1 /* Interprocedural analyses.
2 Copyright (C) 2005-2013 Free Software Foundation, Inc.
4 This file is part of GCC.
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
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
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/>. */
27 #include "alloc-pool.h"
29 /* The following definitions and interfaces are used by
30 interprocedural analyses or parameters. */
32 #define IPA_UNDESCRIBED_USE -1
34 /* ipa-prop.c stuff (ipa-cp, indirect inlining): */
36 /* A jump function for a callsite represents the values passed as actual
37 arguments of the callsite. They were originally proposed in a paper called
38 "Interprocedural Constant Propagation", by David Callahan, Keith D Cooper,
39 Ken Kennedy, Linda Torczon in Comp86, pg 152-161. There are three main
42 Pass-through - the caller's formal parameter is passed as an actual
43 argument, possibly one simple operation performed on it.
44 Constant - a constant (is_gimple_ip_invariant)is passed as an actual
46 Unknown - neither of the above.
48 IPA_JF_ANCESTOR is a special pass-through jump function, which means that
49 the result is an address of a part of the object pointed to by the formal
50 parameter to which the function refers. It is mainly intended to represent
51 getting addresses of of ancestor fields in C++
52 (e.g. &this_1(D)->D.1766.D.1756). Note that if the original pointer is
53 NULL, ancestor jump function must behave like a simple pass-through.
55 Other pass-through functions can either simply pass on an unchanged formal
56 parameter or can apply one simple binary operation to it (such jump
57 functions are called polynomial).
59 IPA_JF_KNOWN_TYPE is a special type of an "unknown" function that applies
60 only to pointer parameters. It means that even though we cannot prove that
61 the passed value is an interprocedural constant, we still know the exact
62 type of the containing object which may be valuable for devirtualization.
64 Jump functions are computed in ipa-prop.c by function
65 update_call_notes_after_inlining. Some information can be lost and jump
66 functions degraded accordingly when inlining, see
67 update_call_notes_after_inlining in the same file. */
71 IPA_JF_UNKNOWN
= 0, /* newly allocated and zeroed jump functions default */
72 IPA_JF_KNOWN_TYPE
, /* represented by field known_type */
73 IPA_JF_CONST
, /* represented by field costant */
74 IPA_JF_PASS_THROUGH
, /* represented by field pass_through */
75 IPA_JF_ANCESTOR
/* represented by field ancestor */
78 /* Structure holding data required to describe a known type jump function. */
79 struct GTY(()) ipa_known_type_data
81 /* Offset of the component of the base_type being described. */
83 /* Type of the whole object. */
85 /* Type of the component of the object that is being described. */
89 struct ipa_cst_ref_desc
;
91 /* Structure holding data required to describe a constant jump function. */
92 struct GTY(()) ipa_constant_data
94 /* THe value of the constant. */
96 /* Pointer to the structure that describes the reference. */
97 struct ipa_cst_ref_desc
GTY((skip
)) *rdesc
;
100 /* Structure holding data required to describe a pass-through jump function. */
102 struct GTY(()) ipa_pass_through_data
104 /* If an operation is to be performed on the original parameter, this is the
105 second (constant) operand. */
107 /* Number of the caller's formal parameter being passed. */
109 /* Operation that is performed on the argument before it is passed on.
110 NOP_EXPR means no operation. Otherwise oper must be a simple binary
111 arithmetic operation where the caller's parameter is the first operand and
112 operand field from this structure is the second one. */
113 enum tree_code operation
;
114 /* When the passed value is a pointer, it is set to true only when we are
115 certain that no write to the object it points to has occurred since the
116 caller functions started execution, except for changes noted in the
117 aggregate part of the jump function (see description of
118 ipa_agg_jump_function). The flag is used only when the operation is
123 /* Structure holding data required to describe an ancestor pass-through
126 struct GTY(()) ipa_ancestor_jf_data
128 /* Offset of the field representing the ancestor. */
129 HOST_WIDE_INT offset
;
130 /* Type of the result. */
132 /* Number of the caller's formal parameter being passed. */
134 /* Flag with the same meaning like agg_preserve in ipa_pass_through_data. */
138 /* An element in an aggegate part of a jump function describing a known value
139 at a given offset. When it is part of a pass-through jump function with
140 agg_preserved set or an ancestor jump function with agg_preserved set, all
141 unlisted positions are assumed to be preserved but the value can be a type
142 node, which means that the particular piece (starting at offset and having
143 the size of the type) is clobbered with an unknown value. When
144 agg_preserved is false or the type of the containing jump function is
145 different, all unlisted parts are assumed to be unknown and all values must
146 fulfill is_gimple_ip_invariant. */
148 typedef struct GTY(()) ipa_agg_jf_item
150 /* The offset at which the known value is located within the aggregate. */
151 HOST_WIDE_INT offset
;
153 /* The known constant or type if this is a clobber. */
158 /* Aggregate jump function - i.e. description of contents of aggregates passed
159 either by reference or value. */
161 struct GTY(()) ipa_agg_jump_function
163 /* Description of the individual items. */
164 vec
<ipa_agg_jf_item_t
, va_gc
> *items
;
165 /* True if the data was passed by reference (as opposed to by value). */
169 typedef struct ipa_agg_jump_function
*ipa_agg_jump_function_p
;
170 typedef struct ipa_agg_jump_function ipa_agg_jump_function_t
;
172 /* A jump function for a callsite represents the values passed as actual
173 arguments of the callsite. See enum jump_func_type for the various
174 types of jump functions supported. */
175 typedef struct GTY (()) ipa_jump_func
177 /* Aggregate contants description. See struct ipa_agg_jump_function and its
179 struct ipa_agg_jump_function agg
;
181 enum jump_func_type type
;
182 /* Represents a value of a jump function. pass_through is used only in jump
183 function context. constant represents the actual constant in constant jump
184 functions and member_cst holds constant c++ member functions. */
185 union jump_func_value
187 struct ipa_known_type_data
GTY ((tag ("IPA_JF_KNOWN_TYPE"))) known_type
;
188 struct ipa_constant_data
GTY ((tag ("IPA_JF_CONST"))) constant
;
189 struct ipa_pass_through_data
GTY ((tag ("IPA_JF_PASS_THROUGH"))) pass_through
;
190 struct ipa_ancestor_jf_data
GTY ((tag ("IPA_JF_ANCESTOR"))) ancestor
;
191 } GTY ((desc ("%1.type"))) value
;
195 /* Return the offset of the component that is described by a known type jump
198 static inline HOST_WIDE_INT
199 ipa_get_jf_known_type_offset (struct ipa_jump_func
*jfunc
)
201 gcc_checking_assert (jfunc
->type
== IPA_JF_KNOWN_TYPE
);
202 return jfunc
->value
.known_type
.offset
;
205 /* Return the base type of a known type jump function JFUNC. */
208 ipa_get_jf_known_type_base_type (struct ipa_jump_func
*jfunc
)
210 gcc_checking_assert (jfunc
->type
== IPA_JF_KNOWN_TYPE
);
211 return jfunc
->value
.known_type
.base_type
;
214 /* Return the component type of a known type jump function JFUNC. */
217 ipa_get_jf_known_type_component_type (struct ipa_jump_func
*jfunc
)
219 gcc_checking_assert (jfunc
->type
== IPA_JF_KNOWN_TYPE
);
220 return jfunc
->value
.known_type
.component_type
;
223 /* Return the constant stored in a constant jump functin JFUNC. */
226 ipa_get_jf_constant (struct ipa_jump_func
*jfunc
)
228 gcc_checking_assert (jfunc
->type
== IPA_JF_CONST
);
229 return jfunc
->value
.constant
.value
;
232 static inline struct ipa_cst_ref_desc
*
233 ipa_get_jf_constant_rdesc (struct ipa_jump_func
*jfunc
)
235 gcc_checking_assert (jfunc
->type
== IPA_JF_CONST
);
236 return jfunc
->value
.constant
.rdesc
;
239 /* Return the operand of a pass through jmp function JFUNC. */
242 ipa_get_jf_pass_through_operand (struct ipa_jump_func
*jfunc
)
244 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
245 return jfunc
->value
.pass_through
.operand
;
248 /* Return the number of the caller's formal parameter that a pass through jump
249 function JFUNC refers to. */
252 ipa_get_jf_pass_through_formal_id (struct ipa_jump_func
*jfunc
)
254 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
255 return jfunc
->value
.pass_through
.formal_id
;
258 /* Return operation of a pass through jump function JFUNC. */
260 static inline enum tree_code
261 ipa_get_jf_pass_through_operation (struct ipa_jump_func
*jfunc
)
263 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
264 return jfunc
->value
.pass_through
.operation
;
267 /* Return the agg_preserved flag of a pass through jump functin JFUNC. */
270 ipa_get_jf_pass_through_agg_preserved (struct ipa_jump_func
*jfunc
)
272 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
273 return jfunc
->value
.pass_through
.agg_preserved
;
276 /* Return the offset of an ancestor jump function JFUNC. */
278 static inline HOST_WIDE_INT
279 ipa_get_jf_ancestor_offset (struct ipa_jump_func
*jfunc
)
281 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
282 return jfunc
->value
.ancestor
.offset
;
285 /* Return the result type of an ancestor jump function JFUNC. */
288 ipa_get_jf_ancestor_type (struct ipa_jump_func
*jfunc
)
290 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
291 return jfunc
->value
.ancestor
.type
;
294 /* Return the number of the caller's formal parameter that an ancestor jump
295 function JFUNC refers to. */
298 ipa_get_jf_ancestor_formal_id (struct ipa_jump_func
*jfunc
)
300 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
301 return jfunc
->value
.ancestor
.formal_id
;
304 /* Return the agg_preserved flag of an ancestor jump functin JFUNC. */
307 ipa_get_jf_ancestor_agg_preserved (struct ipa_jump_func
*jfunc
)
309 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
310 return jfunc
->value
.ancestor
.agg_preserved
;
313 /* Summary describing a single formal parameter. */
315 struct ipa_param_descriptor
317 /* PARAM_DECL of this parameter. */
319 /* If all uses of the parameter are described by ipa-prop structures, this
320 says how many there are. If any use could not be described by means of
321 ipa-prop structures, this is IPA_UNDESCRIBED_USE. */
323 unsigned int move_cost
: 31;
324 /* The parameter is used. */
328 typedef struct ipa_param_descriptor ipa_param_descriptor_t
;
331 /* ipa_node_params stores information related to formal parameters of functions
332 and some other information for interprocedural passes that operate on
333 parameters (such as ipa-cp). */
335 struct ipa_node_params
337 /* Information about individual formal parameters that are gathered when
338 summaries are generated. */
339 vec
<ipa_param_descriptor_t
> descriptors
;
340 /* Pointer to an array of structures describing individual formal
342 struct ipcp_param_lattices
*lattices
;
343 /* Only for versioned nodes this field would not be NULL,
344 it points to the node that IPA cp cloned from. */
345 struct cgraph_node
*ipcp_orig_node
;
346 /* If this node is an ipa-cp clone, these are the known values that describe
347 what it has been specialized for. */
348 vec
<tree
> known_vals
;
349 /* Whether the param uses analysis has already been performed. */
350 unsigned uses_analysis_done
: 1;
351 /* Whether the function is enqueued in ipa-cp propagation stack. */
352 unsigned node_enqueued
: 1;
353 /* Whether we should create a specialized version based on values that are
354 known to be constant in all contexts. */
355 unsigned do_clone_for_all_contexts
: 1;
356 /* Set if this is an IPA-CP clone for all contexts. */
357 unsigned is_all_contexts_clone
: 1;
358 /* Node has been completely replaced by clones and will be removed after
359 ipa-cp is finished. */
360 unsigned node_dead
: 1;
363 /* ipa_node_params access functions. Please use these to access fields that
364 are or will be shared among various passes. */
366 /* Return the number of formal parameters. */
369 ipa_get_param_count (struct ipa_node_params
*info
)
371 return info
->descriptors
.length ();
374 /* Return the declaration of Ith formal parameter of the function corresponding
375 to INFO. Note there is no setter function as this array is built just once
376 using ipa_initialize_node_params. */
379 ipa_get_param (struct ipa_node_params
*info
, int i
)
381 gcc_checking_assert (!flag_wpa
);
382 return info
->descriptors
[i
].decl
;
385 /* Return the move cost of Ith formal parameter of the function corresponding
389 ipa_get_param_move_cost (struct ipa_node_params
*info
, int i
)
391 return info
->descriptors
[i
].move_cost
;
394 /* Set the used flag corresponding to the Ith formal parameter of the function
395 associated with INFO to VAL. */
398 ipa_set_param_used (struct ipa_node_params
*info
, int i
, bool val
)
400 info
->descriptors
[i
].used
= val
;
403 /* Return how many uses described by ipa-prop a parameter has or
404 IPA_UNDESCRIBED_USE if there is a use that is not described by these
407 ipa_get_controlled_uses (struct ipa_node_params
*info
, int i
)
409 return info
->descriptors
[i
].controlled_uses
;
412 /* Set the controlled counter of a given parameter. */
415 ipa_set_controlled_uses (struct ipa_node_params
*info
, int i
, int val
)
417 info
->descriptors
[i
].controlled_uses
= val
;
420 /* Return the used flag corresponding to the Ith formal parameter of the
421 function associated with INFO. */
424 ipa_is_param_used (struct ipa_node_params
*info
, int i
)
426 return info
->descriptors
[i
].used
;
429 /* Information about replacements done in aggregates for a given node (each
430 node has its linked list). */
431 struct GTY(()) ipa_agg_replacement_value
433 /* Next item in the linked list. */
434 struct ipa_agg_replacement_value
*next
;
435 /* Offset within the aggregate. */
436 HOST_WIDE_INT offset
;
437 /* The constant value. */
439 /* The paramter index. */
441 /* Whether the value was passed by reference. */
445 typedef struct ipa_agg_replacement_value
*ipa_agg_replacement_value_p
;
447 void ipa_set_node_agg_value_chain (struct cgraph_node
*node
,
448 struct ipa_agg_replacement_value
*aggvals
);
450 /* ipa_edge_args stores information related to a callsite and particularly its
451 arguments. It can be accessed by the IPA_EDGE_REF macro. */
452 typedef struct GTY(()) ipa_edge_args
454 /* Vector of the callsite's jump function of each parameter. */
455 vec
<ipa_jump_func_t
, va_gc
> *jump_functions
;
458 /* ipa_edge_args access functions. Please use these to access fields that
459 are or will be shared among various passes. */
461 /* Return the number of actual arguments. */
464 ipa_get_cs_argument_count (struct ipa_edge_args
*args
)
466 return vec_safe_length (args
->jump_functions
);
469 /* Returns a pointer to the jump function for the ith argument. Please note
470 there is no setter function as jump functions are all set up in
471 ipa_compute_jump_functions. */
473 static inline struct ipa_jump_func
*
474 ipa_get_ith_jump_func (struct ipa_edge_args
*args
, int i
)
476 return &(*args
->jump_functions
)[i
];
479 /* Vectors need to have typedefs of structures. */
480 typedef struct ipa_node_params ipa_node_params_t
;
482 /* Types of vectors holding the infos. */
484 /* Vector where the parameter infos are actually stored. */
485 extern vec
<ipa_node_params_t
> ipa_node_params_vector
;
486 /* Vector of known aggregate values in cloned nodes. */
487 extern GTY(()) vec
<ipa_agg_replacement_value_p
, va_gc
> *ipa_node_agg_replacements
;
488 /* Vector where the parameter infos are actually stored. */
489 extern GTY(()) vec
<ipa_edge_args_t
, va_gc
> *ipa_edge_args_vector
;
491 /* Return the associated parameter/argument info corresponding to the given
493 #define IPA_NODE_REF(NODE) (&ipa_node_params_vector[(NODE)->uid])
494 #define IPA_EDGE_REF(EDGE) (&(*ipa_edge_args_vector)[(EDGE)->uid])
495 /* This macro checks validity of index returned by
496 ipa_get_param_decl_index function. */
497 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1)
499 /* Creating and freeing ipa_node_params and ipa_edge_args. */
500 void ipa_create_all_node_params (void);
501 void ipa_create_all_edge_args (void);
502 void ipa_free_edge_args_substructures (struct ipa_edge_args
*);
503 void ipa_free_node_params_substructures (struct ipa_node_params
*);
504 void ipa_free_all_node_params (void);
505 void ipa_free_all_edge_args (void);
506 void ipa_free_all_structures_after_ipa_cp (void);
507 void ipa_free_all_structures_after_iinln (void);
508 void ipa_register_cgraph_hooks (void);
510 /* This function ensures the array of node param infos is big enough to
511 accommodate a structure for all nodes and reallocates it if not. */
514 ipa_check_create_node_params (void)
516 if (!ipa_node_params_vector
.exists ())
517 ipa_node_params_vector
.create (cgraph_max_uid
);
519 if (ipa_node_params_vector
.length () <= (unsigned) cgraph_max_uid
)
520 ipa_node_params_vector
.safe_grow_cleared (cgraph_max_uid
+ 1);
523 /* This function ensures the array of edge arguments infos is big enough to
524 accommodate a structure for all edges and reallocates it if not. */
527 ipa_check_create_edge_args (void)
529 if (vec_safe_length (ipa_edge_args_vector
) <= (unsigned) cgraph_edge_max_uid
)
530 vec_safe_grow_cleared (ipa_edge_args_vector
, cgraph_edge_max_uid
+ 1);
533 /* Returns true if the array of edge infos is large enough to accommodate an
534 info for EDGE. The main purpose of this function is that debug dumping
535 function can check info availability without causing reallocations. */
538 ipa_edge_args_info_available_for_edge_p (struct cgraph_edge
*edge
)
540 return ((unsigned) edge
->uid
< vec_safe_length (ipa_edge_args_vector
));
543 /* Return the aggregate replacements for NODE, if there are any. */
545 static inline struct ipa_agg_replacement_value
*
546 ipa_get_agg_replacements_for_node (struct cgraph_node
*node
)
548 if ((unsigned) node
->uid
>= vec_safe_length (ipa_node_agg_replacements
))
550 return (*ipa_node_agg_replacements
)[node
->uid
];
553 /* Function formal parameters related computations. */
554 void ipa_initialize_node_params (struct cgraph_node
*node
);
555 bool ipa_propagate_indirect_call_infos (struct cgraph_edge
*cs
,
556 vec
<cgraph_edge_p
> *new_edges
);
558 /* Indirect edge and binfo processing. */
559 tree
ipa_get_indirect_edge_target (struct cgraph_edge
*ie
,
562 vec
<ipa_agg_jump_function_p
> );
563 struct cgraph_edge
*ipa_make_edge_direct_to_target (struct cgraph_edge
*, tree
);
564 tree
ipa_binfo_from_known_type_jfunc (struct ipa_jump_func
*);
565 tree
ipa_intraprocedural_devirtualization (gimple
);
567 /* Functions related to both. */
568 void ipa_analyze_node (struct cgraph_node
*);
570 /* Aggregate jump function related functions. */
571 tree
ipa_find_agg_cst_for_param (struct ipa_agg_jump_function
*, HOST_WIDE_INT
,
573 bool ipa_load_from_parm_agg (struct ipa_node_params
*, gimple
, tree
, int *,
574 HOST_WIDE_INT
*, bool *);
576 /* Debugging interface. */
577 void ipa_print_node_params (FILE *, struct cgraph_node
*node
);
578 void ipa_print_all_params (FILE *);
579 void ipa_print_node_jump_functions (FILE *f
, struct cgraph_node
*node
);
580 void ipa_print_all_jump_functions (FILE * f
);
581 void ipcp_verify_propagated_values (void);
583 extern alloc_pool ipcp_values_pool
;
584 extern alloc_pool ipcp_sources_pool
;
585 extern alloc_pool ipcp_agg_lattice_pool
;
587 /* Structure to describe transformations of formal parameters and actual
588 arguments. Each instance describes one new parameter and they are meant to
589 be stored in a vector. Additionally, most users will probably want to store
590 adjustments about parameters that are being removed altogether so that SSA
591 names belonging to them can be replaced by SSA names of an artificial
593 struct ipa_parm_adjustment
595 /* The original PARM_DECL itself, helpful for processing of the body of the
596 function itself. Intended for traversing function bodies.
597 ipa_modify_formal_parameters, ipa_modify_call_arguments and
598 ipa_combine_adjustments ignore this and use base_index.
599 ipa_modify_formal_parameters actually sets this. */
602 /* Type of the new parameter. However, if by_ref is true, the real type will
603 be a pointer to this type. */
606 /* Alias refrerence type to be used in MEM_REFs when adjusting caller
610 /* The new declaration when creating/replacing a parameter. Created by
611 ipa_modify_formal_parameters, useful for functions modifying the body
615 /* New declaration of a substitute variable that we may use to replace all
616 non-default-def ssa names when a parm decl is going away. */
619 /* If non-NULL and the original parameter is to be removed (copy_param below
620 is NULL), this is going to be its nonlocalized vars value. */
623 /* Offset into the original parameter (for the cases when the new parameter
624 is a component of an original one). */
625 HOST_WIDE_INT offset
;
627 /* Zero based index of the original parameter this one is based on. (ATM
628 there is no way to insert a new parameter out of the blue because there is
629 no need but if it arises the code can be easily exteded to do so.) */
632 /* This new parameter is an unmodified parameter at index base_index. */
633 unsigned copy_param
: 1;
635 /* This adjustment describes a parameter that is about to be removed
636 completely. Most users will probably need to book keep those so that they
637 don't leave behinfd any non default def ssa names belonging to them. */
638 unsigned remove_param
: 1;
640 /* The parameter is to be passed by reference. */
644 typedef struct ipa_parm_adjustment ipa_parm_adjustment_t
;
646 typedef vec
<ipa_parm_adjustment_t
> ipa_parm_adjustment_vec
;
648 vec
<tree
> ipa_get_vector_of_formal_parms (tree fndecl
);
649 void ipa_modify_formal_parameters (tree fndecl
, ipa_parm_adjustment_vec
,
651 void ipa_modify_call_arguments (struct cgraph_edge
*, gimple
,
652 ipa_parm_adjustment_vec
);
653 ipa_parm_adjustment_vec
ipa_combine_adjustments (ipa_parm_adjustment_vec
,
654 ipa_parm_adjustment_vec
);
655 void ipa_dump_param_adjustments (FILE *, ipa_parm_adjustment_vec
, tree
);
656 void ipa_dump_agg_replacement_values (FILE *f
,
657 struct ipa_agg_replacement_value
*av
);
658 void ipa_prop_write_jump_functions (void);
659 void ipa_prop_read_jump_functions (void);
660 void ipa_prop_write_all_agg_replacement (void);
661 void ipa_prop_read_all_agg_replacement (void);
662 void ipa_update_after_lto_read (void);
663 int ipa_get_param_decl_index (struct ipa_node_params
*, tree
);
664 tree
ipa_value_from_jfunc (struct ipa_node_params
*info
,
665 struct ipa_jump_func
*jfunc
);
666 unsigned int ipcp_transform_function (struct cgraph_node
*node
);
667 void ipa_dump_param (FILE *, struct ipa_node_params
*info
, int i
);
670 /* From tree-sra.c: */
671 tree
build_ref_for_offset (location_t
, tree
, HOST_WIDE_INT
, tree
,
672 gimple_stmt_iterator
*, bool);
674 #endif /* IPA_PROP_H */