re PR fortran/88376 (ICE in is_illegal_recursion, at fortran/resolve.c:1689)
[official-gcc.git] / gcc / multiple_target.c
blob589d059424a31e9dafadc17c79a44417138835ba
1 /* Pass for parsing functions with multiple target attributes.
3 Contributed by Evgeny Stupachenko <evstupac@gmail.com>
5 Copyright (C) 2015-2019 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
12 version.
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
17 for more details.
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/>. */
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "backend.h"
27 #include "tree.h"
28 #include "stringpool.h"
29 #include "gimple.h"
30 #include "diagnostic-core.h"
31 #include "gimple-ssa.h"
32 #include "cgraph.h"
33 #include "tree-pass.h"
34 #include "target.h"
35 #include "attribs.h"
36 #include "pretty-print.h"
37 #include "gimple-iterator.h"
38 #include "gimple-walk.h"
39 #include "tree-inline.h"
40 #include "intl.h"
42 /* Walker callback that replaces all FUNCTION_DECL of a function that's
43 going to be versioned. */
45 static tree
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;
55 *walk_subtrees = 0;
58 return NULL;
61 /* If the call in NODE has multiple target attribute with multiple fields,
62 replace it with dispatcher call and create dispatcher (once). */
64 static void
65 create_dispatcher_calls (struct cgraph_node *node)
67 ipa_ref *ref;
69 if (!DECL_FUNCTION_VERSIONED (node->decl)
70 || !is_function_default_version (node->decl))
71 return;
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");
78 return;
80 else if (!targetm.get_function_versions_dispatcher)
82 error_at (DECL_SOURCE_LOCATION (node->decl),
83 "target does not support function version dispatcher");
84 return;
87 tree idecl = targetm.get_function_versions_dispatcher (node->decl);
88 if (!idecl)
90 error_at (DECL_SOURCE_LOCATION (node->decl),
91 "default %<target_clones%> attribute was not set");
92 return;
95 cgraph_node *inode = cgraph_node::get (idecl);
96 gcc_assert (inode);
97 tree resolver_decl = targetm.generate_version_dispatcher_body (inode);
99 /* Update aliases. */
100 inode->alias = true;
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 auto_vec<ipa_ref *> references_to_redirect;
108 for (unsigned i = 0; node->iterate_referring (i, ref); i++)
109 references_to_redirect.safe_push (ref);
111 /* We need to remember NEXT_CALLER as it could be modified in the loop. */
112 for (cgraph_edge *e = node->callers; e ; e = e->next_caller)
113 edges_to_redirect.safe_push (e);
115 if (!edges_to_redirect.is_empty () || !references_to_redirect.is_empty ())
117 /* Redirect edges. */
118 unsigned i;
119 cgraph_edge *e;
120 FOR_EACH_VEC_ELT (edges_to_redirect, i, e)
122 e->redirect_callee (inode);
123 e->redirect_call_stmt_to_callee ();
126 /* Redirect references. */
127 FOR_EACH_VEC_ELT (references_to_redirect, i, ref)
129 if (ref->use == IPA_REF_ADDR)
131 struct walk_stmt_info wi;
132 memset (&wi, 0, sizeof (wi));
133 wi.info = (void *)node->function_version ();
135 if (dyn_cast<varpool_node *> (ref->referring))
137 hash_set<tree> visited_nodes;
138 walk_tree (&DECL_INITIAL (ref->referring->decl),
139 replace_function_decl, &wi, &visited_nodes);
141 else
143 gimple_stmt_iterator it = gsi_for_stmt (ref->stmt);
144 if (ref->referring->decl != resolver_decl)
145 walk_gimple_stmt (&it, NULL, replace_function_decl, &wi);
148 symtab_node *source = ref->referring;
149 ref->remove_reference ();
150 source->create_reference (inode, IPA_REF_ADDR);
152 else if (ref->use == IPA_REF_ALIAS)
154 symtab_node *source = ref->referring;
155 ref->remove_reference ();
156 source->create_reference (inode, IPA_REF_ALIAS);
157 source->add_to_same_comdat_group (inode);
159 else
160 gcc_unreachable ();
164 symtab->change_decl_assembler_name (node->decl,
165 clone_function_name_numbered (
166 node->decl, "default"));
168 /* FIXME: copy of cgraph_node::make_local that should be cleaned up
169 in next stage1. */
170 node->make_decl_local ();
171 node->set_section (NULL);
172 node->set_comdat_group (NULL);
173 node->externally_visible = false;
174 node->forced_by_abi = false;
175 node->set_section (NULL);
176 node->unique_name = ((node->resolution == LDPR_PREVAILING_DEF_IRONLY
177 || node->resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)
178 && !flag_incremental_link);
179 node->resolution = LDPR_PREVAILING_DEF_IRONLY;
181 DECL_ARTIFICIAL (node->decl) = 1;
182 node->force_output = true;
185 /* Return length of attribute names string,
186 if arglist chain > 1, -1 otherwise. */
188 static int
189 get_attr_len (tree arglist)
191 tree arg;
192 int str_len_sum = 0;
193 int argnum = 0;
195 for (arg = arglist; arg; arg = TREE_CHAIN (arg))
197 const char *str = TREE_STRING_POINTER (TREE_VALUE (arg));
198 size_t len = strlen (str);
199 str_len_sum += len + 1;
200 for (const char *p = strchr (str, ','); p; p = strchr (p + 1, ','))
201 argnum++;
202 argnum++;
204 if (argnum <= 1)
205 return -1;
206 return str_len_sum;
209 /* Create string with attributes separated by comma.
210 Return number of attributes. */
212 static int
213 get_attr_str (tree arglist, char *attr_str)
215 tree arg;
216 size_t str_len_sum = 0;
217 int argnum = 0;
219 for (arg = arglist; arg; arg = TREE_CHAIN (arg))
221 const char *str = TREE_STRING_POINTER (TREE_VALUE (arg));
222 size_t len = strlen (str);
223 for (const char *p = strchr (str, ','); p; p = strchr (p + 1, ','))
224 argnum++;
225 memcpy (attr_str + str_len_sum, str, len);
226 attr_str[str_len_sum + len] = TREE_CHAIN (arg) ? ',' : '\0';
227 str_len_sum += len + 1;
228 argnum++;
230 return argnum;
233 /* Return number of attributes separated by comma and put them into ARGS.
234 If there is no DEFAULT attribute return -1. If there is an empty
235 string in attribute return -2. */
237 static int
238 separate_attrs (char *attr_str, char **attrs, int attrnum)
240 int i = 0;
241 int default_count = 0;
243 for (char *attr = strtok (attr_str, ",");
244 attr != NULL; attr = strtok (NULL, ","))
246 if (strcmp (attr, "default") == 0)
248 default_count++;
249 continue;
251 attrs[i++] = attr;
253 if (default_count == 0)
254 return -1;
255 else if (i + default_count < attrnum)
256 return -2;
258 return i;
261 /* Return true if symbol is valid in assembler name. */
263 static bool
264 is_valid_asm_symbol (char c)
266 if ('a' <= c && c <= 'z')
267 return true;
268 if ('A' <= c && c <= 'Z')
269 return true;
270 if ('0' <= c && c <= '9')
271 return true;
272 if (c == '_')
273 return true;
274 return false;
277 /* Replace all not valid assembler symbols with '_'. */
279 static void
280 create_new_asm_name (char *old_asm_name, char *new_asm_name)
282 int i;
283 int old_name_len = strlen (old_asm_name);
285 /* Replace all not valid assembler symbols with '_'. */
286 for (i = 0; i < old_name_len; i++)
287 if (!is_valid_asm_symbol (old_asm_name[i]))
288 new_asm_name[i] = '_';
289 else
290 new_asm_name[i] = old_asm_name[i];
291 new_asm_name[old_name_len] = '\0';
294 /* Creates target clone of NODE. */
296 static cgraph_node *
297 create_target_clone (cgraph_node *node, bool definition, char *name)
299 cgraph_node *new_node;
301 if (definition)
303 new_node = node->create_version_clone_with_body (vNULL, NULL,
304 NULL, false,
305 NULL, NULL,
306 name);
307 new_node->force_output = true;
309 else
311 tree new_decl = copy_node (node->decl);
312 new_node = cgraph_node::get_create (new_decl);
313 /* Generate a new name for the new version. */
314 symtab->change_decl_assembler_name (new_node->decl,
315 clone_function_name_numbered (
316 node->decl, name));
318 return new_node;
321 /* If the function in NODE has multiple target attributes
322 create the appropriate clone for each valid target attribute. */
324 static bool
325 expand_target_clones (struct cgraph_node *node, bool definition)
327 int i;
328 /* Parsing target attributes separated by comma. */
329 tree attr_target = lookup_attribute ("target_clones",
330 DECL_ATTRIBUTES (node->decl));
331 /* No targets specified. */
332 if (!attr_target)
333 return false;
335 tree arglist = TREE_VALUE (attr_target);
336 int attr_len = get_attr_len (arglist);
338 /* No need to clone for 1 target attribute. */
339 if (attr_len == -1)
341 warning_at (DECL_SOURCE_LOCATION (node->decl),
343 "single %<target_clones%> attribute is ignored");
344 return false;
347 if (node->definition
348 && !tree_versionable_function_p (node->decl))
350 auto_diagnostic_group d;
351 error_at (DECL_SOURCE_LOCATION (node->decl),
352 "clones for %<target_clones%> attribute cannot be created");
353 const char *reason = NULL;
354 if (lookup_attribute ("noclone", DECL_ATTRIBUTES (node->decl)))
355 reason = G_("function %q+F can never be copied "
356 "because it has %<noclone%> attribute");
357 else
358 reason = copy_forbidden (DECL_STRUCT_FUNCTION (node->decl));
359 if (reason)
360 inform (DECL_SOURCE_LOCATION (node->decl), reason, node->decl);
361 return false;
364 char *attr_str = XNEWVEC (char, attr_len);
365 int attrnum = get_attr_str (arglist, attr_str);
366 char **attrs = XNEWVEC (char *, attrnum);
368 attrnum = separate_attrs (attr_str, attrs, attrnum);
369 if (attrnum == -1)
371 error_at (DECL_SOURCE_LOCATION (node->decl),
372 "default target was not set");
373 XDELETEVEC (attrs);
374 XDELETEVEC (attr_str);
375 return false;
377 else if (attrnum == -2)
379 error_at (DECL_SOURCE_LOCATION (node->decl),
380 "an empty string cannot be in %<target_clones%> attribute");
381 XDELETEVEC (attrs);
382 XDELETEVEC (attr_str);
383 return false;
386 cgraph_function_version_info *decl1_v = NULL;
387 cgraph_function_version_info *decl2_v = NULL;
388 cgraph_function_version_info *before = NULL;
389 cgraph_function_version_info *after = NULL;
390 decl1_v = node->function_version ();
391 if (decl1_v == NULL)
392 decl1_v = node->insert_new_function_version ();
393 before = decl1_v;
394 DECL_FUNCTION_VERSIONED (node->decl) = 1;
396 for (i = 0; i < attrnum; i++)
398 char *attr = attrs[i];
399 char *suffix = XNEWVEC (char, strlen (attr) + 1);
401 create_new_asm_name (attr, suffix);
402 /* Create new target clone. */
403 cgraph_node *new_node = create_target_clone (node, definition, suffix);
404 new_node->local.local = false;
405 XDELETEVEC (suffix);
407 /* Set new attribute for the clone. */
408 tree attributes = make_attribute ("target", attr,
409 DECL_ATTRIBUTES (new_node->decl));
410 DECL_ATTRIBUTES (new_node->decl) = attributes;
411 location_t saved_loc = input_location;
412 input_location = DECL_SOURCE_LOCATION (node->decl);
413 if (!targetm.target_option.valid_attribute_p (new_node->decl, NULL,
414 TREE_VALUE (attributes),
416 return false;
418 input_location = saved_loc;
419 decl2_v = new_node->function_version ();
420 if (decl2_v != NULL)
421 continue;
422 decl2_v = new_node->insert_new_function_version ();
424 /* Chain decl2_v and decl1_v. All semantically identical versions
425 will be chained together. */
426 after = decl2_v;
427 while (before->next != NULL)
428 before = before->next;
429 while (after->prev != NULL)
430 after = after->prev;
432 before->next = after;
433 after->prev = before;
434 DECL_FUNCTION_VERSIONED (new_node->decl) = 1;
437 XDELETEVEC (attrs);
438 XDELETEVEC (attr_str);
440 /* Setting new attribute to initial function. */
441 tree attributes = make_attribute ("target", "default",
442 DECL_ATTRIBUTES (node->decl));
443 DECL_ATTRIBUTES (node->decl) = attributes;
444 node->local.local = false;
445 location_t saved_loc = input_location;
446 input_location = DECL_SOURCE_LOCATION (node->decl);
447 bool ret
448 = targetm.target_option.valid_attribute_p (node->decl, NULL,
449 TREE_VALUE (attributes), 0);
450 input_location = saved_loc;
451 return ret;
454 /* When NODE is a target clone, consider all callees and redirect
455 to a clone with equal target attributes. That prevents multiple
456 multi-versioning dispatches and a call-chain can be optimized. */
458 static void
459 redirect_to_specific_clone (cgraph_node *node)
461 cgraph_function_version_info *fv = node->function_version ();
462 if (fv == NULL)
463 return;
465 tree attr_target = lookup_attribute ("target", DECL_ATTRIBUTES (node->decl));
466 if (attr_target == NULL_TREE)
467 return;
469 /* We need to remember NEXT_CALLER as it could be modified in the loop. */
470 for (cgraph_edge *e = node->callees; e ; e = e->next_callee)
472 cgraph_function_version_info *fv2 = e->callee->function_version ();
473 if (!fv2)
474 continue;
476 tree attr_target2 = lookup_attribute ("target",
477 DECL_ATTRIBUTES (e->callee->decl));
479 /* Function is not calling proper target clone. */
480 if (!attribute_list_equal (attr_target, attr_target2))
482 while (fv2->prev != NULL)
483 fv2 = fv2->prev;
485 /* Try to find a clone with equal target attribute. */
486 for (; fv2 != NULL; fv2 = fv2->next)
488 cgraph_node *callee = fv2->this_node;
489 attr_target2 = lookup_attribute ("target",
490 DECL_ATTRIBUTES (callee->decl));
491 if (attribute_list_equal (attr_target, attr_target2))
493 e->redirect_callee (callee);
494 e->redirect_call_stmt_to_callee ();
495 break;
502 static unsigned int
503 ipa_target_clone (void)
505 struct cgraph_node *node;
506 auto_vec<cgraph_node *> to_dispatch;
508 FOR_EACH_FUNCTION (node)
509 if (expand_target_clones (node, node->definition))
510 to_dispatch.safe_push (node);
512 for (unsigned i = 0; i < to_dispatch.length (); i++)
513 create_dispatcher_calls (to_dispatch[i]);
515 FOR_EACH_FUNCTION (node)
516 redirect_to_specific_clone (node);
518 return 0;
521 namespace {
523 const pass_data pass_data_target_clone =
525 SIMPLE_IPA_PASS, /* type */
526 "targetclone", /* name */
527 OPTGROUP_NONE, /* optinfo_flags */
528 TV_NONE, /* tv_id */
529 ( PROP_ssa | PROP_cfg ), /* properties_required */
530 0, /* properties_provided */
531 0, /* properties_destroyed */
532 0, /* todo_flags_start */
533 TODO_update_ssa /* todo_flags_finish */
536 class pass_target_clone : public simple_ipa_opt_pass
538 public:
539 pass_target_clone (gcc::context *ctxt)
540 : simple_ipa_opt_pass (pass_data_target_clone, ctxt)
543 /* opt_pass methods: */
544 virtual bool gate (function *);
545 virtual unsigned int execute (function *) { return ipa_target_clone (); }
548 bool
549 pass_target_clone::gate (function *)
551 return true;
554 } // anon namespace
556 simple_ipa_opt_pass *
557 make_pass_target_clone (gcc::context *ctxt)
559 return new pass_target_clone (ctxt);