1 /* Pass for parsing functions with multiple target attributes.
3 Contributed by Evgeny Stupachenko <evstupac@gmail.com>
5 Copyright (C) 2015-2021 Free Software Foundation, Inc.
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
25 #include "coretypes.h"
28 #include "stringpool.h"
30 #include "diagnostic-core.h"
31 #include "gimple-ssa.h"
33 #include "tree-pass.h"
36 #include "pretty-print.h"
37 #include "gimple-iterator.h"
38 #include "gimple-walk.h"
39 #include "tree-inline.h"
42 /* Walker callback that replaces all FUNCTION_DECL of a function that's
43 going to be versioned. */
46 replace_function_decl (tree
*op
, int *walk_subtrees
, void *data
)
48 struct walk_stmt_info
*wi
= (struct walk_stmt_info
*) data
;
49 cgraph_function_version_info
*info
= (cgraph_function_version_info
*)wi
->info
;
51 if (TREE_CODE (*op
) == FUNCTION_DECL
52 && info
->this_node
->decl
== *op
)
54 *op
= info
->dispatcher_resolver
;
61 /* If the call in NODE has multiple target attribute with multiple fields,
62 replace it with dispatcher call and create dispatcher (once). */
65 create_dispatcher_calls (struct cgraph_node
*node
)
69 if (!DECL_FUNCTION_VERSIONED (node
->decl
)
70 || !is_function_default_version (node
->decl
))
73 if (!targetm
.has_ifunc_p ())
75 error_at (DECL_SOURCE_LOCATION (node
->decl
),
76 "the call requires %<ifunc%>, which is not"
77 " supported by this target");
80 else if (!targetm
.get_function_versions_dispatcher
)
82 error_at (DECL_SOURCE_LOCATION (node
->decl
),
83 "target does not support function version dispatcher");
87 tree idecl
= targetm
.get_function_versions_dispatcher (node
->decl
);
90 error_at (DECL_SOURCE_LOCATION (node
->decl
),
91 "default %<target_clones%> attribute was not set");
95 cgraph_node
*inode
= cgraph_node::get (idecl
);
97 tree resolver_decl
= targetm
.generate_version_dispatcher_body (inode
);
101 inode
->alias_target
= resolver_decl
;
102 if (!inode
->analyzed
)
103 inode
->resolve_alias (cgraph_node::get (resolver_decl
));
105 auto_vec
<cgraph_edge
*> edges_to_redirect
;
106 /* We need to capture the references by value rather than just pointers to them
107 and remove them right away, as removing them later would invalidate what
108 some other reference pointers point to. */
109 auto_vec
<ipa_ref
> references_to_redirect
;
111 while (node
->iterate_referring (0, ref
))
113 references_to_redirect
.safe_push (*ref
);
114 ref
->remove_reference ();
117 /* We need to remember NEXT_CALLER as it could be modified in the loop. */
118 for (cgraph_edge
*e
= node
->callers
; e
; e
= e
->next_caller
)
119 edges_to_redirect
.safe_push (e
);
121 if (!edges_to_redirect
.is_empty () || !references_to_redirect
.is_empty ())
123 /* Redirect edges. */
126 FOR_EACH_VEC_ELT (edges_to_redirect
, i
, e
)
128 e
->redirect_callee (inode
);
129 cgraph_edge::redirect_call_stmt_to_callee (e
);
132 /* Redirect references. */
133 FOR_EACH_VEC_ELT (references_to_redirect
, i
, ref
)
135 if (ref
->use
== IPA_REF_ADDR
)
137 struct walk_stmt_info wi
;
138 memset (&wi
, 0, sizeof (wi
));
139 wi
.info
= (void *)node
->function_version ();
141 if (dyn_cast
<varpool_node
*> (ref
->referring
))
143 hash_set
<tree
> visited_nodes
;
144 walk_tree (&DECL_INITIAL (ref
->referring
->decl
),
145 replace_function_decl
, &wi
, &visited_nodes
);
149 gimple_stmt_iterator it
= gsi_for_stmt (ref
->stmt
);
150 if (ref
->referring
->decl
!= resolver_decl
)
151 walk_gimple_stmt (&it
, NULL
, replace_function_decl
, &wi
);
154 symtab_node
*source
= ref
->referring
;
155 source
->create_reference (inode
, IPA_REF_ADDR
);
157 else if (ref
->use
== IPA_REF_ALIAS
)
159 symtab_node
*source
= ref
->referring
;
160 source
->create_reference (inode
, IPA_REF_ALIAS
);
161 if (inode
->get_comdat_group ())
162 source
->add_to_same_comdat_group (inode
);
169 tree fname
= clone_function_name (node
->decl
, "default");
170 symtab
->change_decl_assembler_name (node
->decl
, fname
);
172 if (node
->definition
)
174 /* FIXME: copy of cgraph_node::make_local that should be cleaned up
176 node
->make_decl_local ();
177 node
->set_section (NULL
);
178 node
->set_comdat_group (NULL
);
179 node
->externally_visible
= false;
180 node
->forced_by_abi
= false;
181 node
->set_section (NULL
);
183 DECL_ARTIFICIAL (node
->decl
) = 1;
184 node
->force_output
= true;
188 /* Return length of attribute names string,
189 if arglist chain > 1, -1 otherwise. */
192 get_attr_len (tree arglist
)
198 for (arg
= arglist
; arg
; arg
= TREE_CHAIN (arg
))
200 const char *str
= TREE_STRING_POINTER (TREE_VALUE (arg
));
201 size_t len
= strlen (str
);
202 str_len_sum
+= len
+ 1;
203 for (const char *p
= strchr (str
, ','); p
; p
= strchr (p
+ 1, ','))
212 /* Create string with attributes separated by comma.
213 Return number of attributes. */
216 get_attr_str (tree arglist
, char *attr_str
)
219 size_t str_len_sum
= 0;
222 for (arg
= arglist
; arg
; arg
= TREE_CHAIN (arg
))
224 const char *str
= TREE_STRING_POINTER (TREE_VALUE (arg
));
225 size_t len
= strlen (str
);
226 for (const char *p
= strchr (str
, ','); p
; p
= strchr (p
+ 1, ','))
228 memcpy (attr_str
+ str_len_sum
, str
, len
);
229 attr_str
[str_len_sum
+ len
] = TREE_CHAIN (arg
) ? ',' : '\0';
230 str_len_sum
+= len
+ 1;
236 /* Return number of attributes separated by comma and put them into ARGS.
237 If there is no DEFAULT attribute return -1.
238 If there is an empty string in attribute return -2.
239 If there are multiple DEFAULT attributes return -3.
243 separate_attrs (char *attr_str
, char **attrs
, int attrnum
)
246 int default_count
= 0;
248 for (char *attr
= strtok (attr_str
, ",");
249 attr
!= NULL
; attr
= strtok (NULL
, ","))
251 if (strcmp (attr
, "default") == 0)
258 if (default_count
== 0)
260 else if (default_count
> 1)
262 else if (i
+ default_count
< attrnum
)
268 /* Return true if symbol is valid in assembler name. */
271 is_valid_asm_symbol (char c
)
273 if ('a' <= c
&& c
<= 'z')
275 if ('A' <= c
&& c
<= 'Z')
277 if ('0' <= c
&& c
<= '9')
284 /* Replace all not valid assembler symbols with '_'. */
287 create_new_asm_name (char *old_asm_name
, char *new_asm_name
)
290 int old_name_len
= strlen (old_asm_name
);
292 /* Replace all not valid assembler symbols with '_'. */
293 for (i
= 0; i
< old_name_len
; i
++)
294 if (!is_valid_asm_symbol (old_asm_name
[i
]))
295 new_asm_name
[i
] = '_';
297 new_asm_name
[i
] = old_asm_name
[i
];
298 new_asm_name
[old_name_len
] = '\0';
301 /* Creates target clone of NODE. */
304 create_target_clone (cgraph_node
*node
, bool definition
, char *name
,
307 cgraph_node
*new_node
;
312 = node
->create_version_clone_with_body (vNULL
, NULL
, NULL
, NULL
, NULL
,
313 name
, attributes
, false);
314 if (new_node
== NULL
)
316 new_node
->force_output
= true;
320 tree new_decl
= copy_node (node
->decl
);
321 new_node
= cgraph_node::get_create (new_decl
);
322 DECL_ATTRIBUTES (new_decl
) = attributes
;
323 /* Generate a new name for the new version. */
324 tree fname
= clone_function_name (node
->decl
, name
);
325 symtab
->change_decl_assembler_name (new_node
->decl
, fname
);
330 /* If the function in NODE has multiple target attributes
331 create the appropriate clone for each valid target attribute. */
334 expand_target_clones (struct cgraph_node
*node
, bool definition
)
337 /* Parsing target attributes separated by comma. */
338 tree attr_target
= lookup_attribute ("target_clones",
339 DECL_ATTRIBUTES (node
->decl
));
340 /* No targets specified. */
344 tree arglist
= TREE_VALUE (attr_target
);
345 int attr_len
= get_attr_len (arglist
);
347 /* No need to clone for 1 target attribute. */
350 warning_at (DECL_SOURCE_LOCATION (node
->decl
),
351 0, "single %<target_clones%> attribute is ignored");
356 && (node
->alias
|| !tree_versionable_function_p (node
->decl
)))
358 auto_diagnostic_group d
;
359 error_at (DECL_SOURCE_LOCATION (node
->decl
),
360 "clones for %<target_clones%> attribute cannot be created");
361 const char *reason
= NULL
;
362 if (lookup_attribute ("noclone", DECL_ATTRIBUTES (node
->decl
)))
363 reason
= G_("function %q+F can never be copied "
364 "because it has %<noclone%> attribute");
365 else if (node
->alias
)
367 = "%<target_clones%> cannot be combined with %<alias%> attribute";
369 reason
= copy_forbidden (DECL_STRUCT_FUNCTION (node
->decl
));
371 inform (DECL_SOURCE_LOCATION (node
->decl
), reason
, node
->decl
);
375 char *attr_str
= XNEWVEC (char, attr_len
);
376 int attrnum
= get_attr_str (arglist
, attr_str
);
377 char **attrs
= XNEWVEC (char *, attrnum
);
379 attrnum
= separate_attrs (attr_str
, attrs
, attrnum
);
383 error_at (DECL_SOURCE_LOCATION (node
->decl
),
384 "%<default%> target was not set");
387 error_at (DECL_SOURCE_LOCATION (node
->decl
),
388 "an empty string cannot be in %<target_clones%> attribute");
391 error_at (DECL_SOURCE_LOCATION (node
->decl
),
392 "multiple %<default%> targets were set");
401 XDELETEVEC (attr_str
);
405 cgraph_function_version_info
*decl1_v
= NULL
;
406 cgraph_function_version_info
*decl2_v
= NULL
;
407 cgraph_function_version_info
*before
= NULL
;
408 cgraph_function_version_info
*after
= NULL
;
409 decl1_v
= node
->function_version ();
411 decl1_v
= node
->insert_new_function_version ();
413 DECL_FUNCTION_VERSIONED (node
->decl
) = 1;
415 for (i
= 0; i
< attrnum
; i
++)
417 char *attr
= attrs
[i
];
418 char *suffix
= XNEWVEC (char, strlen (attr
) + 1);
420 create_new_asm_name (attr
, suffix
);
421 /* Create new target clone. */
422 tree attributes
= make_attribute ("target", attr
,
423 DECL_ATTRIBUTES (node
->decl
));
425 cgraph_node
*new_node
= create_target_clone (node
, definition
, suffix
,
427 if (new_node
== NULL
)
429 new_node
->local
= false;
432 decl2_v
= new_node
->function_version ();
435 decl2_v
= new_node
->insert_new_function_version ();
437 /* Chain decl2_v and decl1_v. All semantically identical versions
438 will be chained together. */
440 while (before
->next
!= NULL
)
441 before
= before
->next
;
442 while (after
->prev
!= NULL
)
445 before
->next
= after
;
446 after
->prev
= before
;
447 DECL_FUNCTION_VERSIONED (new_node
->decl
) = 1;
451 XDELETEVEC (attr_str
);
453 /* Setting new attribute to initial function. */
454 tree attributes
= make_attribute ("target", "default",
455 DECL_ATTRIBUTES (node
->decl
));
456 DECL_ATTRIBUTES (node
->decl
) = attributes
;
461 /* When NODE is a target clone, consider all callees and redirect
462 to a clone with equal target attributes. That prevents multiple
463 multi-versioning dispatches and a call-chain can be optimized. */
466 redirect_to_specific_clone (cgraph_node
*node
)
468 cgraph_function_version_info
*fv
= node
->function_version ();
472 tree attr_target
= lookup_attribute ("target", DECL_ATTRIBUTES (node
->decl
));
473 if (attr_target
== NULL_TREE
)
476 /* We need to remember NEXT_CALLER as it could be modified in the loop. */
477 for (cgraph_edge
*e
= node
->callees
; e
; e
= e
->next_callee
)
479 cgraph_function_version_info
*fv2
= e
->callee
->function_version ();
483 tree attr_target2
= lookup_attribute ("target",
484 DECL_ATTRIBUTES (e
->callee
->decl
));
486 /* Function is not calling proper target clone. */
487 if (attr_target2
== NULL_TREE
488 || !attribute_value_equal (attr_target
, attr_target2
))
490 while (fv2
->prev
!= NULL
)
493 /* Try to find a clone with equal target attribute. */
494 for (; fv2
!= NULL
; fv2
= fv2
->next
)
496 cgraph_node
*callee
= fv2
->this_node
;
497 attr_target2
= lookup_attribute ("target",
498 DECL_ATTRIBUTES (callee
->decl
));
499 if (attr_target2
!= NULL_TREE
500 && attribute_value_equal (attr_target
, attr_target2
))
502 e
->redirect_callee (callee
);
503 cgraph_edge::redirect_call_stmt_to_callee (e
);
512 ipa_target_clone (void)
514 struct cgraph_node
*node
;
515 auto_vec
<cgraph_node
*> to_dispatch
;
517 FOR_EACH_FUNCTION (node
)
518 if (expand_target_clones (node
, node
->definition
))
519 to_dispatch
.safe_push (node
);
521 for (unsigned i
= 0; i
< to_dispatch
.length (); i
++)
522 create_dispatcher_calls (to_dispatch
[i
]);
524 FOR_EACH_FUNCTION (node
)
525 redirect_to_specific_clone (node
);
532 const pass_data pass_data_target_clone
=
534 SIMPLE_IPA_PASS
, /* type */
535 "targetclone", /* name */
536 OPTGROUP_NONE
, /* optinfo_flags */
538 ( PROP_ssa
| PROP_cfg
), /* properties_required */
539 0, /* properties_provided */
540 0, /* properties_destroyed */
541 0, /* todo_flags_start */
542 TODO_update_ssa
/* todo_flags_finish */
545 class pass_target_clone
: public simple_ipa_opt_pass
548 pass_target_clone (gcc::context
*ctxt
)
549 : simple_ipa_opt_pass (pass_data_target_clone
, ctxt
)
552 /* opt_pass methods: */
553 virtual bool gate (function
*);
554 virtual unsigned int execute (function
*) { return ipa_target_clone (); }
558 pass_target_clone::gate (function
*)
565 simple_ipa_opt_pass
*
566 make_pass_target_clone (gcc::context
*ctxt
)
568 return new pass_target_clone (ctxt
);