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