gcc/ipa-prop.h

   1 /* Interprocedural analyses.
   2    Copyright (C) 2005, 2007, 2008 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 #include "tree.h"
  24 #include "vec.h"
  25 #include "cgraph.h"
  26
  27 /* The following definitions and interfaces are used by
  28    interprocedural analyses or parameters.  */
  29
  30 /* ipa-prop.c stuff (ipa-cp, indirect inlining):  */
  31
  32 /* A jump function for a callsite represents the values passed as actual
  33    arguments of the callsite. There are three main types of values :
  34
  35    Pass-through - the caller's formal parameter is passed as an actual
  36                   argument, possibly one simple operation performed on it.
  37    Constant     - a constant (is_gimple_ip_invariant)is passed as an actual
  38                   argument.
  39    Unknown      - neither of the above.
  40
  41    IPA_JF_CONST_MEMBER_PTR stands for C++ member pointers, other constants are
  42    represented with IPA_JF_CONST.
  43
  44    In addition to "ordinary" pass through functions represented by
  45    IPA_JF_PASS_THROUGH, IPA_JF_ANCESTOR represents getting addresses of of
  46    ancestor fields in C++ (e.g. &this_1(D)->D.1766.D.1756).  */
  47 enum jump_func_type
  48 {
  49   IPA_JF_UNKNOWN = 0,  /* newly allocated and zeroed jump functions default */
  50   IPA_JF_CONST,
  51   IPA_JF_CONST_MEMBER_PTR,
  52   IPA_JF_PASS_THROUGH,
  53   IPA_JF_ANCESTOR
  54 };
  55
  56 /* All formal parameters in the program have a lattice associated with it
  57    computed by the interprocedural stage of IPCP.
  58    There are three main values of the lattice:
  59    IPA_TOP - unknown,
  60    IPA_BOTTOM - non constant,
  61    IPA_CONST_VALUE - simple scalar constant,
  62    Cval of formal f will have a constant value if all callsites to this
  63    function have the same constant value passed to f.
  64    Integer and real constants are represented as IPA_CONST_VALUE.  */
  65 enum ipa_lattice_type
  66 {
  67   IPA_BOTTOM,
  68   IPA_CONST_VALUE,
  69   IPA_TOP
  70 };
  71
  72
  73 /* Structure holding data required to describe a pass-through jump function.  */
  74
  75 struct ipa_pass_through_data
  76 {
  77   /* If an operation is to be performed on the original parameter, this is the
  78      second (constant) operand.  */
  79   tree operand;
  80   /* Number of the caller's formal parameter being passed.  */
  81   int formal_id;
  82   /* Operation that is performed on the argument before it is passed on.
  83      NOP_EXPR means no operation.  Otherwise oper must be a simple binary
  84      arithmetic operation where the caller's parameter is the first operand and
  85      operand field from this structure is the second one.  */
  86   enum tree_code operation;
  87 };
  88
  89 /* Structure holding data required to describe and ancestor pass throu
  90    funkci.  */
  91
  92 struct ipa_ancestor_jf_data
  93 {
  94   /* Offset of the field representing the ancestor.  */
  95   HOST_WIDE_INT offset;
  96   /* TYpe of the result.  */
  97   tree type;
  98   /* Number of the caller's formal parameter being passed.  */
  99   int formal_id;
 100 };
 101
 102 /* Structure holding a C++ member pointer constant.  Holds a pointer to the
 103    method and delta offset.  */
 104 struct ipa_member_ptr_cst
 105 {
 106   tree pfn;
 107   tree delta;
 108 };
 109
 110 /* Represents a value of a jump function.  pass_through is used only in jump
 111    function context.  constant represents the actual constant in constant jump
 112    functions and member_cst holds constant c++ member functions.  */
 113 union jump_func_value
 114 {
 115   tree constant;
 116   struct ipa_pass_through_data pass_through;
 117   struct ipa_ancestor_jf_data ancestor;
 118   struct ipa_member_ptr_cst member_cst;
 119 };
 120
 121 /* A jump function for a callsite represents the values passed as actual
 122    arguments of the callsite. See enum jump_func_type for the various
 123    types of jump functions supported.  */
 124 struct ipa_jump_func
 125 {
 126   enum jump_func_type type;
 127   union jump_func_value value;
 128 };
 129
 130 /* All formal parameters in the program have a cval computed by
 131    the interprocedural stage of IPCP. See enum ipa_lattice_type for
 132    the various types of lattices supported */
 133 struct ipcp_lattice
 134 {
 135   enum ipa_lattice_type type;
 136   tree constant;
 137 };
 138
 139 /* Each instance of the following  structure describes a statement that calls a
 140    function parameter.  Those referring  to statements within the same function
 141    are linked in a list.  */
 142 struct ipa_param_call_note
 143 {
 144   /* Linked list's next */
 145   struct ipa_param_call_note *next;
 146   /* Statement that contains the call to the parameter above.  */
 147   gimple stmt;
 148   /* Index of the parameter that is called.  */
 149   int formal_id;
 150   /* Expected number of executions: calculated in profile.c.  */
 151   gcov_type count;
 152   /* Expected frequency of executions within the function. see cgraph_edge in
 153      cgraph.h for more on this. */
 154   int frequency;
 155   /* Depth of loop nest, 1 means no loop nest.  */
 156   int loop_nest;
 157   /* Set when we have already found the target to be a compile time constant
 158      and turned this into an edge or when the note was found unusable for some
 159      reason.  */
 160   bool processed;
 161 };
 162
 163 /* Structure describing a single formal parameter.  */
 164 struct ipa_param_descriptor
 165 {
 166   /* IPA-CP lattice.  */
 167   struct ipcp_lattice ipcp_lattice;
 168   /* PARAM_DECL of this parameter.  */
 169   tree decl;
 170   /* Whether the value parameter has been modified within the function.  */
 171   unsigned modified : 1;
 172   /* Whether the parameter has been used as a call destination. */
 173   unsigned called : 1;
 174 };
 175
 176 /* ipa_node_params stores information related to formal parameters of functions
 177    and some other information for interprocedural passes that operate on
 178    parameters (such as ipa-cp).  */
 179 struct ipa_node_params
 180 {
 181   /* Number of formal parameters of this function.  When set to 0,
 182      this function's parameters would not be analyzed by the different
 183      stages of IPA CP.  */
 184   int param_count;
 185   /* Pointer to an array of structures describing individual formal
 186      parameters.  */
 187   struct ipa_param_descriptor *params;
 188   /* List of structures enumerating calls to a formal parameter.  */
 189   struct ipa_param_call_note *param_calls;
 190   /* Only for versioned nodes this field would not be NULL,
 191      it points to the node that IPA cp cloned from.  */
 192   struct cgraph_node *ipcp_orig_node;
 193   /* Meaningful only for original functions.  Expresses the
 194      ratio between the direct calls and sum of all invocations of
 195      this function (given by profiling info).  It is used to calculate
 196      the profiling information of the original function and the versioned
 197      one.  */
 198   gcov_type count_scale;
 199
 200   /* Whether this function is called with variable number of actual
 201      arguments.  */
 202   unsigned called_with_var_arguments : 1;
 203   /* Whether the modification analysis has already been performed. */
 204   unsigned modification_analysis_done : 1;
 205   /* Whether the param uses analysis has already been performed.  */
 206   unsigned uses_analysis_done : 1;
 207   /* Whether the function is enqueued in an ipa_func_list.  */
 208   unsigned node_enqueued : 1;
 209 };
 210
 211 /* ipa_node_params access functions.  Please use these to access fields that
 212    are or will be shared among various passes.  */
 213
 214 /* Set the number of formal parameters. */
 215
 216 static inline void
 217 ipa_set_param_count (struct ipa_node_params *info, int count)
 218 {
 219   info->param_count = count;
 220 }
 221
 222 /* Return the number of formal parameters. */
 223
 224 static inline int
 225 ipa_get_param_count (struct ipa_node_params *info)
 226 {
 227   return info->param_count;
 228 }
 229
 230 /* Return the declaration of Ith formal parameter of the function corresponding
 231    to INFO.  Note there is no setter function as this array is built just once
 232    using ipa_initialize_node_params. */
 233
 234 static inline tree
 235 ipa_get_param (struct ipa_node_params *info, int i)
 236 {
 237   return info->params[i].decl;
 238 }
 239
 240 /* Return the modification flag corresponding to the Ith formal parameter of
 241    the function associated with INFO.  Note that there is no setter method as
 242    the goal is to set all flags when building the array in
 243    ipa_detect_param_modifications.  */
 244
 245 static inline bool
 246 ipa_is_param_modified (struct ipa_node_params *info, int i)
 247 {
 248   return info->params[i].modified;
 249 }
 250
 251 /* Return the called flag corresponding to the Ith formal parameter of the
 252    function associated with INFO.  Note that there is no setter method as the
 253    goal is to set all flags when building the array in
 254    ipa_detect_called_params.  */
 255
 256 static inline bool
 257 ipa_is_param_called (struct ipa_node_params *info, int i)
 258 {
 259   return info->params[i].called;
 260 }
 261
 262 /* Flag this node as having callers with variable number of arguments.  */
 263
 264 static inline void
 265 ipa_set_called_with_variable_arg (struct ipa_node_params *info)
 266 {
 267   info->called_with_var_arguments = 1;
 268 }
 269
 270 /* Have we detected this node was called with variable number of arguments? */
 271
 272 static inline bool
 273 ipa_is_called_with_var_arguments (struct ipa_node_params *info)
 274 {
 275   return info->called_with_var_arguments;
 276 }
 277
 278
 279
 280 /* ipa_edge_args stores information related to a callsite and particularly
 281    its arguments. It is pointed to by a field in the
 282    callsite's corresponding cgraph_edge.  */
 283 struct ipa_edge_args
 284 {
 285   /* Number of actual arguments in this callsite.  When set to 0,
 286      this callsite's parameters would not be analyzed by the different
 287      stages of IPA CP.  */
 288   int argument_count;
 289   /* Array of the callsite's jump function of each parameter.  */
 290   struct ipa_jump_func *jump_functions;
 291 };
 292
 293 /* ipa_edge_args access functions.  Please use these to access fields that
 294    are or will be shared among various passes.  */
 295
 296 /* Set the number of actual arguments. */
 297
 298 static inline void
 299 ipa_set_cs_argument_count (struct ipa_edge_args *args, int count)
 300 {
 301   args->argument_count = count;
 302 }
 303
 304 /* Return the number of actual arguments. */
 305
 306 static inline int
 307 ipa_get_cs_argument_count (struct ipa_edge_args *args)
 308 {
 309   return args->argument_count;
 310 }
 311
 312 /* Returns a pointer to the jump function for the ith argument.  Please note
 313    there is no setter function as jump functions are all set up in
 314    ipa_compute_jump_functions. */
 315
 316 static inline struct ipa_jump_func *
 317 ipa_get_ith_jump_func (struct ipa_edge_args *args, int i)
 318 {
 319   return &args->jump_functions[i];
 320 }
 321
 322 /* Vectors need to have typedefs of structures.  */
 323 typedef struct ipa_node_params ipa_node_params_t;
 324 typedef struct ipa_edge_args ipa_edge_args_t;
 325
 326 /* Types of vectors holding the infos.  */
 327 DEF_VEC_O (ipa_node_params_t);
 328 DEF_VEC_ALLOC_O (ipa_node_params_t, heap);
 329 DEF_VEC_O (ipa_edge_args_t);
 330 DEF_VEC_ALLOC_O (ipa_edge_args_t, heap);
 331
 332 /* Vector where the parameter infos are actually stored. */
 333 extern VEC (ipa_node_params_t, heap) *ipa_node_params_vector;
 334 /* Vector where the parameter infos are actually stored. */
 335 extern VEC (ipa_edge_args_t, heap) *ipa_edge_args_vector;
 336
 337 /* Return the associated parameter/argument info corresponding to the given
 338    node/edge.  */
 339 #define IPA_NODE_REF(NODE) (VEC_index (ipa_node_params_t, \
 340                                        ipa_node_params_vector, (NODE)->uid))
 341 #define IPA_EDGE_REF(EDGE) (VEC_index (ipa_edge_args_t, \
 342                                        ipa_edge_args_vector, (EDGE)->uid))
 343 /* This macro checks validity of index returned by
 344    ipa_get_param_decl_index function.  */
 345 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1)
 346
 347 /* Creating and freeing ipa_node_params and ipa_edge_args.  */
 348 void ipa_create_all_node_params (void);
 349 void ipa_create_all_edge_args (void);
 350 void ipa_free_edge_args_substructures (struct ipa_edge_args *);
 351 void ipa_free_node_params_substructures (struct ipa_node_params *);
 352 void ipa_free_all_node_params (void);
 353 void ipa_free_all_edge_args (void);
 354 void free_all_ipa_structures_after_ipa_cp (void);
 355 void free_all_ipa_structures_after_iinln (void);
 356 void ipa_register_cgraph_hooks (void);
 357
 358 /* This function ensures the array of node param infos is big enough to
 359    accommodate a structure for all nodes and reallocates it if not.  */
 360
 361 static inline void
 362 ipa_check_create_node_params (void)
 363 {
 364   if (!ipa_node_params_vector)
 365     ipa_node_params_vector = VEC_alloc (ipa_node_params_t, heap,
 366                                         cgraph_max_uid);
 367
 368   if (VEC_length (ipa_node_params_t, ipa_node_params_vector)
 369       <= (unsigned) cgraph_max_uid)
 370     VEC_safe_grow_cleared (ipa_node_params_t, heap,
 371                            ipa_node_params_vector, cgraph_max_uid + 1);
 372 }
 373
 374 /* This function ensures the array of edge arguments infos is big enough to
 375    accommodate a structure for all edges and reallocates it if not.  */
 376
 377 static inline void
 378 ipa_check_create_edge_args (void)
 379 {
 380   if (!ipa_edge_args_vector)
 381     ipa_edge_args_vector = VEC_alloc (ipa_edge_args_t, heap,
 382                                       cgraph_edge_max_uid);
 383
 384   if (VEC_length (ipa_edge_args_t, ipa_edge_args_vector)
 385       <=  (unsigned) cgraph_edge_max_uid)
 386     VEC_safe_grow_cleared (ipa_edge_args_t, heap, ipa_edge_args_vector,
 387                            cgraph_edge_max_uid + 1);
 388 }
 389
 390 /* Returns true if the array of edge infos is large enough to accommodate an
 391    info for EDGE.  The main purpose of this function is that debug dumping
 392    function can check info availability without causing reallocations.  */
 393
 394 static inline bool
 395 ipa_edge_args_info_available_for_edge_p (struct cgraph_edge *edge)
 396 {
 397   return ((unsigned) edge->uid < VEC_length (ipa_edge_args_t,
 398                                              ipa_edge_args_vector));
 399 }
 400
 401 /* A function list element.  It is used to create a temporary worklist used in
 402    the propagation stage of IPCP. (can be used for more IPA optimizations)  */
 403 struct ipa_func_list
 404 {
 405   struct cgraph_node *node;
 406   struct ipa_func_list *next;
 407 };
 408
 409 /* ipa_func_list interface.  */
 410 struct ipa_func_list *ipa_init_func_list (void);
 411 void ipa_push_func_to_list_1 (struct ipa_func_list **, struct cgraph_node *,
 412                               struct ipa_node_params *);
 413 struct cgraph_node *ipa_pop_func_from_list (struct ipa_func_list **);
 414
 415 /* Add cgraph NODE to the worklist WL if it is not already in one.  */
 416
 417 static inline void
 418 ipa_push_func_to_list (struct ipa_func_list **wl, struct cgraph_node *node)
 419 {
 420   struct ipa_node_params *info = IPA_NODE_REF (node);
 421
 422   if (!info->node_enqueued)
 423     ipa_push_func_to_list_1 (wl, node, info);
 424 }
 425
 426 /* Callsite related calculations.  */
 427 void ipa_compute_jump_functions (struct cgraph_edge *);
 428 void ipa_count_arguments (struct cgraph_edge *);
 429
 430 /* Function formal parameters related computations.  */
 431 void ipa_initialize_node_params (struct cgraph_node *node);
 432 void ipa_detect_param_modifications (struct cgraph_node *);
 433 void ipa_analyze_params_uses (struct cgraph_node *);
 434 bool ipa_propagate_indirect_call_infos (struct cgraph_edge *cs,
 435                                         VEC (cgraph_edge_p, heap) **new_edges);
 436
 437 /* Debugging interface.  */
 438 void ipa_print_node_params (FILE *, struct cgraph_node *node);
 439 void ipa_print_all_params (FILE *);
 440 void ipa_print_node_jump_functions (FILE *f, struct cgraph_node *node);
 441 void ipa_print_all_jump_functions (FILE * f);
 442
 443 /* Structure to describe transformations of formal parameters and actual
 444    arguments.  Each instance describes one new parameter and they are meant to
 445    be stored in a vector.  Additionally, most users will probably want to store
 446    adjustments about parameters that are being removed altogether so that SSA
 447    names belonging to them can be replaced by SSA names of an artificial
 448    variable.  */
 449 struct ipa_parm_adjustment
 450 {
 451   /* The original PARM_DECL itself, helpful for processing of the body of the
 452      function itself.  Intended for traversing function bodies.
 453      ipa_modify_formal_parameters, ipa_modify_call_arguments and
 454      ipa_combine_adjustments ignore this and use base_index.
 455      ipa_modify_formal_parameters actually sets this.  */
 456   tree base;
 457
 458   /* Type of the new parameter.  However, if by_ref is true, the real type will
 459      be a pointer to this type.  */
 460   tree type;
 461
 462   /* The new declaration when creating/replacing a parameter.  Created by
 463      ipa_modify_formal_parameters, useful for functions modifying the body
 464      accordingly. */
 465   tree reduction;
 466
 467   /* New declaration of a substitute variable that we may use to replace all
 468      non-default-def ssa names when a parm decl is going away.  */
 469   tree new_ssa_base;
 470
 471   /* If non-NULL and the original parameter is to be removed (copy_param below
 472      is NULL), this is going to be its nonlocalized vars value.  */
 473   tree nonlocal_value;
 474
 475   /* Offset into the original parameter (for the cases when the new parameter
 476      is a component of an original one).  */
 477   HOST_WIDE_INT offset;
 478
 479   /* Zero based index of the original parameter this one is based on.  (ATM
 480      there is no way to insert a new parameter out of the blue because there is
 481      no need but if it arises the code can be easily exteded to do so.)  */
 482   int base_index;
 483
 484   /* This new parameter is an unmodified parameter at index base_index. */
 485   unsigned copy_param : 1;
 486
 487   /* This adjustment describes a parameter that is about to be removed
 488      completely.  Most users will probably need to book keep those so that they
 489      don't leave behinfd any non default def ssa names belonging to them.  */
 490   unsigned remove_param : 1;
 491
 492   /* The parameter is to be passed by reference.  */
 493   unsigned by_ref : 1;
 494 };
 495
 496 typedef struct ipa_parm_adjustment ipa_parm_adjustment_t;
 497 DEF_VEC_O (ipa_parm_adjustment_t);
 498 DEF_VEC_ALLOC_O (ipa_parm_adjustment_t, heap);
 499
 500 typedef VEC (ipa_parm_adjustment_t, heap) *ipa_parm_adjustment_vec;
 501
 502 VEC(tree, heap) *ipa_get_vector_of_formal_parms (tree fndecl);
 503 void ipa_modify_formal_parameters (tree fndecl, ipa_parm_adjustment_vec,
 504                                    const char *);
 505 void ipa_modify_call_arguments (struct cgraph_edge *, gimple,
 506                                 ipa_parm_adjustment_vec);
 507 ipa_parm_adjustment_vec ipa_combine_adjustments (ipa_parm_adjustment_vec,
 508                                                  ipa_parm_adjustment_vec);
 509 void ipa_dump_param_adjustments (FILE *, ipa_parm_adjustment_vec, tree);
 510
 511 /* From tree-sra.c:  */
 512 bool build_ref_for_offset (tree *, tree, HOST_WIDE_INT, tree, bool);
 513
 514 #endif /* IPA_PROP_H */