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_ANCESTOR is a special pass-through jump function, which means that
48 the result is an address of a part of the object pointed to by the formal
49 parameter to which the function refers. It is mainly intended to represent
50 getting addresses of of ancestor fields in C++
51 (e.g. &this_1(D)->D.1766.D.1756). Note that if the original pointer is
52 NULL, ancestor jump function must behave like a simple pass-through.
54 Other pass-through functions can either simply pass on an unchanged formal
55 parameter or can apply one simple binary operation to it (such jump
56 functions are called polynomial).
58 IPA_JF_KNOWN_TYPE is a special type of an "unknown" function that applies
59 only to pointer parameters. It means that even though we cannot prove that
60 the passed value is an interprocedural constant, we still know the exact
61 type of the containing object which may be valuable for devirtualization.
63 Jump functions are computed in ipa-prop.c by function
64 update_call_notes_after_inlining. Some information can be lost and jump
65 functions degraded accordingly when inlining, see
66 update_call_notes_after_inlining in the same file. */
70 IPA_JF_UNKNOWN
= 0, /* newly allocated and zeroed jump functions default */
71 IPA_JF_KNOWN_TYPE
, /* represented by field known_type */
72 IPA_JF_CONST
, /* represented by field costant */
73 IPA_JF_PASS_THROUGH
, /* represented by field pass_through */
74 IPA_JF_ANCESTOR
/* represented by field ancestor */
77 /* Structure holding data required to describe a known type jump function. */
78 struct GTY(()) ipa_known_type_data
80 /* Offset of the component of the base_type being described. */
82 /* Type of the whole object. */
84 /* Type of the component of the object that is being described. */
88 /* Structure holding data required to describe a pass-through jump function. */
90 struct GTY(()) ipa_pass_through_data
92 /* If an operation is to be performed on the original parameter, this is the
93 second (constant) operand. */
95 /* Number of the caller's formal parameter being passed. */
97 /* Operation that is performed on the argument before it is passed on.
98 NOP_EXPR means no operation. Otherwise oper must be a simple binary
99 arithmetic operation where the caller's parameter is the first operand and
100 operand field from this structure is the second one. */
101 enum tree_code operation
;
102 /* When the passed value is a pointer, it is set to true only when we are
103 certain that no write to the object it points to has occurred since the
104 caller functions started execution, except for changes noted in the
105 aggregate part of the jump function (see description of
106 ipa_agg_jump_function). The flag is used only when the operation is
111 /* Structure holding data required to describe an ancestor pass-through
114 struct GTY(()) ipa_ancestor_jf_data
116 /* Offset of the field representing the ancestor. */
117 HOST_WIDE_INT offset
;
118 /* Type of the result. */
120 /* Number of the caller's formal parameter being passed. */
122 /* Flag with the same meaning like agg_preserve in ipa_pass_through_data. */
126 /* An element in an aggegate part of a jump function describing a known value
127 at a given offset. When it is part of a pass-through jump function with
128 agg_preserved set or an ancestor jump function with agg_preserved set, all
129 unlisted positions are assumed to be preserved but the value can be a type
130 node, which means that the particular piece (starting at offset and having
131 the size of the type) is clobbered with an unknown value. When
132 agg_preserved is false or the type of the containing jump function is
133 different, all unlisted parts are assumed to be unknown and all values must
134 fullfill is_gimple_ip_invariant. */
136 typedef struct GTY(()) ipa_agg_jf_item
138 /* The offset at which the known value is located within the aggregate. */
139 HOST_WIDE_INT offset
;
141 /* The known constant or type if this is a clobber. */
146 /* Aggregate jump function - i.e. description of contents of aggregates passed
147 either by reference or value. */
149 struct GTY(()) ipa_agg_jump_function
151 /* Description of the individual items. */
152 vec
<ipa_agg_jf_item_t
, va_gc
> *items
;
153 /* True if the data was passed by reference (as opposed to by value). */
157 typedef struct ipa_agg_jump_function
*ipa_agg_jump_function_p
;
158 typedef struct ipa_agg_jump_function ipa_agg_jump_function_t
;
160 /* A jump function for a callsite represents the values passed as actual
161 arguments of the callsite. See enum jump_func_type for the various
162 types of jump functions supported. */
163 typedef struct GTY (()) ipa_jump_func
165 /* Aggregate contants description. See struct ipa_agg_jump_function and its
167 struct ipa_agg_jump_function agg
;
169 enum jump_func_type type
;
170 /* Represents a value of a jump function. pass_through is used only in jump
171 function context. constant represents the actual constant in constant jump
172 functions and member_cst holds constant c++ member functions. */
173 union jump_func_value
175 struct ipa_known_type_data
GTY ((tag ("IPA_JF_KNOWN_TYPE"))) known_type
;
176 tree
GTY ((tag ("IPA_JF_CONST"))) constant
;
177 struct ipa_pass_through_data
GTY ((tag ("IPA_JF_PASS_THROUGH"))) pass_through
;
178 struct ipa_ancestor_jf_data
GTY ((tag ("IPA_JF_ANCESTOR"))) ancestor
;
179 } GTY ((desc ("%1.type"))) value
;
183 /* Return the offset of the component that is decribed by a known type jump
186 static inline HOST_WIDE_INT
187 ipa_get_jf_known_type_offset (struct ipa_jump_func
*jfunc
)
189 gcc_checking_assert (jfunc
->type
== IPA_JF_KNOWN_TYPE
);
190 return jfunc
->value
.known_type
.offset
;
193 /* Return the base type of a known type jump function JFUNC. */
196 ipa_get_jf_known_type_base_type (struct ipa_jump_func
*jfunc
)
198 gcc_checking_assert (jfunc
->type
== IPA_JF_KNOWN_TYPE
);
199 return jfunc
->value
.known_type
.base_type
;
202 /* Return the component type of a known type jump function JFUNC. */
205 ipa_get_jf_known_type_component_type (struct ipa_jump_func
*jfunc
)
207 gcc_checking_assert (jfunc
->type
== IPA_JF_KNOWN_TYPE
);
208 return jfunc
->value
.known_type
.component_type
;
211 /* Return the constant stored in a constant jump functin JFUNC. */
214 ipa_get_jf_constant (struct ipa_jump_func
*jfunc
)
216 gcc_checking_assert (jfunc
->type
== IPA_JF_CONST
);
217 return jfunc
->value
.constant
;
220 /* Return the operand of a pass through jmp function JFUNC. */
223 ipa_get_jf_pass_through_operand (struct ipa_jump_func
*jfunc
)
225 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
226 return jfunc
->value
.pass_through
.operand
;
229 /* Return the number of the caller's formal parameter that a pass through jump
230 function JFUNC refers to. */
233 ipa_get_jf_pass_through_formal_id (struct ipa_jump_func
*jfunc
)
235 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
236 return jfunc
->value
.pass_through
.formal_id
;
239 /* Return operation of a pass through jump function JFUNC. */
241 static inline enum tree_code
242 ipa_get_jf_pass_through_operation (struct ipa_jump_func
*jfunc
)
244 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
245 return jfunc
->value
.pass_through
.operation
;
248 /* Return the agg_preserved flag of a pass through jump functin JFUNC. */
251 ipa_get_jf_pass_through_agg_preserved (struct ipa_jump_func
*jfunc
)
253 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
254 return jfunc
->value
.pass_through
.agg_preserved
;
257 /* Return the offset of an ancestor jump function JFUNC. */
259 static inline HOST_WIDE_INT
260 ipa_get_jf_ancestor_offset (struct ipa_jump_func
*jfunc
)
262 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
263 return jfunc
->value
.ancestor
.offset
;
266 /* Return the result type of an ancestor jump function JFUNC. */
269 ipa_get_jf_ancestor_type (struct ipa_jump_func
*jfunc
)
271 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
272 return jfunc
->value
.ancestor
.type
;
275 /* Return the number of the caller's formal parameter that an ancestor jump
276 function JFUNC refers to. */
279 ipa_get_jf_ancestor_formal_id (struct ipa_jump_func
*jfunc
)
281 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
282 return jfunc
->value
.ancestor
.formal_id
;
285 /* Return the agg_preserved flag of an ancestor jump functin JFUNC. */
288 ipa_get_jf_ancestor_agg_preserved (struct ipa_jump_func
*jfunc
)
290 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
291 return jfunc
->value
.ancestor
.agg_preserved
;
294 /* Summary describing a single formal parameter. */
296 struct ipa_param_descriptor
298 /* PARAM_DECL of this parameter. */
300 /* The parameter is used. */
304 typedef struct ipa_param_descriptor ipa_param_descriptor_t
;
307 /* ipa_node_params stores information related to formal parameters of functions
308 and some other information for interprocedural passes that operate on
309 parameters (such as ipa-cp). */
311 struct ipa_node_params
313 /* Information about individual formal parameters that are gathered when
314 summaries are generated. */
315 vec
<ipa_param_descriptor_t
> descriptors
;
316 /* Pointer to an array of structures describing individual formal
318 struct ipcp_param_lattices
*lattices
;
319 /* Only for versioned nodes this field would not be NULL,
320 it points to the node that IPA cp cloned from. */
321 struct cgraph_node
*ipcp_orig_node
;
322 /* If this node is an ipa-cp clone, these are the known values that describe
323 what it has been specialized for. */
324 vec
<tree
> known_vals
;
325 /* Whether the param uses analysis has already been performed. */
326 unsigned uses_analysis_done
: 1;
327 /* Whether the function is enqueued in ipa-cp propagation stack. */
328 unsigned node_enqueued
: 1;
329 /* Whether we should create a specialized version based on values that are
330 known to be constant in all contexts. */
331 unsigned clone_for_all_contexts
: 1;
332 /* Node has been completely replaced by clones and will be removed after
333 ipa-cp is finished. */
334 unsigned node_dead
: 1;
337 /* ipa_node_params access functions. Please use these to access fields that
338 are or will be shared among various passes. */
340 /* Return the number of formal parameters. */
343 ipa_get_param_count (struct ipa_node_params
*info
)
345 return info
->descriptors
.length ();
348 /* Return the declaration of Ith formal parameter of the function corresponding
349 to INFO. Note there is no setter function as this array is built just once
350 using ipa_initialize_node_params. */
353 ipa_get_param (struct ipa_node_params
*info
, int i
)
355 return info
->descriptors
[i
].decl
;
358 /* Set the used flag corresponding to the Ith formal parameter of the function
359 associated with INFO to VAL. */
362 ipa_set_param_used (struct ipa_node_params
*info
, int i
, bool val
)
364 info
->descriptors
[i
].used
= val
;
367 /* Return the used flag corresponding to the Ith formal parameter of the
368 function associated with INFO. */
371 ipa_is_param_used (struct ipa_node_params
*info
, int i
)
373 return info
->descriptors
[i
].used
;
376 /* Information about replacements done in aggregates for a given node (each
377 node has its linked list). */
378 struct GTY(()) ipa_agg_replacement_value
380 /* Next item in the linked list. */
381 struct ipa_agg_replacement_value
*next
;
382 /* Offset within the aggregate. */
383 HOST_WIDE_INT offset
;
384 /* The constant value. */
386 /* The paramter index. */
390 typedef struct ipa_agg_replacement_value
*ipa_agg_replacement_value_p
;
392 void ipa_set_node_agg_value_chain (struct cgraph_node
*node
,
393 struct ipa_agg_replacement_value
*aggvals
);
395 /* ipa_edge_args stores information related to a callsite and particularly its
396 arguments. It can be accessed by the IPA_EDGE_REF macro. */
397 typedef struct GTY(()) ipa_edge_args
399 /* Vector of the callsite's jump function of each parameter. */
400 vec
<ipa_jump_func_t
, va_gc
> *jump_functions
;
403 /* ipa_edge_args access functions. Please use these to access fields that
404 are or will be shared among various passes. */
406 /* Return the number of actual arguments. */
409 ipa_get_cs_argument_count (struct ipa_edge_args
*args
)
411 return vec_safe_length (args
->jump_functions
);
414 /* Returns a pointer to the jump function for the ith argument. Please note
415 there is no setter function as jump functions are all set up in
416 ipa_compute_jump_functions. */
418 static inline struct ipa_jump_func
*
419 ipa_get_ith_jump_func (struct ipa_edge_args
*args
, int i
)
421 return &(*args
->jump_functions
)[i
];
424 /* Vectors need to have typedefs of structures. */
425 typedef struct ipa_node_params ipa_node_params_t
;
427 /* Types of vectors holding the infos. */
429 /* Vector where the parameter infos are actually stored. */
430 extern vec
<ipa_node_params_t
> ipa_node_params_vector
;
431 /* Vector of known aggregate values in cloned nodes. */
432 extern GTY(()) vec
<ipa_agg_replacement_value_p
, va_gc
> *ipa_node_agg_replacements
;
433 /* Vector where the parameter infos are actually stored. */
434 extern GTY(()) vec
<ipa_edge_args_t
, va_gc
> *ipa_edge_args_vector
;
436 /* Return the associated parameter/argument info corresponding to the given
438 #define IPA_NODE_REF(NODE) (&ipa_node_params_vector[(NODE)->uid])
439 #define IPA_EDGE_REF(EDGE) (&(*ipa_edge_args_vector)[(EDGE)->uid])
440 /* This macro checks validity of index returned by
441 ipa_get_param_decl_index function. */
442 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1)
444 /* Creating and freeing ipa_node_params and ipa_edge_args. */
445 void ipa_create_all_node_params (void);
446 void ipa_create_all_edge_args (void);
447 void ipa_free_edge_args_substructures (struct ipa_edge_args
*);
448 void ipa_free_node_params_substructures (struct ipa_node_params
*);
449 void ipa_free_all_node_params (void);
450 void ipa_free_all_edge_args (void);
451 void ipa_free_all_structures_after_ipa_cp (void);
452 void ipa_free_all_structures_after_iinln (void);
453 void ipa_register_cgraph_hooks (void);
455 /* This function ensures the array of node param infos is big enough to
456 accommodate a structure for all nodes and reallocates it if not. */
459 ipa_check_create_node_params (void)
461 if (!ipa_node_params_vector
.exists ())
462 ipa_node_params_vector
.create (cgraph_max_uid
);
464 if (ipa_node_params_vector
.length () <= (unsigned) cgraph_max_uid
)
465 ipa_node_params_vector
.safe_grow_cleared (cgraph_max_uid
+ 1);
468 /* This function ensures the array of edge arguments infos is big enough to
469 accommodate a structure for all edges and reallocates it if not. */
472 ipa_check_create_edge_args (void)
474 if (vec_safe_length (ipa_edge_args_vector
) <= (unsigned) cgraph_edge_max_uid
)
475 vec_safe_grow_cleared (ipa_edge_args_vector
, cgraph_edge_max_uid
+ 1);
478 /* Returns true if the array of edge infos is large enough to accommodate an
479 info for EDGE. The main purpose of this function is that debug dumping
480 function can check info availability without causing reallocations. */
483 ipa_edge_args_info_available_for_edge_p (struct cgraph_edge
*edge
)
485 return ((unsigned) edge
->uid
< vec_safe_length (ipa_edge_args_vector
));
488 /* Return the aggregate replacements for NODE, if there are any. */
490 static inline struct ipa_agg_replacement_value
*
491 ipa_get_agg_replacements_for_node (struct cgraph_node
*node
)
493 if ((unsigned) node
->uid
>= vec_safe_length (ipa_node_agg_replacements
))
495 return (*ipa_node_agg_replacements
)[node
->uid
];
498 /* Function formal parameters related computations. */
499 void ipa_initialize_node_params (struct cgraph_node
*node
);
500 bool ipa_propagate_indirect_call_infos (struct cgraph_edge
*cs
,
501 vec
<cgraph_edge_p
> *new_edges
);
503 /* Indirect edge and binfo processing. */
504 tree
ipa_get_indirect_edge_target (struct cgraph_edge
*ie
,
507 vec
<ipa_agg_jump_function_p
> );
508 struct cgraph_edge
*ipa_make_edge_direct_to_target (struct cgraph_edge
*, tree
);
510 /* Functions related to both. */
511 void ipa_analyze_node (struct cgraph_node
*);
513 /* Aggregate jump function related functions. */
514 tree
ipa_find_agg_cst_for_param (struct ipa_agg_jump_function
*, HOST_WIDE_INT
,
516 bool ipa_load_from_parm_agg (struct ipa_node_params
*, gimple
, tree
, int *,
517 HOST_WIDE_INT
*, bool *);
519 /* Debugging interface. */
520 void ipa_print_node_params (FILE *, struct cgraph_node
*node
);
521 void ipa_print_all_params (FILE *);
522 void ipa_print_node_jump_functions (FILE *f
, struct cgraph_node
*node
);
523 void ipa_print_all_jump_functions (FILE * f
);
524 void ipcp_verify_propagated_values (void);
526 extern alloc_pool ipcp_values_pool
;
527 extern alloc_pool ipcp_sources_pool
;
528 extern alloc_pool ipcp_agg_lattice_pool
;
530 /* Structure to describe transformations of formal parameters and actual
531 arguments. Each instance describes one new parameter and they are meant to
532 be stored in a vector. Additionally, most users will probably want to store
533 adjustments about parameters that are being removed altogether so that SSA
534 names belonging to them can be replaced by SSA names of an artificial
536 struct ipa_parm_adjustment
538 /* The original PARM_DECL itself, helpful for processing of the body of the
539 function itself. Intended for traversing function bodies.
540 ipa_modify_formal_parameters, ipa_modify_call_arguments and
541 ipa_combine_adjustments ignore this and use base_index.
542 ipa_modify_formal_parameters actually sets this. */
545 /* Type of the new parameter. However, if by_ref is true, the real type will
546 be a pointer to this type. */
549 /* Alias refrerence type to be used in MEM_REFs when adjusting caller
553 /* The new declaration when creating/replacing a parameter. Created by
554 ipa_modify_formal_parameters, useful for functions modifying the body
558 /* New declaration of a substitute variable that we may use to replace all
559 non-default-def ssa names when a parm decl is going away. */
562 /* If non-NULL and the original parameter is to be removed (copy_param below
563 is NULL), this is going to be its nonlocalized vars value. */
566 /* Offset into the original parameter (for the cases when the new parameter
567 is a component of an original one). */
568 HOST_WIDE_INT offset
;
570 /* Zero based index of the original parameter this one is based on. (ATM
571 there is no way to insert a new parameter out of the blue because there is
572 no need but if it arises the code can be easily exteded to do so.) */
575 /* This new parameter is an unmodified parameter at index base_index. */
576 unsigned copy_param
: 1;
578 /* This adjustment describes a parameter that is about to be removed
579 completely. Most users will probably need to book keep those so that they
580 don't leave behinfd any non default def ssa names belonging to them. */
581 unsigned remove_param
: 1;
583 /* The parameter is to be passed by reference. */
587 typedef struct ipa_parm_adjustment ipa_parm_adjustment_t
;
589 typedef vec
<ipa_parm_adjustment_t
> ipa_parm_adjustment_vec
;
591 vec
<tree
> ipa_get_vector_of_formal_parms (tree fndecl
);
592 void ipa_modify_formal_parameters (tree fndecl
, ipa_parm_adjustment_vec
,
594 void ipa_modify_call_arguments (struct cgraph_edge
*, gimple
,
595 ipa_parm_adjustment_vec
);
596 ipa_parm_adjustment_vec
ipa_combine_adjustments (ipa_parm_adjustment_vec
,
597 ipa_parm_adjustment_vec
);
598 void ipa_dump_param_adjustments (FILE *, ipa_parm_adjustment_vec
, tree
);
599 void ipa_dump_agg_replacement_values (FILE *f
,
600 struct ipa_agg_replacement_value
*av
);
601 void ipa_prop_write_jump_functions (void);
602 void ipa_prop_read_jump_functions (void);
603 void ipa_prop_write_all_agg_replacement (void);
604 void ipa_prop_read_all_agg_replacement (void);
605 void ipa_update_after_lto_read (void);
606 int ipa_get_param_decl_index (struct ipa_node_params
*, tree
);
607 tree
ipa_value_from_jfunc (struct ipa_node_params
*info
,
608 struct ipa_jump_func
*jfunc
);
609 unsigned int ipcp_transform_function (struct cgraph_node
*node
);
612 /* From tree-sra.c: */
613 tree
build_ref_for_offset (location_t
, tree
, HOST_WIDE_INT
, tree
,
614 gimple_stmt_iterator
*, bool);
616 #endif /* IPA_PROP_H */