gcc/ipa-prop.h

   1 /* Interprocedural analyses.
   2    Copyright (C) 2005, 2007, 2008, 2009
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef IPA_PROP_H
  22 #define IPA_PROP_H
  23
  24 #include "tree.h"
  25 #include "vec.h"
  26 #include "cgraph.h"
  27
  28 /* The following definitions and interfaces are used by
  29    interprocedural analyses or parameters.  */
  30
  31 /* ipa-prop.c stuff (ipa-cp, indirect inlining):  */
  32
  33 /* A jump function for a callsite represents the values passed as actual
  34    arguments of the callsite. There are three main types of values :
  35
  36    Pass-through - the caller's formal parameter is passed as an actual
  37                   argument, possibly one simple operation performed on it.
  38    Constant     - a constant (is_gimple_ip_invariant)is passed as an actual
  39                   argument.
  40    Unknown      - neither of the above.
  41
  42    IPA_JF_CONST_MEMBER_PTR stands for C++ member pointers, other constants are
  43    represented with IPA_JF_CONST.
  44
  45    In addition to "ordinary" pass through functions represented by
  46    IPA_JF_PASS_THROUGH, IPA_JF_ANCESTOR represents getting addresses of of
  47    ancestor fields in C++ (e.g. &this_1(D)->D.1766.D.1756).  */
  48 enum jump_func_type
  49 {
  50   IPA_JF_UNKNOWN = 0,  /* newly allocated and zeroed jump functions default */
  51   IPA_JF_CONST,
  52   IPA_JF_CONST_MEMBER_PTR,
  53   IPA_JF_PASS_THROUGH,
  54   IPA_JF_ANCESTOR
  55 };
  56
  57 /* All formal parameters in the program have a lattice associated with it
  58    computed by the interprocedural stage of IPCP.
  59    There are three main values of the lattice:
  60    IPA_TOP - unknown,
  61    IPA_BOTTOM - non constant,
  62    IPA_CONST_VALUE - simple scalar constant,
  63    Cval of formal f will have a constant value if all callsites to this
  64    function have the same constant value passed to f.
  65    Integer and real constants are represented as IPA_CONST_VALUE.  */
  66 enum ipa_lattice_type
  67 {
  68   IPA_BOTTOM,
  69   IPA_CONST_VALUE,
  70   IPA_TOP
  71 };
  72
  73
  74 /* Structure holding data required to describe a pass-through jump function.  */
  75
  76 struct GTY(()) ipa_pass_through_data
  77 {
  78   /* If an operation is to be performed on the original parameter, this is the
  79      second (constant) operand.  */
  80   tree operand;
  81   /* Number of the caller's formal parameter being passed.  */
  82   int formal_id;
  83   /* Operation that is performed on the argument before it is passed on.
  84      NOP_EXPR means no operation.  Otherwise oper must be a simple binary
  85      arithmetic operation where the caller's parameter is the first operand and
  86      operand field from this structure is the second one.  */
  87   enum tree_code operation;
  88 };
  89
  90 /* Structure holding data required to describe and ancestor pass throu
  91    funkci.  */
  92
  93 struct GTY(()) ipa_ancestor_jf_data
  94 {
  95   /* Offset of the field representing the ancestor.  */
  96   HOST_WIDE_INT offset;
  97   /* TYpe of the result.  */
  98   tree type;
  99   /* Number of the caller's formal parameter being passed.  */
 100   int formal_id;
 101 };
 102
 103 /* Structure holding a C++ member pointer constant.  Holds a pointer to the
 104    method and delta offset.  */
 105 struct GTY(()) ipa_member_ptr_cst
 106 {
 107   tree pfn;
 108   tree delta;
 109 };
 110
 111 /* A jump function for a callsite represents the values passed as actual
 112    arguments of the callsite. See enum jump_func_type for the various
 113    types of jump functions supported.  */
 114 struct GTY (()) ipa_jump_func
 115 {
 116   enum jump_func_type type;
 117   /* Represents a value of a jump function.  pass_through is used only in jump
 118      function context.  constant represents the actual constant in constant jump
 119      functions and member_cst holds constant c++ member functions.  */
 120   union jump_func_value
 121   {
 122     tree GTY ((tag ("IPA_JF_CONST"))) constant;
 123     struct ipa_pass_through_data GTY ((tag ("IPA_JF_PASS_THROUGH"))) pass_through;
 124     struct ipa_ancestor_jf_data GTY ((tag ("IPA_JF_ANCESTOR"))) ancestor;
 125     struct ipa_member_ptr_cst GTY ((tag ("IPA_JF_CONST_MEMBER_PTR"))) member_cst;
 126   } GTY ((desc ("%1.type"))) value;
 127 };
 128
 129 /* All formal parameters in the program have a cval computed by
 130    the interprocedural stage of IPCP. See enum ipa_lattice_type for
 131    the various types of lattices supported */
 132 struct ipcp_lattice
 133 {
 134   enum ipa_lattice_type type;
 135   tree constant;
 136 };
 137
 138 /* Structure describing a single formal parameter.  */
 139 struct ipa_param_descriptor
 140 {
 141   /* IPA-CP lattice.  */
 142   struct ipcp_lattice ipcp_lattice;
 143   /* PARAM_DECL of this parameter.  */
 144   tree decl;
 145   /* Whether the value parameter has been modified within the function.  */
 146   unsigned modified : 1;
 147 };
 148
 149 /* ipa_node_params stores information related to formal parameters of functions
 150    and some other information for interprocedural passes that operate on
 151    parameters (such as ipa-cp).  */
 152 struct ipa_node_params
 153 {
 154   /* Number of formal parameters of this function.  When set to 0,
 155      this function's parameters would not be analyzed by the different
 156      stages of IPA CP.  */
 157   int param_count;
 158   /* Whether this function is called with variable number of actual
 159      arguments.  */
 160   unsigned called_with_var_arguments : 1;
 161   /* Whether the modification analysis has already been performed. */
 162   unsigned modification_analysis_done : 1;
 163   /* Whether the param uses analysis has already been performed.  */
 164   unsigned uses_analysis_done : 1;
 165   /* Whether the function is enqueued in an ipa_func_list.  */
 166   unsigned node_enqueued : 1;
 167   /* Pointer to an array of structures describing individual formal
 168      parameters.  */
 169   struct ipa_param_descriptor *params;
 170   /* Only for versioned nodes this field would not be NULL,
 171      it points to the node that IPA cp cloned from.  */
 172   struct cgraph_node *ipcp_orig_node;
 173   /* Meaningful only for original functions.  Expresses the
 174      ratio between the direct calls and sum of all invocations of
 175      this function (given by profiling info).  It is used to calculate
 176      the profiling information of the original function and the versioned
 177      one.  */
 178   gcov_type count_scale;
 179 };
 180
 181 /* ipa_node_params access functions.  Please use these to access fields that
 182    are or will be shared among various passes.  */
 183
 184 /* Set the number of formal parameters. */
 185
 186 static inline void
 187 ipa_set_param_count (struct ipa_node_params *info, int count)
 188 {
 189   info->param_count = count;
 190 }
 191
 192 /* Return the number of formal parameters. */
 193
 194 static inline int
 195 ipa_get_param_count (struct ipa_node_params *info)
 196 {
 197   return info->param_count;
 198 }
 199
 200 /* Return the declaration of Ith formal parameter of the function corresponding
 201    to INFO.  Note there is no setter function as this array is built just once
 202    using ipa_initialize_node_params. */
 203
 204 static inline tree
 205 ipa_get_param (struct ipa_node_params *info, int i)
 206 {
 207   return info->params[i].decl;
 208 }
 209
 210 /* Return the modification flag corresponding to the Ith formal parameter of
 211    the function associated with INFO.  Note that there is no setter method as
 212    the goal is to set all flags when building the array in
 213    ipa_detect_param_modifications.  */
 214
 215 static inline bool
 216 ipa_is_param_modified (struct ipa_node_params *info, int i)
 217 {
 218   return info->params[i].modified;
 219 }
 220
 221 /* Flag this node as having callers with variable number of arguments.  */
 222
 223 static inline void
 224 ipa_set_called_with_variable_arg (struct ipa_node_params *info)
 225 {
 226   info->called_with_var_arguments = 1;
 227 }
 228
 229 /* Have we detected this node was called with variable number of arguments? */
 230
 231 static inline bool
 232 ipa_is_called_with_var_arguments (struct ipa_node_params *info)
 233 {
 234   return info->called_with_var_arguments;
 235 }
 236
 237
 238
 239 /* ipa_edge_args stores information related to a callsite and particularly
 240    its arguments. It is pointed to by a field in the
 241    callsite's corresponding cgraph_edge.  */
 242 typedef struct GTY(()) ipa_edge_args
 243 {
 244   /* Number of actual arguments in this callsite.  When set to 0,
 245      this callsite's parameters would not be analyzed by the different
 246      stages of IPA CP.  */
 247   int argument_count;
 248   /* Array of the callsite's jump function of each parameter.  */
 249   struct ipa_jump_func GTY ((length ("%h.argument_count"))) *jump_functions;
 250 } ipa_edge_args_t;
 251
 252 /* ipa_edge_args access functions.  Please use these to access fields that
 253    are or will be shared among various passes.  */
 254
 255 /* Set the number of actual arguments. */
 256
 257 static inline void
 258 ipa_set_cs_argument_count (struct ipa_edge_args *args, int count)
 259 {
 260   args->argument_count = count;
 261 }
 262
 263 /* Return the number of actual arguments. */
 264
 265 static inline int
 266 ipa_get_cs_argument_count (struct ipa_edge_args *args)
 267 {
 268   return args->argument_count;
 269 }
 270
 271 /* Returns a pointer to the jump function for the ith argument.  Please note
 272    there is no setter function as jump functions are all set up in
 273    ipa_compute_jump_functions. */
 274
 275 static inline struct ipa_jump_func *
 276 ipa_get_ith_jump_func (struct ipa_edge_args *args, int i)
 277 {
 278   return &args->jump_functions[i];
 279 }
 280
 281 /* Vectors need to have typedefs of structures.  */
 282 typedef struct ipa_node_params ipa_node_params_t;
 283
 284 /* Types of vectors holding the infos.  */
 285 DEF_VEC_O (ipa_node_params_t);
 286 DEF_VEC_ALLOC_O (ipa_node_params_t, heap);
 287 DEF_VEC_O (ipa_edge_args_t);
 288 DEF_VEC_ALLOC_O (ipa_edge_args_t, gc);
 289
 290 /* Vector where the parameter infos are actually stored. */
 291 extern VEC (ipa_node_params_t, heap) *ipa_node_params_vector;
 292 /* Vector where the parameter infos are actually stored. */
 293 extern GTY(()) VEC (ipa_edge_args_t, gc) *ipa_edge_args_vector;
 294
 295 /* Return the associated parameter/argument info corresponding to the given
 296    node/edge.  */
 297 #define IPA_NODE_REF(NODE) (VEC_index (ipa_node_params_t, \
 298                                        ipa_node_params_vector, (NODE)->uid))
 299 #define IPA_EDGE_REF(EDGE) (VEC_index (ipa_edge_args_t, \
 300                                        ipa_edge_args_vector, (EDGE)->uid))
 301 /* This macro checks validity of index returned by
 302    ipa_get_param_decl_index function.  */
 303 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1)
 304
 305 /* Creating and freeing ipa_node_params and ipa_edge_args.  */
 306 void ipa_create_all_node_params (void);
 307 void ipa_create_all_edge_args (void);
 308 void ipa_free_edge_args_substructures (struct ipa_edge_args *);
 309 void ipa_free_node_params_substructures (struct ipa_node_params *);
 310 void ipa_free_all_node_params (void);
 311 void ipa_free_all_edge_args (void);
 312 void ipa_create_all_structures_for_iinln (void);
 313 void ipa_free_all_structures_after_ipa_cp (void);
 314 void ipa_free_all_structures_after_iinln (void);
 315 void ipa_register_cgraph_hooks (void);
 316
 317 /* This function ensures the array of node param infos is big enough to
 318    accommodate a structure for all nodes and reallocates it if not.  */
 319
 320 static inline void
 321 ipa_check_create_node_params (void)
 322 {
 323   if (!ipa_node_params_vector)
 324     ipa_node_params_vector = VEC_alloc (ipa_node_params_t, heap,
 325                                         cgraph_max_uid);
 326
 327   if (VEC_length (ipa_node_params_t, ipa_node_params_vector)
 328       <= (unsigned) cgraph_max_uid)
 329     VEC_safe_grow_cleared (ipa_node_params_t, heap,
 330                            ipa_node_params_vector, cgraph_max_uid + 1);
 331 }
 332
 333 /* This function ensures the array of edge arguments infos is big enough to
 334    accommodate a structure for all edges and reallocates it if not.  */
 335
 336 static inline void
 337 ipa_check_create_edge_args (void)
 338 {
 339   if (!ipa_edge_args_vector)
 340     ipa_edge_args_vector = VEC_alloc (ipa_edge_args_t, gc,
 341                                       cgraph_edge_max_uid);
 342
 343   if (VEC_length (ipa_edge_args_t, ipa_edge_args_vector)
 344       <=  (unsigned) cgraph_edge_max_uid)
 345     VEC_safe_grow_cleared (ipa_edge_args_t, gc, ipa_edge_args_vector,
 346                            cgraph_edge_max_uid + 1);
 347 }
 348
 349 /* Returns true if the array of edge infos is large enough to accommodate an
 350    info for EDGE.  The main purpose of this function is that debug dumping
 351    function can check info availability without causing reallocations.  */
 352
 353 static inline bool
 354 ipa_edge_args_info_available_for_edge_p (struct cgraph_edge *edge)
 355 {
 356   return ((unsigned) edge->uid < VEC_length (ipa_edge_args_t,
 357                                              ipa_edge_args_vector));
 358 }
 359
 360 /* A function list element.  It is used to create a temporary worklist used in
 361    the propagation stage of IPCP. (can be used for more IPA optimizations)  */
 362 struct ipa_func_list
 363 {
 364   struct cgraph_node *node;
 365   struct ipa_func_list *next;
 366 };
 367
 368 /* ipa_func_list interface.  */
 369 struct ipa_func_list *ipa_init_func_list (void);
 370 void ipa_push_func_to_list_1 (struct ipa_func_list **, struct cgraph_node *,
 371                               struct ipa_node_params *);
 372 struct cgraph_node *ipa_pop_func_from_list (struct ipa_func_list **);
 373
 374 /* Add cgraph NODE to the worklist WL if it is not already in one.  */
 375
 376 static inline void
 377 ipa_push_func_to_list (struct ipa_func_list **wl, struct cgraph_node *node)
 378 {
 379   struct ipa_node_params *info = IPA_NODE_REF (node);
 380
 381   if (!info->node_enqueued)
 382     ipa_push_func_to_list_1 (wl, node, info);
 383 }
 384
 385 /* Callsite related calculations.  */
 386 void ipa_compute_jump_functions (struct cgraph_edge *);
 387 void ipa_count_arguments (struct cgraph_edge *);
 388
 389 /* Function formal parameters related computations.  */
 390 void ipa_initialize_node_params (struct cgraph_node *node);
 391 void ipa_detect_param_modifications (struct cgraph_node *);
 392 void ipa_analyze_params_uses (struct cgraph_node *);
 393 bool ipa_propagate_indirect_call_infos (struct cgraph_edge *cs,
 394                                         VEC (cgraph_edge_p, heap) **new_edges);
 395
 396 /* Debugging interface.  */
 397 void ipa_print_node_params (FILE *, struct cgraph_node *node);
 398 void ipa_print_all_params (FILE *);
 399 void ipa_print_node_jump_functions (FILE *f, struct cgraph_node *node);
 400 void ipa_print_all_jump_functions (FILE * f);
 401
 402 /* Structure to describe transformations of formal parameters and actual
 403    arguments.  Each instance describes one new parameter and they are meant to
 404    be stored in a vector.  Additionally, most users will probably want to store
 405    adjustments about parameters that are being removed altogether so that SSA
 406    names belonging to them can be replaced by SSA names of an artificial
 407    variable.  */
 408 struct ipa_parm_adjustment
 409 {
 410   /* The original PARM_DECL itself, helpful for processing of the body of the
 411      function itself.  Intended for traversing function bodies.
 412      ipa_modify_formal_parameters, ipa_modify_call_arguments and
 413      ipa_combine_adjustments ignore this and use base_index.
 414      ipa_modify_formal_parameters actually sets this.  */
 415   tree base;
 416
 417   /* Type of the new parameter.  However, if by_ref is true, the real type will
 418      be a pointer to this type.  */
 419   tree type;
 420
 421   /* The new declaration when creating/replacing a parameter.  Created by
 422      ipa_modify_formal_parameters, useful for functions modifying the body
 423      accordingly. */
 424   tree reduction;
 425
 426   /* New declaration of a substitute variable that we may use to replace all
 427      non-default-def ssa names when a parm decl is going away.  */
 428   tree new_ssa_base;
 429
 430   /* If non-NULL and the original parameter is to be removed (copy_param below
 431      is NULL), this is going to be its nonlocalized vars value.  */
 432   tree nonlocal_value;
 433
 434   /* Offset into the original parameter (for the cases when the new parameter
 435      is a component of an original one).  */
 436   HOST_WIDE_INT offset;
 437
 438   /* Zero based index of the original parameter this one is based on.  (ATM
 439      there is no way to insert a new parameter out of the blue because there is
 440      no need but if it arises the code can be easily exteded to do so.)  */
 441   int base_index;
 442
 443   /* This new parameter is an unmodified parameter at index base_index. */
 444   unsigned copy_param : 1;
 445
 446   /* This adjustment describes a parameter that is about to be removed
 447      completely.  Most users will probably need to book keep those so that they
 448      don't leave behinfd any non default def ssa names belonging to them.  */
 449   unsigned remove_param : 1;
 450
 451   /* The parameter is to be passed by reference.  */
 452   unsigned by_ref : 1;
 453 };
 454
 455 typedef struct ipa_parm_adjustment ipa_parm_adjustment_t;
 456 DEF_VEC_O (ipa_parm_adjustment_t);
 457 DEF_VEC_ALLOC_O (ipa_parm_adjustment_t, heap);
 458
 459 typedef VEC (ipa_parm_adjustment_t, heap) *ipa_parm_adjustment_vec;
 460
 461 VEC(tree, heap) *ipa_get_vector_of_formal_parms (tree fndecl);
 462 void ipa_modify_formal_parameters (tree fndecl, ipa_parm_adjustment_vec,
 463                                    const char *);
 464 void ipa_modify_call_arguments (struct cgraph_edge *, gimple,
 465                                 ipa_parm_adjustment_vec);
 466 ipa_parm_adjustment_vec ipa_combine_adjustments (ipa_parm_adjustment_vec,
 467                                                  ipa_parm_adjustment_vec);
 468 void ipa_dump_param_adjustments (FILE *, ipa_parm_adjustment_vec, tree);
 469
 470 void ipa_prop_write_jump_functions (cgraph_node_set set);
 471 void ipa_prop_read_jump_functions (void);
 472 void ipa_update_after_lto_read (void);
 473 void lto_ipa_fixup_call_notes (struct cgraph_node *, gimple *);
 474
 475 /* From tree-sra.c:  */
 476 bool build_ref_for_offset (tree *, tree, HOST_WIDE_INT, tree, bool);
 477
 478 #endif /* IPA_PROP_H */