gcc/gimple-walk.c

   1 /* Gimple walk support.
   2
   3    Copyright (C) 2007-2015 Free Software Foundation, Inc.
   4    Contributed by Aldy Hernandez <aldyh@redhat.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "alias.h"
  27 #include "symtab.h"
  28 #include "tree.h"
  29 #include "predict.h"
  30 #include "hard-reg-set.h"
  31 #include "function.h"
  32 #include "gimple-expr.h"
  33 #include "tree-ssa-alias.h"
  34 #include "basic-block.h"
  35 #include "fold-const.h"
  36 #include "gimple.h"
  37 #include "gimple-iterator.h"
  38 #include "gimple-walk.h"
  39 #include "stmt.h"
  40
  41 /* Walk all the statements in the sequence *PSEQ calling walk_gimple_stmt
  42    on each one.  WI is as in walk_gimple_stmt.
  43
  44    If walk_gimple_stmt returns non-NULL, the walk is stopped, and the
  45    value is stored in WI->CALLBACK_RESULT.  Also, the statement that
  46    produced the value is returned if this statement has not been
  47    removed by a callback (wi->removed_stmt).  If the statement has
  48    been removed, NULL is returned.
  49
  50    Otherwise, all the statements are walked and NULL returned.  */
  51
  52 gimple
  53 walk_gimple_seq_mod (gimple_seq *pseq, walk_stmt_fn callback_stmt,
  54                      walk_tree_fn callback_op, struct walk_stmt_info *wi)
  55 {
  56   gimple_stmt_iterator gsi;
  57
  58   for (gsi = gsi_start (*pseq); !gsi_end_p (gsi); )
  59     {
  60       tree ret = walk_gimple_stmt (&gsi, callback_stmt, callback_op, wi);
  61       if (ret)
  62         {
  63           /* If CALLBACK_STMT or CALLBACK_OP return a value, WI must exist
  64              to hold it.  */
  65           gcc_assert (wi);
  66           wi->callback_result = ret;
  67
  68           return wi->removed_stmt ? NULL : gsi_stmt (gsi);
  69         }
  70
  71       if (!wi->removed_stmt)
  72         gsi_next (&gsi);
  73     }
  74
  75   if (wi)
  76     wi->callback_result = NULL_TREE;
  77
  78   return NULL;
  79 }
  80
  81
  82 /* Like walk_gimple_seq_mod, but ensure that the head of SEQ isn't
  83    changed by the callbacks.  */
  84
  85 gimple
  86 walk_gimple_seq (gimple_seq seq, walk_stmt_fn callback_stmt,
  87                  walk_tree_fn callback_op, struct walk_stmt_info *wi)
  88 {
  89   gimple_seq seq2 = seq;
  90   gimple ret = walk_gimple_seq_mod (&seq2, callback_stmt, callback_op, wi);
  91   gcc_assert (seq2 == seq);
  92   return ret;
  93 }
  94
  95
  96 /* Helper function for walk_gimple_stmt.  Walk operands of a GIMPLE_ASM.  */
  97
  98 static tree
  99 walk_gimple_asm (gasm *stmt, walk_tree_fn callback_op,
 100                  struct walk_stmt_info *wi)
 101 {
 102   tree ret, op;
 103   unsigned noutputs;
 104   const char **oconstraints;
 105   unsigned i, n;
 106   const char *constraint;
 107   bool allows_mem, allows_reg, is_inout;
 108
 109   noutputs = gimple_asm_noutputs (stmt);
 110   oconstraints = (const char **) alloca ((noutputs) * sizeof (const char *));
 111
 112   if (wi)
 113     wi->is_lhs = true;
 114
 115   for (i = 0; i < noutputs; i++)
 116     {
 117       op = gimple_asm_output_op (stmt, i);
 118       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (op)));
 119       oconstraints[i] = constraint;
 120       if (wi)
 121         {
 122           if (parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
 123                                        &allows_reg, &is_inout))
 124             wi->val_only = (allows_reg || !allows_mem);
 125         }
 126       ret = walk_tree (&TREE_VALUE (op), callback_op, wi, NULL);
 127       if (ret)
 128         return ret;
 129     }
 130
 131   n = gimple_asm_ninputs (stmt);
 132   for (i = 0; i < n; i++)
 133     {
 134       op = gimple_asm_input_op (stmt, i);
 135       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (op)));
 136
 137       if (wi)
 138         {
 139           if (parse_input_constraint (&constraint, 0, 0, noutputs, 0,
 140                                       oconstraints, &allows_mem, &allows_reg))
 141             {
 142               wi->val_only = (allows_reg || !allows_mem);
 143               /* Although input "m" is not really a LHS, we need a lvalue.  */
 144               wi->is_lhs = !wi->val_only;
 145             }
 146         }
 147       ret = walk_tree (&TREE_VALUE (op), callback_op, wi, NULL);
 148       if (ret)
 149         return ret;
 150     }
 151
 152   if (wi)
 153     {
 154       wi->is_lhs = false;
 155       wi->val_only = true;
 156     }
 157
 158   n = gimple_asm_nlabels (stmt);
 159   for (i = 0; i < n; i++)
 160     {
 161       op = gimple_asm_label_op (stmt, i);
 162       ret = walk_tree (&TREE_VALUE (op), callback_op, wi, NULL);
 163       if (ret)
 164         return ret;
 165     }
 166
 167   return NULL_TREE;
 168 }
 169
 170
 171 /* Helper function of WALK_GIMPLE_STMT.  Walk every tree operand in
 172    STMT.  CALLBACK_OP and WI are as in WALK_GIMPLE_STMT.
 173
 174    CALLBACK_OP is called on each operand of STMT via walk_tree.
 175    Additional parameters to walk_tree must be stored in WI.  For each operand
 176    OP, walk_tree is called as:
 177
 178         walk_tree (&OP, CALLBACK_OP, WI, WI->PSET)
 179
 180    If CALLBACK_OP returns non-NULL for an operand, the remaining
 181    operands are not scanned.
 182
 183    The return value is that returned by the last call to walk_tree, or
 184    NULL_TREE if no CALLBACK_OP is specified.  */
 185
 186 tree
 187 walk_gimple_op (gimple stmt, walk_tree_fn callback_op,
 188                 struct walk_stmt_info *wi)
 189 {
 190   hash_set<tree> *pset = (wi) ? wi->pset : NULL;
 191   unsigned i;
 192   tree ret = NULL_TREE;
 193
 194   switch (gimple_code (stmt))
 195     {
 196     case GIMPLE_ASSIGN:
 197       /* Walk the RHS operands.  If the LHS is of a non-renamable type or
 198          is a register variable, we may use a COMPONENT_REF on the RHS.  */
 199       if (wi)
 200         {
 201           tree lhs = gimple_assign_lhs (stmt);
 202           wi->val_only
 203             = (is_gimple_reg_type (TREE_TYPE (lhs)) && !is_gimple_reg (lhs))
 204               || gimple_assign_rhs_class (stmt) != GIMPLE_SINGLE_RHS;
 205         }
 206
 207       for (i = 1; i < gimple_num_ops (stmt); i++)
 208         {
 209           ret = walk_tree (gimple_op_ptr (stmt, i), callback_op, wi,
 210                            pset);
 211           if (ret)
 212             return ret;
 213         }
 214
 215       /* Walk the LHS.  If the RHS is appropriate for a memory, we
 216          may use a COMPONENT_REF on the LHS.  */
 217       if (wi)
 218         {
 219           /* If the RHS is of a non-renamable type or is a register variable,
 220              we may use a COMPONENT_REF on the LHS.  */
 221           tree rhs1 = gimple_assign_rhs1 (stmt);
 222           wi->val_only
 223             = (is_gimple_reg_type (TREE_TYPE (rhs1)) && !is_gimple_reg (rhs1))
 224               || gimple_assign_rhs_class (stmt) != GIMPLE_SINGLE_RHS;
 225           wi->is_lhs = true;
 226         }
 227
 228       ret = walk_tree (gimple_op_ptr (stmt, 0), callback_op, wi, pset);
 229       if (ret)
 230         return ret;
 231
 232       if (wi)
 233         {
 234           wi->val_only = true;
 235           wi->is_lhs = false;
 236         }
 237       break;
 238
 239     case GIMPLE_CALL:
 240       if (wi)
 241         {
 242           wi->is_lhs = false;
 243           wi->val_only = true;
 244         }
 245
 246       ret = walk_tree (gimple_call_chain_ptr (as_a <gcall *> (stmt)),
 247                        callback_op, wi, pset);
 248       if (ret)
 249         return ret;
 250
 251       ret = walk_tree (gimple_call_fn_ptr (stmt), callback_op, wi, pset);
 252       if (ret)
 253         return ret;
 254
 255       for (i = 0; i < gimple_call_num_args (stmt); i++)
 256         {
 257           if (wi)
 258             wi->val_only
 259               = is_gimple_reg_type (TREE_TYPE (gimple_call_arg (stmt, i)));
 260           ret = walk_tree (gimple_call_arg_ptr (stmt, i), callback_op, wi,
 261                            pset);
 262           if (ret)
 263             return ret;
 264         }
 265
 266       if (gimple_call_lhs (stmt))
 267         {
 268           if (wi)
 269             {
 270               wi->is_lhs = true;
 271               wi->val_only
 272                 = is_gimple_reg_type (TREE_TYPE (gimple_call_lhs (stmt)));
 273             }
 274
 275           ret = walk_tree (gimple_call_lhs_ptr (stmt), callback_op, wi, pset);
 276           if (ret)
 277             return ret;
 278         }
 279
 280       if (wi)
 281         {
 282           wi->is_lhs = false;
 283           wi->val_only = true;
 284         }
 285       break;
 286
 287     case GIMPLE_CATCH:
 288       ret = walk_tree (gimple_catch_types_ptr (as_a <gcatch *> (stmt)),
 289                        callback_op, wi, pset);
 290       if (ret)
 291         return ret;
 292       break;
 293
 294     case GIMPLE_EH_FILTER:
 295       ret = walk_tree (gimple_eh_filter_types_ptr (stmt), callback_op, wi,
 296                        pset);
 297       if (ret)
 298         return ret;
 299       break;
 300
 301     case GIMPLE_ASM:
 302       ret = walk_gimple_asm (as_a <gasm *> (stmt), callback_op, wi);
 303       if (ret)
 304         return ret;
 305       break;
 306
 307     case GIMPLE_OMP_CONTINUE:
 308       {
 309         gomp_continue *cont_stmt = as_a <gomp_continue *> (stmt);
 310         ret = walk_tree (gimple_omp_continue_control_def_ptr (cont_stmt),
 311                          callback_op, wi, pset);
 312         if (ret)
 313           return ret;
 314
 315         ret = walk_tree (gimple_omp_continue_control_use_ptr (cont_stmt),
 316                          callback_op, wi, pset);
 317         if (ret)
 318           return ret;
 319       }
 320       break;
 321
 322     case GIMPLE_OMP_CRITICAL:
 323       {
 324         gomp_critical *omp_stmt = as_a <gomp_critical *> (stmt);
 325         ret = walk_tree (gimple_omp_critical_name_ptr (omp_stmt),
 326                          callback_op, wi, pset);
 327         if (ret)
 328           return ret;
 329       }
 330       break;
 331
 332     case GIMPLE_OMP_FOR:
 333       ret = walk_tree (gimple_omp_for_clauses_ptr (stmt), callback_op, wi,
 334                        pset);
 335       if (ret)
 336         return ret;
 337       for (i = 0; i < gimple_omp_for_collapse (stmt); i++)
 338         {
 339           ret = walk_tree (gimple_omp_for_index_ptr (stmt, i), callback_op,
 340                            wi, pset);
 341           if (ret)
 342             return ret;
 343           ret = walk_tree (gimple_omp_for_initial_ptr (stmt, i), callback_op,
 344                            wi, pset);
 345           if (ret)
 346             return ret;
 347           ret = walk_tree (gimple_omp_for_final_ptr (stmt, i), callback_op,
 348                            wi, pset);
 349           if (ret)
 350             return ret;
 351           ret = walk_tree (gimple_omp_for_incr_ptr (stmt, i), callback_op,
 352                            wi, pset);
 353           if (ret)
 354             return ret;
 355         }
 356       break;
 357
 358     case GIMPLE_OMP_PARALLEL:
 359       {
 360         gomp_parallel *omp_par_stmt = as_a <gomp_parallel *> (stmt);
 361         ret = walk_tree (gimple_omp_parallel_clauses_ptr (omp_par_stmt),
 362                          callback_op, wi, pset);
 363         if (ret)
 364           return ret;
 365         ret = walk_tree (gimple_omp_parallel_child_fn_ptr (omp_par_stmt),
 366                          callback_op, wi, pset);
 367         if (ret)
 368           return ret;
 369         ret = walk_tree (gimple_omp_parallel_data_arg_ptr (omp_par_stmt),
 370                          callback_op, wi, pset);
 371         if (ret)
 372           return ret;
 373       }
 374       break;
 375
 376     case GIMPLE_OMP_TASK:
 377       ret = walk_tree (gimple_omp_task_clauses_ptr (stmt), callback_op,
 378                        wi, pset);
 379       if (ret)
 380         return ret;
 381       ret = walk_tree (gimple_omp_task_child_fn_ptr (stmt), callback_op,
 382                        wi, pset);
 383       if (ret)
 384         return ret;
 385       ret = walk_tree (gimple_omp_task_data_arg_ptr (stmt), callback_op,
 386                        wi, pset);
 387       if (ret)
 388         return ret;
 389       ret = walk_tree (gimple_omp_task_copy_fn_ptr (stmt), callback_op,
 390                        wi, pset);
 391       if (ret)
 392         return ret;
 393       ret = walk_tree (gimple_omp_task_arg_size_ptr (stmt), callback_op,
 394                        wi, pset);
 395       if (ret)
 396         return ret;
 397       ret = walk_tree (gimple_omp_task_arg_align_ptr (stmt), callback_op,
 398                        wi, pset);
 399       if (ret)
 400         return ret;
 401       break;
 402
 403     case GIMPLE_OMP_SECTIONS:
 404       ret = walk_tree (gimple_omp_sections_clauses_ptr (stmt), callback_op,
 405                        wi, pset);
 406       if (ret)
 407         return ret;
 408       ret = walk_tree (gimple_omp_sections_control_ptr (stmt), callback_op,
 409                        wi, pset);
 410       if (ret)
 411         return ret;
 412
 413       break;
 414
 415     case GIMPLE_OMP_SINGLE:
 416       ret = walk_tree (gimple_omp_single_clauses_ptr (stmt), callback_op, wi,
 417                        pset);
 418       if (ret)
 419         return ret;
 420       break;
 421
 422     case GIMPLE_OMP_TARGET:
 423       {
 424         gomp_target *omp_stmt = as_a <gomp_target *> (stmt);
 425         ret = walk_tree (gimple_omp_target_clauses_ptr (omp_stmt),
 426                          callback_op, wi, pset);
 427         if (ret)
 428           return ret;
 429         ret = walk_tree (gimple_omp_target_child_fn_ptr (omp_stmt),
 430                          callback_op, wi, pset);
 431         if (ret)
 432           return ret;
 433         ret = walk_tree (gimple_omp_target_data_arg_ptr (omp_stmt),
 434                          callback_op, wi, pset);
 435         if (ret)
 436           return ret;
 437       }
 438       break;
 439
 440     case GIMPLE_OMP_TEAMS:
 441       ret = walk_tree (gimple_omp_teams_clauses_ptr (stmt), callback_op, wi,
 442                        pset);
 443       if (ret)
 444         return ret;
 445       break;
 446
 447     case GIMPLE_OMP_ATOMIC_LOAD:
 448       {
 449         gomp_atomic_load *omp_stmt = as_a <gomp_atomic_load *> (stmt);
 450         ret = walk_tree (gimple_omp_atomic_load_lhs_ptr (omp_stmt),
 451                          callback_op, wi, pset);
 452         if (ret)
 453           return ret;
 454         ret = walk_tree (gimple_omp_atomic_load_rhs_ptr (omp_stmt),
 455                          callback_op, wi, pset);
 456         if (ret)
 457           return ret;
 458       }
 459       break;
 460
 461     case GIMPLE_OMP_ATOMIC_STORE:
 462       {
 463         gomp_atomic_store *omp_stmt = as_a <gomp_atomic_store *> (stmt);
 464         ret = walk_tree (gimple_omp_atomic_store_val_ptr (omp_stmt),
 465                          callback_op, wi, pset);
 466         if (ret)
 467           return ret;
 468       }
 469       break;
 470
 471     case GIMPLE_TRANSACTION:
 472       ret = walk_tree (gimple_transaction_label_ptr (
 473                          as_a <gtransaction *> (stmt)),
 474                        callback_op, wi, pset);
 475       if (ret)
 476         return ret;
 477       break;
 478
 479     case GIMPLE_OMP_RETURN:
 480       ret = walk_tree (gimple_omp_return_lhs_ptr (stmt), callback_op, wi,
 481                        pset);
 482       if (ret)
 483         return ret;
 484       break;
 485
 486       /* Tuples that do not have operands.  */
 487     case GIMPLE_NOP:
 488     case GIMPLE_RESX:
 489     case GIMPLE_PREDICT:
 490       break;
 491
 492     default:
 493       {
 494         enum gimple_statement_structure_enum gss;
 495         gss = gimple_statement_structure (stmt);
 496         if (gss == GSS_WITH_OPS || gss == GSS_WITH_MEM_OPS)
 497           for (i = 0; i < gimple_num_ops (stmt); i++)
 498             {
 499               ret = walk_tree (gimple_op_ptr (stmt, i), callback_op, wi, pset);
 500               if (ret)
 501                 return ret;
 502             }
 503       }
 504       break;
 505     }
 506
 507   return NULL_TREE;
 508 }
 509
 510
 511 /* Walk the current statement in GSI (optionally using traversal state
 512    stored in WI).  If WI is NULL, no state is kept during traversal.
 513    The callback CALLBACK_STMT is called.  If CALLBACK_STMT indicates
 514    that it has handled all the operands of the statement, its return
 515    value is returned.  Otherwise, the return value from CALLBACK_STMT
 516    is discarded and its operands are scanned.
 517
 518    If CALLBACK_STMT is NULL or it didn't handle the operands,
 519    CALLBACK_OP is called on each operand of the statement via
 520    walk_gimple_op.  If walk_gimple_op returns non-NULL for any
 521    operand, the remaining operands are not scanned.  In this case, the
 522    return value from CALLBACK_OP is returned.
 523
 524    In any other case, NULL_TREE is returned.  */
 525
 526 tree
 527 walk_gimple_stmt (gimple_stmt_iterator *gsi, walk_stmt_fn callback_stmt,
 528                   walk_tree_fn callback_op, struct walk_stmt_info *wi)
 529 {
 530   gimple ret;
 531   tree tree_ret;
 532   gimple stmt = gsi_stmt (*gsi);
 533
 534   if (wi)
 535     {
 536       wi->gsi = *gsi;
 537       wi->removed_stmt = false;
 538
 539       if (wi->want_locations && gimple_has_location (stmt))
 540         input_location = gimple_location (stmt);
 541     }
 542
 543   ret = NULL;
 544
 545   /* Invoke the statement callback.  Return if the callback handled
 546      all of STMT operands by itself.  */
 547   if (callback_stmt)
 548     {
 549       bool handled_ops = false;
 550       tree_ret = callback_stmt (gsi, &handled_ops, wi);
 551       if (handled_ops)
 552         return tree_ret;
 553
 554       /* If CALLBACK_STMT did not handle operands, it should not have
 555          a value to return.  */
 556       gcc_assert (tree_ret == NULL);
 557
 558       if (wi && wi->removed_stmt)
 559         return NULL;
 560
 561       /* Re-read stmt in case the callback changed it.  */
 562       stmt = gsi_stmt (*gsi);
 563     }
 564
 565   /* If CALLBACK_OP is defined, invoke it on every operand of STMT.  */
 566   if (callback_op)
 567     {
 568       tree_ret = walk_gimple_op (stmt, callback_op, wi);
 569       if (tree_ret)
 570         return tree_ret;
 571     }
 572
 573   /* If STMT can have statements inside (e.g. GIMPLE_BIND), walk them.  */
 574   switch (gimple_code (stmt))
 575     {
 576     case GIMPLE_BIND:
 577       ret = walk_gimple_seq_mod (gimple_bind_body_ptr (as_a <gbind *> (stmt)),
 578                                  callback_stmt, callback_op, wi);
 579       if (ret)
 580         return wi->callback_result;
 581       break;
 582
 583     case GIMPLE_CATCH:
 584       ret = walk_gimple_seq_mod (gimple_catch_handler_ptr (
 585                                    as_a <gcatch *> (stmt)),
 586                                  callback_stmt, callback_op, wi);
 587       if (ret)
 588         return wi->callback_result;
 589       break;
 590
 591     case GIMPLE_EH_FILTER:
 592       ret = walk_gimple_seq_mod (gimple_eh_filter_failure_ptr (stmt), callback_stmt,
 593                              callback_op, wi);
 594       if (ret)
 595         return wi->callback_result;
 596       break;
 597
 598     case GIMPLE_EH_ELSE:
 599       {
 600         geh_else *eh_else_stmt = as_a <geh_else *> (stmt);
 601         ret = walk_gimple_seq_mod (gimple_eh_else_n_body_ptr (eh_else_stmt),
 602                                    callback_stmt, callback_op, wi);
 603         if (ret)
 604           return wi->callback_result;
 605         ret = walk_gimple_seq_mod (gimple_eh_else_e_body_ptr (eh_else_stmt),
 606                                    callback_stmt, callback_op, wi);
 607         if (ret)
 608           return wi->callback_result;
 609       }
 610       break;
 611
 612     case GIMPLE_TRY:
 613       ret = walk_gimple_seq_mod (gimple_try_eval_ptr (stmt), callback_stmt, callback_op,
 614                              wi);
 615       if (ret)
 616         return wi->callback_result;
 617
 618       ret = walk_gimple_seq_mod (gimple_try_cleanup_ptr (stmt), callback_stmt,
 619                              callback_op, wi);
 620       if (ret)
 621         return wi->callback_result;
 622       break;
 623
 624     case GIMPLE_OMP_FOR:
 625       ret = walk_gimple_seq_mod (gimple_omp_for_pre_body_ptr (stmt), callback_stmt,
 626                              callback_op, wi);
 627       if (ret)
 628         return wi->callback_result;
 629
 630       /* FALL THROUGH.  */
 631     case GIMPLE_OMP_CRITICAL:
 632     case GIMPLE_OMP_MASTER:
 633     case GIMPLE_OMP_TASKGROUP:
 634     case GIMPLE_OMP_ORDERED:
 635     case GIMPLE_OMP_SECTION:
 636     case GIMPLE_OMP_PARALLEL:
 637     case GIMPLE_OMP_TASK:
 638     case GIMPLE_OMP_SECTIONS:
 639     case GIMPLE_OMP_SINGLE:
 640     case GIMPLE_OMP_TARGET:
 641     case GIMPLE_OMP_TEAMS:
 642       ret = walk_gimple_seq_mod (gimple_omp_body_ptr (stmt), callback_stmt,
 643                              callback_op, wi);
 644       if (ret)
 645         return wi->callback_result;
 646       break;
 647
 648     case GIMPLE_WITH_CLEANUP_EXPR:
 649       ret = walk_gimple_seq_mod (gimple_wce_cleanup_ptr (stmt), callback_stmt,
 650                              callback_op, wi);
 651       if (ret)
 652         return wi->callback_result;
 653       break;
 654
 655     case GIMPLE_TRANSACTION:
 656       ret = walk_gimple_seq_mod (gimple_transaction_body_ptr (
 657                                    as_a <gtransaction *> (stmt)),
 658                              callback_stmt, callback_op, wi);
 659       if (ret)
 660         return wi->callback_result;
 661       break;
 662
 663     default:
 664       gcc_assert (!gimple_has_substatements (stmt));
 665       break;
 666     }
 667
 668   return NULL;
 669 }
 670
 671 /* From a tree operand OP return the base of a load or store operation
 672    or NULL_TREE if OP is not a load or a store.  */
 673
 674 static tree
 675 get_base_loadstore (tree op)
 676 {
 677   while (handled_component_p (op))
 678     op = TREE_OPERAND (op, 0);
 679   if (DECL_P (op)
 680       || INDIRECT_REF_P (op)
 681       || TREE_CODE (op) == MEM_REF
 682       || TREE_CODE (op) == TARGET_MEM_REF)
 683     return op;
 684   return NULL_TREE;
 685 }
 686
 687
 688 /* For the statement STMT call the callbacks VISIT_LOAD, VISIT_STORE and
 689    VISIT_ADDR if non-NULL on loads, store and address-taken operands
 690    passing the STMT, the base of the operand, the operand itself containing
 691    the base and DATA to it.  The base will be either a decl, an indirect
 692    reference (including TARGET_MEM_REF) or the argument of an address
 693    expression.
 694    Returns the results of these callbacks or'ed.  */
 695
 696 bool
 697 walk_stmt_load_store_addr_ops (gimple stmt, void *data,
 698                                walk_stmt_load_store_addr_fn visit_load,
 699                                walk_stmt_load_store_addr_fn visit_store,
 700                                walk_stmt_load_store_addr_fn visit_addr)
 701 {
 702   bool ret = false;
 703   unsigned i;
 704   if (gimple_assign_single_p (stmt))
 705     {
 706       tree lhs, rhs, arg;
 707       if (visit_store)
 708         {
 709           arg = gimple_assign_lhs (stmt);
 710           lhs = get_base_loadstore (arg);
 711           if (lhs)
 712             ret |= visit_store (stmt, lhs, arg, data);
 713         }
 714       arg = gimple_assign_rhs1 (stmt);
 715       rhs = arg;
 716       while (handled_component_p (rhs))
 717         rhs = TREE_OPERAND (rhs, 0);
 718       if (visit_addr)
 719         {
 720           if (TREE_CODE (rhs) == ADDR_EXPR)
 721             ret |= visit_addr (stmt, TREE_OPERAND (rhs, 0), arg, data);
 722           else if (TREE_CODE (rhs) == TARGET_MEM_REF
 723                    && TREE_CODE (TMR_BASE (rhs)) == ADDR_EXPR)
 724             ret |= visit_addr (stmt, TREE_OPERAND (TMR_BASE (rhs), 0), arg,
 725                                data);
 726           else if (TREE_CODE (rhs) == OBJ_TYPE_REF
 727                    && TREE_CODE (OBJ_TYPE_REF_OBJECT (rhs)) == ADDR_EXPR)
 728             ret |= visit_addr (stmt, TREE_OPERAND (OBJ_TYPE_REF_OBJECT (rhs),
 729                                                    0), arg, data);
 730           else if (TREE_CODE (rhs) == CONSTRUCTOR)
 731             {
 732               unsigned int ix;
 733               tree val;
 734
 735               FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), ix, val)
 736                 if (TREE_CODE (val) == ADDR_EXPR)
 737                   ret |= visit_addr (stmt, TREE_OPERAND (val, 0), arg, data);
 738                 else if (TREE_CODE (val) == OBJ_TYPE_REF
 739                          && TREE_CODE (OBJ_TYPE_REF_OBJECT (val)) == ADDR_EXPR)
 740                   ret |= visit_addr (stmt,
 741                                      TREE_OPERAND (OBJ_TYPE_REF_OBJECT (val),
 742                                                    0), arg, data);
 743             }
 744           lhs = gimple_assign_lhs (stmt);
 745           if (TREE_CODE (lhs) == TARGET_MEM_REF
 746               && TREE_CODE (TMR_BASE (lhs)) == ADDR_EXPR)
 747             ret |= visit_addr (stmt, TREE_OPERAND (TMR_BASE (lhs), 0), lhs, data);
 748         }
 749       if (visit_load)
 750         {
 751           rhs = get_base_loadstore (rhs);
 752           if (rhs)
 753             ret |= visit_load (stmt, rhs, arg, data);
 754         }
 755     }
 756   else if (visit_addr
 757            && (is_gimple_assign (stmt)
 758                || gimple_code (stmt) == GIMPLE_COND))
 759     {
 760       for (i = 0; i < gimple_num_ops (stmt); ++i)
 761         {
 762           tree op = gimple_op (stmt, i);
 763           if (op == NULL_TREE)
 764             ;
 765           else if (TREE_CODE (op) == ADDR_EXPR)
 766             ret |= visit_addr (stmt, TREE_OPERAND (op, 0), op, data);
 767           /* COND_EXPR and VCOND_EXPR rhs1 argument is a comparison
 768              tree with two operands.  */
 769           else if (i == 1 && COMPARISON_CLASS_P (op))
 770             {
 771               if (TREE_CODE (TREE_OPERAND (op, 0)) == ADDR_EXPR)
 772                 ret |= visit_addr (stmt, TREE_OPERAND (TREE_OPERAND (op, 0),
 773                                                        0), op, data);
 774               if (TREE_CODE (TREE_OPERAND (op, 1)) == ADDR_EXPR)
 775                 ret |= visit_addr (stmt, TREE_OPERAND (TREE_OPERAND (op, 1),
 776                                                        0), op, data);
 777             }
 778         }
 779     }
 780   else if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
 781     {
 782       if (visit_store)
 783         {
 784           tree arg = gimple_call_lhs (call_stmt);
 785           if (arg)
 786             {
 787               tree lhs = get_base_loadstore (arg);
 788               if (lhs)
 789                 ret |= visit_store (stmt, lhs, arg, data);
 790             }
 791         }
 792       if (visit_load || visit_addr)
 793         for (i = 0; i < gimple_call_num_args (call_stmt); ++i)
 794           {
 795             tree arg = gimple_call_arg (call_stmt, i);
 796             if (visit_addr
 797                 && TREE_CODE (arg) == ADDR_EXPR)
 798               ret |= visit_addr (stmt, TREE_OPERAND (arg, 0), arg, data);
 799             else if (visit_load)
 800               {
 801                 tree rhs = get_base_loadstore (arg);
 802                 if (rhs)
 803                   ret |= visit_load (stmt, rhs, arg, data);
 804               }
 805           }
 806       if (visit_addr
 807           && gimple_call_chain (call_stmt)
 808           && TREE_CODE (gimple_call_chain (call_stmt)) == ADDR_EXPR)
 809         ret |= visit_addr (stmt, TREE_OPERAND (gimple_call_chain (call_stmt), 0),
 810                            gimple_call_chain (call_stmt), data);
 811       if (visit_addr
 812           && gimple_call_return_slot_opt_p (call_stmt)
 813           && gimple_call_lhs (call_stmt) != NULL_TREE
 814           && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (call_stmt))))
 815         ret |= visit_addr (stmt, gimple_call_lhs (call_stmt),
 816                            gimple_call_lhs (call_stmt), data);
 817     }
 818   else if (gasm *asm_stmt = dyn_cast <gasm *> (stmt))
 819     {
 820       unsigned noutputs;
 821       const char *constraint;
 822       const char **oconstraints;
 823       bool allows_mem, allows_reg, is_inout;
 824       noutputs = gimple_asm_noutputs (asm_stmt);
 825       oconstraints = XALLOCAVEC (const char *, noutputs);
 826       if (visit_store || visit_addr)
 827         for (i = 0; i < gimple_asm_noutputs (asm_stmt); ++i)
 828           {
 829             tree link = gimple_asm_output_op (asm_stmt, i);
 830             tree op = get_base_loadstore (TREE_VALUE (link));
 831             if (op && visit_store)
 832               ret |= visit_store (stmt, op, TREE_VALUE (link), data);
 833             if (visit_addr)
 834               {
 835                 constraint = TREE_STRING_POINTER
 836                     (TREE_VALUE (TREE_PURPOSE (link)));
 837                 oconstraints[i] = constraint;
 838                 parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
 839                                          &allows_reg, &is_inout);
 840                 if (op && !allows_reg && allows_mem)
 841                   ret |= visit_addr (stmt, op, TREE_VALUE (link), data);
 842               }
 843           }
 844       if (visit_load || visit_addr)
 845         for (i = 0; i < gimple_asm_ninputs (asm_stmt); ++i)
 846           {
 847             tree link = gimple_asm_input_op (asm_stmt, i);
 848             tree op = TREE_VALUE (link);
 849             if (visit_addr
 850                 && TREE_CODE (op) == ADDR_EXPR)
 851               ret |= visit_addr (stmt, TREE_OPERAND (op, 0), op, data);
 852             else if (visit_load || visit_addr)
 853               {
 854                 op = get_base_loadstore (op);
 855                 if (op)
 856                   {
 857                     if (visit_load)
 858                       ret |= visit_load (stmt, op, TREE_VALUE (link), data);
 859                     if (visit_addr)
 860                       {
 861                         constraint = TREE_STRING_POINTER
 862                             (TREE_VALUE (TREE_PURPOSE (link)));
 863                         parse_input_constraint (&constraint, 0, 0, noutputs,
 864                                                 0, oconstraints,
 865                                                 &allows_mem, &allows_reg);
 866                         if (!allows_reg && allows_mem)
 867                           ret |= visit_addr (stmt, op, TREE_VALUE (link),
 868                                              data);
 869                       }
 870                   }
 871               }
 872           }
 873     }
 874   else if (greturn *return_stmt = dyn_cast <greturn *> (stmt))
 875     {
 876       tree op = gimple_return_retval (return_stmt);
 877       if (op)
 878         {
 879           if (visit_addr
 880               && TREE_CODE (op) == ADDR_EXPR)
 881             ret |= visit_addr (stmt, TREE_OPERAND (op, 0), op, data);
 882           else if (visit_load)
 883             {
 884               tree base = get_base_loadstore (op);
 885               if (base)
 886                 ret |= visit_load (stmt, base, op, data);
 887             }
 888         }
 889     }
 890   else if (visit_addr
 891            && gimple_code (stmt) == GIMPLE_PHI)
 892     {
 893       for (i = 0; i < gimple_phi_num_args (stmt); ++i)
 894         {
 895           tree op = gimple_phi_arg_def (stmt, i);
 896           if (TREE_CODE (op) == ADDR_EXPR)
 897             ret |= visit_addr (stmt, TREE_OPERAND (op, 0), op, data);
 898         }
 899     }
 900   else if (visit_addr
 901            && gimple_code (stmt) == GIMPLE_GOTO)
 902     {
 903       tree op = gimple_goto_dest (stmt);
 904       if (TREE_CODE (op) == ADDR_EXPR)
 905         ret |= visit_addr (stmt, TREE_OPERAND (op, 0), op, data);
 906     }
 907
 908   return ret;
 909 }
 910
 911 /* Like walk_stmt_load_store_addr_ops but with NULL visit_addr.  IPA-CP
 912    should make a faster clone for this case.  */
 913
 914 bool
 915 walk_stmt_load_store_ops (gimple stmt, void *data,
 916                           walk_stmt_load_store_addr_fn visit_load,
 917                           walk_stmt_load_store_addr_fn visit_store)
 918 {
 919   return walk_stmt_load_store_addr_ops (stmt, data,
 920                                         visit_load, visit_store, NULL);
 921 }