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 #ifdef HAVE_CONFIG_H
  33 #include "config.h"
  34 #endif
  35
  36 #include <limits.h>
  37
  38 #include "obst.h"
  39 #include "debug.h"
  40
  41 #include "irgraph_t.h"
  42 #include "irnode_t.h"
  43 #include "iredges_t.h"
  44 #include "ircons_t.h"
  45 #include "irphase_t.h"
  46 #include "irdump_t.h"
  47 #include "irgwalk.h"
  48 #include "irtools.h"
  49 #include "irbitset.h"
  50 #include "height.h"
  51
  52 #include "benode_t.h"
  53 #include "besched_t.h"
  54 #include "beschedmris.h"
  55 #include "beirg.h"
  56
  57 struct _mris_env_t {
  58         ir_phase          ph;
  59         heights_t         *heights;
  60         const arch_env_t  *aenv;
  61         ir_graph          *irg;
  62         ir_node           *bl;
  63         int               visited;
  64         struct list_head  lineage_head;
  65         struct obstack    obst;
  66         DEBUG_ONLY(firm_dbg_module_t *dbg;)
  67 };
  68
  69 typedef struct _mris_irn_t {
  70         int visited;
  71         ir_node *lineage_start;
  72         ir_node *lineage_next;
  73         ir_node *lineage_end;
  74         struct list_head lineage_list;
  75 } mris_irn_t;
  76
  77 #define to_appear(env, irn) (to_appear_in_schedule(irn) && get_nodes_block(irn) == env->bl)
  78
  79 #define get_mris_irn(env, irn)   ((mris_irn_t *) phase_get_or_set_irn_data(&env->ph, irn))
  80 #define foreach_lineage(env, pos, tmp) list_for_each_entry_safe(mris_irn_t, pos, tmp, &(env)->lineage_head, lineage_list)
  81
  82 static void *mris_irn_data_init(ir_phase *ph, const ir_node *irn, void *data)
  83 {
  84         mris_irn_t *mi = data ? data : phase_alloc(ph, sizeof(mi[0]));
  85         (void) irn;
  86         memset(mi, 0, sizeof(mi[0]));
  87         INIT_LIST_HEAD(&mi->lineage_list);
  88         return mi;
  89 }
  90
  91 #if 0
  92 static int compute_height(mris_env_t *env, ir_node *irn, unsigned long visited)
  93 {
  94         mris_irn_t *mi = get_mris_irn(env, irn);
  95
  96         if(get_irn_visited(irn) >= visited) {
  97                 DBG((env->dbg, LEVEL_3, "\theight of %+F = %d\n", irn, mi->height));
  98                 return mi->height;
  99         }
 100
 101         else {
 102                 const ir_edge_t *edge;
 103
 104                 set_irn_visited(irn, visited);
 105                 mi->height  = 0;
 106
 107                 foreach_out_edge(irn, edge) {
 108                         ir_node *dep = get_edge_src_irn(edge);
 109
 110                         if(!is_Block(dep) && get_nodes_block(dep) == env->bl) {
 111                                 int dep_height = compute_height(env, dep, visited);
 112                                 mi->height     = MAX(mi->height, dep_height);
 113                         }
 114                 }
 115
 116                 mi->height++;
 117                 DBG((env->dbg, LEVEL_3, "\tsetting height of %+F = %d\n", irn, mi->height));
 118         }
 119
 120         return mi->height;
 121 }
 122
 123 static void compute_heights(mris_env_t *env)
 124 {
 125         const ir_edge_t *edge;
 126         unsigned long visited;
 127
 128         visited = get_irg_visited(env->irg) + 1;
 129         set_irg_visited(env->irg, visited);
 130
 131         foreach_out_edge(env->bl, edge) {
 132                 ir_node *dep = get_edge_src_irn(edge);
 133                 if(to_appear(env, dep))
 134                         compute_height(env, dep, visited);
 135         }
 136 }
 137 #endif
 138
 139 #define valid_node(env, dep) (to_appear(env, dep) && !be_is_Keep(dep))
 140
 141 static void grow_all_descendands(mris_env_t *env, ir_node *irn, bitset_t *visited)
 142 {
 143         const ir_edge_t *edge;
 144
 145         // assert(get_irn_mode(irn) != mode_T);
 146
 147         foreach_out_edge(irn, edge) {
 148                 ir_node *desc = get_edge_src_irn(edge);
 149                 if(valid_node(env, desc) && !bitset_contains_irn(visited, desc)) {
 150                         obstack_ptr_grow(&env->obst, desc);
 151                         bitset_add_irn(visited, desc);
 152                 }
 153         }
 154
 155         foreach_out_edge_kind(irn, edge, EDGE_KIND_DEP) {
 156                 ir_node *desc = get_edge_src_irn(edge);
 157                 if(valid_node(env, desc) && !bitset_contains_irn(visited, desc)) {
 158                         obstack_ptr_grow(&env->obst, desc);
 159                         bitset_add_irn(visited, desc);
 160                 }
 161         }
 162 }
 163
 164 static ir_node **all_descendants(mris_env_t *env, ir_node *irn)
 165 {
 166         bitset_t *visited = bitset_irg_malloc(env->irg);
 167
 168         grow_all_descendands(env, irn, visited);
 169
 170 #if 0
 171         if(get_irn_mode(irn) == mode_T) {
 172                 const ir_edge_t *edge;
 173                 foreach_out_edge(irn, edge) {
 174                         ir_node *desc = get_edge_src_irn(edge);
 175                         assert(is_Proj(desc) && get_irn_mode(desc) != mode_T);
 176                         grow_all_descendands(env, desc, visited);
 177                 }
 178         }
 179
 180         else
 181                 grow_all_descendands(env, irn, visited);
 182 #endif
 183         bitset_free(visited);
 184         obstack_ptr_grow(&env->obst, NULL);
 185         return obstack_finish(&env->obst);
 186 }
 187
 188 static ir_node *put_lowest_in_front(mris_env_t *env, ir_node **in)
 189 {
 190         int lowest_index       = 0;
 191         unsigned lowest_height = INT_MAX;
 192         int i;
 193
 194         for(i = 0; in[i]; ++i) {
 195                 unsigned height = get_irn_height(env->heights, in[i]);
 196                 if(height < lowest_height) {
 197                         lowest_height = height;
 198                         lowest_index  = i;
 199                 }
 200         }
 201
 202         if(i > 0) {
 203                 ir_node *tmp     = in[0];
 204                 in[0]            = in[lowest_index];
 205                 in[lowest_index] = tmp;
 206         }
 207
 208         return in[0];
 209 }
 210
 211 #if 0
 212 static void reaches_walker(mris_env_t *env, ir_node *irn, ir_node *tgt, int *found, unsigned long visited)
 213 {
 214         if(get_irn_visited(irn) < visited && get_nodes_block(irn) == env->bl) {
 215
 216                 set_irn_visited(irn, visited);
 217
 218                 if(irn == tgt)
 219                         *found = 1;
 220                 else {
 221                         int i, n;
 222
 223                         for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
 224                                 ir_node *op = get_irn_n(irn, i);
 225                                 if(!*found)
 226                                         reaches_walker(env, op, tgt, found, visited);
 227                         }
 228                 }
 229         }
 230 }
 231
 232 static int reaches(mris_env_t *env, ir_node *src, ir_node *tgt)
 233 {
 234         int found = 0;
 235         unsigned long visited = get_irg_visited(env->irg) + 1;
 236
 237         set_irg_visited(env->irg, visited);
 238         reaches_walker(env, src, tgt, &found, visited);
 239         return found;
 240 }
 241 #endif
 242
 243 static INLINE ir_node *skip_Projs(ir_node *irn)
 244 {
 245         return is_Proj(irn) ? skip_Projs(get_Proj_pred(irn)) : irn;
 246 }
 247
 248 #if 0
 249 static void replace_tuple_by_repr_proj(mris_env_t *env, ir_node **in)
 250 {
 251         int i;
 252
 253         for(i = 0; in[i]; ++i) {
 254                 if(get_irn_mode(in[i]) == mode_T) {
 255                         const ir_edge_t *edge;
 256                         ir_node *proj  = NULL;
 257                         ir_node *first = NULL;
 258
 259                         foreach_out_edge(in[i], edge) {
 260                                 ir_node *desc = get_edge_src_irn(edge);
 261
 262                                 first = first ? first : desc;
 263                                 if(get_irn_mode(desc) == mode_M) {
 264                                         proj = desc;
 265                                         break;
 266                                 }
 267                         }
 268
 269                         proj = proj ? proj : first;
 270                         assert(proj);
 271                         in[i] = proj;
 272                 }
 273         }
 274 }
 275 #endif
 276
 277 static void lineage_formation(mris_env_t *env)
 278 {
 279         DEBUG_ONLY(firm_dbg_module_t *dbg = env->dbg);
 280         ir_nodeset_t                  nodes;
 281         const ir_edge_t              *edge;
 282
 283         ir_nodeset_init(&nodes);
 284
 285         foreach_out_edge(env->bl, edge) {
 286                 ir_node *irn = get_edge_src_irn(edge);
 287                 if(to_appear(env, irn))
 288                         ir_nodeset_insert(&nodes, irn);
 289         }
 290
 291         while(ir_nodeset_size(&nodes) > 0) {
 292                 mris_irn_t *mi;
 293                 ir_node    *irn;
 294                 ir_node    *highest_node = NULL;
 295                 ir_node    *lowest_desc  = NULL;
 296                 ir_node    *start;
 297                 mris_irn_t *start_mi;
 298                 ir_nodeset_iterator_t iter;
 299
 300                 ir_node **in;
 301                 int recompute_height  = 0;
 302                 unsigned  curr_height = 0;
 303
 304                 /* search the highest node which is not yet in a lineage. */
 305                 foreach_ir_nodeset(&nodes, irn, iter) {
 306                         unsigned height = get_irn_height(env->heights, irn);
 307                         if(height > curr_height) {
 308                                 highest_node = irn;
 309                                 curr_height  = height;
 310                         }
 311                 }
 312
 313                 assert(highest_node);
 314                 DBG((dbg, LEVEL_2, "highest node is %+F height %d\n", highest_node, get_irn_height(env->heights, highest_node)));
 315
 316                 start = highest_node;
 317                 mi = start_mi = get_mris_irn(env, highest_node);
 318
 319                 /* start a lineage beginning with highest_node. */
 320                 mi->lineage_start = highest_node;
 321                 mi->lineage_next  = NULL;
 322                 mi->lineage_end   = NULL;
 323                 list_add(&mi->lineage_list, &env->lineage_head);
 324                 ir_nodeset_remove(&nodes, highest_node);
 325
 326                 /*
 327                         put all descendants in an array.
 328                         we also move the lowest descendant in front, so that the other nodes
 329                         are easily accessible as an array, too.
 330                 */
 331                 in          = all_descendants(env, highest_node);
 332                 lowest_desc = put_lowest_in_front(env, in);
 333
 334                 /* as long as the current highest node has still descendants */
 335                 while(lowest_desc) {
 336                         mris_irn_t *lowest_mi  = get_mris_irn(env, lowest_desc);
 337                         mris_irn_t *highest_mi = get_mris_irn(env, highest_node);
 338                         int highest_is_tuple   = get_irn_mode(highest_node) == mode_T;
 339
 340                         int n_desc;
 341
 342                         DBG((dbg, LEVEL_2, "\tlowest descendant %+F height %d\n", lowest_desc, get_irn_height(env->heights, lowest_desc)));
 343
 344                         /* count the number of all descendants which are not the lowest descendant */
 345                         for(n_desc = 0; in[n_desc]; ++n_desc);
 346
 347                         /*
 348                         we insert a CopyKeep node to express the artificial dependencies from the lowest
 349                         descendant to all other descendants.
 350                         */
 351                         if(n_desc > 1 && !be_is_Keep(lowest_desc)) {
 352                                 ir_node *op;
 353                                 int i, n;
 354
 355                                 for(i = 0, n = get_irn_ins_or_deps(lowest_desc); i < n; ++i) {
 356                                         ir_node *cmp;
 357
 358                                         op  = get_irn_in_or_dep(lowest_desc, i);
 359                                         cmp = highest_is_tuple ? skip_Projs(op) : op;
 360
 361                                         // if(cmp == highest_node)
 362                                         if(op == highest_node)
 363                                                 break;
 364                                 }
 365
 366                                 assert(i < n && "could not find operand");
 367
 368                                 //replace_tuple_by_repr_proj(env, &in[1]);
 369                                 if(!is_Proj(lowest_desc))
 370                                         add_irn_dep(lowest_desc, in[1]);
 371                         }
 372                         obstack_free(&env->obst, in);
 373
 374                         /* if the current lowest node is not yet in a lineage, add it to the current one. */
 375                         if(!lowest_mi->lineage_start) {
 376                                 /* mark the current lowest node as the last one in the lineage. */
 377                                 highest_mi->lineage_next = lowest_desc;
 378                                 start_mi->lineage_end    = lowest_desc;
 379
 380                                 lowest_mi->lineage_start = start;
 381                                 ir_nodeset_remove(&nodes, lowest_desc);
 382                         }
 383
 384                         /* else we cannot extend this lineage, so break. */
 385                         else
 386                                 break;
 387
 388                         highest_node = lowest_desc;
 389                         highest_mi   = lowest_mi;
 390
 391                         /* recompute the descendants array and the new lowest descendant. */
 392                         in          = all_descendants(env, highest_node);
 393                         lowest_desc = put_lowest_in_front(env, in);
 394                 }
 395
 396                 /* recompute the heights if desired. */
 397                 if(recompute_height)
 398                         heights_recompute(env->heights);
 399         }
 400
 401         ir_nodeset_destroy(&nodes);
 402 }
 403
 404 static int fuse_two_lineages(mris_env_t *env, mris_irn_t *u, mris_irn_t *v)
 405 {
 406         mris_irn_t *mi;
 407         ir_node *irn, *last;
 408         ir_node *u_end   = u->lineage_end;
 409         ir_node *v_start = v->lineage_start;
 410         ir_node *start   = skip_Projs(v_start);
 411
 412         if(be_is_Keep(start))
 413                 return 0;
 414
 415         /* set lineage end of nodes in u to end of v. */
 416         irn = last = u->lineage_start;
 417         mi         = get_mris_irn(env, irn);
 418         while(irn && irn != u_end) {
 419                 mi = get_mris_irn(env, irn);
 420                 mi->lineage_end = v->lineage_end;
 421                 last = irn;
 422                 irn = mi->lineage_next;
 423         }
 424
 425         /* insert a CopyKeep to make lineage v dependent on u. */
 426         if(get_irn_ins_or_deps(start) == 0)
 427                 return 0;
 428
 429         if(get_irn_mode(last) == mode_T) {
 430                 const ir_edge_t *edge;
 431                 foreach_out_edge(last, edge) {
 432                         last = get_edge_src_irn(edge);
 433                         break;
 434                 }
 435         }
 436
 437         /* irn now points to the last node in lineage u; mi has the info for the node _before_ the terminator of the lineage. */
 438         mi->lineage_next       = v_start;
 439
 440         /* add a dependency from the first node in v's lineage to the last in u's */
 441         add_irn_dep(u_end, v_start);
 442
 443         /* set lineage start of nodes in v to start of u. */
 444         irn = v->lineage_start;
 445         while(irn && irn != v->lineage_end) {
 446                 mris_irn_t *mi = get_mris_irn(env, irn);
 447                 mi->lineage_start = u->lineage_start;
 448                 irn = mi->lineage_next;
 449         }
 450
 451         heights_recompute(env->heights);
 452
 453         mi = get_mris_irn(env, v_start);
 454         list_del(&mi->lineage_list);
 455
 456         return 1;
 457 }
 458
 459 static void fuse_lineages(mris_env_t *env)
 460 {
 461         mris_irn_t *u, *v, *tmp1, *tmp2;
 462
 463 again:
 464         foreach_lineage(env, u, tmp1) {
 465                 foreach_lineage(env, v, tmp2) {
 466                         if(u != v && u->lineage_start && v->lineage_start && u->lineage_end && v->lineage_end
 467                                 && get_nodes_block(u->lineage_start) == get_nodes_block(v->lineage_start)) {
 468                                 int uv = heights_reachable_in_block(env->heights, u->lineage_start, v->lineage_end);
 469                                 int vu = heights_reachable_in_block(env->heights, v->lineage_start, u->lineage_end);
 470
 471                                 if(uv && !vu) {
 472                                         if(fuse_two_lineages(env, u, v))
 473                                                 goto again;
 474                                 }
 475                         }
 476                 }
 477         }
 478 }
 479
 480 static mris_env_t *dump_env = NULL;
 481
 482 static void block_walker(ir_node *bl, void *data)
 483 {
 484         mris_env_t *env = data;
 485         env->bl = bl;
 486         lineage_formation(env);
 487         fuse_lineages(env);
 488 }
 489
 490 static int mris_edge_hook(FILE *F, ir_node *irn)
 491 {
 492         mris_irn_t *mi = get_mris_irn(dump_env, irn);
 493
 494         if(mi->lineage_next) {
 495                 fprintf(F, "edge:{sourcename:\"");
 496                 PRINT_NODEID(mi->lineage_next);
 497                 fprintf(F, "\" targetname:\"");
 498                 PRINT_NODEID(irn);
 499                 fprintf(F, "\" color:lilac}\n");
 500         }
 501         return 1;
 502 }
 503
 504 void dump_ir_block_graph_mris(mris_env_t *env, const char *suffix) {
 505         DUMP_NODE_EDGE_FUNC old = get_dump_node_edge_hook();
 506
 507         dump_consts_local(0);
 508         set_dump_node_edge_hook(mris_edge_hook);
 509         dump_env = env;
 510         dump_ir_block_graph(env->irg, suffix);
 511         set_dump_node_edge_hook(old);
 512 }
 513
 514 mris_env_t *be_sched_mris_preprocess(const be_irg_t *birg)
 515 {
 516         mris_env_t *env = xmalloc(sizeof(env[0]));
 517         ir_graph   *irg = be_get_birg_irg(birg);
 518
 519         phase_init(&env->ph, "mris", irg, 2 * PHASE_DEFAULT_GROWTH, mris_irn_data_init, NULL);
 520         env->aenv     = be_get_birg_arch_env(birg);
 521         env->irg      = irg;
 522         env->visited  = 0;
 523         env->heights  = heights_new(irg);
 524         INIT_LIST_HEAD(&env->lineage_head);
 525         FIRM_DBG_REGISTER(env->dbg, "firm.be.sched.mris");
 526         obstack_init(&env->obst);
 527         irg_walk_graph(irg, firm_clear_link, NULL, NULL);
 528         irg_block_walk_graph(irg, block_walker, NULL, env);
 529         obstack_free(&env->obst, NULL);
 530         // dump_ir_block_graph_mris(env, "-mris");
 531         return env;
 532 }
 533
 534 void be_sched_mris_free(mris_env_t *env)
 535 {
 536         phase_free(&env->ph);
 537         heights_free(env->heights);
 538         free(env);
 539 }