nsz Git - libfirm/blob - ir/be/beschednormal.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  * @brief   Use the strong normal form theorem (though it does not hold)
  22  * @author  Christoph Mallon
  23  * @version $Id$
  24  */
  25 #include "config.h"
  26
  27 #include <stdlib.h>
  28
  29 #include "besched.h"
  30 #include "belistsched.h"
  31 #include "belive_t.h"
  32 #include "beutil.h"
  33 #include "heights.h"
  34 #include "irtools.h"
  35 #include "irgwalk.h"
  36 #include "benode.h"
  37 #include "bemodule.h"
  38 #include "array_t.h"
  39
  40 // XXX there is no one time init for schedulers
  41 //#define NORMAL_DBG
  42 #include "irprintf.h"
  43
  44 /** An instance of the normal scheduler. */
  45 typedef struct instance_t {
  46         ir_graph*      irg;          /**< the IR graph of this instance */
  47         struct obstack obst;         /**< obstack for temporary data */
  48         ir_node*       curr_list;    /**< current block schedule list */
  49 } instance_t;
  50
  51 static int must_be_scheduled(const ir_node* const irn)
  52 {
  53         return !is_Proj(irn) && !is_Sync(irn);
  54 }
  55
  56
  57 static ir_node *normal_select(void *block_env, ir_nodeset_t *ready_set)
  58 {
  59         instance_t* inst = (instance_t*)block_env;
  60         ir_node*    irn;
  61         ir_node*    next;
  62         ir_node*    last = NULL;
  63         ir_nodeset_iterator_t iter;
  64
  65         for (irn = inst->curr_list; irn != NULL; last = irn, irn = next) {
  66                 next = (ir_node*)get_irn_link(irn);
  67                 if (ir_nodeset_contains(ready_set, irn)) {
  68 #if defined NORMAL_DBG
  69                         ir_fprintf(stderr, "scheduling %+F\n", irn);
  70 #endif
  71                         if (last == NULL)
  72                                 inst->curr_list = next;
  73                         else
  74                                 set_irn_link(last, next);
  75                         return irn;
  76                 }
  77         }
  78
  79         ir_nodeset_iterator_init(&iter, ready_set);
  80         irn = ir_nodeset_iterator_next(&iter);
  81         return irn;
  82 }
  83
  84
  85 typedef struct irn_cost_pair {
  86         ir_node* irn;
  87         int      cost;
  88 } irn_cost_pair;
  89
  90 static int cost_cmp(const void* a, const void* b)
  91 {
  92         const irn_cost_pair* const a1 = (const irn_cost_pair*)a;
  93         const irn_cost_pair* const b1 = (const irn_cost_pair*)b;
  94         int ret = b1->cost - a1->cost;
  95         if (ret == 0)
  96                 ret = (int)get_irn_idx(a1->irn) - (int)get_irn_idx(b1->irn);
  97 #if defined NORMAL_DBG
  98         ir_fprintf(stderr, "cost %+F %s %+F\n", a1->irn, ret < 0 ? "<" : ret > 0 ? ">" : "=", b1->irn);
  99 #endif
 100         return ret;
 101 }
 102
 103
 104 typedef struct flag_and_cost {
 105         int no_root;
 106         irn_cost_pair costs[];
 107 } flag_and_cost;
 108
 109 #define get_irn_fc(irn)     ((flag_and_cost*)get_irn_link(irn))
 110 #define set_irn_fc(irn, fc) set_irn_link(irn, fc)
 111
 112
 113 static int count_result(const ir_node* irn)
 114 {
 115         const ir_mode* mode = get_irn_mode(irn);
 116
 117         if (mode == mode_M || mode == mode_X)
 118                 return 0;
 119
 120         if (mode == mode_T)
 121                 return 1;
 122
 123         if (arch_get_register_req_out(irn)->type & arch_register_req_type_ignore)
 124                 return 0;
 125
 126         return 1;
 127 }
 128
 129
 130 /* TODO high cost for store trees
 131  */
 132
 133 static int normal_tree_cost(ir_node* irn, instance_t *inst)
 134 {
 135         flag_and_cost* fc;
 136         int            arity;
 137         ir_node*       last;
 138         int            n_res;
 139         int            cost;
 140         int            n_op_res = 0;
 141         int            i;
 142
 143         if (be_is_Keep(irn))
 144                 return 0;
 145
 146         if (is_Proj(irn)) {
 147                 return normal_tree_cost(get_Proj_pred(irn), inst);
 148         }
 149
 150         arity = get_irn_arity(irn);
 151         fc    = get_irn_fc(irn);
 152
 153         if (fc == NULL) {
 154                 irn_cost_pair* costs;
 155                 ir_node*       block = get_nodes_block(irn);
 156
 157                 fc = OALLOCF(&inst->obst, flag_and_cost, costs, arity);
 158                 fc->no_root = 0;
 159                 costs = fc->costs;
 160
 161                 for (i = 0; i < arity; ++i) {
 162                         ir_node* pred = get_irn_n(irn, i);
 163
 164                         if (is_Phi(irn) || get_irn_mode(pred) == mode_M || is_Block(pred)) {
 165                                 cost = 0;
 166                         } else if (get_nodes_block(pred) != block) {
 167                                 cost = 1;
 168                         } else {
 169                                 flag_and_cost* pred_fc;
 170                                 ir_node*       real_pred;
 171
 172                                 cost = normal_tree_cost(pred, inst);
 173                                 if (!arch_irn_is_ignore(pred)) {
 174                                         real_pred = (is_Proj(pred) ? get_Proj_pred(pred) : pred);
 175                                         pred_fc = get_irn_fc(real_pred);
 176                                         pred_fc->no_root = 1;
 177 #if defined NORMAL_DBG
 178                                         ir_fprintf(stderr, "%+F says that %+F is no root\n", irn, real_pred);
 179 #endif
 180                                 }
 181                         }
 182
 183                         costs[i].irn  = pred;
 184                         costs[i].cost = cost;
 185                 }
 186
 187                 qsort(costs, arity, sizeof(*costs), cost_cmp);
 188                 set_irn_link(irn, fc);
 189         }
 190
 191         cost = 0;
 192         last = 0;
 193         for (i = 0; i < arity; ++i) {
 194                 ir_node* op = fc->costs[i].irn;
 195                 ir_mode* mode;
 196                 if (op == last)
 197                         continue;
 198                 mode = get_irn_mode(op);
 199                 if (mode == mode_M)
 200                         continue;
 201                 if (mode != mode_T && arch_irn_is_ignore(op))
 202                         continue;
 203                 cost = MAX(fc->costs[i].cost + n_op_res, cost);
 204                 last = op;
 205                 ++n_op_res;
 206         }
 207         n_res = count_result(irn);
 208         cost = MAX(n_res, cost);
 209
 210 #if defined NORMAL_DBG
 211         ir_fprintf(stderr, "reguse of %+F is %d\n", irn, cost);
 212 #endif
 213
 214         return cost;
 215 }
 216
 217
 218 static void normal_cost_walker(ir_node* irn, void* env)
 219 {
 220         instance_t *inst = (instance_t*)env;
 221
 222 #if defined NORMAL_DBG
 223         ir_fprintf(stderr, "cost walking node %+F\n", irn);
 224 #endif
 225         if (is_Block(irn)) return;
 226         if (!must_be_scheduled(irn)) return;
 227         normal_tree_cost(irn, inst);
 228 }
 229
 230
 231 static void collect_roots(ir_node* irn, void* env)
 232 {
 233         int is_root;
 234
 235         (void)env;
 236
 237         if (is_Block(irn)) return;
 238         if (!must_be_scheduled(irn)) return;
 239
 240         is_root = be_is_Keep(irn) || !get_irn_fc(irn)->no_root;
 241
 242 #if defined NORMAL_DBG
 243         ir_fprintf(stderr, "%+F is %sroot\n", irn, is_root ? "" : "no ");
 244 #endif
 245
 246         if (is_root) {
 247                 ir_node* block = get_nodes_block(irn);
 248                 ir_node** roots = (ir_node**)get_irn_link(block);
 249                 if (roots == NULL) {
 250                         roots = NEW_ARR_F(ir_node*, 0);
 251                 }
 252                 ARR_APP1(ir_node*, roots, irn);
 253                 set_irn_link(block, roots);
 254         }
 255 }
 256
 257
 258 static ir_node** sched_node(ir_node** sched, ir_node* irn)
 259 {
 260         if (irn_visited_else_mark(irn)) return sched;
 261         if (is_End(irn))                return sched;
 262
 263         if (!is_Phi(irn) && !be_is_Keep(irn)) {
 264                 ir_node*       block = get_nodes_block(irn);
 265                 int            arity = get_irn_arity(irn);
 266                 flag_and_cost* fc    = get_irn_fc(irn);
 267                 irn_cost_pair* irns  = fc->costs;
 268                 int            i;
 269
 270                 for (i = 0; i < arity; ++i) {
 271                         ir_node* pred = irns[i].irn;
 272                         if (get_nodes_block(pred) != block) continue;
 273                         if (get_irn_mode(pred) == mode_M) continue;
 274                         if (is_Proj(pred)) pred = get_Proj_pred(pred);
 275                         sched = sched_node(sched, pred);
 276                 }
 277         }
 278
 279         ARR_APP1(ir_node*, sched, irn);
 280         return sched;
 281 }
 282
 283
 284 static int root_cmp(const void* a, const void* b)
 285 {
 286         const irn_cost_pair* const a1 = (const irn_cost_pair*)a;
 287         const irn_cost_pair* const b1 = (const irn_cost_pair*)b;
 288         int ret;
 289         if (is_irn_forking(a1->irn)) {
 290                 ret = 1;
 291         } else if (is_irn_forking(b1->irn)) {
 292                 ret = -1;
 293         } else {
 294                 ret = b1->cost - a1->cost;
 295                 if (ret == 0) {
 296                         /* place live-out nodes later */
 297                         ret = (count_result(a1->irn) != 0) - (count_result(b1->irn) != 0);
 298                 }
 299         }
 300 #if defined NORMAL_DBG
 301         ir_fprintf(stderr, "root %+F %s %+F\n", a1->irn, ret < 0 ? "<" : ret > 0 ? ">" : "=", b1->irn);
 302 #endif
 303         return ret;
 304 }
 305
 306
 307 static void normal_sched_block(ir_node* block, void* env)
 308 {
 309         ir_node**      roots = (ir_node**)get_irn_link(block);
 310         ir_heights_t*  heights = (ir_heights_t*)env;
 311         int            root_count;
 312         irn_cost_pair* root_costs;
 313         int i;
 314         ir_node**      sched;
 315
 316 #if defined NORMAL_DBG
 317         ir_fprintf(stderr, "sched walking block %+F\n", block);
 318 #endif
 319
 320         if (roots == NULL) {
 321 #if defined NORMAL_DBG
 322                 fprintf(stderr, "has no roots\n");
 323 #endif
 324                 return;
 325         }
 326
 327         root_count = ARR_LEN(roots);
 328         NEW_ARR_A(irn_cost_pair, root_costs, root_count);
 329         for (i = 0; i < root_count; ++i) {
 330                 root_costs[i].irn  = roots[i];
 331                 root_costs[i].cost = get_irn_height(heights, roots[i]);
 332 #if defined NORMAL_DBG
 333                 ir_fprintf(stderr, "height of %+F is %u\n", roots[i], root_costs[i].cost);
 334 #endif
 335         }
 336         qsort(root_costs, root_count, sizeof(*root_costs), root_cmp);
 337 #if defined NORMAL_DBG
 338         {
 339                 int n = root_count;
 340                 int i;
 341
 342                 ir_fprintf(stderr, "Root Scheduling of %+F:\n", block);
 343                 for (i = 0; i < n; ++i) {
 344                         ir_fprintf(stderr, "  %+F\n", root_costs[i].irn);
 345                 }
 346                 fprintf(stderr, "\n");
 347         }
 348 #endif
 349
 350         sched = NEW_ARR_F(ir_node*, 0);
 351         for (i = 0; i < root_count; ++i) {
 352                 ir_node* irn = root_costs[i].irn;
 353                 assert(must_be_scheduled(irn));
 354                 sched = sched_node(sched, irn);
 355         }
 356         set_irn_link(block, sched);
 357         DEL_ARR_F(roots);
 358
 359 #if defined NORMAL_DBG
 360         {
 361                 int n = ARR_LEN(sched);
 362                 int i;
 363
 364                 ir_fprintf(stderr, "Scheduling of %+F:\n", block);
 365                 for (i = 0; i < n; ++i) {
 366                         ir_fprintf(stderr, "  %+F\n", sched[i]);
 367                 }
 368                 fprintf(stderr, "\n");
 369         }
 370 #endif
 371 }
 372
 373
 374 static void *normal_init_graph(ir_graph *irg)
 375 {
 376         instance_t   *inst = XMALLOC(instance_t);
 377         ir_heights_t *heights;
 378
 379         be_clear_links(irg);
 380
 381         obstack_init(&inst->obst);
 382         inst->irg         = irg;
 383
 384         heights = heights_new(irg);
 385
 386         ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
 387         irg_walk_graph(irg, normal_cost_walker,  NULL, inst);
 388         irg_walk_graph(irg, collect_roots, NULL, NULL);
 389         inc_irg_visited(irg);
 390         ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
 391         irg_block_walk_graph(irg, normal_sched_block, NULL, heights);
 392         ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
 393
 394         heights_free(heights);
 395
 396         return inst;
 397 }
 398
 399 static void *normal_init_block(void *graph_env, ir_node *block)
 400 {
 401         instance_t* inst  = (instance_t*)graph_env;
 402         ir_node**   sched = (ir_node**)get_irn_link(block);
 403         ir_node*    first = NULL;
 404         int         i;
 405
 406         /* turn into a list, so we can easily remove nodes.
 407            The link field is used anyway. */
 408         for (i = ARR_LEN(sched) - 1; i >= 0; --i) {
 409                 ir_node* irn = sched[i];
 410                 if (!is_cfop(irn)) {
 411                         set_irn_link(irn, first);
 412                         first = irn;
 413                 }
 414         }
 415         /* note: we can free sched here, there should be no attempt to schedule
 416            a block twice */
 417         DEL_ARR_F(sched);
 418         set_irn_link(block, sched);
 419         inst->curr_list = first;
 420         return inst;
 421 }
 422
 423 static void normal_finish_graph(void *env)
 424 {
 425         instance_t *inst = (instance_t*)env;
 426
 427         /* block uses the link field to store the schedule */
 428         ir_free_resources(inst->irg, IR_RESOURCE_IRN_LINK);
 429         obstack_free(&inst->obst, NULL);
 430         xfree(inst);
 431 }
 432
 433 static void sched_normal(ir_graph *irg)
 434 {
 435         static const list_sched_selector_t normal_selector = {
 436                 normal_init_graph,
 437                 normal_init_block,
 438                 normal_select,
 439                 NULL,              /* node_ready */
 440                 NULL,              /* node_selected */
 441                 NULL,              /* finish_block */
 442                 normal_finish_graph
 443         };
 444         be_list_sched_graph(irg, &normal_selector);
 445 }
 446
 447 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_sched_normal)
 448 void be_init_sched_normal(void)
 449 {
 450         be_register_scheduler("normal", sched_normal);
 451 }