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8b84c596 | 1 | /* Lower TLS operations to emulation functions. |
d1e082c2 | 2 | Copyright (C) 2006-2013 Free Software Foundation, Inc. |
8b84c596 RH |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU General Public License as published by the | |
8 | Free Software Foundation; either version 3, or (at your option) any | |
9 | later version. | |
10 | ||
11 | GCC is distributed in the hope that it will be useful, but WITHOUT | |
12 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
15 | ||
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/>. */ | |
19 | ||
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
23 | #include "tree.h" | |
24 | #include "gimple.h" | |
25 | #include "tree-pass.h" | |
7a300452 | 26 | #include "tree-ssa.h" |
8b84c596 RH |
27 | #include "cgraph.h" |
28 | #include "langhooks.h" | |
29 | #include "target.h" | |
30 | #include "targhooks.h" | |
31 | #include "tree-iterator.h" | |
32 | ||
33 | ||
34 | /* Whenever a target does not support thread-local storage (TLS) natively, | |
35 | we can emulate it with some run-time support in libgcc. This will in | |
36 | turn rely on "keyed storage" a-la pthread_key_create; essentially all | |
37 | thread libraries provide such functionality. | |
38 | ||
39 | In order to coordinate with the libgcc runtime, each TLS variable is | |
40 | described by a "control variable". This control variable records the | |
41 | required size, alignment, and initial value of the TLS variable for | |
42 | instantiation at runtime. It also stores an integer token to be used | |
43 | by the runtime to find the address of the variable within each thread. | |
44 | ||
45 | On the compiler side, this means that we need to replace all instances | |
46 | of "tls_var" in the code with "*__emutls_get_addr(&control_var)". We | |
47 | also need to eliminate "tls_var" from the symbol table and introduce | |
48 | "control_var". | |
49 | ||
50 | We used to perform all of the transformations during conversion to rtl, | |
51 | and the variable substitutions magically within assemble_variable. | |
52 | However, this late fiddling of the symbol table conflicts with LTO and | |
53 | whole-program compilation. Therefore we must now make all the changes | |
54 | to the symbol table early in the GIMPLE optimization path, before we | |
55 | write things out to LTO intermediate files. */ | |
56 | ||
57 | /* These two vectors, once fully populated, are kept in lock-step so that | |
58 | the index of a TLS variable equals the index of its control variable in | |
59 | the other vector. */ | |
60 | static varpool_node_set tls_vars; | |
9771b263 | 61 | static vec<varpool_node_ptr> control_vars; |
8b84c596 RH |
62 | |
63 | /* For the current basic block, an SSA_NAME that has computed the address | |
64 | of the TLS variable at the corresponding index. */ | |
9771b263 | 65 | static vec<tree> access_vars; |
8b84c596 RH |
66 | |
67 | /* The type of the control structure, shared with the emutls.c runtime. */ | |
68 | static tree emutls_object_type; | |
69 | ||
70 | #if !defined (NO_DOT_IN_LABEL) | |
71 | # define EMUTLS_SEPARATOR "." | |
72 | #elif !defined (NO_DOLLAR_IN_LABEL) | |
73 | # define EMUTLS_SEPARATOR "$" | |
74 | #else | |
75 | # define EMUTLS_SEPARATOR "_" | |
76 | #endif | |
77 | ||
78 | /* Create an IDENTIFIER_NODE by prefixing PREFIX to the | |
79 | IDENTIFIER_NODE NAME's name. */ | |
80 | ||
81 | static tree | |
82 | prefix_name (const char *prefix, tree name) | |
83 | { | |
84 | unsigned plen = strlen (prefix); | |
85 | unsigned nlen = strlen (IDENTIFIER_POINTER (name)); | |
86 | char *toname = (char *) alloca (plen + nlen + 1); | |
87 | ||
88 | memcpy (toname, prefix, plen); | |
89 | memcpy (toname + plen, IDENTIFIER_POINTER (name), nlen + 1); | |
90 | ||
91 | return get_identifier (toname); | |
92 | } | |
93 | ||
94 | /* Create an identifier for the struct __emutls_object, given an identifier | |
95 | of the DECL_ASSEMBLY_NAME of the original object. */ | |
96 | ||
97 | static tree | |
98 | get_emutls_object_name (tree name) | |
99 | { | |
100 | const char *prefix = (targetm.emutls.var_prefix | |
101 | ? targetm.emutls.var_prefix | |
102 | : "__emutls_v" EMUTLS_SEPARATOR); | |
103 | return prefix_name (prefix, name); | |
104 | } | |
105 | ||
106 | /* Create the fields of the type for the control variables. Ordinarily | |
107 | this must match struct __emutls_object defined in emutls.c. However | |
108 | this is a target hook so that VxWorks can define its own layout. */ | |
109 | ||
110 | tree | |
111 | default_emutls_var_fields (tree type, tree *name ATTRIBUTE_UNUSED) | |
112 | { | |
113 | tree word_type_node, field, next_field; | |
114 | ||
115 | field = build_decl (UNKNOWN_LOCATION, | |
116 | FIELD_DECL, get_identifier ("__templ"), ptr_type_node); | |
117 | DECL_CONTEXT (field) = type; | |
118 | next_field = field; | |
119 | ||
120 | field = build_decl (UNKNOWN_LOCATION, | |
121 | FIELD_DECL, get_identifier ("__offset"), | |
122 | ptr_type_node); | |
123 | DECL_CONTEXT (field) = type; | |
124 | DECL_CHAIN (field) = next_field; | |
125 | next_field = field; | |
126 | ||
127 | word_type_node = lang_hooks.types.type_for_mode (word_mode, 1); | |
128 | field = build_decl (UNKNOWN_LOCATION, | |
129 | FIELD_DECL, get_identifier ("__align"), | |
130 | word_type_node); | |
131 | DECL_CONTEXT (field) = type; | |
132 | DECL_CHAIN (field) = next_field; | |
133 | next_field = field; | |
134 | ||
135 | field = build_decl (UNKNOWN_LOCATION, | |
136 | FIELD_DECL, get_identifier ("__size"), word_type_node); | |
137 | DECL_CONTEXT (field) = type; | |
138 | DECL_CHAIN (field) = next_field; | |
139 | ||
140 | return field; | |
141 | } | |
142 | ||
143 | /* Initialize emulated tls object TO, which refers to TLS variable DECL and | |
144 | is initialized by PROXY. As above, this is the default implementation of | |
145 | a target hook overridden by VxWorks. */ | |
146 | ||
147 | tree | |
148 | default_emutls_var_init (tree to, tree decl, tree proxy) | |
149 | { | |
9771b263 DN |
150 | vec<constructor_elt, va_gc> *v; |
151 | vec_alloc (v, 4); | |
f32682ca | 152 | constructor_elt elt; |
8b84c596 RH |
153 | tree type = TREE_TYPE (to); |
154 | tree field = TYPE_FIELDS (type); | |
155 | ||
f32682ca DN |
156 | elt.index = field; |
157 | elt.value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl)); | |
9771b263 | 158 | v->quick_push (elt); |
8b84c596 | 159 | |
8b84c596 | 160 | field = DECL_CHAIN (field); |
f32682ca DN |
161 | elt.index = field; |
162 | elt.value = build_int_cst (TREE_TYPE (field), | |
163 | DECL_ALIGN_UNIT (decl)); | |
9771b263 | 164 | v->quick_push (elt); |
8b84c596 | 165 | |
8b84c596 | 166 | field = DECL_CHAIN (field); |
f32682ca DN |
167 | elt.index = field; |
168 | elt.value = null_pointer_node; | |
9771b263 | 169 | v->quick_push (elt); |
8b84c596 | 170 | |
8b84c596 | 171 | field = DECL_CHAIN (field); |
f32682ca DN |
172 | elt.index = field; |
173 | elt.value = proxy; | |
9771b263 | 174 | v->quick_push (elt); |
8b84c596 RH |
175 | |
176 | return build_constructor (type, v); | |
177 | } | |
178 | ||
179 | /* Create the structure for struct __emutls_object. This should match the | |
180 | structure at the top of emutls.c, modulo the union there. */ | |
181 | ||
182 | static tree | |
183 | get_emutls_object_type (void) | |
184 | { | |
185 | tree type, type_name, field; | |
186 | ||
187 | type = emutls_object_type; | |
188 | if (type) | |
189 | return type; | |
190 | ||
191 | emutls_object_type = type = lang_hooks.types.make_type (RECORD_TYPE); | |
192 | type_name = NULL; | |
193 | field = targetm.emutls.var_fields (type, &type_name); | |
194 | if (!type_name) | |
195 | type_name = get_identifier ("__emutls_object"); | |
196 | type_name = build_decl (UNKNOWN_LOCATION, | |
197 | TYPE_DECL, type_name, type); | |
198 | TYPE_NAME (type) = type_name; | |
199 | TYPE_FIELDS (type) = field; | |
200 | layout_type (type); | |
201 | ||
202 | return type; | |
203 | } | |
204 | ||
205 | /* Create a read-only variable like DECL, with the same DECL_INITIAL. | |
206 | This will be used for initializing the emulated tls data area. */ | |
207 | ||
208 | static tree | |
209 | get_emutls_init_templ_addr (tree decl) | |
210 | { | |
211 | tree name, to; | |
212 | ||
213 | if (targetm.emutls.register_common && !DECL_INITIAL (decl) | |
214 | && !DECL_SECTION_NAME (decl)) | |
215 | return null_pointer_node; | |
216 | ||
217 | name = DECL_ASSEMBLER_NAME (decl); | |
218 | if (!targetm.emutls.tmpl_prefix || targetm.emutls.tmpl_prefix[0]) | |
219 | { | |
220 | const char *prefix = (targetm.emutls.tmpl_prefix | |
221 | ? targetm.emutls.tmpl_prefix | |
222 | : "__emutls_t" EMUTLS_SEPARATOR); | |
223 | name = prefix_name (prefix, name); | |
224 | } | |
225 | ||
226 | to = build_decl (DECL_SOURCE_LOCATION (decl), | |
227 | VAR_DECL, name, TREE_TYPE (decl)); | |
228 | SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to)); | |
229 | ||
230 | DECL_ARTIFICIAL (to) = 1; | |
231 | TREE_USED (to) = TREE_USED (decl); | |
232 | TREE_READONLY (to) = 1; | |
233 | DECL_IGNORED_P (to) = 1; | |
234 | DECL_CONTEXT (to) = DECL_CONTEXT (decl); | |
235 | DECL_SECTION_NAME (to) = DECL_SECTION_NAME (decl); | |
236 | DECL_PRESERVE_P (to) = DECL_PRESERVE_P (decl); | |
237 | ||
238 | DECL_WEAK (to) = DECL_WEAK (decl); | |
239 | if (DECL_ONE_ONLY (decl)) | |
240 | { | |
241 | make_decl_one_only (to, DECL_ASSEMBLER_NAME (to)); | |
242 | TREE_STATIC (to) = TREE_STATIC (decl); | |
243 | TREE_PUBLIC (to) = TREE_PUBLIC (decl); | |
244 | DECL_VISIBILITY (to) = DECL_VISIBILITY (decl); | |
245 | } | |
246 | else | |
247 | TREE_STATIC (to) = 1; | |
248 | ||
249 | DECL_VISIBILITY_SPECIFIED (to) = DECL_VISIBILITY_SPECIFIED (decl); | |
250 | DECL_INITIAL (to) = DECL_INITIAL (decl); | |
251 | DECL_INITIAL (decl) = NULL; | |
252 | ||
253 | if (targetm.emutls.tmpl_section) | |
254 | { | |
255 | DECL_SECTION_NAME (to) | |
256 | = build_string (strlen (targetm.emutls.tmpl_section), | |
257 | targetm.emutls.tmpl_section); | |
258 | } | |
259 | ||
1c799342 JH |
260 | /* Create varpool node for the new variable and finalize it if it is |
261 | not external one. */ | |
262 | if (DECL_EXTERNAL (to)) | |
5d59b5e1 | 263 | varpool_node_for_decl (to); |
1c799342 | 264 | else |
38877e98 | 265 | varpool_add_new_variable (to); |
8b84c596 RH |
266 | return build_fold_addr_expr (to); |
267 | } | |
268 | ||
269 | /* Create and return the control variable for the TLS variable DECL. */ | |
270 | ||
271 | static tree | |
75d3e6e3 | 272 | new_emutls_decl (tree decl, tree alias_of) |
8b84c596 RH |
273 | { |
274 | tree name, to; | |
275 | ||
276 | name = DECL_ASSEMBLER_NAME (decl); | |
277 | to = build_decl (DECL_SOURCE_LOCATION (decl), VAR_DECL, | |
278 | get_emutls_object_name (name), | |
279 | get_emutls_object_type ()); | |
280 | ||
281 | SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to)); | |
282 | ||
283 | DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED; | |
284 | DECL_ARTIFICIAL (to) = 1; | |
285 | DECL_IGNORED_P (to) = 1; | |
286 | TREE_READONLY (to) = 0; | |
287 | TREE_STATIC (to) = 1; | |
288 | ||
289 | DECL_PRESERVE_P (to) = DECL_PRESERVE_P (decl); | |
290 | DECL_CONTEXT (to) = DECL_CONTEXT (decl); | |
291 | TREE_USED (to) = TREE_USED (decl); | |
292 | TREE_PUBLIC (to) = TREE_PUBLIC (decl); | |
293 | DECL_EXTERNAL (to) = DECL_EXTERNAL (decl); | |
294 | DECL_COMMON (to) = DECL_COMMON (decl); | |
295 | DECL_WEAK (to) = DECL_WEAK (decl); | |
296 | DECL_VISIBILITY (to) = DECL_VISIBILITY (decl); | |
297 | DECL_VISIBILITY_SPECIFIED (to) = DECL_VISIBILITY_SPECIFIED (decl); | |
8b84c596 RH |
298 | DECL_DLLIMPORT_P (to) = DECL_DLLIMPORT_P (decl); |
299 | ||
300 | DECL_ATTRIBUTES (to) = targetm.merge_decl_attributes (decl, to); | |
301 | ||
302 | if (DECL_ONE_ONLY (decl)) | |
303 | make_decl_one_only (to, DECL_ASSEMBLER_NAME (to)); | |
304 | ||
305 | /* If we're not allowed to change the proxy object's alignment, | |
306 | pretend it has been set by the user. */ | |
307 | if (targetm.emutls.var_align_fixed) | |
308 | DECL_USER_ALIGN (to) = 1; | |
309 | ||
310 | /* If the target wants the control variables grouped, do so. */ | |
311 | if (!DECL_COMMON (to) && targetm.emutls.var_section) | |
312 | { | |
313 | DECL_SECTION_NAME (to) | |
a4a83796 OH |
314 | = build_string (strlen (targetm.emutls.var_section), |
315 | targetm.emutls.var_section); | |
8b84c596 RH |
316 | } |
317 | ||
318 | /* If this variable is defined locally, then we need to initialize the | |
319 | control structure with size and alignment information. Initialization | |
320 | of COMMON block variables happens elsewhere via a constructor. */ | |
321 | if (!DECL_EXTERNAL (to) | |
322 | && (!DECL_COMMON (to) | |
323 | || (DECL_INITIAL (decl) | |
324 | && DECL_INITIAL (decl) != error_mark_node))) | |
325 | { | |
326 | tree tmpl = get_emutls_init_templ_addr (decl); | |
327 | DECL_INITIAL (to) = targetm.emutls.var_init (to, decl, tmpl); | |
328 | record_references_in_initializer (to, false); | |
329 | } | |
330 | ||
1c799342 JH |
331 | /* Create varpool node for the new variable and finalize it if it is |
332 | not external one. */ | |
333 | if (DECL_EXTERNAL (to)) | |
5d59b5e1 | 334 | varpool_node_for_decl (to); |
75d3e6e3 | 335 | else if (!alias_of) |
38877e98 | 336 | varpool_add_new_variable (to); |
75d3e6e3 JH |
337 | else |
338 | varpool_create_variable_alias (to, | |
339 | varpool_node_for_asm | |
f95f017c | 340 | (DECL_ASSEMBLER_NAME (DECL_VALUE_EXPR (alias_of)))->symbol.decl); |
8b84c596 RH |
341 | return to; |
342 | } | |
343 | ||
344 | /* Look up the index of the TLS variable DECL. This index can then be | |
345 | used in both the control_vars and access_vars arrays. */ | |
346 | ||
347 | static unsigned int | |
348 | emutls_index (tree decl) | |
349 | { | |
350 | varpool_node_set_iterator i; | |
351 | ||
352 | i = varpool_node_set_find (tls_vars, varpool_get_node (decl)); | |
353 | gcc_assert (i.index != ~0u); | |
354 | ||
355 | return i.index; | |
356 | } | |
357 | ||
358 | /* Look up the control variable for the TLS variable DECL. */ | |
359 | ||
360 | static tree | |
361 | emutls_decl (tree decl) | |
362 | { | |
363 | struct varpool_node *var; | |
364 | unsigned int i; | |
365 | ||
366 | i = emutls_index (decl); | |
9771b263 | 367 | var = control_vars[i]; |
960bfb69 | 368 | return var->symbol.decl; |
8b84c596 RH |
369 | } |
370 | ||
371 | /* Generate a call statement to initialize CONTROL_DECL for TLS_DECL. | |
372 | This only needs to happen for TLS COMMON variables; non-COMMON | |
373 | variables can be initialized statically. Insert the generated | |
374 | call statement at the end of PSTMTS. */ | |
375 | ||
376 | static void | |
377 | emutls_common_1 (tree tls_decl, tree control_decl, tree *pstmts) | |
378 | { | |
379 | tree x; | |
380 | tree word_type_node; | |
381 | ||
382 | if (! DECL_COMMON (tls_decl) | |
383 | || (DECL_INITIAL (tls_decl) | |
384 | && DECL_INITIAL (tls_decl) != error_mark_node)) | |
385 | return; | |
386 | ||
387 | word_type_node = lang_hooks.types.type_for_mode (word_mode, 1); | |
388 | ||
e79983f4 MM |
389 | x = build_call_expr (builtin_decl_explicit (BUILT_IN_EMUTLS_REGISTER_COMMON), |
390 | 4, build_fold_addr_expr (control_decl), | |
8b84c596 RH |
391 | fold_convert (word_type_node, |
392 | DECL_SIZE_UNIT (tls_decl)), | |
393 | build_int_cst (word_type_node, | |
394 | DECL_ALIGN_UNIT (tls_decl)), | |
395 | get_emutls_init_templ_addr (tls_decl)); | |
396 | ||
397 | append_to_statement_list (x, pstmts); | |
398 | } | |
399 | ||
400 | struct lower_emutls_data | |
401 | { | |
402 | struct cgraph_node *cfun_node; | |
403 | struct cgraph_node *builtin_node; | |
404 | tree builtin_decl; | |
405 | basic_block bb; | |
406 | int bb_freq; | |
407 | location_t loc; | |
408 | gimple_seq seq; | |
409 | }; | |
410 | ||
411 | /* Given a TLS variable DECL, return an SSA_NAME holding its address. | |
412 | Append any new computation statements required to D->SEQ. */ | |
413 | ||
414 | static tree | |
415 | gen_emutls_addr (tree decl, struct lower_emutls_data *d) | |
416 | { | |
417 | unsigned int index; | |
418 | tree addr; | |
419 | ||
420 | /* Compute the address of the TLS variable with help from runtime. */ | |
421 | index = emutls_index (decl); | |
9771b263 | 422 | addr = access_vars[index]; |
8b84c596 RH |
423 | if (addr == NULL) |
424 | { | |
425 | struct varpool_node *cvar; | |
426 | tree cdecl; | |
427 | gimple x; | |
428 | ||
9771b263 | 429 | cvar = control_vars[index]; |
960bfb69 | 430 | cdecl = cvar->symbol.decl; |
8b84c596 RH |
431 | TREE_ADDRESSABLE (cdecl) = 1; |
432 | ||
433 | addr = create_tmp_var (build_pointer_type (TREE_TYPE (decl)), NULL); | |
434 | x = gimple_build_call (d->builtin_decl, 1, build_fold_addr_expr (cdecl)); | |
435 | gimple_set_location (x, d->loc); | |
436 | ||
437 | addr = make_ssa_name (addr, x); | |
438 | gimple_call_set_lhs (x, addr); | |
439 | ||
440 | gimple_seq_add_stmt (&d->seq, x); | |
441 | ||
442 | cgraph_create_edge (d->cfun_node, d->builtin_node, x, | |
898b8927 | 443 | d->bb->count, d->bb_freq); |
8b84c596 RH |
444 | |
445 | /* We may be adding a new reference to a new variable to the function. | |
446 | This means we have to play with the ipa-reference web. */ | |
5932a4d4 | 447 | ipa_record_reference ((symtab_node)d->cfun_node, (symtab_node)cvar, IPA_REF_ADDR, x); |
8b84c596 RH |
448 | |
449 | /* Record this ssa_name for possible use later in the basic block. */ | |
9771b263 | 450 | access_vars[index] = addr; |
8b84c596 RH |
451 | } |
452 | ||
453 | return addr; | |
454 | } | |
455 | ||
456 | /* Callback for walk_gimple_op. D = WI->INFO is a struct lower_emutls_data. | |
457 | Given an operand *PTR within D->STMT, if the operand references a TLS | |
458 | variable, then lower the reference to a call to the runtime. Insert | |
459 | any new statements required into D->SEQ; the caller is responsible for | |
460 | placing those appropriately. */ | |
461 | ||
462 | static tree | |
463 | lower_emutls_1 (tree *ptr, int *walk_subtrees, void *cb_data) | |
464 | { | |
465 | struct walk_stmt_info *wi = (struct walk_stmt_info *) cb_data; | |
466 | struct lower_emutls_data *d = (struct lower_emutls_data *) wi->info; | |
467 | tree t = *ptr; | |
468 | bool is_addr = false; | |
469 | tree addr; | |
470 | ||
471 | *walk_subtrees = 0; | |
472 | ||
473 | switch (TREE_CODE (t)) | |
474 | { | |
475 | case ADDR_EXPR: | |
476 | /* If this is not a straight-forward "&var", but rather something | |
477 | like "&var.a", then we may need special handling. */ | |
478 | if (TREE_CODE (TREE_OPERAND (t, 0)) != VAR_DECL) | |
479 | { | |
480 | bool save_changed; | |
481 | ||
482 | /* If we're allowed more than just is_gimple_val, continue. */ | |
483 | if (!wi->val_only) | |
484 | { | |
485 | *walk_subtrees = 1; | |
486 | return NULL_TREE; | |
487 | } | |
488 | ||
489 | /* See if any substitution would be made. */ | |
490 | save_changed = wi->changed; | |
491 | wi->changed = false; | |
492 | wi->val_only = false; | |
493 | walk_tree (&TREE_OPERAND (t, 0), lower_emutls_1, wi, NULL); | |
494 | wi->val_only = true; | |
495 | ||
496 | /* If so, then extract this entire sub-expression "&p->a" into a | |
497 | new assignment statement, and substitute yet another SSA_NAME. */ | |
498 | if (wi->changed) | |
499 | { | |
500 | gimple x; | |
501 | ||
502 | addr = create_tmp_var (TREE_TYPE (t), NULL); | |
503 | x = gimple_build_assign (addr, t); | |
504 | gimple_set_location (x, d->loc); | |
505 | ||
506 | addr = make_ssa_name (addr, x); | |
507 | gimple_assign_set_lhs (x, addr); | |
508 | ||
509 | gimple_seq_add_stmt (&d->seq, x); | |
510 | ||
511 | *ptr = addr; | |
512 | } | |
513 | else | |
514 | wi->changed = save_changed; | |
515 | ||
516 | return NULL_TREE; | |
517 | } | |
518 | ||
519 | t = TREE_OPERAND (t, 0); | |
520 | is_addr = true; | |
521 | /* FALLTHRU */ | |
522 | ||
523 | case VAR_DECL: | |
524 | if (!DECL_THREAD_LOCAL_P (t)) | |
525 | return NULL_TREE; | |
526 | break; | |
527 | ||
528 | default: | |
529 | /* We're not interested in other decls or types, only subexpressions. */ | |
530 | if (EXPR_P (t)) | |
531 | *walk_subtrees = 1; | |
532 | /* FALLTHRU */ | |
533 | ||
534 | case SSA_NAME: | |
535 | /* Special-case the return of SSA_NAME, since it's so common. */ | |
536 | return NULL_TREE; | |
537 | } | |
538 | ||
539 | addr = gen_emutls_addr (t, d); | |
540 | if (is_addr) | |
541 | { | |
542 | /* Replace "&var" with "addr" in the statement. */ | |
543 | *ptr = addr; | |
544 | } | |
545 | else | |
546 | { | |
547 | /* Replace "var" with "*addr" in the statement. */ | |
548 | t = build2 (MEM_REF, TREE_TYPE (t), addr, | |
549 | build_int_cst (TREE_TYPE (addr), 0)); | |
550 | *ptr = t; | |
551 | } | |
552 | ||
553 | wi->changed = true; | |
554 | return NULL_TREE; | |
555 | } | |
556 | ||
557 | /* Lower all of the operands of STMT. */ | |
558 | ||
559 | static void | |
560 | lower_emutls_stmt (gimple stmt, struct lower_emutls_data *d) | |
561 | { | |
562 | struct walk_stmt_info wi; | |
563 | ||
564 | d->loc = gimple_location (stmt); | |
565 | ||
566 | memset (&wi, 0, sizeof (wi)); | |
567 | wi.info = d; | |
568 | wi.val_only = true; | |
569 | walk_gimple_op (stmt, lower_emutls_1, &wi); | |
570 | ||
571 | if (wi.changed) | |
572 | update_stmt (stmt); | |
573 | } | |
574 | ||
575 | /* Lower the I'th operand of PHI. */ | |
576 | ||
577 | static void | |
578 | lower_emutls_phi_arg (gimple phi, unsigned int i, struct lower_emutls_data *d) | |
579 | { | |
580 | struct walk_stmt_info wi; | |
581 | struct phi_arg_d *pd = gimple_phi_arg (phi, i); | |
582 | ||
583 | /* Early out for a very common case we don't care about. */ | |
584 | if (TREE_CODE (pd->def) == SSA_NAME) | |
585 | return; | |
586 | ||
587 | d->loc = pd->locus; | |
588 | ||
589 | memset (&wi, 0, sizeof (wi)); | |
590 | wi.info = d; | |
591 | wi.val_only = true; | |
592 | walk_tree (&pd->def, lower_emutls_1, &wi, NULL); | |
593 | ||
594 | /* For normal statements, we let update_stmt do its job. But for phi | |
595 | nodes, we have to manipulate the immediate use list by hand. */ | |
596 | if (wi.changed) | |
597 | { | |
598 | gcc_assert (TREE_CODE (pd->def) == SSA_NAME); | |
599 | link_imm_use_stmt (&pd->imm_use, pd->def, phi); | |
600 | } | |
601 | } | |
602 | ||
603 | /* Clear the ACCESS_VARS array, in order to begin a new block. */ | |
604 | ||
605 | static inline void | |
606 | clear_access_vars (void) | |
607 | { | |
9771b263 | 608 | memset (access_vars.address (), 0, |
c3284718 | 609 | access_vars.length () * sizeof (tree)); |
8b84c596 RH |
610 | } |
611 | ||
612 | /* Lower the entire function NODE. */ | |
613 | ||
614 | static void | |
615 | lower_emutls_function_body (struct cgraph_node *node) | |
616 | { | |
617 | struct lower_emutls_data d; | |
618 | bool any_edge_inserts = false; | |
619 | ||
960bfb69 | 620 | push_cfun (DECL_STRUCT_FUNCTION (node->symbol.decl)); |
8b84c596 RH |
621 | |
622 | d.cfun_node = node; | |
e79983f4 | 623 | d.builtin_decl = builtin_decl_explicit (BUILT_IN_EMUTLS_GET_ADDRESS); |
8e5837bc MJ |
624 | /* This is where we introduce the declaration to the IL and so we have to |
625 | create a node for it. */ | |
626 | d.builtin_node = cgraph_get_create_node (d.builtin_decl); | |
8b84c596 RH |
627 | |
628 | FOR_EACH_BB (d.bb) | |
629 | { | |
630 | gimple_stmt_iterator gsi; | |
631 | unsigned int i, nedge; | |
632 | ||
633 | /* Lower each of the PHI nodes of the block, as we may have | |
634 | propagated &tlsvar into a PHI argument. These loops are | |
635 | arranged so that we process each edge at once, and each | |
636 | PHI argument for that edge. */ | |
637 | if (!gimple_seq_empty_p (phi_nodes (d.bb))) | |
638 | { | |
639 | /* The calls will be inserted on the edges, and the frequencies | |
640 | will be computed during the commit process. */ | |
641 | d.bb_freq = 0; | |
642 | ||
643 | nedge = EDGE_COUNT (d.bb->preds); | |
644 | for (i = 0; i < nedge; ++i) | |
645 | { | |
646 | edge e = EDGE_PRED (d.bb, i); | |
647 | ||
648 | /* We can re-use any SSA_NAME created on this edge. */ | |
649 | clear_access_vars (); | |
650 | d.seq = NULL; | |
651 | ||
652 | for (gsi = gsi_start_phis (d.bb); | |
653 | !gsi_end_p (gsi); | |
654 | gsi_next (&gsi)) | |
655 | lower_emutls_phi_arg (gsi_stmt (gsi), i, &d); | |
656 | ||
657 | /* Insert all statements generated by all phi nodes for this | |
658 | particular edge all at once. */ | |
659 | if (d.seq) | |
660 | { | |
661 | gsi_insert_seq_on_edge (e, d.seq); | |
662 | any_edge_inserts = true; | |
663 | } | |
664 | } | |
665 | } | |
666 | ||
667 | d.bb_freq = compute_call_stmt_bb_frequency (current_function_decl, d.bb); | |
668 | ||
669 | /* We can re-use any SSA_NAME created during this basic block. */ | |
670 | clear_access_vars (); | |
671 | ||
672 | /* Lower each of the statements of the block. */ | |
673 | for (gsi = gsi_start_bb (d.bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
674 | { | |
675 | d.seq = NULL; | |
676 | lower_emutls_stmt (gsi_stmt (gsi), &d); | |
677 | ||
678 | /* If any new statements were created, insert them immediately | |
679 | before the first use. This prevents variable lifetimes from | |
680 | becoming unnecessarily long. */ | |
681 | if (d.seq) | |
682 | gsi_insert_seq_before (&gsi, d.seq, GSI_SAME_STMT); | |
683 | } | |
684 | } | |
685 | ||
686 | if (any_edge_inserts) | |
687 | gsi_commit_edge_inserts (); | |
688 | ||
689 | pop_cfun (); | |
8b84c596 RH |
690 | } |
691 | ||
75d3e6e3 JH |
692 | /* Create emutls variable for VAR, DATA is pointer to static |
693 | ctor body we can add constructors to. | |
694 | Callback for varpool_for_variable_and_aliases. */ | |
695 | ||
696 | static bool | |
697 | create_emultls_var (struct varpool_node *var, void *data) | |
698 | { | |
699 | tree cdecl; | |
700 | struct varpool_node *cvar; | |
701 | ||
40a7fe1e JH |
702 | cdecl = new_emutls_decl (var->symbol.decl, |
703 | var->symbol.alias && var->symbol.analyzed | |
704 | ? varpool_alias_target (var)->symbol.decl : NULL); | |
75d3e6e3 JH |
705 | |
706 | cvar = varpool_get_node (cdecl); | |
9771b263 | 707 | control_vars.quick_push (cvar); |
75d3e6e3 | 708 | |
e70670cf | 709 | if (!var->symbol.alias) |
75d3e6e3 JH |
710 | { |
711 | /* Make sure the COMMON block control variable gets initialized. | |
712 | Note that there's no point in doing this for aliases; we only | |
713 | need to do this once for the main variable. */ | |
960bfb69 | 714 | emutls_common_1 (var->symbol.decl, cdecl, (tree *)data); |
75d3e6e3 | 715 | } |
40a7fe1e | 716 | if (var->symbol.alias && !var->symbol.analyzed) |
e70670cf | 717 | cvar->symbol.alias = true; |
75d3e6e3 JH |
718 | |
719 | /* Indicate that the value of the TLS variable may be found elsewhere, | |
720 | preventing the variable from re-appearing in the GIMPLE. We cheat | |
721 | and use the control variable here (rather than a full call_expr), | |
722 | which is special-cased inside the DWARF2 output routines. */ | |
960bfb69 JH |
723 | SET_DECL_VALUE_EXPR (var->symbol.decl, cdecl); |
724 | DECL_HAS_VALUE_EXPR_P (var->symbol.decl) = 1; | |
75d3e6e3 JH |
725 | return false; |
726 | } | |
727 | ||
8b84c596 RH |
728 | /* Main entry point to the tls lowering pass. */ |
729 | ||
730 | static unsigned int | |
731 | ipa_lower_emutls (void) | |
732 | { | |
733 | struct varpool_node *var; | |
734 | struct cgraph_node *func; | |
735 | bool any_aliases = false; | |
736 | tree ctor_body = NULL; | |
737 | unsigned int i, n_tls; | |
738 | ||
739 | tls_vars = varpool_node_set_new (); | |
740 | ||
741 | /* Examine all global variables for TLS variables. */ | |
65c70e6b | 742 | FOR_EACH_VARIABLE (var) |
960bfb69 | 743 | if (DECL_THREAD_LOCAL_P (var->symbol.decl)) |
8b84c596 | 744 | { |
960bfb69 JH |
745 | gcc_checking_assert (TREE_STATIC (var->symbol.decl) |
746 | || DECL_EXTERNAL (var->symbol.decl)); | |
8b84c596 | 747 | varpool_node_set_add (tls_vars, var); |
e70670cf | 748 | if (var->symbol.alias && var->symbol.definition) |
75d3e6e3 | 749 | varpool_node_set_add (tls_vars, varpool_variable_node (var, NULL)); |
8b84c596 RH |
750 | } |
751 | ||
752 | /* If we found no TLS variables, then there is no further work to do. */ | |
9771b263 | 753 | if (!tls_vars->nodes.exists ()) |
8b84c596 RH |
754 | { |
755 | tls_vars = NULL; | |
756 | if (dump_file) | |
757 | fprintf (dump_file, "No TLS variables found.\n"); | |
758 | return 0; | |
759 | } | |
760 | ||
761 | /* Allocate the on-the-side arrays that share indicies with the TLS vars. */ | |
9771b263 DN |
762 | n_tls = tls_vars->nodes.length (); |
763 | control_vars.create (n_tls); | |
764 | access_vars.create (n_tls); | |
765 | access_vars.safe_grow_cleared (n_tls); | |
8b84c596 RH |
766 | |
767 | /* Create the control variables for each TLS variable. */ | |
9771b263 | 768 | FOR_EACH_VEC_ELT (tls_vars->nodes, i, var) |
8b84c596 | 769 | { |
9771b263 | 770 | var = tls_vars->nodes[i]; |
8b84c596 | 771 | |
40a7fe1e | 772 | if (var->symbol.alias && !var->symbol.analyzed) |
75d3e6e3 | 773 | any_aliases = true; |
e70670cf | 774 | else if (!var->symbol.alias) |
75d3e6e3 | 775 | varpool_for_node_and_aliases (var, create_emultls_var, &ctor_body, true); |
8b84c596 RH |
776 | } |
777 | ||
778 | /* If there were any aliases, then frob the alias_pairs vector. */ | |
779 | if (any_aliases) | |
780 | { | |
781 | alias_pair *p; | |
9771b263 | 782 | FOR_EACH_VEC_SAFE_ELT (alias_pairs, i, p) |
8b84c596 RH |
783 | if (DECL_THREAD_LOCAL_P (p->decl)) |
784 | { | |
785 | p->decl = emutls_decl (p->decl); | |
786 | p->target = get_emutls_object_name (p->target); | |
787 | } | |
788 | } | |
789 | ||
790 | /* Adjust all uses of TLS variables within the function bodies. */ | |
65c70e6b | 791 | FOR_EACH_DEFINED_FUNCTION (func) |
93a18a70 | 792 | if (func->lowered) |
8b84c596 RH |
793 | lower_emutls_function_body (func); |
794 | ||
795 | /* Generate the constructor for any COMMON control variables created. */ | |
796 | if (ctor_body) | |
797 | cgraph_build_static_cdtor ('I', ctor_body, DEFAULT_INIT_PRIORITY); | |
798 | ||
9771b263 DN |
799 | control_vars.release (); |
800 | access_vars.release (); | |
1cb1a99f | 801 | free_varpool_node_set (tls_vars); |
8b84c596 | 802 | |
bb313b93 | 803 | return TODO_verify_all; |
8b84c596 RH |
804 | } |
805 | ||
806 | /* If the target supports TLS natively, we need do nothing here. */ | |
807 | ||
808 | static bool | |
809 | gate_emutls (void) | |
810 | { | |
811 | return !targetm.have_tls; | |
812 | } | |
813 | ||
27a4cd48 DM |
814 | namespace { |
815 | ||
816 | const pass_data pass_data_ipa_lower_emutls = | |
8b84c596 | 817 | { |
27a4cd48 DM |
818 | SIMPLE_IPA_PASS, /* type */ |
819 | "emutls", /* name */ | |
820 | OPTGROUP_NONE, /* optinfo_flags */ | |
821 | true, /* has_gate */ | |
822 | true, /* has_execute */ | |
823 | TV_IPA_OPT, /* tv_id */ | |
824 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
825 | 0, /* properties_provided */ | |
826 | 0, /* properties_destroyed */ | |
827 | 0, /* todo_flags_start */ | |
828 | 0, /* todo_flags_finish */ | |
8b84c596 | 829 | }; |
27a4cd48 DM |
830 | |
831 | class pass_ipa_lower_emutls : public simple_ipa_opt_pass | |
832 | { | |
833 | public: | |
c3284718 RS |
834 | pass_ipa_lower_emutls (gcc::context *ctxt) |
835 | : simple_ipa_opt_pass (pass_data_ipa_lower_emutls, ctxt) | |
27a4cd48 DM |
836 | {} |
837 | ||
838 | /* opt_pass methods: */ | |
839 | bool gate () { return gate_emutls (); } | |
840 | unsigned int execute () { return ipa_lower_emutls (); } | |
841 | ||
842 | }; // class pass_ipa_lower_emutls | |
843 | ||
844 | } // anon namespace | |
845 | ||
846 | simple_ipa_opt_pass * | |
847 | make_pass_ipa_lower_emutls (gcc::context *ctxt) | |
848 | { | |
849 | return new pass_ipa_lower_emutls (ctxt); | |
850 | } |