1 /* Interprocedural analyses.
2 Copyright (C) 2005, 2007, 2008, 2009, 2010
3 Free Software Foundation, Inc.
5 This file is part of GCC.
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
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
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/>. */
28 #include "alloc-pool.h"
30 /* The following definitions and interfaces are used by
31 interprocedural analyses or parameters. */
33 /* ipa-prop.c stuff (ipa-cp, indirect inlining): */
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
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
45 Unknown - neither of the above.
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.
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.
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).
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.
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. */
74 IPA_JF_UNKNOWN = 0, /* newly allocated and zeroed jump functions default */
75 IPA_JF_KNOWN_TYPE, /* represented by field base_binfo */
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 */
82 /* Structure holding data required to describe a pass-through jump function. */
84 struct GTY(()) ipa_pass_through_data
86 /* If an operation is to be performed on the original parameter, this is the
87 second (constant) operand. */
89 /* Number of the caller's formal parameter being passed. */
91 /* Operation that is performed on the argument before it is passed on.
92 NOP_EXPR means no operation. Otherwise oper must be a simple binary
93 arithmetic operation where the caller's parameter is the first operand and
94 operand field from this structure is the second one. */
95 enum tree_code operation;
98 /* Structure holding data required to describe an ancestor pass-through
101 struct GTY(()) ipa_ancestor_jf_data
103 /* Offset of the field representing the ancestor. */
104 HOST_WIDE_INT offset;
105 /* TYpe of the result. */
107 /* Number of the caller's formal parameter being passed. */
111 /* Structure holding a C++ member pointer constant. Holds a pointer to the
112 method and delta offset. */
113 struct GTY(()) ipa_member_ptr_cst
119 /* A jump function for a callsite represents the values passed as actual
120 arguments of the callsite. See enum jump_func_type for the various
121 types of jump functions supported. */
122 typedef struct GTY (()) ipa_jump_func
124 enum jump_func_type type;
125 /* Represents a value of a jump function. pass_through is used only in jump
126 function context. constant represents the actual constant in constant jump
127 functions and member_cst holds constant c++ member functions. */
128 union jump_func_value
130 tree GTY ((tag ("IPA_JF_KNOWN_TYPE"))) base_binfo;
131 tree GTY ((tag ("IPA_JF_CONST"))) constant;
132 struct ipa_member_ptr_cst GTY ((tag ("IPA_JF_CONST_MEMBER_PTR"))) member_cst;
133 struct ipa_pass_through_data GTY ((tag ("IPA_JF_PASS_THROUGH"))) pass_through;
134 struct ipa_ancestor_jf_data GTY ((tag ("IPA_JF_ANCESTOR"))) ancestor;
135 } GTY ((desc ("%1.type"))) value;
138 DEF_VEC_O (ipa_jump_func_t);
139 DEF_VEC_ALLOC_O (ipa_jump_func_t, gc);
141 /* Summary describing a single formal parameter. */
143 struct ipa_param_descriptor
145 /* PARAM_DECL of this parameter. */
147 /* The parameter is used. */
151 typedef struct ipa_param_descriptor ipa_param_descriptor_t;
152 DEF_VEC_O (ipa_param_descriptor_t);
153 DEF_VEC_ALLOC_O (ipa_param_descriptor_t, heap);
156 /* ipa_node_params stores information related to formal parameters of functions
157 and some other information for interprocedural passes that operate on
158 parameters (such as ipa-cp). */
160 struct ipa_node_params
162 /* Information about individual formal parameters that are gathered when
163 summaries are generated. */
164 VEC (ipa_param_descriptor_t, heap) *descriptors;
165 /* Pointer to an array of structures describing individual formal
167 struct ipcp_lattice *lattices;
168 /* Only for versioned nodes this field would not be NULL,
169 it points to the node that IPA cp cloned from. */
170 struct cgraph_node *ipcp_orig_node;
171 /* If this node is an ipa-cp clone, these are the known values that describe
172 what it has been specialized for. */
173 VEC (tree, heap) *known_vals;
174 /* Whether the param uses analysis has already been performed. */
175 unsigned uses_analysis_done : 1;
176 /* Whether the function is enqueued in ipa-cp propagation stack. */
177 unsigned node_enqueued : 1;
178 /* Whether we should create a specialized version based on values that are
179 known to be constant in all contexts. */
180 unsigned clone_for_all_contexts : 1;
181 /* Node has been completely replaced by clones and will be removed after
182 ipa-cp is finished. */
183 unsigned node_dead : 1;
186 /* ipa_node_params access functions. Please use these to access fields that
187 are or will be shared among various passes. */
189 /* Return the number of formal parameters. */
192 ipa_get_param_count (struct ipa_node_params *info)
194 return VEC_length (ipa_param_descriptor_t, info->descriptors);
197 /* Return the declaration of Ith formal parameter of the function corresponding
198 to INFO. Note there is no setter function as this array is built just once
199 using ipa_initialize_node_params. */
202 ipa_get_param (struct ipa_node_params *info, int i)
204 return VEC_index (ipa_param_descriptor_t, info->descriptors, i)->decl;
207 /* Set the used flag corresponding to the Ith formal parameter of the function
208 associated with INFO to VAL. */
211 ipa_set_param_used (struct ipa_node_params *info, int i, bool val)
213 VEC_index (ipa_param_descriptor_t, info->descriptors, i)->used = val;
216 /* Return the used flag corresponding to the Ith formal parameter of the
217 function associated with INFO. */
220 ipa_is_param_used (struct ipa_node_params *info, int i)
222 return VEC_index (ipa_param_descriptor_t, info->descriptors, i)->used;
225 /* ipa_edge_args stores information related to a callsite and particularly its
226 arguments. It can be accessed by the IPA_EDGE_REF macro. */
227 typedef struct GTY(()) ipa_edge_args
229 /* Vector of the callsite's jump function of each parameter. */
230 VEC (ipa_jump_func_t, gc) *jump_functions;
233 /* ipa_edge_args access functions. Please use these to access fields that
234 are or will be shared among various passes. */
236 /* Return the number of actual arguments. */
239 ipa_get_cs_argument_count (struct ipa_edge_args *args)
241 return VEC_length (ipa_jump_func_t, args->jump_functions);
244 /* Returns a pointer to the jump function for the ith argument. Please note
245 there is no setter function as jump functions are all set up in
246 ipa_compute_jump_functions. */
248 static inline struct ipa_jump_func *
249 ipa_get_ith_jump_func (struct ipa_edge_args *args, int i)
251 return VEC_index (ipa_jump_func_t, args->jump_functions, i);
254 /* Vectors need to have typedefs of structures. */
255 typedef struct ipa_node_params ipa_node_params_t;
257 /* Types of vectors holding the infos. */
258 DEF_VEC_O (ipa_node_params_t);
259 DEF_VEC_ALLOC_O (ipa_node_params_t, heap);
260 DEF_VEC_O (ipa_edge_args_t);
261 DEF_VEC_ALLOC_O (ipa_edge_args_t, gc);
263 /* Vector where the parameter infos are actually stored. */
264 extern VEC (ipa_node_params_t, heap) *ipa_node_params_vector;
265 /* Vector where the parameter infos are actually stored. */
266 extern GTY(()) VEC (ipa_edge_args_t, gc) *ipa_edge_args_vector;
268 /* Return the associated parameter/argument info corresponding to the given
270 #define IPA_NODE_REF(NODE) (VEC_index (ipa_node_params_t, \
271 ipa_node_params_vector, (NODE)->uid))
272 #define IPA_EDGE_REF(EDGE) (VEC_index (ipa_edge_args_t, \
273 ipa_edge_args_vector, (EDGE)->uid))
274 /* This macro checks validity of index returned by
275 ipa_get_param_decl_index function. */
276 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1)
278 /* Creating and freeing ipa_node_params and ipa_edge_args. */
279 void ipa_create_all_node_params (void);
280 void ipa_create_all_edge_args (void);
281 void ipa_free_edge_args_substructures (struct ipa_edge_args *);
282 void ipa_free_node_params_substructures (struct ipa_node_params *);
283 void ipa_free_all_node_params (void);
284 void ipa_free_all_edge_args (void);
285 void ipa_create_all_structures_for_iinln (void);
286 void ipa_free_all_structures_after_ipa_cp (void);
287 void ipa_free_all_structures_after_iinln (void);
288 void ipa_register_cgraph_hooks (void);
290 /* This function ensures the array of node param infos is big enough to
291 accommodate a structure for all nodes and reallocates it if not. */
294 ipa_check_create_node_params (void)
296 if (!ipa_node_params_vector)
297 ipa_node_params_vector = VEC_alloc (ipa_node_params_t, heap,
300 if (VEC_length (ipa_node_params_t, ipa_node_params_vector)
301 <= (unsigned) cgraph_max_uid)
302 VEC_safe_grow_cleared (ipa_node_params_t, heap,
303 ipa_node_params_vector, cgraph_max_uid + 1);
306 /* This function ensures the array of edge arguments infos is big enough to
307 accommodate a structure for all edges and reallocates it if not. */
310 ipa_check_create_edge_args (void)
312 if (!ipa_edge_args_vector)
313 ipa_edge_args_vector = VEC_alloc (ipa_edge_args_t, gc,
314 cgraph_edge_max_uid);
316 if (VEC_length (ipa_edge_args_t, ipa_edge_args_vector)
317 <= (unsigned) cgraph_edge_max_uid)
318 VEC_safe_grow_cleared (ipa_edge_args_t, gc, ipa_edge_args_vector,
319 cgraph_edge_max_uid + 1);
322 /* Returns true if the array of edge infos is large enough to accommodate an
323 info for EDGE. The main purpose of this function is that debug dumping
324 function can check info availability without causing reallocations. */
327 ipa_edge_args_info_available_for_edge_p (struct cgraph_edge *edge)
329 return ((unsigned) edge->uid < VEC_length (ipa_edge_args_t,
330 ipa_edge_args_vector));
333 /* Function formal parameters related computations. */
334 void ipa_initialize_node_params (struct cgraph_node *node);
335 bool ipa_propagate_indirect_call_infos (struct cgraph_edge *cs,
336 VEC (cgraph_edge_p, heap) **new_edges);
338 /* Indirect edge and binfo processing. */
339 struct cgraph_edge *ipa_make_edge_direct_to_target (struct cgraph_edge *, tree);
341 /* Functions related to both. */
342 void ipa_analyze_node (struct cgraph_node *);
344 /* Debugging interface. */
345 void ipa_print_node_params (FILE *, struct cgraph_node *node);
346 void ipa_print_all_params (FILE *);
347 void ipa_print_node_jump_functions (FILE *f, struct cgraph_node *node);
348 void ipa_print_all_jump_functions (FILE * f);
349 void ipcp_verify_propagated_values (void);
351 extern alloc_pool ipcp_values_pool;
352 extern alloc_pool ipcp_sources_pool;
354 /* Structure to describe transformations of formal parameters and actual
355 arguments. Each instance describes one new parameter and they are meant to
356 be stored in a vector. Additionally, most users will probably want to store
357 adjustments about parameters that are being removed altogether so that SSA
358 names belonging to them can be replaced by SSA names of an artificial
360 struct ipa_parm_adjustment
362 /* The original PARM_DECL itself, helpful for processing of the body of the
363 function itself. Intended for traversing function bodies.
364 ipa_modify_formal_parameters, ipa_modify_call_arguments and
365 ipa_combine_adjustments ignore this and use base_index.
366 ipa_modify_formal_parameters actually sets this. */
369 /* Type of the new parameter. However, if by_ref is true, the real type will
370 be a pointer to this type. */
373 /* Alias refrerence type to be used in MEM_REFs when adjusting caller
377 /* The new declaration when creating/replacing a parameter. Created by
378 ipa_modify_formal_parameters, useful for functions modifying the body
382 /* New declaration of a substitute variable that we may use to replace all
383 non-default-def ssa names when a parm decl is going away. */
386 /* If non-NULL and the original parameter is to be removed (copy_param below
387 is NULL), this is going to be its nonlocalized vars value. */
390 /* Offset into the original parameter (for the cases when the new parameter
391 is a component of an original one). */
392 HOST_WIDE_INT offset;
394 /* Zero based index of the original parameter this one is based on. (ATM
395 there is no way to insert a new parameter out of the blue because there is
396 no need but if it arises the code can be easily exteded to do so.) */
399 /* This new parameter is an unmodified parameter at index base_index. */
400 unsigned copy_param : 1;
402 /* This adjustment describes a parameter that is about to be removed
403 completely. Most users will probably need to book keep those so that they
404 don't leave behinfd any non default def ssa names belonging to them. */
405 unsigned remove_param : 1;
407 /* The parameter is to be passed by reference. */
411 typedef struct ipa_parm_adjustment ipa_parm_adjustment_t;
412 DEF_VEC_O (ipa_parm_adjustment_t);
413 DEF_VEC_ALLOC_O (ipa_parm_adjustment_t, heap);
415 typedef VEC (ipa_parm_adjustment_t, heap) *ipa_parm_adjustment_vec;
417 VEC(tree, heap) *ipa_get_vector_of_formal_parms (tree fndecl);
418 void ipa_modify_formal_parameters (tree fndecl, ipa_parm_adjustment_vec,
420 void ipa_modify_call_arguments (struct cgraph_edge *, gimple,
421 ipa_parm_adjustment_vec);
422 ipa_parm_adjustment_vec ipa_combine_adjustments (ipa_parm_adjustment_vec,
423 ipa_parm_adjustment_vec);
424 void ipa_dump_param_adjustments (FILE *, ipa_parm_adjustment_vec, tree);
426 void ipa_prop_write_jump_functions (cgraph_node_set set);
427 void ipa_prop_read_jump_functions (void);
428 void ipa_update_after_lto_read (void);
429 int ipa_get_param_decl_index (struct ipa_node_params *, tree);
430 tree ipa_cst_from_jfunc (struct ipa_node_params *info,
431 struct ipa_jump_func *jfunc);
434 /* From tree-sra.c: */
435 tree build_ref_for_offset (location_t, tree, HOST_WIDE_INT, tree,
436 gimple_stmt_iterator *, bool);
438 #endif /* IPA_PROP_H */