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