1 /* Interprocedural analyses. 2 Copyright (C) 2005, 2007, 2008, 2009, 2010 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 #include "gimple.h" 28 #include "alloc-pool.h" 29 30 /* The following definitions and interfaces are used by 31 interprocedural analyses or parameters. */ 32 33 /* ipa-prop.c stuff (ipa-cp, indirect inlining): */ 34 35 /* A jump function for a callsite represents the values passed as actual 36 arguments of the callsite. They were originally proposed in a paper called 37 "Interprocedural Constant Propagation", by David Callahan, Keith D Cooper, 38 Ken Kennedy, Linda Torczon in Comp86, pg 152-161. There are three main 39 types of values : 40 41 Pass-through - the caller's formal parameter is passed as an actual 42 argument, possibly one simple operation performed on it. 43 Constant - a constant (is_gimple_ip_invariant)is passed as an actual 44 argument. 45 Unknown - neither of the above. 46 47 IPA_JF_CONST_MEMBER_PTR stands for C++ member pointers, it is a special 48 constant in this regard because it is in fact a structure consisting of two 49 values. Other constants are represented with IPA_JF_CONST. 50 51 IPA_JF_ANCESTOR is a special pass-through jump function, which means that 52 the result is an address of a part of the object pointed to by the formal 53 parameter to which the function refers. It is mainly intended to represent 54 getting addresses of of ancestor fields in C++ 55 (e.g. &this_1(D)->D.1766.D.1756). Note that if the original pointer is 56 NULL, ancestor jump function must behave like a simple pass-through. 57 58 Other pass-through functions can either simply pass on an unchanged formal 59 parameter or can apply one simple binary operation to it (such jump 60 functions are called polynomial). 61 62 IPA_JF_KNOWN_TYPE is a special type of an "unknown" function that applies 63 only to pointer parameters. It means that even though we cannot prove that 64 the passed value is an interprocedural constant, we still know the exact 65 type of the containing object which may be valuable for devirtualization. 66 67 Jump functions are computed in ipa-prop.c by function 68 update_call_notes_after_inlining. Some information can be lost and jump 69 functions degraded accordingly when inlining, see 70 update_call_notes_after_inlining in the same file. */ 71 72 enum jump_func_type 73 { 74 IPA_JF_UNKNOWN = 0, /* newly allocated and zeroed jump functions default */ 75 IPA_JF_KNOWN_TYPE, /* represented by field known_type */ 76 IPA_JF_CONST, /* represented by field costant */ 77 IPA_JF_CONST_MEMBER_PTR, /* represented by field member_cst */ 78 IPA_JF_PASS_THROUGH, /* represented by field pass_through */ 79 IPA_JF_ANCESTOR /* represented by field ancestor */ 80 }; 81 82 /* Structure holding data required to describe a known type jump function. */ 83 struct GTY(()) ipa_known_type_data 84 { 85 /* Offset of the component of the base_type being described. */ 86 HOST_WIDE_INT offset; 87 /* Type of the whole object. */ 88 tree base_type; 89 /* Type of the component of the object that is being described. */ 90 tree component_type; 91 }; 92 93 /* Structure holding data required to describe a pass-through jump function. */ 94 95 struct GTY(()) ipa_pass_through_data 96 { 97 /* If an operation is to be performed on the original parameter, this is the 98 second (constant) operand. */ 99 tree operand; 100 /* Number of the caller's formal parameter being passed. */ 101 int formal_id; 102 /* Operation that is performed on the argument before it is passed on. 103 NOP_EXPR means no operation. Otherwise oper must be a simple binary 104 arithmetic operation where the caller's parameter is the first operand and 105 operand field from this structure is the second one. */ 106 enum tree_code operation; 107 }; 108 109 /* Structure holding data required to describe an ancestor pass-through 110 jump function. */ 111 112 struct GTY(()) ipa_ancestor_jf_data 113 { 114 /* Offset of the field representing the ancestor. */ 115 HOST_WIDE_INT offset; 116 /* TYpe of the result. */ 117 tree type; 118 /* Number of the caller's formal parameter being passed. */ 119 int formal_id; 120 }; 121 122 /* Structure holding a C++ member pointer constant. Holds a pointer to the 123 method and delta offset. */ 124 struct GTY(()) ipa_member_ptr_cst 125 { 126 tree pfn; 127 tree delta; 128 }; 129 130 /* A jump function for a callsite represents the values passed as actual 131 arguments of the callsite. See enum jump_func_type for the various 132 types of jump functions supported. */ 133 typedef struct GTY (()) ipa_jump_func 134 { 135 enum jump_func_type type; 136 /* Represents a value of a jump function. pass_through is used only in jump 137 function context. constant represents the actual constant in constant jump 138 functions and member_cst holds constant c++ member functions. */ 139 union jump_func_value 140 { 141 struct ipa_known_type_data GTY ((tag ("IPA_JF_KNOWN_TYPE"))) known_type; 142 tree GTY ((tag ("IPA_JF_CONST"))) constant; 143 struct ipa_member_ptr_cst GTY ((tag ("IPA_JF_CONST_MEMBER_PTR"))) member_cst; 144 struct ipa_pass_through_data GTY ((tag ("IPA_JF_PASS_THROUGH"))) pass_through; 145 struct ipa_ancestor_jf_data GTY ((tag ("IPA_JF_ANCESTOR"))) ancestor; 146 } GTY ((desc ("%1.type"))) value; 147 } ipa_jump_func_t; 148 149 DEF_VEC_O (ipa_jump_func_t); 150 DEF_VEC_ALLOC_O (ipa_jump_func_t, gc); 151 152 /* Summary describing a single formal parameter. */ 153 154 struct ipa_param_descriptor 155 { 156 /* PARAM_DECL of this parameter. */ 157 tree decl; 158 /* The parameter is used. */ 159 unsigned used : 1; 160 }; 161 162 typedef struct ipa_param_descriptor ipa_param_descriptor_t; 163 DEF_VEC_O (ipa_param_descriptor_t); 164 DEF_VEC_ALLOC_O (ipa_param_descriptor_t, heap); 165 struct ipcp_lattice; 166 167 /* ipa_node_params stores information related to formal parameters of functions 168 and some other information for interprocedural passes that operate on 169 parameters (such as ipa-cp). */ 170 171 struct ipa_node_params 172 { 173 /* Information about individual formal parameters that are gathered when 174 summaries are generated. */ 175 VEC (ipa_param_descriptor_t, heap) *descriptors; 176 /* Pointer to an array of structures describing individual formal 177 parameters. */ 178 struct ipcp_lattice *lattices; 179 /* Only for versioned nodes this field would not be NULL, 180 it points to the node that IPA cp cloned from. */ 181 struct cgraph_node *ipcp_orig_node; 182 /* If this node is an ipa-cp clone, these are the known values that describe 183 what it has been specialized for. */ 184 VEC (tree, heap) *known_vals; 185 /* Whether the param uses analysis has already been performed. */ 186 unsigned uses_analysis_done : 1; 187 /* Whether the function is enqueued in ipa-cp propagation stack. */ 188 unsigned node_enqueued : 1; 189 /* Whether we should create a specialized version based on values that are 190 known to be constant in all contexts. */ 191 unsigned clone_for_all_contexts : 1; 192 /* Node has been completely replaced by clones and will be removed after 193 ipa-cp is finished. */ 194 unsigned node_dead : 1; 195 }; 196 197 /* ipa_node_params access functions. Please use these to access fields that 198 are or will be shared among various passes. */ 199 200 /* Return the number of formal parameters. */ 201 202 static inline int 203 ipa_get_param_count (struct ipa_node_params *info) 204 { 205 return VEC_length (ipa_param_descriptor_t, info->descriptors); 206 } 207 208 /* Return the declaration of Ith formal parameter of the function corresponding 209 to INFO. Note there is no setter function as this array is built just once 210 using ipa_initialize_node_params. */ 211 212 static inline tree 213 ipa_get_param (struct ipa_node_params *info, int i) 214 { 215 return VEC_index (ipa_param_descriptor_t, info->descriptors, i)->decl; 216 } 217 218 /* Set the used flag corresponding to the Ith formal parameter of the function 219 associated with INFO to VAL. */ 220 221 static inline void 222 ipa_set_param_used (struct ipa_node_params *info, int i, bool val) 223 { 224 VEC_index (ipa_param_descriptor_t, info->descriptors, i)->used = val; 225 } 226 227 /* Return the used flag corresponding to the Ith formal parameter of the 228 function associated with INFO. */ 229 230 static inline bool 231 ipa_is_param_used (struct ipa_node_params *info, int i) 232 { 233 return VEC_index (ipa_param_descriptor_t, info->descriptors, i)->used; 234 } 235 236 /* ipa_edge_args stores information related to a callsite and particularly its 237 arguments. It can be accessed by the IPA_EDGE_REF macro. */ 238 typedef struct GTY(()) ipa_edge_args 239 { 240 /* Vector of the callsite's jump function of each parameter. */ 241 VEC (ipa_jump_func_t, gc) *jump_functions; 242 } ipa_edge_args_t; 243 244 /* ipa_edge_args access functions. Please use these to access fields that 245 are or will be shared among various passes. */ 246 247 /* Return the number of actual arguments. */ 248 249 static inline int 250 ipa_get_cs_argument_count (struct ipa_edge_args *args) 251 { 252 return VEC_length (ipa_jump_func_t, args->jump_functions); 253 } 254 255 /* Returns a pointer to the jump function for the ith argument. Please note 256 there is no setter function as jump functions are all set up in 257 ipa_compute_jump_functions. */ 258 259 static inline struct ipa_jump_func * 260 ipa_get_ith_jump_func (struct ipa_edge_args *args, int i) 261 { 262 return VEC_index (ipa_jump_func_t, args->jump_functions, i); 263 } 264 265 /* Vectors need to have typedefs of structures. */ 266 typedef struct ipa_node_params ipa_node_params_t; 267 268 /* Types of vectors holding the infos. */ 269 DEF_VEC_O (ipa_node_params_t); 270 DEF_VEC_ALLOC_O (ipa_node_params_t, heap); 271 DEF_VEC_O (ipa_edge_args_t); 272 DEF_VEC_ALLOC_O (ipa_edge_args_t, gc); 273 274 /* Vector where the parameter infos are actually stored. */ 275 extern VEC (ipa_node_params_t, heap) *ipa_node_params_vector; 276 /* Vector where the parameter infos are actually stored. */ 277 extern GTY(()) VEC (ipa_edge_args_t, gc) *ipa_edge_args_vector; 278 279 /* Return the associated parameter/argument info corresponding to the given 280 node/edge. */ 281 #define IPA_NODE_REF(NODE) (VEC_index (ipa_node_params_t, \ 282 ipa_node_params_vector, (NODE)->uid)) 283 #define IPA_EDGE_REF(EDGE) (VEC_index (ipa_edge_args_t, \ 284 ipa_edge_args_vector, (EDGE)->uid)) 285 /* This macro checks validity of index returned by 286 ipa_get_param_decl_index function. */ 287 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1) 288 289 /* Creating and freeing ipa_node_params and ipa_edge_args. */ 290 void ipa_create_all_node_params (void); 291 void ipa_create_all_edge_args (void); 292 void ipa_free_edge_args_substructures (struct ipa_edge_args *); 293 void ipa_free_node_params_substructures (struct ipa_node_params *); 294 void ipa_free_all_node_params (void); 295 void ipa_free_all_edge_args (void); 296 void ipa_free_all_structures_after_ipa_cp (void); 297 void ipa_free_all_structures_after_iinln (void); 298 void ipa_register_cgraph_hooks (void); 299 300 /* This function ensures the array of node param infos is big enough to 301 accommodate a structure for all nodes and reallocates it if not. */ 302 303 static inline void 304 ipa_check_create_node_params (void) 305 { 306 if (!ipa_node_params_vector) 307 ipa_node_params_vector = VEC_alloc (ipa_node_params_t, heap, 308 cgraph_max_uid); 309 310 if (VEC_length (ipa_node_params_t, ipa_node_params_vector) 311 <= (unsigned) cgraph_max_uid) 312 VEC_safe_grow_cleared (ipa_node_params_t, heap, 313 ipa_node_params_vector, cgraph_max_uid + 1); 314 } 315 316 /* This function ensures the array of edge arguments infos is big enough to 317 accommodate a structure for all edges and reallocates it if not. */ 318 319 static inline void 320 ipa_check_create_edge_args (void) 321 { 322 if (!ipa_edge_args_vector) 323 ipa_edge_args_vector = VEC_alloc (ipa_edge_args_t, gc, 324 cgraph_edge_max_uid); 325 326 if (VEC_length (ipa_edge_args_t, ipa_edge_args_vector) 327 <= (unsigned) cgraph_edge_max_uid) 328 VEC_safe_grow_cleared (ipa_edge_args_t, gc, ipa_edge_args_vector, 329 cgraph_edge_max_uid + 1); 330 } 331 332 /* Returns true if the array of edge infos is large enough to accommodate an 333 info for EDGE. The main purpose of this function is that debug dumping 334 function can check info availability without causing reallocations. */ 335 336 static inline bool 337 ipa_edge_args_info_available_for_edge_p (struct cgraph_edge *edge) 338 { 339 return ((unsigned) edge->uid < VEC_length (ipa_edge_args_t, 340 ipa_edge_args_vector)); 341 } 342 343 /* Function formal parameters related computations. */ 344 void ipa_initialize_node_params (struct cgraph_node *node); 345 bool ipa_propagate_indirect_call_infos (struct cgraph_edge *cs, 346 VEC (cgraph_edge_p, heap) **new_edges); 347 348 /* Indirect edge and binfo processing. */ 349 tree ipa_get_indirect_edge_target (struct cgraph_edge *ie, 350 VEC (tree, heap) *known_csts, 351 VEC (tree, heap) *known_binfs); 352 struct cgraph_edge *ipa_make_edge_direct_to_target (struct cgraph_edge *, tree); 353 354 /* Functions related to both. */ 355 void ipa_analyze_node (struct cgraph_node *); 356 357 /* Debugging interface. */ 358 void ipa_print_node_params (FILE *, struct cgraph_node *node); 359 void ipa_print_all_params (FILE *); 360 void ipa_print_node_jump_functions (FILE *f, struct cgraph_node *node); 361 void ipa_print_all_jump_functions (FILE * f); 362 void ipcp_verify_propagated_values (void); 363 364 extern alloc_pool ipcp_values_pool; 365 extern alloc_pool ipcp_sources_pool; 366 367 /* Structure to describe transformations of formal parameters and actual 368 arguments. Each instance describes one new parameter and they are meant to 369 be stored in a vector. Additionally, most users will probably want to store 370 adjustments about parameters that are being removed altogether so that SSA 371 names belonging to them can be replaced by SSA names of an artificial 372 variable. */ 373 struct ipa_parm_adjustment 374 { 375 /* The original PARM_DECL itself, helpful for processing of the body of the 376 function itself. Intended for traversing function bodies. 377 ipa_modify_formal_parameters, ipa_modify_call_arguments and 378 ipa_combine_adjustments ignore this and use base_index. 379 ipa_modify_formal_parameters actually sets this. */ 380 tree base; 381 382 /* Type of the new parameter. However, if by_ref is true, the real type will 383 be a pointer to this type. */ 384 tree type; 385 386 /* Alias refrerence type to be used in MEM_REFs when adjusting caller 387 arguments. */ 388 tree alias_ptr_type; 389 390 /* The new declaration when creating/replacing a parameter. Created by 391 ipa_modify_formal_parameters, useful for functions modifying the body 392 accordingly. */ 393 tree reduction; 394 395 /* New declaration of a substitute variable that we may use to replace all 396 non-default-def ssa names when a parm decl is going away. */ 397 tree new_ssa_base; 398 399 /* If non-NULL and the original parameter is to be removed (copy_param below 400 is NULL), this is going to be its nonlocalized vars value. */ 401 tree nonlocal_value; 402 403 /* Offset into the original parameter (for the cases when the new parameter 404 is a component of an original one). */ 405 HOST_WIDE_INT offset; 406 407 /* Zero based index of the original parameter this one is based on. (ATM 408 there is no way to insert a new parameter out of the blue because there is 409 no need but if it arises the code can be easily exteded to do so.) */ 410 int base_index; 411 412 /* This new parameter is an unmodified parameter at index base_index. */ 413 unsigned copy_param : 1; 414 415 /* This adjustment describes a parameter that is about to be removed 416 completely. Most users will probably need to book keep those so that they 417 don't leave behinfd any non default def ssa names belonging to them. */ 418 unsigned remove_param : 1; 419 420 /* The parameter is to be passed by reference. */ 421 unsigned by_ref : 1; 422 }; 423 424 typedef struct ipa_parm_adjustment ipa_parm_adjustment_t; 425 DEF_VEC_O (ipa_parm_adjustment_t); 426 DEF_VEC_ALLOC_O (ipa_parm_adjustment_t, heap); 427 428 typedef VEC (ipa_parm_adjustment_t, heap) *ipa_parm_adjustment_vec; 429 430 VEC(tree, heap) *ipa_get_vector_of_formal_parms (tree fndecl); 431 void ipa_modify_formal_parameters (tree fndecl, ipa_parm_adjustment_vec, 432 const char *); 433 void ipa_modify_call_arguments (struct cgraph_edge *, gimple, 434 ipa_parm_adjustment_vec); 435 ipa_parm_adjustment_vec ipa_combine_adjustments (ipa_parm_adjustment_vec, 436 ipa_parm_adjustment_vec); 437 void ipa_dump_param_adjustments (FILE *, ipa_parm_adjustment_vec, tree); 438 439 void ipa_prop_write_jump_functions (cgraph_node_set set); 440 void ipa_prop_read_jump_functions (void); 441 void ipa_update_after_lto_read (void); 442 int ipa_get_param_decl_index (struct ipa_node_params *, tree); 443 tree ipa_value_from_jfunc (struct ipa_node_params *info, 444 struct ipa_jump_func *jfunc); 445 446 447 /* From tree-sra.c: */ 448 tree build_ref_for_offset (location_t, tree, HOST_WIDE_INT, tree, 449 gimple_stmt_iterator *, bool); 450 451 #endif /* IPA_PROP_H */ 452