gcc/ipa-prop.h

   1 /* Interprocedural analyses.
   2    Copyright (C) 2005-2014 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef IPA_PROP_H
  21 #define IPA_PROP_H
  22
  23
  24 /* The following definitions and interfaces are used by
  25    interprocedural analyses or parameters.  */
  26
  27 #define IPA_UNDESCRIBED_USE -1
  28
  29 /* ipa-prop.c stuff (ipa-cp, indirect inlining):  */
  30
  31 /* A jump function for a callsite represents the values passed as actual
  32    arguments of the callsite.  They were originally proposed in a paper called
  33    "Interprocedural Constant Propagation", by David Callahan, Keith D Cooper,
  34    Ken Kennedy, Linda Torczon in Comp86, pg 152-161.  There are three main
  35    types of values :
  36
  37    Pass-through - the caller's formal parameter is passed as an actual
  38                   argument, possibly one simple operation performed on it.
  39    Constant     - a constant (is_gimple_ip_invariant)is passed as an actual
  40                   argument.
  41    Unknown      - neither of the above.
  42
  43    IPA_JF_ANCESTOR is a special pass-through jump function, which means that
  44    the result is an address of a part of the object pointed to by the formal
  45    parameter to which the function refers.  It is mainly intended to represent
  46    getting addresses of of ancestor fields in C++
  47    (e.g. &this_1(D)->D.1766.D.1756).  Note that if the original pointer is
  48    NULL, ancestor jump function must behave like a simple pass-through.
  49
  50    Other pass-through functions can either simply pass on an unchanged formal
  51    parameter or can apply one simple binary operation to it (such jump
  52    functions are called polynomial).
  53
  54    Jump functions are computed in ipa-prop.c by function
  55    update_call_notes_after_inlining.  Some information can be lost and jump
  56    functions degraded accordingly when inlining, see
  57    update_call_notes_after_inlining in the same file.  */
  58
  59 enum jump_func_type
  60 {
  61   IPA_JF_UNKNOWN = 0,  /* newly allocated and zeroed jump functions default */
  62   IPA_JF_CONST,             /* represented by field costant */
  63   IPA_JF_PASS_THROUGH,      /* represented by field pass_through */
  64   IPA_JF_ANCESTOR           /* represented by field ancestor */
  65 };
  66
  67 /* Structure holding data required to describe a known type jump function.  */
  68 struct GTY(()) ipa_known_type_data
  69 {
  70   /* Offset of the component of the base_type being described.  */
  71   HOST_WIDE_INT offset;
  72   /* Type of the whole object.  */
  73   tree base_type;
  74   /* Type of the component of the object that is being described.  */
  75   tree component_type;
  76 };
  77
  78 struct ipa_cst_ref_desc;
  79
  80 /* Structure holding data required to describe a constant jump function.  */
  81 struct GTY(()) ipa_constant_data
  82 {
  83   /* THe value of the constant.  */
  84   tree value;
  85   /* Pointer to the structure that describes the reference.  */
  86   struct ipa_cst_ref_desc GTY((skip)) *rdesc;
  87 };
  88
  89 /* Structure holding data required to describe a pass-through jump function.  */
  90
  91 struct GTY(()) ipa_pass_through_data
  92 {
  93   /* If an operation is to be performed on the original parameter, this is the
  94      second (constant) operand.  */
  95   tree operand;
  96   /* Number of the caller's formal parameter being passed.  */
  97   int formal_id;
  98   /* Operation that is performed on the argument before it is passed on.
  99      NOP_EXPR means no operation.  Otherwise oper must be a simple binary
 100      arithmetic operation where the caller's parameter is the first operand and
 101      operand field from this structure is the second one.  */
 102   enum tree_code operation;
 103   /* When the passed value is a pointer, it is set to true only when we are
 104      certain that no write to the object it points to has occurred since the
 105      caller functions started execution, except for changes noted in the
 106      aggregate part of the jump function (see description of
 107      ipa_agg_jump_function).  The flag is used only when the operation is
 108      NOP_EXPR.  */
 109   unsigned agg_preserved : 1;
 110 };
 111
 112 /* Structure holding data required to describe an ancestor pass-through
 113    jump function.  */
 114
 115 struct GTY(()) ipa_ancestor_jf_data
 116 {
 117   /* Offset of the field representing the ancestor.  */
 118   HOST_WIDE_INT offset;
 119   /* Number of the caller's formal parameter being passed.  */
 120   int formal_id;
 121   /* Flag with the same meaning like agg_preserve in ipa_pass_through_data.  */
 122   unsigned agg_preserved : 1;
 123 };
 124
 125 /* An element in an aggegate part of a jump function describing a known value
 126    at a given offset.  When it is part of a pass-through jump function with
 127    agg_preserved set or an ancestor jump function with agg_preserved set, all
 128    unlisted positions are assumed to be preserved but the value can be a type
 129    node, which means that the particular piece (starting at offset and having
 130    the size of the type) is clobbered with an unknown value.  When
 131    agg_preserved is false or the type of the containing jump function is
 132    different, all unlisted parts are assumed to be unknown and all values must
 133    fulfill is_gimple_ip_invariant.  */
 134
 135 struct GTY(()) ipa_agg_jf_item
 136 {
 137   /* The offset at which the known value is located within the aggregate.  */
 138   HOST_WIDE_INT offset;
 139
 140   /* The known constant or type if this is a clobber.  */
 141   tree value;
 142 };
 143
 144
 145 /* Aggregate jump function - i.e. description of contents of aggregates passed
 146    either by reference or value.  */
 147
 148 struct GTY(()) ipa_agg_jump_function
 149 {
 150   /* Description of the individual items.  */
 151   vec<ipa_agg_jf_item, va_gc> *items;
 152   /* True if the data was passed by reference (as opposed to by value). */
 153   bool by_ref;
 154 };
 155
 156 typedef struct ipa_agg_jump_function *ipa_agg_jump_function_p;
 157
 158 /* A jump function for a callsite represents the values passed as actual
 159    arguments of the callsite. See enum jump_func_type for the various
 160    types of jump functions supported.  */
 161 struct GTY (()) ipa_jump_func
 162 {
 163   /* Aggregate contants description.  See struct ipa_agg_jump_function and its
 164      description.  */
 165   struct ipa_agg_jump_function agg;
 166
 167   enum jump_func_type type;
 168   /* Represents a value of a jump function.  pass_through is used only in jump
 169      function context.  constant represents the actual constant in constant jump
 170      functions and member_cst holds constant c++ member functions.  */
 171   union jump_func_value
 172   {
 173     struct ipa_constant_data GTY ((tag ("IPA_JF_CONST"))) constant;
 174     struct ipa_pass_through_data GTY ((tag ("IPA_JF_PASS_THROUGH"))) pass_through;
 175     struct ipa_ancestor_jf_data GTY ((tag ("IPA_JF_ANCESTOR"))) ancestor;
 176   } GTY ((desc ("%1.type"))) value;
 177 };
 178
 179
 180 /* Return the constant stored in a constant jump functin JFUNC.  */
 181
 182 static inline tree
 183 ipa_get_jf_constant (struct ipa_jump_func *jfunc)
 184 {
 185   gcc_checking_assert (jfunc->type == IPA_JF_CONST);
 186   return jfunc->value.constant.value;
 187 }
 188
 189 static inline struct ipa_cst_ref_desc *
 190 ipa_get_jf_constant_rdesc (struct ipa_jump_func *jfunc)
 191 {
 192   gcc_checking_assert (jfunc->type == IPA_JF_CONST);
 193   return jfunc->value.constant.rdesc;
 194 }
 195
 196 /* Return the operand of a pass through jmp function JFUNC.  */
 197
 198 static inline tree
 199 ipa_get_jf_pass_through_operand (struct ipa_jump_func *jfunc)
 200 {
 201   gcc_checking_assert (jfunc->type == IPA_JF_PASS_THROUGH);
 202   return jfunc->value.pass_through.operand;
 203 }
 204
 205 /* Return the number of the caller's formal parameter that a pass through jump
 206    function JFUNC refers to.  */
 207
 208 static inline int
 209 ipa_get_jf_pass_through_formal_id (struct ipa_jump_func *jfunc)
 210 {
 211   gcc_checking_assert (jfunc->type == IPA_JF_PASS_THROUGH);
 212   return jfunc->value.pass_through.formal_id;
 213 }
 214
 215 /* Return operation of a pass through jump function JFUNC.  */
 216
 217 static inline enum tree_code
 218 ipa_get_jf_pass_through_operation (struct ipa_jump_func *jfunc)
 219 {
 220   gcc_checking_assert (jfunc->type == IPA_JF_PASS_THROUGH);
 221   return jfunc->value.pass_through.operation;
 222 }
 223
 224 /* Return the agg_preserved flag of a pass through jump function JFUNC.  */
 225
 226 static inline bool
 227 ipa_get_jf_pass_through_agg_preserved (struct ipa_jump_func *jfunc)
 228 {
 229   gcc_checking_assert (jfunc->type == IPA_JF_PASS_THROUGH);
 230   return jfunc->value.pass_through.agg_preserved;
 231 }
 232
 233 /* Return true if pass through jump function JFUNC preserves type
 234    information.  */
 235
 236 static inline bool
 237 ipa_get_jf_pass_through_type_preserved (struct ipa_jump_func *jfunc)
 238 {
 239   gcc_checking_assert (jfunc->type == IPA_JF_PASS_THROUGH);
 240   return jfunc->value.pass_through.agg_preserved;
 241 }
 242
 243 /* Return the offset of an ancestor jump function JFUNC.  */
 244
 245 static inline HOST_WIDE_INT
 246 ipa_get_jf_ancestor_offset (struct ipa_jump_func *jfunc)
 247 {
 248   gcc_checking_assert (jfunc->type == IPA_JF_ANCESTOR);
 249   return jfunc->value.ancestor.offset;
 250 }
 251
 252 /* Return the number of the caller's formal parameter that an ancestor jump
 253    function JFUNC refers to.  */
 254
 255 static inline int
 256 ipa_get_jf_ancestor_formal_id (struct ipa_jump_func *jfunc)
 257 {
 258   gcc_checking_assert (jfunc->type == IPA_JF_ANCESTOR);
 259   return jfunc->value.ancestor.formal_id;
 260 }
 261
 262 /* Return the agg_preserved flag of an ancestor jump function JFUNC.  */
 263
 264 static inline bool
 265 ipa_get_jf_ancestor_agg_preserved (struct ipa_jump_func *jfunc)
 266 {
 267   gcc_checking_assert (jfunc->type == IPA_JF_ANCESTOR);
 268   return jfunc->value.ancestor.agg_preserved;
 269 }
 270
 271 /* Return true if ancestor jump function JFUNC presrves type information.  */
 272
 273 static inline bool
 274 ipa_get_jf_ancestor_type_preserved (struct ipa_jump_func *jfunc)
 275 {
 276   gcc_checking_assert (jfunc->type == IPA_JF_ANCESTOR);
 277   return jfunc->value.ancestor.agg_preserved;
 278 }
 279
 280 /* Summary describing a single formal parameter.  */
 281
 282 struct ipa_param_descriptor
 283 {
 284   /* PARAM_DECL of this parameter.  */
 285   tree decl;
 286   /* If all uses of the parameter are described by ipa-prop structures, this
 287      says how many there are.  If any use could not be described by means of
 288      ipa-prop structures, this is IPA_UNDESCRIBED_USE.  */
 289   int controlled_uses;
 290   unsigned int move_cost : 31;
 291   /* The parameter is used.  */
 292   unsigned used : 1;
 293 };
 294
 295 /* ipa_node_params stores information related to formal parameters of functions
 296    and some other information for interprocedural passes that operate on
 297    parameters (such as ipa-cp).  */
 298
 299 struct ipa_node_params
 300 {
 301   /* Information about individual formal parameters that are gathered when
 302      summaries are generated. */
 303   vec<ipa_param_descriptor> descriptors;
 304   /* Pointer to an array of structures describing individual formal
 305      parameters.  */
 306   struct ipcp_param_lattices *lattices;
 307   /* Only for versioned nodes this field would not be NULL,
 308      it points to the node that IPA cp cloned from.  */
 309   struct cgraph_node *ipcp_orig_node;
 310   /* If this node is an ipa-cp clone, these are the known constants that
 311      describe what it has been specialized for.  */
 312   vec<tree> known_csts;
 313   /* If this node is an ipa-cp clone, these are the known polymorphic contexts
 314      that describe what it has been specialized for.  */
 315   vec<ipa_polymorphic_call_context> known_contexts;
 316   /* Whether the param uses analysis and jump function computation has already
 317      been performed.  */
 318   unsigned analysis_done : 1;
 319   /* Whether the function is enqueued in ipa-cp propagation stack.  */
 320   unsigned node_enqueued : 1;
 321   /* Whether we should create a specialized version based on values that are
 322      known to be constant in all contexts.  */
 323   unsigned do_clone_for_all_contexts : 1;
 324   /* Set if this is an IPA-CP clone for all contexts.  */
 325   unsigned is_all_contexts_clone : 1;
 326   /* Node has been completely replaced by clones and will be removed after
 327      ipa-cp is finished.  */
 328   unsigned node_dead : 1;
 329 };
 330
 331 /* ipa_node_params access functions.  Please use these to access fields that
 332    are or will be shared among various passes.  */
 333
 334 /* Return the number of formal parameters. */
 335
 336 static inline int
 337 ipa_get_param_count (struct ipa_node_params *info)
 338 {
 339   return info->descriptors.length ();
 340 }
 341
 342 /* Return the declaration of Ith formal parameter of the function corresponding
 343    to INFO.  Note there is no setter function as this array is built just once
 344    using ipa_initialize_node_params. */
 345
 346 static inline tree
 347 ipa_get_param (struct ipa_node_params *info, int i)
 348 {
 349   gcc_checking_assert (!flag_wpa);
 350   return info->descriptors[i].decl;
 351 }
 352
 353 /* Return the move cost of Ith formal parameter of the function corresponding
 354    to INFO.  */
 355
 356 static inline int
 357 ipa_get_param_move_cost (struct ipa_node_params *info, int i)
 358 {
 359   return info->descriptors[i].move_cost;
 360 }
 361
 362 /* Set the used flag corresponding to the Ith formal parameter of the function
 363    associated with INFO to VAL.  */
 364
 365 static inline void
 366 ipa_set_param_used (struct ipa_node_params *info, int i, bool val)
 367 {
 368   info->descriptors[i].used = val;
 369 }
 370
 371 /* Return how many uses described by ipa-prop a parameter has or
 372    IPA_UNDESCRIBED_USE if there is a use that is not described by these
 373    structures.  */
 374 static inline int
 375 ipa_get_controlled_uses (struct ipa_node_params *info, int i)
 376 {
 377   /* FIXME: introducing speuclation causes out of bounds access here.  */
 378   if (info->descriptors.length () > (unsigned)i)
 379     return info->descriptors[i].controlled_uses;
 380   return IPA_UNDESCRIBED_USE;
 381 }
 382
 383 /* Set the controlled counter of a given parameter.  */
 384
 385 static inline void
 386 ipa_set_controlled_uses (struct ipa_node_params *info, int i, int val)
 387 {
 388   info->descriptors[i].controlled_uses = val;
 389 }
 390
 391 /* Return the used flag corresponding to the Ith formal parameter of the
 392    function associated with INFO.  */
 393
 394 static inline bool
 395 ipa_is_param_used (struct ipa_node_params *info, int i)
 396 {
 397   return info->descriptors[i].used;
 398 }
 399
 400 /* Information about replacements done in aggregates for a given node (each
 401    node has its linked list).  */
 402 struct GTY(()) ipa_agg_replacement_value
 403 {
 404   /* Next item in the linked list.  */
 405   struct ipa_agg_replacement_value *next;
 406   /* Offset within the aggregate.  */
 407   HOST_WIDE_INT offset;
 408   /* The constant value.  */
 409   tree value;
 410   /* The paramter index.  */
 411   int index;
 412   /* Whether the value was passed by reference.  */
 413   bool by_ref;
 414 };
 415
 416 typedef struct ipa_agg_replacement_value *ipa_agg_replacement_value_p;
 417
 418 void ipa_set_node_agg_value_chain (struct cgraph_node *node,
 419                                    struct ipa_agg_replacement_value *aggvals);
 420
 421 /* ipa_edge_args stores information related to a callsite and particularly its
 422    arguments.  It can be accessed by the IPA_EDGE_REF macro.  */
 423 struct GTY(()) ipa_edge_args
 424 {
 425   /* Vector of the callsite's jump function of each parameter.  */
 426   vec<ipa_jump_func, va_gc> *jump_functions;
 427   vec<ipa_polymorphic_call_context, va_gc> *polymorphic_call_contexts;
 428 };
 429
 430 /* ipa_edge_args access functions.  Please use these to access fields that
 431    are or will be shared among various passes.  */
 432
 433 /* Return the number of actual arguments. */
 434
 435 static inline int
 436 ipa_get_cs_argument_count (struct ipa_edge_args *args)
 437 {
 438   return vec_safe_length (args->jump_functions);
 439 }
 440
 441 /* Returns a pointer to the jump function for the ith argument.  Please note
 442    there is no setter function as jump functions are all set up in
 443    ipa_compute_jump_functions. */
 444
 445 static inline struct ipa_jump_func *
 446 ipa_get_ith_jump_func (struct ipa_edge_args *args, int i)
 447 {
 448   return &(*args->jump_functions)[i];
 449 }
 450
 451 /* Returns a pointer to the polymorphic call context for the ith argument.
 452    NULL if contexts are not computed.  */
 453 static inline struct ipa_polymorphic_call_context *
 454 ipa_get_ith_polymorhic_call_context (struct ipa_edge_args *args, int i)
 455 {
 456   if (!args->polymorphic_call_contexts)
 457     return NULL;
 458   return &(*args->polymorphic_call_contexts)[i];
 459 }
 460
 461 /* Types of vectors holding the infos.  */
 462
 463 /* Vector where the parameter infos are actually stored. */
 464 extern vec<ipa_node_params> ipa_node_params_vector;
 465 /* Vector of known aggregate values in cloned nodes.  */
 466 extern GTY(()) vec<ipa_agg_replacement_value_p, va_gc> *ipa_node_agg_replacements;
 467 /* Vector where the parameter infos are actually stored. */
 468 extern GTY(()) vec<ipa_edge_args, va_gc> *ipa_edge_args_vector;
 469
 470 /* Return the associated parameter/argument info corresponding to the given
 471    node/edge.  */
 472 #define IPA_NODE_REF(NODE) (&ipa_node_params_vector[(NODE)->uid])
 473 #define IPA_EDGE_REF(EDGE) (&(*ipa_edge_args_vector)[(EDGE)->uid])
 474 /* This macro checks validity of index returned by
 475    ipa_get_param_decl_index function.  */
 476 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1)
 477
 478 /* Creating and freeing ipa_node_params and ipa_edge_args.  */
 479 void ipa_create_all_node_params (void);
 480 void ipa_create_all_edge_args (void);
 481 void ipa_free_edge_args_substructures (struct ipa_edge_args *);
 482 void ipa_free_node_params_substructures (struct ipa_node_params *);
 483 void ipa_free_all_node_params (void);
 484 void ipa_free_all_edge_args (void);
 485 void ipa_free_all_structures_after_ipa_cp (void);
 486 void ipa_free_all_structures_after_iinln (void);
 487 void ipa_register_cgraph_hooks (void);
 488 int count_formal_params (tree fndecl);
 489
 490 /* This function ensures the array of node param infos is big enough to
 491    accommodate a structure for all nodes and reallocates it if not.  */
 492
 493 static inline void
 494 ipa_check_create_node_params (void)
 495 {
 496   if (!ipa_node_params_vector.exists ())
 497     ipa_node_params_vector.create (symtab->cgraph_max_uid);
 498
 499   if (ipa_node_params_vector.length () <= (unsigned) symtab->cgraph_max_uid)
 500     ipa_node_params_vector.safe_grow_cleared (symtab->cgraph_max_uid + 1);
 501 }
 502
 503 /* This function ensures the array of edge arguments infos is big enough to
 504    accommodate a structure for all edges and reallocates it if not.  */
 505
 506 static inline void
 507 ipa_check_create_edge_args (void)
 508 {
 509   if (vec_safe_length (ipa_edge_args_vector)
 510       <= (unsigned) symtab->edges_max_uid)
 511     vec_safe_grow_cleared (ipa_edge_args_vector, symtab->edges_max_uid + 1);
 512 }
 513
 514 /* Returns true if the array of edge infos is large enough to accommodate an
 515    info for EDGE.  The main purpose of this function is that debug dumping
 516    function can check info availability without causing reallocations.  */
 517
 518 static inline bool
 519 ipa_edge_args_info_available_for_edge_p (struct cgraph_edge *edge)
 520 {
 521   return ((unsigned) edge->uid < vec_safe_length (ipa_edge_args_vector));
 522 }
 523
 524 /* Return the aggregate replacements for NODE, if there are any.  */
 525
 526 static inline struct ipa_agg_replacement_value *
 527 ipa_get_agg_replacements_for_node (struct cgraph_node *node)
 528 {
 529   if ((unsigned) node->uid >= vec_safe_length (ipa_node_agg_replacements))
 530     return NULL;
 531   return (*ipa_node_agg_replacements)[node->uid];
 532 }
 533
 534 /* Function formal parameters related computations.  */
 535 void ipa_initialize_node_params (struct cgraph_node *node);
 536 bool ipa_propagate_indirect_call_infos (struct cgraph_edge *cs,
 537                                         vec<cgraph_edge *> *new_edges);
 538
 539 /* Indirect edge and binfo processing.  */
 540 tree ipa_get_indirect_edge_target (struct cgraph_edge *ie,
 541                                    vec<tree> ,
 542                                    vec<ipa_polymorphic_call_context>,
 543                                    vec<ipa_agg_jump_function_p> );
 544 struct cgraph_edge *ipa_make_edge_direct_to_target (struct cgraph_edge *, tree,
 545                                                     bool speculative = false);
 546 tree ipa_binfo_from_known_type_jfunc (struct ipa_jump_func *);
 547 tree ipa_impossible_devirt_target (struct cgraph_edge *, tree);
 548
 549 /* Functions related to both.  */
 550 void ipa_analyze_node (struct cgraph_node *);
 551
 552 /* Aggregate jump function related functions.  */
 553 tree ipa_find_agg_cst_for_param (struct ipa_agg_jump_function *, HOST_WIDE_INT,
 554                                  bool);
 555 bool ipa_load_from_parm_agg (struct ipa_node_params *, gimple, tree, int *,
 556                              HOST_WIDE_INT *, bool *);
 557
 558 /* Debugging interface.  */
 559 void ipa_print_node_params (FILE *, struct cgraph_node *node);
 560 void ipa_print_all_params (FILE *);
 561 void ipa_print_node_jump_functions (FILE *f, struct cgraph_node *node);
 562 void ipa_print_all_jump_functions (FILE * f);
 563 void ipcp_verify_propagated_values (void);
 564
 565 extern alloc_pool ipcp_cst_values_pool;
 566 extern alloc_pool ipcp_poly_ctx_values_pool;
 567 extern alloc_pool ipcp_sources_pool;
 568 extern alloc_pool ipcp_agg_lattice_pool;
 569
 570 /* Operation to be performed for the parameter in ipa_parm_adjustment
 571    below.  */
 572 enum ipa_parm_op {
 573   IPA_PARM_OP_NONE,
 574
 575   /* This describes a brand new parameter.
 576
 577      The field `type' should be set to the new type, `arg_prefix'
 578      should be set to the string prefix for the new DECL_NAME, and
 579      `new_decl' will ultimately hold the newly created argument.  */
 580   IPA_PARM_OP_NEW,
 581
 582   /* This new parameter is an unmodified parameter at index base_index. */
 583   IPA_PARM_OP_COPY,
 584
 585   /* This adjustment describes a parameter that is about to be removed
 586      completely.  Most users will probably need to book keep those so that they
 587      don't leave behinfd any non default def ssa names belonging to them.  */
 588   IPA_PARM_OP_REMOVE
 589 };
 590
 591 /* Structure to describe transformations of formal parameters and actual
 592    arguments.  Each instance describes one new parameter and they are meant to
 593    be stored in a vector.  Additionally, most users will probably want to store
 594    adjustments about parameters that are being removed altogether so that SSA
 595    names belonging to them can be replaced by SSA names of an artificial
 596    variable.  */
 597 struct ipa_parm_adjustment
 598 {
 599   /* The original PARM_DECL itself, helpful for processing of the body of the
 600      function itself.  Intended for traversing function bodies.
 601      ipa_modify_formal_parameters, ipa_modify_call_arguments and
 602      ipa_combine_adjustments ignore this and use base_index.
 603      ipa_modify_formal_parameters actually sets this.  */
 604   tree base;
 605
 606   /* Type of the new parameter.  However, if by_ref is true, the real type will
 607      be a pointer to this type.  */
 608   tree type;
 609
 610   /* Alias refrerence type to be used in MEM_REFs when adjusting caller
 611      arguments.  */
 612   tree alias_ptr_type;
 613
 614   /* The new declaration when creating/replacing a parameter.  Created
 615      by ipa_modify_formal_parameters, useful for functions modifying
 616      the body accordingly.  For brand new arguments, this is the newly
 617      created argument.  */
 618   tree new_decl;
 619
 620   /* New declaration of a substitute variable that we may use to replace all
 621      non-default-def ssa names when a parm decl is going away.  */
 622   tree new_ssa_base;
 623
 624   /* If non-NULL and the original parameter is to be removed (copy_param below
 625      is NULL), this is going to be its nonlocalized vars value.  */
 626   tree nonlocal_value;
 627
 628   /* This holds the prefix to be used for the new DECL_NAME.  */
 629   const char *arg_prefix;
 630
 631   /* Offset into the original parameter (for the cases when the new parameter
 632      is a component of an original one).  */
 633   HOST_WIDE_INT offset;
 634
 635   /* Zero based index of the original parameter this one is based on.  */
 636   int base_index;
 637
 638   /* Whether this parameter is a new parameter, a copy of an old one,
 639      or one about to be removed.  */
 640   enum ipa_parm_op op;
 641
 642   /* The parameter is to be passed by reference.  */
 643   unsigned by_ref : 1;
 644 };
 645
 646 typedef vec<ipa_parm_adjustment> ipa_parm_adjustment_vec;
 647
 648 vec<tree> ipa_get_vector_of_formal_parms (tree fndecl);
 649 vec<tree> ipa_get_vector_of_formal_parm_types (tree fntype);
 650 void ipa_modify_formal_parameters (tree fndecl, ipa_parm_adjustment_vec);
 651 void ipa_modify_call_arguments (struct cgraph_edge *, gcall *,
 652                                 ipa_parm_adjustment_vec);
 653 ipa_parm_adjustment_vec ipa_combine_adjustments (ipa_parm_adjustment_vec,
 654                                                  ipa_parm_adjustment_vec);
 655 void ipa_dump_param_adjustments (FILE *, ipa_parm_adjustment_vec, tree);
 656 void ipa_dump_agg_replacement_values (FILE *f,
 657                                       struct ipa_agg_replacement_value *av);
 658 void ipa_prop_write_jump_functions (void);
 659 void ipa_prop_read_jump_functions (void);
 660 void ipa_prop_write_all_agg_replacement (void);
 661 void ipa_prop_read_all_agg_replacement (void);
 662 void ipa_update_after_lto_read (void);
 663 int ipa_get_param_decl_index (struct ipa_node_params *, tree);
 664 tree ipa_value_from_jfunc (struct ipa_node_params *info,
 665                            struct ipa_jump_func *jfunc);
 666 unsigned int ipcp_transform_function (struct cgraph_node *node);
 667 ipa_polymorphic_call_context ipa_context_from_jfunc (ipa_node_params *,
 668                                                      cgraph_edge *,
 669                                                      int,
 670                                                      ipa_jump_func *);
 671 void ipa_dump_param (FILE *, struct ipa_node_params *info, int i);
 672 bool ipa_modify_expr (tree *, bool, ipa_parm_adjustment_vec);
 673 ipa_parm_adjustment *ipa_get_adjustment_candidate (tree **, bool *,
 674                                                    ipa_parm_adjustment_vec,
 675                                                    bool);
 676
 677
 678 /* From tree-sra.c:  */
 679 tree build_ref_for_offset (location_t, tree, HOST_WIDE_INT, tree,
 680                            gimple_stmt_iterator *, bool);
 681
 682 /* In ipa-cp.c  */
 683 void ipa_cp_c_finalize (void);
 684
 685 #endif /* IPA_PROP_H */