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 /* ipa-prop.c stuff (ipa-cp, indirect inlining): */
34 /* A jump function for a callsite represents the values passed as actual
35 arguments of the callsite. They were originally proposed in a paper called
36 "Interprocedural Constant Propagation", by David Callahan, Keith D Cooper,
37 Ken Kennedy, Linda Torczon in Comp86, pg 152-161. There are three main
40 Pass-through - the caller's formal parameter is passed as an actual
41 argument, possibly one simple operation performed on it.
42 Constant - a constant (is_gimple_ip_invariant)is passed as an actual
44 Unknown - neither of the above.
46 IPA_JF_ANCESTOR is a special pass-through jump function, which means that
47 the result is an address of a part of the object pointed to by the formal
48 parameter to which the function refers. It is mainly intended to represent
49 getting addresses of of ancestor fields in C++
50 (e.g. &this_1(D)->D.1766.D.1756). Note that if the original pointer is
51 NULL, ancestor jump function must behave like a simple pass-through.
53 Other pass-through functions can either simply pass on an unchanged formal
54 parameter or can apply one simple binary operation to it (such jump
55 functions are called polynomial).
57 IPA_JF_KNOWN_TYPE is a special type of an "unknown" function that applies
58 only to pointer parameters. It means that even though we cannot prove that
59 the passed value is an interprocedural constant, we still know the exact
60 type of the containing object which may be valuable for devirtualization.
62 Jump functions are computed in ipa-prop.c by function
63 update_call_notes_after_inlining. Some information can be lost and jump
64 functions degraded accordingly when inlining, see
65 update_call_notes_after_inlining in the same file. */
69 IPA_JF_UNKNOWN
= 0, /* newly allocated and zeroed jump functions default */
70 IPA_JF_KNOWN_TYPE
, /* represented by field known_type */
71 IPA_JF_CONST
, /* represented by field costant */
72 IPA_JF_PASS_THROUGH
, /* represented by field pass_through */
73 IPA_JF_ANCESTOR
/* represented by field ancestor */
76 /* Structure holding data required to describe a known type jump function. */
77 struct GTY(()) ipa_known_type_data
79 /* Offset of the component of the base_type being described. */
81 /* Type of the whole object. */
83 /* Type of the component of the object that is being described. */
87 /* Structure holding data required to describe a pass-through jump function. */
89 struct GTY(()) ipa_pass_through_data
91 /* If an operation is to be performed on the original parameter, this is the
92 second (constant) operand. */
94 /* Number of the caller's formal parameter being passed. */
96 /* Operation that is performed on the argument before it is passed on.
97 NOP_EXPR means no operation. Otherwise oper must be a simple binary
98 arithmetic operation where the caller's parameter is the first operand and
99 operand field from this structure is the second one. */
100 enum tree_code operation
;
101 /* When the passed value is a pointer, it is set to true only when we are
102 certain that no write to the object it points to has occurred since the
103 caller functions started execution, except for changes noted in the
104 aggregate part of the jump function (see description of
105 ipa_agg_jump_function). The flag is used only when the operation is
110 /* Structure holding data required to describe an ancestor pass-through
113 struct GTY(()) ipa_ancestor_jf_data
115 /* Offset of the field representing the ancestor. */
116 HOST_WIDE_INT offset
;
117 /* Type of the result. */
119 /* Number of the caller's formal parameter being passed. */
121 /* Flag with the same meaning like agg_preserve in ipa_pass_through_data. */
125 /* An element in an aggegate part of a jump function describing a known value
126 at a given offset. When it is part of a pass-through jump function with
127 agg_preserved set or an ancestor jump function with agg_preserved set, all
128 unlisted positions are assumed to be preserved but the value can be a type
129 node, which means that the particular piece (starting at offset and having
130 the size of the type) is clobbered with an unknown value. When
131 agg_preserved is false or the type of the containing jump function is
132 different, all unlisted parts are assumed to be unknown and all values must
133 fullfill is_gimple_ip_invariant. */
135 typedef struct GTY(()) ipa_agg_jf_item
137 /* The offset at which the known value is located within the aggregate. */
138 HOST_WIDE_INT offset
;
140 /* The known constant or type if this is a clobber. */
145 /* Aggregate jump function - i.e. description of contents of aggregates passed
146 either by reference or value. */
148 struct GTY(()) ipa_agg_jump_function
150 /* Description of the individual items. */
151 vec
<ipa_agg_jf_item_t
, va_gc
> *items
;
152 /* True if the data was passed by reference (as opposed to by value). */
156 typedef struct ipa_agg_jump_function
*ipa_agg_jump_function_p
;
157 typedef struct ipa_agg_jump_function ipa_agg_jump_function_t
;
159 /* A jump function for a callsite represents the values passed as actual
160 arguments of the callsite. See enum jump_func_type for the various
161 types of jump functions supported. */
162 typedef struct GTY (()) ipa_jump_func
164 /* Aggregate contants description. See struct ipa_agg_jump_function and its
166 struct ipa_agg_jump_function agg
;
168 enum jump_func_type type
;
169 /* Represents a value of a jump function. pass_through is used only in jump
170 function context. constant represents the actual constant in constant jump
171 functions and member_cst holds constant c++ member functions. */
172 union jump_func_value
174 struct ipa_known_type_data
GTY ((tag ("IPA_JF_KNOWN_TYPE"))) known_type
;
175 tree
GTY ((tag ("IPA_JF_CONST"))) constant
;
176 struct ipa_pass_through_data
GTY ((tag ("IPA_JF_PASS_THROUGH"))) pass_through
;
177 struct ipa_ancestor_jf_data
GTY ((tag ("IPA_JF_ANCESTOR"))) ancestor
;
178 } GTY ((desc ("%1.type"))) value
;
182 /* Return the offset of the component that is decribed by a known type jump
185 static inline HOST_WIDE_INT
186 ipa_get_jf_known_type_offset (struct ipa_jump_func
*jfunc
)
188 gcc_checking_assert (jfunc
->type
== IPA_JF_KNOWN_TYPE
);
189 return jfunc
->value
.known_type
.offset
;
192 /* Return the base type of a known type jump function JFUNC. */
195 ipa_get_jf_known_type_base_type (struct ipa_jump_func
*jfunc
)
197 gcc_checking_assert (jfunc
->type
== IPA_JF_KNOWN_TYPE
);
198 return jfunc
->value
.known_type
.base_type
;
201 /* Return the component type of a known type jump function JFUNC. */
204 ipa_get_jf_known_type_component_type (struct ipa_jump_func
*jfunc
)
206 gcc_checking_assert (jfunc
->type
== IPA_JF_KNOWN_TYPE
);
207 return jfunc
->value
.known_type
.component_type
;
210 /* Return the constant stored in a constant jump functin JFUNC. */
213 ipa_get_jf_constant (struct ipa_jump_func
*jfunc
)
215 gcc_checking_assert (jfunc
->type
== IPA_JF_CONST
);
216 return jfunc
->value
.constant
;
219 /* Return the operand of a pass through jmp function JFUNC. */
222 ipa_get_jf_pass_through_operand (struct ipa_jump_func
*jfunc
)
224 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
225 return jfunc
->value
.pass_through
.operand
;
228 /* Return the number of the caller's formal parameter that a pass through jump
229 function JFUNC refers to. */
232 ipa_get_jf_pass_through_formal_id (struct ipa_jump_func
*jfunc
)
234 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
235 return jfunc
->value
.pass_through
.formal_id
;
238 /* Return operation of a pass through jump function JFUNC. */
240 static inline enum tree_code
241 ipa_get_jf_pass_through_operation (struct ipa_jump_func
*jfunc
)
243 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
244 return jfunc
->value
.pass_through
.operation
;
247 /* Return the agg_preserved flag of a pass through jump functin JFUNC. */
250 ipa_get_jf_pass_through_agg_preserved (struct ipa_jump_func
*jfunc
)
252 gcc_checking_assert (jfunc
->type
== IPA_JF_PASS_THROUGH
);
253 return jfunc
->value
.pass_through
.agg_preserved
;
256 /* Return the offset of an ancestor jump function JFUNC. */
258 static inline HOST_WIDE_INT
259 ipa_get_jf_ancestor_offset (struct ipa_jump_func
*jfunc
)
261 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
262 return jfunc
->value
.ancestor
.offset
;
265 /* Return the result type of an ancestor jump function JFUNC. */
268 ipa_get_jf_ancestor_type (struct ipa_jump_func
*jfunc
)
270 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
271 return jfunc
->value
.ancestor
.type
;
274 /* Return the number of the caller's formal parameter that an ancestor jump
275 function JFUNC refers to. */
278 ipa_get_jf_ancestor_formal_id (struct ipa_jump_func
*jfunc
)
280 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
281 return jfunc
->value
.ancestor
.formal_id
;
284 /* Return the agg_preserved flag of an ancestor jump functin JFUNC. */
287 ipa_get_jf_ancestor_agg_preserved (struct ipa_jump_func
*jfunc
)
289 gcc_checking_assert (jfunc
->type
== IPA_JF_ANCESTOR
);
290 return jfunc
->value
.ancestor
.agg_preserved
;
293 /* Summary describing a single formal parameter. */
295 struct ipa_param_descriptor
297 /* PARAM_DECL of this parameter. */
299 /* The parameter is used. */
303 typedef struct ipa_param_descriptor ipa_param_descriptor_t
;
306 /* ipa_node_params stores information related to formal parameters of functions
307 and some other information for interprocedural passes that operate on
308 parameters (such as ipa-cp). */
310 struct ipa_node_params
312 /* Information about individual formal parameters that are gathered when
313 summaries are generated. */
314 vec
<ipa_param_descriptor_t
> descriptors
;
315 /* Pointer to an array of structures describing individual formal
317 struct ipcp_param_lattices
*lattices
;
318 /* Only for versioned nodes this field would not be NULL,
319 it points to the node that IPA cp cloned from. */
320 struct cgraph_node
*ipcp_orig_node
;
321 /* If this node is an ipa-cp clone, these are the known values that describe
322 what it has been specialized for. */
323 vec
<tree
> known_vals
;
324 /* Whether the param uses analysis has already been performed. */
325 unsigned uses_analysis_done
: 1;
326 /* Whether the function is enqueued in ipa-cp propagation stack. */
327 unsigned node_enqueued
: 1;
328 /* Whether we should create a specialized version based on values that are
329 known to be constant in all contexts. */
330 unsigned do_clone_for_all_contexts
: 1;
331 /* Set if this is an IPA-CP clone for all contexts. */
332 unsigned is_all_contexts_clone
: 1;
333 /* Node has been completely replaced by clones and will be removed after
334 ipa-cp is finished. */
335 unsigned node_dead
: 1;
338 /* ipa_node_params access functions. Please use these to access fields that
339 are or will be shared among various passes. */
341 /* Return the number of formal parameters. */
344 ipa_get_param_count (struct ipa_node_params
*info
)
346 return info
->descriptors
.length ();
349 /* Return the declaration of Ith formal parameter of the function corresponding
350 to INFO. Note there is no setter function as this array is built just once
351 using ipa_initialize_node_params. */
354 ipa_get_param (struct ipa_node_params
*info
, int i
)
356 return info
->descriptors
[i
].decl
;
359 /* Set the used flag corresponding to the Ith formal parameter of the function
360 associated with INFO to VAL. */
363 ipa_set_param_used (struct ipa_node_params
*info
, int i
, bool val
)
365 info
->descriptors
[i
].used
= val
;
368 /* Return the used flag corresponding to the Ith formal parameter of the
369 function associated with INFO. */
372 ipa_is_param_used (struct ipa_node_params
*info
, int i
)
374 return info
->descriptors
[i
].used
;
377 /* Information about replacements done in aggregates for a given node (each
378 node has its linked list). */
379 struct GTY(()) ipa_agg_replacement_value
381 /* Next item in the linked list. */
382 struct ipa_agg_replacement_value
*next
;
383 /* Offset within the aggregate. */
384 HOST_WIDE_INT offset
;
385 /* The constant value. */
387 /* The paramter index. */
391 typedef struct ipa_agg_replacement_value
*ipa_agg_replacement_value_p
;
393 void ipa_set_node_agg_value_chain (struct cgraph_node
*node
,
394 struct ipa_agg_replacement_value
*aggvals
);
396 /* ipa_edge_args stores information related to a callsite and particularly its
397 arguments. It can be accessed by the IPA_EDGE_REF macro. */
398 typedef struct GTY(()) ipa_edge_args
400 /* Vector of the callsite's jump function of each parameter. */
401 vec
<ipa_jump_func_t
, va_gc
> *jump_functions
;
404 /* ipa_edge_args access functions. Please use these to access fields that
405 are or will be shared among various passes. */
407 /* Return the number of actual arguments. */
410 ipa_get_cs_argument_count (struct ipa_edge_args
*args
)
412 return vec_safe_length (args
->jump_functions
);
415 /* Returns a pointer to the jump function for the ith argument. Please note
416 there is no setter function as jump functions are all set up in
417 ipa_compute_jump_functions. */
419 static inline struct ipa_jump_func
*
420 ipa_get_ith_jump_func (struct ipa_edge_args
*args
, int i
)
422 return &(*args
->jump_functions
)[i
];
425 /* Vectors need to have typedefs of structures. */
426 typedef struct ipa_node_params ipa_node_params_t
;
428 /* Types of vectors holding the infos. */
430 /* Vector where the parameter infos are actually stored. */
431 extern vec
<ipa_node_params_t
> ipa_node_params_vector
;
432 /* Vector of known aggregate values in cloned nodes. */
433 extern GTY(()) vec
<ipa_agg_replacement_value_p
, va_gc
> *ipa_node_agg_replacements
;
434 /* Vector where the parameter infos are actually stored. */
435 extern GTY(()) vec
<ipa_edge_args_t
, va_gc
> *ipa_edge_args_vector
;
437 /* Return the associated parameter/argument info corresponding to the given
439 #define IPA_NODE_REF(NODE) (&ipa_node_params_vector[(NODE)->uid])
440 #define IPA_EDGE_REF(EDGE) (&(*ipa_edge_args_vector)[(EDGE)->uid])
441 /* This macro checks validity of index returned by
442 ipa_get_param_decl_index function. */
443 #define IS_VALID_JUMP_FUNC_INDEX(I) ((I) != -1)
445 /* Creating and freeing ipa_node_params and ipa_edge_args. */
446 void ipa_create_all_node_params (void);
447 void ipa_create_all_edge_args (void);
448 void ipa_free_edge_args_substructures (struct ipa_edge_args
*);
449 void ipa_free_node_params_substructures (struct ipa_node_params
*);
450 void ipa_free_all_node_params (void);
451 void ipa_free_all_edge_args (void);
452 void ipa_free_all_structures_after_ipa_cp (void);
453 void ipa_free_all_structures_after_iinln (void);
454 void ipa_register_cgraph_hooks (void);
456 /* This function ensures the array of node param infos is big enough to
457 accommodate a structure for all nodes and reallocates it if not. */
460 ipa_check_create_node_params (void)
462 if (!ipa_node_params_vector
.exists ())
463 ipa_node_params_vector
.create (cgraph_max_uid
);
465 if (ipa_node_params_vector
.length () <= (unsigned) cgraph_max_uid
)
466 ipa_node_params_vector
.safe_grow_cleared (cgraph_max_uid
+ 1);
469 /* This function ensures the array of edge arguments infos is big enough to
470 accommodate a structure for all edges and reallocates it if not. */
473 ipa_check_create_edge_args (void)
475 if (vec_safe_length (ipa_edge_args_vector
) <= (unsigned) cgraph_edge_max_uid
)
476 vec_safe_grow_cleared (ipa_edge_args_vector
, cgraph_edge_max_uid
+ 1);
479 /* Returns true if the array of edge infos is large enough to accommodate an
480 info for EDGE. The main purpose of this function is that debug dumping
481 function can check info availability without causing reallocations. */
484 ipa_edge_args_info_available_for_edge_p (struct cgraph_edge
*edge
)
486 return ((unsigned) edge
->uid
< vec_safe_length (ipa_edge_args_vector
));
489 /* Return the aggregate replacements for NODE, if there are any. */
491 static inline struct ipa_agg_replacement_value
*
492 ipa_get_agg_replacements_for_node (struct cgraph_node
*node
)
494 if ((unsigned) node
->uid
>= vec_safe_length (ipa_node_agg_replacements
))
496 return (*ipa_node_agg_replacements
)[node
->uid
];
499 /* Function formal parameters related computations. */
500 void ipa_initialize_node_params (struct cgraph_node
*node
);
501 bool ipa_propagate_indirect_call_infos (struct cgraph_edge
*cs
,
502 vec
<cgraph_edge_p
> *new_edges
);
504 /* Indirect edge and binfo processing. */
505 tree
ipa_get_indirect_edge_target (struct cgraph_edge
*ie
,
508 vec
<ipa_agg_jump_function_p
> );
509 struct cgraph_edge
*ipa_make_edge_direct_to_target (struct cgraph_edge
*, tree
);
511 /* Functions related to both. */
512 void ipa_analyze_node (struct cgraph_node
*);
514 /* Aggregate jump function related functions. */
515 tree
ipa_find_agg_cst_for_param (struct ipa_agg_jump_function
*, HOST_WIDE_INT
,
517 bool ipa_load_from_parm_agg (struct ipa_node_params
*, gimple
, tree
, int *,
518 HOST_WIDE_INT
*, bool *);
520 /* Debugging interface. */
521 void ipa_print_node_params (FILE *, struct cgraph_node
*node
);
522 void ipa_print_all_params (FILE *);
523 void ipa_print_node_jump_functions (FILE *f
, struct cgraph_node
*node
);
524 void ipa_print_all_jump_functions (FILE * f
);
525 void ipcp_verify_propagated_values (void);
527 extern alloc_pool ipcp_values_pool
;
528 extern alloc_pool ipcp_sources_pool
;
529 extern alloc_pool ipcp_agg_lattice_pool
;
531 /* Structure to describe transformations of formal parameters and actual
532 arguments. Each instance describes one new parameter and they are meant to
533 be stored in a vector. Additionally, most users will probably want to store
534 adjustments about parameters that are being removed altogether so that SSA
535 names belonging to them can be replaced by SSA names of an artificial
537 struct ipa_parm_adjustment
539 /* The original PARM_DECL itself, helpful for processing of the body of the
540 function itself. Intended for traversing function bodies.
541 ipa_modify_formal_parameters, ipa_modify_call_arguments and
542 ipa_combine_adjustments ignore this and use base_index.
543 ipa_modify_formal_parameters actually sets this. */
546 /* Type of the new parameter. However, if by_ref is true, the real type will
547 be a pointer to this type. */
550 /* Alias refrerence type to be used in MEM_REFs when adjusting caller
554 /* The new declaration when creating/replacing a parameter. Created by
555 ipa_modify_formal_parameters, useful for functions modifying the body
559 /* New declaration of a substitute variable that we may use to replace all
560 non-default-def ssa names when a parm decl is going away. */
563 /* If non-NULL and the original parameter is to be removed (copy_param below
564 is NULL), this is going to be its nonlocalized vars value. */
567 /* Offset into the original parameter (for the cases when the new parameter
568 is a component of an original one). */
569 HOST_WIDE_INT offset
;
571 /* Zero based index of the original parameter this one is based on. (ATM
572 there is no way to insert a new parameter out of the blue because there is
573 no need but if it arises the code can be easily exteded to do so.) */
576 /* This new parameter is an unmodified parameter at index base_index. */
577 unsigned copy_param
: 1;
579 /* This adjustment describes a parameter that is about to be removed
580 completely. Most users will probably need to book keep those so that they
581 don't leave behinfd any non default def ssa names belonging to them. */
582 unsigned remove_param
: 1;
584 /* The parameter is to be passed by reference. */
588 typedef struct ipa_parm_adjustment ipa_parm_adjustment_t
;
590 typedef vec
<ipa_parm_adjustment_t
> ipa_parm_adjustment_vec
;
592 vec
<tree
> ipa_get_vector_of_formal_parms (tree fndecl
);
593 void ipa_modify_formal_parameters (tree fndecl
, ipa_parm_adjustment_vec
,
595 void ipa_modify_call_arguments (struct cgraph_edge
*, gimple
,
596 ipa_parm_adjustment_vec
);
597 ipa_parm_adjustment_vec
ipa_combine_adjustments (ipa_parm_adjustment_vec
,
598 ipa_parm_adjustment_vec
);
599 void ipa_dump_param_adjustments (FILE *, ipa_parm_adjustment_vec
, tree
);
600 void ipa_dump_agg_replacement_values (FILE *f
,
601 struct ipa_agg_replacement_value
*av
);
602 void ipa_prop_write_jump_functions (void);
603 void ipa_prop_read_jump_functions (void);
604 void ipa_prop_write_all_agg_replacement (void);
605 void ipa_prop_read_all_agg_replacement (void);
606 void ipa_update_after_lto_read (void);
607 int ipa_get_param_decl_index (struct ipa_node_params
*, tree
);
608 tree
ipa_value_from_jfunc (struct ipa_node_params
*info
,
609 struct ipa_jump_func
*jfunc
);
610 unsigned int ipcp_transform_function (struct cgraph_node
*node
);
613 /* From tree-sra.c: */
614 tree
build_ref_for_offset (location_t
, tree
, HOST_WIDE_INT
, tree
,
615 gimple_stmt_iterator
*, bool);
617 #endif /* IPA_PROP_H */