gcc/tree.c

   1 /* Language-independent node constructors for parse phase of GNU compiler.
   2    Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   3    1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
   4    Free Software Foundation, Inc.
   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 2, 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 COPYING.  If not, write to the Free
  20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  21 02110-1301, USA.  */
  22
  23 /* This file contains the low level primitives for operating on tree nodes,
  24    including allocation, list operations, interning of identifiers,
  25    construction of data type nodes and statement nodes,
  26    and construction of type conversion nodes.  It also contains
  27    tables index by tree code that describe how to take apart
  28    nodes of that code.
  29
  30    It is intended to be language-independent, but occasionally
  31    calls language-dependent routines defined (for C) in typecheck.c.  */
  32
  33 #include "config.h"
  34 #include "system.h"
  35 #include "coretypes.h"
  36 #include "tm.h"
  37 #include "flags.h"
  38 #include "tree.h"
  39 #include "real.h"
  40 #include "tm_p.h"
  41 #include "function.h"
  42 #include "obstack.h"
  43 #include "toplev.h"
  44 #include "ggc.h"
  45 #include "hashtab.h"
  46 #include "output.h"
  47 #include "target.h"
  48 #include "langhooks.h"
  49 #include "tree-iterator.h"
  50 #include "basic-block.h"
  51 #include "tree-flow.h"
  52 #include "params.h"
  53 #include "pointer-set.h"
  54
  55 /* Each tree code class has an associated string representation.
  56    These must correspond to the tree_code_class entries.  */
  57
  58 const char *const tree_code_class_strings[] =
  59 {
  60   "exceptional",
  61   "constant",
  62   "type",
  63   "declaration",
  64   "reference",
  65   "comparison",
  66   "unary",
  67   "binary",
  68   "statement",
  69   "vl_exp",
  70   "expression",
  71   "gimple_stmt"
  72 };
  73
  74 /* obstack.[ch] explicitly declined to prototype this.  */
  75 extern int _obstack_allocated_p (struct obstack *h, void *obj);
  76
  77 #ifdef GATHER_STATISTICS
  78 /* Statistics-gathering stuff.  */
  79
  80 int tree_node_counts[(int) all_kinds];
  81 int tree_node_sizes[(int) all_kinds];
  82
  83 /* Keep in sync with tree.h:enum tree_node_kind.  */
  84 static const char * const tree_node_kind_names[] = {
  85   "decls",
  86   "types",
  87   "blocks",
  88   "stmts",
  89   "refs",
  90   "exprs",
  91   "constants",
  92   "identifiers",
  93   "perm_tree_lists",
  94   "temp_tree_lists",
  95   "vecs",
  96   "binfos",
  97   "phi_nodes",
  98   "ssa names",
  99   "constructors",
 100   "random kinds",
 101   "lang_decl kinds",
 102   "lang_type kinds",
 103   "omp clauses",
 104   "gimple statements"
 105 };
 106 #endif /* GATHER_STATISTICS */
 107
 108 /* Unique id for next decl created.  */
 109 static GTY(()) int next_decl_uid;
 110 /* Unique id for next type created.  */
 111 static GTY(()) int next_type_uid = 1;
 112
 113 /* Since we cannot rehash a type after it is in the table, we have to
 114    keep the hash code.  */
 115
 116 struct type_hash GTY(())
 117 {
 118   unsigned long hash;
 119   tree type;
 120 };
 121
 122 /* Initial size of the hash table (rounded to next prime).  */
 123 #define TYPE_HASH_INITIAL_SIZE 1000
 124
 125 /* Now here is the hash table.  When recording a type, it is added to
 126    the slot whose index is the hash code.  Note that the hash table is
 127    used for several kinds of types (function types, array types and
 128    array index range types, for now).  While all these live in the
 129    same table, they are completely independent, and the hash code is
 130    computed differently for each of these.  */
 131
 132 static GTY ((if_marked ("type_hash_marked_p"), param_is (struct type_hash)))
 133      htab_t type_hash_table;
 134
 135 /* Hash table and temporary node for larger integer const values.  */
 136 static GTY (()) tree int_cst_node;
 137 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
 138      htab_t int_cst_hash_table;
 139
 140 /* General tree->tree mapping  structure for use in hash tables.  */
 141
 142
 143 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
 144      htab_t debug_expr_for_decl;
 145
 146 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
 147      htab_t value_expr_for_decl;
 148
 149 static GTY ((if_marked ("tree_priority_map_marked_p"),
 150              param_is (struct tree_priority_map)))
 151   htab_t init_priority_for_decl;
 152
 153 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
 154   htab_t restrict_base_for_decl;
 155
 156 static void set_type_quals (tree, int);
 157 static int type_hash_eq (const void *, const void *);
 158 static hashval_t type_hash_hash (const void *);
 159 static hashval_t int_cst_hash_hash (const void *);
 160 static int int_cst_hash_eq (const void *, const void *);
 161 static void print_type_hash_statistics (void);
 162 static void print_debug_expr_statistics (void);
 163 static void print_value_expr_statistics (void);
 164 static int type_hash_marked_p (const void *);
 165 static unsigned int type_hash_list (tree, hashval_t);
 166 static unsigned int attribute_hash_list (tree, hashval_t);
 167
 168 tree global_trees[TI_MAX];
 169 tree integer_types[itk_none];
 170
 171 unsigned char tree_contains_struct[MAX_TREE_CODES][64];
 172
 173 /* Number of operands for each OpenMP clause.  */
 174 unsigned const char omp_clause_num_ops[] =
 175 {
 176   0, /* OMP_CLAUSE_ERROR  */
 177   1, /* OMP_CLAUSE_PRIVATE  */
 178   1, /* OMP_CLAUSE_SHARED  */
 179   1, /* OMP_CLAUSE_FIRSTPRIVATE  */
 180   1, /* OMP_CLAUSE_LASTPRIVATE  */
 181   4, /* OMP_CLAUSE_REDUCTION  */
 182   1, /* OMP_CLAUSE_COPYIN  */
 183   1, /* OMP_CLAUSE_COPYPRIVATE  */
 184   1, /* OMP_CLAUSE_IF  */
 185   1, /* OMP_CLAUSE_NUM_THREADS  */
 186   1, /* OMP_CLAUSE_SCHEDULE  */
 187   0, /* OMP_CLAUSE_NOWAIT  */
 188   0, /* OMP_CLAUSE_ORDERED  */
 189   0  /* OMP_CLAUSE_DEFAULT  */
 190 };
 191
 192 const char * const omp_clause_code_name[] =
 193 {
 194   "error_clause",
 195   "private",
 196   "shared",
 197   "firstprivate",
 198   "lastprivate",
 199   "reduction",
 200   "copyin",
 201   "copyprivate",
 202   "if",
 203   "num_threads",
 204   "schedule",
 205   "nowait",
 206   "ordered",
 207   "default"
 208 };
 209 \f
 210 /* Init tree.c.  */
 211
 212 void
 213 init_ttree (void)
 214 {
 215   /* Initialize the hash table of types.  */
 216   type_hash_table = htab_create_ggc (TYPE_HASH_INITIAL_SIZE, type_hash_hash,
 217                                      type_hash_eq, 0);
 218
 219   debug_expr_for_decl = htab_create_ggc (512, tree_map_hash,
 220                                          tree_map_eq, 0);
 221
 222   value_expr_for_decl = htab_create_ggc (512, tree_map_hash,
 223                                          tree_map_eq, 0);
 224   init_priority_for_decl = htab_create_ggc (512, tree_priority_map_hash,
 225                                             tree_priority_map_eq, 0);
 226   restrict_base_for_decl = htab_create_ggc (256, tree_map_hash,
 227                                             tree_map_eq, 0);
 228
 229   int_cst_hash_table = htab_create_ggc (1024, int_cst_hash_hash,
 230                                         int_cst_hash_eq, NULL);
 231
 232   int_cst_node = make_node (INTEGER_CST);
 233
 234   tree_contains_struct[FUNCTION_DECL][TS_DECL_NON_COMMON] = 1;
 235   tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_NON_COMMON] = 1;
 236   tree_contains_struct[TYPE_DECL][TS_DECL_NON_COMMON] = 1;
 237
 238
 239   tree_contains_struct[CONST_DECL][TS_DECL_COMMON] = 1;
 240   tree_contains_struct[VAR_DECL][TS_DECL_COMMON] = 1;
 241   tree_contains_struct[PARM_DECL][TS_DECL_COMMON] = 1;
 242   tree_contains_struct[RESULT_DECL][TS_DECL_COMMON] = 1;
 243   tree_contains_struct[FUNCTION_DECL][TS_DECL_COMMON] = 1;
 244   tree_contains_struct[TYPE_DECL][TS_DECL_COMMON] = 1;
 245   tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_COMMON] = 1;
 246   tree_contains_struct[LABEL_DECL][TS_DECL_COMMON] = 1;
 247   tree_contains_struct[FIELD_DECL][TS_DECL_COMMON] = 1;
 248
 249
 250   tree_contains_struct[CONST_DECL][TS_DECL_WRTL] = 1;
 251   tree_contains_struct[VAR_DECL][TS_DECL_WRTL] = 1;
 252   tree_contains_struct[PARM_DECL][TS_DECL_WRTL] = 1;
 253   tree_contains_struct[RESULT_DECL][TS_DECL_WRTL] = 1;
 254   tree_contains_struct[FUNCTION_DECL][TS_DECL_WRTL] = 1;
 255   tree_contains_struct[LABEL_DECL][TS_DECL_WRTL] = 1;
 256
 257   tree_contains_struct[CONST_DECL][TS_DECL_MINIMAL] = 1;
 258   tree_contains_struct[VAR_DECL][TS_DECL_MINIMAL] = 1;
 259   tree_contains_struct[PARM_DECL][TS_DECL_MINIMAL] = 1;
 260   tree_contains_struct[RESULT_DECL][TS_DECL_MINIMAL] = 1;
 261   tree_contains_struct[FUNCTION_DECL][TS_DECL_MINIMAL] = 1;
 262   tree_contains_struct[TYPE_DECL][TS_DECL_MINIMAL] = 1;
 263   tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_MINIMAL] = 1;
 264   tree_contains_struct[LABEL_DECL][TS_DECL_MINIMAL] = 1;
 265   tree_contains_struct[FIELD_DECL][TS_DECL_MINIMAL] = 1;
 266   tree_contains_struct[STRUCT_FIELD_TAG][TS_DECL_MINIMAL] = 1;
 267   tree_contains_struct[NAME_MEMORY_TAG][TS_DECL_MINIMAL] = 1;
 268   tree_contains_struct[SYMBOL_MEMORY_TAG][TS_DECL_MINIMAL] = 1;
 269   tree_contains_struct[MEMORY_PARTITION_TAG][TS_DECL_MINIMAL] = 1;
 270
 271   tree_contains_struct[STRUCT_FIELD_TAG][TS_MEMORY_TAG] = 1;
 272   tree_contains_struct[NAME_MEMORY_TAG][TS_MEMORY_TAG] = 1;
 273   tree_contains_struct[SYMBOL_MEMORY_TAG][TS_MEMORY_TAG] = 1;
 274   tree_contains_struct[MEMORY_PARTITION_TAG][TS_MEMORY_TAG] = 1;
 275
 276   tree_contains_struct[STRUCT_FIELD_TAG][TS_STRUCT_FIELD_TAG] = 1;
 277   tree_contains_struct[MEMORY_PARTITION_TAG][TS_MEMORY_PARTITION_TAG] = 1;
 278
 279   tree_contains_struct[VAR_DECL][TS_DECL_WITH_VIS] = 1;
 280   tree_contains_struct[FUNCTION_DECL][TS_DECL_WITH_VIS] = 1;
 281   tree_contains_struct[TYPE_DECL][TS_DECL_WITH_VIS] = 1;
 282   tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_WITH_VIS] = 1;
 283
 284   tree_contains_struct[VAR_DECL][TS_VAR_DECL] = 1;
 285   tree_contains_struct[FIELD_DECL][TS_FIELD_DECL] = 1;
 286   tree_contains_struct[PARM_DECL][TS_PARM_DECL] = 1;
 287   tree_contains_struct[LABEL_DECL][TS_LABEL_DECL] = 1;
 288   tree_contains_struct[RESULT_DECL][TS_RESULT_DECL] = 1;
 289   tree_contains_struct[CONST_DECL][TS_CONST_DECL] = 1;
 290   tree_contains_struct[TYPE_DECL][TS_TYPE_DECL] = 1;
 291   tree_contains_struct[FUNCTION_DECL][TS_FUNCTION_DECL] = 1;
 292
 293   lang_hooks.init_ts ();
 294 }
 295
 296 \f
 297 /* The name of the object as the assembler will see it (but before any
 298    translations made by ASM_OUTPUT_LABELREF).  Often this is the same
 299    as DECL_NAME.  It is an IDENTIFIER_NODE.  */
 300 tree
 301 decl_assembler_name (tree decl)
 302 {
 303   if (!DECL_ASSEMBLER_NAME_SET_P (decl))
 304     lang_hooks.set_decl_assembler_name (decl);
 305   return DECL_WITH_VIS_CHECK (decl)->decl_with_vis.assembler_name;
 306 }
 307
 308 /* Compare ASMNAME with the DECL_ASSEMBLER_NAME of DECL.  */
 309
 310 bool
 311 decl_assembler_name_equal (tree decl, tree asmname)
 312 {
 313   tree decl_asmname = DECL_ASSEMBLER_NAME (decl);
 314
 315   if (decl_asmname == asmname)
 316     return true;
 317
 318   /* If the target assembler name was set by the user, things are trickier.
 319      We have a leading '*' to begin with.  After that, it's arguable what
 320      is the correct thing to do with -fleading-underscore.  Arguably, we've
 321      historically been doing the wrong thing in assemble_alias by always
 322      printing the leading underscore.  Since we're not changing that, make
 323      sure user_label_prefix follows the '*' before matching.  */
 324   if (IDENTIFIER_POINTER (decl_asmname)[0] == '*')
 325     {
 326       const char *decl_str = IDENTIFIER_POINTER (decl_asmname) + 1;
 327       size_t ulp_len = strlen (user_label_prefix);
 328
 329       if (ulp_len == 0)
 330         ;
 331       else if (strncmp (decl_str, user_label_prefix, ulp_len) == 0)
 332         decl_str += ulp_len;
 333       else
 334         return false;
 335
 336       return strcmp (decl_str, IDENTIFIER_POINTER (asmname)) == 0;
 337     }
 338
 339   return false;
 340 }
 341
 342 /* Compute the number of bytes occupied by a tree with code CODE.
 343    This function cannot be used for nodes that have variable sizes,
 344    including TREE_VEC, PHI_NODE, STRING_CST, and CALL_EXPR.  */
 345 size_t
 346 tree_code_size (enum tree_code code)
 347 {
 348   switch (TREE_CODE_CLASS (code))
 349     {
 350     case tcc_declaration:  /* A decl node */
 351       {
 352         switch (code)
 353           {
 354           case FIELD_DECL:
 355             return sizeof (struct tree_field_decl);
 356           case PARM_DECL:
 357             return sizeof (struct tree_parm_decl);
 358           case VAR_DECL:
 359             return sizeof (struct tree_var_decl);
 360           case LABEL_DECL:
 361             return sizeof (struct tree_label_decl);
 362           case RESULT_DECL:
 363             return sizeof (struct tree_result_decl);
 364           case CONST_DECL:
 365             return sizeof (struct tree_const_decl);
 366           case TYPE_DECL:
 367             return sizeof (struct tree_type_decl);
 368           case FUNCTION_DECL:
 369             return sizeof (struct tree_function_decl);
 370           case NAME_MEMORY_TAG:
 371           case SYMBOL_MEMORY_TAG:
 372             return sizeof (struct tree_memory_tag);
 373           case STRUCT_FIELD_TAG:
 374             return sizeof (struct tree_struct_field_tag);
 375           case MEMORY_PARTITION_TAG:
 376             return sizeof (struct tree_memory_partition_tag);
 377           default:
 378             return sizeof (struct tree_decl_non_common);
 379           }
 380       }
 381
 382     case tcc_type:  /* a type node */
 383       return sizeof (struct tree_type);
 384
 385     case tcc_reference:   /* a reference */
 386     case tcc_expression:  /* an expression */
 387     case tcc_statement:   /* an expression with side effects */
 388     case tcc_comparison:  /* a comparison expression */
 389     case tcc_unary:       /* a unary arithmetic expression */
 390     case tcc_binary:      /* a binary arithmetic expression */
 391       return (sizeof (struct tree_exp)
 392               + (TREE_CODE_LENGTH (code) - 1) * sizeof (tree));
 393
 394     case tcc_gimple_stmt:
 395       return (sizeof (struct gimple_stmt)
 396               + (TREE_CODE_LENGTH (code) - 1) * sizeof (char *));
 397
 398     case tcc_constant:  /* a constant */
 399       switch (code)
 400         {
 401         case INTEGER_CST:       return sizeof (struct tree_int_cst);
 402         case REAL_CST:          return sizeof (struct tree_real_cst);
 403         case COMPLEX_CST:       return sizeof (struct tree_complex);
 404         case VECTOR_CST:        return sizeof (struct tree_vector);
 405         case STRING_CST:        gcc_unreachable ();
 406         default:
 407           return lang_hooks.tree_size (code);
 408         }
 409
 410     case tcc_exceptional:  /* something random, like an identifier.  */
 411       switch (code)
 412         {
 413         case IDENTIFIER_NODE:   return lang_hooks.identifier_size;
 414         case TREE_LIST:         return sizeof (struct tree_list);
 415
 416         case ERROR_MARK:
 417         case PLACEHOLDER_EXPR:  return sizeof (struct tree_common);
 418
 419         case TREE_VEC:
 420         case OMP_CLAUSE:
 421         case PHI_NODE:          gcc_unreachable ();
 422
 423         case SSA_NAME:          return sizeof (struct tree_ssa_name);
 424
 425         case STATEMENT_LIST:    return sizeof (struct tree_statement_list);
 426         case BLOCK:             return sizeof (struct tree_block);
 427         case VALUE_HANDLE:      return sizeof (struct tree_value_handle);
 428         case CONSTRUCTOR:       return sizeof (struct tree_constructor);
 429
 430         default:
 431           return lang_hooks.tree_size (code);
 432         }
 433
 434     default:
 435       gcc_unreachable ();
 436     }
 437 }
 438
 439 /* Compute the number of bytes occupied by NODE.  This routine only
 440    looks at TREE_CODE, except for those nodes that have variable sizes.  */
 441 size_t
 442 tree_size (tree node)
 443 {
 444   enum tree_code code = TREE_CODE (node);
 445   switch (code)
 446     {
 447     case PHI_NODE:
 448       return (sizeof (struct tree_phi_node)
 449               + (PHI_ARG_CAPACITY (node) - 1) * sizeof (struct phi_arg_d));
 450
 451     case TREE_BINFO:
 452       return (offsetof (struct tree_binfo, base_binfos)
 453               + VEC_embedded_size (tree, BINFO_N_BASE_BINFOS (node)));
 454
 455     case TREE_VEC:
 456       return (sizeof (struct tree_vec)
 457               + (TREE_VEC_LENGTH (node) - 1) * sizeof (tree));
 458
 459     case STRING_CST:
 460       return TREE_STRING_LENGTH (node) + offsetof (struct tree_string, str) + 1;
 461
 462     case OMP_CLAUSE:
 463       return (sizeof (struct tree_omp_clause)
 464               + (omp_clause_num_ops[OMP_CLAUSE_CODE (node)] - 1)
 465                 * sizeof (tree));
 466
 467     default:
 468       if (TREE_CODE_CLASS (code) == tcc_vl_exp)
 469         return (sizeof (struct tree_exp)
 470                 + (VL_EXP_OPERAND_LENGTH (node) - 1) * sizeof (tree));
 471       else
 472         return tree_code_size (code);
 473     }
 474 }
 475
 476 /* Return a newly allocated node of code CODE.  For decl and type
 477    nodes, some other fields are initialized.  The rest of the node is
 478    initialized to zero.  This function cannot be used for PHI_NODE,
 479    TREE_VEC or OMP_CLAUSE nodes, which is enforced by asserts in
 480    tree_code_size.
 481
 482    Achoo!  I got a code in the node.  */
 483
 484 tree
 485 make_node_stat (enum tree_code code MEM_STAT_DECL)
 486 {
 487   tree t;
 488   enum tree_code_class type = TREE_CODE_CLASS (code);
 489   size_t length = tree_code_size (code);
 490 #ifdef GATHER_STATISTICS
 491   tree_node_kind kind;
 492
 493   switch (type)
 494     {
 495     case tcc_declaration:  /* A decl node */
 496       kind = d_kind;
 497       break;
 498
 499     case tcc_type:  /* a type node */
 500       kind = t_kind;
 501       break;
 502
 503     case tcc_statement:  /* an expression with side effects */
 504       kind = s_kind;
 505       break;
 506
 507     case tcc_reference:  /* a reference */
 508       kind = r_kind;
 509       break;
 510
 511     case tcc_expression:  /* an expression */
 512     case tcc_comparison:  /* a comparison expression */
 513     case tcc_unary:  /* a unary arithmetic expression */
 514     case tcc_binary:  /* a binary arithmetic expression */
 515       kind = e_kind;
 516       break;
 517
 518     case tcc_constant:  /* a constant */
 519       kind = c_kind;
 520       break;
 521
 522     case tcc_gimple_stmt:
 523       kind = gimple_stmt_kind;
 524       break;
 525
 526     case tcc_exceptional:  /* something random, like an identifier.  */
 527       switch (code)
 528         {
 529         case IDENTIFIER_NODE:
 530           kind = id_kind;
 531           break;
 532
 533         case TREE_VEC:
 534           kind = vec_kind;
 535           break;
 536
 537         case TREE_BINFO:
 538           kind = binfo_kind;
 539           break;
 540
 541         case PHI_NODE:
 542           kind = phi_kind;
 543           break;
 544
 545         case SSA_NAME:
 546           kind = ssa_name_kind;
 547           break;
 548
 549         case BLOCK:
 550           kind = b_kind;
 551           break;
 552
 553         case CONSTRUCTOR:
 554           kind = constr_kind;
 555           break;
 556
 557         default:
 558           kind = x_kind;
 559           break;
 560         }
 561       break;
 562
 563     default:
 564       gcc_unreachable ();
 565     }
 566
 567   tree_node_counts[(int) kind]++;
 568   tree_node_sizes[(int) kind] += length;
 569 #endif
 570
 571   if (code == IDENTIFIER_NODE)
 572     t = ggc_alloc_zone_pass_stat (length, &tree_id_zone);
 573   else
 574     t = ggc_alloc_zone_pass_stat (length, &tree_zone);
 575
 576   memset (t, 0, length);
 577
 578   TREE_SET_CODE (t, code);
 579
 580   switch (type)
 581     {
 582     case tcc_statement:
 583       TREE_SIDE_EFFECTS (t) = 1;
 584       break;
 585
 586     case tcc_declaration:
 587       if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
 588         DECL_IN_SYSTEM_HEADER (t) = in_system_header;
 589       if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
 590         {
 591           if (code != FUNCTION_DECL)
 592             DECL_ALIGN (t) = 1;
 593           DECL_USER_ALIGN (t) = 0;
 594           /* We have not yet computed the alias set for this declaration.  */
 595           DECL_POINTER_ALIAS_SET (t) = -1;
 596         }
 597       DECL_SOURCE_LOCATION (t) = input_location;
 598       DECL_UID (t) = next_decl_uid++;
 599
 600       break;
 601
 602     case tcc_type:
 603       TYPE_UID (t) = next_type_uid++;
 604       TYPE_ALIGN (t) = BITS_PER_UNIT;
 605       TYPE_USER_ALIGN (t) = 0;
 606       TYPE_MAIN_VARIANT (t) = t;
 607       TYPE_CANONICAL (t) = t;
 608
 609       /* Default to no attributes for type, but let target change that.  */
 610       TYPE_ATTRIBUTES (t) = NULL_TREE;
 611       targetm.set_default_type_attributes (t);
 612
 613       /* We have not yet computed the alias set for this type.  */
 614       TYPE_ALIAS_SET (t) = -1;
 615       break;
 616
 617     case tcc_constant:
 618       TREE_CONSTANT (t) = 1;
 619       TREE_INVARIANT (t) = 1;
 620       break;
 621
 622     case tcc_expression:
 623       switch (code)
 624         {
 625         case INIT_EXPR:
 626         case MODIFY_EXPR:
 627         case VA_ARG_EXPR:
 628         case PREDECREMENT_EXPR:
 629         case PREINCREMENT_EXPR:
 630         case POSTDECREMENT_EXPR:
 631         case POSTINCREMENT_EXPR:
 632           /* All of these have side-effects, no matter what their
 633              operands are.  */
 634           TREE_SIDE_EFFECTS (t) = 1;
 635           break;
 636
 637         default:
 638           break;
 639         }
 640       break;
 641
 642     case tcc_gimple_stmt:
 643       switch (code)
 644         {
 645       case GIMPLE_MODIFY_STMT:
 646         TREE_SIDE_EFFECTS (t) = 1;
 647         break;
 648
 649       default:
 650         break;
 651         }
 652
 653     default:
 654       /* Other classes need no special treatment.  */
 655       break;
 656     }
 657
 658   return t;
 659 }
 660 \f
 661 /* Return a new node with the same contents as NODE except that its
 662    TREE_CHAIN is zero and it has a fresh uid.  */
 663
 664 tree
 665 copy_node_stat (tree node MEM_STAT_DECL)
 666 {
 667   tree t;
 668   enum tree_code code = TREE_CODE (node);
 669   size_t length;
 670
 671   gcc_assert (code != STATEMENT_LIST);
 672
 673   length = tree_size (node);
 674   t = ggc_alloc_zone_pass_stat (length, &tree_zone);
 675   memcpy (t, node, length);
 676
 677   if (!GIMPLE_TUPLE_P (node))
 678     TREE_CHAIN (t) = 0;
 679   TREE_ASM_WRITTEN (t) = 0;
 680   TREE_VISITED (t) = 0;
 681   t->base.ann = 0;
 682
 683   if (TREE_CODE_CLASS (code) == tcc_declaration)
 684     {
 685       DECL_UID (t) = next_decl_uid++;
 686       if ((TREE_CODE (node) == PARM_DECL || TREE_CODE (node) == VAR_DECL)
 687           && DECL_HAS_VALUE_EXPR_P (node))
 688         {
 689           SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (node));
 690           DECL_HAS_VALUE_EXPR_P (t) = 1;
 691         }
 692       if (TREE_CODE (node) == VAR_DECL && DECL_HAS_INIT_PRIORITY_P (node))
 693         {
 694           SET_DECL_INIT_PRIORITY (t, DECL_INIT_PRIORITY (node));
 695           DECL_HAS_INIT_PRIORITY_P (t) = 1;
 696         }
 697       if (TREE_CODE (node) == VAR_DECL && DECL_BASED_ON_RESTRICT_P (node))
 698         {
 699           SET_DECL_RESTRICT_BASE (t, DECL_GET_RESTRICT_BASE (node));
 700           DECL_BASED_ON_RESTRICT_P (t) = 1;
 701         }
 702     }
 703   else if (TREE_CODE_CLASS (code) == tcc_type)
 704     {
 705       TYPE_UID (t) = next_type_uid++;
 706       /* The following is so that the debug code for
 707          the copy is different from the original type.
 708          The two statements usually duplicate each other
 709          (because they clear fields of the same union),
 710          but the optimizer should catch that.  */
 711       TYPE_SYMTAB_POINTER (t) = 0;
 712       TYPE_SYMTAB_ADDRESS (t) = 0;
 713
 714       /* Do not copy the values cache.  */
 715       if (TYPE_CACHED_VALUES_P(t))
 716         {
 717           TYPE_CACHED_VALUES_P (t) = 0;
 718           TYPE_CACHED_VALUES (t) = NULL_TREE;
 719         }
 720     }
 721
 722   return t;
 723 }
 724
 725 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
 726    For example, this can copy a list made of TREE_LIST nodes.  */
 727
 728 tree
 729 copy_list (tree list)
 730 {
 731   tree head;
 732   tree prev, next;
 733
 734   if (list == 0)
 735     return 0;
 736
 737   head = prev = copy_node (list);
 738   next = TREE_CHAIN (list);
 739   while (next)
 740     {
 741       TREE_CHAIN (prev) = copy_node (next);
 742       prev = TREE_CHAIN (prev);
 743       next = TREE_CHAIN (next);
 744     }
 745   return head;
 746 }
 747
 748 \f
 749 /* Create an INT_CST node with a LOW value sign extended.  */
 750
 751 tree
 752 build_int_cst (tree type, HOST_WIDE_INT low)
 753 {
 754   /* Support legacy code.  */
 755   if (!type)
 756     type = integer_type_node;
 757
 758   return build_int_cst_wide (type, low, low < 0 ? -1 : 0);
 759 }
 760
 761 /* Create an INT_CST node with a LOW value zero extended.  */
 762
 763 tree
 764 build_int_cstu (tree type, unsigned HOST_WIDE_INT low)
 765 {
 766   return build_int_cst_wide (type, low, 0);
 767 }
 768
 769 /* Create an INT_CST node with a LOW value in TYPE.  The value is sign extended
 770    if it is negative.  This function is similar to build_int_cst, but
 771    the extra bits outside of the type precision are cleared.  Constants
 772    with these extra bits may confuse the fold so that it detects overflows
 773    even in cases when they do not occur, and in general should be avoided.
 774    We cannot however make this a default behavior of build_int_cst without
 775    more intrusive changes, since there are parts of gcc that rely on the extra
 776    precision of the integer constants.  */
 777
 778 tree
 779 build_int_cst_type (tree type, HOST_WIDE_INT low)
 780 {
 781   unsigned HOST_WIDE_INT low1;
 782   HOST_WIDE_INT hi;
 783
 784   gcc_assert (type);
 785
 786   fit_double_type (low, low < 0 ? -1 : 0, &low1, &hi, type);
 787
 788   return build_int_cst_wide (type, low1, hi);
 789 }
 790
 791 /* Create an INT_CST node of TYPE and value HI:LOW.  The value is truncated
 792    and sign extended according to the value range of TYPE.  */
 793
 794 tree
 795 build_int_cst_wide_type (tree type,
 796                          unsigned HOST_WIDE_INT low, HOST_WIDE_INT high)
 797 {
 798   fit_double_type (low, high, &low, &high, type);
 799   return build_int_cst_wide (type, low, high);
 800 }
 801
 802 /* These are the hash table functions for the hash table of INTEGER_CST
 803    nodes of a sizetype.  */
 804
 805 /* Return the hash code code X, an INTEGER_CST.  */
 806
 807 static hashval_t
 808 int_cst_hash_hash (const void *x)
 809 {
 810   tree t = (tree) x;
 811
 812   return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
 813           ^ htab_hash_pointer (TREE_TYPE (t)));
 814 }
 815
 816 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
 817    is the same as that given by *Y, which is the same.  */
 818
 819 static int
 820 int_cst_hash_eq (const void *x, const void *y)
 821 {
 822   tree xt = (tree) x;
 823   tree yt = (tree) y;
 824
 825   return (TREE_TYPE (xt) == TREE_TYPE (yt)
 826           && TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
 827           && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt));
 828 }
 829
 830 /* Create an INT_CST node of TYPE and value HI:LOW.
 831    The returned node is always shared.  For small integers we use a
 832    per-type vector cache, for larger ones we use a single hash table.  */
 833
 834 tree
 835 build_int_cst_wide (tree type, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
 836 {
 837   tree t;
 838   int ix = -1;
 839   int limit = 0;
 840
 841   gcc_assert (type);
 842
 843   switch (TREE_CODE (type))
 844     {
 845     case POINTER_TYPE:
 846     case REFERENCE_TYPE:
 847       /* Cache NULL pointer.  */
 848       if (!hi && !low)
 849         {
 850           limit = 1;
 851           ix = 0;
 852         }
 853       break;
 854
 855     case BOOLEAN_TYPE:
 856       /* Cache false or true.  */
 857       limit = 2;
 858       if (!hi && low < 2)
 859         ix = low;
 860       break;
 861
 862     case INTEGER_TYPE:
 863     case OFFSET_TYPE:
 864       if (TYPE_UNSIGNED (type))
 865         {
 866           /* Cache 0..N */
 867           limit = INTEGER_SHARE_LIMIT;
 868           if (!hi && low < (unsigned HOST_WIDE_INT)INTEGER_SHARE_LIMIT)
 869             ix = low;
 870         }
 871       else
 872         {
 873           /* Cache -1..N */
 874           limit = INTEGER_SHARE_LIMIT + 1;
 875           if (!hi && low < (unsigned HOST_WIDE_INT)INTEGER_SHARE_LIMIT)
 876             ix = low + 1;
 877           else if (hi == -1 && low == -(unsigned HOST_WIDE_INT)1)
 878             ix = 0;
 879         }
 880       break;
 881
 882     case ENUMERAL_TYPE:
 883       break;
 884
 885     default:
 886       gcc_unreachable ();
 887     }
 888
 889   if (ix >= 0)
 890     {
 891       /* Look for it in the type's vector of small shared ints.  */
 892       if (!TYPE_CACHED_VALUES_P (type))
 893         {
 894           TYPE_CACHED_VALUES_P (type) = 1;
 895           TYPE_CACHED_VALUES (type) = make_tree_vec (limit);
 896         }
 897
 898       t = TREE_VEC_ELT (TYPE_CACHED_VALUES (type), ix);
 899       if (t)
 900         {
 901           /* Make sure no one is clobbering the shared constant.  */
 902           gcc_assert (TREE_TYPE (t) == type);
 903           gcc_assert (TREE_INT_CST_LOW (t) == low);
 904           gcc_assert (TREE_INT_CST_HIGH (t) == hi);
 905         }
 906       else
 907         {
 908           /* Create a new shared int.  */
 909           t = make_node (INTEGER_CST);
 910
 911           TREE_INT_CST_LOW (t) = low;
 912           TREE_INT_CST_HIGH (t) = hi;
 913           TREE_TYPE (t) = type;
 914
 915           TREE_VEC_ELT (TYPE_CACHED_VALUES (type), ix) = t;
 916         }
 917     }
 918   else
 919     {
 920       /* Use the cache of larger shared ints.  */
 921       void **slot;
 922
 923       TREE_INT_CST_LOW (int_cst_node) = low;
 924       TREE_INT_CST_HIGH (int_cst_node) = hi;
 925       TREE_TYPE (int_cst_node) = type;
 926
 927       slot = htab_find_slot (int_cst_hash_table, int_cst_node, INSERT);
 928       t = *slot;
 929       if (!t)
 930         {
 931           /* Insert this one into the hash table.  */
 932           t = int_cst_node;
 933           *slot = t;
 934           /* Make a new node for next time round.  */
 935           int_cst_node = make_node (INTEGER_CST);
 936         }
 937     }
 938
 939   return t;
 940 }
 941
 942 /* Builds an integer constant in TYPE such that lowest BITS bits are ones
 943    and the rest are zeros.  */
 944
 945 tree
 946 build_low_bits_mask (tree type, unsigned bits)
 947 {
 948   unsigned HOST_WIDE_INT low;
 949   HOST_WIDE_INT high;
 950   unsigned HOST_WIDE_INT all_ones = ~(unsigned HOST_WIDE_INT) 0;
 951
 952   gcc_assert (bits <= TYPE_PRECISION (type));
 953
 954   if (bits == TYPE_PRECISION (type)
 955       && !TYPE_UNSIGNED (type))
 956     {
 957       /* Sign extended all-ones mask.  */
 958       low = all_ones;
 959       high = -1;
 960     }
 961   else if (bits <= HOST_BITS_PER_WIDE_INT)
 962     {
 963       low = all_ones >> (HOST_BITS_PER_WIDE_INT - bits);
 964       high = 0;
 965     }
 966   else
 967     {
 968       bits -= HOST_BITS_PER_WIDE_INT;
 969       low = all_ones;
 970       high = all_ones >> (HOST_BITS_PER_WIDE_INT - bits);
 971     }
 972
 973   return build_int_cst_wide (type, low, high);
 974 }
 975
 976 /* Checks that X is integer constant that can be expressed in (unsigned)
 977    HOST_WIDE_INT without loss of precision.  */
 978
 979 bool
 980 cst_and_fits_in_hwi (tree x)
 981 {
 982   if (TREE_CODE (x) != INTEGER_CST)
 983     return false;
 984
 985   if (TYPE_PRECISION (TREE_TYPE (x)) > HOST_BITS_PER_WIDE_INT)
 986     return false;
 987
 988   return (TREE_INT_CST_HIGH (x) == 0
 989           || TREE_INT_CST_HIGH (x) == -1);
 990 }
 991
 992 /* Return a new VECTOR_CST node whose type is TYPE and whose values
 993    are in a list pointed to by VALS.  */
 994
 995 tree
 996 build_vector (tree type, tree vals)
 997 {
 998   tree v = make_node (VECTOR_CST);
 999   int over = 0;
1000   tree link;
1001
1002   TREE_VECTOR_CST_ELTS (v) = vals;
1003   TREE_TYPE (v) = type;
1004
1005   /* Iterate through elements and check for overflow.  */
1006   for (link = vals; link; link = TREE_CHAIN (link))
1007     {
1008       tree value = TREE_VALUE (link);
1009
1010       /* Don't crash if we get an address constant.  */
1011       if (!CONSTANT_CLASS_P (value))
1012         continue;
1013
1014       over |= TREE_OVERFLOW (value);
1015     }
1016
1017   TREE_OVERFLOW (v) = over;
1018   return v;
1019 }
1020
1021 /* Return a new VECTOR_CST node whose type is TYPE and whose values
1022    are extracted from V, a vector of CONSTRUCTOR_ELT.  */
1023
1024 tree
1025 build_vector_from_ctor (tree type, VEC(constructor_elt,gc) *v)
1026 {
1027   tree list = NULL_TREE;
1028   unsigned HOST_WIDE_INT idx;
1029   tree value;
1030
1031   FOR_EACH_CONSTRUCTOR_VALUE (v, idx, value)
1032     list = tree_cons (NULL_TREE, value, list);
1033   return build_vector (type, nreverse (list));
1034 }
1035
1036 /* Return a new CONSTRUCTOR node whose type is TYPE and whose values
1037    are in the VEC pointed to by VALS.  */
1038 tree
1039 build_constructor (tree type, VEC(constructor_elt,gc) *vals)
1040 {
1041   tree c = make_node (CONSTRUCTOR);
1042   TREE_TYPE (c) = type;
1043   CONSTRUCTOR_ELTS (c) = vals;
1044   return c;
1045 }
1046
1047 /* Build a CONSTRUCTOR node made of a single initializer, with the specified
1048    INDEX and VALUE.  */
1049 tree
1050 build_constructor_single (tree type, tree index, tree value)
1051 {
1052   VEC(constructor_elt,gc) *v;
1053   constructor_elt *elt;
1054   tree t;
1055
1056   v = VEC_alloc (constructor_elt, gc, 1);
1057   elt = VEC_quick_push (constructor_elt, v, NULL);
1058   elt->index = index;
1059   elt->value = value;
1060
1061   t = build_constructor (type, v);
1062   TREE_CONSTANT (t) = TREE_CONSTANT (value);
1063   return t;
1064 }
1065
1066
1067 /* Return a new CONSTRUCTOR node whose type is TYPE and whose values
1068    are in a list pointed to by VALS.  */
1069 tree
1070 build_constructor_from_list (tree type, tree vals)
1071 {
1072   tree t, val;
1073   VEC(constructor_elt,gc) *v = NULL;
1074   bool constant_p = true;
1075
1076   if (vals)
1077     {
1078       v = VEC_alloc (constructor_elt, gc, list_length (vals));
1079       for (t = vals; t; t = TREE_CHAIN (t))
1080         {
1081           constructor_elt *elt = VEC_quick_push (constructor_elt, v, NULL);
1082           val = TREE_VALUE (t);
1083           elt->index = TREE_PURPOSE (t);
1084           elt->value = val;
1085           if (!TREE_CONSTANT (val))
1086             constant_p = false;
1087         }
1088     }
1089
1090   t = build_constructor (type, v);
1091   TREE_CONSTANT (t) = constant_p;
1092   return t;
1093 }
1094
1095
1096 /* Return a new REAL_CST node whose type is TYPE and value is D.  */
1097
1098 tree
1099 build_real (tree type, REAL_VALUE_TYPE d)
1100 {
1101   tree v;
1102   REAL_VALUE_TYPE *dp;
1103   int overflow = 0;
1104
1105   /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
1106      Consider doing it via real_convert now.  */
1107
1108   v = make_node (REAL_CST);
1109   dp = ggc_alloc (sizeof (REAL_VALUE_TYPE));
1110   memcpy (dp, &d, sizeof (REAL_VALUE_TYPE));
1111
1112   TREE_TYPE (v) = type;
1113   TREE_REAL_CST_PTR (v) = dp;
1114   TREE_OVERFLOW (v) = overflow;
1115   return v;
1116 }
1117
1118 /* Return a new REAL_CST node whose type is TYPE
1119    and whose value is the integer value of the INTEGER_CST node I.  */
1120
1121 REAL_VALUE_TYPE
1122 real_value_from_int_cst (tree type, tree i)
1123 {
1124   REAL_VALUE_TYPE d;
1125
1126   /* Clear all bits of the real value type so that we can later do
1127      bitwise comparisons to see if two values are the same.  */
1128   memset (&d, 0, sizeof d);
1129
1130   real_from_integer (&d, type ? TYPE_MODE (type) : VOIDmode,
1131                      TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1132                      TYPE_UNSIGNED (TREE_TYPE (i)));
1133   return d;
1134 }
1135
1136 /* Given a tree representing an integer constant I, return a tree
1137    representing the same value as a floating-point constant of type TYPE.  */
1138
1139 tree
1140 build_real_from_int_cst (tree type, tree i)
1141 {
1142   tree v;
1143   int overflow = TREE_OVERFLOW (i);
1144
1145   v = build_real (type, real_value_from_int_cst (type, i));
1146
1147   TREE_OVERFLOW (v) |= overflow;
1148   return v;
1149 }
1150
1151 /* Return a newly constructed STRING_CST node whose value is
1152    the LEN characters at STR.
1153    The TREE_TYPE is not initialized.  */
1154
1155 tree
1156 build_string (int len, const char *str)
1157 {
1158   tree s;
1159   size_t length;
1160
1161   /* Do not waste bytes provided by padding of struct tree_string.  */
1162   length = len + offsetof (struct tree_string, str) + 1;
1163
1164 #ifdef GATHER_STATISTICS
1165   tree_node_counts[(int) c_kind]++;
1166   tree_node_sizes[(int) c_kind] += length;
1167 #endif
1168
1169   s = ggc_alloc_tree (length);
1170
1171   memset (s, 0, sizeof (struct tree_common));
1172   TREE_SET_CODE (s, STRING_CST);
1173   TREE_CONSTANT (s) = 1;
1174   TREE_INVARIANT (s) = 1;
1175   TREE_STRING_LENGTH (s) = len;
1176   memcpy ((char *) TREE_STRING_POINTER (s), str, len);
1177   ((char *) TREE_STRING_POINTER (s))[len] = '\0';
1178
1179   return s;
1180 }
1181
1182 /* Return a newly constructed COMPLEX_CST node whose value is
1183    specified by the real and imaginary parts REAL and IMAG.
1184    Both REAL and IMAG should be constant nodes.  TYPE, if specified,
1185    will be the type of the COMPLEX_CST; otherwise a new type will be made.  */
1186
1187 tree
1188 build_complex (tree type, tree real, tree imag)
1189 {
1190   tree t = make_node (COMPLEX_CST);
1191
1192   TREE_REALPART (t) = real;
1193   TREE_IMAGPART (t) = imag;
1194   TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1195   TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1196   return t;
1197 }
1198
1199 /* Return a constant of arithmetic type TYPE which is the
1200    multiplicative identity of the set TYPE.  */
1201
1202 tree
1203 build_one_cst (tree type)
1204 {
1205   switch (TREE_CODE (type))
1206     {
1207     case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1208     case POINTER_TYPE: case REFERENCE_TYPE:
1209     case OFFSET_TYPE:
1210       return build_int_cst (type, 1);
1211
1212     case REAL_TYPE:
1213       return build_real (type, dconst1);
1214
1215     case VECTOR_TYPE:
1216       {
1217         tree scalar, cst;
1218         int i;
1219
1220         scalar = build_one_cst (TREE_TYPE (type));
1221
1222         /* Create 'vect_cst_ = {cst,cst,...,cst}'  */
1223         cst = NULL_TREE;
1224         for (i = TYPE_VECTOR_SUBPARTS (type); --i >= 0; )
1225           cst = tree_cons (NULL_TREE, scalar, cst);
1226
1227         return build_vector (type, cst);
1228       }
1229
1230     case COMPLEX_TYPE:
1231       return build_complex (type,
1232                             build_one_cst (TREE_TYPE (type)),
1233                             fold_convert (TREE_TYPE (type), integer_zero_node));
1234
1235     default:
1236       gcc_unreachable ();
1237     }
1238 }
1239
1240 /* Build a BINFO with LEN language slots.  */
1241
1242 tree
1243 make_tree_binfo_stat (unsigned base_binfos MEM_STAT_DECL)
1244 {
1245   tree t;
1246   size_t length = (offsetof (struct tree_binfo, base_binfos)
1247                    + VEC_embedded_size (tree, base_binfos));
1248
1249 #ifdef GATHER_STATISTICS
1250   tree_node_counts[(int) binfo_kind]++;
1251   tree_node_sizes[(int) binfo_kind] += length;
1252 #endif
1253
1254   t = ggc_alloc_zone_pass_stat (length, &tree_zone);
1255
1256   memset (t, 0, offsetof (struct tree_binfo, base_binfos));
1257
1258   TREE_SET_CODE (t, TREE_BINFO);
1259
1260   VEC_embedded_init (tree, BINFO_BASE_BINFOS (t), base_binfos);
1261
1262   return t;
1263 }
1264
1265
1266 /* Build a newly constructed TREE_VEC node of length LEN.  */
1267
1268 tree
1269 make_tree_vec_stat (int len MEM_STAT_DECL)
1270 {
1271   tree t;
1272   int length = (len - 1) * sizeof (tree) + sizeof (struct tree_vec);
1273
1274 #ifdef GATHER_STATISTICS
1275   tree_node_counts[(int) vec_kind]++;
1276   tree_node_sizes[(int) vec_kind] += length;
1277 #endif
1278
1279   t = ggc_alloc_zone_pass_stat (length, &tree_zone);
1280
1281   memset (t, 0, length);
1282
1283   TREE_SET_CODE (t, TREE_VEC);
1284   TREE_VEC_LENGTH (t) = len;
1285
1286   return t;
1287 }
1288 \f
1289 /* Return 1 if EXPR is the integer constant zero or a complex constant
1290    of zero.  */
1291
1292 int
1293 integer_zerop (tree expr)
1294 {
1295   STRIP_NOPS (expr);
1296
1297   return ((TREE_CODE (expr) == INTEGER_CST
1298            && TREE_INT_CST_LOW (expr) == 0
1299            && TREE_INT_CST_HIGH (expr) == 0)
1300           || (TREE_CODE (expr) == COMPLEX_CST
1301               && integer_zerop (TREE_REALPART (expr))
1302               && integer_zerop (TREE_IMAGPART (expr))));
1303 }
1304
1305 /* Return 1 if EXPR is the integer constant one or the corresponding
1306    complex constant.  */
1307
1308 int
1309 integer_onep (tree expr)
1310 {
1311   STRIP_NOPS (expr);
1312
1313   return ((TREE_CODE (expr) == INTEGER_CST
1314            && TREE_INT_CST_LOW (expr) == 1
1315            && TREE_INT_CST_HIGH (expr) == 0)
1316           || (TREE_CODE (expr) == COMPLEX_CST
1317               && integer_onep (TREE_REALPART (expr))
1318               && integer_zerop (TREE_IMAGPART (expr))));
1319 }
1320
1321 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1322    it contains.  Likewise for the corresponding complex constant.  */
1323
1324 int
1325 integer_all_onesp (tree expr)
1326 {
1327   int prec;
1328   int uns;
1329
1330   STRIP_NOPS (expr);
1331
1332   if (TREE_CODE (expr) == COMPLEX_CST
1333       && integer_all_onesp (TREE_REALPART (expr))
1334       && integer_zerop (TREE_IMAGPART (expr)))
1335     return 1;
1336
1337   else if (TREE_CODE (expr) != INTEGER_CST)
1338     return 0;
1339
1340   uns = TYPE_UNSIGNED (TREE_TYPE (expr));
1341   if (TREE_INT_CST_LOW (expr) == ~(unsigned HOST_WIDE_INT) 0
1342       && TREE_INT_CST_HIGH (expr) == -1)
1343     return 1;
1344   if (!uns)
1345     return 0;
1346
1347   /* Note that using TYPE_PRECISION here is wrong.  We care about the
1348      actual bits, not the (arbitrary) range of the type.  */
1349   prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1350   if (prec >= HOST_BITS_PER_WIDE_INT)
1351     {
1352       HOST_WIDE_INT high_value;
1353       int shift_amount;
1354
1355       shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1356
1357       /* Can not handle precisions greater than twice the host int size.  */
1358       gcc_assert (shift_amount <= HOST_BITS_PER_WIDE_INT);
1359       if (shift_amount == HOST_BITS_PER_WIDE_INT)
1360         /* Shifting by the host word size is undefined according to the ANSI
1361            standard, so we must handle this as a special case.  */
1362         high_value = -1;
1363       else
1364         high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1365
1366       return (TREE_INT_CST_LOW (expr) == ~(unsigned HOST_WIDE_INT) 0
1367               && TREE_INT_CST_HIGH (expr) == high_value);
1368     }
1369   else
1370     return TREE_INT_CST_LOW (expr) == ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1371 }
1372
1373 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1374    one bit on).  */
1375
1376 int
1377 integer_pow2p (tree expr)
1378 {
1379   int prec;
1380   HOST_WIDE_INT high, low;
1381
1382   STRIP_NOPS (expr);
1383
1384   if (TREE_CODE (expr) == COMPLEX_CST
1385       && integer_pow2p (TREE_REALPART (expr))
1386       && integer_zerop (TREE_IMAGPART (expr)))
1387     return 1;
1388
1389   if (TREE_CODE (expr) != INTEGER_CST)
1390     return 0;
1391
1392   prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1393           ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1394   high = TREE_INT_CST_HIGH (expr);
1395   low = TREE_INT_CST_LOW (expr);
1396
1397   /* First clear all bits that are beyond the type's precision in case
1398      we've been sign extended.  */
1399
1400   if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1401     ;
1402   else if (prec > HOST_BITS_PER_WIDE_INT)
1403     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1404   else
1405     {
1406       high = 0;
1407       if (prec < HOST_BITS_PER_WIDE_INT)
1408         low &= ~((HOST_WIDE_INT) (-1) << prec);
1409     }
1410
1411   if (high == 0 && low == 0)
1412     return 0;
1413
1414   return ((high == 0 && (low & (low - 1)) == 0)
1415           || (low == 0 && (high & (high - 1)) == 0));
1416 }
1417
1418 /* Return 1 if EXPR is an integer constant other than zero or a
1419    complex constant other than zero.  */
1420
1421 int
1422 integer_nonzerop (tree expr)
1423 {
1424   STRIP_NOPS (expr);
1425
1426   return ((TREE_CODE (expr) == INTEGER_CST
1427            && (TREE_INT_CST_LOW (expr) != 0
1428                || TREE_INT_CST_HIGH (expr) != 0))
1429           || (TREE_CODE (expr) == COMPLEX_CST
1430               && (integer_nonzerop (TREE_REALPART (expr))
1431                   || integer_nonzerop (TREE_IMAGPART (expr)))));
1432 }
1433
1434 /* Return the power of two represented by a tree node known to be a
1435    power of two.  */
1436
1437 int
1438 tree_log2 (tree expr)
1439 {
1440   int prec;
1441   HOST_WIDE_INT high, low;
1442
1443   STRIP_NOPS (expr);
1444
1445   if (TREE_CODE (expr) == COMPLEX_CST)
1446     return tree_log2 (TREE_REALPART (expr));
1447
1448   prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1449           ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1450
1451   high = TREE_INT_CST_HIGH (expr);
1452   low = TREE_INT_CST_LOW (expr);
1453
1454   /* First clear all bits that are beyond the type's precision in case
1455      we've been sign extended.  */
1456
1457   if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1458     ;
1459   else if (prec > HOST_BITS_PER_WIDE_INT)
1460     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1461   else
1462     {
1463       high = 0;
1464       if (prec < HOST_BITS_PER_WIDE_INT)
1465         low &= ~((HOST_WIDE_INT) (-1) << prec);
1466     }
1467
1468   return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1469           : exact_log2 (low));
1470 }
1471
1472 /* Similar, but return the largest integer Y such that 2 ** Y is less
1473    than or equal to EXPR.  */
1474
1475 int
1476 tree_floor_log2 (tree expr)
1477 {
1478   int prec;
1479   HOST_WIDE_INT high, low;
1480
1481   STRIP_NOPS (expr);
1482
1483   if (TREE_CODE (expr) == COMPLEX_CST)
1484     return tree_log2 (TREE_REALPART (expr));
1485
1486   prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1487           ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1488
1489   high = TREE_INT_CST_HIGH (expr);
1490   low = TREE_INT_CST_LOW (expr);
1491
1492   /* First clear all bits that are beyond the type's precision in case
1493      we've been sign extended.  Ignore if type's precision hasn't been set
1494      since what we are doing is setting it.  */
1495
1496   if (prec == 2 * HOST_BITS_PER_WIDE_INT || prec == 0)
1497     ;
1498   else if (prec > HOST_BITS_PER_WIDE_INT)
1499     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1500   else
1501     {
1502       high = 0;
1503       if (prec < HOST_BITS_PER_WIDE_INT)
1504         low &= ~((HOST_WIDE_INT) (-1) << prec);
1505     }
1506
1507   return (high != 0 ? HOST_BITS_PER_WIDE_INT + floor_log2 (high)
1508           : floor_log2 (low));
1509 }
1510
1511 /* Return 1 if EXPR is the real constant zero.  */
1512
1513 int
1514 real_zerop (tree expr)
1515 {
1516   STRIP_NOPS (expr);
1517
1518   return ((TREE_CODE (expr) == REAL_CST
1519            && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0))
1520           || (TREE_CODE (expr) == COMPLEX_CST
1521               && real_zerop (TREE_REALPART (expr))
1522               && real_zerop (TREE_IMAGPART (expr))));
1523 }
1524
1525 /* Return 1 if EXPR is the real constant one in real or complex form.  */
1526
1527 int
1528 real_onep (tree expr)
1529 {
1530   STRIP_NOPS (expr);
1531
1532   return ((TREE_CODE (expr) == REAL_CST
1533            && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1))
1534           || (TREE_CODE (expr) == COMPLEX_CST
1535               && real_onep (TREE_REALPART (expr))
1536               && real_zerop (TREE_IMAGPART (expr))));
1537 }
1538
1539 /* Return 1 if EXPR is the real constant two.  */
1540
1541 int
1542 real_twop (tree expr)
1543 {
1544   STRIP_NOPS (expr);
1545
1546   return ((TREE_CODE (expr) == REAL_CST
1547            && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2))
1548           || (TREE_CODE (expr) == COMPLEX_CST
1549               && real_twop (TREE_REALPART (expr))
1550               && real_zerop (TREE_IMAGPART (expr))));
1551 }
1552
1553 /* Return 1 if EXPR is the real constant minus one.  */
1554
1555 int
1556 real_minus_onep (tree expr)
1557 {
1558   STRIP_NOPS (expr);
1559
1560   return ((TREE_CODE (expr) == REAL_CST
1561            && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconstm1))
1562           || (TREE_CODE (expr) == COMPLEX_CST
1563               && real_minus_onep (TREE_REALPART (expr))
1564               && real_zerop (TREE_IMAGPART (expr))));
1565 }
1566
1567 /* Nonzero if EXP is a constant or a cast of a constant.  */
1568
1569 int
1570 really_constant_p (tree exp)
1571 {
1572   /* This is not quite the same as STRIP_NOPS.  It does more.  */
1573   while (TREE_CODE (exp) == NOP_EXPR
1574          || TREE_CODE (exp) == CONVERT_EXPR
1575          || TREE_CODE (exp) == NON_LVALUE_EXPR)
1576     exp = TREE_OPERAND (exp, 0);
1577   return TREE_CONSTANT (exp);
1578 }
1579 \f
1580 /* Return first list element whose TREE_VALUE is ELEM.
1581    Return 0 if ELEM is not in LIST.  */
1582
1583 tree
1584 value_member (tree elem, tree list)
1585 {
1586   while (list)
1587     {
1588       if (elem == TREE_VALUE (list))
1589         return list;
1590       list = TREE_CHAIN (list);
1591     }
1592   return NULL_TREE;
1593 }
1594
1595 /* Return first list element whose TREE_PURPOSE is ELEM.
1596    Return 0 if ELEM is not in LIST.  */
1597
1598 tree
1599 purpose_member (tree elem, tree list)
1600 {
1601   while (list)
1602     {
1603       if (elem == TREE_PURPOSE (list))
1604         return list;
1605       list = TREE_CHAIN (list);
1606     }
1607   return NULL_TREE;
1608 }
1609
1610 /* Return nonzero if ELEM is part of the chain CHAIN.  */
1611
1612 int
1613 chain_member (tree elem, tree chain)
1614 {
1615   while (chain)
1616     {
1617       if (elem == chain)
1618         return 1;
1619       chain = TREE_CHAIN (chain);
1620     }
1621
1622   return 0;
1623 }
1624
1625 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1626    We expect a null pointer to mark the end of the chain.
1627    This is the Lisp primitive `length'.  */
1628
1629 int
1630 list_length (tree t)
1631 {
1632   tree p = t;
1633 #ifdef ENABLE_TREE_CHECKING
1634   tree q = t;
1635 #endif
1636   int len = 0;
1637
1638   while (p)
1639     {
1640       p = TREE_CHAIN (p);
1641 #ifdef ENABLE_TREE_CHECKING
1642       if (len % 2)
1643         q = TREE_CHAIN (q);
1644       gcc_assert (p != q);
1645 #endif
1646       len++;
1647     }
1648
1649   return len;
1650 }
1651
1652 /* Returns the number of FIELD_DECLs in TYPE.  */
1653
1654 int
1655 fields_length (tree type)
1656 {
1657   tree t = TYPE_FIELDS (type);
1658   int count = 0;
1659
1660   for (; t; t = TREE_CHAIN (t))
1661     if (TREE_CODE (t) == FIELD_DECL)
1662       ++count;
1663
1664   return count;
1665 }
1666
1667 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1668    by modifying the last node in chain 1 to point to chain 2.
1669    This is the Lisp primitive `nconc'.  */
1670
1671 tree
1672 chainon (tree op1, tree op2)
1673 {
1674   tree t1;
1675
1676   if (!op1)
1677     return op2;
1678   if (!op2)
1679     return op1;
1680
1681   for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1682     continue;
1683   TREE_CHAIN (t1) = op2;
1684
1685 #ifdef ENABLE_TREE_CHECKING
1686   {
1687     tree t2;
1688     for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1689       gcc_assert (t2 != t1);
1690   }
1691 #endif
1692
1693   return op1;
1694 }
1695
1696 /* Return the last node in a chain of nodes (chained through TREE_CHAIN).  */
1697
1698 tree
1699 tree_last (tree chain)
1700 {
1701   tree next;
1702   if (chain)
1703     while ((next = TREE_CHAIN (chain)))
1704       chain = next;
1705   return chain;
1706 }
1707
1708 /* Reverse the order of elements in the chain T,
1709    and return the new head of the chain (old last element).  */
1710
1711 tree
1712 nreverse (tree t)
1713 {
1714   tree prev = 0, decl, next;
1715   for (decl = t; decl; decl = next)
1716     {
1717       next = TREE_CHAIN (decl);
1718       TREE_CHAIN (decl) = prev;
1719       prev = decl;
1720     }
1721   return prev;
1722 }
1723 \f
1724 /* Return a newly created TREE_LIST node whose
1725    purpose and value fields are PARM and VALUE.  */
1726
1727 tree
1728 build_tree_list_stat (tree parm, tree value MEM_STAT_DECL)
1729 {
1730   tree t = make_node_stat (TREE_LIST PASS_MEM_STAT);
1731   TREE_PURPOSE (t) = parm;
1732   TREE_VALUE (t) = value;
1733   return t;
1734 }
1735
1736 /* Return a newly created TREE_LIST node whose
1737    purpose and value fields are PURPOSE and VALUE
1738    and whose TREE_CHAIN is CHAIN.  */
1739
1740 tree
1741 tree_cons_stat (tree purpose, tree value, tree chain MEM_STAT_DECL)
1742 {
1743   tree node;
1744
1745   node = ggc_alloc_zone_pass_stat (sizeof (struct tree_list), &tree_zone);
1746
1747   memset (node, 0, sizeof (struct tree_common));
1748
1749 #ifdef GATHER_STATISTICS
1750   tree_node_counts[(int) x_kind]++;
1751   tree_node_sizes[(int) x_kind] += sizeof (struct tree_list);
1752 #endif
1753
1754   TREE_SET_CODE (node, TREE_LIST);
1755   TREE_CHAIN (node) = chain;
1756   TREE_PURPOSE (node) = purpose;
1757   TREE_VALUE (node) = value;
1758   return node;
1759 }
1760
1761 \f
1762 /* Return the size nominally occupied by an object of type TYPE
1763    when it resides in memory.  The value is measured in units of bytes,
1764    and its data type is that normally used for type sizes
1765    (which is the first type created by make_signed_type or
1766    make_unsigned_type).  */
1767
1768 tree
1769 size_in_bytes (tree type)
1770 {
1771   tree t;
1772
1773   if (type == error_mark_node)
1774     return integer_zero_node;
1775
1776   type = TYPE_MAIN_VARIANT (type);
1777   t = TYPE_SIZE_UNIT (type);
1778
1779   if (t == 0)
1780     {
1781       lang_hooks.types.incomplete_type_error (NULL_TREE, type);
1782       return size_zero_node;
1783     }
1784
1785   return t;
1786 }
1787
1788 /* Return the size of TYPE (in bytes) as a wide integer
1789    or return -1 if the size can vary or is larger than an integer.  */
1790
1791 HOST_WIDE_INT
1792 int_size_in_bytes (tree type)
1793 {
1794   tree t;
1795
1796   if (type == error_mark_node)
1797     return 0;
1798
1799   type = TYPE_MAIN_VARIANT (type);
1800   t = TYPE_SIZE_UNIT (type);
1801   if (t == 0
1802       || TREE_CODE (t) != INTEGER_CST
1803       || TREE_INT_CST_HIGH (t) != 0
1804       /* If the result would appear negative, it's too big to represent.  */
1805       || (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0)
1806     return -1;
1807
1808   return TREE_INT_CST_LOW (t);
1809 }
1810
1811 /* Return the maximum size of TYPE (in bytes) as a wide integer
1812    or return -1 if the size can vary or is larger than an integer.  */
1813
1814 HOST_WIDE_INT
1815 max_int_size_in_bytes (tree type)
1816 {
1817   HOST_WIDE_INT size = -1;
1818   tree size_tree;
1819
1820   /* If this is an array type, check for a possible MAX_SIZE attached.  */
1821
1822   if (TREE_CODE (type) == ARRAY_TYPE)
1823     {
1824       size_tree = TYPE_ARRAY_MAX_SIZE (type);
1825
1826       if (size_tree && host_integerp (size_tree, 1))
1827         size = tree_low_cst (size_tree, 1);
1828     }
1829
1830   /* If we still haven't been able to get a size, see if the language
1831      can compute a maximum size.  */
1832
1833   if (size == -1)
1834     {
1835       size_tree = lang_hooks.types.max_size (type);
1836
1837       if (size_tree && host_integerp (size_tree, 1))
1838         size = tree_low_cst (size_tree, 1);
1839     }
1840
1841   return size;
1842 }
1843 \f
1844 /* Return the bit position of FIELD, in bits from the start of the record.
1845    This is a tree of type bitsizetype.  */
1846
1847 tree
1848 bit_position (tree field)
1849 {
1850   return bit_from_pos (DECL_FIELD_OFFSET (field),
1851                        DECL_FIELD_BIT_OFFSET (field));
1852 }
1853
1854 /* Likewise, but return as an integer.  It must be representable in
1855    that way (since it could be a signed value, we don't have the
1856    option of returning -1 like int_size_in_byte can.  */
1857
1858 HOST_WIDE_INT
1859 int_bit_position (tree field)
1860 {
1861   return tree_low_cst (bit_position (field), 0);
1862 }
1863 \f
1864 /* Return the byte position of FIELD, in bytes from the start of the record.
1865    This is a tree of type sizetype.  */
1866
1867 tree
1868 byte_position (tree field)
1869 {
1870   return byte_from_pos (DECL_FIELD_OFFSET (field),
1871                         DECL_FIELD_BIT_OFFSET (field));
1872 }
1873
1874 /* Likewise, but return as an integer.  It must be representable in
1875    that way (since it could be a signed value, we don't have the
1876    option of returning -1 like int_size_in_byte can.  */
1877
1878 HOST_WIDE_INT
1879 int_byte_position (tree field)
1880 {
1881   return tree_low_cst (byte_position (field), 0);
1882 }
1883 \f
1884 /* Return the strictest alignment, in bits, that T is known to have.  */
1885
1886 unsigned int
1887 expr_align (tree t)
1888 {
1889   unsigned int align0, align1;
1890
1891   switch (TREE_CODE (t))
1892     {
1893     case NOP_EXPR:  case CONVERT_EXPR:  case NON_LVALUE_EXPR:
1894       /* If we have conversions, we know that the alignment of the
1895          object must meet each of the alignments of the types.  */
1896       align0 = expr_align (TREE_OPERAND (t, 0));
1897       align1 = TYPE_ALIGN (TREE_TYPE (t));
1898       return MAX (align0, align1);
1899
1900     case GIMPLE_MODIFY_STMT:
1901       /* We should never ask for the alignment of a gimple statement.  */
1902       gcc_unreachable ();
1903
1904     case SAVE_EXPR:         case COMPOUND_EXPR:       case MODIFY_EXPR:
1905     case INIT_EXPR:         case TARGET_EXPR:         case WITH_CLEANUP_EXPR:
1906     case CLEANUP_POINT_EXPR:
1907       /* These don't change the alignment of an object.  */
1908       return expr_align (TREE_OPERAND (t, 0));
1909
1910     case COND_EXPR:
1911       /* The best we can do is say that the alignment is the least aligned
1912          of the two arms.  */
1913       align0 = expr_align (TREE_OPERAND (t, 1));
1914       align1 = expr_align (TREE_OPERAND (t, 2));
1915       return MIN (align0, align1);
1916
1917     case LABEL_DECL:     case CONST_DECL:
1918     case VAR_DECL:       case PARM_DECL:   case RESULT_DECL:
1919       if (DECL_ALIGN (t) != 0)
1920         return DECL_ALIGN (t);
1921       break;
1922
1923     case FUNCTION_DECL:
1924       return FUNCTION_BOUNDARY;
1925
1926     default:
1927       break;
1928     }
1929
1930   /* Otherwise take the alignment from that of the type.  */
1931   return TYPE_ALIGN (TREE_TYPE (t));
1932 }
1933 \f
1934 /* Return, as a tree node, the number of elements for TYPE (which is an
1935    ARRAY_TYPE) minus one. This counts only elements of the top array.  */
1936
1937 tree
1938 array_type_nelts (tree type)
1939 {
1940   tree index_type, min, max;
1941
1942   /* If they did it with unspecified bounds, then we should have already
1943      given an error about it before we got here.  */
1944   if (! TYPE_DOMAIN (type))
1945     return error_mark_node;
1946
1947   index_type = TYPE_DOMAIN (type);
1948   min = TYPE_MIN_VALUE (index_type);
1949   max = TYPE_MAX_VALUE (index_type);
1950
1951   return (integer_zerop (min)
1952           ? max
1953           : fold_build2 (MINUS_EXPR, TREE_TYPE (max), max, min));
1954 }
1955 \f
1956 /* If arg is static -- a reference to an object in static storage -- then
1957    return the object.  This is not the same as the C meaning of `static'.
1958    If arg isn't static, return NULL.  */
1959
1960 tree
1961 staticp (tree arg)
1962 {
1963   switch (TREE_CODE (arg))
1964     {
1965     case FUNCTION_DECL:
1966       /* Nested functions are static, even though taking their address will
1967          involve a trampoline as we unnest the nested function and create
1968          the trampoline on the tree level.  */
1969       return arg;
1970
1971     case VAR_DECL:
1972       return ((TREE_STATIC (arg) || DECL_EXTERNAL (arg))
1973               && ! DECL_THREAD_LOCAL_P (arg)
1974               && ! DECL_DLLIMPORT_P (arg)
1975               ? arg : NULL);
1976
1977     case CONST_DECL:
1978       return ((TREE_STATIC (arg) || DECL_EXTERNAL (arg))
1979               ? arg : NULL);
1980
1981     case CONSTRUCTOR:
1982       return TREE_STATIC (arg) ? arg : NULL;
1983
1984     case LABEL_DECL:
1985     case STRING_CST:
1986       return arg;
1987
1988     case COMPONENT_REF:
1989       /* If the thing being referenced is not a field, then it is
1990          something language specific.  */
1991       if (TREE_CODE (TREE_OPERAND (arg, 1)) != FIELD_DECL)
1992         return (*lang_hooks.staticp) (arg);
1993
1994       /* If we are referencing a bitfield, we can't evaluate an
1995          ADDR_EXPR at compile time and so it isn't a constant.  */
1996       if (DECL_BIT_FIELD (TREE_OPERAND (arg, 1)))
1997         return NULL;
1998
1999       return staticp (TREE_OPERAND (arg, 0));
2000
2001     case BIT_FIELD_REF:
2002       return NULL;
2003
2004     case MISALIGNED_INDIRECT_REF:
2005     case ALIGN_INDIRECT_REF:
2006     case INDIRECT_REF:
2007       return TREE_CONSTANT (TREE_OPERAND (arg, 0)) ? arg : NULL;
2008
2009     case ARRAY_REF:
2010     case ARRAY_RANGE_REF:
2011       if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2012           && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2013         return staticp (TREE_OPERAND (arg, 0));
2014       else
2015         return false;
2016
2017     default:
2018       if ((unsigned int) TREE_CODE (arg)
2019           >= (unsigned int) LAST_AND_UNUSED_TREE_CODE)
2020         return lang_hooks.staticp (arg);
2021       else
2022         return NULL;
2023     }
2024 }
2025 \f
2026 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2027    Do this to any expression which may be used in more than one place,
2028    but must be evaluated only once.
2029
2030    Normally, expand_expr would reevaluate the expression each time.
2031    Calling save_expr produces something that is evaluated and recorded
2032    the first time expand_expr is called on it.  Subsequent calls to
2033    expand_expr just reuse the recorded value.
2034
2035    The call to expand_expr that generates code that actually computes
2036    the value is the first call *at compile time*.  Subsequent calls
2037    *at compile time* generate code to use the saved value.
2038    This produces correct result provided that *at run time* control
2039    always flows through the insns made by the first expand_expr
2040    before reaching the other places where the save_expr was evaluated.
2041    You, the caller of save_expr, must make sure this is so.
2042
2043    Constants, and certain read-only nodes, are returned with no
2044    SAVE_EXPR because that is safe.  Expressions containing placeholders
2045    are not touched; see tree.def for an explanation of what these
2046    are used for.  */
2047
2048 tree
2049 save_expr (tree expr)
2050 {
2051   tree t = fold (expr);
2052   tree inner;
2053
2054   /* If the tree evaluates to a constant, then we don't want to hide that
2055      fact (i.e. this allows further folding, and direct checks for constants).
2056      However, a read-only object that has side effects cannot be bypassed.
2057      Since it is no problem to reevaluate literals, we just return the
2058      literal node.  */
2059   inner = skip_simple_arithmetic (t);
2060
2061   if (TREE_INVARIANT (inner)
2062       || (TREE_READONLY (inner) && ! TREE_SIDE_EFFECTS (inner))
2063       || TREE_CODE (inner) == SAVE_EXPR
2064       || TREE_CODE (inner) == ERROR_MARK)
2065     return t;
2066
2067   /* If INNER contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2068      it means that the size or offset of some field of an object depends on
2069      the value within another field.
2070
2071      Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2072      and some variable since it would then need to be both evaluated once and
2073      evaluated more than once.  Front-ends must assure this case cannot
2074      happen by surrounding any such subexpressions in their own SAVE_EXPR
2075      and forcing evaluation at the proper time.  */
2076   if (contains_placeholder_p (inner))
2077     return t;
2078
2079   t = build1 (SAVE_EXPR, TREE_TYPE (expr), t);
2080
2081   /* This expression might be placed ahead of a jump to ensure that the
2082      value was computed on both sides of the jump.  So make sure it isn't
2083      eliminated as dead.  */
2084   TREE_SIDE_EFFECTS (t) = 1;
2085   TREE_INVARIANT (t) = 1;
2086   return t;
2087 }
2088
2089 /* Look inside EXPR and into any simple arithmetic operations.  Return
2090    the innermost non-arithmetic node.  */
2091
2092 tree
2093 skip_simple_arithmetic (tree expr)
2094 {
2095   tree inner;
2096
2097   /* We don't care about whether this can be used as an lvalue in this
2098      context.  */
2099   while (TREE_CODE (expr) == NON_LVALUE_EXPR)
2100     expr = TREE_OPERAND (expr, 0);
2101
2102   /* If we have simple operations applied to a SAVE_EXPR or to a SAVE_EXPR and
2103      a constant, it will be more efficient to not make another SAVE_EXPR since
2104      it will allow better simplification and GCSE will be able to merge the
2105      computations if they actually occur.  */
2106   inner = expr;
2107   while (1)
2108     {
2109       if (UNARY_CLASS_P (inner))
2110         inner = TREE_OPERAND (inner, 0);
2111       else if (BINARY_CLASS_P (inner))
2112         {
2113           if (TREE_INVARIANT (TREE_OPERAND (inner, 1)))
2114             inner = TREE_OPERAND (inner, 0);
2115           else if (TREE_INVARIANT (TREE_OPERAND (inner, 0)))
2116             inner = TREE_OPERAND (inner, 1);
2117           else
2118             break;
2119         }
2120       else
2121         break;
2122     }
2123
2124   return inner;
2125 }
2126
2127 /* Return which tree structure is used by T.  */
2128
2129 enum tree_node_structure_enum
2130 tree_node_structure (tree t)
2131 {
2132   enum tree_code code = TREE_CODE (t);
2133
2134   switch (TREE_CODE_CLASS (code))
2135     {
2136     case tcc_declaration:
2137       {
2138         switch (code)
2139           {
2140           case FIELD_DECL:
2141             return TS_FIELD_DECL;
2142           case PARM_DECL:
2143             return TS_PARM_DECL;
2144           case VAR_DECL:
2145             return TS_VAR_DECL;
2146           case LABEL_DECL:
2147             return TS_LABEL_DECL;
2148           case RESULT_DECL:
2149             return TS_RESULT_DECL;
2150           case CONST_DECL:
2151             return TS_CONST_DECL;
2152           case TYPE_DECL:
2153             return TS_TYPE_DECL;
2154           case FUNCTION_DECL:
2155             return TS_FUNCTION_DECL;
2156           case SYMBOL_MEMORY_TAG:
2157           case NAME_MEMORY_TAG:
2158           case STRUCT_FIELD_TAG:
2159           case MEMORY_PARTITION_TAG:
2160             return TS_MEMORY_TAG;
2161           default:
2162             return TS_DECL_NON_COMMON;
2163           }
2164       }
2165     case tcc_type:
2166       return TS_TYPE;
2167     case tcc_reference:
2168     case tcc_comparison:
2169     case tcc_unary:
2170     case tcc_binary:
2171     case tcc_expression:
2172     case tcc_statement:
2173     case tcc_vl_exp:
2174       return TS_EXP;
2175     case tcc_gimple_stmt:
2176       return TS_GIMPLE_STATEMENT;
2177     default:  /* tcc_constant and tcc_exceptional */
2178       break;
2179     }
2180   switch (code)
2181     {
2182       /* tcc_constant cases.  */
2183     case INTEGER_CST:           return TS_INT_CST;
2184     case REAL_CST:              return TS_REAL_CST;
2185     case COMPLEX_CST:           return TS_COMPLEX;
2186     case VECTOR_CST:            return TS_VECTOR;
2187     case STRING_CST:            return TS_STRING;
2188       /* tcc_exceptional cases.  */
2189     /* FIXME tuples: eventually this should be TS_BASE.  For now, nothing
2190        returns TS_BASE.  */
2191     case ERROR_MARK:            return TS_COMMON;
2192     case IDENTIFIER_NODE:       return TS_IDENTIFIER;
2193     case TREE_LIST:             return TS_LIST;
2194     case TREE_VEC:              return TS_VEC;
2195     case PHI_NODE:              return TS_PHI_NODE;
2196     case SSA_NAME:              return TS_SSA_NAME;
2197     case PLACEHOLDER_EXPR:      return TS_COMMON;
2198     case STATEMENT_LIST:        return TS_STATEMENT_LIST;
2199     case BLOCK:                 return TS_BLOCK;
2200     case CONSTRUCTOR:           return TS_CONSTRUCTOR;
2201     case TREE_BINFO:            return TS_BINFO;
2202     case VALUE_HANDLE:          return TS_VALUE_HANDLE;
2203     case OMP_CLAUSE:            return TS_OMP_CLAUSE;
2204
2205     default:
2206       gcc_unreachable ();
2207     }
2208 }
2209 \f
2210 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2211    or offset that depends on a field within a record.  */
2212
2213 bool
2214 contains_placeholder_p (tree exp)
2215 {
2216   enum tree_code code;
2217
2218   if (!exp)
2219     return 0;
2220
2221   code = TREE_CODE (exp);
2222   if (code == PLACEHOLDER_EXPR)
2223     return 1;
2224
2225   switch (TREE_CODE_CLASS (code))
2226     {
2227     case tcc_reference:
2228       /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2229          position computations since they will be converted into a
2230          WITH_RECORD_EXPR involving the reference, which will assume
2231          here will be valid.  */
2232       return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0));
2233
2234     case tcc_exceptional:
2235       if (code == TREE_LIST)
2236         return (CONTAINS_PLACEHOLDER_P (TREE_VALUE (exp))
2237                 || CONTAINS_PLACEHOLDER_P (TREE_CHAIN (exp)));
2238       break;
2239
2240     case tcc_unary:
2241     case tcc_binary:
2242     case tcc_comparison:
2243     case tcc_expression:
2244       switch (code)
2245         {
2246         case COMPOUND_EXPR:
2247           /* Ignoring the first operand isn't quite right, but works best.  */
2248           return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1));
2249
2250         case COND_EXPR:
2251           return (CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0))
2252                   || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1))
2253                   || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 2)));
2254
2255         default:
2256           break;
2257         }
2258
2259       switch (TREE_CODE_LENGTH (code))
2260         {
2261         case 1:
2262           return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0));
2263         case 2:
2264           return (CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0))
2265                   || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1)));
2266         default:
2267           return 0;
2268         }
2269
2270     case tcc_vl_exp:
2271       switch (code)
2272         {
2273         case CALL_EXPR:
2274           {
2275             tree arg;
2276             call_expr_arg_iterator iter;
2277             FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2278               if (CONTAINS_PLACEHOLDER_P (arg))
2279                 return 1;
2280             return 0;
2281           }
2282         default:
2283           return 0;
2284         }
2285
2286     default:
2287       return 0;
2288     }
2289   return 0;
2290 }
2291
2292 /* Return true if any part of the computation of TYPE involves a
2293    PLACEHOLDER_EXPR.  This includes size, bounds, qualifiers
2294    (for QUAL_UNION_TYPE) and field positions.  */
2295
2296 static bool
2297 type_contains_placeholder_1 (tree type)
2298 {
2299   /* If the size contains a placeholder or the parent type (component type in
2300      the case of arrays) type involves a placeholder, this type does.  */
2301   if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
2302       || CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (type))
2303       || (TREE_TYPE (type) != 0
2304           && type_contains_placeholder_p (TREE_TYPE (type))))
2305     return true;
2306
2307   /* Now do type-specific checks.  Note that the last part of the check above
2308      greatly limits what we have to do below.  */
2309   switch (TREE_CODE (type))
2310     {
2311     case VOID_TYPE:
2312     case COMPLEX_TYPE:
2313     case ENUMERAL_TYPE:
2314     case BOOLEAN_TYPE:
2315     case POINTER_TYPE:
2316     case OFFSET_TYPE:
2317     case REFERENCE_TYPE:
2318     case METHOD_TYPE:
2319     case FUNCTION_TYPE:
2320     case VECTOR_TYPE:
2321       return false;
2322
2323     case INTEGER_TYPE:
2324     case REAL_TYPE:
2325       /* Here we just check the bounds.  */
2326       return (CONTAINS_PLACEHOLDER_P (TYPE_MIN_VALUE (type))
2327               || CONTAINS_PLACEHOLDER_P (TYPE_MAX_VALUE (type)));
2328
2329     case ARRAY_TYPE:
2330       /* We're already checked the component type (TREE_TYPE), so just check
2331          the index type.  */
2332       return type_contains_placeholder_p (TYPE_DOMAIN (type));
2333
2334     case RECORD_TYPE:
2335     case UNION_TYPE:
2336     case QUAL_UNION_TYPE:
2337       {
2338         tree field;
2339
2340         for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
2341           if (TREE_CODE (field) == FIELD_DECL
2342               && (CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (field))
2343                   || (TREE_CODE (type) == QUAL_UNION_TYPE
2344                       && CONTAINS_PLACEHOLDER_P (DECL_QUALIFIER (field)))
2345                   || type_contains_placeholder_p (TREE_TYPE (field))))
2346             return true;
2347
2348         return false;
2349       }
2350
2351     default:
2352       gcc_unreachable ();
2353     }
2354 }
2355
2356 bool
2357 type_contains_placeholder_p (tree type)
2358 {
2359   bool result;
2360
2361   /* If the contains_placeholder_bits field has been initialized,
2362      then we know the answer.  */
2363   if (TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) > 0)
2364     return TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) - 1;
2365
2366   /* Indicate that we've seen this type node, and the answer is false.
2367      This is what we want to return if we run into recursion via fields.  */
2368   TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) = 1;
2369
2370   /* Compute the real value.  */
2371   result = type_contains_placeholder_1 (type);
2372
2373   /* Store the real value.  */
2374   TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) = result + 1;
2375
2376   return result;
2377 }
2378 \f
2379 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2380    return a tree with all occurrences of references to F in a
2381    PLACEHOLDER_EXPR replaced by R.   Note that we assume here that EXP
2382    contains only arithmetic expressions or a CALL_EXPR with a
2383    PLACEHOLDER_EXPR occurring only in its arglist.  */
2384
2385 tree
2386 substitute_in_expr (tree exp, tree f, tree r)
2387 {
2388   enum tree_code code = TREE_CODE (exp);
2389   tree op0, op1, op2, op3;
2390   tree new;
2391   tree inner;
2392
2393   /* We handle TREE_LIST and COMPONENT_REF separately.  */
2394   if (code == TREE_LIST)
2395     {
2396       op0 = SUBSTITUTE_IN_EXPR (TREE_CHAIN (exp), f, r);
2397       op1 = SUBSTITUTE_IN_EXPR (TREE_VALUE (exp), f, r);
2398       if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2399         return exp;
2400
2401       return tree_cons (TREE_PURPOSE (exp), op1, op0);
2402     }
2403   else if (code == COMPONENT_REF)
2404    {
2405      /* If this expression is getting a value from a PLACEHOLDER_EXPR
2406         and it is the right field, replace it with R.  */
2407      for (inner = TREE_OPERAND (exp, 0);
2408           REFERENCE_CLASS_P (inner);
2409           inner = TREE_OPERAND (inner, 0))
2410        ;
2411      if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2412          && TREE_OPERAND (exp, 1) == f)
2413        return r;
2414
2415      /* If this expression hasn't been completed let, leave it alone.  */
2416      if (TREE_CODE (inner) == PLACEHOLDER_EXPR && TREE_TYPE (inner) == 0)
2417        return exp;
2418
2419      op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
2420      if (op0 == TREE_OPERAND (exp, 0))
2421        return exp;
2422
2423      new = fold_build3 (COMPONENT_REF, TREE_TYPE (exp),
2424                         op0, TREE_OPERAND (exp, 1), NULL_TREE);
2425    }
2426   else
2427     switch (TREE_CODE_CLASS (code))
2428       {
2429       case tcc_constant:
2430       case tcc_declaration:
2431         return exp;
2432
2433       case tcc_exceptional:
2434       case tcc_unary:
2435       case tcc_binary:
2436       case tcc_comparison:
2437       case tcc_expression:
2438       case tcc_reference:
2439         switch (TREE_CODE_LENGTH (code))
2440           {
2441           case 0:
2442             return exp;
2443
2444           case 1:
2445             op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
2446             if (op0 == TREE_OPERAND (exp, 0))
2447               return exp;
2448
2449             new = fold_build1 (code, TREE_TYPE (exp), op0);
2450             break;
2451
2452           case 2:
2453             op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
2454             op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
2455
2456             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2457               return exp;
2458
2459             new = fold_build2 (code, TREE_TYPE (exp), op0, op1);
2460             break;
2461
2462           case 3:
2463             op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
2464             op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
2465             op2 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 2), f, r);
2466
2467             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2468                 && op2 == TREE_OPERAND (exp, 2))
2469               return exp;
2470
2471             new = fold_build3 (code, TREE_TYPE (exp), op0, op1, op2);
2472             break;
2473
2474           case 4:
2475             op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
2476             op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
2477             op2 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 2), f, r);
2478             op3 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 3), f, r);
2479
2480             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2481                 && op2 == TREE_OPERAND (exp, 2)
2482                 && op3 == TREE_OPERAND (exp, 3))
2483               return exp;
2484
2485             new = fold (build4 (code, TREE_TYPE (exp), op0, op1, op2, op3));
2486             break;
2487
2488           default:
2489             gcc_unreachable ();
2490           }
2491         break;
2492
2493       case tcc_vl_exp:
2494         {
2495           tree copy = NULL_TREE;
2496           int i;
2497           int n = TREE_OPERAND_LENGTH (exp);
2498           for (i = 1; i < n; i++)
2499             {
2500               tree op = TREE_OPERAND (exp, i);
2501               tree newop = SUBSTITUTE_IN_EXPR (op, f, r);
2502               if (newop != op)
2503                 {
2504                   copy = copy_node (exp);
2505                   TREE_OPERAND (copy, i) = newop;
2506                 }
2507             }
2508           if (copy)
2509             new = fold (copy);
2510           else
2511             return exp;
2512         }
2513
2514       default:
2515         gcc_unreachable ();
2516       }
2517
2518   TREE_READONLY (new) = TREE_READONLY (exp);
2519   return new;
2520 }
2521
2522 /* Similar, but look for a PLACEHOLDER_EXPR in EXP and find a replacement
2523    for it within OBJ, a tree that is an object or a chain of references.  */
2524
2525 tree
2526 substitute_placeholder_in_expr (tree exp, tree obj)
2527 {
2528   enum tree_code code = TREE_CODE (exp);
2529   tree op0, op1, op2, op3;
2530
2531   /* If this is a PLACEHOLDER_EXPR, see if we find a corresponding type
2532      in the chain of OBJ.  */
2533   if (code == PLACEHOLDER_EXPR)
2534     {
2535       tree need_type = TYPE_MAIN_VARIANT (TREE_TYPE (exp));
2536       tree elt;
2537
2538       for (elt = obj; elt != 0;
2539            elt = ((TREE_CODE (elt) == COMPOUND_EXPR
2540                    || TREE_CODE (elt) == COND_EXPR)
2541                   ? TREE_OPERAND (elt, 1)
2542                   : (REFERENCE_CLASS_P (elt)
2543                      || UNARY_CLASS_P (elt)
2544                      || BINARY_CLASS_P (elt)
2545                      || VL_EXP_CLASS_P (elt)
2546                      || EXPRESSION_CLASS_P (elt))
2547                   ? TREE_OPERAND (elt, 0) : 0))
2548         if (TYPE_MAIN_VARIANT (TREE_TYPE (elt)) == need_type)
2549           return elt;
2550
2551       for (elt = obj; elt != 0;
2552            elt = ((TREE_CODE (elt) == COMPOUND_EXPR
2553                    || TREE_CODE (elt) == COND_EXPR)
2554                   ? TREE_OPERAND (elt, 1)
2555                   : (REFERENCE_CLASS_P (elt)
2556                      || UNARY_CLASS_P (elt)
2557                      || BINARY_CLASS_P (elt)
2558                      || VL_EXP_CLASS_P (elt)
2559                      || EXPRESSION_CLASS_P (elt))
2560                   ? TREE_OPERAND (elt, 0) : 0))
2561         if (POINTER_TYPE_P (TREE_TYPE (elt))
2562             && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (elt)))
2563                 == need_type))
2564           return fold_build1 (INDIRECT_REF, need_type, elt);
2565
2566       /* If we didn't find it, return the original PLACEHOLDER_EXPR.  If it
2567          survives until RTL generation, there will be an error.  */
2568       return exp;
2569     }
2570
2571   /* TREE_LIST is special because we need to look at TREE_VALUE
2572      and TREE_CHAIN, not TREE_OPERANDS.  */
2573   else if (code == TREE_LIST)
2574     {
2575       op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_CHAIN (exp), obj);
2576       op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_VALUE (exp), obj);
2577       if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2578         return exp;
2579
2580       return tree_cons (TREE_PURPOSE (exp), op1, op0);
2581     }
2582   else
2583     switch (TREE_CODE_CLASS (code))
2584       {
2585       case tcc_constant:
2586       case tcc_declaration:
2587         return exp;
2588
2589       case tcc_exceptional:
2590       case tcc_unary:
2591       case tcc_binary:
2592       case tcc_comparison:
2593       case tcc_expression:
2594       case tcc_reference:
2595       case tcc_statement:
2596         switch (TREE_CODE_LENGTH (code))
2597           {
2598           case 0:
2599             return exp;
2600
2601           case 1:
2602             op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
2603             if (op0 == TREE_OPERAND (exp, 0))
2604               return exp;
2605             else
2606               return fold_build1 (code, TREE_TYPE (exp), op0);
2607
2608           case 2:
2609             op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
2610             op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
2611
2612             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2613               return exp;
2614             else
2615               return fold_build2 (code, TREE_TYPE (exp), op0, op1);
2616
2617           case 3:
2618             op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
2619             op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
2620             op2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 2), obj);
2621
2622             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2623                 && op2 == TREE_OPERAND (exp, 2))
2624               return exp;
2625             else
2626               return fold_build3 (code, TREE_TYPE (exp), op0, op1, op2);
2627
2628           case 4:
2629             op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
2630             op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
2631             op2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 2), obj);
2632             op3 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 3), obj);
2633
2634             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2635                 && op2 == TREE_OPERAND (exp, 2)
2636                 && op3 == TREE_OPERAND (exp, 3))
2637               return exp;
2638             else
2639               return fold (build4 (code, TREE_TYPE (exp), op0, op1, op2, op3));
2640
2641           default:
2642             gcc_unreachable ();
2643           }
2644         break;
2645
2646       case tcc_vl_exp:
2647         {
2648           tree copy = NULL_TREE;
2649           int i;
2650           int n = TREE_OPERAND_LENGTH (exp);
2651           for (i = 1; i < n; i++)
2652             {
2653               tree op = TREE_OPERAND (exp, i);
2654               tree newop = SUBSTITUTE_PLACEHOLDER_IN_EXPR (op, obj);
2655               if (newop != op)
2656                 {
2657                   if (!copy)
2658                     copy = copy_node (exp);
2659                   TREE_OPERAND (copy, i) = newop;
2660                 }
2661             }
2662           if (copy)
2663             return fold (copy);
2664           else
2665             return exp;
2666         }
2667
2668       default:
2669         gcc_unreachable ();
2670       }
2671 }
2672 \f
2673 /* Stabilize a reference so that we can use it any number of times
2674    without causing its operands to be evaluated more than once.
2675    Returns the stabilized reference.  This works by means of save_expr,
2676    so see the caveats in the comments about save_expr.
2677
2678    Also allows conversion expressions whose operands are references.
2679    Any other kind of expression is returned unchanged.  */
2680
2681 tree
2682 stabilize_reference (tree ref)
2683 {
2684   tree result;
2685   enum tree_code code = TREE_CODE (ref);
2686
2687   switch (code)
2688     {
2689     case VAR_DECL:
2690     case PARM_DECL:
2691     case RESULT_DECL:
2692       /* No action is needed in this case.  */
2693       return ref;
2694
2695     case NOP_EXPR:
2696     case CONVERT_EXPR:
2697     case FLOAT_EXPR:
2698     case FIX_TRUNC_EXPR:
2699       result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2700       break;
2701
2702     case INDIRECT_REF:
2703       result = build_nt (INDIRECT_REF,
2704                          stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2705       break;
2706
2707     case COMPONENT_REF:
2708       result = build_nt (COMPONENT_REF,
2709                          stabilize_reference (TREE_OPERAND (ref, 0)),
2710                          TREE_OPERAND (ref, 1), NULL_TREE);
2711       break;
2712
2713     case BIT_FIELD_REF:
2714       result = build_nt (BIT_FIELD_REF,
2715                          stabilize_reference (TREE_OPERAND (ref, 0)),
2716                          stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2717                          stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2718       break;
2719
2720     case ARRAY_REF:
2721       result = build_nt (ARRAY_REF,
2722                          stabilize_reference (TREE_OPERAND (ref, 0)),
2723                          stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2724                          TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
2725       break;
2726
2727     case ARRAY_RANGE_REF:
2728       result = build_nt (ARRAY_RANGE_REF,
2729                          stabilize_reference (TREE_OPERAND (ref, 0)),
2730                          stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2731                          TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
2732       break;
2733
2734     case COMPOUND_EXPR:
2735       /* We cannot wrap the first expression in a SAVE_EXPR, as then
2736          it wouldn't be ignored.  This matters when dealing with
2737          volatiles.  */
2738       return stabilize_reference_1 (ref);
2739
2740       /* If arg isn't a kind of lvalue we recognize, make no change.
2741          Caller should recognize the error for an invalid lvalue.  */
2742     default:
2743       return ref;
2744
2745     case ERROR_MARK:
2746       return error_mark_node;
2747     }
2748
2749   TREE_TYPE (result) = TREE_TYPE (ref);
2750   TREE_READONLY (result) = TREE_READONLY (ref);
2751   TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2752   TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2753
2754   return result;
2755 }
2756
2757 /* Subroutine of stabilize_reference; this is called for subtrees of
2758    references.  Any expression with side-effects must be put in a SAVE_EXPR
2759    to ensure that it is only evaluated once.
2760
2761    We don't put SAVE_EXPR nodes around everything, because assigning very
2762    simple expressions to temporaries causes us to miss good opportunities
2763    for optimizations.  Among other things, the opportunity to fold in the
2764    addition of a constant into an addressing mode often gets lost, e.g.
2765    "y[i+1] += x;".  In general, we take the approach that we should not make
2766    an assignment unless we are forced into it - i.e., that any non-side effect
2767    operator should be allowed, and that cse should take care of coalescing
2768    multiple utterances of the same expression should that prove fruitful.  */
2769
2770 tree
2771 stabilize_reference_1 (tree e)
2772 {
2773   tree result;
2774   enum tree_code code = TREE_CODE (e);
2775
2776   /* We cannot ignore const expressions because it might be a reference
2777      to a const array but whose index contains side-effects.  But we can
2778      ignore things that are actual constant or that already have been
2779      handled by this function.  */
2780
2781   if (TREE_INVARIANT (e))
2782     return e;
2783
2784   switch (TREE_CODE_CLASS (code))
2785     {
2786     case tcc_exceptional:
2787     case tcc_type:
2788     case tcc_declaration:
2789     case tcc_comparison:
2790     case tcc_statement:
2791     case tcc_expression:
2792     case tcc_reference:
2793     case tcc_vl_exp:
2794       /* If the expression has side-effects, then encase it in a SAVE_EXPR
2795          so that it will only be evaluated once.  */
2796       /* The reference (r) and comparison (<) classes could be handled as
2797          below, but it is generally faster to only evaluate them once.  */
2798       if (TREE_SIDE_EFFECTS (e))
2799         return save_expr (e);
2800       return e;
2801
2802     case tcc_constant:
2803       /* Constants need no processing.  In fact, we should never reach
2804          here.  */
2805       return e;
2806
2807     case tcc_binary:
2808       /* Division is slow and tends to be compiled with jumps,
2809          especially the division by powers of 2 that is often
2810          found inside of an array reference.  So do it just once.  */
2811       if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2812           || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2813           || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2814           || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2815         return save_expr (e);
2816       /* Recursively stabilize each operand.  */
2817       result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2818                          stabilize_reference_1 (TREE_OPERAND (e, 1)));
2819       break;
2820
2821     case tcc_unary:
2822       /* Recursively stabilize each operand.  */
2823       result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2824       break;
2825
2826     default:
2827       gcc_unreachable ();
2828     }
2829
2830   TREE_TYPE (result) = TREE_TYPE (e);
2831   TREE_READONLY (result) = TREE_READONLY (e);
2832   TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2833   TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2834   TREE_INVARIANT (result) = 1;
2835
2836   return result;
2837 }
2838 \f
2839 /* Low-level constructors for expressions.  */
2840
2841 /* A helper function for build1 and constant folders.  Set TREE_CONSTANT,
2842    TREE_INVARIANT, and TREE_SIDE_EFFECTS for an ADDR_EXPR.  */
2843
2844 void
2845 recompute_tree_invariant_for_addr_expr (tree t)
2846 {
2847   tree node;
2848   bool tc = true, ti = true, se = false;
2849
2850   /* We started out assuming this address is both invariant and constant, but
2851      does not have side effects.  Now go down any handled components and see if
2852      any of them involve offsets that are either non-constant or non-invariant.
2853      Also check for side-effects.
2854
2855      ??? Note that this code makes no attempt to deal with the case where
2856      taking the address of something causes a copy due to misalignment.  */
2857
2858 #define UPDATE_TITCSE(NODE)  \
2859 do { tree _node = (NODE); \
2860      if (_node && !TREE_INVARIANT (_node)) ti = false; \
2861      if (_node && !TREE_CONSTANT (_node)) tc = false; \
2862      if (_node && TREE_SIDE_EFFECTS (_node)) se = true; } while (0)
2863
2864   for (node = TREE_OPERAND (t, 0); handled_component_p (node);
2865        node = TREE_OPERAND (node, 0))
2866     {
2867       /* If the first operand doesn't have an ARRAY_TYPE, this is a bogus
2868          array reference (probably made temporarily by the G++ front end),
2869          so ignore all the operands.  */
2870       if ((TREE_CODE (node) == ARRAY_REF
2871            || TREE_CODE (node) == ARRAY_RANGE_REF)
2872           && TREE_CODE (TREE_TYPE (TREE_OPERAND (node, 0))) == ARRAY_TYPE)
2873         {
2874           UPDATE_TITCSE (TREE_OPERAND (node, 1));
2875           if (TREE_OPERAND (node, 2))
2876             UPDATE_TITCSE (TREE_OPERAND (node, 2));
2877           if (TREE_OPERAND (node, 3))
2878             UPDATE_TITCSE (TREE_OPERAND (node, 3));
2879         }
2880       /* Likewise, just because this is a COMPONENT_REF doesn't mean we have a
2881          FIELD_DECL, apparently.  The G++ front end can put something else
2882          there, at least temporarily.  */
2883       else if (TREE_CODE (node) == COMPONENT_REF
2884                && TREE_CODE (TREE_OPERAND (node, 1)) == FIELD_DECL)
2885         {
2886           if (TREE_OPERAND (node, 2))
2887             UPDATE_TITCSE (TREE_OPERAND (node, 2));
2888         }
2889       else if (TREE_CODE (node) == BIT_FIELD_REF)
2890         UPDATE_TITCSE (TREE_OPERAND (node, 2));
2891     }
2892
2893   node = lang_hooks.expr_to_decl (node, &tc, &ti, &se);
2894
2895   /* Now see what's inside.  If it's an INDIRECT_REF, copy our properties from
2896      the address, since &(*a)->b is a form of addition.  If it's a decl, it's
2897      invariant and constant if the decl is static.  It's also invariant if it's
2898      a decl in the current function.  Taking the address of a volatile variable
2899      is not volatile.  If it's a constant, the address is both invariant and
2900      constant.  Otherwise it's neither.  */
2901   if (TREE_CODE (node) == INDIRECT_REF)
2902     UPDATE_TITCSE (TREE_OPERAND (node, 0));
2903   else if (DECL_P (node))
2904     {
2905       if (staticp (node))
2906         ;
2907       else if (decl_function_context (node) == current_function_decl
2908                /* Addresses of thread-local variables are invariant.  */
2909                || (TREE_CODE (node) == VAR_DECL
2910                    && DECL_THREAD_LOCAL_P (node)))
2911         tc = false;
2912       else
2913         ti = tc = false;
2914     }
2915   else if (CONSTANT_CLASS_P (node))
2916     ;
2917   else
2918     {
2919       ti = tc = false;
2920       se |= TREE_SIDE_EFFECTS (node);
2921     }
2922
2923   TREE_CONSTANT (t) = tc;
2924   TREE_INVARIANT (t) = ti;
2925   TREE_SIDE_EFFECTS (t) = se;
2926 #undef UPDATE_TITCSE
2927 }
2928
2929 /* Build an expression of code CODE, data type TYPE, and operands as
2930    specified.  Expressions and reference nodes can be created this way.
2931    Constants, decls, types and misc nodes cannot be.
2932
2933    We define 5 non-variadic functions, from 0 to 4 arguments.  This is
2934    enough for all extant tree codes.  */
2935
2936 tree
2937 build0_stat (enum tree_code code, tree tt MEM_STAT_DECL)
2938 {
2939   tree t;
2940
2941   gcc_assert (TREE_CODE_LENGTH (code) == 0);
2942
2943   t = make_node_stat (code PASS_MEM_STAT);
2944   TREE_TYPE (t) = tt;
2945
2946   return t;
2947 }
2948
2949 tree
2950 build1_stat (enum tree_code code, tree type, tree node MEM_STAT_DECL)
2951 {
2952   int length = sizeof (struct tree_exp);
2953 #ifdef GATHER_STATISTICS
2954   tree_node_kind kind;
2955 #endif
2956   tree t;
2957
2958 #ifdef GATHER_STATISTICS
2959   switch (TREE_CODE_CLASS (code))
2960     {
2961     case tcc_statement:  /* an expression with side effects */
2962       kind = s_kind;
2963       break;
2964     case tcc_reference:  /* a reference */
2965       kind = r_kind;
2966       break;
2967     default:
2968       kind = e_kind;
2969       break;
2970     }
2971
2972   tree_node_counts[(int) kind]++;
2973   tree_node_sizes[(int) kind] += length;
2974 #endif
2975
2976   gcc_assert (TREE_CODE_LENGTH (code) == 1);
2977
2978   t = ggc_alloc_zone_pass_stat (length, &tree_zone);
2979
2980   memset (t, 0, sizeof (struct tree_common));
2981
2982   TREE_SET_CODE (t, code);
2983
2984   TREE_TYPE (t) = type;
2985 #ifdef USE_MAPPED_LOCATION
2986   SET_EXPR_LOCATION (t, UNKNOWN_LOCATION);
2987 #else
2988   SET_EXPR_LOCUS (t, NULL);
2989 #endif
2990   TREE_OPERAND (t, 0) = node;
2991   TREE_BLOCK (t) = NULL_TREE;
2992   if (node && !TYPE_P (node))
2993     {
2994       TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (node);
2995       TREE_READONLY (t) = TREE_READONLY (node);
2996     }
2997
2998   if (TREE_CODE_CLASS (code) == tcc_statement)
2999     TREE_SIDE_EFFECTS (t) = 1;
3000   else switch (code)
3001     {
3002     case VA_ARG_EXPR:
3003       /* All of these have side-effects, no matter what their
3004          operands are.  */
3005       TREE_SIDE_EFFECTS (t) = 1;
3006       TREE_READONLY (t) = 0;
3007       break;
3008
3009     case MISALIGNED_INDIRECT_REF:
3010     case ALIGN_INDIRECT_REF:
3011     case INDIRECT_REF:
3012       /* Whether a dereference is readonly has nothing to do with whether
3013          its operand is readonly.  */
3014       TREE_READONLY (t) = 0;
3015       break;
3016
3017     case ADDR_EXPR:
3018       if (node)
3019         recompute_tree_invariant_for_addr_expr (t);
3020       break;
3021
3022     default:
3023       if ((TREE_CODE_CLASS (code) == tcc_unary || code == VIEW_CONVERT_EXPR)
3024           && node && !TYPE_P (node)
3025           && TREE_CONSTANT (node))
3026         TREE_CONSTANT (t) = 1;
3027       if ((TREE_CODE_CLASS (code) == tcc_unary || code == VIEW_CONVERT_EXPR)
3028           && node && TREE_INVARIANT (node))
3029         TREE_INVARIANT (t) = 1;
3030       if (TREE_CODE_CLASS (code) == tcc_reference
3031           && node && TREE_THIS_VOLATILE (node))
3032         TREE_THIS_VOLATILE (t) = 1;
3033       break;
3034     }
3035
3036   return t;
3037 }
3038
3039 #define PROCESS_ARG(N)                  \
3040   do {                                  \
3041     TREE_OPERAND (t, N) = arg##N;       \
3042     if (arg##N &&!TYPE_P (arg##N))      \
3043       {                                 \
3044         if (TREE_SIDE_EFFECTS (arg##N)) \
3045           side_effects = 1;             \
3046         if (!TREE_READONLY (arg##N))    \
3047           read_only = 0;                \
3048         if (!TREE_CONSTANT (arg##N))    \
3049           constant = 0;                 \
3050         if (!TREE_INVARIANT (arg##N))   \
3051           invariant = 0;                \
3052       }                                 \
3053   } while (0)
3054
3055 tree
3056 build2_stat (enum tree_code code, tree tt, tree arg0, tree arg1 MEM_STAT_DECL)
3057 {
3058   bool constant, read_only, side_effects, invariant;
3059   tree t;
3060
3061   gcc_assert (TREE_CODE_LENGTH (code) == 2);
3062
3063 #if 1
3064   /* FIXME tuples: Statement's aren't expressions!  */
3065   if (code == GIMPLE_MODIFY_STMT)
3066     return build_gimple_modify_stmt_stat (arg0, arg1 PASS_MEM_STAT);
3067 #else
3068   /* Must use build_gimple_modify_stmt to construct GIMPLE_MODIFY_STMTs.  */
3069   gcc_assert (code != GIMPLE_MODIFY_STMT);
3070 #endif
3071
3072   t = make_node_stat (code PASS_MEM_STAT);
3073   TREE_TYPE (t) = tt;
3074
3075   /* Below, we automatically set TREE_SIDE_EFFECTS and TREE_READONLY for the
3076      result based on those same flags for the arguments.  But if the
3077      arguments aren't really even `tree' expressions, we shouldn't be trying
3078      to do this.  */
3079
3080   /* Expressions without side effects may be constant if their
3081      arguments are as well.  */
3082   constant = (TREE_CODE_CLASS (code) == tcc_comparison
3083               || TREE_CODE_CLASS (code) == tcc_binary);
3084   read_only = 1;
3085   side_effects = TREE_SIDE_EFFECTS (t);
3086   invariant = constant;
3087
3088   PROCESS_ARG(0);
3089   PROCESS_ARG(1);
3090
3091   TREE_READONLY (t) = read_only;
3092   TREE_CONSTANT (t) = constant;
3093   TREE_INVARIANT (t) = invariant;
3094   TREE_SIDE_EFFECTS (t) = side_effects;
3095   TREE_THIS_VOLATILE (t)
3096     = (TREE_CODE_CLASS (code) == tcc_reference
3097        && arg0 && TREE_THIS_VOLATILE (arg0));
3098
3099   return t;
3100 }
3101
3102
3103 /* Build a GIMPLE_MODIFY_STMT node.  This tree code doesn't have a
3104    type, so we can't use build2 (a.k.a. build2_stat).  */
3105
3106 tree
3107 build_gimple_modify_stmt_stat (tree arg0, tree arg1 MEM_STAT_DECL)
3108 {
3109   tree t;
3110
3111   t = make_node_stat (GIMPLE_MODIFY_STMT PASS_MEM_STAT);
3112   /* ?? We don't care about setting flags for tuples...  */
3113   GIMPLE_STMT_OPERAND (t, 0) = arg0;
3114   GIMPLE_STMT_OPERAND (t, 1) = arg1;
3115   return t;
3116 }
3117
3118 tree
3119 build3_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3120              tree arg2 MEM_STAT_DECL)
3121 {
3122   bool constant, read_only, side_effects, invariant;
3123   tree t;
3124
3125   gcc_assert (TREE_CODE_LENGTH (code) == 3);
3126   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
3127
3128   t = make_node_stat (code PASS_MEM_STAT);
3129   TREE_TYPE (t) = tt;
3130
3131   /* As a special exception, if COND_EXPR has NULL branches, we
3132      assume that it is a gimple statement and always consider
3133      it to have side effects.  */
3134   if (code == COND_EXPR
3135       && tt == void_type_node
3136       && arg1 == NULL_TREE
3137       && arg2 == NULL_TREE)
3138     side_effects = true;
3139   else
3140     side_effects = TREE_SIDE_EFFECTS (t);
3141
3142   PROCESS_ARG(0);
3143   PROCESS_ARG(1);
3144   PROCESS_ARG(2);
3145
3146   TREE_SIDE_EFFECTS (t) = side_effects;
3147   TREE_THIS_VOLATILE (t)
3148     = (TREE_CODE_CLASS (code) == tcc_reference
3149        && arg0 && TREE_THIS_VOLATILE (arg0));
3150
3151   return t;
3152 }
3153
3154 tree
3155 build4_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3156              tree arg2, tree arg3 MEM_STAT_DECL)
3157 {
3158   bool constant, read_only, side_effects, invariant;
3159   tree t;
3160
3161   gcc_assert (TREE_CODE_LENGTH (code) == 4);
3162
3163   t = make_node_stat (code PASS_MEM_STAT);
3164   TREE_TYPE (t) = tt;
3165
3166   side_effects = TREE_SIDE_EFFECTS (t);
3167
3168   PROCESS_ARG(0);
3169   PROCESS_ARG(1);
3170   PROCESS_ARG(2);
3171   PROCESS_ARG(3);
3172
3173   TREE_SIDE_EFFECTS (t) = side_effects;
3174   TREE_THIS_VOLATILE (t)
3175     = (TREE_CODE_CLASS (code) == tcc_reference
3176        && arg0 && TREE_THIS_VOLATILE (arg0));
3177
3178   return t;
3179 }
3180
3181 tree
3182 build5_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3183              tree arg2, tree arg3, tree arg4 MEM_STAT_DECL)
3184 {
3185   bool constant, read_only, side_effects, invariant;
3186   tree t;
3187
3188   gcc_assert (TREE_CODE_LENGTH (code) == 5);
3189
3190   t = make_node_stat (code PASS_MEM_STAT);
3191   TREE_TYPE (t) = tt;
3192
3193   side_effects = TREE_SIDE_EFFECTS (t);
3194
3195   PROCESS_ARG(0);
3196   PROCESS_ARG(1);
3197   PROCESS_ARG(2);
3198   PROCESS_ARG(3);
3199   PROCESS_ARG(4);
3200
3201   TREE_SIDE_EFFECTS (t) = side_effects;
3202   TREE_THIS_VOLATILE (t)
3203     = (TREE_CODE_CLASS (code) == tcc_reference
3204        && arg0 && TREE_THIS_VOLATILE (arg0));
3205
3206   return t;
3207 }
3208
3209 tree
3210 build7_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3211              tree arg2, tree arg3, tree arg4, tree arg5,
3212              tree arg6 MEM_STAT_DECL)
3213 {
3214   bool constant, read_only, side_effects, invariant;
3215   tree t;
3216
3217   gcc_assert (code == TARGET_MEM_REF);
3218
3219   t = make_node_stat (code PASS_MEM_STAT);
3220   TREE_TYPE (t) = tt;
3221
3222   side_effects = TREE_SIDE_EFFECTS (t);
3223
3224   PROCESS_ARG(0);
3225   PROCESS_ARG(1);
3226   PROCESS_ARG(2);
3227   PROCESS_ARG(3);
3228   PROCESS_ARG(4);
3229   PROCESS_ARG(5);
3230   PROCESS_ARG(6);
3231
3232   TREE_SIDE_EFFECTS (t) = side_effects;
3233   TREE_THIS_VOLATILE (t) = 0;
3234
3235   return t;
3236 }
3237
3238 /* Similar except don't specify the TREE_TYPE
3239    and leave the TREE_SIDE_EFFECTS as 0.
3240    It is permissible for arguments to be null,
3241    or even garbage if their values do not matter.  */
3242
3243 tree
3244 build_nt (enum tree_code code, ...)
3245 {
3246   tree t;
3247   int length;
3248   int i;
3249   va_list p;
3250
3251   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
3252
3253   va_start (p, code);
3254
3255   t = make_node (code);
3256   length = TREE_CODE_LENGTH (code);
3257
3258   for (i = 0; i < length; i++)
3259     TREE_OPERAND (t, i) = va_arg (p, tree);
3260
3261   va_end (p);
3262   return t;
3263 }
3264
3265 /* Similar to build_nt, but for creating a CALL_EXPR object with
3266    ARGLIST passed as a list.  */
3267
3268 tree
3269 build_nt_call_list (tree fn, tree arglist)
3270 {
3271   tree t;
3272   int i;
3273
3274   t = build_vl_exp (CALL_EXPR, list_length (arglist) + 3);
3275   CALL_EXPR_FN (t) = fn;
3276   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
3277   for (i = 0; arglist; arglist = TREE_CHAIN (arglist), i++)
3278     CALL_EXPR_ARG (t, i) = TREE_VALUE (arglist);
3279   return t;
3280 }
3281 \f
3282 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3283    We do NOT enter this node in any sort of symbol table.
3284
3285    layout_decl is used to set up the decl's storage layout.
3286    Other slots are initialized to 0 or null pointers.  */
3287
3288 tree
3289 build_decl_stat (enum tree_code code, tree name, tree type MEM_STAT_DECL)
3290 {
3291   tree t;
3292
3293   t = make_node_stat (code PASS_MEM_STAT);
3294
3295 /*  if (type == error_mark_node)
3296     type = integer_type_node; */
3297 /* That is not done, deliberately, so that having error_mark_node
3298    as the type can suppress useless errors in the use of this variable.  */
3299
3300   DECL_NAME (t) = name;
3301   TREE_TYPE (t) = type;
3302
3303   if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3304     layout_decl (t, 0);
3305   else if (code == FUNCTION_DECL)
3306     DECL_MODE (t) = FUNCTION_MODE;
3307
3308   return t;
3309 }
3310
3311 /* Builds and returns function declaration with NAME and TYPE.  */
3312
3313 tree
3314 build_fn_decl (const char *name, tree type)
3315 {
3316   tree id = get_identifier (name);
3317   tree decl = build_decl (FUNCTION_DECL, id, type);
3318
3319   DECL_EXTERNAL (decl) = 1;
3320   TREE_PUBLIC (decl) = 1;
3321   DECL_ARTIFICIAL (decl) = 1;
3322   TREE_NOTHROW (decl) = 1;
3323
3324   return decl;
3325 }
3326
3327 \f
3328 /* BLOCK nodes are used to represent the structure of binding contours
3329    and declarations, once those contours have been exited and their contents
3330    compiled.  This information is used for outputting debugging info.  */
3331
3332 tree
3333 build_block (tree vars, tree subblocks, tree supercontext, tree chain)
3334 {
3335   tree block = make_node (BLOCK);
3336
3337   BLOCK_VARS (block) = vars;
3338   BLOCK_SUBBLOCKS (block) = subblocks;
3339   BLOCK_SUPERCONTEXT (block) = supercontext;
3340   BLOCK_CHAIN (block) = chain;
3341   return block;
3342 }
3343
3344 #if 1 /* ! defined(USE_MAPPED_LOCATION) */
3345 /* ??? gengtype doesn't handle conditionals */
3346 static GTY(()) source_locus last_annotated_node;
3347 #endif
3348
3349 #ifdef USE_MAPPED_LOCATION
3350
3351 expanded_location
3352 expand_location (source_location loc)
3353 {
3354   expanded_location xloc;
3355   if (loc == 0)
3356     {
3357       xloc.file = NULL;
3358       xloc.line = 0;
3359       xloc.column = 0;
3360     }
3361   else
3362     {
3363       const struct line_map *map = linemap_lookup (&line_table, loc);
3364       xloc.file = map->to_file;
3365       xloc.line = SOURCE_LINE (map, loc);
3366       xloc.column = SOURCE_COLUMN (map, loc);
3367     };
3368   return xloc;
3369 }
3370
3371 #else
3372
3373 /* Record the exact location where an expression or an identifier were
3374    encountered.  */
3375
3376 void
3377 annotate_with_file_line (tree node, const char *file, int line)
3378 {
3379   /* Roughly one percent of the calls to this function are to annotate
3380      a node with the same information already attached to that node!
3381      Just return instead of wasting memory.  */
3382   if (EXPR_LOCUS (node)
3383       && EXPR_LINENO (node) == line
3384       && (EXPR_FILENAME (node) == file
3385           || !strcmp (EXPR_FILENAME (node), file)))
3386     {
3387       last_annotated_node = EXPR_LOCUS (node);
3388       return;
3389     }
3390
3391   /* In heavily macroized code (such as GCC itself) this single
3392      entry cache can reduce the number of allocations by more
3393      than half.  */
3394   if (last_annotated_node
3395       && last_annotated_node->line == line
3396       && (last_annotated_node->file == file
3397           || !strcmp (last_annotated_node->file, file)))
3398     {
3399       SET_EXPR_LOCUS (node, last_annotated_node);
3400       return;
3401     }
3402
3403   SET_EXPR_LOCUS (node, ggc_alloc (sizeof (location_t)));
3404   EXPR_LINENO (node) = line;
3405   EXPR_FILENAME (node) = file;
3406   last_annotated_node = EXPR_LOCUS (node);
3407 }
3408
3409 void
3410 annotate_with_locus (tree node, location_t locus)
3411 {
3412   annotate_with_file_line (node, locus.file, locus.line);
3413 }
3414 #endif
3415 \f
3416 /* Source location accessor functions.  */
3417
3418
3419 /* The source location of this expression.  Non-tree_exp nodes such as
3420    decls and constants can be shared among multiple locations, so
3421    return nothing.  */
3422 location_t
3423 expr_location (tree node)
3424 {
3425 #ifdef USE_MAPPED_LOCATION
3426   if (GIMPLE_STMT_P (node))
3427     return GIMPLE_STMT_LOCUS (node);
3428   return EXPR_P (node) ? node->exp.locus : UNKNOWN_LOCATION;
3429 #else
3430   if (GIMPLE_STMT_P (node))
3431     return EXPR_HAS_LOCATION (node)
3432       ? *GIMPLE_STMT_LOCUS (node) : UNKNOWN_LOCATION;
3433   return EXPR_HAS_LOCATION (node) ? *node->exp.locus : UNKNOWN_LOCATION;
3434 #endif
3435 }
3436
3437 void
3438 set_expr_location (tree node, location_t locus)
3439 {
3440 #ifdef USE_MAPPED_LOCATION
3441   if (GIMPLE_STMT_P (node))
3442     GIMPLE_STMT_LOCUS (node) = locus;
3443   else
3444     EXPR_CHECK (node)->exp.locus = locus;
3445 #else
3446       annotate_with_locus (node, locus);
3447 #endif
3448 }
3449
3450 bool
3451 expr_has_location (tree node)
3452 {
3453 #ifdef USE_MAPPED_LOCATION
3454   return expr_location (node) != UNKNOWN_LOCATION;
3455 #else
3456   return expr_locus (node) != NULL;
3457 #endif
3458 }
3459
3460 #ifdef USE_MAPPED_LOCATION
3461 source_location *
3462 #else
3463 source_locus
3464 #endif
3465 expr_locus (tree node)
3466 {
3467 #ifdef USE_MAPPED_LOCATION
3468   if (GIMPLE_STMT_P (node))
3469     return &GIMPLE_STMT_LOCUS (node);
3470   return EXPR_P (node) ? &node->exp.locus : (location_t *) NULL;
3471 #else
3472   if (GIMPLE_STMT_P (node))
3473     return GIMPLE_STMT_LOCUS (node);
3474   /* ?? The cast below was originally "(location_t *)" in the macro,
3475      but that makes no sense.  ?? */
3476   return EXPR_P (node) ? node->exp.locus : (source_locus) NULL;
3477 #endif
3478 }
3479
3480 void
3481 set_expr_locus (tree node,
3482 #ifdef USE_MAPPED_LOCATION
3483                 source_location *loc
3484 #else
3485                 source_locus loc
3486 #endif
3487                 )
3488 {
3489 #ifdef USE_MAPPED_LOCATION
3490   if (loc == NULL)
3491     {
3492       if (GIMPLE_STMT_P (node))
3493         GIMPLE_STMT_LOCUS (node) = UNKNOWN_LOCATION;
3494       else
3495         EXPR_CHECK (node)->exp.locus = UNKNOWN_LOCATION;
3496     }
3497   else
3498     {
3499       if (GIMPLE_STMT_P (node))
3500         GIMPLE_STMT_LOCUS (node) = *loc;
3501       else
3502         EXPR_CHECK (node)->exp.locus = *loc;
3503     }
3504 #else
3505   if (GIMPLE_STMT_P (node))
3506     GIMPLE_STMT_LOCUS (node) = loc;
3507   else
3508     EXPR_CHECK (node)->exp.locus = loc;
3509 #endif
3510 }
3511
3512 const char **
3513 expr_filename (tree node)
3514 {
3515 #ifdef USE_MAPPED_LOCATION
3516   if (GIMPLE_STMT_P (node))
3517     return &LOCATION_FILE (GIMPLE_STMT_LOCUS (node));
3518   return &LOCATION_FILE (EXPR_CHECK (node)->exp.locus);
3519 #else
3520   if (GIMPLE_STMT_P (node))
3521     return &GIMPLE_STMT_LOCUS (node)->file;
3522   return &(EXPR_CHECK (node)->exp.locus->file);
3523 #endif
3524 }
3525
3526 int *
3527 expr_lineno (tree node)
3528 {
3529 #ifdef USE_MAPPED_LOCATION
3530   if (GIMPLE_STMT_P (node))
3531     return &LOCATION_LINE (GIMPLE_STMT_LOCUS (node));
3532   return &LOCATION_LINE (EXPR_CHECK (node)->exp.locus);
3533 #else
3534   if (GIMPLE_STMT_P (node))
3535     return &GIMPLE_STMT_LOCUS (node)->line;
3536   return &EXPR_CHECK (node)->exp.locus->line;
3537 #endif
3538 }
3539 \f
3540 /* Return a declaration like DDECL except that its DECL_ATTRIBUTES
3541    is ATTRIBUTE.  */
3542
3543 tree
3544 build_decl_attribute_variant (tree ddecl, tree attribute)
3545 {
3546   DECL_ATTRIBUTES (ddecl) = attribute;
3547   return ddecl;
3548 }
3549
3550 /* Borrowed from hashtab.c iterative_hash implementation.  */
3551 #define mix(a,b,c) \
3552 { \
3553   a -= b; a -= c; a ^= (c>>13); \
3554   b -= c; b -= a; b ^= (a<< 8); \
3555   c -= a; c -= b; c ^= ((b&0xffffffff)>>13); \
3556   a -= b; a -= c; a ^= ((c&0xffffffff)>>12); \
3557   b -= c; b -= a; b = (b ^ (a<<16)) & 0xffffffff; \
3558   c -= a; c -= b; c = (c ^ (b>> 5)) & 0xffffffff; \
3559   a -= b; a -= c; a = (a ^ (c>> 3)) & 0xffffffff; \
3560   b -= c; b -= a; b = (b ^ (a<<10)) & 0xffffffff; \
3561   c -= a; c -= b; c = (c ^ (b>>15)) & 0xffffffff; \
3562 }
3563
3564
3565 /* Produce good hash value combining VAL and VAL2.  */
3566 static inline hashval_t
3567 iterative_hash_hashval_t (hashval_t val, hashval_t val2)
3568 {
3569   /* the golden ratio; an arbitrary value.  */
3570   hashval_t a = 0x9e3779b9;
3571
3572   mix (a, val, val2);
3573   return val2;
3574 }
3575
3576 /* Produce good hash value combining PTR and VAL2.  */
3577 static inline hashval_t
3578 iterative_hash_pointer (void *ptr, hashval_t val2)
3579 {
3580   if (sizeof (ptr) == sizeof (hashval_t))
3581     return iterative_hash_hashval_t ((size_t) ptr, val2);
3582   else
3583     {
3584       hashval_t a = (hashval_t) (size_t) ptr;
3585       /* Avoid warnings about shifting of more than the width of the type on
3586          hosts that won't execute this path.  */
3587       int zero = 0;
3588       hashval_t b = (hashval_t) ((size_t) ptr >> (sizeof (hashval_t) * 8 + zero));
3589       mix (a, b, val2);
3590       return val2;
3591     }
3592 }
3593
3594 /* Produce good hash value combining VAL and VAL2.  */
3595 static inline hashval_t
3596 iterative_hash_host_wide_int (HOST_WIDE_INT val, hashval_t val2)
3597 {
3598   if (sizeof (HOST_WIDE_INT) == sizeof (hashval_t))
3599     return iterative_hash_hashval_t (val, val2);
3600   else
3601     {
3602       hashval_t a = (hashval_t) val;
3603       /* Avoid warnings about shifting of more than the width of the type on
3604          hosts that won't execute this path.  */
3605       int zero = 0;
3606       hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 8 + zero));
3607       mix (a, b, val2);
3608       if (sizeof (HOST_WIDE_INT) > 2 * sizeof (hashval_t))
3609         {
3610           hashval_t a = (hashval_t) (val >> (sizeof (hashval_t) * 16 + zero));
3611           hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 24 + zero));
3612           mix (a, b, val2);
3613         }
3614       return val2;
3615     }
3616 }
3617
3618 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3619    is ATTRIBUTE and its qualifiers are QUALS.
3620
3621    Record such modified types already made so we don't make duplicates.  */
3622
3623 static tree
3624 build_type_attribute_qual_variant (tree ttype, tree attribute, int quals)
3625 {
3626   if (! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
3627     {
3628       hashval_t hashcode = 0;
3629       tree ntype;
3630       enum tree_code code = TREE_CODE (ttype);
3631
3632       ntype = copy_node (ttype);
3633
3634       TYPE_POINTER_TO (ntype) = 0;
3635       TYPE_REFERENCE_TO (ntype) = 0;
3636       TYPE_ATTRIBUTES (ntype) = attribute;
3637
3638       if (TYPE_STRUCTURAL_EQUALITY_P (ttype))
3639         SET_TYPE_STRUCTURAL_EQUALITY (ntype);
3640       else
3641         TYPE_CANONICAL (ntype)
3642           = build_qualified_type (TYPE_CANONICAL (ttype), quals);
3643
3644       /* Create a new main variant of TYPE.  */
3645       TYPE_MAIN_VARIANT (ntype) = ntype;
3646       TYPE_NEXT_VARIANT (ntype) = 0;
3647       set_type_quals (ntype, TYPE_UNQUALIFIED);
3648
3649       hashcode = iterative_hash_object (code, hashcode);
3650       if (TREE_TYPE (ntype))
3651         hashcode = iterative_hash_object (TYPE_HASH (TREE_TYPE (ntype)),
3652                                           hashcode);
3653       hashcode = attribute_hash_list (attribute, hashcode);
3654
3655       switch (TREE_CODE (ntype))
3656         {
3657         case FUNCTION_TYPE:
3658           hashcode = type_hash_list (TYPE_ARG_TYPES (ntype), hashcode);
3659           break;
3660         case ARRAY_TYPE:
3661           hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (ntype)),
3662                                             hashcode);
3663           break;
3664         case INTEGER_TYPE:
3665           hashcode = iterative_hash_object
3666             (TREE_INT_CST_LOW (TYPE_MAX_VALUE (ntype)), hashcode);
3667           hashcode = iterative_hash_object
3668             (TREE_INT_CST_HIGH (TYPE_MAX_VALUE (ntype)), hashcode);
3669           break;
3670         case REAL_TYPE:
3671           {
3672             unsigned int precision = TYPE_PRECISION (ntype);
3673             hashcode = iterative_hash_object (precision, hashcode);
3674           }
3675           break;
3676         default:
3677           break;
3678         }
3679
3680       ntype = type_hash_canon (hashcode, ntype);
3681
3682       /* If the target-dependent attributes make NTYPE different from
3683          its canonical type, we will need to use structural equality
3684          checks for this qualified type. */
3685       if (!targetm.comp_type_attributes (ntype, ttype))
3686         SET_TYPE_STRUCTURAL_EQUALITY (ntype);
3687
3688       ttype = build_qualified_type (ntype, quals);
3689     }
3690
3691   return ttype;
3692 }
3693
3694
3695 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3696    is ATTRIBUTE.
3697
3698    Record such modified types already made so we don't make duplicates.  */
3699
3700 tree
3701 build_type_attribute_variant (tree ttype, tree attribute)
3702 {
3703   return build_type_attribute_qual_variant (ttype, attribute,
3704                                             TYPE_QUALS (ttype));
3705 }
3706
3707 /* Return nonzero if IDENT is a valid name for attribute ATTR,
3708    or zero if not.
3709
3710    We try both `text' and `__text__', ATTR may be either one.  */
3711 /* ??? It might be a reasonable simplification to require ATTR to be only
3712    `text'.  One might then also require attribute lists to be stored in
3713    their canonicalized form.  */
3714
3715 static int
3716 is_attribute_with_length_p (const char *attr, int attr_len, tree ident)
3717 {
3718   int ident_len;
3719   const char *p;
3720
3721   if (TREE_CODE (ident) != IDENTIFIER_NODE)
3722     return 0;
3723
3724   p = IDENTIFIER_POINTER (ident);
3725   ident_len = IDENTIFIER_LENGTH (ident);
3726
3727   if (ident_len == attr_len
3728       && strcmp (attr, p) == 0)
3729     return 1;
3730
3731   /* If ATTR is `__text__', IDENT must be `text'; and vice versa.  */
3732   if (attr[0] == '_')
3733     {
3734       gcc_assert (attr[1] == '_');
3735       gcc_assert (attr[attr_len - 2] == '_');
3736       gcc_assert (attr[attr_len - 1] == '_');
3737       if (ident_len == attr_len - 4
3738           && strncmp (attr + 2, p, attr_len - 4) == 0)
3739         return 1;
3740     }
3741   else
3742     {
3743       if (ident_len == attr_len + 4
3744           && p[0] == '_' && p[1] == '_'
3745           && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
3746           && strncmp (attr, p + 2, attr_len) == 0)
3747         return 1;
3748     }
3749
3750   return 0;
3751 }
3752
3753 /* Return nonzero if IDENT is a valid name for attribute ATTR,
3754    or zero if not.
3755
3756    We try both `text' and `__text__', ATTR may be either one.  */
3757
3758 int
3759 is_attribute_p (const char *attr, tree ident)
3760 {
3761   return is_attribute_with_length_p (attr, strlen (attr), ident);
3762 }
3763
3764 /* Given an attribute name and a list of attributes, return a pointer to the
3765    attribute's list element if the attribute is part of the list, or NULL_TREE
3766    if not found.  If the attribute appears more than once, this only
3767    returns the first occurrence; the TREE_CHAIN of the return value should
3768    be passed back in if further occurrences are wanted.  */
3769
3770 tree
3771 lookup_attribute (const char *attr_name, tree list)
3772 {
3773   tree l;
3774   size_t attr_len = strlen (attr_name);
3775
3776   for (l = list; l; l = TREE_CHAIN (l))
3777     {
3778       gcc_assert (TREE_CODE (TREE_PURPOSE (l)) == IDENTIFIER_NODE);
3779       if (is_attribute_with_length_p (attr_name, attr_len, TREE_PURPOSE (l)))
3780         return l;
3781     }
3782
3783   return NULL_TREE;
3784 }
3785
3786 /* Remove any instances of attribute ATTR_NAME in LIST and return the
3787    modified list.  */
3788
3789 tree
3790 remove_attribute (const char *attr_name, tree list)
3791 {
3792   tree *p;
3793   size_t attr_len = strlen (attr_name);
3794
3795   for (p = &list; *p; )
3796     {
3797       tree l = *p;
3798       gcc_assert (TREE_CODE (TREE_PURPOSE (l)) == IDENTIFIER_NODE);
3799       if (is_attribute_with_length_p (attr_name, attr_len, TREE_PURPOSE (l)))
3800         *p = TREE_CHAIN (l);
3801       else
3802         p = &TREE_CHAIN (l);
3803     }
3804
3805   return list;
3806 }
3807
3808 /* Return an attribute list that is the union of a1 and a2.  */
3809
3810 tree
3811 merge_attributes (tree a1, tree a2)
3812 {
3813   tree attributes;
3814
3815   /* Either one unset?  Take the set one.  */
3816
3817   if ((attributes = a1) == 0)
3818     attributes = a2;
3819
3820   /* One that completely contains the other?  Take it.  */
3821
3822   else if (a2 != 0 && ! attribute_list_contained (a1, a2))
3823     {
3824       if (attribute_list_contained (a2, a1))
3825         attributes = a2;
3826       else
3827         {
3828           /* Pick the longest list, and hang on the other list.  */
3829
3830           if (list_length (a1) < list_length (a2))
3831             attributes = a2, a2 = a1;
3832
3833           for (; a2 != 0; a2 = TREE_CHAIN (a2))
3834             {
3835               tree a;
3836               for (a = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3837                                          attributes);
3838                    a != NULL_TREE;
3839                    a = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3840                                          TREE_CHAIN (a)))
3841                 {
3842                   if (TREE_VALUE (a) != NULL
3843                       && TREE_CODE (TREE_VALUE (a)) == TREE_LIST
3844                       && TREE_VALUE (a2) != NULL
3845                       && TREE_CODE (TREE_VALUE (a2)) == TREE_LIST)
3846                     {
3847                       if (simple_cst_list_equal (TREE_VALUE (a),
3848                                                  TREE_VALUE (a2)) == 1)
3849                         break;
3850                     }
3851                   else if (simple_cst_equal (TREE_VALUE (a),
3852                                              TREE_VALUE (a2)) == 1)
3853                     break;
3854                 }
3855               if (a == NULL_TREE)
3856                 {
3857                   a1 = copy_node (a2);
3858                   TREE_CHAIN (a1) = attributes;
3859                   attributes = a1;
3860                 }
3861             }
3862         }
3863     }
3864   return attributes;
3865 }
3866
3867 /* Given types T1 and T2, merge their attributes and return
3868   the result.  */
3869
3870 tree
3871 merge_type_attributes (tree t1, tree t2)
3872 {
3873   return merge_attributes (TYPE_ATTRIBUTES (t1),
3874                            TYPE_ATTRIBUTES (t2));
3875 }
3876
3877 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
3878    the result.  */
3879
3880 tree
3881 merge_decl_attributes (tree olddecl, tree newdecl)
3882 {
3883   return merge_attributes (DECL_ATTRIBUTES (olddecl),
3884                            DECL_ATTRIBUTES (newdecl));
3885 }
3886
3887 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
3888
3889 /* Specialization of merge_decl_attributes for various Windows targets.
3890
3891    This handles the following situation:
3892
3893      __declspec (dllimport) int foo;
3894      int foo;
3895
3896    The second instance of `foo' nullifies the dllimport.  */
3897
3898 tree
3899 merge_dllimport_decl_attributes (tree old, tree new)
3900 {
3901   tree a;
3902   int delete_dllimport_p = 1;
3903
3904   /* What we need to do here is remove from `old' dllimport if it doesn't
3905      appear in `new'.  dllimport behaves like extern: if a declaration is
3906      marked dllimport and a definition appears later, then the object
3907      is not dllimport'd.  We also remove a `new' dllimport if the old list
3908      contains dllexport:  dllexport always overrides dllimport, regardless
3909      of the order of declaration.  */
3910   if (!VAR_OR_FUNCTION_DECL_P (new))
3911     delete_dllimport_p = 0;
3912   else if (DECL_DLLIMPORT_P (new)
3913            && lookup_attribute ("dllexport", DECL_ATTRIBUTES (old)))
3914     {
3915       DECL_DLLIMPORT_P (new) = 0;
3916       warning (OPT_Wattributes, "%q+D already declared with dllexport attribute: "
3917               "dllimport ignored", new);
3918     }
3919   else if (DECL_DLLIMPORT_P (old) && !DECL_DLLIMPORT_P (new))
3920     {
3921       /* Warn about overriding a symbol that has already been used. eg:
3922            extern int __attribute__ ((dllimport)) foo;
3923            int* bar () {return &foo;}
3924            int foo;
3925       */
3926       if (TREE_USED (old))
3927         {
3928           warning (0, "%q+D redeclared without dllimport attribute "
3929                    "after being referenced with dll linkage", new);
3930           /* If we have used a variable's address with dllimport linkage,
3931               keep the old DECL_DLLIMPORT_P flag: the ADDR_EXPR using the
3932               decl may already have had TREE_INVARIANT and TREE_CONSTANT
3933               computed.
3934               We still remove the attribute so that assembler code refers
3935               to '&foo rather than '_imp__foo'.  */
3936           if (TREE_CODE (old) == VAR_DECL && TREE_ADDRESSABLE (old))
3937             DECL_DLLIMPORT_P (new) = 1;
3938         }
3939
3940       /* Let an inline definition silently override the external reference,
3941          but otherwise warn about attribute inconsistency.  */
3942       else if (TREE_CODE (new) == VAR_DECL
3943                || !DECL_DECLARED_INLINE_P (new))
3944         warning (OPT_Wattributes, "%q+D redeclared without dllimport attribute: "
3945                   "previous dllimport ignored", new);
3946     }
3947   else
3948     delete_dllimport_p = 0;
3949
3950   a = merge_attributes (DECL_ATTRIBUTES (old), DECL_ATTRIBUTES (new));
3951
3952   if (delete_dllimport_p)
3953     {
3954       tree prev, t;
3955       const size_t attr_len = strlen ("dllimport");
3956
3957       /* Scan the list for dllimport and delete it.  */
3958       for (prev = NULL_TREE, t = a; t; prev = t, t = TREE_CHAIN (t))
3959         {
3960           if (is_attribute_with_length_p ("dllimport", attr_len,
3961                                           TREE_PURPOSE (t)))
3962             {
3963               if (prev == NULL_TREE)
3964                 a = TREE_CHAIN (a);
3965               else
3966                 TREE_CHAIN (prev) = TREE_CHAIN (t);
3967               break;
3968             }
3969         }
3970     }
3971
3972   return a;
3973 }
3974
3975 /* Handle a "dllimport" or "dllexport" attribute; arguments as in
3976    struct attribute_spec.handler.  */
3977
3978 tree
3979 handle_dll_attribute (tree * pnode, tree name, tree args, int flags,
3980                       bool *no_add_attrs)
3981 {
3982   tree node = *pnode;
3983
3984   /* These attributes may apply to structure and union types being created,
3985      but otherwise should pass to the declaration involved.  */
3986   if (!DECL_P (node))
3987     {
3988       if (flags & ((int) ATTR_FLAG_DECL_NEXT | (int) ATTR_FLAG_FUNCTION_NEXT
3989                    | (int) ATTR_FLAG_ARRAY_NEXT))
3990         {
3991           *no_add_attrs = true;
3992           return tree_cons (name, args, NULL_TREE);
3993         }
3994       if (TREE_CODE (node) != RECORD_TYPE && TREE_CODE (node) != UNION_TYPE)
3995         {
3996           warning (OPT_Wattributes, "%qs attribute ignored",
3997                    IDENTIFIER_POINTER (name));
3998           *no_add_attrs = true;
3999         }
4000
4001       return NULL_TREE;
4002     }
4003
4004   if (TREE_CODE (node) != FUNCTION_DECL
4005       && TREE_CODE (node) != VAR_DECL)
4006     {
4007       *no_add_attrs = true;
4008       warning (OPT_Wattributes, "%qs attribute ignored",
4009                IDENTIFIER_POINTER (name));
4010       return NULL_TREE;
4011     }
4012
4013   /* Report error on dllimport ambiguities seen now before they cause
4014      any damage.  */
4015   else if (is_attribute_p ("dllimport", name))
4016     {
4017       /* Honor any target-specific overrides. */
4018       if (!targetm.valid_dllimport_attribute_p (node))
4019         *no_add_attrs = true;
4020
4021      else if (TREE_CODE (node) == FUNCTION_DECL
4022                 && DECL_DECLARED_INLINE_P (node))
4023         {
4024           warning (OPT_Wattributes, "inline function %q+D declared as "
4025                   " dllimport: attribute ignored", node);
4026           *no_add_attrs = true;
4027         }
4028       /* Like MS, treat definition of dllimported variables and
4029          non-inlined functions on declaration as syntax errors. */
4030      else if (TREE_CODE (node) == FUNCTION_DECL && DECL_INITIAL (node))
4031         {
4032           error ("function %q+D definition is marked dllimport", node);
4033           *no_add_attrs = true;
4034         }
4035
4036      else if (TREE_CODE (node) == VAR_DECL)
4037         {
4038           if (DECL_INITIAL (node))
4039             {
4040               error ("variable %q+D definition is marked dllimport",
4041                      node);
4042               *no_add_attrs = true;
4043             }
4044
4045           /* `extern' needn't be specified with dllimport.
4046              Specify `extern' now and hope for the best.  Sigh.  */
4047           DECL_EXTERNAL (node) = 1;
4048           /* Also, implicitly give dllimport'd variables declared within
4049              a function global scope, unless declared static.  */
4050           if (current_function_decl != NULL_TREE && !TREE_STATIC (node))
4051             TREE_PUBLIC (node) = 1;
4052         }
4053
4054       if (*no_add_attrs == false)
4055         DECL_DLLIMPORT_P (node) = 1;
4056     }
4057
4058   /*  Report error if symbol is not accessible at global scope.  */
4059   if (!TREE_PUBLIC (node)
4060       && (TREE_CODE (node) == VAR_DECL
4061           || TREE_CODE (node) == FUNCTION_DECL))
4062     {
4063       error ("external linkage required for symbol %q+D because of "
4064              "%qs attribute", node, IDENTIFIER_POINTER (name));
4065       *no_add_attrs = true;
4066     }
4067
4068   return NULL_TREE;
4069 }
4070
4071 #endif /* TARGET_DLLIMPORT_DECL_ATTRIBUTES  */
4072 \f
4073 /* Set the type qualifiers for TYPE to TYPE_QUALS, which is a bitmask
4074    of the various TYPE_QUAL values.  */
4075
4076 static void
4077 set_type_quals (tree type, int type_quals)
4078 {
4079   TYPE_READONLY (type) = (type_quals & TYPE_QUAL_CONST) != 0;
4080   TYPE_VOLATILE (type) = (type_quals & TYPE_QUAL_VOLATILE) != 0;
4081   TYPE_RESTRICT (type) = (type_quals & TYPE_QUAL_RESTRICT) != 0;
4082 }
4083
4084 /* Returns true iff cand is equivalent to base with type_quals.  */
4085
4086 bool
4087 check_qualified_type (tree cand, tree base, int type_quals)
4088 {
4089   return (TYPE_QUALS (cand) == type_quals
4090           && TYPE_NAME (cand) == TYPE_NAME (base)
4091           /* Apparently this is needed for Objective-C.  */
4092           && TYPE_CONTEXT (cand) == TYPE_CONTEXT (base)
4093           && attribute_list_equal (TYPE_ATTRIBUTES (cand),
4094                                    TYPE_ATTRIBUTES (base)));
4095 }
4096
4097 /* Return a version of the TYPE, qualified as indicated by the
4098    TYPE_QUALS, if one exists.  If no qualified version exists yet,
4099    return NULL_TREE.  */
4100
4101 tree
4102 get_qualified_type (tree type, int type_quals)
4103 {
4104   tree t;
4105
4106   if (TYPE_QUALS (type) == type_quals)
4107     return type;
4108
4109   /* Search the chain of variants to see if there is already one there just
4110      like the one we need to have.  If so, use that existing one.  We must
4111      preserve the TYPE_NAME, since there is code that depends on this.  */
4112   for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4113     if (check_qualified_type (t, type, type_quals))
4114       return t;
4115
4116   return NULL_TREE;
4117 }
4118
4119 /* Like get_qualified_type, but creates the type if it does not
4120    exist.  This function never returns NULL_TREE.  */
4121
4122 tree
4123 build_qualified_type (tree type, int type_quals)
4124 {
4125   tree t;
4126
4127   /* See if we already have the appropriate qualified variant.  */
4128   t = get_qualified_type (type, type_quals);
4129
4130   /* If not, build it.  */
4131   if (!t)
4132     {
4133       t = build_variant_type_copy (type);
4134       set_type_quals (t, type_quals);
4135
4136       if (TYPE_STRUCTURAL_EQUALITY_P (type))
4137         /* Propagate structural equality. */
4138         SET_TYPE_STRUCTURAL_EQUALITY (t);
4139       else if (TYPE_CANONICAL (type) != type)
4140         /* Build the underlying canonical type, since it is different
4141            from TYPE. */
4142         TYPE_CANONICAL (t) = build_qualified_type (TYPE_CANONICAL (type),
4143                                                    type_quals);
4144       else
4145         /* T is its own canonical type. */
4146         TYPE_CANONICAL (t) = t;
4147
4148     }
4149
4150   return t;
4151 }
4152
4153 /* Create a new distinct copy of TYPE.  The new type is made its own
4154    MAIN_VARIANT. If TYPE requires structural equality checks, the
4155    resulting type requires structural equality checks; otherwise, its
4156    TYPE_CANONICAL points to itself. */
4157
4158 tree
4159 build_distinct_type_copy (tree type)
4160 {
4161   tree t = copy_node (type);
4162
4163   TYPE_POINTER_TO (t) = 0;
4164   TYPE_REFERENCE_TO (t) = 0;
4165
4166   /* Set the canonical type either to a new equivalence class, or
4167      propagate the need for structural equality checks. */
4168   if (TYPE_STRUCTURAL_EQUALITY_P (type))
4169     SET_TYPE_STRUCTURAL_EQUALITY (t);
4170   else
4171     TYPE_CANONICAL (t) = t;
4172
4173   /* Make it its own variant.  */
4174   TYPE_MAIN_VARIANT (t) = t;
4175   TYPE_NEXT_VARIANT (t) = 0;
4176
4177   /* Note that it is now possible for TYPE_MIN_VALUE to be a value
4178      whose TREE_TYPE is not t.  This can also happen in the Ada
4179      frontend when using subtypes.  */
4180
4181   return t;
4182 }
4183
4184 /* Create a new variant of TYPE, equivalent but distinct.  This is so
4185    the caller can modify it. TYPE_CANONICAL for the return type will
4186    be equivalent to TYPE_CANONICAL of TYPE, indicating that the types
4187    are considered equal by the language itself (or that both types
4188    require structural equality checks). */
4189
4190 tree
4191 build_variant_type_copy (tree type)
4192 {
4193   tree t, m = TYPE_MAIN_VARIANT (type);
4194
4195   t = build_distinct_type_copy (type);
4196
4197   /* Since we're building a variant, assume that it is a non-semantic
4198      variant. This also propagates TYPE_STRUCTURAL_EQUALITY_P. */
4199   TYPE_CANONICAL (t) = TYPE_CANONICAL (type);
4200
4201   /* Add the new type to the chain of variants of TYPE.  */
4202   TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
4203   TYPE_NEXT_VARIANT (m) = t;
4204   TYPE_MAIN_VARIANT (t) = m;
4205
4206   return t;
4207 }
4208 \f
4209 /* Return true if the from tree in both tree maps are equal.  */
4210
4211 int
4212 tree_map_base_eq (const void *va, const void *vb)
4213 {
4214   const struct tree_map_base  *a = va, *b = vb;
4215   return (a->from == b->from);
4216 }
4217
4218 /* Hash a from tree in a tree_map.  */
4219
4220 unsigned int
4221 tree_map_base_hash (const void *item)
4222 {
4223   return htab_hash_pointer (((const struct tree_map_base *)item)->from);
4224 }
4225
4226 /* Return true if this tree map structure is marked for garbage collection
4227    purposes.  We simply return true if the from tree is marked, so that this
4228    structure goes away when the from tree goes away.  */
4229
4230 int
4231 tree_map_base_marked_p (const void *p)
4232 {
4233   return ggc_marked_p (((struct tree_map_base *) p)->from);
4234 }
4235
4236 unsigned int
4237 tree_map_hash (const void *item)
4238 {
4239   return (((const struct tree_map *) item)->hash);
4240 }
4241
4242 /* Return the initialization priority for DECL.  */
4243
4244 priority_type
4245 decl_init_priority_lookup (tree decl)
4246 {
4247   struct tree_priority_map *h;
4248   struct tree_map_base in;
4249
4250   gcc_assert (VAR_OR_FUNCTION_DECL_P (decl));
4251   gcc_assert (TREE_CODE (decl) == VAR_DECL
4252               ? DECL_HAS_INIT_PRIORITY_P (decl)
4253               : DECL_STATIC_CONSTRUCTOR (decl));
4254   in.from = decl;
4255   h = htab_find (init_priority_for_decl, &in);
4256   return h ? h->init : DEFAULT_INIT_PRIORITY;
4257 }
4258
4259 /* Return the finalization priority for DECL.  */
4260
4261 priority_type
4262 decl_fini_priority_lookup (tree decl)
4263 {
4264   struct tree_priority_map *h;
4265   struct tree_map_base in;
4266
4267   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
4268   gcc_assert (DECL_STATIC_DESTRUCTOR (decl));
4269   in.from = decl;
4270   h = htab_find (init_priority_for_decl, &in);
4271   return h ? h->fini : DEFAULT_INIT_PRIORITY;
4272 }
4273
4274 /* Return the initialization and finalization priority information for
4275    DECL.  If there is no previous priority information, a freshly
4276    allocated structure is returned.  */
4277
4278 static struct tree_priority_map *
4279 decl_priority_info (tree decl)
4280 {
4281   struct tree_priority_map in;
4282   struct tree_priority_map *h;
4283   void **loc;
4284
4285   in.base.from = decl;
4286   loc = htab_find_slot (init_priority_for_decl, &in, INSERT);
4287   h = *loc;
4288   if (!h)
4289     {
4290       h = GGC_CNEW (struct tree_priority_map);
4291       *loc = h;
4292       h->base.from = decl;
4293       h->init = DEFAULT_INIT_PRIORITY;
4294       h->fini = DEFAULT_INIT_PRIORITY;
4295     }
4296
4297   return h;
4298 }
4299
4300 /* Set the initialization priority for DECL to PRIORITY.  */
4301
4302 void
4303 decl_init_priority_insert (tree decl, priority_type priority)
4304 {
4305   struct tree_priority_map *h;
4306
4307   gcc_assert (VAR_OR_FUNCTION_DECL_P (decl));
4308   h = decl_priority_info (decl);
4309   h->init = priority;
4310 }
4311
4312 /* Set the finalization priority for DECL to PRIORITY.  */
4313
4314 void
4315 decl_fini_priority_insert (tree decl, priority_type priority)
4316 {
4317   struct tree_priority_map *h;
4318
4319   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
4320   h = decl_priority_info (decl);
4321   h->fini = priority;
4322 }
4323
4324 /* Look up a restrict qualified base decl for FROM.  */
4325
4326 tree
4327 decl_restrict_base_lookup (tree from)
4328 {
4329   struct tree_map *h;
4330   struct tree_map in;
4331
4332   in.base.from = from;
4333   h = htab_find_with_hash (restrict_base_for_decl, &in,
4334                            htab_hash_pointer (from));
4335   return h ? h->to : NULL_TREE;
4336 }
4337
4338 /* Record the restrict qualified base TO for FROM.  */
4339
4340 void
4341 decl_restrict_base_insert (tree from, tree to)
4342 {
4343   struct tree_map *h;
4344   void **loc;
4345
4346   h = ggc_alloc (sizeof (struct tree_map));
4347   h->hash = htab_hash_pointer (from);
4348   h->base.from = from;
4349   h->to = to;
4350   loc = htab_find_slot_with_hash (restrict_base_for_decl, h, h->hash, INSERT);
4351   *(struct tree_map **) loc = h;
4352 }
4353
4354 /* Print out the statistics for the DECL_DEBUG_EXPR hash table.  */
4355
4356 static void
4357 print_debug_expr_statistics (void)
4358 {
4359   fprintf (stderr, "DECL_DEBUG_EXPR  hash: size %ld, %ld elements, %f collisions\n",
4360            (long) htab_size (debug_expr_for_decl),
4361            (long) htab_elements (debug_expr_for_decl),
4362            htab_collisions (debug_expr_for_decl));
4363 }
4364
4365 /* Print out the statistics for the DECL_VALUE_EXPR hash table.  */
4366
4367 static void
4368 print_value_expr_statistics (void)
4369 {
4370   fprintf (stderr, "DECL_VALUE_EXPR  hash: size %ld, %ld elements, %f collisions\n",
4371            (long) htab_size (value_expr_for_decl),
4372            (long) htab_elements (value_expr_for_decl),
4373            htab_collisions (value_expr_for_decl));
4374 }
4375
4376 /* Print out statistics for the RESTRICT_BASE_FOR_DECL hash table, but
4377    don't print anything if the table is empty.  */
4378
4379 static void
4380 print_restrict_base_statistics (void)
4381 {
4382   if (htab_elements (restrict_base_for_decl) != 0)
4383     fprintf (stderr,
4384              "RESTRICT_BASE    hash: size %ld, %ld elements, %f collisions\n",
4385              (long) htab_size (restrict_base_for_decl),
4386              (long) htab_elements (restrict_base_for_decl),
4387              htab_collisions (restrict_base_for_decl));
4388 }
4389
4390 /* Lookup a debug expression for FROM, and return it if we find one.  */
4391
4392 tree
4393 decl_debug_expr_lookup (tree from)
4394 {
4395   struct tree_map *h, in;
4396   in.base.from = from;
4397
4398   h = htab_find_with_hash (debug_expr_for_decl, &in, htab_hash_pointer (from));
4399   if (h)
4400     return h->to;
4401   return NULL_TREE;
4402 }
4403
4404 /* Insert a mapping FROM->TO in the debug expression hashtable.  */
4405
4406 void
4407 decl_debug_expr_insert (tree from, tree to)
4408 {
4409   struct tree_map *h;
4410   void **loc;
4411
4412   h = ggc_alloc (sizeof (struct tree_map));
4413   h->hash = htab_hash_pointer (from);
4414   h->base.from = from;
4415   h->to = to;
4416   loc = htab_find_slot_with_hash (debug_expr_for_decl, h, h->hash, INSERT);
4417   *(struct tree_map **) loc = h;
4418 }
4419
4420 /* Lookup a value expression for FROM, and return it if we find one.  */
4421
4422 tree
4423 decl_value_expr_lookup (tree from)
4424 {
4425   struct tree_map *h, in;
4426   in.base.from = from;
4427
4428   h = htab_find_with_hash (value_expr_for_decl, &in, htab_hash_pointer (from));
4429   if (h)
4430     return h->to;
4431   return NULL_TREE;
4432 }
4433
4434 /* Insert a mapping FROM->TO in the value expression hashtable.  */
4435
4436 void
4437 decl_value_expr_insert (tree from, tree to)
4438 {
4439   struct tree_map *h;
4440   void **loc;
4441
4442   h = ggc_alloc (sizeof (struct tree_map));
4443   h->hash = htab_hash_pointer (from);
4444   h->base.from = from;
4445   h->to = to;
4446   loc = htab_find_slot_with_hash (value_expr_for_decl, h, h->hash, INSERT);
4447   *(struct tree_map **) loc = h;
4448 }
4449
4450 /* Hashing of types so that we don't make duplicates.
4451    The entry point is `type_hash_canon'.  */
4452
4453 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
4454    with types in the TREE_VALUE slots), by adding the hash codes
4455    of the individual types.  */
4456
4457 unsigned int
4458 type_hash_list (tree list, hashval_t hashcode)
4459 {
4460   tree tail;
4461
4462   for (tail = list; tail; tail = TREE_CHAIN (tail))
4463     if (TREE_VALUE (tail) != error_mark_node)
4464       hashcode = iterative_hash_object (TYPE_HASH (TREE_VALUE (tail)),
4465                                         hashcode);
4466
4467   return hashcode;
4468 }
4469
4470 /* These are the Hashtable callback functions.  */
4471
4472 /* Returns true iff the types are equivalent.  */
4473
4474 static int
4475 type_hash_eq (const void *va, const void *vb)
4476 {
4477   const struct type_hash *a = va, *b = vb;
4478
4479   /* First test the things that are the same for all types.  */
4480   if (a->hash != b->hash
4481       || TREE_CODE (a->type) != TREE_CODE (b->type)
4482       || TREE_TYPE (a->type) != TREE_TYPE (b->type)
4483       || !attribute_list_equal (TYPE_ATTRIBUTES (a->type),
4484                                  TYPE_ATTRIBUTES (b->type))
4485       || TYPE_ALIGN (a->type) != TYPE_ALIGN (b->type)
4486       || TYPE_MODE (a->type) != TYPE_MODE (b->type))
4487     return 0;
4488
4489   switch (TREE_CODE (a->type))
4490     {
4491     case VOID_TYPE:
4492     case COMPLEX_TYPE:
4493     case POINTER_TYPE:
4494     case REFERENCE_TYPE:
4495       return 1;
4496
4497     case VECTOR_TYPE:
4498       return TYPE_VECTOR_SUBPARTS (a->type) == TYPE_VECTOR_SUBPARTS (b->type);
4499
4500     case ENUMERAL_TYPE:
4501       if (TYPE_VALUES (a->type) != TYPE_VALUES (b->type)
4502           && !(TYPE_VALUES (a->type)
4503                && TREE_CODE (TYPE_VALUES (a->type)) == TREE_LIST
4504                && TYPE_VALUES (b->type)
4505                && TREE_CODE (TYPE_VALUES (b->type)) == TREE_LIST
4506                && type_list_equal (TYPE_VALUES (a->type),
4507                                    TYPE_VALUES (b->type))))
4508         return 0;
4509
4510       /* ... fall through ... */
4511
4512     case INTEGER_TYPE:
4513     case REAL_TYPE:
4514     case BOOLEAN_TYPE:
4515       return ((TYPE_MAX_VALUE (a->type) == TYPE_MAX_VALUE (b->type)
4516                || tree_int_cst_equal (TYPE_MAX_VALUE (a->type),
4517                                       TYPE_MAX_VALUE (b->type)))
4518               && (TYPE_MIN_VALUE (a->type) == TYPE_MIN_VALUE (b->type)
4519                   || tree_int_cst_equal (TYPE_MIN_VALUE (a->type),
4520                                          TYPE_MIN_VALUE (b->type))));
4521
4522     case OFFSET_TYPE:
4523       return TYPE_OFFSET_BASETYPE (a->type) == TYPE_OFFSET_BASETYPE (b->type);
4524
4525     case METHOD_TYPE:
4526       return (TYPE_METHOD_BASETYPE (a->type) == TYPE_METHOD_BASETYPE (b->type)
4527               && (TYPE_ARG_TYPES (a->type) == TYPE_ARG_TYPES (b->type)
4528                   || (TYPE_ARG_TYPES (a->type)
4529                       && TREE_CODE (TYPE_ARG_TYPES (a->type)) == TREE_LIST
4530                       && TYPE_ARG_TYPES (b->type)
4531                       && TREE_CODE (TYPE_ARG_TYPES (b->type)) == TREE_LIST
4532                       && type_list_equal (TYPE_ARG_TYPES (a->type),
4533                                           TYPE_ARG_TYPES (b->type)))));
4534
4535     case ARRAY_TYPE:
4536       return TYPE_DOMAIN (a->type) == TYPE_DOMAIN (b->type);
4537
4538     case RECORD_TYPE:
4539     case UNION_TYPE:
4540     case QUAL_UNION_TYPE:
4541       return (TYPE_FIELDS (a->type) == TYPE_FIELDS (b->type)
4542               || (TYPE_FIELDS (a->type)
4543                   && TREE_CODE (TYPE_FIELDS (a->type)) == TREE_LIST
4544                   && TYPE_FIELDS (b->type)
4545                   && TREE_CODE (TYPE_FIELDS (b->type)) == TREE_LIST
4546                   && type_list_equal (TYPE_FIELDS (a->type),
4547                                       TYPE_FIELDS (b->type))));
4548
4549     case FUNCTION_TYPE:
4550       return (TYPE_ARG_TYPES (a->type) == TYPE_ARG_TYPES (b->type)
4551               || (TYPE_ARG_TYPES (a->type)
4552                   && TREE_CODE (TYPE_ARG_TYPES (a->type)) == TREE_LIST
4553                   && TYPE_ARG_TYPES (b->type)
4554                   && TREE_CODE (TYPE_ARG_TYPES (b->type)) == TREE_LIST
4555                   && type_list_equal (TYPE_ARG_TYPES (a->type),
4556                                       TYPE_ARG_TYPES (b->type))));
4557
4558     default:
4559       return 0;
4560     }
4561 }
4562
4563 /* Return the cached hash value.  */
4564
4565 static hashval_t
4566 type_hash_hash (const void *item)
4567 {
4568   return ((const struct type_hash *) item)->hash;
4569 }
4570
4571 /* Look in the type hash table for a type isomorphic to TYPE.
4572    If one is found, return it.  Otherwise return 0.  */
4573
4574 tree
4575 type_hash_lookup (hashval_t hashcode, tree type)
4576 {
4577   struct type_hash *h, in;
4578
4579   /* The TYPE_ALIGN field of a type is set by layout_type(), so we
4580      must call that routine before comparing TYPE_ALIGNs.  */
4581   layout_type (type);
4582
4583   in.hash = hashcode;
4584   in.type = type;
4585
4586   h = htab_find_with_hash (type_hash_table, &in, hashcode);
4587   if (h)
4588     return h->type;
4589   return NULL_TREE;
4590 }
4591
4592 /* Add an entry to the type-hash-table
4593    for a type TYPE whose hash code is HASHCODE.  */
4594
4595 void
4596 type_hash_add (hashval_t hashcode, tree type)
4597 {
4598   struct type_hash *h;
4599   void **loc;
4600
4601   h = ggc_alloc (sizeof (struct type_hash));
4602   h->hash = hashcode;
4603   h->type = type;
4604   loc = htab_find_slot_with_hash (type_hash_table, h, hashcode, INSERT);
4605   *(struct type_hash **) loc = h;
4606 }
4607
4608 /* Given TYPE, and HASHCODE its hash code, return the canonical
4609    object for an identical type if one already exists.
4610    Otherwise, return TYPE, and record it as the canonical object.
4611
4612    To use this function, first create a type of the sort you want.
4613    Then compute its hash code from the fields of the type that
4614    make it different from other similar types.
4615    Then call this function and use the value.  */
4616
4617 tree
4618 type_hash_canon (unsigned int hashcode, tree type)
4619 {
4620   tree t1;
4621
4622   /* The hash table only contains main variants, so ensure that's what we're
4623      being passed.  */
4624   gcc_assert (TYPE_MAIN_VARIANT (type) == type);
4625
4626   if (!lang_hooks.types.hash_types)
4627     return type;
4628
4629   /* See if the type is in the hash table already.  If so, return it.
4630      Otherwise, add the type.  */
4631   t1 = type_hash_lookup (hashcode, type);
4632   if (t1 != 0)
4633     {
4634 #ifdef GATHER_STATISTICS
4635       tree_node_counts[(int) t_kind]--;
4636       tree_node_sizes[(int) t_kind] -= sizeof (struct tree_type);
4637 #endif
4638       return t1;
4639     }
4640   else
4641     {
4642       type_hash_add (hashcode, type);
4643       return type;
4644     }
4645 }
4646
4647 /* See if the data pointed to by the type hash table is marked.  We consider
4648    it marked if the type is marked or if a debug type number or symbol
4649    table entry has been made for the type.  This reduces the amount of
4650    debugging output and eliminates that dependency of the debug output on
4651    the number of garbage collections.  */
4652
4653 static int
4654 type_hash_marked_p (const void *p)
4655 {
4656   tree type = ((struct type_hash *) p)->type;
4657
4658   return ggc_marked_p (type) || TYPE_SYMTAB_POINTER (type);
4659 }
4660
4661 static void
4662 print_type_hash_statistics (void)
4663 {
4664   fprintf (stderr, "Type hash: size %ld, %ld elements, %f collisions\n",
4665            (long) htab_size (type_hash_table),
4666            (long) htab_elements (type_hash_table),
4667            htab_collisions (type_hash_table));
4668 }
4669
4670 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
4671    with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
4672    by adding the hash codes of the individual attributes.  */
4673
4674 unsigned int
4675 attribute_hash_list (tree list, hashval_t hashcode)
4676 {
4677   tree tail;
4678
4679   for (tail = list; tail; tail = TREE_CHAIN (tail))
4680     /* ??? Do we want to add in TREE_VALUE too? */
4681     hashcode = iterative_hash_object
4682       (IDENTIFIER_HASH_VALUE (TREE_PURPOSE (tail)), hashcode);
4683   return hashcode;
4684 }
4685
4686 /* Given two lists of attributes, return true if list l2 is
4687    equivalent to l1.  */
4688
4689 int
4690 attribute_list_equal (tree l1, tree l2)
4691 {
4692   return attribute_list_contained (l1, l2)
4693          && attribute_list_contained (l2, l1);
4694 }
4695
4696 /* Given two lists of attributes, return true if list L2 is
4697    completely contained within L1.  */
4698 /* ??? This would be faster if attribute names were stored in a canonicalized
4699    form.  Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
4700    must be used to show these elements are equivalent (which they are).  */
4701 /* ??? It's not clear that attributes with arguments will always be handled
4702    correctly.  */
4703
4704 int
4705 attribute_list_contained (tree l1, tree l2)
4706 {
4707   tree t1, t2;
4708
4709   /* First check the obvious, maybe the lists are identical.  */
4710   if (l1 == l2)
4711     return 1;
4712
4713   /* Maybe the lists are similar.  */
4714   for (t1 = l1, t2 = l2;
4715        t1 != 0 && t2 != 0
4716         && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
4717         && TREE_VALUE (t1) == TREE_VALUE (t2);
4718        t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2));
4719
4720   /* Maybe the lists are equal.  */
4721   if (t1 == 0 && t2 == 0)
4722     return 1;
4723
4724   for (; t2 != 0; t2 = TREE_CHAIN (t2))
4725     {
4726       tree attr;
4727       for (attr = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)), l1);
4728            attr != NULL_TREE;
4729            attr = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)),
4730                                     TREE_CHAIN (attr)))
4731         {
4732           if (TREE_VALUE (t2) != NULL
4733               && TREE_CODE (TREE_VALUE (t2)) == TREE_LIST
4734               && TREE_VALUE (attr) != NULL
4735               && TREE_CODE (TREE_VALUE (attr)) == TREE_LIST)
4736             {
4737               if (simple_cst_list_equal (TREE_VALUE (t2),
4738                                          TREE_VALUE (attr)) == 1)
4739                 break;
4740             }
4741           else if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) == 1)
4742             break;
4743         }
4744
4745       if (attr == 0)
4746         return 0;
4747     }
4748
4749   return 1;
4750 }
4751
4752 /* Given two lists of types
4753    (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
4754    return 1 if the lists contain the same types in the same order.
4755    Also, the TREE_PURPOSEs must match.  */
4756
4757 int
4758 type_list_equal (tree l1, tree l2)
4759 {
4760   tree t1, t2;
4761
4762   for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
4763     if (TREE_VALUE (t1) != TREE_VALUE (t2)
4764         || (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
4765             && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
4766                   && (TREE_TYPE (TREE_PURPOSE (t1))
4767                       == TREE_TYPE (TREE_PURPOSE (t2))))))
4768       return 0;
4769
4770   return t1 == t2;
4771 }
4772
4773 /* Returns the number of arguments to the FUNCTION_TYPE or METHOD_TYPE
4774    given by TYPE.  If the argument list accepts variable arguments,
4775    then this function counts only the ordinary arguments.  */
4776
4777 int
4778 type_num_arguments (tree type)
4779 {
4780   int i = 0;
4781   tree t;
4782
4783   for (t = TYPE_ARG_TYPES (type); t; t = TREE_CHAIN (t))
4784     /* If the function does not take a variable number of arguments,
4785        the last element in the list will have type `void'.  */
4786     if (VOID_TYPE_P (TREE_VALUE (t)))
4787       break;
4788     else
4789       ++i;
4790
4791   return i;
4792 }
4793
4794 /* Nonzero if integer constants T1 and T2
4795    represent the same constant value.  */
4796
4797 int
4798 tree_int_cst_equal (tree t1, tree t2)
4799 {
4800   if (t1 == t2)
4801     return 1;
4802
4803   if (t1 == 0 || t2 == 0)
4804     return 0;
4805
4806   if (TREE_CODE (t1) == INTEGER_CST
4807       && TREE_CODE (t2) == INTEGER_CST
4808       && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
4809       && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
4810     return 1;
4811
4812   return 0;
4813 }
4814
4815 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
4816    The precise way of comparison depends on their data type.  */
4817
4818 int
4819 tree_int_cst_lt (tree t1, tree t2)
4820 {
4821   if (t1 == t2)
4822     return 0;
4823
4824   if (TYPE_UNSIGNED (TREE_TYPE (t1)) != TYPE_UNSIGNED (TREE_TYPE (t2)))
4825     {
4826       int t1_sgn = tree_int_cst_sgn (t1);
4827       int t2_sgn = tree_int_cst_sgn (t2);
4828
4829       if (t1_sgn < t2_sgn)
4830         return 1;
4831       else if (t1_sgn > t2_sgn)
4832         return 0;
4833       /* Otherwise, both are non-negative, so we compare them as
4834          unsigned just in case one of them would overflow a signed
4835          type.  */
4836     }
4837   else if (!TYPE_UNSIGNED (TREE_TYPE (t1)))
4838     return INT_CST_LT (t1, t2);
4839
4840   return INT_CST_LT_UNSIGNED (t1, t2);
4841 }
4842
4843 /* Returns -1 if T1 < T2, 0 if T1 == T2, and 1 if T1 > T2.  */
4844
4845 int
4846 tree_int_cst_compare (tree t1, tree t2)
4847 {
4848   if (tree_int_cst_lt (t1, t2))
4849     return -1;
4850   else if (tree_int_cst_lt (t2, t1))
4851     return 1;
4852   else
4853     return 0;
4854 }
4855
4856 /* Return 1 if T is an INTEGER_CST that can be manipulated efficiently on
4857    the host.  If POS is zero, the value can be represented in a single
4858    HOST_WIDE_INT.  If POS is nonzero, the value must be non-negative and can
4859    be represented in a single unsigned HOST_WIDE_INT.  */
4860
4861 int
4862 host_integerp (tree t, int pos)
4863 {
4864   return (TREE_CODE (t) == INTEGER_CST
4865           && ((TREE_INT_CST_HIGH (t) == 0
4866                && (HOST_WIDE_INT) TREE_INT_CST_LOW (t) >= 0)
4867               || (! pos && TREE_INT_CST_HIGH (t) == -1
4868                   && (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0
4869                   && !TYPE_UNSIGNED (TREE_TYPE (t)))
4870               || (pos && TREE_INT_CST_HIGH (t) == 0)));
4871 }
4872
4873 /* Return the HOST_WIDE_INT least significant bits of T if it is an
4874    INTEGER_CST and there is no overflow.  POS is nonzero if the result must
4875    be non-negative.  We must be able to satisfy the above conditions.  */
4876
4877 HOST_WIDE_INT
4878 tree_low_cst (tree t, int pos)
4879 {
4880   gcc_assert (host_integerp (t, pos));
4881   return TREE_INT_CST_LOW (t);
4882 }
4883
4884 /* Return the most significant bit of the integer constant T.  */
4885
4886 int
4887 tree_int_cst_msb (tree t)
4888 {
4889   int prec;
4890   HOST_WIDE_INT h;
4891   unsigned HOST_WIDE_INT l;
4892
4893   /* Note that using TYPE_PRECISION here is wrong.  We care about the
4894      actual bits, not the (arbitrary) range of the type.  */
4895   prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (t))) - 1;
4896   rshift_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t), prec,
4897                  2 * HOST_BITS_PER_WIDE_INT, &l, &h, 0);
4898   return (l & 1) == 1;
4899 }
4900
4901 /* Return an indication of the sign of the integer constant T.
4902    The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
4903    Note that -1 will never be returned if T's type is unsigned.  */
4904
4905 int
4906 tree_int_cst_sgn (tree t)
4907 {
4908   if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
4909     return 0;
4910   else if (TYPE_UNSIGNED (TREE_TYPE (t)))
4911     return 1;
4912   else if (TREE_INT_CST_HIGH (t) < 0)
4913     return -1;
4914   else
4915     return 1;
4916 }
4917
4918 /* Compare two constructor-element-type constants.  Return 1 if the lists
4919    are known to be equal; otherwise return 0.  */
4920
4921 int
4922 simple_cst_list_equal (tree l1, tree l2)
4923 {
4924   while (l1 != NULL_TREE && l2 != NULL_TREE)
4925     {
4926       if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
4927         return 0;
4928
4929       l1 = TREE_CHAIN (l1);
4930       l2 = TREE_CHAIN (l2);
4931     }
4932
4933   return l1 == l2;
4934 }
4935
4936 /* Return truthvalue of whether T1 is the same tree structure as T2.
4937    Return 1 if they are the same.
4938    Return 0 if they are understandably different.
4939    Return -1 if either contains tree structure not understood by
4940    this function.  */
4941
4942 int
4943 simple_cst_equal (tree t1, tree t2)
4944 {
4945   enum tree_code code1, code2;
4946   int cmp;
4947   int i;
4948
4949   if (t1 == t2)
4950     return 1;
4951   if (t1 == 0 || t2 == 0)
4952     return 0;
4953
4954   code1 = TREE_CODE (t1);
4955   code2 = TREE_CODE (t2);
4956
4957   if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
4958     {
4959       if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
4960           || code2 == NON_LVALUE_EXPR)
4961         return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4962       else
4963         return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
4964     }
4965
4966   else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
4967            || code2 == NON_LVALUE_EXPR)
4968     return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
4969
4970   if (code1 != code2)
4971     return 0;
4972
4973   switch (code1)
4974     {
4975     case INTEGER_CST:
4976       return (TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
4977               && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2));
4978
4979     case REAL_CST:
4980       return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
4981
4982     case STRING_CST:
4983       return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
4984               && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
4985                          TREE_STRING_LENGTH (t1)));
4986
4987     case CONSTRUCTOR:
4988       {
4989         unsigned HOST_WIDE_INT idx;
4990         VEC(constructor_elt, gc) *v1 = CONSTRUCTOR_ELTS (t1);
4991         VEC(constructor_elt, gc) *v2 = CONSTRUCTOR_ELTS (t2);
4992
4993         if (VEC_length (constructor_elt, v1) != VEC_length (constructor_elt, v2))
4994           return false;
4995
4996         for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
4997           /* ??? Should we handle also fields here? */
4998           if (!simple_cst_equal (VEC_index (constructor_elt, v1, idx)->value,
4999                                  VEC_index (constructor_elt, v2, idx)->value))
5000             return false;
5001         return true;
5002       }
5003
5004     case SAVE_EXPR:
5005       return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
5006
5007     case CALL_EXPR:
5008       cmp = simple_cst_equal (CALL_EXPR_FN (t1), CALL_EXPR_FN (t2));
5009       if (cmp <= 0)
5010         return cmp;
5011       if (call_expr_nargs (t1) != call_expr_nargs (t2))
5012         return 0;
5013       {
5014         tree arg1, arg2;
5015         call_expr_arg_iterator iter1, iter2;
5016         for (arg1 = first_call_expr_arg (t1, &iter1),
5017                arg2 = first_call_expr_arg (t2, &iter2);
5018              arg1 && arg2;
5019              arg1 = next_call_expr_arg (&iter1),
5020                arg2 = next_call_expr_arg (&iter2))
5021           {
5022             cmp = simple_cst_equal (arg1, arg2);
5023             if (cmp <= 0)
5024               return cmp;
5025           }
5026         return arg1 == arg2;
5027       }
5028
5029     case TARGET_EXPR:
5030       /* Special case: if either target is an unallocated VAR_DECL,
5031          it means that it's going to be unified with whatever the
5032          TARGET_EXPR is really supposed to initialize, so treat it
5033          as being equivalent to anything.  */
5034       if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
5035            && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
5036            && !DECL_RTL_SET_P (TREE_OPERAND (t1, 0)))
5037           || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
5038               && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
5039               && !DECL_RTL_SET_P (TREE_OPERAND (t2, 0))))
5040         cmp = 1;
5041       else
5042         cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
5043
5044       if (cmp <= 0)
5045         return cmp;
5046
5047       return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
5048
5049     case WITH_CLEANUP_EXPR:
5050       cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
5051       if (cmp <= 0)
5052         return cmp;
5053
5054       return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t1, 1));
5055
5056     case COMPONENT_REF:
5057       if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
5058         return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
5059
5060       return 0;
5061
5062     case VAR_DECL:
5063     case PARM_DECL:
5064     case CONST_DECL:
5065     case FUNCTION_DECL:
5066       return 0;
5067
5068     default:
5069       break;
5070     }
5071
5072   /* This general rule works for most tree codes.  All exceptions should be
5073      handled above.  If this is a language-specific tree code, we can't
5074      trust what might be in the operand, so say we don't know
5075      the situation.  */
5076   if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
5077     return -1;
5078
5079   switch (TREE_CODE_CLASS (code1))
5080     {
5081     case tcc_unary:
5082     case tcc_binary:
5083     case tcc_comparison:
5084     case tcc_expression:
5085     case tcc_reference:
5086     case tcc_statement:
5087       cmp = 1;
5088       for (i = 0; i < TREE_CODE_LENGTH (code1); i++)
5089         {
5090           cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
5091           if (cmp <= 0)
5092             return cmp;
5093         }
5094
5095       return cmp;
5096
5097     default:
5098       return -1;
5099     }
5100 }
5101
5102 /* Compare the value of T, an INTEGER_CST, with U, an unsigned integer value.
5103    Return -1, 0, or 1 if the value of T is less than, equal to, or greater
5104    than U, respectively.  */
5105
5106 int
5107 compare_tree_int (tree t, unsigned HOST_WIDE_INT u)
5108 {
5109   if (tree_int_cst_sgn (t) < 0)
5110     return -1;
5111   else if (TREE_INT_CST_HIGH (t) != 0)
5112     return 1;
5113   else if (TREE_INT_CST_LOW (t) == u)
5114     return 0;
5115   else if (TREE_INT_CST_LOW (t) < u)
5116     return -1;
5117   else
5118     return 1;
5119 }
5120
5121 /* Return true if CODE represents an associative tree code.  Otherwise
5122    return false.  */
5123 bool
5124 associative_tree_code (enum tree_code code)
5125 {
5126   switch (code)
5127     {
5128     case BIT_IOR_EXPR:
5129     case BIT_AND_EXPR:
5130     case BIT_XOR_EXPR:
5131     case PLUS_EXPR:
5132     case MULT_EXPR:
5133     case MIN_EXPR:
5134     case MAX_EXPR:
5135       return true;
5136
5137     default:
5138       break;
5139     }
5140   return false;
5141 }
5142
5143 /* Return true if CODE represents a commutative tree code.  Otherwise
5144    return false.  */
5145 bool
5146 commutative_tree_code (enum tree_code code)
5147 {
5148   switch (code)
5149     {
5150     case PLUS_EXPR:
5151     case MULT_EXPR:
5152     case MIN_EXPR:
5153     case MAX_EXPR:
5154     case BIT_IOR_EXPR:
5155     case BIT_XOR_EXPR:
5156     case BIT_AND_EXPR:
5157     case NE_EXPR:
5158     case EQ_EXPR:
5159     case UNORDERED_EXPR:
5160     case ORDERED_EXPR:
5161     case UNEQ_EXPR:
5162     case LTGT_EXPR:
5163     case TRUTH_AND_EXPR:
5164     case TRUTH_XOR_EXPR:
5165     case TRUTH_OR_EXPR:
5166       return true;
5167
5168     default:
5169       break;
5170     }
5171   return false;
5172 }
5173
5174 /* Generate a hash value for an expression.  This can be used iteratively
5175    by passing a previous result as the "val" argument.
5176
5177    This function is intended to produce the same hash for expressions which
5178    would compare equal using operand_equal_p.  */
5179
5180 hashval_t
5181 iterative_hash_expr (tree t, hashval_t val)
5182 {
5183   int i;
5184   enum tree_code code;
5185   char class;
5186
5187   if (t == NULL_TREE)
5188     return iterative_hash_pointer (t, val);
5189
5190   code = TREE_CODE (t);
5191
5192   switch (code)
5193     {
5194     /* Alas, constants aren't shared, so we can't rely on pointer
5195        identity.  */
5196     case INTEGER_CST:
5197       val = iterative_hash_host_wide_int (TREE_INT_CST_LOW (t), val);
5198       return iterative_hash_host_wide_int (TREE_INT_CST_HIGH (t), val);
5199     case REAL_CST:
5200       {
5201         unsigned int val2 = real_hash (TREE_REAL_CST_PTR (t));
5202
5203         return iterative_hash_hashval_t (val2, val);
5204       }
5205     case STRING_CST:
5206       return iterative_hash (TREE_STRING_POINTER (t),
5207                              TREE_STRING_LENGTH (t), val);
5208     case COMPLEX_CST:
5209       val = iterative_hash_expr (TREE_REALPART (t), val);
5210       return iterative_hash_expr (TREE_IMAGPART (t), val);
5211     case VECTOR_CST:
5212       return iterative_hash_expr (TREE_VECTOR_CST_ELTS (t), val);
5213
5214     case SSA_NAME:
5215     case VALUE_HANDLE:
5216       /* we can just compare by pointer.  */
5217       return iterative_hash_pointer (t, val);
5218
5219     case TREE_LIST:
5220       /* A list of expressions, for a CALL_EXPR or as the elements of a
5221          VECTOR_CST.  */
5222       for (; t; t = TREE_CHAIN (t))
5223         val = iterative_hash_expr (TREE_VALUE (t), val);
5224       return val;
5225     case CONSTRUCTOR:
5226       {
5227         unsigned HOST_WIDE_INT idx;
5228         tree field, value;
5229         FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), idx, field, value)
5230           {
5231             val = iterative_hash_expr (field, val);
5232             val = iterative_hash_expr (value, val);
5233           }
5234         return val;
5235       }
5236     case FUNCTION_DECL:
5237       /* When referring to a built-in FUNCTION_DECL, use the
5238          __builtin__ form.  Otherwise nodes that compare equal
5239          according to operand_equal_p might get different
5240          hash codes.  */
5241       if (DECL_BUILT_IN (t))
5242         {
5243           val = iterative_hash_pointer (built_in_decls[DECL_FUNCTION_CODE (t)],
5244                                       val);
5245           return val;
5246         }
5247       /* else FALL THROUGH */
5248     default:
5249       class = TREE_CODE_CLASS (code);
5250
5251       if (class == tcc_declaration)
5252         {
5253           /* DECL's have a unique ID */
5254           val = iterative_hash_host_wide_int (DECL_UID (t), val);
5255         }
5256       else
5257         {
5258           gcc_assert (IS_EXPR_CODE_CLASS (class));
5259
5260           val = iterative_hash_object (code, val);
5261
5262           /* Don't hash the type, that can lead to having nodes which
5263              compare equal according to operand_equal_p, but which
5264              have different hash codes.  */
5265           if (code == NOP_EXPR
5266               || code == CONVERT_EXPR
5267               || code == NON_LVALUE_EXPR)
5268             {
5269               /* Make sure to include signness in the hash computation.  */
5270               val += TYPE_UNSIGNED (TREE_TYPE (t));
5271               val = iterative_hash_expr (TREE_OPERAND (t, 0), val);
5272             }
5273
5274           else if (commutative_tree_code (code))
5275             {
5276               /* It's a commutative expression.  We want to hash it the same
5277                  however it appears.  We do this by first hashing both operands
5278                  and then rehashing based on the order of their independent
5279                  hashes.  */
5280               hashval_t one = iterative_hash_expr (TREE_OPERAND (t, 0), 0);
5281               hashval_t two = iterative_hash_expr (TREE_OPERAND (t, 1), 0);
5282               hashval_t t;
5283
5284               if (one > two)
5285                 t = one, one = two, two = t;
5286
5287               val = iterative_hash_hashval_t (one, val);
5288               val = iterative_hash_hashval_t (two, val);
5289             }
5290           else
5291             for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i)
5292               val = iterative_hash_expr (TREE_OPERAND (t, i), val);
5293         }
5294       return val;
5295       break;
5296     }
5297 }
5298 \f
5299 /* Constructors for pointer, array and function types.
5300    (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
5301    constructed by language-dependent code, not here.)  */
5302
5303 /* Construct, lay out and return the type of pointers to TO_TYPE with
5304    mode MODE.  If CAN_ALIAS_ALL is TRUE, indicate this type can
5305    reference all of memory. If such a type has already been
5306    constructed, reuse it.  */
5307
5308 tree
5309 build_pointer_type_for_mode (tree to_type, enum machine_mode mode,
5310                              bool can_alias_all)
5311 {
5312   tree t;
5313
5314   if (to_type == error_mark_node)
5315     return error_mark_node;
5316
5317   /* In some cases, languages will have things that aren't a POINTER_TYPE
5318      (such as a RECORD_TYPE for fat pointers in Ada) as TYPE_POINTER_TO.
5319      In that case, return that type without regard to the rest of our
5320      operands.
5321
5322      ??? This is a kludge, but consistent with the way this function has
5323      always operated and there doesn't seem to be a good way to avoid this
5324      at the moment.  */
5325   if (TYPE_POINTER_TO (to_type) != 0
5326       && TREE_CODE (TYPE_POINTER_TO (to_type)) != POINTER_TYPE)
5327     return TYPE_POINTER_TO (to_type);
5328
5329   /* First, if we already have a type for pointers to TO_TYPE and it's
5330      the proper mode, use it.  */
5331   for (t = TYPE_POINTER_TO (to_type); t; t = TYPE_NEXT_PTR_TO (t))
5332     if (TYPE_MODE (t) == mode && TYPE_REF_CAN_ALIAS_ALL (t) == can_alias_all)
5333       return t;
5334
5335   t = make_node (POINTER_TYPE);
5336
5337   TREE_TYPE (t) = to_type;
5338   TYPE_MODE (t) = mode;
5339   TYPE_REF_CAN_ALIAS_ALL (t) = can_alias_all;
5340   TYPE_NEXT_PTR_TO (t) = TYPE_POINTER_TO (to_type);
5341   TYPE_POINTER_TO (to_type) = t;
5342
5343   if (TYPE_STRUCTURAL_EQUALITY_P (to_type))
5344     SET_TYPE_STRUCTURAL_EQUALITY (t);
5345   else if (TYPE_CANONICAL (to_type) != to_type)
5346     TYPE_CANONICAL (t)
5347       = build_pointer_type_for_mode (TYPE_CANONICAL (to_type),
5348                                      mode, can_alias_all);
5349
5350   /* Lay out the type.  This function has many callers that are concerned
5351      with expression-construction, and this simplifies them all.  */
5352   layout_type (t);
5353
5354   return t;
5355 }
5356
5357 /* By default build pointers in ptr_mode.  */
5358
5359 tree
5360 build_pointer_type (tree to_type)
5361 {
5362   return build_pointer_type_for_mode (to_type, ptr_mode, false);
5363 }
5364
5365 /* Same as build_pointer_type_for_mode, but for REFERENCE_TYPE.  */
5366
5367 tree
5368 build_reference_type_for_mode (tree to_type, enum machine_mode mode,
5369                                bool can_alias_all)
5370 {
5371   tree t;
5372
5373   /* In some cases, languages will have things that aren't a REFERENCE_TYPE
5374      (such as a RECORD_TYPE for fat pointers in Ada) as TYPE_REFERENCE_TO.
5375      In that case, return that type without regard to the rest of our
5376      operands.
5377
5378      ??? This is a kludge, but consistent with the way this function has
5379      always operated and there doesn't seem to be a good way to avoid this
5380      at the moment.  */
5381   if (TYPE_REFERENCE_TO (to_type) != 0
5382       && TREE_CODE (TYPE_REFERENCE_TO (to_type)) != REFERENCE_TYPE)
5383     return TYPE_REFERENCE_TO (to_type);
5384
5385   /* First, if we already have a type for pointers to TO_TYPE and it's
5386      the proper mode, use it.  */
5387   for (t = TYPE_REFERENCE_TO (to_type); t; t = TYPE_NEXT_REF_TO (t))
5388     if (TYPE_MODE (t) == mode && TYPE_REF_CAN_ALIAS_ALL (t) == can_alias_all)
5389       return t;
5390
5391   t = make_node (REFERENCE_TYPE);
5392
5393   TREE_TYPE (t) = to_type;
5394   TYPE_MODE (t) = mode;
5395   TYPE_REF_CAN_ALIAS_ALL (t) = can_alias_all;
5396   TYPE_NEXT_REF_TO (t) = TYPE_REFERENCE_TO (to_type);
5397   TYPE_REFERENCE_TO (to_type) = t;
5398
5399   if (TYPE_STRUCTURAL_EQUALITY_P (to_type))
5400     SET_TYPE_STRUCTURAL_EQUALITY (t);
5401   else if (TYPE_CANONICAL (to_type) != to_type)
5402     TYPE_CANONICAL (t)
5403       = build_reference_type_for_mode (TYPE_CANONICAL (to_type),
5404                                        mode, can_alias_all);
5405
5406   layout_type (t);
5407
5408   return t;
5409 }
5410
5411
5412 /* Build the node for the type of references-to-TO_TYPE by default
5413    in ptr_mode.  */
5414
5415 tree
5416 build_reference_type (tree to_type)
5417 {
5418   return build_reference_type_for_mode (to_type, ptr_mode, false);
5419 }
5420
5421 /* Build a type that is compatible with t but has no cv quals anywhere
5422    in its type, thus
5423
5424    const char *const *const *  ->  char ***.  */
5425
5426 tree
5427 build_type_no_quals (tree t)
5428 {
5429   switch (TREE_CODE (t))
5430     {
5431     case POINTER_TYPE:
5432       return build_pointer_type_for_mode (build_type_no_quals (TREE_TYPE (t)),
5433                                           TYPE_MODE (t),
5434                                           TYPE_REF_CAN_ALIAS_ALL (t));
5435     case REFERENCE_TYPE:
5436       return
5437         build_reference_type_for_mode (build_type_no_quals (TREE_TYPE (t)),
5438                                        TYPE_MODE (t),
5439                                        TYPE_REF_CAN_ALIAS_ALL (t));
5440     default:
5441       return TYPE_MAIN_VARIANT (t);
5442     }
5443 }
5444
5445 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
5446    MAXVAL should be the maximum value in the domain
5447    (one less than the length of the array).
5448
5449    The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
5450    We don't enforce this limit, that is up to caller (e.g. language front end).
5451    The limit exists because the result is a signed type and we don't handle
5452    sizes that use more than one HOST_WIDE_INT.  */
5453
5454 tree
5455 build_index_type (tree maxval)
5456 {
5457   tree itype = make_node (INTEGER_TYPE);
5458
5459   TREE_TYPE (itype) = sizetype;
5460   TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
5461   TYPE_MIN_VALUE (itype) = size_zero_node;
5462   TYPE_MAX_VALUE (itype) = fold_convert (sizetype, maxval);
5463   TYPE_MODE (itype) = TYPE_MODE (sizetype);
5464   TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
5465   TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (sizetype);
5466   TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
5467   TYPE_USER_ALIGN (itype) = TYPE_USER_ALIGN (sizetype);
5468
5469   if (host_integerp (maxval, 1))
5470     return type_hash_canon (tree_low_cst (maxval, 1), itype);
5471   else
5472     {
5473       /* Since we cannot hash this type, we need to compare it using
5474          structural equality checks. */
5475       SET_TYPE_STRUCTURAL_EQUALITY (itype);
5476       return itype;
5477     }
5478 }
5479
5480 /* Builds a signed or unsigned integer type of precision PRECISION.
5481    Used for C bitfields whose precision does not match that of
5482    built-in target types.  */
5483 tree
5484 build_nonstandard_integer_type (unsigned HOST_WIDE_INT precision,
5485                                 int unsignedp)
5486 {
5487   tree itype = make_node (INTEGER_TYPE);
5488
5489   TYPE_PRECISION (itype) = precision;
5490
5491   if (unsignedp)
5492     fixup_unsigned_type (itype);
5493   else
5494     fixup_signed_type (itype);
5495
5496   if (host_integerp (TYPE_MAX_VALUE (itype), 1))
5497     return type_hash_canon (tree_low_cst (TYPE_MAX_VALUE (itype), 1), itype);
5498
5499   return itype;
5500 }
5501
5502 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
5503    ENUMERAL_TYPE or BOOLEAN_TYPE), with low bound LOWVAL and
5504    high bound HIGHVAL.  If TYPE is NULL, sizetype is used.  */
5505
5506 tree
5507 build_range_type (tree type, tree lowval, tree highval)
5508 {
5509   tree itype = make_node (INTEGER_TYPE);
5510
5511   TREE_TYPE (itype) = type;
5512   if (type == NULL_TREE)
5513     type = sizetype;
5514
5515   TYPE_MIN_VALUE (itype) = fold_convert (type, lowval);
5516   TYPE_MAX_VALUE (itype) = highval ? fold_convert (type, highval) : NULL;
5517
5518   TYPE_PRECISION (itype) = TYPE_PRECISION (type);
5519   TYPE_MODE (itype) = TYPE_MODE (type);
5520   TYPE_SIZE (itype) = TYPE_SIZE (type);
5521   TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (type);
5522   TYPE_ALIGN (itype) = TYPE_ALIGN (type);
5523   TYPE_USER_ALIGN (itype) = TYPE_USER_ALIGN (type);
5524
5525   if (host_integerp (lowval, 0) && highval != 0 && host_integerp (highval, 0))
5526     return type_hash_canon (tree_low_cst (highval, 0)
5527                             - tree_low_cst (lowval, 0),
5528                             itype);
5529   else
5530     return itype;
5531 }
5532
5533 /* Just like build_index_type, but takes lowval and highval instead
5534    of just highval (maxval).  */
5535
5536 tree
5537 build_index_2_type (tree lowval, tree highval)
5538 {
5539   return build_range_type (sizetype, lowval, highval);
5540 }
5541
5542 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
5543    and number of elements specified by the range of values of INDEX_TYPE.
5544    If such a type has already been constructed, reuse it.  */
5545
5546 tree
5547 build_array_type (tree elt_type, tree index_type)
5548 {
5549   tree t;
5550   hashval_t hashcode = 0;
5551
5552   if (TREE_CODE (elt_type) == FUNCTION_TYPE)
5553     {
5554       error ("arrays of functions are not meaningful");
5555       elt_type = integer_type_node;
5556     }
5557
5558   t = make_node (ARRAY_TYPE);
5559   TREE_TYPE (t) = elt_type;
5560   TYPE_DOMAIN (t) = index_type;
5561
5562   if (index_type == 0)
5563     {
5564       tree save = t;
5565       hashcode = iterative_hash_object (TYPE_HASH (elt_type), hashcode);
5566       t = type_hash_canon (hashcode, t);
5567       if (save == t)
5568         layout_type (t);
5569
5570       if (TYPE_CANONICAL (t) == t)
5571         {
5572           if (TYPE_STRUCTURAL_EQUALITY_P (elt_type))
5573             SET_TYPE_STRUCTURAL_EQUALITY (t);
5574           else if (TYPE_CANONICAL (elt_type) != elt_type)
5575             TYPE_CANONICAL (t)
5576               = build_array_type (TYPE_CANONICAL (elt_type), index_type);
5577         }
5578
5579       return t;
5580     }
5581
5582   hashcode = iterative_hash_object (TYPE_HASH (elt_type), hashcode);
5583   hashcode = iterative_hash_object (TYPE_HASH (index_type), hashcode);
5584   t = type_hash_canon (hashcode, t);
5585
5586   if (!COMPLETE_TYPE_P (t))
5587     layout_type (t);
5588
5589   if (TYPE_CANONICAL (t) == t)
5590     {
5591       if (TYPE_STRUCTURAL_EQUALITY_P (elt_type)
5592           || TYPE_STRUCTURAL_EQUALITY_P (index_type))
5593         SET_TYPE_STRUCTURAL_EQUALITY (t);
5594       else if (TYPE_CANONICAL (elt_type) != elt_type
5595                || TYPE_CANONICAL (index_type) != index_type)
5596         TYPE_CANONICAL (t)
5597           = build_array_type (TYPE_CANONICAL (elt_type),
5598                               TYPE_CANONICAL (index_type));
5599     }
5600
5601   return t;
5602 }
5603
5604 /* Return the TYPE of the elements comprising
5605    the innermost dimension of ARRAY.  */
5606
5607 tree
5608 get_inner_array_type (tree array)
5609 {
5610   tree type = TREE_TYPE (array);
5611
5612   while (TREE_CODE (type) == ARRAY_TYPE)
5613     type = TREE_TYPE (type);
5614
5615   return type;
5616 }
5617
5618 /* Construct, lay out and return
5619    the type of functions returning type VALUE_TYPE
5620    given arguments of types ARG_TYPES.
5621    ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
5622    are data type nodes for the arguments of the function.
5623    If such a type has already been constructed, reuse it.  */
5624
5625 tree
5626 build_function_type (tree value_type, tree arg_types)
5627 {
5628   tree t;
5629   hashval_t hashcode = 0;
5630
5631   if (TREE_CODE (value_type) == FUNCTION_TYPE)
5632     {
5633       error ("function return type cannot be function");
5634       value_type = integer_type_node;
5635     }
5636
5637   /* Make a node of the sort we want.  */
5638   t = make_node (FUNCTION_TYPE);
5639   TREE_TYPE (t) = value_type;
5640   TYPE_ARG_TYPES (t) = arg_types;
5641
5642   /* We don't have canonicalization of function types, yet. */
5643   SET_TYPE_STRUCTURAL_EQUALITY (t);
5644
5645   /* If we already have such a type, use the old one.  */
5646   hashcode = iterative_hash_object (TYPE_HASH (value_type), hashcode);
5647   hashcode = type_hash_list (arg_types, hashcode);
5648   t = type_hash_canon (hashcode, t);
5649
5650   if (!COMPLETE_TYPE_P (t))
5651     layout_type (t);
5652   return t;
5653 }
5654
5655 /* Build a function type.  The RETURN_TYPE is the type returned by the
5656    function.  If additional arguments are provided, they are
5657    additional argument types.  The list of argument types must always
5658    be terminated by NULL_TREE.  */
5659
5660 tree
5661 build_function_type_list (tree return_type, ...)
5662 {
5663   tree t, args, last;
5664   va_list p;
5665
5666   va_start (p, return_type);
5667
5668   t = va_arg (p, tree);
5669   for (args = NULL_TREE; t != NULL_TREE; t = va_arg (p, tree))
5670     args = tree_cons (NULL_TREE, t, args);
5671
5672   if (args == NULL_TREE)
5673     args = void_list_node;
5674   else
5675     {
5676       last = args;
5677       args = nreverse (args);
5678       TREE_CHAIN (last) = void_list_node;
5679     }
5680   args = build_function_type (return_type, args);
5681
5682   va_end (p);
5683   return args;
5684 }
5685
5686 /* Build a METHOD_TYPE for a member of BASETYPE.  The RETTYPE (a TYPE)
5687    and ARGTYPES (a TREE_LIST) are the return type and arguments types
5688    for the method.  An implicit additional parameter (of type
5689    pointer-to-BASETYPE) is added to the ARGTYPES.  */
5690
5691 tree
5692 build_method_type_directly (tree basetype,
5693                             tree rettype,
5694                             tree argtypes)
5695 {
5696   tree t;
5697   tree ptype;
5698   int hashcode = 0;
5699
5700   /* Make a node of the sort we want.  */
5701   t = make_node (METHOD_TYPE);
5702
5703   TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
5704   TREE_TYPE (t) = rettype;
5705   ptype = build_pointer_type (basetype);
5706
5707   /* The actual arglist for this function includes a "hidden" argument
5708      which is "this".  Put it into the list of argument types.  */
5709   argtypes = tree_cons (NULL_TREE, ptype, argtypes);
5710   TYPE_ARG_TYPES (t) = argtypes;
5711
5712   /* We don't have canonicalization of method types yet. */
5713   SET_TYPE_STRUCTURAL_EQUALITY (t);
5714
5715   /* If we already have such a type, use the old one.  */
5716   hashcode = iterative_hash_object (TYPE_HASH (basetype), hashcode);
5717   hashcode = iterative_hash_object (TYPE_HASH (rettype), hashcode);
5718   hashcode = type_hash_list (argtypes, hashcode);
5719   t = type_hash_canon (hashcode, t);
5720
5721   if (!COMPLETE_TYPE_P (t))
5722     layout_type (t);
5723
5724   return t;
5725 }
5726
5727 /* Construct, lay out and return the type of methods belonging to class
5728    BASETYPE and whose arguments and values are described by TYPE.
5729    If that type exists already, reuse it.
5730    TYPE must be a FUNCTION_TYPE node.  */
5731
5732 tree
5733 build_method_type (tree basetype, tree type)
5734 {
5735   gcc_assert (TREE_CODE (type) == FUNCTION_TYPE);
5736
5737   return build_method_type_directly (basetype,
5738                                      TREE_TYPE (type),
5739                                      TYPE_ARG_TYPES (type));
5740 }
5741
5742 /* Construct, lay out and return the type of offsets to a value
5743    of type TYPE, within an object of type BASETYPE.
5744    If a suitable offset type exists already, reuse it.  */
5745
5746 tree
5747 build_offset_type (tree basetype, tree type)
5748 {
5749   tree t;
5750   hashval_t hashcode = 0;
5751
5752   /* Make a node of the sort we want.  */
5753   t = make_node (OFFSET_TYPE);
5754
5755   TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
5756   TREE_TYPE (t) = type;
5757
5758   /* If we already have such a type, use the old one.  */
5759   hashcode = iterative_hash_object (TYPE_HASH (basetype), hashcode);
5760   hashcode = iterative_hash_object (TYPE_HASH (type), hashcode);
5761   t = type_hash_canon (hashcode, t);
5762
5763   if (!COMPLETE_TYPE_P (t))
5764     layout_type (t);
5765
5766   if (TYPE_CANONICAL (t) == t)
5767     {
5768       if (TYPE_STRUCTURAL_EQUALITY_P (basetype)
5769           || TYPE_STRUCTURAL_EQUALITY_P (type))
5770         SET_TYPE_STRUCTURAL_EQUALITY (t);
5771       else if (TYPE_CANONICAL (basetype) != basetype
5772                || TYPE_CANONICAL (type) != type)
5773         TYPE_CANONICAL (t)
5774           = build_offset_type (TYPE_CANONICAL (basetype),
5775                                TYPE_CANONICAL (type));
5776     }
5777
5778   return t;
5779 }
5780
5781 /* Create a complex type whose components are COMPONENT_TYPE.  */
5782
5783 tree
5784 build_complex_type (tree component_type)
5785 {
5786   tree t;
5787   hashval_t hashcode;
5788
5789   /* Make a node of the sort we want.  */
5790   t = make_node (COMPLEX_TYPE);
5791
5792   TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
5793
5794   /* If we already have such a type, use the old one.  */
5795   hashcode = iterative_hash_object (TYPE_HASH (component_type), 0);
5796   t = type_hash_canon (hashcode, t);
5797
5798   if (!COMPLETE_TYPE_P (t))
5799     layout_type (t);
5800
5801   if (TYPE_CANONICAL (t) == t)
5802     {
5803       if (TYPE_STRUCTURAL_EQUALITY_P (component_type))
5804         SET_TYPE_STRUCTURAL_EQUALITY (t);
5805       else if (TYPE_CANONICAL (component_type) != component_type)
5806         TYPE_CANONICAL (t)
5807           = build_complex_type (TYPE_CANONICAL (component_type));
5808     }
5809
5810   /* If we are writing Dwarf2 output we need to create a name,
5811      since complex is a fundamental type.  */
5812   if ((write_symbols == DWARF2_DEBUG || write_symbols == VMS_AND_DWARF2_DEBUG)
5813       && ! TYPE_NAME (t))
5814     {
5815       const char *name;
5816       if (component_type == char_type_node)
5817         name = "complex char";
5818       else if (component_type == signed_char_type_node)
5819         name = "complex signed char";
5820       else if (component_type == unsigned_char_type_node)
5821         name = "complex unsigned char";
5822       else if (component_type == short_integer_type_node)
5823         name = "complex short int";
5824       else if (component_type == short_unsigned_type_node)
5825         name = "complex short unsigned int";
5826       else if (component_type == integer_type_node)
5827         name = "complex int";
5828       else if (component_type == unsigned_type_node)
5829         name = "complex unsigned int";
5830       else if (component_type == long_integer_type_node)
5831         name = "complex long int";
5832       else if (component_type == long_unsigned_type_node)
5833         name = "complex long unsigned int";
5834       else if (component_type == long_long_integer_type_node)
5835         name = "complex long long int";
5836       else if (component_type == long_long_unsigned_type_node)
5837         name = "complex long long unsigned int";
5838       else
5839         name = 0;
5840
5841       if (name != 0)
5842         TYPE_NAME (t) = build_decl (TYPE_DECL, get_identifier (name), t);
5843     }
5844
5845   return build_qualified_type (t, TYPE_QUALS (component_type));
5846 }
5847 \f
5848 /* Return OP, stripped of any conversions to wider types as much as is safe.
5849    Converting the value back to OP's type makes a value equivalent to OP.
5850
5851    If FOR_TYPE is nonzero, we return a value which, if converted to
5852    type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
5853
5854    If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
5855    narrowest type that can hold the value, even if they don't exactly fit.
5856    Otherwise, bit-field references are changed to a narrower type
5857    only if they can be fetched directly from memory in that type.
5858
5859    OP must have integer, real or enumeral type.  Pointers are not allowed!
5860
5861    There are some cases where the obvious value we could return
5862    would regenerate to OP if converted to OP's type,
5863    but would not extend like OP to wider types.
5864    If FOR_TYPE indicates such extension is contemplated, we eschew such values.
5865    For example, if OP is (unsigned short)(signed char)-1,
5866    we avoid returning (signed char)-1 if FOR_TYPE is int,
5867    even though extending that to an unsigned short would regenerate OP,
5868    since the result of extending (signed char)-1 to (int)
5869    is different from (int) OP.  */
5870
5871 tree
5872 get_unwidened (tree op, tree for_type)
5873 {
5874   /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension.  */
5875   tree type = TREE_TYPE (op);
5876   unsigned final_prec
5877     = TYPE_PRECISION (for_type != 0 ? for_type : type);
5878   int uns
5879     = (for_type != 0 && for_type != type
5880        && final_prec > TYPE_PRECISION (type)
5881        && TYPE_UNSIGNED (type));
5882   tree win = op;
5883
5884   while (TREE_CODE (op) == NOP_EXPR
5885          || TREE_CODE (op) == CONVERT_EXPR)
5886     {
5887       int bitschange;
5888
5889       /* TYPE_PRECISION on vector types has different meaning
5890          (TYPE_VECTOR_SUBPARTS) and casts from vectors are view conversions,
5891          so avoid them here.  */
5892       if (TREE_CODE (TREE_TYPE (TREE_OPERAND (op, 0))) == VECTOR_TYPE)
5893         break;
5894
5895       bitschange = TYPE_PRECISION (TREE_TYPE (op))
5896                    - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
5897
5898       /* Truncations are many-one so cannot be removed.
5899          Unless we are later going to truncate down even farther.  */
5900       if (bitschange < 0
5901           && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
5902         break;
5903
5904       /* See what's inside this conversion.  If we decide to strip it,
5905          we will set WIN.  */
5906       op = TREE_OPERAND (op, 0);
5907
5908       /* If we have not stripped any zero-extensions (uns is 0),
5909          we can strip any kind of extension.
5910          If we have previously stripped a zero-extension,
5911          only zero-extensions can safely be stripped.
5912          Any extension can be stripped if the bits it would produce
5913          are all going to be discarded later by truncating to FOR_TYPE.  */
5914
5915       if (bitschange > 0)
5916         {
5917           if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
5918             win = op;
5919           /* TYPE_UNSIGNED says whether this is a zero-extension.
5920              Let's avoid computing it if it does not affect WIN
5921              and if UNS will not be needed again.  */
5922           if ((uns
5923                || TREE_CODE (op) == NOP_EXPR
5924                || TREE_CODE (op) == CONVERT_EXPR)
5925               && TYPE_UNSIGNED (TREE_TYPE (op)))
5926             {
5927               uns = 1;
5928               win = op;
5929             }
5930         }
5931     }
5932
5933   if (TREE_CODE (op) == COMPONENT_REF
5934       /* Since type_for_size always gives an integer type.  */
5935       && TREE_CODE (type) != REAL_TYPE
5936       /* Don't crash if field not laid out yet.  */
5937       && DECL_SIZE (TREE_OPERAND (op, 1)) != 0
5938       && host_integerp (DECL_SIZE (TREE_OPERAND (op, 1)), 1))
5939     {
5940       unsigned int innerprec
5941         = tree_low_cst (DECL_SIZE (TREE_OPERAND (op, 1)), 1);
5942       int unsignedp = (DECL_UNSIGNED (TREE_OPERAND (op, 1))
5943                        || TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op, 1))));
5944       type = lang_hooks.types.type_for_size (innerprec, unsignedp);
5945
5946       /* We can get this structure field in the narrowest type it fits in.
5947          If FOR_TYPE is 0, do this only for a field that matches the
5948          narrower type exactly and is aligned for it
5949          The resulting extension to its nominal type (a fullword type)
5950          must fit the same conditions as for other extensions.  */
5951
5952       if (type != 0
5953           && INT_CST_LT_UNSIGNED (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (op)))
5954           && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
5955           && (! uns || final_prec <= innerprec || unsignedp))
5956         {
5957           win = build3 (COMPONENT_REF, type, TREE_OPERAND (op, 0),
5958                         TREE_OPERAND (op, 1), NULL_TREE);
5959           TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
5960           TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
5961         }
5962     }
5963
5964   return win;
5965 }
5966 \f
5967 /* Return OP or a simpler expression for a narrower value
5968    which can be sign-extended or zero-extended to give back OP.
5969    Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
5970    or 0 if the value should be sign-extended.  */
5971
5972 tree
5973 get_narrower (tree op, int *unsignedp_ptr)
5974 {
5975   int uns = 0;
5976   int first = 1;
5977   tree win = op;
5978   bool integral_p = INTEGRAL_TYPE_P (TREE_TYPE (op));
5979
5980   while (TREE_CODE (op) == NOP_EXPR)
5981     {
5982       int bitschange
5983         = (TYPE_PRECISION (TREE_TYPE (op))
5984            - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0))));
5985
5986       /* Truncations are many-one so cannot be removed.  */
5987       if (bitschange < 0)
5988         break;
5989
5990       /* See what's inside this conversion.  If we decide to strip it,
5991          we will set WIN.  */
5992
5993       if (bitschange > 0)
5994         {
5995           op = TREE_OPERAND (op, 0);
5996           /* An extension: the outermost one can be stripped,
5997              but remember whether it is zero or sign extension.  */
5998           if (first)
5999             uns = TYPE_UNSIGNED (TREE_TYPE (op));
6000           /* Otherwise, if a sign extension has been stripped,
6001              only sign extensions can now be stripped;
6002              if a zero extension has been stripped, only zero-extensions.  */
6003           else if (uns != TYPE_UNSIGNED (TREE_TYPE (op)))
6004             break;
6005           first = 0;
6006         }
6007       else /* bitschange == 0 */
6008         {
6009           /* A change in nominal type can always be stripped, but we must
6010              preserve the unsignedness.  */
6011           if (first)
6012             uns = TYPE_UNSIGNED (TREE_TYPE (op));
6013           first = 0;
6014           op = TREE_OPERAND (op, 0);
6015           /* Keep trying to narrow, but don't assign op to win if it
6016              would turn an integral type into something else.  */
6017           if (INTEGRAL_TYPE_P (TREE_TYPE (op)) != integral_p)
6018             continue;
6019         }
6020
6021       win = op;
6022     }
6023
6024   if (TREE_CODE (op) == COMPONENT_REF
6025       /* Since type_for_size always gives an integer type.  */
6026       && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE
6027       /* Ensure field is laid out already.  */
6028       && DECL_SIZE (TREE_OPERAND (op, 1)) != 0
6029       && host_integerp (DECL_SIZE (TREE_OPERAND (op, 1)), 1))
6030     {
6031       unsigned HOST_WIDE_INT innerprec
6032         = tree_low_cst (DECL_SIZE (TREE_OPERAND (op, 1)), 1);
6033       int unsignedp = (DECL_UNSIGNED (TREE_OPERAND (op, 1))
6034                        || TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op, 1))));
6035       tree type = lang_hooks.types.type_for_size (innerprec, unsignedp);
6036
6037       /* We can get this structure field in a narrower type that fits it,
6038          but the resulting extension to its nominal type (a fullword type)
6039          must satisfy the same conditions as for other extensions.
6040
6041          Do this only for fields that are aligned (not bit-fields),
6042          because when bit-field insns will be used there is no
6043          advantage in doing this.  */
6044
6045       if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
6046           && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
6047           && (first || uns == DECL_UNSIGNED (TREE_OPERAND (op, 1)))
6048           && type != 0)
6049         {
6050           if (first)
6051             uns = DECL_UNSIGNED (TREE_OPERAND (op, 1));
6052           win = fold_convert (type, op);
6053         }
6054     }
6055
6056   *unsignedp_ptr = uns;
6057   return win;
6058 }
6059 \f
6060 /* Nonzero if integer constant C has a value that is permissible
6061    for type TYPE (an INTEGER_TYPE).  */
6062
6063 int
6064 int_fits_type_p (tree c, tree type)
6065 {
6066   tree type_low_bound = TYPE_MIN_VALUE (type);
6067   tree type_high_bound = TYPE_MAX_VALUE (type);
6068   bool ok_for_low_bound, ok_for_high_bound;
6069   unsigned HOST_WIDE_INT low;
6070   HOST_WIDE_INT high;
6071
6072   /* If at least one bound of the type is a constant integer, we can check
6073      ourselves and maybe make a decision. If no such decision is possible, but
6074      this type is a subtype, try checking against that.  Otherwise, use
6075      fit_double_type, which checks against the precision.
6076
6077      Compute the status for each possibly constant bound, and return if we see
6078      one does not match. Use ok_for_xxx_bound for this purpose, assigning -1
6079      for "unknown if constant fits", 0 for "constant known *not* to fit" and 1
6080      for "constant known to fit".  */
6081
6082   /* Check if C >= type_low_bound.  */
6083   if (type_low_bound && TREE_CODE (type_low_bound) == INTEGER_CST)
6084     {
6085       if (tree_int_cst_lt (c, type_low_bound))
6086         return 0;
6087       ok_for_low_bound = true;
6088     }
6089   else
6090     ok_for_low_bound = false;
6091
6092   /* Check if c <= type_high_bound.  */
6093   if (type_high_bound && TREE_CODE (type_high_bound) == INTEGER_CST)
6094     {
6095       if (tree_int_cst_lt (type_high_bound, c))
6096         return 0;
6097       ok_for_high_bound = true;
6098     }
6099   else
6100     ok_for_high_bound = false;
6101
6102   /* If the constant fits both bounds, the result is known.  */
6103   if (ok_for_low_bound && ok_for_high_bound)
6104     return 1;
6105
6106   /* Perform some generic filtering which may allow making a decision
6107      even if the bounds are not constant.  First, negative integers
6108      never fit in unsigned types, */
6109   if (TYPE_UNSIGNED (type) && tree_int_cst_sgn (c) < 0)
6110     return 0;
6111
6112   /* Second, narrower types always fit in wider ones.  */
6113   if (TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (c)))
6114     return 1;
6115
6116   /* Third, unsigned integers with top bit set never fit signed types.  */
6117   if (! TYPE_UNSIGNED (type)
6118       && TYPE_UNSIGNED (TREE_TYPE (c))
6119       && tree_int_cst_msb (c))
6120     return 0;
6121
6122   /* If we haven't been able to decide at this point, there nothing more we
6123      can check ourselves here.  Look at the base type if we have one and it
6124      has the same precision.  */
6125   if (TREE_CODE (type) == INTEGER_TYPE
6126       && TREE_TYPE (type) != 0
6127       && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (type)))
6128     return int_fits_type_p (c, TREE_TYPE (type));
6129
6130   /* Or to fit_double_type, if nothing else.  */
6131   low = TREE_INT_CST_LOW (c);
6132   high = TREE_INT_CST_HIGH (c);
6133   return !fit_double_type (low, high, &low, &high, type);
6134 }
6135
6136 /* Stores bounds of an integer TYPE in MIN and MAX.  If TYPE has non-constant
6137    bounds or is a POINTER_TYPE, the maximum and/or minimum values that can be
6138    represented (assuming two's-complement arithmetic) within the bit
6139    precision of the type are returned instead.  */
6140
6141 void
6142 get_type_static_bounds (tree type, mpz_t min, mpz_t max)
6143 {
6144   if (!POINTER_TYPE_P (type) && TYPE_MIN_VALUE (type)
6145       && TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST)
6146     mpz_set_double_int (min, tree_to_double_int (TYPE_MIN_VALUE (type)),
6147                         TYPE_UNSIGNED (type));
6148   else
6149     {
6150       if (TYPE_UNSIGNED (type))
6151         mpz_set_ui (min, 0);
6152       else
6153         {
6154           double_int mn;
6155           mn = double_int_mask (TYPE_PRECISION (type) - 1);
6156           mn = double_int_sext (double_int_add (mn, double_int_one),
6157                                 TYPE_PRECISION (type));
6158           mpz_set_double_int (min, mn, false);
6159         }
6160     }
6161
6162   if (!POINTER_TYPE_P (type) && TYPE_MAX_VALUE (type)
6163       && TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST)
6164     mpz_set_double_int (max, tree_to_double_int (TYPE_MAX_VALUE (type)),
6165                         TYPE_UNSIGNED (type));
6166   else
6167     {
6168       if (TYPE_UNSIGNED (type))
6169         mpz_set_double_int (max, double_int_mask (TYPE_PRECISION (type)),
6170                             true);
6171       else
6172         mpz_set_double_int (max, double_int_mask (TYPE_PRECISION (type) - 1),
6173                             true);
6174     }
6175 }
6176
6177 /* Subprogram of following function.  Called by walk_tree.
6178
6179    Return *TP if it is an automatic variable or parameter of the
6180    function passed in as DATA.  */
6181
6182 static tree
6183 find_var_from_fn (tree *tp, int *walk_subtrees, void *data)
6184 {
6185   tree fn = (tree) data;
6186
6187   if (TYPE_P (*tp))
6188     *walk_subtrees = 0;
6189
6190   else if (DECL_P (*tp)
6191            && lang_hooks.tree_inlining.auto_var_in_fn_p (*tp, fn))
6192     return *tp;
6193
6194   return NULL_TREE;
6195 }
6196
6197 /* Returns true if T is, contains, or refers to a type with variable
6198    size.  For METHOD_TYPEs and FUNCTION_TYPEs we exclude the
6199    arguments, but not the return type.  If FN is nonzero, only return
6200    true if a modifier of the type or position of FN is a variable or
6201    parameter inside FN.
6202
6203    This concept is more general than that of C99 'variably modified types':
6204    in C99, a struct type is never variably modified because a VLA may not
6205    appear as a structure member.  However, in GNU C code like:
6206
6207      struct S { int i[f()]; };
6208
6209    is valid, and other languages may define similar constructs.  */
6210
6211 bool
6212 variably_modified_type_p (tree type, tree fn)
6213 {
6214   tree t;
6215
6216 /* Test if T is either variable (if FN is zero) or an expression containing
6217    a variable in FN.  */
6218 #define RETURN_TRUE_IF_VAR(T)                                           \
6219   do { tree _t = (T);                                                   \
6220     if (_t && _t != error_mark_node && TREE_CODE (_t) != INTEGER_CST    \
6221         && (!fn || walk_tree (&_t, find_var_from_fn, fn, NULL)))        \
6222       return true;  } while (0)
6223
6224   if (type == error_mark_node)
6225     return false;
6226
6227   /* If TYPE itself has variable size, it is variably modified.  */
6228   RETURN_TRUE_IF_VAR (TYPE_SIZE (type));
6229   RETURN_TRUE_IF_VAR (TYPE_SIZE_UNIT (type));
6230
6231   switch (TREE_CODE (type))
6232     {
6233     case POINTER_TYPE:
6234     case REFERENCE_TYPE:
6235     case VECTOR_TYPE:
6236       if (variably_modified_type_p (TREE_TYPE (type), fn))
6237         return true;
6238       break;
6239
6240     case FUNCTION_TYPE:
6241     case METHOD_TYPE:
6242       /* If TYPE is a function type, it is variably modified if the
6243          return type is variably modified.  */
6244       if (variably_modified_type_p (TREE_TYPE (type), fn))
6245           return true;
6246       break;
6247
6248     case INTEGER_TYPE:
6249     case REAL_TYPE:
6250     case ENUMERAL_TYPE:
6251     case BOOLEAN_TYPE:
6252       /* Scalar types are variably modified if their end points
6253          aren't constant.  */
6254       RETURN_TRUE_IF_VAR (TYPE_MIN_VALUE (type));
6255       RETURN_TRUE_IF_VAR (TYPE_MAX_VALUE (type));
6256       break;
6257
6258     case RECORD_TYPE:
6259     case UNION_TYPE:
6260     case QUAL_UNION_TYPE:
6261       /* We can't see if any of the fields are variably-modified by the
6262          definition we normally use, since that would produce infinite
6263          recursion via pointers.  */
6264       /* This is variably modified if some field's type is.  */
6265       for (t = TYPE_FIELDS (type); t; t = TREE_CHAIN (t))
6266         if (TREE_CODE (t) == FIELD_DECL)
6267           {
6268             RETURN_TRUE_IF_VAR (DECL_FIELD_OFFSET (t));
6269             RETURN_TRUE_IF_VAR (DECL_SIZE (t));
6270             RETURN_TRUE_IF_VAR (DECL_SIZE_UNIT (t));
6271
6272             if (TREE_CODE (type) == QUAL_UNION_TYPE)
6273               RETURN_TRUE_IF_VAR (DECL_QUALIFIER (t));
6274           }
6275         break;
6276
6277     case ARRAY_TYPE:
6278       /* Do not call ourselves to avoid infinite recursion.  This is
6279          variably modified if the element type is.  */
6280       RETURN_TRUE_IF_VAR (TYPE_SIZE (TREE_TYPE (type)));
6281       RETURN_TRUE_IF_VAR (TYPE_SIZE_UNIT (TREE_TYPE (type)));
6282       break;
6283
6284     default:
6285       break;
6286     }
6287
6288   /* The current language may have other cases to check, but in general,
6289      all other types are not variably modified.  */
6290   return lang_hooks.tree_inlining.var_mod_type_p (type, fn);
6291
6292 #undef RETURN_TRUE_IF_VAR
6293 }
6294
6295 /* Given a DECL or TYPE, return the scope in which it was declared, or
6296    NULL_TREE if there is no containing scope.  */
6297
6298 tree
6299 get_containing_scope (tree t)
6300 {
6301   return (TYPE_P (t) ? TYPE_CONTEXT (t) : DECL_CONTEXT (t));
6302 }
6303
6304 /* Return the innermost context enclosing DECL that is
6305    a FUNCTION_DECL, or zero if none.  */
6306
6307 tree
6308 decl_function_context (tree decl)
6309 {
6310   tree context;
6311
6312   if (TREE_CODE (decl) == ERROR_MARK)
6313     return 0;
6314
6315   /* C++ virtual functions use DECL_CONTEXT for the class of the vtable
6316      where we look up the function at runtime.  Such functions always take
6317      a first argument of type 'pointer to real context'.
6318
6319      C++ should really be fixed to use DECL_CONTEXT for the real context,
6320      and use something else for the "virtual context".  */
6321   else if (TREE_CODE (decl) == FUNCTION_DECL && DECL_VINDEX (decl))
6322     context
6323       = TYPE_MAIN_VARIANT
6324         (TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (decl)))));
6325   else
6326     context = DECL_CONTEXT (decl);
6327
6328   while (context && TREE_CODE (context) != FUNCTION_DECL)
6329     {
6330       if (TREE_CODE (context) == BLOCK)
6331         context = BLOCK_SUPERCONTEXT (context);
6332       else
6333         context = get_containing_scope (context);
6334     }
6335
6336   return context;
6337 }
6338
6339 /* Return the innermost context enclosing DECL that is
6340    a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
6341    TYPE_DECLs and FUNCTION_DECLs are transparent to this function.  */
6342
6343 tree
6344 decl_type_context (tree decl)
6345 {
6346   tree context = DECL_CONTEXT (decl);
6347
6348   while (context)
6349     switch (TREE_CODE (context))
6350       {
6351       case NAMESPACE_DECL:
6352       case TRANSLATION_UNIT_DECL:
6353         return NULL_TREE;
6354
6355       case RECORD_TYPE:
6356       case UNION_TYPE:
6357       case QUAL_UNION_TYPE:
6358         return context;
6359
6360       case TYPE_DECL:
6361       case FUNCTION_DECL:
6362         context = DECL_CONTEXT (context);
6363         break;
6364
6365       case BLOCK:
6366         context = BLOCK_SUPERCONTEXT (context);
6367         break;
6368
6369       default:
6370         gcc_unreachable ();
6371       }
6372
6373   return NULL_TREE;
6374 }
6375
6376 /* CALL is a CALL_EXPR.  Return the declaration for the function
6377    called, or NULL_TREE if the called function cannot be
6378    determined.  */
6379
6380 tree
6381 get_callee_fndecl (tree call)
6382 {
6383   tree addr;
6384
6385   if (call == error_mark_node)
6386     return call;
6387
6388   /* It's invalid to call this function with anything but a
6389      CALL_EXPR.  */
6390   gcc_assert (TREE_CODE (call) == CALL_EXPR);
6391
6392   /* The first operand to the CALL is the address of the function
6393      called.  */
6394   addr = CALL_EXPR_FN (call);
6395
6396   STRIP_NOPS (addr);
6397
6398   /* If this is a readonly function pointer, extract its initial value.  */
6399   if (DECL_P (addr) && TREE_CODE (addr) != FUNCTION_DECL
6400       && TREE_READONLY (addr) && ! TREE_THIS_VOLATILE (addr)
6401       && DECL_INITIAL (addr))
6402     addr = DECL_INITIAL (addr);
6403
6404   /* If the address is just `&f' for some function `f', then we know
6405      that `f' is being called.  */
6406   if (TREE_CODE (addr) == ADDR_EXPR
6407       && TREE_CODE (TREE_OPERAND (addr, 0)) == FUNCTION_DECL)
6408     return TREE_OPERAND (addr, 0);
6409
6410   /* We couldn't figure out what was being called.  Maybe the front
6411      end has some idea.  */
6412   return lang_hooks.lang_get_callee_fndecl (call);
6413 }
6414
6415 /* Print debugging information about tree nodes generated during the compile,
6416    and any language-specific information.  */
6417
6418 void
6419 dump_tree_statistics (void)
6420 {
6421 #ifdef GATHER_STATISTICS
6422   int i;
6423   int total_nodes, total_bytes;
6424 #endif
6425
6426   fprintf (stderr, "\n??? tree nodes created\n\n");
6427 #ifdef GATHER_STATISTICS
6428   fprintf (stderr, "Kind                   Nodes      Bytes\n");
6429   fprintf (stderr, "---------------------------------------\n");
6430   total_nodes = total_bytes = 0;
6431   for (i = 0; i < (int) all_kinds; i++)
6432     {
6433       fprintf (stderr, "%-20s %7d %10d\n", tree_node_kind_names[i],
6434                tree_node_counts[i], tree_node_sizes[i]);
6435       total_nodes += tree_node_counts[i];
6436       total_bytes += tree_node_sizes[i];
6437     }
6438   fprintf (stderr, "---------------------------------------\n");
6439   fprintf (stderr, "%-20s %7d %10d\n", "Total", total_nodes, total_bytes);
6440   fprintf (stderr, "---------------------------------------\n");
6441   ssanames_print_statistics ();
6442   phinodes_print_statistics ();
6443 #else
6444   fprintf (stderr, "(No per-node statistics)\n");
6445 #endif
6446   print_type_hash_statistics ();
6447   print_debug_expr_statistics ();
6448   print_value_expr_statistics ();
6449   print_restrict_base_statistics ();
6450   lang_hooks.print_statistics ();
6451 }
6452 \f
6453 #define FILE_FUNCTION_FORMAT "_GLOBAL__%s_%s"
6454
6455 /* Generate a crc32 of a string.  */
6456
6457 unsigned
6458 crc32_string (unsigned chksum, const char *string)
6459 {
6460   do
6461     {
6462       unsigned value = *string << 24;
6463       unsigned ix;
6464
6465       for (ix = 8; ix--; value <<= 1)
6466         {
6467           unsigned feedback;
6468
6469           feedback = (value ^ chksum) & 0x80000000 ? 0x04c11db7 : 0;
6470           chksum <<= 1;
6471           chksum ^= feedback;
6472         }
6473     }
6474   while (*string++);
6475   return chksum;
6476 }
6477
6478 /* P is a string that will be used in a symbol.  Mask out any characters
6479    that are not valid in that context.  */
6480
6481 void
6482 clean_symbol_name (char *p)
6483 {
6484   for (; *p; p++)
6485     if (! (ISALNUM (*p)
6486 #ifndef NO_DOLLAR_IN_LABEL      /* this for `$'; unlikely, but... -- kr */
6487             || *p == '$'
6488 #endif
6489 #ifndef NO_DOT_IN_LABEL         /* this for `.'; unlikely, but...  */
6490             || *p == '.'
6491 #endif
6492            ))
6493       *p = '_';
6494 }
6495
6496 /* Generate a name for a special-purpose function function.
6497    The generated name may need to be unique across the whole link.
6498    TYPE is some string to identify the purpose of this function to the
6499    linker or collect2; it must start with an uppercase letter,
6500    one of:
6501    I - for constructors
6502    D - for destructors
6503    N - for C++ anonymous namespaces
6504    F - for DWARF unwind frame information.  */
6505
6506 tree
6507 get_file_function_name (const char *type)
6508 {
6509   char *buf;
6510   const char *p;
6511   char *q;
6512
6513   /* If we already have a name we know to be unique, just use that.  */
6514   if (first_global_object_name)
6515     p = first_global_object_name;
6516   /* If the target is handling the constructors/destructors, they
6517      will be local to this file and the name is only necessary for
6518      debugging purposes.  */
6519   else if ((type[0] == 'I' || type[0] == 'D') && targetm.have_ctors_dtors)
6520     {
6521       const char *file = main_input_filename;
6522       if (! file)
6523         file = input_filename;
6524       /* Just use the file's basename, because the full pathname
6525          might be quite long.  */
6526       p = strrchr (file, '/');
6527       if (p)
6528         p++;
6529       else
6530         p = file;
6531       p = q = ASTRDUP (p);
6532       clean_symbol_name (q);
6533     }
6534   else
6535     {
6536       /* Otherwise, the name must be unique across the entire link.
6537          We don't have anything that we know to be unique to this translation
6538          unit, so use what we do have and throw in some randomness.  */
6539       unsigned len;
6540       const char *name = weak_global_object_name;
6541       const char *file = main_input_filename;
6542
6543       if (! name)
6544         name = "";
6545       if (! file)
6546         file = input_filename;
6547
6548       len = strlen (file);
6549       q = alloca (9 * 2 + len + 1);
6550       memcpy (q, file, len + 1);
6551       clean_symbol_name (q);
6552
6553       sprintf (q + len, "_%08X_%08X", crc32_string (0, name),
6554                crc32_string (0, get_random_seed (false)));
6555
6556       p = q;
6557     }
6558
6559   buf = alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p) + strlen (type));
6560
6561   /* Set up the name of the file-level functions we may need.
6562      Use a global object (which is already required to be unique over
6563      the program) rather than the file name (which imposes extra
6564      constraints).  */
6565   sprintf (buf, FILE_FUNCTION_FORMAT, type, p);
6566
6567   return get_identifier (buf);
6568 }
6569 \f
6570 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
6571
6572 /* Complain that the tree code of NODE does not match the expected 0
6573    terminated list of trailing codes. The trailing code list can be
6574    empty, for a more vague error message.  FILE, LINE, and FUNCTION
6575    are of the caller.  */
6576
6577 void
6578 tree_check_failed (const tree node, const char *file,
6579                    int line, const char *function, ...)
6580 {
6581   va_list args;
6582   char *buffer;
6583   unsigned length = 0;
6584   int code;
6585
6586   va_start (args, function);
6587   while ((code = va_arg (args, int)))
6588     length += 4 + strlen (tree_code_name[code]);
6589   va_end (args);
6590   if (length)
6591     {
6592       va_start (args, function);
6593       length += strlen ("expected ");
6594       buffer = alloca (length);
6595       length = 0;
6596       while ((code = va_arg (args, int)))
6597         {
6598           const char *prefix = length ? " or " : "expected ";
6599
6600           strcpy (buffer + length, prefix);
6601           length += strlen (prefix);
6602           strcpy (buffer + length, tree_code_name[code]);
6603           length += strlen (tree_code_name[code]);
6604         }
6605       va_end (args);
6606     }
6607   else
6608     buffer = (char *)"unexpected node";
6609
6610   internal_error ("tree check: %s, have %s in %s, at %s:%d",
6611                   buffer, tree_code_name[TREE_CODE (node)],
6612                   function, trim_filename (file), line);
6613 }
6614
6615 /* Complain that the tree code of NODE does match the expected 0
6616    terminated list of trailing codes. FILE, LINE, and FUNCTION are of
6617    the caller.  */
6618
6619 void
6620 tree_not_check_failed (const tree node, const char *file,
6621                        int line, const char *function, ...)
6622 {
6623   va_list args;
6624   char *buffer;
6625   unsigned length = 0;
6626   int code;
6627
6628   va_start (args, function);
6629   while ((code = va_arg (args, int)))
6630     length += 4 + strlen (tree_code_name[code]);
6631   va_end (args);
6632   va_start (args, function);
6633   buffer = alloca (length);
6634   length = 0;
6635   while ((code = va_arg (args, int)))
6636     {
6637       if (length)
6638         {
6639           strcpy (buffer + length, " or ");
6640           length += 4;
6641         }
6642       strcpy (buffer + length, tree_code_name[code]);
6643       length += strlen (tree_code_name[code]);
6644     }
6645   va_end (args);
6646
6647   internal_error ("tree check: expected none of %s, have %s in %s, at %s:%d",
6648                   buffer, tree_code_name[TREE_CODE (node)],
6649                   function, trim_filename (file), line);
6650 }
6651
6652 /* Similar to tree_check_failed, except that we check for a class of tree
6653    code, given in CL.  */
6654
6655 void
6656 tree_class_check_failed (const tree node, const enum tree_code_class cl,
6657                          const char *file, int line, const char *function)
6658 {
6659   internal_error
6660     ("tree check: expected class %qs, have %qs (%s) in %s, at %s:%d",
6661      TREE_CODE_CLASS_STRING (cl),
6662      TREE_CODE_CLASS_STRING (TREE_CODE_CLASS (TREE_CODE (node))),
6663      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
6664 }
6665
6666 /* Similar to tree_check_failed, except that instead of specifying a
6667    dozen codes, use the knowledge that they're all sequential.  */
6668
6669 void
6670 tree_range_check_failed (const tree node, const char *file, int line,
6671                          const char *function, enum tree_code c1,
6672                          enum tree_code c2)
6673 {
6674   char *buffer;
6675   unsigned length = 0;
6676   enum tree_code c;
6677
6678   for (c = c1; c <= c2; ++c)
6679     length += 4 + strlen (tree_code_name[c]);
6680
6681   length += strlen ("expected ");
6682   buffer = alloca (length);
6683   length = 0;
6684
6685   for (c = c1; c <= c2; ++c)
6686     {
6687       const char *prefix = length ? " or " : "expected ";
6688
6689       strcpy (buffer + length, prefix);
6690       length += strlen (prefix);
6691       strcpy (buffer + length, tree_code_name[c]);
6692       length += strlen (tree_code_name[c]);
6693     }
6694
6695   internal_error ("tree check: %s, have %s in %s, at %s:%d",
6696                   buffer, tree_code_name[TREE_CODE (node)],
6697                   function, trim_filename (file), line);
6698 }
6699
6700
6701 /* Similar to tree_check_failed, except that we check that a tree does
6702    not have the specified code, given in CL.  */
6703
6704 void
6705 tree_not_class_check_failed (const tree node, const enum tree_code_class cl,
6706                              const char *file, int line, const char *function)
6707 {
6708   internal_error
6709     ("tree check: did not expect class %qs, have %qs (%s) in %s, at %s:%d",
6710      TREE_CODE_CLASS_STRING (cl),
6711      TREE_CODE_CLASS_STRING (TREE_CODE_CLASS (TREE_CODE (node))),
6712      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
6713 }
6714
6715
6716 /* Similar to tree_check_failed but applied to OMP_CLAUSE codes.  */
6717
6718 void
6719 omp_clause_check_failed (const tree node, const char *file, int line,
6720                          const char *function, enum omp_clause_code code)
6721 {
6722   internal_error ("tree check: expected omp_clause %s, have %s in %s, at %s:%d",
6723                   omp_clause_code_name[code], tree_code_name[TREE_CODE (node)],
6724                   function, trim_filename (file), line);
6725 }
6726
6727
6728 /* Similar to tree_range_check_failed but applied to OMP_CLAUSE codes.  */
6729
6730 void
6731 omp_clause_range_check_failed (const tree node, const char *file, int line,
6732                                const char *function, enum omp_clause_code c1,
6733                                enum omp_clause_code c2)
6734 {
6735   char *buffer;
6736   unsigned length = 0;
6737   enum omp_clause_code c;
6738
6739   for (c = c1; c <= c2; ++c)
6740     length += 4 + strlen (omp_clause_code_name[c]);
6741
6742   length += strlen ("expected ");
6743   buffer = alloca (length);
6744   length = 0;
6745
6746   for (c = c1; c <= c2; ++c)
6747     {
6748       const char *prefix = length ? " or " : "expected ";
6749
6750       strcpy (buffer + length, prefix);
6751       length += strlen (prefix);
6752       strcpy (buffer + length, omp_clause_code_name[c]);
6753       length += strlen (omp_clause_code_name[c]);
6754     }
6755
6756   internal_error ("tree check: %s, have %s in %s, at %s:%d",
6757                   buffer, omp_clause_code_name[TREE_CODE (node)],
6758                   function, trim_filename (file), line);
6759 }
6760
6761
6762 #undef DEFTREESTRUCT
6763 #define DEFTREESTRUCT(VAL, NAME) NAME,
6764
6765 static const char *ts_enum_names[] = {
6766 #include "treestruct.def"
6767 };
6768 #undef DEFTREESTRUCT
6769
6770 #define TS_ENUM_NAME(EN) (ts_enum_names[(EN)])
6771
6772 /* Similar to tree_class_check_failed, except that we check for
6773    whether CODE contains the tree structure identified by EN.  */
6774
6775 void
6776 tree_contains_struct_check_failed (const tree node,
6777                                    const enum tree_node_structure_enum en,
6778                                    const char *file, int line,
6779                                    const char *function)
6780 {
6781   internal_error
6782     ("tree check: expected tree that contains %qs structure, have %qs in %s, at %s:%d",
6783      TS_ENUM_NAME(en),
6784      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
6785 }
6786
6787
6788 /* Similar to above, except that the check is for the bounds of a TREE_VEC's
6789    (dynamically sized) vector.  */
6790
6791 void
6792 tree_vec_elt_check_failed (int idx, int len, const char *file, int line,
6793                            const char *function)
6794 {
6795   internal_error
6796     ("tree check: accessed elt %d of tree_vec with %d elts in %s, at %s:%d",
6797      idx + 1, len, function, trim_filename (file), line);
6798 }
6799
6800 /* Similar to above, except that the check is for the bounds of a PHI_NODE's
6801    (dynamically sized) vector.  */
6802
6803 void
6804 phi_node_elt_check_failed (int idx, int len, const char *file, int line,
6805                             const char *function)
6806 {
6807   internal_error
6808     ("tree check: accessed elt %d of phi_node with %d elts in %s, at %s:%d",
6809      idx + 1, len, function, trim_filename (file), line);
6810 }
6811
6812 /* Similar to above, except that the check is for the bounds of the operand
6813    vector of an expression node EXP.  */
6814
6815 void
6816 tree_operand_check_failed (int idx, tree exp, const char *file,
6817                            int line, const char *function)
6818 {
6819   int code = TREE_CODE (exp);
6820   internal_error
6821     ("tree check: accessed operand %d of %s with %d operands in %s, at %s:%d",
6822      idx + 1, tree_code_name[code], TREE_OPERAND_LENGTH (exp),
6823      function, trim_filename (file), line);
6824 }
6825
6826 /* Similar to above, except that the check is for the number of
6827    operands of an OMP_CLAUSE node.  */
6828
6829 void
6830 omp_clause_operand_check_failed (int idx, tree t, const char *file,
6831                                  int line, const char *function)
6832 {
6833   internal_error
6834     ("tree check: accessed operand %d of omp_clause %s with %d operands "
6835      "in %s, at %s:%d", idx + 1, omp_clause_code_name[OMP_CLAUSE_CODE (t)],
6836      omp_clause_num_ops [OMP_CLAUSE_CODE (t)], function,
6837      trim_filename (file), line);
6838 }
6839 #endif /* ENABLE_TREE_CHECKING */
6840 \f
6841 /* Create a new vector type node holding SUBPARTS units of type INNERTYPE,
6842    and mapped to the machine mode MODE.  Initialize its fields and build
6843    the information necessary for debugging output.  */
6844
6845 static tree
6846 make_vector_type (tree innertype, int nunits, enum machine_mode mode)
6847 {
6848   tree t;
6849   hashval_t hashcode = 0;
6850
6851   /* Build a main variant, based on the main variant of the inner type, then
6852      use it to build the variant we return.  */
6853   if ((TYPE_ATTRIBUTES (innertype) || TYPE_QUALS (innertype))
6854       && TYPE_MAIN_VARIANT (innertype) != innertype)
6855     return build_type_attribute_qual_variant (
6856             make_vector_type (TYPE_MAIN_VARIANT (innertype), nunits, mode),
6857             TYPE_ATTRIBUTES (innertype),
6858             TYPE_QUALS (innertype));
6859
6860   t = make_node (VECTOR_TYPE);
6861   TREE_TYPE (t) = TYPE_MAIN_VARIANT (innertype);
6862   SET_TYPE_VECTOR_SUBPARTS (t, nunits);
6863   TYPE_MODE (t) = mode;
6864   TYPE_READONLY (t) = TYPE_READONLY (innertype);
6865   TYPE_VOLATILE (t) = TYPE_VOLATILE (innertype);
6866
6867   if (TYPE_STRUCTURAL_EQUALITY_P (innertype))
6868     SET_TYPE_STRUCTURAL_EQUALITY (t);
6869   else if (TYPE_CANONICAL (innertype) != innertype
6870            || mode != VOIDmode)
6871     TYPE_CANONICAL (t)
6872       = make_vector_type (TYPE_CANONICAL (innertype), nunits, VOIDmode);
6873
6874   layout_type (t);
6875
6876   {
6877     tree index = build_int_cst (NULL_TREE, nunits - 1);
6878     tree array = build_array_type (innertype, build_index_type (index));
6879     tree rt = make_node (RECORD_TYPE);
6880
6881     TYPE_FIELDS (rt) = build_decl (FIELD_DECL, get_identifier ("f"), array);
6882     DECL_CONTEXT (TYPE_FIELDS (rt)) = rt;
6883     layout_type (rt);
6884     TYPE_DEBUG_REPRESENTATION_TYPE (t) = rt;
6885     /* In dwarfout.c, type lookup uses TYPE_UID numbers.  We want to output
6886        the representation type, and we want to find that die when looking up
6887        the vector type.  This is most easily achieved by making the TYPE_UID
6888        numbers equal.  */
6889     TYPE_UID (rt) = TYPE_UID (t);
6890   }
6891
6892   hashcode = iterative_hash_host_wide_int (VECTOR_TYPE, hashcode);
6893   hashcode = iterative_hash_host_wide_int (mode, hashcode);
6894   hashcode = iterative_hash_object (TYPE_HASH (innertype), hashcode);
6895   return type_hash_canon (hashcode, t);
6896 }
6897
6898 static tree
6899 make_or_reuse_type (unsigned size, int unsignedp)
6900 {
6901   if (size == INT_TYPE_SIZE)
6902     return unsignedp ? unsigned_type_node : integer_type_node;
6903   if (size == CHAR_TYPE_SIZE)
6904     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
6905   if (size == SHORT_TYPE_SIZE)
6906     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
6907   if (size == LONG_TYPE_SIZE)
6908     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
6909   if (size == LONG_LONG_TYPE_SIZE)
6910     return (unsignedp ? long_long_unsigned_type_node
6911             : long_long_integer_type_node);
6912
6913   if (unsignedp)
6914     return make_unsigned_type (size);
6915   else
6916     return make_signed_type (size);
6917 }
6918
6919 /* Create nodes for all integer types (and error_mark_node) using the sizes
6920    of C datatypes.  The caller should call set_sizetype soon after calling
6921    this function to select one of the types as sizetype.  */
6922
6923 void
6924 build_common_tree_nodes (bool signed_char, bool signed_sizetype)
6925 {
6926   error_mark_node = make_node (ERROR_MARK);
6927   TREE_TYPE (error_mark_node) = error_mark_node;
6928
6929   initialize_sizetypes (signed_sizetype);
6930
6931   /* Define both `signed char' and `unsigned char'.  */
6932   signed_char_type_node = make_signed_type (CHAR_TYPE_SIZE);
6933   TYPE_STRING_FLAG (signed_char_type_node) = 1;
6934   unsigned_char_type_node = make_unsigned_type (CHAR_TYPE_SIZE);
6935   TYPE_STRING_FLAG (unsigned_char_type_node) = 1;
6936
6937   /* Define `char', which is like either `signed char' or `unsigned char'
6938      but not the same as either.  */
6939   char_type_node
6940     = (signed_char
6941        ? make_signed_type (CHAR_TYPE_SIZE)
6942        : make_unsigned_type (CHAR_TYPE_SIZE));
6943   TYPE_STRING_FLAG (char_type_node) = 1;
6944
6945   short_integer_type_node = make_signed_type (SHORT_TYPE_SIZE);
6946   short_unsigned_type_node = make_unsigned_type (SHORT_TYPE_SIZE);
6947   integer_type_node = make_signed_type (INT_TYPE_SIZE);
6948   unsigned_type_node = make_unsigned_type (INT_TYPE_SIZE);
6949   long_integer_type_node = make_signed_type (LONG_TYPE_SIZE);
6950   long_unsigned_type_node = make_unsigned_type (LONG_TYPE_SIZE);
6951   long_long_integer_type_node = make_signed_type (LONG_LONG_TYPE_SIZE);
6952   long_long_unsigned_type_node = make_unsigned_type (LONG_LONG_TYPE_SIZE);
6953
6954   /* Define a boolean type.  This type only represents boolean values but
6955      may be larger than char depending on the value of BOOL_TYPE_SIZE.
6956      Front ends which want to override this size (i.e. Java) can redefine
6957      boolean_type_node before calling build_common_tree_nodes_2.  */
6958   boolean_type_node = make_unsigned_type (BOOL_TYPE_SIZE);
6959   TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);
6960   TYPE_MAX_VALUE (boolean_type_node) = build_int_cst (boolean_type_node, 1);
6961   TYPE_PRECISION (boolean_type_node) = 1;
6962
6963   /* Fill in the rest of the sized types.  Reuse existing type nodes
6964      when possible.  */
6965   intQI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (QImode), 0);
6966   intHI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (HImode), 0);
6967   intSI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (SImode), 0);
6968   intDI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (DImode), 0);
6969   intTI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (TImode), 0);
6970
6971   unsigned_intQI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (QImode), 1);
6972   unsigned_intHI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (HImode), 1);
6973   unsigned_intSI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (SImode), 1);
6974   unsigned_intDI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (DImode), 1);
6975   unsigned_intTI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (TImode), 1);
6976
6977   access_public_node = get_identifier ("public");
6978   access_protected_node = get_identifier ("protected");
6979   access_private_node = get_identifier ("private");
6980 }
6981
6982 /* Call this function after calling build_common_tree_nodes and set_sizetype.
6983    It will create several other common tree nodes.  */
6984
6985 void
6986 build_common_tree_nodes_2 (int short_double)
6987 {
6988   /* Define these next since types below may used them.  */
6989   integer_zero_node = build_int_cst (NULL_TREE, 0);
6990   integer_one_node = build_int_cst (NULL_TREE, 1);
6991   integer_minus_one_node = build_int_cst (NULL_TREE, -1);
6992
6993   size_zero_node = size_int (0);
6994   size_one_node = size_int (1);
6995   bitsize_zero_node = bitsize_int (0);
6996   bitsize_one_node = bitsize_int (1);
6997   bitsize_unit_node = bitsize_int (BITS_PER_UNIT);
6998
6999   boolean_false_node = TYPE_MIN_VALUE (boolean_type_node);
7000   boolean_true_node = TYPE_MAX_VALUE (boolean_type_node);
7001
7002   void_type_node = make_node (VOID_TYPE);
7003   layout_type (void_type_node);
7004
7005   /* We are not going to have real types in C with less than byte alignment,
7006      so we might as well not have any types that claim to have it.  */
7007   TYPE_ALIGN (void_type_node) = BITS_PER_UNIT;
7008   TYPE_USER_ALIGN (void_type_node) = 0;
7009
7010   null_pointer_node = build_int_cst (build_pointer_type (void_type_node), 0);
7011   layout_type (TREE_TYPE (null_pointer_node));
7012
7013   ptr_type_node = build_pointer_type (void_type_node);
7014   const_ptr_type_node
7015     = build_pointer_type (build_type_variant (void_type_node, 1, 0));
7016   fileptr_type_node = ptr_type_node;
7017
7018   float_type_node = make_node (REAL_TYPE);
7019   TYPE_PRECISION (float_type_node) = FLOAT_TYPE_SIZE;
7020   layout_type (float_type_node);
7021
7022   double_type_node = make_node (REAL_TYPE);
7023   if (short_double)
7024     TYPE_PRECISION (double_type_node) = FLOAT_TYPE_SIZE;
7025   else
7026     TYPE_PRECISION (double_type_node) = DOUBLE_TYPE_SIZE;
7027   layout_type (double_type_node);
7028
7029   long_double_type_node = make_node (REAL_TYPE);
7030   TYPE_PRECISION (long_double_type_node) = LONG_DOUBLE_TYPE_SIZE;
7031   layout_type (long_double_type_node);
7032
7033   float_ptr_type_node = build_pointer_type (float_type_node);
7034   double_ptr_type_node = build_pointer_type (double_type_node);
7035   long_double_ptr_type_node = build_pointer_type (long_double_type_node);
7036   integer_ptr_type_node = build_pointer_type (integer_type_node);
7037
7038   /* Fixed size integer types.  */
7039   uint32_type_node = build_nonstandard_integer_type (32, true);
7040   uint64_type_node = build_nonstandard_integer_type (64, true);
7041
7042   /* Decimal float types. */
7043   dfloat32_type_node = make_node (REAL_TYPE);
7044   TYPE_PRECISION (dfloat32_type_node) = DECIMAL32_TYPE_SIZE;
7045   layout_type (dfloat32_type_node);
7046   TYPE_MODE (dfloat32_type_node) = SDmode;
7047   dfloat32_ptr_type_node = build_pointer_type (dfloat32_type_node);
7048
7049   dfloat64_type_node = make_node (REAL_TYPE);
7050   TYPE_PRECISION (dfloat64_type_node) = DECIMAL64_TYPE_SIZE;
7051   layout_type (dfloat64_type_node);
7052   TYPE_MODE (dfloat64_type_node) = DDmode;
7053   dfloat64_ptr_type_node = build_pointer_type (dfloat64_type_node);
7054
7055   dfloat128_type_node = make_node (REAL_TYPE);
7056   TYPE_PRECISION (dfloat128_type_node) = DECIMAL128_TYPE_SIZE;
7057   layout_type (dfloat128_type_node);
7058   TYPE_MODE (dfloat128_type_node) = TDmode;
7059   dfloat128_ptr_type_node = build_pointer_type (dfloat128_type_node);
7060
7061   complex_integer_type_node = build_complex_type (integer_type_node);
7062   complex_float_type_node = build_complex_type (float_type_node);
7063   complex_double_type_node = build_complex_type (double_type_node);
7064   complex_long_double_type_node = build_complex_type (long_double_type_node);
7065
7066   {
7067     tree t = targetm.build_builtin_va_list ();
7068
7069     /* Many back-ends define record types without setting TYPE_NAME.
7070        If we copied the record type here, we'd keep the original
7071        record type without a name.  This breaks name mangling.  So,
7072        don't copy record types and let c_common_nodes_and_builtins()
7073        declare the type to be __builtin_va_list.  */
7074     if (TREE_CODE (t) != RECORD_TYPE)
7075       t = build_variant_type_copy (t);
7076
7077     va_list_type_node = t;
7078   }
7079 }
7080
7081 /* A subroutine of build_common_builtin_nodes.  Define a builtin function.  */
7082
7083 static void
7084 local_define_builtin (const char *name, tree type, enum built_in_function code,
7085                       const char *library_name, int ecf_flags)
7086 {
7087   tree decl;
7088
7089   decl = add_builtin_function (name, type, code, BUILT_IN_NORMAL,
7090                                library_name, NULL_TREE);
7091   if (ecf_flags & ECF_CONST)
7092     TREE_READONLY (decl) = 1;
7093   if (ecf_flags & ECF_PURE)
7094     DECL_IS_PURE (decl) = 1;
7095   if (ecf_flags & ECF_NORETURN)
7096     TREE_THIS_VOLATILE (decl) = 1;
7097   if (ecf_flags & ECF_NOTHROW)
7098     TREE_NOTHROW (decl) = 1;
7099   if (ecf_flags & ECF_MALLOC)
7100     DECL_IS_MALLOC (decl) = 1;
7101
7102   built_in_decls[code] = decl;
7103   implicit_built_in_decls[code] = decl;
7104 }
7105
7106 /* Call this function after instantiating all builtins that the language
7107    front end cares about.  This will build the rest of the builtins that
7108    are relied upon by the tree optimizers and the middle-end.  */
7109
7110 void
7111 build_common_builtin_nodes (void)
7112 {
7113   tree tmp, ftype;
7114
7115   if (built_in_decls[BUILT_IN_MEMCPY] == NULL
7116       || built_in_decls[BUILT_IN_MEMMOVE] == NULL)
7117     {
7118       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
7119       tmp = tree_cons (NULL_TREE, const_ptr_type_node, tmp);
7120       tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7121       ftype = build_function_type (ptr_type_node, tmp);
7122
7123       if (built_in_decls[BUILT_IN_MEMCPY] == NULL)
7124         local_define_builtin ("__builtin_memcpy", ftype, BUILT_IN_MEMCPY,
7125                               "memcpy", ECF_NOTHROW);
7126       if (built_in_decls[BUILT_IN_MEMMOVE] == NULL)
7127         local_define_builtin ("__builtin_memmove", ftype, BUILT_IN_MEMMOVE,
7128                               "memmove", ECF_NOTHROW);
7129     }
7130
7131   if (built_in_decls[BUILT_IN_MEMCMP] == NULL)
7132     {
7133       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
7134       tmp = tree_cons (NULL_TREE, const_ptr_type_node, tmp);
7135       tmp = tree_cons (NULL_TREE, const_ptr_type_node, tmp);
7136       ftype = build_function_type (integer_type_node, tmp);
7137       local_define_builtin ("__builtin_memcmp", ftype, BUILT_IN_MEMCMP,
7138                             "memcmp", ECF_PURE | ECF_NOTHROW);
7139     }
7140
7141   if (built_in_decls[BUILT_IN_MEMSET] == NULL)
7142     {
7143       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
7144       tmp = tree_cons (NULL_TREE, integer_type_node, tmp);
7145       tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7146       ftype = build_function_type (ptr_type_node, tmp);
7147       local_define_builtin ("__builtin_memset", ftype, BUILT_IN_MEMSET,
7148                             "memset", ECF_NOTHROW);
7149     }
7150
7151   if (built_in_decls[BUILT_IN_ALLOCA] == NULL)
7152     {
7153       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
7154       ftype = build_function_type (ptr_type_node, tmp);
7155       local_define_builtin ("__builtin_alloca", ftype, BUILT_IN_ALLOCA,
7156                             "alloca", ECF_NOTHROW | ECF_MALLOC);
7157     }
7158
7159   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7160   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7161   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7162   ftype = build_function_type (void_type_node, tmp);
7163   local_define_builtin ("__builtin_init_trampoline", ftype,
7164                         BUILT_IN_INIT_TRAMPOLINE,
7165                         "__builtin_init_trampoline", ECF_NOTHROW);
7166
7167   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7168   ftype = build_function_type (ptr_type_node, tmp);
7169   local_define_builtin ("__builtin_adjust_trampoline", ftype,
7170                         BUILT_IN_ADJUST_TRAMPOLINE,
7171                         "__builtin_adjust_trampoline",
7172                         ECF_CONST | ECF_NOTHROW);
7173
7174   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7175   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7176   ftype = build_function_type (void_type_node, tmp);
7177   local_define_builtin ("__builtin_nonlocal_goto", ftype,
7178                         BUILT_IN_NONLOCAL_GOTO,
7179                         "__builtin_nonlocal_goto",
7180                         ECF_NORETURN | ECF_NOTHROW);
7181
7182   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7183   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7184   ftype = build_function_type (void_type_node, tmp);
7185   local_define_builtin ("__builtin_setjmp_setup", ftype,
7186                         BUILT_IN_SETJMP_SETUP,
7187                         "__builtin_setjmp_setup", ECF_NOTHROW);
7188
7189   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7190   ftype = build_function_type (ptr_type_node, tmp);
7191   local_define_builtin ("__builtin_setjmp_dispatcher", ftype,
7192                         BUILT_IN_SETJMP_DISPATCHER,
7193                         "__builtin_setjmp_dispatcher",
7194                         ECF_PURE | ECF_NOTHROW);
7195
7196   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7197   ftype = build_function_type (void_type_node, tmp);
7198   local_define_builtin ("__builtin_setjmp_receiver", ftype,
7199                         BUILT_IN_SETJMP_RECEIVER,
7200                         "__builtin_setjmp_receiver", ECF_NOTHROW);
7201
7202   ftype = build_function_type (ptr_type_node, void_list_node);
7203   local_define_builtin ("__builtin_stack_save", ftype, BUILT_IN_STACK_SAVE,
7204                         "__builtin_stack_save", ECF_NOTHROW);
7205
7206   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7207   ftype = build_function_type (void_type_node, tmp);
7208   local_define_builtin ("__builtin_stack_restore", ftype,
7209                         BUILT_IN_STACK_RESTORE,
7210                         "__builtin_stack_restore", ECF_NOTHROW);
7211
7212   ftype = build_function_type (void_type_node, void_list_node);
7213   local_define_builtin ("__builtin_profile_func_enter", ftype,
7214                         BUILT_IN_PROFILE_FUNC_ENTER, "profile_func_enter", 0);
7215   local_define_builtin ("__builtin_profile_func_exit", ftype,
7216                         BUILT_IN_PROFILE_FUNC_EXIT, "profile_func_exit", 0);
7217
7218   /* Complex multiplication and division.  These are handled as builtins
7219      rather than optabs because emit_library_call_value doesn't support
7220      complex.  Further, we can do slightly better with folding these
7221      beasties if the real and complex parts of the arguments are separate.  */
7222   {
7223     enum machine_mode mode;
7224
7225     for (mode = MIN_MODE_COMPLEX_FLOAT; mode <= MAX_MODE_COMPLEX_FLOAT; ++mode)
7226       {
7227         char mode_name_buf[4], *q;
7228         const char *p;
7229         enum built_in_function mcode, dcode;
7230         tree type, inner_type;
7231
7232         type = lang_hooks.types.type_for_mode (mode, 0);
7233         if (type == NULL)
7234           continue;
7235         inner_type = TREE_TYPE (type);
7236
7237         tmp = tree_cons (NULL_TREE, inner_type, void_list_node);
7238         tmp = tree_cons (NULL_TREE, inner_type, tmp);
7239         tmp = tree_cons (NULL_TREE, inner_type, tmp);
7240         tmp = tree_cons (NULL_TREE, inner_type, tmp);
7241         ftype = build_function_type (type, tmp);
7242
7243         mcode = BUILT_IN_COMPLEX_MUL_MIN + mode - MIN_MODE_COMPLEX_FLOAT;
7244         dcode = BUILT_IN_COMPLEX_DIV_MIN + mode - MIN_MODE_COMPLEX_FLOAT;
7245
7246         for (p = GET_MODE_NAME (mode), q = mode_name_buf; *p; p++, q++)
7247           *q = TOLOWER (*p);
7248         *q = '\0';
7249
7250         built_in_names[mcode] = concat ("__mul", mode_name_buf, "3", NULL);
7251         local_define_builtin (built_in_names[mcode], ftype, mcode,
7252                               built_in_names[mcode], ECF_CONST | ECF_NOTHROW);
7253
7254         built_in_names[dcode] = concat ("__div", mode_name_buf, "3", NULL);
7255         local_define_builtin (built_in_names[dcode], ftype, dcode,
7256                               built_in_names[dcode], ECF_CONST | ECF_NOTHROW);
7257       }
7258   }
7259 }
7260
7261 /* HACK.  GROSS.  This is absolutely disgusting.  I wish there was a
7262    better way.
7263
7264    If we requested a pointer to a vector, build up the pointers that
7265    we stripped off while looking for the inner type.  Similarly for
7266    return values from functions.
7267
7268    The argument TYPE is the top of the chain, and BOTTOM is the
7269    new type which we will point to.  */
7270
7271 tree
7272 reconstruct_complex_type (tree type, tree bottom)
7273 {
7274   tree inner, outer;
7275
7276   if (TREE_CODE (type) == POINTER_TYPE)
7277     {
7278       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
7279       outer = build_pointer_type_for_mode (inner, TYPE_MODE (type),
7280                                            TYPE_REF_CAN_ALIAS_ALL (type));
7281     }
7282   else if (TREE_CODE (type) == REFERENCE_TYPE)
7283     {
7284       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
7285       outer = build_reference_type_for_mode (inner, TYPE_MODE (type),
7286                                              TYPE_REF_CAN_ALIAS_ALL (type));
7287     }
7288   else if (TREE_CODE (type) == ARRAY_TYPE)
7289     {
7290       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
7291       outer = build_array_type (inner, TYPE_DOMAIN (type));
7292     }
7293   else if (TREE_CODE (type) == FUNCTION_TYPE)
7294     {
7295       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
7296       outer = build_function_type (inner, TYPE_ARG_TYPES (type));
7297     }
7298   else if (TREE_CODE (type) == METHOD_TYPE)
7299     {
7300       tree argtypes;
7301       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
7302       /* The build_method_type_directly() routine prepends 'this' to argument list,
7303          so we must compensate by getting rid of it.  */
7304       argtypes = TYPE_ARG_TYPES (type);
7305       outer = build_method_type_directly (TYPE_METHOD_BASETYPE (type),
7306                                           inner,
7307                                           TYPE_ARG_TYPES (type));
7308       TYPE_ARG_TYPES (outer) = argtypes;
7309     }
7310   else
7311     return bottom;
7312
7313   TYPE_READONLY (outer) = TYPE_READONLY (type);
7314   TYPE_VOLATILE (outer) = TYPE_VOLATILE (type);
7315
7316   return outer;
7317 }
7318
7319 /* Returns a vector tree node given a mode (integer, vector, or BLKmode) and
7320    the inner type.  */
7321 tree
7322 build_vector_type_for_mode (tree innertype, enum machine_mode mode)
7323 {
7324   int nunits;
7325
7326   switch (GET_MODE_CLASS (mode))
7327     {
7328     case MODE_VECTOR_INT:
7329     case MODE_VECTOR_FLOAT:
7330       nunits = GET_MODE_NUNITS (mode);
7331       break;
7332
7333     case MODE_INT:
7334       /* Check that there are no leftover bits.  */
7335       gcc_assert (GET_MODE_BITSIZE (mode)
7336                   % TREE_INT_CST_LOW (TYPE_SIZE (innertype)) == 0);
7337
7338       nunits = GET_MODE_BITSIZE (mode)
7339                / TREE_INT_CST_LOW (TYPE_SIZE (innertype));
7340       break;
7341
7342     default:
7343       gcc_unreachable ();
7344     }
7345
7346   return make_vector_type (innertype, nunits, mode);
7347 }
7348
7349 /* Similarly, but takes the inner type and number of units, which must be
7350    a power of two.  */
7351
7352 tree
7353 build_vector_type (tree innertype, int nunits)
7354 {
7355   return make_vector_type (innertype, nunits, VOIDmode);
7356 }
7357
7358
7359 /* Build RESX_EXPR with given REGION_NUMBER.  */
7360 tree
7361 build_resx (int region_number)
7362 {
7363   tree t;
7364   t = build1 (RESX_EXPR, void_type_node,
7365               build_int_cst (NULL_TREE, region_number));
7366   return t;
7367 }
7368
7369 /* Given an initializer INIT, return TRUE if INIT is zero or some
7370    aggregate of zeros.  Otherwise return FALSE.  */
7371 bool
7372 initializer_zerop (tree init)
7373 {
7374   tree elt;
7375
7376   STRIP_NOPS (init);
7377
7378   switch (TREE_CODE (init))
7379     {
7380     case INTEGER_CST:
7381       return integer_zerop (init);
7382
7383     case REAL_CST:
7384       /* ??? Note that this is not correct for C4X float formats.  There,
7385          a bit pattern of all zeros is 1.0; 0.0 is encoded with the most
7386          negative exponent.  */
7387       return real_zerop (init)
7388         && ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (init));
7389
7390     case COMPLEX_CST:
7391       return integer_zerop (init)
7392         || (real_zerop (init)
7393             && ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (TREE_REALPART (init)))
7394             && ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (TREE_IMAGPART (init))));
7395
7396     case VECTOR_CST:
7397       for (elt = TREE_VECTOR_CST_ELTS (init); elt; elt = TREE_CHAIN (elt))
7398         if (!initializer_zerop (TREE_VALUE (elt)))
7399           return false;
7400       return true;
7401
7402     case CONSTRUCTOR:
7403       {
7404         unsigned HOST_WIDE_INT idx;
7405
7406         FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (init), idx, elt)
7407           if (!initializer_zerop (elt))
7408             return false;
7409         return true;
7410       }
7411
7412     default:
7413       return false;
7414     }
7415 }
7416
7417 /* Build an empty statement.  */
7418
7419 tree
7420 build_empty_stmt (void)
7421 {
7422   return build1 (NOP_EXPR, void_type_node, size_zero_node);
7423 }
7424
7425
7426 /* Build an OpenMP clause with code CODE.  */
7427
7428 tree
7429 build_omp_clause (enum omp_clause_code code)
7430 {
7431   tree t;
7432   int size, length;
7433
7434   length = omp_clause_num_ops[code];
7435   size = (sizeof (struct tree_omp_clause) + (length - 1) * sizeof (tree));
7436
7437   t = ggc_alloc (size);
7438   memset (t, 0, size);
7439   TREE_SET_CODE (t, OMP_CLAUSE);
7440   OMP_CLAUSE_SET_CODE (t, code);
7441
7442 #ifdef GATHER_STATISTICS
7443   tree_node_counts[(int) omp_clause_kind]++;
7444   tree_node_sizes[(int) omp_clause_kind] += size;
7445 #endif
7446
7447   return t;
7448 }
7449
7450 /* Set various status flags when building a CALL_EXPR object T.  */
7451
7452 static void
7453 process_call_operands (tree t)
7454 {
7455   bool side_effects;
7456
7457   side_effects = TREE_SIDE_EFFECTS (t);
7458   if (!side_effects)
7459     {
7460       int i, n;
7461       n = TREE_OPERAND_LENGTH (t);
7462       for (i = 1; i < n; i++)
7463         {
7464           tree op = TREE_OPERAND (t, i);
7465           if (op && TREE_SIDE_EFFECTS (op))
7466             {
7467               side_effects = 1;
7468               break;
7469             }
7470         }
7471     }
7472   if (!side_effects)
7473     {
7474       int i;
7475
7476       /* Calls have side-effects, except those to const or
7477          pure functions.  */
7478       i = call_expr_flags (t);
7479       if (!(i & (ECF_CONST | ECF_PURE)))
7480         side_effects = 1;
7481     }
7482   TREE_SIDE_EFFECTS (t) = side_effects;
7483 }
7484
7485 /* Build a tcc_vl_exp object with code CODE and room for LEN operands.  LEN
7486    includes the implicit operand count in TREE_OPERAND 0, and so must be >= 1.
7487    Except for the CODE and operand count field, other storage for the
7488    object is initialized to zeros.  */
7489
7490 tree
7491 build_vl_exp_stat (enum tree_code code, int len MEM_STAT_DECL)
7492 {
7493   tree t;
7494   int length = (len - 1) * sizeof (tree) + sizeof (struct tree_exp);
7495
7496   gcc_assert (TREE_CODE_CLASS (code) == tcc_vl_exp);
7497   gcc_assert (len >= 1);
7498
7499 #ifdef GATHER_STATISTICS
7500   tree_node_counts[(int) e_kind]++;
7501   tree_node_sizes[(int) e_kind] += length;
7502 #endif
7503
7504   t = ggc_alloc_zone_pass_stat (length, &tree_zone);
7505
7506   memset (t, 0, length);
7507
7508   TREE_SET_CODE (t, code);
7509
7510   /* Can't use TREE_OPERAND to store the length because if checking is
7511      enabled, it will try to check the length before we store it.  :-P  */
7512   t->exp.operands[0] = build_int_cst (sizetype, len);
7513
7514   return t;
7515 }
7516
7517
7518 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE
7519    and FN and a null static chain slot.  ARGLIST is a TREE_LIST of the
7520    arguments.  */
7521
7522 tree
7523 build_call_list (tree return_type, tree fn, tree arglist)
7524 {
7525   tree t;
7526   int i;
7527
7528   t = build_vl_exp (CALL_EXPR, list_length (arglist) + 3);
7529   TREE_TYPE (t) = return_type;
7530   CALL_EXPR_FN (t) = fn;
7531   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
7532   for (i = 0; arglist; arglist = TREE_CHAIN (arglist), i++)
7533     CALL_EXPR_ARG (t, i) = TREE_VALUE (arglist);
7534   process_call_operands (t);
7535   return t;
7536 }
7537
7538 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
7539    FN and a null static chain slot.  NARGS is the number of call arguments
7540    which are specified as "..." arguments.  */
7541
7542 tree
7543 build_call_nary (tree return_type, tree fn, int nargs, ...)
7544 {
7545   tree ret;
7546   va_list args;
7547   va_start (args, nargs);
7548   ret = build_call_valist (return_type, fn, nargs, args);
7549   va_end (args);
7550   return ret;
7551 }
7552
7553 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
7554    FN and a null static chain slot.  NARGS is the number of call arguments
7555    which are specified as a va_list ARGS.  */
7556
7557 tree
7558 build_call_valist (tree return_type, tree fn, int nargs, va_list args)
7559 {
7560   tree t;
7561   int i;
7562
7563   t = build_vl_exp (CALL_EXPR, nargs + 3);
7564   TREE_TYPE (t) = return_type;
7565   CALL_EXPR_FN (t) = fn;
7566   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
7567   for (i = 0; i < nargs; i++)
7568     CALL_EXPR_ARG (t, i) = va_arg (args, tree);
7569   process_call_operands (t);
7570   return t;
7571 }
7572
7573 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
7574    FN and a null static chain slot.  NARGS is the number of call arguments
7575    which are specified as a tree array ARGS.  */
7576
7577 tree
7578 build_call_array (tree return_type, tree fn, int nargs, tree *args)
7579 {
7580   tree t;
7581   int i;
7582
7583   t = build_vl_exp (CALL_EXPR, nargs + 3);
7584   TREE_TYPE (t) = return_type;
7585   CALL_EXPR_FN (t) = fn;
7586   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
7587   for (i = 0; i < nargs; i++)
7588     CALL_EXPR_ARG (t, i) = args[i];
7589   process_call_operands (t);
7590   return t;
7591 }
7592
7593
7594 /* Returns true if it is possible to prove that the index of
7595    an array access REF (an ARRAY_REF expression) falls into the
7596    array bounds.  */
7597
7598 bool
7599 in_array_bounds_p (tree ref)
7600 {
7601   tree idx = TREE_OPERAND (ref, 1);
7602   tree min, max;
7603
7604   if (TREE_CODE (idx) != INTEGER_CST)
7605     return false;
7606
7607   min = array_ref_low_bound (ref);
7608   max = array_ref_up_bound (ref);
7609   if (!min
7610       || !max
7611       || TREE_CODE (min) != INTEGER_CST
7612       || TREE_CODE (max) != INTEGER_CST)
7613     return false;
7614
7615   if (tree_int_cst_lt (idx, min)
7616       || tree_int_cst_lt (max, idx))
7617     return false;
7618
7619   return true;
7620 }
7621
7622 /* Returns true if it is possible to prove that the range of
7623    an array access REF (an ARRAY_RANGE_REF expression) falls
7624    into the array bounds.  */
7625
7626 bool
7627 range_in_array_bounds_p (tree ref)
7628 {
7629   tree domain_type = TYPE_DOMAIN (TREE_TYPE (ref));
7630   tree range_min, range_max, min, max;
7631
7632   range_min = TYPE_MIN_VALUE (domain_type);
7633   range_max = TYPE_MAX_VALUE (domain_type);
7634   if (!range_min
7635       || !range_max
7636       || TREE_CODE (range_min) != INTEGER_CST
7637       || TREE_CODE (range_max) != INTEGER_CST)
7638     return false;
7639
7640   min = array_ref_low_bound (ref);
7641   max = array_ref_up_bound (ref);
7642   if (!min
7643       || !max
7644       || TREE_CODE (min) != INTEGER_CST
7645       || TREE_CODE (max) != INTEGER_CST)
7646     return false;
7647
7648   if (tree_int_cst_lt (range_min, min)
7649       || tree_int_cst_lt (max, range_max))
7650     return false;
7651
7652   return true;
7653 }
7654
7655 /* Return true if T (assumed to be a DECL) must be assigned a memory
7656    location.  */
7657
7658 bool
7659 needs_to_live_in_memory (tree t)
7660 {
7661   if (TREE_CODE (t) == SSA_NAME)
7662     t = SSA_NAME_VAR (t);
7663
7664   return (TREE_ADDRESSABLE (t)
7665           || is_global_var (t)
7666           || (TREE_CODE (t) == RESULT_DECL
7667               && aggregate_value_p (t, current_function_decl)));
7668 }
7669
7670 /* There are situations in which a language considers record types
7671    compatible which have different field lists.  Decide if two fields
7672    are compatible.  It is assumed that the parent records are compatible.  */
7673
7674 bool
7675 fields_compatible_p (tree f1, tree f2)
7676 {
7677   if (!operand_equal_p (DECL_FIELD_BIT_OFFSET (f1),
7678                         DECL_FIELD_BIT_OFFSET (f2), OEP_ONLY_CONST))
7679     return false;
7680
7681   if (!operand_equal_p (DECL_FIELD_OFFSET (f1),
7682                         DECL_FIELD_OFFSET (f2), OEP_ONLY_CONST))
7683     return false;
7684
7685   if (!lang_hooks.types_compatible_p (TREE_TYPE (f1), TREE_TYPE (f2)))
7686     return false;
7687
7688   return true;
7689 }
7690
7691 /* Locate within RECORD a field that is compatible with ORIG_FIELD.  */
7692
7693 tree
7694 find_compatible_field (tree record, tree orig_field)
7695 {
7696   tree f;
7697
7698   for (f = TYPE_FIELDS (record); f ; f = TREE_CHAIN (f))
7699     if (TREE_CODE (f) == FIELD_DECL
7700         && fields_compatible_p (f, orig_field))
7701       return f;
7702
7703   /* ??? Why isn't this on the main fields list?  */
7704   f = TYPE_VFIELD (record);
7705   if (f && TREE_CODE (f) == FIELD_DECL
7706       && fields_compatible_p (f, orig_field))
7707     return f;
7708
7709   /* ??? We should abort here, but Java appears to do Bad Things
7710      with inherited fields.  */
7711   return orig_field;
7712 }
7713
7714 /* Return value of a constant X.  */
7715
7716 HOST_WIDE_INT
7717 int_cst_value (tree x)
7718 {
7719   unsigned bits = TYPE_PRECISION (TREE_TYPE (x));
7720   unsigned HOST_WIDE_INT val = TREE_INT_CST_LOW (x);
7721   bool negative = ((val >> (bits - 1)) & 1) != 0;
7722
7723   gcc_assert (bits <= HOST_BITS_PER_WIDE_INT);
7724
7725   if (negative)
7726     val |= (~(unsigned HOST_WIDE_INT) 0) << (bits - 1) << 1;
7727   else
7728     val &= ~((~(unsigned HOST_WIDE_INT) 0) << (bits - 1) << 1);
7729
7730   return val;
7731 }
7732
7733
7734 /* Return an unsigned type the same as TYPE in other respects.  */
7735
7736 static tree
7737 get_unsigned_type (tree type)
7738 {
7739   return get_signed_or_unsigned_type (1, type);
7740 }
7741
7742 /* Returns unsigned variant of TYPE.  */
7743
7744 tree
7745 unsigned_type_for (tree type)
7746 {
7747   if (POINTER_TYPE_P (type))
7748     return get_unsigned_type (size_type_node);
7749   return get_unsigned_type (type);
7750 }
7751
7752 /* Returns signed variant of TYPE.  */
7753
7754 tree
7755 signed_type_for (tree type)
7756 {
7757   if (POINTER_TYPE_P (type))
7758     return lang_hooks.types.signed_type (size_type_node);
7759   return lang_hooks.types.signed_type (type);
7760 }
7761
7762 /* Returns the largest value obtainable by casting something in INNER type to
7763    OUTER type.  */
7764
7765 tree
7766 upper_bound_in_type (tree outer, tree inner)
7767 {
7768   unsigned HOST_WIDE_INT lo, hi;
7769   unsigned int det = 0;
7770   unsigned oprec = TYPE_PRECISION (outer);
7771   unsigned iprec = TYPE_PRECISION (inner);
7772   unsigned prec;
7773
7774   /* Compute a unique number for every combination.  */
7775   det |= (oprec > iprec) ? 4 : 0;
7776   det |= TYPE_UNSIGNED (outer) ? 2 : 0;
7777   det |= TYPE_UNSIGNED (inner) ? 1 : 0;
7778
7779   /* Determine the exponent to use.  */
7780   switch (det)
7781     {
7782     case 0:
7783     case 1:
7784       /* oprec <= iprec, outer: signed, inner: don't care.  */
7785       prec = oprec - 1;
7786       break;
7787     case 2:
7788     case 3:
7789       /* oprec <= iprec, outer: unsigned, inner: don't care.  */
7790       prec = oprec;
7791       break;
7792     case 4:
7793       /* oprec > iprec, outer: signed, inner: signed.  */
7794       prec = iprec - 1;
7795       break;
7796     case 5:
7797       /* oprec > iprec, outer: signed, inner: unsigned.  */
7798       prec = iprec;
7799       break;
7800     case 6:
7801       /* oprec > iprec, outer: unsigned, inner: signed.  */
7802       prec = oprec;
7803       break;
7804     case 7:
7805       /* oprec > iprec, outer: unsigned, inner: unsigned.  */
7806       prec = iprec;
7807       break;
7808     default:
7809       gcc_unreachable ();
7810     }
7811
7812   /* Compute 2^^prec - 1.  */
7813   if (prec <= HOST_BITS_PER_WIDE_INT)
7814     {
7815       hi = 0;
7816       lo = ((~(unsigned HOST_WIDE_INT) 0)
7817             >> (HOST_BITS_PER_WIDE_INT - prec));
7818     }
7819   else
7820     {
7821       hi = ((~(unsigned HOST_WIDE_INT) 0)
7822             >> (2 * HOST_BITS_PER_WIDE_INT - prec));
7823       lo = ~(unsigned HOST_WIDE_INT) 0;
7824     }
7825
7826   return build_int_cst_wide (outer, lo, hi);
7827 }
7828
7829 /* Returns the smallest value obtainable by casting something in INNER type to
7830    OUTER type.  */
7831
7832 tree
7833 lower_bound_in_type (tree outer, tree inner)
7834 {
7835   unsigned HOST_WIDE_INT lo, hi;
7836   unsigned oprec = TYPE_PRECISION (outer);
7837   unsigned iprec = TYPE_PRECISION (inner);
7838
7839   /* If OUTER type is unsigned, we can definitely cast 0 to OUTER type
7840      and obtain 0.  */
7841   if (TYPE_UNSIGNED (outer)
7842       /* If we are widening something of an unsigned type, OUTER type
7843          contains all values of INNER type.  In particular, both INNER
7844          and OUTER types have zero in common.  */
7845       || (oprec > iprec && TYPE_UNSIGNED (inner)))
7846     lo = hi = 0;
7847   else
7848     {
7849       /* If we are widening a signed type to another signed type, we
7850          want to obtain -2^^(iprec-1).  If we are keeping the
7851          precision or narrowing to a signed type, we want to obtain
7852          -2^(oprec-1).  */
7853       unsigned prec = oprec > iprec ? iprec : oprec;
7854
7855       if (prec <= HOST_BITS_PER_WIDE_INT)
7856         {
7857           hi = ~(unsigned HOST_WIDE_INT) 0;
7858           lo = (~(unsigned HOST_WIDE_INT) 0) << (prec - 1);
7859         }
7860       else
7861         {
7862           hi = ((~(unsigned HOST_WIDE_INT) 0)
7863                 << (prec - HOST_BITS_PER_WIDE_INT - 1));
7864           lo = 0;
7865         }
7866     }
7867
7868   return build_int_cst_wide (outer, lo, hi);
7869 }
7870
7871 /* Return nonzero if two operands that are suitable for PHI nodes are
7872    necessarily equal.  Specifically, both ARG0 and ARG1 must be either
7873    SSA_NAME or invariant.  Note that this is strictly an optimization.
7874    That is, callers of this function can directly call operand_equal_p
7875    and get the same result, only slower.  */
7876
7877 int
7878 operand_equal_for_phi_arg_p (tree arg0, tree arg1)
7879 {
7880   if (arg0 == arg1)
7881     return 1;
7882   if (TREE_CODE (arg0) == SSA_NAME || TREE_CODE (arg1) == SSA_NAME)
7883     return 0;
7884   return operand_equal_p (arg0, arg1, 0);
7885 }
7886
7887 /* Returns number of zeros at the end of binary representation of X.
7888
7889    ??? Use ffs if available?  */
7890
7891 tree
7892 num_ending_zeros (tree x)
7893 {
7894   unsigned HOST_WIDE_INT fr, nfr;
7895   unsigned num, abits;
7896   tree type = TREE_TYPE (x);
7897
7898   if (TREE_INT_CST_LOW (x) == 0)
7899     {
7900       num = HOST_BITS_PER_WIDE_INT;
7901       fr = TREE_INT_CST_HIGH (x);
7902     }
7903   else
7904     {
7905       num = 0;
7906       fr = TREE_INT_CST_LOW (x);
7907     }
7908
7909   for (abits = HOST_BITS_PER_WIDE_INT / 2; abits; abits /= 2)
7910     {
7911       nfr = fr >> abits;
7912       if (nfr << abits == fr)
7913         {
7914           num += abits;
7915           fr = nfr;
7916         }
7917     }
7918
7919   if (num > TYPE_PRECISION (type))
7920     num = TYPE_PRECISION (type);
7921
7922   return build_int_cst_type (type, num);
7923 }
7924
7925
7926 #define WALK_SUBTREE(NODE)                              \
7927   do                                                    \
7928     {                                                   \
7929       result = walk_tree (&(NODE), func, data, pset);   \
7930       if (result)                                       \
7931         return result;                                  \
7932     }                                                   \
7933   while (0)
7934
7935 /* This is a subroutine of walk_tree that walks field of TYPE that are to
7936    be walked whenever a type is seen in the tree.  Rest of operands and return
7937    value are as for walk_tree.  */
7938
7939 static tree
7940 walk_type_fields (tree type, walk_tree_fn func, void *data,
7941                   struct pointer_set_t *pset)
7942 {
7943   tree result = NULL_TREE;
7944
7945   switch (TREE_CODE (type))
7946     {
7947     case POINTER_TYPE:
7948     case REFERENCE_TYPE:
7949       /* We have to worry about mutually recursive pointers.  These can't
7950          be written in C.  They can in Ada.  It's pathological, but
7951          there's an ACATS test (c38102a) that checks it.  Deal with this
7952          by checking if we're pointing to another pointer, that one
7953          points to another pointer, that one does too, and we have no htab.
7954          If so, get a hash table.  We check three levels deep to avoid
7955          the cost of the hash table if we don't need one.  */
7956       if (POINTER_TYPE_P (TREE_TYPE (type))
7957           && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (type)))
7958           && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (TREE_TYPE (type))))
7959           && !pset)
7960         {
7961           result = walk_tree_without_duplicates (&TREE_TYPE (type),
7962                                                  func, data);
7963           if (result)
7964             return result;
7965
7966           break;
7967         }
7968
7969       /* ... fall through ... */
7970
7971     case COMPLEX_TYPE:
7972       WALK_SUBTREE (TREE_TYPE (type));
7973       break;
7974
7975     case METHOD_TYPE:
7976       WALK_SUBTREE (TYPE_METHOD_BASETYPE (type));
7977
7978       /* Fall through.  */
7979
7980     case FUNCTION_TYPE:
7981       WALK_SUBTREE (TREE_TYPE (type));
7982       {
7983         tree arg;
7984
7985         /* We never want to walk into default arguments.  */
7986         for (arg = TYPE_ARG_TYPES (type); arg; arg = TREE_CHAIN (arg))
7987           WALK_SUBTREE (TREE_VALUE (arg));
7988       }
7989       break;
7990
7991     case ARRAY_TYPE:
7992       /* Don't follow this nodes's type if a pointer for fear that
7993          we'll have infinite recursion.  If we have a PSET, then we
7994          need not fear.  */
7995       if (pset
7996           || (!POINTER_TYPE_P (TREE_TYPE (type))
7997               && TREE_CODE (TREE_TYPE (type)) != OFFSET_TYPE))
7998         WALK_SUBTREE (TREE_TYPE (type));
7999       WALK_SUBTREE (TYPE_DOMAIN (type));
8000       break;
8001
8002     case OFFSET_TYPE:
8003       WALK_SUBTREE (TREE_TYPE (type));
8004       WALK_SUBTREE (TYPE_OFFSET_BASETYPE (type));
8005       break;
8006
8007     default:
8008       break;
8009     }
8010
8011   return NULL_TREE;
8012 }
8013
8014 /* Apply FUNC to all the sub-trees of TP in a pre-order traversal.  FUNC is
8015    called with the DATA and the address of each sub-tree.  If FUNC returns a
8016    non-NULL value, the traversal is stopped, and the value returned by FUNC
8017    is returned.  If PSET is non-NULL it is used to record the nodes visited,
8018    and to avoid visiting a node more than once.  */
8019
8020 tree
8021 walk_tree (tree *tp, walk_tree_fn func, void *data, struct pointer_set_t *pset)
8022 {
8023   enum tree_code code;
8024   int walk_subtrees;
8025   tree result;
8026
8027 #define WALK_SUBTREE_TAIL(NODE)                         \
8028   do                                                    \
8029     {                                                   \
8030        tp = & (NODE);                                   \
8031        goto tail_recurse;                               \
8032     }                                                   \
8033   while (0)
8034
8035  tail_recurse:
8036   /* Skip empty subtrees.  */
8037   if (!*tp)
8038     return NULL_TREE;
8039
8040   /* Don't walk the same tree twice, if the user has requested
8041      that we avoid doing so.  */
8042   if (pset && pointer_set_insert (pset, *tp))
8043     return NULL_TREE;
8044
8045   /* Call the function.  */
8046   walk_subtrees = 1;
8047   result = (*func) (tp, &walk_subtrees, data);
8048
8049   /* If we found something, return it.  */
8050   if (result)
8051     return result;
8052
8053   code = TREE_CODE (*tp);
8054
8055   /* Even if we didn't, FUNC may have decided that there was nothing
8056      interesting below this point in the tree.  */
8057   if (!walk_subtrees)
8058     {
8059       /* But we still need to check our siblings.  */
8060       if (code == TREE_LIST)
8061         WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
8062       else if (code == OMP_CLAUSE)
8063         WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
8064       else
8065         return NULL_TREE;
8066     }
8067
8068   result = lang_hooks.tree_inlining.walk_subtrees (tp, &walk_subtrees, func,
8069                                                    data, pset);
8070   if (result || !walk_subtrees)
8071     return result;
8072
8073   switch (code)
8074     {
8075     case ERROR_MARK:
8076     case IDENTIFIER_NODE:
8077     case INTEGER_CST:
8078     case REAL_CST:
8079     case VECTOR_CST:
8080     case STRING_CST:
8081     case BLOCK:
8082     case PLACEHOLDER_EXPR:
8083     case SSA_NAME:
8084     case FIELD_DECL:
8085     case RESULT_DECL:
8086       /* None of these have subtrees other than those already walked
8087          above.  */
8088       break;
8089
8090     case TREE_LIST:
8091       WALK_SUBTREE (TREE_VALUE (*tp));
8092       WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
8093       break;
8094
8095     case TREE_VEC:
8096       {
8097         int len = TREE_VEC_LENGTH (*tp);
8098
8099         if (len == 0)
8100           break;
8101
8102         /* Walk all elements but the first.  */
8103         while (--len)
8104           WALK_SUBTREE (TREE_VEC_ELT (*tp, len));
8105
8106         /* Now walk the first one as a tail call.  */
8107         WALK_SUBTREE_TAIL (TREE_VEC_ELT (*tp, 0));
8108       }
8109
8110     case COMPLEX_CST:
8111       WALK_SUBTREE (TREE_REALPART (*tp));
8112       WALK_SUBTREE_TAIL (TREE_IMAGPART (*tp));
8113
8114     case CONSTRUCTOR:
8115       {
8116         unsigned HOST_WIDE_INT idx;
8117         constructor_elt *ce;
8118
8119         for (idx = 0;
8120              VEC_iterate(constructor_elt, CONSTRUCTOR_ELTS (*tp), idx, ce);
8121              idx++)
8122           WALK_SUBTREE (ce->value);
8123       }
8124       break;
8125
8126     case SAVE_EXPR:
8127       WALK_SUBTREE_TAIL (TREE_OPERAND (*tp, 0));
8128
8129     case BIND_EXPR:
8130       {
8131         tree decl;
8132         for (decl = BIND_EXPR_VARS (*tp); decl; decl = TREE_CHAIN (decl))
8133           {
8134             /* Walk the DECL_INITIAL and DECL_SIZE.  We don't want to walk
8135                into declarations that are just mentioned, rather than
8136                declared; they don't really belong to this part of the tree.
8137                And, we can see cycles: the initializer for a declaration
8138                can refer to the declaration itself.  */
8139             WALK_SUBTREE (DECL_INITIAL (decl));
8140             WALK_SUBTREE (DECL_SIZE (decl));
8141             WALK_SUBTREE (DECL_SIZE_UNIT (decl));
8142           }
8143         WALK_SUBTREE_TAIL (BIND_EXPR_BODY (*tp));
8144       }
8145
8146     case STATEMENT_LIST:
8147       {
8148         tree_stmt_iterator i;
8149         for (i = tsi_start (*tp); !tsi_end_p (i); tsi_next (&i))
8150           WALK_SUBTREE (*tsi_stmt_ptr (i));
8151       }
8152       break;
8153
8154     case OMP_CLAUSE:
8155       switch (OMP_CLAUSE_CODE (*tp))
8156         {
8157         case OMP_CLAUSE_PRIVATE:
8158         case OMP_CLAUSE_SHARED:
8159         case OMP_CLAUSE_FIRSTPRIVATE:
8160         case OMP_CLAUSE_LASTPRIVATE:
8161         case OMP_CLAUSE_COPYIN:
8162         case OMP_CLAUSE_COPYPRIVATE:
8163         case OMP_CLAUSE_IF:
8164         case OMP_CLAUSE_NUM_THREADS:
8165         case OMP_CLAUSE_SCHEDULE:
8166           WALK_SUBTREE (OMP_CLAUSE_OPERAND (*tp, 0));
8167           /* FALLTHRU */
8168
8169         case OMP_CLAUSE_NOWAIT:
8170         case OMP_CLAUSE_ORDERED:
8171         case OMP_CLAUSE_DEFAULT:
8172           WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
8173
8174         case OMP_CLAUSE_REDUCTION:
8175           {
8176             int i;
8177             for (i = 0; i < 4; i++)
8178               WALK_SUBTREE (OMP_CLAUSE_OPERAND (*tp, i));
8179             WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
8180           }
8181
8182         default:
8183           gcc_unreachable ();
8184         }
8185       break;
8186
8187     case TARGET_EXPR:
8188       {
8189         int i, len;
8190
8191         /* TARGET_EXPRs are peculiar: operands 1 and 3 can be the same.
8192            But, we only want to walk once.  */
8193         len = (TREE_OPERAND (*tp, 3) == TREE_OPERAND (*tp, 1)) ? 2 : 3;
8194         for (i = 0; i < len; ++i)
8195           WALK_SUBTREE (TREE_OPERAND (*tp, i));
8196         WALK_SUBTREE_TAIL (TREE_OPERAND (*tp, len));
8197       }
8198
8199     case DECL_EXPR:
8200       /* If this is a TYPE_DECL, walk into the fields of the type that it's
8201          defining.  We only want to walk into these fields of a type in this
8202          case and not in the general case of a mere reference to the type.
8203
8204          The criterion is as follows: if the field can be an expression, it
8205          must be walked only here.  This should be in keeping with the fields
8206          that are directly gimplified in gimplify_type_sizes in order for the
8207          mark/copy-if-shared/unmark machinery of the gimplifier to work with
8208          variable-sized types.
8209
8210          Note that DECLs get walked as part of processing the BIND_EXPR.  */
8211       if (TREE_CODE (DECL_EXPR_DECL (*tp)) == TYPE_DECL)
8212         {
8213           tree *type_p = &TREE_TYPE (DECL_EXPR_DECL (*tp));
8214           if (TREE_CODE (*type_p) == ERROR_MARK)
8215             return NULL_TREE;
8216
8217           /* Call the function for the type.  See if it returns anything or
8218              doesn't want us to continue.  If we are to continue, walk both
8219              the normal fields and those for the declaration case.  */
8220           result = (*func) (type_p, &walk_subtrees, data);
8221           if (result || !walk_subtrees)
8222             return result;
8223
8224           result = walk_type_fields (*type_p, func, data, pset);
8225           if (result)
8226             return result;
8227
8228           /* If this is a record type, also walk the fields.  */
8229           if (TREE_CODE (*type_p) == RECORD_TYPE
8230               || TREE_CODE (*type_p) == UNION_TYPE
8231               || TREE_CODE (*type_p) == QUAL_UNION_TYPE)
8232             {
8233               tree field;
8234
8235               for (field = TYPE_FIELDS (*type_p); field;
8236                    field = TREE_CHAIN (field))
8237                 {
8238                   /* We'd like to look at the type of the field, but we can
8239                      easily get infinite recursion.  So assume it's pointed
8240                      to elsewhere in the tree.  Also, ignore things that
8241                      aren't fields.  */
8242                   if (TREE_CODE (field) != FIELD_DECL)
8243                     continue;
8244
8245                   WALK_SUBTREE (DECL_FIELD_OFFSET (field));
8246                   WALK_SUBTREE (DECL_SIZE (field));
8247                   WALK_SUBTREE (DECL_SIZE_UNIT (field));
8248                   if (TREE_CODE (*type_p) == QUAL_UNION_TYPE)
8249                     WALK_SUBTREE (DECL_QUALIFIER (field));
8250                 }
8251             }
8252
8253           /* Same for scalar types.  */
8254           else if (TREE_CODE (*type_p) == BOOLEAN_TYPE
8255                    || TREE_CODE (*type_p) == ENUMERAL_TYPE
8256                    || TREE_CODE (*type_p) == INTEGER_TYPE
8257                    || TREE_CODE (*type_p) == REAL_TYPE)
8258             {
8259               WALK_SUBTREE (TYPE_MIN_VALUE (*type_p));
8260               WALK_SUBTREE (TYPE_MAX_VALUE (*type_p));
8261             }
8262
8263           WALK_SUBTREE (TYPE_SIZE (*type_p));
8264           WALK_SUBTREE_TAIL (TYPE_SIZE_UNIT (*type_p));
8265         }
8266       /* FALLTHRU */
8267
8268     default:
8269       if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))
8270           || IS_GIMPLE_STMT_CODE_CLASS (TREE_CODE_CLASS (code)))
8271         {
8272           int i, len;
8273
8274           /* Walk over all the sub-trees of this operand.  */
8275           len = TREE_OPERAND_LENGTH (*tp);
8276
8277           /* Go through the subtrees.  We need to do this in forward order so
8278              that the scope of a FOR_EXPR is handled properly.  */
8279           if (len)
8280             {
8281               for (i = 0; i < len - 1; ++i)
8282                 WALK_SUBTREE (GENERIC_TREE_OPERAND (*tp, i));
8283               WALK_SUBTREE_TAIL (GENERIC_TREE_OPERAND (*tp, len - 1));
8284             }
8285         }
8286       /* If this is a type, walk the needed fields in the type.  */
8287       else if (TYPE_P (*tp))
8288         return walk_type_fields (*tp, func, data, pset);
8289       break;
8290     }
8291
8292   /* We didn't find what we were looking for.  */
8293   return NULL_TREE;
8294
8295 #undef WALK_SUBTREE_TAIL
8296 }
8297 #undef WALK_SUBTREE
8298
8299 /* Like walk_tree, but does not walk duplicate nodes more than once.  */
8300
8301 tree
8302 walk_tree_without_duplicates (tree *tp, walk_tree_fn func, void *data)
8303 {
8304   tree result;
8305   struct pointer_set_t *pset;
8306
8307   pset = pointer_set_create ();
8308   result = walk_tree (tp, func, data, pset);
8309   pointer_set_destroy (pset);
8310   return result;
8311 }
8312
8313
8314 /* Return true if STMT is an empty statement or contains nothing but
8315    empty statements.  */
8316
8317 bool
8318 empty_body_p (tree stmt)
8319 {
8320   tree_stmt_iterator i;
8321   tree body;
8322
8323   if (IS_EMPTY_STMT (stmt))
8324     return true;
8325   else if (TREE_CODE (stmt) == BIND_EXPR)
8326     body = BIND_EXPR_BODY (stmt);
8327   else if (TREE_CODE (stmt) == STATEMENT_LIST)
8328     body = stmt;
8329   else
8330     return false;
8331
8332   for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i))
8333     if (!empty_body_p (tsi_stmt (i)))
8334       return false;
8335
8336   return true;
8337 }
8338
8339 tree *
8340 tree_block (tree t)
8341 {
8342   char const c = TREE_CODE_CLASS (TREE_CODE (t));
8343
8344   if (IS_EXPR_CODE_CLASS (c))
8345     return &t->exp.block;
8346   else if (IS_GIMPLE_STMT_CODE_CLASS (c))
8347     return &GIMPLE_STMT_BLOCK (t);
8348   gcc_unreachable ();
8349   return NULL;
8350 }
8351
8352 tree *
8353 generic_tree_operand (tree node, int i)
8354 {
8355   if (GIMPLE_STMT_P (node))
8356     return &GIMPLE_STMT_OPERAND (node, i);
8357   return &TREE_OPERAND (node, i);
8358 }
8359
8360 tree *
8361 generic_tree_type (tree node)
8362 {
8363   if (GIMPLE_STMT_P (node))
8364     return &void_type_node;
8365   return &TREE_TYPE (node);
8366 }
8367
8368 /* Build and return a TREE_LIST of arguments in the CALL_EXPR exp.
8369    FIXME: don't use this function.  It exists for compatibility with
8370    the old representation of CALL_EXPRs where a list was used to hold the
8371    arguments.  Places that currently extract the arglist from a CALL_EXPR
8372    ought to be rewritten to use the CALL_EXPR itself.  */
8373 tree
8374 call_expr_arglist (tree exp)
8375 {
8376   tree arglist = NULL_TREE;
8377   int i;
8378   for (i = call_expr_nargs (exp) - 1; i >= 0; i--)
8379     arglist = tree_cons (NULL_TREE, CALL_EXPR_ARG (exp, i), arglist);
8380   return arglist;
8381 }
8382
8383 #include "gt-tree.h"