nsz Git - libfirm/blob - ir/be/beschedmris.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       Implements a list scheduler for the MRIS algorithm.
  23  * @author      Sebastian Hack
  24  * @date        04.04.2006
  25  * @version     $Id$
  26  *
  27  * Implements a list scheduler for the MRIS algorithm in:
  28  * Govindarajan, Yang, Amaral, Zhang, Gao
  29  * Minimum Register Instruction Sequencing to Reduce Register Spills
  30  * in out-of-order issue superscalar architectures
  31  */
  32 #include "config.h"
  33
  34 #include <limits.h>
  35
  36 #include "obst.h"
  37 #include "debug.h"
  38
  39 #include "irgraph_t.h"
  40 #include "irnode_t.h"
  41 #include "iredges_t.h"
  42 #include "ircons_t.h"
  43 #include "irphase_t.h"
  44 #include "irdump_t.h"
  45 #include "irgwalk.h"
  46 #include "irtools.h"
  47 #include "irbitset.h"
  48 #include "height.h"
  49
  50 #include "benode_t.h"
  51 #include "besched_t.h"
  52 #include "beschedmris.h"
  53 #include "beirg.h"
  54
  55 struct _mris_env_t {
  56         ir_phase          ph;
  57         heights_t         *heights;
  58         const arch_env_t  *aenv;
  59         ir_graph          *irg;
  60         ir_node           *bl;
  61         int               visited;
  62         struct list_head  lineage_head;
  63         struct obstack    obst;
  64         DEBUG_ONLY(firm_dbg_module_t *dbg;)
  65 };
  66
  67 typedef struct _mris_irn_t {
  68         int visited;
  69         ir_node *lineage_start;
  70         ir_node *lineage_next;
  71         ir_node *lineage_end;
  72         struct list_head lineage_list;
  73 } mris_irn_t;
  74
  75 #define to_appear(env, irn) (to_appear_in_schedule(irn) && get_nodes_block(irn) == env->bl)
  76
  77 #define get_mris_irn(env, irn)   ((mris_irn_t *) phase_get_or_set_irn_data(&env->ph, irn))
  78 #define foreach_lineage(env, pos, tmp) list_for_each_entry_safe(mris_irn_t, pos, tmp, &(env)->lineage_head, lineage_list)
  79
  80 static void *mris_irn_data_init(ir_phase *ph, const ir_node *irn, void *data)
  81 {
  82         mris_irn_t *mi = data ? data : phase_alloc(ph, sizeof(mi[0]));
  83         (void) irn;
  84         memset(mi, 0, sizeof(mi[0]));
  85         INIT_LIST_HEAD(&mi->lineage_list);
  86         return mi;
  87 }
  88
  89 #if 0
  90 static int compute_height(mris_env_t *env, ir_node *irn, ir_visited_t visited)
  91 {
  92         mris_irn_t *mi = get_mris_irn(env, irn);
  93
  94         if(get_irn_visited(irn) >= visited) {
  95                 DBG((env->dbg, LEVEL_3, "\theight of %+F = %d\n", irn, mi->height));
  96                 return mi->height;
  97         }
  98
  99         else {
 100                 const ir_edge_t *edge;
 101
 102                 set_irn_visited(irn, visited);
 103                 mi->height  = 0;
 104
 105                 foreach_out_edge(irn, edge) {
 106                         ir_node *dep = get_edge_src_irn(edge);
 107
 108                         if(!is_Block(dep) && get_nodes_block(dep) == env->bl) {
 109                                 int dep_height = compute_height(env, dep, visited);
 110                                 mi->height     = MAX(mi->height, dep_height);
 111                         }
 112                 }
 113
 114                 mi->height++;
 115                 DBG((env->dbg, LEVEL_3, "\tsetting height of %+F = %d\n", irn, mi->height));
 116         }
 117
 118         return mi->height;
 119 }
 120
 121 static void compute_heights(mris_env_t *env)
 122 {
 123         const ir_edge_t *edge;
 124         ir_visited_t visited;
 125
 126         visited = get_irg_visited(env->irg) + 1;
 127         set_irg_visited(env->irg, visited);
 128
 129         foreach_out_edge(env->bl, edge) {
 130                 ir_node *dep = get_edge_src_irn(edge);
 131                 if(to_appear(env, dep))
 132                         compute_height(env, dep, visited);
 133         }
 134 }
 135 #endif
 136
 137 #define valid_node(env, dep) (to_appear(env, dep) && !be_is_Keep(dep))
 138
 139 static void grow_all_descendands(mris_env_t *env, ir_node *irn, bitset_t *visited)
 140 {
 141         const ir_edge_t *edge;
 142
 143         // assert(get_irn_mode(irn) != mode_T);
 144
 145         foreach_out_edge(irn, edge) {
 146                 ir_node *desc = get_edge_src_irn(edge);
 147                 if(valid_node(env, desc) && !bitset_contains_irn(visited, desc)) {
 148                         obstack_ptr_grow(&env->obst, desc);
 149                         bitset_add_irn(visited, desc);
 150                 }
 151         }
 152
 153         foreach_out_edge_kind(irn, edge, EDGE_KIND_DEP) {
 154                 ir_node *desc = get_edge_src_irn(edge);
 155                 if(valid_node(env, desc) && !bitset_contains_irn(visited, desc)) {
 156                         obstack_ptr_grow(&env->obst, desc);
 157                         bitset_add_irn(visited, desc);
 158                 }
 159         }
 160 }
 161
 162 static ir_node **all_descendants(mris_env_t *env, ir_node *irn)
 163 {
 164         bitset_t *visited = bitset_irg_malloc(env->irg);
 165
 166         grow_all_descendands(env, irn, visited);
 167
 168 #if 0
 169         if(get_irn_mode(irn) == mode_T) {
 170                 const ir_edge_t *edge;
 171                 foreach_out_edge(irn, edge) {
 172                         ir_node *desc = get_edge_src_irn(edge);
 173                         assert(is_Proj(desc) && get_irn_mode(desc) != mode_T);
 174                         grow_all_descendands(env, desc, visited);
 175                 }
 176         }
 177
 178         else
 179                 grow_all_descendands(env, irn, visited);
 180 #endif
 181         bitset_free(visited);
 182         obstack_ptr_grow(&env->obst, NULL);
 183         return obstack_finish(&env->obst);
 184 }
 185
 186 static ir_node *put_lowest_in_front(mris_env_t *env, ir_node **in)
 187 {
 188         int lowest_index       = 0;
 189         unsigned lowest_height = INT_MAX;
 190         int i;
 191
 192         for(i = 0; in[i]; ++i) {
 193                 unsigned height = get_irn_height(env->heights, in[i]);
 194                 if(height < lowest_height) {
 195                         lowest_height = height;
 196                         lowest_index  = i;
 197                 }
 198         }
 199
 200         if(i > 0) {
 201                 ir_node *tmp     = in[0];
 202                 in[0]            = in[lowest_index];
 203                 in[lowest_index] = tmp;
 204         }
 205
 206         return in[0];
 207 }
 208
 209 #if 0
 210 static void reaches_walker(mris_env_t *env, ir_node *irn, ir_node *tgt, int *found, ir_visited_t visited)
 211 {
 212         if(get_irn_visited(irn) < visited && get_nodes_block(irn) == env->bl) {
 213
 214                 set_irn_visited(irn, visited);
 215
 216                 if(irn == tgt)
 217                         *found = 1;
 218                 else {
 219                         int i, n;
 220
 221                         for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
 222                                 ir_node *op = get_irn_n(irn, i);
 223                                 if(!*found)
 224                                         reaches_walker(env, op, tgt, found, visited);
 225                         }
 226                 }
 227         }
 228 }
 229
 230 static int reaches(mris_env_t *env, ir_node *src, ir_node *tgt)
 231 {
 232         int found = 0;
 233         ir_visited_t visited = get_irg_visited(env->irg) + 1;
 234
 235         set_irg_visited(env->irg, visited);
 236         reaches_walker(env, src, tgt, &found, visited);
 237         return found;
 238 }
 239 #endif
 240
 241 static INLINE ir_node *skip_Projs(ir_node *irn)
 242 {
 243         return is_Proj(irn) ? skip_Projs(get_Proj_pred(irn)) : irn;
 244 }
 245
 246 #if 0
 247 static void replace_tuple_by_repr_proj(mris_env_t *env, ir_node **in)
 248 {
 249         int i;
 250
 251         for(i = 0; in[i]; ++i) {
 252                 if(get_irn_mode(in[i]) == mode_T) {
 253                         const ir_edge_t *edge;
 254                         ir_node *proj  = NULL;
 255                         ir_node *first = NULL;
 256
 257                         foreach_out_edge(in[i], edge) {
 258                                 ir_node *desc = get_edge_src_irn(edge);
 259
 260                                 first = first ? first : desc;
 261                                 if(get_irn_mode(desc) == mode_M) {
 262                                         proj = desc;
 263                                         break;
 264                                 }
 265                         }
 266
 267                         proj = proj ? proj : first;
 268                         assert(proj);
 269                         in[i] = proj;
 270                 }
 271         }
 272 }
 273 #endif
 274
 275 static void lineage_formation(mris_env_t *env)
 276 {
 277         DEBUG_ONLY(firm_dbg_module_t *dbg = env->dbg);
 278         ir_nodeset_t                  nodes;
 279         const ir_edge_t              *edge;
 280
 281         ir_nodeset_init(&nodes);
 282
 283         foreach_out_edge(env->bl, edge) {
 284                 ir_node *irn = get_edge_src_irn(edge);
 285                 if(to_appear(env, irn))
 286                         ir_nodeset_insert(&nodes, irn);
 287         }
 288
 289         while(ir_nodeset_size(&nodes) > 0) {
 290                 mris_irn_t *mi;
 291                 ir_node    *irn;
 292                 ir_node    *highest_node = NULL;
 293                 ir_node    *lowest_desc  = NULL;
 294                 ir_node    *start;
 295                 mris_irn_t *start_mi;
 296                 ir_nodeset_iterator_t iter;
 297
 298                 ir_node **in;
 299                 int recompute_height  = 0;
 300                 unsigned  curr_height = 0;
 301
 302                 /* search the highest node which is not yet in a lineage. */
 303                 foreach_ir_nodeset(&nodes, irn, iter) {
 304                         unsigned height = get_irn_height(env->heights, irn);
 305                         if(height > curr_height) {
 306                                 highest_node = irn;
 307                                 curr_height  = height;
 308                         }
 309                 }
 310
 311                 assert(highest_node);
 312                 DBG((dbg, LEVEL_2, "highest node is %+F height %d\n", highest_node, get_irn_height(env->heights, highest_node)));
 313
 314                 start = highest_node;
 315                 mi = start_mi = get_mris_irn(env, highest_node);
 316
 317                 /* start a lineage beginning with highest_node. */
 318                 mi->lineage_start = highest_node;
 319                 mi->lineage_next  = NULL;
 320                 mi->lineage_end   = NULL;
 321                 list_add(&mi->lineage_list, &env->lineage_head);
 322                 ir_nodeset_remove(&nodes, highest_node);
 323
 324                 /*
 325                         put all descendants in an array.
 326                         we also move the lowest descendant in front, so that the other nodes
 327                         are easily accessible as an array, too.
 328                 */
 329                 in          = all_descendants(env, highest_node);
 330                 lowest_desc = put_lowest_in_front(env, in);
 331
 332                 /* as long as the current highest node has still descendants */
 333                 while(lowest_desc) {
 334                         mris_irn_t *lowest_mi  = get_mris_irn(env, lowest_desc);
 335                         mris_irn_t *highest_mi = get_mris_irn(env, highest_node);
 336                         int highest_is_tuple   = get_irn_mode(highest_node) == mode_T;
 337
 338                         int n_desc;
 339
 340                         DBG((dbg, LEVEL_2, "\tlowest descendant %+F height %d\n", lowest_desc, get_irn_height(env->heights, lowest_desc)));
 341
 342                         /* count the number of all descendants which are not the lowest descendant */
 343                         for(n_desc = 0; in[n_desc]; ++n_desc);
 344
 345                         /*
 346                         we insert a CopyKeep node to express the artificial dependencies from the lowest
 347                         descendant to all other descendants.
 348                         */
 349                         if(n_desc > 1 && !be_is_Keep(lowest_desc)) {
 350                                 ir_node *op;
 351                                 int i, n;
 352
 353                                 for(i = 0, n = get_irn_ins_or_deps(lowest_desc); i < n; ++i) {
 354                                         ir_node *cmp;
 355
 356                                         op  = get_irn_in_or_dep(lowest_desc, i);
 357                                         cmp = highest_is_tuple ? skip_Projs(op) : op;
 358
 359                                         // if(cmp == highest_node)
 360                                         if(op == highest_node)
 361                                                 break;
 362                                 }
 363
 364                                 assert(i < n && "could not find operand");
 365
 366                                 //replace_tuple_by_repr_proj(env, &in[1]);
 367                                 if(!is_Proj(lowest_desc))
 368                                         add_irn_dep(lowest_desc, in[1]);
 369                         }
 370                         obstack_free(&env->obst, in);
 371
 372                         /* if the current lowest node is not yet in a lineage, add it to the current one. */
 373                         if(!lowest_mi->lineage_start) {
 374                                 /* mark the current lowest node as the last one in the lineage. */
 375                                 highest_mi->lineage_next = lowest_desc;
 376                                 start_mi->lineage_end    = lowest_desc;
 377
 378                                 lowest_mi->lineage_start = start;
 379                                 ir_nodeset_remove(&nodes, lowest_desc);
 380                         }
 381
 382                         /* else we cannot extend this lineage, so break. */
 383                         else
 384                                 break;
 385
 386                         highest_node = lowest_desc;
 387                         highest_mi   = lowest_mi;
 388
 389                         /* recompute the descendants array and the new lowest descendant. */
 390                         in          = all_descendants(env, highest_node);
 391                         lowest_desc = put_lowest_in_front(env, in);
 392                 }
 393
 394                 /* recompute the heights if desired. */
 395                 if(recompute_height)
 396                         heights_recompute(env->heights);
 397         }
 398
 399         ir_nodeset_destroy(&nodes);
 400 }
 401
 402 static int fuse_two_lineages(mris_env_t *env, mris_irn_t *u, mris_irn_t *v)
 403 {
 404         mris_irn_t *mi;
 405         ir_node *irn, *last;
 406         ir_node *u_end   = u->lineage_end;
 407         ir_node *v_start = v->lineage_start;
 408         ir_node *start   = skip_Projs(v_start);
 409
 410         if(be_is_Keep(start))
 411                 return 0;
 412
 413         /* set lineage end of nodes in u to end of v. */
 414         irn = last = u->lineage_start;
 415         mi         = get_mris_irn(env, irn);
 416         while(irn && irn != u_end) {
 417                 mi = get_mris_irn(env, irn);
 418                 mi->lineage_end = v->lineage_end;
 419                 last = irn;
 420                 irn = mi->lineage_next;
 421         }
 422
 423         /* insert a CopyKeep to make lineage v dependent on u. */
 424         if(get_irn_ins_or_deps(start) == 0)
 425                 return 0;
 426
 427         if(get_irn_mode(last) == mode_T) {
 428                 const ir_edge_t *edge;
 429                 foreach_out_edge(last, edge) {
 430                         last = get_edge_src_irn(edge);
 431                         break;
 432                 }
 433         }
 434
 435         /* irn now points to the last node in lineage u; mi has the info for the node _before_ the terminator of the lineage. */
 436         mi->lineage_next       = v_start;
 437
 438         /* add a dependency from the first node in v's lineage to the last in u's */
 439         add_irn_dep(u_end, v_start);
 440
 441         /* set lineage start of nodes in v to start of u. */
 442         irn = v->lineage_start;
 443         while(irn && irn != v->lineage_end) {
 444                 mris_irn_t *mi = get_mris_irn(env, irn);
 445                 mi->lineage_start = u->lineage_start;
 446                 irn = mi->lineage_next;
 447         }
 448
 449         heights_recompute(env->heights);
 450
 451         mi = get_mris_irn(env, v_start);
 452         list_del(&mi->lineage_list);
 453
 454         return 1;
 455 }
 456
 457 static void fuse_lineages(mris_env_t *env)
 458 {
 459         mris_irn_t *u, *v, *tmp1, *tmp2;
 460
 461 again:
 462         foreach_lineage(env, u, tmp1) {
 463                 foreach_lineage(env, v, tmp2) {
 464                         if(u != v && u->lineage_start && v->lineage_start && u->lineage_end && v->lineage_end
 465                                 && get_nodes_block(u->lineage_start) == get_nodes_block(v->lineage_start)) {
 466                                 int uv = heights_reachable_in_block(env->heights, u->lineage_start, v->lineage_end);
 467                                 int vu = heights_reachable_in_block(env->heights, v->lineage_start, u->lineage_end);
 468
 469                                 if(uv && !vu) {
 470                                         if(fuse_two_lineages(env, u, v))
 471                                                 goto again;
 472                                 }
 473                         }
 474                 }
 475         }
 476 }
 477
 478 static mris_env_t *dump_env = NULL;
 479
 480 static void block_walker(ir_node *bl, void *data)
 481 {
 482         mris_env_t *env = data;
 483         env->bl = bl;
 484         lineage_formation(env);
 485         fuse_lineages(env);
 486 }
 487
 488 static int mris_edge_hook(FILE *F, ir_node *irn)
 489 {
 490         mris_irn_t *mi = get_mris_irn(dump_env, irn);
 491
 492         if(mi->lineage_next) {
 493                 fprintf(F, "edge:{sourcename:\"");
 494                 PRINT_NODEID(mi->lineage_next);
 495                 fprintf(F, "\" targetname:\"");
 496                 PRINT_NODEID(irn);
 497                 fprintf(F, "\" color:lilac}\n");
 498         }
 499         return 1;
 500 }
 501
 502 void dump_ir_block_graph_mris(mris_env_t *env, const char *suffix) {
 503         DUMP_NODE_EDGE_FUNC old = get_dump_node_edge_hook();
 504
 505         dump_consts_local(0);
 506         set_dump_node_edge_hook(mris_edge_hook);
 507         dump_env = env;
 508         dump_ir_block_graph(env->irg, suffix);
 509         set_dump_node_edge_hook(old);
 510 }
 511
 512 mris_env_t *be_sched_mris_preprocess(const be_irg_t *birg)
 513 {
 514         mris_env_t *env = XMALLOC(mris_env_t);
 515         ir_graph   *irg = be_get_birg_irg(birg);
 516
 517         phase_init(&env->ph, "mris", irg, 2 * PHASE_DEFAULT_GROWTH, mris_irn_data_init, NULL);
 518         env->aenv     = be_get_birg_arch_env(birg);
 519         env->irg      = irg;
 520         env->visited  = 0;
 521         env->heights  = heights_new(irg);
 522         INIT_LIST_HEAD(&env->lineage_head);
 523         FIRM_DBG_REGISTER(env->dbg, "firm.be.sched.mris");
 524         obstack_init(&env->obst);
 525         irg_walk_graph(irg, firm_clear_link, NULL, NULL);
 526         irg_block_walk_graph(irg, block_walker, NULL, env);
 527         obstack_free(&env->obst, NULL);
 528         // dump_ir_block_graph_mris(env, "-mris");
 529         return env;
 530 }
 531
 532 void be_sched_mris_free(mris_env_t *env)
 533 {
 534         phase_free(&env->ph);
 535         heights_free(env->heights);
 536         free(env);
 537 }