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_t.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 (arch_get_register_req_out(irn)->type & arch_register_req_type_ignore)
 123                 return 0;
 124
 125         return 1;
 126 }
 127
 128
 129 /* TODO high cost for store trees
 130  */
 131
 132 static int normal_tree_cost(ir_node* irn, instance_t *inst)
 133 {
 134         flag_and_cost* fc;
 135         int            arity;
 136         ir_node*       last;
 137         int            n_res;
 138         int            cost;
 139         int            n_op_res = 0;
 140         int            i;
 141
 142         if (be_is_Keep(irn))
 143                 return 0;
 144
 145         if (is_Proj(irn)) {
 146                 return normal_tree_cost(get_Proj_pred(irn), inst);
 147         }
 148
 149         arity = get_irn_arity(irn);
 150         fc    = get_irn_fc(irn);
 151
 152         if (fc == NULL) {
 153                 irn_cost_pair* costs;
 154                 int            i;
 155                 ir_node*       block = get_nodes_block(irn);
 156
 157                 fc = obstack_alloc(&inst->obst, sizeof(*fc) + sizeof(*fc->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                         int cost;
 164
 165                         if (is_Phi(irn) || get_irn_mode(pred) == mode_M || is_Block(pred)) {
 166                                 cost = 0;
 167                         } else if (get_nodes_block(pred) != block) {
 168                                 cost = 1;
 169                         } else {
 170                                 flag_and_cost* pred_fc;
 171                                 ir_node*       real_pred;
 172
 173                                 cost = normal_tree_cost(pred, inst);
 174                                 if (be_is_Barrier(pred)) cost = 1; // XXX hack: the barrier causes all users to have a reguse of #regs
 175                                 if (!arch_irn_is_ignore(pred)) {
 176                                         real_pred = (is_Proj(pred) ? get_Proj_pred(pred) : pred);
 177                                         pred_fc = get_irn_fc(real_pred);
 178                                         pred_fc->no_root = 1;
 179 #if defined NORMAL_DBG
 180                                         ir_fprintf(stderr, "%+F says that %+F is no root\n", irn, real_pred);
 181 #endif
 182                                 }
 183                         }
 184
 185                         costs[i].irn  = pred;
 186                         costs[i].cost = cost;
 187                 }
 188
 189                 qsort(costs, arity, sizeof(*costs), cost_cmp);
 190                 set_irn_link(irn, fc);
 191         }
 192
 193         cost = 0;
 194         last = 0;
 195         for (i = 0; i < arity; ++i) {
 196                 ir_node* op = fc->costs[i].irn;
 197                 if (op == last)                 continue;
 198                 if (get_irn_mode(op) == mode_M) continue;
 199                 if (arch_irn_is_ignore(op))     continue;
 200                 cost = MAX(fc->costs[i].cost + n_op_res, cost);
 201                 last = op;
 202                 ++n_op_res;
 203         }
 204         n_res = count_result(irn);
 205         cost = MAX(n_res, cost);
 206
 207 #if defined NORMAL_DBG
 208         ir_fprintf(stderr, "reguse of %+F is %d\n", irn, cost);
 209 #endif
 210
 211         return cost;
 212 }
 213
 214
 215 static void normal_cost_walker(ir_node* irn, void* env)
 216 {
 217         instance_t *inst = env;
 218
 219 #if defined NORMAL_DBG
 220         ir_fprintf(stderr, "cost walking node %+F\n", irn);
 221 #endif
 222         if (is_Block(irn)) return;
 223         if (!must_be_scheduled(irn)) return;
 224         normal_tree_cost(irn, inst);
 225 }
 226
 227
 228 static void collect_roots(ir_node* irn, void* env)
 229 {
 230         int is_root;
 231
 232         (void)env;
 233
 234         if (is_Block(irn)) return;
 235         if (!must_be_scheduled(irn)) return;
 236
 237         is_root = be_is_Keep(irn) || !get_irn_fc(irn)->no_root;
 238
 239 #if defined NORMAL_DBG
 240         ir_fprintf(stderr, "%+F is %sroot\n", irn, is_root ? "" : "no ");
 241 #endif
 242
 243         if (is_root) {
 244                 ir_node* block = get_nodes_block(irn);
 245                 ir_node** roots = get_irn_link(block);
 246                 if (roots == NULL) {
 247                         roots = NEW_ARR_F(ir_node*, 0);
 248                 }
 249                 ARR_APP1(ir_node*, roots, irn);
 250                 set_irn_link(block, roots);
 251         }
 252 }
 253
 254
 255 static ir_node** sched_node(ir_node** sched, ir_node* irn)
 256 {
 257         if (irn_visited_else_mark(irn)) return sched;
 258         if (is_End(irn))                return sched;
 259
 260         if (!is_Phi(irn) && !be_is_Keep(irn)) {
 261                 ir_node*       block = get_nodes_block(irn);
 262                 int            arity = get_irn_arity(irn);
 263                 flag_and_cost* fc    = get_irn_fc(irn);
 264                 irn_cost_pair* irns  = fc->costs;
 265                 int            i;
 266
 267                 for (i = 0; i < arity; ++i) {
 268                         ir_node* pred = irns[i].irn;
 269                         if (get_nodes_block(pred) != block) continue;
 270                         if (get_irn_mode(pred) == mode_M) continue;
 271                         if (is_Proj(pred)) pred = get_Proj_pred(pred);
 272                         sched = sched_node(sched, pred);
 273                 }
 274         }
 275
 276         ARR_APP1(ir_node*, sched, irn);
 277         return sched;
 278 }
 279
 280
 281 static int root_cmp(const void* a, const void* b)
 282 {
 283         const irn_cost_pair* const a1 = a;
 284         const irn_cost_pair* const b1 = b;
 285         int ret;
 286         if (is_irn_forking(a1->irn)) {
 287                 ret = 1;
 288         } else if (is_irn_forking(b1->irn)) {
 289                 ret = -1;
 290         } else {
 291                 ret = b1->cost - a1->cost;
 292                 if (ret == 0) {
 293                         /* place live-out nodes later */
 294                         ret = (count_result(a1->irn) != 0) - (count_result(b1->irn) != 0);
 295                 }
 296         }
 297 #if defined NORMAL_DBG
 298         ir_fprintf(stderr, "root %+F %s %+F\n", a1->irn, ret < 0 ? "<" : ret > 0 ? ">" : "=", b1->irn);
 299 #endif
 300         return ret;
 301 }
 302
 303
 304 static void normal_sched_block(ir_node* block, void* env)
 305 {
 306         ir_node**      roots = get_irn_link(block);
 307         heights_t*     heights = env;
 308         int            root_count;
 309         irn_cost_pair* root_costs;
 310         int i;
 311         ir_node**      sched;
 312
 313 #if defined NORMAL_DBG
 314         ir_fprintf(stderr, "sched walking block %+F\n", block);
 315 #endif
 316
 317         if (roots == NULL) {
 318 #if defined NORMAL_DBG
 319                 fprintf(stderr, "has no roots\n");
 320 #endif
 321                 return;
 322         }
 323
 324         root_count = ARR_LEN(roots);
 325         NEW_ARR_A(irn_cost_pair, root_costs, root_count);
 326         for (i = 0; i < root_count; ++i) {
 327                 root_costs[i].irn  = roots[i];
 328                 root_costs[i].cost = get_irn_height(heights, roots[i]);
 329 #if defined NORMAL_DBG
 330                 ir_fprintf(stderr, "height of %+F is %u\n", roots[i], root_costs[i].cost);
 331 #endif
 332         }
 333         qsort(root_costs, root_count, sizeof(*root_costs), root_cmp);
 334 #if defined NORMAL_DBG
 335         {
 336                 int n = root_count;
 337                 int i;
 338
 339                 ir_fprintf(stderr, "Root Scheduling of %+F:\n", block);
 340                 for (i = 0; i < n; ++i) {
 341                         ir_fprintf(stderr, "  %+F\n", root_costs[i].irn);
 342                 }
 343                 fprintf(stderr, "\n");
 344         }
 345 #endif
 346
 347         sched = NEW_ARR_F(ir_node*, 0);
 348         for (i = 0; i < root_count; ++i) {
 349                 ir_node* irn = root_costs[i].irn;
 350                 assert(must_be_scheduled(irn));
 351                 sched = sched_node(sched, irn);
 352         }
 353         set_irn_link(block, sched);
 354         DEL_ARR_F(roots);
 355
 356 #if defined NORMAL_DBG
 357         {
 358                 int n = ARR_LEN(sched);
 359                 int i;
 360
 361                 ir_fprintf(stderr, "Scheduling of %+F:\n", block);
 362                 for (i = 0; i < n; ++i) {
 363                         ir_fprintf(stderr, "  %+F\n", sched[i]);
 364                 }
 365                 fprintf(stderr, "\n");
 366         }
 367 #endif
 368 }
 369
 370
 371 static void *normal_init_graph(const list_sched_selector_t *vtab,
 372                                const be_irg_t *birg)
 373 {
 374         instance_t* inst = XMALLOC(instance_t);
 375         ir_graph*   irg = be_get_birg_irg(birg);
 376         heights_t*  heights;
 377
 378         (void)vtab;
 379
 380         be_clear_links(irg);
 381
 382         obstack_init(&inst->obst);
 383         inst->irg         = irg;
 384
 385         heights = heights_new(irg);
 386
 387         ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
 388         irg_walk_graph(irg, normal_cost_walker,  NULL, inst);
 389         irg_walk_graph(irg, collect_roots, NULL, NULL);
 390         inc_irg_visited(irg);
 391         ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
 392         irg_block_walk_graph(irg, normal_sched_block, NULL, heights);
 393         ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
 394
 395         heights_free(heights);
 396
 397         return inst;
 398 }
 399
 400 static void *normal_init_block(void *graph_env, ir_node *block)
 401 {
 402         instance_t* inst  = graph_env;
 403         ir_node**   sched = get_irn_link(block);
 404         ir_node*    first = NULL;
 405         int         i;
 406
 407         /* turn into a list, so we can easily remove nodes.
 408            The link field is used anyway. */
 409         for (i = ARR_LEN(sched) - 1; i >= 0; --i) {
 410                 ir_node* irn = sched[i];
 411                 if (!arch_irn_class_is(irn, branch)) {
 412                         set_irn_link(irn, first);
 413                         first = irn;
 414                 }
 415         }
 416         /* note: we can free sched here, there should be no attempt to schedule
 417            a block twice */
 418         DEL_ARR_F(sched);
 419         set_irn_link(block, sched);
 420         inst->curr_list = first;
 421         return inst;
 422 }
 423
 424 void normal_finish_graph(void *env)
 425 {
 426         instance_t *inst = env;
 427
 428         /* block uses the link field to store the schedule */
 429         ir_free_resources(inst->irg, IR_RESOURCE_IRN_LINK);
 430         obstack_free(&inst->obst, NULL);
 431         xfree(inst);
 432 }
 433
 434 const list_sched_selector_t normal_selector = {
 435         normal_init_graph,
 436         normal_init_block,
 437         normal_select,
 438         NULL,              /* to_appear_in_schedule */
 439         NULL,              /* node_ready */
 440         NULL,              /* node_selected */
 441         NULL,              /* exectime */
 442         NULL,              /* latency */
 443         NULL,              /* finish_block */
 444         normal_finish_graph
 445 };