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 "backend.h"
  26 #include "tree.h"
  27 #include "gimple.h"
  28 #include "hard-reg-set.h"
  29 #include "alias.h"
  30 #include "fold-const.h"
  31 #include "gimple-iterator.h"
  32 #include "gimple-walk.h"
  33 #include "stmt.h"
  34
  35 /* Walk all the statements in the sequence *PSEQ calling walk_gimple_stmt
  36    on each one.  WI is as in walk_gimple_stmt.
  37
  38    If walk_gimple_stmt returns non-NULL, the walk is stopped, and the
  39    value is stored in WI->CALLBACK_RESULT.  Also, the statement that
  40    produced the value is returned if this statement has not been
  41    removed by a callback (wi->removed_stmt).  If the statement has
  42    been removed, NULL is returned.
  43
  44    Otherwise, all the statements are walked and NULL returned.  */
  45
  46 gimple *
  47 walk_gimple_seq_mod (gimple_seq *pseq, walk_stmt_fn callback_stmt,
  48                      walk_tree_fn callback_op, struct walk_stmt_info *wi)
  49 {
  50   gimple_stmt_iterator gsi;
  51
  52   for (gsi = gsi_start (*pseq); !gsi_end_p (gsi); )
  53     {
  54       tree ret = walk_gimple_stmt (&gsi, callback_stmt, callback_op, wi);
  55       if (ret)
  56         {
  57           /* If CALLBACK_STMT or CALLBACK_OP return a value, WI must exist
  58              to hold it.  */
  59           gcc_assert (wi);
  60           wi->callback_result = ret;
  61
  62           return wi->removed_stmt ? NULL : gsi_stmt (gsi);
  63         }
  64
  65       if (!wi->removed_stmt)
  66         gsi_next (&gsi);
  67     }
  68
  69   if (wi)
  70     wi->callback_result = NULL_TREE;
  71
  72   return NULL;
  73 }
  74
  75
  76 /* Like walk_gimple_seq_mod, but ensure that the head of SEQ isn't
  77    changed by the callbacks.  */
  78
  79 gimple *
  80 walk_gimple_seq (gimple_seq seq, walk_stmt_fn callback_stmt,
  81                  walk_tree_fn callback_op, struct walk_stmt_info *wi)
  82 {
  83   gimple_seq seq2 = seq;
  84   gimple *ret = walk_gimple_seq_mod (&seq2, callback_stmt, callback_op, wi);
  85   gcc_assert (seq2 == seq);
  86   return ret;
  87 }
  88
  89
  90 /* Helper function for walk_gimple_stmt.  Walk operands of a GIMPLE_ASM.  */
  91
  92 static tree
  93 walk_gimple_asm (gasm *stmt, walk_tree_fn callback_op,
  94                  struct walk_stmt_info *wi)
  95 {
  96   tree ret, op;
  97   unsigned noutputs;
  98   const char **oconstraints;
  99   unsigned i, n;
 100   const char *constraint;
 101   bool allows_mem, allows_reg, is_inout;
 102
 103   noutputs = gimple_asm_noutputs (stmt);
 104   oconstraints = (const char **) alloca ((noutputs) * sizeof (const char *));
 105
 106   if (wi)
 107     wi->is_lhs = true;
 108
 109   for (i = 0; i < noutputs; i++)
 110     {
 111       op = gimple_asm_output_op (stmt, i);
 112       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (op)));
 113       oconstraints[i] = constraint;
 114       if (wi)
 115         {
 116           if (parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
 117                                        &allows_reg, &is_inout))
 118             wi->val_only = (allows_reg || !allows_mem);
 119         }
 120       ret = walk_tree (&TREE_VALUE (op), callback_op, wi, NULL);
 121       if (ret)
 122         return ret;
 123     }
 124
 125   n = gimple_asm_ninputs (stmt);
 126   for (i = 0; i < n; i++)
 127     {
 128       op = gimple_asm_input_op (stmt, i);
 129       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (op)));
 130
 131       if (wi)
 132         {
 133           if (parse_input_constraint (&constraint, 0, 0, noutputs, 0,
 134                                       oconstraints, &allows_mem, &allows_reg))
 135             {
 136               wi->val_only = (allows_reg || !allows_mem);
 137               /* Although input "m" is not really a LHS, we need a lvalue.  */
 138               wi->is_lhs = !wi->val_only;
 139             }
 140         }
 141       ret = walk_tree (&TREE_VALUE (op), callback_op, wi, NULL);
 142       if (ret)
 143         return ret;
 144     }
 145
 146   if (wi)
 147     {
 148       wi->is_lhs = false;
 149       wi->val_only = true;
 150     }
 151
 152   n = gimple_asm_nlabels (stmt);
 153   for (i = 0; i < n; i++)
 154     {
 155       op = gimple_asm_label_op (stmt, i);
 156       ret = walk_tree (&TREE_VALUE (op), callback_op, wi, NULL);
 157       if (ret)
 158         return ret;
 159     }
 160
 161   return NULL_TREE;
 162 }
 163
 164
 165 /* Helper function of WALK_GIMPLE_STMT.  Walk every tree operand in
 166    STMT.  CALLBACK_OP and WI are as in WALK_GIMPLE_STMT.
 167
 168    CALLBACK_OP is called on each operand of STMT via walk_tree.
 169    Additional parameters to walk_tree must be stored in WI.  For each operand
 170    OP, walk_tree is called as:
 171
 172         walk_tree (&OP, CALLBACK_OP, WI, WI->PSET)
 173
 174    If CALLBACK_OP returns non-NULL for an operand, the remaining
 175    operands are not scanned.
 176
 177    The return value is that returned by the last call to walk_tree, or
 178    NULL_TREE if no CALLBACK_OP is specified.  */
 179
 180 tree
 181 walk_gimple_op (gimple *stmt, walk_tree_fn callback_op,
 182                 struct walk_stmt_info *wi)
 183 {
 184   hash_set<tree> *pset = (wi) ? wi->pset : NULL;
 185   unsigned i;
 186   tree ret = NULL_TREE;
 187
 188   switch (gimple_code (stmt))
 189     {
 190     case GIMPLE_ASSIGN:
 191       /* Walk the RHS operands.  If the LHS is of a non-renamable type or
 192          is a register variable, we may use a COMPONENT_REF on the RHS.  */
 193       if (wi)
 194         {
 195           tree lhs = gimple_assign_lhs (stmt);
 196           wi->val_only
 197             = (is_gimple_reg_type (TREE_TYPE (lhs)) && !is_gimple_reg (lhs))
 198               || gimple_assign_rhs_class (stmt) != GIMPLE_SINGLE_RHS;
 199         }
 200
 201       for (i = 1; i < gimple_num_ops (stmt); i++)
 202         {
 203           ret = walk_tree (gimple_op_ptr (stmt, i), callback_op, wi,
 204                            pset);
 205           if (ret)
 206             return ret;
 207         }
 208
 209       /* Walk the LHS.  If the RHS is appropriate for a memory, we
 210          may use a COMPONENT_REF on the LHS.  */
 211       if (wi)
 212         {
 213           /* If the RHS is of a non-renamable type or is a register variable,
 214              we may use a COMPONENT_REF on the LHS.  */
 215           tree rhs1 = gimple_assign_rhs1 (stmt);
 216           wi->val_only
 217             = (is_gimple_reg_type (TREE_TYPE (rhs1)) && !is_gimple_reg (rhs1))
 218               || gimple_assign_rhs_class (stmt) != GIMPLE_SINGLE_RHS;
 219           wi->is_lhs = true;
 220         }
 221
 222       ret = walk_tree (gimple_op_ptr (stmt, 0), callback_op, wi, pset);
 223       if (ret)
 224         return ret;
 225
 226       if (wi)
 227         {
 228           wi->val_only = true;
 229           wi->is_lhs = false;
 230         }
 231       break;
 232
 233     case GIMPLE_CALL:
 234       if (wi)
 235         {
 236           wi->is_lhs = false;
 237           wi->val_only = true;
 238         }
 239
 240       ret = walk_tree (gimple_call_chain_ptr (as_a <gcall *> (stmt)),
 241                        callback_op, wi, pset);
 242       if (ret)
 243         return ret;
 244
 245       ret = walk_tree (gimple_call_fn_ptr (stmt), callback_op, wi, pset);
 246       if (ret)
 247         return ret;
 248
 249       for (i = 0; i < gimple_call_num_args (stmt); i++)
 250         {
 251           if (wi)
 252             wi->val_only
 253               = is_gimple_reg_type (TREE_TYPE (gimple_call_arg (stmt, i)));
 254           ret = walk_tree (gimple_call_arg_ptr (stmt, i), callback_op, wi,
 255                            pset);
 256           if (ret)
 257             return ret;
 258         }
 259
 260       if (gimple_call_lhs (stmt))
 261         {
 262           if (wi)
 263             {
 264               wi->is_lhs = true;
 265               wi->val_only
 266                 = is_gimple_reg_type (TREE_TYPE (gimple_call_lhs (stmt)));
 267             }
 268
 269           ret = walk_tree (gimple_call_lhs_ptr (stmt), callback_op, wi, pset);
 270           if (ret)
 271             return ret;
 272         }
 273
 274       if (wi)
 275         {
 276           wi->is_lhs = false;
 277           wi->val_only = true;
 278         }
 279       break;
 280
 281     case GIMPLE_CATCH:
 282       ret = walk_tree (gimple_catch_types_ptr (as_a <gcatch *> (stmt)),
 283                        callback_op, wi, pset);
 284       if (ret)
 285         return ret;
 286       break;
 287
 288     case GIMPLE_EH_FILTER:
 289       ret = walk_tree (gimple_eh_filter_types_ptr (stmt), callback_op, wi,
 290                        pset);
 291       if (ret)
 292         return ret;
 293       break;
 294
 295     case GIMPLE_ASM:
 296       ret = walk_gimple_asm (as_a <gasm *> (stmt), callback_op, wi);
 297       if (ret)
 298         return ret;
 299       break;
 300
 301     case GIMPLE_OMP_CONTINUE:
 302       {
 303         gomp_continue *cont_stmt = as_a <gomp_continue *> (stmt);
 304         ret = walk_tree (gimple_omp_continue_control_def_ptr (cont_stmt),
 305                          callback_op, wi, pset);
 306         if (ret)
 307           return ret;
 308
 309         ret = walk_tree (gimple_omp_continue_control_use_ptr (cont_stmt),
 310                          callback_op, wi, pset);
 311         if (ret)
 312           return ret;
 313       }
 314       break;
 315
 316     case GIMPLE_OMP_CRITICAL:
 317       {
 318         gomp_critical *omp_stmt = as_a <gomp_critical *> (stmt);
 319         ret = walk_tree (gimple_omp_critical_name_ptr (omp_stmt),
 320                          callback_op, wi, pset);
 321         if (ret)
 322           return ret;
 323         ret = walk_tree (gimple_omp_critical_clauses_ptr (omp_stmt),
 324                          callback_op, wi, pset);
 325         if (ret)
 326           return ret;
 327       }
 328       break;
 329
 330     case GIMPLE_OMP_ORDERED:
 331       {
 332         gomp_ordered *omp_stmt = as_a <gomp_ordered *> (stmt);
 333         ret = walk_tree (gimple_omp_ordered_clauses_ptr (omp_stmt),
 334                          callback_op, wi, pset);
 335         if (ret)
 336           return ret;
 337       }
 338       break;
 339
 340     case GIMPLE_OMP_FOR:
 341       ret = walk_tree (gimple_omp_for_clauses_ptr (stmt), callback_op, wi,
 342                        pset);
 343       if (ret)
 344         return ret;
 345       for (i = 0; i < gimple_omp_for_collapse (stmt); i++)
 346         {
 347           ret = walk_tree (gimple_omp_for_index_ptr (stmt, i), callback_op,
 348                            wi, pset);
 349           if (ret)
 350             return ret;
 351           ret = walk_tree (gimple_omp_for_initial_ptr (stmt, i), callback_op,
 352                            wi, pset);
 353           if (ret)
 354             return ret;
 355           ret = walk_tree (gimple_omp_for_final_ptr (stmt, i), callback_op,
 356                            wi, pset);
 357           if (ret)
 358             return ret;
 359           ret = walk_tree (gimple_omp_for_incr_ptr (stmt, i), callback_op,
 360                            wi, pset);
 361           if (ret)
 362             return ret;
 363         }
 364       break;
 365
 366     case GIMPLE_OMP_PARALLEL:
 367       {
 368         gomp_parallel *omp_par_stmt = as_a <gomp_parallel *> (stmt);
 369         ret = walk_tree (gimple_omp_parallel_clauses_ptr (omp_par_stmt),
 370                          callback_op, wi, pset);
 371         if (ret)
 372           return ret;
 373         ret = walk_tree (gimple_omp_parallel_child_fn_ptr (omp_par_stmt),
 374                          callback_op, wi, pset);
 375         if (ret)
 376           return ret;
 377         ret = walk_tree (gimple_omp_parallel_data_arg_ptr (omp_par_stmt),
 378                          callback_op, wi, pset);
 379         if (ret)
 380           return ret;
 381       }
 382       break;
 383
 384     case GIMPLE_OMP_TASK:
 385       ret = walk_tree (gimple_omp_task_clauses_ptr (stmt), callback_op,
 386                        wi, pset);
 387       if (ret)
 388         return ret;
 389       ret = walk_tree (gimple_omp_task_child_fn_ptr (stmt), callback_op,
 390                        wi, pset);
 391       if (ret)
 392         return ret;
 393       ret = walk_tree (gimple_omp_task_data_arg_ptr (stmt), callback_op,
 394                        wi, pset);
 395       if (ret)
 396         return ret;
 397       ret = walk_tree (gimple_omp_task_copy_fn_ptr (stmt), callback_op,
 398                        wi, pset);
 399       if (ret)
 400         return ret;
 401       ret = walk_tree (gimple_omp_task_arg_size_ptr (stmt), callback_op,
 402                        wi, pset);
 403       if (ret)
 404         return ret;
 405       ret = walk_tree (gimple_omp_task_arg_align_ptr (stmt), callback_op,
 406                        wi, pset);
 407       if (ret)
 408         return ret;
 409       break;
 410
 411     case GIMPLE_OMP_SECTIONS:
 412       ret = walk_tree (gimple_omp_sections_clauses_ptr (stmt), callback_op,
 413                        wi, pset);
 414       if (ret)
 415         return ret;
 416       ret = walk_tree (gimple_omp_sections_control_ptr (stmt), callback_op,
 417                        wi, pset);
 418       if (ret)
 419         return ret;
 420
 421       break;
 422
 423     case GIMPLE_OMP_SINGLE:
 424       ret = walk_tree (gimple_omp_single_clauses_ptr (stmt), callback_op, wi,
 425                        pset);
 426       if (ret)
 427         return ret;
 428       break;
 429
 430     case GIMPLE_OMP_TARGET:
 431       {
 432         gomp_target *omp_stmt = as_a <gomp_target *> (stmt);
 433         ret = walk_tree (gimple_omp_target_clauses_ptr (omp_stmt),
 434                          callback_op, wi, pset);
 435         if (ret)
 436           return ret;
 437         ret = walk_tree (gimple_omp_target_child_fn_ptr (omp_stmt),
 438                          callback_op, wi, pset);
 439         if (ret)
 440           return ret;
 441         ret = walk_tree (gimple_omp_target_data_arg_ptr (omp_stmt),
 442                          callback_op, wi, pset);
 443         if (ret)
 444           return ret;
 445       }
 446       break;
 447
 448     case GIMPLE_OMP_TEAMS:
 449       ret = walk_tree (gimple_omp_teams_clauses_ptr (stmt), callback_op, wi,
 450                        pset);
 451       if (ret)
 452         return ret;
 453       break;
 454
 455     case GIMPLE_OMP_ATOMIC_LOAD:
 456       {
 457         gomp_atomic_load *omp_stmt = as_a <gomp_atomic_load *> (stmt);
 458         ret = walk_tree (gimple_omp_atomic_load_lhs_ptr (omp_stmt),
 459                          callback_op, wi, pset);
 460         if (ret)
 461           return ret;
 462         ret = walk_tree (gimple_omp_atomic_load_rhs_ptr (omp_stmt),
 463                          callback_op, wi, pset);
 464         if (ret)
 465           return ret;
 466       }
 467       break;
 468
 469     case GIMPLE_OMP_ATOMIC_STORE:
 470       {
 471         gomp_atomic_store *omp_stmt = as_a <gomp_atomic_store *> (stmt);
 472         ret = walk_tree (gimple_omp_atomic_store_val_ptr (omp_stmt),
 473                          callback_op, wi, pset);
 474         if (ret)
 475           return ret;
 476       }
 477       break;
 478
 479     case GIMPLE_TRANSACTION:
 480       ret = walk_tree (gimple_transaction_label_ptr (
 481                          as_a <gtransaction *> (stmt)),
 482                        callback_op, wi, pset);
 483       if (ret)
 484         return ret;
 485       break;
 486
 487     case GIMPLE_OMP_RETURN:
 488       ret = walk_tree (gimple_omp_return_lhs_ptr (stmt), callback_op, wi,
 489                        pset);
 490       if (ret)
 491         return ret;
 492       break;
 493
 494       /* Tuples that do not have operands.  */
 495     case GIMPLE_NOP:
 496     case GIMPLE_RESX:
 497     case GIMPLE_PREDICT:
 498       break;
 499
 500     default:
 501       {
 502         enum gimple_statement_structure_enum gss;
 503         gss = gimple_statement_structure (stmt);
 504         if (gss == GSS_WITH_OPS || gss == GSS_WITH_MEM_OPS)
 505           for (i = 0; i < gimple_num_ops (stmt); i++)
 506             {
 507               ret = walk_tree (gimple_op_ptr (stmt, i), callback_op, wi, pset);
 508               if (ret)
 509                 return ret;
 510             }
 511       }
 512       break;
 513     }
 514
 515   return NULL_TREE;
 516 }
 517
 518
 519 /* Walk the current statement in GSI (optionally using traversal state
 520    stored in WI).  If WI is NULL, no state is kept during traversal.
 521    The callback CALLBACK_STMT is called.  If CALLBACK_STMT indicates
 522    that it has handled all the operands of the statement, its return
 523    value is returned.  Otherwise, the return value from CALLBACK_STMT
 524    is discarded and its operands are scanned.
 525
 526    If CALLBACK_STMT is NULL or it didn't handle the operands,
 527    CALLBACK_OP is called on each operand of the statement via
 528    walk_gimple_op.  If walk_gimple_op returns non-NULL for any
 529    operand, the remaining operands are not scanned.  In this case, the
 530    return value from CALLBACK_OP is returned.
 531
 532    In any other case, NULL_TREE is returned.  */
 533
 534 tree
 535 walk_gimple_stmt (gimple_stmt_iterator *gsi, walk_stmt_fn callback_stmt,
 536                   walk_tree_fn callback_op, struct walk_stmt_info *wi)
 537 {
 538   gimple *ret;
 539   tree tree_ret;
 540   gimple *stmt = gsi_stmt (*gsi);
 541
 542   if (wi)
 543     {
 544       wi->gsi = *gsi;
 545       wi->removed_stmt = false;
 546
 547       if (wi->want_locations && gimple_has_location (stmt))
 548         input_location = gimple_location (stmt);
 549     }
 550
 551   ret = NULL;
 552
 553   /* Invoke the statement callback.  Return if the callback handled
 554      all of STMT operands by itself.  */
 555   if (callback_stmt)
 556     {
 557       bool handled_ops = false;
 558       tree_ret = callback_stmt (gsi, &handled_ops, wi);
 559       if (handled_ops)
 560         return tree_ret;
 561
 562       /* If CALLBACK_STMT did not handle operands, it should not have
 563          a value to return.  */
 564       gcc_assert (tree_ret == NULL);
 565
 566       if (wi && wi->removed_stmt)
 567         return NULL;
 568
 569       /* Re-read stmt in case the callback changed it.  */
 570       stmt = gsi_stmt (*gsi);
 571     }
 572
 573   /* If CALLBACK_OP is defined, invoke it on every operand of STMT.  */
 574   if (callback_op)
 575     {
 576       tree_ret = walk_gimple_op (stmt, callback_op, wi);
 577       if (tree_ret)
 578         return tree_ret;
 579     }
 580
 581   /* If STMT can have statements inside (e.g. GIMPLE_BIND), walk them.  */
 582   switch (gimple_code (stmt))
 583     {
 584     case GIMPLE_BIND:
 585       ret = walk_gimple_seq_mod (gimple_bind_body_ptr (as_a <gbind *> (stmt)),
 586                                  callback_stmt, callback_op, wi);
 587       if (ret)
 588         return wi->callback_result;
 589       break;
 590
 591     case GIMPLE_CATCH:
 592       ret = walk_gimple_seq_mod (gimple_catch_handler_ptr (
 593                                    as_a <gcatch *> (stmt)),
 594                                  callback_stmt, callback_op, wi);
 595       if (ret)
 596         return wi->callback_result;
 597       break;
 598
 599     case GIMPLE_EH_FILTER:
 600       ret = walk_gimple_seq_mod (gimple_eh_filter_failure_ptr (stmt), callback_stmt,
 601                              callback_op, wi);
 602       if (ret)
 603         return wi->callback_result;
 604       break;
 605
 606     case GIMPLE_EH_ELSE:
 607       {
 608         geh_else *eh_else_stmt = as_a <geh_else *> (stmt);
 609         ret = walk_gimple_seq_mod (gimple_eh_else_n_body_ptr (eh_else_stmt),
 610                                    callback_stmt, callback_op, wi);
 611         if (ret)
 612           return wi->callback_result;
 613         ret = walk_gimple_seq_mod (gimple_eh_else_e_body_ptr (eh_else_stmt),
 614                                    callback_stmt, callback_op, wi);
 615         if (ret)
 616           return wi->callback_result;
 617       }
 618       break;
 619
 620     case GIMPLE_TRY:
 621       ret = walk_gimple_seq_mod (gimple_try_eval_ptr (stmt), callback_stmt, callback_op,
 622                              wi);
 623       if (ret)
 624         return wi->callback_result;
 625
 626       ret = walk_gimple_seq_mod (gimple_try_cleanup_ptr (stmt), callback_stmt,
 627                              callback_op, wi);
 628       if (ret)
 629         return wi->callback_result;
 630       break;
 631
 632     case GIMPLE_OMP_FOR:
 633       ret = walk_gimple_seq_mod (gimple_omp_for_pre_body_ptr (stmt), callback_stmt,
 634                              callback_op, wi);
 635       if (ret)
 636         return wi->callback_result;
 637
 638       /* FALL THROUGH.  */
 639     case GIMPLE_OMP_CRITICAL:
 640     case GIMPLE_OMP_MASTER:
 641     case GIMPLE_OMP_TASKGROUP:
 642     case GIMPLE_OMP_ORDERED:
 643     case GIMPLE_OMP_SECTION:
 644     case GIMPLE_OMP_PARALLEL:
 645     case GIMPLE_OMP_TASK:
 646     case GIMPLE_OMP_SECTIONS:
 647     case GIMPLE_OMP_SINGLE:
 648     case GIMPLE_OMP_TARGET:
 649     case GIMPLE_OMP_TEAMS:
 650       ret = walk_gimple_seq_mod (gimple_omp_body_ptr (stmt), callback_stmt,
 651                              callback_op, wi);
 652       if (ret)
 653         return wi->callback_result;
 654       break;
 655
 656     case GIMPLE_WITH_CLEANUP_EXPR:
 657       ret = walk_gimple_seq_mod (gimple_wce_cleanup_ptr (stmt), callback_stmt,
 658                              callback_op, wi);
 659       if (ret)
 660         return wi->callback_result;
 661       break;
 662
 663     case GIMPLE_TRANSACTION:
 664       ret = walk_gimple_seq_mod (gimple_transaction_body_ptr (
 665                                    as_a <gtransaction *> (stmt)),
 666                              callback_stmt, callback_op, wi);
 667       if (ret)
 668         return wi->callback_result;
 669       break;
 670
 671     default:
 672       gcc_assert (!gimple_has_substatements (stmt));
 673       break;
 674     }
 675
 676   return NULL;
 677 }
 678
 679 /* From a tree operand OP return the base of a load or store operation
 680    or NULL_TREE if OP is not a load or a store.  */
 681
 682 static tree
 683 get_base_loadstore (tree op)
 684 {
 685   while (handled_component_p (op))
 686     op = TREE_OPERAND (op, 0);
 687   if (DECL_P (op)
 688       || INDIRECT_REF_P (op)
 689       || TREE_CODE (op) == MEM_REF
 690       || TREE_CODE (op) == TARGET_MEM_REF)
 691     return op;
 692   return NULL_TREE;
 693 }
 694
 695
 696 /* For the statement STMT call the callbacks VISIT_LOAD, VISIT_STORE and
 697    VISIT_ADDR if non-NULL on loads, store and address-taken operands
 698    passing the STMT, the base of the operand, the operand itself containing
 699    the base and DATA to it.  The base will be either a decl, an indirect
 700    reference (including TARGET_MEM_REF) or the argument of an address
 701    expression.
 702    Returns the results of these callbacks or'ed.  */
 703
 704 bool
 705 walk_stmt_load_store_addr_ops (gimple *stmt, void *data,
 706                                walk_stmt_load_store_addr_fn visit_load,
 707                                walk_stmt_load_store_addr_fn visit_store,
 708                                walk_stmt_load_store_addr_fn visit_addr)
 709 {
 710   bool ret = false;
 711   unsigned i;
 712   if (gimple_assign_single_p (stmt))
 713     {
 714       tree lhs, rhs, arg;
 715       if (visit_store)
 716         {
 717           arg = gimple_assign_lhs (stmt);
 718           lhs = get_base_loadstore (arg);
 719           if (lhs)
 720             ret |= visit_store (stmt, lhs, arg, data);
 721         }
 722       arg = gimple_assign_rhs1 (stmt);
 723       rhs = arg;
 724       while (handled_component_p (rhs))
 725         rhs = TREE_OPERAND (rhs, 0);
 726       if (visit_addr)
 727         {
 728           if (TREE_CODE (rhs) == ADDR_EXPR)
 729             ret |= visit_addr (stmt, TREE_OPERAND (rhs, 0), arg, data);
 730           else if (TREE_CODE (rhs) == TARGET_MEM_REF
 731                    && TREE_CODE (TMR_BASE (rhs)) == ADDR_EXPR)
 732             ret |= visit_addr (stmt, TREE_OPERAND (TMR_BASE (rhs), 0), arg,
 733                                data);
 734           else if (TREE_CODE (rhs) == OBJ_TYPE_REF
 735                    && TREE_CODE (OBJ_TYPE_REF_OBJECT (rhs)) == ADDR_EXPR)
 736             ret |= visit_addr (stmt, TREE_OPERAND (OBJ_TYPE_REF_OBJECT (rhs),
 737                                                    0), arg, data);
 738           else if (TREE_CODE (rhs) == CONSTRUCTOR)
 739             {
 740               unsigned int ix;
 741               tree val;
 742
 743               FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), ix, val)
 744                 if (TREE_CODE (val) == ADDR_EXPR)
 745                   ret |= visit_addr (stmt, TREE_OPERAND (val, 0), arg, data);
 746                 else if (TREE_CODE (val) == OBJ_TYPE_REF
 747                          && TREE_CODE (OBJ_TYPE_REF_OBJECT (val)) == ADDR_EXPR)
 748                   ret |= visit_addr (stmt,
 749                                      TREE_OPERAND (OBJ_TYPE_REF_OBJECT (val),
 750                                                    0), arg, data);
 751             }
 752           lhs = gimple_assign_lhs (stmt);
 753           if (TREE_CODE (lhs) == TARGET_MEM_REF
 754               && TREE_CODE (TMR_BASE (lhs)) == ADDR_EXPR)
 755             ret |= visit_addr (stmt, TREE_OPERAND (TMR_BASE (lhs), 0), lhs, data);
 756         }
 757       if (visit_load)
 758         {
 759           rhs = get_base_loadstore (rhs);
 760           if (rhs)
 761             ret |= visit_load (stmt, rhs, arg, data);
 762         }
 763     }
 764   else if (visit_addr
 765            && (is_gimple_assign (stmt)
 766                || gimple_code (stmt) == GIMPLE_COND))
 767     {
 768       for (i = 0; i < gimple_num_ops (stmt); ++i)
 769         {
 770           tree op = gimple_op (stmt, i);
 771           if (op == NULL_TREE)
 772             ;
 773           else if (TREE_CODE (op) == ADDR_EXPR)
 774             ret |= visit_addr (stmt, TREE_OPERAND (op, 0), op, data);
 775           /* COND_EXPR and VCOND_EXPR rhs1 argument is a comparison
 776              tree with two operands.  */
 777           else if (i == 1 && COMPARISON_CLASS_P (op))
 778             {
 779               if (TREE_CODE (TREE_OPERAND (op, 0)) == ADDR_EXPR)
 780                 ret |= visit_addr (stmt, TREE_OPERAND (TREE_OPERAND (op, 0),
 781                                                        0), op, data);
 782               if (TREE_CODE (TREE_OPERAND (op, 1)) == ADDR_EXPR)
 783                 ret |= visit_addr (stmt, TREE_OPERAND (TREE_OPERAND (op, 1),
 784                                                        0), op, data);
 785             }
 786         }
 787     }
 788   else if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
 789     {
 790       if (visit_store)
 791         {
 792           tree arg = gimple_call_lhs (call_stmt);
 793           if (arg)
 794             {
 795               tree lhs = get_base_loadstore (arg);
 796               if (lhs)
 797                 ret |= visit_store (stmt, lhs, arg, data);
 798             }
 799         }
 800       if (visit_load || visit_addr)
 801         for (i = 0; i < gimple_call_num_args (call_stmt); ++i)
 802           {
 803             tree arg = gimple_call_arg (call_stmt, i);
 804             if (visit_addr
 805                 && TREE_CODE (arg) == ADDR_EXPR)
 806               ret |= visit_addr (stmt, TREE_OPERAND (arg, 0), arg, data);
 807             else if (visit_load)
 808               {
 809                 tree rhs = get_base_loadstore (arg);
 810                 if (rhs)
 811                   ret |= visit_load (stmt, rhs, arg, data);
 812               }
 813           }
 814       if (visit_addr
 815           && gimple_call_chain (call_stmt)
 816           && TREE_CODE (gimple_call_chain (call_stmt)) == ADDR_EXPR)
 817         ret |= visit_addr (stmt, TREE_OPERAND (gimple_call_chain (call_stmt), 0),
 818                            gimple_call_chain (call_stmt), data);
 819       if (visit_addr
 820           && gimple_call_return_slot_opt_p (call_stmt)
 821           && gimple_call_lhs (call_stmt) != NULL_TREE
 822           && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (call_stmt))))
 823         ret |= visit_addr (stmt, gimple_call_lhs (call_stmt),
 824                            gimple_call_lhs (call_stmt), data);
 825     }
 826   else if (gasm *asm_stmt = dyn_cast <gasm *> (stmt))
 827     {
 828       unsigned noutputs;
 829       const char *constraint;
 830       const char **oconstraints;
 831       bool allows_mem, allows_reg, is_inout;
 832       noutputs = gimple_asm_noutputs (asm_stmt);
 833       oconstraints = XALLOCAVEC (const char *, noutputs);
 834       if (visit_store || visit_addr)
 835         for (i = 0; i < gimple_asm_noutputs (asm_stmt); ++i)
 836           {
 837             tree link = gimple_asm_output_op (asm_stmt, i);
 838             tree op = get_base_loadstore (TREE_VALUE (link));
 839             if (op && visit_store)
 840               ret |= visit_store (stmt, op, TREE_VALUE (link), data);
 841             if (visit_addr)
 842               {
 843                 constraint = TREE_STRING_POINTER
 844                     (TREE_VALUE (TREE_PURPOSE (link)));
 845                 oconstraints[i] = constraint;
 846                 parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
 847                                          &allows_reg, &is_inout);
 848                 if (op && !allows_reg && allows_mem)
 849                   ret |= visit_addr (stmt, op, TREE_VALUE (link), data);
 850               }
 851           }
 852       if (visit_load || visit_addr)
 853         for (i = 0; i < gimple_asm_ninputs (asm_stmt); ++i)
 854           {
 855             tree link = gimple_asm_input_op (asm_stmt, i);
 856             tree op = TREE_VALUE (link);
 857             if (visit_addr
 858                 && TREE_CODE (op) == ADDR_EXPR)
 859               ret |= visit_addr (stmt, TREE_OPERAND (op, 0), op, data);
 860             else if (visit_load || visit_addr)
 861               {
 862                 op = get_base_loadstore (op);
 863                 if (op)
 864                   {
 865                     if (visit_load)
 866                       ret |= visit_load (stmt, op, TREE_VALUE (link), data);
 867                     if (visit_addr)
 868                       {
 869                         constraint = TREE_STRING_POINTER
 870                             (TREE_VALUE (TREE_PURPOSE (link)));
 871                         parse_input_constraint (&constraint, 0, 0, noutputs,
 872                                                 0, oconstraints,
 873                                                 &allows_mem, &allows_reg);
 874                         if (!allows_reg && allows_mem)
 875                           ret |= visit_addr (stmt, op, TREE_VALUE (link),
 876                                              data);
 877                       }
 878                   }
 879               }
 880           }
 881     }
 882   else if (greturn *return_stmt = dyn_cast <greturn *> (stmt))
 883     {
 884       tree op = gimple_return_retval (return_stmt);
 885       if (op)
 886         {
 887           if (visit_addr
 888               && TREE_CODE (op) == ADDR_EXPR)
 889             ret |= visit_addr (stmt, TREE_OPERAND (op, 0), op, data);
 890           else if (visit_load)
 891             {
 892               tree base = get_base_loadstore (op);
 893               if (base)
 894                 ret |= visit_load (stmt, base, op, data);
 895             }
 896         }
 897     }
 898   else if (visit_addr
 899            && gimple_code (stmt) == GIMPLE_PHI)
 900     {
 901       for (i = 0; i < gimple_phi_num_args (stmt); ++i)
 902         {
 903           tree op = gimple_phi_arg_def (stmt, i);
 904           if (TREE_CODE (op) == ADDR_EXPR)
 905             ret |= visit_addr (stmt, TREE_OPERAND (op, 0), op, data);
 906         }
 907     }
 908   else if (visit_addr
 909            && gimple_code (stmt) == GIMPLE_GOTO)
 910     {
 911       tree op = gimple_goto_dest (stmt);
 912       if (TREE_CODE (op) == ADDR_EXPR)
 913         ret |= visit_addr (stmt, TREE_OPERAND (op, 0), op, data);
 914     }
 915
 916   return ret;
 917 }
 918
 919 /* Like walk_stmt_load_store_addr_ops but with NULL visit_addr.  IPA-CP
 920    should make a faster clone for this case.  */
 921
 922 bool
 923 walk_stmt_load_store_ops (gimple *stmt, void *data,
 924                           walk_stmt_load_store_addr_fn visit_load,
 925                           walk_stmt_load_store_addr_fn visit_store)
 926 {
 927   return walk_stmt_load_store_addr_ops (stmt, data,
 928                                         visit_load, visit_store, NULL);
 929 }