]>
Commit | Line | Data |
---|---|---|
6de9cd9a | 1 | /* Rewrite a program in Normal form into SSA. |
23a5b65a | 2 | Copyright (C) 2001-2014 Free Software Foundation, Inc. |
6de9cd9a DN |
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 | |
9dcd6f09 | 9 | the Free Software Foundation; either version 3, or (at your option) |
6de9cd9a DN |
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 | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
6de9cd9a DN |
20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "tree.h" | |
26 | #include "flags.h" | |
6de9cd9a DN |
27 | #include "tm_p.h" |
28 | #include "langhooks.h" | |
6de9cd9a | 29 | #include "basic-block.h" |
6de9cd9a | 30 | #include "function.h" |
cf835838 | 31 | #include "gimple-pretty-print.h" |
2fb9a547 AM |
32 | #include "hash-table.h" |
33 | #include "tree-ssa-alias.h" | |
34 | #include "internal-fn.h" | |
35 | #include "gimple-expr.h" | |
36 | #include "is-a.h" | |
726a989a | 37 | #include "gimple.h" |
5be5c238 | 38 | #include "gimple-iterator.h" |
442b4905 AM |
39 | #include "gimple-ssa.h" |
40 | #include "tree-cfg.h" | |
41 | #include "tree-phinodes.h" | |
42 | #include "ssa-iterators.h" | |
d8a2d370 | 43 | #include "stringpool.h" |
442b4905 AM |
44 | #include "tree-ssanames.h" |
45 | #include "tree-into-ssa.h" | |
d8a2d370 | 46 | #include "expr.h" |
442b4905 AM |
47 | #include "tree-dfa.h" |
48 | #include "tree-ssa.h" | |
6de9cd9a | 49 | #include "tree-inline.h" |
6de9cd9a DN |
50 | #include "tree-pass.h" |
51 | #include "cfgloop.h" | |
52 | #include "domwalk.h" | |
84d65814 | 53 | #include "params.h" |
d8d707b4 | 54 | #include "diagnostic-core.h" |
cf2d1b38 | 55 | #include "tree-into-ssa.h" |
6de9cd9a | 56 | |
1fe37220 | 57 | #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y)) |
726a989a | 58 | |
6de9cd9a DN |
59 | /* This file builds the SSA form for a function as described in: |
60 | R. Cytron, J. Ferrante, B. Rosen, M. Wegman, and K. Zadeck. Efficiently | |
61 | Computing Static Single Assignment Form and the Control Dependence | |
62 | Graph. ACM Transactions on Programming Languages and Systems, | |
63 | 13(4):451-490, October 1991. */ | |
64 | ||
6de9cd9a DN |
65 | /* Structure to map a variable VAR to the set of blocks that contain |
66 | definitions for VAR. */ | |
67 | struct def_blocks_d | |
68 | { | |
6de9cd9a DN |
69 | /* Blocks that contain definitions of VAR. Bit I will be set if the |
70 | Ith block contains a definition of VAR. */ | |
71 | bitmap def_blocks; | |
72 | ||
7256233c | 73 | /* Blocks that contain a PHI node for VAR. */ |
5f240ec4 ZD |
74 | bitmap phi_blocks; |
75 | ||
6de9cd9a DN |
76 | /* Blocks where VAR is live-on-entry. Similar semantics as |
77 | DEF_BLOCKS. */ | |
78 | bitmap livein_blocks; | |
79 | }; | |
80 | ||
d9ed2fbd RG |
81 | typedef struct def_blocks_d *def_blocks_p; |
82 | ||
6de9cd9a | 83 | |
9fae925b | 84 | /* Stack of trees used to restore the global currdefs to its original |
0bca51f0 DN |
85 | state after completing rewriting of a block and its dominator |
86 | children. Its elements have the following properties: | |
9fae925b | 87 | |
38635499 DN |
88 | - An SSA_NAME (N) indicates that the current definition of the |
89 | underlying variable should be set to the given SSA_NAME. If the | |
90 | symbol associated with the SSA_NAME is not a GIMPLE register, the | |
91 | next slot in the stack must be a _DECL node (SYM). In this case, | |
92 | the name N in the previous slot is the current reaching | |
93 | definition for SYM. | |
9fae925b | 94 | |
0bca51f0 DN |
95 | - A _DECL node indicates that the underlying variable has no |
96 | current definition. | |
7256233c | 97 | |
38635499 | 98 | - A NULL node at the top entry is used to mark the last slot |
0bca51f0 | 99 | associated with the current block. */ |
9771b263 | 100 | static vec<tree> block_defs_stack; |
3a2e4b46 | 101 | |
726a989a | 102 | |
0bca51f0 DN |
103 | /* Set of existing SSA names being replaced by update_ssa. */ |
104 | static sbitmap old_ssa_names; | |
105 | ||
106 | /* Set of new SSA names being added by update_ssa. Note that both | |
107 | NEW_SSA_NAMES and OLD_SSA_NAMES are dense bitmaps because most of | |
108 | the operations done on them are presence tests. */ | |
109 | static sbitmap new_ssa_names; | |
110 | ||
16876bdc | 111 | static sbitmap interesting_blocks; |
726a989a | 112 | |
0bca51f0 DN |
113 | /* Set of SSA names that have been marked to be released after they |
114 | were registered in the replacement table. They will be finally | |
115 | released after we finish updating the SSA web. */ | |
116 | static bitmap names_to_release; | |
117 | ||
9771b263 | 118 | /* vec of vec of PHIs to rewrite in a basic block. Element I corresponds |
580b2c2e SB |
119 | the to basic block with index I. Allocated once per compilation, *not* |
120 | released between different functions. */ | |
9771b263 | 121 | static vec<gimple_vec> phis_to_rewrite; |
2ce79879 ZD |
122 | |
123 | /* The bitmap of non-NULL elements of PHIS_TO_REWRITE. */ | |
2ce79879 ZD |
124 | static bitmap blocks_with_phis_to_rewrite; |
125 | ||
0bca51f0 | 126 | /* Growth factor for NEW_SSA_NAMES and OLD_SSA_NAMES. These sets need |
45db3141 RG |
127 | to grow as the callers to create_new_def_for will create new names on |
128 | the fly. | |
129 | FIXME. Currently set to 1/3 to avoid frequent reallocations but still | |
130 | need to find a reasonable growth strategy. */ | |
0bca51f0 DN |
131 | #define NAME_SETS_GROWTH_FACTOR (MAX (3, num_ssa_names / 3)) |
132 | ||
0bca51f0 | 133 | |
5006671f | 134 | /* The function the SSA updating data structures have been initialized for. |
45db3141 | 135 | NULL if they need to be initialized by create_new_def_for. */ |
5006671f | 136 | static struct function *update_ssa_initialized_fn = NULL; |
0bca51f0 | 137 | |
6de9cd9a DN |
138 | /* Global data to attach to the main dominator walk structure. */ |
139 | struct mark_def_sites_global_data | |
140 | { | |
0bca51f0 DN |
141 | /* This bitmap contains the variables which are set before they |
142 | are used in a basic block. */ | |
7d793e36 | 143 | bitmap kills; |
6de9cd9a DN |
144 | }; |
145 | ||
80560f95 AM |
146 | /* It is advantageous to avoid things like life analysis for variables which |
147 | do not need PHI nodes. This enum describes whether or not a particular | |
148 | variable may need a PHI node. */ | |
149 | ||
150 | enum need_phi_state { | |
151 | /* This is the default. If we are still in this state after finding | |
152 | all the definition and use sites, then we will assume the variable | |
153 | needs PHI nodes. This is probably an overly conservative assumption. */ | |
154 | NEED_PHI_STATE_UNKNOWN, | |
155 | ||
156 | /* This state indicates that we have seen one or more sets of the | |
157 | variable in a single basic block and that the sets dominate all | |
158 | uses seen so far. If after finding all definition and use sites | |
159 | we are still in this state, then the variable does not need any | |
160 | PHI nodes. */ | |
161 | NEED_PHI_STATE_NO, | |
162 | ||
163 | /* This state indicates that we have either seen multiple definitions of | |
164 | the variable in multiple blocks, or that we encountered a use in a | |
165 | block that was not dominated by the block containing the set(s) of | |
166 | this variable. This variable is assumed to need PHI nodes. */ | |
167 | NEED_PHI_STATE_MAYBE | |
168 | }; | |
169 | ||
8812aab1 RG |
170 | /* Information stored for both SSA names and decls. */ |
171 | struct common_info_d | |
b4e209fd | 172 | { |
b4e209fd RG |
173 | /* This field indicates whether or not the variable may need PHI nodes. |
174 | See the enum's definition for more detailed information about the | |
175 | states. */ | |
176 | ENUM_BITFIELD (need_phi_state) need_phi_state : 2; | |
177 | ||
8812aab1 | 178 | /* The current reaching definition replacing this var. */ |
b4e209fd RG |
179 | tree current_def; |
180 | ||
8812aab1 | 181 | /* Definitions for this var. */ |
b4e209fd RG |
182 | struct def_blocks_d def_blocks; |
183 | }; | |
184 | ||
8812aab1 RG |
185 | /* The information associated with decls and SSA names. */ |
186 | typedef struct common_info_d *common_info_p; | |
187 | ||
188 | /* Information stored for decls. */ | |
189 | struct var_info_d | |
190 | { | |
191 | /* The variable. */ | |
192 | tree var; | |
193 | ||
194 | /* Information stored for both SSA names and decls. */ | |
195 | struct common_info_d info; | |
196 | }; | |
197 | ||
b4e209fd RG |
198 | /* The information associated with decls. */ |
199 | typedef struct var_info_d *var_info_p; | |
200 | ||
b4e209fd | 201 | |
bf190e8d LC |
202 | /* VAR_INFOS hashtable helpers. */ |
203 | ||
204 | struct var_info_hasher : typed_free_remove <var_info_d> | |
205 | { | |
206 | typedef var_info_d value_type; | |
207 | typedef var_info_d compare_type; | |
208 | static inline hashval_t hash (const value_type *); | |
209 | static inline bool equal (const value_type *, const compare_type *); | |
210 | }; | |
211 | ||
212 | inline hashval_t | |
213 | var_info_hasher::hash (const value_type *p) | |
214 | { | |
215 | return DECL_UID (p->var); | |
216 | } | |
217 | ||
218 | inline bool | |
219 | var_info_hasher::equal (const value_type *p1, const compare_type *p2) | |
220 | { | |
221 | return p1->var == p2->var; | |
222 | } | |
223 | ||
224 | ||
b4e209fd RG |
225 | /* Each entry in VAR_INFOS contains an element of type STRUCT |
226 | VAR_INFO_D. */ | |
c203e8a7 | 227 | static hash_table<var_info_hasher> *var_infos; |
b4e209fd RG |
228 | |
229 | ||
0bca51f0 | 230 | /* Information stored for SSA names. */ |
5f240ec4 ZD |
231 | struct ssa_name_info |
232 | { | |
891f2df6 RG |
233 | /* Age of this record (so that info_for_ssa_name table can be cleared |
234 | quickly); if AGE < CURRENT_INFO_FOR_SSA_NAME_AGE, then the fields | |
235 | are assumed to be null. */ | |
236 | unsigned age; | |
95dd3097 | 237 | |
891f2df6 RG |
238 | /* Replacement mappings, allocated from update_ssa_obstack. */ |
239 | bitmap repl_set; | |
b4e209fd | 240 | |
8812aab1 RG |
241 | /* Information stored for both SSA names and decls. */ |
242 | struct common_info_d info; | |
5f240ec4 | 243 | }; |
6de9cd9a | 244 | |
95dd3097 ZD |
245 | /* The information associated with names. */ |
246 | typedef struct ssa_name_info *ssa_name_info_p; | |
95dd3097 | 247 | |
9771b263 | 248 | static vec<ssa_name_info_p> info_for_ssa_name; |
95dd3097 ZD |
249 | static unsigned current_info_for_ssa_name_age; |
250 | ||
891f2df6 RG |
251 | static bitmap_obstack update_ssa_obstack; |
252 | ||
95dd3097 | 253 | /* The set of blocks affected by update_ssa. */ |
95dd3097 | 254 | static bitmap blocks_to_update; |
6de9cd9a | 255 | |
0bca51f0 DN |
256 | /* The main entry point to the SSA renamer (rewrite_blocks) may be |
257 | called several times to do different, but related, tasks. | |
258 | Initially, we need it to rename the whole program into SSA form. | |
259 | At other times, we may need it to only rename into SSA newly | |
260 | exposed symbols. Finally, we can also call it to incrementally fix | |
261 | an already built SSA web. */ | |
262 | enum rewrite_mode { | |
263 | /* Convert the whole function into SSA form. */ | |
264 | REWRITE_ALL, | |
265 | ||
266 | /* Incrementally update the SSA web by replacing existing SSA | |
267 | names with new ones. See update_ssa for details. */ | |
268 | REWRITE_UPDATE | |
269 | }; | |
270 | ||
13714310 RG |
271 | /* The set of symbols we ought to re-write into SSA form in update_ssa. */ |
272 | static bitmap symbols_to_rename_set; | |
9771b263 | 273 | static vec<tree> symbols_to_rename; |
13714310 RG |
274 | |
275 | /* Mark SYM for renaming. */ | |
276 | ||
277 | static void | |
278 | mark_for_renaming (tree sym) | |
279 | { | |
280 | if (!symbols_to_rename_set) | |
281 | symbols_to_rename_set = BITMAP_ALLOC (NULL); | |
282 | if (bitmap_set_bit (symbols_to_rename_set, DECL_UID (sym))) | |
9771b263 | 283 | symbols_to_rename.safe_push (sym); |
13714310 RG |
284 | } |
285 | ||
286 | /* Return true if SYM is marked for renaming. */ | |
287 | ||
288 | static bool | |
289 | marked_for_renaming (tree sym) | |
290 | { | |
70b5e7dc | 291 | if (!symbols_to_rename_set || sym == NULL_TREE) |
13714310 RG |
292 | return false; |
293 | return bitmap_bit_p (symbols_to_rename_set, DECL_UID (sym)); | |
294 | } | |
295 | ||
296 | ||
726a989a RB |
297 | /* Return true if STMT needs to be rewritten. When renaming a subset |
298 | of the variables, not all statements will be processed. This is | |
299 | decided in mark_def_sites. */ | |
300 | ||
301 | static inline bool | |
302 | rewrite_uses_p (gimple stmt) | |
303 | { | |
304 | return gimple_visited_p (stmt); | |
305 | } | |
306 | ||
307 | ||
308 | /* Set the rewrite marker on STMT to the value given by REWRITE_P. */ | |
309 | ||
310 | static inline void | |
311 | set_rewrite_uses (gimple stmt, bool rewrite_p) | |
312 | { | |
313 | gimple_set_visited (stmt, rewrite_p); | |
314 | } | |
315 | ||
316 | ||
317 | /* Return true if the DEFs created by statement STMT should be | |
318 | registered when marking new definition sites. This is slightly | |
319 | different than rewrite_uses_p: it's used by update_ssa to | |
320 | distinguish statements that need to have both uses and defs | |
321 | processed from those that only need to have their defs processed. | |
322 | Statements that define new SSA names only need to have their defs | |
323 | registered, but they don't need to have their uses renamed. */ | |
324 | ||
325 | static inline bool | |
326 | register_defs_p (gimple stmt) | |
327 | { | |
328 | return gimple_plf (stmt, GF_PLF_1) != 0; | |
329 | } | |
330 | ||
331 | ||
332 | /* If REGISTER_DEFS_P is true, mark STMT to have its DEFs registered. */ | |
333 | ||
334 | static inline void | |
335 | set_register_defs (gimple stmt, bool register_defs_p) | |
336 | { | |
337 | gimple_set_plf (stmt, GF_PLF_1, register_defs_p); | |
338 | } | |
339 | ||
340 | ||
5f240ec4 ZD |
341 | /* Get the information associated with NAME. */ |
342 | ||
38635499 | 343 | static inline ssa_name_info_p |
5f240ec4 ZD |
344 | get_ssa_name_ann (tree name) |
345 | { | |
95dd3097 | 346 | unsigned ver = SSA_NAME_VERSION (name); |
9771b263 | 347 | unsigned len = info_for_ssa_name.length (); |
95dd3097 ZD |
348 | struct ssa_name_info *info; |
349 | ||
f5843d08 | 350 | /* Re-allocate the vector at most once per update/into-SSA. */ |
95dd3097 | 351 | if (ver >= len) |
9771b263 | 352 | info_for_ssa_name.safe_grow_cleared (num_ssa_names); |
f5843d08 RG |
353 | |
354 | /* But allocate infos lazily. */ | |
9771b263 | 355 | info = info_for_ssa_name[ver]; |
f5843d08 | 356 | if (!info) |
95dd3097 | 357 | { |
f5843d08 RG |
358 | info = XCNEW (struct ssa_name_info); |
359 | info->age = current_info_for_ssa_name_age; | |
360 | info->info.need_phi_state = NEED_PHI_STATE_UNKNOWN; | |
9771b263 | 361 | info_for_ssa_name[ver] = info; |
95dd3097 ZD |
362 | } |
363 | ||
95dd3097 ZD |
364 | if (info->age < current_info_for_ssa_name_age) |
365 | { | |
95dd3097 | 366 | info->age = current_info_for_ssa_name_age; |
8812aab1 RG |
367 | info->repl_set = NULL; |
368 | info->info.need_phi_state = NEED_PHI_STATE_UNKNOWN; | |
369 | info->info.current_def = NULL_TREE; | |
370 | info->info.def_blocks.def_blocks = NULL; | |
371 | info->info.def_blocks.phi_blocks = NULL; | |
372 | info->info.def_blocks.livein_blocks = NULL; | |
95dd3097 | 373 | } |
5f240ec4 | 374 | |
95dd3097 | 375 | return info; |
5f240ec4 ZD |
376 | } |
377 | ||
b4e209fd RG |
378 | /* Return and allocate the auxiliar information for DECL. */ |
379 | ||
380 | static inline var_info_p | |
381 | get_var_info (tree decl) | |
382 | { | |
383 | struct var_info_d vi; | |
bf190e8d | 384 | var_info_d **slot; |
b4e209fd | 385 | vi.var = decl; |
c203e8a7 | 386 | slot = var_infos->find_slot_with_hash (&vi, DECL_UID (decl), INSERT); |
b4e209fd RG |
387 | if (*slot == NULL) |
388 | { | |
389 | var_info_p v = XCNEW (struct var_info_d); | |
390 | v->var = decl; | |
bf190e8d | 391 | *slot = v; |
b4e209fd RG |
392 | return v; |
393 | } | |
bf190e8d | 394 | return *slot; |
b4e209fd RG |
395 | } |
396 | ||
38635499 DN |
397 | |
398 | /* Clears info for SSA names. */ | |
95dd3097 ZD |
399 | |
400 | static void | |
401 | clear_ssa_name_info (void) | |
402 | { | |
403 | current_info_for_ssa_name_age++; | |
891f2df6 RG |
404 | |
405 | /* If current_info_for_ssa_name_age wraps we use stale information. | |
406 | Asser that this does not happen. */ | |
407 | gcc_assert (current_info_for_ssa_name_age != 0); | |
95dd3097 | 408 | } |
7256233c | 409 | |
38635499 | 410 | |
8812aab1 | 411 | /* Get access to the auxiliar information stored per SSA name or decl. */ |
5f240ec4 | 412 | |
8812aab1 RG |
413 | static inline common_info_p |
414 | get_common_info (tree var) | |
5f240ec4 ZD |
415 | { |
416 | if (TREE_CODE (var) == SSA_NAME) | |
8812aab1 | 417 | return &get_ssa_name_ann (var)->info; |
5f240ec4 | 418 | else |
8812aab1 | 419 | return &get_var_info (var)->info; |
5f240ec4 ZD |
420 | } |
421 | ||
7256233c | 422 | |
5f240ec4 ZD |
423 | /* Return the current definition for VAR. */ |
424 | ||
84d65814 | 425 | tree |
5f240ec4 ZD |
426 | get_current_def (tree var) |
427 | { | |
8812aab1 | 428 | return get_common_info (var)->current_def; |
5f240ec4 ZD |
429 | } |
430 | ||
7256233c | 431 | |
5f240ec4 ZD |
432 | /* Sets current definition of VAR to DEF. */ |
433 | ||
84d65814 | 434 | void |
5f240ec4 ZD |
435 | set_current_def (tree var, tree def) |
436 | { | |
8812aab1 | 437 | get_common_info (var)->current_def = def; |
5f240ec4 ZD |
438 | } |
439 | ||
95dd3097 ZD |
440 | /* Cleans up the REWRITE_THIS_STMT and REGISTER_DEFS_IN_THIS_STMT flags for |
441 | all statements in basic block BB. */ | |
442 | ||
443 | static void | |
444 | initialize_flags_in_bb (basic_block bb) | |
445 | { | |
726a989a RB |
446 | gimple stmt; |
447 | gimple_stmt_iterator gsi; | |
95dd3097 | 448 | |
726a989a | 449 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
95dd3097 | 450 | { |
726a989a RB |
451 | gimple phi = gsi_stmt (gsi); |
452 | set_rewrite_uses (phi, false); | |
453 | set_register_defs (phi, false); | |
95dd3097 ZD |
454 | } |
455 | ||
726a989a | 456 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
95dd3097 | 457 | { |
726a989a RB |
458 | stmt = gsi_stmt (gsi); |
459 | ||
95dd3097 ZD |
460 | /* We are going to use the operand cache API, such as |
461 | SET_USE, SET_DEF, and FOR_EACH_IMM_USE_FAST. The operand | |
462 | cache for each statement should be up-to-date. */ | |
4ad14919 | 463 | gcc_checking_assert (!gimple_modified_p (stmt)); |
726a989a RB |
464 | set_rewrite_uses (stmt, false); |
465 | set_register_defs (stmt, false); | |
95dd3097 ZD |
466 | } |
467 | } | |
468 | ||
469 | /* Mark block BB as interesting for update_ssa. */ | |
470 | ||
471 | static void | |
472 | mark_block_for_update (basic_block bb) | |
473 | { | |
4ad14919 | 474 | gcc_checking_assert (blocks_to_update != NULL); |
f3cf730b | 475 | if (!bitmap_set_bit (blocks_to_update, bb->index)) |
95dd3097 | 476 | return; |
95dd3097 ZD |
477 | initialize_flags_in_bb (bb); |
478 | } | |
479 | ||
7256233c DN |
480 | /* Return the set of blocks where variable VAR is defined and the blocks |
481 | where VAR is live on entry (livein). If no entry is found in | |
482 | DEF_BLOCKS, a new one is created and returned. */ | |
6de9cd9a | 483 | |
7256233c | 484 | static inline struct def_blocks_d * |
8812aab1 | 485 | get_def_blocks_for (common_info_p info) |
6de9cd9a | 486 | { |
8812aab1 | 487 | struct def_blocks_d *db_p = &info->def_blocks; |
b4e209fd | 488 | if (!db_p->def_blocks) |
6de9cd9a | 489 | { |
b4e209fd RG |
490 | db_p->def_blocks = BITMAP_ALLOC (&update_ssa_obstack); |
491 | db_p->phi_blocks = BITMAP_ALLOC (&update_ssa_obstack); | |
492 | db_p->livein_blocks = BITMAP_ALLOC (&update_ssa_obstack); | |
a32b97a2 BB |
493 | } |
494 | ||
7256233c | 495 | return db_p; |
6de9cd9a DN |
496 | } |
497 | ||
7d5f9cc6 | 498 | |
5f240ec4 | 499 | /* Mark block BB as the definition site for variable VAR. PHI_P is true if |
0bca51f0 | 500 | VAR is defined by a PHI node. */ |
6de9cd9a DN |
501 | |
502 | static void | |
0bca51f0 | 503 | set_def_block (tree var, basic_block bb, bool phi_p) |
6de9cd9a DN |
504 | { |
505 | struct def_blocks_d *db_p; | |
8812aab1 | 506 | common_info_p info; |
34eb8991 | 507 | |
8812aab1 RG |
508 | info = get_common_info (var); |
509 | db_p = get_def_blocks_for (info); | |
6de9cd9a DN |
510 | |
511 | /* Set the bit corresponding to the block where VAR is defined. */ | |
512 | bitmap_set_bit (db_p->def_blocks, bb->index); | |
5f240ec4 ZD |
513 | if (phi_p) |
514 | bitmap_set_bit (db_p->phi_blocks, bb->index); | |
6de9cd9a | 515 | |
7256233c | 516 | /* Keep track of whether or not we may need to insert PHI nodes. |
6de9cd9a DN |
517 | |
518 | If we are in the UNKNOWN state, then this is the first definition | |
519 | of VAR. Additionally, we have not seen any uses of VAR yet, so | |
7256233c | 520 | we do not need a PHI node for this variable at this time (i.e., |
6de9cd9a DN |
521 | transition to NEED_PHI_STATE_NO). |
522 | ||
523 | If we are in any other state, then we either have multiple definitions | |
524 | of this variable occurring in different blocks or we saw a use of the | |
525 | variable which was not dominated by the block containing the | |
526 | definition(s). In this case we may need a PHI node, so enter | |
527 | state NEED_PHI_STATE_MAYBE. */ | |
8812aab1 RG |
528 | if (info->need_phi_state == NEED_PHI_STATE_UNKNOWN) |
529 | info->need_phi_state = NEED_PHI_STATE_NO; | |
6de9cd9a | 530 | else |
8812aab1 | 531 | info->need_phi_state = NEED_PHI_STATE_MAYBE; |
6de9cd9a DN |
532 | } |
533 | ||
534 | ||
535 | /* Mark block BB as having VAR live at the entry to BB. */ | |
536 | ||
537 | static void | |
538 | set_livein_block (tree var, basic_block bb) | |
539 | { | |
8812aab1 | 540 | common_info_p info; |
6de9cd9a | 541 | struct def_blocks_d *db_p; |
6de9cd9a | 542 | |
8812aab1 RG |
543 | info = get_common_info (var); |
544 | db_p = get_def_blocks_for (info); | |
6de9cd9a DN |
545 | |
546 | /* Set the bit corresponding to the block where VAR is live in. */ | |
547 | bitmap_set_bit (db_p->livein_blocks, bb->index); | |
548 | ||
7256233c | 549 | /* Keep track of whether or not we may need to insert PHI nodes. |
6de9cd9a DN |
550 | |
551 | If we reach here in NEED_PHI_STATE_NO, see if this use is dominated | |
552 | by the single block containing the definition(s) of this variable. If | |
553 | it is, then we remain in NEED_PHI_STATE_NO, otherwise we transition to | |
554 | NEED_PHI_STATE_MAYBE. */ | |
8812aab1 | 555 | if (info->need_phi_state == NEED_PHI_STATE_NO) |
6de9cd9a DN |
556 | { |
557 | int def_block_index = bitmap_first_set_bit (db_p->def_blocks); | |
558 | ||
559 | if (def_block_index == -1 | |
560 | || ! dominated_by_p (CDI_DOMINATORS, bb, | |
06e28de2 | 561 | BASIC_BLOCK_FOR_FN (cfun, def_block_index))) |
8812aab1 | 562 | info->need_phi_state = NEED_PHI_STATE_MAYBE; |
6de9cd9a DN |
563 | } |
564 | else | |
8812aab1 | 565 | info->need_phi_state = NEED_PHI_STATE_MAYBE; |
6de9cd9a DN |
566 | } |
567 | ||
568 | ||
0bca51f0 | 569 | /* Return true if NAME is in OLD_SSA_NAMES. */ |
6de9cd9a | 570 | |
0bca51f0 DN |
571 | static inline bool |
572 | is_old_name (tree name) | |
573 | { | |
84d65814 | 574 | unsigned ver = SSA_NAME_VERSION (name); |
5006671f RG |
575 | if (!new_ssa_names) |
576 | return false; | |
5829cc0f | 577 | return (ver < SBITMAP_SIZE (new_ssa_names) |
d7c028c0 | 578 | && bitmap_bit_p (old_ssa_names, ver)); |
0bca51f0 DN |
579 | } |
580 | ||
581 | ||
582 | /* Return true if NAME is in NEW_SSA_NAMES. */ | |
34eb8991 | 583 | |
0bca51f0 DN |
584 | static inline bool |
585 | is_new_name (tree name) | |
586 | { | |
84d65814 | 587 | unsigned ver = SSA_NAME_VERSION (name); |
5006671f RG |
588 | if (!new_ssa_names) |
589 | return false; | |
5829cc0f | 590 | return (ver < SBITMAP_SIZE (new_ssa_names) |
d7c028c0 | 591 | && bitmap_bit_p (new_ssa_names, ver)); |
6de9cd9a DN |
592 | } |
593 | ||
7256233c | 594 | |
82d6e6fc | 595 | /* Return the names replaced by NEW_TREE (i.e., REPL_TBL[NEW_TREE].SET). */ |
0bca51f0 DN |
596 | |
597 | static inline bitmap | |
82d6e6fc | 598 | names_replaced_by (tree new_tree) |
0bca51f0 | 599 | { |
891f2df6 | 600 | return get_ssa_name_ann (new_tree)->repl_set; |
0bca51f0 DN |
601 | } |
602 | ||
603 | ||
82d6e6fc | 604 | /* Add OLD to REPL_TBL[NEW_TREE].SET. */ |
0bca51f0 DN |
605 | |
606 | static inline void | |
82d6e6fc | 607 | add_to_repl_tbl (tree new_tree, tree old) |
0bca51f0 | 608 | { |
891f2df6 RG |
609 | bitmap *set = &get_ssa_name_ann (new_tree)->repl_set; |
610 | if (!*set) | |
611 | *set = BITMAP_ALLOC (&update_ssa_obstack); | |
612 | bitmap_set_bit (*set, SSA_NAME_VERSION (old)); | |
0bca51f0 DN |
613 | } |
614 | ||
615 | ||
82d6e6fc | 616 | /* Add a new mapping NEW_TREE -> OLD REPL_TBL. Every entry N_i in REPL_TBL |
0bca51f0 DN |
617 | represents the set of names O_1 ... O_j replaced by N_i. This is |
618 | used by update_ssa and its helpers to introduce new SSA names in an | |
619 | already formed SSA web. */ | |
620 | ||
621 | static void | |
82d6e6fc | 622 | add_new_name_mapping (tree new_tree, tree old) |
0bca51f0 | 623 | { |
82d6e6fc | 624 | /* OLD and NEW_TREE must be different SSA names for the same symbol. */ |
4ad14919 RG |
625 | gcc_checking_assert (new_tree != old |
626 | && SSA_NAME_VAR (new_tree) == SSA_NAME_VAR (old)); | |
84d65814 | 627 | |
38635499 DN |
628 | /* We may need to grow NEW_SSA_NAMES and OLD_SSA_NAMES because our |
629 | caller may have created new names since the set was created. */ | |
5829cc0f | 630 | if (SBITMAP_SIZE (new_ssa_names) <= num_ssa_names - 1) |
38635499 DN |
631 | { |
632 | unsigned int new_sz = num_ssa_names + NAME_SETS_GROWTH_FACTOR; | |
633 | new_ssa_names = sbitmap_resize (new_ssa_names, new_sz, 0); | |
634 | old_ssa_names = sbitmap_resize (old_ssa_names, new_sz, 0); | |
0bca51f0 DN |
635 | } |
636 | ||
0bca51f0 | 637 | /* Update the REPL_TBL table. */ |
82d6e6fc | 638 | add_to_repl_tbl (new_tree, old); |
d00ad49b | 639 | |
0bca51f0 | 640 | /* If OLD had already been registered as a new name, then all the |
82d6e6fc | 641 | names that OLD replaces should also be replaced by NEW_TREE. */ |
0bca51f0 | 642 | if (is_new_name (old)) |
82d6e6fc | 643 | bitmap_ior_into (names_replaced_by (new_tree), names_replaced_by (old)); |
0bca51f0 | 644 | |
82d6e6fc | 645 | /* Register NEW_TREE and OLD in NEW_SSA_NAMES and OLD_SSA_NAMES, |
0bca51f0 | 646 | respectively. */ |
d7c028c0 LC |
647 | bitmap_set_bit (new_ssa_names, SSA_NAME_VERSION (new_tree)); |
648 | bitmap_set_bit (old_ssa_names, SSA_NAME_VERSION (old)); | |
d00ad49b | 649 | } |
6de9cd9a | 650 | |
6de9cd9a | 651 | |
7256233c DN |
652 | /* Call back for walk_dominator_tree used to collect definition sites |
653 | for every variable in the function. For every statement S in block | |
654 | BB: | |
6de9cd9a | 655 | |
f47c96aa | 656 | 1- Variables defined by S in the DEFS of S are marked in the bitmap |
ccf5c864 | 657 | KILLS. |
6de9cd9a | 658 | |
7256233c | 659 | 2- If S uses a variable VAR and there is no preceding kill of VAR, |
7b71de26 | 660 | then it is marked in the LIVEIN_BLOCKS bitmap associated with VAR. |
6de9cd9a | 661 | |
7256233c DN |
662 | This information is used to determine which variables are live |
663 | across block boundaries to reduce the number of PHI nodes | |
664 | we create. */ | |
6de9cd9a | 665 | |
7256233c | 666 | static void |
ccf5c864 | 667 | mark_def_sites (basic_block bb, gimple stmt, bitmap kills) |
7256233c | 668 | { |
726a989a | 669 | tree def; |
7256233c | 670 | use_operand_p use_p; |
7256233c DN |
671 | ssa_op_iter iter; |
672 | ||
726a989a RB |
673 | /* Since this is the first time that we rewrite the program into SSA |
674 | form, force an operand scan on every statement. */ | |
726a989a | 675 | update_stmt (stmt); |
7256233c | 676 | |
4ad14919 | 677 | gcc_checking_assert (blocks_to_update == NULL); |
726a989a RB |
678 | set_register_defs (stmt, false); |
679 | set_rewrite_uses (stmt, false); | |
7256233c | 680 | |
b5b8b0ac | 681 | if (is_gimple_debug (stmt)) |
ddb555ed JJ |
682 | { |
683 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) | |
684 | { | |
685 | tree sym = USE_FROM_PTR (use_p); | |
4ad14919 | 686 | gcc_checking_assert (DECL_P (sym)); |
ddb555ed JJ |
687 | set_rewrite_uses (stmt, true); |
688 | } | |
689 | if (rewrite_uses_p (stmt)) | |
d7c028c0 | 690 | bitmap_set_bit (interesting_blocks, bb->index); |
ddb555ed JJ |
691 | return; |
692 | } | |
b5b8b0ac | 693 | |
7256233c DN |
694 | /* If a variable is used before being set, then the variable is live |
695 | across a block boundary, so mark it live-on-entry to BB. */ | |
39c58b3a | 696 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES) |
7256233c | 697 | { |
0bca51f0 | 698 | tree sym = USE_FROM_PTR (use_p); |
4ad14919 | 699 | gcc_checking_assert (DECL_P (sym)); |
a3648cfc | 700 | if (!bitmap_bit_p (kills, DECL_UID (sym))) |
0bca51f0 | 701 | set_livein_block (sym, bb); |
726a989a | 702 | set_rewrite_uses (stmt, true); |
7256233c | 703 | } |
b8698a0f | 704 | |
38635499 DN |
705 | /* Now process the defs. Mark BB as the definition block and add |
706 | each def to the set of killed symbols. */ | |
39c58b3a | 707 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
7256233c | 708 | { |
4ad14919 | 709 | gcc_checking_assert (DECL_P (def)); |
0bca51f0 | 710 | set_def_block (def, bb, false); |
a3648cfc | 711 | bitmap_set_bit (kills, DECL_UID (def)); |
726a989a | 712 | set_register_defs (stmt, true); |
7256233c | 713 | } |
0bca51f0 DN |
714 | |
715 | /* If we found the statement interesting then also mark the block BB | |
716 | as interesting. */ | |
726a989a | 717 | if (rewrite_uses_p (stmt) || register_defs_p (stmt)) |
d7c028c0 | 718 | bitmap_set_bit (interesting_blocks, bb->index); |
7256233c DN |
719 | } |
720 | ||
f074ff6c ZD |
721 | /* Structure used by prune_unused_phi_nodes to record bounds of the intervals |
722 | in the dfs numbering of the dominance tree. */ | |
723 | ||
724 | struct dom_dfsnum | |
725 | { | |
726 | /* Basic block whose index this entry corresponds to. */ | |
727 | unsigned bb_index; | |
728 | ||
729 | /* The dfs number of this node. */ | |
730 | unsigned dfs_num; | |
731 | }; | |
732 | ||
733 | /* Compares two entries of type struct dom_dfsnum by dfs_num field. Callback | |
734 | for qsort. */ | |
735 | ||
736 | static int | |
737 | cmp_dfsnum (const void *a, const void *b) | |
738 | { | |
3d9a9f94 KG |
739 | const struct dom_dfsnum *const da = (const struct dom_dfsnum *) a; |
740 | const struct dom_dfsnum *const db = (const struct dom_dfsnum *) b; | |
f074ff6c ZD |
741 | |
742 | return (int) da->dfs_num - (int) db->dfs_num; | |
743 | } | |
744 | ||
745 | /* Among the intervals starting at the N points specified in DEFS, find | |
746 | the one that contains S, and return its bb_index. */ | |
747 | ||
748 | static unsigned | |
749 | find_dfsnum_interval (struct dom_dfsnum *defs, unsigned n, unsigned s) | |
750 | { | |
751 | unsigned f = 0, t = n, m; | |
752 | ||
753 | while (t > f + 1) | |
754 | { | |
755 | m = (f + t) / 2; | |
756 | if (defs[m].dfs_num <= s) | |
757 | f = m; | |
758 | else | |
759 | t = m; | |
760 | } | |
761 | ||
762 | return defs[f].bb_index; | |
763 | } | |
764 | ||
765 | /* Clean bits from PHIS for phi nodes whose value cannot be used in USES. | |
766 | KILLS is a bitmap of blocks where the value is defined before any use. */ | |
767 | ||
768 | static void | |
769 | prune_unused_phi_nodes (bitmap phis, bitmap kills, bitmap uses) | |
770 | { | |
f074ff6c ZD |
771 | bitmap_iterator bi; |
772 | unsigned i, b, p, u, top; | |
773 | bitmap live_phis; | |
774 | basic_block def_bb, use_bb; | |
775 | edge e; | |
776 | edge_iterator ei; | |
777 | bitmap to_remove; | |
778 | struct dom_dfsnum *defs; | |
779 | unsigned n_defs, adef; | |
780 | ||
781 | if (bitmap_empty_p (uses)) | |
782 | { | |
783 | bitmap_clear (phis); | |
784 | return; | |
785 | } | |
786 | ||
787 | /* The phi must dominate a use, or an argument of a live phi. Also, we | |
788 | do not create any phi nodes in def blocks, unless they are also livein. */ | |
789 | to_remove = BITMAP_ALLOC (NULL); | |
790 | bitmap_and_compl (to_remove, kills, uses); | |
791 | bitmap_and_compl_into (phis, to_remove); | |
792 | if (bitmap_empty_p (phis)) | |
793 | { | |
794 | BITMAP_FREE (to_remove); | |
795 | return; | |
796 | } | |
797 | ||
798 | /* We want to remove the unnecessary phi nodes, but we do not want to compute | |
799 | liveness information, as that may be linear in the size of CFG, and if | |
800 | there are lot of different variables to rewrite, this may lead to quadratic | |
801 | behavior. | |
802 | ||
803 | Instead, we basically emulate standard dce. We put all uses to worklist, | |
804 | then for each of them find the nearest def that dominates them. If this | |
805 | def is a phi node, we mark it live, and if it was not live before, we | |
806 | add the predecessors of its basic block to the worklist. | |
b8698a0f | 807 | |
f074ff6c ZD |
808 | To quickly locate the nearest def that dominates use, we use dfs numbering |
809 | of the dominance tree (that is already available in order to speed up | |
810 | queries). For each def, we have the interval given by the dfs number on | |
811 | entry to and on exit from the corresponding subtree in the dominance tree. | |
812 | The nearest dominator for a given use is the smallest of these intervals | |
813 | that contains entry and exit dfs numbers for the basic block with the use. | |
814 | If we store the bounds for all the uses to an array and sort it, we can | |
815 | locate the nearest dominating def in logarithmic time by binary search.*/ | |
816 | bitmap_ior (to_remove, kills, phis); | |
817 | n_defs = bitmap_count_bits (to_remove); | |
818 | defs = XNEWVEC (struct dom_dfsnum, 2 * n_defs + 1); | |
819 | defs[0].bb_index = 1; | |
820 | defs[0].dfs_num = 0; | |
821 | adef = 1; | |
822 | EXECUTE_IF_SET_IN_BITMAP (to_remove, 0, i, bi) | |
823 | { | |
06e28de2 | 824 | def_bb = BASIC_BLOCK_FOR_FN (cfun, i); |
f074ff6c ZD |
825 | defs[adef].bb_index = i; |
826 | defs[adef].dfs_num = bb_dom_dfs_in (CDI_DOMINATORS, def_bb); | |
827 | defs[adef + 1].bb_index = i; | |
828 | defs[adef + 1].dfs_num = bb_dom_dfs_out (CDI_DOMINATORS, def_bb); | |
829 | adef += 2; | |
830 | } | |
831 | BITMAP_FREE (to_remove); | |
832 | gcc_assert (adef == 2 * n_defs + 1); | |
833 | qsort (defs, adef, sizeof (struct dom_dfsnum), cmp_dfsnum); | |
834 | gcc_assert (defs[0].bb_index == 1); | |
835 | ||
836 | /* Now each DEFS entry contains the number of the basic block to that the | |
837 | dfs number corresponds. Change them to the number of basic block that | |
838 | corresponds to the interval following the dfs number. Also, for the | |
839 | dfs_out numbers, increase the dfs number by one (so that it corresponds | |
840 | to the start of the following interval, not to the end of the current | |
841 | one). We use WORKLIST as a stack. */ | |
ef062b13 | 842 | auto_vec<int> worklist (n_defs + 1); |
9771b263 | 843 | worklist.quick_push (1); |
f074ff6c ZD |
844 | top = 1; |
845 | n_defs = 1; | |
846 | for (i = 1; i < adef; i++) | |
847 | { | |
848 | b = defs[i].bb_index; | |
849 | if (b == top) | |
850 | { | |
851 | /* This is a closing element. Interval corresponding to the top | |
852 | of the stack after removing it follows. */ | |
9771b263 DN |
853 | worklist.pop (); |
854 | top = worklist[worklist.length () - 1]; | |
f074ff6c ZD |
855 | defs[n_defs].bb_index = top; |
856 | defs[n_defs].dfs_num = defs[i].dfs_num + 1; | |
857 | } | |
858 | else | |
859 | { | |
860 | /* Opening element. Nothing to do, just push it to the stack and move | |
861 | it to the correct position. */ | |
862 | defs[n_defs].bb_index = defs[i].bb_index; | |
863 | defs[n_defs].dfs_num = defs[i].dfs_num; | |
9771b263 | 864 | worklist.quick_push (b); |
f074ff6c ZD |
865 | top = b; |
866 | } | |
867 | ||
868 | /* If this interval starts at the same point as the previous one, cancel | |
869 | the previous one. */ | |
870 | if (defs[n_defs].dfs_num == defs[n_defs - 1].dfs_num) | |
871 | defs[n_defs - 1].bb_index = defs[n_defs].bb_index; | |
872 | else | |
873 | n_defs++; | |
874 | } | |
9771b263 DN |
875 | worklist.pop (); |
876 | gcc_assert (worklist.is_empty ()); | |
f074ff6c ZD |
877 | |
878 | /* Now process the uses. */ | |
879 | live_phis = BITMAP_ALLOC (NULL); | |
880 | EXECUTE_IF_SET_IN_BITMAP (uses, 0, i, bi) | |
881 | { | |
9771b263 | 882 | worklist.safe_push (i); |
f074ff6c ZD |
883 | } |
884 | ||
9771b263 | 885 | while (!worklist.is_empty ()) |
f074ff6c | 886 | { |
9771b263 | 887 | b = worklist.pop (); |
f074ff6c ZD |
888 | if (b == ENTRY_BLOCK) |
889 | continue; | |
890 | ||
891 | /* If there is a phi node in USE_BB, it is made live. Otherwise, | |
892 | find the def that dominates the immediate dominator of USE_BB | |
893 | (the kill in USE_BB does not dominate the use). */ | |
894 | if (bitmap_bit_p (phis, b)) | |
895 | p = b; | |
896 | else | |
897 | { | |
06e28de2 DM |
898 | use_bb = get_immediate_dominator (CDI_DOMINATORS, |
899 | BASIC_BLOCK_FOR_FN (cfun, b)); | |
f074ff6c ZD |
900 | p = find_dfsnum_interval (defs, n_defs, |
901 | bb_dom_dfs_in (CDI_DOMINATORS, use_bb)); | |
902 | if (!bitmap_bit_p (phis, p)) | |
903 | continue; | |
904 | } | |
905 | ||
906 | /* If the phi node is already live, there is nothing to do. */ | |
fcaa4ca4 | 907 | if (!bitmap_set_bit (live_phis, p)) |
f074ff6c ZD |
908 | continue; |
909 | ||
fcaa4ca4 | 910 | /* Add the new uses to the worklist. */ |
06e28de2 | 911 | def_bb = BASIC_BLOCK_FOR_FN (cfun, p); |
f074ff6c ZD |
912 | FOR_EACH_EDGE (e, ei, def_bb->preds) |
913 | { | |
914 | u = e->src->index; | |
915 | if (bitmap_bit_p (uses, u)) | |
916 | continue; | |
917 | ||
1e5787ef ZD |
918 | /* In case there is a kill directly in the use block, do not record |
919 | the use (this is also necessary for correctness, as we assume that | |
920 | uses dominated by a def directly in their block have been filtered | |
921 | out before). */ | |
922 | if (bitmap_bit_p (kills, u)) | |
923 | continue; | |
924 | ||
f074ff6c | 925 | bitmap_set_bit (uses, u); |
9771b263 | 926 | worklist.safe_push (u); |
f074ff6c ZD |
927 | } |
928 | } | |
929 | ||
f074ff6c ZD |
930 | bitmap_copy (phis, live_phis); |
931 | BITMAP_FREE (live_phis); | |
932 | free (defs); | |
933 | } | |
7256233c | 934 | |
7256233c DN |
935 | /* Return the set of blocks where variable VAR is defined and the blocks |
936 | where VAR is live on entry (livein). Return NULL, if no entry is | |
937 | found in DEF_BLOCKS. */ | |
938 | ||
939 | static inline struct def_blocks_d * | |
940 | find_def_blocks_for (tree var) | |
941 | { | |
8812aab1 | 942 | def_blocks_p p = &get_common_info (var)->def_blocks; |
b4e209fd RG |
943 | if (!p->def_blocks) |
944 | return NULL; | |
945 | return p; | |
7256233c DN |
946 | } |
947 | ||
948 | ||
2ce79879 ZD |
949 | /* Marks phi node PHI in basic block BB for rewrite. */ |
950 | ||
951 | static void | |
726a989a | 952 | mark_phi_for_rewrite (basic_block bb, gimple phi) |
2ce79879 | 953 | { |
726a989a | 954 | gimple_vec phis; |
580b2c2e | 955 | unsigned n, idx = bb->index; |
2ce79879 | 956 | |
726a989a | 957 | if (rewrite_uses_p (phi)) |
2ce79879 | 958 | return; |
38635499 | 959 | |
726a989a | 960 | set_rewrite_uses (phi, true); |
2ce79879 ZD |
961 | |
962 | if (!blocks_with_phis_to_rewrite) | |
963 | return; | |
964 | ||
965 | bitmap_set_bit (blocks_with_phis_to_rewrite, idx); | |
580b2c2e | 966 | |
8b1c6fd7 | 967 | n = (unsigned) last_basic_block_for_fn (cfun) + 1; |
9771b263 DN |
968 | if (phis_to_rewrite.length () < n) |
969 | phis_to_rewrite.safe_grow_cleared (n); | |
2ce79879 | 970 | |
9771b263 DN |
971 | phis = phis_to_rewrite[idx]; |
972 | phis.reserve (10); | |
2ce79879 | 973 | |
9771b263 DN |
974 | phis.safe_push (phi); |
975 | phis_to_rewrite[idx] = phis; | |
2ce79879 ZD |
976 | } |
977 | ||
7256233c | 978 | /* Insert PHI nodes for variable VAR using the iterated dominance |
0bca51f0 | 979 | frontier given in PHI_INSERTION_POINTS. If UPDATE_P is true, this |
38635499 DN |
980 | function assumes that the caller is incrementally updating the |
981 | existing SSA form, in which case VAR may be an SSA name instead of | |
982 | a symbol. | |
0bca51f0 DN |
983 | |
984 | PHI_INSERTION_POINTS is updated to reflect nodes that already had a | |
985 | PHI node for VAR. On exit, only the nodes that received a PHI node | |
986 | for VAR will be present in PHI_INSERTION_POINTS. */ | |
7256233c DN |
987 | |
988 | static void | |
0bca51f0 | 989 | insert_phi_nodes_for (tree var, bitmap phi_insertion_points, bool update_p) |
7256233c DN |
990 | { |
991 | unsigned bb_index; | |
992 | edge e; | |
726a989a | 993 | gimple phi; |
7256233c DN |
994 | basic_block bb; |
995 | bitmap_iterator bi; | |
4ad14919 | 996 | struct def_blocks_d *def_map = find_def_blocks_for (var); |
7256233c DN |
997 | |
998 | /* Remove the blocks where we already have PHI nodes for VAR. */ | |
999 | bitmap_and_compl_into (phi_insertion_points, def_map->phi_blocks); | |
1000 | ||
f074ff6c ZD |
1001 | /* Remove obviously useless phi nodes. */ |
1002 | prune_unused_phi_nodes (phi_insertion_points, def_map->def_blocks, | |
1003 | def_map->livein_blocks); | |
7256233c DN |
1004 | |
1005 | /* And insert the PHI nodes. */ | |
f074ff6c | 1006 | EXECUTE_IF_SET_IN_BITMAP (phi_insertion_points, 0, bb_index, bi) |
7256233c | 1007 | { |
06e28de2 | 1008 | bb = BASIC_BLOCK_FOR_FN (cfun, bb_index); |
95dd3097 ZD |
1009 | if (update_p) |
1010 | mark_block_for_update (bb); | |
7256233c | 1011 | |
fa5556de RB |
1012 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1013 | { | |
1014 | fprintf (dump_file, "creating PHI node in block #%d for ", bb_index); | |
1015 | print_generic_expr (dump_file, var, TDF_SLIM); | |
1016 | fprintf (dump_file, "\n"); | |
1017 | } | |
726a989a | 1018 | phi = NULL; |
38635499 DN |
1019 | |
1020 | if (TREE_CODE (var) == SSA_NAME) | |
7256233c | 1021 | { |
84d65814 DN |
1022 | /* If we are rewriting SSA names, create the LHS of the PHI |
1023 | node by duplicating VAR. This is useful in the case of | |
1024 | pointers, to also duplicate pointer attributes (alias | |
1025 | information, in particular). */ | |
7256233c | 1026 | edge_iterator ei; |
84d65814 | 1027 | tree new_lhs; |
0bca51f0 | 1028 | |
4ad14919 | 1029 | gcc_checking_assert (update_p); |
dcc748dd RG |
1030 | new_lhs = duplicate_ssa_name (var, NULL); |
1031 | phi = create_phi_node (new_lhs, bb); | |
84d65814 | 1032 | add_new_name_mapping (new_lhs, var); |
0bca51f0 DN |
1033 | |
1034 | /* Add VAR to every argument slot of PHI. We need VAR in | |
1035 | every argument so that rewrite_update_phi_arguments knows | |
1036 | which name is this PHI node replacing. If VAR is a | |
1037 | symbol marked for renaming, this is not necessary, the | |
1038 | renamer will use the symbol on the LHS to get its | |
1039 | reaching definition. */ | |
7256233c | 1040 | FOR_EACH_EDGE (e, ei, bb->preds) |
9e227d60 | 1041 | add_phi_arg (phi, var, e, UNKNOWN_LOCATION); |
7256233c | 1042 | } |
84d65814 DN |
1043 | else |
1044 | { | |
b5b8b0ac | 1045 | tree tracked_var; |
3a56edc7 | 1046 | |
4ad14919 | 1047 | gcc_checking_assert (DECL_P (var)); |
e24c4814 | 1048 | phi = create_phi_node (var, bb); |
3a56edc7 AO |
1049 | |
1050 | tracked_var = target_for_debug_bind (var); | |
1051 | if (tracked_var) | |
b5b8b0ac AO |
1052 | { |
1053 | gimple note = gimple_build_debug_bind (tracked_var, | |
1054 | PHI_RESULT (phi), | |
1055 | phi); | |
1056 | gimple_stmt_iterator si = gsi_after_labels (bb); | |
1057 | gsi_insert_before (&si, note, GSI_SAME_STMT); | |
1058 | } | |
84d65814 | 1059 | } |
0bca51f0 DN |
1060 | |
1061 | /* Mark this PHI node as interesting for update_ssa. */ | |
726a989a | 1062 | set_register_defs (phi, true); |
2ce79879 | 1063 | mark_phi_for_rewrite (bb, phi); |
7256233c DN |
1064 | } |
1065 | } | |
1066 | ||
b4e209fd | 1067 | /* Sort var_infos after DECL_UID of their var. */ |
d9ed2fbd RG |
1068 | |
1069 | static int | |
b4e209fd | 1070 | insert_phi_nodes_compare_var_infos (const void *a, const void *b) |
d9ed2fbd | 1071 | { |
b4e209fd RG |
1072 | const struct var_info_d *defa = *(struct var_info_d * const *)a; |
1073 | const struct var_info_d *defb = *(struct var_info_d * const *)b; | |
d9ed2fbd RG |
1074 | if (DECL_UID (defa->var) < DECL_UID (defb->var)) |
1075 | return -1; | |
1076 | else | |
1077 | return 1; | |
1078 | } | |
7256233c | 1079 | |
7256233c DN |
1080 | /* Insert PHI nodes at the dominance frontier of blocks with variable |
1081 | definitions. DFS contains the dominance frontier information for | |
38635499 | 1082 | the flowgraph. */ |
7256233c DN |
1083 | |
1084 | static void | |
0fc555fb | 1085 | insert_phi_nodes (bitmap_head *dfs) |
7256233c | 1086 | { |
c203e8a7 | 1087 | hash_table<var_info_hasher>::iterator hi; |
d9ed2fbd | 1088 | unsigned i; |
b4e209fd | 1089 | var_info_p info; |
7256233c DN |
1090 | |
1091 | timevar_push (TV_TREE_INSERT_PHI_NODES); | |
b8698a0f | 1092 | |
c203e8a7 TS |
1093 | auto_vec<var_info_p> vars (var_infos->elements ()); |
1094 | FOR_EACH_HASH_TABLE_ELEMENT (*var_infos, info, var_info_p, hi) | |
8812aab1 | 1095 | if (info->info.need_phi_state != NEED_PHI_STATE_NO) |
9771b263 | 1096 | vars.quick_push (info); |
d9ed2fbd | 1097 | |
e68c7b43 RG |
1098 | /* Do two stages to avoid code generation differences for UID |
1099 | differences but no UID ordering differences. */ | |
9771b263 | 1100 | vars.qsort (insert_phi_nodes_compare_var_infos); |
e68c7b43 | 1101 | |
9771b263 | 1102 | FOR_EACH_VEC_ELT (vars, i, info) |
5f240ec4 | 1103 | { |
8812aab1 | 1104 | bitmap idf = compute_idf (info->info.def_blocks.def_blocks, dfs); |
b4e209fd | 1105 | insert_phi_nodes_for (info->var, idf, false); |
e68c7b43 RG |
1106 | BITMAP_FREE (idf); |
1107 | } | |
1108 | ||
6de9cd9a DN |
1109 | timevar_pop (TV_TREE_INSERT_PHI_NODES); |
1110 | } | |
1111 | ||
1112 | ||
38635499 DN |
1113 | /* Push SYM's current reaching definition into BLOCK_DEFS_STACK and |
1114 | register DEF (an SSA_NAME) to be a new definition for SYM. */ | |
7256233c | 1115 | |
cfaab3a9 | 1116 | static void |
38635499 | 1117 | register_new_def (tree def, tree sym) |
7256233c | 1118 | { |
8812aab1 | 1119 | common_info_p info = get_common_info (sym); |
7256233c | 1120 | tree currdef; |
b8698a0f | 1121 | |
7256233c DN |
1122 | /* If this variable is set in a single basic block and all uses are |
1123 | dominated by the set(s) in that single basic block, then there is | |
1124 | no reason to record anything for this variable in the block local | |
1125 | definition stacks. Doing so just wastes time and memory. | |
1126 | ||
1127 | This is the same test to prune the set of variables which may | |
1128 | need PHI nodes. So we just use that information since it's already | |
1129 | computed and available for us to use. */ | |
8812aab1 | 1130 | if (info->need_phi_state == NEED_PHI_STATE_NO) |
7256233c | 1131 | { |
8812aab1 | 1132 | info->current_def = def; |
7256233c DN |
1133 | return; |
1134 | } | |
1135 | ||
8812aab1 | 1136 | currdef = info->current_def; |
7256233c | 1137 | |
38635499 DN |
1138 | /* If SYM is not a GIMPLE register, then CURRDEF may be a name whose |
1139 | SSA_NAME_VAR is not necessarily SYM. In this case, also push SYM | |
1140 | in the stack so that we know which symbol is being defined by | |
1141 | this SSA name when we unwind the stack. */ | |
1142 | if (currdef && !is_gimple_reg (sym)) | |
9771b263 | 1143 | block_defs_stack.safe_push (sym); |
7256233c | 1144 | |
38635499 DN |
1145 | /* Push the current reaching definition into BLOCK_DEFS_STACK. This |
1146 | stack is later used by the dominator tree callbacks to restore | |
1147 | the reaching definitions for all the variables defined in the | |
1148 | block after a recursive visit to all its immediately dominated | |
1149 | blocks. If there is no current reaching definition, then just | |
1150 | record the underlying _DECL node. */ | |
9771b263 | 1151 | block_defs_stack.safe_push (currdef ? currdef : sym); |
38635499 DN |
1152 | |
1153 | /* Set the current reaching definition for SYM to be DEF. */ | |
8812aab1 | 1154 | info->current_def = def; |
7256233c DN |
1155 | } |
1156 | ||
1157 | ||
6de9cd9a DN |
1158 | /* Perform a depth-first traversal of the dominator tree looking for |
1159 | variables to rename. BB is the block where to start searching. | |
1160 | Renaming is a five step process: | |
1161 | ||
1162 | 1- Every definition made by PHI nodes at the start of the blocks is | |
1163 | registered as the current definition for the corresponding variable. | |
1164 | ||
1165 | 2- Every statement in BB is rewritten. USE and VUSE operands are | |
1166 | rewritten with their corresponding reaching definition. DEF and | |
1167 | VDEF targets are registered as new definitions. | |
b8698a0f | 1168 | |
6de9cd9a DN |
1169 | 3- All the PHI nodes in successor blocks of BB are visited. The |
1170 | argument corresponding to BB is replaced with its current reaching | |
1171 | definition. | |
1172 | ||
1173 | 4- Recursively rewrite every dominator child block of BB. | |
1174 | ||
1175 | 5- Restore (in reverse order) the current reaching definition for every | |
1176 | new definition introduced in this block. This is done so that when | |
1177 | we return from the recursive call, all the current reaching | |
1178 | definitions are restored to the names that were valid in the | |
1179 | dominator parent of BB. */ | |
1180 | ||
7256233c | 1181 | /* Return the current definition for variable VAR. If none is found, |
38635499 | 1182 | create a new SSA name to act as the zeroth definition for VAR. */ |
5f240ec4 | 1183 | |
7256233c DN |
1184 | static tree |
1185 | get_reaching_def (tree var) | |
1186 | { | |
8812aab1 | 1187 | common_info_p info = get_common_info (var); |
38635499 | 1188 | tree currdef; |
b8698a0f | 1189 | |
7256233c | 1190 | /* Lookup the current reaching definition for VAR. */ |
8812aab1 | 1191 | currdef = info->current_def; |
5f240ec4 | 1192 | |
7256233c DN |
1193 | /* If there is no reaching definition for VAR, create and register a |
1194 | default definition for it (if needed). */ | |
38635499 | 1195 | if (currdef == NULL_TREE) |
7256233c | 1196 | { |
38635499 | 1197 | tree sym = DECL_P (var) ? var : SSA_NAME_VAR (var); |
32244553 | 1198 | currdef = get_or_create_ssa_default_def (cfun, sym); |
7256233c DN |
1199 | } |
1200 | ||
1201 | /* Return the current reaching definition for VAR, or the default | |
1202 | definition, if we had to create one. */ | |
38635499 | 1203 | return currdef; |
7256233c DN |
1204 | } |
1205 | ||
1206 | ||
ddb555ed JJ |
1207 | /* Helper function for rewrite_stmt. Rewrite uses in a debug stmt. */ |
1208 | ||
1209 | static void | |
1210 | rewrite_debug_stmt_uses (gimple stmt) | |
1211 | { | |
1212 | use_operand_p use_p; | |
1213 | ssa_op_iter iter; | |
1214 | bool update = false; | |
1215 | ||
1216 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) | |
1217 | { | |
5f564b8f | 1218 | tree var = USE_FROM_PTR (use_p), def; |
8812aab1 | 1219 | common_info_p info = get_common_info (var); |
4ad14919 | 1220 | gcc_checking_assert (DECL_P (var)); |
8812aab1 | 1221 | def = info->current_def; |
5f564b8f | 1222 | if (!def) |
ddb555ed | 1223 | { |
fefa31b5 DM |
1224 | if (TREE_CODE (var) == PARM_DECL |
1225 | && single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun))) | |
ddb555ed JJ |
1226 | { |
1227 | gimple_stmt_iterator gsi | |
fefa31b5 DM |
1228 | = |
1229 | gsi_after_labels (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun))); | |
ddb555ed JJ |
1230 | int lim; |
1231 | /* Search a few source bind stmts at the start of first bb to | |
1232 | see if a DEBUG_EXPR_DECL can't be reused. */ | |
1233 | for (lim = 32; | |
1234 | !gsi_end_p (gsi) && lim > 0; | |
1235 | gsi_next (&gsi), lim--) | |
1236 | { | |
1237 | gimple gstmt = gsi_stmt (gsi); | |
1238 | if (!gimple_debug_source_bind_p (gstmt)) | |
1239 | break; | |
1240 | if (gimple_debug_source_bind_get_value (gstmt) == var) | |
1241 | { | |
1242 | def = gimple_debug_source_bind_get_var (gstmt); | |
1243 | if (TREE_CODE (def) == DEBUG_EXPR_DECL) | |
1244 | break; | |
1245 | else | |
1246 | def = NULL_TREE; | |
1247 | } | |
1248 | } | |
1249 | /* If not, add a new source bind stmt. */ | |
1250 | if (def == NULL_TREE) | |
1251 | { | |
1252 | gimple def_temp; | |
1253 | def = make_node (DEBUG_EXPR_DECL); | |
1254 | def_temp = gimple_build_debug_source_bind (def, var, NULL); | |
1255 | DECL_ARTIFICIAL (def) = 1; | |
1256 | TREE_TYPE (def) = TREE_TYPE (var); | |
1257 | DECL_MODE (def) = DECL_MODE (var); | |
fefa31b5 DM |
1258 | gsi = |
1259 | gsi_after_labels (single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun))); | |
ddb555ed JJ |
1260 | gsi_insert_before (&gsi, def_temp, GSI_SAME_STMT); |
1261 | } | |
1262 | update = true; | |
1263 | } | |
1264 | } | |
1265 | else | |
15923c25 | 1266 | { |
8812aab1 | 1267 | /* Check if info->current_def can be trusted. */ |
5f564b8f MM |
1268 | basic_block bb = gimple_bb (stmt); |
1269 | basic_block def_bb | |
1270 | = SSA_NAME_IS_DEFAULT_DEF (def) | |
1271 | ? NULL : gimple_bb (SSA_NAME_DEF_STMT (def)); | |
1272 | ||
1273 | /* If definition is in current bb, it is fine. */ | |
1274 | if (bb == def_bb) | |
1275 | ; | |
1276 | /* If definition bb doesn't dominate the current bb, | |
1277 | it can't be used. */ | |
1278 | else if (def_bb && !dominated_by_p (CDI_DOMINATORS, bb, def_bb)) | |
1279 | def = NULL; | |
1280 | /* If there is just one definition and dominates the current | |
1281 | bb, it is fine. */ | |
8812aab1 | 1282 | else if (info->need_phi_state == NEED_PHI_STATE_NO) |
5f564b8f MM |
1283 | ; |
1284 | else | |
15923c25 | 1285 | { |
8812aab1 | 1286 | struct def_blocks_d *db_p = get_def_blocks_for (info); |
15923c25 | 1287 | |
5f564b8f MM |
1288 | /* If there are some non-debug uses in the current bb, |
1289 | it is fine. */ | |
1290 | if (bitmap_bit_p (db_p->livein_blocks, bb->index)) | |
15923c25 | 1291 | ; |
5f564b8f | 1292 | /* Otherwise give up for now. */ |
15923c25 | 1293 | else |
5f564b8f | 1294 | def = NULL; |
15923c25 JJ |
1295 | } |
1296 | } | |
ddb555ed JJ |
1297 | if (def == NULL) |
1298 | { | |
1299 | gimple_debug_bind_reset_value (stmt); | |
1300 | update_stmt (stmt); | |
1301 | return; | |
1302 | } | |
1303 | SET_USE (use_p, def); | |
1304 | } | |
1305 | if (update) | |
1306 | update_stmt (stmt); | |
1307 | } | |
1308 | ||
7256233c DN |
1309 | /* SSA Rewriting Step 2. Rewrite every variable used in each statement in |
1310 | the block with its immediate reaching definitions. Update the current | |
1311 | definition of a variable when a new real or virtual definition is found. */ | |
5f240ec4 ZD |
1312 | |
1313 | static void | |
5f33a4fc | 1314 | rewrite_stmt (gimple_stmt_iterator *si) |
5f240ec4 | 1315 | { |
7256233c DN |
1316 | use_operand_p use_p; |
1317 | def_operand_p def_p; | |
1318 | ssa_op_iter iter; | |
5f33a4fc | 1319 | gimple stmt = gsi_stmt (*si); |
7256233c | 1320 | |
7256233c DN |
1321 | /* If mark_def_sites decided that we don't need to rewrite this |
1322 | statement, ignore it. */ | |
95dd3097 | 1323 | gcc_assert (blocks_to_update == NULL); |
726a989a | 1324 | if (!rewrite_uses_p (stmt) && !register_defs_p (stmt)) |
7256233c | 1325 | return; |
5f240ec4 ZD |
1326 | |
1327 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
7256233c DN |
1328 | { |
1329 | fprintf (dump_file, "Renaming statement "); | |
726a989a | 1330 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
7256233c DN |
1331 | fprintf (dump_file, "\n"); |
1332 | } | |
5f240ec4 | 1333 | |
38635499 | 1334 | /* Step 1. Rewrite USES in the statement. */ |
726a989a | 1335 | if (rewrite_uses_p (stmt)) |
ddb555ed JJ |
1336 | { |
1337 | if (is_gimple_debug (stmt)) | |
1338 | rewrite_debug_stmt_uses (stmt); | |
1339 | else | |
39c58b3a | 1340 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES) |
ddb555ed JJ |
1341 | { |
1342 | tree var = USE_FROM_PTR (use_p); | |
4ad14919 | 1343 | gcc_checking_assert (DECL_P (var)); |
ddb555ed JJ |
1344 | SET_USE (use_p, get_reaching_def (var)); |
1345 | } | |
1346 | } | |
5f240ec4 | 1347 | |
38635499 | 1348 | /* Step 2. Register the statement's DEF operands. */ |
726a989a | 1349 | if (register_defs_p (stmt)) |
39c58b3a | 1350 | FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, iter, SSA_OP_ALL_DEFS) |
0bca51f0 DN |
1351 | { |
1352 | tree var = DEF_FROM_PTR (def_p); | |
5f33a4fc | 1353 | tree name; |
b5b8b0ac | 1354 | tree tracked_var; |
5f33a4fc | 1355 | |
4ad14919 | 1356 | gcc_checking_assert (DECL_P (var)); |
5f33a4fc RG |
1357 | |
1358 | if (gimple_clobber_p (stmt) | |
1359 | && is_gimple_reg (var)) | |
1360 | { | |
1361 | /* If we rewrite a DECL into SSA form then drop its | |
1362 | clobber stmts and replace uses with a new default def. */ | |
4ad14919 RG |
1363 | gcc_checking_assert (TREE_CODE (var) == VAR_DECL |
1364 | && !gimple_vdef (stmt)); | |
5f33a4fc RG |
1365 | gsi_replace (si, gimple_build_nop (), true); |
1366 | register_new_def (get_or_create_ssa_default_def (cfun, var), var); | |
1367 | break; | |
1368 | } | |
1369 | ||
1370 | name = make_ssa_name (var, stmt); | |
b5b8b0ac | 1371 | SET_DEF (def_p, name); |
38635499 | 1372 | register_new_def (DEF_FROM_PTR (def_p), var); |
b5b8b0ac AO |
1373 | |
1374 | tracked_var = target_for_debug_bind (var); | |
1375 | if (tracked_var) | |
1376 | { | |
1377 | gimple note = gimple_build_debug_bind (tracked_var, name, stmt); | |
5f33a4fc | 1378 | gsi_insert_after (si, note, GSI_SAME_STMT); |
b5b8b0ac | 1379 | } |
0bca51f0 | 1380 | } |
5f240ec4 | 1381 | } |
6de9cd9a | 1382 | |
7256233c | 1383 | |
6de9cd9a DN |
1384 | /* SSA Rewriting Step 3. Visit all the successor blocks of BB looking for |
1385 | PHI nodes. For every PHI node found, add a new argument containing the | |
1386 | current reaching definition for the variable and the edge through which | |
471854f8 | 1387 | that definition is reaching the PHI node. */ |
6de9cd9a DN |
1388 | |
1389 | static void | |
ccf5c864 | 1390 | rewrite_add_phi_arguments (basic_block bb) |
6de9cd9a DN |
1391 | { |
1392 | edge e; | |
628f6a4e | 1393 | edge_iterator ei; |
6de9cd9a | 1394 | |
628f6a4e | 1395 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a | 1396 | { |
726a989a RB |
1397 | gimple phi; |
1398 | gimple_stmt_iterator gsi; | |
6de9cd9a | 1399 | |
726a989a RB |
1400 | for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi); |
1401 | gsi_next (&gsi)) | |
6de9cd9a | 1402 | { |
ffc5b2bb RB |
1403 | tree currdef, res; |
1404 | location_t loc; | |
f5045c96 | 1405 | |
726a989a | 1406 | phi = gsi_stmt (gsi); |
ffc5b2bb RB |
1407 | res = gimple_phi_result (phi); |
1408 | currdef = get_reaching_def (SSA_NAME_VAR (res)); | |
1409 | /* Virtual operand PHI args do not need a location. */ | |
1410 | if (virtual_operand_p (res)) | |
1411 | loc = UNKNOWN_LOCATION; | |
1412 | else | |
1413 | loc = gimple_location (SSA_NAME_DEF_STMT (currdef)); | |
1414 | add_phi_arg (phi, currdef, e, loc); | |
6de9cd9a DN |
1415 | } |
1416 | } | |
1417 | } | |
1418 | ||
4d9192b5 TS |
1419 | class rewrite_dom_walker : public dom_walker |
1420 | { | |
1421 | public: | |
1422 | rewrite_dom_walker (cdi_direction direction) : dom_walker (direction) {} | |
1423 | ||
1424 | virtual void before_dom_children (basic_block); | |
1425 | virtual void after_dom_children (basic_block); | |
1426 | }; | |
1427 | ||
ccf5c864 PB |
1428 | /* SSA Rewriting Step 1. Initialization, create a block local stack |
1429 | of reaching definitions for new SSA names produced in this block | |
1430 | (BLOCK_DEFS). Register new definitions for every PHI node in the | |
1431 | block. */ | |
1432 | ||
4d9192b5 TS |
1433 | void |
1434 | rewrite_dom_walker::before_dom_children (basic_block bb) | |
ccf5c864 | 1435 | { |
ccf5c864 PB |
1436 | gimple_stmt_iterator gsi; |
1437 | ||
1438 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1439 | fprintf (dump_file, "\n\nRenaming block #%d\n\n", bb->index); | |
1440 | ||
1441 | /* Mark the unwind point for this block. */ | |
9771b263 | 1442 | block_defs_stack.safe_push (NULL_TREE); |
ccf5c864 PB |
1443 | |
1444 | /* Step 1. Register new definitions for every PHI node in the block. | |
1445 | Conceptually, all the PHI nodes are executed in parallel and each PHI | |
1446 | node introduces a new version for the associated variable. */ | |
1447 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1448 | { | |
39c58b3a | 1449 | tree result = gimple_phi_result (gsi_stmt (gsi)); |
ccf5c864 PB |
1450 | register_new_def (result, SSA_NAME_VAR (result)); |
1451 | } | |
1452 | ||
1453 | /* Step 2. Rewrite every variable used in each statement in the block | |
1454 | with its immediate reaching definitions. Update the current definition | |
1455 | of a variable when a new real or virtual definition is found. */ | |
d7c028c0 | 1456 | if (bitmap_bit_p (interesting_blocks, bb->index)) |
ccf5c864 | 1457 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
5f33a4fc | 1458 | rewrite_stmt (&gsi); |
ccf5c864 PB |
1459 | |
1460 | /* Step 3. Visit all the successor blocks of BB looking for PHI nodes. | |
1461 | For every PHI node found, add a new argument containing the current | |
1462 | reaching definition for the variable and the edge through which that | |
1463 | definition is reaching the PHI node. */ | |
1464 | rewrite_add_phi_arguments (bb); | |
1465 | } | |
1466 | ||
1467 | ||
7256233c | 1468 | |
38635499 DN |
1469 | /* Called after visiting all the statements in basic block BB and all |
1470 | of its dominator children. Restore CURRDEFS to its original value. */ | |
6de9cd9a | 1471 | |
4d9192b5 TS |
1472 | void |
1473 | rewrite_dom_walker::after_dom_children (basic_block bb ATTRIBUTE_UNUSED) | |
6de9cd9a | 1474 | { |
9fae925b | 1475 | /* Restore CURRDEFS to its original state. */ |
9771b263 | 1476 | while (block_defs_stack.length () > 0) |
6de9cd9a | 1477 | { |
9771b263 | 1478 | tree tmp = block_defs_stack.pop (); |
6de9cd9a DN |
1479 | tree saved_def, var; |
1480 | ||
9fae925b JL |
1481 | if (tmp == NULL_TREE) |
1482 | break; | |
1483 | ||
6de9cd9a DN |
1484 | if (TREE_CODE (tmp) == SSA_NAME) |
1485 | { | |
38635499 DN |
1486 | /* If we recorded an SSA_NAME, then make the SSA_NAME the |
1487 | current definition of its underlying variable. Note that | |
1488 | if the SSA_NAME is not for a GIMPLE register, the symbol | |
1489 | being defined is stored in the next slot in the stack. | |
1490 | This mechanism is needed because an SSA name for a | |
1491 | non-register symbol may be the definition for more than | |
1492 | one symbol (e.g., SFTs, aliased variables, etc). */ | |
6de9cd9a DN |
1493 | saved_def = tmp; |
1494 | var = SSA_NAME_VAR (saved_def); | |
38635499 | 1495 | if (!is_gimple_reg (var)) |
9771b263 | 1496 | var = block_defs_stack.pop (); |
6de9cd9a DN |
1497 | } |
1498 | else | |
1499 | { | |
38635499 DN |
1500 | /* If we recorded anything else, it must have been a _DECL |
1501 | node and its current reaching definition must have been | |
1502 | NULL. */ | |
6de9cd9a DN |
1503 | saved_def = NULL; |
1504 | var = tmp; | |
1505 | } | |
b8698a0f | 1506 | |
8812aab1 | 1507 | get_common_info (var)->current_def = saved_def; |
6de9cd9a DN |
1508 | } |
1509 | } | |
1510 | ||
1511 | ||
38635499 DN |
1512 | /* Dump bitmap SET (assumed to contain VAR_DECLs) to FILE. */ |
1513 | ||
24e47c76 | 1514 | DEBUG_FUNCTION void |
38635499 DN |
1515 | debug_decl_set (bitmap set) |
1516 | { | |
1517 | dump_decl_set (stderr, set); | |
5006671f | 1518 | fprintf (stderr, "\n"); |
38635499 DN |
1519 | } |
1520 | ||
1521 | ||
1522 | /* Dump the renaming stack (block_defs_stack) to FILE. Traverse the | |
1523 | stack up to a maximum of N levels. If N is -1, the whole stack is | |
1524 | dumped. New levels are created when the dominator tree traversal | |
1525 | used for renaming enters a new sub-tree. */ | |
1526 | ||
1527 | void | |
1528 | dump_defs_stack (FILE *file, int n) | |
1529 | { | |
1530 | int i, j; | |
1531 | ||
1532 | fprintf (file, "\n\nRenaming stack"); | |
1533 | if (n > 0) | |
1534 | fprintf (file, " (up to %d levels)", n); | |
1535 | fprintf (file, "\n\n"); | |
1536 | ||
1537 | i = 1; | |
1538 | fprintf (file, "Level %d (current level)\n", i); | |
9771b263 | 1539 | for (j = (int) block_defs_stack.length () - 1; j >= 0; j--) |
38635499 DN |
1540 | { |
1541 | tree name, var; | |
b8698a0f | 1542 | |
9771b263 | 1543 | name = block_defs_stack[j]; |
38635499 DN |
1544 | if (name == NULL_TREE) |
1545 | { | |
1546 | i++; | |
1547 | if (n > 0 && i > n) | |
1548 | break; | |
1549 | fprintf (file, "\nLevel %d\n", i); | |
1550 | continue; | |
1551 | } | |
1552 | ||
1553 | if (DECL_P (name)) | |
1554 | { | |
1555 | var = name; | |
1556 | name = NULL_TREE; | |
1557 | } | |
1558 | else | |
1559 | { | |
1560 | var = SSA_NAME_VAR (name); | |
1561 | if (!is_gimple_reg (var)) | |
1562 | { | |
1563 | j--; | |
9771b263 | 1564 | var = block_defs_stack[j]; |
38635499 DN |
1565 | } |
1566 | } | |
1567 | ||
1568 | fprintf (file, " Previous CURRDEF ("); | |
1569 | print_generic_expr (file, var, 0); | |
1570 | fprintf (file, ") = "); | |
1571 | if (name) | |
1572 | print_generic_expr (file, name, 0); | |
1573 | else | |
1574 | fprintf (file, "<NIL>"); | |
1575 | fprintf (file, "\n"); | |
1576 | } | |
1577 | } | |
1578 | ||
1579 | ||
1580 | /* Dump the renaming stack (block_defs_stack) to stderr. Traverse the | |
1581 | stack up to a maximum of N levels. If N is -1, the whole stack is | |
1582 | dumped. New levels are created when the dominator tree traversal | |
1583 | used for renaming enters a new sub-tree. */ | |
1584 | ||
24e47c76 | 1585 | DEBUG_FUNCTION void |
38635499 DN |
1586 | debug_defs_stack (int n) |
1587 | { | |
1588 | dump_defs_stack (stderr, n); | |
1589 | } | |
1590 | ||
1591 | ||
1592 | /* Dump the current reaching definition of every symbol to FILE. */ | |
1593 | ||
1594 | void | |
1595 | dump_currdefs (FILE *file) | |
1596 | { | |
13714310 | 1597 | unsigned i; |
38635499 DN |
1598 | tree var; |
1599 | ||
9771b263 | 1600 | if (symbols_to_rename.is_empty ()) |
13714310 RG |
1601 | return; |
1602 | ||
38635499 | 1603 | fprintf (file, "\n\nCurrent reaching definitions\n\n"); |
9771b263 | 1604 | FOR_EACH_VEC_ELT (symbols_to_rename, i, var) |
13714310 | 1605 | { |
8812aab1 | 1606 | common_info_p info = get_common_info (var); |
13714310 RG |
1607 | fprintf (file, "CURRDEF ("); |
1608 | print_generic_expr (file, var, 0); | |
1609 | fprintf (file, ") = "); | |
8812aab1 RG |
1610 | if (info->current_def) |
1611 | print_generic_expr (file, info->current_def, 0); | |
13714310 RG |
1612 | else |
1613 | fprintf (file, "<NIL>"); | |
1614 | fprintf (file, "\n"); | |
1615 | } | |
38635499 DN |
1616 | } |
1617 | ||
1618 | ||
1619 | /* Dump the current reaching definition of every symbol to stderr. */ | |
1620 | ||
24e47c76 | 1621 | DEBUG_FUNCTION void |
38635499 DN |
1622 | debug_currdefs (void) |
1623 | { | |
1624 | dump_currdefs (stderr); | |
1625 | } | |
1626 | ||
1627 | ||
6de9cd9a DN |
1628 | /* Dump SSA information to FILE. */ |
1629 | ||
1630 | void | |
1631 | dump_tree_ssa (FILE *file) | |
1632 | { | |
6de9cd9a | 1633 | const char *funcname |
673fda6b | 1634 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
6de9cd9a | 1635 | |
38635499 | 1636 | fprintf (file, "SSA renaming information for %s\n\n", funcname); |
6de9cd9a | 1637 | |
b4e209fd | 1638 | dump_var_infos (file); |
38635499 DN |
1639 | dump_defs_stack (file, -1); |
1640 | dump_currdefs (file); | |
1641 | dump_tree_ssa_stats (file); | |
6de9cd9a DN |
1642 | } |
1643 | ||
1644 | ||
1645 | /* Dump SSA information to stderr. */ | |
1646 | ||
24e47c76 | 1647 | DEBUG_FUNCTION void |
6de9cd9a DN |
1648 | debug_tree_ssa (void) |
1649 | { | |
1650 | dump_tree_ssa (stderr); | |
1651 | } | |
1652 | ||
1653 | ||
7256233c DN |
1654 | /* Dump statistics for the hash table HTAB. */ |
1655 | ||
1656 | static void | |
c203e8a7 | 1657 | htab_statistics (FILE *file, const hash_table<var_info_hasher> &htab) |
7256233c DN |
1658 | { |
1659 | fprintf (file, "size %ld, %ld elements, %f collision/search ratio\n", | |
bf190e8d LC |
1660 | (long) htab.size (), |
1661 | (long) htab.elements (), | |
1662 | htab.collisions ()); | |
7256233c DN |
1663 | } |
1664 | ||
1665 | ||
6de9cd9a DN |
1666 | /* Dump SSA statistics on FILE. */ |
1667 | ||
1668 | void | |
1669 | dump_tree_ssa_stats (FILE *file) | |
1670 | { | |
c203e8a7 | 1671 | if (var_infos) |
38635499 | 1672 | { |
b4e209fd RG |
1673 | fprintf (file, "\nHash table statistics:\n"); |
1674 | fprintf (file, " var_infos: "); | |
c203e8a7 | 1675 | htab_statistics (file, *var_infos); |
b4e209fd | 1676 | fprintf (file, "\n"); |
38635499 | 1677 | } |
6de9cd9a DN |
1678 | } |
1679 | ||
1680 | ||
1681 | /* Dump SSA statistics on stderr. */ | |
1682 | ||
24e47c76 | 1683 | DEBUG_FUNCTION void |
6de9cd9a DN |
1684 | debug_tree_ssa_stats (void) |
1685 | { | |
1686 | dump_tree_ssa_stats (stderr); | |
1687 | } | |
1688 | ||
1689 | ||
b4e209fd | 1690 | /* Callback for htab_traverse to dump the VAR_INFOS hash table. */ |
6de9cd9a | 1691 | |
bf190e8d LC |
1692 | int |
1693 | debug_var_infos_r (var_info_d **slot, FILE *file) | |
7256233c | 1694 | { |
bf190e8d | 1695 | struct var_info_d *info = *slot; |
b8698a0f | 1696 | |
38635499 | 1697 | fprintf (file, "VAR: "); |
8812aab1 RG |
1698 | print_generic_expr (file, info->var, dump_flags); |
1699 | bitmap_print (file, info->info.def_blocks.def_blocks, | |
1700 | ", DEF_BLOCKS: { ", "}"); | |
1701 | bitmap_print (file, info->info.def_blocks.livein_blocks, | |
1702 | ", LIVEIN_BLOCKS: { ", "}"); | |
1703 | bitmap_print (file, info->info.def_blocks.phi_blocks, | |
1704 | ", PHI_BLOCKS: { ", "}\n"); | |
6de9cd9a | 1705 | |
7256233c DN |
1706 | return 1; |
1707 | } | |
6de9cd9a | 1708 | |
6de9cd9a | 1709 | |
b4e209fd | 1710 | /* Dump the VAR_INFOS hash table on FILE. */ |
38635499 DN |
1711 | |
1712 | void | |
b4e209fd | 1713 | dump_var_infos (FILE *file) |
38635499 DN |
1714 | { |
1715 | fprintf (file, "\n\nDefinition and live-in blocks:\n\n"); | |
c203e8a7 TS |
1716 | if (var_infos) |
1717 | var_infos->traverse <FILE *, debug_var_infos_r> (file); | |
38635499 DN |
1718 | } |
1719 | ||
1720 | ||
b4e209fd | 1721 | /* Dump the VAR_INFOS hash table on stderr. */ |
6de9cd9a | 1722 | |
24e47c76 | 1723 | DEBUG_FUNCTION void |
b4e209fd | 1724 | debug_var_infos (void) |
7256233c | 1725 | { |
b4e209fd | 1726 | dump_var_infos (stderr); |
7256233c | 1727 | } |
6de9cd9a | 1728 | |
5f240ec4 | 1729 | |
0bca51f0 | 1730 | /* Register NEW_NAME to be the new reaching definition for OLD_NAME. */ |
6de9cd9a | 1731 | |
0bca51f0 DN |
1732 | static inline void |
1733 | register_new_update_single (tree new_name, tree old_name) | |
1734 | { | |
8812aab1 RG |
1735 | common_info_p info = get_common_info (old_name); |
1736 | tree currdef = info->current_def; | |
5f240ec4 | 1737 | |
38635499 | 1738 | /* Push the current reaching definition into BLOCK_DEFS_STACK. |
0bca51f0 DN |
1739 | This stack is later used by the dominator tree callbacks to |
1740 | restore the reaching definitions for all the variables | |
1741 | defined in the block after a recursive visit to all its | |
1742 | immediately dominated blocks. */ | |
9771b263 DN |
1743 | block_defs_stack.reserve (2); |
1744 | block_defs_stack.quick_push (currdef); | |
1745 | block_defs_stack.quick_push (old_name); | |
5f240ec4 | 1746 | |
0bca51f0 DN |
1747 | /* Set the current reaching definition for OLD_NAME to be |
1748 | NEW_NAME. */ | |
8812aab1 | 1749 | info->current_def = new_name; |
0bca51f0 | 1750 | } |
7256233c | 1751 | |
6de9cd9a | 1752 | |
0bca51f0 DN |
1753 | /* Register NEW_NAME to be the new reaching definition for all the |
1754 | names in OLD_NAMES. Used by the incremental SSA update routines to | |
1755 | replace old SSA names with new ones. */ | |
7256233c | 1756 | |
0bca51f0 DN |
1757 | static inline void |
1758 | register_new_update_set (tree new_name, bitmap old_names) | |
1759 | { | |
1760 | bitmap_iterator bi; | |
1761 | unsigned i; | |
7256233c | 1762 | |
0bca51f0 DN |
1763 | EXECUTE_IF_SET_IN_BITMAP (old_names, 0, i, bi) |
1764 | register_new_update_single (new_name, ssa_name (i)); | |
6de9cd9a DN |
1765 | } |
1766 | ||
7256233c | 1767 | |
0bca51f0 | 1768 | |
84d65814 DN |
1769 | /* If the operand pointed to by USE_P is a name in OLD_SSA_NAMES or |
1770 | it is a symbol marked for renaming, replace it with USE_P's current | |
1771 | reaching definition. */ | |
1772 | ||
1773 | static inline void | |
1774 | maybe_replace_use (use_operand_p use_p) | |
1775 | { | |
1776 | tree rdef = NULL_TREE; | |
1777 | tree use = USE_FROM_PTR (use_p); | |
1778 | tree sym = DECL_P (use) ? use : SSA_NAME_VAR (use); | |
1779 | ||
13714310 | 1780 | if (marked_for_renaming (sym)) |
84d65814 DN |
1781 | rdef = get_reaching_def (sym); |
1782 | else if (is_old_name (use)) | |
1783 | rdef = get_reaching_def (use); | |
1784 | ||
1785 | if (rdef && rdef != use) | |
1786 | SET_USE (use_p, rdef); | |
1787 | } | |
1788 | ||
1789 | ||
b5b8b0ac AO |
1790 | /* Same as maybe_replace_use, but without introducing default stmts, |
1791 | returning false to indicate a need to do so. */ | |
1792 | ||
1793 | static inline bool | |
1794 | maybe_replace_use_in_debug_stmt (use_operand_p use_p) | |
1795 | { | |
1796 | tree rdef = NULL_TREE; | |
1797 | tree use = USE_FROM_PTR (use_p); | |
1798 | tree sym = DECL_P (use) ? use : SSA_NAME_VAR (use); | |
1799 | ||
13714310 | 1800 | if (marked_for_renaming (sym)) |
8812aab1 | 1801 | rdef = get_var_info (sym)->info.current_def; |
b5b8b0ac AO |
1802 | else if (is_old_name (use)) |
1803 | { | |
8812aab1 | 1804 | rdef = get_ssa_name_ann (use)->info.current_def; |
b5b8b0ac AO |
1805 | /* We can't assume that, if there's no current definition, the |
1806 | default one should be used. It could be the case that we've | |
1807 | rearranged blocks so that the earlier definition no longer | |
1808 | dominates the use. */ | |
1809 | if (!rdef && SSA_NAME_IS_DEFAULT_DEF (use)) | |
1810 | rdef = use; | |
1811 | } | |
1812 | else | |
1813 | rdef = use; | |
1814 | ||
1815 | if (rdef && rdef != use) | |
1816 | SET_USE (use_p, rdef); | |
1817 | ||
1818 | return rdef != NULL_TREE; | |
1819 | } | |
1820 | ||
1821 | ||
84d65814 DN |
1822 | /* If the operand pointed to by DEF_P is an SSA name in NEW_SSA_NAMES |
1823 | or OLD_SSA_NAMES, or if it is a symbol marked for renaming, | |
1824 | register it as the current definition for the names replaced by | |
1825 | DEF_P. */ | |
1826 | ||
1827 | static inline void | |
3a56edc7 AO |
1828 | maybe_register_def (def_operand_p def_p, gimple stmt, |
1829 | gimple_stmt_iterator gsi) | |
84d65814 DN |
1830 | { |
1831 | tree def = DEF_FROM_PTR (def_p); | |
1832 | tree sym = DECL_P (def) ? def : SSA_NAME_VAR (def); | |
1833 | ||
38635499 DN |
1834 | /* If DEF is a naked symbol that needs renaming, create a new |
1835 | name for it. */ | |
13714310 | 1836 | if (marked_for_renaming (sym)) |
84d65814 DN |
1837 | { |
1838 | if (DECL_P (def)) | |
1839 | { | |
3a56edc7 AO |
1840 | tree tracked_var; |
1841 | ||
84d65814 DN |
1842 | def = make_ssa_name (def, stmt); |
1843 | SET_DEF (def_p, def); | |
3a56edc7 AO |
1844 | |
1845 | tracked_var = target_for_debug_bind (sym); | |
1846 | if (tracked_var) | |
1847 | { | |
1848 | gimple note = gimple_build_debug_bind (tracked_var, def, stmt); | |
c47987fa JJ |
1849 | /* If stmt ends the bb, insert the debug stmt on the single |
1850 | non-EH edge from the stmt. */ | |
1851 | if (gsi_one_before_end_p (gsi) && stmt_ends_bb_p (stmt)) | |
1852 | { | |
1853 | basic_block bb = gsi_bb (gsi); | |
1854 | edge_iterator ei; | |
1855 | edge e, ef = NULL; | |
1856 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1857 | if (!(e->flags & EDGE_EH)) | |
1858 | { | |
4ad14919 | 1859 | gcc_checking_assert (!ef); |
c47987fa JJ |
1860 | ef = e; |
1861 | } | |
23d5ed5d AO |
1862 | /* If there are other predecessors to ef->dest, then |
1863 | there must be PHI nodes for the modified | |
1864 | variable, and therefore there will be debug bind | |
1865 | stmts after the PHI nodes. The debug bind notes | |
1866 | we'd insert would force the creation of a new | |
1867 | block (diverging codegen) and be redundant with | |
1868 | the post-PHI bind stmts, so don't add them. | |
1869 | ||
1870 | As for the exit edge, there wouldn't be redundant | |
1871 | bind stmts, but there wouldn't be a PC to bind | |
1872 | them to either, so avoid diverging the CFG. */ | |
1873 | if (ef && single_pred_p (ef->dest) | |
fefa31b5 | 1874 | && ef->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23d5ed5d AO |
1875 | { |
1876 | /* If there were PHI nodes in the node, we'd | |
1877 | have to make sure the value we're binding | |
1878 | doesn't need rewriting. But there shouldn't | |
1879 | be PHI nodes in a single-predecessor block, | |
1880 | so we just add the note. */ | |
1881 | gsi_insert_on_edge_immediate (ef, note); | |
1882 | } | |
c47987fa JJ |
1883 | } |
1884 | else | |
1885 | gsi_insert_after (&gsi, note, GSI_SAME_STMT); | |
3a56edc7 | 1886 | } |
84d65814 DN |
1887 | } |
1888 | ||
1889 | register_new_update_single (def, sym); | |
1890 | } | |
1891 | else | |
1892 | { | |
1893 | /* If DEF is a new name, register it as a new definition | |
1894 | for all the names replaced by DEF. */ | |
1895 | if (is_new_name (def)) | |
1896 | register_new_update_set (def, names_replaced_by (def)); | |
1897 | ||
1898 | /* If DEF is an old name, register DEF as a new | |
1899 | definition for itself. */ | |
1900 | if (is_old_name (def)) | |
1901 | register_new_update_single (def, def); | |
1902 | } | |
1903 | } | |
1904 | ||
1905 | ||
0bca51f0 DN |
1906 | /* Update every variable used in the statement pointed-to by SI. The |
1907 | statement is assumed to be in SSA form already. Names in | |
1908 | OLD_SSA_NAMES used by SI will be updated to their current reaching | |
1909 | definition. Names in OLD_SSA_NAMES or NEW_SSA_NAMES defined by SI | |
1910 | will be registered as a new definition for their corresponding name | |
1911 | in OLD_SSA_NAMES. */ | |
1912 | ||
1913 | static void | |
3a56edc7 | 1914 | rewrite_update_stmt (gimple stmt, gimple_stmt_iterator gsi) |
0bca51f0 | 1915 | { |
0bca51f0 DN |
1916 | use_operand_p use_p; |
1917 | def_operand_p def_p; | |
1918 | ssa_op_iter iter; | |
1919 | ||
0bca51f0 | 1920 | /* Only update marked statements. */ |
726a989a | 1921 | if (!rewrite_uses_p (stmt) && !register_defs_p (stmt)) |
0bca51f0 DN |
1922 | return; |
1923 | ||
1924 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1925 | { | |
1926 | fprintf (dump_file, "Updating SSA information for statement "); | |
726a989a | 1927 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
0bca51f0 DN |
1928 | } |
1929 | ||
1930 | /* Rewrite USES included in OLD_SSA_NAMES and USES whose underlying | |
1931 | symbol is marked for renaming. */ | |
726a989a | 1932 | if (rewrite_uses_p (stmt)) |
b5b8b0ac AO |
1933 | { |
1934 | if (is_gimple_debug (stmt)) | |
1935 | { | |
1936 | bool failed = false; | |
1937 | ||
1938 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) | |
1939 | if (!maybe_replace_use_in_debug_stmt (use_p)) | |
1940 | { | |
1941 | failed = true; | |
1942 | break; | |
1943 | } | |
1944 | ||
1945 | if (failed) | |
1946 | { | |
1947 | /* DOM sometimes threads jumps in such a way that a | |
1948 | debug stmt ends up referencing a SSA variable that no | |
1949 | longer dominates the debug stmt, but such that all | |
1950 | incoming definitions refer to the same definition in | |
1951 | an earlier dominator. We could try to recover that | |
1952 | definition somehow, but this will have to do for now. | |
1953 | ||
1954 | Introducing a default definition, which is what | |
1955 | maybe_replace_use() would do in such cases, may | |
1956 | modify code generation, for the otherwise-unused | |
1957 | default definition would never go away, modifying SSA | |
1958 | version numbers all over. */ | |
1959 | gimple_debug_bind_reset_value (stmt); | |
1960 | update_stmt (stmt); | |
1961 | } | |
1962 | } | |
1963 | else | |
1964 | { | |
1965 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES) | |
1966 | maybe_replace_use (use_p); | |
1967 | } | |
1968 | } | |
0bca51f0 DN |
1969 | |
1970 | /* Register definitions of names in NEW_SSA_NAMES and OLD_SSA_NAMES. | |
1971 | Also register definitions for names whose underlying symbol is | |
1972 | marked for renaming. */ | |
726a989a | 1973 | if (register_defs_p (stmt)) |
5006671f | 1974 | FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, iter, SSA_OP_ALL_DEFS) |
3a56edc7 | 1975 | maybe_register_def (def_p, stmt, gsi); |
0bca51f0 DN |
1976 | } |
1977 | ||
1978 | ||
1979 | /* Visit all the successor blocks of BB looking for PHI nodes. For | |
1980 | every PHI node found, check if any of its arguments is in | |
1981 | OLD_SSA_NAMES. If so, and if the argument has a current reaching | |
1982 | definition, replace it. */ | |
1983 | ||
1984 | static void | |
ccf5c864 | 1985 | rewrite_update_phi_arguments (basic_block bb) |
0bca51f0 DN |
1986 | { |
1987 | edge e; | |
1988 | edge_iterator ei; | |
2ce79879 | 1989 | unsigned i; |
0bca51f0 DN |
1990 | |
1991 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1992 | { | |
726a989a RB |
1993 | gimple phi; |
1994 | gimple_vec phis; | |
0bca51f0 | 1995 | |
2ce79879 ZD |
1996 | if (!bitmap_bit_p (blocks_with_phis_to_rewrite, e->dest->index)) |
1997 | continue; | |
b8698a0f | 1998 | |
9771b263 DN |
1999 | phis = phis_to_rewrite[e->dest->index]; |
2000 | FOR_EACH_VEC_ELT (phis, i, phi) | |
0bca51f0 | 2001 | { |
f5045c96 | 2002 | tree arg, lhs_sym, reaching_def = NULL; |
0bca51f0 DN |
2003 | use_operand_p arg_p; |
2004 | ||
4ad14919 | 2005 | gcc_checking_assert (rewrite_uses_p (phi)); |
0bca51f0 DN |
2006 | |
2007 | arg_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, e); | |
2008 | arg = USE_FROM_PTR (arg_p); | |
2009 | ||
2010 | if (arg && !DECL_P (arg) && TREE_CODE (arg) != SSA_NAME) | |
2011 | continue; | |
2012 | ||
726a989a | 2013 | lhs_sym = SSA_NAME_VAR (gimple_phi_result (phi)); |
38635499 | 2014 | |
0bca51f0 DN |
2015 | if (arg == NULL_TREE) |
2016 | { | |
2017 | /* When updating a PHI node for a recently introduced | |
2018 | symbol we may find NULL arguments. That's why we | |
2019 | take the symbol from the LHS of the PHI node. */ | |
f5045c96 AM |
2020 | reaching_def = get_reaching_def (lhs_sym); |
2021 | ||
0bca51f0 DN |
2022 | } |
2023 | else | |
2024 | { | |
2025 | tree sym = DECL_P (arg) ? arg : SSA_NAME_VAR (arg); | |
2026 | ||
13714310 | 2027 | if (marked_for_renaming (sym)) |
f5045c96 | 2028 | reaching_def = get_reaching_def (sym); |
0bca51f0 | 2029 | else if (is_old_name (arg)) |
f5045c96 AM |
2030 | reaching_def = get_reaching_def (arg); |
2031 | } | |
2032 | ||
2033 | /* Update the argument if there is a reaching def. */ | |
2034 | if (reaching_def) | |
2035 | { | |
f5045c96 AM |
2036 | source_location locus; |
2037 | int arg_i = PHI_ARG_INDEX_FROM_USE (arg_p); | |
2038 | ||
2039 | SET_USE (arg_p, reaching_def); | |
f5045c96 | 2040 | |
ffc5b2bb RB |
2041 | /* Virtual operands do not need a location. */ |
2042 | if (virtual_operand_p (reaching_def)) | |
2043 | locus = UNKNOWN_LOCATION; | |
f5045c96 | 2044 | else |
ffc5b2bb RB |
2045 | { |
2046 | gimple stmt = SSA_NAME_DEF_STMT (reaching_def); | |
2047 | ||
2048 | /* Single element PHI nodes behave like copies, so get the | |
2049 | location from the phi argument. */ | |
2050 | if (gimple_code (stmt) == GIMPLE_PHI | |
2051 | && gimple_phi_num_args (stmt) == 1) | |
2052 | locus = gimple_phi_arg_location (stmt, 0); | |
2053 | else | |
2054 | locus = gimple_location (stmt); | |
2055 | } | |
f5045c96 AM |
2056 | |
2057 | gimple_phi_arg_set_location (phi, arg_i, locus); | |
0bca51f0 DN |
2058 | } |
2059 | ||
f5045c96 | 2060 | |
0bca51f0 DN |
2061 | if (e->flags & EDGE_ABNORMAL) |
2062 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (USE_FROM_PTR (arg_p)) = 1; | |
2063 | } | |
2064 | } | |
2065 | } | |
2066 | ||
4d9192b5 TS |
2067 | class rewrite_update_dom_walker : public dom_walker |
2068 | { | |
2069 | public: | |
2070 | rewrite_update_dom_walker (cdi_direction direction) : dom_walker (direction) {} | |
2071 | ||
2072 | virtual void before_dom_children (basic_block); | |
2073 | virtual void after_dom_children (basic_block); | |
2074 | }; | |
0bca51f0 | 2075 | |
ccf5c864 PB |
2076 | /* Initialization of block data structures for the incremental SSA |
2077 | update pass. Create a block local stack of reaching definitions | |
2078 | for new SSA names produced in this block (BLOCK_DEFS). Register | |
2079 | new definitions for every PHI node in the block. */ | |
2080 | ||
4d9192b5 TS |
2081 | void |
2082 | rewrite_update_dom_walker::before_dom_children (basic_block bb) | |
ccf5c864 | 2083 | { |
ccf5c864 PB |
2084 | bool is_abnormal_phi; |
2085 | gimple_stmt_iterator gsi; | |
2086 | ||
2087 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
427f99e2 | 2088 | fprintf (dump_file, "Registering new PHI nodes in block #%d\n", |
ccf5c864 PB |
2089 | bb->index); |
2090 | ||
2091 | /* Mark the unwind point for this block. */ | |
9771b263 | 2092 | block_defs_stack.safe_push (NULL_TREE); |
ccf5c864 PB |
2093 | |
2094 | if (!bitmap_bit_p (blocks_to_update, bb->index)) | |
2095 | return; | |
2096 | ||
2097 | /* Mark the LHS if any of the arguments flows through an abnormal | |
2098 | edge. */ | |
31ff2426 | 2099 | is_abnormal_phi = bb_has_abnormal_pred (bb); |
ccf5c864 PB |
2100 | |
2101 | /* If any of the PHI nodes is a replacement for a name in | |
2102 | OLD_SSA_NAMES or it's one of the names in NEW_SSA_NAMES, then | |
2103 | register it as a new definition for its corresponding name. Also | |
2104 | register definitions for names whose underlying symbols are | |
2105 | marked for renaming. */ | |
2106 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2107 | { | |
2108 | tree lhs, lhs_sym; | |
2109 | gimple phi = gsi_stmt (gsi); | |
2110 | ||
2111 | if (!register_defs_p (phi)) | |
2112 | continue; | |
b8698a0f | 2113 | |
ccf5c864 PB |
2114 | lhs = gimple_phi_result (phi); |
2115 | lhs_sym = SSA_NAME_VAR (lhs); | |
2116 | ||
13714310 | 2117 | if (marked_for_renaming (lhs_sym)) |
ccf5c864 PB |
2118 | register_new_update_single (lhs, lhs_sym); |
2119 | else | |
2120 | { | |
2121 | ||
2122 | /* If LHS is a new name, register a new definition for all | |
2123 | the names replaced by LHS. */ | |
2124 | if (is_new_name (lhs)) | |
2125 | register_new_update_set (lhs, names_replaced_by (lhs)); | |
b8698a0f | 2126 | |
ccf5c864 PB |
2127 | /* If LHS is an OLD name, register it as a new definition |
2128 | for itself. */ | |
2129 | if (is_old_name (lhs)) | |
2130 | register_new_update_single (lhs, lhs); | |
2131 | } | |
2132 | ||
2133 | if (is_abnormal_phi) | |
2134 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs) = 1; | |
2135 | } | |
2136 | ||
2137 | /* Step 2. Rewrite every variable used in each statement in the block. */ | |
d7c028c0 | 2138 | if (bitmap_bit_p (interesting_blocks, bb->index)) |
3a56edc7 | 2139 | { |
4ad14919 | 2140 | gcc_checking_assert (bitmap_bit_p (blocks_to_update, bb->index)); |
ccf5c864 | 2141 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
3a56edc7 AO |
2142 | rewrite_update_stmt (gsi_stmt (gsi), gsi); |
2143 | } | |
ccf5c864 PB |
2144 | |
2145 | /* Step 3. Update PHI nodes. */ | |
2146 | rewrite_update_phi_arguments (bb); | |
2147 | } | |
2148 | ||
2149 | /* Called after visiting block BB. Unwind BLOCK_DEFS_STACK to restore | |
2150 | the current reaching definition of every name re-written in BB to | |
2151 | the original reaching definition before visiting BB. This | |
2152 | unwinding must be done in the opposite order to what is done in | |
2153 | register_new_update_set. */ | |
2154 | ||
4d9192b5 TS |
2155 | void |
2156 | rewrite_update_dom_walker::after_dom_children (basic_block bb ATTRIBUTE_UNUSED) | |
ccf5c864 | 2157 | { |
9771b263 | 2158 | while (block_defs_stack.length () > 0) |
ccf5c864 | 2159 | { |
9771b263 | 2160 | tree var = block_defs_stack.pop (); |
ccf5c864 | 2161 | tree saved_def; |
b8698a0f | 2162 | |
ccf5c864 PB |
2163 | /* NULL indicates the unwind stop point for this block (see |
2164 | rewrite_update_enter_block). */ | |
2165 | if (var == NULL) | |
2166 | return; | |
2167 | ||
9771b263 | 2168 | saved_def = block_defs_stack.pop (); |
8812aab1 | 2169 | get_common_info (var)->current_def = saved_def; |
ccf5c864 PB |
2170 | } |
2171 | } | |
2172 | ||
2173 | ||
0bca51f0 | 2174 | /* Rewrite the actual blocks, statements, and PHI arguments, to be in SSA |
b8698a0f | 2175 | form. |
0bca51f0 DN |
2176 | |
2177 | ENTRY indicates the block where to start. Every block dominated by | |
2178 | ENTRY will be rewritten. | |
2179 | ||
2180 | WHAT indicates what actions will be taken by the renamer (see enum | |
2181 | rewrite_mode). | |
2182 | ||
2183 | BLOCKS are the set of interesting blocks for the dominator walker | |
2184 | to process. If this set is NULL, then all the nodes dominated | |
2185 | by ENTRY are walked. Otherwise, blocks dominated by ENTRY that | |
2186 | are not present in BLOCKS are ignored. */ | |
2187 | ||
2188 | static void | |
ccf5c864 | 2189 | rewrite_blocks (basic_block entry, enum rewrite_mode what) |
0bca51f0 | 2190 | { |
0bca51f0 DN |
2191 | /* Rewrite all the basic blocks in the program. */ |
2192 | timevar_push (TV_TREE_SSA_REWRITE_BLOCKS); | |
2193 | ||
4d9192b5 | 2194 | block_defs_stack.create (10); |
0bca51f0 | 2195 | |
4d9192b5 TS |
2196 | /* Recursively walk the dominator tree rewriting each statement in |
2197 | each basic block. */ | |
0bca51f0 | 2198 | if (what == REWRITE_ALL) |
4d9192b5 | 2199 | rewrite_dom_walker (CDI_DOMINATORS).walk (entry); |
0bca51f0 | 2200 | else if (what == REWRITE_UPDATE) |
4d9192b5 | 2201 | rewrite_update_dom_walker (CDI_DOMINATORS).walk (entry); |
0bca51f0 DN |
2202 | else |
2203 | gcc_unreachable (); | |
2204 | ||
0bca51f0 DN |
2205 | /* Debugging dumps. */ |
2206 | if (dump_file && (dump_flags & TDF_STATS)) | |
2207 | { | |
2208 | dump_dfa_stats (dump_file); | |
c203e8a7 | 2209 | if (var_infos) |
0bca51f0 DN |
2210 | dump_tree_ssa_stats (dump_file); |
2211 | } | |
b8698a0f | 2212 | |
9771b263 | 2213 | block_defs_stack.release (); |
0bca51f0 DN |
2214 | |
2215 | timevar_pop (TV_TREE_SSA_REWRITE_BLOCKS); | |
2216 | } | |
2217 | ||
4d9192b5 | 2218 | class mark_def_dom_walker : public dom_walker |
7256233c | 2219 | { |
4d9192b5 TS |
2220 | public: |
2221 | mark_def_dom_walker (cdi_direction direction); | |
2222 | ~mark_def_dom_walker (); | |
5f240ec4 | 2223 | |
4d9192b5 | 2224 | virtual void before_dom_children (basic_block); |
5f240ec4 | 2225 | |
4d9192b5 | 2226 | private: |
7256233c DN |
2227 | /* Notice that this bitmap is indexed using variable UIDs, so it must be |
2228 | large enough to accommodate all the variables referenced in the | |
2229 | function, not just the ones we are renaming. */ | |
65d3284b | 2230 | bitmap m_kills; |
4d9192b5 | 2231 | }; |
6de9cd9a | 2232 | |
4d9192b5 | 2233 | mark_def_dom_walker::mark_def_dom_walker (cdi_direction direction) |
65d3284b | 2234 | : dom_walker (direction), m_kills (BITMAP_ALLOC (NULL)) |
4d9192b5 TS |
2235 | { |
2236 | } | |
7256233c | 2237 | |
4d9192b5 TS |
2238 | mark_def_dom_walker::~mark_def_dom_walker () |
2239 | { | |
65d3284b | 2240 | BITMAP_FREE (m_kills); |
4d9192b5 | 2241 | } |
7256233c | 2242 | |
4d9192b5 TS |
2243 | /* Block processing routine for mark_def_sites. Clear the KILLS bitmap |
2244 | at the start of each block, and call mark_def_sites for each statement. */ | |
7256233c | 2245 | |
4d9192b5 TS |
2246 | void |
2247 | mark_def_dom_walker::before_dom_children (basic_block bb) | |
2248 | { | |
2249 | gimple_stmt_iterator gsi; | |
7256233c | 2250 | |
65d3284b | 2251 | bitmap_clear (m_kills); |
4d9192b5 | 2252 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
65d3284b | 2253 | mark_def_sites (bb, gsi_stmt (gsi), m_kills); |
6de9cd9a DN |
2254 | } |
2255 | ||
38635499 DN |
2256 | /* Initialize internal data needed during renaming. */ |
2257 | ||
2258 | static void | |
2259 | init_ssa_renamer (void) | |
2260 | { | |
38635499 DN |
2261 | cfun->gimple_df->in_ssa_p = false; |
2262 | ||
2263 | /* Allocate memory for the DEF_BLOCKS hash table. */ | |
c203e8a7 TS |
2264 | gcc_assert (!var_infos); |
2265 | var_infos = new hash_table<var_info_hasher> | |
2266 | (vec_safe_length (cfun->local_decls)); | |
38635499 | 2267 | |
b4e209fd | 2268 | bitmap_obstack_initialize (&update_ssa_obstack); |
38635499 DN |
2269 | } |
2270 | ||
2271 | ||
2272 | /* Deallocate internal data structures used by the renamer. */ | |
2273 | ||
2274 | static void | |
2275 | fini_ssa_renamer (void) | |
2276 | { | |
c203e8a7 TS |
2277 | delete var_infos; |
2278 | var_infos = NULL; | |
38635499 | 2279 | |
b4e209fd RG |
2280 | bitmap_obstack_release (&update_ssa_obstack); |
2281 | ||
13714310 RG |
2282 | cfun->gimple_df->ssa_renaming_needed = 0; |
2283 | cfun->gimple_df->rename_vops = 0; | |
38635499 DN |
2284 | cfun->gimple_df->in_ssa_p = true; |
2285 | } | |
2286 | ||
7256233c | 2287 | /* Main entry point into the SSA builder. The renaming process |
0bca51f0 | 2288 | proceeds in four main phases: |
6de9cd9a | 2289 | |
0bca51f0 DN |
2290 | 1- Compute dominance frontier and immediate dominators, needed to |
2291 | insert PHI nodes and rename the function in dominator tree | |
2292 | order. | |
6de9cd9a | 2293 | |
4d9192b5 | 2294 | 2- Find and mark all the blocks that define variables. |
6de9cd9a | 2295 | |
0bca51f0 | 2296 | 3- Insert PHI nodes at dominance frontiers (insert_phi_nodes). |
6de9cd9a | 2297 | |
0bca51f0 | 2298 | 4- Rename all the blocks (rewrite_blocks) and statements in the program. |
6de9cd9a | 2299 | |
77bfa778 | 2300 | Steps 3 and 4 are done using the dominator tree walker |
0bca51f0 | 2301 | (walk_dominator_tree). */ |
7256233c | 2302 | |
be55bfe6 TS |
2303 | namespace { |
2304 | ||
2305 | const pass_data pass_data_build_ssa = | |
2306 | { | |
2307 | GIMPLE_PASS, /* type */ | |
2308 | "ssa", /* name */ | |
2309 | OPTGROUP_NONE, /* optinfo_flags */ | |
2310 | true, /* has_execute */ | |
2311 | TV_TREE_SSA_OTHER, /* tv_id */ | |
2312 | PROP_cfg, /* properties_required */ | |
2313 | PROP_ssa, /* properties_provided */ | |
2314 | 0, /* properties_destroyed */ | |
2315 | 0, /* todo_flags_start */ | |
3bea341f | 2316 | TODO_remove_unused_locals, /* todo_flags_finish */ |
be55bfe6 TS |
2317 | }; |
2318 | ||
2319 | class pass_build_ssa : public gimple_opt_pass | |
2320 | { | |
2321 | public: | |
2322 | pass_build_ssa (gcc::context *ctxt) | |
2323 | : gimple_opt_pass (pass_data_build_ssa, ctxt) | |
2324 | {} | |
2325 | ||
2326 | /* opt_pass methods: */ | |
2327 | virtual bool gate (function *fun) | |
2328 | { | |
2329 | /* Do nothing for funcions that was produced already in SSA form. */ | |
2330 | return !(fun->curr_properties & PROP_ssa); | |
2331 | } | |
2332 | ||
2333 | virtual unsigned int execute (function *); | |
2334 | ||
2335 | }; // class pass_build_ssa | |
2336 | ||
2337 | unsigned int | |
2338 | pass_build_ssa::execute (function *fun) | |
6de9cd9a | 2339 | { |
0fc555fb | 2340 | bitmap_head *dfs; |
7256233c | 2341 | basic_block bb; |
70b5e7dc | 2342 | unsigned i; |
b8698a0f | 2343 | |
0bca51f0 | 2344 | /* Initialize operand data structures. */ |
be55bfe6 | 2345 | init_ssa_operands (fun); |
6de9cd9a | 2346 | |
38635499 DN |
2347 | /* Initialize internal data needed by the renamer. */ |
2348 | init_ssa_renamer (); | |
2349 | ||
0bca51f0 DN |
2350 | /* Initialize the set of interesting blocks. The callback |
2351 | mark_def_sites will add to this set those blocks that the renamer | |
2352 | should process. */ | |
be55bfe6 | 2353 | interesting_blocks = sbitmap_alloc (last_basic_block_for_fn (fun)); |
f61e445a | 2354 | bitmap_clear (interesting_blocks); |
6de9cd9a | 2355 | |
af5d3a18 | 2356 | /* Initialize dominance frontier. */ |
be55bfe6 TS |
2357 | dfs = XNEWVEC (bitmap_head, last_basic_block_for_fn (fun)); |
2358 | FOR_EACH_BB_FN (bb, fun) | |
0fc555fb | 2359 | bitmap_initialize (&dfs[bb->index], &bitmap_default_obstack); |
6de9cd9a | 2360 | |
0bca51f0 DN |
2361 | /* 1- Compute dominance frontiers. */ |
2362 | calculate_dominance_info (CDI_DOMINATORS); | |
7256233c | 2363 | compute_dominance_frontiers (dfs); |
6de9cd9a | 2364 | |
0bca51f0 | 2365 | /* 2- Find and mark definition sites. */ |
be55bfe6 | 2366 | mark_def_dom_walker (CDI_DOMINATORS).walk (fun->cfg->x_entry_block_ptr); |
0bca51f0 DN |
2367 | |
2368 | /* 3- Insert PHI nodes at dominance frontiers of definition blocks. */ | |
84d65814 | 2369 | insert_phi_nodes (dfs); |
6de9cd9a | 2370 | |
0bca51f0 | 2371 | /* 4- Rename all the blocks. */ |
be55bfe6 | 2372 | rewrite_blocks (ENTRY_BLOCK_PTR_FOR_FN (fun), REWRITE_ALL); |
6de9cd9a | 2373 | |
7256233c | 2374 | /* Free allocated memory. */ |
be55bfe6 | 2375 | FOR_EACH_BB_FN (bb, fun) |
0fc555fb | 2376 | bitmap_clear (&dfs[bb->index]); |
7256233c | 2377 | free (dfs); |
6de9cd9a | 2378 | |
b5dcb2b9 JL |
2379 | sbitmap_free (interesting_blocks); |
2380 | ||
38635499 DN |
2381 | fini_ssa_renamer (); |
2382 | ||
70b5e7dc RG |
2383 | /* Try to get rid of all gimplifier generated temporaries by making |
2384 | its SSA names anonymous. This way we can garbage collect them | |
2385 | all after removing unused locals which we do in our TODO. */ | |
2386 | for (i = 1; i < num_ssa_names; ++i) | |
2387 | { | |
2388 | tree decl, name = ssa_name (i); | |
2389 | if (!name | |
2390 | || SSA_NAME_IS_DEFAULT_DEF (name)) | |
2391 | continue; | |
2392 | decl = SSA_NAME_VAR (name); | |
2393 | if (decl | |
2394 | && TREE_CODE (decl) == VAR_DECL | |
2395 | && !VAR_DECL_IS_VIRTUAL_OPERAND (decl) | |
74fc8b8a RB |
2396 | && DECL_IGNORED_P (decl)) |
2397 | SET_SSA_NAME_VAR_OR_IDENTIFIER (name, DECL_NAME (decl)); | |
70b5e7dc RG |
2398 | } |
2399 | ||
c2924966 | 2400 | return 0; |
6de9cd9a DN |
2401 | } |
2402 | ||
27a4cd48 DM |
2403 | } // anon namespace |
2404 | ||
2405 | gimple_opt_pass * | |
2406 | make_pass_build_ssa (gcc::context *ctxt) | |
2407 | { | |
2408 | return new pass_build_ssa (ctxt); | |
2409 | } | |
2410 | ||
6de9cd9a | 2411 | |
0bca51f0 DN |
2412 | /* Mark the definition of VAR at STMT and BB as interesting for the |
2413 | renamer. BLOCKS is the set of blocks that need updating. */ | |
6de9cd9a | 2414 | |
0bca51f0 | 2415 | static void |
726a989a | 2416 | mark_def_interesting (tree var, gimple stmt, basic_block bb, bool insert_phi_p) |
6de9cd9a | 2417 | { |
4ad14919 | 2418 | gcc_checking_assert (bitmap_bit_p (blocks_to_update, bb->index)); |
726a989a | 2419 | set_register_defs (stmt, true); |
0bca51f0 DN |
2420 | |
2421 | if (insert_phi_p) | |
2422 | { | |
726a989a | 2423 | bool is_phi_p = gimple_code (stmt) == GIMPLE_PHI; |
0bca51f0 | 2424 | |
0bca51f0 DN |
2425 | set_def_block (var, bb, is_phi_p); |
2426 | ||
2427 | /* If VAR is an SSA name in NEW_SSA_NAMES, this is a definition | |
2428 | site for both itself and all the old names replaced by it. */ | |
2429 | if (TREE_CODE (var) == SSA_NAME && is_new_name (var)) | |
2430 | { | |
2431 | bitmap_iterator bi; | |
2432 | unsigned i; | |
2433 | bitmap set = names_replaced_by (var); | |
2434 | if (set) | |
2435 | EXECUTE_IF_SET_IN_BITMAP (set, 0, i, bi) | |
2436 | set_def_block (ssa_name (i), bb, is_phi_p); | |
2437 | } | |
2438 | } | |
2439 | } | |
2440 | ||
2441 | ||
2442 | /* Mark the use of VAR at STMT and BB as interesting for the | |
2443 | renamer. INSERT_PHI_P is true if we are going to insert new PHI | |
95dd3097 | 2444 | nodes. */ |
0bca51f0 DN |
2445 | |
2446 | static inline void | |
726a989a | 2447 | mark_use_interesting (tree var, gimple stmt, basic_block bb, bool insert_phi_p) |
0bca51f0 | 2448 | { |
726a989a | 2449 | basic_block def_bb = gimple_bb (stmt); |
2ce79879 | 2450 | |
95dd3097 ZD |
2451 | mark_block_for_update (def_bb); |
2452 | mark_block_for_update (bb); | |
2453 | ||
726a989a | 2454 | if (gimple_code (stmt) == GIMPLE_PHI) |
2ce79879 ZD |
2455 | mark_phi_for_rewrite (def_bb, stmt); |
2456 | else | |
b5b8b0ac AO |
2457 | { |
2458 | set_rewrite_uses (stmt, true); | |
2459 | ||
2460 | if (is_gimple_debug (stmt)) | |
2461 | return; | |
2462 | } | |
0bca51f0 DN |
2463 | |
2464 | /* If VAR has not been defined in BB, then it is live-on-entry | |
2465 | to BB. Note that we cannot just use the block holding VAR's | |
2466 | definition because if VAR is one of the names in OLD_SSA_NAMES, | |
2467 | it will have several definitions (itself and all the names that | |
2468 | replace it). */ | |
2469 | if (insert_phi_p) | |
2470 | { | |
8812aab1 | 2471 | struct def_blocks_d *db_p = get_def_blocks_for (get_common_info (var)); |
0bca51f0 DN |
2472 | if (!bitmap_bit_p (db_p->def_blocks, bb->index)) |
2473 | set_livein_block (var, bb); | |
2474 | } | |
2475 | } | |
2476 | ||
2477 | ||
0bca51f0 | 2478 | /* Do a dominator walk starting at BB processing statements that |
13714310 | 2479 | reference symbols in SSA operands. This is very similar to |
84d65814 | 2480 | mark_def_sites, but the scan handles statements whose operands may |
95dd3097 | 2481 | already be SSA names. |
0bca51f0 | 2482 | |
84d65814 DN |
2483 | If INSERT_PHI_P is true, mark those uses as live in the |
2484 | corresponding block. This is later used by the PHI placement | |
38635499 DN |
2485 | algorithm to make PHI pruning decisions. |
2486 | ||
2487 | FIXME. Most of this would be unnecessary if we could associate a | |
2488 | symbol to all the SSA names that reference it. But that | |
2489 | sounds like it would be expensive to maintain. Still, it | |
2490 | would be interesting to see if it makes better sense to do | |
2491 | that. */ | |
0bca51f0 DN |
2492 | |
2493 | static void | |
95dd3097 | 2494 | prepare_block_for_update (basic_block bb, bool insert_phi_p) |
0bca51f0 DN |
2495 | { |
2496 | basic_block son; | |
726a989a | 2497 | gimple_stmt_iterator si; |
f074ff6c ZD |
2498 | edge e; |
2499 | edge_iterator ei; | |
0bca51f0 | 2500 | |
95dd3097 ZD |
2501 | mark_block_for_update (bb); |
2502 | ||
0bca51f0 | 2503 | /* Process PHI nodes marking interesting those that define or use |
84d65814 | 2504 | the symbols that we are interested in. */ |
726a989a | 2505 | for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) |
0bca51f0 | 2506 | { |
726a989a RB |
2507 | gimple phi = gsi_stmt (si); |
2508 | tree lhs_sym, lhs = gimple_phi_result (phi); | |
0bca51f0 | 2509 | |
13714310 | 2510 | if (TREE_CODE (lhs) == SSA_NAME |
a471762f RG |
2511 | && (! virtual_operand_p (lhs) |
2512 | || ! cfun->gimple_df->rename_vops)) | |
f074ff6c | 2513 | continue; |
726a989a | 2514 | |
a471762f | 2515 | lhs_sym = DECL_P (lhs) ? lhs : SSA_NAME_VAR (lhs); |
13714310 | 2516 | mark_for_renaming (lhs_sym); |
f074ff6c ZD |
2517 | mark_def_interesting (lhs_sym, phi, bb, insert_phi_p); |
2518 | ||
2519 | /* Mark the uses in phi nodes as interesting. It would be more correct | |
2520 | to process the arguments of the phi nodes of the successor edges of | |
2521 | BB at the end of prepare_block_for_update, however, that turns out | |
2522 | to be significantly more expensive. Doing it here is conservatively | |
2523 | correct -- it may only cause us to believe a value to be live in a | |
2524 | block that also contains its definition, and thus insert a few more | |
2525 | phi nodes for it. */ | |
2526 | FOR_EACH_EDGE (e, ei, bb->preds) | |
726a989a | 2527 | mark_use_interesting (lhs_sym, phi, e->src, insert_phi_p); |
0bca51f0 DN |
2528 | } |
2529 | ||
2530 | /* Process the statements. */ | |
726a989a | 2531 | for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) |
0bca51f0 | 2532 | { |
726a989a | 2533 | gimple stmt; |
0bca51f0 DN |
2534 | ssa_op_iter i; |
2535 | use_operand_p use_p; | |
2536 | def_operand_p def_p; | |
b8698a0f | 2537 | |
726a989a | 2538 | stmt = gsi_stmt (si); |
0bca51f0 | 2539 | |
13714310 RG |
2540 | if (cfun->gimple_df->rename_vops |
2541 | && gimple_vuse (stmt)) | |
0bca51f0 | 2542 | { |
13714310 | 2543 | tree use = gimple_vuse (stmt); |
0bca51f0 | 2544 | tree sym = DECL_P (use) ? use : SSA_NAME_VAR (use); |
13714310 RG |
2545 | mark_for_renaming (sym); |
2546 | mark_use_interesting (sym, stmt, bb, insert_phi_p); | |
0bca51f0 DN |
2547 | } |
2548 | ||
13714310 | 2549 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, i, SSA_OP_USE) |
0bca51f0 | 2550 | { |
13714310 RG |
2551 | tree use = USE_FROM_PTR (use_p); |
2552 | if (!DECL_P (use)) | |
2553 | continue; | |
2554 | mark_for_renaming (use); | |
2555 | mark_use_interesting (use, stmt, bb, insert_phi_p); | |
2556 | } | |
2557 | ||
2558 | if (cfun->gimple_df->rename_vops | |
2559 | && gimple_vdef (stmt)) | |
2560 | { | |
2561 | tree def = gimple_vdef (stmt); | |
0bca51f0 | 2562 | tree sym = DECL_P (def) ? def : SSA_NAME_VAR (def); |
13714310 RG |
2563 | mark_for_renaming (sym); |
2564 | mark_def_interesting (sym, stmt, bb, insert_phi_p); | |
2565 | } | |
2566 | ||
2567 | FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, i, SSA_OP_DEF) | |
2568 | { | |
2569 | tree def = DEF_FROM_PTR (def_p); | |
2570 | if (!DECL_P (def)) | |
2571 | continue; | |
2572 | mark_for_renaming (def); | |
2573 | mark_def_interesting (def, stmt, bb, insert_phi_p); | |
0bca51f0 DN |
2574 | } |
2575 | } | |
2576 | ||
2577 | /* Now visit all the blocks dominated by BB. */ | |
84d65814 | 2578 | for (son = first_dom_son (CDI_DOMINATORS, bb); |
38635499 DN |
2579 | son; |
2580 | son = next_dom_son (CDI_DOMINATORS, son)) | |
95dd3097 | 2581 | prepare_block_for_update (son, insert_phi_p); |
84d65814 DN |
2582 | } |
2583 | ||
2584 | ||
2585 | /* Helper for prepare_names_to_update. Mark all the use sites for | |
2586 | NAME as interesting. BLOCKS and INSERT_PHI_P are as in | |
2587 | prepare_names_to_update. */ | |
2588 | ||
2589 | static void | |
95dd3097 | 2590 | prepare_use_sites_for (tree name, bool insert_phi_p) |
84d65814 DN |
2591 | { |
2592 | use_operand_p use_p; | |
2593 | imm_use_iterator iter; | |
2594 | ||
2595 | FOR_EACH_IMM_USE_FAST (use_p, iter, name) | |
2596 | { | |
726a989a RB |
2597 | gimple stmt = USE_STMT (use_p); |
2598 | basic_block bb = gimple_bb (stmt); | |
84d65814 | 2599 | |
726a989a | 2600 | if (gimple_code (stmt) == GIMPLE_PHI) |
84d65814 | 2601 | { |
f074ff6c | 2602 | int ix = PHI_ARG_INDEX_FROM_USE (use_p); |
726a989a | 2603 | edge e = gimple_phi_arg_edge (stmt, ix); |
f074ff6c | 2604 | mark_use_interesting (name, stmt, e->src, insert_phi_p); |
84d65814 DN |
2605 | } |
2606 | else | |
2607 | { | |
2608 | /* For regular statements, mark this as an interesting use | |
2609 | for NAME. */ | |
95dd3097 | 2610 | mark_use_interesting (name, stmt, bb, insert_phi_p); |
84d65814 DN |
2611 | } |
2612 | } | |
0bca51f0 DN |
2613 | } |
2614 | ||
2615 | ||
84d65814 DN |
2616 | /* Helper for prepare_names_to_update. Mark the definition site for |
2617 | NAME as interesting. BLOCKS and INSERT_PHI_P are as in | |
2618 | prepare_names_to_update. */ | |
0bca51f0 DN |
2619 | |
2620 | static void | |
95dd3097 | 2621 | prepare_def_site_for (tree name, bool insert_phi_p) |
0bca51f0 | 2622 | { |
726a989a | 2623 | gimple stmt; |
0bca51f0 DN |
2624 | basic_block bb; |
2625 | ||
4ad14919 RG |
2626 | gcc_checking_assert (names_to_release == NULL |
2627 | || !bitmap_bit_p (names_to_release, | |
2628 | SSA_NAME_VERSION (name))); | |
0bca51f0 DN |
2629 | |
2630 | stmt = SSA_NAME_DEF_STMT (name); | |
726a989a | 2631 | bb = gimple_bb (stmt); |
0bca51f0 DN |
2632 | if (bb) |
2633 | { | |
8b1c6fd7 | 2634 | gcc_checking_assert (bb->index < last_basic_block_for_fn (cfun)); |
95dd3097 ZD |
2635 | mark_block_for_update (bb); |
2636 | mark_def_interesting (name, stmt, bb, insert_phi_p); | |
0bca51f0 DN |
2637 | } |
2638 | } | |
2639 | ||
2640 | ||
84d65814 | 2641 | /* Mark definition and use sites of names in NEW_SSA_NAMES and |
95dd3097 ZD |
2642 | OLD_SSA_NAMES. INSERT_PHI_P is true if the caller wants to insert |
2643 | PHI nodes for newly created names. */ | |
0bca51f0 DN |
2644 | |
2645 | static void | |
95dd3097 | 2646 | prepare_names_to_update (bool insert_phi_p) |
0bca51f0 | 2647 | { |
dfea6c85 | 2648 | unsigned i = 0; |
0bca51f0 | 2649 | bitmap_iterator bi; |
b6e7e9af | 2650 | sbitmap_iterator sbi; |
0bca51f0 DN |
2651 | |
2652 | /* If a name N from NEW_SSA_NAMES is also marked to be released, | |
2653 | remove it from NEW_SSA_NAMES so that we don't try to visit its | |
2654 | defining basic block (which most likely doesn't exist). Notice | |
2655 | that we cannot do the same with names in OLD_SSA_NAMES because we | |
2656 | want to replace existing instances. */ | |
2657 | if (names_to_release) | |
2658 | EXECUTE_IF_SET_IN_BITMAP (names_to_release, 0, i, bi) | |
d7c028c0 | 2659 | bitmap_clear_bit (new_ssa_names, i); |
0bca51f0 | 2660 | |
84d65814 DN |
2661 | /* First process names in NEW_SSA_NAMES. Otherwise, uses of old |
2662 | names may be considered to be live-in on blocks that contain | |
2663 | definitions for their replacements. */ | |
d4ac4ce2 | 2664 | EXECUTE_IF_SET_IN_BITMAP (new_ssa_names, 0, i, sbi) |
95dd3097 | 2665 | prepare_def_site_for (ssa_name (i), insert_phi_p); |
84d65814 | 2666 | |
0bca51f0 DN |
2667 | /* If an old name is in NAMES_TO_RELEASE, we cannot remove it from |
2668 | OLD_SSA_NAMES, but we have to ignore its definition site. */ | |
d4ac4ce2 | 2669 | EXECUTE_IF_SET_IN_BITMAP (old_ssa_names, 0, i, sbi) |
84d65814 DN |
2670 | { |
2671 | if (names_to_release == NULL || !bitmap_bit_p (names_to_release, i)) | |
95dd3097 ZD |
2672 | prepare_def_site_for (ssa_name (i), insert_phi_p); |
2673 | prepare_use_sites_for (ssa_name (i), insert_phi_p); | |
b6e7e9af | 2674 | } |
0bca51f0 DN |
2675 | } |
2676 | ||
2677 | ||
2678 | /* Dump all the names replaced by NAME to FILE. */ | |
2679 | ||
2680 | void | |
2681 | dump_names_replaced_by (FILE *file, tree name) | |
2682 | { | |
2683 | unsigned i; | |
2684 | bitmap old_set; | |
2685 | bitmap_iterator bi; | |
2686 | ||
2687 | print_generic_expr (file, name, 0); | |
2688 | fprintf (file, " -> { "); | |
2689 | ||
2690 | old_set = names_replaced_by (name); | |
2691 | EXECUTE_IF_SET_IN_BITMAP (old_set, 0, i, bi) | |
2692 | { | |
2693 | print_generic_expr (file, ssa_name (i), 0); | |
2694 | fprintf (file, " "); | |
2695 | } | |
2696 | ||
2697 | fprintf (file, "}\n"); | |
2698 | } | |
2699 | ||
2700 | ||
2701 | /* Dump all the names replaced by NAME to stderr. */ | |
2702 | ||
24e47c76 | 2703 | DEBUG_FUNCTION void |
0bca51f0 DN |
2704 | debug_names_replaced_by (tree name) |
2705 | { | |
2706 | dump_names_replaced_by (stderr, name); | |
2707 | } | |
2708 | ||
2709 | ||
84d65814 | 2710 | /* Dump SSA update information to FILE. */ |
0bca51f0 DN |
2711 | |
2712 | void | |
84d65814 | 2713 | dump_update_ssa (FILE *file) |
0bca51f0 | 2714 | { |
dfea6c85 | 2715 | unsigned i = 0; |
0bca51f0 DN |
2716 | bitmap_iterator bi; |
2717 | ||
5006671f | 2718 | if (!need_ssa_update_p (cfun)) |
0bca51f0 DN |
2719 | return; |
2720 | ||
f61e445a | 2721 | if (new_ssa_names && bitmap_first_set_bit (new_ssa_names) >= 0) |
0bca51f0 | 2722 | { |
b6e7e9af KH |
2723 | sbitmap_iterator sbi; |
2724 | ||
0bca51f0 DN |
2725 | fprintf (file, "\nSSA replacement table\n"); |
2726 | fprintf (file, "N_i -> { O_1 ... O_j } means that N_i replaces " | |
2727 | "O_1, ..., O_j\n\n"); | |
2728 | ||
d4ac4ce2 | 2729 | EXECUTE_IF_SET_IN_BITMAP (new_ssa_names, 0, i, sbi) |
b6e7e9af | 2730 | dump_names_replaced_by (file, ssa_name (i)); |
0bca51f0 DN |
2731 | } |
2732 | ||
13714310 | 2733 | if (symbols_to_rename_set && !bitmap_empty_p (symbols_to_rename_set)) |
0bca51f0 | 2734 | { |
427f99e2 | 2735 | fprintf (file, "\nSymbols to be put in SSA form\n"); |
13714310 | 2736 | dump_decl_set (file, symbols_to_rename_set); |
5006671f | 2737 | fprintf (file, "\n"); |
0bca51f0 DN |
2738 | } |
2739 | ||
0bca51f0 DN |
2740 | if (names_to_release && !bitmap_empty_p (names_to_release)) |
2741 | { | |
427f99e2 | 2742 | fprintf (file, "\nSSA names to release after updating the SSA web\n\n"); |
0bca51f0 DN |
2743 | EXECUTE_IF_SET_IN_BITMAP (names_to_release, 0, i, bi) |
2744 | { | |
2745 | print_generic_expr (file, ssa_name (i), 0); | |
2746 | fprintf (file, " "); | |
2747 | } | |
427f99e2 | 2748 | fprintf (file, "\n"); |
0bca51f0 | 2749 | } |
0bca51f0 DN |
2750 | } |
2751 | ||
2752 | ||
84d65814 | 2753 | /* Dump SSA update information to stderr. */ |
0bca51f0 | 2754 | |
24e47c76 | 2755 | DEBUG_FUNCTION void |
84d65814 | 2756 | debug_update_ssa (void) |
0bca51f0 | 2757 | { |
84d65814 | 2758 | dump_update_ssa (stderr); |
0bca51f0 DN |
2759 | } |
2760 | ||
2761 | ||
2762 | /* Initialize data structures used for incremental SSA updates. */ | |
2763 | ||
2764 | static void | |
5006671f | 2765 | init_update_ssa (struct function *fn) |
0bca51f0 | 2766 | { |
84d65814 | 2767 | /* Reserve more space than the current number of names. The calls to |
0bca51f0 DN |
2768 | add_new_name_mapping are typically done after creating new SSA |
2769 | names, so we'll need to reallocate these arrays. */ | |
2770 | old_ssa_names = sbitmap_alloc (num_ssa_names + NAME_SETS_GROWTH_FACTOR); | |
f61e445a | 2771 | bitmap_clear (old_ssa_names); |
0bca51f0 DN |
2772 | |
2773 | new_ssa_names = sbitmap_alloc (num_ssa_names + NAME_SETS_GROWTH_FACTOR); | |
f61e445a | 2774 | bitmap_clear (new_ssa_names); |
0bca51f0 | 2775 | |
891f2df6 RG |
2776 | bitmap_obstack_initialize (&update_ssa_obstack); |
2777 | ||
0bca51f0 | 2778 | names_to_release = NULL; |
5006671f | 2779 | update_ssa_initialized_fn = fn; |
0bca51f0 DN |
2780 | } |
2781 | ||
2782 | ||
2783 | /* Deallocate data structures used for incremental SSA updates. */ | |
2784 | ||
84d65814 | 2785 | void |
0bca51f0 DN |
2786 | delete_update_ssa (void) |
2787 | { | |
2788 | unsigned i; | |
2789 | bitmap_iterator bi; | |
2790 | ||
2791 | sbitmap_free (old_ssa_names); | |
2792 | old_ssa_names = NULL; | |
2793 | ||
2794 | sbitmap_free (new_ssa_names); | |
2795 | new_ssa_names = NULL; | |
2796 | ||
13714310 RG |
2797 | BITMAP_FREE (symbols_to_rename_set); |
2798 | symbols_to_rename_set = NULL; | |
9771b263 | 2799 | symbols_to_rename.release (); |
0bca51f0 DN |
2800 | |
2801 | if (names_to_release) | |
2802 | { | |
2803 | EXECUTE_IF_SET_IN_BITMAP (names_to_release, 0, i, bi) | |
2804 | release_ssa_name (ssa_name (i)); | |
2805 | BITMAP_FREE (names_to_release); | |
2806 | } | |
2807 | ||
95dd3097 | 2808 | clear_ssa_name_info (); |
38635499 DN |
2809 | |
2810 | fini_ssa_renamer (); | |
2811 | ||
2812 | if (blocks_with_phis_to_rewrite) | |
2813 | EXECUTE_IF_SET_IN_BITMAP (blocks_with_phis_to_rewrite, 0, i, bi) | |
2814 | { | |
9771b263 DN |
2815 | gimple_vec phis = phis_to_rewrite[i]; |
2816 | phis.release (); | |
2817 | phis_to_rewrite[i].create (0); | |
38635499 DN |
2818 | } |
2819 | ||
2820 | BITMAP_FREE (blocks_with_phis_to_rewrite); | |
2821 | BITMAP_FREE (blocks_to_update); | |
891f2df6 | 2822 | |
5006671f | 2823 | update_ssa_initialized_fn = NULL; |
0bca51f0 DN |
2824 | } |
2825 | ||
2826 | ||
2827 | /* Create a new name for OLD_NAME in statement STMT and replace the | |
45db3141 RG |
2828 | operand pointed to by DEF_P with the newly created name. If DEF_P |
2829 | is NULL then STMT should be a GIMPLE assignment. | |
2830 | Return the new name and register the replacement mapping <NEW, OLD> in | |
0bca51f0 DN |
2831 | update_ssa's tables. */ |
2832 | ||
2833 | tree | |
726a989a | 2834 | create_new_def_for (tree old_name, gimple stmt, def_operand_p def) |
0bca51f0 | 2835 | { |
45db3141 | 2836 | tree new_name; |
0bca51f0 | 2837 | |
45db3141 RG |
2838 | timevar_push (TV_TREE_SSA_INCREMENTAL); |
2839 | ||
2840 | if (!update_ssa_initialized_fn) | |
2841 | init_update_ssa (cfun); | |
2842 | ||
2843 | gcc_assert (update_ssa_initialized_fn == cfun); | |
2844 | ||
2845 | new_name = duplicate_ssa_name (old_name, stmt); | |
2846 | if (def) | |
2847 | SET_DEF (def, new_name); | |
2848 | else | |
2849 | gimple_assign_set_lhs (stmt, new_name); | |
0bca51f0 | 2850 | |
726a989a | 2851 | if (gimple_code (stmt) == GIMPLE_PHI) |
0bca51f0 | 2852 | { |
726a989a | 2853 | basic_block bb = gimple_bb (stmt); |
0bca51f0 DN |
2854 | |
2855 | /* If needed, mark NEW_NAME as occurring in an abnormal PHI node. */ | |
31ff2426 | 2856 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_name) = bb_has_abnormal_pred (bb); |
0bca51f0 DN |
2857 | } |
2858 | ||
45db3141 | 2859 | add_new_name_mapping (new_name, old_name); |
0bca51f0 DN |
2860 | |
2861 | /* For the benefit of passes that will be updating the SSA form on | |
2862 | their own, set the current reaching definition of OLD_NAME to be | |
2863 | NEW_NAME. */ | |
8812aab1 | 2864 | get_ssa_name_ann (old_name)->info.current_def = new_name; |
0bca51f0 | 2865 | |
45db3141 | 2866 | timevar_pop (TV_TREE_SSA_INCREMENTAL); |
0bca51f0 | 2867 | |
45db3141 | 2868 | return new_name; |
0bca51f0 DN |
2869 | } |
2870 | ||
2871 | ||
525174a2 | 2872 | /* Mark virtual operands of FN for renaming by update_ssa. */ |
0bca51f0 DN |
2873 | |
2874 | void | |
525174a2 | 2875 | mark_virtual_operands_for_renaming (struct function *fn) |
0bca51f0 | 2876 | { |
525174a2 RG |
2877 | fn->gimple_df->ssa_renaming_needed = 1; |
2878 | fn->gimple_df->rename_vops = 1; | |
0bca51f0 DN |
2879 | } |
2880 | ||
3d9c733e AM |
2881 | /* Replace all uses of NAME by underlying variable and mark it |
2882 | for renaming. This assumes the defining statement of NAME is | |
2883 | going to be removed. */ | |
2884 | ||
2885 | void | |
2886 | mark_virtual_operand_for_renaming (tree name) | |
2887 | { | |
2888 | tree name_var = SSA_NAME_VAR (name); | |
2889 | bool used = false; | |
2890 | imm_use_iterator iter; | |
2891 | use_operand_p use_p; | |
2892 | gimple stmt; | |
2893 | ||
2894 | gcc_assert (VAR_DECL_IS_VIRTUAL_OPERAND (name_var)); | |
2895 | FOR_EACH_IMM_USE_STMT (stmt, iter, name) | |
2896 | { | |
2897 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) | |
2898 | SET_USE (use_p, name_var); | |
2899 | used = true; | |
2900 | } | |
2901 | if (used) | |
2902 | mark_virtual_operands_for_renaming (cfun); | |
2903 | } | |
2904 | ||
2905 | /* Replace all uses of the virtual PHI result by its underlying variable | |
2906 | and mark it for renaming. This assumes the PHI node is going to be | |
2907 | removed. */ | |
2908 | ||
2909 | void | |
2910 | mark_virtual_phi_result_for_renaming (gimple phi) | |
2911 | { | |
2912 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2913 | { | |
2914 | fprintf (dump_file, "Marking result for renaming : "); | |
2915 | print_gimple_stmt (dump_file, phi, 0, TDF_SLIM); | |
2916 | fprintf (dump_file, "\n"); | |
2917 | } | |
2918 | ||
2919 | mark_virtual_operand_for_renaming (gimple_phi_result (phi)); | |
2920 | } | |
0bca51f0 | 2921 | |
5006671f RG |
2922 | /* Return true if there is any work to be done by update_ssa |
2923 | for function FN. */ | |
0bca51f0 DN |
2924 | |
2925 | bool | |
5006671f | 2926 | need_ssa_update_p (struct function *fn) |
0bca51f0 | 2927 | { |
5006671f RG |
2928 | gcc_assert (fn != NULL); |
2929 | return (update_ssa_initialized_fn == fn | |
13714310 | 2930 | || (fn->gimple_df && fn->gimple_df->ssa_renaming_needed)); |
0bca51f0 DN |
2931 | } |
2932 | ||
0bca51f0 DN |
2933 | /* Return true if name N has been registered in the replacement table. */ |
2934 | ||
2935 | bool | |
726a989a | 2936 | name_registered_for_update_p (tree n ATTRIBUTE_UNUSED) |
0bca51f0 | 2937 | { |
5006671f | 2938 | if (!update_ssa_initialized_fn) |
0bca51f0 DN |
2939 | return false; |
2940 | ||
5006671f RG |
2941 | gcc_assert (update_ssa_initialized_fn == cfun); |
2942 | ||
2943 | return is_new_name (n) || is_old_name (n); | |
0bca51f0 DN |
2944 | } |
2945 | ||
2946 | ||
0bca51f0 DN |
2947 | /* Mark NAME to be released after update_ssa has finished. */ |
2948 | ||
2949 | void | |
2950 | release_ssa_name_after_update_ssa (tree name) | |
2951 | { | |
5006671f | 2952 | gcc_assert (cfun && update_ssa_initialized_fn == cfun); |
0bca51f0 DN |
2953 | |
2954 | if (names_to_release == NULL) | |
2955 | names_to_release = BITMAP_ALLOC (NULL); | |
2956 | ||
2957 | bitmap_set_bit (names_to_release, SSA_NAME_VERSION (name)); | |
2958 | } | |
2959 | ||
2960 | ||
2961 | /* Insert new PHI nodes to replace VAR. DFS contains dominance | |
2962 | frontier information. BLOCKS is the set of blocks to be updated. | |
2963 | ||
2964 | This is slightly different than the regular PHI insertion | |
2965 | algorithm. The value of UPDATE_FLAGS controls how PHI nodes for | |
2966 | real names (i.e., GIMPLE registers) are inserted: | |
b8698a0f | 2967 | |
0bca51f0 DN |
2968 | - If UPDATE_FLAGS == TODO_update_ssa, we are only interested in PHI |
2969 | nodes inside the region affected by the block that defines VAR | |
2970 | and the blocks that define all its replacements. All these | |
84d65814 | 2971 | definition blocks are stored in DEF_BLOCKS[VAR]->DEF_BLOCKS. |
0bca51f0 DN |
2972 | |
2973 | First, we compute the entry point to the region (ENTRY). This is | |
2974 | given by the nearest common dominator to all the definition | |
2975 | blocks. When computing the iterated dominance frontier (IDF), any | |
2976 | block not strictly dominated by ENTRY is ignored. | |
2977 | ||
2978 | We then call the standard PHI insertion algorithm with the pruned | |
2979 | IDF. | |
2980 | ||
2981 | - If UPDATE_FLAGS == TODO_update_ssa_full_phi, the IDF for real | |
2982 | names is not pruned. PHI nodes are inserted at every IDF block. */ | |
2983 | ||
2984 | static void | |
0fc555fb | 2985 | insert_updated_phi_nodes_for (tree var, bitmap_head *dfs, bitmap blocks, |
0bca51f0 DN |
2986 | unsigned update_flags) |
2987 | { | |
2988 | basic_block entry; | |
2989 | struct def_blocks_d *db; | |
2990 | bitmap idf, pruned_idf; | |
2991 | bitmap_iterator bi; | |
2992 | unsigned i; | |
2993 | ||
0bca51f0 | 2994 | if (TREE_CODE (var) == SSA_NAME) |
77a74ed7 | 2995 | gcc_checking_assert (is_old_name (var)); |
0bca51f0 | 2996 | else |
13714310 | 2997 | gcc_checking_assert (marked_for_renaming (var)); |
0bca51f0 DN |
2998 | |
2999 | /* Get all the definition sites for VAR. */ | |
3000 | db = find_def_blocks_for (var); | |
3001 | ||
3002 | /* No need to do anything if there were no definitions to VAR. */ | |
3003 | if (db == NULL || bitmap_empty_p (db->def_blocks)) | |
3004 | return; | |
3005 | ||
3006 | /* Compute the initial iterated dominance frontier. */ | |
38635499 | 3007 | idf = compute_idf (db->def_blocks, dfs); |
0bca51f0 DN |
3008 | pruned_idf = BITMAP_ALLOC (NULL); |
3009 | ||
3010 | if (TREE_CODE (var) == SSA_NAME) | |
3011 | { | |
3012 | if (update_flags == TODO_update_ssa) | |
3013 | { | |
3014 | /* If doing regular SSA updates for GIMPLE registers, we are | |
3015 | only interested in IDF blocks dominated by the nearest | |
3016 | common dominator of all the definition blocks. */ | |
3017 | entry = nearest_common_dominator_for_set (CDI_DOMINATORS, | |
3018 | db->def_blocks); | |
fefa31b5 | 3019 | if (entry != ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
0bca51f0 | 3020 | EXECUTE_IF_SET_IN_BITMAP (idf, 0, i, bi) |
06e28de2 DM |
3021 | if (BASIC_BLOCK_FOR_FN (cfun, i) != entry |
3022 | && dominated_by_p (CDI_DOMINATORS, | |
3023 | BASIC_BLOCK_FOR_FN (cfun, i), entry)) | |
0bca51f0 DN |
3024 | bitmap_set_bit (pruned_idf, i); |
3025 | } | |
3026 | else | |
3027 | { | |
3028 | /* Otherwise, do not prune the IDF for VAR. */ | |
4ad14919 | 3029 | gcc_checking_assert (update_flags == TODO_update_ssa_full_phi); |
0bca51f0 DN |
3030 | bitmap_copy (pruned_idf, idf); |
3031 | } | |
3032 | } | |
3033 | else | |
3034 | { | |
3035 | /* Otherwise, VAR is a symbol that needs to be put into SSA form | |
3036 | for the first time, so we need to compute the full IDF for | |
3037 | it. */ | |
3038 | bitmap_copy (pruned_idf, idf); | |
0bca51f0 DN |
3039 | } |
3040 | ||
3041 | if (!bitmap_empty_p (pruned_idf)) | |
3042 | { | |
3043 | /* Make sure that PRUNED_IDF blocks and all their feeding blocks | |
3044 | are included in the region to be updated. The feeding blocks | |
3045 | are important to guarantee that the PHI arguments are renamed | |
3046 | properly. */ | |
38635499 DN |
3047 | |
3048 | /* FIXME, this is not needed if we are updating symbols. We are | |
3049 | already starting at the ENTRY block anyway. */ | |
0bca51f0 DN |
3050 | bitmap_ior_into (blocks, pruned_idf); |
3051 | EXECUTE_IF_SET_IN_BITMAP (pruned_idf, 0, i, bi) | |
3052 | { | |
3053 | edge e; | |
3054 | edge_iterator ei; | |
06e28de2 | 3055 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i); |
0bca51f0 DN |
3056 | |
3057 | FOR_EACH_EDGE (e, ei, bb->preds) | |
3058 | if (e->src->index >= 0) | |
3059 | bitmap_set_bit (blocks, e->src->index); | |
3060 | } | |
3061 | ||
3062 | insert_phi_nodes_for (var, pruned_idf, true); | |
3063 | } | |
3064 | ||
3065 | BITMAP_FREE (pruned_idf); | |
3066 | BITMAP_FREE (idf); | |
3067 | } | |
3068 | ||
fa5556de RB |
3069 | /* Sort symbols_to_rename after their DECL_UID. */ |
3070 | ||
3071 | static int | |
3072 | insert_updated_phi_nodes_compare_uids (const void *a, const void *b) | |
3073 | { | |
3074 | const_tree syma = *(const const_tree *)a; | |
3075 | const_tree symb = *(const const_tree *)b; | |
3076 | if (DECL_UID (syma) == DECL_UID (symb)) | |
3077 | return 0; | |
3078 | return DECL_UID (syma) < DECL_UID (symb) ? -1 : 1; | |
3079 | } | |
0bca51f0 DN |
3080 | |
3081 | /* Given a set of newly created SSA names (NEW_SSA_NAMES) and a set of | |
3082 | existing SSA names (OLD_SSA_NAMES), update the SSA form so that: | |
3083 | ||
3084 | 1- The names in OLD_SSA_NAMES dominated by the definitions of | |
3085 | NEW_SSA_NAMES are all re-written to be reached by the | |
3086 | appropriate definition from NEW_SSA_NAMES. | |
3087 | ||
3088 | 2- If needed, new PHI nodes are added to the iterated dominance | |
3089 | frontier of the blocks where each of NEW_SSA_NAMES are defined. | |
3090 | ||
3091 | The mapping between OLD_SSA_NAMES and NEW_SSA_NAMES is setup by | |
45db3141 | 3092 | calling create_new_def_for to create new defs for names that the |
0bca51f0 DN |
3093 | caller wants to replace. |
3094 | ||
45db3141 RG |
3095 | The caller cretaes the new names to be inserted and the names that need |
3096 | to be replaced by calling create_new_def_for for each old definition | |
3097 | to be replaced. Note that the function assumes that the | |
3098 | new defining statement has already been inserted in the IL. | |
0bca51f0 DN |
3099 | |
3100 | For instance, given the following code: | |
3101 | ||
3102 | 1 L0: | |
3103 | 2 x_1 = PHI (0, x_5) | |
3104 | 3 if (x_1 < 10) | |
3105 | 4 if (x_1 > 7) | |
3106 | 5 y_2 = 0 | |
3107 | 6 else | |
3108 | 7 y_3 = x_1 + x_7 | |
3109 | 8 endif | |
3110 | 9 x_5 = x_1 + 1 | |
3111 | 10 goto L0; | |
3112 | 11 endif | |
3113 | ||
3114 | Suppose that we insert new names x_10 and x_11 (lines 4 and 8). | |
3115 | ||
3116 | 1 L0: | |
3117 | 2 x_1 = PHI (0, x_5) | |
3118 | 3 if (x_1 < 10) | |
3119 | 4 x_10 = ... | |
3120 | 5 if (x_1 > 7) | |
3121 | 6 y_2 = 0 | |
3122 | 7 else | |
3123 | 8 x_11 = ... | |
3124 | 9 y_3 = x_1 + x_7 | |
3125 | 10 endif | |
3126 | 11 x_5 = x_1 + 1 | |
3127 | 12 goto L0; | |
3128 | 13 endif | |
3129 | ||
3130 | We want to replace all the uses of x_1 with the new definitions of | |
3131 | x_10 and x_11. Note that the only uses that should be replaced are | |
3132 | those at lines 5, 9 and 11. Also, the use of x_7 at line 9 should | |
3133 | *not* be replaced (this is why we cannot just mark symbol 'x' for | |
3134 | renaming). | |
3135 | ||
3136 | Additionally, we may need to insert a PHI node at line 11 because | |
3137 | that is a merge point for x_10 and x_11. So the use of x_1 at line | |
3138 | 11 will be replaced with the new PHI node. The insertion of PHI | |
3139 | nodes is optional. They are not strictly necessary to preserve the | |
3140 | SSA form, and depending on what the caller inserted, they may not | |
3141 | even be useful for the optimizers. UPDATE_FLAGS controls various | |
3142 | aspects of how update_ssa operates, see the documentation for | |
3143 | TODO_update_ssa*. */ | |
3144 | ||
3145 | void | |
3146 | update_ssa (unsigned update_flags) | |
3147 | { | |
0bca51f0 DN |
3148 | basic_block bb, start_bb; |
3149 | bitmap_iterator bi; | |
dfea6c85 | 3150 | unsigned i = 0; |
0bca51f0 | 3151 | bool insert_phi_p; |
b6e7e9af | 3152 | sbitmap_iterator sbi; |
13714310 | 3153 | tree sym; |
0bca51f0 | 3154 | |
580b2c2e SB |
3155 | /* Only one update flag should be set. */ |
3156 | gcc_assert (update_flags == TODO_update_ssa | |
3157 | || update_flags == TODO_update_ssa_no_phi | |
3158 | || update_flags == TODO_update_ssa_full_phi | |
3159 | || update_flags == TODO_update_ssa_only_virtuals); | |
3160 | ||
5006671f | 3161 | if (!need_ssa_update_p (cfun)) |
0bca51f0 DN |
3162 | return; |
3163 | ||
3164 | timevar_push (TV_TREE_SSA_INCREMENTAL); | |
3165 | ||
427f99e2 MJ |
3166 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3167 | fprintf (dump_file, "\nUpdating SSA:\n"); | |
3168 | ||
5006671f RG |
3169 | if (!update_ssa_initialized_fn) |
3170 | init_update_ssa (cfun); | |
580b2c2e SB |
3171 | else if (update_flags == TODO_update_ssa_only_virtuals) |
3172 | { | |
3173 | /* If we only need to update virtuals, remove all the mappings for | |
3174 | real names before proceeding. The caller is responsible for | |
3175 | having dealt with the name mappings before calling update_ssa. */ | |
f61e445a LC |
3176 | bitmap_clear (old_ssa_names); |
3177 | bitmap_clear (new_ssa_names); | |
580b2c2e SB |
3178 | } |
3179 | ||
5006671f RG |
3180 | gcc_assert (update_ssa_initialized_fn == cfun); |
3181 | ||
2ce79879 | 3182 | blocks_with_phis_to_rewrite = BITMAP_ALLOC (NULL); |
9771b263 | 3183 | if (!phis_to_rewrite.exists ()) |
8b1c6fd7 | 3184 | phis_to_rewrite.create (last_basic_block_for_fn (cfun) + 1); |
95dd3097 | 3185 | blocks_to_update = BITMAP_ALLOC (NULL); |
2ce79879 | 3186 | |
0bca51f0 DN |
3187 | /* Ensure that the dominance information is up-to-date. */ |
3188 | calculate_dominance_info (CDI_DOMINATORS); | |
3189 | ||
84d65814 | 3190 | insert_phi_p = (update_flags != TODO_update_ssa_no_phi); |
0bca51f0 | 3191 | |
84d65814 DN |
3192 | /* If there are names defined in the replacement table, prepare |
3193 | definition and use sites for all the names in NEW_SSA_NAMES and | |
3194 | OLD_SSA_NAMES. */ | |
f61e445a | 3195 | if (bitmap_first_set_bit (new_ssa_names) >= 0) |
84d65814 | 3196 | { |
95dd3097 | 3197 | prepare_names_to_update (insert_phi_p); |
84d65814 DN |
3198 | |
3199 | /* If all the names in NEW_SSA_NAMES had been marked for | |
3200 | removal, and there are no symbols to rename, then there's | |
3201 | nothing else to do. */ | |
f61e445a | 3202 | if (bitmap_first_set_bit (new_ssa_names) < 0 |
13714310 | 3203 | && !cfun->gimple_df->ssa_renaming_needed) |
84d65814 DN |
3204 | goto done; |
3205 | } | |
3206 | ||
3207 | /* Next, determine the block at which to start the renaming process. */ | |
13714310 | 3208 | if (cfun->gimple_df->ssa_renaming_needed) |
84d65814 | 3209 | { |
b4e209fd RG |
3210 | /* If we rename bare symbols initialize the mapping to |
3211 | auxiliar info we need to keep track of. */ | |
c203e8a7 | 3212 | var_infos = new hash_table<var_info_hasher> (47); |
b4e209fd | 3213 | |
84d65814 DN |
3214 | /* If we have to rename some symbols from scratch, we need to |
3215 | start the process at the root of the CFG. FIXME, it should | |
3216 | be possible to determine the nearest block that had a | |
3217 | definition for each of the symbols that are marked for | |
3218 | updating. For now this seems more work than it's worth. */ | |
fefa31b5 | 3219 | start_bb = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
84d65814 | 3220 | |
38635499 | 3221 | /* Traverse the CFG looking for existing definitions and uses of |
13714310 | 3222 | symbols in SSA operands. Mark interesting blocks and |
38635499 DN |
3223 | statements and set local live-in information for the PHI |
3224 | placement heuristics. */ | |
95dd3097 | 3225 | prepare_block_for_update (start_bb, insert_phi_p); |
343c5d46 RG |
3226 | |
3227 | #ifdef ENABLE_CHECKING | |
3228 | for (i = 1; i < num_ssa_names; ++i) | |
3229 | { | |
3230 | tree name = ssa_name (i); | |
3231 | if (!name | |
3232 | || virtual_operand_p (name)) | |
3233 | continue; | |
3234 | ||
3235 | /* For all but virtual operands, which do not have SSA names | |
3236 | with overlapping life ranges, ensure that symbols marked | |
3237 | for renaming do not have existing SSA names associated with | |
3238 | them as we do not re-write them out-of-SSA before going | |
3239 | into SSA for the remaining symbol uses. */ | |
3240 | if (marked_for_renaming (SSA_NAME_VAR (name))) | |
3241 | { | |
3242 | fprintf (stderr, "Existing SSA name for symbol marked for " | |
3243 | "renaming: "); | |
3244 | print_generic_expr (stderr, name, TDF_SLIM); | |
3245 | fprintf (stderr, "\n"); | |
3246 | internal_error ("SSA corruption"); | |
3247 | } | |
3248 | } | |
3249 | #endif | |
0bca51f0 DN |
3250 | } |
3251 | else | |
84d65814 DN |
3252 | { |
3253 | /* Otherwise, the entry block to the region is the nearest | |
3254 | common dominator for the blocks in BLOCKS. */ | |
95dd3097 ZD |
3255 | start_bb = nearest_common_dominator_for_set (CDI_DOMINATORS, |
3256 | blocks_to_update); | |
84d65814 | 3257 | } |
0bca51f0 DN |
3258 | |
3259 | /* If requested, insert PHI nodes at the iterated dominance frontier | |
84d65814 | 3260 | of every block, creating new definitions for names in OLD_SSA_NAMES |
13714310 | 3261 | and for symbols found. */ |
0bca51f0 DN |
3262 | if (insert_phi_p) |
3263 | { | |
0fc555fb | 3264 | bitmap_head *dfs; |
9caf90a8 KH |
3265 | |
3266 | /* If the caller requested PHI nodes to be added, compute | |
3267 | dominance frontiers. */ | |
8b1c6fd7 | 3268 | dfs = XNEWVEC (bitmap_head, last_basic_block_for_fn (cfun)); |
11cd3bed | 3269 | FOR_EACH_BB_FN (bb, cfun) |
0fc555fb | 3270 | bitmap_initialize (&dfs[bb->index], &bitmap_default_obstack); |
9caf90a8 KH |
3271 | compute_dominance_frontiers (dfs); |
3272 | ||
f61e445a | 3273 | if (bitmap_first_set_bit (old_ssa_names) >= 0) |
0bca51f0 | 3274 | { |
b6e7e9af KH |
3275 | sbitmap_iterator sbi; |
3276 | ||
84d65814 DN |
3277 | /* insert_update_phi_nodes_for will call add_new_name_mapping |
3278 | when inserting new PHI nodes, so the set OLD_SSA_NAMES | |
3279 | will grow while we are traversing it (but it will not | |
3280 | gain any new members). Copy OLD_SSA_NAMES to a temporary | |
3281 | for traversal. */ | |
5829cc0f | 3282 | sbitmap tmp = sbitmap_alloc (SBITMAP_SIZE (old_ssa_names)); |
f61e445a | 3283 | bitmap_copy (tmp, old_ssa_names); |
d4ac4ce2 | 3284 | EXECUTE_IF_SET_IN_BITMAP (tmp, 0, i, sbi) |
95dd3097 | 3285 | insert_updated_phi_nodes_for (ssa_name (i), dfs, blocks_to_update, |
b6e7e9af | 3286 | update_flags); |
0bca51f0 DN |
3287 | sbitmap_free (tmp); |
3288 | } | |
3289 | ||
fa5556de | 3290 | symbols_to_rename.qsort (insert_updated_phi_nodes_compare_uids); |
9771b263 | 3291 | FOR_EACH_VEC_ELT (symbols_to_rename, i, sym) |
13714310 | 3292 | insert_updated_phi_nodes_for (sym, dfs, blocks_to_update, |
38635499 | 3293 | update_flags); |
0bca51f0 | 3294 | |
11cd3bed | 3295 | FOR_EACH_BB_FN (bb, cfun) |
0fc555fb | 3296 | bitmap_clear (&dfs[bb->index]); |
9caf90a8 KH |
3297 | free (dfs); |
3298 | ||
0bca51f0 DN |
3299 | /* Insertion of PHI nodes may have added blocks to the region. |
3300 | We need to re-compute START_BB to include the newly added | |
3301 | blocks. */ | |
fefa31b5 | 3302 | if (start_bb != ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
95dd3097 ZD |
3303 | start_bb = nearest_common_dominator_for_set (CDI_DOMINATORS, |
3304 | blocks_to_update); | |
0bca51f0 DN |
3305 | } |
3306 | ||
3307 | /* Reset the current definition for name and symbol before renaming | |
3308 | the sub-graph. */ | |
d4ac4ce2 | 3309 | EXECUTE_IF_SET_IN_BITMAP (old_ssa_names, 0, i, sbi) |
8812aab1 | 3310 | get_ssa_name_ann (ssa_name (i))->info.current_def = NULL_TREE; |
0bca51f0 | 3311 | |
9771b263 | 3312 | FOR_EACH_VEC_ELT (symbols_to_rename, i, sym) |
8812aab1 | 3313 | get_var_info (sym)->info.current_def = NULL_TREE; |
0bca51f0 DN |
3314 | |
3315 | /* Now start the renaming process at START_BB. */ | |
8b1c6fd7 | 3316 | interesting_blocks = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
f61e445a | 3317 | bitmap_clear (interesting_blocks); |
95dd3097 | 3318 | EXECUTE_IF_SET_IN_BITMAP (blocks_to_update, 0, i, bi) |
d7c028c0 | 3319 | bitmap_set_bit (interesting_blocks, i); |
0bca51f0 | 3320 | |
ccf5c864 | 3321 | rewrite_blocks (start_bb, REWRITE_UPDATE); |
0bca51f0 | 3322 | |
ccf5c864 | 3323 | sbitmap_free (interesting_blocks); |
0bca51f0 DN |
3324 | |
3325 | /* Debugging dumps. */ | |
3326 | if (dump_file) | |
3327 | { | |
3328 | int c; | |
3329 | unsigned i; | |
3330 | ||
84d65814 | 3331 | dump_update_ssa (dump_file); |
0bca51f0 | 3332 | |
427f99e2 | 3333 | fprintf (dump_file, "Incremental SSA update started at block: %d\n", |
0bca51f0 DN |
3334 | start_bb->index); |
3335 | ||
3336 | c = 0; | |
95dd3097 | 3337 | EXECUTE_IF_SET_IN_BITMAP (blocks_to_update, 0, i, bi) |
0bca51f0 | 3338 | c++; |
8b1c6fd7 DM |
3339 | fprintf (dump_file, "Number of blocks in CFG: %d\n", |
3340 | last_basic_block_for_fn (cfun)); | |
427f99e2 | 3341 | fprintf (dump_file, "Number of blocks to update: %d (%3.0f%%)\n", |
8b1c6fd7 | 3342 | c, PERCENT (c, last_basic_block_for_fn (cfun))); |
0bca51f0 DN |
3343 | |
3344 | if (dump_flags & TDF_DETAILS) | |
3345 | { | |
0eb09f31 | 3346 | fprintf (dump_file, "Affected blocks:"); |
95dd3097 | 3347 | EXECUTE_IF_SET_IN_BITMAP (blocks_to_update, 0, i, bi) |
0eb09f31 | 3348 | fprintf (dump_file, " %u", i); |
0bca51f0 DN |
3349 | fprintf (dump_file, "\n"); |
3350 | } | |
3351 | ||
3352 | fprintf (dump_file, "\n\n"); | |
3353 | } | |
3354 | ||
3355 | /* Free allocated memory. */ | |
84d65814 | 3356 | done: |
0bca51f0 DN |
3357 | delete_update_ssa (); |
3358 | ||
3359 | timevar_pop (TV_TREE_SSA_INCREMENTAL); | |
3360 | } |