @ %d -> add to loophead orgjump %ld\n", loophead->node_nr, i, orgjmp->node_nr);
 733                                 ++lheadin_c;
 734
 735                                 loopheadnins[lheadin_c] = copyjmp;      /* former bes of the peeled code origin now from the loophead */
 736                                 //set_not_backedge(loophead, lheadin_c);
 737
 738                                 /* get_irn_n( get_copy_of(phi), i) <!=> get_copy_of(get_irn_n( phi, i))
 739                                  * Order is crucial! Preds outside of the loop are non existent, like Const.
 740                                  */
 741                                 for_each_phi(loophead, phi) {
 742                                         //printf("normalbe phi %ld @ %d -> %ld\n", phi->node_nr, i,  get_irn_n( get_copy_of(phi), i)->node_nr);
 743                                         get_lstate( phi )->ins[lheadin_c] =     get_irn_n( get_copy(phi), i) ;
 744                                 }
 745                                 //printf("normalbe %ld @ %d -> add to loophead copyjump %ld\n", loophead->node_nr, i, copyjmp->node_nr);
 746                                 ++lheadin_c;
 747                         }
 748                 } else {
 749                         peelheadnins[pheadin_c] = orgjmp;
 750                         //set_not_backedge(peelhead, pheadin_c);
 751
 752                         for_each_phi(peelhead, phi) {
 753                                 //printf("edge phi %ld @ %d -> %ld\n", phi->node_nr, i, get_irn_n( phi, i)->node_nr);
 754                                 get_lstate( phi )->ins[pheadin_c] = get_irn_n(phi, i);
 755                         }
 756                         //printf("edge %ld @ %d -> add to peelhead orgjump %ld\n", peelhead->node_nr, i, orgjmp->node_nr);
 757                         ++pheadin_c;
 758                 }
 759         }/* for */
 760
 761 //      printf("pheadin %d  arr %d            lheadin %d arr %d \n",
 762 //                      pheadin_c, ARR_LEN(peelheadnins),
 763 //                      lheadin_c, ARR_LEN(loopheadnins));
 764
 765         assert(pheadin_c == ARR_LEN(peelheadnins) &&
 766                         lheadin_c == ARR_LEN(loopheadnins) &&
 767                         "the number of head elements does not match the predefined one");
 768
 769         set_irn_in(loophead, ARR_LEN(loopheadnins), loopheadnins);
 770         set_irn_in(peelhead, ARR_LEN(peelheadnins), peelheadnins);
 771
 772         for_each_phi(loophead, phi) {
 773                 ir_node **ins = get_lstate( phi )->ins;
 774                 set_irn_in(phi, lhead_arity, ins);
 775         }
 776
 777         for_each_phi(peelhead, phi) {
 778                 ir_node **ins = get_lstate( phi )->ins;
 779                 set_irn_in(phi, phead_arity, ins);
 780         }
 781 }
 782
 783 ir_node *rawcopy_node(ir_node *node)
 784 {
 785         ir_node *cp;
 786         link_node_state_t *cpstate;
 787
 788         cp = exact_copy(node);
 789         set_copy(node, cp);
 790         cpstate = XMALLOCZ(link_node_state_t);
 791         cp->link = cpstate;
 792         if (is_Block(cp))
 793                 cp->loop = NULL;                /* the copy does not belong to the loop */
 794         set_irn_visited(cp, current_ir_graph->visited);
 795         return cp;
 796 }
 797
 798 /**
 799  * Peels the loop by copying the contents. Graph needs some rewiring after that.
 800  */
 801 void peel_walk(ir_node *node)
 802 {
 803         int i;
 804         int arity;
 805         ir_node *cp;
 806         ir_node **cpin;
 807         ir_graph *irg = current_ir_graph;
 808
 809         //(void) env;
 810
 811         link_node_state_t *nodestate = get_lstate(node);
 812
 813         /**
 814          * break condition and cycle resolver, creating temporary node copies
 815          */
 816         if (node->visited >= irg->visited)
 817         {
 818                 if (!nodestate->cloned && !nodestate->temp)
 819                 {
 820                         /** temporary clone this node
 821                          * because we were here before and would walk into a cycle
 822                          */
 823                         rawcopy_node(node);
 824                         nodestate->temp=1;
 825                 }
 826                 return;
 827         }
 828         //printf("  -----  WALK %ld -----  \n", node->node_nr);
 829
 830         /**
 831          * WALK
 832          */
 833         set_irn_visited(node, irg->visited);
 834
 835         if ( !is_Block(node) ) {
 836                 ir_node *pred = get_irn_n(node, -1);
 837                 if (is_in_loop(pred))
 838                         peel_walk(pred);
 839         }
 840
 841         arity = get_irn_arity(node);
 842
 843         NEW_ARR_A(ir_node *, cpin, arity);
 844
 845
 846         for (i = get_irn_arity(node) - 1; i >= 0; --i) {
 847                 ir_node *pred = get_irn_n(node, i);
 848
 849                 /* collect head entries */
 850                 if ( is_in_head(pred) && !is_in_head(node) )
 851                 {
 852                         loop_entry_t entry;
 853                         entry.node = node;
 854                         entry.pred_irn_n = i;
 855                         ARR_APP1(loop_entry_t, head_entries, entry);
 856                 }
 857
 858                 if (is_in_loop(pred))
 859                 {
 860                         peel_walk(pred);
 861                         cpin[i] = get_copy(pred);  //get_lstate(pred)->link;
 862                         //printf("copy of %ld gets in %ld", node->node_nr, cpin[i]->node_nr);
 863                 } else {
 864                         cpin[i] = pred;
 865                 }
 866                 //printf("copy of %ld gets in %ld \n", node->node_nr, cpin[i]->node_nr);
 867         }
 868
 869         /**
 870          *  copy node / finalize temp node
 871          */
 872         if (!nodestate->temp) {
 873 //              if (!is_Const(node) && !is_SymConst(node)) {
 874                         cp = rawcopy_node(node);
 875 //              } else {
 876 //                      cp = node;
 877 //                      //DBG
 878 //                      printf("CONST FINAL: %ld -F> %ld \n", node->node_nr, cp->node_nr);
 879 //                      nodestate->link = cp;
 880 //              }
 881         } else {
 882                 /* temporary copy is existent but without correct ins */
 883                 cp = get_copy(node);  // nodestate->link;
 884                 //printf("FINALIZE: %ld \n", cp->node_nr);
 885         }
 886
 887         // special treatment for the head/condition: we need 3 heads for a tail-controlled and peeled loop
 888         if (is_in_head(node)) {
 889                 // head/condition for the tail-controlled loop
 890                 // These copies are linked to the copies
 891                 rawcopy_node(cp);
 892         }
 893
 894         if (!is_Block(node))
 895         {
 896                 ir_node *cpblock = get_copy(get_nodes_block(node));
 897
 898                 /* set the block of the copy to the copied block */
 899                 //printf("    PRE  NODE %ld   BLOCK %ld \n", cp->node_nr, get_nodes_block(cp)->node_nr);
 900                 set_nodes_block(cp, cpblock );
 901                 //printf("    POST NODE %ld   BLOCK %ld \n", cp->node_nr, get_nodes_block(cp)->node_nr);
 902
 903                 /* fix the phi information in attr.phis (does not add the phi node to the block) */
 904                 if( is_Phi(cp) )
 905                 {
 906                         add_Block_phi(cpblock, cp);
 907                         //printf("PHI-BLOCK block %ld got its phi %ld\n", cpblock->node_nr, cp->node_nr);
 908                 }
 909         }
 910         else {
 911                 /* macroblock info is not copied */
 912                 set_Block_MacroBlock(cp, cp);
 913         }
 914
 915         //dbg valid ins?
 916 //      for(i=0; i<ARR_LEN(cpin); i++)
 917 //              printf(" cpin of %ld (cp %ld):  %ld \n ", node->node_nr, cp->node_nr, cpin[i]->node_nr);
 918
 919         set_irn_in(cp, ARR_LEN(cpin), cpin);
 920
 921 //      for(i=0; i< ARR_LEN(cpin); i++)
 922 //      {
 923 //              printf("ins %ld: %ld \n", cp->node_nr, cpin[i]->node_nr);
 924 //      }
 925
 926 //TODO REM
 927 //      if (!nodestate->temp)
 928 //      {
 929 //              nodestate->link = cp;
 930 //              cpstate = XMALLOCZ(link_node_state_t);
 931 //              cp->link = cpstate;
 932 //      } else {
 933 //              /* temporary copy is existent but without correct ins */
 934 //              cp = nodestate->link;
 935 //      }
 936
 937
 938         nodestate->temp = 0;
 939         nodestate->cloned = 1;
 940 }
 941
 942 //void chklink (ir_node *n, void * e)
 943 //{
 944 //      ir_node *link = n->link;
 945 //      link_node_state_t *l = (link_node_state_t *)link;
 946 //
 947 //      printf("n %ld\n", n->node_nr);
 948 //      printf("l p %ld\n", l->link);
 949 //      if (l->link)
 950 //              printf("l %ld\n", l->link->node_nr);
 951 //
 952 //}
 953
 954 /**
 955  * Loop peeling, and fix the cf for the loop entry nodes, which have now more preds
 956  */
 957 void peel(void)
 958 {
 959         int i;
 960         ir_node **entry_buffer;
 961         int entry_c = 0;
 962         int entry_i;
 963
 964         NEW_ARR_A(ir_node *, entry_buffer, ARR_LEN(loop_entries));
 965
 966         for(i = 0; i < ARR_LEN(loop_entries); i++)
 967         {
 968                 loop_entry_t entry = loop_entries[i];
 969                 ir_node *node = entry.node;
 970                 ir_node *pred = get_irn_n(entry.node, entry.pred_irn_n);
 971
 972                 if (is_Block(node)) {
 973                         /* node is block and the given pred points inside the loop  */
 974                         ir_node *cppred;
 975
 976                         peel_walk( pred );
 977
 978                         // leave keepalives out
 979                         if (is_End(node) && (is_Block(pred) || is_Phi(pred)) ) {
 980                                 //add_End_keepalive(get_irg_end(current_ir_graph), get_copy_of(pred) );
 981                         } else {
 982                                 cppred = get_copy(pred);
 983                                 //printf("fix block entry %ld to cp %ld\n", node->node_nr, cppred->node_nr);
 984                                 add_pred( node, cppred );
 985                                 //printf("fix block entry %ld to cp %ld\n", node->node_nr, cppred->node_nr);
 986                         }
 987
 988                         //add_End_keepalive(get_irg_end(current_ir_graph), get_copy_of(pred) );
 989
 990                         //DBG
 991                         //phifix(node, cppred);
 992                 } else {
 993                         /* node is somewhere in the graph, outside of the loop */
 994                         //ir_node *cppred;
 995                         //ir_node *block;
 996                         //ir_node *cpblock;
 997                         peel_walk( pred );
 998
 999                         // no ssa for keepalives
1000                         if (is_End(node) && (is_Block(pred) || is_Phi(pred)) ) {
1001                                 //add_End_keepalive(get_irg_end(current_ir_graph), get_copy_of(pred) );
1002                         } else {
1003                                 //printf("fix entry %ld to %ld\n", node->node_nr, pred->node_nr);
1004                                 entry_buffer[entry_c++] = pred;
1005                         }
1006
1007                         //add_End_keepalive(get_irg_end(current_ir_graph), get_copy_of(pred) );
1008
1009                         // cannot construct_ssa here, because it needs another walker
1010
1011                 } /* is block */
1012         } /* for */
1013
1014         //irg_walk_graph(current_ir_graph, chklink, NULL, NULL);
1015
1016         fix_head(loop_cf_head);
1017
1018         //printf (" FIXHEAD DONE :D \n");
1019
1020         entry_i = 0;
1021
1022         /* Generate phis for values from peeled code and original loop */
1023         for(i = 0; entry_i < entry_c; i++)
1024         {
1025                 loop_entry_t entry = loop_entries[i];
1026                 ir_node *node = entry.node;
1027
1028                 if (is_Block(node))
1029                 {
1030                         /* block */
1031                         ir_node *phi=get_Block_phis(node);
1032
1033                         while(phi)
1034                         {
1035                                 add_pred(phi, entry_buffer[entry_i++]);
1036                                 phi=get_Phi_next(phi);
1037                         }
1038                 } else {
1039                         /* not block */
1040
1041                         ir_node *cppred, *block, *cpblock, *pred;
1042
1043                         /**
1044                          * pred = get_irn_n(entry.node, entry.pred_irn_n);
1045                          * does not work, because we could have changed the nodes preds in construct_ssa
1046                          */
1047
1048                         pred = entry_buffer[entry_i++];
1049
1050                         //printf("pred %ld\n", pred->node_nr);
1051                         cppred = get_copy(pred);
1052                         //printf("cppred %ld\n", cppred->node_nr);
1053                         block = get_nodes_block(pred);
1054                         //printf("block %ld\n", block->node_nr);
1055                         cpblock = get_nodes_block(cppred);
1056                         //printf("cpblock %ld\n", cpblock->node_nr);
1057
1058
1059                         //dump_ir_block_graph(current_ir_graph, "vorher");
1060                         construct_ssa(block, pred, cpblock, cppred);
1061                         //add_End_keepalive(get_irg_end(current_ir_graph), cppred);
1062
1063
1064                         //add_pred(get_irg_end(current_ir_graph), cppred);
1065                         //dump_ir_block_graph(current_ir_graph, "nachher");
1066
1067                 }
1068         }
1069 }
1070
1071 void alloc_linkstructs(ir_node *node, void *env)
1072 {
1073         link_node_state_t *state = XMALLOCZ(link_node_state_t);
1074         (void) env;
1075         node->link = (void *)state;
1076 }
1077
1078 void free_linkstructs(ir_node *node, void *env)
1079 {
1080         (void) env;
1081         xfree( (link_node_state_t*) node->link);
1082 }
1083
1084 void decision_maker(void)
1085 {
1086         //inc_irg_visited(current_ir_graph);
1087         //loop_walker( loop_entries, NULL, get_invariants, NULL );
1088
1089
1090         inc_irg_visited(current_ir_graph);
1091         irg_walk_graph(current_ir_graph, alloc_linkstructs, NULL, NULL);
1092
1093         inc_irg_visited(current_ir_graph);
1094         peel();
1095
1096         inc_irg_visited(current_ir_graph);
1097         irg_walk_graph(current_ir_graph, free_linkstructs, NULL, NULL);
1098 }
1099
1100
1101 /**
1102  * TODO use list , not arr_F
1103  */
1104 void analyze_loop(ir_loop *loop)
1105 {
1106         /* Init new for every loop */
1107         loop_cf_head = NULL;
1108         loop_cf_head_valid = 1;
1109         //loop_entries_n = 0;
1110         backedges_n = 0;
1111         has_sto = 0;
1112
1113         cur_loop = loop;
1114
1115         /* arrays */
1116         //backedges = NEW_ARR_F(loop_entry_t, 0);
1117         //alien_backedges = NEW_ARR_F(loop_entry_t, 0);
1118         //head_edges = NEW_ARR_F(loop_entry_t, 0);
1119
1120         loop_entries = NEW_ARR_F(loop_entry_t, 0);
1121         head_entries = NEW_ARR_F(loop_entry_t, 0);
1122
1123         inc_irg_visited( current_ir_graph );
1124         irg_walk_graph( current_ir_graph, block_phi_walker, NULL, NULL );
1125
1126         /* Collect all backedges */
1127         for_each_loop_block(loop, collect_backedges, NULL );
1128
1129         /* Find loop entries walk, find head */
1130         inc_irg_visited( current_ir_graph );
1131         irg_walk_graph( current_ir_graph, find_loop_entries_walk, NULL, NULL );
1132
1133         /* RETURN if there is no valid head */
1134         if (!loop_cf_head || !loop_cf_head_valid)
1135         {
1136                 //DBG printf("NOTE: There is no valid loop head. Nothing done.\n");
1137                 return;
1138         }
1139
1140         decision_maker();
1141
1142         // TODO free all link states... or better put them on functionstack
1143
1144         /* FREE */
1145         DEL_ARR_F(loop_entries);
1146         DEL_ARR_F(head_entries);
1147         //DEL_ARR_F(backedges);
1148         //DEL_ARR_F(alien_backedges);
1149         //DEL_ARR_F(head_edges);
1150
1151         //dump_ir_block_graph(current_ir_graph, "-lu1");
1152 }
1153
1154 /**
1155  *      Find most inner loops and send them to analyze_loop
1156  */
1157 void analyze_inner_loop(ir_loop *loop)
1158 {
1159         /* descend into sons */
1160         int sons = get_loop_n_sons(loop);
1161
1162         //printf("found %d loops \n", sons);
1163
1164         if (sons==0)
1165         {
1166                 //printf("analyze loop %ld\n", loop->loop_nr);
1167                 analyze_loop(loop);
1168         }
1169         else
1170         {
1171                 int s;
1172                 for(s=0; s<sons; s++)
1173                 {
1174                         //printf("descend into loop son %ld\n", get_loop_son(loop, s)->loop_nr);
1175                         analyze_inner_loop( get_loop_son(loop, s) );
1176                 }
1177         }
1178 }
1179
1180 void loop_optimization(ir_graph *irg)
1181 {
1182         //printf(" --- loop unroll start --- \n");
1183
1184         //irg_walk_graph(irg, phicheck, NULL, NULL);
1185
1186         ir_loop *loop;
1187         int     sons, nr;
1188
1189         assure_cf_loop(irg);
1190
1191         loop = get_irg_loop(irg);
1192         sons = get_loop_n_sons(loop);
1193         //printf("FOUND %d LOOPS \n", sons);
1194
1195         for (nr=0; nr<sons; nr++)
1196         {
1197                 analyze_inner_loop( get_loop_son(loop, nr) );
1198         }
1199
1200         //DBG
1201         //printf(" --- loop unroll done --- \n");
1202 }
1203
1204 //struct loop_unroll_pass_t {
1205 //      ir_graph_pass_t pass;
1206 //};
1207
1208 /**
1209  * Wrapper to run loop_unroll() as a ir_prog pass.
1210  */
1211 //static int loop_unroll_wrapper(ir_graph *irg, void *context) {
1212 //
1213 //      (void)context;
1214 //      loop_unroll(irg);
1215 //      return 0;
1216 //}
1217
1218
1219 //ir_graph_pass_t *loop_unroll_pass(const char *name)
1220 //{
1221 //      struct loop_unroll_pass_t *pass =
1222 //              XMALLOCZ(struct loop_unroll_pass_t);
1223 //
1224 //      return def_graph_pass_constructor(
1225 //              &pass->pass, name ? name : "loop_unroll",
1226 //              loop_unroll_wrapper);
1227 //}
1228
1229 /*
1230 void firm_init_loopunroll(void) {
1231         FIRM_DBG_REGISTER(dbg, "firm.opt.loopunroll");
1232 }*/