]>
Commit | Line | Data |
---|---|---|
ca6c03ca JH |
1 | /* Control flow graph manipulation code for GNU compiler. |
2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
6a58eee9 | 3 | 1999, 2000, 2001, 2002 Free Software Foundation, Inc. |
ca6c03ca JH |
4 | |
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 2, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING. If not, write to the Free | |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
21 | ||
5f0d2358 RK |
22 | /* This file contains low level functions to manipulate the CFG and analyze it |
23 | that are aware of the RTL intermediate language. | |
ca6c03ca JH |
24 | |
25 | Available functionality: | |
5f0d2358 | 26 | - CFG-aware instruction chain manipulation |
ca6c03ca JH |
27 | delete_insn, delete_insn_chain |
28 | - Basic block manipulation | |
5f0d2358 RK |
29 | create_basic_block, flow_delete_block, split_block, |
30 | merge_blocks_nomove | |
31 | - Infrastructure to determine quickly basic block for insn | |
ca6c03ca | 32 | compute_bb_for_insn, update_bb_for_insn, set_block_for_insn, |
5f0d2358 RK |
33 | - Edge redirection with updating and optimizing of insn chain |
34 | block_label, redirect_edge_and_branch, | |
35 | redirect_edge_and_branch_force, tidy_fallthru_edge, force_nonfallthru | |
95bd1dd7 | 36 | - Edge splitting and committing to edges |
5f0d2358 | 37 | split_edge, insert_insn_on_edge, commit_edge_insertions |
eaec9b3d | 38 | - Dumping and debugging |
5f0d2358 | 39 | print_rtl_with_bb, dump_bb, debug_bb, debug_bb_n |
ca6c03ca | 40 | - Consistency checking |
5f0d2358 | 41 | verify_flow_info |
ca6c03ca | 42 | - CFG updating after constant propagation |
5f0d2358 | 43 | purge_dead_edges, purge_all_dead_edges */ |
ca6c03ca JH |
44 | \f |
45 | #include "config.h" | |
46 | #include "system.h" | |
4977bab6 ZW |
47 | #include "coretypes.h" |
48 | #include "tm.h" | |
ca6c03ca JH |
49 | #include "tree.h" |
50 | #include "rtl.h" | |
51 | #include "hard-reg-set.h" | |
52 | #include "basic-block.h" | |
53 | #include "regs.h" | |
54 | #include "flags.h" | |
55 | #include "output.h" | |
56 | #include "function.h" | |
57 | #include "except.h" | |
58 | #include "toplev.h" | |
59 | #include "tm_p.h" | |
60 | #include "obstack.h" | |
0a2ed1f1 | 61 | #include "insn-config.h" |
ca6c03ca | 62 | |
5f0d2358 | 63 | /* Stubs in case we don't have a return insn. */ |
ca6c03ca JH |
64 | #ifndef HAVE_return |
65 | #define HAVE_return 0 | |
66 | #define gen_return() NULL_RTX | |
67 | #endif | |
68 | ||
ca6c03ca JH |
69 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ |
70 | /* ??? Should probably be using LABEL_NUSES instead. It would take a | |
71 | bit of surgery to be able to use or co-opt the routines in jump. */ | |
ca6c03ca JH |
72 | rtx label_value_list; |
73 | rtx tail_recursion_label_list; | |
74 | ||
75 | static int can_delete_note_p PARAMS ((rtx)); | |
76 | static int can_delete_label_p PARAMS ((rtx)); | |
3dec4024 | 77 | static void commit_one_edge_insertion PARAMS ((edge, int)); |
ca6c03ca JH |
78 | static bool try_redirect_by_replacing_jump PARAMS ((edge, basic_block)); |
79 | static rtx last_loop_beg_note PARAMS ((rtx)); | |
80 | static bool back_edge_of_syntactic_loop_p PARAMS ((basic_block, basic_block)); | |
81 | static basic_block force_nonfallthru_and_redirect PARAMS ((edge, basic_block)); | |
82 | \f | |
83 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 84 | so that we may simply delete it. */ |
ca6c03ca JH |
85 | |
86 | static int | |
87 | can_delete_note_p (note) | |
88 | rtx note; | |
89 | { | |
90 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
969d70ca | 91 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK |
f87c27b4 | 92 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_PREDICTION); |
ca6c03ca JH |
93 | } |
94 | ||
95 | /* True if a given label can be deleted. */ | |
96 | ||
97 | static int | |
98 | can_delete_label_p (label) | |
99 | rtx label; | |
100 | { | |
5f0d2358 RK |
101 | return (!LABEL_PRESERVE_P (label) |
102 | /* User declared labels must be preserved. */ | |
103 | && LABEL_NAME (label) == 0 | |
104 | && !in_expr_list_p (forced_labels, label) | |
6a58eee9 | 105 | && !in_expr_list_p (label_value_list, label)); |
ca6c03ca JH |
106 | } |
107 | ||
108 | /* Delete INSN by patching it out. Return the next insn. */ | |
109 | ||
110 | rtx | |
111 | delete_insn (insn) | |
112 | rtx insn; | |
113 | { | |
114 | rtx next = NEXT_INSN (insn); | |
115 | rtx note; | |
116 | bool really_delete = true; | |
117 | ||
118 | if (GET_CODE (insn) == CODE_LABEL) | |
119 | { | |
120 | /* Some labels can't be directly removed from the INSN chain, as they | |
f87c27b4 | 121 | might be references via variables, constant pool etc. |
ca6c03ca JH |
122 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ |
123 | if (! can_delete_label_p (insn)) | |
124 | { | |
125 | const char *name = LABEL_NAME (insn); | |
126 | ||
127 | really_delete = false; | |
128 | PUT_CODE (insn, NOTE); | |
129 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
130 | NOTE_SOURCE_FILE (insn) = name; | |
131 | } | |
5f0d2358 | 132 | |
ca6c03ca JH |
133 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
134 | } | |
135 | ||
136 | if (really_delete) | |
137 | { | |
cda94cbb RH |
138 | /* If this insn has already been deleted, something is very wrong. */ |
139 | if (INSN_DELETED_P (insn)) | |
140 | abort (); | |
ca6c03ca JH |
141 | remove_insn (insn); |
142 | INSN_DELETED_P (insn) = 1; | |
143 | } | |
144 | ||
145 | /* If deleting a jump, decrement the use count of the label. Deleting | |
146 | the label itself should happen in the normal course of block merging. */ | |
147 | if (GET_CODE (insn) == JUMP_INSN | |
148 | && JUMP_LABEL (insn) | |
149 | && GET_CODE (JUMP_LABEL (insn)) == CODE_LABEL) | |
150 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
151 | ||
152 | /* Also if deleting an insn that references a label. */ | |
153 | else if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX | |
154 | && GET_CODE (XEXP (note, 0)) == CODE_LABEL) | |
155 | LABEL_NUSES (XEXP (note, 0))--; | |
156 | ||
157 | if (GET_CODE (insn) == JUMP_INSN | |
158 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
159 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
160 | { | |
161 | rtx pat = PATTERN (insn); | |
162 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
163 | int len = XVECLEN (pat, diff_vec_p); | |
164 | int i; | |
165 | ||
166 | for (i = 0; i < len; i++) | |
a124fcda RH |
167 | { |
168 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
169 | ||
170 | /* When deleting code in bulk (e.g. removing many unreachable | |
171 | blocks) we can delete a label that's a target of the vector | |
172 | before deleting the vector itself. */ | |
173 | if (GET_CODE (label) != NOTE) | |
174 | LABEL_NUSES (label)--; | |
175 | } | |
ca6c03ca JH |
176 | } |
177 | ||
178 | return next; | |
179 | } | |
180 | ||
3dec4024 JH |
181 | /* Like delete_insn but also purge dead edges from BB. */ |
182 | rtx | |
183 | delete_insn_and_edges (insn) | |
184 | rtx insn; | |
185 | { | |
186 | rtx x; | |
187 | bool purge = false; | |
188 | ||
ba4f7968 | 189 | if (INSN_P (insn) |
3dec4024 JH |
190 | && BLOCK_FOR_INSN (insn) |
191 | && BLOCK_FOR_INSN (insn)->end == insn) | |
192 | purge = true; | |
193 | x = delete_insn (insn); | |
194 | if (purge) | |
195 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
196 | return x; | |
197 | } | |
198 | ||
ca6c03ca JH |
199 | /* Unlink a chain of insns between START and FINISH, leaving notes |
200 | that must be paired. */ | |
201 | ||
202 | void | |
203 | delete_insn_chain (start, finish) | |
204 | rtx start, finish; | |
205 | { | |
ca6c03ca JH |
206 | rtx next; |
207 | ||
5f0d2358 RK |
208 | /* Unchain the insns one by one. It would be quicker to delete all of these |
209 | with a single unchaining, rather than one at a time, but we need to keep | |
210 | the NOTE's. */ | |
ca6c03ca JH |
211 | while (1) |
212 | { | |
213 | next = NEXT_INSN (start); | |
214 | if (GET_CODE (start) == NOTE && !can_delete_note_p (start)) | |
215 | ; | |
216 | else | |
217 | next = delete_insn (start); | |
218 | ||
219 | if (start == finish) | |
220 | break; | |
221 | start = next; | |
222 | } | |
223 | } | |
3dec4024 JH |
224 | |
225 | /* Like delete_insn but also purge dead edges from BB. */ | |
226 | void | |
227 | delete_insn_chain_and_edges (first, last) | |
228 | rtx first, last; | |
229 | { | |
230 | bool purge = false; | |
231 | ||
ba4f7968 | 232 | if (INSN_P (last) |
3dec4024 JH |
233 | && BLOCK_FOR_INSN (last) |
234 | && BLOCK_FOR_INSN (last)->end == last) | |
235 | purge = true; | |
236 | delete_insn_chain (first, last); | |
237 | if (purge) | |
238 | purge_dead_edges (BLOCK_FOR_INSN (last)); | |
239 | } | |
ca6c03ca | 240 | \f |
5f0d2358 RK |
241 | /* Create a new basic block consisting of the instructions between HEAD and END |
242 | inclusive. This function is designed to allow fast BB construction - reuses | |
243 | the note and basic block struct in BB_NOTE, if any and do not grow | |
244 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
245 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
246 | and HEAD can be NULL to create basic block at the end of INSN chain. |
247 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
248 | |
249 | basic_block | |
852c6ec7 | 250 | create_basic_block_structure (head, end, bb_note, after) |
ca6c03ca | 251 | rtx head, end, bb_note; |
918ed612 | 252 | basic_block after; |
ca6c03ca JH |
253 | { |
254 | basic_block bb; | |
255 | ||
256 | if (bb_note | |
257 | && ! RTX_INTEGRATED_P (bb_note) | |
258 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL | |
259 | && bb->aux == NULL) | |
260 | { | |
261 | /* If we found an existing note, thread it back onto the chain. */ | |
262 | ||
263 | rtx after; | |
264 | ||
265 | if (GET_CODE (head) == CODE_LABEL) | |
266 | after = head; | |
267 | else | |
268 | { | |
269 | after = PREV_INSN (head); | |
270 | head = bb_note; | |
271 | } | |
272 | ||
273 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 274 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
275 | } |
276 | else | |
277 | { | |
278 | /* Otherwise we must create a note and a basic block structure. */ | |
279 | ||
280 | bb = alloc_block (); | |
281 | ||
282 | if (!head && !end) | |
5f0d2358 RK |
283 | head = end = bb_note |
284 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
ca6c03ca JH |
285 | else if (GET_CODE (head) == CODE_LABEL && end) |
286 | { | |
287 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
288 | if (head == end) | |
289 | end = bb_note; | |
290 | } | |
291 | else | |
292 | { | |
293 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
294 | head = bb_note; | |
295 | if (!end) | |
296 | end = head; | |
297 | } | |
5f0d2358 | 298 | |
ca6c03ca JH |
299 | NOTE_BASIC_BLOCK (bb_note) = bb; |
300 | } | |
301 | ||
302 | /* Always include the bb note in the block. */ | |
303 | if (NEXT_INSN (end) == bb_note) | |
304 | end = bb_note; | |
305 | ||
306 | bb->head = head; | |
307 | bb->end = end; | |
852c6ec7 | 308 | bb->index = last_basic_block++; |
38c1593d | 309 | bb->flags = BB_NEW; |
918ed612 | 310 | link_block (bb, after); |
852c6ec7 | 311 | BASIC_BLOCK (bb->index) = bb; |
ba4f7968 | 312 | update_bb_for_insn (bb); |
ca6c03ca JH |
313 | |
314 | /* Tag the block so that we know it has been used when considering | |
315 | other basic block notes. */ | |
316 | bb->aux = bb; | |
317 | ||
318 | return bb; | |
319 | } | |
320 | ||
5f0d2358 | 321 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 322 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
323 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
324 | create basic block at the end of INSN chain. */ | |
ca6c03ca JH |
325 | |
326 | basic_block | |
918ed612 | 327 | create_basic_block (head, end, after) |
ca6c03ca | 328 | rtx head, end; |
918ed612 | 329 | basic_block after; |
ca6c03ca JH |
330 | { |
331 | basic_block bb; | |
0b17ab2f | 332 | |
bf77398c | 333 | /* Place the new block just after the end. */ |
852c6ec7 | 334 | VARRAY_GROW (basic_block_info, last_basic_block+1); |
0b17ab2f | 335 | |
bf77398c | 336 | n_basic_blocks++; |
ca6c03ca | 337 | |
852c6ec7 | 338 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
339 | bb->aux = NULL; |
340 | return bb; | |
341 | } | |
342 | \f | |
343 | /* Delete the insns in a (non-live) block. We physically delete every | |
344 | non-deleted-note insn, and update the flow graph appropriately. | |
345 | ||
346 | Return nonzero if we deleted an exception handler. */ | |
347 | ||
348 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
349 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
350 | ||
351 | int | |
6a58eee9 | 352 | flow_delete_block_noexpunge (b) |
ca6c03ca JH |
353 | basic_block b; |
354 | { | |
355 | int deleted_handler = 0; | |
356 | rtx insn, end, tmp; | |
357 | ||
358 | /* If the head of this block is a CODE_LABEL, then it might be the | |
359 | label for an exception handler which can't be reached. | |
360 | ||
361 | We need to remove the label from the exception_handler_label list | |
362 | and remove the associated NOTE_INSN_EH_REGION_BEG and | |
363 | NOTE_INSN_EH_REGION_END notes. */ | |
364 | ||
07532fad RS |
365 | /* Get rid of all NOTE_INSN_PREDICTIONs and NOTE_INSN_LOOP_CONTs |
366 | hanging before the block. */ | |
f87c27b4 | 367 | |
969d70ca JH |
368 | for (insn = PREV_INSN (b->head); insn; insn = PREV_INSN (insn)) |
369 | { | |
370 | if (GET_CODE (insn) != NOTE) | |
f87c27b4 | 371 | break; |
07532fad RS |
372 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PREDICTION |
373 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT) | |
f87c27b4 | 374 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; |
969d70ca JH |
375 | } |
376 | ||
ca6c03ca JH |
377 | insn = b->head; |
378 | ||
56d44285 | 379 | never_reached_warning (insn, b->end); |
ca6c03ca JH |
380 | |
381 | if (GET_CODE (insn) == CODE_LABEL) | |
382 | maybe_remove_eh_handler (insn); | |
383 | ||
384 | /* Include any jump table following the basic block. */ | |
385 | end = b->end; | |
386 | if (GET_CODE (end) == JUMP_INSN | |
387 | && (tmp = JUMP_LABEL (end)) != NULL_RTX | |
388 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
389 | && GET_CODE (tmp) == JUMP_INSN | |
390 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
391 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
392 | end = tmp; | |
393 | ||
394 | /* Include any barrier that may follow the basic block. */ | |
395 | tmp = next_nonnote_insn (end); | |
396 | if (tmp && GET_CODE (tmp) == BARRIER) | |
397 | end = tmp; | |
398 | ||
399 | /* Selectively delete the entire chain. */ | |
400 | b->head = NULL; | |
401 | delete_insn_chain (insn, end); | |
402 | ||
403 | /* Remove the edges into and out of this block. Note that there may | |
404 | indeed be edges in, if we are removing an unreachable loop. */ | |
405 | while (b->pred != NULL) | |
406 | remove_edge (b->pred); | |
407 | while (b->succ != NULL) | |
408 | remove_edge (b->succ); | |
409 | ||
410 | b->pred = NULL; | |
411 | b->succ = NULL; | |
412 | ||
6a58eee9 RH |
413 | return deleted_handler; |
414 | } | |
415 | ||
416 | int | |
417 | flow_delete_block (b) | |
418 | basic_block b; | |
419 | { | |
420 | int deleted_handler = flow_delete_block_noexpunge (b); | |
f87c27b4 | 421 | |
bf77398c | 422 | /* Remove the basic block from the array. */ |
ca6c03ca JH |
423 | expunge_block (b); |
424 | ||
425 | return deleted_handler; | |
426 | } | |
427 | \f | |
852c6ec7 | 428 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
429 | |
430 | void | |
852c6ec7 | 431 | compute_bb_for_insn () |
ca6c03ca | 432 | { |
e0082a72 | 433 | basic_block bb; |
ca6c03ca | 434 | |
e0082a72 | 435 | FOR_EACH_BB (bb) |
ca6c03ca | 436 | { |
5f0d2358 RK |
437 | rtx end = bb->end; |
438 | rtx insn; | |
ca6c03ca | 439 | |
5f0d2358 | 440 | for (insn = bb->head; ; insn = NEXT_INSN (insn)) |
ca6c03ca | 441 | { |
ba4f7968 | 442 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
443 | if (insn == end) |
444 | break; | |
ca6c03ca JH |
445 | } |
446 | } | |
447 | } | |
448 | ||
449 | /* Release the basic_block_for_insn array. */ | |
450 | ||
451 | void | |
452 | free_bb_for_insn () | |
453 | { | |
ba4f7968 JH |
454 | rtx insn; |
455 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
456 | if (GET_CODE (insn) != BARRIER) | |
457 | BLOCK_FOR_INSN (insn) = NULL; | |
ca6c03ca JH |
458 | } |
459 | ||
460 | /* Update insns block within BB. */ | |
461 | ||
462 | void | |
463 | update_bb_for_insn (bb) | |
464 | basic_block bb; | |
465 | { | |
466 | rtx insn; | |
467 | ||
ca6c03ca JH |
468 | for (insn = bb->head; ; insn = NEXT_INSN (insn)) |
469 | { | |
470 | set_block_for_insn (insn, bb); | |
ca6c03ca JH |
471 | if (insn == bb->end) |
472 | break; | |
473 | } | |
474 | } | |
ca6c03ca JH |
475 | \f |
476 | /* Split a block BB after insn INSN creating a new fallthru edge. | |
477 | Return the new edge. Note that to keep other parts of the compiler happy, | |
478 | this function renumbers all the basic blocks so that the new | |
479 | one has a number one greater than the block split. */ | |
480 | ||
481 | edge | |
482 | split_block (bb, insn) | |
483 | basic_block bb; | |
484 | rtx insn; | |
485 | { | |
486 | basic_block new_bb; | |
487 | edge new_edge; | |
488 | edge e; | |
489 | ||
490 | /* There is no point splitting the block after its end. */ | |
491 | if (bb->end == insn) | |
492 | return 0; | |
493 | ||
494 | /* Create the new basic block. */ | |
918ed612 | 495 | new_bb = create_basic_block (NEXT_INSN (insn), bb->end, bb); |
ca6c03ca JH |
496 | new_bb->count = bb->count; |
497 | new_bb->frequency = bb->frequency; | |
498 | new_bb->loop_depth = bb->loop_depth; | |
499 | bb->end = insn; | |
500 | ||
501 | /* Redirect the outgoing edges. */ | |
502 | new_bb->succ = bb->succ; | |
503 | bb->succ = NULL; | |
504 | for (e = new_bb->succ; e; e = e->succ_next) | |
505 | e->src = new_bb; | |
506 | ||
507 | new_edge = make_single_succ_edge (bb, new_bb, EDGE_FALLTHRU); | |
508 | ||
509 | if (bb->global_live_at_start) | |
510 | { | |
511 | new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
512 | new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
513 | COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end); | |
514 | ||
515 | /* We now have to calculate which registers are live at the end | |
516 | of the split basic block and at the start of the new basic | |
517 | block. Start with those registers that are known to be live | |
518 | at the end of the original basic block and get | |
519 | propagate_block to determine which registers are live. */ | |
520 | COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end); | |
521 | propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0); | |
522 | COPY_REG_SET (bb->global_live_at_end, | |
523 | new_bb->global_live_at_start); | |
0a2ed1f1 JH |
524 | #ifdef HAVE_conditional_execution |
525 | /* In the presence of conditional execution we are not able to update | |
526 | liveness precisely. */ | |
527 | if (reload_completed) | |
528 | { | |
529 | bb->flags |= BB_DIRTY; | |
530 | new_bb->flags |= BB_DIRTY; | |
531 | } | |
532 | #endif | |
ca6c03ca JH |
533 | } |
534 | ||
535 | return new_edge; | |
536 | } | |
537 | ||
538 | /* Blocks A and B are to be merged into a single block A. The insns | |
539 | are already contiguous, hence `nomove'. */ | |
540 | ||
541 | void | |
542 | merge_blocks_nomove (a, b) | |
543 | basic_block a, b; | |
544 | { | |
5f0d2358 | 545 | rtx b_head = b->head, b_end = b->end, a_end = a->end; |
ca6c03ca JH |
546 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
547 | int b_empty = 0; | |
5f0d2358 | 548 | edge e; |
ca6c03ca JH |
549 | |
550 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
ca6c03ca JH |
551 | if (GET_CODE (b_head) == CODE_LABEL) |
552 | { | |
553 | /* Detect basic blocks with nothing but a label. This can happen | |
554 | in particular at the end of a function. */ | |
555 | if (b_head == b_end) | |
556 | b_empty = 1; | |
5f0d2358 | 557 | |
ca6c03ca JH |
558 | del_first = del_last = b_head; |
559 | b_head = NEXT_INSN (b_head); | |
560 | } | |
561 | ||
5f0d2358 RK |
562 | /* Delete the basic block note and handle blocks containing just that |
563 | note. */ | |
ca6c03ca JH |
564 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
565 | { | |
566 | if (b_head == b_end) | |
567 | b_empty = 1; | |
568 | if (! del_last) | |
569 | del_first = b_head; | |
5f0d2358 | 570 | |
ca6c03ca JH |
571 | del_last = b_head; |
572 | b_head = NEXT_INSN (b_head); | |
573 | } | |
574 | ||
575 | /* If there was a jump out of A, delete it. */ | |
ca6c03ca JH |
576 | if (GET_CODE (a_end) == JUMP_INSN) |
577 | { | |
578 | rtx prev; | |
579 | ||
580 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
581 | if (GET_CODE (prev) != NOTE | |
582 | || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK | |
583 | || prev == a->head) | |
584 | break; | |
585 | ||
586 | del_first = a_end; | |
587 | ||
588 | #ifdef HAVE_cc0 | |
589 | /* If this was a conditional jump, we need to also delete | |
590 | the insn that set cc0. */ | |
591 | if (only_sets_cc0_p (prev)) | |
592 | { | |
593 | rtx tmp = prev; | |
5f0d2358 | 594 | |
ca6c03ca JH |
595 | prev = prev_nonnote_insn (prev); |
596 | if (!prev) | |
597 | prev = a->head; | |
598 | del_first = tmp; | |
599 | } | |
600 | #endif | |
601 | ||
602 | a_end = PREV_INSN (del_first); | |
603 | } | |
604 | else if (GET_CODE (NEXT_INSN (a_end)) == BARRIER) | |
605 | del_first = NEXT_INSN (a_end); | |
606 | ||
607 | /* Normally there should only be one successor of A and that is B, but | |
608 | partway though the merge of blocks for conditional_execution we'll | |
609 | be merging a TEST block with THEN and ELSE successors. Free the | |
610 | whole lot of them and hope the caller knows what they're doing. */ | |
611 | while (a->succ) | |
612 | remove_edge (a->succ); | |
613 | ||
614 | /* Adjust the edges out of B for the new owner. */ | |
615 | for (e = b->succ; e; e = e->succ_next) | |
616 | e->src = a; | |
617 | a->succ = b->succ; | |
38c1593d | 618 | a->flags |= b->flags; |
ca6c03ca JH |
619 | |
620 | /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */ | |
621 | b->pred = b->succ = NULL; | |
7dddfb65 | 622 | a->global_live_at_end = b->global_live_at_end; |
ca6c03ca JH |
623 | |
624 | expunge_block (b); | |
625 | ||
626 | /* Delete everything marked above as well as crap that might be | |
627 | hanging out between the two blocks. */ | |
628 | delete_insn_chain (del_first, del_last); | |
629 | ||
630 | /* Reassociate the insns of B with A. */ | |
631 | if (!b_empty) | |
632 | { | |
ba4f7968 | 633 | rtx x; |
5f0d2358 | 634 | |
ba4f7968 JH |
635 | for (x = a_end; x != b_end; x = NEXT_INSN (x)) |
636 | set_block_for_insn (x, a); | |
5f0d2358 | 637 | |
ba4f7968 | 638 | set_block_for_insn (b_end, a); |
5f0d2358 | 639 | |
ca6c03ca JH |
640 | a_end = b_end; |
641 | } | |
5f0d2358 | 642 | |
ca6c03ca JH |
643 | a->end = a_end; |
644 | } | |
645 | \f | |
5f0d2358 RK |
646 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
647 | exist. */ | |
ca6c03ca JH |
648 | |
649 | rtx | |
650 | block_label (block) | |
651 | basic_block block; | |
652 | { | |
653 | if (block == EXIT_BLOCK_PTR) | |
654 | return NULL_RTX; | |
5f0d2358 | 655 | |
ca6c03ca JH |
656 | if (GET_CODE (block->head) != CODE_LABEL) |
657 | { | |
658 | block->head = emit_label_before (gen_label_rtx (), block->head); | |
ca6c03ca | 659 | } |
5f0d2358 | 660 | |
ca6c03ca JH |
661 | return block->head; |
662 | } | |
663 | ||
664 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
665 | instruction by unconditional jump or removing jump completely. This can |
666 | apply only if all edges now point to the same block. The parameters and | |
667 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca JH |
668 | |
669 | static bool | |
670 | try_redirect_by_replacing_jump (e, target) | |
671 | edge e; | |
672 | basic_block target; | |
673 | { | |
674 | basic_block src = e->src; | |
675 | rtx insn = src->end, kill_from; | |
676 | edge tmp; | |
1b6763cf | 677 | rtx set, table; |
ca6c03ca JH |
678 | int fallthru = 0; |
679 | ||
680 | /* Verify that all targets will be TARGET. */ | |
681 | for (tmp = src->succ; tmp; tmp = tmp->succ_next) | |
682 | if (tmp->dest != target && tmp != e) | |
683 | break; | |
5f0d2358 | 684 | |
ca6c03ca JH |
685 | if (tmp || !onlyjump_p (insn)) |
686 | return false; | |
ef3e9886 | 687 | if (flow2_completed && JUMP_LABEL (insn) |
1b6763cf JH |
688 | && (table = NEXT_INSN (JUMP_LABEL (insn))) != NULL_RTX |
689 | && GET_CODE (table) == JUMP_INSN | |
690 | && (GET_CODE (PATTERN (table)) == ADDR_VEC | |
691 | || GET_CODE (PATTERN (table)) == ADDR_DIFF_VEC)) | |
692 | return false; | |
ca6c03ca JH |
693 | |
694 | /* Avoid removing branch with side effects. */ | |
695 | set = single_set (insn); | |
696 | if (!set || side_effects_p (set)) | |
697 | return false; | |
698 | ||
699 | /* In case we zap a conditional jump, we'll need to kill | |
700 | the cc0 setter too. */ | |
701 | kill_from = insn; | |
702 | #ifdef HAVE_cc0 | |
703 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
704 | kill_from = PREV_INSN (insn); | |
705 | #endif | |
706 | ||
707 | /* See if we can create the fallthru edge. */ | |
708 | if (can_fallthru (src, target)) | |
709 | { | |
710 | if (rtl_dump_file) | |
711 | fprintf (rtl_dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
712 | fallthru = 1; | |
713 | ||
eaec9b3d | 714 | /* Selectively unlink whole insn chain. */ |
ca6c03ca JH |
715 | delete_insn_chain (kill_from, PREV_INSN (target->head)); |
716 | } | |
5f0d2358 | 717 | |
ca6c03ca JH |
718 | /* If this already is simplejump, redirect it. */ |
719 | else if (simplejump_p (insn)) | |
720 | { | |
721 | if (e->dest == target) | |
722 | return false; | |
723 | if (rtl_dump_file) | |
724 | fprintf (rtl_dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 725 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
726 | if (!redirect_jump (insn, block_label (target), 0)) |
727 | { | |
728 | if (target == EXIT_BLOCK_PTR) | |
729 | return false; | |
730 | abort (); | |
731 | } | |
ca6c03ca | 732 | } |
5f0d2358 | 733 | |
6ee3c8e4 JJ |
734 | /* Cannot do anything for target exit block. */ |
735 | else if (target == EXIT_BLOCK_PTR) | |
736 | return false; | |
737 | ||
ca6c03ca JH |
738 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
739 | else | |
740 | { | |
741 | rtx target_label = block_label (target); | |
5b1cacd8 | 742 | rtx barrier, tmp; |
ca6c03ca | 743 | |
09eb1aab | 744 | emit_jump_insn_after (gen_jump (target_label), insn); |
ca6c03ca JH |
745 | JUMP_LABEL (src->end) = target_label; |
746 | LABEL_NUSES (target_label)++; | |
747 | if (rtl_dump_file) | |
748 | fprintf (rtl_dump_file, "Replacing insn %i by jump %i\n", | |
749 | INSN_UID (insn), INSN_UID (src->end)); | |
750 | ||
5b1cacd8 | 751 | |
ca6c03ca JH |
752 | delete_insn_chain (kill_from, insn); |
753 | ||
5b1cacd8 JL |
754 | /* Recognize a tablejump that we are converting to a |
755 | simple jump and remove its associated CODE_LABEL | |
756 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
757 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
758 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
759 | && GET_CODE (tmp) == JUMP_INSN | |
760 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
761 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
762 | { | |
763 | delete_insn_chain (JUMP_LABEL (insn), tmp); | |
764 | } | |
765 | ||
ca6c03ca JH |
766 | barrier = next_nonnote_insn (src->end); |
767 | if (!barrier || GET_CODE (barrier) != BARRIER) | |
768 | emit_barrier_after (src->end); | |
769 | } | |
770 | ||
771 | /* Keep only one edge out and set proper flags. */ | |
772 | while (src->succ->succ_next) | |
773 | remove_edge (src->succ); | |
774 | e = src->succ; | |
775 | if (fallthru) | |
776 | e->flags = EDGE_FALLTHRU; | |
777 | else | |
778 | e->flags = 0; | |
5f0d2358 | 779 | |
ca6c03ca JH |
780 | e->probability = REG_BR_PROB_BASE; |
781 | e->count = src->count; | |
782 | ||
783 | /* We don't want a block to end on a line-number note since that has | |
784 | the potential of changing the code between -g and not -g. */ | |
785 | while (GET_CODE (e->src->end) == NOTE | |
786 | && NOTE_LINE_NUMBER (e->src->end) >= 0) | |
787 | delete_insn (e->src->end); | |
788 | ||
789 | if (e->dest != target) | |
790 | redirect_edge_succ (e, target); | |
5f0d2358 | 791 | |
ca6c03ca JH |
792 | return true; |
793 | } | |
794 | ||
795 | /* Return last loop_beg note appearing after INSN, before start of next | |
796 | basic block. Return INSN if there are no such notes. | |
797 | ||
09da1532 | 798 | When emitting jump to redirect a fallthru edge, it should always appear |
5f0d2358 RK |
799 | after the LOOP_BEG notes, as loop optimizer expect loop to either start by |
800 | fallthru edge or jump following the LOOP_BEG note jumping to the loop exit | |
801 | test. */ | |
ca6c03ca JH |
802 | |
803 | static rtx | |
804 | last_loop_beg_note (insn) | |
805 | rtx insn; | |
806 | { | |
807 | rtx last = insn; | |
5f0d2358 RK |
808 | |
809 | for (insn = NEXT_INSN (insn); insn && GET_CODE (insn) == NOTE | |
810 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK; | |
811 | insn = NEXT_INSN (insn)) | |
812 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
813 | last = insn; | |
814 | ||
ca6c03ca JH |
815 | return last; |
816 | } | |
817 | ||
5f0d2358 RK |
818 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on |
819 | expense of adding new instructions or reordering basic blocks. | |
ca6c03ca | 820 | |
5f0d2358 RK |
821 | Function can be also called with edge destination equivalent to the TARGET. |
822 | Then it should try the simplifications and do nothing if none is possible. | |
ca6c03ca | 823 | |
5f0d2358 RK |
824 | Return true if transformation succeeded. We still return false in case E |
825 | already destinated TARGET and we didn't managed to simplify instruction | |
ca6c03ca JH |
826 | stream. */ |
827 | ||
828 | bool | |
829 | redirect_edge_and_branch (e, target) | |
830 | edge e; | |
831 | basic_block target; | |
832 | { | |
833 | rtx tmp; | |
834 | rtx old_label = e->dest->head; | |
835 | basic_block src = e->src; | |
836 | rtx insn = src->end; | |
837 | ||
25b44be5 | 838 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
ca6c03ca JH |
839 | return false; |
840 | ||
841 | if (try_redirect_by_replacing_jump (e, target)) | |
842 | return true; | |
5f0d2358 | 843 | |
ca6c03ca JH |
844 | /* Do this fast path late, as we want above code to simplify for cases |
845 | where called on single edge leaving basic block containing nontrivial | |
846 | jump insn. */ | |
847 | else if (e->dest == target) | |
848 | return false; | |
849 | ||
850 | /* We can only redirect non-fallthru edges of jump insn. */ | |
851 | if (e->flags & EDGE_FALLTHRU) | |
852 | return false; | |
5f0d2358 | 853 | else if (GET_CODE (insn) != JUMP_INSN) |
ca6c03ca JH |
854 | return false; |
855 | ||
856 | /* Recognize a tablejump and adjust all matching cases. */ | |
857 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
858 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
859 | && GET_CODE (tmp) == JUMP_INSN | |
860 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
861 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
862 | { | |
863 | rtvec vec; | |
864 | int j; | |
865 | rtx new_label = block_label (target); | |
866 | ||
6ee3c8e4 JJ |
867 | if (target == EXIT_BLOCK_PTR) |
868 | return false; | |
ca6c03ca JH |
869 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
870 | vec = XVEC (PATTERN (tmp), 0); | |
871 | else | |
872 | vec = XVEC (PATTERN (tmp), 1); | |
873 | ||
874 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
875 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
876 | { | |
877 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
878 | --LABEL_NUSES (old_label); | |
879 | ++LABEL_NUSES (new_label); | |
880 | } | |
881 | ||
882 | /* Handle casesi dispatch insns */ | |
883 | if ((tmp = single_set (insn)) != NULL | |
884 | && SET_DEST (tmp) == pc_rtx | |
885 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
886 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
887 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
888 | { | |
889 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, | |
890 | new_label); | |
891 | --LABEL_NUSES (old_label); | |
892 | ++LABEL_NUSES (new_label); | |
893 | } | |
894 | } | |
895 | else | |
896 | { | |
897 | /* ?? We may play the games with moving the named labels from | |
898 | one basic block to the other in case only one computed_jump is | |
899 | available. */ | |
5f0d2358 RK |
900 | if (computed_jump_p (insn) |
901 | /* A return instruction can't be redirected. */ | |
902 | || returnjump_p (insn)) | |
ca6c03ca JH |
903 | return false; |
904 | ||
905 | /* If the insn doesn't go where we think, we're confused. */ | |
6ee3c8e4 | 906 | if (JUMP_LABEL (insn) != old_label) |
a3623c48 | 907 | abort (); |
6ee3c8e4 JJ |
908 | |
909 | /* If the substitution doesn't succeed, die. This can happen | |
910 | if the back end emitted unrecognizable instructions or if | |
911 | target is exit block on some arches. */ | |
912 | if (!redirect_jump (insn, block_label (target), 0)) | |
913 | { | |
914 | if (target == EXIT_BLOCK_PTR) | |
915 | return false; | |
916 | abort (); | |
917 | } | |
ca6c03ca JH |
918 | } |
919 | ||
920 | if (rtl_dump_file) | |
921 | fprintf (rtl_dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 922 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 923 | |
ca6c03ca JH |
924 | if (e->dest != target) |
925 | redirect_edge_succ_nodup (e, target); | |
5f0d2358 | 926 | |
ca6c03ca JH |
927 | return true; |
928 | } | |
929 | ||
4fe9b91c | 930 | /* Like force_nonfallthru below, but additionally performs redirection |
ca6c03ca JH |
931 | Used by redirect_edge_and_branch_force. */ |
932 | ||
933 | static basic_block | |
934 | force_nonfallthru_and_redirect (e, target) | |
935 | edge e; | |
936 | basic_block target; | |
937 | { | |
a3716585 | 938 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
939 | rtx note; |
940 | edge new_edge; | |
a3716585 | 941 | int abnormal_edge_flags = 0; |
ca6c03ca JH |
942 | |
943 | if (e->flags & EDGE_ABNORMAL) | |
a3716585 JH |
944 | { |
945 | /* Irritating special case - fallthru edge to the same block as abnormal | |
946 | edge. | |
947 | We can't redirect abnormal edge, but we still can split the fallthru | |
948 | one and create separate abnormal edge to original destination. | |
949 | This allows bb-reorder to make such edge non-fallthru. */ | |
950 | if (e->dest != target) | |
951 | abort (); | |
952 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); | |
953 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
954 | } | |
5f0d2358 | 955 | else if (!(e->flags & EDGE_FALLTHRU)) |
ca6c03ca | 956 | abort (); |
24c545ff BS |
957 | else if (e->src == ENTRY_BLOCK_PTR) |
958 | { | |
959 | /* We can't redirect the entry block. Create an empty block at the | |
960 | start of the function which we use to add the new jump. */ | |
961 | edge *pe1; | |
918ed612 | 962 | basic_block bb = create_basic_block (e->dest->head, NULL, ENTRY_BLOCK_PTR); |
24c545ff BS |
963 | |
964 | /* Change the existing edge's source to be the new block, and add | |
965 | a new edge from the entry block to the new block. */ | |
966 | e->src = bb; | |
967 | for (pe1 = &ENTRY_BLOCK_PTR->succ; *pe1; pe1 = &(*pe1)->succ_next) | |
968 | if (*pe1 == e) | |
969 | { | |
970 | *pe1 = e->succ_next; | |
971 | break; | |
972 | } | |
973 | e->succ_next = 0; | |
974 | bb->succ = e; | |
975 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); | |
976 | } | |
977 | ||
a3716585 | 978 | if (e->src->succ->succ_next || abnormal_edge_flags) |
ca6c03ca JH |
979 | { |
980 | /* Create the new structures. */ | |
31a78298 RH |
981 | |
982 | /* Position the new block correctly relative to loop notes. */ | |
ca6c03ca | 983 | note = last_loop_beg_note (e->src->end); |
31a78298 RH |
984 | note = NEXT_INSN (note); |
985 | ||
986 | /* ... and ADDR_VECs. */ | |
987 | if (note != NULL | |
988 | && GET_CODE (note) == CODE_LABEL | |
989 | && NEXT_INSN (note) | |
990 | && GET_CODE (NEXT_INSN (note)) == JUMP_INSN | |
991 | && (GET_CODE (PATTERN (NEXT_INSN (note))) == ADDR_DIFF_VEC | |
992 | || GET_CODE (PATTERN (NEXT_INSN (note))) == ADDR_VEC)) | |
993 | note = NEXT_INSN (NEXT_INSN (note)); | |
994 | ||
995 | jump_block = create_basic_block (note, NULL, e->src); | |
ca6c03ca JH |
996 | jump_block->count = e->count; |
997 | jump_block->frequency = EDGE_FREQUENCY (e); | |
998 | jump_block->loop_depth = target->loop_depth; | |
999 | ||
1000 | if (target->global_live_at_start) | |
1001 | { | |
5f0d2358 RK |
1002 | jump_block->global_live_at_start |
1003 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1004 | jump_block->global_live_at_end | |
1005 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
ca6c03ca JH |
1006 | COPY_REG_SET (jump_block->global_live_at_start, |
1007 | target->global_live_at_start); | |
1008 | COPY_REG_SET (jump_block->global_live_at_end, | |
1009 | target->global_live_at_start); | |
1010 | } | |
1011 | ||
1012 | /* Wire edge in. */ | |
1013 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1014 | new_edge->probability = e->probability; | |
1015 | new_edge->count = e->count; | |
1016 | ||
1017 | /* Redirect old edge. */ | |
1018 | redirect_edge_pred (e, jump_block); | |
1019 | e->probability = REG_BR_PROB_BASE; | |
1020 | ||
1021 | new_bb = jump_block; | |
1022 | } | |
1023 | else | |
1024 | jump_block = e->src; | |
5f0d2358 | 1025 | |
ca6c03ca JH |
1026 | e->flags &= ~EDGE_FALLTHRU; |
1027 | if (target == EXIT_BLOCK_PTR) | |
1028 | { | |
1029 | if (HAVE_return) | |
1030 | emit_jump_insn_after (gen_return (), jump_block->end); | |
1031 | else | |
1032 | abort (); | |
1033 | } | |
1034 | else | |
1035 | { | |
1036 | rtx label = block_label (target); | |
1037 | emit_jump_insn_after (gen_jump (label), jump_block->end); | |
1038 | JUMP_LABEL (jump_block->end) = label; | |
1039 | LABEL_NUSES (label)++; | |
1040 | } | |
5f0d2358 | 1041 | |
ca6c03ca JH |
1042 | emit_barrier_after (jump_block->end); |
1043 | redirect_edge_succ_nodup (e, target); | |
1044 | ||
a3716585 JH |
1045 | if (abnormal_edge_flags) |
1046 | make_edge (src, target, abnormal_edge_flags); | |
1047 | ||
ca6c03ca JH |
1048 | return new_bb; |
1049 | } | |
1050 | ||
1051 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1052 | (and possibly create new basic block) to make edge non-fallthru. | |
1053 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1054 | |
ca6c03ca JH |
1055 | basic_block |
1056 | force_nonfallthru (e) | |
1057 | edge e; | |
1058 | { | |
1059 | return force_nonfallthru_and_redirect (e, e->dest); | |
1060 | } | |
1061 | ||
1062 | /* Redirect edge even at the expense of creating new jump insn or | |
1063 | basic block. Return new basic block if created, NULL otherwise. | |
eaec9b3d | 1064 | Abort if conversion is impossible. */ |
ca6c03ca JH |
1065 | |
1066 | basic_block | |
1067 | redirect_edge_and_branch_force (e, target) | |
1068 | edge e; | |
1069 | basic_block target; | |
1070 | { | |
5f0d2358 RK |
1071 | if (redirect_edge_and_branch (e, target) |
1072 | || e->dest == target) | |
ca6c03ca JH |
1073 | return NULL; |
1074 | ||
1075 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1076 | and redirect newly created simplejump. */ | |
5f0d2358 | 1077 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1078 | } |
1079 | ||
1080 | /* The given edge should potentially be a fallthru edge. If that is in | |
1081 | fact true, delete the jump and barriers that are in the way. */ | |
1082 | ||
1083 | void | |
1084 | tidy_fallthru_edge (e, b, c) | |
1085 | edge e; | |
1086 | basic_block b, c; | |
1087 | { | |
1088 | rtx q; | |
1089 | ||
1090 | /* ??? In a late-running flow pass, other folks may have deleted basic | |
1091 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
1092 | and the target label. They ought to be chastized and fixed. | |
1093 | ||
1094 | We can also wind up with a sequence of undeletable labels between | |
1095 | one block and the next. | |
1096 | ||
1097 | So search through a sequence of barriers, labels, and notes for | |
1098 | the head of block C and assert that we really do fall through. */ | |
1099 | ||
9c0a0632 RH |
1100 | for (q = NEXT_INSN (b->end); q != c->head; q = NEXT_INSN (q)) |
1101 | if (INSN_P (q)) | |
1102 | return; | |
ca6c03ca JH |
1103 | |
1104 | /* Remove what will soon cease being the jump insn from the source block. | |
1105 | If block B consisted only of this single jump, turn it into a deleted | |
1106 | note. */ | |
1107 | q = b->end; | |
1108 | if (GET_CODE (q) == JUMP_INSN | |
1109 | && onlyjump_p (q) | |
1110 | && (any_uncondjump_p (q) | |
1111 | || (b->succ == e && e->succ_next == NULL))) | |
1112 | { | |
1113 | #ifdef HAVE_cc0 | |
1114 | /* If this was a conditional jump, we need to also delete | |
1115 | the insn that set cc0. */ | |
1116 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1117 | q = PREV_INSN (q); | |
1118 | #endif | |
1119 | ||
1120 | q = PREV_INSN (q); | |
1121 | ||
1122 | /* We don't want a block to end on a line-number note since that has | |
1123 | the potential of changing the code between -g and not -g. */ | |
1124 | while (GET_CODE (q) == NOTE && NOTE_LINE_NUMBER (q) >= 0) | |
1125 | q = PREV_INSN (q); | |
1126 | } | |
1127 | ||
1128 | /* Selectively unlink the sequence. */ | |
1129 | if (q != PREV_INSN (c->head)) | |
1130 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (c->head)); | |
1131 | ||
1132 | e->flags |= EDGE_FALLTHRU; | |
1133 | } | |
1134 | ||
1135 | /* Fix up edges that now fall through, or rather should now fall through | |
1136 | but previously required a jump around now deleted blocks. Simplify | |
1137 | the search by only examining blocks numerically adjacent, since this | |
1138 | is how find_basic_blocks created them. */ | |
1139 | ||
1140 | void | |
1141 | tidy_fallthru_edges () | |
1142 | { | |
e0082a72 ZD |
1143 | basic_block b, c; |
1144 | ||
1145 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) | |
1146 | return; | |
ca6c03ca | 1147 | |
e0082a72 | 1148 | FOR_BB_BETWEEN (b, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, next_bb) |
ca6c03ca | 1149 | { |
ca6c03ca JH |
1150 | edge s; |
1151 | ||
e0082a72 ZD |
1152 | c = b->next_bb; |
1153 | ||
ca6c03ca JH |
1154 | /* We care about simple conditional or unconditional jumps with |
1155 | a single successor. | |
1156 | ||
1157 | If we had a conditional branch to the next instruction when | |
1158 | find_basic_blocks was called, then there will only be one | |
1159 | out edge for the block which ended with the conditional | |
1160 | branch (since we do not create duplicate edges). | |
1161 | ||
1162 | Furthermore, the edge will be marked as a fallthru because we | |
1163 | merge the flags for the duplicate edges. So we do not want to | |
1164 | check that the edge is not a FALLTHRU edge. */ | |
5f0d2358 | 1165 | |
ca6c03ca JH |
1166 | if ((s = b->succ) != NULL |
1167 | && ! (s->flags & EDGE_COMPLEX) | |
1168 | && s->succ_next == NULL | |
1169 | && s->dest == c | |
1170 | /* If the jump insn has side effects, we can't tidy the edge. */ | |
1171 | && (GET_CODE (b->end) != JUMP_INSN | |
1172 | || onlyjump_p (b->end))) | |
1173 | tidy_fallthru_edge (s, b, c); | |
1174 | } | |
1175 | } | |
1176 | \f | |
1177 | /* Helper function for split_edge. Return true in case edge BB2 to BB1 | |
1178 | is back edge of syntactic loop. */ | |
1179 | ||
1180 | static bool | |
1181 | back_edge_of_syntactic_loop_p (bb1, bb2) | |
1182 | basic_block bb1, bb2; | |
1183 | { | |
1184 | rtx insn; | |
1185 | int count = 0; | |
bf77398c | 1186 | basic_block bb; |
ca6c03ca | 1187 | |
bf77398c | 1188 | if (bb1 == bb2) |
0b17ab2f | 1189 | return true; |
355e4ec4 | 1190 | |
bf77398c ZD |
1191 | /* ??? Could we guarantee that bb indices are monotone, so that we could |
1192 | just compare them? */ | |
1193 | for (bb = bb1; bb && bb != bb2; bb = bb->next_bb) | |
1194 | continue; | |
1195 | ||
1196 | if (!bb) | |
1197 | return false; | |
1198 | ||
ca6c03ca JH |
1199 | for (insn = bb1->end; insn != bb2->head && count >= 0; |
1200 | insn = NEXT_INSN (insn)) | |
1201 | if (GET_CODE (insn) == NOTE) | |
1202 | { | |
1203 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1204 | count++; | |
5f0d2358 | 1205 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) |
ca6c03ca JH |
1206 | count--; |
1207 | } | |
1208 | ||
1209 | return count >= 0; | |
1210 | } | |
1211 | ||
1212 | /* Split a (typically critical) edge. Return the new block. | |
1213 | Abort on abnormal edges. | |
1214 | ||
1215 | ??? The code generally expects to be called on critical edges. | |
1216 | The case of a block ending in an unconditional jump to a | |
1217 | block with multiple predecessors is not handled optimally. */ | |
1218 | ||
1219 | basic_block | |
1220 | split_edge (edge_in) | |
1221 | edge edge_in; | |
1222 | { | |
1223 | basic_block bb; | |
ca6c03ca JH |
1224 | rtx before; |
1225 | ||
1226 | /* Abnormal edges cannot be split. */ | |
1227 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1228 | abort (); | |
1229 | ||
1230 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1231 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1232 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1233 | { | |
1234 | edge e; | |
5f0d2358 | 1235 | |
ca6c03ca JH |
1236 | for (e = edge_in->dest->pred; e; e = e->pred_next) |
1237 | if (e->flags & EDGE_FALLTHRU) | |
1238 | break; | |
1239 | ||
1240 | if (e) | |
1241 | force_nonfallthru (e); | |
1242 | } | |
1243 | ||
1244 | /* Create the basic block note. | |
1245 | ||
f63d1bf7 | 1246 | Where we place the note can have a noticeable impact on the generated |
ca6c03ca JH |
1247 | code. Consider this cfg: |
1248 | ||
1249 | E | |
1250 | | | |
1251 | 0 | |
1252 | / \ | |
1253 | +->1-->2--->E | |
1254 | | | | |
1255 | +--+ | |
1256 | ||
1257 | If we need to insert an insn on the edge from block 0 to block 1, | |
1258 | we want to ensure the instructions we insert are outside of any | |
1259 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1260 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1261 | ||
1262 | if (edge_in->dest != EXIT_BLOCK_PTR | |
1263 | && PREV_INSN (edge_in->dest->head) | |
1264 | && GET_CODE (PREV_INSN (edge_in->dest->head)) == NOTE | |
5f0d2358 RK |
1265 | && (NOTE_LINE_NUMBER (PREV_INSN (edge_in->dest->head)) |
1266 | == NOTE_INSN_LOOP_BEG) | |
ca6c03ca JH |
1267 | && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src)) |
1268 | before = PREV_INSN (edge_in->dest->head); | |
1269 | else if (edge_in->dest != EXIT_BLOCK_PTR) | |
1270 | before = edge_in->dest->head; | |
1271 | else | |
1272 | before = NULL_RTX; | |
1273 | ||
918ed612 | 1274 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); |
ca6c03ca JH |
1275 | bb->count = edge_in->count; |
1276 | bb->frequency = EDGE_FREQUENCY (edge_in); | |
1277 | ||
1278 | /* ??? This info is likely going to be out of date very soon. */ | |
1279 | if (edge_in->dest->global_live_at_start) | |
1280 | { | |
1281 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1282 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
5f0d2358 RK |
1283 | COPY_REG_SET (bb->global_live_at_start, |
1284 | edge_in->dest->global_live_at_start); | |
1285 | COPY_REG_SET (bb->global_live_at_end, | |
1286 | edge_in->dest->global_live_at_start); | |
ca6c03ca JH |
1287 | } |
1288 | ||
4977bab6 | 1289 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca JH |
1290 | |
1291 | /* For non-fallthry edges, we must adjust the predecessor's | |
1292 | jump instruction to target our new block. */ | |
1293 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1294 | { | |
1295 | if (!redirect_edge_and_branch (edge_in, bb)) | |
1296 | abort (); | |
1297 | } | |
1298 | else | |
1299 | redirect_edge_succ (edge_in, bb); | |
1300 | ||
1301 | return bb; | |
1302 | } | |
1303 | ||
1304 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1305 | The new instructions and basic blocks (if any) will not appear in the | |
1306 | CFG until commit_edge_insertions is called. */ | |
1307 | ||
1308 | void | |
1309 | insert_insn_on_edge (pattern, e) | |
1310 | rtx pattern; | |
1311 | edge e; | |
1312 | { | |
1313 | /* We cannot insert instructions on an abnormal critical edge. | |
1314 | It will be easier to find the culprit if we die now. */ | |
1315 | if ((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e)) | |
1316 | abort (); | |
1317 | ||
1318 | if (e->insns == NULL_RTX) | |
1319 | start_sequence (); | |
1320 | else | |
1321 | push_to_sequence (e->insns); | |
1322 | ||
1323 | emit_insn (pattern); | |
1324 | ||
1325 | e->insns = get_insns (); | |
1326 | end_sequence (); | |
1327 | } | |
1328 | ||
1329 | /* Update the CFG for the instructions queued on edge E. */ | |
1330 | ||
1331 | static void | |
3dec4024 | 1332 | commit_one_edge_insertion (e, watch_calls) |
ca6c03ca | 1333 | edge e; |
3dec4024 | 1334 | int watch_calls; |
ca6c03ca JH |
1335 | { |
1336 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1337 | basic_block bb = NULL; |
ca6c03ca JH |
1338 | |
1339 | /* Pull the insns off the edge now since the edge might go away. */ | |
1340 | insns = e->insns; | |
1341 | e->insns = NULL_RTX; | |
1342 | ||
3dec4024 JH |
1343 | /* Special case -- avoid inserting code between call and storing |
1344 | its return value. */ | |
1345 | if (watch_calls && (e->flags & EDGE_FALLTHRU) && !e->dest->pred->pred_next | |
1346 | && e->src != ENTRY_BLOCK_PTR | |
1347 | && GET_CODE (e->src->end) == CALL_INSN) | |
ca6c03ca | 1348 | { |
3dec4024 | 1349 | rtx next = next_nonnote_insn (e->src->end); |
ca6c03ca | 1350 | |
3dec4024 JH |
1351 | after = e->dest->head; |
1352 | /* The first insn after the call may be a stack pop, skip it. */ | |
1353 | while (next | |
1354 | && keep_with_call_p (next)) | |
f87c27b4 KH |
1355 | { |
1356 | after = next; | |
3dec4024 JH |
1357 | next = next_nonnote_insn (next); |
1358 | } | |
1359 | bb = e->dest; | |
ca6c03ca | 1360 | } |
3dec4024 | 1361 | if (!before && !after) |
ca6c03ca | 1362 | { |
3dec4024 JH |
1363 | /* Figure out where to put these things. If the destination has |
1364 | one predecessor, insert there. Except for the exit block. */ | |
1365 | if (e->dest->pred->pred_next == NULL && e->dest != EXIT_BLOCK_PTR) | |
ca6c03ca | 1366 | { |
3dec4024 JH |
1367 | bb = e->dest; |
1368 | ||
1369 | /* Get the location correct wrt a code label, and "nice" wrt | |
1370 | a basic block note, and before everything else. */ | |
1371 | tmp = bb->head; | |
1372 | if (GET_CODE (tmp) == CODE_LABEL) | |
1373 | tmp = NEXT_INSN (tmp); | |
1374 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1375 | tmp = NEXT_INSN (tmp); | |
1376 | if (tmp == bb->head) | |
1377 | before = tmp; | |
1378 | else if (tmp) | |
1379 | after = PREV_INSN (tmp); | |
1380 | else | |
1381 | after = get_last_insn (); | |
1382 | } | |
1383 | ||
1384 | /* If the source has one successor and the edge is not abnormal, | |
1385 | insert there. Except for the entry block. */ | |
1386 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1387 | && e->src->succ->succ_next == NULL | |
1388 | && e->src != ENTRY_BLOCK_PTR) | |
1389 | { | |
1390 | bb = e->src; | |
1391 | ||
1392 | /* It is possible to have a non-simple jump here. Consider a target | |
1393 | where some forms of unconditional jumps clobber a register. This | |
1394 | happens on the fr30 for example. | |
1395 | ||
1396 | We know this block has a single successor, so we can just emit | |
1397 | the queued insns before the jump. */ | |
1398 | if (GET_CODE (bb->end) == JUMP_INSN) | |
1399 | for (before = bb->end; | |
1400 | GET_CODE (PREV_INSN (before)) == NOTE | |
1401 | && NOTE_LINE_NUMBER (PREV_INSN (before)) == | |
1402 | NOTE_INSN_LOOP_BEG; before = PREV_INSN (before)) | |
1403 | ; | |
1404 | else | |
1405 | { | |
1406 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1407 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1408 | abort (); | |
ca6c03ca | 1409 | |
3dec4024 JH |
1410 | after = bb->end; |
1411 | } | |
1412 | } | |
1413 | /* Otherwise we must split the edge. */ | |
1414 | else | |
1415 | { | |
1416 | bb = split_edge (e); | |
ca6c03ca JH |
1417 | after = bb->end; |
1418 | } | |
1419 | } | |
1420 | ||
ca6c03ca JH |
1421 | /* Now that we've found the spot, do the insertion. */ |
1422 | ||
1423 | if (before) | |
1424 | { | |
2f937369 | 1425 | emit_insn_before (insns, before); |
ca6c03ca JH |
1426 | last = prev_nonnote_insn (before); |
1427 | } | |
1428 | else | |
2f937369 | 1429 | last = emit_insn_after (insns, after); |
ca6c03ca JH |
1430 | |
1431 | if (returnjump_p (last)) | |
1432 | { | |
1433 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
1434 | This is not currently a problem because this only happens | |
3dec4024 JH |
1435 | for the (single) epilogue, which already has a fallthru edge |
1436 | to EXIT. */ | |
ca6c03ca JH |
1437 | |
1438 | e = bb->succ; | |
1439 | if (e->dest != EXIT_BLOCK_PTR | |
3dec4024 | 1440 | || e->succ_next != NULL || (e->flags & EDGE_FALLTHRU) == 0) |
ca6c03ca | 1441 | abort (); |
ca6c03ca | 1442 | |
5f0d2358 | 1443 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1444 | emit_barrier_after (last); |
0b17ab2f | 1445 | |
ca6c03ca JH |
1446 | if (before) |
1447 | delete_insn (before); | |
1448 | } | |
1449 | else if (GET_CODE (last) == JUMP_INSN) | |
1450 | abort (); | |
5f0d2358 | 1451 | |
9dca2ad5 JH |
1452 | /* Mark the basic block for find_sub_basic_blocks. */ |
1453 | bb->aux = &bb->aux; | |
ca6c03ca JH |
1454 | } |
1455 | ||
1456 | /* Update the CFG for all queued instructions. */ | |
1457 | ||
1458 | void | |
1459 | commit_edge_insertions () | |
1460 | { | |
ca6c03ca | 1461 | basic_block bb; |
9dca2ad5 | 1462 | sbitmap blocks; |
9809a362 | 1463 | bool changed = false; |
ca6c03ca JH |
1464 | |
1465 | #ifdef ENABLE_CHECKING | |
1466 | verify_flow_info (); | |
1467 | #endif | |
1468 | ||
e0082a72 | 1469 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca JH |
1470 | { |
1471 | edge e, next; | |
1472 | ||
1473 | for (e = bb->succ; e; e = next) | |
1474 | { | |
1475 | next = e->succ_next; | |
1476 | if (e->insns) | |
9809a362 JH |
1477 | { |
1478 | changed = true; | |
1479 | commit_one_edge_insertion (e, false); | |
1480 | } | |
3dec4024 | 1481 | } |
3dec4024 | 1482 | } |
9dca2ad5 | 1483 | |
9809a362 JH |
1484 | if (!changed) |
1485 | return; | |
1486 | ||
9dca2ad5 JH |
1487 | blocks = sbitmap_alloc (last_basic_block); |
1488 | sbitmap_zero (blocks); | |
1489 | FOR_EACH_BB (bb) | |
1490 | if (bb->aux) | |
1491 | { | |
1492 | SET_BIT (blocks, bb->index); | |
1493 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1494 | call. */ | |
1495 | if (bb->aux != &bb->aux) | |
1496 | abort (); | |
1497 | bb->aux = NULL; | |
1498 | } | |
1499 | find_many_sub_basic_blocks (blocks); | |
1500 | sbitmap_free (blocks); | |
3dec4024 JH |
1501 | } |
1502 | \f | |
1503 | /* Update the CFG for all queued instructions, taking special care of inserting | |
1504 | code on edges between call and storing its return value. */ | |
1505 | ||
1506 | void | |
1507 | commit_edge_insertions_watch_calls () | |
1508 | { | |
3dec4024 | 1509 | basic_block bb; |
9809a362 JH |
1510 | sbitmap blocks; |
1511 | bool changed = false; | |
3dec4024 JH |
1512 | |
1513 | #ifdef ENABLE_CHECKING | |
1514 | verify_flow_info (); | |
1515 | #endif | |
1516 | ||
e0082a72 | 1517 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
3dec4024 JH |
1518 | { |
1519 | edge e, next; | |
1520 | ||
1521 | for (e = bb->succ; e; e = next) | |
1522 | { | |
1523 | next = e->succ_next; | |
1524 | if (e->insns) | |
9809a362 JH |
1525 | { |
1526 | changed = true; | |
1527 | commit_one_edge_insertion (e, true); | |
1528 | } | |
ca6c03ca | 1529 | } |
ca6c03ca | 1530 | } |
9809a362 JH |
1531 | |
1532 | if (!changed) | |
1533 | return; | |
1534 | ||
1535 | blocks = sbitmap_alloc (last_basic_block); | |
1536 | sbitmap_zero (blocks); | |
1537 | FOR_EACH_BB (bb) | |
1538 | if (bb->aux) | |
1539 | { | |
1540 | SET_BIT (blocks, bb->index); | |
1541 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1542 | call. */ | |
1543 | if (bb->aux != &bb->aux) | |
1544 | abort (); | |
1545 | bb->aux = NULL; | |
1546 | } | |
1547 | find_many_sub_basic_blocks (blocks); | |
1548 | sbitmap_free (blocks); | |
ca6c03ca JH |
1549 | } |
1550 | \f | |
1551 | /* Print out one basic block with live information at start and end. */ | |
1552 | ||
1553 | void | |
1554 | dump_bb (bb, outf) | |
1555 | basic_block bb; | |
1556 | FILE *outf; | |
1557 | { | |
1558 | rtx insn; | |
1559 | rtx last; | |
1560 | edge e; | |
1561 | ||
1562 | fprintf (outf, ";; Basic block %d, loop depth %d, count ", | |
0b17ab2f | 1563 | bb->index, bb->loop_depth); |
ca6c03ca JH |
1564 | fprintf (outf, HOST_WIDEST_INT_PRINT_DEC, (HOST_WIDEST_INT) bb->count); |
1565 | putc ('\n', outf); | |
1566 | ||
1567 | fputs (";; Predecessors: ", outf); | |
1568 | for (e = bb->pred; e; e = e->pred_next) | |
1569 | dump_edge_info (outf, e, 0); | |
1570 | putc ('\n', outf); | |
1571 | ||
1572 | fputs (";; Registers live at start:", outf); | |
1573 | dump_regset (bb->global_live_at_start, outf); | |
1574 | putc ('\n', outf); | |
1575 | ||
5f0d2358 | 1576 | for (insn = bb->head, last = NEXT_INSN (bb->end); insn != last; |
ca6c03ca JH |
1577 | insn = NEXT_INSN (insn)) |
1578 | print_rtl_single (outf, insn); | |
1579 | ||
1580 | fputs (";; Registers live at end:", outf); | |
1581 | dump_regset (bb->global_live_at_end, outf); | |
1582 | putc ('\n', outf); | |
1583 | ||
1584 | fputs (";; Successors: ", outf); | |
1585 | for (e = bb->succ; e; e = e->succ_next) | |
1586 | dump_edge_info (outf, e, 1); | |
1587 | putc ('\n', outf); | |
1588 | } | |
1589 | ||
1590 | void | |
1591 | debug_bb (bb) | |
1592 | basic_block bb; | |
1593 | { | |
1594 | dump_bb (bb, stderr); | |
1595 | } | |
1596 | ||
35b07080 | 1597 | basic_block |
ca6c03ca JH |
1598 | debug_bb_n (n) |
1599 | int n; | |
1600 | { | |
35b07080 ZD |
1601 | basic_block bb = BASIC_BLOCK (n); |
1602 | dump_bb (bb, stderr); | |
1603 | return bb; | |
ca6c03ca JH |
1604 | } |
1605 | \f | |
1606 | /* Like print_rtl, but also print out live information for the start of each | |
1607 | basic block. */ | |
1608 | ||
1609 | void | |
1610 | print_rtl_with_bb (outf, rtx_first) | |
1611 | FILE *outf; | |
1612 | rtx rtx_first; | |
1613 | { | |
b3694847 | 1614 | rtx tmp_rtx; |
ca6c03ca JH |
1615 | |
1616 | if (rtx_first == 0) | |
1617 | fprintf (outf, "(nil)\n"); | |
1618 | else | |
1619 | { | |
ca6c03ca JH |
1620 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1621 | int max_uid = get_max_uid (); | |
5f0d2358 RK |
1622 | basic_block *start |
1623 | = (basic_block *) xcalloc (max_uid, sizeof (basic_block)); | |
1624 | basic_block *end | |
1625 | = (basic_block *) xcalloc (max_uid, sizeof (basic_block)); | |
1626 | enum bb_state *in_bb_p | |
1627 | = (enum bb_state *) xcalloc (max_uid, sizeof (enum bb_state)); | |
ca6c03ca | 1628 | |
e0082a72 ZD |
1629 | basic_block bb; |
1630 | ||
1631 | FOR_EACH_BB_REVERSE (bb) | |
ca6c03ca | 1632 | { |
ca6c03ca JH |
1633 | rtx x; |
1634 | ||
1635 | start[INSN_UID (bb->head)] = bb; | |
1636 | end[INSN_UID (bb->end)] = bb; | |
1637 | for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x)) | |
1638 | { | |
1639 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1640 | |
ca6c03ca JH |
1641 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1642 | state = IN_ONE_BB; | |
1643 | in_bb_p[INSN_UID (x)] = state; | |
1644 | ||
1645 | if (x == bb->end) | |
1646 | break; | |
1647 | } | |
1648 | } | |
1649 | ||
1650 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1651 | { | |
1652 | int did_output; | |
ca6c03ca JH |
1653 | |
1654 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) | |
1655 | { | |
1656 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
0b17ab2f | 1657 | bb->index); |
ca6c03ca JH |
1658 | dump_regset (bb->global_live_at_start, outf); |
1659 | putc ('\n', outf); | |
1660 | } | |
1661 | ||
1662 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
1663 | && GET_CODE (tmp_rtx) != NOTE | |
1664 | && GET_CODE (tmp_rtx) != BARRIER) | |
1665 | fprintf (outf, ";; Insn is not within a basic block\n"); | |
1666 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1667 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1668 | ||
1669 | did_output = print_rtl_single (outf, tmp_rtx); | |
1670 | ||
1671 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1672 | { | |
1673 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
0b17ab2f | 1674 | bb->index); |
ca6c03ca JH |
1675 | dump_regset (bb->global_live_at_end, outf); |
1676 | putc ('\n', outf); | |
1677 | } | |
1678 | ||
1679 | if (did_output) | |
1680 | putc ('\n', outf); | |
1681 | } | |
1682 | ||
1683 | free (start); | |
1684 | free (end); | |
1685 | free (in_bb_p); | |
1686 | } | |
1687 | ||
1688 | if (current_function_epilogue_delay_list != 0) | |
1689 | { | |
1690 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
1691 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
1692 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
1693 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1694 | } | |
1695 | } | |
1696 | \f | |
b446e5a2 JH |
1697 | void |
1698 | update_br_prob_note (bb) | |
1699 | basic_block bb; | |
1700 | { | |
1701 | rtx note; | |
1702 | if (GET_CODE (bb->end) != JUMP_INSN) | |
1703 | return; | |
1704 | note = find_reg_note (bb->end, REG_BR_PROB, NULL_RTX); | |
1705 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) | |
1706 | return; | |
1707 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1708 | } | |
1709 | \f | |
ca6c03ca JH |
1710 | /* Verify the CFG consistency. This function check some CFG invariants and |
1711 | aborts when something is wrong. Hope that this function will help to | |
1712 | convert many optimization passes to preserve CFG consistent. | |
1713 | ||
1714 | Currently it does following checks: | |
1715 | ||
1716 | - test head/end pointers | |
1717 | - overlapping of basic blocks | |
1718 | - edge list correctness | |
1719 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) | |
f63d1bf7 | 1720 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1721 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1722 | and NOTE_INSN_BASIC_BLOCK | |
1723 | - check that all insns are in the basic blocks | |
5f0d2358 | 1724 | (except the switch handling code, barriers and notes) |
ca6c03ca JH |
1725 | - check that all returns are followed by barriers |
1726 | ||
1727 | In future it can be extended check a lot of other stuff as well | |
1728 | (reachability of basic blocks, life information, etc. etc.). */ | |
1729 | ||
1730 | void | |
1731 | verify_flow_info () | |
1732 | { | |
1733 | const int max_uid = get_max_uid (); | |
1734 | const rtx rtx_first = get_insns (); | |
1735 | rtx last_head = get_last_insn (); | |
1736 | basic_block *bb_info, *last_visited; | |
1737 | size_t *edge_checksum; | |
1738 | rtx x; | |
bf77398c | 1739 | int num_bb_notes, err = 0; |
918ed612 | 1740 | basic_block bb, last_bb_seen; |
ca6c03ca JH |
1741 | |
1742 | bb_info = (basic_block *) xcalloc (max_uid, sizeof (basic_block)); | |
d55bc081 | 1743 | last_visited = (basic_block *) xcalloc (last_basic_block + 2, |
ca6c03ca | 1744 | sizeof (basic_block)); |
d55bc081 | 1745 | edge_checksum = (size_t *) xcalloc (last_basic_block + 2, sizeof (size_t)); |
ca6c03ca | 1746 | |
918ed612 ZD |
1747 | /* Check bb chain & numbers. */ |
1748 | last_bb_seen = ENTRY_BLOCK_PTR; | |
1749 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb, NULL, next_bb) | |
1750 | { | |
1751 | if (bb != EXIT_BLOCK_PTR | |
1752 | && bb != BASIC_BLOCK (bb->index)) | |
1753 | { | |
1754 | error ("bb %d on wrong place", bb->index); | |
1755 | err = 1; | |
1756 | } | |
1757 | ||
1758 | if (bb->prev_bb != last_bb_seen) | |
1759 | { | |
1760 | error ("prev_bb of %d should be %d, not %d", | |
1761 | bb->index, last_bb_seen->index, bb->prev_bb->index); | |
1762 | err = 1; | |
1763 | } | |
1764 | ||
918ed612 ZD |
1765 | last_bb_seen = bb; |
1766 | } | |
1767 | ||
e0082a72 | 1768 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1769 | { |
ca6c03ca JH |
1770 | rtx head = bb->head; |
1771 | rtx end = bb->end; | |
1772 | ||
1773 | /* Verify the end of the basic block is in the INSN chain. */ | |
1774 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
1775 | if (x == end) | |
1776 | break; | |
5f0d2358 | 1777 | |
ca6c03ca JH |
1778 | if (!x) |
1779 | { | |
1f978f5f | 1780 | error ("end insn %d for block %d not found in the insn stream", |
0b17ab2f | 1781 | INSN_UID (end), bb->index); |
ca6c03ca JH |
1782 | err = 1; |
1783 | } | |
1784 | ||
1785 | /* Work backwards from the end to the head of the basic block | |
1786 | to verify the head is in the RTL chain. */ | |
1787 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
1788 | { | |
1789 | /* While walking over the insn chain, verify insns appear | |
1790 | in only one basic block and initialize the BB_INFO array | |
1791 | used by other passes. */ | |
1792 | if (bb_info[INSN_UID (x)] != NULL) | |
1793 | { | |
1f978f5f | 1794 | error ("insn %d is in multiple basic blocks (%d and %d)", |
0b17ab2f | 1795 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); |
ca6c03ca JH |
1796 | err = 1; |
1797 | } | |
5f0d2358 | 1798 | |
ca6c03ca JH |
1799 | bb_info[INSN_UID (x)] = bb; |
1800 | ||
1801 | if (x == head) | |
1802 | break; | |
1803 | } | |
1804 | if (!x) | |
1805 | { | |
1f978f5f | 1806 | error ("head insn %d for block %d not found in the insn stream", |
0b17ab2f | 1807 | INSN_UID (head), bb->index); |
ca6c03ca JH |
1808 | err = 1; |
1809 | } | |
1810 | ||
1811 | last_head = x; | |
1812 | } | |
1813 | ||
1814 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1815 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1816 | { |
3dec4024 | 1817 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
ca6c03ca | 1818 | edge e; |
5a1a3e5e | 1819 | rtx note; |
ca6c03ca | 1820 | |
5a1a3e5e | 1821 | if (INSN_P (bb->end) |
1e3881c2 | 1822 | && (note = find_reg_note (bb->end, REG_BR_PROB, NULL_RTX)) |
3e638a90 | 1823 | && bb->succ && bb->succ->succ_next |
1e3881c2 | 1824 | && any_condjump_p (bb->end)) |
5a1a3e5e | 1825 | { |
5a1a3e5e JH |
1826 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability) |
1827 | { | |
1828 | error ("verify_flow_info: REG_BR_PROB does not match cfg %i %i", | |
1829 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); | |
1830 | err = 1; | |
1831 | } | |
1832 | } | |
1833 | if (bb->count < 0) | |
f87c27b4 KH |
1834 | { |
1835 | error ("verify_flow_info: Wrong count of block %i %i", | |
0b17ab2f | 1836 | bb->index, (int)bb->count); |
f87c27b4 KH |
1837 | err = 1; |
1838 | } | |
5a1a3e5e | 1839 | if (bb->frequency < 0) |
f87c27b4 KH |
1840 | { |
1841 | error ("verify_flow_info: Wrong frequency of block %i %i", | |
0b17ab2f | 1842 | bb->index, bb->frequency); |
f87c27b4 KH |
1843 | err = 1; |
1844 | } | |
5f0d2358 | 1845 | for (e = bb->succ; e; e = e->succ_next) |
ca6c03ca | 1846 | { |
0b17ab2f | 1847 | if (last_visited [e->dest->index + 2] == bb) |
ca6c03ca JH |
1848 | { |
1849 | error ("verify_flow_info: Duplicate edge %i->%i", | |
0b17ab2f | 1850 | e->src->index, e->dest->index); |
ca6c03ca JH |
1851 | err = 1; |
1852 | } | |
5a1a3e5e JH |
1853 | if (e->probability < 0 || e->probability > REG_BR_PROB_BASE) |
1854 | { | |
1855 | error ("verify_flow_info: Wrong probability of edge %i->%i %i", | |
0b17ab2f | 1856 | e->src->index, e->dest->index, e->probability); |
5a1a3e5e JH |
1857 | err = 1; |
1858 | } | |
1859 | if (e->count < 0) | |
1860 | { | |
1861 | error ("verify_flow_info: Wrong count of edge %i->%i %i", | |
0b17ab2f | 1862 | e->src->index, e->dest->index, (int)e->count); |
5a1a3e5e JH |
1863 | err = 1; |
1864 | } | |
5f0d2358 | 1865 | |
0b17ab2f | 1866 | last_visited [e->dest->index + 2] = bb; |
ca6c03ca JH |
1867 | |
1868 | if (e->flags & EDGE_FALLTHRU) | |
3dec4024 JH |
1869 | n_fallthru++; |
1870 | ||
35b07080 | 1871 | if ((e->flags & ~(EDGE_DFS_BACK | EDGE_CAN_FALLTHRU | EDGE_IRREDUCIBLE_LOOP)) == 0) |
3dec4024 JH |
1872 | n_branch++; |
1873 | ||
1874 | if (e->flags & EDGE_ABNORMAL_CALL) | |
1875 | n_call++; | |
1876 | ||
1877 | if (e->flags & EDGE_EH) | |
1878 | n_eh++; | |
1879 | else if (e->flags & EDGE_ABNORMAL) | |
1880 | n_abnormal++; | |
ca6c03ca JH |
1881 | |
1882 | if ((e->flags & EDGE_FALLTHRU) | |
1883 | && e->src != ENTRY_BLOCK_PTR | |
1884 | && e->dest != EXIT_BLOCK_PTR) | |
1885 | { | |
1886 | rtx insn; | |
5f0d2358 | 1887 | |
f6366fc7 | 1888 | if (e->src->next_bb != e->dest) |
ca6c03ca | 1889 | { |
5f0d2358 RK |
1890 | error |
1891 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
0b17ab2f | 1892 | e->src->index, e->dest->index); |
5f0d2358 | 1893 | err = 1; |
ca6c03ca JH |
1894 | } |
1895 | else | |
1896 | for (insn = NEXT_INSN (e->src->end); insn != e->dest->head; | |
1897 | insn = NEXT_INSN (insn)) | |
32a6f30e JDA |
1898 | if (GET_CODE (insn) == BARRIER |
1899 | #ifndef CASE_DROPS_THROUGH | |
5f0d2358 | 1900 | || INSN_P (insn) |
32a6f30e | 1901 | #else |
5f0d2358 | 1902 | || (INSN_P (insn) && ! JUMP_TABLE_DATA_P (insn)) |
32a6f30e | 1903 | #endif |
5f0d2358 | 1904 | ) |
ca6c03ca JH |
1905 | { |
1906 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
0b17ab2f | 1907 | e->src->index, e->dest->index); |
1f978f5f | 1908 | fatal_insn ("wrong insn in the fallthru edge", insn); |
ca6c03ca JH |
1909 | err = 1; |
1910 | } | |
1911 | } | |
5f0d2358 | 1912 | |
ca6c03ca JH |
1913 | if (e->src != bb) |
1914 | { | |
1915 | error ("verify_flow_info: Basic block %d succ edge is corrupted", | |
0b17ab2f | 1916 | bb->index); |
ca6c03ca JH |
1917 | fprintf (stderr, "Predecessor: "); |
1918 | dump_edge_info (stderr, e, 0); | |
1919 | fprintf (stderr, "\nSuccessor: "); | |
1920 | dump_edge_info (stderr, e, 1); | |
1921 | fprintf (stderr, "\n"); | |
1922 | err = 1; | |
1923 | } | |
5f0d2358 | 1924 | |
0b17ab2f | 1925 | edge_checksum[e->dest->index + 2] += (size_t) e; |
ca6c03ca | 1926 | } |
5f0d2358 | 1927 | |
a2877a09 JH |
1928 | if (n_eh && GET_CODE (PATTERN (bb->end)) != RESX |
1929 | && !find_reg_note (bb->end, REG_EH_REGION, NULL_RTX)) | |
3dec4024 | 1930 | { |
0b17ab2f | 1931 | error ("Missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
1932 | err = 1; |
1933 | } | |
1934 | if (n_branch | |
1935 | && (GET_CODE (bb->end) != JUMP_INSN | |
1936 | || (n_branch > 1 && (any_uncondjump_p (bb->end) | |
1937 | || any_condjump_p (bb->end))))) | |
1938 | { | |
0b17ab2f | 1939 | error ("Too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
1940 | err = 1; |
1941 | } | |
1942 | if (n_fallthru && any_uncondjump_p (bb->end)) | |
1943 | { | |
0b17ab2f | 1944 | error ("Fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
1945 | err = 1; |
1946 | } | |
1947 | if (n_branch != 1 && any_uncondjump_p (bb->end)) | |
1948 | { | |
0b17ab2f | 1949 | error ("Wrong amount of branch edges after unconditional jump %i", bb->index); |
3dec4024 JH |
1950 | err = 1; |
1951 | } | |
1952 | if (n_branch != 1 && any_condjump_p (bb->end) | |
f6366fc7 | 1953 | && JUMP_LABEL (bb->end) != bb->next_bb->head) |
3dec4024 | 1954 | { |
0b17ab2f | 1955 | error ("Wrong amount of branch edges after conditional jump %i", bb->index); |
3dec4024 JH |
1956 | err = 1; |
1957 | } | |
1958 | if (n_call && GET_CODE (bb->end) != CALL_INSN) | |
1959 | { | |
0b17ab2f | 1960 | error ("Call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
1961 | err = 1; |
1962 | } | |
1963 | if (n_abnormal | |
1964 | && (GET_CODE (bb->end) != CALL_INSN && n_call != n_abnormal) | |
1965 | && (GET_CODE (bb->end) != JUMP_INSN | |
1966 | || any_condjump_p (bb->end) | |
1967 | || any_uncondjump_p (bb->end))) | |
1968 | { | |
0b17ab2f | 1969 | error ("Abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
1970 | err = 1; |
1971 | } | |
f87c27b4 | 1972 | |
3dec4024 | 1973 | if (!n_fallthru) |
ca6c03ca | 1974 | { |
09eb1aab | 1975 | rtx insn; |
ca6c03ca JH |
1976 | |
1977 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
09eb1aab | 1978 | for (insn = bb->end; !insn || GET_CODE (insn) != BARRIER; |
ca6c03ca JH |
1979 | insn = NEXT_INSN (insn)) |
1980 | if (!insn | |
1981 | || (GET_CODE (insn) == NOTE | |
1982 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)) | |
1983 | { | |
0b17ab2f | 1984 | error ("missing barrier after block %i", bb->index); |
ca6c03ca | 1985 | err = 1; |
09eb1aab | 1986 | break; |
ca6c03ca JH |
1987 | } |
1988 | } | |
1989 | ||
5f0d2358 | 1990 | for (e = bb->pred; e; e = e->pred_next) |
ca6c03ca JH |
1991 | { |
1992 | if (e->dest != bb) | |
1993 | { | |
0b17ab2f | 1994 | error ("basic block %d pred edge is corrupted", bb->index); |
ca6c03ca JH |
1995 | fputs ("Predecessor: ", stderr); |
1996 | dump_edge_info (stderr, e, 0); | |
1997 | fputs ("\nSuccessor: ", stderr); | |
1998 | dump_edge_info (stderr, e, 1); | |
1999 | fputc ('\n', stderr); | |
2000 | err = 1; | |
2001 | } | |
0b17ab2f | 2002 | edge_checksum[e->dest->index + 2] -= (size_t) e; |
ca6c03ca | 2003 | } |
5f0d2358 RK |
2004 | |
2005 | for (x = bb->head; x != NEXT_INSN (bb->end); x = NEXT_INSN (x)) | |
ba4f7968 | 2006 | if (BLOCK_FOR_INSN (x) != bb) |
5f0d2358 RK |
2007 | { |
2008 | debug_rtx (x); | |
2009 | if (! BLOCK_FOR_INSN (x)) | |
2010 | error | |
2011 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 2012 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2013 | else |
2014 | error | |
2015 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 2016 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
2017 | |
2018 | err = 1; | |
2019 | } | |
ca6c03ca JH |
2020 | |
2021 | /* OK pointers are correct. Now check the header of basic | |
2022 | block. It ought to contain optional CODE_LABEL followed | |
2023 | by NOTE_BASIC_BLOCK. */ | |
2024 | x = bb->head; | |
2025 | if (GET_CODE (x) == CODE_LABEL) | |
2026 | { | |
2027 | if (bb->end == x) | |
2028 | { | |
2029 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2030 | bb->index); |
ca6c03ca JH |
2031 | err = 1; |
2032 | } | |
5f0d2358 | 2033 | |
ca6c03ca JH |
2034 | x = NEXT_INSN (x); |
2035 | } | |
5f0d2358 | 2036 | |
ca6c03ca JH |
2037 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2038 | { | |
2039 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2040 | bb->index); |
ca6c03ca JH |
2041 | err = 1; |
2042 | } | |
2043 | ||
2044 | if (bb->end == x) | |
5f0d2358 RK |
2045 | /* Do checks for empty blocks her. e */ |
2046 | ; | |
ca6c03ca | 2047 | else |
5f0d2358 RK |
2048 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2049 | { | |
2050 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2051 | { | |
2052 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2053 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2054 | err = 1; |
2055 | } | |
2056 | ||
2057 | if (x == bb->end) | |
2058 | break; | |
ca6c03ca | 2059 | |
83fd323c | 2060 | if (control_flow_insn_p (x)) |
5f0d2358 | 2061 | { |
0b17ab2f | 2062 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2063 | fatal_insn ("flow control insn inside a basic block", x); |
2064 | } | |
2065 | } | |
ca6c03ca JH |
2066 | } |
2067 | ||
2068 | /* Complete edge checksumming for ENTRY and EXIT. */ | |
2069 | { | |
2070 | edge e; | |
5f0d2358 | 2071 | |
ca6c03ca | 2072 | for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next) |
0b17ab2f | 2073 | edge_checksum[e->dest->index + 2] += (size_t) e; |
5f0d2358 | 2074 | |
ca6c03ca | 2075 | for (e = EXIT_BLOCK_PTR->pred; e ; e = e->pred_next) |
0b17ab2f | 2076 | edge_checksum[e->dest->index + 2] -= (size_t) e; |
ca6c03ca JH |
2077 | } |
2078 | ||
bf77398c ZD |
2079 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) |
2080 | if (edge_checksum[bb->index + 2]) | |
ca6c03ca | 2081 | { |
bf77398c | 2082 | error ("basic block %i edge lists are corrupted", bb->index); |
ca6c03ca JH |
2083 | err = 1; |
2084 | } | |
2085 | ||
ca6c03ca | 2086 | num_bb_notes = 0; |
e0082a72 ZD |
2087 | last_bb_seen = ENTRY_BLOCK_PTR; |
2088 | ||
5f0d2358 | 2089 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2090 | { |
2091 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2092 | { | |
bf77398c | 2093 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2094 | |
ca6c03ca | 2095 | num_bb_notes++; |
e0082a72 | 2096 | if (bb != last_bb_seen->next_bb) |
c725bd79 | 2097 | internal_error ("basic blocks not numbered consecutively"); |
ca6c03ca | 2098 | |
e0082a72 | 2099 | last_bb_seen = bb; |
ca6c03ca JH |
2100 | } |
2101 | ||
2102 | if (!bb_info[INSN_UID (x)]) | |
2103 | { | |
2104 | switch (GET_CODE (x)) | |
2105 | { | |
2106 | case BARRIER: | |
2107 | case NOTE: | |
2108 | break; | |
2109 | ||
2110 | case CODE_LABEL: | |
2111 | /* An addr_vec is placed outside any block block. */ | |
2112 | if (NEXT_INSN (x) | |
2113 | && GET_CODE (NEXT_INSN (x)) == JUMP_INSN | |
2114 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC | |
2115 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5f0d2358 | 2116 | x = NEXT_INSN (x); |
ca6c03ca JH |
2117 | |
2118 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2119 | break; | |
2120 | ||
2121 | default: | |
1f978f5f | 2122 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2123 | } |
2124 | } | |
2125 | ||
2126 | if (INSN_P (x) | |
2127 | && GET_CODE (x) == JUMP_INSN | |
2128 | && returnjump_p (x) && ! condjump_p (x) | |
2129 | && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER)) | |
1f978f5f | 2130 | fatal_insn ("return not followed by barrier", x); |
ca6c03ca JH |
2131 | } |
2132 | ||
0b17ab2f | 2133 | if (num_bb_notes != n_basic_blocks) |
ca6c03ca | 2134 | internal_error |
0b17ab2f RH |
2135 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2136 | num_bb_notes, n_basic_blocks); | |
ca6c03ca JH |
2137 | |
2138 | if (err) | |
c725bd79 | 2139 | internal_error ("verify_flow_info failed"); |
ca6c03ca JH |
2140 | |
2141 | /* Clean up. */ | |
2142 | free (bb_info); | |
2143 | free (last_visited); | |
2144 | free (edge_checksum); | |
2145 | } | |
2146 | \f | |
eaec9b3d | 2147 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2148 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2149 | Return true if any edges are eliminated. */ | |
2150 | ||
2151 | bool | |
2152 | purge_dead_edges (bb) | |
2153 | basic_block bb; | |
2154 | { | |
2155 | edge e, next; | |
89753b3a | 2156 | rtx insn = bb->end, note; |
ca6c03ca JH |
2157 | bool purged = false; |
2158 | ||
70da1d03 JH |
2159 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
2160 | if (GET_CODE (insn) == INSN | |
2161 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) | |
2162 | { | |
2163 | rtx eqnote; | |
2164 | ||
2165 | if (! may_trap_p (PATTERN (insn)) | |
2166 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2167 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2168 | remove_note (insn, note); | |
2169 | } | |
2170 | ||
546c093e RH |
2171 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
2172 | for (e = bb->succ; e; e = next) | |
2173 | { | |
2174 | next = e->succ_next; | |
2175 | if (e->flags & EDGE_EH) | |
2176 | { | |
2177 | if (can_throw_internal (bb->end)) | |
2178 | continue; | |
2179 | } | |
2180 | else if (e->flags & EDGE_ABNORMAL_CALL) | |
2181 | { | |
2182 | if (GET_CODE (bb->end) == CALL_INSN | |
2183 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) | |
2184 | || INTVAL (XEXP (note, 0)) >= 0)) | |
2185 | continue; | |
2186 | } | |
2187 | else | |
2188 | continue; | |
2189 | ||
2190 | remove_edge (e); | |
2191 | bb->flags |= BB_DIRTY; | |
2192 | purged = true; | |
2193 | } | |
5f0d2358 | 2194 | |
ca6c03ca JH |
2195 | if (GET_CODE (insn) == JUMP_INSN) |
2196 | { | |
2197 | rtx note; | |
2198 | edge b,f; | |
5f0d2358 | 2199 | |
ca6c03ca JH |
2200 | /* We do care only about conditional jumps and simplejumps. */ |
2201 | if (!any_condjump_p (insn) | |
2202 | && !returnjump_p (insn) | |
2203 | && !simplejump_p (insn)) | |
c51d95ec | 2204 | return purged; |
5f0d2358 | 2205 | |
5a1a3e5e JH |
2206 | /* Branch probability/prediction notes are defined only for |
2207 | condjumps. We've possibly turned condjump into simplejump. */ | |
2208 | if (simplejump_p (insn)) | |
2209 | { | |
2210 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2211 | if (note) | |
2212 | remove_note (insn, note); | |
2213 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2214 | remove_note (insn, note); | |
2215 | } | |
2216 | ||
ca6c03ca JH |
2217 | for (e = bb->succ; e; e = next) |
2218 | { | |
2219 | next = e->succ_next; | |
2220 | ||
7fcd7218 JH |
2221 | /* Avoid abnormal flags to leak from computed jumps turned |
2222 | into simplejumps. */ | |
f87c27b4 | 2223 | |
0e1638d4 | 2224 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2225 | |
5a566bed MM |
2226 | /* See if this edge is one we should keep. */ |
2227 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2228 | /* A conditional jump can fall through into the next | |
2229 | block, so we should keep the edge. */ | |
ca6c03ca | 2230 | continue; |
5f0d2358 RK |
2231 | else if (e->dest != EXIT_BLOCK_PTR |
2232 | && e->dest->head == JUMP_LABEL (insn)) | |
5a566bed MM |
2233 | /* If the destination block is the target of the jump, |
2234 | keep the edge. */ | |
2235 | continue; | |
2236 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) | |
2237 | /* If the destination block is the exit block, and this | |
2238 | instruction is a return, then keep the edge. */ | |
ca6c03ca | 2239 | continue; |
5a566bed MM |
2240 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2241 | /* Keep the edges that correspond to exceptions thrown by | |
2242 | this instruction. */ | |
ca6c03ca | 2243 | continue; |
5f0d2358 | 2244 | |
5a566bed | 2245 | /* We do not need this edge. */ |
c51d95ec | 2246 | bb->flags |= BB_DIRTY; |
ca6c03ca JH |
2247 | purged = true; |
2248 | remove_edge (e); | |
2249 | } | |
5f0d2358 | 2250 | |
ca6c03ca | 2251 | if (!bb->succ || !purged) |
c51d95ec | 2252 | return purged; |
5f0d2358 | 2253 | |
ca6c03ca | 2254 | if (rtl_dump_file) |
0b17ab2f | 2255 | fprintf (rtl_dump_file, "Purged edges from bb %i\n", bb->index); |
5f0d2358 | 2256 | |
ca6c03ca JH |
2257 | if (!optimize) |
2258 | return purged; | |
2259 | ||
2260 | /* Redistribute probabilities. */ | |
2261 | if (!bb->succ->succ_next) | |
2262 | { | |
2263 | bb->succ->probability = REG_BR_PROB_BASE; | |
2264 | bb->succ->count = bb->count; | |
f87c27b4 | 2265 | } |
ca6c03ca JH |
2266 | else |
2267 | { | |
2268 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2269 | if (!note) | |
2270 | return purged; | |
5f0d2358 | 2271 | |
ca6c03ca JH |
2272 | b = BRANCH_EDGE (bb); |
2273 | f = FALLTHRU_EDGE (bb); | |
2274 | b->probability = INTVAL (XEXP (note, 0)); | |
2275 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2276 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2277 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2278 | } | |
5f0d2358 | 2279 | |
ca6c03ca JH |
2280 | return purged; |
2281 | } | |
2282 | ||
ca6c03ca JH |
2283 | /* If we don't see a jump insn, we don't know exactly why the block would |
2284 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2285 | as these are only created by conditional branches. If we find such an | |
2286 | edge we know that there used to be a jump here and can then safely | |
2287 | remove all non-fallthru edges. */ | |
2288 | for (e = bb->succ; e && (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU)); | |
5f0d2358 RK |
2289 | e = e->succ_next) |
2290 | ; | |
2291 | ||
ca6c03ca JH |
2292 | if (!e) |
2293 | return purged; | |
5f0d2358 | 2294 | |
ca6c03ca JH |
2295 | for (e = bb->succ; e; e = next) |
2296 | { | |
2297 | next = e->succ_next; | |
2298 | if (!(e->flags & EDGE_FALLTHRU)) | |
c51d95ec JH |
2299 | { |
2300 | bb->flags |= BB_DIRTY; | |
2301 | remove_edge (e); | |
2302 | purged = true; | |
2303 | } | |
ca6c03ca | 2304 | } |
5f0d2358 | 2305 | |
ca6c03ca JH |
2306 | if (!bb->succ || bb->succ->succ_next) |
2307 | abort (); | |
5f0d2358 | 2308 | |
ca6c03ca JH |
2309 | bb->succ->probability = REG_BR_PROB_BASE; |
2310 | bb->succ->count = bb->count; | |
2311 | ||
2312 | if (rtl_dump_file) | |
2313 | fprintf (rtl_dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2314 | bb->index); |
ca6c03ca JH |
2315 | return purged; |
2316 | } | |
2317 | ||
5f0d2358 RK |
2318 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2319 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2320 | |
2321 | bool | |
473fb060 | 2322 | purge_all_dead_edges (update_life_p) |
00baba68 | 2323 | int update_life_p; |
ca6c03ca | 2324 | { |
e0082a72 | 2325 | int purged = false; |
710af899 | 2326 | sbitmap blocks = 0; |
e0082a72 | 2327 | basic_block bb; |
473fb060 JH |
2328 | |
2329 | if (update_life_p) | |
2330 | { | |
d55bc081 | 2331 | blocks = sbitmap_alloc (last_basic_block); |
473fb060 JH |
2332 | sbitmap_zero (blocks); |
2333 | } | |
5f0d2358 | 2334 | |
e0082a72 | 2335 | FOR_EACH_BB (bb) |
473fb060 | 2336 | { |
e0082a72 | 2337 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2338 | |
473fb060 JH |
2339 | purged |= purged_here; |
2340 | if (purged_here && update_life_p) | |
e0082a72 | 2341 | SET_BIT (blocks, bb->index); |
473fb060 | 2342 | } |
5f0d2358 | 2343 | |
473fb060 JH |
2344 | if (update_life_p && purged) |
2345 | update_life_info (blocks, UPDATE_LIFE_GLOBAL, | |
2346 | PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE | |
2347 | | PROP_KILL_DEAD_CODE); | |
5f0d2358 | 2348 | |
473fb060 JH |
2349 | if (update_life_p) |
2350 | sbitmap_free (blocks); | |
ca6c03ca JH |
2351 | return purged; |
2352 | } |