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 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 /* This file contains the low level primitives for operating on tree nodes,
  23    including allocation, list operations, interning of identifiers,
  24    construction of data type nodes and statement nodes,
  25    and construction of type conversion nodes.  It also contains
  26    tables index by tree code that describe how to take apart
  27    nodes of that code.
  28
  29    It is intended to be language-independent, but occasionally
  30    calls language-dependent routines defined (for C) in typecheck.c.  */
  31
  32 #include "config.h"
  33 #include "system.h"
  34 #include "coretypes.h"
  35 #include "tm.h"
  36 #include "flags.h"
  37 #include "tree.h"
  38 #include "real.h"
  39 #include "tm_p.h"
  40 #include "function.h"
  41 #include "obstack.h"
  42 #include "toplev.h"
  43 #include "ggc.h"
  44 #include "hashtab.h"
  45 #include "output.h"
  46 #include "target.h"
  47 #include "langhooks.h"
  48 #include "tree-iterator.h"
  49 #include "basic-block.h"
  50 #include "tree-flow.h"
  51 #include "params.h"
  52 #include "pointer-set.h"
  53 #include "fixed-value.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 (const_tree, hashval_t);
 166 static unsigned int attribute_hash_list (const_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 FIXED_CST:         return sizeof (struct tree_fixed_cst);
 404         case COMPLEX_CST:       return sizeof (struct tree_complex);
 405         case VECTOR_CST:        return sizeof (struct tree_vector);
 406         case STRING_CST:        gcc_unreachable ();
 407         default:
 408           return lang_hooks.tree_size (code);
 409         }
 410
 411     case tcc_exceptional:  /* something random, like an identifier.  */
 412       switch (code)
 413         {
 414         case IDENTIFIER_NODE:   return lang_hooks.identifier_size;
 415         case TREE_LIST:         return sizeof (struct tree_list);
 416
 417         case ERROR_MARK:
 418         case PLACEHOLDER_EXPR:  return sizeof (struct tree_common);
 419
 420         case TREE_VEC:
 421         case OMP_CLAUSE:
 422         case PHI_NODE:          gcc_unreachable ();
 423
 424         case SSA_NAME:          return sizeof (struct tree_ssa_name);
 425
 426         case STATEMENT_LIST:    return sizeof (struct tree_statement_list);
 427         case BLOCK:             return sizeof (struct tree_block);
 428         case VALUE_HANDLE:      return sizeof (struct tree_value_handle);
 429         case CONSTRUCTOR:       return sizeof (struct tree_constructor);
 430
 431         default:
 432           return lang_hooks.tree_size (code);
 433         }
 434
 435     default:
 436       gcc_unreachable ();
 437     }
 438 }
 439
 440 /* Compute the number of bytes occupied by NODE.  This routine only
 441    looks at TREE_CODE, except for those nodes that have variable sizes.  */
 442 size_t
 443 tree_size (const_tree node)
 444 {
 445   const enum tree_code code = TREE_CODE (node);
 446   switch (code)
 447     {
 448     case PHI_NODE:
 449       return (sizeof (struct tree_phi_node)
 450               + (PHI_ARG_CAPACITY (node) - 1) * sizeof (struct phi_arg_d));
 451
 452     case TREE_BINFO:
 453       return (offsetof (struct tree_binfo, base_binfos)
 454               + VEC_embedded_size (tree, BINFO_N_BASE_BINFOS (node)));
 455
 456     case TREE_VEC:
 457       return (sizeof (struct tree_vec)
 458               + (TREE_VEC_LENGTH (node) - 1) * sizeof (tree));
 459
 460     case STRING_CST:
 461       return TREE_STRING_LENGTH (node) + offsetof (struct tree_string, str) + 1;
 462
 463     case OMP_CLAUSE:
 464       return (sizeof (struct tree_omp_clause)
 465               + (omp_clause_num_ops[OMP_CLAUSE_CODE (node)] - 1)
 466                 * sizeof (tree));
 467
 468     default:
 469       if (TREE_CODE_CLASS (code) == tcc_vl_exp)
 470         return (sizeof (struct tree_exp)
 471                 + (VL_EXP_OPERAND_LENGTH (node) - 1) * sizeof (tree));
 472       else
 473         return tree_code_size (code);
 474     }
 475 }
 476
 477 /* Return a newly allocated node of code CODE.  For decl and type
 478    nodes, some other fields are initialized.  The rest of the node is
 479    initialized to zero.  This function cannot be used for PHI_NODE,
 480    TREE_VEC or OMP_CLAUSE nodes, which is enforced by asserts in
 481    tree_code_size.
 482
 483    Achoo!  I got a code in the node.  */
 484
 485 tree
 486 make_node_stat (enum tree_code code MEM_STAT_DECL)
 487 {
 488   tree t;
 489   enum tree_code_class type = TREE_CODE_CLASS (code);
 490   size_t length = tree_code_size (code);
 491 #ifdef GATHER_STATISTICS
 492   tree_node_kind kind;
 493
 494   switch (type)
 495     {
 496     case tcc_declaration:  /* A decl node */
 497       kind = d_kind;
 498       break;
 499
 500     case tcc_type:  /* a type node */
 501       kind = t_kind;
 502       break;
 503
 504     case tcc_statement:  /* an expression with side effects */
 505       kind = s_kind;
 506       break;
 507
 508     case tcc_reference:  /* a reference */
 509       kind = r_kind;
 510       break;
 511
 512     case tcc_expression:  /* an expression */
 513     case tcc_comparison:  /* a comparison expression */
 514     case tcc_unary:  /* a unary arithmetic expression */
 515     case tcc_binary:  /* a binary arithmetic expression */
 516       kind = e_kind;
 517       break;
 518
 519     case tcc_constant:  /* a constant */
 520       kind = c_kind;
 521       break;
 522
 523     case tcc_gimple_stmt:
 524       kind = gimple_stmt_kind;
 525       break;
 526
 527     case tcc_exceptional:  /* something random, like an identifier.  */
 528       switch (code)
 529         {
 530         case IDENTIFIER_NODE:
 531           kind = id_kind;
 532           break;
 533
 534         case TREE_VEC:
 535           kind = vec_kind;
 536           break;
 537
 538         case TREE_BINFO:
 539           kind = binfo_kind;
 540           break;
 541
 542         case PHI_NODE:
 543           kind = phi_kind;
 544           break;
 545
 546         case SSA_NAME:
 547           kind = ssa_name_kind;
 548           break;
 549
 550         case BLOCK:
 551           kind = b_kind;
 552           break;
 553
 554         case CONSTRUCTOR:
 555           kind = constr_kind;
 556           break;
 557
 558         default:
 559           kind = x_kind;
 560           break;
 561         }
 562       break;
 563
 564     default:
 565       gcc_unreachable ();
 566     }
 567
 568   tree_node_counts[(int) kind]++;
 569   tree_node_sizes[(int) kind] += length;
 570 #endif
 571
 572   if (code == IDENTIFIER_NODE)
 573     t = ggc_alloc_zone_pass_stat (length, &tree_id_zone);
 574   else
 575     t = ggc_alloc_zone_pass_stat (length, &tree_zone);
 576
 577   memset (t, 0, length);
 578
 579   TREE_SET_CODE (t, code);
 580
 581   switch (type)
 582     {
 583     case tcc_statement:
 584       TREE_SIDE_EFFECTS (t) = 1;
 585       break;
 586
 587     case tcc_declaration:
 588       if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
 589         DECL_IN_SYSTEM_HEADER (t) = in_system_header;
 590       if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
 591         {
 592           if (code == FUNCTION_DECL)
 593             {
 594               DECL_ALIGN (t) = FUNCTION_BOUNDARY;
 595               DECL_MODE (t) = FUNCTION_MODE;
 596             }
 597           else
 598             DECL_ALIGN (t) = 1;
 599           /* We have not yet computed the alias set for this declaration.  */
 600           DECL_POINTER_ALIAS_SET (t) = -1;
 601         }
 602       DECL_SOURCE_LOCATION (t) = input_location;
 603       DECL_UID (t) = next_decl_uid++;
 604
 605       break;
 606
 607     case tcc_type:
 608       TYPE_UID (t) = next_type_uid++;
 609       TYPE_ALIGN (t) = BITS_PER_UNIT;
 610       TYPE_USER_ALIGN (t) = 0;
 611       TYPE_MAIN_VARIANT (t) = t;
 612       TYPE_CANONICAL (t) = t;
 613
 614       /* Default to no attributes for type, but let target change that.  */
 615       TYPE_ATTRIBUTES (t) = NULL_TREE;
 616       targetm.set_default_type_attributes (t);
 617
 618       /* We have not yet computed the alias set for this type.  */
 619       TYPE_ALIAS_SET (t) = -1;
 620       break;
 621
 622     case tcc_constant:
 623       TREE_CONSTANT (t) = 1;
 624       TREE_INVARIANT (t) = 1;
 625       break;
 626
 627     case tcc_expression:
 628       switch (code)
 629         {
 630         case INIT_EXPR:
 631         case MODIFY_EXPR:
 632         case VA_ARG_EXPR:
 633         case PREDECREMENT_EXPR:
 634         case PREINCREMENT_EXPR:
 635         case POSTDECREMENT_EXPR:
 636         case POSTINCREMENT_EXPR:
 637           /* All of these have side-effects, no matter what their
 638              operands are.  */
 639           TREE_SIDE_EFFECTS (t) = 1;
 640           break;
 641
 642         default:
 643           break;
 644         }
 645       break;
 646
 647     case tcc_gimple_stmt:
 648       switch (code)
 649         {
 650       case GIMPLE_MODIFY_STMT:
 651         TREE_SIDE_EFFECTS (t) = 1;
 652         break;
 653
 654       default:
 655         break;
 656         }
 657
 658     default:
 659       /* Other classes need no special treatment.  */
 660       break;
 661     }
 662
 663   return t;
 664 }
 665 \f
 666 /* Return a new node with the same contents as NODE except that its
 667    TREE_CHAIN is zero and it has a fresh uid.  */
 668
 669 tree
 670 copy_node_stat (tree node MEM_STAT_DECL)
 671 {
 672   tree t;
 673   enum tree_code code = TREE_CODE (node);
 674   size_t length;
 675
 676   gcc_assert (code != STATEMENT_LIST);
 677
 678   length = tree_size (node);
 679   t = ggc_alloc_zone_pass_stat (length, &tree_zone);
 680   memcpy (t, node, length);
 681
 682   if (!GIMPLE_TUPLE_P (node))
 683     TREE_CHAIN (t) = 0;
 684   TREE_ASM_WRITTEN (t) = 0;
 685   TREE_VISITED (t) = 0;
 686   t->base.ann = 0;
 687
 688   if (TREE_CODE_CLASS (code) == tcc_declaration)
 689     {
 690       DECL_UID (t) = next_decl_uid++;
 691       if ((TREE_CODE (node) == PARM_DECL || TREE_CODE (node) == VAR_DECL)
 692           && DECL_HAS_VALUE_EXPR_P (node))
 693         {
 694           SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (node));
 695           DECL_HAS_VALUE_EXPR_P (t) = 1;
 696         }
 697       if (TREE_CODE (node) == VAR_DECL && DECL_HAS_INIT_PRIORITY_P (node))
 698         {
 699           SET_DECL_INIT_PRIORITY (t, DECL_INIT_PRIORITY (node));
 700           DECL_HAS_INIT_PRIORITY_P (t) = 1;
 701         }
 702       if (TREE_CODE (node) == VAR_DECL && DECL_BASED_ON_RESTRICT_P (node))
 703         {
 704           SET_DECL_RESTRICT_BASE (t, DECL_GET_RESTRICT_BASE (node));
 705           DECL_BASED_ON_RESTRICT_P (t) = 1;
 706         }
 707     }
 708   else if (TREE_CODE_CLASS (code) == tcc_type)
 709     {
 710       TYPE_UID (t) = next_type_uid++;
 711       /* The following is so that the debug code for
 712          the copy is different from the original type.
 713          The two statements usually duplicate each other
 714          (because they clear fields of the same union),
 715          but the optimizer should catch that.  */
 716       TYPE_SYMTAB_POINTER (t) = 0;
 717       TYPE_SYMTAB_ADDRESS (t) = 0;
 718
 719       /* Do not copy the values cache.  */
 720       if (TYPE_CACHED_VALUES_P(t))
 721         {
 722           TYPE_CACHED_VALUES_P (t) = 0;
 723           TYPE_CACHED_VALUES (t) = NULL_TREE;
 724         }
 725     }
 726
 727   return t;
 728 }
 729
 730 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
 731    For example, this can copy a list made of TREE_LIST nodes.  */
 732
 733 tree
 734 copy_list (tree list)
 735 {
 736   tree head;
 737   tree prev, next;
 738
 739   if (list == 0)
 740     return 0;
 741
 742   head = prev = copy_node (list);
 743   next = TREE_CHAIN (list);
 744   while (next)
 745     {
 746       TREE_CHAIN (prev) = copy_node (next);
 747       prev = TREE_CHAIN (prev);
 748       next = TREE_CHAIN (next);
 749     }
 750   return head;
 751 }
 752
 753 \f
 754 /* Create an INT_CST node with a LOW value sign extended.  */
 755
 756 tree
 757 build_int_cst (tree type, HOST_WIDE_INT low)
 758 {
 759   /* Support legacy code.  */
 760   if (!type)
 761     type = integer_type_node;
 762
 763   return build_int_cst_wide (type, low, low < 0 ? -1 : 0);
 764 }
 765
 766 /* Create an INT_CST node with a LOW value zero extended.  */
 767
 768 tree
 769 build_int_cstu (tree type, unsigned HOST_WIDE_INT low)
 770 {
 771   return build_int_cst_wide (type, low, 0);
 772 }
 773
 774 /* Create an INT_CST node with a LOW value in TYPE.  The value is sign extended
 775    if it is negative.  This function is similar to build_int_cst, but
 776    the extra bits outside of the type precision are cleared.  Constants
 777    with these extra bits may confuse the fold so that it detects overflows
 778    even in cases when they do not occur, and in general should be avoided.
 779    We cannot however make this a default behavior of build_int_cst without
 780    more intrusive changes, since there are parts of gcc that rely on the extra
 781    precision of the integer constants.  */
 782
 783 tree
 784 build_int_cst_type (tree type, HOST_WIDE_INT low)
 785 {
 786   unsigned HOST_WIDE_INT low1;
 787   HOST_WIDE_INT hi;
 788
 789   gcc_assert (type);
 790
 791   fit_double_type (low, low < 0 ? -1 : 0, &low1, &hi, type);
 792
 793   return build_int_cst_wide (type, low1, hi);
 794 }
 795
 796 /* Create an INT_CST node of TYPE and value HI:LOW.  The value is truncated
 797    and sign extended according to the value range of TYPE.  */
 798
 799 tree
 800 build_int_cst_wide_type (tree type,
 801                          unsigned HOST_WIDE_INT low, HOST_WIDE_INT high)
 802 {
 803   fit_double_type (low, high, &low, &high, type);
 804   return build_int_cst_wide (type, low, high);
 805 }
 806
 807 /* These are the hash table functions for the hash table of INTEGER_CST
 808    nodes of a sizetype.  */
 809
 810 /* Return the hash code code X, an INTEGER_CST.  */
 811
 812 static hashval_t
 813 int_cst_hash_hash (const void *x)
 814 {
 815   const_tree const t = (const_tree) x;
 816
 817   return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
 818           ^ htab_hash_pointer (TREE_TYPE (t)));
 819 }
 820
 821 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
 822    is the same as that given by *Y, which is the same.  */
 823
 824 static int
 825 int_cst_hash_eq (const void *x, const void *y)
 826 {
 827   const_tree const xt = (const_tree) x;
 828   const_tree const yt = (const_tree) y;
 829
 830   return (TREE_TYPE (xt) == TREE_TYPE (yt)
 831           && TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
 832           && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt));
 833 }
 834
 835 /* Create an INT_CST node of TYPE and value HI:LOW.
 836    The returned node is always shared.  For small integers we use a
 837    per-type vector cache, for larger ones we use a single hash table.  */
 838
 839 tree
 840 build_int_cst_wide (tree type, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
 841 {
 842   tree t;
 843   int ix = -1;
 844   int limit = 0;
 845
 846   gcc_assert (type);
 847
 848   switch (TREE_CODE (type))
 849     {
 850     case POINTER_TYPE:
 851     case REFERENCE_TYPE:
 852       /* Cache NULL pointer.  */
 853       if (!hi && !low)
 854         {
 855           limit = 1;
 856           ix = 0;
 857         }
 858       break;
 859
 860     case BOOLEAN_TYPE:
 861       /* Cache false or true.  */
 862       limit = 2;
 863       if (!hi && low < 2)
 864         ix = low;
 865       break;
 866
 867     case INTEGER_TYPE:
 868     case OFFSET_TYPE:
 869       if (TYPE_UNSIGNED (type))
 870         {
 871           /* Cache 0..N */
 872           limit = INTEGER_SHARE_LIMIT;
 873           if (!hi && low < (unsigned HOST_WIDE_INT)INTEGER_SHARE_LIMIT)
 874             ix = low;
 875         }
 876       else
 877         {
 878           /* Cache -1..N */
 879           limit = INTEGER_SHARE_LIMIT + 1;
 880           if (!hi && low < (unsigned HOST_WIDE_INT)INTEGER_SHARE_LIMIT)
 881             ix = low + 1;
 882           else if (hi == -1 && low == -(unsigned HOST_WIDE_INT)1)
 883             ix = 0;
 884         }
 885       break;
 886
 887     case ENUMERAL_TYPE:
 888       break;
 889
 890     default:
 891       gcc_unreachable ();
 892     }
 893
 894   if (ix >= 0)
 895     {
 896       /* Look for it in the type's vector of small shared ints.  */
 897       if (!TYPE_CACHED_VALUES_P (type))
 898         {
 899           TYPE_CACHED_VALUES_P (type) = 1;
 900           TYPE_CACHED_VALUES (type) = make_tree_vec (limit);
 901         }
 902
 903       t = TREE_VEC_ELT (TYPE_CACHED_VALUES (type), ix);
 904       if (t)
 905         {
 906           /* Make sure no one is clobbering the shared constant.  */
 907           gcc_assert (TREE_TYPE (t) == type);
 908           gcc_assert (TREE_INT_CST_LOW (t) == low);
 909           gcc_assert (TREE_INT_CST_HIGH (t) == hi);
 910         }
 911       else
 912         {
 913           /* Create a new shared int.  */
 914           t = make_node (INTEGER_CST);
 915
 916           TREE_INT_CST_LOW (t) = low;
 917           TREE_INT_CST_HIGH (t) = hi;
 918           TREE_TYPE (t) = type;
 919
 920           TREE_VEC_ELT (TYPE_CACHED_VALUES (type), ix) = t;
 921         }
 922     }
 923   else
 924     {
 925       /* Use the cache of larger shared ints.  */
 926       void **slot;
 927
 928       TREE_INT_CST_LOW (int_cst_node) = low;
 929       TREE_INT_CST_HIGH (int_cst_node) = hi;
 930       TREE_TYPE (int_cst_node) = type;
 931
 932       slot = htab_find_slot (int_cst_hash_table, int_cst_node, INSERT);
 933       t = *slot;
 934       if (!t)
 935         {
 936           /* Insert this one into the hash table.  */
 937           t = int_cst_node;
 938           *slot = t;
 939           /* Make a new node for next time round.  */
 940           int_cst_node = make_node (INTEGER_CST);
 941         }
 942     }
 943
 944   return t;
 945 }
 946
 947 /* Builds an integer constant in TYPE such that lowest BITS bits are ones
 948    and the rest are zeros.  */
 949
 950 tree
 951 build_low_bits_mask (tree type, unsigned bits)
 952 {
 953   unsigned HOST_WIDE_INT low;
 954   HOST_WIDE_INT high;
 955   unsigned HOST_WIDE_INT all_ones = ~(unsigned HOST_WIDE_INT) 0;
 956
 957   gcc_assert (bits <= TYPE_PRECISION (type));
 958
 959   if (bits == TYPE_PRECISION (type)
 960       && !TYPE_UNSIGNED (type))
 961     {
 962       /* Sign extended all-ones mask.  */
 963       low = all_ones;
 964       high = -1;
 965     }
 966   else if (bits <= HOST_BITS_PER_WIDE_INT)
 967     {
 968       low = all_ones >> (HOST_BITS_PER_WIDE_INT - bits);
 969       high = 0;
 970     }
 971   else
 972     {
 973       bits -= HOST_BITS_PER_WIDE_INT;
 974       low = all_ones;
 975       high = all_ones >> (HOST_BITS_PER_WIDE_INT - bits);
 976     }
 977
 978   return build_int_cst_wide (type, low, high);
 979 }
 980
 981 /* Checks that X is integer constant that can be expressed in (unsigned)
 982    HOST_WIDE_INT without loss of precision.  */
 983
 984 bool
 985 cst_and_fits_in_hwi (const_tree x)
 986 {
 987   if (TREE_CODE (x) != INTEGER_CST)
 988     return false;
 989
 990   if (TYPE_PRECISION (TREE_TYPE (x)) > HOST_BITS_PER_WIDE_INT)
 991     return false;
 992
 993   return (TREE_INT_CST_HIGH (x) == 0
 994           || TREE_INT_CST_HIGH (x) == -1);
 995 }
 996
 997 /* Return a new VECTOR_CST node whose type is TYPE and whose values
 998    are in a list pointed to by VALS.  */
 999
1000 tree
1001 build_vector (tree type, tree vals)
1002 {
1003   tree v = make_node (VECTOR_CST);
1004   int over = 0;
1005   tree link;
1006
1007   TREE_VECTOR_CST_ELTS (v) = vals;
1008   TREE_TYPE (v) = type;
1009
1010   /* Iterate through elements and check for overflow.  */
1011   for (link = vals; link; link = TREE_CHAIN (link))
1012     {
1013       tree value = TREE_VALUE (link);
1014
1015       /* Don't crash if we get an address constant.  */
1016       if (!CONSTANT_CLASS_P (value))
1017         continue;
1018
1019       over |= TREE_OVERFLOW (value);
1020     }
1021
1022   TREE_OVERFLOW (v) = over;
1023   return v;
1024 }
1025
1026 /* Return a new VECTOR_CST node whose type is TYPE and whose values
1027    are extracted from V, a vector of CONSTRUCTOR_ELT.  */
1028
1029 tree
1030 build_vector_from_ctor (tree type, VEC(constructor_elt,gc) *v)
1031 {
1032   tree list = NULL_TREE;
1033   unsigned HOST_WIDE_INT idx;
1034   tree value;
1035
1036   FOR_EACH_CONSTRUCTOR_VALUE (v, idx, value)
1037     list = tree_cons (NULL_TREE, value, list);
1038   return build_vector (type, nreverse (list));
1039 }
1040
1041 /* Return a new CONSTRUCTOR node whose type is TYPE and whose values
1042    are in the VEC pointed to by VALS.  */
1043 tree
1044 build_constructor (tree type, VEC(constructor_elt,gc) *vals)
1045 {
1046   tree c = make_node (CONSTRUCTOR);
1047   TREE_TYPE (c) = type;
1048   CONSTRUCTOR_ELTS (c) = vals;
1049   return c;
1050 }
1051
1052 /* Build a CONSTRUCTOR node made of a single initializer, with the specified
1053    INDEX and VALUE.  */
1054 tree
1055 build_constructor_single (tree type, tree index, tree value)
1056 {
1057   VEC(constructor_elt,gc) *v;
1058   constructor_elt *elt;
1059   tree t;
1060
1061   v = VEC_alloc (constructor_elt, gc, 1);
1062   elt = VEC_quick_push (constructor_elt, v, NULL);
1063   elt->index = index;
1064   elt->value = value;
1065
1066   t = build_constructor (type, v);
1067   TREE_CONSTANT (t) = TREE_CONSTANT (value);
1068   return t;
1069 }
1070
1071
1072 /* Return a new CONSTRUCTOR node whose type is TYPE and whose values
1073    are in a list pointed to by VALS.  */
1074 tree
1075 build_constructor_from_list (tree type, tree vals)
1076 {
1077   tree t, val;
1078   VEC(constructor_elt,gc) *v = NULL;
1079   bool constant_p = true;
1080
1081   if (vals)
1082     {
1083       v = VEC_alloc (constructor_elt, gc, list_length (vals));
1084       for (t = vals; t; t = TREE_CHAIN (t))
1085         {
1086           constructor_elt *elt = VEC_quick_push (constructor_elt, v, NULL);
1087           val = TREE_VALUE (t);
1088           elt->index = TREE_PURPOSE (t);
1089           elt->value = val;
1090           if (!TREE_CONSTANT (val))
1091             constant_p = false;
1092         }
1093     }
1094
1095   t = build_constructor (type, v);
1096   TREE_CONSTANT (t) = constant_p;
1097   return t;
1098 }
1099
1100 /* Return a new FIXED_CST node whose type is TYPE and value is F.  */
1101
1102 tree
1103 build_fixed (tree type, FIXED_VALUE_TYPE f)
1104 {
1105   tree v;
1106   FIXED_VALUE_TYPE *fp;
1107
1108   v = make_node (FIXED_CST);
1109   fp = ggc_alloc (sizeof (FIXED_VALUE_TYPE));
1110   memcpy (fp, &f, sizeof (FIXED_VALUE_TYPE));
1111
1112   TREE_TYPE (v) = type;
1113   TREE_FIXED_CST_PTR (v) = fp;
1114   return v;
1115 }
1116
1117 /* Return a new REAL_CST node whose type is TYPE and value is D.  */
1118
1119 tree
1120 build_real (tree type, REAL_VALUE_TYPE d)
1121 {
1122   tree v;
1123   REAL_VALUE_TYPE *dp;
1124   int overflow = 0;
1125
1126   /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
1127      Consider doing it via real_convert now.  */
1128
1129   v = make_node (REAL_CST);
1130   dp = ggc_alloc (sizeof (REAL_VALUE_TYPE));
1131   memcpy (dp, &d, sizeof (REAL_VALUE_TYPE));
1132
1133   TREE_TYPE (v) = type;
1134   TREE_REAL_CST_PTR (v) = dp;
1135   TREE_OVERFLOW (v) = overflow;
1136   return v;
1137 }
1138
1139 /* Return a new REAL_CST node whose type is TYPE
1140    and whose value is the integer value of the INTEGER_CST node I.  */
1141
1142 REAL_VALUE_TYPE
1143 real_value_from_int_cst (const_tree type, const_tree i)
1144 {
1145   REAL_VALUE_TYPE d;
1146
1147   /* Clear all bits of the real value type so that we can later do
1148      bitwise comparisons to see if two values are the same.  */
1149   memset (&d, 0, sizeof d);
1150
1151   real_from_integer (&d, type ? TYPE_MODE (type) : VOIDmode,
1152                      TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1153                      TYPE_UNSIGNED (TREE_TYPE (i)));
1154   return d;
1155 }
1156
1157 /* Given a tree representing an integer constant I, return a tree
1158    representing the same value as a floating-point constant of type TYPE.  */
1159
1160 tree
1161 build_real_from_int_cst (tree type, const_tree i)
1162 {
1163   tree v;
1164   int overflow = TREE_OVERFLOW (i);
1165
1166   v = build_real (type, real_value_from_int_cst (type, i));
1167
1168   TREE_OVERFLOW (v) |= overflow;
1169   return v;
1170 }
1171
1172 /* Return a newly constructed STRING_CST node whose value is
1173    the LEN characters at STR.
1174    The TREE_TYPE is not initialized.  */
1175
1176 tree
1177 build_string (int len, const char *str)
1178 {
1179   tree s;
1180   size_t length;
1181
1182   /* Do not waste bytes provided by padding of struct tree_string.  */
1183   length = len + offsetof (struct tree_string, str) + 1;
1184
1185 #ifdef GATHER_STATISTICS
1186   tree_node_counts[(int) c_kind]++;
1187   tree_node_sizes[(int) c_kind] += length;
1188 #endif
1189
1190   s = ggc_alloc_tree (length);
1191
1192   memset (s, 0, sizeof (struct tree_common));
1193   TREE_SET_CODE (s, STRING_CST);
1194   TREE_CONSTANT (s) = 1;
1195   TREE_INVARIANT (s) = 1;
1196   TREE_STRING_LENGTH (s) = len;
1197   memcpy (s->string.str, str, len);
1198   s->string.str[len] = '\0';
1199
1200   return s;
1201 }
1202
1203 /* Return a newly constructed COMPLEX_CST node whose value is
1204    specified by the real and imaginary parts REAL and IMAG.
1205    Both REAL and IMAG should be constant nodes.  TYPE, if specified,
1206    will be the type of the COMPLEX_CST; otherwise a new type will be made.  */
1207
1208 tree
1209 build_complex (tree type, tree real, tree imag)
1210 {
1211   tree t = make_node (COMPLEX_CST);
1212
1213   TREE_REALPART (t) = real;
1214   TREE_IMAGPART (t) = imag;
1215   TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1216   TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1217   return t;
1218 }
1219
1220 /* Return a constant of arithmetic type TYPE which is the
1221    multiplicative identity of the set TYPE.  */
1222
1223 tree
1224 build_one_cst (tree type)
1225 {
1226   switch (TREE_CODE (type))
1227     {
1228     case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1229     case POINTER_TYPE: case REFERENCE_TYPE:
1230     case OFFSET_TYPE:
1231       return build_int_cst (type, 1);
1232
1233     case REAL_TYPE:
1234       return build_real (type, dconst1);
1235
1236     case FIXED_POINT_TYPE:
1237       /* We can only generate 1 for accum types.  */
1238       gcc_assert (ALL_SCALAR_ACCUM_MODE_P (TYPE_MODE (type)));
1239       return build_fixed (type, FCONST1(TYPE_MODE (type)));
1240
1241     case VECTOR_TYPE:
1242       {
1243         tree scalar, cst;
1244         int i;
1245
1246         scalar = build_one_cst (TREE_TYPE (type));
1247
1248         /* Create 'vect_cst_ = {cst,cst,...,cst}'  */
1249         cst = NULL_TREE;
1250         for (i = TYPE_VECTOR_SUBPARTS (type); --i >= 0; )
1251           cst = tree_cons (NULL_TREE, scalar, cst);
1252
1253         return build_vector (type, cst);
1254       }
1255
1256     case COMPLEX_TYPE:
1257       return build_complex (type,
1258                             build_one_cst (TREE_TYPE (type)),
1259                             fold_convert (TREE_TYPE (type), integer_zero_node));
1260
1261     default:
1262       gcc_unreachable ();
1263     }
1264 }
1265
1266 /* Build a BINFO with LEN language slots.  */
1267
1268 tree
1269 make_tree_binfo_stat (unsigned base_binfos MEM_STAT_DECL)
1270 {
1271   tree t;
1272   size_t length = (offsetof (struct tree_binfo, base_binfos)
1273                    + VEC_embedded_size (tree, base_binfos));
1274
1275 #ifdef GATHER_STATISTICS
1276   tree_node_counts[(int) binfo_kind]++;
1277   tree_node_sizes[(int) binfo_kind] += length;
1278 #endif
1279
1280   t = ggc_alloc_zone_pass_stat (length, &tree_zone);
1281
1282   memset (t, 0, offsetof (struct tree_binfo, base_binfos));
1283
1284   TREE_SET_CODE (t, TREE_BINFO);
1285
1286   VEC_embedded_init (tree, BINFO_BASE_BINFOS (t), base_binfos);
1287
1288   return t;
1289 }
1290
1291
1292 /* Build a newly constructed TREE_VEC node of length LEN.  */
1293
1294 tree
1295 make_tree_vec_stat (int len MEM_STAT_DECL)
1296 {
1297   tree t;
1298   int length = (len - 1) * sizeof (tree) + sizeof (struct tree_vec);
1299
1300 #ifdef GATHER_STATISTICS
1301   tree_node_counts[(int) vec_kind]++;
1302   tree_node_sizes[(int) vec_kind] += length;
1303 #endif
1304
1305   t = ggc_alloc_zone_pass_stat (length, &tree_zone);
1306
1307   memset (t, 0, length);
1308
1309   TREE_SET_CODE (t, TREE_VEC);
1310   TREE_VEC_LENGTH (t) = len;
1311
1312   return t;
1313 }
1314 \f
1315 /* Return 1 if EXPR is the integer constant zero or a complex constant
1316    of zero.  */
1317
1318 int
1319 integer_zerop (const_tree expr)
1320 {
1321   STRIP_NOPS (expr);
1322
1323   return ((TREE_CODE (expr) == INTEGER_CST
1324            && TREE_INT_CST_LOW (expr) == 0
1325            && TREE_INT_CST_HIGH (expr) == 0)
1326           || (TREE_CODE (expr) == COMPLEX_CST
1327               && integer_zerop (TREE_REALPART (expr))
1328               && integer_zerop (TREE_IMAGPART (expr))));
1329 }
1330
1331 /* Return 1 if EXPR is the integer constant one or the corresponding
1332    complex constant.  */
1333
1334 int
1335 integer_onep (const_tree expr)
1336 {
1337   STRIP_NOPS (expr);
1338
1339   return ((TREE_CODE (expr) == INTEGER_CST
1340            && TREE_INT_CST_LOW (expr) == 1
1341            && TREE_INT_CST_HIGH (expr) == 0)
1342           || (TREE_CODE (expr) == COMPLEX_CST
1343               && integer_onep (TREE_REALPART (expr))
1344               && integer_zerop (TREE_IMAGPART (expr))));
1345 }
1346
1347 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1348    it contains.  Likewise for the corresponding complex constant.  */
1349
1350 int
1351 integer_all_onesp (const_tree expr)
1352 {
1353   int prec;
1354   int uns;
1355
1356   STRIP_NOPS (expr);
1357
1358   if (TREE_CODE (expr) == COMPLEX_CST
1359       && integer_all_onesp (TREE_REALPART (expr))
1360       && integer_zerop (TREE_IMAGPART (expr)))
1361     return 1;
1362
1363   else if (TREE_CODE (expr) != INTEGER_CST)
1364     return 0;
1365
1366   uns = TYPE_UNSIGNED (TREE_TYPE (expr));
1367   if (TREE_INT_CST_LOW (expr) == ~(unsigned HOST_WIDE_INT) 0
1368       && TREE_INT_CST_HIGH (expr) == -1)
1369     return 1;
1370   if (!uns)
1371     return 0;
1372
1373   /* Note that using TYPE_PRECISION here is wrong.  We care about the
1374      actual bits, not the (arbitrary) range of the type.  */
1375   prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1376   if (prec >= HOST_BITS_PER_WIDE_INT)
1377     {
1378       HOST_WIDE_INT high_value;
1379       int shift_amount;
1380
1381       shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1382
1383       /* Can not handle precisions greater than twice the host int size.  */
1384       gcc_assert (shift_amount <= HOST_BITS_PER_WIDE_INT);
1385       if (shift_amount == HOST_BITS_PER_WIDE_INT)
1386         /* Shifting by the host word size is undefined according to the ANSI
1387            standard, so we must handle this as a special case.  */
1388         high_value = -1;
1389       else
1390         high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1391
1392       return (TREE_INT_CST_LOW (expr) == ~(unsigned HOST_WIDE_INT) 0
1393               && TREE_INT_CST_HIGH (expr) == high_value);
1394     }
1395   else
1396     return TREE_INT_CST_LOW (expr) == ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1397 }
1398
1399 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1400    one bit on).  */
1401
1402 int
1403 integer_pow2p (const_tree expr)
1404 {
1405   int prec;
1406   HOST_WIDE_INT high, low;
1407
1408   STRIP_NOPS (expr);
1409
1410   if (TREE_CODE (expr) == COMPLEX_CST
1411       && integer_pow2p (TREE_REALPART (expr))
1412       && integer_zerop (TREE_IMAGPART (expr)))
1413     return 1;
1414
1415   if (TREE_CODE (expr) != INTEGER_CST)
1416     return 0;
1417
1418   prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1419           ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1420   high = TREE_INT_CST_HIGH (expr);
1421   low = TREE_INT_CST_LOW (expr);
1422
1423   /* First clear all bits that are beyond the type's precision in case
1424      we've been sign extended.  */
1425
1426   if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1427     ;
1428   else if (prec > HOST_BITS_PER_WIDE_INT)
1429     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1430   else
1431     {
1432       high = 0;
1433       if (prec < HOST_BITS_PER_WIDE_INT)
1434         low &= ~((HOST_WIDE_INT) (-1) << prec);
1435     }
1436
1437   if (high == 0 && low == 0)
1438     return 0;
1439
1440   return ((high == 0 && (low & (low - 1)) == 0)
1441           || (low == 0 && (high & (high - 1)) == 0));
1442 }
1443
1444 /* Return 1 if EXPR is an integer constant other than zero or a
1445    complex constant other than zero.  */
1446
1447 int
1448 integer_nonzerop (const_tree expr)
1449 {
1450   STRIP_NOPS (expr);
1451
1452   return ((TREE_CODE (expr) == INTEGER_CST
1453            && (TREE_INT_CST_LOW (expr) != 0
1454                || TREE_INT_CST_HIGH (expr) != 0))
1455           || (TREE_CODE (expr) == COMPLEX_CST
1456               && (integer_nonzerop (TREE_REALPART (expr))
1457                   || integer_nonzerop (TREE_IMAGPART (expr)))));
1458 }
1459
1460 /* Return 1 if EXPR is the fixed-point constant zero.  */
1461
1462 int
1463 fixed_zerop (const_tree expr)
1464 {
1465   return (TREE_CODE (expr) == FIXED_CST
1466           && double_int_zero_p (TREE_FIXED_CST (expr).data));
1467 }
1468
1469 /* Return the power of two represented by a tree node known to be a
1470    power of two.  */
1471
1472 int
1473 tree_log2 (const_tree expr)
1474 {
1475   int prec;
1476   HOST_WIDE_INT high, low;
1477
1478   STRIP_NOPS (expr);
1479
1480   if (TREE_CODE (expr) == COMPLEX_CST)
1481     return tree_log2 (TREE_REALPART (expr));
1482
1483   prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1484           ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1485
1486   high = TREE_INT_CST_HIGH (expr);
1487   low = TREE_INT_CST_LOW (expr);
1488
1489   /* First clear all bits that are beyond the type's precision in case
1490      we've been sign extended.  */
1491
1492   if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1493     ;
1494   else if (prec > HOST_BITS_PER_WIDE_INT)
1495     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1496   else
1497     {
1498       high = 0;
1499       if (prec < HOST_BITS_PER_WIDE_INT)
1500         low &= ~((HOST_WIDE_INT) (-1) << prec);
1501     }
1502
1503   return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1504           : exact_log2 (low));
1505 }
1506
1507 /* Similar, but return the largest integer Y such that 2 ** Y is less
1508    than or equal to EXPR.  */
1509
1510 int
1511 tree_floor_log2 (const_tree expr)
1512 {
1513   int prec;
1514   HOST_WIDE_INT high, low;
1515
1516   STRIP_NOPS (expr);
1517
1518   if (TREE_CODE (expr) == COMPLEX_CST)
1519     return tree_log2 (TREE_REALPART (expr));
1520
1521   prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1522           ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1523
1524   high = TREE_INT_CST_HIGH (expr);
1525   low = TREE_INT_CST_LOW (expr);
1526
1527   /* First clear all bits that are beyond the type's precision in case
1528      we've been sign extended.  Ignore if type's precision hasn't been set
1529      since what we are doing is setting it.  */
1530
1531   if (prec == 2 * HOST_BITS_PER_WIDE_INT || prec == 0)
1532     ;
1533   else if (prec > HOST_BITS_PER_WIDE_INT)
1534     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1535   else
1536     {
1537       high = 0;
1538       if (prec < HOST_BITS_PER_WIDE_INT)
1539         low &= ~((HOST_WIDE_INT) (-1) << prec);
1540     }
1541
1542   return (high != 0 ? HOST_BITS_PER_WIDE_INT + floor_log2 (high)
1543           : floor_log2 (low));
1544 }
1545
1546 /* Return 1 if EXPR is the real constant zero.  */
1547
1548 int
1549 real_zerop (const_tree expr)
1550 {
1551   STRIP_NOPS (expr);
1552
1553   return ((TREE_CODE (expr) == REAL_CST
1554            && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0))
1555           || (TREE_CODE (expr) == COMPLEX_CST
1556               && real_zerop (TREE_REALPART (expr))
1557               && real_zerop (TREE_IMAGPART (expr))));
1558 }
1559
1560 /* Return 1 if EXPR is the real constant one in real or complex form.  */
1561
1562 int
1563 real_onep (const_tree expr)
1564 {
1565   STRIP_NOPS (expr);
1566
1567   return ((TREE_CODE (expr) == REAL_CST
1568            && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1))
1569           || (TREE_CODE (expr) == COMPLEX_CST
1570               && real_onep (TREE_REALPART (expr))
1571               && real_zerop (TREE_IMAGPART (expr))));
1572 }
1573
1574 /* Return 1 if EXPR is the real constant two.  */
1575
1576 int
1577 real_twop (const_tree expr)
1578 {
1579   STRIP_NOPS (expr);
1580
1581   return ((TREE_CODE (expr) == REAL_CST
1582            && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2))
1583           || (TREE_CODE (expr) == COMPLEX_CST
1584               && real_twop (TREE_REALPART (expr))
1585               && real_zerop (TREE_IMAGPART (expr))));
1586 }
1587
1588 /* Return 1 if EXPR is the real constant minus one.  */
1589
1590 int
1591 real_minus_onep (const_tree expr)
1592 {
1593   STRIP_NOPS (expr);
1594
1595   return ((TREE_CODE (expr) == REAL_CST
1596            && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconstm1))
1597           || (TREE_CODE (expr) == COMPLEX_CST
1598               && real_minus_onep (TREE_REALPART (expr))
1599               && real_zerop (TREE_IMAGPART (expr))));
1600 }
1601
1602 /* Nonzero if EXP is a constant or a cast of a constant.  */
1603
1604 int
1605 really_constant_p (const_tree exp)
1606 {
1607   /* This is not quite the same as STRIP_NOPS.  It does more.  */
1608   while (TREE_CODE (exp) == NOP_EXPR
1609          || TREE_CODE (exp) == CONVERT_EXPR
1610          || TREE_CODE (exp) == NON_LVALUE_EXPR)
1611     exp = TREE_OPERAND (exp, 0);
1612   return TREE_CONSTANT (exp);
1613 }
1614 \f
1615 /* Return first list element whose TREE_VALUE is ELEM.
1616    Return 0 if ELEM is not in LIST.  */
1617
1618 tree
1619 value_member (tree elem, tree list)
1620 {
1621   while (list)
1622     {
1623       if (elem == TREE_VALUE (list))
1624         return list;
1625       list = TREE_CHAIN (list);
1626     }
1627   return NULL_TREE;
1628 }
1629
1630 /* Return first list element whose TREE_PURPOSE is ELEM.
1631    Return 0 if ELEM is not in LIST.  */
1632
1633 tree
1634 purpose_member (const_tree elem, tree list)
1635 {
1636   while (list)
1637     {
1638       if (elem == TREE_PURPOSE (list))
1639         return list;
1640       list = TREE_CHAIN (list);
1641     }
1642   return NULL_TREE;
1643 }
1644
1645 /* Return nonzero if ELEM is part of the chain CHAIN.  */
1646
1647 int
1648 chain_member (const_tree elem, const_tree chain)
1649 {
1650   while (chain)
1651     {
1652       if (elem == chain)
1653         return 1;
1654       chain = TREE_CHAIN (chain);
1655     }
1656
1657   return 0;
1658 }
1659
1660 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1661    We expect a null pointer to mark the end of the chain.
1662    This is the Lisp primitive `length'.  */
1663
1664 int
1665 list_length (const_tree t)
1666 {
1667   const_tree p = t;
1668 #ifdef ENABLE_TREE_CHECKING
1669   const_tree q = t;
1670 #endif
1671   int len = 0;
1672
1673   while (p)
1674     {
1675       p = TREE_CHAIN (p);
1676 #ifdef ENABLE_TREE_CHECKING
1677       if (len % 2)
1678         q = TREE_CHAIN (q);
1679       gcc_assert (p != q);
1680 #endif
1681       len++;
1682     }
1683
1684   return len;
1685 }
1686
1687 /* Returns the number of FIELD_DECLs in TYPE.  */
1688
1689 int
1690 fields_length (const_tree type)
1691 {
1692   tree t = TYPE_FIELDS (type);
1693   int count = 0;
1694
1695   for (; t; t = TREE_CHAIN (t))
1696     if (TREE_CODE (t) == FIELD_DECL)
1697       ++count;
1698
1699   return count;
1700 }
1701
1702 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1703    by modifying the last node in chain 1 to point to chain 2.
1704    This is the Lisp primitive `nconc'.  */
1705
1706 tree
1707 chainon (tree op1, tree op2)
1708 {
1709   tree t1;
1710
1711   if (!op1)
1712     return op2;
1713   if (!op2)
1714     return op1;
1715
1716   for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1717     continue;
1718   TREE_CHAIN (t1) = op2;
1719
1720 #ifdef ENABLE_TREE_CHECKING
1721   {
1722     tree t2;
1723     for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1724       gcc_assert (t2 != t1);
1725   }
1726 #endif
1727
1728   return op1;
1729 }
1730
1731 /* Return the last node in a chain of nodes (chained through TREE_CHAIN).  */
1732
1733 tree
1734 tree_last (tree chain)
1735 {
1736   tree next;
1737   if (chain)
1738     while ((next = TREE_CHAIN (chain)))
1739       chain = next;
1740   return chain;
1741 }
1742
1743 /* Reverse the order of elements in the chain T,
1744    and return the new head of the chain (old last element).  */
1745
1746 tree
1747 nreverse (tree t)
1748 {
1749   tree prev = 0, decl, next;
1750   for (decl = t; decl; decl = next)
1751     {
1752       next = TREE_CHAIN (decl);
1753       TREE_CHAIN (decl) = prev;
1754       prev = decl;
1755     }
1756   return prev;
1757 }
1758 \f
1759 /* Return a newly created TREE_LIST node whose
1760    purpose and value fields are PARM and VALUE.  */
1761
1762 tree
1763 build_tree_list_stat (tree parm, tree value MEM_STAT_DECL)
1764 {
1765   tree t = make_node_stat (TREE_LIST PASS_MEM_STAT);
1766   TREE_PURPOSE (t) = parm;
1767   TREE_VALUE (t) = value;
1768   return t;
1769 }
1770
1771 /* Return a newly created TREE_LIST node whose
1772    purpose and value fields are PURPOSE and VALUE
1773    and whose TREE_CHAIN is CHAIN.  */
1774
1775 tree
1776 tree_cons_stat (tree purpose, tree value, tree chain MEM_STAT_DECL)
1777 {
1778   tree node;
1779
1780   node = ggc_alloc_zone_pass_stat (sizeof (struct tree_list), &tree_zone);
1781
1782   memset (node, 0, sizeof (struct tree_common));
1783
1784 #ifdef GATHER_STATISTICS
1785   tree_node_counts[(int) x_kind]++;
1786   tree_node_sizes[(int) x_kind] += sizeof (struct tree_list);
1787 #endif
1788
1789   TREE_SET_CODE (node, TREE_LIST);
1790   TREE_CHAIN (node) = chain;
1791   TREE_PURPOSE (node) = purpose;
1792   TREE_VALUE (node) = value;
1793   return node;
1794 }
1795
1796 \f
1797 /* Return the size nominally occupied by an object of type TYPE
1798    when it resides in memory.  The value is measured in units of bytes,
1799    and its data type is that normally used for type sizes
1800    (which is the first type created by make_signed_type or
1801    make_unsigned_type).  */
1802
1803 tree
1804 size_in_bytes (const_tree type)
1805 {
1806   tree t;
1807
1808   if (type == error_mark_node)
1809     return integer_zero_node;
1810
1811   type = TYPE_MAIN_VARIANT (type);
1812   t = TYPE_SIZE_UNIT (type);
1813
1814   if (t == 0)
1815     {
1816       lang_hooks.types.incomplete_type_error (NULL_TREE, type);
1817       return size_zero_node;
1818     }
1819
1820   return t;
1821 }
1822
1823 /* Return the size of TYPE (in bytes) as a wide integer
1824    or return -1 if the size can vary or is larger than an integer.  */
1825
1826 HOST_WIDE_INT
1827 int_size_in_bytes (const_tree type)
1828 {
1829   tree t;
1830
1831   if (type == error_mark_node)
1832     return 0;
1833
1834   type = TYPE_MAIN_VARIANT (type);
1835   t = TYPE_SIZE_UNIT (type);
1836   if (t == 0
1837       || TREE_CODE (t) != INTEGER_CST
1838       || TREE_INT_CST_HIGH (t) != 0
1839       /* If the result would appear negative, it's too big to represent.  */
1840       || (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0)
1841     return -1;
1842
1843   return TREE_INT_CST_LOW (t);
1844 }
1845
1846 /* Return the maximum size of TYPE (in bytes) as a wide integer
1847    or return -1 if the size can vary or is larger than an integer.  */
1848
1849 HOST_WIDE_INT
1850 max_int_size_in_bytes (const_tree type)
1851 {
1852   HOST_WIDE_INT size = -1;
1853   tree size_tree;
1854
1855   /* If this is an array type, check for a possible MAX_SIZE attached.  */
1856
1857   if (TREE_CODE (type) == ARRAY_TYPE)
1858     {
1859       size_tree = TYPE_ARRAY_MAX_SIZE (type);
1860
1861       if (size_tree && host_integerp (size_tree, 1))
1862         size = tree_low_cst (size_tree, 1);
1863     }
1864
1865   /* If we still haven't been able to get a size, see if the language
1866      can compute a maximum size.  */
1867
1868   if (size == -1)
1869     {
1870       size_tree = lang_hooks.types.max_size (type);
1871
1872       if (size_tree && host_integerp (size_tree, 1))
1873         size = tree_low_cst (size_tree, 1);
1874     }
1875
1876   return size;
1877 }
1878 \f
1879 /* Return the bit position of FIELD, in bits from the start of the record.
1880    This is a tree of type bitsizetype.  */
1881
1882 tree
1883 bit_position (const_tree field)
1884 {
1885   return bit_from_pos (DECL_FIELD_OFFSET (field),
1886                        DECL_FIELD_BIT_OFFSET (field));
1887 }
1888
1889 /* Likewise, but return as an integer.  It must be representable in
1890    that way (since it could be a signed value, we don't have the
1891    option of returning -1 like int_size_in_byte can.  */
1892
1893 HOST_WIDE_INT
1894 int_bit_position (const_tree field)
1895 {
1896   return tree_low_cst (bit_position (field), 0);
1897 }
1898 \f
1899 /* Return the byte position of FIELD, in bytes from the start of the record.
1900    This is a tree of type sizetype.  */
1901
1902 tree
1903 byte_position (const_tree field)
1904 {
1905   return byte_from_pos (DECL_FIELD_OFFSET (field),
1906                         DECL_FIELD_BIT_OFFSET (field));
1907 }
1908
1909 /* Likewise, but return as an integer.  It must be representable in
1910    that way (since it could be a signed value, we don't have the
1911    option of returning -1 like int_size_in_byte can.  */
1912
1913 HOST_WIDE_INT
1914 int_byte_position (const_tree field)
1915 {
1916   return tree_low_cst (byte_position (field), 0);
1917 }
1918 \f
1919 /* Return the strictest alignment, in bits, that T is known to have.  */
1920
1921 unsigned int
1922 expr_align (const_tree t)
1923 {
1924   unsigned int align0, align1;
1925
1926   switch (TREE_CODE (t))
1927     {
1928     case NOP_EXPR:  case CONVERT_EXPR:  case NON_LVALUE_EXPR:
1929       /* If we have conversions, we know that the alignment of the
1930          object must meet each of the alignments of the types.  */
1931       align0 = expr_align (TREE_OPERAND (t, 0));
1932       align1 = TYPE_ALIGN (TREE_TYPE (t));
1933       return MAX (align0, align1);
1934
1935     case GIMPLE_MODIFY_STMT:
1936       /* We should never ask for the alignment of a gimple statement.  */
1937       gcc_unreachable ();
1938
1939     case SAVE_EXPR:         case COMPOUND_EXPR:       case MODIFY_EXPR:
1940     case INIT_EXPR:         case TARGET_EXPR:         case WITH_CLEANUP_EXPR:
1941     case CLEANUP_POINT_EXPR:
1942       /* These don't change the alignment of an object.  */
1943       return expr_align (TREE_OPERAND (t, 0));
1944
1945     case COND_EXPR:
1946       /* The best we can do is say that the alignment is the least aligned
1947          of the two arms.  */
1948       align0 = expr_align (TREE_OPERAND (t, 1));
1949       align1 = expr_align (TREE_OPERAND (t, 2));
1950       return MIN (align0, align1);
1951
1952       /* FIXME: LABEL_DECL and CONST_DECL never have DECL_ALIGN set
1953          meaningfully, it's always 1.  */
1954     case LABEL_DECL:     case CONST_DECL:
1955     case VAR_DECL:       case PARM_DECL:   case RESULT_DECL:
1956     case FUNCTION_DECL:
1957       gcc_assert (DECL_ALIGN (t) != 0);
1958       return DECL_ALIGN (t);
1959
1960     default:
1961       break;
1962     }
1963
1964   /* Otherwise take the alignment from that of the type.  */
1965   return TYPE_ALIGN (TREE_TYPE (t));
1966 }
1967 \f
1968 /* Return, as a tree node, the number of elements for TYPE (which is an
1969    ARRAY_TYPE) minus one. This counts only elements of the top array.  */
1970
1971 tree
1972 array_type_nelts (const_tree type)
1973 {
1974   tree index_type, min, max;
1975
1976   /* If they did it with unspecified bounds, then we should have already
1977      given an error about it before we got here.  */
1978   if (! TYPE_DOMAIN (type))
1979     return error_mark_node;
1980
1981   index_type = TYPE_DOMAIN (type);
1982   min = TYPE_MIN_VALUE (index_type);
1983   max = TYPE_MAX_VALUE (index_type);
1984
1985   return (integer_zerop (min)
1986           ? max
1987           : fold_build2 (MINUS_EXPR, TREE_TYPE (max), max, min));
1988 }
1989 \f
1990 /* If arg is static -- a reference to an object in static storage -- then
1991    return the object.  This is not the same as the C meaning of `static'.
1992    If arg isn't static, return NULL.  */
1993
1994 tree
1995 staticp (tree arg)
1996 {
1997   switch (TREE_CODE (arg))
1998     {
1999     case FUNCTION_DECL:
2000       /* Nested functions are static, even though taking their address will
2001          involve a trampoline as we unnest the nested function and create
2002          the trampoline on the tree level.  */
2003       return arg;
2004
2005     case VAR_DECL:
2006       return ((TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2007               && ! DECL_THREAD_LOCAL_P (arg)
2008               && ! DECL_DLLIMPORT_P (arg)
2009               ? arg : NULL);
2010
2011     case CONST_DECL:
2012       return ((TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2013               ? arg : NULL);
2014
2015     case CONSTRUCTOR:
2016       return TREE_STATIC (arg) ? arg : NULL;
2017
2018     case LABEL_DECL:
2019     case STRING_CST:
2020       return arg;
2021
2022     case COMPONENT_REF:
2023       /* If the thing being referenced is not a field, then it is
2024          something language specific.  */
2025       if (TREE_CODE (TREE_OPERAND (arg, 1)) != FIELD_DECL)
2026         return (*lang_hooks.staticp) (arg);
2027
2028       /* If we are referencing a bitfield, we can't evaluate an
2029          ADDR_EXPR at compile time and so it isn't a constant.  */
2030       if (DECL_BIT_FIELD (TREE_OPERAND (arg, 1)))
2031         return NULL;
2032
2033       return staticp (TREE_OPERAND (arg, 0));
2034
2035     case BIT_FIELD_REF:
2036       return NULL;
2037
2038     case MISALIGNED_INDIRECT_REF:
2039     case ALIGN_INDIRECT_REF:
2040     case INDIRECT_REF:
2041       return TREE_CONSTANT (TREE_OPERAND (arg, 0)) ? arg : NULL;
2042
2043     case ARRAY_REF:
2044     case ARRAY_RANGE_REF:
2045       if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2046           && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2047         return staticp (TREE_OPERAND (arg, 0));
2048       else
2049         return false;
2050
2051     default:
2052       if ((unsigned int) TREE_CODE (arg)
2053           >= (unsigned int) LAST_AND_UNUSED_TREE_CODE)
2054         return lang_hooks.staticp (arg);
2055       else
2056         return NULL;
2057     }
2058 }
2059 \f
2060 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2061    Do this to any expression which may be used in more than one place,
2062    but must be evaluated only once.
2063
2064    Normally, expand_expr would reevaluate the expression each time.
2065    Calling save_expr produces something that is evaluated and recorded
2066    the first time expand_expr is called on it.  Subsequent calls to
2067    expand_expr just reuse the recorded value.
2068
2069    The call to expand_expr that generates code that actually computes
2070    the value is the first call *at compile time*.  Subsequent calls
2071    *at compile time* generate code to use the saved value.
2072    This produces correct result provided that *at run time* control
2073    always flows through the insns made by the first expand_expr
2074    before reaching the other places where the save_expr was evaluated.
2075    You, the caller of save_expr, must make sure this is so.
2076
2077    Constants, and certain read-only nodes, are returned with no
2078    SAVE_EXPR because that is safe.  Expressions containing placeholders
2079    are not touched; see tree.def for an explanation of what these
2080    are used for.  */
2081
2082 tree
2083 save_expr (tree expr)
2084 {
2085   tree t = fold (expr);
2086   tree inner;
2087
2088   /* If the tree evaluates to a constant, then we don't want to hide that
2089      fact (i.e. this allows further folding, and direct checks for constants).
2090      However, a read-only object that has side effects cannot be bypassed.
2091      Since it is no problem to reevaluate literals, we just return the
2092      literal node.  */
2093   inner = skip_simple_arithmetic (t);
2094
2095   if (TREE_INVARIANT (inner)
2096       || (TREE_READONLY (inner) && ! TREE_SIDE_EFFECTS (inner))
2097       || TREE_CODE (inner) == SAVE_EXPR
2098       || TREE_CODE (inner) == ERROR_MARK)
2099     return t;
2100
2101   /* If INNER contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2102      it means that the size or offset of some field of an object depends on
2103      the value within another field.
2104
2105      Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2106      and some variable since it would then need to be both evaluated once and
2107      evaluated more than once.  Front-ends must assure this case cannot
2108      happen by surrounding any such subexpressions in their own SAVE_EXPR
2109      and forcing evaluation at the proper time.  */
2110   if (contains_placeholder_p (inner))
2111     return t;
2112
2113   t = build1 (SAVE_EXPR, TREE_TYPE (expr), t);
2114
2115   /* This expression might be placed ahead of a jump to ensure that the
2116      value was computed on both sides of the jump.  So make sure it isn't
2117      eliminated as dead.  */
2118   TREE_SIDE_EFFECTS (t) = 1;
2119   TREE_INVARIANT (t) = 1;
2120   return t;
2121 }
2122
2123 /* Look inside EXPR and into any simple arithmetic operations.  Return
2124    the innermost non-arithmetic node.  */
2125
2126 tree
2127 skip_simple_arithmetic (tree expr)
2128 {
2129   tree inner;
2130
2131   /* We don't care about whether this can be used as an lvalue in this
2132      context.  */
2133   while (TREE_CODE (expr) == NON_LVALUE_EXPR)
2134     expr = TREE_OPERAND (expr, 0);
2135
2136   /* If we have simple operations applied to a SAVE_EXPR or to a SAVE_EXPR and
2137      a constant, it will be more efficient to not make another SAVE_EXPR since
2138      it will allow better simplification and GCSE will be able to merge the
2139      computations if they actually occur.  */
2140   inner = expr;
2141   while (1)
2142     {
2143       if (UNARY_CLASS_P (inner))
2144         inner = TREE_OPERAND (inner, 0);
2145       else if (BINARY_CLASS_P (inner))
2146         {
2147           if (TREE_INVARIANT (TREE_OPERAND (inner, 1)))
2148             inner = TREE_OPERAND (inner, 0);
2149           else if (TREE_INVARIANT (TREE_OPERAND (inner, 0)))
2150             inner = TREE_OPERAND (inner, 1);
2151           else
2152             break;
2153         }
2154       else
2155         break;
2156     }
2157
2158   return inner;
2159 }
2160
2161 /* Return which tree structure is used by T.  */
2162
2163 enum tree_node_structure_enum
2164 tree_node_structure (const_tree t)
2165 {
2166   const enum tree_code code = TREE_CODE (t);
2167
2168   switch (TREE_CODE_CLASS (code))
2169     {
2170     case tcc_declaration:
2171       {
2172         switch (code)
2173           {
2174           case FIELD_DECL:
2175             return TS_FIELD_DECL;
2176           case PARM_DECL:
2177             return TS_PARM_DECL;
2178           case VAR_DECL:
2179             return TS_VAR_DECL;
2180           case LABEL_DECL:
2181             return TS_LABEL_DECL;
2182           case RESULT_DECL:
2183             return TS_RESULT_DECL;
2184           case CONST_DECL:
2185             return TS_CONST_DECL;
2186           case TYPE_DECL:
2187             return TS_TYPE_DECL;
2188           case FUNCTION_DECL:
2189             return TS_FUNCTION_DECL;
2190           case SYMBOL_MEMORY_TAG:
2191           case NAME_MEMORY_TAG:
2192           case STRUCT_FIELD_TAG:
2193           case MEMORY_PARTITION_TAG:
2194             return TS_MEMORY_TAG;
2195           default:
2196             return TS_DECL_NON_COMMON;
2197           }
2198       }
2199     case tcc_type:
2200       return TS_TYPE;
2201     case tcc_reference:
2202     case tcc_comparison:
2203     case tcc_unary:
2204     case tcc_binary:
2205     case tcc_expression:
2206     case tcc_statement:
2207     case tcc_vl_exp:
2208       return TS_EXP;
2209     case tcc_gimple_stmt:
2210       return TS_GIMPLE_STATEMENT;
2211     default:  /* tcc_constant and tcc_exceptional */
2212       break;
2213     }
2214   switch (code)
2215     {
2216       /* tcc_constant cases.  */
2217     case INTEGER_CST:           return TS_INT_CST;
2218     case REAL_CST:              return TS_REAL_CST;
2219     case FIXED_CST:             return TS_FIXED_CST;
2220     case COMPLEX_CST:           return TS_COMPLEX;
2221     case VECTOR_CST:            return TS_VECTOR;
2222     case STRING_CST:            return TS_STRING;
2223       /* tcc_exceptional cases.  */
2224     /* FIXME tuples: eventually this should be TS_BASE.  For now, nothing
2225        returns TS_BASE.  */
2226     case ERROR_MARK:            return TS_COMMON;
2227     case IDENTIFIER_NODE:       return TS_IDENTIFIER;
2228     case TREE_LIST:             return TS_LIST;
2229     case TREE_VEC:              return TS_VEC;
2230     case PHI_NODE:              return TS_PHI_NODE;
2231     case SSA_NAME:              return TS_SSA_NAME;
2232     case PLACEHOLDER_EXPR:      return TS_COMMON;
2233     case STATEMENT_LIST:        return TS_STATEMENT_LIST;
2234     case BLOCK:                 return TS_BLOCK;
2235     case CONSTRUCTOR:           return TS_CONSTRUCTOR;
2236     case TREE_BINFO:            return TS_BINFO;
2237     case VALUE_HANDLE:          return TS_VALUE_HANDLE;
2238     case OMP_CLAUSE:            return TS_OMP_CLAUSE;
2239
2240     default:
2241       gcc_unreachable ();
2242     }
2243 }
2244 \f
2245 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2246    or offset that depends on a field within a record.  */
2247
2248 bool
2249 contains_placeholder_p (const_tree exp)
2250 {
2251   enum tree_code code;
2252
2253   if (!exp)
2254     return 0;
2255
2256   code = TREE_CODE (exp);
2257   if (code == PLACEHOLDER_EXPR)
2258     return 1;
2259
2260   switch (TREE_CODE_CLASS (code))
2261     {
2262     case tcc_reference:
2263       /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2264          position computations since they will be converted into a
2265          WITH_RECORD_EXPR involving the reference, which will assume
2266          here will be valid.  */
2267       return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0));
2268
2269     case tcc_exceptional:
2270       if (code == TREE_LIST)
2271         return (CONTAINS_PLACEHOLDER_P (TREE_VALUE (exp))
2272                 || CONTAINS_PLACEHOLDER_P (TREE_CHAIN (exp)));
2273       break;
2274
2275     case tcc_unary:
2276     case tcc_binary:
2277     case tcc_comparison:
2278     case tcc_expression:
2279       switch (code)
2280         {
2281         case COMPOUND_EXPR:
2282           /* Ignoring the first operand isn't quite right, but works best.  */
2283           return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1));
2284
2285         case COND_EXPR:
2286           return (CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0))
2287                   || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1))
2288                   || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 2)));
2289
2290         default:
2291           break;
2292         }
2293
2294       switch (TREE_CODE_LENGTH (code))
2295         {
2296         case 1:
2297           return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0));
2298         case 2:
2299           return (CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0))
2300                   || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1)));
2301         default:
2302           return 0;
2303         }
2304
2305     case tcc_vl_exp:
2306       switch (code)
2307         {
2308         case CALL_EXPR:
2309           {
2310             const_tree arg;
2311             const_call_expr_arg_iterator iter;
2312             FOR_EACH_CONST_CALL_EXPR_ARG (arg, iter, exp)
2313               if (CONTAINS_PLACEHOLDER_P (arg))
2314                 return 1;
2315             return 0;
2316           }
2317         default:
2318           return 0;
2319         }
2320
2321     default:
2322       return 0;
2323     }
2324   return 0;
2325 }
2326
2327 /* Return true if any part of the computation of TYPE involves a
2328    PLACEHOLDER_EXPR.  This includes size, bounds, qualifiers
2329    (for QUAL_UNION_TYPE) and field positions.  */
2330
2331 static bool
2332 type_contains_placeholder_1 (const_tree type)
2333 {
2334   /* If the size contains a placeholder or the parent type (component type in
2335      the case of arrays) type involves a placeholder, this type does.  */
2336   if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
2337       || CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (type))
2338       || (TREE_TYPE (type) != 0
2339           && type_contains_placeholder_p (TREE_TYPE (type))))
2340     return true;
2341
2342   /* Now do type-specific checks.  Note that the last part of the check above
2343      greatly limits what we have to do below.  */
2344   switch (TREE_CODE (type))
2345     {
2346     case VOID_TYPE:
2347     case COMPLEX_TYPE:
2348     case ENUMERAL_TYPE:
2349     case BOOLEAN_TYPE:
2350     case POINTER_TYPE:
2351     case OFFSET_TYPE:
2352     case REFERENCE_TYPE:
2353     case METHOD_TYPE:
2354     case FUNCTION_TYPE:
2355     case VECTOR_TYPE:
2356       return false;
2357
2358     case INTEGER_TYPE:
2359     case REAL_TYPE:
2360     case FIXED_POINT_TYPE:
2361       /* Here we just check the bounds.  */
2362       return (CONTAINS_PLACEHOLDER_P (TYPE_MIN_VALUE (type))
2363               || CONTAINS_PLACEHOLDER_P (TYPE_MAX_VALUE (type)));
2364
2365     case ARRAY_TYPE:
2366       /* We're already checked the component type (TREE_TYPE), so just check
2367          the index type.  */
2368       return type_contains_placeholder_p (TYPE_DOMAIN (type));
2369
2370     case RECORD_TYPE:
2371     case UNION_TYPE:
2372     case QUAL_UNION_TYPE:
2373       {
2374         tree field;
2375
2376         for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
2377           if (TREE_CODE (field) == FIELD_DECL
2378               && (CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (field))
2379                   || (TREE_CODE (type) == QUAL_UNION_TYPE
2380                       && CONTAINS_PLACEHOLDER_P (DECL_QUALIFIER (field)))
2381                   || type_contains_placeholder_p (TREE_TYPE (field))))
2382             return true;
2383
2384         return false;
2385       }
2386
2387     default:
2388       gcc_unreachable ();
2389     }
2390 }
2391
2392 bool
2393 type_contains_placeholder_p (tree type)
2394 {
2395   bool result;
2396
2397   /* If the contains_placeholder_bits field has been initialized,
2398      then we know the answer.  */
2399   if (TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) > 0)
2400     return TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) - 1;
2401
2402   /* Indicate that we've seen this type node, and the answer is false.
2403      This is what we want to return if we run into recursion via fields.  */
2404   TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) = 1;
2405
2406   /* Compute the real value.  */
2407   result = type_contains_placeholder_1 (type);
2408
2409   /* Store the real value.  */
2410   TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) = result + 1;
2411
2412   return result;
2413 }
2414 \f
2415 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2416    return a tree with all occurrences of references to F in a
2417    PLACEHOLDER_EXPR replaced by R.   Note that we assume here that EXP
2418    contains only arithmetic expressions or a CALL_EXPR with a
2419    PLACEHOLDER_EXPR occurring only in its arglist.  */
2420
2421 tree
2422 substitute_in_expr (tree exp, tree f, tree r)
2423 {
2424   enum tree_code code = TREE_CODE (exp);
2425   tree op0, op1, op2, op3;
2426   tree new;
2427   tree inner;
2428
2429   /* We handle TREE_LIST and COMPONENT_REF separately.  */
2430   if (code == TREE_LIST)
2431     {
2432       op0 = SUBSTITUTE_IN_EXPR (TREE_CHAIN (exp), f, r);
2433       op1 = SUBSTITUTE_IN_EXPR (TREE_VALUE (exp), f, r);
2434       if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2435         return exp;
2436
2437       return tree_cons (TREE_PURPOSE (exp), op1, op0);
2438     }
2439   else if (code == COMPONENT_REF)
2440    {
2441      /* If this expression is getting a value from a PLACEHOLDER_EXPR
2442         and it is the right field, replace it with R.  */
2443      for (inner = TREE_OPERAND (exp, 0);
2444           REFERENCE_CLASS_P (inner);
2445           inner = TREE_OPERAND (inner, 0))
2446        ;
2447      if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2448          && TREE_OPERAND (exp, 1) == f)
2449        return r;
2450
2451      /* If this expression hasn't been completed let, leave it alone.  */
2452      if (TREE_CODE (inner) == PLACEHOLDER_EXPR && TREE_TYPE (inner) == 0)
2453        return exp;
2454
2455      op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
2456      if (op0 == TREE_OPERAND (exp, 0))
2457        return exp;
2458
2459      new = fold_build3 (COMPONENT_REF, TREE_TYPE (exp),
2460                         op0, TREE_OPERAND (exp, 1), NULL_TREE);
2461    }
2462   else
2463     switch (TREE_CODE_CLASS (code))
2464       {
2465       case tcc_constant:
2466       case tcc_declaration:
2467         return exp;
2468
2469       case tcc_exceptional:
2470       case tcc_unary:
2471       case tcc_binary:
2472       case tcc_comparison:
2473       case tcc_expression:
2474       case tcc_reference:
2475         switch (TREE_CODE_LENGTH (code))
2476           {
2477           case 0:
2478             return exp;
2479
2480           case 1:
2481             op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
2482             if (op0 == TREE_OPERAND (exp, 0))
2483               return exp;
2484
2485             new = fold_build1 (code, TREE_TYPE (exp), op0);
2486             break;
2487
2488           case 2:
2489             op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
2490             op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
2491
2492             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2493               return exp;
2494
2495             new = fold_build2 (code, TREE_TYPE (exp), op0, op1);
2496             break;
2497
2498           case 3:
2499             op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
2500             op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
2501             op2 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 2), f, r);
2502
2503             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2504                 && op2 == TREE_OPERAND (exp, 2))
2505               return exp;
2506
2507             new = fold_build3 (code, TREE_TYPE (exp), op0, op1, op2);
2508             break;
2509
2510           case 4:
2511             op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
2512             op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
2513             op2 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 2), f, r);
2514             op3 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 3), f, r);
2515
2516             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2517                 && op2 == TREE_OPERAND (exp, 2)
2518                 && op3 == TREE_OPERAND (exp, 3))
2519               return exp;
2520
2521             new = fold (build4 (code, TREE_TYPE (exp), op0, op1, op2, op3));
2522             break;
2523
2524           default:
2525             gcc_unreachable ();
2526           }
2527         break;
2528
2529       case tcc_vl_exp:
2530         {
2531           tree copy = NULL_TREE;
2532           int i;
2533           int n = TREE_OPERAND_LENGTH (exp);
2534           for (i = 1; i < n; i++)
2535             {
2536               tree op = TREE_OPERAND (exp, i);
2537               tree newop = SUBSTITUTE_IN_EXPR (op, f, r);
2538               if (newop != op)
2539                 {
2540                   copy = copy_node (exp);
2541                   TREE_OPERAND (copy, i) = newop;
2542                 }
2543             }
2544           if (copy)
2545             new = fold (copy);
2546           else
2547             return exp;
2548         }
2549
2550       default:
2551         gcc_unreachable ();
2552       }
2553
2554   TREE_READONLY (new) = TREE_READONLY (exp);
2555   return new;
2556 }
2557
2558 /* Similar, but look for a PLACEHOLDER_EXPR in EXP and find a replacement
2559    for it within OBJ, a tree that is an object or a chain of references.  */
2560
2561 tree
2562 substitute_placeholder_in_expr (tree exp, tree obj)
2563 {
2564   enum tree_code code = TREE_CODE (exp);
2565   tree op0, op1, op2, op3;
2566
2567   /* If this is a PLACEHOLDER_EXPR, see if we find a corresponding type
2568      in the chain of OBJ.  */
2569   if (code == PLACEHOLDER_EXPR)
2570     {
2571       tree need_type = TYPE_MAIN_VARIANT (TREE_TYPE (exp));
2572       tree elt;
2573
2574       for (elt = obj; elt != 0;
2575            elt = ((TREE_CODE (elt) == COMPOUND_EXPR
2576                    || TREE_CODE (elt) == COND_EXPR)
2577                   ? TREE_OPERAND (elt, 1)
2578                   : (REFERENCE_CLASS_P (elt)
2579                      || UNARY_CLASS_P (elt)
2580                      || BINARY_CLASS_P (elt)
2581                      || VL_EXP_CLASS_P (elt)
2582                      || EXPRESSION_CLASS_P (elt))
2583                   ? TREE_OPERAND (elt, 0) : 0))
2584         if (TYPE_MAIN_VARIANT (TREE_TYPE (elt)) == need_type)
2585           return elt;
2586
2587       for (elt = obj; elt != 0;
2588            elt = ((TREE_CODE (elt) == COMPOUND_EXPR
2589                    || TREE_CODE (elt) == COND_EXPR)
2590                   ? TREE_OPERAND (elt, 1)
2591                   : (REFERENCE_CLASS_P (elt)
2592                      || UNARY_CLASS_P (elt)
2593                      || BINARY_CLASS_P (elt)
2594                      || VL_EXP_CLASS_P (elt)
2595                      || EXPRESSION_CLASS_P (elt))
2596                   ? TREE_OPERAND (elt, 0) : 0))
2597         if (POINTER_TYPE_P (TREE_TYPE (elt))
2598             && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (elt)))
2599                 == need_type))
2600           return fold_build1 (INDIRECT_REF, need_type, elt);
2601
2602       /* If we didn't find it, return the original PLACEHOLDER_EXPR.  If it
2603          survives until RTL generation, there will be an error.  */
2604       return exp;
2605     }
2606
2607   /* TREE_LIST is special because we need to look at TREE_VALUE
2608      and TREE_CHAIN, not TREE_OPERANDS.  */
2609   else if (code == TREE_LIST)
2610     {
2611       op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_CHAIN (exp), obj);
2612       op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_VALUE (exp), obj);
2613       if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2614         return exp;
2615
2616       return tree_cons (TREE_PURPOSE (exp), op1, op0);
2617     }
2618   else
2619     switch (TREE_CODE_CLASS (code))
2620       {
2621       case tcc_constant:
2622       case tcc_declaration:
2623         return exp;
2624
2625       case tcc_exceptional:
2626       case tcc_unary:
2627       case tcc_binary:
2628       case tcc_comparison:
2629       case tcc_expression:
2630       case tcc_reference:
2631       case tcc_statement:
2632         switch (TREE_CODE_LENGTH (code))
2633           {
2634           case 0:
2635             return exp;
2636
2637           case 1:
2638             op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
2639             if (op0 == TREE_OPERAND (exp, 0))
2640               return exp;
2641             else
2642               return fold_build1 (code, TREE_TYPE (exp), op0);
2643
2644           case 2:
2645             op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
2646             op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
2647
2648             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2649               return exp;
2650             else
2651               return fold_build2 (code, TREE_TYPE (exp), op0, op1);
2652
2653           case 3:
2654             op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
2655             op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
2656             op2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 2), obj);
2657
2658             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2659                 && op2 == TREE_OPERAND (exp, 2))
2660               return exp;
2661             else
2662               return fold_build3 (code, TREE_TYPE (exp), op0, op1, op2);
2663
2664           case 4:
2665             op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
2666             op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
2667             op2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 2), obj);
2668             op3 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 3), obj);
2669
2670             if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2671                 && op2 == TREE_OPERAND (exp, 2)
2672                 && op3 == TREE_OPERAND (exp, 3))
2673               return exp;
2674             else
2675               return fold (build4 (code, TREE_TYPE (exp), op0, op1, op2, op3));
2676
2677           default:
2678             gcc_unreachable ();
2679           }
2680         break;
2681
2682       case tcc_vl_exp:
2683         {
2684           tree copy = NULL_TREE;
2685           int i;
2686           int n = TREE_OPERAND_LENGTH (exp);
2687           for (i = 1; i < n; i++)
2688             {
2689               tree op = TREE_OPERAND (exp, i);
2690               tree newop = SUBSTITUTE_PLACEHOLDER_IN_EXPR (op, obj);
2691               if (newop != op)
2692                 {
2693                   if (!copy)
2694                     copy = copy_node (exp);
2695                   TREE_OPERAND (copy, i) = newop;
2696                 }
2697             }
2698           if (copy)
2699             return fold (copy);
2700           else
2701             return exp;
2702         }
2703
2704       default:
2705         gcc_unreachable ();
2706       }
2707 }
2708 \f
2709 /* Stabilize a reference so that we can use it any number of times
2710    without causing its operands to be evaluated more than once.
2711    Returns the stabilized reference.  This works by means of save_expr,
2712    so see the caveats in the comments about save_expr.
2713
2714    Also allows conversion expressions whose operands are references.
2715    Any other kind of expression is returned unchanged.  */
2716
2717 tree
2718 stabilize_reference (tree ref)
2719 {
2720   tree result;
2721   enum tree_code code = TREE_CODE (ref);
2722
2723   switch (code)
2724     {
2725     case VAR_DECL:
2726     case PARM_DECL:
2727     case RESULT_DECL:
2728       /* No action is needed in this case.  */
2729       return ref;
2730
2731     case NOP_EXPR:
2732     case CONVERT_EXPR:
2733     case FLOAT_EXPR:
2734     case FIX_TRUNC_EXPR:
2735       result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2736       break;
2737
2738     case INDIRECT_REF:
2739       result = build_nt (INDIRECT_REF,
2740                          stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2741       break;
2742
2743     case COMPONENT_REF:
2744       result = build_nt (COMPONENT_REF,
2745                          stabilize_reference (TREE_OPERAND (ref, 0)),
2746                          TREE_OPERAND (ref, 1), NULL_TREE);
2747       break;
2748
2749     case BIT_FIELD_REF:
2750       result = build_nt (BIT_FIELD_REF,
2751                          stabilize_reference (TREE_OPERAND (ref, 0)),
2752                          stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2753                          stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2754       break;
2755
2756     case ARRAY_REF:
2757       result = build_nt (ARRAY_REF,
2758                          stabilize_reference (TREE_OPERAND (ref, 0)),
2759                          stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2760                          TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
2761       break;
2762
2763     case ARRAY_RANGE_REF:
2764       result = build_nt (ARRAY_RANGE_REF,
2765                          stabilize_reference (TREE_OPERAND (ref, 0)),
2766                          stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2767                          TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
2768       break;
2769
2770     case COMPOUND_EXPR:
2771       /* We cannot wrap the first expression in a SAVE_EXPR, as then
2772          it wouldn't be ignored.  This matters when dealing with
2773          volatiles.  */
2774       return stabilize_reference_1 (ref);
2775
2776       /* If arg isn't a kind of lvalue we recognize, make no change.
2777          Caller should recognize the error for an invalid lvalue.  */
2778     default:
2779       return ref;
2780
2781     case ERROR_MARK:
2782       return error_mark_node;
2783     }
2784
2785   TREE_TYPE (result) = TREE_TYPE (ref);
2786   TREE_READONLY (result) = TREE_READONLY (ref);
2787   TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2788   TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2789
2790   return result;
2791 }
2792
2793 /* Subroutine of stabilize_reference; this is called for subtrees of
2794    references.  Any expression with side-effects must be put in a SAVE_EXPR
2795    to ensure that it is only evaluated once.
2796
2797    We don't put SAVE_EXPR nodes around everything, because assigning very
2798    simple expressions to temporaries causes us to miss good opportunities
2799    for optimizations.  Among other things, the opportunity to fold in the
2800    addition of a constant into an addressing mode often gets lost, e.g.
2801    "y[i+1] += x;".  In general, we take the approach that we should not make
2802    an assignment unless we are forced into it - i.e., that any non-side effect
2803    operator should be allowed, and that cse should take care of coalescing
2804    multiple utterances of the same expression should that prove fruitful.  */
2805
2806 tree
2807 stabilize_reference_1 (tree e)
2808 {
2809   tree result;
2810   enum tree_code code = TREE_CODE (e);
2811
2812   /* We cannot ignore const expressions because it might be a reference
2813      to a const array but whose index contains side-effects.  But we can
2814      ignore things that are actual constant or that already have been
2815      handled by this function.  */
2816
2817   if (TREE_INVARIANT (e))
2818     return e;
2819
2820   switch (TREE_CODE_CLASS (code))
2821     {
2822     case tcc_exceptional:
2823     case tcc_type:
2824     case tcc_declaration:
2825     case tcc_comparison:
2826     case tcc_statement:
2827     case tcc_expression:
2828     case tcc_reference:
2829     case tcc_vl_exp:
2830       /* If the expression has side-effects, then encase it in a SAVE_EXPR
2831          so that it will only be evaluated once.  */
2832       /* The reference (r) and comparison (<) classes could be handled as
2833          below, but it is generally faster to only evaluate them once.  */
2834       if (TREE_SIDE_EFFECTS (e))
2835         return save_expr (e);
2836       return e;
2837
2838     case tcc_constant:
2839       /* Constants need no processing.  In fact, we should never reach
2840          here.  */
2841       return e;
2842
2843     case tcc_binary:
2844       /* Division is slow and tends to be compiled with jumps,
2845          especially the division by powers of 2 that is often
2846          found inside of an array reference.  So do it just once.  */
2847       if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2848           || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2849           || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2850           || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2851         return save_expr (e);
2852       /* Recursively stabilize each operand.  */
2853       result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2854                          stabilize_reference_1 (TREE_OPERAND (e, 1)));
2855       break;
2856
2857     case tcc_unary:
2858       /* Recursively stabilize each operand.  */
2859       result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2860       break;
2861
2862     default:
2863       gcc_unreachable ();
2864     }
2865
2866   TREE_TYPE (result) = TREE_TYPE (e);
2867   TREE_READONLY (result) = TREE_READONLY (e);
2868   TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2869   TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2870   TREE_INVARIANT (result) = 1;
2871
2872   return result;
2873 }
2874 \f
2875 /* Low-level constructors for expressions.  */
2876
2877 /* A helper function for build1 and constant folders.  Set TREE_CONSTANT,
2878    TREE_INVARIANT, and TREE_SIDE_EFFECTS for an ADDR_EXPR.  */
2879
2880 void
2881 recompute_tree_invariant_for_addr_expr (tree t)
2882 {
2883   tree node;
2884   bool tc = true, ti = true, se = false;
2885
2886   /* We started out assuming this address is both invariant and constant, but
2887      does not have side effects.  Now go down any handled components and see if
2888      any of them involve offsets that are either non-constant or non-invariant.
2889      Also check for side-effects.
2890
2891      ??? Note that this code makes no attempt to deal with the case where
2892      taking the address of something causes a copy due to misalignment.  */
2893
2894 #define UPDATE_TITCSE(NODE)  \
2895 do { tree _node = (NODE); \
2896      if (_node && !TREE_INVARIANT (_node)) ti = false; \
2897      if (_node && !TREE_CONSTANT (_node)) tc = false; \
2898      if (_node && TREE_SIDE_EFFECTS (_node)) se = true; } while (0)
2899
2900   for (node = TREE_OPERAND (t, 0); handled_component_p (node);
2901        node = TREE_OPERAND (node, 0))
2902     {
2903       /* If the first operand doesn't have an ARRAY_TYPE, this is a bogus
2904          array reference (probably made temporarily by the G++ front end),
2905          so ignore all the operands.  */
2906       if ((TREE_CODE (node) == ARRAY_REF
2907            || TREE_CODE (node) == ARRAY_RANGE_REF)
2908           && TREE_CODE (TREE_TYPE (TREE_OPERAND (node, 0))) == ARRAY_TYPE)
2909         {
2910           UPDATE_TITCSE (TREE_OPERAND (node, 1));
2911           if (TREE_OPERAND (node, 2))
2912             UPDATE_TITCSE (TREE_OPERAND (node, 2));
2913           if (TREE_OPERAND (node, 3))
2914             UPDATE_TITCSE (TREE_OPERAND (node, 3));
2915         }
2916       /* Likewise, just because this is a COMPONENT_REF doesn't mean we have a
2917          FIELD_DECL, apparently.  The G++ front end can put something else
2918          there, at least temporarily.  */
2919       else if (TREE_CODE (node) == COMPONENT_REF
2920                && TREE_CODE (TREE_OPERAND (node, 1)) == FIELD_DECL)
2921         {
2922           if (TREE_OPERAND (node, 2))
2923             UPDATE_TITCSE (TREE_OPERAND (node, 2));
2924         }
2925       else if (TREE_CODE (node) == BIT_FIELD_REF)
2926         UPDATE_TITCSE (TREE_OPERAND (node, 2));
2927     }
2928
2929   node = lang_hooks.expr_to_decl (node, &tc, &ti, &se);
2930
2931   /* Now see what's inside.  If it's an INDIRECT_REF, copy our properties from
2932      the address, since &(*a)->b is a form of addition.  If it's a decl, it's
2933      invariant and constant if the decl is static.  It's also invariant if it's
2934      a decl in the current function.  Taking the address of a volatile variable
2935      is not volatile.  If it's a constant, the address is both invariant and
2936      constant.  Otherwise it's neither.  */
2937   if (TREE_CODE (node) == INDIRECT_REF)
2938     UPDATE_TITCSE (TREE_OPERAND (node, 0));
2939   else if (DECL_P (node))
2940     {
2941       if (staticp (node))
2942         ;
2943       else if (decl_function_context (node) == current_function_decl
2944                /* Addresses of thread-local variables are invariant.  */
2945                || (TREE_CODE (node) == VAR_DECL
2946                    && DECL_THREAD_LOCAL_P (node)))
2947         tc = false;
2948       else
2949         ti = tc = false;
2950     }
2951   else if (CONSTANT_CLASS_P (node))
2952     ;
2953   else
2954     {
2955       ti = tc = false;
2956       se |= TREE_SIDE_EFFECTS (node);
2957     }
2958
2959   TREE_CONSTANT (t) = tc;
2960   TREE_INVARIANT (t) = ti;
2961   TREE_SIDE_EFFECTS (t) = se;
2962 #undef UPDATE_TITCSE
2963 }
2964
2965 /* Build an expression of code CODE, data type TYPE, and operands as
2966    specified.  Expressions and reference nodes can be created this way.
2967    Constants, decls, types and misc nodes cannot be.
2968
2969    We define 5 non-variadic functions, from 0 to 4 arguments.  This is
2970    enough for all extant tree codes.  */
2971
2972 tree
2973 build0_stat (enum tree_code code, tree tt MEM_STAT_DECL)
2974 {
2975   tree t;
2976
2977   gcc_assert (TREE_CODE_LENGTH (code) == 0);
2978
2979   t = make_node_stat (code PASS_MEM_STAT);
2980   TREE_TYPE (t) = tt;
2981
2982   return t;
2983 }
2984
2985 tree
2986 build1_stat (enum tree_code code, tree type, tree node MEM_STAT_DECL)
2987 {
2988   int length = sizeof (struct tree_exp);
2989 #ifdef GATHER_STATISTICS
2990   tree_node_kind kind;
2991 #endif
2992   tree t;
2993
2994 #ifdef GATHER_STATISTICS
2995   switch (TREE_CODE_CLASS (code))
2996     {
2997     case tcc_statement:  /* an expression with side effects */
2998       kind = s_kind;
2999       break;
3000     case tcc_reference:  /* a reference */
3001       kind = r_kind;
3002       break;
3003     default:
3004       kind = e_kind;
3005       break;
3006     }
3007
3008   tree_node_counts[(int) kind]++;
3009   tree_node_sizes[(int) kind] += length;
3010 #endif
3011
3012   gcc_assert (TREE_CODE_LENGTH (code) == 1);
3013
3014   t = ggc_alloc_zone_pass_stat (length, &tree_zone);
3015
3016   memset (t, 0, sizeof (struct tree_common));
3017
3018   TREE_SET_CODE (t, code);
3019
3020   TREE_TYPE (t) = type;
3021 #ifdef USE_MAPPED_LOCATION
3022   SET_EXPR_LOCATION (t, UNKNOWN_LOCATION);
3023 #else
3024   SET_EXPR_LOCUS (t, NULL);
3025 #endif
3026   TREE_OPERAND (t, 0) = node;
3027   TREE_BLOCK (t) = NULL_TREE;
3028   if (node && !TYPE_P (node))
3029     {
3030       TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (node);
3031       TREE_READONLY (t) = TREE_READONLY (node);
3032     }
3033
3034   if (TREE_CODE_CLASS (code) == tcc_statement)
3035     TREE_SIDE_EFFECTS (t) = 1;
3036   else switch (code)
3037     {
3038     case VA_ARG_EXPR:
3039       /* All of these have side-effects, no matter what their
3040          operands are.  */
3041       TREE_SIDE_EFFECTS (t) = 1;
3042       TREE_READONLY (t) = 0;
3043       break;
3044
3045     case MISALIGNED_INDIRECT_REF:
3046     case ALIGN_INDIRECT_REF:
3047     case INDIRECT_REF:
3048       /* Whether a dereference is readonly has nothing to do with whether
3049          its operand is readonly.  */
3050       TREE_READONLY (t) = 0;
3051       break;
3052
3053     case ADDR_EXPR:
3054       if (node)
3055         recompute_tree_invariant_for_addr_expr (t);
3056       break;
3057
3058     default:
3059       if ((TREE_CODE_CLASS (code) == tcc_unary || code == VIEW_CONVERT_EXPR)
3060           && node && !TYPE_P (node)
3061           && TREE_CONSTANT (node))
3062         TREE_CONSTANT (t) = 1;
3063       if ((TREE_CODE_CLASS (code) == tcc_unary || code == VIEW_CONVERT_EXPR)
3064           && node && TREE_INVARIANT (node))
3065         TREE_INVARIANT (t) = 1;
3066       if (TREE_CODE_CLASS (code) == tcc_reference
3067           && node && TREE_THIS_VOLATILE (node))
3068         TREE_THIS_VOLATILE (t) = 1;
3069       break;
3070     }
3071
3072   return t;
3073 }
3074
3075 #define PROCESS_ARG(N)                  \
3076   do {                                  \
3077     TREE_OPERAND (t, N) = arg##N;       \
3078     if (arg##N &&!TYPE_P (arg##N))      \
3079       {                                 \
3080         if (TREE_SIDE_EFFECTS (arg##N)) \
3081           side_effects = 1;             \
3082         if (!TREE_READONLY (arg##N))    \
3083           read_only = 0;                \
3084         if (!TREE_CONSTANT (arg##N))    \
3085           constant = 0;                 \
3086         if (!TREE_INVARIANT (arg##N))   \
3087           invariant = 0;                \
3088       }                                 \
3089   } while (0)
3090
3091 tree
3092 build2_stat (enum tree_code code, tree tt, tree arg0, tree arg1 MEM_STAT_DECL)
3093 {
3094   bool constant, read_only, side_effects, invariant;
3095   tree t;
3096
3097   gcc_assert (TREE_CODE_LENGTH (code) == 2);
3098
3099 #if 1
3100   /* FIXME tuples: Statement's aren't expressions!  */
3101   if (code == GIMPLE_MODIFY_STMT)
3102     return build_gimple_modify_stmt_stat (arg0, arg1 PASS_MEM_STAT);
3103 #else
3104   /* Must use build_gimple_modify_stmt to construct GIMPLE_MODIFY_STMTs.  */
3105   gcc_assert (code != GIMPLE_MODIFY_STMT);
3106 #endif
3107
3108   if ((code == MINUS_EXPR || code == PLUS_EXPR || code == MULT_EXPR)
3109       && arg0 && arg1 && tt && POINTER_TYPE_P (tt))
3110     gcc_assert (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST);
3111
3112   if (code == POINTER_PLUS_EXPR && arg0 && arg1 && tt)
3113     gcc_assert (POINTER_TYPE_P (tt) && POINTER_TYPE_P (TREE_TYPE (arg0))
3114                 && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
3115                 && useless_type_conversion_p (sizetype, TREE_TYPE (arg1)));
3116
3117   t = make_node_stat (code PASS_MEM_STAT);
3118   TREE_TYPE (t) = tt;
3119
3120   /* Below, we automatically set TREE_SIDE_EFFECTS and TREE_READONLY for the
3121      result based on those same flags for the arguments.  But if the
3122      arguments aren't really even `tree' expressions, we shouldn't be trying
3123      to do this.  */
3124
3125   /* Expressions without side effects may be constant if their
3126      arguments are as well.  */
3127   constant = (TREE_CODE_CLASS (code) == tcc_comparison
3128               || TREE_CODE_CLASS (code) == tcc_binary);
3129   read_only = 1;
3130   side_effects = TREE_SIDE_EFFECTS (t);
3131   invariant = constant;
3132
3133   PROCESS_ARG(0);
3134   PROCESS_ARG(1);
3135
3136   TREE_READONLY (t) = read_only;
3137   TREE_CONSTANT (t) = constant;
3138   TREE_INVARIANT (t) = invariant;
3139   TREE_SIDE_EFFECTS (t) = side_effects;
3140   TREE_THIS_VOLATILE (t)
3141     = (TREE_CODE_CLASS (code) == tcc_reference
3142        && arg0 && TREE_THIS_VOLATILE (arg0));
3143
3144   return t;
3145 }
3146
3147
3148 /* Build a GIMPLE_MODIFY_STMT node.  This tree code doesn't have a
3149    type, so we can't use build2 (a.k.a. build2_stat).  */
3150
3151 tree
3152 build_gimple_modify_stmt_stat (tree arg0, tree arg1 MEM_STAT_DECL)
3153 {
3154   tree t;
3155
3156   t = make_node_stat (GIMPLE_MODIFY_STMT PASS_MEM_STAT);
3157   /* ?? We don't care about setting flags for tuples...  */
3158   GIMPLE_STMT_OPERAND (t, 0) = arg0;
3159   GIMPLE_STMT_OPERAND (t, 1) = arg1;
3160   return t;
3161 }
3162
3163 tree
3164 build3_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3165              tree arg2 MEM_STAT_DECL)
3166 {
3167   bool constant, read_only, side_effects, invariant;
3168   tree t;
3169
3170   gcc_assert (TREE_CODE_LENGTH (code) == 3);
3171   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
3172
3173   t = make_node_stat (code PASS_MEM_STAT);
3174   TREE_TYPE (t) = tt;
3175
3176   /* As a special exception, if COND_EXPR has NULL branches, we
3177      assume that it is a gimple statement and always consider
3178      it to have side effects.  */
3179   if (code == COND_EXPR
3180       && tt == void_type_node
3181       && arg1 == NULL_TREE
3182       && arg2 == NULL_TREE)
3183     side_effects = true;
3184   else
3185     side_effects = TREE_SIDE_EFFECTS (t);
3186
3187   PROCESS_ARG(0);
3188   PROCESS_ARG(1);
3189   PROCESS_ARG(2);
3190
3191   TREE_SIDE_EFFECTS (t) = side_effects;
3192   TREE_THIS_VOLATILE (t)
3193     = (TREE_CODE_CLASS (code) == tcc_reference
3194        && arg0 && TREE_THIS_VOLATILE (arg0));
3195
3196   return t;
3197 }
3198
3199 tree
3200 build4_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3201              tree arg2, tree arg3 MEM_STAT_DECL)
3202 {
3203   bool constant, read_only, side_effects, invariant;
3204   tree t;
3205
3206   gcc_assert (TREE_CODE_LENGTH (code) == 4);
3207
3208   t = make_node_stat (code PASS_MEM_STAT);
3209   TREE_TYPE (t) = tt;
3210
3211   side_effects = TREE_SIDE_EFFECTS (t);
3212
3213   PROCESS_ARG(0);
3214   PROCESS_ARG(1);
3215   PROCESS_ARG(2);
3216   PROCESS_ARG(3);
3217
3218   TREE_SIDE_EFFECTS (t) = side_effects;
3219   TREE_THIS_VOLATILE (t)
3220     = (TREE_CODE_CLASS (code) == tcc_reference
3221        && arg0 && TREE_THIS_VOLATILE (arg0));
3222
3223   return t;
3224 }
3225
3226 tree
3227 build5_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3228              tree arg2, tree arg3, tree arg4 MEM_STAT_DECL)
3229 {
3230   bool constant, read_only, side_effects, invariant;
3231   tree t;
3232
3233   gcc_assert (TREE_CODE_LENGTH (code) == 5);
3234
3235   t = make_node_stat (code PASS_MEM_STAT);
3236   TREE_TYPE (t) = tt;
3237
3238   side_effects = TREE_SIDE_EFFECTS (t);
3239
3240   PROCESS_ARG(0);
3241   PROCESS_ARG(1);
3242   PROCESS_ARG(2);
3243   PROCESS_ARG(3);
3244   PROCESS_ARG(4);
3245
3246   TREE_SIDE_EFFECTS (t) = side_effects;
3247   TREE_THIS_VOLATILE (t)
3248     = (TREE_CODE_CLASS (code) == tcc_reference
3249        && arg0 && TREE_THIS_VOLATILE (arg0));
3250
3251   return t;
3252 }
3253
3254 tree
3255 build7_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3256              tree arg2, tree arg3, tree arg4, tree arg5,
3257              tree arg6 MEM_STAT_DECL)
3258 {
3259   bool constant, read_only, side_effects, invariant;
3260   tree t;
3261
3262   gcc_assert (code == TARGET_MEM_REF);
3263
3264   t = make_node_stat (code PASS_MEM_STAT);
3265   TREE_TYPE (t) = tt;
3266
3267   side_effects = TREE_SIDE_EFFECTS (t);
3268
3269   PROCESS_ARG(0);
3270   PROCESS_ARG(1);
3271   PROCESS_ARG(2);
3272   PROCESS_ARG(3);
3273   PROCESS_ARG(4);
3274   PROCESS_ARG(5);
3275   PROCESS_ARG(6);
3276
3277   TREE_SIDE_EFFECTS (t) = side_effects;
3278   TREE_THIS_VOLATILE (t) = 0;
3279
3280   return t;
3281 }
3282
3283 /* Similar except don't specify the TREE_TYPE
3284    and leave the TREE_SIDE_EFFECTS as 0.
3285    It is permissible for arguments to be null,
3286    or even garbage if their values do not matter.  */
3287
3288 tree
3289 build_nt (enum tree_code code, ...)
3290 {
3291   tree t;
3292   int length;
3293   int i;
3294   va_list p;
3295
3296   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
3297
3298   va_start (p, code);
3299
3300   t = make_node (code);
3301   length = TREE_CODE_LENGTH (code);
3302
3303   for (i = 0; i < length; i++)
3304     TREE_OPERAND (t, i) = va_arg (p, tree);
3305
3306   va_end (p);
3307   return t;
3308 }
3309
3310 /* Similar to build_nt, but for creating a CALL_EXPR object with
3311    ARGLIST passed as a list.  */
3312
3313 tree
3314 build_nt_call_list (tree fn, tree arglist)
3315 {
3316   tree t;
3317   int i;
3318
3319   t = build_vl_exp (CALL_EXPR, list_length (arglist) + 3);
3320   CALL_EXPR_FN (t) = fn;
3321   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
3322   for (i = 0; arglist; arglist = TREE_CHAIN (arglist), i++)
3323     CALL_EXPR_ARG (t, i) = TREE_VALUE (arglist);
3324   return t;
3325 }
3326 \f
3327 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3328    We do NOT enter this node in any sort of symbol table.
3329
3330    layout_decl is used to set up the decl's storage layout.
3331    Other slots are initialized to 0 or null pointers.  */
3332
3333 tree
3334 build_decl_stat (enum tree_code code, tree name, tree type MEM_STAT_DECL)
3335 {
3336   tree t;
3337
3338   t = make_node_stat (code PASS_MEM_STAT);
3339
3340 /*  if (type == error_mark_node)
3341     type = integer_type_node; */
3342 /* That is not done, deliberately, so that having error_mark_node
3343    as the type can suppress useless errors in the use of this variable.  */
3344
3345   DECL_NAME (t) = name;
3346   TREE_TYPE (t) = type;
3347
3348   if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3349     layout_decl (t, 0);
3350
3351   return t;
3352 }
3353
3354 /* Builds and returns function declaration with NAME and TYPE.  */
3355
3356 tree
3357 build_fn_decl (const char *name, tree type)
3358 {
3359   tree id = get_identifier (name);
3360   tree decl = build_decl (FUNCTION_DECL, id, type);
3361
3362   DECL_EXTERNAL (decl) = 1;
3363   TREE_PUBLIC (decl) = 1;
3364   DECL_ARTIFICIAL (decl) = 1;
3365   TREE_NOTHROW (decl) = 1;
3366
3367   return decl;
3368 }
3369
3370 \f
3371 /* BLOCK nodes are used to represent the structure of binding contours
3372    and declarations, once those contours have been exited and their contents
3373    compiled.  This information is used for outputting debugging info.  */
3374
3375 tree
3376 build_block (tree vars, tree subblocks, tree supercontext, tree chain)
3377 {
3378   tree block = make_node (BLOCK);
3379
3380   BLOCK_VARS (block) = vars;
3381   BLOCK_SUBBLOCKS (block) = subblocks;
3382   BLOCK_SUPERCONTEXT (block) = supercontext;
3383   BLOCK_CHAIN (block) = chain;
3384   return block;
3385 }
3386
3387 #if 1 /* ! defined(USE_MAPPED_LOCATION) */
3388 /* ??? gengtype doesn't handle conditionals */
3389 static GTY(()) source_locus last_annotated_node;
3390 #endif
3391
3392 #ifdef USE_MAPPED_LOCATION
3393
3394 expanded_location
3395 expand_location (source_location loc)
3396 {
3397   expanded_location xloc;
3398   if (loc == 0)
3399     {
3400       xloc.file = NULL;
3401       xloc.line = 0;
3402       xloc.column = 0;
3403     }
3404   else
3405     {
3406       const struct line_map *map = linemap_lookup (&line_table, loc);
3407       xloc.file = map->to_file;
3408       xloc.line = SOURCE_LINE (map, loc);
3409       xloc.column = SOURCE_COLUMN (map, loc);
3410     };
3411   return xloc;
3412 }
3413
3414 #else
3415
3416 /* Record the exact location where an expression or an identifier were
3417    encountered.  */
3418
3419 void
3420 annotate_with_file_line (tree node, const char *file, int line)
3421 {
3422   /* Roughly one percent of the calls to this function are to annotate
3423      a node with the same information already attached to that node!
3424      Just return instead of wasting memory.  */
3425   if (EXPR_LOCUS (node)
3426       && EXPR_LINENO (node) == line
3427       && (EXPR_FILENAME (node) == file
3428           || !strcmp (EXPR_FILENAME (node), file)))
3429     {
3430       last_annotated_node = EXPR_LOCUS (node);
3431       return;
3432     }
3433
3434   /* In heavily macroized code (such as GCC itself) this single
3435      entry cache can reduce the number of allocations by more
3436      than half.  */
3437   if (last_annotated_node
3438       && last_annotated_node->line == line
3439       && (last_annotated_node->file == file
3440           || !strcmp (last_annotated_node->file, file)))
3441     {
3442       SET_EXPR_LOCUS (node, last_annotated_node);
3443       return;
3444     }
3445
3446   SET_EXPR_LOCUS (node, ggc_alloc (sizeof (location_t)));
3447   EXPR_LINENO (node) = line;
3448   EXPR_FILENAME (node) = file;
3449   last_annotated_node = EXPR_LOCUS (node);
3450 }
3451
3452 void
3453 annotate_with_locus (tree node, location_t locus)
3454 {
3455   annotate_with_file_line (node, locus.file, locus.line);
3456 }
3457 #endif
3458 \f
3459 /* Source location accessor functions.  */
3460
3461
3462 /* The source location of this expression.  Non-tree_exp nodes such as
3463    decls and constants can be shared among multiple locations, so
3464    return nothing.  */
3465 location_t
3466 expr_location (const_tree node)
3467 {
3468 #ifdef USE_MAPPED_LOCATION
3469   if (GIMPLE_STMT_P (node))
3470     return GIMPLE_STMT_LOCUS (node);
3471   return EXPR_P (node) ? node->exp.locus : UNKNOWN_LOCATION;
3472 #else
3473   if (GIMPLE_STMT_P (node))
3474     return EXPR_HAS_LOCATION (node)
3475       ? *GIMPLE_STMT_LOCUS (node) : UNKNOWN_LOCATION;
3476   return EXPR_HAS_LOCATION (node) ? *node->exp.locus : UNKNOWN_LOCATION;
3477 #endif
3478 }
3479
3480 void
3481 set_expr_location (tree node, location_t locus)
3482 {
3483 #ifdef USE_MAPPED_LOCATION
3484   if (GIMPLE_STMT_P (node))
3485     GIMPLE_STMT_LOCUS (node) = locus;
3486   else
3487     EXPR_CHECK (node)->exp.locus = locus;
3488 #else
3489       annotate_with_locus (node, locus);
3490 #endif
3491 }
3492
3493 bool
3494 expr_has_location (const_tree node)
3495 {
3496 #ifdef USE_MAPPED_LOCATION
3497   return expr_location (node) != UNKNOWN_LOCATION;
3498 #else
3499   return expr_locus (node) != NULL;
3500 #endif
3501 }
3502
3503 #ifdef USE_MAPPED_LOCATION
3504 source_location *
3505 #else
3506 source_locus
3507 #endif
3508 expr_locus (const_tree node)
3509 {
3510 #ifdef USE_MAPPED_LOCATION
3511   if (GIMPLE_STMT_P (node))
3512     return &GIMPLE_STMT_LOCUS (node);
3513   return EXPR_P (node) ? &node->exp.locus : (location_t *) NULL;
3514 #else
3515   if (GIMPLE_STMT_P (node))
3516     return GIMPLE_STMT_LOCUS (node);
3517   /* ?? The cast below was originally "(location_t *)" in the macro,
3518      but that makes no sense.  ?? */
3519   return EXPR_P (node) ? node->exp.locus : (source_locus) NULL;
3520 #endif
3521 }
3522
3523 void
3524 set_expr_locus (tree node,
3525 #ifdef USE_MAPPED_LOCATION
3526                 source_location *loc
3527 #else
3528                 source_locus loc
3529 #endif
3530                 )
3531 {
3532 #ifdef USE_MAPPED_LOCATION
3533   if (loc == NULL)
3534     {
3535       if (GIMPLE_STMT_P (node))
3536         GIMPLE_STMT_LOCUS (node) = UNKNOWN_LOCATION;
3537       else
3538         EXPR_CHECK (node)->exp.locus = UNKNOWN_LOCATION;
3539     }
3540   else
3541     {
3542       if (GIMPLE_STMT_P (node))
3543         GIMPLE_STMT_LOCUS (node) = *loc;
3544       else
3545         EXPR_CHECK (node)->exp.locus = *loc;
3546     }
3547 #else
3548   if (GIMPLE_STMT_P (node))
3549     GIMPLE_STMT_LOCUS (node) = loc;
3550   else
3551     EXPR_CHECK (node)->exp.locus = loc;
3552 #endif
3553 }
3554
3555 const char **
3556 expr_filename (const_tree node)
3557 {
3558 #ifdef USE_MAPPED_LOCATION
3559   if (GIMPLE_STMT_P (node))
3560     return &LOCATION_FILE (GIMPLE_STMT_LOCUS (node));
3561   return &LOCATION_FILE (EXPR_CHECK (node)->exp.locus);
3562 #else
3563   if (GIMPLE_STMT_P (node))
3564     return &GIMPLE_STMT_LOCUS (node)->file;
3565   return &(EXPR_CHECK (node)->exp.locus->file);
3566 #endif
3567 }
3568
3569 int *
3570 expr_lineno (const_tree node)
3571 {
3572 #ifdef USE_MAPPED_LOCATION
3573   if (GIMPLE_STMT_P (node))
3574     return &LOCATION_LINE (GIMPLE_STMT_LOCUS (node));
3575   return &LOCATION_LINE (EXPR_CHECK (node)->exp.locus);
3576 #else
3577   if (GIMPLE_STMT_P (node))
3578     return &GIMPLE_STMT_LOCUS (node)->line;
3579   return &EXPR_CHECK (node)->exp.locus->line;
3580 #endif
3581 }
3582 \f
3583 /* Return a declaration like DDECL except that its DECL_ATTRIBUTES
3584    is ATTRIBUTE.  */
3585
3586 tree
3587 build_decl_attribute_variant (tree ddecl, tree attribute)
3588 {
3589   DECL_ATTRIBUTES (ddecl) = attribute;
3590   return ddecl;
3591 }
3592
3593 /* Borrowed from hashtab.c iterative_hash implementation.  */
3594 #define mix(a,b,c) \
3595 { \
3596   a -= b; a -= c; a ^= (c>>13); \
3597   b -= c; b -= a; b ^= (a<< 8); \
3598   c -= a; c -= b; c ^= ((b&0xffffffff)>>13); \
3599   a -= b; a -= c; a ^= ((c&0xffffffff)>>12); \
3600   b -= c; b -= a; b = (b ^ (a<<16)) & 0xffffffff; \
3601   c -= a; c -= b; c = (c ^ (b>> 5)) & 0xffffffff; \
3602   a -= b; a -= c; a = (a ^ (c>> 3)) & 0xffffffff; \
3603   b -= c; b -= a; b = (b ^ (a<<10)) & 0xffffffff; \
3604   c -= a; c -= b; c = (c ^ (b>>15)) & 0xffffffff; \
3605 }
3606
3607
3608 /* Produce good hash value combining VAL and VAL2.  */
3609 static inline hashval_t
3610 iterative_hash_hashval_t (hashval_t val, hashval_t val2)
3611 {
3612   /* the golden ratio; an arbitrary value.  */
3613   hashval_t a = 0x9e3779b9;
3614
3615   mix (a, val, val2);
3616   return val2;
3617 }
3618
3619 /* Produce good hash value combining PTR and VAL2.  */
3620 static inline hashval_t
3621 iterative_hash_pointer (const void *ptr, hashval_t val2)
3622 {
3623   if (sizeof (ptr) == sizeof (hashval_t))
3624     return iterative_hash_hashval_t ((size_t) ptr, val2);
3625   else
3626     {
3627       hashval_t a = (hashval_t) (size_t) ptr;
3628       /* Avoid warnings about shifting of more than the width of the type on
3629          hosts that won't execute this path.  */
3630       int zero = 0;
3631       hashval_t b = (hashval_t) ((size_t) ptr >> (sizeof (hashval_t) * 8 + zero));
3632       mix (a, b, val2);
3633       return val2;
3634     }
3635 }
3636
3637 /* Produce good hash value combining VAL and VAL2.  */
3638 static inline hashval_t
3639 iterative_hash_host_wide_int (HOST_WIDE_INT val, hashval_t val2)
3640 {
3641   if (sizeof (HOST_WIDE_INT) == sizeof (hashval_t))
3642     return iterative_hash_hashval_t (val, val2);
3643   else
3644     {
3645       hashval_t a = (hashval_t) val;
3646       /* Avoid warnings about shifting of more than the width of the type on
3647          hosts that won't execute this path.  */
3648       int zero = 0;
3649       hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 8 + zero));
3650       mix (a, b, val2);
3651       if (sizeof (HOST_WIDE_INT) > 2 * sizeof (hashval_t))
3652         {
3653           hashval_t a = (hashval_t) (val >> (sizeof (hashval_t) * 16 + zero));
3654           hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 24 + zero));
3655           mix (a, b, val2);
3656         }
3657       return val2;
3658     }
3659 }
3660
3661 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3662    is ATTRIBUTE and its qualifiers are QUALS.
3663
3664    Record such modified types already made so we don't make duplicates.  */
3665
3666 static tree
3667 build_type_attribute_qual_variant (tree ttype, tree attribute, int quals)
3668 {
3669   if (! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
3670     {
3671       hashval_t hashcode = 0;
3672       tree ntype;
3673       enum tree_code code = TREE_CODE (ttype);
3674
3675       ntype = copy_node (ttype);
3676
3677       TYPE_POINTER_TO (ntype) = 0;
3678       TYPE_REFERENCE_TO (ntype) = 0;
3679       TYPE_ATTRIBUTES (ntype) = attribute;
3680
3681       /* Create a new main variant of TYPE.  */
3682       TYPE_MAIN_VARIANT (ntype) = ntype;
3683       TYPE_NEXT_VARIANT (ntype) = 0;
3684       set_type_quals (ntype, TYPE_UNQUALIFIED);
3685
3686       hashcode = iterative_hash_object (code, hashcode);
3687       if (TREE_TYPE (ntype))
3688         hashcode = iterative_hash_object (TYPE_HASH (TREE_TYPE (ntype)),
3689                                           hashcode);
3690       hashcode = attribute_hash_list (attribute, hashcode);
3691
3692       switch (TREE_CODE (ntype))
3693         {
3694         case FUNCTION_TYPE:
3695           hashcode = type_hash_list (TYPE_ARG_TYPES (ntype), hashcode);
3696           break;
3697         case ARRAY_TYPE:
3698           hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (ntype)),
3699                                             hashcode);
3700           break;
3701         case INTEGER_TYPE:
3702           hashcode = iterative_hash_object
3703             (TREE_INT_CST_LOW (TYPE_MAX_VALUE (ntype)), hashcode);
3704           hashcode = iterative_hash_object
3705             (TREE_INT_CST_HIGH (TYPE_MAX_VALUE (ntype)), hashcode);
3706           break;
3707         case REAL_TYPE:
3708         case FIXED_POINT_TYPE:
3709           {
3710             unsigned int precision = TYPE_PRECISION (ntype);
3711             hashcode = iterative_hash_object (precision, hashcode);
3712           }
3713           break;
3714         default:
3715           break;
3716         }
3717
3718       ntype = type_hash_canon (hashcode, ntype);
3719
3720       /* If the target-dependent attributes make NTYPE different from
3721          its canonical type, we will need to use structural equality
3722          checks for this qualified type. */
3723       ttype = build_qualified_type (ttype, TYPE_UNQUALIFIED);
3724       if (TYPE_STRUCTURAL_EQUALITY_P (ttype)
3725           || !targetm.comp_type_attributes (ntype, ttype))
3726         SET_TYPE_STRUCTURAL_EQUALITY (ntype);
3727       else
3728         TYPE_CANONICAL (ntype) = TYPE_CANONICAL (ttype);
3729
3730       ttype = build_qualified_type (ntype, quals);
3731     }
3732
3733   return ttype;
3734 }
3735
3736
3737 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3738    is ATTRIBUTE.
3739
3740    Record such modified types already made so we don't make duplicates.  */
3741
3742 tree
3743 build_type_attribute_variant (tree ttype, tree attribute)
3744 {
3745   return build_type_attribute_qual_variant (ttype, attribute,
3746                                             TYPE_QUALS (ttype));
3747 }
3748
3749 /* Return nonzero if IDENT is a valid name for attribute ATTR,
3750    or zero if not.
3751
3752    We try both `text' and `__text__', ATTR may be either one.  */
3753 /* ??? It might be a reasonable simplification to require ATTR to be only
3754    `text'.  One might then also require attribute lists to be stored in
3755    their canonicalized form.  */
3756
3757 static int
3758 is_attribute_with_length_p (const char *attr, int attr_len, const_tree ident)
3759 {
3760   int ident_len;
3761   const char *p;
3762
3763   if (TREE_CODE (ident) != IDENTIFIER_NODE)
3764     return 0;
3765
3766   p = IDENTIFIER_POINTER (ident);
3767   ident_len = IDENTIFIER_LENGTH (ident);
3768
3769   if (ident_len == attr_len
3770       && strcmp (attr, p) == 0)
3771     return 1;
3772
3773   /* If ATTR is `__text__', IDENT must be `text'; and vice versa.  */
3774   if (attr[0] == '_')
3775     {
3776       gcc_assert (attr[1] == '_');
3777       gcc_assert (attr[attr_len - 2] == '_');
3778       gcc_assert (attr[attr_len - 1] == '_');
3779       if (ident_len == attr_len - 4
3780           && strncmp (attr + 2, p, attr_len - 4) == 0)
3781         return 1;
3782     }
3783   else
3784     {
3785       if (ident_len == attr_len + 4
3786           && p[0] == '_' && p[1] == '_'
3787           && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
3788           && strncmp (attr, p + 2, attr_len) == 0)
3789         return 1;
3790     }
3791
3792   return 0;
3793 }
3794
3795 /* Return nonzero if IDENT is a valid name for attribute ATTR,
3796    or zero if not.
3797
3798    We try both `text' and `__text__', ATTR may be either one.  */
3799
3800 int
3801 is_attribute_p (const char *attr, const_tree ident)
3802 {
3803   return is_attribute_with_length_p (attr, strlen (attr), ident);
3804 }
3805
3806 /* Given an attribute name and a list of attributes, return a pointer to the
3807    attribute's list element if the attribute is part of the list, or NULL_TREE
3808    if not found.  If the attribute appears more than once, this only
3809    returns the first occurrence; the TREE_CHAIN of the return value should
3810    be passed back in if further occurrences are wanted.  */
3811
3812 tree
3813 lookup_attribute (const char *attr_name, tree list)
3814 {
3815   tree l;
3816   size_t attr_len = strlen (attr_name);
3817
3818   for (l = list; l; l = TREE_CHAIN (l))
3819     {
3820       gcc_assert (TREE_CODE (TREE_PURPOSE (l)) == IDENTIFIER_NODE);
3821       if (is_attribute_with_length_p (attr_name, attr_len, TREE_PURPOSE (l)))
3822         return l;
3823     }
3824   return NULL_TREE;
3825 }
3826
3827 /* Remove any instances of attribute ATTR_NAME in LIST and return the
3828    modified list.  */
3829
3830 tree
3831 remove_attribute (const char *attr_name, tree list)
3832 {
3833   tree *p;
3834   size_t attr_len = strlen (attr_name);
3835
3836   for (p = &list; *p; )
3837     {
3838       tree l = *p;
3839       gcc_assert (TREE_CODE (TREE_PURPOSE (l)) == IDENTIFIER_NODE);
3840       if (is_attribute_with_length_p (attr_name, attr_len, TREE_PURPOSE (l)))
3841         *p = TREE_CHAIN (l);
3842       else
3843         p = &TREE_CHAIN (l);
3844     }
3845
3846   return list;
3847 }
3848
3849 /* Return an attribute list that is the union of a1 and a2.  */
3850
3851 tree
3852 merge_attributes (tree a1, tree a2)
3853 {
3854   tree attributes;
3855
3856   /* Either one unset?  Take the set one.  */
3857
3858   if ((attributes = a1) == 0)
3859     attributes = a2;
3860
3861   /* One that completely contains the other?  Take it.  */
3862
3863   else if (a2 != 0 && ! attribute_list_contained (a1, a2))
3864     {
3865       if (attribute_list_contained (a2, a1))
3866         attributes = a2;
3867       else
3868         {
3869           /* Pick the longest list, and hang on the other list.  */
3870
3871           if (list_length (a1) < list_length (a2))
3872             attributes = a2, a2 = a1;
3873
3874           for (; a2 != 0; a2 = TREE_CHAIN (a2))
3875             {
3876               tree a;
3877               for (a = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3878                                          attributes);
3879                    a != NULL_TREE;
3880                    a = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3881                                          TREE_CHAIN (a)))
3882                 {
3883                   if (TREE_VALUE (a) != NULL
3884                       && TREE_CODE (TREE_VALUE (a)) == TREE_LIST
3885                       && TREE_VALUE (a2) != NULL
3886                       && TREE_CODE (TREE_VALUE (a2)) == TREE_LIST)
3887                     {
3888                       if (simple_cst_list_equal (TREE_VALUE (a),
3889                                                  TREE_VALUE (a2)) == 1)
3890                         break;
3891                     }
3892                   else if (simple_cst_equal (TREE_VALUE (a),
3893                                              TREE_VALUE (a2)) == 1)
3894                     break;
3895                 }
3896               if (a == NULL_TREE)
3897                 {
3898                   a1 = copy_node (a2);
3899                   TREE_CHAIN (a1) = attributes;
3900                   attributes = a1;
3901                 }
3902             }
3903         }
3904     }
3905   return attributes;
3906 }
3907
3908 /* Given types T1 and T2, merge their attributes and return
3909   the result.  */
3910
3911 tree
3912 merge_type_attributes (tree t1, tree t2)
3913 {
3914   return merge_attributes (TYPE_ATTRIBUTES (t1),
3915                            TYPE_ATTRIBUTES (t2));
3916 }
3917
3918 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
3919    the result.  */
3920
3921 tree
3922 merge_decl_attributes (tree olddecl, tree newdecl)
3923 {
3924   return merge_attributes (DECL_ATTRIBUTES (olddecl),
3925                            DECL_ATTRIBUTES (newdecl));
3926 }
3927
3928 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
3929
3930 /* Specialization of merge_decl_attributes for various Windows targets.
3931
3932    This handles the following situation:
3933
3934      __declspec (dllimport) int foo;
3935      int foo;
3936
3937    The second instance of `foo' nullifies the dllimport.  */
3938
3939 tree
3940 merge_dllimport_decl_attributes (tree old, tree new)
3941 {
3942   tree a;
3943   int delete_dllimport_p = 1;
3944
3945   /* What we need to do here is remove from `old' dllimport if it doesn't
3946      appear in `new'.  dllimport behaves like extern: if a declaration is
3947      marked dllimport and a definition appears later, then the object
3948      is not dllimport'd.  We also remove a `new' dllimport if the old list
3949      contains dllexport:  dllexport always overrides dllimport, regardless
3950      of the order of declaration.  */
3951   if (!VAR_OR_FUNCTION_DECL_P (new))
3952     delete_dllimport_p = 0;
3953   else if (DECL_DLLIMPORT_P (new)
3954            && lookup_attribute ("dllexport", DECL_ATTRIBUTES (old)))
3955     {
3956       DECL_DLLIMPORT_P (new) = 0;
3957       warning (OPT_Wattributes, "%q+D already declared with dllexport attribute: "
3958               "dllimport ignored", new);
3959     }
3960   else if (DECL_DLLIMPORT_P (old) && !DECL_DLLIMPORT_P (new))
3961     {
3962       /* Warn about overriding a symbol that has already been used. eg:
3963            extern int __attribute__ ((dllimport)) foo;
3964            int* bar () {return &foo;}
3965            int foo;
3966       */
3967       if (TREE_USED (old))
3968         {
3969           warning (0, "%q+D redeclared without dllimport attribute "
3970                    "after being referenced with dll linkage", new);
3971           /* If we have used a variable's address with dllimport linkage,
3972               keep the old DECL_DLLIMPORT_P flag: the ADDR_EXPR using the
3973               decl may already have had TREE_INVARIANT and TREE_CONSTANT
3974               computed.
3975               We still remove the attribute so that assembler code refers
3976               to '&foo rather than '_imp__foo'.  */
3977           if (TREE_CODE (old) == VAR_DECL && TREE_ADDRESSABLE (old))
3978             DECL_DLLIMPORT_P (new) = 1;
3979         }
3980
3981       /* Let an inline definition silently override the external reference,
3982          but otherwise warn about attribute inconsistency.  */
3983       else if (TREE_CODE (new) == VAR_DECL
3984                || !DECL_DECLARED_INLINE_P (new))
3985         warning (OPT_Wattributes, "%q+D redeclared without dllimport attribute: "
3986                   "previous dllimport ignored", new);
3987     }
3988   else
3989     delete_dllimport_p = 0;
3990
3991   a = merge_attributes (DECL_ATTRIBUTES (old), DECL_ATTRIBUTES (new));
3992
3993   if (delete_dllimport_p)
3994     {
3995       tree prev, t;
3996       const size_t attr_len = strlen ("dllimport");
3997
3998       /* Scan the list for dllimport and delete it.  */
3999       for (prev = NULL_TREE, t = a; t; prev = t, t = TREE_CHAIN (t))
4000         {
4001           if (is_attribute_with_length_p ("dllimport", attr_len,
4002                                           TREE_PURPOSE (t)))
4003             {
4004               if (prev == NULL_TREE)
4005                 a = TREE_CHAIN (a);
4006               else
4007                 TREE_CHAIN (prev) = TREE_CHAIN (t);
4008               break;
4009             }
4010         }
4011     }
4012
4013   return a;
4014 }
4015
4016 /* Handle a "dllimport" or "dllexport" attribute; arguments as in
4017    struct attribute_spec.handler.  */
4018
4019 tree
4020 handle_dll_attribute (tree * pnode, tree name, tree args, int flags,
4021                       bool *no_add_attrs)
4022 {
4023   tree node = *pnode;
4024
4025   /* These attributes may apply to structure and union types being created,
4026      but otherwise should pass to the declaration involved.  */
4027   if (!DECL_P (node))
4028     {
4029       if (flags & ((int) ATTR_FLAG_DECL_NEXT | (int) ATTR_FLAG_FUNCTION_NEXT
4030                    | (int) ATTR_FLAG_ARRAY_NEXT))
4031         {
4032           *no_add_attrs = true;
4033           return tree_cons (name, args, NULL_TREE);
4034         }
4035       if (TREE_CODE (node) == RECORD_TYPE
4036           || TREE_CODE (node) == UNION_TYPE)
4037         {
4038           node = TYPE_NAME (node);
4039           if (!node)
4040             return NULL_TREE;
4041         }
4042       else
4043         {
4044           warning (OPT_Wattributes, "%qs attribute ignored",
4045                    IDENTIFIER_POINTER (name));
4046           *no_add_attrs = true;
4047           return NULL_TREE;
4048         }
4049     }
4050
4051   if (TREE_CODE (node) != FUNCTION_DECL
4052       && TREE_CODE (node) != VAR_DECL
4053       && TREE_CODE (node) != TYPE_DECL)
4054     {
4055       *no_add_attrs = true;
4056       warning (OPT_Wattributes, "%qs attribute ignored",
4057                IDENTIFIER_POINTER (name));
4058       return NULL_TREE;
4059     }
4060
4061   /* Report error on dllimport ambiguities seen now before they cause
4062      any damage.  */
4063   else if (is_attribute_p ("dllimport", name))
4064     {
4065       /* Honor any target-specific overrides. */
4066       if (!targetm.valid_dllimport_attribute_p (node))
4067         *no_add_attrs = true;
4068
4069      else if (TREE_CODE (node) == FUNCTION_DECL
4070                 && DECL_DECLARED_INLINE_P (node))
4071         {
4072           warning (OPT_Wattributes, "inline function %q+D declared as "
4073                   " dllimport: attribute ignored", node);
4074           *no_add_attrs = true;
4075         }
4076       /* Like MS, treat definition of dllimported variables and
4077          non-inlined functions on declaration as syntax errors. */
4078      else if (TREE_CODE (node) == FUNCTION_DECL && DECL_INITIAL (node))
4079         {
4080           error ("function %q+D definition is marked dllimport", node);
4081           *no_add_attrs = true;
4082         }
4083
4084      else if (TREE_CODE (node) == VAR_DECL)
4085         {
4086           if (DECL_INITIAL (node))
4087             {
4088               error ("variable %q+D definition is marked dllimport",
4089                      node);
4090               *no_add_attrs = true;
4091             }
4092
4093           /* `extern' needn't be specified with dllimport.
4094              Specify `extern' now and hope for the best.  Sigh.  */
4095           DECL_EXTERNAL (node) = 1;
4096           /* Also, implicitly give dllimport'd variables declared within
4097              a function global scope, unless declared static.  */
4098           if (current_function_decl != NULL_TREE && !TREE_STATIC (node))
4099             TREE_PUBLIC (node) = 1;
4100         }
4101
4102       if (*no_add_attrs == false)
4103         DECL_DLLIMPORT_P (node) = 1;
4104     }
4105
4106   /*  Report error if symbol is not accessible at global scope.  */
4107   if (!TREE_PUBLIC (node)
4108       && (TREE_CODE (node) == VAR_DECL
4109           || TREE_CODE (node) == FUNCTION_DECL))
4110     {
4111       error ("external linkage required for symbol %q+D because of "
4112              "%qs attribute", node, IDENTIFIER_POINTER (name));
4113       *no_add_attrs = true;
4114     }
4115
4116   /* A dllexport'd entity must have default visibility so that other
4117      program units (shared libraries or the main executable) can see
4118      it.  A dllimport'd entity must have default visibility so that
4119      the linker knows that undefined references within this program
4120      unit can be resolved by the dynamic linker.  */
4121   if (!*no_add_attrs)
4122     {
4123       if (DECL_VISIBILITY_SPECIFIED (node)
4124           && DECL_VISIBILITY (node) != VISIBILITY_DEFAULT)
4125         error ("%qs implies default visibility, but %qD has already "
4126                "been declared with a different visibility",
4127                IDENTIFIER_POINTER (name), node);
4128       DECL_VISIBILITY (node) = VISIBILITY_DEFAULT;
4129       DECL_VISIBILITY_SPECIFIED (node) = 1;
4130     }
4131
4132   return NULL_TREE;
4133 }
4134
4135 #endif /* TARGET_DLLIMPORT_DECL_ATTRIBUTES  */
4136 \f
4137 /* Set the type qualifiers for TYPE to TYPE_QUALS, which is a bitmask
4138    of the various TYPE_QUAL values.  */
4139
4140 static void
4141 set_type_quals (tree type, int type_quals)
4142 {
4143   TYPE_READONLY (type) = (type_quals & TYPE_QUAL_CONST) != 0;
4144   TYPE_VOLATILE (type) = (type_quals & TYPE_QUAL_VOLATILE) != 0;
4145   TYPE_RESTRICT (type) = (type_quals & TYPE_QUAL_RESTRICT) != 0;
4146 }
4147
4148 /* Returns true iff cand is equivalent to base with type_quals.  */
4149
4150 bool
4151 check_qualified_type (const_tree cand, const_tree base, int type_quals)
4152 {
4153   return (TYPE_QUALS (cand) == type_quals
4154           && TYPE_NAME (cand) == TYPE_NAME (base)
4155           /* Apparently this is needed for Objective-C.  */
4156           && TYPE_CONTEXT (cand) == TYPE_CONTEXT (base)
4157           && attribute_list_equal (TYPE_ATTRIBUTES (cand),
4158                                    TYPE_ATTRIBUTES (base)));
4159 }
4160
4161 /* Return a version of the TYPE, qualified as indicated by the
4162    TYPE_QUALS, if one exists.  If no qualified version exists yet,
4163    return NULL_TREE.  */
4164
4165 tree
4166 get_qualified_type (tree type, int type_quals)
4167 {
4168   tree t;
4169
4170   if (TYPE_QUALS (type) == type_quals)
4171     return type;
4172
4173   /* Search the chain of variants to see if there is already one there just
4174      like the one we need to have.  If so, use that existing one.  We must
4175      preserve the TYPE_NAME, since there is code that depends on this.  */
4176   for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4177     if (check_qualified_type (t, type, type_quals))
4178       return t;
4179
4180   return NULL_TREE;
4181 }
4182
4183 /* Like get_qualified_type, but creates the type if it does not
4184    exist.  This function never returns NULL_TREE.  */
4185
4186 tree
4187 build_qualified_type (tree type, int type_quals)
4188 {
4189   tree t;
4190
4191   /* See if we already have the appropriate qualified variant.  */
4192   t = get_qualified_type (type, type_quals);
4193
4194   /* If not, build it.  */
4195   if (!t)
4196     {
4197       t = build_variant_type_copy (type);
4198       set_type_quals (t, type_quals);
4199
4200       if (TYPE_STRUCTURAL_EQUALITY_P (type))
4201         /* Propagate structural equality. */
4202         SET_TYPE_STRUCTURAL_EQUALITY (t);
4203       else if (TYPE_CANONICAL (type) != type)
4204         /* Build the underlying canonical type, since it is different
4205            from TYPE. */
4206         TYPE_CANONICAL (t) = build_qualified_type (TYPE_CANONICAL (type),
4207                                                    type_quals);
4208       else
4209         /* T is its own canonical type. */
4210         TYPE_CANONICAL (t) = t;
4211
4212     }
4213
4214   return t;
4215 }
4216
4217 /* Create a new distinct copy of TYPE.  The new type is made its own
4218    MAIN_VARIANT. If TYPE requires structural equality checks, the
4219    resulting type requires structural equality checks; otherwise, its
4220    TYPE_CANONICAL points to itself. */
4221
4222 tree
4223 build_distinct_type_copy (tree type)
4224 {
4225   tree t = copy_node (type);
4226
4227   TYPE_POINTER_TO (t) = 0;
4228   TYPE_REFERENCE_TO (t) = 0;
4229
4230   /* Set the canonical type either to a new equivalence class, or
4231      propagate the need for structural equality checks. */
4232   if (TYPE_STRUCTURAL_EQUALITY_P (type))
4233     SET_TYPE_STRUCTURAL_EQUALITY (t);
4234   else
4235     TYPE_CANONICAL (t) = t;
4236
4237   /* Make it its own variant.  */
4238   TYPE_MAIN_VARIANT (t) = t;
4239   TYPE_NEXT_VARIANT (t) = 0;
4240
4241   /* Note that it is now possible for TYPE_MIN_VALUE to be a value
4242      whose TREE_TYPE is not t.  This can also happen in the Ada
4243      frontend when using subtypes.  */
4244
4245   return t;
4246 }
4247
4248 /* Create a new variant of TYPE, equivalent but distinct.  This is so
4249    the caller can modify it. TYPE_CANONICAL for the return type will
4250    be equivalent to TYPE_CANONICAL of TYPE, indicating that the types
4251    are considered equal by the language itself (or that both types
4252    require structural equality checks). */
4253
4254 tree
4255 build_variant_type_copy (tree type)
4256 {
4257   tree t, m = TYPE_MAIN_VARIANT (type);
4258
4259   t = build_distinct_type_copy (type);
4260
4261   /* Since we're building a variant, assume that it is a non-semantic
4262      variant. This also propagates TYPE_STRUCTURAL_EQUALITY_P. */
4263   TYPE_CANONICAL (t) = TYPE_CANONICAL (type);
4264
4265   /* Add the new type to the chain of variants of TYPE.  */
4266   TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
4267   TYPE_NEXT_VARIANT (m) = t;
4268   TYPE_MAIN_VARIANT (t) = m;
4269
4270   return t;
4271 }
4272 \f
4273 /* Return true if the from tree in both tree maps are equal.  */
4274
4275 int
4276 tree_map_base_eq (const void *va, const void *vb)
4277 {
4278   const struct tree_map_base  *const a = va, *const b = vb;
4279   return (a->from == b->from);
4280 }
4281
4282 /* Hash a from tree in a tree_map.  */
4283
4284 unsigned int
4285 tree_map_base_hash (const void *item)
4286 {
4287   return htab_hash_pointer (((const struct tree_map_base *)item)->from);
4288 }
4289
4290 /* Return true if this tree map structure is marked for garbage collection
4291    purposes.  We simply return true if the from tree is marked, so that this
4292    structure goes away when the from tree goes away.  */
4293
4294 int
4295 tree_map_base_marked_p (const void *p)
4296 {
4297   return ggc_marked_p (((const struct tree_map_base *) p)->from);
4298 }
4299
4300 unsigned int
4301 tree_map_hash (const void *item)
4302 {
4303   return (((const struct tree_map *) item)->hash);
4304 }
4305
4306 /* Return the initialization priority for DECL.  */
4307
4308 priority_type
4309 decl_init_priority_lookup (tree decl)
4310 {
4311   struct tree_priority_map *h;
4312   struct tree_map_base in;
4313
4314   gcc_assert (VAR_OR_FUNCTION_DECL_P (decl));
4315   gcc_assert (TREE_CODE (decl) == VAR_DECL
4316               ? DECL_HAS_INIT_PRIORITY_P (decl)
4317               : DECL_STATIC_CONSTRUCTOR (decl));
4318   in.from = decl;
4319   h = htab_find (init_priority_for_decl, &in);
4320   return h ? h->init : DEFAULT_INIT_PRIORITY;
4321 }
4322
4323 /* Return the finalization priority for DECL.  */
4324
4325 priority_type
4326 decl_fini_priority_lookup (tree decl)
4327 {
4328   struct tree_priority_map *h;
4329   struct tree_map_base in;
4330
4331   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
4332   gcc_assert (DECL_STATIC_DESTRUCTOR (decl));
4333   in.from = decl;
4334   h = htab_find (init_priority_for_decl, &in);
4335   return h ? h->fini : DEFAULT_INIT_PRIORITY;
4336 }
4337
4338 /* Return the initialization and finalization priority information for
4339    DECL.  If there is no previous priority information, a freshly
4340    allocated structure is returned.  */
4341
4342 static struct tree_priority_map *
4343 decl_priority_info (tree decl)
4344 {
4345   struct tree_priority_map in;
4346   struct tree_priority_map *h;
4347   void **loc;
4348
4349   in.base.from = decl;
4350   loc = htab_find_slot (init_priority_for_decl, &in, INSERT);
4351   h = *loc;
4352   if (!h)
4353     {
4354       h = GGC_CNEW (struct tree_priority_map);
4355       *loc = h;
4356       h->base.from = decl;
4357       h->init = DEFAULT_INIT_PRIORITY;
4358       h->fini = DEFAULT_INIT_PRIORITY;
4359     }
4360
4361   return h;
4362 }
4363
4364 /* Set the initialization priority for DECL to PRIORITY.  */
4365
4366 void
4367 decl_init_priority_insert (tree decl, priority_type priority)
4368 {
4369   struct tree_priority_map *h;
4370
4371   gcc_assert (VAR_OR_FUNCTION_DECL_P (decl));
4372   h = decl_priority_info (decl);
4373   h->init = priority;
4374 }
4375
4376 /* Set the finalization priority for DECL to PRIORITY.  */
4377
4378 void
4379 decl_fini_priority_insert (tree decl, priority_type priority)
4380 {
4381   struct tree_priority_map *h;
4382
4383   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
4384   h = decl_priority_info (decl);
4385   h->fini = priority;
4386 }
4387
4388 /* Look up a restrict qualified base decl for FROM.  */
4389
4390 tree
4391 decl_restrict_base_lookup (tree from)
4392 {
4393   struct tree_map *h;
4394   struct tree_map in;
4395
4396   in.base.from = from;
4397   h = htab_find_with_hash (restrict_base_for_decl, &in,
4398                            htab_hash_pointer (from));
4399   return h ? h->to : NULL_TREE;
4400 }
4401
4402 /* Record the restrict qualified base TO for FROM.  */
4403
4404 void
4405 decl_restrict_base_insert (tree from, tree to)
4406 {
4407   struct tree_map *h;
4408   void **loc;
4409
4410   h = ggc_alloc (sizeof (struct tree_map));
4411   h->hash = htab_hash_pointer (from);
4412   h->base.from = from;
4413   h->to = to;
4414   loc = htab_find_slot_with_hash (restrict_base_for_decl, h, h->hash, INSERT);
4415   *(struct tree_map **) loc = h;
4416 }
4417
4418 /* Print out the statistics for the DECL_DEBUG_EXPR hash table.  */
4419
4420 static void
4421 print_debug_expr_statistics (void)
4422 {
4423   fprintf (stderr, "DECL_DEBUG_EXPR  hash: size %ld, %ld elements, %f collisions\n",
4424            (long) htab_size (debug_expr_for_decl),
4425            (long) htab_elements (debug_expr_for_decl),
4426            htab_collisions (debug_expr_for_decl));
4427 }
4428
4429 /* Print out the statistics for the DECL_VALUE_EXPR hash table.  */
4430
4431 static void
4432 print_value_expr_statistics (void)
4433 {
4434   fprintf (stderr, "DECL_VALUE_EXPR  hash: size %ld, %ld elements, %f collisions\n",
4435            (long) htab_size (value_expr_for_decl),
4436            (long) htab_elements (value_expr_for_decl),
4437            htab_collisions (value_expr_for_decl));
4438 }
4439
4440 /* Print out statistics for the RESTRICT_BASE_FOR_DECL hash table, but
4441    don't print anything if the table is empty.  */
4442
4443 static void
4444 print_restrict_base_statistics (void)
4445 {
4446   if (htab_elements (restrict_base_for_decl) != 0)
4447     fprintf (stderr,
4448              "RESTRICT_BASE    hash: size %ld, %ld elements, %f collisions\n",
4449              (long) htab_size (restrict_base_for_decl),
4450              (long) htab_elements (restrict_base_for_decl),
4451              htab_collisions (restrict_base_for_decl));
4452 }
4453
4454 /* Lookup a debug expression for FROM, and return it if we find one.  */
4455
4456 tree
4457 decl_debug_expr_lookup (tree from)
4458 {
4459   struct tree_map *h, in;
4460   in.base.from = from;
4461
4462   h = htab_find_with_hash (debug_expr_for_decl, &in, htab_hash_pointer (from));
4463   if (h)
4464     return h->to;
4465   return NULL_TREE;
4466 }
4467
4468 /* Insert a mapping FROM->TO in the debug expression hashtable.  */
4469
4470 void
4471 decl_debug_expr_insert (tree from, tree to)
4472 {
4473   struct tree_map *h;
4474   void **loc;
4475
4476   h = ggc_alloc (sizeof (struct tree_map));
4477   h->hash = htab_hash_pointer (from);
4478   h->base.from = from;
4479   h->to = to;
4480   loc = htab_find_slot_with_hash (debug_expr_for_decl, h, h->hash, INSERT);
4481   *(struct tree_map **) loc = h;
4482 }
4483
4484 /* Lookup a value expression for FROM, and return it if we find one.  */
4485
4486 tree
4487 decl_value_expr_lookup (tree from)
4488 {
4489   struct tree_map *h, in;
4490   in.base.from = from;
4491
4492   h = htab_find_with_hash (value_expr_for_decl, &in, htab_hash_pointer (from));
4493   if (h)
4494     return h->to;
4495   return NULL_TREE;
4496 }
4497
4498 /* Insert a mapping FROM->TO in the value expression hashtable.  */
4499
4500 void
4501 decl_value_expr_insert (tree from, tree to)
4502 {
4503   struct tree_map *h;
4504   void **loc;
4505
4506   h = ggc_alloc (sizeof (struct tree_map));
4507   h->hash = htab_hash_pointer (from);
4508   h->base.from = from;
4509   h->to = to;
4510   loc = htab_find_slot_with_hash (value_expr_for_decl, h, h->hash, INSERT);
4511   *(struct tree_map **) loc = h;
4512 }
4513
4514 /* Hashing of types so that we don't make duplicates.
4515    The entry point is `type_hash_canon'.  */
4516
4517 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
4518    with types in the TREE_VALUE slots), by adding the hash codes
4519    of the individual types.  */
4520
4521 static unsigned int
4522 type_hash_list (const_tree list, hashval_t hashcode)
4523 {
4524   const_tree tail;
4525
4526   for (tail = list; tail; tail = TREE_CHAIN (tail))
4527     if (TREE_VALUE (tail) != error_mark_node)
4528       hashcode = iterative_hash_object (TYPE_HASH (TREE_VALUE (tail)),
4529                                         hashcode);
4530
4531   return hashcode;
4532 }
4533
4534 /* These are the Hashtable callback functions.  */
4535
4536 /* Returns true iff the types are equivalent.  */
4537
4538 static int
4539 type_hash_eq (const void *va, const void *vb)
4540 {
4541   const struct type_hash *const a = va, *const b = vb;
4542
4543   /* First test the things that are the same for all types.  */
4544   if (a->hash != b->hash
4545       || TREE_CODE (a->type) != TREE_CODE (b->type)
4546       || TREE_TYPE (a->type) != TREE_TYPE (b->type)
4547       || !attribute_list_equal (TYPE_ATTRIBUTES (a->type),
4548                                  TYPE_ATTRIBUTES (b->type))
4549       || TYPE_ALIGN (a->type) != TYPE_ALIGN (b->type)
4550       || TYPE_MODE (a->type) != TYPE_MODE (b->type))
4551     return 0;
4552
4553   switch (TREE_CODE (a->type))
4554     {
4555     case VOID_TYPE:
4556     case COMPLEX_TYPE:
4557     case POINTER_TYPE:
4558     case REFERENCE_TYPE:
4559       return 1;
4560
4561     case VECTOR_TYPE:
4562       return TYPE_VECTOR_SUBPARTS (a->type) == TYPE_VECTOR_SUBPARTS (b->type);
4563
4564     case ENUMERAL_TYPE:
4565       if (TYPE_VALUES (a->type) != TYPE_VALUES (b->type)
4566           && !(TYPE_VALUES (a->type)
4567                && TREE_CODE (TYPE_VALUES (a->type)) == TREE_LIST
4568                && TYPE_VALUES (b->type)
4569                && TREE_CODE (TYPE_VALUES (b->type)) == TREE_LIST
4570                && type_list_equal (TYPE_VALUES (a->type),
4571                                    TYPE_VALUES (b->type))))
4572         return 0;
4573
4574       /* ... fall through ... */
4575
4576     case INTEGER_TYPE:
4577     case REAL_TYPE:
4578     case BOOLEAN_TYPE:
4579       return ((TYPE_MAX_VALUE (a->type) == TYPE_MAX_VALUE (b->type)
4580                || tree_int_cst_equal (TYPE_MAX_VALUE (a->type),
4581                                       TYPE_MAX_VALUE (b->type)))
4582               && (TYPE_MIN_VALUE (a->type) == TYPE_MIN_VALUE (b->type)
4583                   || tree_int_cst_equal (TYPE_MIN_VALUE (a->type),
4584                                          TYPE_MIN_VALUE (b->type))));
4585
4586     case FIXED_POINT_TYPE:
4587       return TYPE_SATURATING (a->type) == TYPE_SATURATING (b->type);
4588
4589     case OFFSET_TYPE:
4590       return TYPE_OFFSET_BASETYPE (a->type) == TYPE_OFFSET_BASETYPE (b->type);
4591
4592     case METHOD_TYPE:
4593       return (TYPE_METHOD_BASETYPE (a->type) == TYPE_METHOD_BASETYPE (b->type)
4594               && (TYPE_ARG_TYPES (a->type) == TYPE_ARG_TYPES (b->type)
4595                   || (TYPE_ARG_TYPES (a->type)
4596                       && TREE_CODE (TYPE_ARG_TYPES (a->type)) == TREE_LIST
4597                       && TYPE_ARG_TYPES (b->type)
4598                       && TREE_CODE (TYPE_ARG_TYPES (b->type)) == TREE_LIST
4599                       && type_list_equal (TYPE_ARG_TYPES (a->type),
4600                                           TYPE_ARG_TYPES (b->type)))));
4601
4602     case ARRAY_TYPE:
4603       return TYPE_DOMAIN (a->type) == TYPE_DOMAIN (b->type);
4604
4605     case RECORD_TYPE:
4606     case UNION_TYPE:
4607     case QUAL_UNION_TYPE:
4608       return (TYPE_FIELDS (a->type) == TYPE_FIELDS (b->type)
4609               || (TYPE_FIELDS (a->type)
4610                   && TREE_CODE (TYPE_FIELDS (a->type)) == TREE_LIST
4611                   && TYPE_FIELDS (b->type)
4612                   && TREE_CODE (TYPE_FIELDS (b->type)) == TREE_LIST
4613                   && type_list_equal (TYPE_FIELDS (a->type),
4614                                       TYPE_FIELDS (b->type))));
4615
4616     case FUNCTION_TYPE:
4617       return (TYPE_ARG_TYPES (a->type) == TYPE_ARG_TYPES (b->type)
4618               || (TYPE_ARG_TYPES (a->type)
4619                   && TREE_CODE (TYPE_ARG_TYPES (a->type)) == TREE_LIST
4620                   && TYPE_ARG_TYPES (b->type)
4621                   && TREE_CODE (TYPE_ARG_TYPES (b->type)) == TREE_LIST
4622                   && type_list_equal (TYPE_ARG_TYPES (a->type),
4623                                       TYPE_ARG_TYPES (b->type))));
4624
4625     default:
4626       return 0;
4627     }
4628 }
4629
4630 /* Return the cached hash value.  */
4631
4632 static hashval_t
4633 type_hash_hash (const void *item)
4634 {
4635   return ((const struct type_hash *) item)->hash;
4636 }
4637
4638 /* Look in the type hash table for a type isomorphic to TYPE.
4639    If one is found, return it.  Otherwise return 0.  */
4640
4641 tree
4642 type_hash_lookup (hashval_t hashcode, tree type)
4643 {
4644   struct type_hash *h, in;
4645
4646   /* The TYPE_ALIGN field of a type is set by layout_type(), so we
4647      must call that routine before comparing TYPE_ALIGNs.  */
4648   layout_type (type);
4649
4650   in.hash = hashcode;
4651   in.type = type;
4652
4653   h = htab_find_with_hash (type_hash_table, &in, hashcode);
4654   if (h)
4655     return h->type;
4656   return NULL_TREE;
4657 }
4658
4659 /* Add an entry to the type-hash-table
4660    for a type TYPE whose hash code is HASHCODE.  */
4661
4662 void
4663 type_hash_add (hashval_t hashcode, tree type)
4664 {
4665   struct type_hash *h;
4666   void **loc;
4667
4668   h = ggc_alloc (sizeof (struct type_hash));
4669   h->hash = hashcode;
4670   h->type = type;
4671   loc = htab_find_slot_with_hash (type_hash_table, h, hashcode, INSERT);
4672   *(struct type_hash **) loc = h;
4673 }
4674
4675 /* Given TYPE, and HASHCODE its hash code, return the canonical
4676    object for an identical type if one already exists.
4677    Otherwise, return TYPE, and record it as the canonical object.
4678
4679    To use this function, first create a type of the sort you want.
4680    Then compute its hash code from the fields of the type that
4681    make it different from other similar types.
4682    Then call this function and use the value.  */
4683
4684 tree
4685 type_hash_canon (unsigned int hashcode, tree type)
4686 {
4687   tree t1;
4688
4689   /* The hash table only contains main variants, so ensure that's what we're
4690      being passed.  */
4691   gcc_assert (TYPE_MAIN_VARIANT (type) == type);
4692
4693   if (!lang_hooks.types.hash_types)
4694     return type;
4695
4696   /* See if the type is in the hash table already.  If so, return it.
4697      Otherwise, add the type.  */
4698   t1 = type_hash_lookup (hashcode, type);
4699   if (t1 != 0)
4700     {
4701 #ifdef GATHER_STATISTICS
4702       tree_node_counts[(int) t_kind]--;
4703       tree_node_sizes[(int) t_kind] -= sizeof (struct tree_type);
4704 #endif
4705       return t1;
4706     }
4707   else
4708     {
4709       type_hash_add (hashcode, type);
4710       return type;
4711     }
4712 }
4713
4714 /* See if the data pointed to by the type hash table is marked.  We consider
4715    it marked if the type is marked or if a debug type number or symbol
4716    table entry has been made for the type.  This reduces the amount of
4717    debugging output and eliminates that dependency of the debug output on
4718    the number of garbage collections.  */
4719
4720 static int
4721 type_hash_marked_p (const void *p)
4722 {
4723   const_tree const type = ((const struct type_hash *) p)->type;
4724
4725   return ggc_marked_p (type) || TYPE_SYMTAB_POINTER (type);
4726 }
4727
4728 static void
4729 print_type_hash_statistics (void)
4730 {
4731   fprintf (stderr, "Type hash: size %ld, %ld elements, %f collisions\n",
4732            (long) htab_size (type_hash_table),
4733            (long) htab_elements (type_hash_table),
4734            htab_collisions (type_hash_table));
4735 }
4736
4737 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
4738    with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
4739    by adding the hash codes of the individual attributes.  */
4740
4741 static unsigned int
4742 attribute_hash_list (const_tree list, hashval_t hashcode)
4743 {
4744   const_tree tail;
4745
4746   for (tail = list; tail; tail = TREE_CHAIN (tail))
4747     /* ??? Do we want to add in TREE_VALUE too? */
4748     hashcode = iterative_hash_object
4749       (IDENTIFIER_HASH_VALUE (TREE_PURPOSE (tail)), hashcode);
4750   return hashcode;
4751 }
4752
4753 /* Given two lists of attributes, return true if list l2 is
4754    equivalent to l1.  */
4755
4756 int
4757 attribute_list_equal (const_tree l1, const_tree l2)
4758 {
4759   return attribute_list_contained (l1, l2)
4760          && attribute_list_contained (l2, l1);
4761 }
4762
4763 /* Given two lists of attributes, return true if list L2 is
4764    completely contained within L1.  */
4765 /* ??? This would be faster if attribute names were stored in a canonicalized
4766    form.  Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
4767    must be used to show these elements are equivalent (which they are).  */
4768 /* ??? It's not clear that attributes with arguments will always be handled
4769    correctly.  */
4770
4771 int
4772 attribute_list_contained (const_tree l1, const_tree l2)
4773 {
4774   const_tree t1, t2;
4775
4776   /* First check the obvious, maybe the lists are identical.  */
4777   if (l1 == l2)
4778     return 1;
4779
4780   /* Maybe the lists are similar.  */
4781   for (t1 = l1, t2 = l2;
4782        t1 != 0 && t2 != 0
4783         && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
4784         && TREE_VALUE (t1) == TREE_VALUE (t2);
4785        t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2));
4786
4787   /* Maybe the lists are equal.  */
4788   if (t1 == 0 && t2 == 0)
4789     return 1;
4790
4791   for (; t2 != 0; t2 = TREE_CHAIN (t2))
4792     {
4793       const_tree attr;
4794       /* This CONST_CAST is okay because lookup_attribute does not
4795          modify its argument and the return value is assigned to a
4796          const_tree.  */
4797       for (attr = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)),
4798                                     CONST_CAST_TREE(l1));
4799            attr != NULL_TREE;
4800            attr = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)),
4801                                     TREE_CHAIN (attr)))
4802         {
4803           if (TREE_VALUE (t2) != NULL
4804               && TREE_CODE (TREE_VALUE (t2)) == TREE_LIST
4805               && TREE_VALUE (attr) != NULL
4806               && TREE_CODE (TREE_VALUE (attr)) == TREE_LIST)
4807             {
4808               if (simple_cst_list_equal (TREE_VALUE (t2),
4809                                          TREE_VALUE (attr)) == 1)
4810                 break;
4811             }
4812           else if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) == 1)
4813             break;
4814         }
4815
4816       if (attr == 0)
4817         return 0;
4818     }
4819
4820   return 1;
4821 }
4822
4823 /* Given two lists of types
4824    (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
4825    return 1 if the lists contain the same types in the same order.
4826    Also, the TREE_PURPOSEs must match.  */
4827
4828 int
4829 type_list_equal (const_tree l1, const_tree l2)
4830 {
4831   const_tree t1, t2;
4832
4833   for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
4834     if (TREE_VALUE (t1) != TREE_VALUE (t2)
4835         || (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
4836             && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
4837                   && (TREE_TYPE (TREE_PURPOSE (t1))
4838                       == TREE_TYPE (TREE_PURPOSE (t2))))))
4839       return 0;
4840
4841   return t1 == t2;
4842 }
4843
4844 /* Returns the number of arguments to the FUNCTION_TYPE or METHOD_TYPE
4845    given by TYPE.  If the argument list accepts variable arguments,
4846    then this function counts only the ordinary arguments.  */
4847
4848 int
4849 type_num_arguments (const_tree type)
4850 {
4851   int i = 0;
4852   tree t;
4853
4854   for (t = TYPE_ARG_TYPES (type); t; t = TREE_CHAIN (t))
4855     /* If the function does not take a variable number of arguments,
4856        the last element in the list will have type `void'.  */
4857     if (VOID_TYPE_P (TREE_VALUE (t)))
4858       break;
4859     else
4860       ++i;
4861
4862   return i;
4863 }
4864
4865 /* Nonzero if integer constants T1 and T2
4866    represent the same constant value.  */
4867
4868 int
4869 tree_int_cst_equal (const_tree t1, const_tree t2)
4870 {
4871   if (t1 == t2)
4872     return 1;
4873
4874   if (t1 == 0 || t2 == 0)
4875     return 0;
4876
4877   if (TREE_CODE (t1) == INTEGER_CST
4878       && TREE_CODE (t2) == INTEGER_CST
4879       && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
4880       && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
4881     return 1;
4882
4883   return 0;
4884 }
4885
4886 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
4887    The precise way of comparison depends on their data type.  */
4888
4889 int
4890 tree_int_cst_lt (const_tree t1, const_tree t2)
4891 {
4892   if (t1 == t2)
4893     return 0;
4894
4895   if (TYPE_UNSIGNED (TREE_TYPE (t1)) != TYPE_UNSIGNED (TREE_TYPE (t2)))
4896     {
4897       int t1_sgn = tree_int_cst_sgn (t1);
4898       int t2_sgn = tree_int_cst_sgn (t2);
4899
4900       if (t1_sgn < t2_sgn)
4901         return 1;
4902       else if (t1_sgn > t2_sgn)
4903         return 0;
4904       /* Otherwise, both are non-negative, so we compare them as
4905          unsigned just in case one of them would overflow a signed
4906          type.  */
4907     }
4908   else if (!TYPE_UNSIGNED (TREE_TYPE (t1)))
4909     return INT_CST_LT (t1, t2);
4910
4911   return INT_CST_LT_UNSIGNED (t1, t2);
4912 }
4913
4914 /* Returns -1 if T1 < T2, 0 if T1 == T2, and 1 if T1 > T2.  */
4915
4916 int
4917 tree_int_cst_compare (const_tree t1, const_tree t2)
4918 {
4919   if (tree_int_cst_lt (t1, t2))
4920     return -1;
4921   else if (tree_int_cst_lt (t2, t1))
4922     return 1;
4923   else
4924     return 0;
4925 }
4926
4927 /* Return 1 if T is an INTEGER_CST that can be manipulated efficiently on
4928    the host.  If POS is zero, the value can be represented in a single
4929    HOST_WIDE_INT.  If POS is nonzero, the value must be non-negative and can
4930    be represented in a single unsigned HOST_WIDE_INT.  */
4931
4932 int
4933 host_integerp (const_tree t, int pos)
4934 {
4935   return (TREE_CODE (t) == INTEGER_CST
4936           && ((TREE_INT_CST_HIGH (t) == 0
4937                && (HOST_WIDE_INT) TREE_INT_CST_LOW (t) >= 0)
4938               || (! pos && TREE_INT_CST_HIGH (t) == -1
4939                   && (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0
4940                   && (!TYPE_UNSIGNED (TREE_TYPE (t))
4941                       || TYPE_IS_SIZETYPE (TREE_TYPE (t))))
4942               || (pos && TREE_INT_CST_HIGH (t) == 0)));
4943 }
4944
4945 /* Return the HOST_WIDE_INT least significant bits of T if it is an
4946    INTEGER_CST and there is no overflow.  POS is nonzero if the result must
4947    be non-negative.  We must be able to satisfy the above conditions.  */
4948
4949 HOST_WIDE_INT
4950 tree_low_cst (const_tree t, int pos)
4951 {
4952   gcc_assert (host_integerp (t, pos));
4953   return TREE_INT_CST_LOW (t);
4954 }
4955
4956 /* Return the most significant bit of the integer constant T.  */
4957
4958 int
4959 tree_int_cst_msb (const_tree t)
4960 {
4961   int prec;
4962   HOST_WIDE_INT h;
4963   unsigned HOST_WIDE_INT l;
4964
4965   /* Note that using TYPE_PRECISION here is wrong.  We care about the
4966      actual bits, not the (arbitrary) range of the type.  */
4967   prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (t))) - 1;
4968   rshift_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t), prec,
4969                  2 * HOST_BITS_PER_WIDE_INT, &l, &h, 0);
4970   return (l & 1) == 1;
4971 }
4972
4973 /* Return an indication of the sign of the integer constant T.
4974    The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
4975    Note that -1 will never be returned if T's type is unsigned.  */
4976
4977 int
4978 tree_int_cst_sgn (const_tree t)
4979 {
4980   if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
4981     return 0;
4982   else if (TYPE_UNSIGNED (TREE_TYPE (t)))
4983     return 1;
4984   else if (TREE_INT_CST_HIGH (t) < 0)
4985     return -1;
4986   else
4987     return 1;
4988 }
4989
4990 /* Compare two constructor-element-type constants.  Return 1 if the lists
4991    are known to be equal; otherwise return 0.  */
4992
4993 int
4994 simple_cst_list_equal (const_tree l1, const_tree l2)
4995 {
4996   while (l1 != NULL_TREE && l2 != NULL_TREE)
4997     {
4998       if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
4999         return 0;
5000
5001       l1 = TREE_CHAIN (l1);
5002       l2 = TREE_CHAIN (l2);
5003     }
5004
5005   return l1 == l2;
5006 }
5007
5008 /* Return truthvalue of whether T1 is the same tree structure as T2.
5009    Return 1 if they are the same.
5010    Return 0 if they are understandably different.
5011    Return -1 if either contains tree structure not understood by
5012    this function.  */
5013
5014 int
5015 simple_cst_equal (const_tree t1, const_tree t2)
5016 {
5017   enum tree_code code1, code2;
5018   int cmp;
5019   int i;
5020
5021   if (t1 == t2)
5022     return 1;
5023   if (t1 == 0 || t2 == 0)
5024     return 0;
5025
5026   code1 = TREE_CODE (t1);
5027   code2 = TREE_CODE (t2);
5028
5029   if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
5030     {
5031       if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
5032           || code2 == NON_LVALUE_EXPR)
5033         return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
5034       else
5035         return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
5036     }
5037
5038   else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
5039            || code2 == NON_LVALUE_EXPR)
5040     return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
5041
5042   if (code1 != code2)
5043     return 0;
5044
5045   switch (code1)
5046     {
5047     case INTEGER_CST:
5048       return (TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
5049               && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2));
5050
5051     case REAL_CST:
5052       return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
5053
5054     case FIXED_CST:
5055       return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
5056
5057     case STRING_CST:
5058       return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
5059               && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
5060                          TREE_STRING_LENGTH (t1)));
5061
5062     case CONSTRUCTOR:
5063       {
5064         unsigned HOST_WIDE_INT idx;
5065         VEC(constructor_elt, gc) *v1 = CONSTRUCTOR_ELTS (t1);
5066         VEC(constructor_elt, gc) *v2 = CONSTRUCTOR_ELTS (t2);
5067
5068         if (VEC_length (constructor_elt, v1) != VEC_length (constructor_elt, v2))
5069           return false;
5070
5071         for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
5072           /* ??? Should we handle also fields here? */
5073           if (!simple_cst_equal (VEC_index (constructor_elt, v1, idx)->value,
5074                                  VEC_index (constructor_elt, v2, idx)->value))
5075             return false;
5076         return true;
5077       }
5078
5079     case SAVE_EXPR:
5080       return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
5081
5082     case CALL_EXPR:
5083       cmp = simple_cst_equal (CALL_EXPR_FN (t1), CALL_EXPR_FN (t2));
5084       if (cmp <= 0)
5085         return cmp;
5086       if (call_expr_nargs (t1) != call_expr_nargs (t2))
5087         return 0;
5088       {
5089         const_tree arg1, arg2;
5090         const_call_expr_arg_iterator iter1, iter2;
5091         for (arg1 = first_const_call_expr_arg (t1, &iter1),
5092                arg2 = first_const_call_expr_arg (t2, &iter2);
5093              arg1 && arg2;
5094              arg1 = next_const_call_expr_arg (&iter1),
5095                arg2 = next_const_call_expr_arg (&iter2))
5096           {
5097             cmp = simple_cst_equal (arg1, arg2);
5098             if (cmp <= 0)
5099               return cmp;
5100           }
5101         return arg1 == arg2;
5102       }
5103
5104     case TARGET_EXPR:
5105       /* Special case: if either target is an unallocated VAR_DECL,
5106          it means that it's going to be unified with whatever the
5107          TARGET_EXPR is really supposed to initialize, so treat it
5108          as being equivalent to anything.  */
5109       if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
5110            && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
5111            && !DECL_RTL_SET_P (TREE_OPERAND (t1, 0)))
5112           || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
5113               && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
5114               && !DECL_RTL_SET_P (TREE_OPERAND (t2, 0))))
5115         cmp = 1;
5116       else
5117         cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
5118
5119       if (cmp <= 0)
5120         return cmp;
5121
5122       return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
5123
5124     case WITH_CLEANUP_EXPR:
5125       cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
5126       if (cmp <= 0)
5127         return cmp;
5128
5129       return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t1, 1));
5130
5131     case COMPONENT_REF:
5132       if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
5133         return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
5134
5135       return 0;
5136
5137     case VAR_DECL:
5138     case PARM_DECL:
5139     case CONST_DECL:
5140     case FUNCTION_DECL:
5141       return 0;
5142
5143     default:
5144       break;
5145     }
5146
5147   /* This general rule works for most tree codes.  All exceptions should be
5148      handled above.  If this is a language-specific tree code, we can't
5149      trust what might be in the operand, so say we don't know
5150      the situation.  */
5151   if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
5152     return -1;
5153
5154   switch (TREE_CODE_CLASS (code1))
5155     {
5156     case tcc_unary:
5157     case tcc_binary:
5158     case tcc_comparison:
5159     case tcc_expression:
5160     case tcc_reference:
5161     case tcc_statement:
5162       cmp = 1;
5163       for (i = 0; i < TREE_CODE_LENGTH (code1); i++)
5164         {
5165           cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
5166           if (cmp <= 0)
5167             return cmp;
5168         }
5169
5170       return cmp;
5171
5172     default:
5173       return -1;
5174     }
5175 }
5176
5177 /* Compare the value of T, an INTEGER_CST, with U, an unsigned integer value.
5178    Return -1, 0, or 1 if the value of T is less than, equal to, or greater
5179    than U, respectively.  */
5180
5181 int
5182 compare_tree_int (const_tree t, unsigned HOST_WIDE_INT u)
5183 {
5184   if (tree_int_cst_sgn (t) < 0)
5185     return -1;
5186   else if (TREE_INT_CST_HIGH (t) != 0)
5187     return 1;
5188   else if (TREE_INT_CST_LOW (t) == u)
5189     return 0;
5190   else if (TREE_INT_CST_LOW (t) < u)
5191     return -1;
5192   else
5193     return 1;
5194 }
5195
5196 /* Return true if CODE represents an associative tree code.  Otherwise
5197    return false.  */
5198 bool
5199 associative_tree_code (enum tree_code code)
5200 {
5201   switch (code)
5202     {
5203     case BIT_IOR_EXPR:
5204     case BIT_AND_EXPR:
5205     case BIT_XOR_EXPR:
5206     case PLUS_EXPR:
5207     case MULT_EXPR:
5208     case MIN_EXPR:
5209     case MAX_EXPR:
5210       return true;
5211
5212     default:
5213       break;
5214     }
5215   return false;
5216 }
5217
5218 /* Return true if CODE represents a commutative tree code.  Otherwise
5219    return false.  */
5220 bool
5221 commutative_tree_code (enum tree_code code)
5222 {
5223   switch (code)
5224     {
5225     case PLUS_EXPR:
5226     case MULT_EXPR:
5227     case MIN_EXPR:
5228     case MAX_EXPR:
5229     case BIT_IOR_EXPR:
5230     case BIT_XOR_EXPR:
5231     case BIT_AND_EXPR:
5232     case NE_EXPR:
5233     case EQ_EXPR:
5234     case UNORDERED_EXPR:
5235     case ORDERED_EXPR:
5236     case UNEQ_EXPR:
5237     case LTGT_EXPR:
5238     case TRUTH_AND_EXPR:
5239     case TRUTH_XOR_EXPR:
5240     case TRUTH_OR_EXPR:
5241       return true;
5242
5243     default:
5244       break;
5245     }
5246   return false;
5247 }
5248
5249 /* Generate a hash value for an expression.  This can be used iteratively
5250    by passing a previous result as the "val" argument.
5251
5252    This function is intended to produce the same hash for expressions which
5253    would compare equal using operand_equal_p.  */
5254
5255 hashval_t
5256 iterative_hash_expr (const_tree t, hashval_t val)
5257 {
5258   int i;
5259   enum tree_code code;
5260   char class;
5261
5262   if (t == NULL_TREE)
5263     return iterative_hash_pointer (t, val);
5264
5265   code = TREE_CODE (t);
5266
5267   switch (code)
5268     {
5269     /* Alas, constants aren't shared, so we can't rely on pointer
5270        identity.  */
5271     case INTEGER_CST:
5272       val = iterative_hash_host_wide_int (TREE_INT_CST_LOW (t), val);
5273       return iterative_hash_host_wide_int (TREE_INT_CST_HIGH (t), val);
5274     case REAL_CST:
5275       {
5276         unsigned int val2 = real_hash (TREE_REAL_CST_PTR (t));
5277
5278         return iterative_hash_hashval_t (val2, val);
5279       }
5280     case FIXED_CST:
5281       {
5282         unsigned int val2 = fixed_hash (TREE_FIXED_CST_PTR (t));
5283
5284         return iterative_hash_hashval_t (val2, val);
5285       }
5286     case STRING_CST:
5287       return iterative_hash (TREE_STRING_POINTER (t),
5288                              TREE_STRING_LENGTH (t), val);
5289     case COMPLEX_CST:
5290       val = iterative_hash_expr (TREE_REALPART (t), val);
5291       return iterative_hash_expr (TREE_IMAGPART (t), val);
5292     case VECTOR_CST:
5293       return iterative_hash_expr (TREE_VECTOR_CST_ELTS (t), val);
5294
5295     case SSA_NAME:
5296     case VALUE_HANDLE:
5297       /* we can just compare by pointer.  */
5298       return iterative_hash_pointer (t, val);
5299
5300     case TREE_LIST:
5301       /* A list of expressions, for a CALL_EXPR or as the elements of a
5302          VECTOR_CST.  */
5303       for (; t; t = TREE_CHAIN (t))
5304         val = iterative_hash_expr (TREE_VALUE (t), val);
5305       return val;
5306     case CONSTRUCTOR:
5307       {
5308         unsigned HOST_WIDE_INT idx;
5309         tree field, value;
5310         FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), idx, field, value)
5311           {
5312             val = iterative_hash_expr (field, val);
5313             val = iterative_hash_expr (value, val);
5314           }
5315         return val;
5316       }
5317     case FUNCTION_DECL:
5318       /* When referring to a built-in FUNCTION_DECL, use the
5319          __builtin__ form.  Otherwise nodes that compare equal
5320          according to operand_equal_p might get different
5321          hash codes.  */
5322       if (DECL_BUILT_IN (t))
5323         {
5324           val = iterative_hash_pointer (built_in_decls[DECL_FUNCTION_CODE (t)],
5325                                       val);
5326           return val;
5327         }
5328       /* else FALL THROUGH */
5329     default:
5330       class = TREE_CODE_CLASS (code);
5331
5332       if (class == tcc_declaration)
5333         {
5334           /* DECL's have a unique ID */
5335           val = iterative_hash_host_wide_int (DECL_UID (t), val);
5336         }
5337       else
5338         {
5339           gcc_assert (IS_EXPR_CODE_CLASS (class));
5340
5341           val = iterative_hash_object (code, val);
5342
5343           /* Don't hash the type, that can lead to having nodes which
5344              compare equal according to operand_equal_p, but which
5345              have different hash codes.  */
5346           if (code == NOP_EXPR
5347               || code == CONVERT_EXPR
5348               || code == NON_LVALUE_EXPR)
5349             {
5350               /* Make sure to include signness in the hash computation.  */
5351               val += TYPE_UNSIGNED (TREE_TYPE (t));
5352               val = iterative_hash_expr (TREE_OPERAND (t, 0), val);
5353             }
5354
5355           else if (commutative_tree_code (code))
5356             {
5357               /* It's a commutative expression.  We want to hash it the same
5358                  however it appears.  We do this by first hashing both operands
5359                  and then rehashing based on the order of their independent
5360                  hashes.  */
5361               hashval_t one = iterative_hash_expr (TREE_OPERAND (t, 0), 0);
5362               hashval_t two = iterative_hash_expr (TREE_OPERAND (t, 1), 0);
5363               hashval_t t;
5364
5365               if (one > two)
5366                 t = one, one = two, two = t;
5367
5368               val = iterative_hash_hashval_t (one, val);
5369               val = iterative_hash_hashval_t (two, val);
5370             }
5371           else
5372             for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i)
5373               val = iterative_hash_expr (TREE_OPERAND (t, i), val);
5374         }
5375       return val;
5376       break;
5377     }
5378 }
5379 \f
5380 /* Constructors for pointer, array and function types.
5381    (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
5382    constructed by language-dependent code, not here.)  */
5383
5384 /* Construct, lay out and return the type of pointers to TO_TYPE with
5385    mode MODE.  If CAN_ALIAS_ALL is TRUE, indicate this type can
5386    reference all of memory. If such a type has already been
5387    constructed, reuse it.  */
5388
5389 tree
5390 build_pointer_type_for_mode (tree to_type, enum machine_mode mode,
5391                              bool can_alias_all)
5392 {
5393   tree t;
5394
5395   if (to_type == error_mark_node)
5396     return error_mark_node;
5397
5398   /* In some cases, languages will have things that aren't a POINTER_TYPE
5399      (such as a RECORD_TYPE for fat pointers in Ada) as TYPE_POINTER_TO.
5400      In that case, return that type without regard to the rest of our
5401      operands.
5402
5403      ??? This is a kludge, but consistent with the way this function has
5404      always operated and there doesn't seem to be a good way to avoid this
5405      at the moment.  */
5406   if (TYPE_POINTER_TO (to_type) != 0
5407       && TREE_CODE (TYPE_POINTER_TO (to_type)) != POINTER_TYPE)
5408     return TYPE_POINTER_TO (to_type);
5409
5410   /* First, if we already have a type for pointers to TO_TYPE and it's
5411      the proper mode, use it.  */
5412   for (t = TYPE_POINTER_TO (to_type); t; t = TYPE_NEXT_PTR_TO (t))
5413     if (TYPE_MODE (t) == mode && TYPE_REF_CAN_ALIAS_ALL (t) == can_alias_all)
5414       return t;
5415
5416   t = make_node (POINTER_TYPE);
5417
5418   TREE_TYPE (t) = to_type;
5419   TYPE_MODE (t) = mode;
5420   TYPE_REF_CAN_ALIAS_ALL (t) = can_alias_all;
5421   TYPE_NEXT_PTR_TO (t) = TYPE_POINTER_TO (to_type);
5422   TYPE_POINTER_TO (to_type) = t;
5423
5424   if (TYPE_STRUCTURAL_EQUALITY_P (to_type))
5425     SET_TYPE_STRUCTURAL_EQUALITY (t);
5426   else if (TYPE_CANONICAL (to_type) != to_type)
5427     TYPE_CANONICAL (t)
5428       = build_pointer_type_for_mode (TYPE_CANONICAL (to_type),
5429                                      mode, can_alias_all);
5430
5431   /* Lay out the type.  This function has many callers that are concerned
5432      with expression-construction, and this simplifies them all.  */
5433   layout_type (t);
5434
5435   return t;
5436 }
5437
5438 /* By default build pointers in ptr_mode.  */
5439
5440 tree
5441 build_pointer_type (tree to_type)
5442 {
5443   return build_pointer_type_for_mode (to_type, ptr_mode, false);
5444 }
5445
5446 /* Same as build_pointer_type_for_mode, but for REFERENCE_TYPE.  */
5447
5448 tree
5449 build_reference_type_for_mode (tree to_type, enum machine_mode mode,
5450                                bool can_alias_all)
5451 {
5452   tree t;
5453
5454   /* In some cases, languages will have things that aren't a REFERENCE_TYPE
5455      (such as a RECORD_TYPE for fat pointers in Ada) as TYPE_REFERENCE_TO.
5456      In that case, return that type without regard to the rest of our
5457      operands.
5458
5459      ??? This is a kludge, but consistent with the way this function has
5460      always operated and there doesn't seem to be a good way to avoid this
5461      at the moment.  */
5462   if (TYPE_REFERENCE_TO (to_type) != 0
5463       && TREE_CODE (TYPE_REFERENCE_TO (to_type)) != REFERENCE_TYPE)
5464     return TYPE_REFERENCE_TO (to_type);
5465
5466   /* First, if we already have a type for pointers to TO_TYPE and it's
5467      the proper mode, use it.  */
5468   for (t = TYPE_REFERENCE_TO (to_type); t; t = TYPE_NEXT_REF_TO (t))
5469     if (TYPE_MODE (t) == mode && TYPE_REF_CAN_ALIAS_ALL (t) == can_alias_all)
5470       return t;
5471
5472   t = make_node (REFERENCE_TYPE);
5473
5474   TREE_TYPE (t) = to_type;
5475   TYPE_MODE (t) = mode;
5476   TYPE_REF_CAN_ALIAS_ALL (t) = can_alias_all;
5477   TYPE_NEXT_REF_TO (t) = TYPE_REFERENCE_TO (to_type);
5478   TYPE_REFERENCE_TO (to_type) = t;
5479
5480   if (TYPE_STRUCTURAL_EQUALITY_P (to_type))
5481     SET_TYPE_STRUCTURAL_EQUALITY (t);
5482   else if (TYPE_CANONICAL (to_type) != to_type)
5483     TYPE_CANONICAL (t)
5484       = build_reference_type_for_mode (TYPE_CANONICAL (to_type),
5485                                        mode, can_alias_all);
5486
5487   layout_type (t);
5488
5489   return t;
5490 }
5491
5492
5493 /* Build the node for the type of references-to-TO_TYPE by default
5494    in ptr_mode.  */
5495
5496 tree
5497 build_reference_type (tree to_type)
5498 {
5499   return build_reference_type_for_mode (to_type, ptr_mode, false);
5500 }
5501
5502 /* Build a type that is compatible with t but has no cv quals anywhere
5503    in its type, thus
5504
5505    const char *const *const *  ->  char ***.  */
5506
5507 tree
5508 build_type_no_quals (tree t)
5509 {
5510   switch (TREE_CODE (t))
5511     {
5512     case POINTER_TYPE:
5513       return build_pointer_type_for_mode (build_type_no_quals (TREE_TYPE (t)),
5514                                           TYPE_MODE (t),
5515                                           TYPE_REF_CAN_ALIAS_ALL (t));
5516     case REFERENCE_TYPE:
5517       return
5518         build_reference_type_for_mode (build_type_no_quals (TREE_TYPE (t)),
5519                                        TYPE_MODE (t),
5520                                        TYPE_REF_CAN_ALIAS_ALL (t));
5521     default:
5522       return TYPE_MAIN_VARIANT (t);
5523     }
5524 }
5525
5526 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
5527    MAXVAL should be the maximum value in the domain
5528    (one less than the length of the array).
5529
5530    The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
5531    We don't enforce this limit, that is up to caller (e.g. language front end).
5532    The limit exists because the result is a signed type and we don't handle
5533    sizes that use more than one HOST_WIDE_INT.  */
5534
5535 tree
5536 build_index_type (tree maxval)
5537 {
5538   tree itype = make_node (INTEGER_TYPE);
5539
5540   TREE_TYPE (itype) = sizetype;
5541   TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
5542   TYPE_MIN_VALUE (itype) = size_zero_node;
5543   TYPE_MAX_VALUE (itype) = fold_convert (sizetype, maxval);
5544   TYPE_MODE (itype) = TYPE_MODE (sizetype);
5545   TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
5546   TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (sizetype);
5547   TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
5548   TYPE_USER_ALIGN (itype) = TYPE_USER_ALIGN (sizetype);
5549
5550   if (host_integerp (maxval, 1))
5551     return type_hash_canon (tree_low_cst (maxval, 1), itype);
5552   else
5553     {
5554       /* Since we cannot hash this type, we need to compare it using
5555          structural equality checks. */
5556       SET_TYPE_STRUCTURAL_EQUALITY (itype);
5557       return itype;
5558     }
5559 }
5560
5561 /* Builds a signed or unsigned integer type of precision PRECISION.
5562    Used for C bitfields whose precision does not match that of
5563    built-in target types.  */
5564 tree
5565 build_nonstandard_integer_type (unsigned HOST_WIDE_INT precision,
5566                                 int unsignedp)
5567 {
5568   tree itype = make_node (INTEGER_TYPE);
5569
5570   TYPE_PRECISION (itype) = precision;
5571
5572   if (unsignedp)
5573     fixup_unsigned_type (itype);
5574   else
5575     fixup_signed_type (itype);
5576
5577   if (host_integerp (TYPE_MAX_VALUE (itype), 1))
5578     return type_hash_canon (tree_low_cst (TYPE_MAX_VALUE (itype), 1), itype);
5579
5580   return itype;
5581 }
5582
5583 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
5584    ENUMERAL_TYPE or BOOLEAN_TYPE), with low bound LOWVAL and
5585    high bound HIGHVAL.  If TYPE is NULL, sizetype is used.  */
5586
5587 tree
5588 build_range_type (tree type, tree lowval, tree highval)
5589 {
5590   tree itype = make_node (INTEGER_TYPE);
5591
5592   TREE_TYPE (itype) = type;
5593   if (type == NULL_TREE)
5594     type = sizetype;
5595
5596   TYPE_MIN_VALUE (itype) = fold_convert (type, lowval);
5597   TYPE_MAX_VALUE (itype) = highval ? fold_convert (type, highval) : NULL;
5598
5599   TYPE_PRECISION (itype) = TYPE_PRECISION (type);
5600   TYPE_MODE (itype) = TYPE_MODE (type);
5601   TYPE_SIZE (itype) = TYPE_SIZE (type);
5602   TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (type);
5603   TYPE_ALIGN (itype) = TYPE_ALIGN (type);
5604   TYPE_USER_ALIGN (itype) = TYPE_USER_ALIGN (type);
5605
5606   if (host_integerp (lowval, 0) && highval != 0 && host_integerp (highval, 0))
5607     return type_hash_canon (tree_low_cst (highval, 0)
5608                             - tree_low_cst (lowval, 0),
5609                             itype);
5610   else
5611     return itype;
5612 }
5613
5614 /* Just like build_index_type, but takes lowval and highval instead
5615    of just highval (maxval).  */
5616
5617 tree
5618 build_index_2_type (tree lowval, tree highval)
5619 {
5620   return build_range_type (sizetype, lowval, highval);
5621 }
5622
5623 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
5624    and number of elements specified by the range of values of INDEX_TYPE.
5625    If such a type has already been constructed, reuse it.  */
5626
5627 tree
5628 build_array_type (tree elt_type, tree index_type)
5629 {
5630   tree t;
5631   hashval_t hashcode = 0;
5632
5633   if (TREE_CODE (elt_type) == FUNCTION_TYPE)
5634     {
5635       error ("arrays of functions are not meaningful");
5636       elt_type = integer_type_node;
5637     }
5638
5639   t = make_node (ARRAY_TYPE);
5640   TREE_TYPE (t) = elt_type;
5641   TYPE_DOMAIN (t) = index_type;
5642
5643   if (index_type == 0)
5644     {
5645       tree save = t;
5646       hashcode = iterative_hash_object (TYPE_HASH (elt_type), hashcode);
5647       t = type_hash_canon (hashcode, t);
5648       if (save == t)
5649         layout_type (t);
5650
5651       if (TYPE_CANONICAL (t) == t)
5652         {
5653           if (TYPE_STRUCTURAL_EQUALITY_P (elt_type))
5654             SET_TYPE_STRUCTURAL_EQUALITY (t);
5655           else if (TYPE_CANONICAL (elt_type) != elt_type)
5656             TYPE_CANONICAL (t)
5657               = build_array_type (TYPE_CANONICAL (elt_type), index_type);
5658         }
5659
5660       return t;
5661     }
5662
5663   hashcode = iterative_hash_object (TYPE_HASH (elt_type), hashcode);
5664   hashcode = iterative_hash_object (TYPE_HASH (index_type), hashcode);
5665   t = type_hash_canon (hashcode, t);
5666
5667   if (!COMPLETE_TYPE_P (t))
5668     layout_type (t);
5669
5670   if (TYPE_CANONICAL (t) == t)
5671     {
5672       if (TYPE_STRUCTURAL_EQUALITY_P (elt_type)
5673           || TYPE_STRUCTURAL_EQUALITY_P (index_type))
5674         SET_TYPE_STRUCTURAL_EQUALITY (t);
5675       else if (TYPE_CANONICAL (elt_type) != elt_type
5676                || TYPE_CANONICAL (index_type) != index_type)
5677         TYPE_CANONICAL (t)
5678           = build_array_type (TYPE_CANONICAL (elt_type),
5679                               TYPE_CANONICAL (index_type));
5680     }
5681
5682   return t;
5683 }
5684
5685 /* Return the TYPE of the elements comprising
5686    the innermost dimension of ARRAY.  */
5687
5688 tree
5689 get_inner_array_type (const_tree array)
5690 {
5691   tree type = TREE_TYPE (array);
5692
5693   while (TREE_CODE (type) == ARRAY_TYPE)
5694     type = TREE_TYPE (type);
5695
5696   return type;
5697 }
5698
5699 /* Computes the canonical argument types from the argument type list
5700    ARGTYPES.
5701
5702    Upon return, *ANY_STRUCTURAL_P will be true iff either it was true
5703    on entry to this function, or if any of the ARGTYPES are
5704    structural.
5705
5706    Upon return, *ANY_NONCANONICAL_P will be true iff either it was
5707    true on entry to this function, or if any of the ARGTYPES are
5708    non-canonical.
5709
5710    Returns a canonical argument list, which may be ARGTYPES when the
5711    canonical argument list is unneeded (i.e., *ANY_STRUCTURAL_P is
5712    true) or would not differ from ARGTYPES.  */
5713
5714 static tree
5715 maybe_canonicalize_argtypes(tree argtypes,
5716                             bool *any_structural_p,
5717                             bool *any_noncanonical_p)
5718 {
5719   tree arg;
5720   bool any_noncanonical_argtypes_p = false;
5721
5722   for (arg = argtypes; arg && !(*any_structural_p); arg = TREE_CHAIN (arg))
5723     {
5724       if (!TREE_VALUE (arg) || TREE_VALUE (arg) == error_mark_node)
5725         /* Fail gracefully by stating that the type is structural.  */
5726         *any_structural_p = true;
5727       else if (TYPE_STRUCTURAL_EQUALITY_P (TREE_VALUE (arg)))
5728         *any_structural_p = true;
5729       else if (TYPE_CANONICAL (TREE_VALUE (arg)) != TREE_VALUE (arg)
5730                || TREE_PURPOSE (arg))
5731         /* If the argument has a default argument, we consider it
5732            non-canonical even though the type itself is canonical.
5733            That way, different variants of function and method types
5734            with default arguments will all point to the variant with
5735            no defaults as their canonical type.  */
5736         any_noncanonical_argtypes_p = true;
5737     }
5738
5739   if (*any_structural_p)
5740     return argtypes;
5741
5742   if (any_noncanonical_argtypes_p)
5743     {
5744       /* Build the canonical list of argument types.  */
5745       tree canon_argtypes = NULL_TREE;
5746       bool is_void = false;
5747
5748       for (arg = argtypes; arg; arg = TREE_CHAIN (arg))
5749         {
5750           if (arg == void_list_node)
5751             is_void = true;
5752           else
5753             canon_argtypes = tree_cons (NULL_TREE,
5754                                         TYPE_CANONICAL (TREE_VALUE (arg)),
5755                                         canon_argtypes);
5756         }
5757
5758       canon_argtypes = nreverse (canon_argtypes);
5759       if (is_void)
5760         canon_argtypes = chainon (canon_argtypes, void_list_node);
5761
5762       /* There is a non-canonical type.  */
5763       *any_noncanonical_p = true;
5764       return canon_argtypes;
5765     }
5766
5767   /* The canonical argument types are the same as ARGTYPES.  */
5768   return argtypes;
5769 }
5770
5771 /* Construct, lay out and return
5772    the type of functions returning type VALUE_TYPE
5773    given arguments of types ARG_TYPES.
5774    ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
5775    are data type nodes for the arguments of the function.
5776    If such a type has already been constructed, reuse it.  */
5777
5778 tree
5779 build_function_type (tree value_type, tree arg_types)
5780 {
5781   tree t;
5782   hashval_t hashcode = 0;
5783   bool any_structural_p, any_noncanonical_p;
5784   tree canon_argtypes;
5785
5786   if (TREE_CODE (value_type) == FUNCTION_TYPE)
5787     {
5788       error ("function return type cannot be function");
5789       value_type = integer_type_node;
5790     }
5791
5792   /* Make a node of the sort we want.  */
5793   t = make_node (FUNCTION_TYPE);
5794   TREE_TYPE (t) = value_type;
5795   TYPE_ARG_TYPES (t) = arg_types;
5796
5797   /* If we already have such a type, use the old one.  */
5798   hashcode = iterative_hash_object (TYPE_HASH (value_type), hashcode);
5799   hashcode = type_hash_list (arg_types, hashcode);
5800   t = type_hash_canon (hashcode, t);
5801
5802   /* Set up the canonical type. */
5803   any_structural_p   = TYPE_STRUCTURAL_EQUALITY_P (value_type);
5804   any_noncanonical_p = TYPE_CANONICAL (value_type) != value_type;
5805   canon_argtypes = maybe_canonicalize_argtypes (arg_types,
5806                                                 &any_structural_p,
5807                                                 &any_noncanonical_p);
5808   if (any_structural_p)
5809     SET_TYPE_STRUCTURAL_EQUALITY (t);
5810   else if (any_noncanonical_p)
5811     TYPE_CANONICAL (t) = build_function_type (TYPE_CANONICAL (value_type),
5812                                               canon_argtypes);
5813
5814   if (!COMPLETE_TYPE_P (t))
5815     layout_type (t);
5816   return t;
5817 }
5818
5819 /* Build a function type.  The RETURN_TYPE is the type returned by the
5820    function.  If additional arguments are provided, they are
5821    additional argument types.  The list of argument types must always
5822    be terminated by NULL_TREE.  */
5823
5824 tree
5825 build_function_type_list (tree return_type, ...)
5826 {
5827   tree t, args, last;
5828   va_list p;
5829
5830   va_start (p, return_type);
5831
5832   t = va_arg (p, tree);
5833   for (args = NULL_TREE; t != NULL_TREE; t = va_arg (p, tree))
5834     args = tree_cons (NULL_TREE, t, args);
5835
5836   if (args == NULL_TREE)
5837     args = void_list_node;
5838   else
5839     {
5840       last = args;
5841       args = nreverse (args);
5842       TREE_CHAIN (last) = void_list_node;
5843     }
5844   args = build_function_type (return_type, args);
5845
5846   va_end (p);
5847   return args;
5848 }
5849
5850 /* Build a METHOD_TYPE for a member of BASETYPE.  The RETTYPE (a TYPE)
5851    and ARGTYPES (a TREE_LIST) are the return type and arguments types
5852    for the method.  An implicit additional parameter (of type
5853    pointer-to-BASETYPE) is added to the ARGTYPES.  */
5854
5855 tree
5856 build_method_type_directly (tree basetype,
5857                             tree rettype,
5858                             tree argtypes)
5859 {
5860   tree t;
5861   tree ptype;
5862   int hashcode = 0;
5863   bool any_structural_p, any_noncanonical_p;
5864   tree canon_argtypes;
5865
5866   /* Make a node of the sort we want.  */
5867   t = make_node (METHOD_TYPE);
5868
5869   TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
5870   TREE_TYPE (t) = rettype;
5871   ptype = build_pointer_type (basetype);
5872
5873   /* The actual arglist for this function includes a "hidden" argument
5874      which is "this".  Put it into the list of argument types.  */
5875   argtypes = tree_cons (NULL_TREE, ptype, argtypes);
5876   TYPE_ARG_TYPES (t) = argtypes;
5877
5878   /* If we already have such a type, use the old one.  */
5879   hashcode = iterative_hash_object (TYPE_HASH (basetype), hashcode);
5880   hashcode = iterative_hash_object (TYPE_HASH (rettype), hashcode);
5881   hashcode = type_hash_list (argtypes, hashcode);
5882   t = type_hash_canon (hashcode, t);
5883
5884   /* Set up the canonical type. */
5885   any_structural_p
5886     = (TYPE_STRUCTURAL_EQUALITY_P (basetype)
5887        || TYPE_STRUCTURAL_EQUALITY_P (rettype));
5888   any_noncanonical_p
5889     = (TYPE_CANONICAL (basetype) != basetype
5890        || TYPE_CANONICAL (rettype) != rettype);
5891   canon_argtypes = maybe_canonicalize_argtypes (TREE_CHAIN (argtypes),
5892                                                 &any_structural_p,
5893                                                 &any_noncanonical_p);
5894   if (any_structural_p)
5895     SET_TYPE_STRUCTURAL_EQUALITY (t);
5896   else if (any_noncanonical_p)
5897     TYPE_CANONICAL (t)
5898       = build_method_type_directly (TYPE_CANONICAL (basetype),
5899                                     TYPE_CANONICAL (rettype),
5900                                     canon_argtypes);
5901   if (!COMPLETE_TYPE_P (t))
5902     layout_type (t);
5903
5904   return t;
5905 }
5906
5907 /* Construct, lay out and return the type of methods belonging to class
5908    BASETYPE and whose arguments and values are described by TYPE.
5909    If that type exists already, reuse it.
5910    TYPE must be a FUNCTION_TYPE node.  */
5911
5912 tree
5913 build_method_type (tree basetype, tree type)
5914 {
5915   gcc_assert (TREE_CODE (type) == FUNCTION_TYPE);
5916
5917   return build_method_type_directly (basetype,
5918                                      TREE_TYPE (type),
5919                                      TYPE_ARG_TYPES (type));
5920 }
5921
5922 /* Construct, lay out and return the type of offsets to a value
5923    of type TYPE, within an object of type BASETYPE.
5924    If a suitable offset type exists already, reuse it.  */
5925
5926 tree
5927 build_offset_type (tree basetype, tree type)
5928 {
5929   tree t;
5930   hashval_t hashcode = 0;
5931
5932   /* Make a node of the sort we want.  */
5933   t = make_node (OFFSET_TYPE);
5934
5935   TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
5936   TREE_TYPE (t) = type;
5937
5938   /* If we already have such a type, use the old one.  */
5939   hashcode = iterative_hash_object (TYPE_HASH (basetype), hashcode);
5940   hashcode = iterative_hash_object (TYPE_HASH (type), hashcode);
5941   t = type_hash_canon (hashcode, t);
5942
5943   if (!COMPLETE_TYPE_P (t))
5944     layout_type (t);
5945
5946   if (TYPE_CANONICAL (t) == t)
5947     {
5948       if (TYPE_STRUCTURAL_EQUALITY_P (basetype)
5949           || TYPE_STRUCTURAL_EQUALITY_P (type))
5950         SET_TYPE_STRUCTURAL_EQUALITY (t);
5951       else if (TYPE_CANONICAL (basetype) != basetype
5952                || TYPE_CANONICAL (type) != type)
5953         TYPE_CANONICAL (t)
5954           = build_offset_type (TYPE_CANONICAL (basetype),
5955                                TYPE_CANONICAL (type));
5956     }
5957
5958   return t;
5959 }
5960
5961 /* Create a complex type whose components are COMPONENT_TYPE.  */
5962
5963 tree
5964 build_complex_type (tree component_type)
5965 {
5966   tree t;
5967   hashval_t hashcode;
5968
5969   /* Make a node of the sort we want.  */
5970   t = make_node (COMPLEX_TYPE);
5971
5972   TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
5973
5974   /* If we already have such a type, use the old one.  */
5975   hashcode = iterative_hash_object (TYPE_HASH (component_type), 0);
5976   t = type_hash_canon (hashcode, t);
5977
5978   if (!COMPLETE_TYPE_P (t))
5979     layout_type (t);
5980
5981   if (TYPE_CANONICAL (t) == t)
5982     {
5983       if (TYPE_STRUCTURAL_EQUALITY_P (component_type))
5984         SET_TYPE_STRUCTURAL_EQUALITY (t);
5985       else if (TYPE_CANONICAL (component_type) != component_type)
5986         TYPE_CANONICAL (t)
5987           = build_complex_type (TYPE_CANONICAL (component_type));
5988     }
5989
5990   /* We need to create a name, since complex is a fundamental type.  */
5991   if (! TYPE_NAME (t))
5992     {
5993       const char *name;
5994       if (component_type == char_type_node)
5995         name = "complex char";
5996       else if (component_type == signed_char_type_node)
5997         name = "complex signed char";
5998       else if (component_type == unsigned_char_type_node)
5999         name = "complex unsigned char";
6000       else if (component_type == short_integer_type_node)
6001         name = "complex short int";
6002       else if (component_type == short_unsigned_type_node)
6003         name = "complex short unsigned int";
6004       else if (component_type == integer_type_node)
6005         name = "complex int";
6006       else if (component_type == unsigned_type_node)
6007         name = "complex unsigned int";
6008       else if (component_type == long_integer_type_node)
6009         name = "complex long int";
6010       else if (component_type == long_unsigned_type_node)
6011         name = "complex long unsigned int";
6012       else if (component_type == long_long_integer_type_node)
6013         name = "complex long long int";
6014       else if (component_type == long_long_unsigned_type_node)
6015         name = "complex long long unsigned int";
6016       else
6017         name = 0;
6018
6019       if (name != 0)
6020         TYPE_NAME (t) = build_decl (TYPE_DECL, get_identifier (name), t);
6021     }
6022
6023   return build_qualified_type (t, TYPE_QUALS (component_type));
6024 }
6025 \f
6026 /* Return OP, stripped of any conversions to wider types as much as is safe.
6027    Converting the value back to OP's type makes a value equivalent to OP.
6028
6029    If FOR_TYPE is nonzero, we return a value which, if converted to
6030    type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
6031
6032    If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
6033    narrowest type that can hold the value, even if they don't exactly fit.
6034    Otherwise, bit-field references are changed to a narrower type
6035    only if they can be fetched directly from memory in that type.
6036
6037    OP must have integer, real or enumeral type.  Pointers are not allowed!
6038
6039    There are some cases where the obvious value we could return
6040    would regenerate to OP if converted to OP's type,
6041    but would not extend like OP to wider types.
6042    If FOR_TYPE indicates such extension is contemplated, we eschew such values.
6043    For example, if OP is (unsigned short)(signed char)-1,
6044    we avoid returning (signed char)-1 if FOR_TYPE is int,
6045    even though extending that to an unsigned short would regenerate OP,
6046    since the result of extending (signed char)-1 to (int)
6047    is different from (int) OP.  */
6048
6049 tree
6050 get_unwidened (tree op, tree for_type)
6051 {
6052   /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension.  */
6053   tree type = TREE_TYPE (op);
6054   unsigned final_prec
6055     = TYPE_PRECISION (for_type != 0 ? for_type : type);
6056   int uns
6057     = (for_type != 0 && for_type != type
6058        && final_prec > TYPE_PRECISION (type)
6059        && TYPE_UNSIGNED (type));
6060   tree win = op;
6061
6062   while (TREE_CODE (op) == NOP_EXPR
6063          || TREE_CODE (op) == CONVERT_EXPR)
6064     {
6065       int bitschange;
6066
6067       /* TYPE_PRECISION on vector types has different meaning
6068          (TYPE_VECTOR_SUBPARTS) and casts from vectors are view conversions,
6069          so avoid them here.  */
6070       if (TREE_CODE (TREE_TYPE (TREE_OPERAND (op, 0))) == VECTOR_TYPE)
6071         break;
6072
6073       bitschange = TYPE_PRECISION (TREE_TYPE (op))
6074                    - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
6075
6076       /* Truncations are many-one so cannot be removed.
6077          Unless we are later going to truncate down even farther.  */
6078       if (bitschange < 0
6079           && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
6080         break;
6081
6082       /* See what's inside this conversion.  If we decide to strip it,
6083          we will set WIN.  */
6084       op = TREE_OPERAND (op, 0);
6085
6086       /* If we have not stripped any zero-extensions (uns is 0),
6087          we can strip any kind of extension.
6088          If we have previously stripped a zero-extension,
6089          only zero-extensions can safely be stripped.
6090          Any extension can be stripped if the bits it would produce
6091          are all going to be discarded later by truncating to FOR_TYPE.  */
6092
6093       if (bitschange > 0)
6094         {
6095           if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
6096             win = op;
6097           /* TYPE_UNSIGNED says whether this is a zero-extension.
6098              Let's avoid computing it if it does not affect WIN
6099              and if UNS will not be needed again.  */
6100           if ((uns
6101                || TREE_CODE (op) == NOP_EXPR
6102                || TREE_CODE (op) == CONVERT_EXPR)
6103               && TYPE_UNSIGNED (TREE_TYPE (op)))
6104             {
6105               uns = 1;
6106               win = op;
6107             }
6108         }
6109     }
6110
6111   if (TREE_CODE (op) == COMPONENT_REF
6112       /* Since type_for_size always gives an integer type.  */
6113       && TREE_CODE (type) != REAL_TYPE
6114       && TREE_CODE (type) != FIXED_POINT_TYPE
6115       /* Don't crash if field not laid out yet.  */
6116       && DECL_SIZE (TREE_OPERAND (op, 1)) != 0
6117       && host_integerp (DECL_SIZE (TREE_OPERAND (op, 1)), 1))
6118     {
6119       unsigned int innerprec
6120         = tree_low_cst (DECL_SIZE (TREE_OPERAND (op, 1)), 1);
6121       int unsignedp = (DECL_UNSIGNED (TREE_OPERAND (op, 1))
6122                        || TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op, 1))));
6123       type = lang_hooks.types.type_for_size (innerprec, unsignedp);
6124
6125       /* We can get this structure field in the narrowest type it fits in.
6126          If FOR_TYPE is 0, do this only for a field that matches the
6127          narrower type exactly and is aligned for it
6128          The resulting extension to its nominal type (a fullword type)
6129          must fit the same conditions as for other extensions.  */
6130
6131       if (type != 0
6132           && INT_CST_LT_UNSIGNED (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (op)))
6133           && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
6134           && (! uns || final_prec <= innerprec || unsignedp))
6135         {
6136           win = build3 (COMPONENT_REF, type, TREE_OPERAND (op, 0),
6137                         TREE_OPERAND (op, 1), NULL_TREE);
6138           TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
6139           TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
6140         }
6141     }
6142
6143   return win;
6144 }
6145 \f
6146 /* Return OP or a simpler expression for a narrower value
6147    which can be sign-extended or zero-extended to give back OP.
6148    Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
6149    or 0 if the value should be sign-extended.  */
6150
6151 tree
6152 get_narrower (tree op, int *unsignedp_ptr)
6153 {
6154   int uns = 0;
6155   int first = 1;
6156   tree win = op;
6157   bool integral_p = INTEGRAL_TYPE_P (TREE_TYPE (op));
6158
6159   while (TREE_CODE (op) == NOP_EXPR)
6160     {
6161       int bitschange
6162         = (TYPE_PRECISION (TREE_TYPE (op))
6163            - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0))));
6164
6165       /* Truncations are many-one so cannot be removed.  */
6166       if (bitschange < 0)
6167         break;
6168
6169       /* See what's inside this conversion.  If we decide to strip it,
6170          we will set WIN.  */
6171
6172       if (bitschange > 0)
6173         {
6174           op = TREE_OPERAND (op, 0);
6175           /* An extension: the outermost one can be stripped,
6176              but remember whether it is zero or sign extension.  */
6177           if (first)
6178             uns = TYPE_UNSIGNED (TREE_TYPE (op));
6179           /* Otherwise, if a sign extension has been stripped,
6180              only sign extensions can now be stripped;
6181              if a zero extension has been stripped, only zero-extensions.  */
6182           else if (uns != TYPE_UNSIGNED (TREE_TYPE (op)))
6183             break;
6184           first = 0;
6185         }
6186       else /* bitschange == 0 */
6187         {
6188           /* A change in nominal type can always be stripped, but we must
6189              preserve the unsignedness.  */
6190           if (first)
6191             uns = TYPE_UNSIGNED (TREE_TYPE (op));
6192           first = 0;
6193           op = TREE_OPERAND (op, 0);
6194           /* Keep trying to narrow, but don't assign op to win if it
6195              would turn an integral type into something else.  */
6196           if (INTEGRAL_TYPE_P (TREE_TYPE (op)) != integral_p)
6197             continue;
6198         }
6199
6200       win = op;
6201     }
6202
6203   if (TREE_CODE (op) == COMPONENT_REF
6204       /* Since type_for_size always gives an integer type.  */
6205       && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE
6206       && TREE_CODE (TREE_TYPE (op)) != FIXED_POINT_TYPE
6207       /* Ensure field is laid out already.  */
6208       && DECL_SIZE (TREE_OPERAND (op, 1)) != 0
6209       && host_integerp (DECL_SIZE (TREE_OPERAND (op, 1)), 1))
6210     {
6211       unsigned HOST_WIDE_INT innerprec
6212         = tree_low_cst (DECL_SIZE (TREE_OPERAND (op, 1)), 1);
6213       int unsignedp = (DECL_UNSIGNED (TREE_OPERAND (op, 1))
6214                        || TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op, 1))));
6215       tree type = lang_hooks.types.type_for_size (innerprec, unsignedp);
6216
6217       /* We can get this structure field in a narrower type that fits it,
6218          but the resulting extension to its nominal type (a fullword type)
6219          must satisfy the same conditions as for other extensions.
6220
6221          Do this only for fields that are aligned (not bit-fields),
6222          because when bit-field insns will be used there is no
6223          advantage in doing this.  */
6224
6225       if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
6226           && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
6227           && (first || uns == DECL_UNSIGNED (TREE_OPERAND (op, 1)))
6228           && type != 0)
6229         {
6230           if (first)
6231             uns = DECL_UNSIGNED (TREE_OPERAND (op, 1));
6232           win = fold_convert (type, op);
6233         }
6234     }
6235
6236   *unsignedp_ptr = uns;
6237   return win;
6238 }
6239 \f
6240 /* Nonzero if integer constant C has a value that is permissible
6241    for type TYPE (an INTEGER_TYPE).  */
6242
6243 int
6244 int_fits_type_p (const_tree c, const_tree type)
6245 {
6246   tree type_low_bound = TYPE_MIN_VALUE (type);
6247   tree type_high_bound = TYPE_MAX_VALUE (type);
6248   bool ok_for_low_bound, ok_for_high_bound;
6249   unsigned HOST_WIDE_INT low;
6250   HOST_WIDE_INT high;
6251
6252   /* If at least one bound of the type is a constant integer, we can check
6253      ourselves and maybe make a decision. If no such decision is possible, but
6254      this type is a subtype, try checking against that.  Otherwise, use
6255      fit_double_type, which checks against the precision.
6256
6257      Compute the status for each possibly constant bound, and return if we see
6258      one does not match. Use ok_for_xxx_bound for this purpose, assigning -1
6259      for "unknown if constant fits", 0 for "constant known *not* to fit" and 1
6260      for "constant known to fit".  */
6261
6262   /* Check if C >= type_low_bound.  */
6263   if (type_low_bound && TREE_CODE (type_low_bound) == INTEGER_CST)
6264     {
6265       if (tree_int_cst_lt (c, type_low_bound))
6266         return 0;
6267       ok_for_low_bound = true;
6268     }
6269   else
6270     ok_for_low_bound = false;
6271
6272   /* Check if c <= type_high_bound.  */
6273   if (type_high_bound && TREE_CODE (type_high_bound) == INTEGER_CST)
6274     {
6275       if (tree_int_cst_lt (type_high_bound, c))
6276         return 0;
6277       ok_for_high_bound = true;
6278     }
6279   else
6280     ok_for_high_bound = false;
6281
6282   /* If the constant fits both bounds, the result is known.  */
6283   if (ok_for_low_bound && ok_for_high_bound)
6284     return 1;
6285
6286   /* Perform some generic filtering which may allow making a decision
6287      even if the bounds are not constant.  First, negative integers
6288      never fit in unsigned types, */
6289   if (TYPE_UNSIGNED (type) && tree_int_cst_sgn (c) < 0)
6290     return 0;
6291
6292   /* Second, narrower types always fit in wider ones.  */
6293   if (TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (c)))
6294     return 1;
6295
6296   /* Third, unsigned integers with top bit set never fit signed types.  */
6297   if (! TYPE_UNSIGNED (type)
6298       && TYPE_UNSIGNED (TREE_TYPE (c))
6299       && tree_int_cst_msb (c))
6300     return 0;
6301
6302   /* If we haven't been able to decide at this point, there nothing more we
6303      can check ourselves here.  Look at the base type if we have one and it
6304      has the same precision.  */
6305   if (TREE_CODE (type) == INTEGER_TYPE
6306       && TREE_TYPE (type) != 0
6307       && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (type)))
6308     return int_fits_type_p (c, TREE_TYPE (type));
6309
6310   /* Or to fit_double_type, if nothing else.  */
6311   low = TREE_INT_CST_LOW (c);
6312   high = TREE_INT_CST_HIGH (c);
6313   return !fit_double_type (low, high, &low, &high, type);
6314 }
6315
6316 /* Stores bounds of an integer TYPE in MIN and MAX.  If TYPE has non-constant
6317    bounds or is a POINTER_TYPE, the maximum and/or minimum values that can be
6318    represented (assuming two's-complement arithmetic) within the bit
6319    precision of the type are returned instead.  */
6320
6321 void
6322 get_type_static_bounds (const_tree type, mpz_t min, mpz_t max)
6323 {
6324   if (!POINTER_TYPE_P (type) && TYPE_MIN_VALUE (type)
6325       && TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST)
6326     mpz_set_double_int (min, tree_to_double_int (TYPE_MIN_VALUE (type)),
6327                         TYPE_UNSIGNED (type));
6328   else
6329     {
6330       if (TYPE_UNSIGNED (type))
6331         mpz_set_ui (min, 0);
6332       else
6333         {
6334           double_int mn;
6335           mn = double_int_mask (TYPE_PRECISION (type) - 1);
6336           mn = double_int_sext (double_int_add (mn, double_int_one),
6337                                 TYPE_PRECISION (type));
6338           mpz_set_double_int (min, mn, false);
6339         }
6340     }
6341
6342   if (!POINTER_TYPE_P (type) && TYPE_MAX_VALUE (type)
6343       && TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST)
6344     mpz_set_double_int (max, tree_to_double_int (TYPE_MAX_VALUE (type)),
6345                         TYPE_UNSIGNED (type));
6346   else
6347     {
6348       if (TYPE_UNSIGNED (type))
6349         mpz_set_double_int (max, double_int_mask (TYPE_PRECISION (type)),
6350                             true);
6351       else
6352         mpz_set_double_int (max, double_int_mask (TYPE_PRECISION (type) - 1),
6353                             true);
6354     }
6355 }
6356
6357 /* auto_var_in_fn_p is called to determine whether VAR is an automatic
6358    variable defined in function FN.  */
6359
6360 bool
6361 auto_var_in_fn_p (const_tree var, const_tree fn)
6362 {
6363   return (DECL_P (var) && DECL_CONTEXT (var) == fn
6364           && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL)
6365                && ! TREE_STATIC (var))
6366               || TREE_CODE (var) == LABEL_DECL
6367               || TREE_CODE (var) == RESULT_DECL));
6368 }
6369
6370 /* Subprogram of following function.  Called by walk_tree.
6371
6372    Return *TP if it is an automatic variable or parameter of the
6373    function passed in as DATA.  */
6374
6375 static tree
6376 find_var_from_fn (tree *tp, int *walk_subtrees, void *data)
6377 {
6378   tree fn = (tree) data;
6379
6380   if (TYPE_P (*tp))
6381     *walk_subtrees = 0;
6382
6383   else if (DECL_P (*tp)
6384            && auto_var_in_fn_p (*tp, fn))
6385     return *tp;
6386
6387   return NULL_TREE;
6388 }
6389
6390 /* Returns true if T is, contains, or refers to a type with variable
6391    size.  For METHOD_TYPEs and FUNCTION_TYPEs we exclude the
6392    arguments, but not the return type.  If FN is nonzero, only return
6393    true if a modifier of the type or position of FN is a variable or
6394    parameter inside FN.
6395
6396    This concept is more general than that of C99 'variably modified types':
6397    in C99, a struct type is never variably modified because a VLA may not
6398    appear as a structure member.  However, in GNU C code like:
6399
6400      struct S { int i[f()]; };
6401
6402    is valid, and other languages may define similar constructs.  */
6403
6404 bool
6405 variably_modified_type_p (tree type, tree fn)
6406 {
6407   tree t;
6408
6409 /* Test if T is either variable (if FN is zero) or an expression containing
6410    a variable in FN.  */
6411 #define RETURN_TRUE_IF_VAR(T)                                           \
6412   do { tree _t = (T);                                                   \
6413     if (_t && _t != error_mark_node && TREE_CODE (_t) != INTEGER_CST    \
6414         && (!fn || walk_tree (&_t, find_var_from_fn, fn, NULL)))        \
6415       return true;  } while (0)
6416
6417   if (type == error_mark_node)
6418     return false;
6419
6420   /* If TYPE itself has variable size, it is variably modified.  */
6421   RETURN_TRUE_IF_VAR (TYPE_SIZE (type));
6422   RETURN_TRUE_IF_VAR (TYPE_SIZE_UNIT (type));
6423
6424   switch (TREE_CODE (type))
6425     {
6426     case POINTER_TYPE:
6427     case REFERENCE_TYPE:
6428     case VECTOR_TYPE:
6429       if (variably_modified_type_p (TREE_TYPE (type), fn))
6430         return true;
6431       break;
6432
6433     case FUNCTION_TYPE:
6434     case METHOD_TYPE:
6435       /* If TYPE is a function type, it is variably modified if the
6436          return type is variably modified.  */
6437       if (variably_modified_type_p (TREE_TYPE (type), fn))
6438           return true;
6439       break;
6440
6441     case INTEGER_TYPE:
6442     case REAL_TYPE:
6443     case FIXED_POINT_TYPE:
6444     case ENUMERAL_TYPE:
6445     case BOOLEAN_TYPE:
6446       /* Scalar types are variably modified if their end points
6447          aren't constant.  */
6448       RETURN_TRUE_IF_VAR (TYPE_MIN_VALUE (type));
6449       RETURN_TRUE_IF_VAR (TYPE_MAX_VALUE (type));
6450       break;
6451
6452     case RECORD_TYPE:
6453     case UNION_TYPE:
6454     case QUAL_UNION_TYPE:
6455       /* We can't see if any of the fields are variably-modified by the
6456          definition we normally use, since that would produce infinite
6457          recursion via pointers.  */
6458       /* This is variably modified if some field's type is.  */
6459       for (t = TYPE_FIELDS (type); t; t = TREE_CHAIN (t))
6460         if (TREE_CODE (t) == FIELD_DECL)
6461           {
6462             RETURN_TRUE_IF_VAR (DECL_FIELD_OFFSET (t));
6463             RETURN_TRUE_IF_VAR (DECL_SIZE (t));
6464             RETURN_TRUE_IF_VAR (DECL_SIZE_UNIT (t));
6465
6466             if (TREE_CODE (type) == QUAL_UNION_TYPE)
6467               RETURN_TRUE_IF_VAR (DECL_QUALIFIER (t));
6468           }
6469         break;
6470
6471     case ARRAY_TYPE:
6472       /* Do not call ourselves to avoid infinite recursion.  This is
6473          variably modified if the element type is.  */
6474       RETURN_TRUE_IF_VAR (TYPE_SIZE (TREE_TYPE (type)));
6475       RETURN_TRUE_IF_VAR (TYPE_SIZE_UNIT (TREE_TYPE (type)));
6476       break;
6477
6478     default:
6479       break;
6480     }
6481
6482   /* The current language may have other cases to check, but in general,
6483      all other types are not variably modified.  */
6484   return lang_hooks.tree_inlining.var_mod_type_p (type, fn);
6485
6486 #undef RETURN_TRUE_IF_VAR
6487 }
6488
6489 /* Given a DECL or TYPE, return the scope in which it was declared, or
6490    NULL_TREE if there is no containing scope.  */
6491
6492 tree
6493 get_containing_scope (const_tree t)
6494 {
6495   return (TYPE_P (t) ? TYPE_CONTEXT (t) : DECL_CONTEXT (t));
6496 }
6497
6498 /* Return the innermost context enclosing DECL that is
6499    a FUNCTION_DECL, or zero if none.  */
6500
6501 tree
6502 decl_function_context (const_tree decl)
6503 {
6504   tree context;
6505
6506   if (TREE_CODE (decl) == ERROR_MARK)
6507     return 0;
6508
6509   /* C++ virtual functions use DECL_CONTEXT for the class of the vtable
6510      where we look up the function at runtime.  Such functions always take
6511      a first argument of type 'pointer to real context'.
6512
6513      C++ should really be fixed to use DECL_CONTEXT for the real context,
6514      and use something else for the "virtual context".  */
6515   else if (TREE_CODE (decl) == FUNCTION_DECL && DECL_VINDEX (decl))
6516     context
6517       = TYPE_MAIN_VARIANT
6518         (TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (decl)))));
6519   else
6520     context = DECL_CONTEXT (decl);
6521
6522   while (context && TREE_CODE (context) != FUNCTION_DECL)
6523     {
6524       if (TREE_CODE (context) == BLOCK)
6525         context = BLOCK_SUPERCONTEXT (context);
6526       else
6527         context = get_containing_scope (context);
6528     }
6529
6530   return context;
6531 }
6532
6533 /* Return the innermost context enclosing DECL that is
6534    a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
6535    TYPE_DECLs and FUNCTION_DECLs are transparent to this function.  */
6536
6537 tree
6538 decl_type_context (const_tree decl)
6539 {
6540   tree context = DECL_CONTEXT (decl);
6541
6542   while (context)
6543     switch (TREE_CODE (context))
6544       {
6545       case NAMESPACE_DECL:
6546       case TRANSLATION_UNIT_DECL:
6547         return NULL_TREE;
6548
6549       case RECORD_TYPE:
6550       case UNION_TYPE:
6551       case QUAL_UNION_TYPE:
6552         return context;
6553
6554       case TYPE_DECL:
6555       case FUNCTION_DECL:
6556         context = DECL_CONTEXT (context);
6557         break;
6558
6559       case BLOCK:
6560         context = BLOCK_SUPERCONTEXT (context);
6561         break;
6562
6563       default:
6564         gcc_unreachable ();
6565       }
6566
6567   return NULL_TREE;
6568 }
6569
6570 /* CALL is a CALL_EXPR.  Return the declaration for the function
6571    called, or NULL_TREE if the called function cannot be
6572    determined.  */
6573
6574 tree
6575 get_callee_fndecl (const_tree call)
6576 {
6577   tree addr;
6578
6579   if (call == error_mark_node)
6580     return error_mark_node;
6581
6582   /* It's invalid to call this function with anything but a
6583      CALL_EXPR.  */
6584   gcc_assert (TREE_CODE (call) == CALL_EXPR);
6585
6586   /* The first operand to the CALL is the address of the function
6587      called.  */
6588   addr = CALL_EXPR_FN (call);
6589
6590   STRIP_NOPS (addr);
6591
6592   /* If this is a readonly function pointer, extract its initial value.  */
6593   if (DECL_P (addr) && TREE_CODE (addr) != FUNCTION_DECL
6594       && TREE_READONLY (addr) && ! TREE_THIS_VOLATILE (addr)
6595       && DECL_INITIAL (addr))
6596     addr = DECL_INITIAL (addr);
6597
6598   /* If the address is just `&f' for some function `f', then we know
6599      that `f' is being called.  */
6600   if (TREE_CODE (addr) == ADDR_EXPR
6601       && TREE_CODE (TREE_OPERAND (addr, 0)) == FUNCTION_DECL)
6602     return TREE_OPERAND (addr, 0);
6603
6604   /* We couldn't figure out what was being called.  Maybe the front
6605      end has some idea.  */
6606   return lang_hooks.lang_get_callee_fndecl (call);
6607 }
6608
6609 /* Print debugging information about tree nodes generated during the compile,
6610    and any language-specific information.  */
6611
6612 void
6613 dump_tree_statistics (void)
6614 {
6615 #ifdef GATHER_STATISTICS
6616   int i;
6617   int total_nodes, total_bytes;
6618 #endif
6619
6620   fprintf (stderr, "\n??? tree nodes created\n\n");
6621 #ifdef GATHER_STATISTICS
6622   fprintf (stderr, "Kind                   Nodes      Bytes\n");
6623   fprintf (stderr, "---------------------------------------\n");
6624   total_nodes = total_bytes = 0;
6625   for (i = 0; i < (int) all_kinds; i++)
6626     {
6627       fprintf (stderr, "%-20s %7d %10d\n", tree_node_kind_names[i],
6628                tree_node_counts[i], tree_node_sizes[i]);
6629       total_nodes += tree_node_counts[i];
6630       total_bytes += tree_node_sizes[i];
6631     }
6632   fprintf (stderr, "---------------------------------------\n");
6633   fprintf (stderr, "%-20s %7d %10d\n", "Total", total_nodes, total_bytes);
6634   fprintf (stderr, "---------------------------------------\n");
6635   ssanames_print_statistics ();
6636   phinodes_print_statistics ();
6637 #else
6638   fprintf (stderr, "(No per-node statistics)\n");
6639 #endif
6640   print_type_hash_statistics ();
6641   print_debug_expr_statistics ();
6642   print_value_expr_statistics ();
6643   print_restrict_base_statistics ();
6644   lang_hooks.print_statistics ();
6645 }
6646 \f
6647 #define FILE_FUNCTION_FORMAT "_GLOBAL__%s_%s"
6648
6649 /* Generate a crc32 of a string.  */
6650
6651 unsigned
6652 crc32_string (unsigned chksum, const char *string)
6653 {
6654   do
6655     {
6656       unsigned value = *string << 24;
6657       unsigned ix;
6658
6659       for (ix = 8; ix--; value <<= 1)
6660         {
6661           unsigned feedback;
6662
6663           feedback = (value ^ chksum) & 0x80000000 ? 0x04c11db7 : 0;
6664           chksum <<= 1;
6665           chksum ^= feedback;
6666         }
6667     }
6668   while (*string++);
6669   return chksum;
6670 }
6671
6672 /* P is a string that will be used in a symbol.  Mask out any characters
6673    that are not valid in that context.  */
6674
6675 void
6676 clean_symbol_name (char *p)
6677 {
6678   for (; *p; p++)
6679     if (! (ISALNUM (*p)
6680 #ifndef NO_DOLLAR_IN_LABEL      /* this for `$'; unlikely, but... -- kr */
6681             || *p == '$'
6682 #endif
6683 #ifndef NO_DOT_IN_LABEL         /* this for `.'; unlikely, but...  */
6684             || *p == '.'
6685 #endif
6686            ))
6687       *p = '_';
6688 }
6689
6690 /* Generate a name for a special-purpose function function.
6691    The generated name may need to be unique across the whole link.
6692    TYPE is some string to identify the purpose of this function to the
6693    linker or collect2; it must start with an uppercase letter,
6694    one of:
6695    I - for constructors
6696    D - for destructors
6697    N - for C++ anonymous namespaces
6698    F - for DWARF unwind frame information.  */
6699
6700 tree
6701 get_file_function_name (const char *type)
6702 {
6703   char *buf;
6704   const char *p;
6705   char *q;
6706
6707   /* If we already have a name we know to be unique, just use that.  */
6708   if (first_global_object_name)
6709     p = first_global_object_name;
6710   /* If the target is handling the constructors/destructors, they
6711      will be local to this file and the name is only necessary for
6712      debugging purposes.  */
6713   else if ((type[0] == 'I' || type[0] == 'D') && targetm.have_ctors_dtors)
6714     {
6715       const char *file = main_input_filename;
6716       if (! file)
6717         file = input_filename;
6718       /* Just use the file's basename, because the full pathname
6719          might be quite long.  */
6720       p = strrchr (file, '/');
6721       if (p)
6722         p++;
6723       else
6724         p = file;
6725       p = q = ASTRDUP (p);
6726       clean_symbol_name (q);
6727     }
6728   else
6729     {
6730       /* Otherwise, the name must be unique across the entire link.
6731          We don't have anything that we know to be unique to this translation
6732          unit, so use what we do have and throw in some randomness.  */
6733       unsigned len;
6734       const char *name = weak_global_object_name;
6735       const char *file = main_input_filename;
6736
6737       if (! name)
6738         name = "";
6739       if (! file)
6740         file = input_filename;
6741
6742       len = strlen (file);
6743       q = alloca (9 * 2 + len + 1);
6744       memcpy (q, file, len + 1);
6745       clean_symbol_name (q);
6746
6747       sprintf (q + len, "_%08X_%08X", crc32_string (0, name),
6748                crc32_string (0, get_random_seed (false)));
6749
6750       p = q;
6751     }
6752
6753   buf = alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p) + strlen (type));
6754
6755   /* Set up the name of the file-level functions we may need.
6756      Use a global object (which is already required to be unique over
6757      the program) rather than the file name (which imposes extra
6758      constraints).  */
6759   sprintf (buf, FILE_FUNCTION_FORMAT, type, p);
6760
6761   return get_identifier (buf);
6762 }
6763 \f
6764 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
6765
6766 /* Complain that the tree code of NODE does not match the expected 0
6767    terminated list of trailing codes. The trailing code list can be
6768    empty, for a more vague error message.  FILE, LINE, and FUNCTION
6769    are of the caller.  */
6770
6771 void
6772 tree_check_failed (const_tree node, const char *file,
6773                    int line, const char *function, ...)
6774 {
6775   va_list args;
6776   const char *buffer;
6777   unsigned length = 0;
6778   int code;
6779
6780   va_start (args, function);
6781   while ((code = va_arg (args, int)))
6782     length += 4 + strlen (tree_code_name[code]);
6783   va_end (args);
6784   if (length)
6785     {
6786       char *tmp;
6787       va_start (args, function);
6788       length += strlen ("expected ");
6789       buffer = tmp = alloca (length);
6790       length = 0;
6791       while ((code = va_arg (args, int)))
6792         {
6793           const char *prefix = length ? " or " : "expected ";
6794
6795           strcpy (tmp + length, prefix);
6796           length += strlen (prefix);
6797           strcpy (tmp + length, tree_code_name[code]);
6798           length += strlen (tree_code_name[code]);
6799         }
6800       va_end (args);
6801     }
6802   else
6803     buffer = "unexpected node";
6804
6805   internal_error ("tree check: %s, have %s in %s, at %s:%d",
6806                   buffer, tree_code_name[TREE_CODE (node)],
6807                   function, trim_filename (file), line);
6808 }
6809
6810 /* Complain that the tree code of NODE does match the expected 0
6811    terminated list of trailing codes. FILE, LINE, and FUNCTION are of
6812    the caller.  */
6813
6814 void
6815 tree_not_check_failed (const_tree node, const char *file,
6816                        int line, const char *function, ...)
6817 {
6818   va_list args;
6819   char *buffer;
6820   unsigned length = 0;
6821   int code;
6822
6823   va_start (args, function);
6824   while ((code = va_arg (args, int)))
6825     length += 4 + strlen (tree_code_name[code]);
6826   va_end (args);
6827   va_start (args, function);
6828   buffer = alloca (length);
6829   length = 0;
6830   while ((code = va_arg (args, int)))
6831     {
6832       if (length)
6833         {
6834           strcpy (buffer + length, " or ");
6835           length += 4;
6836         }
6837       strcpy (buffer + length, tree_code_name[code]);
6838       length += strlen (tree_code_name[code]);
6839     }
6840   va_end (args);
6841
6842   internal_error ("tree check: expected none of %s, have %s in %s, at %s:%d",
6843                   buffer, tree_code_name[TREE_CODE (node)],
6844                   function, trim_filename (file), line);
6845 }
6846
6847 /* Similar to tree_check_failed, except that we check for a class of tree
6848    code, given in CL.  */
6849
6850 void
6851 tree_class_check_failed (const_tree node, const enum tree_code_class cl,
6852                          const char *file, int line, const char *function)
6853 {
6854   internal_error
6855     ("tree check: expected class %qs, have %qs (%s) in %s, at %s:%d",
6856      TREE_CODE_CLASS_STRING (cl),
6857      TREE_CODE_CLASS_STRING (TREE_CODE_CLASS (TREE_CODE (node))),
6858      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
6859 }
6860
6861 /* Similar to tree_check_failed, except that instead of specifying a
6862    dozen codes, use the knowledge that they're all sequential.  */
6863
6864 void
6865 tree_range_check_failed (const_tree node, const char *file, int line,
6866                          const char *function, enum tree_code c1,
6867                          enum tree_code c2)
6868 {
6869   char *buffer;
6870   unsigned length = 0;
6871   enum tree_code c;
6872
6873   for (c = c1; c <= c2; ++c)
6874     length += 4 + strlen (tree_code_name[c]);
6875
6876   length += strlen ("expected ");
6877   buffer = alloca (length);
6878   length = 0;
6879
6880   for (c = c1; c <= c2; ++c)
6881     {
6882       const char *prefix = length ? " or " : "expected ";
6883
6884       strcpy (buffer + length, prefix);
6885       length += strlen (prefix);
6886       strcpy (buffer + length, tree_code_name[c]);
6887       length += strlen (tree_code_name[c]);
6888     }
6889
6890   internal_error ("tree check: %s, have %s in %s, at %s:%d",
6891                   buffer, tree_code_name[TREE_CODE (node)],
6892                   function, trim_filename (file), line);
6893 }
6894
6895
6896 /* Similar to tree_check_failed, except that we check that a tree does
6897    not have the specified code, given in CL.  */
6898
6899 void
6900 tree_not_class_check_failed (const_tree node, const enum tree_code_class cl,
6901                              const char *file, int line, const char *function)
6902 {
6903   internal_error
6904     ("tree check: did not expect class %qs, have %qs (%s) in %s, at %s:%d",
6905      TREE_CODE_CLASS_STRING (cl),
6906      TREE_CODE_CLASS_STRING (TREE_CODE_CLASS (TREE_CODE (node))),
6907      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
6908 }
6909
6910
6911 /* Similar to tree_check_failed but applied to OMP_CLAUSE codes.  */
6912
6913 void
6914 omp_clause_check_failed (const_tree node, const char *file, int line,
6915                          const char *function, enum omp_clause_code code)
6916 {
6917   internal_error ("tree check: expected omp_clause %s, have %s in %s, at %s:%d",
6918                   omp_clause_code_name[code], tree_code_name[TREE_CODE (node)],
6919                   function, trim_filename (file), line);
6920 }
6921
6922
6923 /* Similar to tree_range_check_failed but applied to OMP_CLAUSE codes.  */
6924
6925 void
6926 omp_clause_range_check_failed (const_tree node, const char *file, int line,
6927                                const char *function, enum omp_clause_code c1,
6928                                enum omp_clause_code c2)
6929 {
6930   char *buffer;
6931   unsigned length = 0;
6932   enum omp_clause_code c;
6933
6934   for (c = c1; c <= c2; ++c)
6935     length += 4 + strlen (omp_clause_code_name[c]);
6936
6937   length += strlen ("expected ");
6938   buffer = alloca (length);
6939   length = 0;
6940
6941   for (c = c1; c <= c2; ++c)
6942     {
6943       const char *prefix = length ? " or " : "expected ";
6944
6945       strcpy (buffer + length, prefix);
6946       length += strlen (prefix);
6947       strcpy (buffer + length, omp_clause_code_name[c]);
6948       length += strlen (omp_clause_code_name[c]);
6949     }
6950
6951   internal_error ("tree check: %s, have %s in %s, at %s:%d",
6952                   buffer, omp_clause_code_name[TREE_CODE (node)],
6953                   function, trim_filename (file), line);
6954 }
6955
6956
6957 #undef DEFTREESTRUCT
6958 #define DEFTREESTRUCT(VAL, NAME) NAME,
6959
6960 static const char *ts_enum_names[] = {
6961 #include "treestruct.def"
6962 };
6963 #undef DEFTREESTRUCT
6964
6965 #define TS_ENUM_NAME(EN) (ts_enum_names[(EN)])
6966
6967 /* Similar to tree_class_check_failed, except that we check for
6968    whether CODE contains the tree structure identified by EN.  */
6969
6970 void
6971 tree_contains_struct_check_failed (const_tree node,
6972                                    const enum tree_node_structure_enum en,
6973                                    const char *file, int line,
6974                                    const char *function)
6975 {
6976   internal_error
6977     ("tree check: expected tree that contains %qs structure, have %qs in %s, at %s:%d",
6978      TS_ENUM_NAME(en),
6979      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
6980 }
6981
6982
6983 /* Similar to above, except that the check is for the bounds of a TREE_VEC's
6984    (dynamically sized) vector.  */
6985
6986 void
6987 tree_vec_elt_check_failed (int idx, int len, const char *file, int line,
6988                            const char *function)
6989 {
6990   internal_error
6991     ("tree check: accessed elt %d of tree_vec with %d elts in %s, at %s:%d",
6992      idx + 1, len, function, trim_filename (file), line);
6993 }
6994
6995 /* Similar to above, except that the check is for the bounds of a PHI_NODE's
6996    (dynamically sized) vector.  */
6997
6998 void
6999 phi_node_elt_check_failed (int idx, int len, const char *file, int line,
7000                             const char *function)
7001 {
7002   internal_error
7003     ("tree check: accessed elt %d of phi_node with %d elts in %s, at %s:%d",
7004      idx + 1, len, function, trim_filename (file), line);
7005 }
7006
7007 /* Similar to above, except that the check is for the bounds of the operand
7008    vector of an expression node EXP.  */
7009
7010 void
7011 tree_operand_check_failed (int idx, const_tree exp, const char *file,
7012                            int line, const char *function)
7013 {
7014   int code = TREE_CODE (exp);
7015   internal_error
7016     ("tree check: accessed operand %d of %s with %d operands in %s, at %s:%d",
7017      idx + 1, tree_code_name[code], TREE_OPERAND_LENGTH (exp),
7018      function, trim_filename (file), line);
7019 }
7020
7021 /* Similar to above, except that the check is for the number of
7022    operands of an OMP_CLAUSE node.  */
7023
7024 void
7025 omp_clause_operand_check_failed (int idx, const_tree t, const char *file,
7026                                  int line, const char *function)
7027 {
7028   internal_error
7029     ("tree check: accessed operand %d of omp_clause %s with %d operands "
7030      "in %s, at %s:%d", idx + 1, omp_clause_code_name[OMP_CLAUSE_CODE (t)],
7031      omp_clause_num_ops [OMP_CLAUSE_CODE (t)], function,
7032      trim_filename (file), line);
7033 }
7034 #endif /* ENABLE_TREE_CHECKING */
7035 \f
7036 /* Create a new vector type node holding SUBPARTS units of type INNERTYPE,
7037    and mapped to the machine mode MODE.  Initialize its fields and build
7038    the information necessary for debugging output.  */
7039
7040 static tree
7041 make_vector_type (tree innertype, int nunits, enum machine_mode mode)
7042 {
7043   tree t;
7044   hashval_t hashcode = 0;
7045
7046   /* Build a main variant, based on the main variant of the inner type, then
7047      use it to build the variant we return.  */
7048   if ((TYPE_ATTRIBUTES (innertype) || TYPE_QUALS (innertype))
7049       && TYPE_MAIN_VARIANT (innertype) != innertype)
7050     return build_type_attribute_qual_variant (
7051             make_vector_type (TYPE_MAIN_VARIANT (innertype), nunits, mode),
7052             TYPE_ATTRIBUTES (innertype),
7053             TYPE_QUALS (innertype));
7054
7055   t = make_node (VECTOR_TYPE);
7056   TREE_TYPE (t) = TYPE_MAIN_VARIANT (innertype);
7057   SET_TYPE_VECTOR_SUBPARTS (t, nunits);
7058   TYPE_MODE (t) = mode;
7059   TYPE_READONLY (t) = TYPE_READONLY (innertype);
7060   TYPE_VOLATILE (t) = TYPE_VOLATILE (innertype);
7061
7062   if (TYPE_STRUCTURAL_EQUALITY_P (innertype))
7063     SET_TYPE_STRUCTURAL_EQUALITY (t);
7064   else if (TYPE_CANONICAL (innertype) != innertype
7065            || mode != VOIDmode)
7066     TYPE_CANONICAL (t)
7067       = make_vector_type (TYPE_CANONICAL (innertype), nunits, VOIDmode);
7068
7069   layout_type (t);
7070
7071   {
7072     tree index = build_int_cst (NULL_TREE, nunits - 1);
7073     tree array = build_array_type (innertype, build_index_type (index));
7074     tree rt = make_node (RECORD_TYPE);
7075
7076     TYPE_FIELDS (rt) = build_decl (FIELD_DECL, get_identifier ("f"), array);
7077     DECL_CONTEXT (TYPE_FIELDS (rt)) = rt;
7078     layout_type (rt);
7079     TYPE_DEBUG_REPRESENTATION_TYPE (t) = rt;
7080     /* In dwarfout.c, type lookup uses TYPE_UID numbers.  We want to output
7081        the representation type, and we want to find that die when looking up
7082        the vector type.  This is most easily achieved by making the TYPE_UID
7083        numbers equal.  */
7084     TYPE_UID (rt) = TYPE_UID (t);
7085   }
7086
7087   hashcode = iterative_hash_host_wide_int (VECTOR_TYPE, hashcode);
7088   hashcode = iterative_hash_host_wide_int (mode, hashcode);
7089   hashcode = iterative_hash_object (TYPE_HASH (innertype), hashcode);
7090   return type_hash_canon (hashcode, t);
7091 }
7092
7093 static tree
7094 make_or_reuse_type (unsigned size, int unsignedp)
7095 {
7096   if (size == INT_TYPE_SIZE)
7097     return unsignedp ? unsigned_type_node : integer_type_node;
7098   if (size == CHAR_TYPE_SIZE)
7099     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
7100   if (size == SHORT_TYPE_SIZE)
7101     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
7102   if (size == LONG_TYPE_SIZE)
7103     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
7104   if (size == LONG_LONG_TYPE_SIZE)
7105     return (unsignedp ? long_long_unsigned_type_node
7106             : long_long_integer_type_node);
7107
7108   if (unsignedp)
7109     return make_unsigned_type (size);
7110   else
7111     return make_signed_type (size);
7112 }
7113
7114 /* Create or reuse a fract type by SIZE, UNSIGNEDP, and SATP.  */
7115
7116 static tree
7117 make_or_reuse_fract_type (unsigned size, int unsignedp, int satp)
7118 {
7119   if (satp)
7120     {
7121       if (size == SHORT_FRACT_TYPE_SIZE)
7122         return unsignedp ? sat_unsigned_short_fract_type_node
7123                          : sat_short_fract_type_node;
7124       if (size == FRACT_TYPE_SIZE)
7125         return unsignedp ? sat_unsigned_fract_type_node : sat_fract_type_node;
7126       if (size == LONG_FRACT_TYPE_SIZE)
7127         return unsignedp ? sat_unsigned_long_fract_type_node
7128                          : sat_long_fract_type_node;
7129       if (size == LONG_LONG_FRACT_TYPE_SIZE)
7130         return unsignedp ? sat_unsigned_long_long_fract_type_node
7131                          : sat_long_long_fract_type_node;
7132     }
7133   else
7134     {
7135       if (size == SHORT_FRACT_TYPE_SIZE)
7136         return unsignedp ? unsigned_short_fract_type_node
7137                          : short_fract_type_node;
7138       if (size == FRACT_TYPE_SIZE)
7139         return unsignedp ? unsigned_fract_type_node : fract_type_node;
7140       if (size == LONG_FRACT_TYPE_SIZE)
7141         return unsignedp ? unsigned_long_fract_type_node
7142                          : long_fract_type_node;
7143       if (size == LONG_LONG_FRACT_TYPE_SIZE)
7144         return unsignedp ? unsigned_long_long_fract_type_node
7145                          : long_long_fract_type_node;
7146     }
7147
7148   return make_fract_type (size, unsignedp, satp);
7149 }
7150
7151 /* Create or reuse an accum type by SIZE, UNSIGNEDP, and SATP.  */
7152
7153 static tree
7154 make_or_reuse_accum_type (unsigned size, int unsignedp, int satp)
7155 {
7156   if (satp)
7157     {
7158       if (size == SHORT_ACCUM_TYPE_SIZE)
7159         return unsignedp ? sat_unsigned_short_accum_type_node
7160                          : sat_short_accum_type_node;
7161       if (size == ACCUM_TYPE_SIZE)
7162         return unsignedp ? sat_unsigned_accum_type_node : sat_accum_type_node;
7163       if (size == LONG_ACCUM_TYPE_SIZE)
7164         return unsignedp ? sat_unsigned_long_accum_type_node
7165                          : sat_long_accum_type_node;
7166       if (size == LONG_LONG_ACCUM_TYPE_SIZE)
7167         return unsignedp ? sat_unsigned_long_long_accum_type_node
7168                          : sat_long_long_accum_type_node;
7169     }
7170   else
7171     {
7172       if (size == SHORT_ACCUM_TYPE_SIZE)
7173         return unsignedp ? unsigned_short_accum_type_node
7174                          : short_accum_type_node;
7175       if (size == ACCUM_TYPE_SIZE)
7176         return unsignedp ? unsigned_accum_type_node : accum_type_node;
7177       if (size == LONG_ACCUM_TYPE_SIZE)
7178         return unsignedp ? unsigned_long_accum_type_node
7179                          : long_accum_type_node;
7180       if (size == LONG_LONG_ACCUM_TYPE_SIZE)
7181         return unsignedp ? unsigned_long_long_accum_type_node
7182                          : long_long_accum_type_node;
7183     }
7184
7185   return make_accum_type (size, unsignedp, satp);
7186 }
7187
7188 /* Create nodes for all integer types (and error_mark_node) using the sizes
7189    of C datatypes.  The caller should call set_sizetype soon after calling
7190    this function to select one of the types as sizetype.  */
7191
7192 void
7193 build_common_tree_nodes (bool signed_char, bool signed_sizetype)
7194 {
7195   error_mark_node = make_node (ERROR_MARK);
7196   TREE_TYPE (error_mark_node) = error_mark_node;
7197
7198   initialize_sizetypes (signed_sizetype);
7199
7200   /* Define both `signed char' and `unsigned char'.  */
7201   signed_char_type_node = make_signed_type (CHAR_TYPE_SIZE);
7202   TYPE_STRING_FLAG (signed_char_type_node) = 1;
7203   unsigned_char_type_node = make_unsigned_type (CHAR_TYPE_SIZE);
7204   TYPE_STRING_FLAG (unsigned_char_type_node) = 1;
7205
7206   /* Define `char', which is like either `signed char' or `unsigned char'
7207      but not the same as either.  */
7208   char_type_node
7209     = (signed_char
7210        ? make_signed_type (CHAR_TYPE_SIZE)
7211        : make_unsigned_type (CHAR_TYPE_SIZE));
7212   TYPE_STRING_FLAG (char_type_node) = 1;
7213
7214   short_integer_type_node = make_signed_type (SHORT_TYPE_SIZE);
7215   short_unsigned_type_node = make_unsigned_type (SHORT_TYPE_SIZE);
7216   integer_type_node = make_signed_type (INT_TYPE_SIZE);
7217   unsigned_type_node = make_unsigned_type (INT_TYPE_SIZE);
7218   long_integer_type_node = make_signed_type (LONG_TYPE_SIZE);
7219   long_unsigned_type_node = make_unsigned_type (LONG_TYPE_SIZE);
7220   long_long_integer_type_node = make_signed_type (LONG_LONG_TYPE_SIZE);
7221   long_long_unsigned_type_node = make_unsigned_type (LONG_LONG_TYPE_SIZE);
7222
7223   /* Define a boolean type.  This type only represents boolean values but
7224      may be larger than char depending on the value of BOOL_TYPE_SIZE.
7225      Front ends which want to override this size (i.e. Java) can redefine
7226      boolean_type_node before calling build_common_tree_nodes_2.  */
7227   boolean_type_node = make_unsigned_type (BOOL_TYPE_SIZE);
7228   TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);
7229   TYPE_MAX_VALUE (boolean_type_node) = build_int_cst (boolean_type_node, 1);
7230   TYPE_PRECISION (boolean_type_node) = 1;
7231
7232   /* Fill in the rest of the sized types.  Reuse existing type nodes
7233      when possible.  */
7234   intQI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (QImode), 0);
7235   intHI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (HImode), 0);
7236   intSI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (SImode), 0);
7237   intDI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (DImode), 0);
7238   intTI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (TImode), 0);
7239
7240   unsigned_intQI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (QImode), 1);
7241   unsigned_intHI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (HImode), 1);
7242   unsigned_intSI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (SImode), 1);
7243   unsigned_intDI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (DImode), 1);
7244   unsigned_intTI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (TImode), 1);
7245
7246   access_public_node = get_identifier ("public");
7247   access_protected_node = get_identifier ("protected");
7248   access_private_node = get_identifier ("private");
7249 }
7250
7251 /* Call this function after calling build_common_tree_nodes and set_sizetype.
7252    It will create several other common tree nodes.  */
7253
7254 void
7255 build_common_tree_nodes_2 (int short_double)
7256 {
7257   /* Define these next since types below may used them.  */
7258   integer_zero_node = build_int_cst (NULL_TREE, 0);
7259   integer_one_node = build_int_cst (NULL_TREE, 1);
7260   integer_minus_one_node = build_int_cst (NULL_TREE, -1);
7261
7262   size_zero_node = size_int (0);
7263   size_one_node = size_int (1);
7264   bitsize_zero_node = bitsize_int (0);
7265   bitsize_one_node = bitsize_int (1);
7266   bitsize_unit_node = bitsize_int (BITS_PER_UNIT);
7267
7268   boolean_false_node = TYPE_MIN_VALUE (boolean_type_node);
7269   boolean_true_node = TYPE_MAX_VALUE (boolean_type_node);
7270
7271   void_type_node = make_node (VOID_TYPE);
7272   layout_type (void_type_node);
7273
7274   /* We are not going to have real types in C with less than byte alignment,
7275      so we might as well not have any types that claim to have it.  */
7276   TYPE_ALIGN (void_type_node) = BITS_PER_UNIT;
7277   TYPE_USER_ALIGN (void_type_node) = 0;
7278
7279   null_pointer_node = build_int_cst (build_pointer_type (void_type_node), 0);
7280   layout_type (TREE_TYPE (null_pointer_node));
7281
7282   ptr_type_node = build_pointer_type (void_type_node);
7283   const_ptr_type_node
7284     = build_pointer_type (build_type_variant (void_type_node, 1, 0));
7285   fileptr_type_node = ptr_type_node;
7286
7287   float_type_node = make_node (REAL_TYPE);
7288   TYPE_PRECISION (float_type_node) = FLOAT_TYPE_SIZE;
7289   layout_type (float_type_node);
7290
7291   double_type_node = make_node (REAL_TYPE);
7292   if (short_double)
7293     TYPE_PRECISION (double_type_node) = FLOAT_TYPE_SIZE;
7294   else
7295     TYPE_PRECISION (double_type_node) = DOUBLE_TYPE_SIZE;
7296   layout_type (double_type_node);
7297
7298   long_double_type_node = make_node (REAL_TYPE);
7299   TYPE_PRECISION (long_double_type_node) = LONG_DOUBLE_TYPE_SIZE;
7300   layout_type (long_double_type_node);
7301
7302   float_ptr_type_node = build_pointer_type (float_type_node);
7303   double_ptr_type_node = build_pointer_type (double_type_node);
7304   long_double_ptr_type_node = build_pointer_type (long_double_type_node);
7305   integer_ptr_type_node = build_pointer_type (integer_type_node);
7306
7307   /* Fixed size integer types.  */
7308   uint32_type_node = build_nonstandard_integer_type (32, true);
7309   uint64_type_node = build_nonstandard_integer_type (64, true);
7310
7311   /* Decimal float types. */
7312   dfloat32_type_node = make_node (REAL_TYPE);
7313   TYPE_PRECISION (dfloat32_type_node) = DECIMAL32_TYPE_SIZE;
7314   layout_type (dfloat32_type_node);
7315   TYPE_MODE (dfloat32_type_node) = SDmode;
7316   dfloat32_ptr_type_node = build_pointer_type (dfloat32_type_node);
7317
7318   dfloat64_type_node = make_node (REAL_TYPE);
7319   TYPE_PRECISION (dfloat64_type_node) = DECIMAL64_TYPE_SIZE;
7320   layout_type (dfloat64_type_node);
7321   TYPE_MODE (dfloat64_type_node) = DDmode;
7322   dfloat64_ptr_type_node = build_pointer_type (dfloat64_type_node);
7323
7324   dfloat128_type_node = make_node (REAL_TYPE);
7325   TYPE_PRECISION (dfloat128_type_node) = DECIMAL128_TYPE_SIZE;
7326   layout_type (dfloat128_type_node);
7327   TYPE_MODE (dfloat128_type_node) = TDmode;
7328   dfloat128_ptr_type_node = build_pointer_type (dfloat128_type_node);
7329
7330   complex_integer_type_node = build_complex_type (integer_type_node);
7331   complex_float_type_node = build_complex_type (float_type_node);
7332   complex_double_type_node = build_complex_type (double_type_node);
7333   complex_long_double_type_node = build_complex_type (long_double_type_node);
7334
7335 /* Make fixed-point nodes based on sat/non-sat and signed/unsigned.  */
7336 #define MAKE_FIXED_TYPE_NODE(KIND,WIDTH,SIZE) \
7337   sat_ ## WIDTH ## KIND ## _type_node = \
7338     make_sat_signed_ ## KIND ## _type (SIZE); \
7339   sat_unsigned_ ## WIDTH ## KIND ## _type_node = \
7340     make_sat_unsigned_ ## KIND ## _type (SIZE); \
7341   WIDTH ## KIND ## _type_node = make_signed_ ## KIND ## _type (SIZE); \
7342   unsigned_ ## WIDTH ## KIND ## _type_node = \
7343     make_unsigned_ ## KIND ## _type (SIZE);
7344
7345 /* Make fixed-point type nodes based on four different widths.  */
7346 #define MAKE_FIXED_TYPE_NODE_FAMILY(N1,N2) \
7347   MAKE_FIXED_TYPE_NODE (N1, short_, SHORT_ ## N2 ## _TYPE_SIZE) \
7348   MAKE_FIXED_TYPE_NODE (N1, , N2 ## _TYPE_SIZE) \
7349   MAKE_FIXED_TYPE_NODE (N1, long_, LONG_ ## N2 ## _TYPE_SIZE) \
7350   MAKE_FIXED_TYPE_NODE (N1, long_long_, LONG_LONG_ ## N2 ## _TYPE_SIZE)
7351
7352 /* Make fixed-point mode nodes based on sat/non-sat and signed/unsigned.  */
7353 #define MAKE_FIXED_MODE_NODE(KIND,NAME,MODE) \
7354   NAME ## _type_node = \
7355     make_or_reuse_signed_ ## KIND ## _type (GET_MODE_BITSIZE (MODE ## mode)); \
7356   u ## NAME ## _type_node = \
7357     make_or_reuse_unsigned_ ## KIND ## _type \
7358       (GET_MODE_BITSIZE (U ## MODE ## mode)); \
7359   sat_ ## NAME ## _type_node = \
7360     make_or_reuse_sat_signed_ ## KIND ## _type \
7361       (GET_MODE_BITSIZE (MODE ## mode)); \
7362   sat_u ## NAME ## _type_node = \
7363     make_or_reuse_sat_unsigned_ ## KIND ## _type \
7364       (GET_MODE_BITSIZE (U ## MODE ## mode));
7365
7366   /* Fixed-point type and mode nodes.  */
7367   MAKE_FIXED_TYPE_NODE_FAMILY (fract, FRACT)
7368   MAKE_FIXED_TYPE_NODE_FAMILY (accum, ACCUM)
7369   MAKE_FIXED_MODE_NODE (fract, qq, QQ)
7370   MAKE_FIXED_MODE_NODE (fract, hq, HQ)
7371   MAKE_FIXED_MODE_NODE (fract, sq, SQ)
7372   MAKE_FIXED_MODE_NODE (fract, dq, DQ)
7373   MAKE_FIXED_MODE_NODE (fract, tq, TQ)
7374   MAKE_FIXED_MODE_NODE (accum, ha, HA)
7375   MAKE_FIXED_MODE_NODE (accum, sa, SA)
7376   MAKE_FIXED_MODE_NODE (accum, da, DA)
7377   MAKE_FIXED_MODE_NODE (accum, ta, TA)
7378
7379   {
7380     tree t = targetm.build_builtin_va_list ();
7381
7382     /* Many back-ends define record types without setting TYPE_NAME.
7383        If we copied the record type here, we'd keep the original
7384        record type without a name.  This breaks name mangling.  So,
7385        don't copy record types and let c_common_nodes_and_builtins()
7386        declare the type to be __builtin_va_list.  */
7387     if (TREE_CODE (t) != RECORD_TYPE)
7388       t = build_variant_type_copy (t);
7389
7390     va_list_type_node = t;
7391   }
7392 }
7393
7394 /* A subroutine of build_common_builtin_nodes.  Define a builtin function.  */
7395
7396 static void
7397 local_define_builtin (const char *name, tree type, enum built_in_function code,
7398                       const char *library_name, int ecf_flags)
7399 {
7400   tree decl;
7401
7402   decl = add_builtin_function (name, type, code, BUILT_IN_NORMAL,
7403                                library_name, NULL_TREE);
7404   if (ecf_flags & ECF_CONST)
7405     TREE_READONLY (decl) = 1;
7406   if (ecf_flags & ECF_PURE)
7407     DECL_IS_PURE (decl) = 1;
7408   if (ecf_flags & ECF_NORETURN)
7409     TREE_THIS_VOLATILE (decl) = 1;
7410   if (ecf_flags & ECF_NOTHROW)
7411     TREE_NOTHROW (decl) = 1;
7412   if (ecf_flags & ECF_MALLOC)
7413     DECL_IS_MALLOC (decl) = 1;
7414
7415   built_in_decls[code] = decl;
7416   implicit_built_in_decls[code] = decl;
7417 }
7418
7419 /* Call this function after instantiating all builtins that the language
7420    front end cares about.  This will build the rest of the builtins that
7421    are relied upon by the tree optimizers and the middle-end.  */
7422
7423 void
7424 build_common_builtin_nodes (void)
7425 {
7426   tree tmp, ftype;
7427
7428   if (built_in_decls[BUILT_IN_MEMCPY] == NULL
7429       || built_in_decls[BUILT_IN_MEMMOVE] == NULL)
7430     {
7431       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
7432       tmp = tree_cons (NULL_TREE, const_ptr_type_node, tmp);
7433       tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7434       ftype = build_function_type (ptr_type_node, tmp);
7435
7436       if (built_in_decls[BUILT_IN_MEMCPY] == NULL)
7437         local_define_builtin ("__builtin_memcpy", ftype, BUILT_IN_MEMCPY,
7438                               "memcpy", ECF_NOTHROW);
7439       if (built_in_decls[BUILT_IN_MEMMOVE] == NULL)
7440         local_define_builtin ("__builtin_memmove", ftype, BUILT_IN_MEMMOVE,
7441                               "memmove", ECF_NOTHROW);
7442     }
7443
7444   if (built_in_decls[BUILT_IN_MEMCMP] == NULL)
7445     {
7446       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
7447       tmp = tree_cons (NULL_TREE, const_ptr_type_node, tmp);
7448       tmp = tree_cons (NULL_TREE, const_ptr_type_node, tmp);
7449       ftype = build_function_type (integer_type_node, tmp);
7450       local_define_builtin ("__builtin_memcmp", ftype, BUILT_IN_MEMCMP,
7451                             "memcmp", ECF_PURE | ECF_NOTHROW);
7452     }
7453
7454   if (built_in_decls[BUILT_IN_MEMSET] == NULL)
7455     {
7456       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
7457       tmp = tree_cons (NULL_TREE, integer_type_node, tmp);
7458       tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7459       ftype = build_function_type (ptr_type_node, tmp);
7460       local_define_builtin ("__builtin_memset", ftype, BUILT_IN_MEMSET,
7461                             "memset", ECF_NOTHROW);
7462     }
7463
7464   if (built_in_decls[BUILT_IN_ALLOCA] == NULL)
7465     {
7466       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
7467       ftype = build_function_type (ptr_type_node, tmp);
7468       local_define_builtin ("__builtin_alloca", ftype, BUILT_IN_ALLOCA,
7469                             "alloca", ECF_NOTHROW | ECF_MALLOC);
7470     }
7471
7472   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7473   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7474   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7475   ftype = build_function_type (void_type_node, tmp);
7476   local_define_builtin ("__builtin_init_trampoline", ftype,
7477                         BUILT_IN_INIT_TRAMPOLINE,
7478                         "__builtin_init_trampoline", ECF_NOTHROW);
7479
7480   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7481   ftype = build_function_type (ptr_type_node, tmp);
7482   local_define_builtin ("__builtin_adjust_trampoline", ftype,
7483                         BUILT_IN_ADJUST_TRAMPOLINE,
7484                         "__builtin_adjust_trampoline",
7485                         ECF_CONST | ECF_NOTHROW);
7486
7487   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7488   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7489   ftype = build_function_type (void_type_node, tmp);
7490   local_define_builtin ("__builtin_nonlocal_goto", ftype,
7491                         BUILT_IN_NONLOCAL_GOTO,
7492                         "__builtin_nonlocal_goto",
7493                         ECF_NORETURN | ECF_NOTHROW);
7494
7495   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7496   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
7497   ftype = build_function_type (void_type_node, tmp);
7498   local_define_builtin ("__builtin_setjmp_setup", ftype,
7499                         BUILT_IN_SETJMP_SETUP,
7500                         "__builtin_setjmp_setup", ECF_NOTHROW);
7501
7502   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7503   ftype = build_function_type (ptr_type_node, tmp);
7504   local_define_builtin ("__builtin_setjmp_dispatcher", ftype,
7505                         BUILT_IN_SETJMP_DISPATCHER,
7506                         "__builtin_setjmp_dispatcher",
7507                         ECF_PURE | ECF_NOTHROW);
7508
7509   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7510   ftype = build_function_type (void_type_node, tmp);
7511   local_define_builtin ("__builtin_setjmp_receiver", ftype,
7512                         BUILT_IN_SETJMP_RECEIVER,
7513                         "__builtin_setjmp_receiver", ECF_NOTHROW);
7514
7515   ftype = build_function_type (ptr_type_node, void_list_node);
7516   local_define_builtin ("__builtin_stack_save", ftype, BUILT_IN_STACK_SAVE,
7517                         "__builtin_stack_save", ECF_NOTHROW);
7518
7519   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
7520   ftype = build_function_type (void_type_node, tmp);
7521   local_define_builtin ("__builtin_stack_restore", ftype,
7522                         BUILT_IN_STACK_RESTORE,
7523                         "__builtin_stack_restore", ECF_NOTHROW);
7524
7525   ftype = build_function_type (void_type_node, void_list_node);
7526   local_define_builtin ("__builtin_profile_func_enter", ftype,
7527                         BUILT_IN_PROFILE_FUNC_ENTER, "profile_func_enter", 0);
7528   local_define_builtin ("__builtin_profile_func_exit", ftype,
7529                         BUILT_IN_PROFILE_FUNC_EXIT, "profile_func_exit", 0);
7530
7531   /* Complex multiplication and division.  These are handled as builtins
7532      rather than optabs because emit_library_call_value doesn't support
7533      complex.  Further, we can do slightly better with folding these
7534      beasties if the real and complex parts of the arguments are separate.  */
7535   {
7536     enum machine_mode mode;
7537
7538     for (mode = MIN_MODE_COMPLEX_FLOAT; mode <= MAX_MODE_COMPLEX_FLOAT; ++mode)
7539       {
7540         char mode_name_buf[4], *q;
7541         const char *p;
7542         enum built_in_function mcode, dcode;
7543         tree type, inner_type;
7544
7545         type = lang_hooks.types.type_for_mode (mode, 0);
7546         if (type == NULL)
7547           continue;
7548         inner_type = TREE_TYPE (type);
7549
7550         tmp = tree_cons (NULL_TREE, inner_type, void_list_node);
7551         tmp = tree_cons (NULL_TREE, inner_type, tmp);
7552         tmp = tree_cons (NULL_TREE, inner_type, tmp);
7553         tmp = tree_cons (NULL_TREE, inner_type, tmp);
7554         ftype = build_function_type (type, tmp);
7555
7556         mcode = BUILT_IN_COMPLEX_MUL_MIN + mode - MIN_MODE_COMPLEX_FLOAT;
7557         dcode = BUILT_IN_COMPLEX_DIV_MIN + mode - MIN_MODE_COMPLEX_FLOAT;
7558
7559         for (p = GET_MODE_NAME (mode), q = mode_name_buf; *p; p++, q++)
7560           *q = TOLOWER (*p);
7561         *q = '\0';
7562
7563         built_in_names[mcode] = concat ("__mul", mode_name_buf, "3", NULL);
7564         local_define_builtin (built_in_names[mcode], ftype, mcode,
7565                               built_in_names[mcode], ECF_CONST | ECF_NOTHROW);
7566
7567         built_in_names[dcode] = concat ("__div", mode_name_buf, "3", NULL);
7568         local_define_builtin (built_in_names[dcode], ftype, dcode,
7569                               built_in_names[dcode], ECF_CONST | ECF_NOTHROW);
7570       }
7571   }
7572 }
7573
7574 /* HACK.  GROSS.  This is absolutely disgusting.  I wish there was a
7575    better way.
7576
7577    If we requested a pointer to a vector, build up the pointers that
7578    we stripped off while looking for the inner type.  Similarly for
7579    return values from functions.
7580
7581    The argument TYPE is the top of the chain, and BOTTOM is the
7582    new type which we will point to.  */
7583
7584 tree
7585 reconstruct_complex_type (tree type, tree bottom)
7586 {
7587   tree inner, outer;
7588
7589   if (TREE_CODE (type) == POINTER_TYPE)
7590     {
7591       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
7592       outer = build_pointer_type_for_mode (inner, TYPE_MODE (type),
7593                                            TYPE_REF_CAN_ALIAS_ALL (type));
7594     }
7595   else if (TREE_CODE (type) == REFERENCE_TYPE)
7596     {
7597       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
7598       outer = build_reference_type_for_mode (inner, TYPE_MODE (type),
7599                                              TYPE_REF_CAN_ALIAS_ALL (type));
7600     }
7601   else if (TREE_CODE (type) == ARRAY_TYPE)
7602     {
7603       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
7604       outer = build_array_type (inner, TYPE_DOMAIN (type));
7605     }
7606   else if (TREE_CODE (type) == FUNCTION_TYPE)
7607     {
7608       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
7609       outer = build_function_type (inner, TYPE_ARG_TYPES (type));
7610     }
7611   else if (TREE_CODE (type) == METHOD_TYPE)
7612     {
7613       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
7614       /* The build_method_type_directly() routine prepends 'this' to argument list,
7615          so we must compensate by getting rid of it.  */
7616       outer
7617         = build_method_type_directly
7618             (TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (type))),
7619              inner,
7620              TREE_CHAIN (TYPE_ARG_TYPES (type)));
7621     }
7622   else
7623     return bottom;
7624
7625   return build_qualified_type (outer, TYPE_QUALS (type));
7626 }
7627
7628 /* Returns a vector tree node given a mode (integer, vector, or BLKmode) and
7629    the inner type.  */
7630 tree
7631 build_vector_type_for_mode (tree innertype, enum machine_mode mode)
7632 {
7633   int nunits;
7634
7635   switch (GET_MODE_CLASS (mode))
7636     {
7637     case MODE_VECTOR_INT:
7638     case MODE_VECTOR_FLOAT:
7639     case MODE_VECTOR_FRACT:
7640     case MODE_VECTOR_UFRACT:
7641     case MODE_VECTOR_ACCUM:
7642     case MODE_VECTOR_UACCUM:
7643       nunits = GET_MODE_NUNITS (mode);
7644       break;
7645
7646     case MODE_INT:
7647       /* Check that there are no leftover bits.  */
7648       gcc_assert (GET_MODE_BITSIZE (mode)
7649                   % TREE_INT_CST_LOW (TYPE_SIZE (innertype)) == 0);
7650
7651       nunits = GET_MODE_BITSIZE (mode)
7652                / TREE_INT_CST_LOW (TYPE_SIZE (innertype));
7653       break;
7654
7655     default:
7656       gcc_unreachable ();
7657     }
7658
7659   return make_vector_type (innertype, nunits, mode);
7660 }
7661
7662 /* Similarly, but takes the inner type and number of units, which must be
7663    a power of two.  */
7664
7665 tree
7666 build_vector_type (tree innertype, int nunits)
7667 {
7668   return make_vector_type (innertype, nunits, VOIDmode);
7669 }
7670
7671
7672 /* Build RESX_EXPR with given REGION_NUMBER.  */
7673 tree
7674 build_resx (int region_number)
7675 {
7676   tree t;
7677   t = build1 (RESX_EXPR, void_type_node,
7678               build_int_cst (NULL_TREE, region_number));
7679   return t;
7680 }
7681
7682 /* Given an initializer INIT, return TRUE if INIT is zero or some
7683    aggregate of zeros.  Otherwise return FALSE.  */
7684 bool
7685 initializer_zerop (const_tree init)
7686 {
7687   tree elt;
7688
7689   STRIP_NOPS (init);
7690
7691   switch (TREE_CODE (init))
7692     {
7693     case INTEGER_CST:
7694       return integer_zerop (init);
7695
7696     case REAL_CST:
7697       /* ??? Note that this is not correct for C4X float formats.  There,
7698          a bit pattern of all zeros is 1.0; 0.0 is encoded with the most
7699          negative exponent.  */
7700       return real_zerop (init)
7701         && ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (init));
7702
7703     case FIXED_CST:
7704       return fixed_zerop (init);
7705
7706     case COMPLEX_CST:
7707       return integer_zerop (init)
7708         || (real_zerop (init)
7709             && ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (TREE_REALPART (init)))
7710             && ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (TREE_IMAGPART (init))));
7711
7712     case VECTOR_CST:
7713       for (elt = TREE_VECTOR_CST_ELTS (init); elt; elt = TREE_CHAIN (elt))
7714         if (!initializer_zerop (TREE_VALUE (elt)))
7715           return false;
7716       return true;
7717
7718     case CONSTRUCTOR:
7719       {
7720         unsigned HOST_WIDE_INT idx;
7721
7722         FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (init), idx, elt)
7723           if (!initializer_zerop (elt))
7724             return false;
7725         return true;
7726       }
7727
7728     default:
7729       return false;
7730     }
7731 }
7732
7733 /* Build an empty statement.  */
7734
7735 tree
7736 build_empty_stmt (void)
7737 {
7738   return build1 (NOP_EXPR, void_type_node, size_zero_node);
7739 }
7740
7741
7742 /* Build an OpenMP clause with code CODE.  */
7743
7744 tree
7745 build_omp_clause (enum omp_clause_code code)
7746 {
7747   tree t;
7748   int size, length;
7749
7750   length = omp_clause_num_ops[code];
7751   size = (sizeof (struct tree_omp_clause) + (length - 1) * sizeof (tree));
7752
7753   t = ggc_alloc (size);
7754   memset (t, 0, size);
7755   TREE_SET_CODE (t, OMP_CLAUSE);
7756   OMP_CLAUSE_SET_CODE (t, code);
7757
7758 #ifdef GATHER_STATISTICS
7759   tree_node_counts[(int) omp_clause_kind]++;
7760   tree_node_sizes[(int) omp_clause_kind] += size;
7761 #endif
7762
7763   return t;
7764 }
7765
7766 /* Set various status flags when building a CALL_EXPR object T.  */
7767
7768 static void
7769 process_call_operands (tree t)
7770 {
7771   bool side_effects;
7772
7773   side_effects = TREE_SIDE_EFFECTS (t);
7774   if (!side_effects)
7775     {
7776       int i, n;
7777       n = TREE_OPERAND_LENGTH (t);
7778       for (i = 1; i < n; i++)
7779         {
7780           tree op = TREE_OPERAND (t, i);
7781           if (op && TREE_SIDE_EFFECTS (op))
7782             {
7783               side_effects = 1;
7784               break;
7785             }
7786         }
7787     }
7788   if (!side_effects)
7789     {
7790       int i;
7791
7792       /* Calls have side-effects, except those to const or
7793          pure functions.  */
7794       i = call_expr_flags (t);
7795       if (!(i & (ECF_CONST | ECF_PURE)))
7796         side_effects = 1;
7797     }
7798   TREE_SIDE_EFFECTS (t) = side_effects;
7799 }
7800
7801 /* Build a tcc_vl_exp object with code CODE and room for LEN operands.  LEN
7802    includes the implicit operand count in TREE_OPERAND 0, and so must be >= 1.
7803    Except for the CODE and operand count field, other storage for the
7804    object is initialized to zeros.  */
7805
7806 tree
7807 build_vl_exp_stat (enum tree_code code, int len MEM_STAT_DECL)
7808 {
7809   tree t;
7810   int length = (len - 1) * sizeof (tree) + sizeof (struct tree_exp);
7811
7812   gcc_assert (TREE_CODE_CLASS (code) == tcc_vl_exp);
7813   gcc_assert (len >= 1);
7814
7815 #ifdef GATHER_STATISTICS
7816   tree_node_counts[(int) e_kind]++;
7817   tree_node_sizes[(int) e_kind] += length;
7818 #endif
7819
7820   t = ggc_alloc_zone_pass_stat (length, &tree_zone);
7821
7822   memset (t, 0, length);
7823
7824   TREE_SET_CODE (t, code);
7825
7826   /* Can't use TREE_OPERAND to store the length because if checking is
7827      enabled, it will try to check the length before we store it.  :-P  */
7828   t->exp.operands[0] = build_int_cst (sizetype, len);
7829
7830   return t;
7831 }
7832
7833
7834 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE
7835    and FN and a null static chain slot.  ARGLIST is a TREE_LIST of the
7836    arguments.  */
7837
7838 tree
7839 build_call_list (tree return_type, tree fn, tree arglist)
7840 {
7841   tree t;
7842   int i;
7843
7844   t = build_vl_exp (CALL_EXPR, list_length (arglist) + 3);
7845   TREE_TYPE (t) = return_type;
7846   CALL_EXPR_FN (t) = fn;
7847   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
7848   for (i = 0; arglist; arglist = TREE_CHAIN (arglist), i++)
7849     CALL_EXPR_ARG (t, i) = TREE_VALUE (arglist);
7850   process_call_operands (t);
7851   return t;
7852 }
7853
7854 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
7855    FN and a null static chain slot.  NARGS is the number of call arguments
7856    which are specified as "..." arguments.  */
7857
7858 tree
7859 build_call_nary (tree return_type, tree fn, int nargs, ...)
7860 {
7861   tree ret;
7862   va_list args;
7863   va_start (args, nargs);
7864   ret = build_call_valist (return_type, fn, nargs, args);
7865   va_end (args);
7866   return ret;
7867 }
7868
7869 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
7870    FN and a null static chain slot.  NARGS is the number of call arguments
7871    which are specified as a va_list ARGS.  */
7872
7873 tree
7874 build_call_valist (tree return_type, tree fn, int nargs, va_list args)
7875 {
7876   tree t;
7877   int i;
7878
7879   t = build_vl_exp (CALL_EXPR, nargs + 3);
7880   TREE_TYPE (t) = return_type;
7881   CALL_EXPR_FN (t) = fn;
7882   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
7883   for (i = 0; i < nargs; i++)
7884     CALL_EXPR_ARG (t, i) = va_arg (args, tree);
7885   process_call_operands (t);
7886   return t;
7887 }
7888
7889 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
7890    FN and a null static chain slot.  NARGS is the number of call arguments
7891    which are specified as a tree array ARGS.  */
7892
7893 tree
7894 build_call_array (tree return_type, tree fn, int nargs, tree *args)
7895 {
7896   tree t;
7897   int i;
7898
7899   t = build_vl_exp (CALL_EXPR, nargs + 3);
7900   TREE_TYPE (t) = return_type;
7901   CALL_EXPR_FN (t) = fn;
7902   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
7903   for (i = 0; i < nargs; i++)
7904     CALL_EXPR_ARG (t, i) = args[i];
7905   process_call_operands (t);
7906   return t;
7907 }
7908
7909
7910 /* Returns true if it is possible to prove that the index of
7911    an array access REF (an ARRAY_REF expression) falls into the
7912    array bounds.  */
7913
7914 bool
7915 in_array_bounds_p (tree ref)
7916 {
7917   tree idx = TREE_OPERAND (ref, 1);
7918   tree min, max;
7919
7920   if (TREE_CODE (idx) != INTEGER_CST)
7921     return false;
7922
7923   min = array_ref_low_bound (ref);
7924   max = array_ref_up_bound (ref);
7925   if (!min
7926       || !max
7927       || TREE_CODE (min) != INTEGER_CST
7928       || TREE_CODE (max) != INTEGER_CST)
7929     return false;
7930
7931   if (tree_int_cst_lt (idx, min)
7932       || tree_int_cst_lt (max, idx))
7933     return false;
7934
7935   return true;
7936 }
7937
7938 /* Returns true if it is possible to prove that the range of
7939    an array access REF (an ARRAY_RANGE_REF expression) falls
7940    into the array bounds.  */
7941
7942 bool
7943 range_in_array_bounds_p (tree ref)
7944 {
7945   tree domain_type = TYPE_DOMAIN (TREE_TYPE (ref));
7946   tree range_min, range_max, min, max;
7947
7948   range_min = TYPE_MIN_VALUE (domain_type);
7949   range_max = TYPE_MAX_VALUE (domain_type);
7950   if (!range_min
7951       || !range_max
7952       || TREE_CODE (range_min) != INTEGER_CST
7953       || TREE_CODE (range_max) != INTEGER_CST)
7954     return false;
7955
7956   min = array_ref_low_bound (ref);
7957   max = array_ref_up_bound (ref);
7958   if (!min
7959       || !max
7960       || TREE_CODE (min) != INTEGER_CST
7961       || TREE_CODE (max) != INTEGER_CST)
7962     return false;
7963
7964   if (tree_int_cst_lt (range_min, min)
7965       || tree_int_cst_lt (max, range_max))
7966     return false;
7967
7968   return true;
7969 }
7970
7971 /* Return true if T (assumed to be a DECL) must be assigned a memory
7972    location.  */
7973
7974 bool
7975 needs_to_live_in_memory (const_tree t)
7976 {
7977   if (TREE_CODE (t) == SSA_NAME)
7978     t = SSA_NAME_VAR (t);
7979
7980   return (TREE_ADDRESSABLE (t)
7981           || is_global_var (t)
7982           || (TREE_CODE (t) == RESULT_DECL
7983               && aggregate_value_p (t, current_function_decl)));
7984 }
7985
7986 /* There are situations in which a language considers record types
7987    compatible which have different field lists.  Decide if two fields
7988    are compatible.  It is assumed that the parent records are compatible.  */
7989
7990 bool
7991 fields_compatible_p (const_tree f1, const_tree f2)
7992 {
7993   if (!operand_equal_p (DECL_FIELD_BIT_OFFSET (f1),
7994                         DECL_FIELD_BIT_OFFSET (f2), OEP_ONLY_CONST))
7995     return false;
7996
7997   if (!operand_equal_p (DECL_FIELD_OFFSET (f1),
7998                         DECL_FIELD_OFFSET (f2), OEP_ONLY_CONST))
7999     return false;
8000
8001   if (!types_compatible_p (TREE_TYPE (f1), TREE_TYPE (f2)))
8002     return false;
8003
8004   return true;
8005 }
8006
8007 /* Locate within RECORD a field that is compatible with ORIG_FIELD.  */
8008
8009 tree
8010 find_compatible_field (tree record, tree orig_field)
8011 {
8012   tree f;
8013
8014   for (f = TYPE_FIELDS (record); f ; f = TREE_CHAIN (f))
8015     if (TREE_CODE (f) == FIELD_DECL
8016         && fields_compatible_p (f, orig_field))
8017       return f;
8018
8019   /* ??? Why isn't this on the main fields list?  */
8020   f = TYPE_VFIELD (record);
8021   if (f && TREE_CODE (f) == FIELD_DECL
8022       && fields_compatible_p (f, orig_field))
8023     return f;
8024
8025   /* ??? We should abort here, but Java appears to do Bad Things
8026      with inherited fields.  */
8027   return orig_field;
8028 }
8029
8030 /* Return value of a constant X.  */
8031
8032 HOST_WIDE_INT
8033 int_cst_value (const_tree x)
8034 {
8035   unsigned bits = TYPE_PRECISION (TREE_TYPE (x));
8036   unsigned HOST_WIDE_INT val = TREE_INT_CST_LOW (x);
8037   bool negative = ((val >> (bits - 1)) & 1) != 0;
8038
8039   gcc_assert (bits <= HOST_BITS_PER_WIDE_INT);
8040
8041   if (negative)
8042     val |= (~(unsigned HOST_WIDE_INT) 0) << (bits - 1) << 1;
8043   else
8044     val &= ~((~(unsigned HOST_WIDE_INT) 0) << (bits - 1) << 1);
8045
8046   return val;
8047 }
8048
8049 /* If TYPE is an integral type, return an equivalent type which is
8050     unsigned iff UNSIGNEDP is true.  If TYPE is not an integral type,
8051     return TYPE itself.  */
8052
8053 tree
8054 signed_or_unsigned_type_for (int unsignedp, tree type)
8055 {
8056   tree t = type;
8057   if (POINTER_TYPE_P (type))
8058     t = size_type_node;
8059
8060   if (!INTEGRAL_TYPE_P (t) || TYPE_UNSIGNED (t) == unsignedp)
8061     return t;
8062
8063   return lang_hooks.types.type_for_size (TYPE_PRECISION (t), unsignedp);
8064 }
8065
8066 /* Returns unsigned variant of TYPE.  */
8067
8068 tree
8069 unsigned_type_for (tree type)
8070 {
8071   return signed_or_unsigned_type_for (1, type);
8072 }
8073
8074 /* Returns signed variant of TYPE.  */
8075
8076 tree
8077 signed_type_for (tree type)
8078 {
8079   return signed_or_unsigned_type_for (0, type);
8080 }
8081
8082 /* Returns the largest value obtainable by casting something in INNER type to
8083    OUTER type.  */
8084
8085 tree
8086 upper_bound_in_type (tree outer, tree inner)
8087 {
8088   unsigned HOST_WIDE_INT lo, hi;
8089   unsigned int det = 0;
8090   unsigned oprec = TYPE_PRECISION (outer);
8091   unsigned iprec = TYPE_PRECISION (inner);
8092   unsigned prec;
8093
8094   /* Compute a unique number for every combination.  */
8095   det |= (oprec > iprec) ? 4 : 0;
8096   det |= TYPE_UNSIGNED (outer) ? 2 : 0;
8097   det |= TYPE_UNSIGNED (inner) ? 1 : 0;
8098
8099   /* Determine the exponent to use.  */
8100   switch (det)
8101     {
8102     case 0:
8103     case 1:
8104       /* oprec <= iprec, outer: signed, inner: don't care.  */
8105       prec = oprec - 1;
8106       break;
8107     case 2:
8108     case 3:
8109       /* oprec <= iprec, outer: unsigned, inner: don't care.  */
8110       prec = oprec;
8111       break;
8112     case 4:
8113       /* oprec > iprec, outer: signed, inner: signed.  */
8114       prec = iprec - 1;
8115       break;
8116     case 5:
8117       /* oprec > iprec, outer: signed, inner: unsigned.  */
8118       prec = iprec;
8119       break;
8120     case 6:
8121       /* oprec > iprec, outer: unsigned, inner: signed.  */
8122       prec = oprec;
8123       break;
8124     case 7:
8125       /* oprec > iprec, outer: unsigned, inner: unsigned.  */
8126       prec = iprec;
8127       break;
8128     default:
8129       gcc_unreachable ();
8130     }
8131
8132   /* Compute 2^^prec - 1.  */
8133   if (prec <= HOST_BITS_PER_WIDE_INT)
8134     {
8135       hi = 0;
8136       lo = ((~(unsigned HOST_WIDE_INT) 0)
8137             >> (HOST_BITS_PER_WIDE_INT - prec));
8138     }
8139   else
8140     {
8141       hi = ((~(unsigned HOST_WIDE_INT) 0)
8142             >> (2 * HOST_BITS_PER_WIDE_INT - prec));
8143       lo = ~(unsigned HOST_WIDE_INT) 0;
8144     }
8145
8146   return build_int_cst_wide (outer, lo, hi);
8147 }
8148
8149 /* Returns the smallest value obtainable by casting something in INNER type to
8150    OUTER type.  */
8151
8152 tree
8153 lower_bound_in_type (tree outer, tree inner)
8154 {
8155   unsigned HOST_WIDE_INT lo, hi;
8156   unsigned oprec = TYPE_PRECISION (outer);
8157   unsigned iprec = TYPE_PRECISION (inner);
8158
8159   /* If OUTER type is unsigned, we can definitely cast 0 to OUTER type
8160      and obtain 0.  */
8161   if (TYPE_UNSIGNED (outer)
8162       /* If we are widening something of an unsigned type, OUTER type
8163          contains all values of INNER type.  In particular, both INNER
8164          and OUTER types have zero in common.  */
8165       || (oprec > iprec && TYPE_UNSIGNED (inner)))
8166     lo = hi = 0;
8167   else
8168     {
8169       /* If we are widening a signed type to another signed type, we
8170          want to obtain -2^^(iprec-1).  If we are keeping the
8171          precision or narrowing to a signed type, we want to obtain
8172          -2^(oprec-1).  */
8173       unsigned prec = oprec > iprec ? iprec : oprec;
8174
8175       if (prec <= HOST_BITS_PER_WIDE_INT)
8176         {
8177           hi = ~(unsigned HOST_WIDE_INT) 0;
8178           lo = (~(unsigned HOST_WIDE_INT) 0) << (prec - 1);
8179         }
8180       else
8181         {
8182           hi = ((~(unsigned HOST_WIDE_INT) 0)
8183                 << (prec - HOST_BITS_PER_WIDE_INT - 1));
8184           lo = 0;
8185         }
8186     }
8187
8188   return build_int_cst_wide (outer, lo, hi);
8189 }
8190
8191 /* Return nonzero if two operands that are suitable for PHI nodes are
8192    necessarily equal.  Specifically, both ARG0 and ARG1 must be either
8193    SSA_NAME or invariant.  Note that this is strictly an optimization.
8194    That is, callers of this function can directly call operand_equal_p
8195    and get the same result, only slower.  */
8196
8197 int
8198 operand_equal_for_phi_arg_p (const_tree arg0, const_tree arg1)
8199 {
8200   if (arg0 == arg1)
8201     return 1;
8202   if (TREE_CODE (arg0) == SSA_NAME || TREE_CODE (arg1) == SSA_NAME)
8203     return 0;
8204   return operand_equal_p (arg0, arg1, 0);
8205 }
8206
8207 /* Returns number of zeros at the end of binary representation of X.
8208
8209    ??? Use ffs if available?  */
8210
8211 tree
8212 num_ending_zeros (const_tree x)
8213 {
8214   unsigned HOST_WIDE_INT fr, nfr;
8215   unsigned num, abits;
8216   tree type = TREE_TYPE (x);
8217
8218   if (TREE_INT_CST_LOW (x) == 0)
8219     {
8220       num = HOST_BITS_PER_WIDE_INT;
8221       fr = TREE_INT_CST_HIGH (x);
8222     }
8223   else
8224     {
8225       num = 0;
8226       fr = TREE_INT_CST_LOW (x);
8227     }
8228
8229   for (abits = HOST_BITS_PER_WIDE_INT / 2; abits; abits /= 2)
8230     {
8231       nfr = fr >> abits;
8232       if (nfr << abits == fr)
8233         {
8234           num += abits;
8235           fr = nfr;
8236         }
8237     }
8238
8239   if (num > TYPE_PRECISION (type))
8240     num = TYPE_PRECISION (type);
8241
8242   return build_int_cst_type (type, num);
8243 }
8244
8245
8246 #define WALK_SUBTREE(NODE)                              \
8247   do                                                    \
8248     {                                                   \
8249       result = walk_tree_1 (&(NODE), func, data, pset, lh);     \
8250       if (result)                                       \
8251         return result;                                  \
8252     }                                                   \
8253   while (0)
8254
8255 /* This is a subroutine of walk_tree that walks field of TYPE that are to
8256    be walked whenever a type is seen in the tree.  Rest of operands and return
8257    value are as for walk_tree.  */
8258
8259 static tree
8260 walk_type_fields (tree type, walk_tree_fn func, void *data,
8261                   struct pointer_set_t *pset, walk_tree_lh lh)
8262 {
8263   tree result = NULL_TREE;
8264
8265   switch (TREE_CODE (type))
8266     {
8267     case POINTER_TYPE:
8268     case REFERENCE_TYPE:
8269       /* We have to worry about mutually recursive pointers.  These can't
8270          be written in C.  They can in Ada.  It's pathological, but
8271          there's an ACATS test (c38102a) that checks it.  Deal with this
8272          by checking if we're pointing to another pointer, that one
8273          points to another pointer, that one does too, and we have no htab.
8274          If so, get a hash table.  We check three levels deep to avoid
8275          the cost of the hash table if we don't need one.  */
8276       if (POINTER_TYPE_P (TREE_TYPE (type))
8277           && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (type)))
8278           && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (TREE_TYPE (type))))
8279           && !pset)
8280         {
8281           result = walk_tree_without_duplicates (&TREE_TYPE (type),
8282                                                  func, data);
8283           if (result)
8284             return result;
8285
8286           break;
8287         }
8288
8289       /* ... fall through ... */
8290
8291     case COMPLEX_TYPE:
8292       WALK_SUBTREE (TREE_TYPE (type));
8293       break;
8294
8295     case METHOD_TYPE:
8296       WALK_SUBTREE (TYPE_METHOD_BASETYPE (type));
8297
8298       /* Fall through.  */
8299
8300     case FUNCTION_TYPE:
8301       WALK_SUBTREE (TREE_TYPE (type));
8302       {
8303         tree arg;
8304
8305         /* We never want to walk into default arguments.  */
8306         for (arg = TYPE_ARG_TYPES (type); arg; arg = TREE_CHAIN (arg))
8307           WALK_SUBTREE (TREE_VALUE (arg));
8308       }
8309       break;
8310
8311     case ARRAY_TYPE:
8312       /* Don't follow this nodes's type if a pointer for fear that
8313          we'll have infinite recursion.  If we have a PSET, then we
8314          need not fear.  */
8315       if (pset
8316           || (!POINTER_TYPE_P (TREE_TYPE (type))
8317               && TREE_CODE (TREE_TYPE (type)) != OFFSET_TYPE))
8318         WALK_SUBTREE (TREE_TYPE (type));
8319       WALK_SUBTREE (TYPE_DOMAIN (type));
8320       break;
8321
8322     case OFFSET_TYPE:
8323       WALK_SUBTREE (TREE_TYPE (type));
8324       WALK_SUBTREE (TYPE_OFFSET_BASETYPE (type));
8325       break;
8326
8327     default:
8328       break;
8329     }
8330
8331   return NULL_TREE;
8332 }
8333
8334 /* Apply FUNC to all the sub-trees of TP in a pre-order traversal.  FUNC is
8335    called with the DATA and the address of each sub-tree.  If FUNC returns a
8336    non-NULL value, the traversal is stopped, and the value returned by FUNC
8337    is returned.  If PSET is non-NULL it is used to record the nodes visited,
8338    and to avoid visiting a node more than once.  */
8339
8340 tree
8341 walk_tree_1 (tree *tp, walk_tree_fn func, void *data,
8342              struct pointer_set_t *pset, walk_tree_lh lh)
8343 {
8344   enum tree_code code;
8345   int walk_subtrees;
8346   tree result;
8347
8348 #define WALK_SUBTREE_TAIL(NODE)                         \
8349   do                                                    \
8350     {                                                   \
8351        tp = & (NODE);                                   \
8352        goto tail_recurse;                               \
8353     }                                                   \
8354   while (0)
8355
8356  tail_recurse:
8357   /* Skip empty subtrees.  */
8358   if (!*tp)
8359     return NULL_TREE;
8360
8361   /* Don't walk the same tree twice, if the user has requested
8362      that we avoid doing so.  */
8363   if (pset && pointer_set_insert (pset, *tp))
8364     return NULL_TREE;
8365
8366   /* Call the function.  */
8367   walk_subtrees = 1;
8368   result = (*func) (tp, &walk_subtrees, data);
8369
8370   /* If we found something, return it.  */
8371   if (result)
8372     return result;
8373
8374   code = TREE_CODE (*tp);
8375
8376   /* Even if we didn't, FUNC may have decided that there was nothing
8377      interesting below this point in the tree.  */
8378   if (!walk_subtrees)
8379     {
8380       /* But we still need to check our siblings.  */
8381       if (code == TREE_LIST)
8382         WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
8383       else if (code == OMP_CLAUSE)
8384         WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
8385       else
8386         return NULL_TREE;
8387     }
8388
8389   if (lh)
8390     {
8391       result = (*lh) (tp, &walk_subtrees, func, data, pset);
8392       if (result || !walk_subtrees)
8393         return result;
8394     }
8395
8396   switch (code)
8397     {
8398     case ERROR_MARK:
8399     case IDENTIFIER_NODE:
8400     case INTEGER_CST:
8401     case REAL_CST:
8402     case FIXED_CST:
8403     case VECTOR_CST:
8404     case STRING_CST:
8405     case BLOCK:
8406     case PLACEHOLDER_EXPR:
8407     case SSA_NAME:
8408     case FIELD_DECL:
8409     case RESULT_DECL:
8410       /* None of these have subtrees other than those already walked
8411          above.  */
8412       break;
8413
8414     case TREE_LIST:
8415       WALK_SUBTREE (TREE_VALUE (*tp));
8416       WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
8417       break;
8418
8419     case TREE_VEC:
8420       {
8421         int len = TREE_VEC_LENGTH (*tp);
8422
8423         if (len == 0)
8424           break;
8425
8426         /* Walk all elements but the first.  */
8427         while (--len)
8428           WALK_SUBTREE (TREE_VEC_ELT (*tp, len));
8429
8430         /* Now walk the first one as a tail call.  */
8431         WALK_SUBTREE_TAIL (TREE_VEC_ELT (*tp, 0));
8432       }
8433
8434     case COMPLEX_CST:
8435       WALK_SUBTREE (TREE_REALPART (*tp));
8436       WALK_SUBTREE_TAIL (TREE_IMAGPART (*tp));
8437
8438     case CONSTRUCTOR:
8439       {
8440         unsigned HOST_WIDE_INT idx;
8441         constructor_elt *ce;
8442
8443         for (idx = 0;
8444              VEC_iterate(constructor_elt, CONSTRUCTOR_ELTS (*tp), idx, ce);
8445              idx++)
8446           WALK_SUBTREE (ce->value);
8447       }
8448       break;
8449
8450     case SAVE_EXPR:
8451       WALK_SUBTREE_TAIL (TREE_OPERAND (*tp, 0));
8452
8453     case BIND_EXPR:
8454       {
8455         tree decl;
8456         for (decl = BIND_EXPR_VARS (*tp); decl; decl = TREE_CHAIN (decl))
8457           {
8458             /* Walk the DECL_INITIAL and DECL_SIZE.  We don't want to walk
8459                into declarations that are just mentioned, rather than
8460                declared; they don't really belong to this part of the tree.
8461                And, we can see cycles: the initializer for a declaration
8462                can refer to the declaration itself.  */
8463             WALK_SUBTREE (DECL_INITIAL (decl));
8464             WALK_SUBTREE (DECL_SIZE (decl));
8465             WALK_SUBTREE (DECL_SIZE_UNIT (decl));
8466           }
8467         WALK_SUBTREE_TAIL (BIND_EXPR_BODY (*tp));
8468       }
8469
8470     case STATEMENT_LIST:
8471       {
8472         tree_stmt_iterator i;
8473         for (i = tsi_start (*tp); !tsi_end_p (i); tsi_next (&i))
8474           WALK_SUBTREE (*tsi_stmt_ptr (i));
8475       }
8476       break;
8477
8478     case OMP_CLAUSE:
8479       switch (OMP_CLAUSE_CODE (*tp))
8480         {
8481         case OMP_CLAUSE_PRIVATE:
8482         case OMP_CLAUSE_SHARED:
8483         case OMP_CLAUSE_FIRSTPRIVATE:
8484         case OMP_CLAUSE_LASTPRIVATE:
8485         case OMP_CLAUSE_COPYIN:
8486         case OMP_CLAUSE_COPYPRIVATE:
8487         case OMP_CLAUSE_IF:
8488         case OMP_CLAUSE_NUM_THREADS:
8489         case OMP_CLAUSE_SCHEDULE:
8490           WALK_SUBTREE (OMP_CLAUSE_OPERAND (*tp, 0));
8491           /* FALLTHRU */
8492
8493         case OMP_CLAUSE_NOWAIT:
8494         case OMP_CLAUSE_ORDERED:
8495         case OMP_CLAUSE_DEFAULT:
8496           WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
8497
8498         case OMP_CLAUSE_REDUCTION:
8499           {
8500             int i;
8501             for (i = 0; i < 4; i++)
8502               WALK_SUBTREE (OMP_CLAUSE_OPERAND (*tp, i));
8503             WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
8504           }
8505
8506         default:
8507           gcc_unreachable ();
8508         }
8509       break;
8510
8511     case TARGET_EXPR:
8512       {
8513         int i, len;
8514
8515         /* TARGET_EXPRs are peculiar: operands 1 and 3 can be the same.
8516            But, we only want to walk once.  */
8517         len = (TREE_OPERAND (*tp, 3) == TREE_OPERAND (*tp, 1)) ? 2 : 3;
8518         for (i = 0; i < len; ++i)
8519           WALK_SUBTREE (TREE_OPERAND (*tp, i));
8520         WALK_SUBTREE_TAIL (TREE_OPERAND (*tp, len));
8521       }
8522
8523     case DECL_EXPR:
8524       /* If this is a TYPE_DECL, walk into the fields of the type that it's
8525          defining.  We only want to walk into these fields of a type in this
8526          case and not in the general case of a mere reference to the type.
8527
8528          The criterion is as follows: if the field can be an expression, it
8529          must be walked only here.  This should be in keeping with the fields
8530          that are directly gimplified in gimplify_type_sizes in order for the
8531          mark/copy-if-shared/unmark machinery of the gimplifier to work with
8532          variable-sized types.
8533
8534          Note that DECLs get walked as part of processing the BIND_EXPR.  */
8535       if (TREE_CODE (DECL_EXPR_DECL (*tp)) == TYPE_DECL)
8536         {
8537           tree *type_p = &TREE_TYPE (DECL_EXPR_DECL (*tp));
8538           if (TREE_CODE (*type_p) == ERROR_MARK)
8539             return NULL_TREE;
8540
8541           /* Call the function for the type.  See if it returns anything or
8542              doesn't want us to continue.  If we are to continue, walk both
8543              the normal fields and those for the declaration case.  */
8544           result = (*func) (type_p, &walk_subtrees, data);
8545           if (result || !walk_subtrees)
8546             return result;
8547
8548           result = walk_type_fields (*type_p, func, data, pset, lh);
8549           if (result)
8550             return result;
8551
8552           /* If this is a record type, also walk the fields.  */
8553           if (TREE_CODE (*type_p) == RECORD_TYPE
8554               || TREE_CODE (*type_p) == UNION_TYPE
8555               || TREE_CODE (*type_p) == QUAL_UNION_TYPE)
8556             {
8557               tree field;
8558
8559               for (field = TYPE_FIELDS (*type_p); field;
8560                    field = TREE_CHAIN (field))
8561                 {
8562                   /* We'd like to look at the type of the field, but we can
8563                      easily get infinite recursion.  So assume it's pointed
8564                      to elsewhere in the tree.  Also, ignore things that
8565                      aren't fields.  */
8566                   if (TREE_CODE (field) != FIELD_DECL)
8567                     continue;
8568
8569                   WALK_SUBTREE (DECL_FIELD_OFFSET (field));
8570                   WALK_SUBTREE (DECL_SIZE (field));
8571                   WALK_SUBTREE (DECL_SIZE_UNIT (field));
8572                   if (TREE_CODE (*type_p) == QUAL_UNION_TYPE)
8573                     WALK_SUBTREE (DECL_QUALIFIER (field));
8574                 }
8575             }
8576
8577           /* Same for scalar types.  */
8578           else if (TREE_CODE (*type_p) == BOOLEAN_TYPE
8579                    || TREE_CODE (*type_p) == ENUMERAL_TYPE
8580                    || TREE_CODE (*type_p) == INTEGER_TYPE
8581                    || TREE_CODE (*type_p) == FIXED_POINT_TYPE
8582                    || TREE_CODE (*type_p) == REAL_TYPE)
8583             {
8584               WALK_SUBTREE (TYPE_MIN_VALUE (*type_p));
8585               WALK_SUBTREE (TYPE_MAX_VALUE (*type_p));
8586             }
8587
8588           WALK_SUBTREE (TYPE_SIZE (*type_p));
8589           WALK_SUBTREE_TAIL (TYPE_SIZE_UNIT (*type_p));
8590         }
8591       /* FALLTHRU */
8592
8593     default:
8594       if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))
8595           || IS_GIMPLE_STMT_CODE_CLASS (TREE_CODE_CLASS (code)))
8596         {
8597           int i, len;
8598
8599           /* Walk over all the sub-trees of this operand.  */
8600           len = TREE_OPERAND_LENGTH (*tp);
8601
8602           /* Go through the subtrees.  We need to do this in forward order so
8603              that the scope of a FOR_EXPR is handled properly.  */
8604           if (len)
8605             {
8606               for (i = 0; i < len - 1; ++i)
8607                 WALK_SUBTREE (GENERIC_TREE_OPERAND (*tp, i));
8608               WALK_SUBTREE_TAIL (GENERIC_TREE_OPERAND (*tp, len - 1));
8609             }
8610         }
8611       /* If this is a type, walk the needed fields in the type.  */
8612       else if (TYPE_P (*tp))
8613         return walk_type_fields (*tp, func, data, pset, lh);
8614       break;
8615     }
8616
8617   /* We didn't find what we were looking for.  */
8618   return NULL_TREE;
8619
8620 #undef WALK_SUBTREE_TAIL
8621 }
8622 #undef WALK_SUBTREE
8623
8624 /* Like walk_tree, but does not walk duplicate nodes more than once.  */
8625
8626 tree
8627 walk_tree_without_duplicates_1 (tree *tp, walk_tree_fn func, void *data,
8628                                 walk_tree_lh lh)
8629 {
8630   tree result;
8631   struct pointer_set_t *pset;
8632
8633   pset = pointer_set_create ();
8634   result = walk_tree_1 (tp, func, data, pset, lh);
8635   pointer_set_destroy (pset);
8636   return result;
8637 }
8638
8639
8640 /* Return true if STMT is an empty statement or contains nothing but
8641    empty statements.  */
8642
8643 bool
8644 empty_body_p (const_tree stmt)
8645 {
8646   const_tree_stmt_iterator i;
8647   const_tree body;
8648
8649   if (IS_EMPTY_STMT (stmt))
8650     return true;
8651   else if (TREE_CODE (stmt) == BIND_EXPR)
8652     body = BIND_EXPR_BODY (stmt);
8653   else if (TREE_CODE (stmt) == STATEMENT_LIST)
8654     body = stmt;
8655   else
8656     return false;
8657
8658   for (i = ctsi_start (body); !ctsi_end_p (i); ctsi_next (&i))
8659     if (!empty_body_p (ctsi_stmt (i)))
8660       return false;
8661
8662   return true;
8663 }
8664
8665 tree *
8666 tree_block (tree t)
8667 {
8668   char const c = TREE_CODE_CLASS (TREE_CODE (t));
8669
8670   if (IS_EXPR_CODE_CLASS (c))
8671     return &t->exp.block;
8672   else if (IS_GIMPLE_STMT_CODE_CLASS (c))
8673     return &GIMPLE_STMT_BLOCK (t);
8674   gcc_unreachable ();
8675   return NULL;
8676 }
8677
8678 tree *
8679 generic_tree_operand (tree node, int i)
8680 {
8681   if (GIMPLE_STMT_P (node))
8682     return &GIMPLE_STMT_OPERAND (node, i);
8683   return &TREE_OPERAND (node, i);
8684 }
8685
8686 tree *
8687 generic_tree_type (tree node)
8688 {
8689   if (GIMPLE_STMT_P (node))
8690     return &void_type_node;
8691   return &TREE_TYPE (node);
8692 }
8693
8694 /* Build and return a TREE_LIST of arguments in the CALL_EXPR exp.
8695    FIXME: don't use this function.  It exists for compatibility with
8696    the old representation of CALL_EXPRs where a list was used to hold the
8697    arguments.  Places that currently extract the arglist from a CALL_EXPR
8698    ought to be rewritten to use the CALL_EXPR itself.  */
8699 tree
8700 call_expr_arglist (tree exp)
8701 {
8702   tree arglist = NULL_TREE;
8703   int i;
8704   for (i = call_expr_nargs (exp) - 1; i >= 0; i--)
8705     arglist = tree_cons (NULL_TREE, CALL_EXPR_ARG (exp, i), arglist);
8706   return arglist;
8707 }
8708
8709 #include "gt-tree.h"