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                 int            i;
 156                 ir_node*       block = get_nodes_block(irn);
 157
 158                 fc = OALLOCF(&inst->obst, flag_and_cost, costs, arity);
 159                 fc->no_root = 0;
 160                 costs = fc->costs;
 161
 162                 for (i = 0; i < arity; ++i) {
 163                         ir_node* pred = get_irn_n(irn, i);
 164                         int cost;
 165
 166                         if (is_Phi(irn) || get_irn_mode(pred) == mode_M || is_Block(pred)) {
 167                                 cost = 0;
 168                         } else if (get_nodes_block(pred) != block) {
 169                                 cost = 1;
 170                         } else {
 171                                 flag_and_cost* pred_fc;
 172                                 ir_node*       real_pred;
 173
 174                                 cost = normal_tree_cost(pred, inst);
 175                                 if (be_is_Barrier(pred)) cost = 1; // XXX hack: the barrier causes all users to have a reguse of #regs
 176                                 if (!arch_irn_is_ignore(pred)) {
 177                                         real_pred = (is_Proj(pred) ? get_Proj_pred(pred) : pred);
 178                                         pred_fc = get_irn_fc(real_pred);
 179                                         pred_fc->no_root = 1;
 180 #if defined NORMAL_DBG
 181                                         ir_fprintf(stderr, "%+F says that %+F is no root\n", irn, real_pred);
 182 #endif
 183                                 }
 184                         }
 185
 186                         costs[i].irn  = pred;
 187                         costs[i].cost = cost;
 188                 }
 189
 190                 qsort(costs, arity, sizeof(*costs), cost_cmp);
 191                 set_irn_link(irn, fc);
 192         }
 193
 194         cost = 0;
 195         last = 0;
 196         for (i = 0; i < arity; ++i) {
 197                 ir_node* op = fc->costs[i].irn;
 198                 ir_mode* mode;
 199                 if (op == last)
 200                         continue;
 201                 mode = get_irn_mode(op);
 202                 if (mode == mode_M)
 203                         continue;
 204                 if (mode != mode_T && arch_irn_is_ignore(op))
 205                         continue;
 206                 cost = MAX(fc->costs[i].cost + n_op_res, cost);
 207                 last = op;
 208                 ++n_op_res;
 209         }
 210         n_res = count_result(irn);
 211         cost = MAX(n_res, cost);
 212
 213 #if defined NORMAL_DBG
 214         ir_fprintf(stderr, "reguse of %+F is %d\n", irn, cost);
 215 #endif
 216
 217         return cost;
 218 }
 219
 220
 221 static void normal_cost_walker(ir_node* irn, void* env)
 222 {
 223         instance_t *inst = (instance_t*)env;
 224
 225 #if defined NORMAL_DBG
 226         ir_fprintf(stderr, "cost walking node %+F\n", irn);
 227 #endif
 228         if (is_Block(irn)) return;
 229         if (!must_be_scheduled(irn)) return;
 230         normal_tree_cost(irn, inst);
 231 }
 232
 233
 234 static void collect_roots(ir_node* irn, void* env)
 235 {
 236         int is_root;
 237
 238         (void)env;
 239
 240         if (is_Block(irn)) return;
 241         if (!must_be_scheduled(irn)) return;
 242
 243         is_root = be_is_Keep(irn) || !get_irn_fc(irn)->no_root;
 244
 245 #if defined NORMAL_DBG
 246         ir_fprintf(stderr, "%+F is %sroot\n", irn, is_root ? "" : "no ");
 247 #endif
 248
 249         if (is_root) {
 250                 ir_node* block = get_nodes_block(irn);
 251                 ir_node** roots = (ir_node**)get_irn_link(block);
 252                 if (roots == NULL) {
 253                         roots = NEW_ARR_F(ir_node*, 0);
 254                 }
 255                 ARR_APP1(ir_node*, roots, irn);
 256                 set_irn_link(block, roots);
 257         }
 258 }
 259
 260
 261 static ir_node** sched_node(ir_node** sched, ir_node* irn)
 262 {
 263         if (irn_visited_else_mark(irn)) return sched;
 264         if (is_End(irn))                return sched;
 265
 266         if (!is_Phi(irn) && !be_is_Keep(irn)) {
 267                 ir_node*       block = get_nodes_block(irn);
 268                 int            arity = get_irn_arity(irn);
 269                 flag_and_cost* fc    = get_irn_fc(irn);
 270                 irn_cost_pair* irns  = fc->costs;
 271                 int            i;
 272
 273                 for (i = 0; i < arity; ++i) {
 274                         ir_node* pred = irns[i].irn;
 275                         if (get_nodes_block(pred) != block) continue;
 276                         if (get_irn_mode(pred) == mode_M) continue;
 277                         if (is_Proj(pred)) pred = get_Proj_pred(pred);
 278                         sched = sched_node(sched, pred);
 279                 }
 280         }
 281
 282         ARR_APP1(ir_node*, sched, irn);
 283         return sched;
 284 }
 285
 286
 287 static int root_cmp(const void* a, const void* b)
 288 {
 289         const irn_cost_pair* const a1 = (const irn_cost_pair*)a;
 290         const irn_cost_pair* const b1 = (const irn_cost_pair*)b;
 291         int ret;
 292         if (is_irn_forking(a1->irn)) {
 293                 ret = 1;
 294         } else if (is_irn_forking(b1->irn)) {
 295                 ret = -1;
 296         } else {
 297                 ret = b1->cost - a1->cost;
 298                 if (ret == 0) {
 299                         /* place live-out nodes later */
 300                         ret = (count_result(a1->irn) != 0) - (count_result(b1->irn) != 0);
 301                 }
 302         }
 303 #if defined NORMAL_DBG
 304         ir_fprintf(stderr, "root %+F %s %+F\n", a1->irn, ret < 0 ? "<" : ret > 0 ? ">" : "=", b1->irn);
 305 #endif
 306         return ret;
 307 }
 308
 309
 310 static void normal_sched_block(ir_node* block, void* env)
 311 {
 312         ir_node**      roots = (ir_node**)get_irn_link(block);
 313         ir_heights_t*  heights = (ir_heights_t*)env;
 314         int            root_count;
 315         irn_cost_pair* root_costs;
 316         int i;
 317         ir_node**      sched;
 318
 319 #if defined NORMAL_DBG
 320         ir_fprintf(stderr, "sched walking block %+F\n", block);
 321 #endif
 322
 323         if (roots == NULL) {
 324 #if defined NORMAL_DBG
 325                 fprintf(stderr, "has no roots\n");
 326 #endif
 327                 return;
 328         }
 329
 330         root_count = ARR_LEN(roots);
 331         NEW_ARR_A(irn_cost_pair, root_costs, root_count);
 332         for (i = 0; i < root_count; ++i) {
 333                 root_costs[i].irn  = roots[i];
 334                 root_costs[i].cost = get_irn_height(heights, roots[i]);
 335 #if defined NORMAL_DBG
 336                 ir_fprintf(stderr, "height of %+F is %u\n", roots[i], root_costs[i].cost);
 337 #endif
 338         }
 339         qsort(root_costs, root_count, sizeof(*root_costs), root_cmp);
 340 #if defined NORMAL_DBG
 341         {
 342                 int n = root_count;
 343                 int i;
 344
 345                 ir_fprintf(stderr, "Root Scheduling of %+F:\n", block);
 346                 for (i = 0; i < n; ++i) {
 347                         ir_fprintf(stderr, "  %+F\n", root_costs[i].irn);
 348                 }
 349                 fprintf(stderr, "\n");
 350         }
 351 #endif
 352
 353         sched = NEW_ARR_F(ir_node*, 0);
 354         for (i = 0; i < root_count; ++i) {
 355                 ir_node* irn = root_costs[i].irn;
 356                 assert(must_be_scheduled(irn));
 357                 sched = sched_node(sched, irn);
 358         }
 359         set_irn_link(block, sched);
 360         DEL_ARR_F(roots);
 361
 362 #if defined NORMAL_DBG
 363         {
 364                 int n = ARR_LEN(sched);
 365                 int i;
 366
 367                 ir_fprintf(stderr, "Scheduling of %+F:\n", block);
 368                 for (i = 0; i < n; ++i) {
 369                         ir_fprintf(stderr, "  %+F\n", sched[i]);
 370                 }
 371                 fprintf(stderr, "\n");
 372         }
 373 #endif
 374 }
 375
 376
 377 static void *normal_init_graph(ir_graph *irg)
 378 {
 379         instance_t   *inst = XMALLOC(instance_t);
 380         ir_heights_t *heights;
 381
 382         be_clear_links(irg);
 383
 384         obstack_init(&inst->obst);
 385         inst->irg         = irg;
 386
 387         heights = heights_new(irg);
 388
 389         ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
 390         irg_walk_graph(irg, normal_cost_walker,  NULL, inst);
 391         irg_walk_graph(irg, collect_roots, NULL, NULL);
 392         inc_irg_visited(irg);
 393         ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
 394         irg_block_walk_graph(irg, normal_sched_block, NULL, heights);
 395         ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
 396
 397         heights_free(heights);
 398
 399         return inst;
 400 }
 401
 402 static void *normal_init_block(void *graph_env, ir_node *block)
 403 {
 404         instance_t* inst  = (instance_t*)graph_env;
 405         ir_node**   sched = (ir_node**)get_irn_link(block);
 406         ir_node*    first = NULL;
 407         int         i;
 408
 409         /* turn into a list, so we can easily remove nodes.
 410            The link field is used anyway. */
 411         for (i = ARR_LEN(sched) - 1; i >= 0; --i) {
 412                 ir_node* irn = sched[i];
 413                 if (!is_cfop(irn)) {
 414                         set_irn_link(irn, first);
 415                         first = irn;
 416                 }
 417         }
 418         /* note: we can free sched here, there should be no attempt to schedule
 419            a block twice */
 420         DEL_ARR_F(sched);
 421         set_irn_link(block, sched);
 422         inst->curr_list = first;
 423         return inst;
 424 }
 425
 426 static void normal_finish_graph(void *env)
 427 {
 428         instance_t *inst = (instance_t*)env;
 429
 430         /* block uses the link field to store the schedule */
 431         ir_free_resources(inst->irg, IR_RESOURCE_IRN_LINK);
 432         obstack_free(&inst->obst, NULL);
 433         xfree(inst);
 434 }
 435
 436 static void sched_normal(ir_graph *irg)
 437 {
 438         static const list_sched_selector_t normal_selector = {
 439                 normal_init_graph,
 440                 normal_init_block,
 441                 normal_select,
 442                 NULL,              /* node_ready */
 443                 NULL,              /* node_selected */
 444                 NULL,              /* finish_block */
 445                 normal_finish_graph
 446         };
 447         be_list_sched_graph(irg, &normal_selector);
 448 }
 449
 450 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_sched_normal);
 451 void be_init_sched_normal(void)
 452 {
 453         be_register_scheduler("normal", sched_normal);
 454 }