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