nsz Git - libfirm/blob - ir/be/beifg_std.c

   1 /**
   2  * @file   beifg_std.c
   3  * @date   18.11.2005
   4  * @author Sebastian Hack
   5  *
   6  * Copyright (C) 2005 Universitaet Karlsruhe
   7  * Released under the GPL
   8  */
   9
  10 #ifdef HAVE_CONFIG_H
  11 #include "config.h"
  12 #endif
  13
  14 #include <stdlib.h>
  15
  16 #include "list.h"
  17
  18 #include "irnode_t.h"
  19 #include "irgraph_t.h"
  20 #include "irgwalk.h"
  21
  22 #include "be_t.h"
  23 #include "belive_t.h"
  24 #include "bera.h"
  25 #include "beifg_t.h"
  26 #include "bechordal_t.h"
  27
  28 #define MAX(x, y) ((x) > (y) ? (x) : (y))
  29
  30 typedef struct _ifg_std_t ifg_std_t;
  31
  32 struct _ifg_std_t {
  33         const be_ifg_impl_t *impl;
  34         const be_chordal_env_t *env;
  35 };
  36
  37 static void ifg_std_free(void *self)
  38 {
  39         free(self);
  40 }
  41
  42 static int ifg_std_connected(const void *self, const ir_node *a, const ir_node *b)
  43 {
  44         return values_interfere(a, b);
  45 }
  46
  47 typedef struct _nodes_iter_t {
  48         const be_chordal_env_t *env;
  49         struct obstack obst;
  50         int n;
  51         int curr;
  52         ir_node **nodes;
  53 } nodes_iter_t;
  54
  55 static void nodes_walker(ir_node *bl, void *data)
  56 {
  57         nodes_iter_t *it = data;
  58         struct list_head *head = get_block_border_head(it->env, bl);
  59
  60         border_t *b;
  61
  62         foreach_border_head(head, b) {
  63                 if(b->is_def && b->is_real) {
  64                         obstack_ptr_grow(&it->obst, b->irn);
  65                         it->n++;
  66                 }
  67         }
  68 }
  69
  70 static void find_nodes(const void *self, void *iter) {
  71         const ifg_std_t *ifg = self;
  72         nodes_iter_t *it = iter;
  73
  74         obstack_init(&it->obst);
  75         it->n     = 0;
  76         it->curr  = 0;
  77         it->env   = ifg->env;
  78
  79         irg_block_walk_graph(ifg->env->irg, nodes_walker, NULL, iter);
  80         it->nodes = obstack_finish(&it->obst);
  81 }
  82
  83 static INLINE void node_break(nodes_iter_t *it, int force)
  84 {
  85         if((it->curr >= it->n || force) && it->nodes) {
  86                 obstack_free(&it->obst, NULL);
  87                 it->nodes = NULL;
  88         }
  89 }
  90
  91 static ir_node *get_next_node(void *iter)
  92 {
  93         nodes_iter_t *it = iter;
  94         ir_node *res     = NULL;
  95
  96         if(it->curr < it->n)
  97                 res = it->nodes[it->curr++];
  98
  99         node_break(it, 0);
 100
 101         return res;
 102 }
 103
 104 static ir_node *ifg_std_nodes_begin(const void *self, void *iter)
 105 {
 106         find_nodes(self, iter);
 107         return get_next_node(iter);
 108 }
 109
 110 static ir_node *ifg_std_nodes_next(const void *self, void *iter)
 111 {
 112         return get_next_node(iter);
 113 }
 114
 115 static void ifg_std_nodes_break(const void *self, void *iter)
 116 {
 117         node_break(iter, 1);
 118 }
 119
 120 typedef struct _adj_iter_t {
 121         const be_chordal_env_t *env;
 122         const ir_node *irn;
 123         int reached_end;
 124         pset *neighbours;
 125 } adj_iter_t;
 126
 127 static void find_neighbour_walker(ir_node *block, void *data)
 128 {
 129         adj_iter_t *it          = data;
 130         struct list_head *head  = get_block_border_head(it->env, block);
 131
 132         border_t *b;
 133         int has_started = 0;
 134
 135         if(!is_live_in(block, it->irn) && block != get_nodes_block(it->irn))
 136                 return;
 137
 138         foreach_border_head(head, b) {
 139                 ir_node *irn = b->irn;
 140
 141                 if(irn == it->irn) {
 142                         if(b->is_def)
 143                                 has_started = 1;
 144                         else
 145                                 break; /* if we reached the end of the node's lifetime we can safely break */
 146                 }
 147                 else if(b->is_def) {
 148                         /* if any other node than the one in question starts living, add it to the set */
 149                         pset_insert_ptr(it->neighbours, irn);
 150                 }
 151                 else if(!has_started) {
 152                         /* we only delete, if the live range in question has not yet started */
 153                         pset_remove_ptr(it->neighbours, irn);
 154                 }
 155
 156         }
 157 }
 158
 159 static void find_neighbours(const ifg_std_t *ifg, adj_iter_t *it, const ir_node *irn)
 160 {
 161         it->env         = ifg->env;
 162         it->irn         = irn;
 163         it->neighbours  = pset_new_ptr(16);
 164         it->reached_end = 0;
 165
 166         dom_tree_walk(get_nodes_block(irn), find_neighbour_walker, NULL, it);
 167 }
 168
 169 static INLINE void neighbours_break(adj_iter_t *it, int force)
 170 {
 171         if((it->reached_end || force) && it->neighbours) {
 172                 del_pset(it->neighbours);
 173                 it->neighbours = NULL;
 174         }
 175 }
 176
 177 static ir_node *get_next_neighbour(adj_iter_t *it) {
 178         ir_node *res = pset_next(it->neighbours);
 179
 180         it->reached_end = res == NULL;
 181         neighbours_break(it, 0);
 182
 183         return res;
 184 }
 185
 186 static ir_node *ifg_std_neighbours_begin(const void *self, void *iter, const ir_node *irn)
 187 {
 188         adj_iter_t *it = iter;
 189         find_neighbours(self, iter, irn);
 190         return pset_first(it->neighbours);
 191 }
 192
 193 static ir_node *ifg_std_neighbours_next(const void *self, void *iter)
 194 {
 195         return get_next_neighbour(iter);
 196 }
 197
 198 static void ifg_std_neighbours_break(const void *self, void *iter)
 199 {
 200         neighbours_break(iter, 1);
 201 }
 202
 203 typedef struct _cliques_iter_t {
 204         struct obstack ob;
 205         const be_chordal_env_t *cenv;
 206         ir_node **buf;
 207         ir_node **blocks;
 208         int n_blocks, blk;
 209         struct list_head *bor;
 210         pset *living;
 211 } cliques_iter_t;
 212
 213 static INLINE void free_clique_iter(cliques_iter_t *it) {
 214         it->n_blocks = -1;
 215         obstack_free(&it->ob, NULL);
 216         del_pset(it->living);
 217 }
 218
 219 static void get_blocks_dom_order(ir_node *blk, void *env) {
 220         cliques_iter_t *it = env;
 221         obstack_ptr_grow(&it->ob, blk);
 222 }
 223
 224 #define pset_foreach(pset, irn)  for(irn=pset_first(pset); irn; irn=pset_next(pset))
 225
 226
 227 /**
 228  * NOTE: Be careful when changing this function!
 229  *       First understand the control flow of consecutive calls.
 230  */
 231 static INLINE int get_next_clique(cliques_iter_t *it) {
 232
 233         /* continue in the block we left the last time */
 234         for (; it->blk < it->n_blocks; it->blk++) {
 235                 int output_on_shrink = 0;
 236                 struct list_head *head = get_block_border_head(it->cenv, it->blocks[it->blk]);
 237
 238                 /* on entry to a new block set the first border ... */
 239                 if (!it->bor)
 240                         it->bor = head->prev;
 241
 242                 /* ... otherwise continue with the border we left the last time */
 243                 for (; it->bor != head; it->bor = it->bor->prev) {
 244                         border_t *b = list_entry(it->bor, border_t, list);
 245
 246                         /* if its a definition irn starts living */
 247                         if (b->is_def) {
 248                                 pset_insert_ptr(it->living, b->irn);
 249                                 if (b->is_real)
 250                                         output_on_shrink = 1;
 251                         } else
 252
 253                         /* if its the last usage the irn dies */
 254                         {
 255                                 /* before shrinking the set, return the current maximal clique */
 256                                 if (output_on_shrink) {
 257                                         int count = 0;
 258                                         ir_node *irn;
 259
 260                                         /* fill the output buffer */
 261                                         pset_foreach(it->living, irn)
 262                                                 it->buf[count++] = irn;
 263
 264                                         assert(count > 0 && "We have a 'last usage', so there must be sth. in it->living");
 265
 266                                         return count;
 267                                 }
 268
 269                                 pset_remove_ptr(it->living, b->irn);
 270                         }
 271                 }
 272
 273                 it->bor = NULL;
 274                 assert(0 == pset_count(it->living) && "Something has survived! (At the end of the block it->living must be empty)");
 275         }
 276
 277         if (it->n_blocks != -1)
 278                 free_clique_iter(it);
 279
 280         return -1;
 281 }
 282
 283 static int ifg_std_cliques_begin(const void *self, void *iter, ir_node **buf)
 284 {
 285         const ifg_std_t *ifg = self;
 286         cliques_iter_t *it = iter;
 287         ir_node *start_bl = get_irg_start_block(ifg->env->irg);
 288
 289         obstack_init(&it->ob);
 290         dom_tree_walk(start_bl, get_blocks_dom_order, NULL, it);
 291
 292         it->cenv     = ifg->env;
 293         it->buf      = buf;
 294         it->n_blocks = obstack_object_size(&it->ob) / sizeof(void *);
 295         it->blocks   = obstack_finish(&it->ob);
 296         it->blk      = 0;
 297         it->bor      = NULL;
 298         it->living   = pset_new_ptr(2 * arch_register_class_n_regs(it->cenv->cls));
 299
 300         return get_next_clique(it);
 301 }
 302
 303 static int ifg_std_cliques_next(const void *self, void *iter)
 304 {
 305         return get_next_clique(iter);
 306 }
 307
 308 static void ifg_std_cliques_break(const void *self, void *iter)
 309 {
 310         free_clique_iter(iter);
 311 }
 312
 313
 314 static int ifg_std_degree(const void *self, const ir_node *irn)
 315 {
 316         adj_iter_t it;
 317         int degree;
 318         find_neighbours(self, &it, irn);
 319         degree = pset_count(it.neighbours);
 320         neighbours_break(&it, 1);
 321         return degree;
 322 }
 323
 324 static const be_ifg_impl_t ifg_std_impl = {
 325         sizeof(nodes_iter_t),
 326         sizeof(adj_iter_t),
 327         sizeof(cliques_iter_t),
 328
 329         ifg_std_free,
 330         ifg_std_connected,
 331         ifg_std_neighbours_begin,
 332         ifg_std_neighbours_next,
 333         ifg_std_neighbours_break,
 334         ifg_std_nodes_begin,
 335         ifg_std_nodes_next,
 336         ifg_std_nodes_break,
 337         ifg_std_cliques_begin,
 338         ifg_std_cliques_next,
 339         ifg_std_cliques_break,
 340         ifg_std_degree
 341 };
 342
 343 be_ifg_t *be_ifg_std_new(const be_chordal_env_t *env)
 344 {
 345         ifg_std_t *ifg = xmalloc(sizeof(*ifg));
 346
 347         ifg->impl = &ifg_std_impl;
 348         ifg->env  = env;
 349
 350         return (be_ifg_t *) ifg;
 351 }