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 "irnodeset.h"
  49 #include "height.h"
  50
  51 #include "benode.h"
  52 #include "besched.h"
  53 #include "beschedmris.h"
  54 #include "beirg.h"
  55
  56 struct _mris_env_t {
  57         ir_phase          ph;
  58         heights_t         *heights;
  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 #define valid_node(env, dep) (to_appear(env, dep) && !be_is_Keep(dep))
  90
  91 static void grow_all_descendands(mris_env_t *env, ir_node *irn, bitset_t *visited)
  92 {
  93         const ir_edge_t *edge;
  94
  95         // assert(get_irn_mode(irn) != mode_T);
  96
  97         foreach_out_edge(irn, edge) {
  98                 ir_node *desc = get_edge_src_irn(edge);
  99                 if(valid_node(env, desc) && !bitset_contains_irn(visited, desc)) {
 100                         obstack_ptr_grow(&env->obst, desc);
 101                         bitset_add_irn(visited, desc);
 102                 }
 103         }
 104
 105         foreach_out_edge_kind(irn, edge, EDGE_KIND_DEP) {
 106                 ir_node *desc = get_edge_src_irn(edge);
 107                 if(valid_node(env, desc) && !bitset_contains_irn(visited, desc)) {
 108                         obstack_ptr_grow(&env->obst, desc);
 109                         bitset_add_irn(visited, desc);
 110                 }
 111         }
 112 }
 113
 114 static ir_node **all_descendants(mris_env_t *env, ir_node *irn)
 115 {
 116         bitset_t *visited = bitset_irg_malloc(env->irg);
 117
 118         grow_all_descendands(env, irn, visited);
 119
 120 #if 0
 121         if(get_irn_mode(irn) == mode_T) {
 122                 const ir_edge_t *edge;
 123                 foreach_out_edge(irn, edge) {
 124                         ir_node *desc = get_edge_src_irn(edge);
 125                         assert(is_Proj(desc) && get_irn_mode(desc) != mode_T);
 126                         grow_all_descendands(env, desc, visited);
 127                 }
 128         }
 129
 130         else
 131                 grow_all_descendands(env, irn, visited);
 132 #endif
 133         bitset_free(visited);
 134         obstack_ptr_grow(&env->obst, NULL);
 135         return obstack_finish(&env->obst);
 136 }
 137
 138 static ir_node *put_lowest_in_front(mris_env_t *env, ir_node **in)
 139 {
 140         int lowest_index       = 0;
 141         unsigned lowest_height = INT_MAX;
 142         int i;
 143
 144         for(i = 0; in[i]; ++i) {
 145                 unsigned height = get_irn_height(env->heights, in[i]);
 146                 if(height < lowest_height) {
 147                         lowest_height = height;
 148                         lowest_index  = i;
 149                 }
 150         }
 151
 152         if(i > 0) {
 153                 ir_node *tmp     = in[0];
 154                 in[0]            = in[lowest_index];
 155                 in[lowest_index] = tmp;
 156         }
 157
 158         return in[0];
 159 }
 160
 161 static inline ir_node *skip_Projs(ir_node *irn)
 162 {
 163         return is_Proj(irn) ? skip_Projs(get_Proj_pred(irn)) : irn;
 164 }
 165
 166 static void lineage_formation(mris_env_t *env)
 167 {
 168         DEBUG_ONLY(firm_dbg_module_t *dbg = env->dbg);
 169         ir_nodeset_t                  nodes;
 170         const ir_edge_t              *edge;
 171
 172         ir_nodeset_init(&nodes);
 173
 174         foreach_out_edge(env->bl, edge) {
 175                 ir_node *irn = get_edge_src_irn(edge);
 176                 if(to_appear(env, irn))
 177                         ir_nodeset_insert(&nodes, irn);
 178         }
 179
 180         while(ir_nodeset_size(&nodes) > 0) {
 181                 mris_irn_t *mi;
 182                 ir_node    *irn;
 183                 ir_node    *highest_node = NULL;
 184                 ir_node    *lowest_desc  = NULL;
 185                 ir_node    *start;
 186                 mris_irn_t *start_mi;
 187                 ir_nodeset_iterator_t iter;
 188
 189                 ir_node **in;
 190                 int recompute_height  = 0;
 191                 unsigned  curr_height = 0;
 192
 193                 /* search the highest node which is not yet in a lineage. */
 194                 foreach_ir_nodeset(&nodes, irn, iter) {
 195                         unsigned height = get_irn_height(env->heights, irn);
 196                         if(height > curr_height) {
 197                                 highest_node = irn;
 198                                 curr_height  = height;
 199                         }
 200                 }
 201
 202                 assert(highest_node);
 203                 DBG((dbg, LEVEL_2, "highest node is %+F height %d\n", highest_node, get_irn_height(env->heights, highest_node)));
 204
 205                 start = highest_node;
 206                 mi = start_mi = get_mris_irn(env, highest_node);
 207
 208                 /* start a lineage beginning with highest_node. */
 209                 mi->lineage_start = highest_node;
 210                 mi->lineage_next  = NULL;
 211                 mi->lineage_end   = NULL;
 212                 list_add(&mi->lineage_list, &env->lineage_head);
 213                 ir_nodeset_remove(&nodes, highest_node);
 214
 215                 /*
 216                         put all descendants in an array.
 217                         we also move the lowest descendant in front, so that the other nodes
 218                         are easily accessible as an array, too.
 219                 */
 220                 in          = all_descendants(env, highest_node);
 221                 lowest_desc = put_lowest_in_front(env, in);
 222
 223                 /* as long as the current highest node has still descendants */
 224                 while(lowest_desc) {
 225                         mris_irn_t *lowest_mi  = get_mris_irn(env, lowest_desc);
 226                         mris_irn_t *highest_mi = get_mris_irn(env, highest_node);
 227                         int highest_is_tuple   = get_irn_mode(highest_node) == mode_T;
 228
 229                         int n_desc;
 230
 231                         DBG((dbg, LEVEL_2, "\tlowest descendant %+F height %d\n", lowest_desc, get_irn_height(env->heights, lowest_desc)));
 232
 233                         /* count the number of all descendants which are not the lowest descendant */
 234                         for(n_desc = 0; in[n_desc]; ++n_desc);
 235
 236                         /*
 237                         we insert a CopyKeep node to express the artificial dependencies from the lowest
 238                         descendant to all other descendants.
 239                         */
 240                         if(n_desc > 1 && !be_is_Keep(lowest_desc)) {
 241                                 ir_node *op;
 242                                 int i, n;
 243
 244                                 for(i = 0, n = get_irn_ins_or_deps(lowest_desc); i < n; ++i) {
 245                                         ir_node *cmp;
 246
 247                                         op  = get_irn_in_or_dep(lowest_desc, i);
 248                                         cmp = highest_is_tuple ? skip_Projs(op) : op;
 249
 250                                         // if(cmp == highest_node)
 251                                         if(op == highest_node)
 252                                                 break;
 253                                 }
 254
 255                                 assert(i < n && "could not find operand");
 256
 257                                 //replace_tuple_by_repr_proj(env, &in[1]);
 258                                 if(!is_Proj(lowest_desc))
 259                                         add_irn_dep(lowest_desc, in[1]);
 260                         }
 261                         obstack_free(&env->obst, in);
 262
 263                         /* if the current lowest node is not yet in a lineage, add it to the current one. */
 264                         if(!lowest_mi->lineage_start) {
 265                                 /* mark the current lowest node as the last one in the lineage. */
 266                                 highest_mi->lineage_next = lowest_desc;
 267                                 start_mi->lineage_end    = lowest_desc;
 268
 269                                 lowest_mi->lineage_start = start;
 270                                 ir_nodeset_remove(&nodes, lowest_desc);
 271                         }
 272
 273                         /* else we cannot extend this lineage, so break. */
 274                         else
 275                                 break;
 276
 277                         highest_node = lowest_desc;
 278                         highest_mi   = lowest_mi;
 279
 280                         /* recompute the descendants array and the new lowest descendant. */
 281                         in          = all_descendants(env, highest_node);
 282                         lowest_desc = put_lowest_in_front(env, in);
 283                 }
 284
 285                 /* recompute the heights if desired. */
 286                 if(recompute_height)
 287                         heights_recompute(env->heights);
 288         }
 289
 290         ir_nodeset_destroy(&nodes);
 291 }
 292
 293 static int fuse_two_lineages(mris_env_t *env, mris_irn_t *u, mris_irn_t *v)
 294 {
 295         mris_irn_t *mi;
 296         ir_node *irn, *last;
 297         ir_node *u_end   = u->lineage_end;
 298         ir_node *v_start = v->lineage_start;
 299         ir_node *start   = skip_Projs(v_start);
 300
 301         if(be_is_Keep(start))
 302                 return 0;
 303
 304         /* set lineage end of nodes in u to end of v. */
 305         irn = last = u->lineage_start;
 306         mi         = get_mris_irn(env, irn);
 307         while(irn && irn != u_end) {
 308                 mi = get_mris_irn(env, irn);
 309                 mi->lineage_end = v->lineage_end;
 310                 last = irn;
 311                 irn = mi->lineage_next;
 312         }
 313
 314         /* insert a CopyKeep to make lineage v dependent on u. */
 315         if(get_irn_ins_or_deps(start) == 0)
 316                 return 0;
 317
 318         if(get_irn_mode(last) == mode_T) {
 319                 const ir_edge_t *edge;
 320                 foreach_out_edge(last, edge) {
 321                         last = get_edge_src_irn(edge);
 322                         break;
 323                 }
 324         }
 325
 326         /* irn now points to the last node in lineage u; mi has the info for the node _before_ the terminator of the lineage. */
 327         mi->lineage_next       = v_start;
 328
 329         /* add a dependency from the first node in v's lineage to the last in u's */
 330         add_irn_dep(u_end, v_start);
 331
 332         /* set lineage start of nodes in v to start of u. */
 333         irn = v->lineage_start;
 334         while(irn && irn != v->lineage_end) {
 335                 mris_irn_t *mi = get_mris_irn(env, irn);
 336                 mi->lineage_start = u->lineage_start;
 337                 irn = mi->lineage_next;
 338         }
 339
 340         heights_recompute(env->heights);
 341
 342         mi = get_mris_irn(env, v_start);
 343         list_del(&mi->lineage_list);
 344
 345         return 1;
 346 }
 347
 348 static void fuse_lineages(mris_env_t *env)
 349 {
 350         mris_irn_t *u, *v, *tmp1, *tmp2;
 351
 352 again:
 353         foreach_lineage(env, u, tmp1) {
 354                 foreach_lineage(env, v, tmp2) {
 355                         if(u != v && u->lineage_start && v->lineage_start && u->lineage_end && v->lineage_end
 356                                 && get_nodes_block(u->lineage_start) == get_nodes_block(v->lineage_start)) {
 357                                 int uv = heights_reachable_in_block(env->heights, u->lineage_start, v->lineage_end);
 358                                 int vu = heights_reachable_in_block(env->heights, v->lineage_start, u->lineage_end);
 359
 360                                 if(uv && !vu) {
 361                                         if(fuse_two_lineages(env, u, v))
 362                                                 goto again;
 363                                 }
 364                         }
 365                 }
 366         }
 367 }
 368
 369 static mris_env_t *dump_env = NULL;
 370
 371 static void block_walker(ir_node *bl, void *data)
 372 {
 373         mris_env_t *env = data;
 374         env->bl = bl;
 375         lineage_formation(env);
 376         fuse_lineages(env);
 377 }
 378
 379 static int mris_edge_hook(FILE *F, ir_node *irn)
 380 {
 381         mris_irn_t *mi = get_mris_irn(dump_env, irn);
 382
 383         if(mi->lineage_next) {
 384                 fprintf(F, "edge:{sourcename:\"");
 385                 PRINT_NODEID(mi->lineage_next);
 386                 fprintf(F, "\" targetname:\"");
 387                 PRINT_NODEID(irn);
 388                 fprintf(F, "\" color:lilac}\n");
 389         }
 390         return 1;
 391 }
 392
 393 void dump_ir_block_graph_mris(mris_env_t *env, const char *suffix) {
 394         DUMP_NODE_EDGE_FUNC old = get_dump_node_edge_hook();
 395
 396         dump_consts_local(0);
 397         set_dump_node_edge_hook(mris_edge_hook);
 398         dump_env = env;
 399         dump_ir_block_graph(env->irg, suffix);
 400         set_dump_node_edge_hook(old);
 401 }
 402
 403 mris_env_t *be_sched_mris_preprocess(const be_irg_t *birg)
 404 {
 405         mris_env_t *env = XMALLOC(mris_env_t);
 406         ir_graph   *irg = be_get_birg_irg(birg);
 407
 408         phase_init(&env->ph, "mris", irg, 2 * PHASE_DEFAULT_GROWTH, mris_irn_data_init, NULL);
 409         env->irg      = irg;
 410         env->visited  = 0;
 411         env->heights  = heights_new(irg);
 412         INIT_LIST_HEAD(&env->lineage_head);
 413         FIRM_DBG_REGISTER(env->dbg, "firm.be.sched.mris");
 414         obstack_init(&env->obst);
 415         irg_walk_graph(irg, firm_clear_link, NULL, NULL);
 416         irg_block_walk_graph(irg, block_walker, NULL, env);
 417         obstack_free(&env->obst, NULL);
 418         // dump_ir_block_graph_mris(env, "-mris");
 419         return env;
 420 }
 421
 422 void be_sched_mris_free(mris_env_t *env)
 423 {
 424         phase_free(&env->ph);
 425         heights_free(env->heights);
 426         free(env);
 427 }