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 "height.h"
  34 #include "irtools.h"
  35 #include "irgwalk.h"
  36 #include "benode.h"
  37 #include "array_t.h"
  38
  39 // XXX there is no one time init for schedulers
  40 //#define NORMAL_DBG
  41 #include "irprintf.h"
  42
  43 /** An instance of the normal scheduler. */
  44 typedef struct instance_t {
  45         ir_graph*      irg;          /**< the IR graph of this instance */
  46         struct obstack obst;         /**< obstack for temporary data */
  47         ir_node*       curr_list;    /**< current block schedule list */
  48 } instance_t;
  49
  50 static int must_be_scheduled(const ir_node* const irn)
  51 {
  52         return !is_Proj(irn) && !is_Sync(irn);
  53 }
  54
  55
  56 static ir_node *normal_select(void *block_env, ir_nodeset_t *ready_set,
  57                               ir_nodeset_t *live_set)
  58 {
  59         instance_t* inst = block_env;
  60         ir_node*    irn;
  61         ir_node*    next;
  62         ir_node*    last = NULL;
  63         ir_nodeset_iterator_t iter;
  64
  65         (void)live_set;
  66
  67         for (irn = inst->curr_list; irn != NULL; last = irn, irn = next) {
  68                 next = get_irn_link(irn);
  69                 if (ir_nodeset_contains(ready_set, irn)) {
  70 #if defined NORMAL_DBG
  71                         ir_fprintf(stderr, "scheduling %+F\n", irn);
  72 #endif
  73                         if (last == NULL)
  74                                 inst->curr_list = next;
  75                         else
  76                                 set_irn_link(last, next);
  77                         return irn;
  78                 }
  79         }
  80
  81         ir_nodeset_iterator_init(&iter, ready_set);
  82         irn = ir_nodeset_iterator_next(&iter);
  83         return irn;
  84 }
  85
  86
  87 typedef struct irn_cost_pair {
  88         ir_node* irn;
  89         int      cost;
  90 } irn_cost_pair;
  91
  92 static int cost_cmp(const void* a, const void* b)
  93 {
  94         const irn_cost_pair* const a1 = a;
  95         const irn_cost_pair* const b1 = b;
  96         int ret = b1->cost - a1->cost;
  97         if (ret == 0)
  98                 ret = (int)get_irn_idx(a1->irn) - (int)get_irn_idx(b1->irn);
  99 #if defined NORMAL_DBG
 100         ir_fprintf(stderr, "cost %+F %s %+F\n", a1->irn, ret < 0 ? "<" : ret > 0 ? ">" : "=", b1->irn);
 101 #endif
 102         return ret;
 103 }
 104
 105
 106 typedef struct flag_and_cost {
 107         int no_root;
 108         irn_cost_pair costs[];
 109 } flag_and_cost;
 110
 111 #define get_irn_fc(irn)     ((flag_and_cost*)get_irn_link(irn))
 112 #define set_irn_fc(irn, fc) set_irn_link(irn, fc)
 113
 114
 115 static int count_result(const ir_node* irn)
 116 {
 117         const ir_mode* mode = get_irn_mode(irn);
 118
 119         if (mode == mode_M || mode == mode_X)
 120                 return 0;
 121
 122         if (mode == mode_T)
 123                 return 1;
 124
 125         if (arch_get_register_req_out(irn)->type & arch_register_req_type_ignore)
 126                 return 0;
 127
 128         return 1;
 129 }
 130
 131
 132 /* TODO high cost for store trees
 133  */
 134
 135 static int normal_tree_cost(ir_node* irn, instance_t *inst)
 136 {
 137         flag_and_cost* fc;
 138         int            arity;
 139         ir_node*       last;
 140         int            n_res;
 141         int            cost;
 142         int            n_op_res = 0;
 143         int            i;
 144
 145         if (be_is_Keep(irn))
 146                 return 0;
 147
 148         if (is_Proj(irn)) {
 149                 return normal_tree_cost(get_Proj_pred(irn), inst);
 150         }
 151
 152         arity = get_irn_arity(irn);
 153         fc    = get_irn_fc(irn);
 154
 155         if (fc == NULL) {
 156                 irn_cost_pair* costs;
 157                 int            i;
 158                 ir_node*       block = get_nodes_block(irn);
 159
 160                 fc = OALLOCF(&inst->obst, flag_and_cost, costs, arity);
 161                 fc->no_root = 0;
 162                 costs = fc->costs;
 163
 164                 for (i = 0; i < arity; ++i) {
 165                         ir_node* pred = get_irn_n(irn, i);
 166                         int cost;
 167
 168                         if (is_Phi(irn) || get_irn_mode(pred) == mode_M || is_Block(pred)) {
 169                                 cost = 0;
 170                         } else if (get_nodes_block(pred) != block) {
 171                                 cost = 1;
 172                         } else {
 173                                 flag_and_cost* pred_fc;
 174                                 ir_node*       real_pred;
 175
 176                                 cost = normal_tree_cost(pred, inst);
 177                                 if (be_is_Barrier(pred)) cost = 1; // XXX hack: the barrier causes all users to have a reguse of #regs
 178                                 if (!arch_irn_is_ignore(pred)) {
 179                                         real_pred = (is_Proj(pred) ? get_Proj_pred(pred) : pred);
 180                                         pred_fc = get_irn_fc(real_pred);
 181                                         pred_fc->no_root = 1;
 182 #if defined NORMAL_DBG
 183                                         ir_fprintf(stderr, "%+F says that %+F is no root\n", irn, real_pred);
 184 #endif
 185                                 }
 186                         }
 187
 188                         costs[i].irn  = pred;
 189                         costs[i].cost = cost;
 190                 }
 191
 192                 qsort(costs, arity, sizeof(*costs), cost_cmp);
 193                 set_irn_link(irn, fc);
 194         }
 195
 196         cost = 0;
 197         last = 0;
 198         for (i = 0; i < arity; ++i) {
 199                 ir_node* op = fc->costs[i].irn;
 200                 ir_mode* mode;
 201                 if (op == last)
 202                         continue;
 203                 mode = get_irn_mode(op);
 204                 if (mode == mode_M)
 205                         continue;
 206                 if (mode != mode_T && arch_irn_is_ignore(op))
 207                         continue;
 208                 cost = MAX(fc->costs[i].cost + n_op_res, cost);
 209                 last = op;
 210                 ++n_op_res;
 211         }
 212         n_res = count_result(irn);
 213         cost = MAX(n_res, cost);
 214
 215 #if defined NORMAL_DBG
 216         ir_fprintf(stderr, "reguse of %+F is %d\n", irn, cost);
 217 #endif
 218
 219         return cost;
 220 }
 221
 222
 223 static void normal_cost_walker(ir_node* irn, void* env)
 224 {
 225         instance_t *inst = env;
 226
 227 #if defined NORMAL_DBG
 228         ir_fprintf(stderr, "cost walking node %+F\n", irn);
 229 #endif
 230         if (is_Block(irn)) return;
 231         if (!must_be_scheduled(irn)) return;
 232         normal_tree_cost(irn, inst);
 233 }
 234
 235
 236 static void collect_roots(ir_node* irn, void* env)
 237 {
 238         int is_root;
 239
 240         (void)env;
 241
 242         if (is_Block(irn)) return;
 243         if (!must_be_scheduled(irn)) return;
 244
 245         is_root = be_is_Keep(irn) || !get_irn_fc(irn)->no_root;
 246
 247 #if defined NORMAL_DBG
 248         ir_fprintf(stderr, "%+F is %sroot\n", irn, is_root ? "" : "no ");
 249 #endif
 250
 251         if (is_root) {
 252                 ir_node* block = get_nodes_block(irn);
 253                 ir_node** roots = get_irn_link(block);
 254                 if (roots == NULL) {
 255                         roots = NEW_ARR_F(ir_node*, 0);
 256                 }
 257                 ARR_APP1(ir_node*, roots, irn);
 258                 set_irn_link(block, roots);
 259         }
 260 }
 261
 262
 263 static ir_node** sched_node(ir_node** sched, ir_node* irn)
 264 {
 265         if (irn_visited_else_mark(irn)) return sched;
 266         if (is_End(irn))                return sched;
 267
 268         if (!is_Phi(irn) && !be_is_Keep(irn)) {
 269                 ir_node*       block = get_nodes_block(irn);
 270                 int            arity = get_irn_arity(irn);
 271                 flag_and_cost* fc    = get_irn_fc(irn);
 272                 irn_cost_pair* irns  = fc->costs;
 273                 int            i;
 274
 275                 for (i = 0; i < arity; ++i) {
 276                         ir_node* pred = irns[i].irn;
 277                         if (get_nodes_block(pred) != block) continue;
 278                         if (get_irn_mode(pred) == mode_M) continue;
 279                         if (is_Proj(pred)) pred = get_Proj_pred(pred);
 280                         sched = sched_node(sched, pred);
 281                 }
 282         }
 283
 284         ARR_APP1(ir_node*, sched, irn);
 285         return sched;
 286 }
 287
 288
 289 static int root_cmp(const void* a, const void* b)
 290 {
 291         const irn_cost_pair* const a1 = a;
 292         const irn_cost_pair* const b1 = b;
 293         int ret;
 294         if (is_irn_forking(a1->irn)) {
 295                 ret = 1;
 296         } else if (is_irn_forking(b1->irn)) {
 297                 ret = -1;
 298         } else {
 299                 ret = b1->cost - a1->cost;
 300                 if (ret == 0) {
 301                         /* place live-out nodes later */
 302                         ret = (count_result(a1->irn) != 0) - (count_result(b1->irn) != 0);
 303                 }
 304         }
 305 #if defined NORMAL_DBG
 306         ir_fprintf(stderr, "root %+F %s %+F\n", a1->irn, ret < 0 ? "<" : ret > 0 ? ">" : "=", b1->irn);
 307 #endif
 308         return ret;
 309 }
 310
 311
 312 static void normal_sched_block(ir_node* block, void* env)
 313 {
 314         ir_node**      roots = get_irn_link(block);
 315         heights_t*     heights = env;
 316         int            root_count;
 317         irn_cost_pair* root_costs;
 318         int i;
 319         ir_node**      sched;
 320
 321 #if defined NORMAL_DBG
 322         ir_fprintf(stderr, "sched walking block %+F\n", block);
 323 #endif
 324
 325         if (roots == NULL) {
 326 #if defined NORMAL_DBG
 327                 fprintf(stderr, "has no roots\n");
 328 #endif
 329                 return;
 330         }
 331
 332         root_count = ARR_LEN(roots);
 333         NEW_ARR_A(irn_cost_pair, root_costs, root_count);
 334         for (i = 0; i < root_count; ++i) {
 335                 root_costs[i].irn  = roots[i];
 336                 root_costs[i].cost = get_irn_height(heights, roots[i]);
 337 #if defined NORMAL_DBG
 338                 ir_fprintf(stderr, "height of %+F is %u\n", roots[i], root_costs[i].cost);
 339 #endif
 340         }
 341         qsort(root_costs, root_count, sizeof(*root_costs), root_cmp);
 342 #if defined NORMAL_DBG
 343         {
 344                 int n = root_count;
 345                 int i;
 346
 347                 ir_fprintf(stderr, "Root Scheduling of %+F:\n", block);
 348                 for (i = 0; i < n; ++i) {
 349                         ir_fprintf(stderr, "  %+F\n", root_costs[i].irn);
 350                 }
 351                 fprintf(stderr, "\n");
 352         }
 353 #endif
 354
 355         sched = NEW_ARR_F(ir_node*, 0);
 356         for (i = 0; i < root_count; ++i) {
 357                 ir_node* irn = root_costs[i].irn;
 358                 assert(must_be_scheduled(irn));
 359                 sched = sched_node(sched, irn);
 360         }
 361         set_irn_link(block, sched);
 362         DEL_ARR_F(roots);
 363
 364 #if defined NORMAL_DBG
 365         {
 366                 int n = ARR_LEN(sched);
 367                 int i;
 368
 369                 ir_fprintf(stderr, "Scheduling of %+F:\n", block);
 370                 for (i = 0; i < n; ++i) {
 371                         ir_fprintf(stderr, "  %+F\n", sched[i]);
 372                 }
 373                 fprintf(stderr, "\n");
 374         }
 375 #endif
 376 }
 377
 378
 379 static void *normal_init_graph(const list_sched_selector_t *vtab,
 380                                const be_irg_t *birg)
 381 {
 382         instance_t* inst = XMALLOC(instance_t);
 383         ir_graph*   irg = be_get_birg_irg(birg);
 384         heights_t*  heights;
 385
 386         (void)vtab;
 387
 388         be_clear_links(irg);
 389
 390         obstack_init(&inst->obst);
 391         inst->irg         = irg;
 392
 393         heights = heights_new(irg);
 394
 395         ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
 396         irg_walk_graph(irg, normal_cost_walker,  NULL, inst);
 397         irg_walk_graph(irg, collect_roots, NULL, NULL);
 398         inc_irg_visited(irg);
 399         ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
 400         irg_block_walk_graph(irg, normal_sched_block, NULL, heights);
 401         ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
 402
 403         heights_free(heights);
 404
 405         return inst;
 406 }
 407
 408 static void *normal_init_block(void *graph_env, ir_node *block)
 409 {
 410         instance_t* inst  = graph_env;
 411         ir_node**   sched = get_irn_link(block);
 412         ir_node*    first = NULL;
 413         int         i;
 414
 415         /* turn into a list, so we can easily remove nodes.
 416            The link field is used anyway. */
 417         for (i = ARR_LEN(sched) - 1; i >= 0; --i) {
 418                 ir_node* irn = sched[i];
 419                 if (!is_cfop(irn)) {
 420                         set_irn_link(irn, first);
 421                         first = irn;
 422                 }
 423         }
 424         /* note: we can free sched here, there should be no attempt to schedule
 425            a block twice */
 426         DEL_ARR_F(sched);
 427         set_irn_link(block, sched);
 428         inst->curr_list = first;
 429         return inst;
 430 }
 431
 432 static void normal_finish_graph(void *env)
 433 {
 434         instance_t *inst = env;
 435
 436         /* block uses the link field to store the schedule */
 437         ir_free_resources(inst->irg, IR_RESOURCE_IRN_LINK);
 438         obstack_free(&inst->obst, NULL);
 439         xfree(inst);
 440 }
 441
 442 const list_sched_selector_t normal_selector = {
 443         normal_init_graph,
 444         normal_init_block,
 445         normal_select,
 446         NULL,              /* to_appear_in_schedule */
 447         NULL,              /* node_ready */
 448         NULL,              /* node_selected */
 449         NULL,              /* exectime */
 450         NULL,              /* latency */
 451         NULL,              /* finish_block */
 452         normal_finish_graph
 453 };