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.  */
  29
  30 /* A jump function for a callsite represents the values passed as actual
  31    arguments of the callsite. There are three main types of values :
  32    Formal - the caller's formal parameter is passed as an actual argument.
  33    Constant - a constant is passed as an actual argument.
  34    Unknown - neither of the above.
  35    Integer and real constants are represented as IPA_CONST.
  36    Finally, IPA_CONST_MEMBER_PTR stands for C++ member pointers constants.  */
  37 enum jump_func_type
  38 {
  39   IPA_UNKNOWN = 0,     /* newly allocated and zeroed jump functions default */
  40   IPA_CONST,
  41   IPA_CONST_MEMBER_PTR,
  42   IPA_PASS_THROUGH
  43 };
  44
  45 /* All formal parameters in the program have a lattice associated with it
  46    computed by the interprocedural stage of IPCP.
  47    There are three main values of the lattice:
  48    IPA_TOP - unknown,
  49    IPA_BOTTOM - non constant,
  50    IPA_CONST_VALUE - simple scalar constant,
  51    Cval of formal f will have a constant value if all callsites to this
  52    function have the same constant value passed to f.
  53    Integer and real constants are represented as IPA_CONST.  */
  54 enum ipa_lattice_type
  55 {
  56   IPA_BOTTOM,
  57   IPA_CONST_VALUE,
  58   IPA_TOP
  59 };
  60
  61 /* Structure holding a C++ member pointer constant.  Holds a pointer to the
  62    method and delta offset.  */
  63 struct ipa_member_ptr_cst
  64 {
  65   tree pfn;
  66   tree delta;
  67 };
  68
  69 /* Represents a value of a jump function.  formal_id is used only in jump
  70    function context and represents pass-through parameter (the formal parameter
  71    of the caller is passed as argument).  constant represents the actual
  72    constant in constant jump functions and member_cst holds constant c++ member
  73    functions.  */
  74 union jump_func_value
  75 {
  76   unsigned int formal_id;
  77   tree constant;
  78   struct ipa_member_ptr_cst member_cst;
  79 };
  80
  81 /* A jump function for a callsite represents the values passed as actual
  82    arguments of the callsite. See enum jump_func_type for the various
  83    types of jump functions supported.  */
  84 struct ipa_jump_func
  85 {
  86   enum jump_func_type type;
  87   union jump_func_value value;
  88 };
  89
  90 /* All formal parameters in the program have a cval computed by
  91    the interprocedural stage of IPCP. See enum ipa_lattice_type for
  92    the various types of lattices supported */
  93 struct ipcp_lattice
  94 {
  95   enum ipa_lattice_type type;
  96   tree constant;
  97 };
  98
  99 /* Represent which DECL tree (or reference to such tree)
 100    will be replaced by another tree while versioning.  */
 101 struct ipa_replace_map
 102 {
 103   /* The tree that will be replaced.  */
 104   tree old_tree;
 105   /* The new (replacing) tree.  */
 106   tree new_tree;
 107   /* True when a substitution should be done, false otherwise.  */
 108   bool replace_p;
 109   /* True when we replace a reference to old_tree.  */
 110   bool ref_p;
 111 };
 112
 113 /* Each instance of the following  structure describes a statement that calls a
 114    function parameter.  Those referring  to statements within the same function
 115    are linked in a list.  */
 116 struct ipa_param_call_note
 117 {
 118   /* Linked list's next */
 119   struct ipa_param_call_note *next;
 120   /* Statement that contains the call to the parameter above.  */
 121   gimple stmt;
 122   /* Index of the parameter that is called.  */
 123   unsigned int formal_id;
 124   /* Expected number of executions: calculated in profile.c.  */
 125   gcov_type count;
 126   /* Expected frequency of executions within the function. see cgraph_edge in
 127      cgraph.h for more on this. */
 128   int frequency;
 129   /* Depth of loop nest, 1 means no loop nest.  */
 130   int loop_nest;
 131   /* Set when we have already found the target to be a compile time constant
 132      and turned this into an edge or when the note was found unusable for some
 133      reason.  */
 134   bool processed;
 135 };
 136
 137 /* Structure describing a single formal parameter.  */
 138 struct ipa_param_descriptor
 139 {
 140   /* IPA-CP lattice.  */
 141   struct ipcp_lattice ipcp_lattice;
 142   /* PARAM_DECL of this parameter.  */
 143   tree decl;
 144   /* Whether the value parameter has been modified within the function.  */
 145   unsigned modified : 1;
 146   /* Whether the parameter has been used as a call destination. */
 147   unsigned called : 1;
 148 };
 149
 150 /* ipa_node_params stores information related to formal parameters of functions
 151    and some other information for interprocedural passes that operate on
 152    parameters (such as ipa-cp).  */
 153 struct ipa_node_params
 154 {
 155   /* Number of formal parameters of this function.  When set to 0,
 156      this function's parameters would not be analyzed by the different
 157      stages of IPA CP.  */
 158   int param_count;
 159   /* Pointer to an array of structures describing individual formal
 160      parameters.  */
 161   struct ipa_param_descriptor *params;
 162   /* List of structures enumerating calls to a formal parameter.  */
 163   struct ipa_param_call_note *param_calls;
 164   /* Only for versioned nodes this field would not be NULL,
 165      it points to the node that IPA cp cloned from.  */
 166   struct cgraph_node *ipcp_orig_node;
 167   /* Meaningful only for original functions.  Expresses the
 168      ratio between the direct calls and sum of all invocations of
 169      this function (given by profiling info).  It is used to calculate
 170      the profiling information of the original function and the versioned
 171      one.  */
 172   gcov_type count_scale;
 173
 174   /* Whether this function is called with variable number of actual
 175      arguments.  */
 176   unsigned called_with_var_arguments : 1;
 177   /* Whether the modification analysis has already been performed. */
 178   unsigned modification_analysis_done : 1;
 179   /* Whether the param uses analysis has already been performed.  */
 180   unsigned uses_analysis_done : 1;
 181 };
 182
 183 /* ipa_node_params access functions.  Please use these to access fields that
 184    are or will be shared among various passes.  */
 185
 186 /* Set the number of formal parameters. */
 187
 188 static inline void
 189 ipa_set_param_count (struct ipa_node_params *info, int count)
 190 {
 191   info->param_count = count;
 192 }
 193
 194 /* Return the number of formal parameters. */
 195
 196 static inline int
 197 ipa_get_param_count (struct ipa_node_params *info)
 198 {
 199   return info->param_count;
 200 }
 201
 202 /* Return the declaration of Ith formal parameter of the function corresponding
 203    to INFO.  Note there is no setter function as this array is built just once
 204    using ipa_initialize_node_params. */
 205
 206 static inline tree
 207 ipa_get_param (struct ipa_node_params *info, int i)
 208 {
 209   return info->params[i].decl;
 210 }
 211
 212 /* Return the modification flag corresponding to the Ith formal parameter of
 213    the function associated with INFO.  Note that there is no setter method as
 214    the goal is to set all flags when building the array in
 215    ipa_detect_param_modifications.  */
 216
 217 static inline bool
 218 ipa_is_param_modified (struct ipa_node_params *info, int i)
 219 {
 220   return info->params[i].modified;
 221 }
 222
 223 /* Return the called flag corresponding to the Ith formal parameter of the
 224    function associated with INFO.  Note that there is no setter method as the
 225    goal is to set all flags when building the array in
 226    ipa_detect_called_params.  */
 227
 228 static inline bool
 229 ipa_is_param_called (struct ipa_node_params *info, int i)
 230 {
 231   return info->params[i].called;
 232 }
 233
 234 /* Flag this node as having callers with variable number of arguments.  */
 235
 236 static inline void
 237 ipa_set_called_with_variable_arg (struct ipa_node_params *info)
 238 {
 239   info->called_with_var_arguments = 1;
 240 }
 241
 242 /* Have we detected this node was called with variable number of arguments? */
 243
 244 static inline bool
 245 ipa_is_called_with_var_arguments (struct ipa_node_params *info)
 246 {
 247   return info->called_with_var_arguments;
 248 }
 249
 250
 251
 252 /* ipa_edge_args stores information related to a callsite and particularly
 253    its arguments. It is pointed to by a field in the
 254    callsite's corresponding cgraph_edge.  */
 255 struct ipa_edge_args
 256 {
 257   /* Number of actual arguments in this callsite.  When set to 0,
 258      this callsite's parameters would not be analyzed by the different
 259      stages of IPA CP.  */
 260   int argument_count;
 261   /* Array of the callsite's jump function of each parameter.  */
 262   struct ipa_jump_func *jump_functions;
 263 };
 264
 265 /* ipa_edge_args access functions.  Please use these to access fields that
 266    are or will be shared among various passes.  */
 267
 268 /* Set the number of actual arguments. */
 269
 270 static inline void
 271 ipa_set_cs_argument_count (struct ipa_edge_args *args, int count)
 272 {
 273   args->argument_count = count;
 274 }
 275
 276 /* Return the number of actual arguments. */
 277
 278 static inline int
 279 ipa_get_cs_argument_count (struct ipa_edge_args *args)
 280 {
 281   return args->argument_count;
 282 }
 283
 284 /* Returns a pointer to the jump function for the ith argument.  Please note
 285    there is no setter function as jump functions are all set up in
 286    ipa_compute_jump_functions. */
 287
 288 static inline struct ipa_jump_func *
 289 ipa_get_ith_jump_func (struct ipa_edge_args *args, int i)
 290 {
 291   return &args->jump_functions[i];
 292 }
 293
 294 /* Vectors need to have typedefs of structures.  */
 295 typedef struct ipa_node_params ipa_node_params_t;
 296 typedef struct ipa_edge_args ipa_edge_args_t;
 297
 298 /* Types of vectors holding the infos.  */
 299 DEF_VEC_O (ipa_node_params_t);
 300 DEF_VEC_ALLOC_O (ipa_node_params_t, heap);
 301 DEF_VEC_O (ipa_edge_args_t);
 302 DEF_VEC_ALLOC_O (ipa_edge_args_t, heap);
 303
 304 /* Vector where the parameter infos are actually stored. */
 305 extern VEC (ipa_node_params_t, heap) *ipa_node_params_vector;
 306 /* Vector where the parameter infos are actually stored. */
 307 extern VEC (ipa_edge_args_t, heap) *ipa_edge_args_vector;
 308
 309 /* Return the associated parameter/argument info corresponding to the given
 310    node/edge.  */
 311 #define IPA_NODE_REF(NODE) (VEC_index (ipa_node_params_t, \
 312                                        ipa_node_params_vector, (NODE)->uid))
 313 #define IPA_EDGE_REF(EDGE) (VEC_index (ipa_edge_args_t, \
 314                                        ipa_edge_args_vector, (EDGE)->uid))
 315 /* This macro checks validity of index returned by
 316    ipa_get_param_decl_index function.  */
 317 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1)
 318
 319 /* Creating and freeing ipa_node_params and ipa_edge_args.  */
 320 void ipa_create_all_node_params (void);
 321 void ipa_create_all_edge_args (void);
 322 void ipa_free_edge_args_substructures (struct ipa_edge_args *);
 323 void ipa_free_node_params_substructures (struct ipa_node_params *);
 324 void ipa_free_all_node_params (void);
 325 void ipa_free_all_edge_args (void);
 326 void free_all_ipa_structures_after_ipa_cp (void);
 327 void free_all_ipa_structures_after_iinln (void);
 328 void ipa_register_cgraph_hooks (void);
 329
 330 /* This function ensures the array of node param infos is big enough to
 331    accommodate a structure for all nodes and reallocates it if not.  */
 332
 333 static inline void
 334 ipa_check_create_node_params (void)
 335 {
 336   if (!ipa_node_params_vector)
 337     ipa_node_params_vector = VEC_alloc (ipa_node_params_t, heap,
 338                                         cgraph_max_uid);
 339
 340   if (VEC_length (ipa_node_params_t, ipa_node_params_vector)
 341       <= (unsigned) cgraph_max_uid)
 342     VEC_safe_grow_cleared (ipa_node_params_t, heap,
 343                            ipa_node_params_vector, cgraph_max_uid + 1);
 344 }
 345
 346 /* This function ensures the array of edge arguments infos is big enough to
 347    accommodate a structure for all edges and reallocates it if not.  */
 348
 349 static inline void
 350 ipa_check_create_edge_args (void)
 351 {
 352   if (!ipa_edge_args_vector)
 353     ipa_edge_args_vector = VEC_alloc (ipa_edge_args_t, heap,
 354                                       cgraph_edge_max_uid);
 355
 356   if (VEC_length (ipa_edge_args_t, ipa_edge_args_vector)
 357       <=  (unsigned) cgraph_edge_max_uid)
 358     VEC_safe_grow_cleared (ipa_edge_args_t, heap, ipa_edge_args_vector,
 359                            cgraph_edge_max_uid + 1);
 360 }
 361
 362 /* Returns true if the array of edge infos is large enough to accommodate an
 363    info for EDGE.  The main purpose of this function is that debug dumping
 364    function can check info availability without causing reallocations.  */
 365
 366 static inline bool
 367 ipa_edge_args_info_available_for_edge_p (struct cgraph_edge *edge)
 368 {
 369   return ((unsigned) edge->uid < VEC_length (ipa_edge_args_t,
 370                                              ipa_edge_args_vector));
 371 }
 372
 373 /* A function list element.  It is used to create a temporary worklist used in
 374    the propagation stage of IPCP. (can be used for more IPA optimizations)  */
 375 struct ipa_func_list
 376 {
 377   struct cgraph_node *node;
 378   struct ipa_func_list *next;
 379 };
 380
 381 /* ipa_func_list interface.  */
 382 struct ipa_func_list *ipa_init_func_list (void);
 383 void ipa_push_func_to_list (struct ipa_func_list **, struct cgraph_node *);
 384 struct cgraph_node *ipa_pop_func_from_list (struct ipa_func_list **);
 385
 386 /* Callsite related calculations.  */
 387 void ipa_compute_jump_functions (struct cgraph_edge *);
 388 void ipa_count_arguments (struct cgraph_edge *);
 389
 390 /* Function formal parameters related computations.  */
 391 void ipa_initialize_node_params (struct cgraph_node *node);
 392 void ipa_detect_param_modifications (struct cgraph_node *);
 393 void ipa_analyze_params_uses (struct cgraph_node *);
 394 bool ipa_propagate_indirect_call_infos (struct cgraph_edge *cs,
 395                                         VEC (cgraph_edge_p, heap) **new_edges);
 396
 397 /* Debugging interface.  */
 398 void ipa_print_node_params (FILE *, struct cgraph_node *node);
 399 void ipa_print_all_params (FILE *);
 400 void ipa_print_node_jump_functions (FILE *f, struct cgraph_node *node);
 401 void ipa_print_all_jump_functions (FILE * f);
 402
 403 #endif /* IPA_PROP_H */