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         const ifg_std_t *ifg = self;
  45         be_lv_t *lv = ifg->env->birg->lv;
  46         return values_interfere(lv, a, b);
  47 }
  48
  49 typedef struct _nodes_iter_t {
  50         const be_chordal_env_t *env;
  51         struct obstack obst;
  52         int n;
  53         int curr;
  54         ir_node **nodes;
  55 } nodes_iter_t;
  56
  57 static void nodes_walker(ir_node *bl, void *data)
  58 {
  59         nodes_iter_t *it = data;
  60         struct list_head *head = get_block_border_head(it->env, bl);
  61
  62         border_t *b;
  63
  64         foreach_border_head(head, b) {
  65                 if(b->is_def && b->is_real) {
  66                         obstack_ptr_grow(&it->obst, b->irn);
  67                         it->n++;
  68                 }
  69         }
  70 }
  71
  72 static void find_nodes(const void *self, void *iter) {
  73         const ifg_std_t *ifg = self;
  74         nodes_iter_t *it = iter;
  75
  76         obstack_init(&it->obst);
  77         it->n     = 0;
  78         it->curr  = 0;
  79         it->env   = ifg->env;
  80
  81         irg_block_walk_graph(ifg->env->irg, nodes_walker, NULL, iter);
  82         obstack_ptr_grow(&it->obst, NULL);
  83         it->nodes = obstack_finish(&it->obst);
  84 }
  85
  86 static INLINE void node_break(nodes_iter_t *it, int force)
  87 {
  88         if((it->curr >= it->n || force) && it->nodes) {
  89                 obstack_free(&it->obst, NULL);
  90                 it->nodes = NULL;
  91         }
  92 }
  93
  94 static ir_node *get_next_node(void *iter)
  95 {
  96         nodes_iter_t *it = iter;
  97         ir_node *res     = NULL;
  98
  99         if(it->curr < it->n)
 100                 res = it->nodes[it->curr++];
 101
 102         node_break(it, 0);
 103
 104         return res;
 105 }
 106
 107 static ir_node *ifg_std_nodes_begin(const void *self, void *iter)
 108 {
 109         find_nodes(self, iter);
 110         return get_next_node(iter);
 111 }
 112
 113 static ir_node *ifg_std_nodes_next(const void *self, void *iter)
 114 {
 115         return get_next_node(iter);
 116 }
 117
 118 static void ifg_std_nodes_break(const void *self, void *iter)
 119 {
 120         node_break(iter, 1);
 121 }
 122
 123 typedef struct _adj_iter_t {
 124         const be_chordal_env_t *env;
 125         const ir_node *irn;
 126         int reached_end;
 127         pset *neighbours;
 128 } adj_iter_t;
 129
 130 static void find_neighbour_walker(ir_node *block, void *data)
 131 {
 132         adj_iter_t *it          = data;
 133         struct list_head *head  = get_block_border_head(it->env, block);
 134
 135         border_t *b;
 136         int has_started = 0;
 137
 138         if(!be_is_live_in(it->env->birg->lv, block, it->irn) && block != get_nodes_block(it->irn))
 139                 return;
 140
 141         foreach_border_head(head, b) {
 142                 ir_node *irn = b->irn;
 143
 144                 if(irn == it->irn) {
 145                         if(b->is_def)
 146                                 has_started = 1;
 147                         else
 148                                 break; /* if we reached the end of the node's lifetime we can safely break */
 149                 }
 150                 else if(b->is_def) {
 151                         /* if any other node than the one in question starts living, add it to the set */
 152                         pset_insert_ptr(it->neighbours, irn);
 153                 }
 154                 else if(!has_started) {
 155                         /* we only delete, if the live range in question has not yet started */
 156                         pset_remove_ptr(it->neighbours, irn);
 157                 }
 158
 159         }
 160 }
 161
 162 static void find_neighbours(const ifg_std_t *ifg, adj_iter_t *it, const ir_node *irn)
 163 {
 164         it->env         = ifg->env;
 165         it->irn         = irn;
 166         it->neighbours  = pset_new_ptr(16);
 167         it->reached_end = 0;
 168
 169         dom_tree_walk(get_nodes_block(irn), find_neighbour_walker, NULL, it);
 170 }
 171
 172 static INLINE void neighbours_break(adj_iter_t *it, int force)
 173 {
 174         if((it->reached_end || force) && it->neighbours) {
 175                 del_pset(it->neighbours);
 176                 it->neighbours = NULL;
 177         }
 178 }
 179
 180 static ir_node *get_next_neighbour(adj_iter_t *it) {
 181         ir_node *res = pset_next(it->neighbours);
 182
 183         it->reached_end = res == NULL;
 184         neighbours_break(it, 0);
 185
 186         return res;
 187 }
 188
 189 static ir_node *ifg_std_neighbours_begin(const void *self, void *iter, const ir_node *irn)
 190 {
 191         adj_iter_t *it = iter;
 192         find_neighbours(self, iter, irn);
 193         return pset_first(it->neighbours);
 194 }
 195
 196 static ir_node *ifg_std_neighbours_next(const void *self, void *iter)
 197 {
 198         return get_next_neighbour(iter);
 199 }
 200
 201 static void ifg_std_neighbours_break(const void *self, void *iter)
 202 {
 203         neighbours_break(iter, 1);
 204 }
 205
 206 typedef struct _cliques_iter_t {
 207         struct obstack ob;
 208         const be_chordal_env_t *cenv;
 209         ir_node **buf;
 210         ir_node **blocks;
 211         int n_blocks, blk;
 212         struct list_head *bor;
 213         pset *living;
 214 } cliques_iter_t;
 215
 216 static INLINE void free_clique_iter(cliques_iter_t *it) {
 217         it->n_blocks = -1;
 218         obstack_free(&it->ob, NULL);
 219         del_pset(it->living);
 220 }
 221
 222 static void get_blocks_dom_order(ir_node *blk, void *env) {
 223         cliques_iter_t *it = env;
 224         obstack_ptr_grow(&it->ob, blk);
 225 }
 226
 227 #define pset_foreach(pset, irn)  for(irn=pset_first(pset); irn; irn=pset_next(pset))
 228
 229
 230 /**
 231  * NOTE: Be careful when changing this function!
 232  *       First understand the control flow of consecutive calls.
 233  */
 234 static INLINE int get_next_clique(cliques_iter_t *it) {
 235
 236         /* continue in the block we left the last time */
 237         for (; it->blk < it->n_blocks; it->blk++) {
 238                 int output_on_shrink = 0;
 239                 struct list_head *head = get_block_border_head(it->cenv, it->blocks[it->blk]);
 240
 241                 /* on entry to a new block set the first border ... */
 242                 if (!it->bor)
 243                         it->bor = head->prev;
 244
 245                 /* ... otherwise continue with the border we left the last time */
 246                 for (; it->bor != head; it->bor = it->bor->prev) {
 247                         border_t *b = list_entry(it->bor, border_t, list);
 248
 249                         /* if its a definition irn starts living */
 250                         if (b->is_def) {
 251                                 pset_insert_ptr(it->living, b->irn);
 252                                 if (b->is_real)
 253                                         output_on_shrink = 1;
 254                         } else
 255
 256                         /* if its the last usage the irn dies */
 257                         {
 258                                 /* before shrinking the set, return the current maximal clique */
 259                                 if (output_on_shrink) {
 260                                         int count = 0;
 261                                         ir_node *irn;
 262
 263                                         /* fill the output buffer */
 264                                         pset_foreach(it->living, irn)
 265                                                 it->buf[count++] = irn;
 266
 267                                         assert(count > 0 && "We have a 'last usage', so there must be sth. in it->living");
 268
 269                                         return count;
 270                                 }
 271
 272                                 pset_remove_ptr(it->living, b->irn);
 273                         }
 274                 }
 275
 276                 it->bor = NULL;
 277                 assert(0 == pset_count(it->living) && "Something has survived! (At the end of the block it->living must be empty)");
 278         }
 279
 280         if (it->n_blocks != -1)
 281                 free_clique_iter(it);
 282
 283         return -1;
 284 }
 285
 286 static int ifg_std_cliques_begin(const void *self, void *iter, ir_node **buf)
 287 {
 288         const ifg_std_t *ifg = self;
 289         cliques_iter_t *it = iter;
 290         ir_node *start_bl = get_irg_start_block(ifg->env->irg);
 291
 292         obstack_init(&it->ob);
 293         dom_tree_walk(start_bl, get_blocks_dom_order, NULL, it);
 294
 295         it->cenv     = ifg->env;
 296         it->buf      = buf;
 297         it->n_blocks = obstack_object_size(&it->ob) / sizeof(void *);
 298         it->blocks   = obstack_finish(&it->ob);
 299         it->blk      = 0;
 300         it->bor      = NULL;
 301         it->living   = pset_new_ptr(2 * arch_register_class_n_regs(it->cenv->cls));
 302
 303         return get_next_clique(it);
 304 }
 305
 306 static int ifg_std_cliques_next(const void *self, void *iter)
 307 {
 308         return get_next_clique(iter);
 309 }
 310
 311 static void ifg_std_cliques_break(const void *self, void *iter)
 312 {
 313         free_clique_iter(iter);
 314 }
 315
 316
 317 static int ifg_std_degree(const void *self, const ir_node *irn)
 318 {
 319         adj_iter_t it;
 320         int degree;
 321         find_neighbours(self, &it, irn);
 322         degree = pset_count(it.neighbours);
 323         neighbours_break(&it, 1);
 324         return degree;
 325 }
 326
 327 static const be_ifg_impl_t ifg_std_impl = {
 328         sizeof(nodes_iter_t),
 329         sizeof(adj_iter_t),
 330         sizeof(cliques_iter_t),
 331
 332         ifg_std_free,
 333         ifg_std_connected,
 334         ifg_std_neighbours_begin,
 335         ifg_std_neighbours_next,
 336         ifg_std_neighbours_break,
 337         ifg_std_nodes_begin,
 338         ifg_std_nodes_next,
 339         ifg_std_nodes_break,
 340         ifg_std_cliques_begin,
 341         ifg_std_cliques_next,
 342         ifg_std_cliques_break,
 343         ifg_std_degree
 344 };
 345
 346 be_ifg_t *be_ifg_std_new(const be_chordal_env_t *env)
 347 {
 348         ifg_std_t *ifg = xmalloc(sizeof(*ifg));
 349
 350         ifg->impl = &ifg_std_impl;
 351         ifg->env  = env;
 352
 353         return (be_ifg_t *) ifg;
 354 }