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4ee9c684 | 1 | /* Rewrite a program in Normal form into SSA. |
d353bf18 | 2 | Copyright (C) 2001-2015 Free Software Foundation, Inc. |
4ee9c684 | 3 | Contributed by Diego Novillo <dnovillo@redhat.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
8c4c00c1 | 9 | the Free Software Foundation; either version 3, or (at your option) |
4ee9c684 | 10 | any later version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
b20a8bb4 | 25 | #include "hash-set.h" |
b20a8bb4 | 26 | #include "vec.h" |
b20a8bb4 | 27 | #include "input.h" |
28 | #include "alias.h" | |
29 | #include "symtab.h" | |
b20a8bb4 | 30 | #include "inchash.h" |
4ee9c684 | 31 | #include "tree.h" |
b20a8bb4 | 32 | #include "fold-const.h" |
4ee9c684 | 33 | #include "flags.h" |
4ee9c684 | 34 | #include "tm_p.h" |
35 | #include "langhooks.h" | |
94ea8568 | 36 | #include "predict.h" |
a3020f2f | 37 | #include "hard-reg-set.h" |
4ee9c684 | 38 | #include "function.h" |
94ea8568 | 39 | #include "dominance.h" |
40 | #include "cfg.h" | |
41 | #include "cfganal.h" | |
42 | #include "basic-block.h" | |
ce084dfc | 43 | #include "gimple-pretty-print.h" |
bc61cadb | 44 | #include "hash-table.h" |
45 | #include "tree-ssa-alias.h" | |
46 | #include "internal-fn.h" | |
47 | #include "gimple-expr.h" | |
48 | #include "is-a.h" | |
75a70cf9 | 49 | #include "gimple.h" |
dcf1a1ec | 50 | #include "gimple-iterator.h" |
073c1fd5 | 51 | #include "gimple-ssa.h" |
52 | #include "tree-cfg.h" | |
53 | #include "tree-phinodes.h" | |
54 | #include "ssa-iterators.h" | |
9ed99284 | 55 | #include "stringpool.h" |
073c1fd5 | 56 | #include "tree-ssanames.h" |
57 | #include "tree-into-ssa.h" | |
d53441c8 | 58 | #include "hashtab.h" |
59 | #include "rtl.h" | |
60 | #include "statistics.h" | |
d53441c8 | 61 | #include "insn-config.h" |
62 | #include "expmed.h" | |
63 | #include "dojump.h" | |
64 | #include "explow.h" | |
65 | #include "calls.h" | |
66 | #include "emit-rtl.h" | |
67 | #include "varasm.h" | |
68 | #include "stmt.h" | |
9ed99284 | 69 | #include "expr.h" |
073c1fd5 | 70 | #include "tree-dfa.h" |
71 | #include "tree-ssa.h" | |
4ee9c684 | 72 | #include "tree-inline.h" |
4ee9c684 | 73 | #include "tree-pass.h" |
74 | #include "cfgloop.h" | |
75 | #include "domwalk.h" | |
095dcfa3 | 76 | #include "params.h" |
b4fa1427 | 77 | #include "diagnostic-core.h" |
4ee9c684 | 78 | |
e797f49f | 79 | #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y)) |
75a70cf9 | 80 | |
4ee9c684 | 81 | /* This file builds the SSA form for a function as described in: |
82 | R. Cytron, J. Ferrante, B. Rosen, M. Wegman, and K. Zadeck. Efficiently | |
83 | Computing Static Single Assignment Form and the Control Dependence | |
84 | Graph. ACM Transactions on Programming Languages and Systems, | |
85 | 13(4):451-490, October 1991. */ | |
86 | ||
4ee9c684 | 87 | /* Structure to map a variable VAR to the set of blocks that contain |
88 | definitions for VAR. */ | |
89 | struct def_blocks_d | |
90 | { | |
4ee9c684 | 91 | /* Blocks that contain definitions of VAR. Bit I will be set if the |
92 | Ith block contains a definition of VAR. */ | |
93 | bitmap def_blocks; | |
94 | ||
e551bd1a | 95 | /* Blocks that contain a PHI node for VAR. */ |
f3d9a16c | 96 | bitmap phi_blocks; |
97 | ||
4ee9c684 | 98 | /* Blocks where VAR is live-on-entry. Similar semantics as |
99 | DEF_BLOCKS. */ | |
100 | bitmap livein_blocks; | |
101 | }; | |
102 | ||
c86a4051 | 103 | typedef struct def_blocks_d *def_blocks_p; |
104 | ||
4ee9c684 | 105 | |
dd2d357d | 106 | /* Stack of trees used to restore the global currdefs to its original |
88dbf20f | 107 | state after completing rewriting of a block and its dominator |
108 | children. Its elements have the following properties: | |
dd2d357d | 109 | |
4fb5e5ca | 110 | - An SSA_NAME (N) indicates that the current definition of the |
111 | underlying variable should be set to the given SSA_NAME. If the | |
112 | symbol associated with the SSA_NAME is not a GIMPLE register, the | |
113 | next slot in the stack must be a _DECL node (SYM). In this case, | |
114 | the name N in the previous slot is the current reaching | |
115 | definition for SYM. | |
dd2d357d | 116 | |
88dbf20f | 117 | - A _DECL node indicates that the underlying variable has no |
118 | current definition. | |
e551bd1a | 119 | |
4fb5e5ca | 120 | - A NULL node at the top entry is used to mark the last slot |
88dbf20f | 121 | associated with the current block. */ |
f1f41a6c | 122 | static vec<tree> block_defs_stack; |
486b57c7 | 123 | |
75a70cf9 | 124 | |
88dbf20f | 125 | /* Set of existing SSA names being replaced by update_ssa. */ |
126 | static sbitmap old_ssa_names; | |
127 | ||
128 | /* Set of new SSA names being added by update_ssa. Note that both | |
129 | NEW_SSA_NAMES and OLD_SSA_NAMES are dense bitmaps because most of | |
130 | the operations done on them are presence tests. */ | |
131 | static sbitmap new_ssa_names; | |
132 | ||
47c1894f | 133 | static sbitmap interesting_blocks; |
75a70cf9 | 134 | |
88dbf20f | 135 | /* Set of SSA names that have been marked to be released after they |
136 | were registered in the replacement table. They will be finally | |
137 | released after we finish updating the SSA web. */ | |
138 | static bitmap names_to_release; | |
139 | ||
f1f41a6c | 140 | /* vec of vec of PHIs to rewrite in a basic block. Element I corresponds |
2670407e | 141 | the to basic block with index I. Allocated once per compilation, *not* |
142 | released between different functions. */ | |
1a91d914 | 143 | static vec< vec<gphi *> > phis_to_rewrite; |
70630fcd | 144 | |
145 | /* The bitmap of non-NULL elements of PHIS_TO_REWRITE. */ | |
70630fcd | 146 | static bitmap blocks_with_phis_to_rewrite; |
147 | ||
88dbf20f | 148 | /* Growth factor for NEW_SSA_NAMES and OLD_SSA_NAMES. These sets need |
0dc262e0 | 149 | to grow as the callers to create_new_def_for will create new names on |
150 | the fly. | |
151 | FIXME. Currently set to 1/3 to avoid frequent reallocations but still | |
152 | need to find a reasonable growth strategy. */ | |
88dbf20f | 153 | #define NAME_SETS_GROWTH_FACTOR (MAX (3, num_ssa_names / 3)) |
154 | ||
88dbf20f | 155 | |
dd277d48 | 156 | /* The function the SSA updating data structures have been initialized for. |
0dc262e0 | 157 | NULL if they need to be initialized by create_new_def_for. */ |
dd277d48 | 158 | static struct function *update_ssa_initialized_fn = NULL; |
88dbf20f | 159 | |
4ee9c684 | 160 | /* Global data to attach to the main dominator walk structure. */ |
161 | struct mark_def_sites_global_data | |
162 | { | |
88dbf20f | 163 | /* This bitmap contains the variables which are set before they |
164 | are used in a basic block. */ | |
ecddc799 | 165 | bitmap kills; |
4ee9c684 | 166 | }; |
167 | ||
8f6fa493 | 168 | /* It is advantageous to avoid things like life analysis for variables which |
169 | do not need PHI nodes. This enum describes whether or not a particular | |
170 | variable may need a PHI node. */ | |
171 | ||
172 | enum need_phi_state { | |
173 | /* This is the default. If we are still in this state after finding | |
174 | all the definition and use sites, then we will assume the variable | |
175 | needs PHI nodes. This is probably an overly conservative assumption. */ | |
176 | NEED_PHI_STATE_UNKNOWN, | |
177 | ||
178 | /* This state indicates that we have seen one or more sets of the | |
179 | variable in a single basic block and that the sets dominate all | |
180 | uses seen so far. If after finding all definition and use sites | |
181 | we are still in this state, then the variable does not need any | |
182 | PHI nodes. */ | |
183 | NEED_PHI_STATE_NO, | |
184 | ||
185 | /* This state indicates that we have either seen multiple definitions of | |
186 | the variable in multiple blocks, or that we encountered a use in a | |
187 | block that was not dominated by the block containing the set(s) of | |
188 | this variable. This variable is assumed to need PHI nodes. */ | |
189 | NEED_PHI_STATE_MAYBE | |
190 | }; | |
191 | ||
74105c0d | 192 | /* Information stored for both SSA names and decls. */ |
193 | struct common_info_d | |
22d6c74e | 194 | { |
22d6c74e | 195 | /* This field indicates whether or not the variable may need PHI nodes. |
196 | See the enum's definition for more detailed information about the | |
197 | states. */ | |
198 | ENUM_BITFIELD (need_phi_state) need_phi_state : 2; | |
199 | ||
74105c0d | 200 | /* The current reaching definition replacing this var. */ |
22d6c74e | 201 | tree current_def; |
202 | ||
74105c0d | 203 | /* Definitions for this var. */ |
22d6c74e | 204 | struct def_blocks_d def_blocks; |
205 | }; | |
206 | ||
74105c0d | 207 | /* The information associated with decls and SSA names. */ |
208 | typedef struct common_info_d *common_info_p; | |
209 | ||
210 | /* Information stored for decls. */ | |
211 | struct var_info_d | |
212 | { | |
213 | /* The variable. */ | |
214 | tree var; | |
215 | ||
216 | /* Information stored for both SSA names and decls. */ | |
217 | struct common_info_d info; | |
218 | }; | |
219 | ||
22d6c74e | 220 | /* The information associated with decls. */ |
221 | typedef struct var_info_d *var_info_p; | |
222 | ||
22d6c74e | 223 | |
3e871d4d | 224 | /* VAR_INFOS hashtable helpers. */ |
225 | ||
226 | struct var_info_hasher : typed_free_remove <var_info_d> | |
227 | { | |
2933f7af | 228 | typedef var_info_d *value_type; |
229 | typedef var_info_d *compare_type; | |
2933f7af | 230 | static inline hashval_t hash (const value_type &); |
231 | static inline bool equal (const value_type &, const compare_type &); | |
3e871d4d | 232 | }; |
233 | ||
234 | inline hashval_t | |
2933f7af | 235 | var_info_hasher::hash (const value_type &p) |
3e871d4d | 236 | { |
237 | return DECL_UID (p->var); | |
238 | } | |
239 | ||
240 | inline bool | |
2933f7af | 241 | var_info_hasher::equal (const value_type &p1, const compare_type &p2) |
3e871d4d | 242 | { |
243 | return p1->var == p2->var; | |
244 | } | |
245 | ||
246 | ||
22d6c74e | 247 | /* Each entry in VAR_INFOS contains an element of type STRUCT |
248 | VAR_INFO_D. */ | |
c1f445d2 | 249 | static hash_table<var_info_hasher> *var_infos; |
22d6c74e | 250 | |
251 | ||
88dbf20f | 252 | /* Information stored for SSA names. */ |
f3d9a16c | 253 | struct ssa_name_info |
254 | { | |
5eeafc2d | 255 | /* Age of this record (so that info_for_ssa_name table can be cleared |
256 | quickly); if AGE < CURRENT_INFO_FOR_SSA_NAME_AGE, then the fields | |
257 | are assumed to be null. */ | |
258 | unsigned age; | |
2920559d | 259 | |
5eeafc2d | 260 | /* Replacement mappings, allocated from update_ssa_obstack. */ |
261 | bitmap repl_set; | |
22d6c74e | 262 | |
74105c0d | 263 | /* Information stored for both SSA names and decls. */ |
264 | struct common_info_d info; | |
f3d9a16c | 265 | }; |
4ee9c684 | 266 | |
2920559d | 267 | /* The information associated with names. */ |
268 | typedef struct ssa_name_info *ssa_name_info_p; | |
2920559d | 269 | |
f1f41a6c | 270 | static vec<ssa_name_info_p> info_for_ssa_name; |
2920559d | 271 | static unsigned current_info_for_ssa_name_age; |
272 | ||
5eeafc2d | 273 | static bitmap_obstack update_ssa_obstack; |
274 | ||
2920559d | 275 | /* The set of blocks affected by update_ssa. */ |
2920559d | 276 | static bitmap blocks_to_update; |
4ee9c684 | 277 | |
88dbf20f | 278 | /* The main entry point to the SSA renamer (rewrite_blocks) may be |
279 | called several times to do different, but related, tasks. | |
280 | Initially, we need it to rename the whole program into SSA form. | |
281 | At other times, we may need it to only rename into SSA newly | |
282 | exposed symbols. Finally, we can also call it to incrementally fix | |
283 | an already built SSA web. */ | |
284 | enum rewrite_mode { | |
285 | /* Convert the whole function into SSA form. */ | |
286 | REWRITE_ALL, | |
287 | ||
288 | /* Incrementally update the SSA web by replacing existing SSA | |
289 | names with new ones. See update_ssa for details. */ | |
290 | REWRITE_UPDATE | |
291 | }; | |
292 | ||
e70e8b13 | 293 | /* The set of symbols we ought to re-write into SSA form in update_ssa. */ |
294 | static bitmap symbols_to_rename_set; | |
f1f41a6c | 295 | static vec<tree> symbols_to_rename; |
e70e8b13 | 296 | |
297 | /* Mark SYM for renaming. */ | |
298 | ||
299 | static void | |
300 | mark_for_renaming (tree sym) | |
301 | { | |
302 | if (!symbols_to_rename_set) | |
303 | symbols_to_rename_set = BITMAP_ALLOC (NULL); | |
304 | if (bitmap_set_bit (symbols_to_rename_set, DECL_UID (sym))) | |
f1f41a6c | 305 | symbols_to_rename.safe_push (sym); |
e70e8b13 | 306 | } |
307 | ||
308 | /* Return true if SYM is marked for renaming. */ | |
309 | ||
310 | static bool | |
311 | marked_for_renaming (tree sym) | |
312 | { | |
ec11736b | 313 | if (!symbols_to_rename_set || sym == NULL_TREE) |
e70e8b13 | 314 | return false; |
315 | return bitmap_bit_p (symbols_to_rename_set, DECL_UID (sym)); | |
316 | } | |
317 | ||
318 | ||
75a70cf9 | 319 | /* Return true if STMT needs to be rewritten. When renaming a subset |
320 | of the variables, not all statements will be processed. This is | |
321 | decided in mark_def_sites. */ | |
322 | ||
323 | static inline bool | |
324 | rewrite_uses_p (gimple stmt) | |
325 | { | |
326 | return gimple_visited_p (stmt); | |
327 | } | |
328 | ||
329 | ||
330 | /* Set the rewrite marker on STMT to the value given by REWRITE_P. */ | |
331 | ||
332 | static inline void | |
333 | set_rewrite_uses (gimple stmt, bool rewrite_p) | |
334 | { | |
335 | gimple_set_visited (stmt, rewrite_p); | |
336 | } | |
337 | ||
338 | ||
339 | /* Return true if the DEFs created by statement STMT should be | |
340 | registered when marking new definition sites. This is slightly | |
341 | different than rewrite_uses_p: it's used by update_ssa to | |
342 | distinguish statements that need to have both uses and defs | |
343 | processed from those that only need to have their defs processed. | |
344 | Statements that define new SSA names only need to have their defs | |
345 | registered, but they don't need to have their uses renamed. */ | |
346 | ||
347 | static inline bool | |
348 | register_defs_p (gimple stmt) | |
349 | { | |
350 | return gimple_plf (stmt, GF_PLF_1) != 0; | |
351 | } | |
352 | ||
353 | ||
354 | /* If REGISTER_DEFS_P is true, mark STMT to have its DEFs registered. */ | |
355 | ||
356 | static inline void | |
357 | set_register_defs (gimple stmt, bool register_defs_p) | |
358 | { | |
359 | gimple_set_plf (stmt, GF_PLF_1, register_defs_p); | |
360 | } | |
361 | ||
362 | ||
f3d9a16c | 363 | /* Get the information associated with NAME. */ |
364 | ||
4fb5e5ca | 365 | static inline ssa_name_info_p |
f3d9a16c | 366 | get_ssa_name_ann (tree name) |
367 | { | |
2920559d | 368 | unsigned ver = SSA_NAME_VERSION (name); |
f1f41a6c | 369 | unsigned len = info_for_ssa_name.length (); |
2920559d | 370 | struct ssa_name_info *info; |
371 | ||
83b709f2 | 372 | /* Re-allocate the vector at most once per update/into-SSA. */ |
2920559d | 373 | if (ver >= len) |
f1f41a6c | 374 | info_for_ssa_name.safe_grow_cleared (num_ssa_names); |
83b709f2 | 375 | |
376 | /* But allocate infos lazily. */ | |
f1f41a6c | 377 | info = info_for_ssa_name[ver]; |
83b709f2 | 378 | if (!info) |
2920559d | 379 | { |
83b709f2 | 380 | info = XCNEW (struct ssa_name_info); |
381 | info->age = current_info_for_ssa_name_age; | |
382 | info->info.need_phi_state = NEED_PHI_STATE_UNKNOWN; | |
f1f41a6c | 383 | info_for_ssa_name[ver] = info; |
2920559d | 384 | } |
385 | ||
2920559d | 386 | if (info->age < current_info_for_ssa_name_age) |
387 | { | |
2920559d | 388 | info->age = current_info_for_ssa_name_age; |
74105c0d | 389 | info->repl_set = NULL; |
390 | info->info.need_phi_state = NEED_PHI_STATE_UNKNOWN; | |
391 | info->info.current_def = NULL_TREE; | |
392 | info->info.def_blocks.def_blocks = NULL; | |
393 | info->info.def_blocks.phi_blocks = NULL; | |
394 | info->info.def_blocks.livein_blocks = NULL; | |
2920559d | 395 | } |
f3d9a16c | 396 | |
2920559d | 397 | return info; |
f3d9a16c | 398 | } |
399 | ||
22d6c74e | 400 | /* Return and allocate the auxiliar information for DECL. */ |
401 | ||
402 | static inline var_info_p | |
403 | get_var_info (tree decl) | |
404 | { | |
405 | struct var_info_d vi; | |
3e871d4d | 406 | var_info_d **slot; |
22d6c74e | 407 | vi.var = decl; |
c1f445d2 | 408 | slot = var_infos->find_slot_with_hash (&vi, DECL_UID (decl), INSERT); |
22d6c74e | 409 | if (*slot == NULL) |
410 | { | |
411 | var_info_p v = XCNEW (struct var_info_d); | |
412 | v->var = decl; | |
3e871d4d | 413 | *slot = v; |
22d6c74e | 414 | return v; |
415 | } | |
3e871d4d | 416 | return *slot; |
22d6c74e | 417 | } |
418 | ||
4fb5e5ca | 419 | |
420 | /* Clears info for SSA names. */ | |
2920559d | 421 | |
422 | static void | |
423 | clear_ssa_name_info (void) | |
424 | { | |
425 | current_info_for_ssa_name_age++; | |
5eeafc2d | 426 | |
427 | /* If current_info_for_ssa_name_age wraps we use stale information. | |
428 | Asser that this does not happen. */ | |
429 | gcc_assert (current_info_for_ssa_name_age != 0); | |
2920559d | 430 | } |
e551bd1a | 431 | |
4fb5e5ca | 432 | |
74105c0d | 433 | /* Get access to the auxiliar information stored per SSA name or decl. */ |
f3d9a16c | 434 | |
74105c0d | 435 | static inline common_info_p |
436 | get_common_info (tree var) | |
f3d9a16c | 437 | { |
438 | if (TREE_CODE (var) == SSA_NAME) | |
74105c0d | 439 | return &get_ssa_name_ann (var)->info; |
f3d9a16c | 440 | else |
74105c0d | 441 | return &get_var_info (var)->info; |
f3d9a16c | 442 | } |
443 | ||
e551bd1a | 444 | |
f3d9a16c | 445 | /* Return the current definition for VAR. */ |
446 | ||
095dcfa3 | 447 | tree |
f3d9a16c | 448 | get_current_def (tree var) |
449 | { | |
74105c0d | 450 | return get_common_info (var)->current_def; |
f3d9a16c | 451 | } |
452 | ||
e551bd1a | 453 | |
f3d9a16c | 454 | /* Sets current definition of VAR to DEF. */ |
455 | ||
095dcfa3 | 456 | void |
f3d9a16c | 457 | set_current_def (tree var, tree def) |
458 | { | |
74105c0d | 459 | get_common_info (var)->current_def = def; |
f3d9a16c | 460 | } |
461 | ||
2920559d | 462 | /* Cleans up the REWRITE_THIS_STMT and REGISTER_DEFS_IN_THIS_STMT flags for |
463 | all statements in basic block BB. */ | |
464 | ||
465 | static void | |
466 | initialize_flags_in_bb (basic_block bb) | |
467 | { | |
75a70cf9 | 468 | gimple stmt; |
469 | gimple_stmt_iterator gsi; | |
2920559d | 470 | |
75a70cf9 | 471 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
2920559d | 472 | { |
75a70cf9 | 473 | gimple phi = gsi_stmt (gsi); |
474 | set_rewrite_uses (phi, false); | |
475 | set_register_defs (phi, false); | |
2920559d | 476 | } |
477 | ||
75a70cf9 | 478 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
2920559d | 479 | { |
75a70cf9 | 480 | stmt = gsi_stmt (gsi); |
481 | ||
2920559d | 482 | /* We are going to use the operand cache API, such as |
483 | SET_USE, SET_DEF, and FOR_EACH_IMM_USE_FAST. The operand | |
484 | cache for each statement should be up-to-date. */ | |
88536563 | 485 | gcc_checking_assert (!gimple_modified_p (stmt)); |
75a70cf9 | 486 | set_rewrite_uses (stmt, false); |
487 | set_register_defs (stmt, false); | |
2920559d | 488 | } |
489 | } | |
490 | ||
491 | /* Mark block BB as interesting for update_ssa. */ | |
492 | ||
493 | static void | |
494 | mark_block_for_update (basic_block bb) | |
495 | { | |
88536563 | 496 | gcc_checking_assert (blocks_to_update != NULL); |
39192870 | 497 | if (!bitmap_set_bit (blocks_to_update, bb->index)) |
2920559d | 498 | return; |
2920559d | 499 | initialize_flags_in_bb (bb); |
500 | } | |
501 | ||
e551bd1a | 502 | /* Return the set of blocks where variable VAR is defined and the blocks |
503 | where VAR is live on entry (livein). If no entry is found in | |
504 | DEF_BLOCKS, a new one is created and returned. */ | |
4ee9c684 | 505 | |
e551bd1a | 506 | static inline struct def_blocks_d * |
74105c0d | 507 | get_def_blocks_for (common_info_p info) |
4ee9c684 | 508 | { |
74105c0d | 509 | struct def_blocks_d *db_p = &info->def_blocks; |
22d6c74e | 510 | if (!db_p->def_blocks) |
4ee9c684 | 511 | { |
22d6c74e | 512 | db_p->def_blocks = BITMAP_ALLOC (&update_ssa_obstack); |
513 | db_p->phi_blocks = BITMAP_ALLOC (&update_ssa_obstack); | |
514 | db_p->livein_blocks = BITMAP_ALLOC (&update_ssa_obstack); | |
2cf24776 | 515 | } |
516 | ||
e551bd1a | 517 | return db_p; |
4ee9c684 | 518 | } |
519 | ||
6cf80e5b | 520 | |
f3d9a16c | 521 | /* Mark block BB as the definition site for variable VAR. PHI_P is true if |
88dbf20f | 522 | VAR is defined by a PHI node. */ |
4ee9c684 | 523 | |
524 | static void | |
88dbf20f | 525 | set_def_block (tree var, basic_block bb, bool phi_p) |
4ee9c684 | 526 | { |
527 | struct def_blocks_d *db_p; | |
74105c0d | 528 | common_info_p info; |
ce898113 | 529 | |
74105c0d | 530 | info = get_common_info (var); |
531 | db_p = get_def_blocks_for (info); | |
4ee9c684 | 532 | |
533 | /* Set the bit corresponding to the block where VAR is defined. */ | |
534 | bitmap_set_bit (db_p->def_blocks, bb->index); | |
f3d9a16c | 535 | if (phi_p) |
536 | bitmap_set_bit (db_p->phi_blocks, bb->index); | |
4ee9c684 | 537 | |
e551bd1a | 538 | /* Keep track of whether or not we may need to insert PHI nodes. |
4ee9c684 | 539 | |
540 | If we are in the UNKNOWN state, then this is the first definition | |
541 | of VAR. Additionally, we have not seen any uses of VAR yet, so | |
e551bd1a | 542 | we do not need a PHI node for this variable at this time (i.e., |
4ee9c684 | 543 | transition to NEED_PHI_STATE_NO). |
544 | ||
545 | If we are in any other state, then we either have multiple definitions | |
546 | of this variable occurring in different blocks or we saw a use of the | |
547 | variable which was not dominated by the block containing the | |
548 | definition(s). In this case we may need a PHI node, so enter | |
549 | state NEED_PHI_STATE_MAYBE. */ | |
74105c0d | 550 | if (info->need_phi_state == NEED_PHI_STATE_UNKNOWN) |
551 | info->need_phi_state = NEED_PHI_STATE_NO; | |
4ee9c684 | 552 | else |
74105c0d | 553 | info->need_phi_state = NEED_PHI_STATE_MAYBE; |
4ee9c684 | 554 | } |
555 | ||
556 | ||
557 | /* Mark block BB as having VAR live at the entry to BB. */ | |
558 | ||
559 | static void | |
560 | set_livein_block (tree var, basic_block bb) | |
561 | { | |
74105c0d | 562 | common_info_p info; |
4ee9c684 | 563 | struct def_blocks_d *db_p; |
4ee9c684 | 564 | |
74105c0d | 565 | info = get_common_info (var); |
566 | db_p = get_def_blocks_for (info); | |
4ee9c684 | 567 | |
568 | /* Set the bit corresponding to the block where VAR is live in. */ | |
569 | bitmap_set_bit (db_p->livein_blocks, bb->index); | |
570 | ||
e551bd1a | 571 | /* Keep track of whether or not we may need to insert PHI nodes. |
4ee9c684 | 572 | |
573 | If we reach here in NEED_PHI_STATE_NO, see if this use is dominated | |
574 | by the single block containing the definition(s) of this variable. If | |
575 | it is, then we remain in NEED_PHI_STATE_NO, otherwise we transition to | |
576 | NEED_PHI_STATE_MAYBE. */ | |
74105c0d | 577 | if (info->need_phi_state == NEED_PHI_STATE_NO) |
4ee9c684 | 578 | { |
579 | int def_block_index = bitmap_first_set_bit (db_p->def_blocks); | |
580 | ||
581 | if (def_block_index == -1 | |
582 | || ! dominated_by_p (CDI_DOMINATORS, bb, | |
f5a6b05f | 583 | BASIC_BLOCK_FOR_FN (cfun, def_block_index))) |
74105c0d | 584 | info->need_phi_state = NEED_PHI_STATE_MAYBE; |
4ee9c684 | 585 | } |
586 | else | |
74105c0d | 587 | info->need_phi_state = NEED_PHI_STATE_MAYBE; |
4ee9c684 | 588 | } |
589 | ||
590 | ||
88dbf20f | 591 | /* Return true if NAME is in OLD_SSA_NAMES. */ |
4ee9c684 | 592 | |
88dbf20f | 593 | static inline bool |
594 | is_old_name (tree name) | |
595 | { | |
095dcfa3 | 596 | unsigned ver = SSA_NAME_VERSION (name); |
100be96d | 597 | if (!old_ssa_names) |
dd277d48 | 598 | return false; |
100be96d | 599 | return (ver < SBITMAP_SIZE (old_ssa_names) |
08b7917c | 600 | && bitmap_bit_p (old_ssa_names, ver)); |
88dbf20f | 601 | } |
602 | ||
603 | ||
604 | /* Return true if NAME is in NEW_SSA_NAMES. */ | |
ce898113 | 605 | |
88dbf20f | 606 | static inline bool |
607 | is_new_name (tree name) | |
608 | { | |
095dcfa3 | 609 | unsigned ver = SSA_NAME_VERSION (name); |
dd277d48 | 610 | if (!new_ssa_names) |
611 | return false; | |
156093aa | 612 | return (ver < SBITMAP_SIZE (new_ssa_names) |
08b7917c | 613 | && bitmap_bit_p (new_ssa_names, ver)); |
4ee9c684 | 614 | } |
615 | ||
e551bd1a | 616 | |
f4e36c33 | 617 | /* Return the names replaced by NEW_TREE (i.e., REPL_TBL[NEW_TREE].SET). */ |
88dbf20f | 618 | |
619 | static inline bitmap | |
f4e36c33 | 620 | names_replaced_by (tree new_tree) |
88dbf20f | 621 | { |
5eeafc2d | 622 | return get_ssa_name_ann (new_tree)->repl_set; |
88dbf20f | 623 | } |
624 | ||
625 | ||
f4e36c33 | 626 | /* Add OLD to REPL_TBL[NEW_TREE].SET. */ |
88dbf20f | 627 | |
628 | static inline void | |
f4e36c33 | 629 | add_to_repl_tbl (tree new_tree, tree old) |
88dbf20f | 630 | { |
5eeafc2d | 631 | bitmap *set = &get_ssa_name_ann (new_tree)->repl_set; |
632 | if (!*set) | |
633 | *set = BITMAP_ALLOC (&update_ssa_obstack); | |
634 | bitmap_set_bit (*set, SSA_NAME_VERSION (old)); | |
88dbf20f | 635 | } |
636 | ||
637 | ||
f4e36c33 | 638 | /* Add a new mapping NEW_TREE -> OLD REPL_TBL. Every entry N_i in REPL_TBL |
88dbf20f | 639 | represents the set of names O_1 ... O_j replaced by N_i. This is |
640 | used by update_ssa and its helpers to introduce new SSA names in an | |
641 | already formed SSA web. */ | |
642 | ||
643 | static void | |
f4e36c33 | 644 | add_new_name_mapping (tree new_tree, tree old) |
88dbf20f | 645 | { |
f4e36c33 | 646 | /* OLD and NEW_TREE must be different SSA names for the same symbol. */ |
88536563 | 647 | gcc_checking_assert (new_tree != old |
648 | && SSA_NAME_VAR (new_tree) == SSA_NAME_VAR (old)); | |
095dcfa3 | 649 | |
4fb5e5ca | 650 | /* We may need to grow NEW_SSA_NAMES and OLD_SSA_NAMES because our |
651 | caller may have created new names since the set was created. */ | |
156093aa | 652 | if (SBITMAP_SIZE (new_ssa_names) <= num_ssa_names - 1) |
4fb5e5ca | 653 | { |
654 | unsigned int new_sz = num_ssa_names + NAME_SETS_GROWTH_FACTOR; | |
655 | new_ssa_names = sbitmap_resize (new_ssa_names, new_sz, 0); | |
656 | old_ssa_names = sbitmap_resize (old_ssa_names, new_sz, 0); | |
88dbf20f | 657 | } |
658 | ||
88dbf20f | 659 | /* Update the REPL_TBL table. */ |
f4e36c33 | 660 | add_to_repl_tbl (new_tree, old); |
56004dc5 | 661 | |
88dbf20f | 662 | /* If OLD had already been registered as a new name, then all the |
f4e36c33 | 663 | names that OLD replaces should also be replaced by NEW_TREE. */ |
88dbf20f | 664 | if (is_new_name (old)) |
f4e36c33 | 665 | bitmap_ior_into (names_replaced_by (new_tree), names_replaced_by (old)); |
88dbf20f | 666 | |
f4e36c33 | 667 | /* Register NEW_TREE and OLD in NEW_SSA_NAMES and OLD_SSA_NAMES, |
88dbf20f | 668 | respectively. */ |
08b7917c | 669 | bitmap_set_bit (new_ssa_names, SSA_NAME_VERSION (new_tree)); |
670 | bitmap_set_bit (old_ssa_names, SSA_NAME_VERSION (old)); | |
56004dc5 | 671 | } |
4ee9c684 | 672 | |
4ee9c684 | 673 | |
e551bd1a | 674 | /* Call back for walk_dominator_tree used to collect definition sites |
675 | for every variable in the function. For every statement S in block | |
676 | BB: | |
4ee9c684 | 677 | |
b66731e8 | 678 | 1- Variables defined by S in the DEFS of S are marked in the bitmap |
6bf320fb | 679 | KILLS. |
4ee9c684 | 680 | |
e551bd1a | 681 | 2- If S uses a variable VAR and there is no preceding kill of VAR, |
5cdd0289 | 682 | then it is marked in the LIVEIN_BLOCKS bitmap associated with VAR. |
4ee9c684 | 683 | |
e551bd1a | 684 | This information is used to determine which variables are live |
685 | across block boundaries to reduce the number of PHI nodes | |
686 | we create. */ | |
4ee9c684 | 687 | |
e551bd1a | 688 | static void |
6bf320fb | 689 | mark_def_sites (basic_block bb, gimple stmt, bitmap kills) |
e551bd1a | 690 | { |
75a70cf9 | 691 | tree def; |
e551bd1a | 692 | use_operand_p use_p; |
e551bd1a | 693 | ssa_op_iter iter; |
694 | ||
75a70cf9 | 695 | /* Since this is the first time that we rewrite the program into SSA |
696 | form, force an operand scan on every statement. */ | |
75a70cf9 | 697 | update_stmt (stmt); |
e551bd1a | 698 | |
88536563 | 699 | gcc_checking_assert (blocks_to_update == NULL); |
75a70cf9 | 700 | set_register_defs (stmt, false); |
701 | set_rewrite_uses (stmt, false); | |
e551bd1a | 702 | |
9845d120 | 703 | if (is_gimple_debug (stmt)) |
841424cc | 704 | { |
705 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) | |
706 | { | |
707 | tree sym = USE_FROM_PTR (use_p); | |
88536563 | 708 | gcc_checking_assert (DECL_P (sym)); |
841424cc | 709 | set_rewrite_uses (stmt, true); |
710 | } | |
711 | if (rewrite_uses_p (stmt)) | |
08b7917c | 712 | bitmap_set_bit (interesting_blocks, bb->index); |
841424cc | 713 | return; |
714 | } | |
9845d120 | 715 | |
e551bd1a | 716 | /* If a variable is used before being set, then the variable is live |
717 | across a block boundary, so mark it live-on-entry to BB. */ | |
5aabc5f2 | 718 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES) |
e551bd1a | 719 | { |
88dbf20f | 720 | tree sym = USE_FROM_PTR (use_p); |
88536563 | 721 | gcc_checking_assert (DECL_P (sym)); |
a55dc2cd | 722 | if (!bitmap_bit_p (kills, DECL_UID (sym))) |
88dbf20f | 723 | set_livein_block (sym, bb); |
75a70cf9 | 724 | set_rewrite_uses (stmt, true); |
e551bd1a | 725 | } |
48e1416a | 726 | |
4fb5e5ca | 727 | /* Now process the defs. Mark BB as the definition block and add |
728 | each def to the set of killed symbols. */ | |
5aabc5f2 | 729 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
e551bd1a | 730 | { |
88536563 | 731 | gcc_checking_assert (DECL_P (def)); |
88dbf20f | 732 | set_def_block (def, bb, false); |
a55dc2cd | 733 | bitmap_set_bit (kills, DECL_UID (def)); |
75a70cf9 | 734 | set_register_defs (stmt, true); |
e551bd1a | 735 | } |
88dbf20f | 736 | |
737 | /* If we found the statement interesting then also mark the block BB | |
738 | as interesting. */ | |
75a70cf9 | 739 | if (rewrite_uses_p (stmt) || register_defs_p (stmt)) |
08b7917c | 740 | bitmap_set_bit (interesting_blocks, bb->index); |
e551bd1a | 741 | } |
742 | ||
f50cf978 | 743 | /* Structure used by prune_unused_phi_nodes to record bounds of the intervals |
744 | in the dfs numbering of the dominance tree. */ | |
745 | ||
746 | struct dom_dfsnum | |
747 | { | |
748 | /* Basic block whose index this entry corresponds to. */ | |
749 | unsigned bb_index; | |
750 | ||
751 | /* The dfs number of this node. */ | |
752 | unsigned dfs_num; | |
753 | }; | |
754 | ||
755 | /* Compares two entries of type struct dom_dfsnum by dfs_num field. Callback | |
756 | for qsort. */ | |
757 | ||
758 | static int | |
759 | cmp_dfsnum (const void *a, const void *b) | |
760 | { | |
45ba1503 | 761 | const struct dom_dfsnum *const da = (const struct dom_dfsnum *) a; |
762 | const struct dom_dfsnum *const db = (const struct dom_dfsnum *) b; | |
f50cf978 | 763 | |
764 | return (int) da->dfs_num - (int) db->dfs_num; | |
765 | } | |
766 | ||
767 | /* Among the intervals starting at the N points specified in DEFS, find | |
768 | the one that contains S, and return its bb_index. */ | |
769 | ||
770 | static unsigned | |
771 | find_dfsnum_interval (struct dom_dfsnum *defs, unsigned n, unsigned s) | |
772 | { | |
773 | unsigned f = 0, t = n, m; | |
774 | ||
775 | while (t > f + 1) | |
776 | { | |
777 | m = (f + t) / 2; | |
778 | if (defs[m].dfs_num <= s) | |
779 | f = m; | |
780 | else | |
781 | t = m; | |
782 | } | |
783 | ||
784 | return defs[f].bb_index; | |
785 | } | |
786 | ||
787 | /* Clean bits from PHIS for phi nodes whose value cannot be used in USES. | |
788 | KILLS is a bitmap of blocks where the value is defined before any use. */ | |
789 | ||
790 | static void | |
791 | prune_unused_phi_nodes (bitmap phis, bitmap kills, bitmap uses) | |
792 | { | |
f50cf978 | 793 | bitmap_iterator bi; |
794 | unsigned i, b, p, u, top; | |
795 | bitmap live_phis; | |
796 | basic_block def_bb, use_bb; | |
797 | edge e; | |
798 | edge_iterator ei; | |
799 | bitmap to_remove; | |
800 | struct dom_dfsnum *defs; | |
801 | unsigned n_defs, adef; | |
802 | ||
803 | if (bitmap_empty_p (uses)) | |
804 | { | |
805 | bitmap_clear (phis); | |
806 | return; | |
807 | } | |
808 | ||
809 | /* The phi must dominate a use, or an argument of a live phi. Also, we | |
810 | do not create any phi nodes in def blocks, unless they are also livein. */ | |
811 | to_remove = BITMAP_ALLOC (NULL); | |
812 | bitmap_and_compl (to_remove, kills, uses); | |
813 | bitmap_and_compl_into (phis, to_remove); | |
814 | if (bitmap_empty_p (phis)) | |
815 | { | |
816 | BITMAP_FREE (to_remove); | |
817 | return; | |
818 | } | |
819 | ||
820 | /* We want to remove the unnecessary phi nodes, but we do not want to compute | |
821 | liveness information, as that may be linear in the size of CFG, and if | |
822 | there are lot of different variables to rewrite, this may lead to quadratic | |
823 | behavior. | |
824 | ||
825 | Instead, we basically emulate standard dce. We put all uses to worklist, | |
826 | then for each of them find the nearest def that dominates them. If this | |
827 | def is a phi node, we mark it live, and if it was not live before, we | |
828 | add the predecessors of its basic block to the worklist. | |
48e1416a | 829 | |
f50cf978 | 830 | To quickly locate the nearest def that dominates use, we use dfs numbering |
831 | of the dominance tree (that is already available in order to speed up | |
832 | queries). For each def, we have the interval given by the dfs number on | |
833 | entry to and on exit from the corresponding subtree in the dominance tree. | |
834 | The nearest dominator for a given use is the smallest of these intervals | |
835 | that contains entry and exit dfs numbers for the basic block with the use. | |
836 | If we store the bounds for all the uses to an array and sort it, we can | |
837 | locate the nearest dominating def in logarithmic time by binary search.*/ | |
838 | bitmap_ior (to_remove, kills, phis); | |
839 | n_defs = bitmap_count_bits (to_remove); | |
840 | defs = XNEWVEC (struct dom_dfsnum, 2 * n_defs + 1); | |
841 | defs[0].bb_index = 1; | |
842 | defs[0].dfs_num = 0; | |
843 | adef = 1; | |
844 | EXECUTE_IF_SET_IN_BITMAP (to_remove, 0, i, bi) | |
845 | { | |
f5a6b05f | 846 | def_bb = BASIC_BLOCK_FOR_FN (cfun, i); |
f50cf978 | 847 | defs[adef].bb_index = i; |
848 | defs[adef].dfs_num = bb_dom_dfs_in (CDI_DOMINATORS, def_bb); | |
849 | defs[adef + 1].bb_index = i; | |
850 | defs[adef + 1].dfs_num = bb_dom_dfs_out (CDI_DOMINATORS, def_bb); | |
851 | adef += 2; | |
852 | } | |
853 | BITMAP_FREE (to_remove); | |
854 | gcc_assert (adef == 2 * n_defs + 1); | |
855 | qsort (defs, adef, sizeof (struct dom_dfsnum), cmp_dfsnum); | |
856 | gcc_assert (defs[0].bb_index == 1); | |
857 | ||
858 | /* Now each DEFS entry contains the number of the basic block to that the | |
859 | dfs number corresponds. Change them to the number of basic block that | |
860 | corresponds to the interval following the dfs number. Also, for the | |
861 | dfs_out numbers, increase the dfs number by one (so that it corresponds | |
862 | to the start of the following interval, not to the end of the current | |
863 | one). We use WORKLIST as a stack. */ | |
c2078b80 | 864 | auto_vec<int> worklist (n_defs + 1); |
f1f41a6c | 865 | worklist.quick_push (1); |
f50cf978 | 866 | top = 1; |
867 | n_defs = 1; | |
868 | for (i = 1; i < adef; i++) | |
869 | { | |
870 | b = defs[i].bb_index; | |
871 | if (b == top) | |
872 | { | |
873 | /* This is a closing element. Interval corresponding to the top | |
874 | of the stack after removing it follows. */ | |
f1f41a6c | 875 | worklist.pop (); |
876 | top = worklist[worklist.length () - 1]; | |
f50cf978 | 877 | defs[n_defs].bb_index = top; |
878 | defs[n_defs].dfs_num = defs[i].dfs_num + 1; | |
879 | } | |
880 | else | |
881 | { | |
882 | /* Opening element. Nothing to do, just push it to the stack and move | |
883 | it to the correct position. */ | |
884 | defs[n_defs].bb_index = defs[i].bb_index; | |
885 | defs[n_defs].dfs_num = defs[i].dfs_num; | |
f1f41a6c | 886 | worklist.quick_push (b); |
f50cf978 | 887 | top = b; |
888 | } | |
889 | ||
890 | /* If this interval starts at the same point as the previous one, cancel | |
891 | the previous one. */ | |
892 | if (defs[n_defs].dfs_num == defs[n_defs - 1].dfs_num) | |
893 | defs[n_defs - 1].bb_index = defs[n_defs].bb_index; | |
894 | else | |
895 | n_defs++; | |
896 | } | |
f1f41a6c | 897 | worklist.pop (); |
898 | gcc_assert (worklist.is_empty ()); | |
f50cf978 | 899 | |
900 | /* Now process the uses. */ | |
901 | live_phis = BITMAP_ALLOC (NULL); | |
902 | EXECUTE_IF_SET_IN_BITMAP (uses, 0, i, bi) | |
903 | { | |
f1f41a6c | 904 | worklist.safe_push (i); |
f50cf978 | 905 | } |
906 | ||
f1f41a6c | 907 | while (!worklist.is_empty ()) |
f50cf978 | 908 | { |
f1f41a6c | 909 | b = worklist.pop (); |
f50cf978 | 910 | if (b == ENTRY_BLOCK) |
911 | continue; | |
912 | ||
913 | /* If there is a phi node in USE_BB, it is made live. Otherwise, | |
914 | find the def that dominates the immediate dominator of USE_BB | |
915 | (the kill in USE_BB does not dominate the use). */ | |
916 | if (bitmap_bit_p (phis, b)) | |
917 | p = b; | |
918 | else | |
919 | { | |
f5a6b05f | 920 | use_bb = get_immediate_dominator (CDI_DOMINATORS, |
921 | BASIC_BLOCK_FOR_FN (cfun, b)); | |
f50cf978 | 922 | p = find_dfsnum_interval (defs, n_defs, |
923 | bb_dom_dfs_in (CDI_DOMINATORS, use_bb)); | |
924 | if (!bitmap_bit_p (phis, p)) | |
925 | continue; | |
926 | } | |
927 | ||
928 | /* If the phi node is already live, there is nothing to do. */ | |
6ef9bbe0 | 929 | if (!bitmap_set_bit (live_phis, p)) |
f50cf978 | 930 | continue; |
931 | ||
6ef9bbe0 | 932 | /* Add the new uses to the worklist. */ |
f5a6b05f | 933 | def_bb = BASIC_BLOCK_FOR_FN (cfun, p); |
f50cf978 | 934 | FOR_EACH_EDGE (e, ei, def_bb->preds) |
935 | { | |
936 | u = e->src->index; | |
937 | if (bitmap_bit_p (uses, u)) | |
938 | continue; | |
939 | ||
94858f65 | 940 | /* In case there is a kill directly in the use block, do not record |
941 | the use (this is also necessary for correctness, as we assume that | |
942 | uses dominated by a def directly in their block have been filtered | |
943 | out before). */ | |
944 | if (bitmap_bit_p (kills, u)) | |
945 | continue; | |
946 | ||
f50cf978 | 947 | bitmap_set_bit (uses, u); |
f1f41a6c | 948 | worklist.safe_push (u); |
f50cf978 | 949 | } |
950 | } | |
951 | ||
f50cf978 | 952 | bitmap_copy (phis, live_phis); |
953 | BITMAP_FREE (live_phis); | |
954 | free (defs); | |
955 | } | |
e551bd1a | 956 | |
e551bd1a | 957 | /* Return the set of blocks where variable VAR is defined and the blocks |
958 | where VAR is live on entry (livein). Return NULL, if no entry is | |
959 | found in DEF_BLOCKS. */ | |
960 | ||
961 | static inline struct def_blocks_d * | |
962 | find_def_blocks_for (tree var) | |
963 | { | |
74105c0d | 964 | def_blocks_p p = &get_common_info (var)->def_blocks; |
22d6c74e | 965 | if (!p->def_blocks) |
966 | return NULL; | |
967 | return p; | |
e551bd1a | 968 | } |
969 | ||
970 | ||
70630fcd | 971 | /* Marks phi node PHI in basic block BB for rewrite. */ |
972 | ||
973 | static void | |
1a91d914 | 974 | mark_phi_for_rewrite (basic_block bb, gphi *phi) |
70630fcd | 975 | { |
1a91d914 | 976 | vec<gphi *> phis; |
2670407e | 977 | unsigned n, idx = bb->index; |
70630fcd | 978 | |
75a70cf9 | 979 | if (rewrite_uses_p (phi)) |
70630fcd | 980 | return; |
4fb5e5ca | 981 | |
75a70cf9 | 982 | set_rewrite_uses (phi, true); |
70630fcd | 983 | |
984 | if (!blocks_with_phis_to_rewrite) | |
985 | return; | |
986 | ||
987 | bitmap_set_bit (blocks_with_phis_to_rewrite, idx); | |
2670407e | 988 | |
fe672ac0 | 989 | n = (unsigned) last_basic_block_for_fn (cfun) + 1; |
f1f41a6c | 990 | if (phis_to_rewrite.length () < n) |
991 | phis_to_rewrite.safe_grow_cleared (n); | |
70630fcd | 992 | |
f1f41a6c | 993 | phis = phis_to_rewrite[idx]; |
994 | phis.reserve (10); | |
70630fcd | 995 | |
f1f41a6c | 996 | phis.safe_push (phi); |
997 | phis_to_rewrite[idx] = phis; | |
70630fcd | 998 | } |
999 | ||
e551bd1a | 1000 | /* Insert PHI nodes for variable VAR using the iterated dominance |
88dbf20f | 1001 | frontier given in PHI_INSERTION_POINTS. If UPDATE_P is true, this |
4fb5e5ca | 1002 | function assumes that the caller is incrementally updating the |
1003 | existing SSA form, in which case VAR may be an SSA name instead of | |
1004 | a symbol. | |
88dbf20f | 1005 | |
1006 | PHI_INSERTION_POINTS is updated to reflect nodes that already had a | |
1007 | PHI node for VAR. On exit, only the nodes that received a PHI node | |
1008 | for VAR will be present in PHI_INSERTION_POINTS. */ | |
e551bd1a | 1009 | |
1010 | static void | |
88dbf20f | 1011 | insert_phi_nodes_for (tree var, bitmap phi_insertion_points, bool update_p) |
e551bd1a | 1012 | { |
1013 | unsigned bb_index; | |
1014 | edge e; | |
1a91d914 | 1015 | gphi *phi; |
e551bd1a | 1016 | basic_block bb; |
1017 | bitmap_iterator bi; | |
88536563 | 1018 | struct def_blocks_d *def_map = find_def_blocks_for (var); |
e551bd1a | 1019 | |
1020 | /* Remove the blocks where we already have PHI nodes for VAR. */ | |
1021 | bitmap_and_compl_into (phi_insertion_points, def_map->phi_blocks); | |
1022 | ||
f50cf978 | 1023 | /* Remove obviously useless phi nodes. */ |
1024 | prune_unused_phi_nodes (phi_insertion_points, def_map->def_blocks, | |
1025 | def_map->livein_blocks); | |
e551bd1a | 1026 | |
1027 | /* And insert the PHI nodes. */ | |
f50cf978 | 1028 | EXECUTE_IF_SET_IN_BITMAP (phi_insertion_points, 0, bb_index, bi) |
e551bd1a | 1029 | { |
f5a6b05f | 1030 | bb = BASIC_BLOCK_FOR_FN (cfun, bb_index); |
2920559d | 1031 | if (update_p) |
1032 | mark_block_for_update (bb); | |
e551bd1a | 1033 | |
487c79c3 | 1034 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1035 | { | |
1036 | fprintf (dump_file, "creating PHI node in block #%d for ", bb_index); | |
1037 | print_generic_expr (dump_file, var, TDF_SLIM); | |
1038 | fprintf (dump_file, "\n"); | |
1039 | } | |
75a70cf9 | 1040 | phi = NULL; |
4fb5e5ca | 1041 | |
1042 | if (TREE_CODE (var) == SSA_NAME) | |
e551bd1a | 1043 | { |
095dcfa3 | 1044 | /* If we are rewriting SSA names, create the LHS of the PHI |
1045 | node by duplicating VAR. This is useful in the case of | |
1046 | pointers, to also duplicate pointer attributes (alias | |
1047 | information, in particular). */ | |
e551bd1a | 1048 | edge_iterator ei; |
095dcfa3 | 1049 | tree new_lhs; |
88dbf20f | 1050 | |
88536563 | 1051 | gcc_checking_assert (update_p); |
9c06f260 | 1052 | new_lhs = duplicate_ssa_name (var, NULL); |
1053 | phi = create_phi_node (new_lhs, bb); | |
095dcfa3 | 1054 | add_new_name_mapping (new_lhs, var); |
88dbf20f | 1055 | |
1056 | /* Add VAR to every argument slot of PHI. We need VAR in | |
1057 | every argument so that rewrite_update_phi_arguments knows | |
1058 | which name is this PHI node replacing. If VAR is a | |
1059 | symbol marked for renaming, this is not necessary, the | |
1060 | renamer will use the symbol on the LHS to get its | |
1061 | reaching definition. */ | |
e551bd1a | 1062 | FOR_EACH_EDGE (e, ei, bb->preds) |
60d535d2 | 1063 | add_phi_arg (phi, var, e, UNKNOWN_LOCATION); |
e551bd1a | 1064 | } |
095dcfa3 | 1065 | else |
1066 | { | |
9845d120 | 1067 | tree tracked_var; |
cd610ee6 | 1068 | |
88536563 | 1069 | gcc_checking_assert (DECL_P (var)); |
25ae9ba2 | 1070 | phi = create_phi_node (var, bb); |
cd610ee6 | 1071 | |
1072 | tracked_var = target_for_debug_bind (var); | |
1073 | if (tracked_var) | |
9845d120 | 1074 | { |
1075 | gimple note = gimple_build_debug_bind (tracked_var, | |
1076 | PHI_RESULT (phi), | |
1077 | phi); | |
1078 | gimple_stmt_iterator si = gsi_after_labels (bb); | |
1079 | gsi_insert_before (&si, note, GSI_SAME_STMT); | |
1080 | } | |
095dcfa3 | 1081 | } |
88dbf20f | 1082 | |
1083 | /* Mark this PHI node as interesting for update_ssa. */ | |
75a70cf9 | 1084 | set_register_defs (phi, true); |
70630fcd | 1085 | mark_phi_for_rewrite (bb, phi); |
e551bd1a | 1086 | } |
1087 | } | |
1088 | ||
22d6c74e | 1089 | /* Sort var_infos after DECL_UID of their var. */ |
c86a4051 | 1090 | |
1091 | static int | |
22d6c74e | 1092 | insert_phi_nodes_compare_var_infos (const void *a, const void *b) |
c86a4051 | 1093 | { |
22d6c74e | 1094 | const struct var_info_d *defa = *(struct var_info_d * const *)a; |
1095 | const struct var_info_d *defb = *(struct var_info_d * const *)b; | |
c86a4051 | 1096 | if (DECL_UID (defa->var) < DECL_UID (defb->var)) |
1097 | return -1; | |
1098 | else | |
1099 | return 1; | |
1100 | } | |
e551bd1a | 1101 | |
e551bd1a | 1102 | /* Insert PHI nodes at the dominance frontier of blocks with variable |
1103 | definitions. DFS contains the dominance frontier information for | |
4fb5e5ca | 1104 | the flowgraph. */ |
e551bd1a | 1105 | |
1106 | static void | |
8a2980be | 1107 | insert_phi_nodes (bitmap_head *dfs) |
e551bd1a | 1108 | { |
c1f445d2 | 1109 | hash_table<var_info_hasher>::iterator hi; |
c86a4051 | 1110 | unsigned i; |
22d6c74e | 1111 | var_info_p info; |
e551bd1a | 1112 | |
1113 | timevar_push (TV_TREE_INSERT_PHI_NODES); | |
48e1416a | 1114 | |
c1f445d2 | 1115 | auto_vec<var_info_p> vars (var_infos->elements ()); |
1116 | FOR_EACH_HASH_TABLE_ELEMENT (*var_infos, info, var_info_p, hi) | |
74105c0d | 1117 | if (info->info.need_phi_state != NEED_PHI_STATE_NO) |
f1f41a6c | 1118 | vars.quick_push (info); |
c86a4051 | 1119 | |
409a375f | 1120 | /* Do two stages to avoid code generation differences for UID |
1121 | differences but no UID ordering differences. */ | |
f1f41a6c | 1122 | vars.qsort (insert_phi_nodes_compare_var_infos); |
409a375f | 1123 | |
f1f41a6c | 1124 | FOR_EACH_VEC_ELT (vars, i, info) |
f3d9a16c | 1125 | { |
74105c0d | 1126 | bitmap idf = compute_idf (info->info.def_blocks.def_blocks, dfs); |
22d6c74e | 1127 | insert_phi_nodes_for (info->var, idf, false); |
409a375f | 1128 | BITMAP_FREE (idf); |
1129 | } | |
1130 | ||
4ee9c684 | 1131 | timevar_pop (TV_TREE_INSERT_PHI_NODES); |
1132 | } | |
1133 | ||
1134 | ||
4fb5e5ca | 1135 | /* Push SYM's current reaching definition into BLOCK_DEFS_STACK and |
1136 | register DEF (an SSA_NAME) to be a new definition for SYM. */ | |
e551bd1a | 1137 | |
de6ed584 | 1138 | static void |
4fb5e5ca | 1139 | register_new_def (tree def, tree sym) |
e551bd1a | 1140 | { |
74105c0d | 1141 | common_info_p info = get_common_info (sym); |
e551bd1a | 1142 | tree currdef; |
48e1416a | 1143 | |
e551bd1a | 1144 | /* If this variable is set in a single basic block and all uses are |
1145 | dominated by the set(s) in that single basic block, then there is | |
1146 | no reason to record anything for this variable in the block local | |
1147 | definition stacks. Doing so just wastes time and memory. | |
1148 | ||
1149 | This is the same test to prune the set of variables which may | |
1150 | need PHI nodes. So we just use that information since it's already | |
1151 | computed and available for us to use. */ | |
74105c0d | 1152 | if (info->need_phi_state == NEED_PHI_STATE_NO) |
e551bd1a | 1153 | { |
74105c0d | 1154 | info->current_def = def; |
e551bd1a | 1155 | return; |
1156 | } | |
1157 | ||
74105c0d | 1158 | currdef = info->current_def; |
e551bd1a | 1159 | |
4fb5e5ca | 1160 | /* If SYM is not a GIMPLE register, then CURRDEF may be a name whose |
1161 | SSA_NAME_VAR is not necessarily SYM. In this case, also push SYM | |
1162 | in the stack so that we know which symbol is being defined by | |
1163 | this SSA name when we unwind the stack. */ | |
1164 | if (currdef && !is_gimple_reg (sym)) | |
f1f41a6c | 1165 | block_defs_stack.safe_push (sym); |
e551bd1a | 1166 | |
4fb5e5ca | 1167 | /* Push the current reaching definition into BLOCK_DEFS_STACK. This |
1168 | stack is later used by the dominator tree callbacks to restore | |
1169 | the reaching definitions for all the variables defined in the | |
1170 | block after a recursive visit to all its immediately dominated | |
1171 | blocks. If there is no current reaching definition, then just | |
1172 | record the underlying _DECL node. */ | |
f1f41a6c | 1173 | block_defs_stack.safe_push (currdef ? currdef : sym); |
4fb5e5ca | 1174 | |
1175 | /* Set the current reaching definition for SYM to be DEF. */ | |
74105c0d | 1176 | info->current_def = def; |
e551bd1a | 1177 | } |
1178 | ||
1179 | ||
4ee9c684 | 1180 | /* Perform a depth-first traversal of the dominator tree looking for |
1181 | variables to rename. BB is the block where to start searching. | |
1182 | Renaming is a five step process: | |
1183 | ||
1184 | 1- Every definition made by PHI nodes at the start of the blocks is | |
1185 | registered as the current definition for the corresponding variable. | |
1186 | ||
1187 | 2- Every statement in BB is rewritten. USE and VUSE operands are | |
1188 | rewritten with their corresponding reaching definition. DEF and | |
1189 | VDEF targets are registered as new definitions. | |
48e1416a | 1190 | |
4ee9c684 | 1191 | 3- All the PHI nodes in successor blocks of BB are visited. The |
1192 | argument corresponding to BB is replaced with its current reaching | |
1193 | definition. | |
1194 | ||
1195 | 4- Recursively rewrite every dominator child block of BB. | |
1196 | ||
1197 | 5- Restore (in reverse order) the current reaching definition for every | |
1198 | new definition introduced in this block. This is done so that when | |
1199 | we return from the recursive call, all the current reaching | |
1200 | definitions are restored to the names that were valid in the | |
1201 | dominator parent of BB. */ | |
1202 | ||
e551bd1a | 1203 | /* Return the current definition for variable VAR. If none is found, |
4fb5e5ca | 1204 | create a new SSA name to act as the zeroth definition for VAR. */ |
f3d9a16c | 1205 | |
e551bd1a | 1206 | static tree |
1207 | get_reaching_def (tree var) | |
1208 | { | |
74105c0d | 1209 | common_info_p info = get_common_info (var); |
4fb5e5ca | 1210 | tree currdef; |
48e1416a | 1211 | |
e551bd1a | 1212 | /* Lookup the current reaching definition for VAR. */ |
74105c0d | 1213 | currdef = info->current_def; |
f3d9a16c | 1214 | |
e551bd1a | 1215 | /* If there is no reaching definition for VAR, create and register a |
1216 | default definition for it (if needed). */ | |
4fb5e5ca | 1217 | if (currdef == NULL_TREE) |
e551bd1a | 1218 | { |
4fb5e5ca | 1219 | tree sym = DECL_P (var) ? var : SSA_NAME_VAR (var); |
c6dfe037 | 1220 | currdef = get_or_create_ssa_default_def (cfun, sym); |
e551bd1a | 1221 | } |
1222 | ||
1223 | /* Return the current reaching definition for VAR, or the default | |
1224 | definition, if we had to create one. */ | |
4fb5e5ca | 1225 | return currdef; |
e551bd1a | 1226 | } |
1227 | ||
1228 | ||
841424cc | 1229 | /* Helper function for rewrite_stmt. Rewrite uses in a debug stmt. */ |
1230 | ||
1231 | static void | |
1232 | rewrite_debug_stmt_uses (gimple stmt) | |
1233 | { | |
1234 | use_operand_p use_p; | |
1235 | ssa_op_iter iter; | |
1236 | bool update = false; | |
1237 | ||
1238 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) | |
1239 | { | |
4ae5778c | 1240 | tree var = USE_FROM_PTR (use_p), def; |
74105c0d | 1241 | common_info_p info = get_common_info (var); |
88536563 | 1242 | gcc_checking_assert (DECL_P (var)); |
74105c0d | 1243 | def = info->current_def; |
4ae5778c | 1244 | if (!def) |
841424cc | 1245 | { |
34154e27 | 1246 | if (TREE_CODE (var) == PARM_DECL |
1247 | && single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun))) | |
841424cc | 1248 | { |
1249 | gimple_stmt_iterator gsi | |
34154e27 | 1250 | = |
1251 | gsi_after_labels (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun))); | |
841424cc | 1252 | int lim; |
1253 | /* Search a few source bind stmts at the start of first bb to | |
1254 | see if a DEBUG_EXPR_DECL can't be reused. */ | |
1255 | for (lim = 32; | |
1256 | !gsi_end_p (gsi) && lim > 0; | |
1257 | gsi_next (&gsi), lim--) | |
1258 | { | |
1259 | gimple gstmt = gsi_stmt (gsi); | |
1260 | if (!gimple_debug_source_bind_p (gstmt)) | |
1261 | break; | |
1262 | if (gimple_debug_source_bind_get_value (gstmt) == var) | |
1263 | { | |
1264 | def = gimple_debug_source_bind_get_var (gstmt); | |
1265 | if (TREE_CODE (def) == DEBUG_EXPR_DECL) | |
1266 | break; | |
1267 | else | |
1268 | def = NULL_TREE; | |
1269 | } | |
1270 | } | |
1271 | /* If not, add a new source bind stmt. */ | |
1272 | if (def == NULL_TREE) | |
1273 | { | |
1274 | gimple def_temp; | |
1275 | def = make_node (DEBUG_EXPR_DECL); | |
1276 | def_temp = gimple_build_debug_source_bind (def, var, NULL); | |
1277 | DECL_ARTIFICIAL (def) = 1; | |
1278 | TREE_TYPE (def) = TREE_TYPE (var); | |
1279 | DECL_MODE (def) = DECL_MODE (var); | |
34154e27 | 1280 | gsi = |
1281 | gsi_after_labels (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun))); | |
841424cc | 1282 | gsi_insert_before (&gsi, def_temp, GSI_SAME_STMT); |
1283 | } | |
1284 | update = true; | |
1285 | } | |
1286 | } | |
1287 | else | |
824651eb | 1288 | { |
74105c0d | 1289 | /* Check if info->current_def can be trusted. */ |
4ae5778c | 1290 | basic_block bb = gimple_bb (stmt); |
1291 | basic_block def_bb | |
1292 | = SSA_NAME_IS_DEFAULT_DEF (def) | |
1293 | ? NULL : gimple_bb (SSA_NAME_DEF_STMT (def)); | |
1294 | ||
1295 | /* If definition is in current bb, it is fine. */ | |
1296 | if (bb == def_bb) | |
1297 | ; | |
1298 | /* If definition bb doesn't dominate the current bb, | |
1299 | it can't be used. */ | |
1300 | else if (def_bb && !dominated_by_p (CDI_DOMINATORS, bb, def_bb)) | |
1301 | def = NULL; | |
1302 | /* If there is just one definition and dominates the current | |
1303 | bb, it is fine. */ | |
74105c0d | 1304 | else if (info->need_phi_state == NEED_PHI_STATE_NO) |
4ae5778c | 1305 | ; |
1306 | else | |
824651eb | 1307 | { |
74105c0d | 1308 | struct def_blocks_d *db_p = get_def_blocks_for (info); |
824651eb | 1309 | |
4ae5778c | 1310 | /* If there are some non-debug uses in the current bb, |
1311 | it is fine. */ | |
1312 | if (bitmap_bit_p (db_p->livein_blocks, bb->index)) | |
824651eb | 1313 | ; |
4ae5778c | 1314 | /* Otherwise give up for now. */ |
824651eb | 1315 | else |
4ae5778c | 1316 | def = NULL; |
824651eb | 1317 | } |
1318 | } | |
841424cc | 1319 | if (def == NULL) |
1320 | { | |
1321 | gimple_debug_bind_reset_value (stmt); | |
1322 | update_stmt (stmt); | |
1323 | return; | |
1324 | } | |
1325 | SET_USE (use_p, def); | |
1326 | } | |
1327 | if (update) | |
1328 | update_stmt (stmt); | |
1329 | } | |
1330 | ||
e551bd1a | 1331 | /* SSA Rewriting Step 2. Rewrite every variable used in each statement in |
1332 | the block with its immediate reaching definitions. Update the current | |
1333 | definition of a variable when a new real or virtual definition is found. */ | |
f3d9a16c | 1334 | |
1335 | static void | |
eb54054d | 1336 | rewrite_stmt (gimple_stmt_iterator *si) |
f3d9a16c | 1337 | { |
e551bd1a | 1338 | use_operand_p use_p; |
1339 | def_operand_p def_p; | |
1340 | ssa_op_iter iter; | |
eb54054d | 1341 | gimple stmt = gsi_stmt (*si); |
e551bd1a | 1342 | |
e551bd1a | 1343 | /* If mark_def_sites decided that we don't need to rewrite this |
1344 | statement, ignore it. */ | |
2920559d | 1345 | gcc_assert (blocks_to_update == NULL); |
75a70cf9 | 1346 | if (!rewrite_uses_p (stmt) && !register_defs_p (stmt)) |
e551bd1a | 1347 | return; |
f3d9a16c | 1348 | |
1349 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
e551bd1a | 1350 | { |
1351 | fprintf (dump_file, "Renaming statement "); | |
75a70cf9 | 1352 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
e551bd1a | 1353 | fprintf (dump_file, "\n"); |
1354 | } | |
f3d9a16c | 1355 | |
4fb5e5ca | 1356 | /* Step 1. Rewrite USES in the statement. */ |
75a70cf9 | 1357 | if (rewrite_uses_p (stmt)) |
841424cc | 1358 | { |
1359 | if (is_gimple_debug (stmt)) | |
1360 | rewrite_debug_stmt_uses (stmt); | |
1361 | else | |
5aabc5f2 | 1362 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES) |
841424cc | 1363 | { |
1364 | tree var = USE_FROM_PTR (use_p); | |
88536563 | 1365 | gcc_checking_assert (DECL_P (var)); |
841424cc | 1366 | SET_USE (use_p, get_reaching_def (var)); |
1367 | } | |
1368 | } | |
f3d9a16c | 1369 | |
4fb5e5ca | 1370 | /* Step 2. Register the statement's DEF operands. */ |
75a70cf9 | 1371 | if (register_defs_p (stmt)) |
5aabc5f2 | 1372 | FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, iter, SSA_OP_ALL_DEFS) |
88dbf20f | 1373 | { |
1374 | tree var = DEF_FROM_PTR (def_p); | |
eb54054d | 1375 | tree name; |
9845d120 | 1376 | tree tracked_var; |
eb54054d | 1377 | |
88536563 | 1378 | gcc_checking_assert (DECL_P (var)); |
eb54054d | 1379 | |
1380 | if (gimple_clobber_p (stmt) | |
1381 | && is_gimple_reg (var)) | |
1382 | { | |
1383 | /* If we rewrite a DECL into SSA form then drop its | |
1384 | clobber stmts and replace uses with a new default def. */ | |
88536563 | 1385 | gcc_checking_assert (TREE_CODE (var) == VAR_DECL |
1386 | && !gimple_vdef (stmt)); | |
eb54054d | 1387 | gsi_replace (si, gimple_build_nop (), true); |
1388 | register_new_def (get_or_create_ssa_default_def (cfun, var), var); | |
1389 | break; | |
1390 | } | |
1391 | ||
1392 | name = make_ssa_name (var, stmt); | |
9845d120 | 1393 | SET_DEF (def_p, name); |
4fb5e5ca | 1394 | register_new_def (DEF_FROM_PTR (def_p), var); |
9845d120 | 1395 | |
1396 | tracked_var = target_for_debug_bind (var); | |
1397 | if (tracked_var) | |
1398 | { | |
1399 | gimple note = gimple_build_debug_bind (tracked_var, name, stmt); | |
eb54054d | 1400 | gsi_insert_after (si, note, GSI_SAME_STMT); |
9845d120 | 1401 | } |
88dbf20f | 1402 | } |
f3d9a16c | 1403 | } |
4ee9c684 | 1404 | |
e551bd1a | 1405 | |
4ee9c684 | 1406 | /* SSA Rewriting Step 3. Visit all the successor blocks of BB looking for |
1407 | PHI nodes. For every PHI node found, add a new argument containing the | |
1408 | current reaching definition for the variable and the edge through which | |
dac49aa5 | 1409 | that definition is reaching the PHI node. */ |
4ee9c684 | 1410 | |
1411 | static void | |
6bf320fb | 1412 | rewrite_add_phi_arguments (basic_block bb) |
4ee9c684 | 1413 | { |
1414 | edge e; | |
cd665a06 | 1415 | edge_iterator ei; |
4ee9c684 | 1416 | |
cd665a06 | 1417 | FOR_EACH_EDGE (e, ei, bb->succs) |
4ee9c684 | 1418 | { |
1a91d914 | 1419 | gphi *phi; |
1420 | gphi_iterator gsi; | |
4ee9c684 | 1421 | |
75a70cf9 | 1422 | for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi); |
1423 | gsi_next (&gsi)) | |
4ee9c684 | 1424 | { |
e60062ea | 1425 | tree currdef, res; |
1426 | location_t loc; | |
efbcb6de | 1427 | |
1a91d914 | 1428 | phi = gsi.phi (); |
e60062ea | 1429 | res = gimple_phi_result (phi); |
1430 | currdef = get_reaching_def (SSA_NAME_VAR (res)); | |
1431 | /* Virtual operand PHI args do not need a location. */ | |
1432 | if (virtual_operand_p (res)) | |
1433 | loc = UNKNOWN_LOCATION; | |
1434 | else | |
1435 | loc = gimple_location (SSA_NAME_DEF_STMT (currdef)); | |
1436 | add_phi_arg (phi, currdef, e, loc); | |
4ee9c684 | 1437 | } |
1438 | } | |
1439 | } | |
1440 | ||
54c91640 | 1441 | class rewrite_dom_walker : public dom_walker |
1442 | { | |
1443 | public: | |
1444 | rewrite_dom_walker (cdi_direction direction) : dom_walker (direction) {} | |
1445 | ||
1446 | virtual void before_dom_children (basic_block); | |
1447 | virtual void after_dom_children (basic_block); | |
1448 | }; | |
1449 | ||
6bf320fb | 1450 | /* SSA Rewriting Step 1. Initialization, create a block local stack |
1451 | of reaching definitions for new SSA names produced in this block | |
1452 | (BLOCK_DEFS). Register new definitions for every PHI node in the | |
1453 | block. */ | |
1454 | ||
54c91640 | 1455 | void |
1456 | rewrite_dom_walker::before_dom_children (basic_block bb) | |
6bf320fb | 1457 | { |
6bf320fb | 1458 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1459 | fprintf (dump_file, "\n\nRenaming block #%d\n\n", bb->index); | |
1460 | ||
1461 | /* Mark the unwind point for this block. */ | |
f1f41a6c | 1462 | block_defs_stack.safe_push (NULL_TREE); |
6bf320fb | 1463 | |
1464 | /* Step 1. Register new definitions for every PHI node in the block. | |
1465 | Conceptually, all the PHI nodes are executed in parallel and each PHI | |
1466 | node introduces a new version for the associated variable. */ | |
1a91d914 | 1467 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
1468 | gsi_next (&gsi)) | |
6bf320fb | 1469 | { |
5aabc5f2 | 1470 | tree result = gimple_phi_result (gsi_stmt (gsi)); |
6bf320fb | 1471 | register_new_def (result, SSA_NAME_VAR (result)); |
1472 | } | |
1473 | ||
1474 | /* Step 2. Rewrite every variable used in each statement in the block | |
1475 | with its immediate reaching definitions. Update the current definition | |
1476 | of a variable when a new real or virtual definition is found. */ | |
08b7917c | 1477 | if (bitmap_bit_p (interesting_blocks, bb->index)) |
1a91d914 | 1478 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); |
1479 | gsi_next (&gsi)) | |
eb54054d | 1480 | rewrite_stmt (&gsi); |
6bf320fb | 1481 | |
1482 | /* Step 3. Visit all the successor blocks of BB looking for PHI nodes. | |
1483 | For every PHI node found, add a new argument containing the current | |
1484 | reaching definition for the variable and the edge through which that | |
1485 | definition is reaching the PHI node. */ | |
1486 | rewrite_add_phi_arguments (bb); | |
1487 | } | |
1488 | ||
1489 | ||
e551bd1a | 1490 | |
4fb5e5ca | 1491 | /* Called after visiting all the statements in basic block BB and all |
1492 | of its dominator children. Restore CURRDEFS to its original value. */ | |
4ee9c684 | 1493 | |
54c91640 | 1494 | void |
1495 | rewrite_dom_walker::after_dom_children (basic_block bb ATTRIBUTE_UNUSED) | |
4ee9c684 | 1496 | { |
dd2d357d | 1497 | /* Restore CURRDEFS to its original state. */ |
f1f41a6c | 1498 | while (block_defs_stack.length () > 0) |
4ee9c684 | 1499 | { |
f1f41a6c | 1500 | tree tmp = block_defs_stack.pop (); |
4ee9c684 | 1501 | tree saved_def, var; |
1502 | ||
dd2d357d | 1503 | if (tmp == NULL_TREE) |
1504 | break; | |
1505 | ||
4ee9c684 | 1506 | if (TREE_CODE (tmp) == SSA_NAME) |
1507 | { | |
4fb5e5ca | 1508 | /* If we recorded an SSA_NAME, then make the SSA_NAME the |
1509 | current definition of its underlying variable. Note that | |
1510 | if the SSA_NAME is not for a GIMPLE register, the symbol | |
1511 | being defined is stored in the next slot in the stack. | |
1512 | This mechanism is needed because an SSA name for a | |
1513 | non-register symbol may be the definition for more than | |
1514 | one symbol (e.g., SFTs, aliased variables, etc). */ | |
4ee9c684 | 1515 | saved_def = tmp; |
1516 | var = SSA_NAME_VAR (saved_def); | |
4fb5e5ca | 1517 | if (!is_gimple_reg (var)) |
f1f41a6c | 1518 | var = block_defs_stack.pop (); |
4ee9c684 | 1519 | } |
1520 | else | |
1521 | { | |
4fb5e5ca | 1522 | /* If we recorded anything else, it must have been a _DECL |
1523 | node and its current reaching definition must have been | |
1524 | NULL. */ | |
4ee9c684 | 1525 | saved_def = NULL; |
1526 | var = tmp; | |
1527 | } | |
48e1416a | 1528 | |
74105c0d | 1529 | get_common_info (var)->current_def = saved_def; |
4ee9c684 | 1530 | } |
1531 | } | |
1532 | ||
1533 | ||
4fb5e5ca | 1534 | /* Dump bitmap SET (assumed to contain VAR_DECLs) to FILE. */ |
1535 | ||
4b987fac | 1536 | DEBUG_FUNCTION void |
4fb5e5ca | 1537 | debug_decl_set (bitmap set) |
1538 | { | |
1539 | dump_decl_set (stderr, set); | |
dd277d48 | 1540 | fprintf (stderr, "\n"); |
4fb5e5ca | 1541 | } |
1542 | ||
1543 | ||
1544 | /* Dump the renaming stack (block_defs_stack) to FILE. Traverse the | |
1545 | stack up to a maximum of N levels. If N is -1, the whole stack is | |
1546 | dumped. New levels are created when the dominator tree traversal | |
1547 | used for renaming enters a new sub-tree. */ | |
1548 | ||
1549 | void | |
1550 | dump_defs_stack (FILE *file, int n) | |
1551 | { | |
1552 | int i, j; | |
1553 | ||
1554 | fprintf (file, "\n\nRenaming stack"); | |
1555 | if (n > 0) | |
1556 | fprintf (file, " (up to %d levels)", n); | |
1557 | fprintf (file, "\n\n"); | |
1558 | ||
1559 | i = 1; | |
1560 | fprintf (file, "Level %d (current level)\n", i); | |
f1f41a6c | 1561 | for (j = (int) block_defs_stack.length () - 1; j >= 0; j--) |
4fb5e5ca | 1562 | { |
1563 | tree name, var; | |
48e1416a | 1564 | |
f1f41a6c | 1565 | name = block_defs_stack[j]; |
4fb5e5ca | 1566 | if (name == NULL_TREE) |
1567 | { | |
1568 | i++; | |
1569 | if (n > 0 && i > n) | |
1570 | break; | |
1571 | fprintf (file, "\nLevel %d\n", i); | |
1572 | continue; | |
1573 | } | |
1574 | ||
1575 | if (DECL_P (name)) | |
1576 | { | |
1577 | var = name; | |
1578 | name = NULL_TREE; | |
1579 | } | |
1580 | else | |
1581 | { | |
1582 | var = SSA_NAME_VAR (name); | |
1583 | if (!is_gimple_reg (var)) | |
1584 | { | |
1585 | j--; | |
f1f41a6c | 1586 | var = block_defs_stack[j]; |
4fb5e5ca | 1587 | } |
1588 | } | |
1589 | ||
1590 | fprintf (file, " Previous CURRDEF ("); | |
1591 | print_generic_expr (file, var, 0); | |
1592 | fprintf (file, ") = "); | |
1593 | if (name) | |
1594 | print_generic_expr (file, name, 0); | |
1595 | else | |
1596 | fprintf (file, "<NIL>"); | |
1597 | fprintf (file, "\n"); | |
1598 | } | |
1599 | } | |
1600 | ||
1601 | ||
1602 | /* Dump the renaming stack (block_defs_stack) to stderr. Traverse the | |
1603 | stack up to a maximum of N levels. If N is -1, the whole stack is | |
1604 | dumped. New levels are created when the dominator tree traversal | |
1605 | used for renaming enters a new sub-tree. */ | |
1606 | ||
4b987fac | 1607 | DEBUG_FUNCTION void |
4fb5e5ca | 1608 | debug_defs_stack (int n) |
1609 | { | |
1610 | dump_defs_stack (stderr, n); | |
1611 | } | |
1612 | ||
1613 | ||
1614 | /* Dump the current reaching definition of every symbol to FILE. */ | |
1615 | ||
1616 | void | |
1617 | dump_currdefs (FILE *file) | |
1618 | { | |
e70e8b13 | 1619 | unsigned i; |
4fb5e5ca | 1620 | tree var; |
1621 | ||
f1f41a6c | 1622 | if (symbols_to_rename.is_empty ()) |
e70e8b13 | 1623 | return; |
1624 | ||
4fb5e5ca | 1625 | fprintf (file, "\n\nCurrent reaching definitions\n\n"); |
f1f41a6c | 1626 | FOR_EACH_VEC_ELT (symbols_to_rename, i, var) |
e70e8b13 | 1627 | { |
74105c0d | 1628 | common_info_p info = get_common_info (var); |
e70e8b13 | 1629 | fprintf (file, "CURRDEF ("); |
1630 | print_generic_expr (file, var, 0); | |
1631 | fprintf (file, ") = "); | |
74105c0d | 1632 | if (info->current_def) |
1633 | print_generic_expr (file, info->current_def, 0); | |
e70e8b13 | 1634 | else |
1635 | fprintf (file, "<NIL>"); | |
1636 | fprintf (file, "\n"); | |
1637 | } | |
4fb5e5ca | 1638 | } |
1639 | ||
1640 | ||
1641 | /* Dump the current reaching definition of every symbol to stderr. */ | |
1642 | ||
4b987fac | 1643 | DEBUG_FUNCTION void |
4fb5e5ca | 1644 | debug_currdefs (void) |
1645 | { | |
1646 | dump_currdefs (stderr); | |
1647 | } | |
1648 | ||
1649 | ||
4ee9c684 | 1650 | /* Dump SSA information to FILE. */ |
1651 | ||
1652 | void | |
1653 | dump_tree_ssa (FILE *file) | |
1654 | { | |
4ee9c684 | 1655 | const char *funcname |
5135beeb | 1656 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
4ee9c684 | 1657 | |
4fb5e5ca | 1658 | fprintf (file, "SSA renaming information for %s\n\n", funcname); |
4ee9c684 | 1659 | |
22d6c74e | 1660 | dump_var_infos (file); |
4fb5e5ca | 1661 | dump_defs_stack (file, -1); |
1662 | dump_currdefs (file); | |
1663 | dump_tree_ssa_stats (file); | |
4ee9c684 | 1664 | } |
1665 | ||
1666 | ||
1667 | /* Dump SSA information to stderr. */ | |
1668 | ||
4b987fac | 1669 | DEBUG_FUNCTION void |
4ee9c684 | 1670 | debug_tree_ssa (void) |
1671 | { | |
1672 | dump_tree_ssa (stderr); | |
1673 | } | |
1674 | ||
1675 | ||
e551bd1a | 1676 | /* Dump statistics for the hash table HTAB. */ |
1677 | ||
1678 | static void | |
c1f445d2 | 1679 | htab_statistics (FILE *file, const hash_table<var_info_hasher> &htab) |
e551bd1a | 1680 | { |
1681 | fprintf (file, "size %ld, %ld elements, %f collision/search ratio\n", | |
3e871d4d | 1682 | (long) htab.size (), |
1683 | (long) htab.elements (), | |
1684 | htab.collisions ()); | |
e551bd1a | 1685 | } |
1686 | ||
1687 | ||
4ee9c684 | 1688 | /* Dump SSA statistics on FILE. */ |
1689 | ||
1690 | void | |
1691 | dump_tree_ssa_stats (FILE *file) | |
1692 | { | |
c1f445d2 | 1693 | if (var_infos) |
4fb5e5ca | 1694 | { |
22d6c74e | 1695 | fprintf (file, "\nHash table statistics:\n"); |
1696 | fprintf (file, " var_infos: "); | |
c1f445d2 | 1697 | htab_statistics (file, *var_infos); |
22d6c74e | 1698 | fprintf (file, "\n"); |
4fb5e5ca | 1699 | } |
4ee9c684 | 1700 | } |
1701 | ||
1702 | ||
1703 | /* Dump SSA statistics on stderr. */ | |
1704 | ||
4b987fac | 1705 | DEBUG_FUNCTION void |
4ee9c684 | 1706 | debug_tree_ssa_stats (void) |
1707 | { | |
1708 | dump_tree_ssa_stats (stderr); | |
1709 | } | |
1710 | ||
1711 | ||
22d6c74e | 1712 | /* Callback for htab_traverse to dump the VAR_INFOS hash table. */ |
4ee9c684 | 1713 | |
3e871d4d | 1714 | int |
1715 | debug_var_infos_r (var_info_d **slot, FILE *file) | |
e551bd1a | 1716 | { |
3e871d4d | 1717 | struct var_info_d *info = *slot; |
48e1416a | 1718 | |
4fb5e5ca | 1719 | fprintf (file, "VAR: "); |
74105c0d | 1720 | print_generic_expr (file, info->var, dump_flags); |
1721 | bitmap_print (file, info->info.def_blocks.def_blocks, | |
1722 | ", DEF_BLOCKS: { ", "}"); | |
1723 | bitmap_print (file, info->info.def_blocks.livein_blocks, | |
1724 | ", LIVEIN_BLOCKS: { ", "}"); | |
1725 | bitmap_print (file, info->info.def_blocks.phi_blocks, | |
1726 | ", PHI_BLOCKS: { ", "}\n"); | |
4ee9c684 | 1727 | |
e551bd1a | 1728 | return 1; |
1729 | } | |
4ee9c684 | 1730 | |
4ee9c684 | 1731 | |
22d6c74e | 1732 | /* Dump the VAR_INFOS hash table on FILE. */ |
4fb5e5ca | 1733 | |
1734 | void | |
22d6c74e | 1735 | dump_var_infos (FILE *file) |
4fb5e5ca | 1736 | { |
1737 | fprintf (file, "\n\nDefinition and live-in blocks:\n\n"); | |
c1f445d2 | 1738 | if (var_infos) |
1739 | var_infos->traverse <FILE *, debug_var_infos_r> (file); | |
4fb5e5ca | 1740 | } |
1741 | ||
1742 | ||
22d6c74e | 1743 | /* Dump the VAR_INFOS hash table on stderr. */ |
4ee9c684 | 1744 | |
4b987fac | 1745 | DEBUG_FUNCTION void |
22d6c74e | 1746 | debug_var_infos (void) |
e551bd1a | 1747 | { |
22d6c74e | 1748 | dump_var_infos (stderr); |
e551bd1a | 1749 | } |
4ee9c684 | 1750 | |
f3d9a16c | 1751 | |
88dbf20f | 1752 | /* Register NEW_NAME to be the new reaching definition for OLD_NAME. */ |
4ee9c684 | 1753 | |
88dbf20f | 1754 | static inline void |
1755 | register_new_update_single (tree new_name, tree old_name) | |
1756 | { | |
74105c0d | 1757 | common_info_p info = get_common_info (old_name); |
1758 | tree currdef = info->current_def; | |
f3d9a16c | 1759 | |
4fb5e5ca | 1760 | /* Push the current reaching definition into BLOCK_DEFS_STACK. |
88dbf20f | 1761 | This stack is later used by the dominator tree callbacks to |
1762 | restore the reaching definitions for all the variables | |
1763 | defined in the block after a recursive visit to all its | |
1764 | immediately dominated blocks. */ | |
f1f41a6c | 1765 | block_defs_stack.reserve (2); |
1766 | block_defs_stack.quick_push (currdef); | |
1767 | block_defs_stack.quick_push (old_name); | |
f3d9a16c | 1768 | |
88dbf20f | 1769 | /* Set the current reaching definition for OLD_NAME to be |
1770 | NEW_NAME. */ | |
74105c0d | 1771 | info->current_def = new_name; |
88dbf20f | 1772 | } |
e551bd1a | 1773 | |
4ee9c684 | 1774 | |
88dbf20f | 1775 | /* Register NEW_NAME to be the new reaching definition for all the |
1776 | names in OLD_NAMES. Used by the incremental SSA update routines to | |
1777 | replace old SSA names with new ones. */ | |
e551bd1a | 1778 | |
88dbf20f | 1779 | static inline void |
1780 | register_new_update_set (tree new_name, bitmap old_names) | |
1781 | { | |
1782 | bitmap_iterator bi; | |
1783 | unsigned i; | |
e551bd1a | 1784 | |
88dbf20f | 1785 | EXECUTE_IF_SET_IN_BITMAP (old_names, 0, i, bi) |
1786 | register_new_update_single (new_name, ssa_name (i)); | |
4ee9c684 | 1787 | } |
1788 | ||
e551bd1a | 1789 | |
88dbf20f | 1790 | |
095dcfa3 | 1791 | /* If the operand pointed to by USE_P is a name in OLD_SSA_NAMES or |
1792 | it is a symbol marked for renaming, replace it with USE_P's current | |
1793 | reaching definition. */ | |
1794 | ||
1795 | static inline void | |
1796 | maybe_replace_use (use_operand_p use_p) | |
1797 | { | |
1798 | tree rdef = NULL_TREE; | |
1799 | tree use = USE_FROM_PTR (use_p); | |
1800 | tree sym = DECL_P (use) ? use : SSA_NAME_VAR (use); | |
1801 | ||
e70e8b13 | 1802 | if (marked_for_renaming (sym)) |
095dcfa3 | 1803 | rdef = get_reaching_def (sym); |
1804 | else if (is_old_name (use)) | |
1805 | rdef = get_reaching_def (use); | |
1806 | ||
1807 | if (rdef && rdef != use) | |
1808 | SET_USE (use_p, rdef); | |
1809 | } | |
1810 | ||
1811 | ||
9845d120 | 1812 | /* Same as maybe_replace_use, but without introducing default stmts, |
1813 | returning false to indicate a need to do so. */ | |
1814 | ||
1815 | static inline bool | |
1816 | maybe_replace_use_in_debug_stmt (use_operand_p use_p) | |
1817 | { | |
1818 | tree rdef = NULL_TREE; | |
1819 | tree use = USE_FROM_PTR (use_p); | |
1820 | tree sym = DECL_P (use) ? use : SSA_NAME_VAR (use); | |
1821 | ||
e70e8b13 | 1822 | if (marked_for_renaming (sym)) |
74105c0d | 1823 | rdef = get_var_info (sym)->info.current_def; |
9845d120 | 1824 | else if (is_old_name (use)) |
1825 | { | |
74105c0d | 1826 | rdef = get_ssa_name_ann (use)->info.current_def; |
9845d120 | 1827 | /* We can't assume that, if there's no current definition, the |
1828 | default one should be used. It could be the case that we've | |
1829 | rearranged blocks so that the earlier definition no longer | |
1830 | dominates the use. */ | |
1831 | if (!rdef && SSA_NAME_IS_DEFAULT_DEF (use)) | |
1832 | rdef = use; | |
1833 | } | |
1834 | else | |
1835 | rdef = use; | |
1836 | ||
1837 | if (rdef && rdef != use) | |
1838 | SET_USE (use_p, rdef); | |
1839 | ||
1840 | return rdef != NULL_TREE; | |
1841 | } | |
1842 | ||
1843 | ||
095dcfa3 | 1844 | /* If the operand pointed to by DEF_P is an SSA name in NEW_SSA_NAMES |
1845 | or OLD_SSA_NAMES, or if it is a symbol marked for renaming, | |
1846 | register it as the current definition for the names replaced by | |
4d8d655b | 1847 | DEF_P. Returns whether the statement should be removed. */ |
095dcfa3 | 1848 | |
4d8d655b | 1849 | static inline bool |
cd610ee6 | 1850 | maybe_register_def (def_operand_p def_p, gimple stmt, |
1851 | gimple_stmt_iterator gsi) | |
095dcfa3 | 1852 | { |
1853 | tree def = DEF_FROM_PTR (def_p); | |
1854 | tree sym = DECL_P (def) ? def : SSA_NAME_VAR (def); | |
4d8d655b | 1855 | bool to_delete = false; |
095dcfa3 | 1856 | |
4fb5e5ca | 1857 | /* If DEF is a naked symbol that needs renaming, create a new |
1858 | name for it. */ | |
e70e8b13 | 1859 | if (marked_for_renaming (sym)) |
095dcfa3 | 1860 | { |
1861 | if (DECL_P (def)) | |
1862 | { | |
4d8d655b | 1863 | if (gimple_clobber_p (stmt) && is_gimple_reg (sym)) |
1864 | { | |
1865 | gcc_checking_assert (TREE_CODE (sym) == VAR_DECL); | |
1866 | /* Replace clobber stmts with a default def. This new use of a | |
1867 | default definition may make it look like SSA_NAMEs have | |
1868 | conflicting lifetimes, so we need special code to let them | |
1869 | coalesce properly. */ | |
1870 | to_delete = true; | |
1871 | def = get_or_create_ssa_default_def (cfun, sym); | |
1872 | } | |
1873 | else | |
1874 | def = make_ssa_name (def, stmt); | |
095dcfa3 | 1875 | SET_DEF (def_p, def); |
cd610ee6 | 1876 | |
4d8d655b | 1877 | tree tracked_var = target_for_debug_bind (sym); |
cd610ee6 | 1878 | if (tracked_var) |
1879 | { | |
1880 | gimple note = gimple_build_debug_bind (tracked_var, def, stmt); | |
8d7f27c3 | 1881 | /* If stmt ends the bb, insert the debug stmt on the single |
1882 | non-EH edge from the stmt. */ | |
1883 | if (gsi_one_before_end_p (gsi) && stmt_ends_bb_p (stmt)) | |
1884 | { | |
1885 | basic_block bb = gsi_bb (gsi); | |
1886 | edge_iterator ei; | |
1887 | edge e, ef = NULL; | |
1888 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1889 | if (!(e->flags & EDGE_EH)) | |
1890 | { | |
88536563 | 1891 | gcc_checking_assert (!ef); |
8d7f27c3 | 1892 | ef = e; |
1893 | } | |
36a2709b | 1894 | /* If there are other predecessors to ef->dest, then |
1895 | there must be PHI nodes for the modified | |
1896 | variable, and therefore there will be debug bind | |
1897 | stmts after the PHI nodes. The debug bind notes | |
1898 | we'd insert would force the creation of a new | |
1899 | block (diverging codegen) and be redundant with | |
1900 | the post-PHI bind stmts, so don't add them. | |
1901 | ||
1902 | As for the exit edge, there wouldn't be redundant | |
1903 | bind stmts, but there wouldn't be a PC to bind | |
1904 | them to either, so avoid diverging the CFG. */ | |
1905 | if (ef && single_pred_p (ef->dest) | |
34154e27 | 1906 | && ef->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
36a2709b | 1907 | { |
1908 | /* If there were PHI nodes in the node, we'd | |
1909 | have to make sure the value we're binding | |
1910 | doesn't need rewriting. But there shouldn't | |
1911 | be PHI nodes in a single-predecessor block, | |
1912 | so we just add the note. */ | |
1913 | gsi_insert_on_edge_immediate (ef, note); | |
1914 | } | |
8d7f27c3 | 1915 | } |
1916 | else | |
1917 | gsi_insert_after (&gsi, note, GSI_SAME_STMT); | |
cd610ee6 | 1918 | } |
095dcfa3 | 1919 | } |
1920 | ||
1921 | register_new_update_single (def, sym); | |
1922 | } | |
1923 | else | |
1924 | { | |
1925 | /* If DEF is a new name, register it as a new definition | |
1926 | for all the names replaced by DEF. */ | |
1927 | if (is_new_name (def)) | |
1928 | register_new_update_set (def, names_replaced_by (def)); | |
1929 | ||
1930 | /* If DEF is an old name, register DEF as a new | |
1931 | definition for itself. */ | |
1932 | if (is_old_name (def)) | |
1933 | register_new_update_single (def, def); | |
1934 | } | |
4d8d655b | 1935 | |
1936 | return to_delete; | |
095dcfa3 | 1937 | } |
1938 | ||
1939 | ||
88dbf20f | 1940 | /* Update every variable used in the statement pointed-to by SI. The |
1941 | statement is assumed to be in SSA form already. Names in | |
1942 | OLD_SSA_NAMES used by SI will be updated to their current reaching | |
1943 | definition. Names in OLD_SSA_NAMES or NEW_SSA_NAMES defined by SI | |
1944 | will be registered as a new definition for their corresponding name | |
4d8d655b | 1945 | in OLD_SSA_NAMES. Returns whether STMT should be removed. */ |
88dbf20f | 1946 | |
4d8d655b | 1947 | static bool |
cd610ee6 | 1948 | rewrite_update_stmt (gimple stmt, gimple_stmt_iterator gsi) |
88dbf20f | 1949 | { |
88dbf20f | 1950 | use_operand_p use_p; |
1951 | def_operand_p def_p; | |
1952 | ssa_op_iter iter; | |
1953 | ||
88dbf20f | 1954 | /* Only update marked statements. */ |
75a70cf9 | 1955 | if (!rewrite_uses_p (stmt) && !register_defs_p (stmt)) |
4d8d655b | 1956 | return false; |
88dbf20f | 1957 | |
1958 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1959 | { | |
1960 | fprintf (dump_file, "Updating SSA information for statement "); | |
75a70cf9 | 1961 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
88dbf20f | 1962 | } |
1963 | ||
1964 | /* Rewrite USES included in OLD_SSA_NAMES and USES whose underlying | |
1965 | symbol is marked for renaming. */ | |
75a70cf9 | 1966 | if (rewrite_uses_p (stmt)) |
9845d120 | 1967 | { |
1968 | if (is_gimple_debug (stmt)) | |
1969 | { | |
1970 | bool failed = false; | |
1971 | ||
1972 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) | |
1973 | if (!maybe_replace_use_in_debug_stmt (use_p)) | |
1974 | { | |
1975 | failed = true; | |
1976 | break; | |
1977 | } | |
1978 | ||
1979 | if (failed) | |
1980 | { | |
1981 | /* DOM sometimes threads jumps in such a way that a | |
1982 | debug stmt ends up referencing a SSA variable that no | |
1983 | longer dominates the debug stmt, but such that all | |
1984 | incoming definitions refer to the same definition in | |
1985 | an earlier dominator. We could try to recover that | |
1986 | definition somehow, but this will have to do for now. | |
1987 | ||
1988 | Introducing a default definition, which is what | |
1989 | maybe_replace_use() would do in such cases, may | |
1990 | modify code generation, for the otherwise-unused | |
1991 | default definition would never go away, modifying SSA | |
1992 | version numbers all over. */ | |
1993 | gimple_debug_bind_reset_value (stmt); | |
1994 | update_stmt (stmt); | |
1995 | } | |
1996 | } | |
1997 | else | |
1998 | { | |
1999 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES) | |
2000 | maybe_replace_use (use_p); | |
2001 | } | |
2002 | } | |
88dbf20f | 2003 | |
2004 | /* Register definitions of names in NEW_SSA_NAMES and OLD_SSA_NAMES. | |
2005 | Also register definitions for names whose underlying symbol is | |
2006 | marked for renaming. */ | |
4d8d655b | 2007 | bool to_delete = false; |
75a70cf9 | 2008 | if (register_defs_p (stmt)) |
dd277d48 | 2009 | FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, iter, SSA_OP_ALL_DEFS) |
4d8d655b | 2010 | to_delete |= maybe_register_def (def_p, stmt, gsi); |
2011 | ||
2012 | return to_delete; | |
88dbf20f | 2013 | } |
2014 | ||
2015 | ||
2016 | /* Visit all the successor blocks of BB looking for PHI nodes. For | |
2017 | every PHI node found, check if any of its arguments is in | |
2018 | OLD_SSA_NAMES. If so, and if the argument has a current reaching | |
2019 | definition, replace it. */ | |
2020 | ||
2021 | static void | |
6bf320fb | 2022 | rewrite_update_phi_arguments (basic_block bb) |
88dbf20f | 2023 | { |
2024 | edge e; | |
2025 | edge_iterator ei; | |
70630fcd | 2026 | unsigned i; |
88dbf20f | 2027 | |
2028 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2029 | { | |
1a91d914 | 2030 | gphi *phi; |
2031 | vec<gphi *> phis; | |
88dbf20f | 2032 | |
70630fcd | 2033 | if (!bitmap_bit_p (blocks_with_phis_to_rewrite, e->dest->index)) |
2034 | continue; | |
48e1416a | 2035 | |
f1f41a6c | 2036 | phis = phis_to_rewrite[e->dest->index]; |
2037 | FOR_EACH_VEC_ELT (phis, i, phi) | |
88dbf20f | 2038 | { |
efbcb6de | 2039 | tree arg, lhs_sym, reaching_def = NULL; |
88dbf20f | 2040 | use_operand_p arg_p; |
2041 | ||
88536563 | 2042 | gcc_checking_assert (rewrite_uses_p (phi)); |
88dbf20f | 2043 | |
2044 | arg_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, e); | |
2045 | arg = USE_FROM_PTR (arg_p); | |
2046 | ||
2047 | if (arg && !DECL_P (arg) && TREE_CODE (arg) != SSA_NAME) | |
2048 | continue; | |
2049 | ||
75a70cf9 | 2050 | lhs_sym = SSA_NAME_VAR (gimple_phi_result (phi)); |
4fb5e5ca | 2051 | |
88dbf20f | 2052 | if (arg == NULL_TREE) |
2053 | { | |
2054 | /* When updating a PHI node for a recently introduced | |
2055 | symbol we may find NULL arguments. That's why we | |
2056 | take the symbol from the LHS of the PHI node. */ | |
efbcb6de | 2057 | reaching_def = get_reaching_def (lhs_sym); |
2058 | ||
88dbf20f | 2059 | } |
2060 | else | |
2061 | { | |
2062 | tree sym = DECL_P (arg) ? arg : SSA_NAME_VAR (arg); | |
2063 | ||
e70e8b13 | 2064 | if (marked_for_renaming (sym)) |
efbcb6de | 2065 | reaching_def = get_reaching_def (sym); |
88dbf20f | 2066 | else if (is_old_name (arg)) |
efbcb6de | 2067 | reaching_def = get_reaching_def (arg); |
2068 | } | |
2069 | ||
2070 | /* Update the argument if there is a reaching def. */ | |
2071 | if (reaching_def) | |
2072 | { | |
efbcb6de | 2073 | source_location locus; |
2074 | int arg_i = PHI_ARG_INDEX_FROM_USE (arg_p); | |
2075 | ||
2076 | SET_USE (arg_p, reaching_def); | |
efbcb6de | 2077 | |
e60062ea | 2078 | /* Virtual operands do not need a location. */ |
2079 | if (virtual_operand_p (reaching_def)) | |
2080 | locus = UNKNOWN_LOCATION; | |
efbcb6de | 2081 | else |
e60062ea | 2082 | { |
2083 | gimple stmt = SSA_NAME_DEF_STMT (reaching_def); | |
1a91d914 | 2084 | gphi *other_phi = dyn_cast <gphi *> (stmt); |
e60062ea | 2085 | |
2086 | /* Single element PHI nodes behave like copies, so get the | |
2087 | location from the phi argument. */ | |
1a91d914 | 2088 | if (other_phi |
2089 | && gimple_phi_num_args (other_phi) == 1) | |
2090 | locus = gimple_phi_arg_location (other_phi, 0); | |
e60062ea | 2091 | else |
2092 | locus = gimple_location (stmt); | |
2093 | } | |
efbcb6de | 2094 | |
2095 | gimple_phi_arg_set_location (phi, arg_i, locus); | |
88dbf20f | 2096 | } |
2097 | ||
efbcb6de | 2098 | |
88dbf20f | 2099 | if (e->flags & EDGE_ABNORMAL) |
2100 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (USE_FROM_PTR (arg_p)) = 1; | |
2101 | } | |
2102 | } | |
2103 | } | |
2104 | ||
54c91640 | 2105 | class rewrite_update_dom_walker : public dom_walker |
2106 | { | |
2107 | public: | |
2108 | rewrite_update_dom_walker (cdi_direction direction) : dom_walker (direction) {} | |
2109 | ||
2110 | virtual void before_dom_children (basic_block); | |
2111 | virtual void after_dom_children (basic_block); | |
2112 | }; | |
88dbf20f | 2113 | |
6bf320fb | 2114 | /* Initialization of block data structures for the incremental SSA |
2115 | update pass. Create a block local stack of reaching definitions | |
2116 | for new SSA names produced in this block (BLOCK_DEFS). Register | |
2117 | new definitions for every PHI node in the block. */ | |
2118 | ||
54c91640 | 2119 | void |
2120 | rewrite_update_dom_walker::before_dom_children (basic_block bb) | |
6bf320fb | 2121 | { |
6bf320fb | 2122 | bool is_abnormal_phi; |
6bf320fb | 2123 | |
2124 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
0ffbb1b6 | 2125 | fprintf (dump_file, "Registering new PHI nodes in block #%d\n", |
6bf320fb | 2126 | bb->index); |
2127 | ||
2128 | /* Mark the unwind point for this block. */ | |
f1f41a6c | 2129 | block_defs_stack.safe_push (NULL_TREE); |
6bf320fb | 2130 | |
2131 | if (!bitmap_bit_p (blocks_to_update, bb->index)) | |
2132 | return; | |
2133 | ||
2134 | /* Mark the LHS if any of the arguments flows through an abnormal | |
2135 | edge. */ | |
f1047120 | 2136 | is_abnormal_phi = bb_has_abnormal_pred (bb); |
6bf320fb | 2137 | |
2138 | /* If any of the PHI nodes is a replacement for a name in | |
2139 | OLD_SSA_NAMES or it's one of the names in NEW_SSA_NAMES, then | |
2140 | register it as a new definition for its corresponding name. Also | |
2141 | register definitions for names whose underlying symbols are | |
2142 | marked for renaming. */ | |
1a91d914 | 2143 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
2144 | gsi_next (&gsi)) | |
6bf320fb | 2145 | { |
2146 | tree lhs, lhs_sym; | |
1a91d914 | 2147 | gphi *phi = gsi.phi (); |
6bf320fb | 2148 | |
2149 | if (!register_defs_p (phi)) | |
2150 | continue; | |
48e1416a | 2151 | |
6bf320fb | 2152 | lhs = gimple_phi_result (phi); |
2153 | lhs_sym = SSA_NAME_VAR (lhs); | |
2154 | ||
e70e8b13 | 2155 | if (marked_for_renaming (lhs_sym)) |
6bf320fb | 2156 | register_new_update_single (lhs, lhs_sym); |
2157 | else | |
2158 | { | |
2159 | ||
2160 | /* If LHS is a new name, register a new definition for all | |
2161 | the names replaced by LHS. */ | |
2162 | if (is_new_name (lhs)) | |
2163 | register_new_update_set (lhs, names_replaced_by (lhs)); | |
48e1416a | 2164 | |
6bf320fb | 2165 | /* If LHS is an OLD name, register it as a new definition |
2166 | for itself. */ | |
2167 | if (is_old_name (lhs)) | |
2168 | register_new_update_single (lhs, lhs); | |
2169 | } | |
2170 | ||
2171 | if (is_abnormal_phi) | |
2172 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs) = 1; | |
2173 | } | |
2174 | ||
2175 | /* Step 2. Rewrite every variable used in each statement in the block. */ | |
08b7917c | 2176 | if (bitmap_bit_p (interesting_blocks, bb->index)) |
cd610ee6 | 2177 | { |
88536563 | 2178 | gcc_checking_assert (bitmap_bit_p (blocks_to_update, bb->index)); |
1a91d914 | 2179 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) |
4d8d655b | 2180 | if (rewrite_update_stmt (gsi_stmt (gsi), gsi)) |
2181 | gsi_remove (&gsi, true); | |
2182 | else | |
2183 | gsi_next (&gsi); | |
cd610ee6 | 2184 | } |
6bf320fb | 2185 | |
2186 | /* Step 3. Update PHI nodes. */ | |
2187 | rewrite_update_phi_arguments (bb); | |
2188 | } | |
2189 | ||
2190 | /* Called after visiting block BB. Unwind BLOCK_DEFS_STACK to restore | |
2191 | the current reaching definition of every name re-written in BB to | |
2192 | the original reaching definition before visiting BB. This | |
2193 | unwinding must be done in the opposite order to what is done in | |
2194 | register_new_update_set. */ | |
2195 | ||
54c91640 | 2196 | void |
2197 | rewrite_update_dom_walker::after_dom_children (basic_block bb ATTRIBUTE_UNUSED) | |
6bf320fb | 2198 | { |
f1f41a6c | 2199 | while (block_defs_stack.length () > 0) |
6bf320fb | 2200 | { |
f1f41a6c | 2201 | tree var = block_defs_stack.pop (); |
6bf320fb | 2202 | tree saved_def; |
48e1416a | 2203 | |
6bf320fb | 2204 | /* NULL indicates the unwind stop point for this block (see |
2205 | rewrite_update_enter_block). */ | |
2206 | if (var == NULL) | |
2207 | return; | |
2208 | ||
f1f41a6c | 2209 | saved_def = block_defs_stack.pop (); |
74105c0d | 2210 | get_common_info (var)->current_def = saved_def; |
6bf320fb | 2211 | } |
2212 | } | |
2213 | ||
2214 | ||
88dbf20f | 2215 | /* Rewrite the actual blocks, statements, and PHI arguments, to be in SSA |
48e1416a | 2216 | form. |
88dbf20f | 2217 | |
2218 | ENTRY indicates the block where to start. Every block dominated by | |
2219 | ENTRY will be rewritten. | |
2220 | ||
2221 | WHAT indicates what actions will be taken by the renamer (see enum | |
2222 | rewrite_mode). | |
2223 | ||
2224 | BLOCKS are the set of interesting blocks for the dominator walker | |
2225 | to process. If this set is NULL, then all the nodes dominated | |
2226 | by ENTRY are walked. Otherwise, blocks dominated by ENTRY that | |
2227 | are not present in BLOCKS are ignored. */ | |
2228 | ||
2229 | static void | |
6bf320fb | 2230 | rewrite_blocks (basic_block entry, enum rewrite_mode what) |
88dbf20f | 2231 | { |
88dbf20f | 2232 | /* Rewrite all the basic blocks in the program. */ |
2233 | timevar_push (TV_TREE_SSA_REWRITE_BLOCKS); | |
2234 | ||
54c91640 | 2235 | block_defs_stack.create (10); |
88dbf20f | 2236 | |
54c91640 | 2237 | /* Recursively walk the dominator tree rewriting each statement in |
2238 | each basic block. */ | |
88dbf20f | 2239 | if (what == REWRITE_ALL) |
54c91640 | 2240 | rewrite_dom_walker (CDI_DOMINATORS).walk (entry); |
88dbf20f | 2241 | else if (what == REWRITE_UPDATE) |
54c91640 | 2242 | rewrite_update_dom_walker (CDI_DOMINATORS).walk (entry); |
88dbf20f | 2243 | else |
2244 | gcc_unreachable (); | |
2245 | ||
88dbf20f | 2246 | /* Debugging dumps. */ |
2247 | if (dump_file && (dump_flags & TDF_STATS)) | |
2248 | { | |
2249 | dump_dfa_stats (dump_file); | |
c1f445d2 | 2250 | if (var_infos) |
88dbf20f | 2251 | dump_tree_ssa_stats (dump_file); |
2252 | } | |
48e1416a | 2253 | |
f1f41a6c | 2254 | block_defs_stack.release (); |
88dbf20f | 2255 | |
2256 | timevar_pop (TV_TREE_SSA_REWRITE_BLOCKS); | |
2257 | } | |
2258 | ||
54c91640 | 2259 | class mark_def_dom_walker : public dom_walker |
e551bd1a | 2260 | { |
54c91640 | 2261 | public: |
2262 | mark_def_dom_walker (cdi_direction direction); | |
2263 | ~mark_def_dom_walker (); | |
f3d9a16c | 2264 | |
54c91640 | 2265 | virtual void before_dom_children (basic_block); |
f3d9a16c | 2266 | |
54c91640 | 2267 | private: |
e551bd1a | 2268 | /* Notice that this bitmap is indexed using variable UIDs, so it must be |
2269 | large enough to accommodate all the variables referenced in the | |
2270 | function, not just the ones we are renaming. */ | |
ae84f584 | 2271 | bitmap m_kills; |
54c91640 | 2272 | }; |
4ee9c684 | 2273 | |
54c91640 | 2274 | mark_def_dom_walker::mark_def_dom_walker (cdi_direction direction) |
ae84f584 | 2275 | : dom_walker (direction), m_kills (BITMAP_ALLOC (NULL)) |
54c91640 | 2276 | { |
2277 | } | |
e551bd1a | 2278 | |
54c91640 | 2279 | mark_def_dom_walker::~mark_def_dom_walker () |
2280 | { | |
ae84f584 | 2281 | BITMAP_FREE (m_kills); |
54c91640 | 2282 | } |
e551bd1a | 2283 | |
54c91640 | 2284 | /* Block processing routine for mark_def_sites. Clear the KILLS bitmap |
2285 | at the start of each block, and call mark_def_sites for each statement. */ | |
e551bd1a | 2286 | |
54c91640 | 2287 | void |
2288 | mark_def_dom_walker::before_dom_children (basic_block bb) | |
2289 | { | |
2290 | gimple_stmt_iterator gsi; | |
e551bd1a | 2291 | |
ae84f584 | 2292 | bitmap_clear (m_kills); |
54c91640 | 2293 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
ae84f584 | 2294 | mark_def_sites (bb, gsi_stmt (gsi), m_kills); |
4ee9c684 | 2295 | } |
2296 | ||
4fb5e5ca | 2297 | /* Initialize internal data needed during renaming. */ |
2298 | ||
2299 | static void | |
2300 | init_ssa_renamer (void) | |
2301 | { | |
4fb5e5ca | 2302 | cfun->gimple_df->in_ssa_p = false; |
2303 | ||
2304 | /* Allocate memory for the DEF_BLOCKS hash table. */ | |
c1f445d2 | 2305 | gcc_assert (!var_infos); |
2306 | var_infos = new hash_table<var_info_hasher> | |
2307 | (vec_safe_length (cfun->local_decls)); | |
4fb5e5ca | 2308 | |
22d6c74e | 2309 | bitmap_obstack_initialize (&update_ssa_obstack); |
4fb5e5ca | 2310 | } |
2311 | ||
2312 | ||
2313 | /* Deallocate internal data structures used by the renamer. */ | |
2314 | ||
2315 | static void | |
2316 | fini_ssa_renamer (void) | |
2317 | { | |
c1f445d2 | 2318 | delete var_infos; |
2319 | var_infos = NULL; | |
4fb5e5ca | 2320 | |
22d6c74e | 2321 | bitmap_obstack_release (&update_ssa_obstack); |
2322 | ||
e70e8b13 | 2323 | cfun->gimple_df->ssa_renaming_needed = 0; |
2324 | cfun->gimple_df->rename_vops = 0; | |
4fb5e5ca | 2325 | cfun->gimple_df->in_ssa_p = true; |
2326 | } | |
2327 | ||
e551bd1a | 2328 | /* Main entry point into the SSA builder. The renaming process |
88dbf20f | 2329 | proceeds in four main phases: |
4ee9c684 | 2330 | |
88dbf20f | 2331 | 1- Compute dominance frontier and immediate dominators, needed to |
2332 | insert PHI nodes and rename the function in dominator tree | |
2333 | order. | |
4ee9c684 | 2334 | |
54c91640 | 2335 | 2- Find and mark all the blocks that define variables. |
4ee9c684 | 2336 | |
88dbf20f | 2337 | 3- Insert PHI nodes at dominance frontiers (insert_phi_nodes). |
4ee9c684 | 2338 | |
88dbf20f | 2339 | 4- Rename all the blocks (rewrite_blocks) and statements in the program. |
4ee9c684 | 2340 | |
21bdfe89 | 2341 | Steps 3 and 4 are done using the dominator tree walker |
88dbf20f | 2342 | (walk_dominator_tree). */ |
e551bd1a | 2343 | |
65b0537f | 2344 | namespace { |
2345 | ||
2346 | const pass_data pass_data_build_ssa = | |
2347 | { | |
2348 | GIMPLE_PASS, /* type */ | |
2349 | "ssa", /* name */ | |
2350 | OPTGROUP_NONE, /* optinfo_flags */ | |
65b0537f | 2351 | TV_TREE_SSA_OTHER, /* tv_id */ |
2352 | PROP_cfg, /* properties_required */ | |
2353 | PROP_ssa, /* properties_provided */ | |
2354 | 0, /* properties_destroyed */ | |
2355 | 0, /* todo_flags_start */ | |
8b88439e | 2356 | TODO_remove_unused_locals, /* todo_flags_finish */ |
65b0537f | 2357 | }; |
2358 | ||
2359 | class pass_build_ssa : public gimple_opt_pass | |
2360 | { | |
2361 | public: | |
2362 | pass_build_ssa (gcc::context *ctxt) | |
2363 | : gimple_opt_pass (pass_data_build_ssa, ctxt) | |
2364 | {} | |
2365 | ||
2366 | /* opt_pass methods: */ | |
2367 | virtual bool gate (function *fun) | |
2368 | { | |
2369 | /* Do nothing for funcions that was produced already in SSA form. */ | |
2370 | return !(fun->curr_properties & PROP_ssa); | |
2371 | } | |
2372 | ||
2373 | virtual unsigned int execute (function *); | |
2374 | ||
2375 | }; // class pass_build_ssa | |
2376 | ||
2377 | unsigned int | |
2378 | pass_build_ssa::execute (function *fun) | |
4ee9c684 | 2379 | { |
8a2980be | 2380 | bitmap_head *dfs; |
e551bd1a | 2381 | basic_block bb; |
ec11736b | 2382 | unsigned i; |
48e1416a | 2383 | |
88dbf20f | 2384 | /* Initialize operand data structures. */ |
65b0537f | 2385 | init_ssa_operands (fun); |
4ee9c684 | 2386 | |
4fb5e5ca | 2387 | /* Initialize internal data needed by the renamer. */ |
2388 | init_ssa_renamer (); | |
2389 | ||
88dbf20f | 2390 | /* Initialize the set of interesting blocks. The callback |
2391 | mark_def_sites will add to this set those blocks that the renamer | |
2392 | should process. */ | |
65b0537f | 2393 | interesting_blocks = sbitmap_alloc (last_basic_block_for_fn (fun)); |
53c5d9d4 | 2394 | bitmap_clear (interesting_blocks); |
4ee9c684 | 2395 | |
71797bf6 | 2396 | /* Initialize dominance frontier. */ |
65b0537f | 2397 | dfs = XNEWVEC (bitmap_head, last_basic_block_for_fn (fun)); |
2398 | FOR_EACH_BB_FN (bb, fun) | |
8a2980be | 2399 | bitmap_initialize (&dfs[bb->index], &bitmap_default_obstack); |
4ee9c684 | 2400 | |
88dbf20f | 2401 | /* 1- Compute dominance frontiers. */ |
2402 | calculate_dominance_info (CDI_DOMINATORS); | |
e551bd1a | 2403 | compute_dominance_frontiers (dfs); |
4ee9c684 | 2404 | |
88dbf20f | 2405 | /* 2- Find and mark definition sites. */ |
65b0537f | 2406 | mark_def_dom_walker (CDI_DOMINATORS).walk (fun->cfg->x_entry_block_ptr); |
88dbf20f | 2407 | |
2408 | /* 3- Insert PHI nodes at dominance frontiers of definition blocks. */ | |
095dcfa3 | 2409 | insert_phi_nodes (dfs); |
4ee9c684 | 2410 | |
88dbf20f | 2411 | /* 4- Rename all the blocks. */ |
65b0537f | 2412 | rewrite_blocks (ENTRY_BLOCK_PTR_FOR_FN (fun), REWRITE_ALL); |
4ee9c684 | 2413 | |
e551bd1a | 2414 | /* Free allocated memory. */ |
65b0537f | 2415 | FOR_EACH_BB_FN (bb, fun) |
8a2980be | 2416 | bitmap_clear (&dfs[bb->index]); |
e551bd1a | 2417 | free (dfs); |
4ee9c684 | 2418 | |
acf11b62 | 2419 | sbitmap_free (interesting_blocks); |
2420 | ||
4fb5e5ca | 2421 | fini_ssa_renamer (); |
2422 | ||
ec11736b | 2423 | /* Try to get rid of all gimplifier generated temporaries by making |
2424 | its SSA names anonymous. This way we can garbage collect them | |
2425 | all after removing unused locals which we do in our TODO. */ | |
2426 | for (i = 1; i < num_ssa_names; ++i) | |
2427 | { | |
2428 | tree decl, name = ssa_name (i); | |
2429 | if (!name | |
2430 | || SSA_NAME_IS_DEFAULT_DEF (name)) | |
2431 | continue; | |
2432 | decl = SSA_NAME_VAR (name); | |
2433 | if (decl | |
2434 | && TREE_CODE (decl) == VAR_DECL | |
2435 | && !VAR_DECL_IS_VIRTUAL_OPERAND (decl) | |
382c2352 | 2436 | && DECL_IGNORED_P (decl)) |
2437 | SET_SSA_NAME_VAR_OR_IDENTIFIER (name, DECL_NAME (decl)); | |
ec11736b | 2438 | } |
2439 | ||
2a1990e9 | 2440 | return 0; |
4ee9c684 | 2441 | } |
2442 | ||
cbe8bda8 | 2443 | } // anon namespace |
2444 | ||
2445 | gimple_opt_pass * | |
2446 | make_pass_build_ssa (gcc::context *ctxt) | |
2447 | { | |
2448 | return new pass_build_ssa (ctxt); | |
2449 | } | |
2450 | ||
4ee9c684 | 2451 | |
88dbf20f | 2452 | /* Mark the definition of VAR at STMT and BB as interesting for the |
2453 | renamer. BLOCKS is the set of blocks that need updating. */ | |
4ee9c684 | 2454 | |
88dbf20f | 2455 | static void |
75a70cf9 | 2456 | mark_def_interesting (tree var, gimple stmt, basic_block bb, bool insert_phi_p) |
4ee9c684 | 2457 | { |
88536563 | 2458 | gcc_checking_assert (bitmap_bit_p (blocks_to_update, bb->index)); |
75a70cf9 | 2459 | set_register_defs (stmt, true); |
88dbf20f | 2460 | |
2461 | if (insert_phi_p) | |
2462 | { | |
75a70cf9 | 2463 | bool is_phi_p = gimple_code (stmt) == GIMPLE_PHI; |
88dbf20f | 2464 | |
88dbf20f | 2465 | set_def_block (var, bb, is_phi_p); |
2466 | ||
2467 | /* If VAR is an SSA name in NEW_SSA_NAMES, this is a definition | |
2468 | site for both itself and all the old names replaced by it. */ | |
2469 | if (TREE_CODE (var) == SSA_NAME && is_new_name (var)) | |
2470 | { | |
2471 | bitmap_iterator bi; | |
2472 | unsigned i; | |
2473 | bitmap set = names_replaced_by (var); | |
2474 | if (set) | |
2475 | EXECUTE_IF_SET_IN_BITMAP (set, 0, i, bi) | |
2476 | set_def_block (ssa_name (i), bb, is_phi_p); | |
2477 | } | |
2478 | } | |
2479 | } | |
2480 | ||
2481 | ||
2482 | /* Mark the use of VAR at STMT and BB as interesting for the | |
2483 | renamer. INSERT_PHI_P is true if we are going to insert new PHI | |
2920559d | 2484 | nodes. */ |
88dbf20f | 2485 | |
2486 | static inline void | |
75a70cf9 | 2487 | mark_use_interesting (tree var, gimple stmt, basic_block bb, bool insert_phi_p) |
88dbf20f | 2488 | { |
75a70cf9 | 2489 | basic_block def_bb = gimple_bb (stmt); |
70630fcd | 2490 | |
2920559d | 2491 | mark_block_for_update (def_bb); |
2492 | mark_block_for_update (bb); | |
2493 | ||
75a70cf9 | 2494 | if (gimple_code (stmt) == GIMPLE_PHI) |
1a91d914 | 2495 | mark_phi_for_rewrite (def_bb, as_a <gphi *> (stmt)); |
70630fcd | 2496 | else |
9845d120 | 2497 | { |
2498 | set_rewrite_uses (stmt, true); | |
2499 | ||
2500 | if (is_gimple_debug (stmt)) | |
2501 | return; | |
2502 | } | |
88dbf20f | 2503 | |
2504 | /* If VAR has not been defined in BB, then it is live-on-entry | |
2505 | to BB. Note that we cannot just use the block holding VAR's | |
2506 | definition because if VAR is one of the names in OLD_SSA_NAMES, | |
2507 | it will have several definitions (itself and all the names that | |
2508 | replace it). */ | |
2509 | if (insert_phi_p) | |
2510 | { | |
74105c0d | 2511 | struct def_blocks_d *db_p = get_def_blocks_for (get_common_info (var)); |
88dbf20f | 2512 | if (!bitmap_bit_p (db_p->def_blocks, bb->index)) |
2513 | set_livein_block (var, bb); | |
2514 | } | |
2515 | } | |
2516 | ||
2517 | ||
88dbf20f | 2518 | /* Do a dominator walk starting at BB processing statements that |
e70e8b13 | 2519 | reference symbols in SSA operands. This is very similar to |
095dcfa3 | 2520 | mark_def_sites, but the scan handles statements whose operands may |
2920559d | 2521 | already be SSA names. |
88dbf20f | 2522 | |
095dcfa3 | 2523 | If INSERT_PHI_P is true, mark those uses as live in the |
2524 | corresponding block. This is later used by the PHI placement | |
4fb5e5ca | 2525 | algorithm to make PHI pruning decisions. |
2526 | ||
2527 | FIXME. Most of this would be unnecessary if we could associate a | |
2528 | symbol to all the SSA names that reference it. But that | |
2529 | sounds like it would be expensive to maintain. Still, it | |
2530 | would be interesting to see if it makes better sense to do | |
2531 | that. */ | |
88dbf20f | 2532 | |
2533 | static void | |
2920559d | 2534 | prepare_block_for_update (basic_block bb, bool insert_phi_p) |
88dbf20f | 2535 | { |
2536 | basic_block son; | |
f50cf978 | 2537 | edge e; |
2538 | edge_iterator ei; | |
88dbf20f | 2539 | |
2920559d | 2540 | mark_block_for_update (bb); |
2541 | ||
88dbf20f | 2542 | /* Process PHI nodes marking interesting those that define or use |
095dcfa3 | 2543 | the symbols that we are interested in. */ |
1a91d914 | 2544 | for (gphi_iterator si = gsi_start_phis (bb); !gsi_end_p (si); |
2545 | gsi_next (&si)) | |
88dbf20f | 2546 | { |
1a91d914 | 2547 | gphi *phi = si.phi (); |
75a70cf9 | 2548 | tree lhs_sym, lhs = gimple_phi_result (phi); |
88dbf20f | 2549 | |
e70e8b13 | 2550 | if (TREE_CODE (lhs) == SSA_NAME |
0087edc6 | 2551 | && (! virtual_operand_p (lhs) |
2552 | || ! cfun->gimple_df->rename_vops)) | |
f50cf978 | 2553 | continue; |
75a70cf9 | 2554 | |
0087edc6 | 2555 | lhs_sym = DECL_P (lhs) ? lhs : SSA_NAME_VAR (lhs); |
e70e8b13 | 2556 | mark_for_renaming (lhs_sym); |
f50cf978 | 2557 | mark_def_interesting (lhs_sym, phi, bb, insert_phi_p); |
2558 | ||
2559 | /* Mark the uses in phi nodes as interesting. It would be more correct | |
2560 | to process the arguments of the phi nodes of the successor edges of | |
2561 | BB at the end of prepare_block_for_update, however, that turns out | |
2562 | to be significantly more expensive. Doing it here is conservatively | |
2563 | correct -- it may only cause us to believe a value to be live in a | |
2564 | block that also contains its definition, and thus insert a few more | |
2565 | phi nodes for it. */ | |
2566 | FOR_EACH_EDGE (e, ei, bb->preds) | |
75a70cf9 | 2567 | mark_use_interesting (lhs_sym, phi, e->src, insert_phi_p); |
88dbf20f | 2568 | } |
2569 | ||
2570 | /* Process the statements. */ | |
1a91d914 | 2571 | for (gimple_stmt_iterator si = gsi_start_bb (bb); !gsi_end_p (si); |
2572 | gsi_next (&si)) | |
88dbf20f | 2573 | { |
75a70cf9 | 2574 | gimple stmt; |
88dbf20f | 2575 | ssa_op_iter i; |
2576 | use_operand_p use_p; | |
2577 | def_operand_p def_p; | |
48e1416a | 2578 | |
75a70cf9 | 2579 | stmt = gsi_stmt (si); |
88dbf20f | 2580 | |
e70e8b13 | 2581 | if (cfun->gimple_df->rename_vops |
2582 | && gimple_vuse (stmt)) | |
88dbf20f | 2583 | { |
e70e8b13 | 2584 | tree use = gimple_vuse (stmt); |
88dbf20f | 2585 | tree sym = DECL_P (use) ? use : SSA_NAME_VAR (use); |
e70e8b13 | 2586 | mark_for_renaming (sym); |
2587 | mark_use_interesting (sym, stmt, bb, insert_phi_p); | |
88dbf20f | 2588 | } |
2589 | ||
e70e8b13 | 2590 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, i, SSA_OP_USE) |
88dbf20f | 2591 | { |
e70e8b13 | 2592 | tree use = USE_FROM_PTR (use_p); |
2593 | if (!DECL_P (use)) | |
2594 | continue; | |
2595 | mark_for_renaming (use); | |
2596 | mark_use_interesting (use, stmt, bb, insert_phi_p); | |
2597 | } | |
2598 | ||
2599 | if (cfun->gimple_df->rename_vops | |
2600 | && gimple_vdef (stmt)) | |
2601 | { | |
2602 | tree def = gimple_vdef (stmt); | |
88dbf20f | 2603 | tree sym = DECL_P (def) ? def : SSA_NAME_VAR (def); |
e70e8b13 | 2604 | mark_for_renaming (sym); |
2605 | mark_def_interesting (sym, stmt, bb, insert_phi_p); | |
2606 | } | |
2607 | ||
2608 | FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, i, SSA_OP_DEF) | |
2609 | { | |
2610 | tree def = DEF_FROM_PTR (def_p); | |
2611 | if (!DECL_P (def)) | |
2612 | continue; | |
2613 | mark_for_renaming (def); | |
2614 | mark_def_interesting (def, stmt, bb, insert_phi_p); | |
88dbf20f | 2615 | } |
2616 | } | |
2617 | ||
2618 | /* Now visit all the blocks dominated by BB. */ | |
095dcfa3 | 2619 | for (son = first_dom_son (CDI_DOMINATORS, bb); |
4fb5e5ca | 2620 | son; |
2621 | son = next_dom_son (CDI_DOMINATORS, son)) | |
2920559d | 2622 | prepare_block_for_update (son, insert_phi_p); |
095dcfa3 | 2623 | } |
2624 | ||
2625 | ||
2626 | /* Helper for prepare_names_to_update. Mark all the use sites for | |
2627 | NAME as interesting. BLOCKS and INSERT_PHI_P are as in | |
2628 | prepare_names_to_update. */ | |
2629 | ||
2630 | static void | |
2920559d | 2631 | prepare_use_sites_for (tree name, bool insert_phi_p) |
095dcfa3 | 2632 | { |
2633 | use_operand_p use_p; | |
2634 | imm_use_iterator iter; | |
2635 | ||
2636 | FOR_EACH_IMM_USE_FAST (use_p, iter, name) | |
2637 | { | |
75a70cf9 | 2638 | gimple stmt = USE_STMT (use_p); |
2639 | basic_block bb = gimple_bb (stmt); | |
095dcfa3 | 2640 | |
75a70cf9 | 2641 | if (gimple_code (stmt) == GIMPLE_PHI) |
095dcfa3 | 2642 | { |
f50cf978 | 2643 | int ix = PHI_ARG_INDEX_FROM_USE (use_p); |
1a91d914 | 2644 | edge e = gimple_phi_arg_edge (as_a <gphi *> (stmt), ix); |
f50cf978 | 2645 | mark_use_interesting (name, stmt, e->src, insert_phi_p); |
095dcfa3 | 2646 | } |
2647 | else | |
2648 | { | |
2649 | /* For regular statements, mark this as an interesting use | |
2650 | for NAME. */ | |
2920559d | 2651 | mark_use_interesting (name, stmt, bb, insert_phi_p); |
095dcfa3 | 2652 | } |
2653 | } | |
88dbf20f | 2654 | } |
2655 | ||
2656 | ||
095dcfa3 | 2657 | /* Helper for prepare_names_to_update. Mark the definition site for |
2658 | NAME as interesting. BLOCKS and INSERT_PHI_P are as in | |
2659 | prepare_names_to_update. */ | |
88dbf20f | 2660 | |
2661 | static void | |
2920559d | 2662 | prepare_def_site_for (tree name, bool insert_phi_p) |
88dbf20f | 2663 | { |
75a70cf9 | 2664 | gimple stmt; |
88dbf20f | 2665 | basic_block bb; |
2666 | ||
88536563 | 2667 | gcc_checking_assert (names_to_release == NULL |
2668 | || !bitmap_bit_p (names_to_release, | |
2669 | SSA_NAME_VERSION (name))); | |
88dbf20f | 2670 | |
2671 | stmt = SSA_NAME_DEF_STMT (name); | |
75a70cf9 | 2672 | bb = gimple_bb (stmt); |
88dbf20f | 2673 | if (bb) |
2674 | { | |
fe672ac0 | 2675 | gcc_checking_assert (bb->index < last_basic_block_for_fn (cfun)); |
2920559d | 2676 | mark_block_for_update (bb); |
2677 | mark_def_interesting (name, stmt, bb, insert_phi_p); | |
88dbf20f | 2678 | } |
2679 | } | |
2680 | ||
2681 | ||
095dcfa3 | 2682 | /* Mark definition and use sites of names in NEW_SSA_NAMES and |
2920559d | 2683 | OLD_SSA_NAMES. INSERT_PHI_P is true if the caller wants to insert |
2684 | PHI nodes for newly created names. */ | |
88dbf20f | 2685 | |
2686 | static void | |
2920559d | 2687 | prepare_names_to_update (bool insert_phi_p) |
88dbf20f | 2688 | { |
86c1585a | 2689 | unsigned i = 0; |
88dbf20f | 2690 | bitmap_iterator bi; |
3e790786 | 2691 | sbitmap_iterator sbi; |
88dbf20f | 2692 | |
2693 | /* If a name N from NEW_SSA_NAMES is also marked to be released, | |
2694 | remove it from NEW_SSA_NAMES so that we don't try to visit its | |
2695 | defining basic block (which most likely doesn't exist). Notice | |
2696 | that we cannot do the same with names in OLD_SSA_NAMES because we | |
2697 | want to replace existing instances. */ | |
2698 | if (names_to_release) | |
2699 | EXECUTE_IF_SET_IN_BITMAP (names_to_release, 0, i, bi) | |
08b7917c | 2700 | bitmap_clear_bit (new_ssa_names, i); |
88dbf20f | 2701 | |
095dcfa3 | 2702 | /* First process names in NEW_SSA_NAMES. Otherwise, uses of old |
2703 | names may be considered to be live-in on blocks that contain | |
2704 | definitions for their replacements. */ | |
0d211963 | 2705 | EXECUTE_IF_SET_IN_BITMAP (new_ssa_names, 0, i, sbi) |
2920559d | 2706 | prepare_def_site_for (ssa_name (i), insert_phi_p); |
095dcfa3 | 2707 | |
88dbf20f | 2708 | /* If an old name is in NAMES_TO_RELEASE, we cannot remove it from |
2709 | OLD_SSA_NAMES, but we have to ignore its definition site. */ | |
0d211963 | 2710 | EXECUTE_IF_SET_IN_BITMAP (old_ssa_names, 0, i, sbi) |
095dcfa3 | 2711 | { |
2712 | if (names_to_release == NULL || !bitmap_bit_p (names_to_release, i)) | |
2920559d | 2713 | prepare_def_site_for (ssa_name (i), insert_phi_p); |
2714 | prepare_use_sites_for (ssa_name (i), insert_phi_p); | |
3e790786 | 2715 | } |
88dbf20f | 2716 | } |
2717 | ||
2718 | ||
2719 | /* Dump all the names replaced by NAME to FILE. */ | |
2720 | ||
2721 | void | |
2722 | dump_names_replaced_by (FILE *file, tree name) | |
2723 | { | |
2724 | unsigned i; | |
2725 | bitmap old_set; | |
2726 | bitmap_iterator bi; | |
2727 | ||
2728 | print_generic_expr (file, name, 0); | |
2729 | fprintf (file, " -> { "); | |
2730 | ||
2731 | old_set = names_replaced_by (name); | |
2732 | EXECUTE_IF_SET_IN_BITMAP (old_set, 0, i, bi) | |
2733 | { | |
2734 | print_generic_expr (file, ssa_name (i), 0); | |
2735 | fprintf (file, " "); | |
2736 | } | |
2737 | ||
2738 | fprintf (file, "}\n"); | |
2739 | } | |
2740 | ||
2741 | ||
2742 | /* Dump all the names replaced by NAME to stderr. */ | |
2743 | ||
4b987fac | 2744 | DEBUG_FUNCTION void |
88dbf20f | 2745 | debug_names_replaced_by (tree name) |
2746 | { | |
2747 | dump_names_replaced_by (stderr, name); | |
2748 | } | |
2749 | ||
2750 | ||
095dcfa3 | 2751 | /* Dump SSA update information to FILE. */ |
88dbf20f | 2752 | |
2753 | void | |
095dcfa3 | 2754 | dump_update_ssa (FILE *file) |
88dbf20f | 2755 | { |
86c1585a | 2756 | unsigned i = 0; |
88dbf20f | 2757 | bitmap_iterator bi; |
2758 | ||
dd277d48 | 2759 | if (!need_ssa_update_p (cfun)) |
88dbf20f | 2760 | return; |
2761 | ||
53c5d9d4 | 2762 | if (new_ssa_names && bitmap_first_set_bit (new_ssa_names) >= 0) |
88dbf20f | 2763 | { |
3e790786 | 2764 | sbitmap_iterator sbi; |
2765 | ||
88dbf20f | 2766 | fprintf (file, "\nSSA replacement table\n"); |
2767 | fprintf (file, "N_i -> { O_1 ... O_j } means that N_i replaces " | |
2768 | "O_1, ..., O_j\n\n"); | |
2769 | ||
0d211963 | 2770 | EXECUTE_IF_SET_IN_BITMAP (new_ssa_names, 0, i, sbi) |
3e790786 | 2771 | dump_names_replaced_by (file, ssa_name (i)); |
88dbf20f | 2772 | } |
2773 | ||
e70e8b13 | 2774 | if (symbols_to_rename_set && !bitmap_empty_p (symbols_to_rename_set)) |
88dbf20f | 2775 | { |
0ffbb1b6 | 2776 | fprintf (file, "\nSymbols to be put in SSA form\n"); |
e70e8b13 | 2777 | dump_decl_set (file, symbols_to_rename_set); |
dd277d48 | 2778 | fprintf (file, "\n"); |
88dbf20f | 2779 | } |
2780 | ||
88dbf20f | 2781 | if (names_to_release && !bitmap_empty_p (names_to_release)) |
2782 | { | |
0ffbb1b6 | 2783 | fprintf (file, "\nSSA names to release after updating the SSA web\n\n"); |
88dbf20f | 2784 | EXECUTE_IF_SET_IN_BITMAP (names_to_release, 0, i, bi) |
2785 | { | |
2786 | print_generic_expr (file, ssa_name (i), 0); | |
2787 | fprintf (file, " "); | |
2788 | } | |
0ffbb1b6 | 2789 | fprintf (file, "\n"); |
88dbf20f | 2790 | } |
88dbf20f | 2791 | } |
2792 | ||
2793 | ||
095dcfa3 | 2794 | /* Dump SSA update information to stderr. */ |
88dbf20f | 2795 | |
4b987fac | 2796 | DEBUG_FUNCTION void |
095dcfa3 | 2797 | debug_update_ssa (void) |
88dbf20f | 2798 | { |
095dcfa3 | 2799 | dump_update_ssa (stderr); |
88dbf20f | 2800 | } |
2801 | ||
2802 | ||
2803 | /* Initialize data structures used for incremental SSA updates. */ | |
2804 | ||
2805 | static void | |
dd277d48 | 2806 | init_update_ssa (struct function *fn) |
88dbf20f | 2807 | { |
095dcfa3 | 2808 | /* Reserve more space than the current number of names. The calls to |
88dbf20f | 2809 | add_new_name_mapping are typically done after creating new SSA |
2810 | names, so we'll need to reallocate these arrays. */ | |
2811 | old_ssa_names = sbitmap_alloc (num_ssa_names + NAME_SETS_GROWTH_FACTOR); | |
53c5d9d4 | 2812 | bitmap_clear (old_ssa_names); |
88dbf20f | 2813 | |
2814 | new_ssa_names = sbitmap_alloc (num_ssa_names + NAME_SETS_GROWTH_FACTOR); | |
53c5d9d4 | 2815 | bitmap_clear (new_ssa_names); |
88dbf20f | 2816 | |
5eeafc2d | 2817 | bitmap_obstack_initialize (&update_ssa_obstack); |
2818 | ||
88dbf20f | 2819 | names_to_release = NULL; |
dd277d48 | 2820 | update_ssa_initialized_fn = fn; |
88dbf20f | 2821 | } |
2822 | ||
2823 | ||
2824 | /* Deallocate data structures used for incremental SSA updates. */ | |
2825 | ||
095dcfa3 | 2826 | void |
88dbf20f | 2827 | delete_update_ssa (void) |
2828 | { | |
2829 | unsigned i; | |
2830 | bitmap_iterator bi; | |
2831 | ||
2832 | sbitmap_free (old_ssa_names); | |
2833 | old_ssa_names = NULL; | |
2834 | ||
2835 | sbitmap_free (new_ssa_names); | |
2836 | new_ssa_names = NULL; | |
2837 | ||
e70e8b13 | 2838 | BITMAP_FREE (symbols_to_rename_set); |
2839 | symbols_to_rename_set = NULL; | |
f1f41a6c | 2840 | symbols_to_rename.release (); |
88dbf20f | 2841 | |
2842 | if (names_to_release) | |
2843 | { | |
2844 | EXECUTE_IF_SET_IN_BITMAP (names_to_release, 0, i, bi) | |
2845 | release_ssa_name (ssa_name (i)); | |
2846 | BITMAP_FREE (names_to_release); | |
2847 | } | |
2848 | ||
2920559d | 2849 | clear_ssa_name_info (); |
4fb5e5ca | 2850 | |
2851 | fini_ssa_renamer (); | |
2852 | ||
2853 | if (blocks_with_phis_to_rewrite) | |
2854 | EXECUTE_IF_SET_IN_BITMAP (blocks_with_phis_to_rewrite, 0, i, bi) | |
2855 | { | |
1a91d914 | 2856 | vec<gphi *> phis = phis_to_rewrite[i]; |
f1f41a6c | 2857 | phis.release (); |
2858 | phis_to_rewrite[i].create (0); | |
4fb5e5ca | 2859 | } |
2860 | ||
2861 | BITMAP_FREE (blocks_with_phis_to_rewrite); | |
2862 | BITMAP_FREE (blocks_to_update); | |
5eeafc2d | 2863 | |
dd277d48 | 2864 | update_ssa_initialized_fn = NULL; |
88dbf20f | 2865 | } |
2866 | ||
2867 | ||
2868 | /* Create a new name for OLD_NAME in statement STMT and replace the | |
0dc262e0 | 2869 | operand pointed to by DEF_P with the newly created name. If DEF_P |
2870 | is NULL then STMT should be a GIMPLE assignment. | |
2871 | Return the new name and register the replacement mapping <NEW, OLD> in | |
88dbf20f | 2872 | update_ssa's tables. */ |
2873 | ||
2874 | tree | |
75a70cf9 | 2875 | create_new_def_for (tree old_name, gimple stmt, def_operand_p def) |
88dbf20f | 2876 | { |
0dc262e0 | 2877 | tree new_name; |
88dbf20f | 2878 | |
0dc262e0 | 2879 | timevar_push (TV_TREE_SSA_INCREMENTAL); |
2880 | ||
2881 | if (!update_ssa_initialized_fn) | |
2882 | init_update_ssa (cfun); | |
2883 | ||
2884 | gcc_assert (update_ssa_initialized_fn == cfun); | |
2885 | ||
2886 | new_name = duplicate_ssa_name (old_name, stmt); | |
2887 | if (def) | |
2888 | SET_DEF (def, new_name); | |
2889 | else | |
2890 | gimple_assign_set_lhs (stmt, new_name); | |
88dbf20f | 2891 | |
75a70cf9 | 2892 | if (gimple_code (stmt) == GIMPLE_PHI) |
88dbf20f | 2893 | { |
75a70cf9 | 2894 | basic_block bb = gimple_bb (stmt); |
88dbf20f | 2895 | |
2896 | /* If needed, mark NEW_NAME as occurring in an abnormal PHI node. */ | |
f1047120 | 2897 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_name) = bb_has_abnormal_pred (bb); |
88dbf20f | 2898 | } |
2899 | ||
0dc262e0 | 2900 | add_new_name_mapping (new_name, old_name); |
88dbf20f | 2901 | |
2902 | /* For the benefit of passes that will be updating the SSA form on | |
2903 | their own, set the current reaching definition of OLD_NAME to be | |
2904 | NEW_NAME. */ | |
74105c0d | 2905 | get_ssa_name_ann (old_name)->info.current_def = new_name; |
88dbf20f | 2906 | |
0dc262e0 | 2907 | timevar_pop (TV_TREE_SSA_INCREMENTAL); |
88dbf20f | 2908 | |
0dc262e0 | 2909 | return new_name; |
88dbf20f | 2910 | } |
2911 | ||
2912 | ||
278611f2 | 2913 | /* Mark virtual operands of FN for renaming by update_ssa. */ |
88dbf20f | 2914 | |
2915 | void | |
278611f2 | 2916 | mark_virtual_operands_for_renaming (struct function *fn) |
88dbf20f | 2917 | { |
278611f2 | 2918 | fn->gimple_df->ssa_renaming_needed = 1; |
2919 | fn->gimple_df->rename_vops = 1; | |
88dbf20f | 2920 | } |
2921 | ||
ba4d2b2f | 2922 | /* Replace all uses of NAME by underlying variable and mark it |
2923 | for renaming. This assumes the defining statement of NAME is | |
2924 | going to be removed. */ | |
2925 | ||
2926 | void | |
2927 | mark_virtual_operand_for_renaming (tree name) | |
2928 | { | |
2929 | tree name_var = SSA_NAME_VAR (name); | |
2930 | bool used = false; | |
2931 | imm_use_iterator iter; | |
2932 | use_operand_p use_p; | |
2933 | gimple stmt; | |
2934 | ||
2935 | gcc_assert (VAR_DECL_IS_VIRTUAL_OPERAND (name_var)); | |
2936 | FOR_EACH_IMM_USE_STMT (stmt, iter, name) | |
2937 | { | |
2938 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) | |
2939 | SET_USE (use_p, name_var); | |
2940 | used = true; | |
2941 | } | |
2942 | if (used) | |
2943 | mark_virtual_operands_for_renaming (cfun); | |
2944 | } | |
2945 | ||
2946 | /* Replace all uses of the virtual PHI result by its underlying variable | |
2947 | and mark it for renaming. This assumes the PHI node is going to be | |
2948 | removed. */ | |
2949 | ||
2950 | void | |
1a91d914 | 2951 | mark_virtual_phi_result_for_renaming (gphi *phi) |
ba4d2b2f | 2952 | { |
2953 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2954 | { | |
2955 | fprintf (dump_file, "Marking result for renaming : "); | |
2956 | print_gimple_stmt (dump_file, phi, 0, TDF_SLIM); | |
2957 | fprintf (dump_file, "\n"); | |
2958 | } | |
2959 | ||
2960 | mark_virtual_operand_for_renaming (gimple_phi_result (phi)); | |
2961 | } | |
88dbf20f | 2962 | |
dd277d48 | 2963 | /* Return true if there is any work to be done by update_ssa |
2964 | for function FN. */ | |
88dbf20f | 2965 | |
2966 | bool | |
dd277d48 | 2967 | need_ssa_update_p (struct function *fn) |
88dbf20f | 2968 | { |
dd277d48 | 2969 | gcc_assert (fn != NULL); |
2970 | return (update_ssa_initialized_fn == fn | |
e70e8b13 | 2971 | || (fn->gimple_df && fn->gimple_df->ssa_renaming_needed)); |
88dbf20f | 2972 | } |
2973 | ||
88dbf20f | 2974 | /* Return true if name N has been registered in the replacement table. */ |
2975 | ||
2976 | bool | |
75a70cf9 | 2977 | name_registered_for_update_p (tree n ATTRIBUTE_UNUSED) |
88dbf20f | 2978 | { |
dd277d48 | 2979 | if (!update_ssa_initialized_fn) |
88dbf20f | 2980 | return false; |
2981 | ||
dd277d48 | 2982 | gcc_assert (update_ssa_initialized_fn == cfun); |
2983 | ||
2984 | return is_new_name (n) || is_old_name (n); | |
88dbf20f | 2985 | } |
2986 | ||
2987 | ||
88dbf20f | 2988 | /* Mark NAME to be released after update_ssa has finished. */ |
2989 | ||
2990 | void | |
2991 | release_ssa_name_after_update_ssa (tree name) | |
2992 | { | |
dd277d48 | 2993 | gcc_assert (cfun && update_ssa_initialized_fn == cfun); |
88dbf20f | 2994 | |
2995 | if (names_to_release == NULL) | |
2996 | names_to_release = BITMAP_ALLOC (NULL); | |
2997 | ||
2998 | bitmap_set_bit (names_to_release, SSA_NAME_VERSION (name)); | |
2999 | } | |
3000 | ||
3001 | ||
3002 | /* Insert new PHI nodes to replace VAR. DFS contains dominance | |
3003 | frontier information. BLOCKS is the set of blocks to be updated. | |
3004 | ||
3005 | This is slightly different than the regular PHI insertion | |
3006 | algorithm. The value of UPDATE_FLAGS controls how PHI nodes for | |
3007 | real names (i.e., GIMPLE registers) are inserted: | |
48e1416a | 3008 | |
88dbf20f | 3009 | - If UPDATE_FLAGS == TODO_update_ssa, we are only interested in PHI |
3010 | nodes inside the region affected by the block that defines VAR | |
3011 | and the blocks that define all its replacements. All these | |
095dcfa3 | 3012 | definition blocks are stored in DEF_BLOCKS[VAR]->DEF_BLOCKS. |
88dbf20f | 3013 | |
3014 | First, we compute the entry point to the region (ENTRY). This is | |
3015 | given by the nearest common dominator to all the definition | |
3016 | blocks. When computing the iterated dominance frontier (IDF), any | |
3017 | block not strictly dominated by ENTRY is ignored. | |
3018 | ||
3019 | We then call the standard PHI insertion algorithm with the pruned | |
3020 | IDF. | |
3021 | ||
3022 | - If UPDATE_FLAGS == TODO_update_ssa_full_phi, the IDF for real | |
3023 | names is not pruned. PHI nodes are inserted at every IDF block. */ | |
3024 | ||
3025 | static void | |
8a2980be | 3026 | insert_updated_phi_nodes_for (tree var, bitmap_head *dfs, bitmap blocks, |
88dbf20f | 3027 | unsigned update_flags) |
3028 | { | |
3029 | basic_block entry; | |
3030 | struct def_blocks_d *db; | |
3031 | bitmap idf, pruned_idf; | |
3032 | bitmap_iterator bi; | |
3033 | unsigned i; | |
3034 | ||
88dbf20f | 3035 | if (TREE_CODE (var) == SSA_NAME) |
1b4345f7 | 3036 | gcc_checking_assert (is_old_name (var)); |
88dbf20f | 3037 | else |
e70e8b13 | 3038 | gcc_checking_assert (marked_for_renaming (var)); |
88dbf20f | 3039 | |
3040 | /* Get all the definition sites for VAR. */ | |
3041 | db = find_def_blocks_for (var); | |
3042 | ||
3043 | /* No need to do anything if there were no definitions to VAR. */ | |
3044 | if (db == NULL || bitmap_empty_p (db->def_blocks)) | |
3045 | return; | |
3046 | ||
3047 | /* Compute the initial iterated dominance frontier. */ | |
4fb5e5ca | 3048 | idf = compute_idf (db->def_blocks, dfs); |
88dbf20f | 3049 | pruned_idf = BITMAP_ALLOC (NULL); |
3050 | ||
3051 | if (TREE_CODE (var) == SSA_NAME) | |
3052 | { | |
3053 | if (update_flags == TODO_update_ssa) | |
3054 | { | |
3055 | /* If doing regular SSA updates for GIMPLE registers, we are | |
3056 | only interested in IDF blocks dominated by the nearest | |
3057 | common dominator of all the definition blocks. */ | |
3058 | entry = nearest_common_dominator_for_set (CDI_DOMINATORS, | |
3059 | db->def_blocks); | |
34154e27 | 3060 | if (entry != ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
88dbf20f | 3061 | EXECUTE_IF_SET_IN_BITMAP (idf, 0, i, bi) |
f5a6b05f | 3062 | if (BASIC_BLOCK_FOR_FN (cfun, i) != entry |
3063 | && dominated_by_p (CDI_DOMINATORS, | |
3064 | BASIC_BLOCK_FOR_FN (cfun, i), entry)) | |
88dbf20f | 3065 | bitmap_set_bit (pruned_idf, i); |
3066 | } | |
3067 | else | |
3068 | { | |
3069 | /* Otherwise, do not prune the IDF for VAR. */ | |
88536563 | 3070 | gcc_checking_assert (update_flags == TODO_update_ssa_full_phi); |
88dbf20f | 3071 | bitmap_copy (pruned_idf, idf); |
3072 | } | |
3073 | } | |
3074 | else | |
3075 | { | |
3076 | /* Otherwise, VAR is a symbol that needs to be put into SSA form | |
3077 | for the first time, so we need to compute the full IDF for | |
3078 | it. */ | |
3079 | bitmap_copy (pruned_idf, idf); | |
88dbf20f | 3080 | } |
3081 | ||
3082 | if (!bitmap_empty_p (pruned_idf)) | |
3083 | { | |
3084 | /* Make sure that PRUNED_IDF blocks and all their feeding blocks | |
3085 | are included in the region to be updated. The feeding blocks | |
3086 | are important to guarantee that the PHI arguments are renamed | |
3087 | properly. */ | |
4fb5e5ca | 3088 | |
3089 | /* FIXME, this is not needed if we are updating symbols. We are | |
3090 | already starting at the ENTRY block anyway. */ | |
88dbf20f | 3091 | bitmap_ior_into (blocks, pruned_idf); |
3092 | EXECUTE_IF_SET_IN_BITMAP (pruned_idf, 0, i, bi) | |
3093 | { | |
3094 | edge e; | |
3095 | edge_iterator ei; | |
f5a6b05f | 3096 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i); |
88dbf20f | 3097 | |
3098 | FOR_EACH_EDGE (e, ei, bb->preds) | |
3099 | if (e->src->index >= 0) | |
3100 | bitmap_set_bit (blocks, e->src->index); | |
3101 | } | |
3102 | ||
3103 | insert_phi_nodes_for (var, pruned_idf, true); | |
3104 | } | |
3105 | ||
3106 | BITMAP_FREE (pruned_idf); | |
3107 | BITMAP_FREE (idf); | |
3108 | } | |
3109 | ||
487c79c3 | 3110 | /* Sort symbols_to_rename after their DECL_UID. */ |
3111 | ||
3112 | static int | |
3113 | insert_updated_phi_nodes_compare_uids (const void *a, const void *b) | |
3114 | { | |
3115 | const_tree syma = *(const const_tree *)a; | |
3116 | const_tree symb = *(const const_tree *)b; | |
3117 | if (DECL_UID (syma) == DECL_UID (symb)) | |
3118 | return 0; | |
3119 | return DECL_UID (syma) < DECL_UID (symb) ? -1 : 1; | |
3120 | } | |
88dbf20f | 3121 | |
3122 | /* Given a set of newly created SSA names (NEW_SSA_NAMES) and a set of | |
3123 | existing SSA names (OLD_SSA_NAMES), update the SSA form so that: | |
3124 | ||
3125 | 1- The names in OLD_SSA_NAMES dominated by the definitions of | |
3126 | NEW_SSA_NAMES are all re-written to be reached by the | |
3127 | appropriate definition from NEW_SSA_NAMES. | |
3128 | ||
3129 | 2- If needed, new PHI nodes are added to the iterated dominance | |
3130 | frontier of the blocks where each of NEW_SSA_NAMES are defined. | |
3131 | ||
3132 | The mapping between OLD_SSA_NAMES and NEW_SSA_NAMES is setup by | |
0dc262e0 | 3133 | calling create_new_def_for to create new defs for names that the |
88dbf20f | 3134 | caller wants to replace. |
3135 | ||
0dc262e0 | 3136 | The caller cretaes the new names to be inserted and the names that need |
3137 | to be replaced by calling create_new_def_for for each old definition | |
3138 | to be replaced. Note that the function assumes that the | |
3139 | new defining statement has already been inserted in the IL. | |
88dbf20f | 3140 | |
3141 | For instance, given the following code: | |
3142 | ||
3143 | 1 L0: | |
3144 | 2 x_1 = PHI (0, x_5) | |
3145 | 3 if (x_1 < 10) | |
3146 | 4 if (x_1 > 7) | |
3147 | 5 y_2 = 0 | |
3148 | 6 else | |
3149 | 7 y_3 = x_1 + x_7 | |
3150 | 8 endif | |
3151 | 9 x_5 = x_1 + 1 | |
3152 | 10 goto L0; | |
3153 | 11 endif | |
3154 | ||
3155 | Suppose that we insert new names x_10 and x_11 (lines 4 and 8). | |
3156 | ||
3157 | 1 L0: | |
3158 | 2 x_1 = PHI (0, x_5) | |
3159 | 3 if (x_1 < 10) | |
3160 | 4 x_10 = ... | |
3161 | 5 if (x_1 > 7) | |
3162 | 6 y_2 = 0 | |
3163 | 7 else | |
3164 | 8 x_11 = ... | |
3165 | 9 y_3 = x_1 + x_7 | |
3166 | 10 endif | |
3167 | 11 x_5 = x_1 + 1 | |
3168 | 12 goto L0; | |
3169 | 13 endif | |
3170 | ||
3171 | We want to replace all the uses of x_1 with the new definitions of | |
3172 | x_10 and x_11. Note that the only uses that should be replaced are | |
3173 | those at lines 5, 9 and 11. Also, the use of x_7 at line 9 should | |
3174 | *not* be replaced (this is why we cannot just mark symbol 'x' for | |
3175 | renaming). | |
3176 | ||
3177 | Additionally, we may need to insert a PHI node at line 11 because | |
3178 | that is a merge point for x_10 and x_11. So the use of x_1 at line | |
3179 | 11 will be replaced with the new PHI node. The insertion of PHI | |
3180 | nodes is optional. They are not strictly necessary to preserve the | |
3181 | SSA form, and depending on what the caller inserted, they may not | |
3182 | even be useful for the optimizers. UPDATE_FLAGS controls various | |
3183 | aspects of how update_ssa operates, see the documentation for | |
3184 | TODO_update_ssa*. */ | |
3185 | ||
3186 | void | |
3187 | update_ssa (unsigned update_flags) | |
3188 | { | |
88dbf20f | 3189 | basic_block bb, start_bb; |
3190 | bitmap_iterator bi; | |
86c1585a | 3191 | unsigned i = 0; |
88dbf20f | 3192 | bool insert_phi_p; |
3e790786 | 3193 | sbitmap_iterator sbi; |
e70e8b13 | 3194 | tree sym; |
88dbf20f | 3195 | |
2670407e | 3196 | /* Only one update flag should be set. */ |
3197 | gcc_assert (update_flags == TODO_update_ssa | |
3198 | || update_flags == TODO_update_ssa_no_phi | |
3199 | || update_flags == TODO_update_ssa_full_phi | |
3200 | || update_flags == TODO_update_ssa_only_virtuals); | |
3201 | ||
dd277d48 | 3202 | if (!need_ssa_update_p (cfun)) |
88dbf20f | 3203 | return; |
3204 | ||
9e8385f4 | 3205 | #ifdef ENABLE_CHECKING |
3206 | timevar_push (TV_TREE_STMT_VERIFY); | |
3207 | ||
3208 | bool err = false; | |
3209 | ||
3210 | FOR_EACH_BB_FN (bb, cfun) | |
3211 | { | |
3212 | gimple_stmt_iterator gsi; | |
3213 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
3214 | { | |
3215 | gimple stmt = gsi_stmt (gsi); | |
3216 | ||
3217 | ssa_op_iter i; | |
3218 | use_operand_p use_p; | |
3219 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, i, SSA_OP_ALL_USES) | |
3220 | { | |
3221 | tree use = USE_FROM_PTR (use_p); | |
3222 | if (TREE_CODE (use) != SSA_NAME) | |
3223 | continue; | |
3224 | ||
3225 | if (SSA_NAME_IN_FREE_LIST (use)) | |
3226 | { | |
3227 | error ("statement uses released SSA name:"); | |
3228 | debug_gimple_stmt (stmt); | |
3229 | fprintf (stderr, "The use of "); | |
3230 | print_generic_expr (stderr, use, 0); | |
3231 | fprintf (stderr," should have been replaced\n"); | |
3232 | err = true; | |
3233 | } | |
3234 | } | |
3235 | } | |
3236 | } | |
3237 | ||
3238 | if (err) | |
3239 | internal_error ("cannot update SSA form"); | |
3240 | ||
3241 | timevar_pop (TV_TREE_STMT_VERIFY); | |
3242 | #endif | |
3243 | ||
88dbf20f | 3244 | timevar_push (TV_TREE_SSA_INCREMENTAL); |
3245 | ||
0ffbb1b6 | 3246 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3247 | fprintf (dump_file, "\nUpdating SSA:\n"); | |
3248 | ||
dd277d48 | 3249 | if (!update_ssa_initialized_fn) |
3250 | init_update_ssa (cfun); | |
2670407e | 3251 | else if (update_flags == TODO_update_ssa_only_virtuals) |
3252 | { | |
3253 | /* If we only need to update virtuals, remove all the mappings for | |
3254 | real names before proceeding. The caller is responsible for | |
3255 | having dealt with the name mappings before calling update_ssa. */ | |
53c5d9d4 | 3256 | bitmap_clear (old_ssa_names); |
3257 | bitmap_clear (new_ssa_names); | |
2670407e | 3258 | } |
3259 | ||
dd277d48 | 3260 | gcc_assert (update_ssa_initialized_fn == cfun); |
3261 | ||
70630fcd | 3262 | blocks_with_phis_to_rewrite = BITMAP_ALLOC (NULL); |
f1f41a6c | 3263 | if (!phis_to_rewrite.exists ()) |
fe672ac0 | 3264 | phis_to_rewrite.create (last_basic_block_for_fn (cfun) + 1); |
2920559d | 3265 | blocks_to_update = BITMAP_ALLOC (NULL); |
70630fcd | 3266 | |
88dbf20f | 3267 | /* Ensure that the dominance information is up-to-date. */ |
3268 | calculate_dominance_info (CDI_DOMINATORS); | |
3269 | ||
095dcfa3 | 3270 | insert_phi_p = (update_flags != TODO_update_ssa_no_phi); |
88dbf20f | 3271 | |
095dcfa3 | 3272 | /* If there are names defined in the replacement table, prepare |
3273 | definition and use sites for all the names in NEW_SSA_NAMES and | |
3274 | OLD_SSA_NAMES. */ | |
53c5d9d4 | 3275 | if (bitmap_first_set_bit (new_ssa_names) >= 0) |
095dcfa3 | 3276 | { |
2920559d | 3277 | prepare_names_to_update (insert_phi_p); |
095dcfa3 | 3278 | |
3279 | /* If all the names in NEW_SSA_NAMES had been marked for | |
3280 | removal, and there are no symbols to rename, then there's | |
3281 | nothing else to do. */ | |
53c5d9d4 | 3282 | if (bitmap_first_set_bit (new_ssa_names) < 0 |
e70e8b13 | 3283 | && !cfun->gimple_df->ssa_renaming_needed) |
095dcfa3 | 3284 | goto done; |
3285 | } | |
3286 | ||
3287 | /* Next, determine the block at which to start the renaming process. */ | |
e70e8b13 | 3288 | if (cfun->gimple_df->ssa_renaming_needed) |
095dcfa3 | 3289 | { |
22d6c74e | 3290 | /* If we rename bare symbols initialize the mapping to |
3291 | auxiliar info we need to keep track of. */ | |
c1f445d2 | 3292 | var_infos = new hash_table<var_info_hasher> (47); |
22d6c74e | 3293 | |
095dcfa3 | 3294 | /* If we have to rename some symbols from scratch, we need to |
3295 | start the process at the root of the CFG. FIXME, it should | |
3296 | be possible to determine the nearest block that had a | |
3297 | definition for each of the symbols that are marked for | |
3298 | updating. For now this seems more work than it's worth. */ | |
34154e27 | 3299 | start_bb = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
095dcfa3 | 3300 | |
4fb5e5ca | 3301 | /* Traverse the CFG looking for existing definitions and uses of |
e70e8b13 | 3302 | symbols in SSA operands. Mark interesting blocks and |
4fb5e5ca | 3303 | statements and set local live-in information for the PHI |
3304 | placement heuristics. */ | |
2920559d | 3305 | prepare_block_for_update (start_bb, insert_phi_p); |
f8aa507d | 3306 | |
3307 | #ifdef ENABLE_CHECKING | |
3308 | for (i = 1; i < num_ssa_names; ++i) | |
3309 | { | |
3310 | tree name = ssa_name (i); | |
3311 | if (!name | |
3312 | || virtual_operand_p (name)) | |
3313 | continue; | |
3314 | ||
3315 | /* For all but virtual operands, which do not have SSA names | |
3316 | with overlapping life ranges, ensure that symbols marked | |
3317 | for renaming do not have existing SSA names associated with | |
3318 | them as we do not re-write them out-of-SSA before going | |
3319 | into SSA for the remaining symbol uses. */ | |
3320 | if (marked_for_renaming (SSA_NAME_VAR (name))) | |
3321 | { | |
3322 | fprintf (stderr, "Existing SSA name for symbol marked for " | |
3323 | "renaming: "); | |
3324 | print_generic_expr (stderr, name, TDF_SLIM); | |
3325 | fprintf (stderr, "\n"); | |
3326 | internal_error ("SSA corruption"); | |
3327 | } | |
3328 | } | |
3329 | #endif | |
88dbf20f | 3330 | } |
3331 | else | |
095dcfa3 | 3332 | { |
3333 | /* Otherwise, the entry block to the region is the nearest | |
3334 | common dominator for the blocks in BLOCKS. */ | |
2920559d | 3335 | start_bb = nearest_common_dominator_for_set (CDI_DOMINATORS, |
3336 | blocks_to_update); | |
095dcfa3 | 3337 | } |
88dbf20f | 3338 | |
3339 | /* If requested, insert PHI nodes at the iterated dominance frontier | |
095dcfa3 | 3340 | of every block, creating new definitions for names in OLD_SSA_NAMES |
e70e8b13 | 3341 | and for symbols found. */ |
88dbf20f | 3342 | if (insert_phi_p) |
3343 | { | |
8a2980be | 3344 | bitmap_head *dfs; |
66d00abf | 3345 | |
3346 | /* If the caller requested PHI nodes to be added, compute | |
3347 | dominance frontiers. */ | |
fe672ac0 | 3348 | dfs = XNEWVEC (bitmap_head, last_basic_block_for_fn (cfun)); |
fc00614f | 3349 | FOR_EACH_BB_FN (bb, cfun) |
8a2980be | 3350 | bitmap_initialize (&dfs[bb->index], &bitmap_default_obstack); |
66d00abf | 3351 | compute_dominance_frontiers (dfs); |
3352 | ||
53c5d9d4 | 3353 | if (bitmap_first_set_bit (old_ssa_names) >= 0) |
88dbf20f | 3354 | { |
3e790786 | 3355 | sbitmap_iterator sbi; |
3356 | ||
095dcfa3 | 3357 | /* insert_update_phi_nodes_for will call add_new_name_mapping |
3358 | when inserting new PHI nodes, so the set OLD_SSA_NAMES | |
3359 | will grow while we are traversing it (but it will not | |
3360 | gain any new members). Copy OLD_SSA_NAMES to a temporary | |
3361 | for traversal. */ | |
156093aa | 3362 | sbitmap tmp = sbitmap_alloc (SBITMAP_SIZE (old_ssa_names)); |
53c5d9d4 | 3363 | bitmap_copy (tmp, old_ssa_names); |
0d211963 | 3364 | EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, sbi) |
2920559d | 3365 | insert_updated_phi_nodes_for (ssa_name (i), dfs, blocks_to_update, |
3e790786 | 3366 | update_flags); |
88dbf20f | 3367 | sbitmap_free (tmp); |
3368 | } | |
3369 | ||
487c79c3 | 3370 | symbols_to_rename.qsort (insert_updated_phi_nodes_compare_uids); |
f1f41a6c | 3371 | FOR_EACH_VEC_ELT (symbols_to_rename, i, sym) |
e70e8b13 | 3372 | insert_updated_phi_nodes_for (sym, dfs, blocks_to_update, |
4fb5e5ca | 3373 | update_flags); |
88dbf20f | 3374 | |
fc00614f | 3375 | FOR_EACH_BB_FN (bb, cfun) |
8a2980be | 3376 | bitmap_clear (&dfs[bb->index]); |
66d00abf | 3377 | free (dfs); |
3378 | ||
88dbf20f | 3379 | /* Insertion of PHI nodes may have added blocks to the region. |
3380 | We need to re-compute START_BB to include the newly added | |
3381 | blocks. */ | |
34154e27 | 3382 | if (start_bb != ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
2920559d | 3383 | start_bb = nearest_common_dominator_for_set (CDI_DOMINATORS, |
3384 | blocks_to_update); | |
88dbf20f | 3385 | } |
3386 | ||
3387 | /* Reset the current definition for name and symbol before renaming | |
3388 | the sub-graph. */ | |
0d211963 | 3389 | EXECUTE_IF_SET_IN_BITMAP (old_ssa_names, 0, i, sbi) |
74105c0d | 3390 | get_ssa_name_ann (ssa_name (i))->info.current_def = NULL_TREE; |
88dbf20f | 3391 | |
f1f41a6c | 3392 | FOR_EACH_VEC_ELT (symbols_to_rename, i, sym) |
74105c0d | 3393 | get_var_info (sym)->info.current_def = NULL_TREE; |
88dbf20f | 3394 | |
3395 | /* Now start the renaming process at START_BB. */ | |
fe672ac0 | 3396 | interesting_blocks = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 3397 | bitmap_clear (interesting_blocks); |
2920559d | 3398 | EXECUTE_IF_SET_IN_BITMAP (blocks_to_update, 0, i, bi) |
08b7917c | 3399 | bitmap_set_bit (interesting_blocks, i); |
88dbf20f | 3400 | |
6bf320fb | 3401 | rewrite_blocks (start_bb, REWRITE_UPDATE); |
88dbf20f | 3402 | |
6bf320fb | 3403 | sbitmap_free (interesting_blocks); |
88dbf20f | 3404 | |
3405 | /* Debugging dumps. */ | |
3406 | if (dump_file) | |
3407 | { | |
3408 | int c; | |
3409 | unsigned i; | |
3410 | ||
095dcfa3 | 3411 | dump_update_ssa (dump_file); |
88dbf20f | 3412 | |
0ffbb1b6 | 3413 | fprintf (dump_file, "Incremental SSA update started at block: %d\n", |
88dbf20f | 3414 | start_bb->index); |
3415 | ||
3416 | c = 0; | |
2920559d | 3417 | EXECUTE_IF_SET_IN_BITMAP (blocks_to_update, 0, i, bi) |
88dbf20f | 3418 | c++; |
fe672ac0 | 3419 | fprintf (dump_file, "Number of blocks in CFG: %d\n", |
3420 | last_basic_block_for_fn (cfun)); | |
0ffbb1b6 | 3421 | fprintf (dump_file, "Number of blocks to update: %d (%3.0f%%)\n", |
fe672ac0 | 3422 | c, PERCENT (c, last_basic_block_for_fn (cfun))); |
88dbf20f | 3423 | |
3424 | if (dump_flags & TDF_DETAILS) | |
3425 | { | |
7ef97146 | 3426 | fprintf (dump_file, "Affected blocks:"); |
2920559d | 3427 | EXECUTE_IF_SET_IN_BITMAP (blocks_to_update, 0, i, bi) |
7ef97146 | 3428 | fprintf (dump_file, " %u", i); |
88dbf20f | 3429 | fprintf (dump_file, "\n"); |
3430 | } | |
3431 | ||
3432 | fprintf (dump_file, "\n\n"); | |
3433 | } | |
3434 | ||
3435 | /* Free allocated memory. */ | |
095dcfa3 | 3436 | done: |
88dbf20f | 3437 | delete_update_ssa (); |
3438 | ||
3439 | timevar_pop (TV_TREE_SSA_INCREMENTAL); | |
3440 | } |