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    Formal - the caller's formal parameter is passed as an actual argument.
  35    Constant - a constant is passed as an actual argument.
  36    Unknown - neither of the above.
  37    Integer and real constants are represented as IPA_JF_CONST.
  38    Finally, IPA_JF_CONST_MEMBER_PTR stands for C++ member pointers
  39    constants.  */
  40 enum jump_func_type
  41 {
  42   IPA_JF_UNKNOWN = 0,  /* newly allocated and zeroed jump functions default */
  43   IPA_JF_CONST,
  44   IPA_JF_CONST_MEMBER_PTR,
  45   IPA_JF_PASS_THROUGH
  46 };
  47
  48 /* All formal parameters in the program have a lattice associated with it
  49    computed by the interprocedural stage of IPCP.
  50    There are three main values of the lattice:
  51    IPA_TOP - unknown,
  52    IPA_BOTTOM - non constant,
  53    IPA_CONST_VALUE - simple scalar constant,
  54    Cval of formal f will have a constant value if all callsites to this
  55    function have the same constant value passed to f.
  56    Integer and real constants are represented as IPA_CONST_VALUE.  */
  57 enum ipa_lattice_type
  58 {
  59   IPA_BOTTOM,
  60   IPA_CONST_VALUE,
  61   IPA_TOP
  62 };
  63
  64 /* Structure holding a C++ member pointer constant.  Holds a pointer to the
  65    method and delta offset.  */
  66 struct ipa_member_ptr_cst
  67 {
  68   tree pfn;
  69   tree delta;
  70 };
  71
  72 /* Represents a value of a jump function.  formal_id is used only in jump
  73    function context and represents pass-through parameter (the formal parameter
  74    of the caller is passed as argument).  constant represents the actual
  75    constant in constant jump functions and member_cst holds constant c++ member
  76    functions.  */
  77 union jump_func_value
  78 {
  79   unsigned int formal_id;
  80   tree constant;
  81   struct ipa_member_ptr_cst member_cst;
  82 };
  83
  84 /* A jump function for a callsite represents the values passed as actual
  85    arguments of the callsite. See enum jump_func_type for the various
  86    types of jump functions supported.  */
  87 struct ipa_jump_func
  88 {
  89   enum jump_func_type type;
  90   union jump_func_value value;
  91 };
  92
  93 /* All formal parameters in the program have a cval computed by
  94    the interprocedural stage of IPCP. See enum ipa_lattice_type for
  95    the various types of lattices supported */
  96 struct ipcp_lattice
  97 {
  98   enum ipa_lattice_type type;
  99   tree constant;
 100 };
 101
 102 /* Represent which DECL tree (or reference to such tree)
 103    will be replaced by another tree while versioning.  */
 104 struct ipa_replace_map
 105 {
 106   /* The tree that will be replaced.  */
 107   tree old_tree;
 108   /* The new (replacing) tree.  */
 109   tree new_tree;
 110   /* True when a substitution should be done, false otherwise.  */
 111   bool replace_p;
 112   /* True when we replace a reference to old_tree.  */
 113   bool ref_p;
 114 };
 115
 116 /* Each instance of the following  structure describes a statement that calls a
 117    function parameter.  Those referring  to statements within the same function
 118    are linked in a list.  */
 119 struct ipa_param_call_note
 120 {
 121   /* Linked list's next */
 122   struct ipa_param_call_note *next;
 123   /* Statement that contains the call to the parameter above.  */
 124   gimple stmt;
 125   /* Index of the parameter that is called.  */
 126   unsigned int formal_id;
 127   /* Expected number of executions: calculated in profile.c.  */
 128   gcov_type count;
 129   /* Expected frequency of executions within the function. see cgraph_edge in
 130      cgraph.h for more on this. */
 131   int frequency;
 132   /* Depth of loop nest, 1 means no loop nest.  */
 133   int loop_nest;
 134   /* Set when we have already found the target to be a compile time constant
 135      and turned this into an edge or when the note was found unusable for some
 136      reason.  */
 137   bool processed;
 138 };
 139
 140 /* Structure describing a single formal parameter.  */
 141 struct ipa_param_descriptor
 142 {
 143   /* IPA-CP lattice.  */
 144   struct ipcp_lattice ipcp_lattice;
 145   /* PARAM_DECL of this parameter.  */
 146   tree decl;
 147   /* Whether the value parameter has been modified within the function.  */
 148   unsigned modified : 1;
 149   /* Whether the parameter has been used as a call destination. */
 150   unsigned called : 1;
 151 };
 152
 153 /* ipa_node_params stores information related to formal parameters of functions
 154    and some other information for interprocedural passes that operate on
 155    parameters (such as ipa-cp).  */
 156 struct ipa_node_params
 157 {
 158   /* Number of formal parameters of this function.  When set to 0,
 159      this function's parameters would not be analyzed by the different
 160      stages of IPA CP.  */
 161   int param_count;
 162   /* Pointer to an array of structures describing individual formal
 163      parameters.  */
 164   struct ipa_param_descriptor *params;
 165   /* List of structures enumerating calls to a formal parameter.  */
 166   struct ipa_param_call_note *param_calls;
 167   /* Only for versioned nodes this field would not be NULL,
 168      it points to the node that IPA cp cloned from.  */
 169   struct cgraph_node *ipcp_orig_node;
 170   /* Meaningful only for original functions.  Expresses the
 171      ratio between the direct calls and sum of all invocations of
 172      this function (given by profiling info).  It is used to calculate
 173      the profiling information of the original function and the versioned
 174      one.  */
 175   gcov_type count_scale;
 176
 177   /* Whether this function is called with variable number of actual
 178      arguments.  */
 179   unsigned called_with_var_arguments : 1;
 180   /* Whether the modification analysis has already been performed. */
 181   unsigned modification_analysis_done : 1;
 182   /* Whether the param uses analysis has already been performed.  */
 183   unsigned uses_analysis_done : 1;
 184 };
 185
 186 /* ipa_node_params access functions.  Please use these to access fields that
 187    are or will be shared among various passes.  */
 188
 189 /* Set the number of formal parameters. */
 190
 191 static inline void
 192 ipa_set_param_count (struct ipa_node_params *info, int count)
 193 {
 194   info->param_count = count;
 195 }
 196
 197 /* Return the number of formal parameters. */
 198
 199 static inline int
 200 ipa_get_param_count (struct ipa_node_params *info)
 201 {
 202   return info->param_count;
 203 }
 204
 205 /* Return the declaration of Ith formal parameter of the function corresponding
 206    to INFO.  Note there is no setter function as this array is built just once
 207    using ipa_initialize_node_params. */
 208
 209 static inline tree
 210 ipa_get_param (struct ipa_node_params *info, int i)
 211 {
 212   return info->params[i].decl;
 213 }
 214
 215 /* Return the modification flag corresponding to the Ith formal parameter of
 216    the function associated with INFO.  Note that there is no setter method as
 217    the goal is to set all flags when building the array in
 218    ipa_detect_param_modifications.  */
 219
 220 static inline bool
 221 ipa_is_param_modified (struct ipa_node_params *info, int i)
 222 {
 223   return info->params[i].modified;
 224 }
 225
 226 /* Return the called flag corresponding to the Ith formal parameter of the
 227    function associated with INFO.  Note that there is no setter method as the
 228    goal is to set all flags when building the array in
 229    ipa_detect_called_params.  */
 230
 231 static inline bool
 232 ipa_is_param_called (struct ipa_node_params *info, int i)
 233 {
 234   return info->params[i].called;
 235 }
 236
 237 /* Flag this node as having callers with variable number of arguments.  */
 238
 239 static inline void
 240 ipa_set_called_with_variable_arg (struct ipa_node_params *info)
 241 {
 242   info->called_with_var_arguments = 1;
 243 }
 244
 245 /* Have we detected this node was called with variable number of arguments? */
 246
 247 static inline bool
 248 ipa_is_called_with_var_arguments (struct ipa_node_params *info)
 249 {
 250   return info->called_with_var_arguments;
 251 }
 252
 253
 254
 255 /* ipa_edge_args stores information related to a callsite and particularly
 256    its arguments. It is pointed to by a field in the
 257    callsite's corresponding cgraph_edge.  */
 258 struct ipa_edge_args
 259 {
 260   /* Number of actual arguments in this callsite.  When set to 0,
 261      this callsite's parameters would not be analyzed by the different
 262      stages of IPA CP.  */
 263   int argument_count;
 264   /* Array of the callsite's jump function of each parameter.  */
 265   struct ipa_jump_func *jump_functions;
 266 };
 267
 268 /* ipa_edge_args access functions.  Please use these to access fields that
 269    are or will be shared among various passes.  */
 270
 271 /* Set the number of actual arguments. */
 272
 273 static inline void
 274 ipa_set_cs_argument_count (struct ipa_edge_args *args, int count)
 275 {
 276   args->argument_count = count;
 277 }
 278
 279 /* Return the number of actual arguments. */
 280
 281 static inline int
 282 ipa_get_cs_argument_count (struct ipa_edge_args *args)
 283 {
 284   return args->argument_count;
 285 }
 286
 287 /* Returns a pointer to the jump function for the ith argument.  Please note
 288    there is no setter function as jump functions are all set up in
 289    ipa_compute_jump_functions. */
 290
 291 static inline struct ipa_jump_func *
 292 ipa_get_ith_jump_func (struct ipa_edge_args *args, int i)
 293 {
 294   return &args->jump_functions[i];
 295 }
 296
 297 /* Vectors need to have typedefs of structures.  */
 298 typedef struct ipa_node_params ipa_node_params_t;
 299 typedef struct ipa_edge_args ipa_edge_args_t;
 300
 301 /* Types of vectors holding the infos.  */
 302 DEF_VEC_O (ipa_node_params_t);
 303 DEF_VEC_ALLOC_O (ipa_node_params_t, heap);
 304 DEF_VEC_O (ipa_edge_args_t);
 305 DEF_VEC_ALLOC_O (ipa_edge_args_t, heap);
 306
 307 /* Vector where the parameter infos are actually stored. */
 308 extern VEC (ipa_node_params_t, heap) *ipa_node_params_vector;
 309 /* Vector where the parameter infos are actually stored. */
 310 extern VEC (ipa_edge_args_t, heap) *ipa_edge_args_vector;
 311
 312 /* Return the associated parameter/argument info corresponding to the given
 313    node/edge.  */
 314 #define IPA_NODE_REF(NODE) (VEC_index (ipa_node_params_t, \
 315                                        ipa_node_params_vector, (NODE)->uid))
 316 #define IPA_EDGE_REF(EDGE) (VEC_index (ipa_edge_args_t, \
 317                                        ipa_edge_args_vector, (EDGE)->uid))
 318 /* This macro checks validity of index returned by
 319    ipa_get_param_decl_index function.  */
 320 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1)
 321
 322 /* Creating and freeing ipa_node_params and ipa_edge_args.  */
 323 void ipa_create_all_node_params (void);
 324 void ipa_create_all_edge_args (void);
 325 void ipa_free_edge_args_substructures (struct ipa_edge_args *);
 326 void ipa_free_node_params_substructures (struct ipa_node_params *);
 327 void ipa_free_all_node_params (void);
 328 void ipa_free_all_edge_args (void);
 329 void free_all_ipa_structures_after_ipa_cp (void);
 330 void free_all_ipa_structures_after_iinln (void);
 331 void ipa_register_cgraph_hooks (void);
 332
 333 /* This function ensures the array of node param infos is big enough to
 334    accommodate a structure for all nodes and reallocates it if not.  */
 335
 336 static inline void
 337 ipa_check_create_node_params (void)
 338 {
 339   if (!ipa_node_params_vector)
 340     ipa_node_params_vector = VEC_alloc (ipa_node_params_t, heap,
 341                                         cgraph_max_uid);
 342
 343   if (VEC_length (ipa_node_params_t, ipa_node_params_vector)
 344       <= (unsigned) cgraph_max_uid)
 345     VEC_safe_grow_cleared (ipa_node_params_t, heap,
 346                            ipa_node_params_vector, cgraph_max_uid + 1);
 347 }
 348
 349 /* This function ensures the array of edge arguments infos is big enough to
 350    accommodate a structure for all edges and reallocates it if not.  */
 351
 352 static inline void
 353 ipa_check_create_edge_args (void)
 354 {
 355   if (!ipa_edge_args_vector)
 356     ipa_edge_args_vector = VEC_alloc (ipa_edge_args_t, heap,
 357                                       cgraph_edge_max_uid);
 358
 359   if (VEC_length (ipa_edge_args_t, ipa_edge_args_vector)
 360       <=  (unsigned) cgraph_edge_max_uid)
 361     VEC_safe_grow_cleared (ipa_edge_args_t, heap, ipa_edge_args_vector,
 362                            cgraph_edge_max_uid + 1);
 363 }
 364
 365 /* Returns true if the array of edge infos is large enough to accommodate an
 366    info for EDGE.  The main purpose of this function is that debug dumping
 367    function can check info availability without causing reallocations.  */
 368
 369 static inline bool
 370 ipa_edge_args_info_available_for_edge_p (struct cgraph_edge *edge)
 371 {
 372   return ((unsigned) edge->uid < VEC_length (ipa_edge_args_t,
 373                                              ipa_edge_args_vector));
 374 }
 375
 376 /* A function list element.  It is used to create a temporary worklist used in
 377    the propagation stage of IPCP. (can be used for more IPA optimizations)  */
 378 struct ipa_func_list
 379 {
 380   struct cgraph_node *node;
 381   struct ipa_func_list *next;
 382 };
 383
 384 /* ipa_func_list interface.  */
 385 struct ipa_func_list *ipa_init_func_list (void);
 386 void ipa_push_func_to_list (struct ipa_func_list **, struct cgraph_node *);
 387 struct cgraph_node *ipa_pop_func_from_list (struct ipa_func_list **);
 388
 389 /* Callsite related calculations.  */
 390 void ipa_compute_jump_functions (struct cgraph_edge *);
 391 void ipa_count_arguments (struct cgraph_edge *);
 392
 393 /* Function formal parameters related computations.  */
 394 void ipa_initialize_node_params (struct cgraph_node *node);
 395 void ipa_detect_param_modifications (struct cgraph_node *);
 396 void ipa_analyze_params_uses (struct cgraph_node *);
 397 bool ipa_propagate_indirect_call_infos (struct cgraph_edge *cs,
 398                                         VEC (cgraph_edge_p, heap) **new_edges);
 399
 400 /* Debugging interface.  */
 401 void ipa_print_node_params (FILE *, struct cgraph_node *node);
 402 void ipa_print_all_params (FILE *);
 403 void ipa_print_node_jump_functions (FILE *f, struct cgraph_node *node);
 404 void ipa_print_all_jump_functions (FILE * f);
 405
 406 #endif /* IPA_PROP_H */