nsz Git - libfirm/blob - ir/opt/boolopt.c

   1 #include <assert.h>
   2 #include <string.h>
   3
   4 #include "adt/obst.h"
   5 #include "ircons.h"
   6 #include "irgmod.h"
   7 #include "irgwalk.h"
   8 #include "irprintf.h"
   9 #include "irnode.h"
  10 #include "tv.h"
  11
  12 typedef struct cond_pair {
  13         ir_node *cmp_lo;
  14         ir_node *cmp_hi;
  15         pn_Cmp   pnc_lo;
  16         pn_Cmp   pnc_hi;
  17         ir_node *proj_lo;
  18         ir_node *proj_hi;
  19         tarval  *tv_lo;
  20         tarval  *tv_hi;
  21 } cond_pair;
  22
  23 static int find_cond_pair(ir_node *const l, ir_node *const r, cond_pair *const res)
  24 {
  25         if (is_Proj(l) && is_Proj(r)) {
  26                 ir_node *const lo = get_Proj_pred(l);
  27                 ir_node *const ro = get_Proj_pred(r);
  28
  29                 if (is_Cmp(lo) && is_Cmp(ro)) {
  30                         ir_node *const lol = get_Cmp_left(lo);
  31                         ir_node *const lor = get_Cmp_right(lo);
  32                         ir_node *const rol = get_Cmp_left(ro);
  33                         ir_node *const ror = get_Cmp_right(ro);
  34
  35                         if(is_Const(lor) && is_Const_null(lor) && is_Const(ror) && is_Const_null(ror) && get_Proj_proj(l) == pn_Cmp_Lg && get_Proj_proj(r) == pn_Cmp_Lg) {
  36                                 ir_fprintf(stderr, "found zero zero\n");
  37                         }
  38
  39                         /* TODO float */
  40                         /* The constants shall be unequal.  Local optimisations handle the
  41                          * equal case */
  42                         if (lol == rol && mode_is_int(get_irn_mode(lol)) && lor != ror && is_Const(lor) && is_Const(ror)) {
  43                                 tarval *const tv_l  = get_Const_tarval(lor);
  44                                 tarval *const tv_r  = get_Const_tarval(ror);
  45                                 pn_Cmp  const pnc_l = get_Proj_proj(l);
  46                                 pn_Cmp  const pnc_r = get_Proj_proj(r);
  47                                 pn_Cmp  const rel   = tarval_cmp(tv_l, tv_r);
  48
  49                                 assert(rel != pn_Cmp_Eq);
  50
  51                                 if (rel == pn_Cmp_Lt) {
  52                                         res->cmp_lo  = lo;
  53                                         res->cmp_hi  = ro;
  54                                         res->pnc_lo  = pnc_l;
  55                                         res->pnc_hi  = pnc_r;
  56                                         res->proj_lo = l;
  57                                         res->proj_hi = r;
  58                                         res->tv_lo   = tv_l;
  59                                         res->tv_hi   = tv_r;
  60                                 } else {
  61                                         assert(rel == pn_Cmp_Gt);
  62                                         res->cmp_lo  = ro;
  63                                         res->cmp_hi  = lo;
  64                                         res->pnc_lo  = pnc_r;
  65                                         res->pnc_hi  = pnc_l;
  66                                         res->proj_lo = r;
  67                                         res->proj_hi = l;
  68                                         res->tv_lo   = tv_r;
  69                                         res->tv_hi   = tv_l;
  70                                 }
  71                                 return 1;
  72                         }
  73                 }
  74         }
  75         return 0;
  76 }
  77
  78 static ir_node *bool_and(cond_pair* const cpair)
  79 {
  80         ir_node *const cmp_lo  = cpair->cmp_lo;
  81         ir_node *const cmp_hi  = cpair->cmp_hi;
  82         pn_Cmp   const pnc_lo  = cpair->pnc_lo;
  83         pn_Cmp   const pnc_hi  = cpair->pnc_hi;
  84         ir_node *const proj_lo = cpair->proj_lo;
  85         ir_node *const proj_hi = cpair->proj_hi;
  86         tarval  *const tv_lo   = cpair->tv_lo;
  87         tarval  *const tv_hi   = cpair->tv_hi;
  88
  89         if ((pnc_lo == pn_Cmp_Lt || pnc_lo == pn_Cmp_Le || pnc_lo == pn_Cmp_Eq) &&
  90                         (pnc_hi == pn_Cmp_Eq || pnc_hi == pn_Cmp_Ge || pnc_hi == pn_Cmp_Gt)) {
  91                 /* x <|<=|== lo | x ==|>=|> hi -> false */
  92                 ir_node *const t = new_Const(mode_b, tarval_b_false);
  93                 return t;
  94         } else if ((pnc_lo == pn_Cmp_Lt || pnc_lo == pn_Cmp_Le || pnc_lo == pn_Cmp_Eq) &&
  95                                                  (pnc_hi == pn_Cmp_Lt || pnc_hi == pn_Cmp_Le || pnc_hi == pn_Cmp_Ne)) {
  96                 /* x <|<=|== lo && x <|<=|!= hi -> x <|<=|== lo */
  97                 return proj_lo;
  98         } else if ((pnc_lo == pn_Cmp_Ge || pnc_lo == pn_Cmp_Gt || pnc_lo == pn_Cmp_Ne) &&
  99                                                  (pnc_hi == pn_Cmp_Eq || pnc_hi == pn_Cmp_Ge || pnc_hi == pn_Cmp_Gt)) {
 100                 /* x >=|>|!= lo || x ==|>=|> hi -> x ==|>=|> hi */
 101                 return proj_hi;
 102         } else if (tarval_is_one(tarval_sub(tv_hi, tv_lo))) { /* lo + 1 == hi */
 103                 if (pnc_lo == pn_Cmp_Ge && pnc_hi == pn_Cmp_Lt) {
 104                         /* x >= c || x < c + 1 -> x == c */
 105                         ir_graph *const irg   = current_ir_graph;
 106                         ir_node  *const block = get_nodes_block(cmp_lo);
 107                         ir_node  *const p = new_r_Proj(irg, block, cmp_lo, mode_b, pn_Cmp_Eq);
 108                         return p;
 109                 } else if (pnc_lo == pn_Cmp_Gt) {
 110                         if (pnc_hi == pn_Cmp_Ne) {
 111                                 /* x > c || x != c + 1 -> x > c + 1 */
 112                                 ir_graph *const irg   = current_ir_graph;
 113                                 ir_node  *const block = get_nodes_block(cmp_hi);
 114                                 ir_node  *const p = new_r_Proj(irg, block, cmp_hi, mode_b, pn_Cmp_Gt);
 115                                 return p;
 116                         } else if (pnc_hi == pn_Cmp_Lt) {
 117                                 /* x > c || x < c + 1 -> false */
 118                                 ir_node *const t = new_Const(mode_b, tarval_b_false);
 119                                 return t;
 120                         } else if (pnc_hi == pn_Cmp_Le) {
 121                                 /* x > c || x <= c + 1 -> x != c + 1 */
 122                                 ir_graph *const irg   = current_ir_graph;
 123                                 ir_node  *const block = get_nodes_block(cmp_hi);
 124                                 ir_node  *const p = new_r_Proj(irg, block, cmp_hi, mode_b, pn_Cmp_Eq);
 125                                 return p;
 126                         }
 127                 } else if (pnc_lo == pn_Cmp_Ne && pnc_hi == pn_Cmp_Lt) {
 128                         /* x != c || c < c + 1 -> x < c */
 129                         ir_graph *const irg   = current_ir_graph;
 130                         ir_node  *const block = get_nodes_block(cmp_lo);
 131                         ir_node  *const p     = new_r_Proj(irg, block, cmp_lo, mode_b, pn_Cmp_Lt);
 132                         return p;
 133                 }
 134         }
 135         return NULL;
 136 }
 137
 138 static ir_node *bool_or(cond_pair *const cpair)
 139 {
 140         ir_node *const cmp_lo  = cpair->cmp_lo;
 141         ir_node *const cmp_hi  = cpair->cmp_hi;
 142         pn_Cmp   const pnc_lo  = cpair->pnc_lo;
 143         pn_Cmp   const pnc_hi  = cpair->pnc_hi;
 144         ir_node *const proj_lo = cpair->proj_lo;
 145         ir_node *const proj_hi = cpair->proj_hi;
 146         tarval  *const tv_lo   = cpair->tv_lo;
 147         tarval  *const tv_hi   = cpair->tv_hi;
 148
 149         if ((pnc_lo == pn_Cmp_Ge || pnc_lo == pn_Cmp_Gt || pnc_lo == pn_Cmp_Ne) &&
 150                         (pnc_hi == pn_Cmp_Lt || pnc_hi == pn_Cmp_Le || pnc_hi == pn_Cmp_Ne)) {
 151                 /* x >=|>|!= lo | x <|<=|!= hi -> true */
 152                 ir_node *const t = new_Const(mode_b, tarval_b_true);
 153                 return t;
 154         } else if ((pnc_lo == pn_Cmp_Lt || pnc_lo == pn_Cmp_Le || pnc_lo == pn_Cmp_Eq) &&
 155                                                  (pnc_hi == pn_Cmp_Lt || pnc_hi == pn_Cmp_Le || pnc_hi == pn_Cmp_Ne)) {
 156                 /* x <|<=|== lo || x <|<=|!= hi -> x <|<=|!= hi */
 157                 return proj_hi;
 158         } else if ((pnc_lo == pn_Cmp_Ge || pnc_lo == pn_Cmp_Gt || pnc_lo == pn_Cmp_Ne) &&
 159                                                  (pnc_hi == pn_Cmp_Eq || pnc_hi == pn_Cmp_Ge || pnc_hi == pn_Cmp_Gt)) {
 160                 /* x >=|>|!= lo || x ==|>=|> hi -> x >=|>|!= lo */
 161                 return proj_lo;
 162         } else if (tarval_is_one(tarval_sub(tv_hi, tv_lo))) { /* lo + 1 == hi */
 163                 if (pnc_lo == pn_Cmp_Lt && pnc_hi == pn_Cmp_Ge) {
 164                         /* x < c || x >= c + 1 -> x != c */
 165                         ir_graph *const irg   = current_ir_graph;
 166                         ir_node  *const block = get_nodes_block(cmp_lo);
 167                         ir_node  *const p = new_r_Proj(irg, block, cmp_lo, mode_b, pn_Cmp_Ne);
 168                         return p;
 169                 } else if (pnc_lo == pn_Cmp_Le) {
 170                         if (pnc_hi == pn_Cmp_Eq) {
 171                                 /* x <= c || x == c + 1 -> x <= c + 1 */
 172                                 ir_graph *const irg   = current_ir_graph;
 173                                 ir_node  *const block = get_nodes_block(cmp_hi);
 174                                 ir_node  *const p = new_r_Proj(irg, block, cmp_hi, mode_b, pn_Cmp_Le);
 175                                 return p;
 176                         } else if (pnc_hi == pn_Cmp_Ge) {
 177                                 /* x <= c || x >= c + 1 -> true */
 178                                 ir_node *const t = new_Const(mode_b, tarval_b_true);
 179                                 return t;
 180                         } else if (pnc_hi == pn_Cmp_Gt) {
 181                                 /* x <= c || x > c + 1 -> x != c + 1 */
 182                                 ir_graph *const irg   = current_ir_graph;
 183                                 ir_node  *const block = get_nodes_block(cmp_hi);
 184                                 ir_node  *const p = new_r_Proj(irg, block, cmp_hi, mode_b, pn_Cmp_Ne);
 185                                 return p;
 186                         }
 187                 } else if (pnc_lo == pn_Cmp_Eq && pnc_hi == pn_Cmp_Ge) {
 188                         /* x == c || c >= c + 1 -> x >= c */
 189                         ir_graph *const irg   = current_ir_graph;
 190                         ir_node  *const block = get_nodes_block(cmp_lo);
 191                         ir_node  *const p     = new_r_Proj(irg, block, cmp_lo, mode_b, pn_Cmp_Ge);
 192                         return p;
 193                 }
 194         }
 195         return NULL;
 196 }
 197
 198 static void bool_walk(ir_node *n, void *env)
 199 {
 200         (void)env;
 201
 202         if (get_irn_mode(n) != mode_b)
 203                 return;
 204
 205         if (is_And(n)) {
 206                 ir_node *const l = get_And_left(n);
 207                 ir_node *const r = get_And_right(n);
 208                 ir_node *      replacement;
 209                 cond_pair      cpair;
 210                 if (!find_cond_pair(l, r, &cpair))
 211                         return;
 212                 replacement = bool_and(&cpair);
 213                 if (replacement)
 214                         exchange(n, replacement);
 215         } else if (is_Or(n)) {
 216                 ir_node *const l = get_Or_left(n);
 217                 ir_node *const r = get_Or_right(n);
 218                 ir_node *      replacement;
 219                 cond_pair      cpair;
 220                 if (!find_cond_pair(l, r, &cpair))
 221                         return;
 222                 replacement = bool_or(&cpair);
 223                 if (replacement)
 224                         exchange(n, replacement);
 225         }
 226 }
 227
 228 static struct obstack obst;
 229
 230 typedef struct block_info_t {
 231         ir_node *phi;   /**< head of the Phi list */
 232         int has_pinned; /**< set if the block contains instructions that cannot be
 233                              moved */
 234 } block_info_t;
 235
 236 static block_info_t* get_block_blockinfo(ir_node* block)
 237 {
 238         return get_irn_link(block);
 239 }
 240
 241 static void create_blockinfos(ir_node *node, void *env)
 242 {
 243         block_info_t *block_info;
 244         (void) env;
 245
 246         /* we visit blocks before any other nodes (from the block) */
 247         if (!is_Block(node))
 248                 return;
 249
 250         block_info = obstack_alloc(&obst, sizeof(block_info[0]));
 251         memset(block_info, 0, sizeof(block_info[0]));
 252         set_irn_link(node, block_info);
 253 }
 254
 255 static void collect_phis(ir_node *node, void *env)
 256 {
 257         (void) env;
 258
 259         if (is_Phi(node)) {
 260                 ir_node      *block = get_nodes_block(node);
 261                 block_info_t *bi    = get_block_blockinfo(block);
 262
 263                 set_irn_link(node, bi->phi);
 264                 bi->phi = node;
 265                 return;
 266         }
 267
 268         /* Ignore control flow nodes, these will be removed. */
 269         if (get_irn_pinned(node) == op_pin_state_pinned &&
 270                         !is_Block(node) && !is_cfop(node)) {
 271                 ir_node      *block = get_nodes_block(node);
 272                 block_info_t *bi    = get_block_blockinfo(block);
 273
 274                 bi->has_pinned = 1;
 275         }
 276 }
 277
 278 ir_node *skip_empty_block(ir_node *node)
 279 {
 280         ir_node      *block;
 281         block_info_t *block_info;
 282
 283         if(!is_Jmp(node))
 284                 return node;
 285
 286         block = get_nodes_block(node);
 287         if(get_Block_n_cfgpreds(block) != 1)
 288                 return node;
 289
 290         block_info = get_block_blockinfo(block);
 291         if(block_info->has_pinned)
 292                 return node;
 293
 294         return get_Block_cfgpred(block, 0);
 295 }
 296
 297 static void find_cf_and_or_walker(ir_node *block, void *env)
 298 {
 299         int i, i2;
 300         int n_cfgpreds = get_Block_n_cfgpreds(block);
 301         (void) env;
 302
 303         if(n_cfgpreds < 2)
 304                 return;
 305
 306         /* Find the following structure:
 307          *
 308          *        upper_block
 309          *         /       |
 310          *        /        |
 311          *   lower_block   |
 312          *     /  \        |
 313          *   ...   \       |
 314          *           block
 315          */
 316
 317 restart:
 318         for(i = 0; i < n_cfgpreds; ++i) {
 319                 ir_node      *lower_block;
 320                 ir_node      *lower_cf;
 321                 ir_node      *cond;
 322                 ir_node      *cond_selector;
 323                 block_info_t *block_info;
 324                 ir_node      *lower_pred;
 325
 326                 lower_cf = get_Block_cfgpred(block, i);
 327                 lower_cf = skip_empty_block(lower_cf);
 328                 if(!is_Proj(lower_cf))
 329                         continue;
 330
 331                 lower_block = get_nodes_block(lower_cf);
 332                 if(get_Block_n_cfgpreds(lower_block) != 1)
 333                         continue;
 334
 335                 cond = get_Proj_pred(lower_cf);
 336                 if(!is_Cond(cond))
 337                         continue;
 338
 339                 cond_selector = get_Cond_selector(cond);
 340                 if(get_irn_mode(cond_selector) != mode_b)
 341                         continue;
 342
 343                 /* the block must not produce any side-effects */
 344                 block_info = get_block_blockinfo(lower_block);
 345                 if(block_info->has_pinned)
 346                         continue;
 347
 348                 lower_pred = get_Block_cfgpred_block(lower_block, 0);
 349
 350                 for(i2 = 0; i2 < n_cfgpreds; ++i2) {
 351                         ir_node   *upper_block;
 352                         ir_node   *upper_cf;
 353                         ir_node   *upper_cond;
 354                         ir_node   *upper_cond_selector;
 355                         ir_node   *replacement;
 356                         ir_graph  *irg;
 357                         cond_pair  cpair;
 358
 359                         upper_cf    = get_Block_cfgpred(block, i2);
 360                         upper_cf    = skip_empty_block(upper_cf);
 361                         if(is_Bad(upper_cf))
 362                                 continue;
 363                         upper_block = get_nodes_block(upper_cf);
 364                         if(upper_block != lower_pred)
 365                                 continue;
 366
 367                         assert(is_Proj(upper_cf));
 368                         upper_cond = get_Proj_pred(upper_cf);
 369                         assert(is_Cond(upper_cond));
 370                         upper_cond_selector = get_Cond_selector(upper_cond);
 371                         if(get_irn_mode(upper_cond_selector) != mode_b)
 372                                 continue;
 373
 374                         /* we have found the structure */
 375                         /* TODO: check phis */
 376                         if(!find_cond_pair(cond_selector, upper_cond_selector, &cpair))
 377                                 continue;
 378
 379                         /* normalize pncs: we need the true case to jump into the
 380                          * common block */
 381                         irg = current_ir_graph;
 382                         if(get_Proj_proj(lower_cf) == pn_Cond_false) {
 383                                 if(cpair.proj_lo == cond_selector) {
 384                                         ir_mode *mode = get_tarval_mode(cpair.tv_lo);
 385                                         cpair.pnc_lo  = get_negated_pnc(cpair.pnc_lo, mode);
 386                                         cpair.proj_lo = new_r_Proj(irg, lower_block,
 387                                                         get_Proj_pred(cpair.proj_lo), mode_b, cpair.pnc_lo);
 388                                 } else {
 389                                         assert(cpair.proj_hi == cond_selector);
 390                                         ir_mode *mode = get_tarval_mode(cpair.tv_hi);
 391                                         cpair.pnc_hi  = get_negated_pnc(cpair.pnc_hi, mode);
 392                                         cpair.proj_hi = new_r_Proj(irg, lower_block,
 393                                                         get_Proj_pred(cpair.proj_hi), mode_b, cpair.pnc_hi);
 394                                 }
 395                         }
 396                         if(get_Proj_proj(upper_cf) == pn_Cond_false) {
 397                                 if(cpair.proj_lo == upper_cond_selector) {
 398                                         ir_mode *mode = get_tarval_mode(cpair.tv_lo);
 399                                         cpair.pnc_lo  = get_negated_pnc(cpair.pnc_lo, mode);
 400                                         cpair.proj_lo = new_r_Proj(irg, upper_block,
 401                                                         get_Proj_pred(cpair.proj_lo), mode_b, cpair.pnc_lo);
 402                                 } else {
 403                                         assert(cpair.proj_hi == upper_cond_selector);
 404                                         ir_mode *mode = get_tarval_mode(cpair.tv_hi);
 405                                         cpair.pnc_hi  = get_negated_pnc(cpair.pnc_hi, mode);
 406                                         cpair.proj_hi = new_r_Proj(irg, upper_block,
 407                                                         get_Proj_pred(cpair.proj_hi), mode_b, cpair.pnc_hi);
 408                                 }
 409                         }
 410
 411                         /* can we optimize the case? */
 412                         replacement = bool_or(&cpair);
 413                         if(replacement == NULL)
 414                                 continue;
 415
 416                         /* move all nodes from lower block to upper block */
 417                         exchange(lower_block, upper_block);
 418
 419                         set_Block_cfgpred(block, i2, new_Bad());
 420
 421                         /* the optimisations expected the true case to jump */
 422                         if(get_Proj_proj(lower_cf) == pn_Cond_false) {
 423                                 ir_node *block = get_nodes_block(replacement);
 424                                 replacement    = new_rd_Not(NULL, current_ir_graph, block,
 425                                                             replacement, mode_b);
 426                         }
 427                         set_Cond_selector(cond, replacement);
 428
 429                         ir_fprintf(stderr, "replaced (ub %+F)\n", upper_block);
 430                         goto restart;
 431                 }
 432         }
 433 }
 434
 435 void opt_bool(ir_graph *const irg)
 436 {
 437         irg_walk_graph(irg, NULL, bool_walk, NULL);
 438
 439         set_using_irn_link(irg);
 440
 441         obstack_init(&obst);
 442
 443         irg_walk_graph(irg, create_blockinfos, collect_phis, NULL);
 444
 445         irg_block_walk_graph(irg, NULL, find_cf_and_or_walker, NULL);
 446
 447         obstack_free(&obst, NULL);
 448
 449         set_irg_outs_inconsistent(irg);
 450         set_irg_doms_inconsistent(irg);
 451         set_irg_extblk_inconsistent(irg);
 452         set_irg_loopinfo_inconsistent(irg);
 453
 454         clear_using_irn_link(irg);
 455 }