nsz Git - libfirm/blob - ir/be/beschedmris.c

   1 /*
   2  * Copyright (C) 1995-2007 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  * Implements a list scheduler for the MRIS algorithm in:
  22  * Govindarajan, Yang, Amaral, Zhang, Gao
  23  * Minimum Register Instruction Sequencing to Reduce Register Spills
  24  * in out-of-order issue superscalar architectures
  25  * @author Sebastian Hack
  26  * @date   04.04.2006
  27  */
  28 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31
  32 #include <limits.h>
  33
  34 #include "obst.h"
  35 #include "debug.h"
  36
  37 #include "irgraph_t.h"
  38 #include "irnode_t.h"
  39 #include "iredges_t.h"
  40 #include "ircons_t.h"
  41 #include "irphase_t.h"
  42 #include "irdump_t.h"
  43 #include "irgwalk.h"
  44 #include "irtools.h"
  45 #include "irbitset.h"
  46
  47 #include "height.h"
  48
  49 #include "benode_t.h"
  50 #include "besched_t.h"
  51 #include "beschedmris.h"
  52 #include "benodesets.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, ir_node *irn, void *data)
  81 {
  82         mris_irn_t *mi = data ? data : phase_alloc(ph, sizeof(mi[0]));
  83         memset(mi, 0, sizeof(mi[0]));
  84         INIT_LIST_HEAD(&mi->lineage_list);
  85         return mi;
  86 }
  87
  88 #if 0
  89 static int compute_height(mris_env_t *env, ir_node *irn, unsigned long visited)
  90 {
  91         mris_irn_t *mi = get_mris_irn(env, irn);
  92
  93         if(get_irn_visited(irn) >= visited) {
  94                 DBG((env->dbg, LEVEL_3, "\theight of %+F = %d\n", irn, mi->height));
  95                 return mi->height;
  96         }
  97
  98         else {
  99                 const ir_edge_t *edge;
 100
 101                 set_irn_visited(irn, visited);
 102                 mi->height  = 0;
 103
 104                 foreach_out_edge(irn, edge) {
 105                         ir_node *dep = get_edge_src_irn(edge);
 106
 107                         if(!is_Block(dep) && get_nodes_block(dep) == env->bl) {
 108                                 int dep_height = compute_height(env, dep, visited);
 109                                 mi->height     = MAX(mi->height, dep_height);
 110                         }
 111                 }
 112
 113                 mi->height++;
 114                 DBG((env->dbg, LEVEL_3, "\tsetting height of %+F = %d\n", irn, mi->height));
 115         }
 116
 117         return mi->height;
 118 }
 119
 120 static void compute_heights(mris_env_t *env)
 121 {
 122         const ir_edge_t *edge;
 123         unsigned long visited;
 124
 125         visited = get_irg_visited(env->irg) + 1;
 126         set_irg_visited(env->irg, visited);
 127
 128         foreach_out_edge(env->bl, edge) {
 129                 ir_node *dep = get_edge_src_irn(edge);
 130                 if(to_appear(env, dep))
 131                         compute_height(env, dep, visited);
 132         }
 133 }
 134 #endif
 135
 136 #define valid_node(env, dep) (to_appear(env, dep) && !be_is_Keep(dep))
 137
 138 static void grow_all_descendands(mris_env_t *env, ir_node *irn, bitset_t *visited)
 139 {
 140         const ir_edge_t *edge;
 141
 142         // assert(get_irn_mode(irn) != mode_T);
 143
 144         foreach_out_edge(irn, edge) {
 145                 ir_node *desc = get_edge_src_irn(edge);
 146                 if(valid_node(env, desc) && !bitset_contains_irn(visited, desc)) {
 147                         obstack_ptr_grow(&env->obst, desc);
 148                         bitset_add_irn(visited, desc);
 149                 }
 150         }
 151
 152         foreach_out_edge_kind(irn, edge, EDGE_KIND_DEP) {
 153                 ir_node *desc = get_edge_src_irn(edge);
 154                 if(valid_node(env, desc) && !bitset_contains_irn(visited, desc)) {
 155                         obstack_ptr_grow(&env->obst, desc);
 156                         bitset_add_irn(visited, desc);
 157                 }
 158         }
 159 }
 160
 161 static ir_node **all_descendants(mris_env_t *env, ir_node *irn)
 162 {
 163         bitset_t *visited = bitset_irg_malloc(env->irg);
 164
 165         grow_all_descendands(env, irn, visited);
 166
 167 #if 0
 168         if(get_irn_mode(irn) == mode_T) {
 169                 const ir_edge_t *edge;
 170                 foreach_out_edge(irn, edge) {
 171                         ir_node *desc = get_edge_src_irn(edge);
 172                         assert(is_Proj(desc) && get_irn_mode(desc) != mode_T);
 173                         grow_all_descendands(env, desc, visited);
 174                 }
 175         }
 176
 177         else
 178                 grow_all_descendands(env, irn, visited);
 179 #endif
 180         bitset_free(visited);
 181         obstack_ptr_grow(&env->obst, NULL);
 182         return obstack_finish(&env->obst);
 183 }
 184
 185 static ir_node *put_lowest_in_front(mris_env_t *env, ir_node **in)
 186 {
 187         int lowest_index       = 0;
 188         unsigned lowest_height = INT_MAX;
 189         int i;
 190
 191         for(i = 0; in[i]; ++i) {
 192                 unsigned height = get_irn_height(env->heights, in[i]);
 193                 if(height < lowest_height) {
 194                         lowest_height = height;
 195                         lowest_index  = i;
 196                 }
 197         }
 198
 199         if(i > 0) {
 200                 ir_node *tmp     = in[0];
 201                 in[0]            = in[lowest_index];
 202                 in[lowest_index] = tmp;
 203         }
 204
 205         return in[0];
 206 }
 207
 208 #if 0
 209 static void reaches_walker(mris_env_t *env, ir_node *irn, ir_node *tgt, int *found, unsigned long visited)
 210 {
 211         if(get_irn_visited(irn) < visited && get_nodes_block(irn) == env->bl) {
 212
 213                 set_irn_visited(irn, visited);
 214
 215                 if(irn == tgt)
 216                         *found = 1;
 217                 else {
 218                         int i, n;
 219
 220                         for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
 221                                 ir_node *op = get_irn_n(irn, i);
 222                                 if(!*found)
 223                                         reaches_walker(env, op, tgt, found, visited);
 224                         }
 225                 }
 226         }
 227 }
 228
 229 static int reaches(mris_env_t *env, ir_node *src, ir_node *tgt)
 230 {
 231         int found = 0;
 232         unsigned long visited = get_irg_visited(env->irg) + 1;
 233
 234         set_irg_visited(env->irg, visited);
 235         reaches_walker(env, src, tgt, &found, visited);
 236         return found;
 237 }
 238 #endif
 239
 240 static INLINE ir_node *skip_Projs(ir_node *irn)
 241 {
 242         return is_Proj(irn) ? skip_Projs(get_Proj_pred(irn)) : irn;
 243 }
 244
 245 #if 0
 246 static void replace_tuple_by_repr_proj(mris_env_t *env, ir_node **in)
 247 {
 248         int i;
 249
 250         for(i = 0; in[i]; ++i) {
 251                 if(get_irn_mode(in[i]) == mode_T) {
 252                         const ir_edge_t *edge;
 253                         ir_node *proj  = NULL;
 254                         ir_node *first = NULL;
 255
 256                         foreach_out_edge(in[i], edge) {
 257                                 ir_node *desc = get_edge_src_irn(edge);
 258
 259                                 first = first ? first : desc;
 260                                 if(get_irn_mode(desc) == mode_M) {
 261                                         proj = desc;
 262                                         break;
 263                                 }
 264                         }
 265
 266                         proj = proj ? proj : first;
 267                         assert(proj);
 268                         in[i] = proj;
 269                 }
 270         }
 271 }
 272 #endif
 273
 274 static void lineage_formation(mris_env_t *env)
 275 {
 276         DEBUG_ONLY(firm_dbg_module_t *dbg = env->dbg);
 277         nodeset *nodes         = new_nodeset(128);
 278
 279         const ir_edge_t *edge;
 280
 281         foreach_out_edge(env->bl, edge) {
 282                 ir_node *irn = get_edge_src_irn(edge);
 283                 if(to_appear(env, irn))
 284                         nodeset_insert(nodes, irn);
 285         }
 286
 287         while(nodeset_count(nodes) > 0) {
 288                 mris_irn_t *mi;
 289                 ir_node *irn;
 290                 ir_node *highest_node = NULL;
 291                 ir_node *lowest_desc  = NULL;
 292                 ir_node *start;
 293                 mris_irn_t *start_mi;
 294
 295                 ir_node **in;
 296                 int recompute_height  = 0;
 297                 unsigned  curr_height = 0;
 298
 299                 /* search the highest node which is not yet in a lineage. */
 300                 for(irn = nodeset_first(nodes); irn; irn = nodeset_next(nodes)) {
 301                         unsigned height = get_irn_height(env->heights, irn);
 302                         if(height > curr_height) {
 303                                 highest_node = irn;
 304                                 curr_height  = height;
 305                         }
 306                 }
 307
 308                 assert(highest_node);
 309                 DBG((dbg, LEVEL_2, "highest node is %+F height %d\n", highest_node, get_irn_height(env->heights, highest_node)));
 310
 311                 start = highest_node;
 312                 mi = start_mi = get_mris_irn(env, highest_node);
 313
 314                 /* start a lineage beginning with highest_node. */
 315                 mi->lineage_start = highest_node;
 316                 mi->lineage_next  = NULL;
 317                 mi->lineage_end   = NULL;
 318                 list_add(&mi->lineage_list, &env->lineage_head);
 319                 nodeset_remove(nodes, highest_node);
 320
 321                 /*
 322                         put all descendants in an array.
 323                         we also move the lowest descendant in front, so that the other nodes
 324                         are easily accessible as an array, too.
 325                 */
 326                 in          = all_descendants(env, highest_node);
 327                 lowest_desc = put_lowest_in_front(env, in);
 328
 329                 /* as long as the current highest node has still descendants */
 330                 while(lowest_desc) {
 331                         mris_irn_t *lowest_mi  = get_mris_irn(env, lowest_desc);
 332                         mris_irn_t *highest_mi = get_mris_irn(env, highest_node);
 333                         int highest_is_tuple   = get_irn_mode(highest_node) == mode_T;
 334
 335                         int n_desc;
 336
 337                         DBG((dbg, LEVEL_2, "\tlowest descendant %+F height %d\n", lowest_desc, get_irn_height(env->heights, lowest_desc)));
 338
 339                         /* count the number of all descendants which are not the lowest descendant */
 340                         for(n_desc = 0; in[n_desc]; ++n_desc);
 341
 342                         /*
 343                         we insert a CopyKeep node to express the artificial dependencies from the lowest
 344                         descendant to all other descendants.
 345                         */
 346                         if(n_desc > 1 && !be_is_Keep(lowest_desc)) {
 347                                 ir_node *op;
 348                                 int i, n;
 349
 350                                 for(i = 0, n = get_irn_ins_or_deps(lowest_desc); i < n; ++i) {
 351                                         ir_node *cmp;
 352
 353                                         op  = get_irn_in_or_dep(lowest_desc, i);
 354                                         cmp = highest_is_tuple ? skip_Projs(op) : op;
 355
 356                                         // if(cmp == highest_node)
 357                                         if(op == highest_node)
 358                                                 break;
 359                                 }
 360
 361                                 assert(i < n && "could not find operand");
 362
 363                                 //replace_tuple_by_repr_proj(env, &in[1]);
 364                                 if(!is_Proj(lowest_desc))
 365                                         add_irn_dep(lowest_desc, in[1]);
 366                         }
 367                         obstack_free(&env->obst, in);
 368
 369                         /* if the current lowest node is not yet in a lineage, add it to the current one. */
 370                         if(!lowest_mi->lineage_start) {
 371                                 /* mark the current lowest node as the last one in the lineage. */
 372                                 highest_mi->lineage_next = lowest_desc;
 373                                 start_mi->lineage_end    = lowest_desc;
 374
 375                                 lowest_mi->lineage_start = start;
 376                                 nodeset_remove(nodes, lowest_desc);
 377                         }
 378
 379                         /* else we cannot extend this lineage, so break. */
 380                         else
 381                                 break;
 382
 383                         highest_node = lowest_desc;
 384                         highest_mi   = lowest_mi;
 385
 386                         /* recompute the descendants array and the new lowest descendant. */
 387                         in          = all_descendants(env, highest_node);
 388                         lowest_desc = put_lowest_in_front(env, in);
 389                 }
 390
 391                 /* recompute the heights if desired. */
 392                 if(recompute_height)
 393                         heights_recompute(env->heights);
 394         }
 395 }
 396
 397 static int fuse_two_lineages(mris_env_t *env, mris_irn_t *u, mris_irn_t *v)
 398 {
 399         mris_irn_t *mi;
 400         ir_node *irn, *last;
 401         ir_node *u_end   = u->lineage_end;
 402         ir_node *v_start = v->lineage_start;
 403         ir_node *start   = skip_Projs(v_start);
 404
 405         if(be_is_Keep(start))
 406                 return 0;
 407
 408         /* set lineage end of nodes in u to end of v. */
 409         irn = last = u->lineage_start;
 410         mi         = get_mris_irn(env, irn);
 411         while(irn && irn != u_end) {
 412                 mi = get_mris_irn(env, irn);
 413                 mi->lineage_end = v->lineage_end;
 414                 last = irn;
 415                 irn = mi->lineage_next;
 416         }
 417
 418         /* insert a CopyKeep to make lineage v dependent on u. */
 419         if(get_irn_ins_or_deps(start) == 0)
 420                 return 0;
 421
 422         if(get_irn_mode(last) == mode_T) {
 423                 const ir_edge_t *edge;
 424                 foreach_out_edge(last, edge) {
 425                         last = get_edge_src_irn(edge);
 426                         break;
 427                 }
 428         }
 429
 430         /* irn now points to the last node in lineage u; mi has the info for the node _before_ the terminator of the lineage. */
 431         mi->lineage_next       = v_start;
 432
 433         /* add a dependency from the first node in v's lineage to the last in u's */
 434         add_irn_dep(u_end, v_start);
 435
 436         /* set lineage start of nodes in v to start of u. */
 437         irn = v->lineage_start;
 438         while(irn && irn != v->lineage_end) {
 439                 mris_irn_t *mi = get_mris_irn(env, irn);
 440                 mi->lineage_start = u->lineage_start;
 441                 irn = mi->lineage_next;
 442         }
 443
 444         heights_recompute(env->heights);
 445
 446         mi = get_mris_irn(env, v_start);
 447         list_del(&mi->lineage_list);
 448
 449         return 1;
 450 }
 451
 452 static void fuse_lineages(mris_env_t *env)
 453 {
 454         mris_irn_t *u, *v, *tmp1, *tmp2;
 455
 456 again:
 457         foreach_lineage(env, u, tmp1) {
 458                 foreach_lineage(env, v, tmp2) {
 459                         if(u != v && u->lineage_start && v->lineage_start && u->lineage_end && v->lineage_end
 460                                 && get_nodes_block(u->lineage_start) == get_nodes_block(v->lineage_start)) {
 461                                 int uv = heights_reachable_in_block(env->heights, u->lineage_start, v->lineage_end);
 462                                 int vu = heights_reachable_in_block(env->heights, v->lineage_start, u->lineage_end);
 463
 464                                 if(uv && !vu) {
 465                                         if(fuse_two_lineages(env, u, v))
 466                                                 goto again;
 467                                 }
 468                         }
 469                 }
 470         }
 471 }
 472
 473 static mris_env_t *dump_env = NULL;
 474
 475 static void block_walker(ir_node *bl, void *data)
 476 {
 477         mris_env_t *env = data;
 478         env->bl = bl;
 479         lineage_formation(env);
 480         fuse_lineages(env);
 481 }
 482
 483 static int mris_edge_hook(FILE *F, ir_node *irn)
 484 {
 485         mris_irn_t *mi = get_mris_irn(dump_env, irn);
 486
 487         if(mi->lineage_next) {
 488                 fprintf(F, "edge:{sourcename:\"");
 489                 PRINT_NODEID(mi->lineage_next);
 490                 fprintf(F, "\" targetname:\"");
 491                 PRINT_NODEID(irn);
 492                 fprintf(F, "\" color:lilac}\n");
 493         }
 494         return 1;
 495 }
 496
 497 void dump_ir_block_graph_mris(mris_env_t *env, const char *suffix) {
 498         DUMP_NODE_EDGE_FUNC old = get_dump_node_edge_hook();
 499
 500         dump_consts_local(0);
 501         set_dump_node_edge_hook(mris_edge_hook);
 502         dump_env = env;
 503         dump_ir_block_graph(env->irg, suffix);
 504         set_dump_node_edge_hook(old);
 505 }
 506
 507 mris_env_t *be_sched_mris_preprocess(const be_irg_t *birg)
 508 {
 509         mris_env_t *env = xmalloc(sizeof(env[0]));
 510         ir_graph   *irg = be_get_birg_irg(birg);
 511
 512         phase_init(&env->ph, "mris", irg, 2 * PHASE_DEFAULT_GROWTH, mris_irn_data_init, NULL);
 513         env->aenv     = be_get_birg_arch_env(birg);
 514         env->irg      = irg;
 515         env->visited  = 0;
 516         env->heights  = heights_new(irg);
 517         INIT_LIST_HEAD(&env->lineage_head);
 518         FIRM_DBG_REGISTER(env->dbg, "firm.be.sched.mris");
 519         obstack_init(&env->obst);
 520         irg_walk_graph(irg, firm_clear_link, NULL, NULL);
 521         irg_block_walk_graph(irg, block_walker, NULL, env);
 522         obstack_free(&env->obst, NULL);
 523         // dump_ir_block_graph_mris(env, "-mris");
 524         return env;
 525 }
 526
 527 void be_sched_mris_free(mris_env_t *env)
 528 {
 529         phase_free(&env->ph);
 530         heights_free(env->heights);
 531         free(env);
 532 }